The Journal of Arthroplasty

In-Hospital Patient Falls After Total Joint Arthroplasty: Incidence, Demographics, and Risk Factors in the United States

2011-11-24

Abstract: In-hospital falls (IFs) increase morbidity, cost, and may result in litigation. We analyzed the Nationwide Inpatient Sample to quantify the incidence of IFs in patients who underwent hip and knee arthroplasty and to define trends, patient's demographics, risk factors, complications, and hospital cost. Patients operated on between 1998 and 2007 were identified and grouped depending on the presence of a diagnosis of IF. Of those, 0.85% had an IF, representing 2.1 falls per 1000 inpatient days. The incidence of IF increased from 0.4% to 1.3% during the study period. Independent risk factors included revision surgery, advanced age, male sex, minority race, and the presence of comorbidities. Patients having IF had a longer hospital stay and were less likely to be discharged to their primary residence. In-hospital mortality, complications, and cost were higher in patients sustaining IF. Given the associated morbidity, mortality, and increased cost, resources should be allocated to minimize the risk of IF in this population.

Proximal Femoral Allograft in Revision Hip Surgery With Severe Femoral Bone Loss: A Systematic Review and Meta-Analysis

2011-12-09

Abstract: This study provides an objective appraisal of available evidence regarding the outcome of proximal femoral allograft for reconstruction of massive proximal femoral bone loss. The primary outcomes were rates of success, structural failure, and infection. A systematic literature review identified 16 studies with a minimum 2-year follow-up. Estimated pooled effect analysis performed with heterogeneity quantified using I2 and τ2. The total cohort included 498 patients with a mean follow-up of 8.1 years. The pooled success rate was 81%, pooled structural failure rate of 15%, and pooled infection rate of 8%. Significant heterogeneity was observed in structural failure rates (I2 = 47.9, τ2 = 0.29, P < .05). Proximal femoral allografts afford viable reconstruction for massive femoral bone loss when performed by experienced.

Comparison of Total Hip and Knee Arthroplasty Cohorts and Short-Term Outcomes From a Single-Center Joint Registry

2012-03-05

Abstract: The purpose of this study was to compare short-term clinical outcomes between total hip arthroplasty (THA) and total knee arthroplasty (TKA) patient cohorts, adjusting for confounding variables including age, sex, body mass index, operative time, length of stay, and preoperative Western Ontario and McMaster Universities and 12-Item Short-Form Health Survey. A total of 349 patients who met inclusion and exclusion criteria created 2 cohorts: THA, 194, and TKA, 155, for statistical analysis via multiple regression and analysis of covariance measures. Outcome measures included Western Ontario and McMaster Universities and 12-Item Short-Form Health Survey data, collected prospectively at baseline and 2 years of follow-up. The current study showed that baseline characteristics of TKA patients have more factors with negative effect on postoperative outcome than THA. However, despite controlling for the possible confounding effect of these variables, THA patients experienced a significantly better functional outcome than TKA patients.

Design, Implementation, and Comparison of Methods for Collecting Implant Registry Data at Different Hospital Types

2012-01-30

Abstract: Practical issues surrounding the official establishment of a national arthroplasty registry in the United States remain. The purpose of this study was to compare compliance and accuracy rates associated with 3 methods for voluntarily collecting implant registry data at 3 different hospital types. Methods examined included (1) scannable paper forms, (2) online forms comprising keypunching for implant data input, and (3) the same electronic form but incorporating barcode scanning for implant data entry. Overall compliance was low (930/1761; 52.8%) and decreased with each successive data collection phase. Total accuracy rate was 62.5% (578/925) and varied significantly among sites (P < .001). Even with relatively simple reporting systems, compliance was poor. This emphasizes the need for direct surgeon involvement, strict oversight, and a feedback system to ensure validity, particularly if a volunteer-based system is used.

Effect of Immediate Postoperative Physical Therapy on Length of Stay for Total Joint Arthroplasty Patients

Antonia F. Chen, Melissa K. Stewart, Alma E. Heyl, Brian A. Klatt — 2012-03-05

Abstract: The isolated effect of physical therapy (PT) on total joint arthroplasty hospital length of stay (LOS) has not been studied. A prospective cohort study was conducted on 136 primary total joint arthroplasties (58 hips, 78 knees). The LOS was determined by the operative start time until the time of discharge. On postoperative day (POD) 0, 60 joints remained in bed, 51 moved to a chair, and 25 received PT (22 ambulated, 3 moved to a chair). Length of stay differed for patients receiving PT on POD 0 (2.8 ± 0.8 days) compared with POD 1 (3.7 ± 1.8 days) (P = .02). There was no difference in PT treatment based on nausea/vomiting, pain levels, or discharge location. Isolated PT intervention on POD 0 shortened hospital LOS, regardless of the intervention performed.

The Preoperative Prediction of Success Following Irrigation and Debridement With Polyethylene Exchange for Hip and Knee Prosthetic Joint Infections

2012-03-09

Abstract: Although the criterion standard for the treatment of prosthetic joint infections (PJIs) is 2-stage revision with interim placement of an antibiotic-loaded spacer, irrigation and debridement with polyethylene exchange offer advantages such as fewer surgeries, reduced potential for intraoperative complications, and lower direct costs. The purpose of this study was to develop a tool to preoperatively predict the probability of successful infection eradication following irrigation and debridement with polyethylene exchange for hip or knee PJIs. A total of 10 411 surgical cases were retrospectively reviewed, and data were collected from 309 charts. Overall, 149 (48.2%) cases failed to eradicate the infection following irrigation and debridement with polyethylene exchange. Univariate analysis identified multiple variables independently associated with reinfection including duration of symptoms, preoperative inflammatory markers, and infecting organism. Logistic regression was used to generate a model (bootstrap-corrected concordance index of 0.645) to predict successful eradication of the infection, which was the basis for a nomogram. Using commonly obtained preoperative variables, the nomogram can be used to predict the probability of infection-free survival at 1, 2, 3, 4, and 5 years. Preoperative knowledge of the probability that a treatment strategy will eradicate a patient's PJI may improve risk assessment.

Patient Perspective Survey of Total Hip vs Total Knee Arthroplasty Surgery

2012-02-15

Abstract: A 42-item survey was developed and administered to determine patient perception of and satisfaction with total hip arthroplasty (THA) vs total knee arthroplasty (TKA). A total of 153 patients who had both primary THA and TKA for osteoarthritis with 1-year follow-up were identified. Survey response rate was 72%. Patients were more satisfied with THA meeting expectations for improvement in function and quality of life (P < .05), whereas pain relief expectations were equivalent. Most patients (70.9%) reported that TKA required more physiotherapy. One-year Oxford score and improvement in Oxford score from preoperative to 1 year were superior for THAs (P = .000). Despite equivalent pain relief, THAs trend toward higher satisfaction compared with TKAs. THA is more likely to “feel normal” with greater improvement in Oxford score. Recovery from TKA requires more physiotherapy and a longer time to achieve a satisfactory recovery status. Patients should be counseled accordingly.

The Persistence of Staphylococcus aureus Decolonization After Mupirocin and Topical Chlorhexidine: Implications for Patients Requiring Multiple or Delayed Procedures

2012-03-09

Abstract: Preoperative screening and decolonization of methicillin-sensitive and methicillin-resistant Staphylococcus aureus (MSSA and MRSA, respectively) are advocated to reduce surgical site infections. We determined the rate and duration of decolonization in patients undergoing elective orthopedic surgery. Patients undergoing elective orthopedic surgery were seen in our preoperative testing program (PAT) and had their anterior nares cultured for MRSA and MSSA. All patients were treated with intranasal mupirocin and a topical chlorhexidine solution. A cohort of patients returned to PAT before a subsequent elective procedure and were recultured. All culture results and time between PAT visits were recorded, and the rates of successful initial and persistent decolonization were determined. Six hundred ten patients visited PAT 1290 times. Overall, 94 (70.1%) of 134 patients with initially MRSA- or MSSA-positive cultures remained decolonized at a mean time of 156 days (SD=140), whereas 40 patients (29.9%) were not decolonized by the time of repeat testing at a mean time of 213 days (SD=187). At repeat testing, there were 2 newly MRSA-positive and 35 newly MSSA-positive patients. Staphylococcus aureus decolonization with intranasal mupirocin and topical chlorhexidine was effective but not persistent in a significant proportion of patients. A small number of previously uncolonized patients became colonized. Staphylococcus aureus screening and decolonization protocols must be repeated before any readmission, regardless of prior colonization status.

Periprosthetic Joint Infection: Are Patients With Multiple Prosthetic Joints at Risk?

2012-03-05

Abstract: Patients who present with a periprosthetic joint infection in a single joint may have multiple prosthetic joints. The risk of these patients developing a subsequent infection in another prosthetic joint is unknown. Our purposes were (1) to identify the risk of developing a subsequent infection in another prosthetic joint and (2) to describe the time span and organism profile to the second prosthetic infection. We retrospectively identified 55 patients with periprosthetic joint infection who had another prosthetic joint in place at the time of presentation. Of the 55 patients, 11 (20%) developed a periprosthetic joint infection in a second joint. The type of organism was the same as the first infection in 4 (36%) of 11 patients. The time to developing a second infection averaged 2.0 years (range, 0-6.9 years).

Total Joint Arthroplasty in Patients With Rheumatoid Arthritis: A United States Experience From 1992 Through 2005

2012-02-15

Abstract: To determine whether total joint arthroplasty (TJA) for patients with rheumatoid arthritis (RA) is decreasing, we collected Nationwide Inpatient Sample database information (1992 through 2005) on (1) the number of primary TJAs for all patient diagnoses, (2) the number of primary TJAs for patients with RA, and (3) distribution of age and sex in both groups. To account for population growth, a given year's arthroplasty estimate was normalized against its population. The trends over time were analyzed using a multivariable Poisson regression model (significance, P < .05). We found that the number of primary TJA procedures increased in the general and RA populations but that, after adjusting for population growth, age, and sex, the rate was significantly lower in patients with RA.

Outcomes of Total Hip and Knee Arthroplasty After Cardiac Transplantation

Garrett R. Leonard, Charles M. Davis — 2012-02-24

Abstract: The outcomes of 18 primary or revision total hip (THA) and knee arthroplasties (TKA) in 9 patients with cardiac transplants were reviewed. Primary total joint arthroplasties were performed for osteonecrosis (5 hips) or osteoarthritis (5 hips, 4 knees). There were no infections in any of these patients. Final Harris Hip Scores were 71.8 for patients with osteonecrosis and 88.6 for osteoarthritis. Eight of 10 hips were pain-free at final follow-up. Two of the 10 primary THAs required late revision at 7 and 10 years after the index arthroplasty. One patient (2 hips and 1 knee) had chronic bilateral lower extremity pain. Total knee arthroplasty range of motion averaged from 7.5° to 118°. Average final Knee Society function score was 79, and objective score was 88. One of 4 patients with primary TKA required a manipulation under anesthesia. No reoperations were required in this group. Overall, patients with heart transplantations on immunosuppression had generally good pain relief after THA and TKA. There were no infections in this small cohort; however, there were many complications.

Ultrasound Screening of Periarticular Soft Tissue Abnormality Around Metal-on-Metal Bearings

Takashi Nishii, Takashi Sakai, Masaki Takao, Hideki Yoshikawa, Nobuhiko Sugano — 2011-11-02

Abstract: Although metal hypersensitivity or pseudotumors are concerns for metal-on-metal (MoM) bearings, detailed pathologies of patterns, severity, and incidence of periprosthetic soft tissue lesions are incompletely understood. We examined the potential of ultrasound for screening of periarticular soft tissue lesions around MoM bearings. Ultrasound examinations were conducted in 88 hips (79 patients) with MoM hip resurfacings or MoM total hip arthroplasties with a large femoral head. Four qualitative ultrasound patterns were shown, including normal pattern in 69 hips, joint-expansion pattern in 11 hips, cystic pattern in 5 hips, and mass pattern in 3 hips. Hips with the latter 3 abnormal patterns showed significantly higher frequency of clinical symptoms, without significant differences of sex, duration of implantation, head sizes, and cup abduction/anteversion angles, compared with hips with normal pattern. Ultrasound examination provides sensitive screening of soft tissue reactions around MoM bearings and may be useful in monitoring progression and defining treatment for periarticular soft tissue abnormalities.

The Optimal Skin Incision for Minimally Invasive Total Hip Arthroplasty Performed via the Anterolateral Approach

2011-12-12

Abstract: Twelve total hip arthroplasty procedures were performed in fresh cadaveric specimens via the anterolateral approach using straight 9-cm incisions placed in 2 different locations with respect to anatomical landmarks. During each procedure, the forces applied to the wound edges by each of the hip instruments and the pressures and strains generated along the wound edges were measured. Pressures ranging from 40 to 190 kPa were developed between the retractors and the wound edges during acetabular reaming and femoral rasping. The resulting strain along the wound edges averaged 28% during acetabular reaming and 34% during femoral broaching (P < .0001). Maximum strains were recorded at the ends of each incision and averaged 58% and 61%, respectively (P < .0001). These results were independent of the anatomical placement of the skin incision. In total hip arthroplasty, the mechanical trauma associated with the procedure is primarily determined by the surgical approach to the hip and the properties of the subcutaneous tissues, and not the anatomical location of the skin incision itself.

Squeaking After Third-Generation Ceramic-on-Ceramic Total Hip Arthroplasty

Rehan-Ul Haq, Kyung Soon Park, Jong Keun Seon, Taek Rim Yoon — 2011-11-24

Abstract: We retrospectively reviewed records of 1002 patients who underwent a third-generation ceramic-on-ceramic total hip arthroplasty. Fifteen patients complained of squeaking, at any time after their arthroplasty. Of these 15 patients, 14 were evaluated clinically and radiologically. These 14 patients were found to have significantly higher mean body mass index of 25.8 kg/m2 as compared with all the other patients who did not complain of squeaking (mean, 23.7 kg/m2) (P = .022). The acetabular opening angle was significantly lower (mean, 34°) than a matched control group (mean, 38°) (P = .016). Limb length shortening of more than 5 mm was observed in 12 (85.7%) of the 14 patients as compared with only 4 (28.6%) of 14 patients in the matched control group. Flexion and sitting cross legged were identified as the movements, which most commonly (11/12) resulted in squeaking. The incidence of squeaking was found to be low (1.5%), and we identified high body mass index, decreased acetabular opening angle, and limb length shortening as factors associated with squeaking.

Anteversion of the Acetabular Component Aligned With the Transverse Acetabular Ligament in Total Hip Arthroplasty

Hideaki Miyoshi, Hiroshi Mikami, Koichi Oba, Rui Amari — 2011-12-12

Abstract: In total hip arthroplasty (THA), accurately positioning the cup is crucial for achieving an adequate postoperative range of motion and stability. For 47 THA cases in which the inferomedial rim of the cup had been positioned parallel to the transverse acetabular ligament, we retrospectively performed the measurements of the radiographic cup anteversion angle relative to the anterior pelvic plane using 3-dimensional reconstruction computed tomography. The mean anteversion angle was 21.2°, with no significant difference detected in mean cup anteversion between the dysplastic hip group (15 hips) and the control group (15 hips). We suggest that the transverse acetabular ligament is a practical anatomical landmark for determining cup anteversion in THA for both dysplastic and nondysplastic hip cases.

Repeat 2-Stage Exchange for Infected Total Hip Arthroplasty: A Viable Option?

2012-01-09

Abstract: We investigated whether performing a repeat 2-stage exchange eradicates infection in patients who previously underwent 2-stage treatment for an infected total hip arthroplasty. We identified 15 patients who had failed a 2-stage total hip arthroplasty and underwent a planned repeat 2-stage between 2000 and 2009. Of the 15 patients, 8 were treated with a complete 2-stage procedure, whereas the remaining 7 patients were treated only with a first-stage resection of the infected implant. Of the 8 patients who underwent complete 2-stage exchange, 1 died because of in-hospital complications, and 1 had a recurrent infection. Repeat infection is highly associated with resistant organisms, obesity, and poor patient health. Of the 7 patients who underwent resection without reimplantation, 3 had a recurrent infection. Our data suggest that if infection can be adequately controlled after repeat resection of the joint prosthesis, reimplantation is a reasonable option.

Long-Term Femoral Bone Remodeling After Cemented Hip Arthroplasty With the Müller Straight Stem in the Operated and Nonoperated Femora

2011-11-16

Abstract: We investigated the cortical bone changes in 35 patients with total hip arthroplasty operated on only for osteoarthritis with more than 10 years of follow-up and with nonrevised femoral components and without radiologic signs of loosening. The mean follow-up was 16 ± 5 years. The thicknesses of femoral cortices were measured medially and laterally at 6 levels from the first postoperative and the last follow-up x-rays. A comparison with 10 patients who had a nonoperated contralateral hip was performed. We found a significant decrease in cortical thicknesses in total hip arthroplasty. The cortical thinning was significant at all periprosthetic levels but less expressed distally. Prosthetic femora were associated with greater cortical thinning as compared with the contralateral nonoperated femora, exceeding that caused by natural aging.

Shortening Cemented Femoral Implants: An In Vitro Investigation to Quantify Exeter Femoral Implant Rotational Stability vs Simulated Implant Length

Lance J. Wilson, John A. Roe, Mark J. Pearcy, Ross W. Crawford — 2011-12-07

Abstract: The Exeter stems vary in length from 90 to 150 mm. The shorter stems generally have lower offsets. The purpose of this study was to determine if length of stem, with fixed offset, affected rotational stability. Mechanical testing was carried out on 10 implant-cement constructs with 2 loading profiles, rising from chair and stair climbing, at different simulated implant lengths using purpose-built apparatus. This paper presents a mechanism for clinically observed rotational stability and explains the mechanical characteristics required for rotational stability in Exeter femoral stems.

Change in Pelvic Tilt Angle 2 to 4 Years After Total Hip Arthroplasty

Naoya Taki, Naoto Mitsugi, Yuichi Mochida, Yasushi Akamatsu, Tomoyuki Saito — 2011-11-24

Abstract: The purpose of this study was to evaluate the change in pelvic tilt angle (PA) in the sagittal plane in the standing and supine positions for 2 to 4 years after total hip arthroplasty (THA). Anteroposterior pelvic radiographs of 21 male and 65 female patients were investigated before and after THA yearly over 2 to 4 years. Both the standing and supine PA significantly posteriorly tilted after THA. The difference in PA between the standing and supine positions (dPA) significantly increased after THA. Although the PA in the standing and supine positions plateaued 1 year after THA, the dPA gradually increased. In addition, the percentage of patients who showed a difference of more than 10° in dPA tended to increase yearly. In particular, elderly female patients who showed posterior tilt in PA in the standing or supine positions or a large dPA before THA tended to show a dPA of more than 10° after THA.

Anterior Pelvic Soft Tissue Thickness Influences Acetabular Cup Positioning with Imageless Navigation

Erik Hohmann, Adam Bryant, Kevin Tetsworth — 2011-10-31

Abstract: The purpose of this study was to investigate acetabular component position after total hip arthroplasty correlating both version and inclination to anterior pelvic soft tissue thickness. Thirty patients with a mean age of 66.5 ± 14 (28-87) years and an average body mass index of 30.04 ± 4.6 were included. The same surgeon operated on all 30 patients, using an anterolateral approach in a supine position and an imageless navigation system. Postoperative assessment of cup inclination, cup anteversion, and soft tissue thickness was measured by an independent research associate using computed tomographic scans. Pearson's moment correlations did not reveal any significant relationships between body mass index, soft tissue thickness, final intraoperative, or postoperative cup position. Anterior soft tissue thickness had no significant effect on the accuracy of acetabular cup positioning.

The Effect of Hip Position on the Length of Trochanteric Muscles: Potential Implications for Early Postoperative Management of Hip Arthroplasty

2011-11-07

Abstract: We investigated the effect several lower limb positions have on muscles that are detached to perform hip arthroplasty through posterior and lateral approaches. We used string models and computer navigation to measure the length changes in these muscles throughout hip movements in the anatomical planes and while simulating several sitting and lying postures. Piriformis and the obturators were shortened by sitting and lying postures when the femur was externally rotated and abducted; the clinical implication being that such postures have the potential to best protect their repair after a posterior approach. The anterior part of gluteus medius was lengthened with femoral external rotation. This lengthening was prevented, and therefore, theoretically, the gluteus medius repair protected after a lateral approach, by neutral or internal femoral rotation.

Predicting Need for Allogeneic Transfusion After Total Knee Arthroplasty

2012-06-01

Abstract: Total knee arthroplasty (TKA) can lead to substantial blood loss. To avoid the high costs of autologous blood predonation programs and efficiently allocate limited blood resources, we sought to identify preoperative and intraoperative factors associated with allogeneic blood transfusion (AllTx) after primary TKA and, subsequently, develop a model to predict patients who will require AllTx. We analyzed 31 independent variables in 644 primary unilateral TKAs without autologous blood predonation for requirement of AllTx. Seventy-one procedures (11.0%) required AllTx. Age, comorbid anemia, preoperative hemoglobin concentration, and surgical time were significant predictors for requiring AllTx. When applied to an independent cohort, our model for predicting the need for AllTx after TKA was 90% sensitive and 52.5% specific.

Chinese Experience With Metal-on-Metal Hip Resurfacing

2012-02-15

Abstract: The aim of this study was to study the actual clinical and laboratory results of metal-on-metal resurfacing hip arthroplasties by comparing with other implants. A total of 127 cases were operated on at the Department of Orthopaedics of Wuhan Union Hospital from 2005 to 2011. An important cause of failure is the fracture of the femoral neck. The chromium and cobalt levels of resurfacing hip arthroplasty and large-diameter head total hip arthroplasty (THA) are higher than those of a conventional metal-on-polyethylene total hip arthroplasty. There was a high ion level associated with an abduction angle of more than 45° and repetitive extreme hip motion in the 3 revision cases. The findings of this study are novel and quite controversial with that of the previously published literature.

Large-Diameter Modular Metal-on-Metal Total Hip Arthroplasty: Incidence of Revision for Adverse Reaction to Metallic Debris

William P. Barrett, Kirk A. Kindsfater, James P. Lesko — 2012-03-15

Abstract: Large-diameter modular metal-on-metal (MOM) total hip arthroplasty (THA) may offer reduction in wear debris and improved stability. Four studies are summarized here that used a large-diameter modular MOM system. A total of 1076 THAs were performed. This article presents data from 779 of these THAs with minimum 2-year follow-up (mean, 4.2 years) or revision since index THA (21 hips, with 1 more pending). Overall survivorship at 2 years was 98.6%; at 5 years, it was 97.0%. Seven revisions for an adverse reaction to metallic debris (ARMED), and 1 additional pending revision for ARMED, showed marked variability in presenting symptoms and intraoperative and postoperative findings. Data show good clinical performance of the modular MOM system, but suggest that surgeons must be diligent in monitoring MOM THA patients and aggressive in diagnosing and revising patients with a potential ARMED.

Are Hip Resurfacing Arthroplasties Meeting the Needs of Our Patients? A 2-Year Follow-Up Study

Jennifer K. Bow, John F. Rudan, Heather J. Grant, Stephen M. Mann, Manuela Kunz — 2012-03-15

Abstract: Hip resurfacing arthroplasty (HRA) is a treatment of end-stage hip arthritis in young patients with excellent bone stock. One hundred four consecutive HRAs (Depuy ASR, Warsaw, Ind) were performed with 36-Item Short Form Health Survey (SF-36), Western Ontario and McMaster University Osteoarthritis Index, Harris Hip Scores, and University of California, Los Angeles activity ratings obtained preoperatively, at 6 months, and at 1 and 2 years postoperatively. Four patients required conversion to total hip arthroplasty. All patients showed significant improvements in their activity, pain, stiffness, and function postoperatively. Patients with lower SF-36 mental component scores (MCSs) improved their MCS compared with those of the general population, as well as improving their pain and physical functioning scores. These findings demonstrate reliable improvements in standard quality of life measures in patients undergoing HRA, including those with low preoperative SF-36 MCS.

Cobalt and Chromium Ion Release After Large-Diameter Metal-on-Metal Total Hip Arthroplasty

Masahiro Hasegawa, Kakunoshin Yoshida, Hiroki Wakabayashi, Akihiro Sudo — 2012-02-10

Abstract: Seventy-five patients underwent unilateral metal-on-metal total hip arthroplasty using a large-diameter head. Serum levels of cobalt and chromium were determined. Significant increases in both cobalt and chromium were observed at 3 months (cobalt, 1.4 μg/L; chromium, 1.4 μg/L) compared with preoperative values (P < .001). At 1 year, the median cobalt and chromium levels were 2.3 and 2.1 μg/L, respectively, and the levels had increased significantly compared with 3 months (P < .001). There were no significant differences between levels of either metal at 1 or 2 years (cobalt, 2.3 μg/L; chromium, 1.6 μg/L). Pseudotumor occurred in 2 hips. Patients with large-diameter metal-on-metal total hip arthroplasty had higher circulating metal ion levels at 3 months and 1 year, with no additional significant increases at 2 years.

Early Complications of Hip Resurfacing

Lawrence Kohan, Clarice J. Field, Dennis R. Kerr — 2012-04-16

Abstract: There has been a rapid increase in the number of hip resurfacing procedures for the treatment of symptomatic osteoarthritis over the last decade. We examine our early complications associated with this procedure. Eight hundred forty consecutive hip resurfacing procedures by 1 surgeon using 1 prosthesis were assessed. The complications seen within the first 12-month postoperative period were analyzed. Specific patient selection criteria were used. Complications such as loosening, femoral neck notching, femoral neck fracture, deep vein thrombosis, stress fracture, nerve palsy, and infection were noted. Complications linked with loosening were categorized to either the femoral or acetabular component. A total of 86 early complications were observed in the 840 resurfacings. Twenty-three (2.7%) required operative intervention, and 10 (1.2%) were converted to stemmed hip arthroplasties. Of these 86 complications, the most common complication was deep vein thrombosis, 19 instances (2.26% occurrence in 840), followed by femoral neck fracture, 11 (1.31%); infection, 10 (1.19%); femoral notching, 10 (1.19%); transient nerve palsy, 8 (0.95%); acetabular loosening, 6 (0.71%); hematoma, 5 (0.60%); and stress fracture, 4 (0.48%). The fractures occurred mostly in patients older than 60 years.

Early Results of Total Hip Arthroplasty in Patients With Slipped Upper Femoral Epiphysis Compared With Patients With Osteoarthritis

Matthew J. Boyle, Christopher M.A. Frampton, Haemish A. Crawford — 2012-02-15

Abstract: We have investigated the results of primary total hip arthroplasty (THA) performed in patients with slipped upper femoral epiphysis (SUFE). Through the New Zealand Joint Registry, we identified all patients with SUFE undergoing primary THA (n = 117) and all patients with primary osteoarthritis (OA) undergoing primary THA (n = 40 589) between January 1, 1999, and December 31, 2008. Baseline information, operative characteristics, and postoperative outcomes were analyzed and compared between the SUFE and the OA groups. There was no significant difference in postoperative Oxford Hip Score or revision rate between the 2 groups. Our results support THA as a successful surgical option in the management of degenerative arthritis in SUFE, with comparable functional outcomes and revision rates to THA performed for primary OA.

Hip Squeaking: A 10-Year Follow-Up Study

2012-03-15

Abstract: The aim of the study was to analyze the incidence of squeaking with ceramic-on-ceramic total hip arthroplasty (THA) after 10 years of follow-up and the potential complications that could occur related to this phenomenon. One hundred THAs implanted between November 1999 and December 2000 were evaluated. Incidence of squeaking was investigated clinically with a questionnaire. Implant positioning was analyzed on x-rays and computer tomography. Of the 100 THAs, 5 patients presented with squeaking. All of them were active, sporty, and heavy men. Functional scores were comparable with nonsqueaking patients. There was no malpositioning on the x-ray analysis, no wear, and no loosening. We could not demonstrate any relation between squeaking and ceramic fracture. Squeaking noise appeared at a mean of 66 months postsurgery. It appears to be an isolated phenomenon without any consequences at 10-year follow-up.

Modern Proximally Tapered Uncemented Stems Can Be Safely Used in Dorr Type C Femoral Bone

David F. Dalury, Todd C. Kelley, Mary Jo Adams — 2012-02-10

Abstract: Cementless femoral fixation has become widely accepted in modern total hip arthroplasty. Treating patients who have a stovepipe-shaped femur (Dorr type C) with cementless implants has traditionally been challenging. We treated 53 consecutive patients (60 hips) who had type C bone with identical tapered, proximally coated implants and postoperative weight bearing as tolerated. At 6 weeks, all 60 hips had radiographically documented bony integration, and at 1 year, there was no evidence of fracture, subsidence, thigh pain, stress shielding, loose stems, or risk of failure. Of those patients, 40 (43 hips) had midterm follow-up (average, 6 years; range, 4-9 years); the findings were the same. We conclude that modern proximally tapered stems can be used with early weight bearing in patients with type C bone.

Leg Length Change in Total Hip Arthroplasty With Subtrochanteric Femoral Shortening Osteotomy for Crowe Type IV Developmental Hip Dysplasia

2012-04-05

Abstract: Primary total hip arthroplasties were performed in 70 hips for the treatment of Crowe type IV developmental dysplasia of the hip. The patients were subdivided into 2 groups with or without iliofemoral osteoarthritis. Leg length change was measured radiographically. Preoperative hip motion was reviewed from medical records and defined as either higher or lower motion groups. The leg length change in patients without iliofemoral osteoarthritis was significantly greater than that in patients with iliofemoral osteoarthritis, and the higher hip motion group had greater leg length change in total hip arthroplasty than the lower motion group. The current study identifies several features that might help predict leg length change during the preoperative planning of total hip arthroplasty for Crowe type IV developmental hip dysplasia.

Do Previous Operative Reports Provide the Critical Information Necessary for Revision Total Hip Arthroplasty?

2012-03-22

Abstract: An operative note is a vital component of a patient's medical-legal record, permitting the surgical team to safely administer perioperative care. Despite this critical function, operative note contents are neither standardized nor regulated; this is especially concerning in orthopedic surgery. As younger patients undergo total hip arthroplasty (THA) and outlive their prostheses, the need for revision THA cannot be ignored. Surgeons performing primary THA must be cognizant to record detailed implant characteristics to ensure that if necessary, the revision surgeon will have all pertinent information to optimally treat the patient. Our survey of operative notes reveals the dismal nature of component documentation during primary THA; implementation of a standardized procedure-specific operative note guideline may minimize incomplete dictations and drive surgeons to include all pertinent information.

Unplanned Admission to the Intensive Care Unit After Total Hip Arthroplasty

2012-03-09

Abstract: Triage to the intensive care unit (ICU) after elective total hip arthroplasty proves a complex medical and resource decision point. A total of 1259 consecutive total hip arthroplasties were reviewed; 89 patients experienced unplanned ICU admissions. Significant risk factors for ICU admission in univariate analysis were age greater than 75 years, revision surgery, obstructive sleep apnea, creatinine clearance less than 60 mL/min, prior myocardial infarction, American Society of Anesthesiologist class 3 or greater, use of vasopressors intraoperatively, and body mass index greater than 35 kg/m2. With multiple regression, age greater than 75 years (odds ratio [OR], 2.6 [1.2-5.6]), revision surgery (OR, 5.8 [3.0-11.4]), creatinine clearance less than 60 mL/min (OR, 6.5 [2.5-16.3]), prior myocardial infarction (OR, 7.2 [2.0-25.4]), and body mass index greater than 35 kg/m2 (OR, 2.9 [1.4-6.2]) were predictive of unplanned ICU admission. With 1 risk factor, the risk of ICU admission was 40%, 2 (75%), 3 (93.5%), 4 (98.5%), and 5 (>99%). A prospective study of these risk factors is needed to establish a threshold for planned ICU admission.

Retrospective Evaluation of Inpatient Celecoxib Use After Total Hip and Knee Arthroplasty at a Veterans Affairs Medical Center

2012-03-05

Abstract: A retrospective cohort study (1.5 years) was performed to investigate the efficacy of celecoxib vs non–celecoxib use in patient who underwent total knee arthroplasty (TKA) and total hip arthroplasty (THA). Study time frame encompassed a pre and post period of a local policy decision opening access to short-term celecoxib use after TKA/THA. Primary end point was the amount of opioid use during their inpatient stay postprocedure. The TKA (n = 81) and THA (n = 60) groups were analyzed independently. Both celecoxib groups used significantly less opioids during their inpatient stay vs noncelecoxib groups, given in oral morphine milligram equivalents (TKA: 203 vs 337 mg, P = .002; THA: 214 vs 336 mg, P = .005). Other secondary outcome measures showed that the celecoxib groups also reported reduction in pain scores, total as needed (PRN) opioid doses, PRN opioid doses per day, average dose of PRN opioids, total PRN opioids, use of intravenous opioids, and rehabilitation facility admissions (in the TKA group only). Linear regression analysis showed a statistically significant inverse relationship between opioid consumption and age. Short-term celecoxib use after TKA/THA may lead to a reduction in overall opioid use and improved pain scores; however, further studies will be required to validate the results of this study.

Revision Total Hip Arthroplasty in Patients 80 Years or Older

2012-03-15

Abstract: We evaluated all revisions performed from March 1996 to December 2008 and compared complications, mortality, and clinical outcomes between patients 80 years and older and patients younger than 80 years. Data were collected prospectively. There were 325 revisions, 84 (25.8%) in patients 80 years and older and 241 in patients younger than 80 years (62% revision for aseptic loosening in both groups). The mean follow-up was 4.3 years. The results, 80 years and older vs younger than 80 years, revealed the following: mortality, 5% vs 0% 3 months postoperatively; medical complications in 23.8% vs 6.2%; postoperative fractures, 9.5% vs 2.5%; and improved Merle d'Aubigné scores from 9.6 to 13.0 vs 10.4 to 14.3. Revision total hip arthroplasty in patients 80 years and older was associated with substantial clinical improvement and patient satisfaction. However, medical complications and 90-day mortality were higher, and postoperative fractures occurred more frequently.

Interobserver and Intraobserver Reliability and Validity of the Vancouver Classification System of Periprosthetic Femoral Fractures After Hip Arthroplasty

Gohar A. Naqvi, Shakoor A. Baig, Nasir Awan — 2012-03-15

Abstract: The Vancouver classification system of periprosthetic fractures has been revalidated in this study, using the radiographs of 45 patients. Three consultants and 3 trainees reviewed the radiographs independently, on 2 separate occasions, at least 2 weeks apart. Interobserver and intraobserver agreement and validity were analyzed, using weighted κ statistics. The mean κ value for interobserver agreement was found to be 0.69 (0.63-0.72) for consultants and 0.61 (0.56-0.65) for the trainees, both representing substantial agreement. Intraobserver κ values ranged from 0.74 to 0.90, showing substantial agreement. Validity analysis of 37 type B cases revealed 81% agreement within B1, B2, and B3 subgroups with a κ value of 0.68 (substantial agreement). This study has reconfirmed the reliability and validity of the Vancouver classification while it also emphasizes the intraoperative assessment of implant stability.

Recovery Room Radiographs After Total Hip Arthroplasty: Tradition vs Utility?

Anthony Ndu, Kolawole Jegede, Daniel D. Bohl, Kristaps Keggi, Jonathan N. Grauer — 2012-02-10

Abstract: Routine inpatient radiographs after total hip arthroplasty can be taken in the recovery room immediately after surgery or in the radiology suite later in the hospital stay. In a review of 632 consecutive recovery room series, we found that 17% of series were inadequate to detect technical issues. We identified technical issues on 12 series (1.9%) and technical issues that impacted inpatient management on 2 series (0.3%). One of these 2 was a dislocation that was detected clinically before imaging. The other was a medial penetration of an acetabular screw that probably did not require the immediate revision that it received. Findings suggest that the single routine inpatient series should be taken in the radiology suite, rather than in the recovery room.

A Minimum of 10-Year Follow-Up of the Burch-Schneider Cage and Bulk Allografts for the Revision of Pelvic Discontinuity

Dario Regis, Andrea Sandri, Ingrid Bonetti, Oscar Bortolami, Pietro Bartolozzi — 2012-03-07

Abstract: Eighteen consecutive hips with pelvic discontinuity and associated periprosthetic bone deficiency were treated with bulk allografts and Burch-Schneider antiprotrusio cage. Clinical and radiographic follow-up was performed at an average of 13.5 (range, 10.5-16.6) years. Three cages required re-revision because of infection (1) and aseptic loosening (2). Average Harris hip score improved from 31.9 to 77.0 points (P < .001). A severe resorption of the bone graft occurred in 2 hips. The stability of the cage was detected in 13 cases. The cumulative survival rate at 16.6 years with acetabular revision for any reason, radiographic loosening, or unhealing of the discontinuity as the end point was 72.2%. The use of Burch-Schneider cage and bulk allografts is an effective technique for the treatment of pelvic discontinuity.

Wear Analysis of First-Generation Highly Cross-Linked Polyethylene in Primary Total Hip Arthroplasty: An Average 9-Year Follow-Up

Shaun E. Reynolds, Arthur L. Malkani, Rama Ramakrishnan, Madhusudhan R. Yakkanti — 2012-03-15

Abstract: This is a retrospective review of 46 primary total hip arthroplasties using a first-generation highly cross-linked ultrahigh-molecular-weight polyethylene liner (Crossfire; Stryker, Mahwah, NJ) with an average of 9-year follow-up. The purpose of this study was to measure linear penetration rate of first-generation polyethylene to determine if it maintains its wear resistance and fatigue strength over an extended period compared with conventional polyethylene. The mean (SD) total penetration was 0.339 (0.204) mm, and the mean (SD) penetration rate was 0.037 (0.022) mm/y. Our study demonstrated a 74% reduction in total penetration of highly cross-linked polyethylene when compared with historical controls using conventional polyethylene at an average of 9 years. Our results support the belief that highly cross-linked polyethylene does retain its wear resistance over an extended period.

Imaging Periprosthetic Osteolysis Around Total Knee Arthroplasties Using a Human Cadaver Model

2011-11-16

Abstract: We examined the sensitivity and accuracy of measuring osteolysis around total knee arthroplasty (TKA) on radiographs, computed tomography (CT), and magnetic resonance imaging (MRI) in a cadaver model. Fifty-four simulated osteolytic defects ranging from 0.7 to 14 cm3 were created in 6 cadaver knees implanted with either a cemented or an uncemented TKA. Three blinded investigators assessed the presence, location, and volume of defects on radiographs and CT and MRI scans with metal reduction protocols. Both CT and MRI had significantly higher sensitivities and specificities than did plain radiographs (P < .005). Overall, there was no difference in the accuracy of defect volume measurements between CT and MRI (P = .574). This study demonstrates the limitations of radiographs and the high sensitivity and specificity of both CT and MRI in assessing osteolysis around TKA.

The Effect of Patellar Replacement Technique on Patellofemoral Complications and Anterior Knee Pain

2011-12-26

Abstract: Routine patella replacement with total knee arthroplasty has not been universally adopted because of associated patellofemoral complications such as anterior knee pain (AKP). In the proposed technique, the articular surface of the lateral facet of the patella is excised to the depth of the subchondral bone, and the medial facet is then cut parallel to the anterior surface. We evaluated any correlation between various radiographic parameters and AKP in 100 consecutive fixed-bearing posterior-stabilized total knee arthroplasties. There were no cases of fracture, avascular necrosis, subluxation, dislocation, patellar baja, or overstuffing of the patella. Anterior knee pain was present in 11% of cases, and no cases were severe or disabling. There were no correlations between AKP, range of motion, patellar size and shape, and any of the radiographic parameters.

Hi-Flexion and Gender-Specific Designs Fail to Provide Significant Increases in Range of Motion During Cruciate-Retaining Total Knee Arthroplasty

2011-11-24

Abstract: The effects of different femoral component designs on intraoperative range of motion were examined in 40 female patients during primary cruciate-retaining (CR) total knee arthroplasty. After complete bone resection and soft tissue balancing, standard CR, high-flexion, and gender-specific knee trials were sequentially inserted, and maximal flexion and extension under gravity were measured using a navigation system. Average maximal flexions were 134.3° for standard CR knees, 136.2° for high-flexion knees, and 136.4° for gender-specific knees. No significant intergroup differences in intraoperative maximal flexion and extension were found (P > .05). High-flexion and gender-specific femoral designs were found to show subtle increases in intraoperative range of motion as compared with the standard design but no significant differences.

The Influence of Sterilization Method on Articular Surface Damage of Retrieved Cruciate-Retaining Tibial Inserts

Matthew T. Greulich, Marcel E. Roy, Leo A. Whiteside — 2011-12-19

Abstract: This observational study was designed to determine the importance of sterilization method and insert thickness as predictors of articular damage of cruciate-retaining polyethylene components used in total knee arthroplasty. Ninety-nine explanted tibial inserts were evaluated for surface damage. Severe damage modes were observed in 36 of 52 of γ-irradiated inserts but none of those sterilized by ethylene oxide. Articular damage significantly correlated to time in vivo but not to insert thickness. Inserts sterilized by ethylene oxide gas in gas-permeable packaging exhibited a significantly lower damage accumulation rate compared with inserts sterilized by γ radiation and stored in air or an inert environment. γ irradiation and storage in argon instead of air reduced the frequency of severe damage such as delamination but not the overall damage rate.

Sagittal Flexion of the Femoral Component Affects Flexion Gap and Sizing in Total Knee Arthroplasty

Tadashi Tsukeoka, Tae Hyun Lee — 2011-12-09

Abstract: The purpose of this study was to determine how much sagittal rotation of the femoral component affects the flexion gap and femoral component sizing using a computer-simulation technique. The study comprised 25 knees scheduled for total knee arthroplasty (TKA). The femoral component was positioned at −2°, 0°, 2°, 4°, or 6° of flexion to the anterior femoral cortex, and the resected portion of the posterior medial femoral condyle was measured for 3 total knee systems. The amount of the resected bone of the posterior medial condyle decreased approximately 1 mm for every 2° of additional flexion in all TKA systems. Intentional sagittal flexion of the femoral component by several degrees during TKA can be a useful downsizing technique for the femoral component without excessively increasing the flexion gap.

Improvements in Knee Range and Symptomatic and Functional Behavior After Knee Arthroplasty Based on Preoperative Restriction in Range

2011-11-07

Abstract: Recovery of knee range and Oxford Knee Score post knee arthroplasty based on preoperative knee range is described. A total of 191 patients recruited across 5 hospitals were assessed preoperatively, at 8 weeks postoperatively and 1 year. Preoperative knee range was categorized into “low” (≤109), “moderate” (>109 to ≤120), and “high” (>120°) flexion and “normal” (± −5) and “restricted” (> +5°) terminal extension. Recovery was analyzed using MIXED modeling procedures. The low-flexion group gained flexion across time. The moderate-flexion and high-flexion groups lost flexion initially then recovered, but 1-year flexion remained lower than preoperative values. The restricted terminal extension group gained extension across time. The normal terminal extension group lost extension initially then recovered to preoperative values at 1 year. Recovery in Oxford score was independent of preoperative knee range limitation. Improvement in knee range postoperatively, but not self-reported behavior, is highly dependent on the initial restriction in range.

Function and Quality of Life in Patients With Recurvatum Deformity After Primary Total Knee Arthroplasty: A Review of Our Joint Registry

2011-12-12

Abstract: The aim of this paper is to assess function and quality of life in patients with recurvatum at 2 years after primary total knee arthroplasty. This prospective study involves 2587 total knee arthroplasty from 2004 to 2008 with 2-year follow-up. Patients' demographics, diagnosis, implants, range of motion, laxity, and knee and SF-36 scores were recorded. Recurvatum deformity of 0°, 1° to 5°, 6° to 10°, and more than 10° were classified as grades 0, 1, 2, and 3, respectively. Grade 1 had similar functional scores to grade 0 but significantly better SF1, SF4, SF5, and SF8 when compared with grades 2 and 3. Patients with mediolateral translation of more than 5 mm were more likely to have grades 2 and 3 recurvatum (P = .01), indicating global laxity. Postoperative recurvatum of more than 5° significantly impacts function and quality of life of patients.

Hybrid Component Fixation in Total Knee Arthroplasty: Minimum of 10-Year Follow-Up Study

Jae-Hyuk Yang, Jung-Ro Yoon, Chi-Hun Oh, Taik-Sun Kim — 2011-10-24

Abstract: Hybrid total knee arthroplasty (TKA) (uncemented femur with cemented tibia and patella) was introduced in the late 1980s to gain the theoretical advantage of durable cementless femoral fixation while avoiding the problems noted with cementless tibial fixation. From December 1992 to July 2000, 215 patients (235 knees) who underwent hybrid TKA were enrolled in this study. Five types of prosthesis (AGC, Maxim, LCS-M, LCS-APG, and Scorpio) were used. Revision rate for aseptic loosening was 16 (6.8%) of 235 knees. At 10 and 15 years, survivorship with tibial or femoral revision as the end point was 0.95 and 0.92, respectively. Hybrid TKA provides durable fixation with clinical and radiographic performance at minimum 10 years comparable with cemented series.

Cutting Error of the Distal Femur in Total Knee Arthroplasty by Use of a Navigation System

2011-10-24

Abstract: The aim of this study was to evaluate the alignment of the distal femoral cutting surface using a navigation system to determine the accuracy of bone cutting.We evaluated 20 knees in 20 patients. After cutting the distal femur, the cutting surface was validated using the navigated cutting block adapter, and the angular difference between the cutting surface and that preoperatively planned in the sagittal and coronal planes was recorded. The average error of all knees was 1.6° ± 2.2° in extension, and 14 (70%) of 20 knees were cut in an extended position. Our tendency is to cut the distal femur in an extended position with the first femoral cut in the sagittal plane.

A Comparison of Patellar Vascularity Between the Medial Parapatellar and Subvastus Approaches in Total Knee Arthroplasty

2012-03-22

Abstract: A complication of total knee arthroplasty is patellar avascular necrosis. Surgical approaches for total knee arthroplasty include the medial parapatellar approach (MPa) and, less commonly, the subvastus approach (SVa). The argument that SVa retains better patellar vascularity than the MPa was investigated on 20 participants, (SVa, n = 10; MPa, n = 10) 18 months postoperatively. Outcomes were a radionuclide bone imaging technique, a new bone vascularity scale, and an anterior knee pain numerical assessment scale. Results indicated no significant difference between groups on imaging (P = .935), the components of the bone vascularity scale, or anterior knee pain (P > .999). The SVa appears to offer no benefit over the MPa in terms of patellar vascularity or anterior knee pain.

Incidence of Clinically Significant Venous Thromboembolic Events in Asian Patients Undergoing Total Knee Arthroplasty Without Anticoagulation

2011-11-16

Abstract: This study aimed to evaluate the incidence of clinically significant venous thromboembolic events (VTE) in Asian patients undergoing total knee arthroplasty (TKA) without anticoagulation. All patients who underwent TKA by a single surgeon from 2006 to 2010 in Singapore General Hospital were reviewed. Only symptomatic patients were referred for ultrasonography. Of the 531 patients reviewed, 3 patients developed symptoms of deep vein thrombosis with subsequent ultrasonographic confirmation, whereas 1 patient developed fatal pulmonary embolism without any clinical or radiologic evidence of deep vein thrombosis. Hence, the incidence of clinically significant VTE was 0.75%. Given the low incidence of clinically significant VTE, there is a need to review the current practice of routine chemoprophylaxis in Asian patients undergoing TKA.

Unipolar vs Bipolar Hemostasis in Total Knee Arthroplasty: A Prospective Randomized Trial

2011-11-07

Abstract: The purpose of this study was to investigate whether unipolar or bipolar hemostasis is more effective in reducing blood loss associated with primary total knee arthroplasty. We randomized 113 consecutive patients undergoing primary total knee arthroplasty into unipolar and bipolar hemostasis treatment groups. The mean postoperative drain output in the unipolar group was 776.5 mL compared with 778.7 mL and was not statistically significant (P = .97). There were no statistically significant differences in postoperative day 1 through 3 hemoglobin level (P = .2-.6) or hematocrit (P = .17-.46) values. The transfusion requirement in the unipolar group was 36% and 40% in the bipolar group (P = .67). Use of bipolar sealer compared with standard unipolar electrocauterization showed no significant difference in postoperative drain output, postoperative hemoglobin level and hematocrit values, or transfusion requirements.

Tibial Component Fixation with a Peri-Apatite Coating: Evaluation by Radiostereometric Analysis in a Canine Total Knee Arthroplasty Model

2012-02-24

Abstract: Cementless fixation for the tibial component in total knee arthroplasty (TKA) remains problematic. Peri-Apatite (PA), a solution-deposited hydroxyapatite, is under investigation as an option for improving the fixation of cementless tibial components. In this study, radiostereometric analysis was used to document implant migration in 48 dogs that underwent TKA with cementless, PA-coated, or cemented tibial components. Migration at 12 weeks was similar in the 2 groups. At 12 months, there was greater migration in the PA-coated group, but the difference between the 2 groups was below the threshold considered clinically significant. In this canine TKA model, cementless fixation with PA performed less well than did cemented fixation, but not to a degree that would make a clinical difference in the short term.

Custom-Fit Total Knee Arthroplasty: Our Initial Experience in 32 Knees

Kamal Bali, Peter Walker, Warwick Bruce — 2012-01-30

Abstract: We share our initial experience of total knee arthroplasty (TKA) using customized cutting block technology in 32 TKAs from May 2010 to March 2011. Ten of these patients had prior TKA done on the other side using conventional or navigation-assisted TKA. Customized cutting blocks were generated for each of the knee using preoperative magnetic resonance imaging of knee and long-leg weight-bearing radiographs. At 6 weeks, long-leg radiographs were obtained to evaluate the coronal alignment. There were no adverse intraoperative events. Twenty-nine of the 32 knees had a mechanical axis restored to within 3°° of neutral. Of 10 patients with prior TKA without custom-fit technology, the mean blood loss and the mean skin-to-skin time was found to be lower in knees that had undergone custom-fit TKA. We conclude that this technology can be safely used in most of the cases of osteoarthritis.

Changes in Posterior Condylar Offset After Total Knee Arthroplasty Cannot be Determined by Radiographic Measurements Alone

Henry D. Clarke — 2012-02-17

Abstract: Restoration of femoral posterior condylar offset (PCO) may contribute to maximum flexion after total knee arthroplasty. Accurate radiographic measurement of postoperative PCO is possible, as the prosthesis margins can be easily identified; however, preoperative measurement of PCO may be inaccurate, as the remaining cartilage thickness of the posterior condyles is not included. This error may contribute to the controversy surrounding the importance of PCO. In this institutional review board–approved study, the cartilage thickness of posterior condylar specimens resected during total knee arthroplasty was measured. Mean cartilage thicknesses of the posterior condyles were 1.7 mm (range, 0-4 mm) medially and 2.0 mm (range, 0-5 mm) laterally. As the cartilage thickness is variable, future studies of PCO must adjust the preoperative radiographic measurements by the cartilage thickness measured intraoperatively.

Outpatient Unicompartment Knee Arthroplasty With Indwelling Femoral Nerve Catheter

2012-03-29

Abstract: Contemporary multimodal anesthesia regimens allow the performance of unicompartment knee arthroplasty (UKA) on an outpatient basis. Our initial pilot experience is presented using a continuous femoral nerve block as an adjunct for 24 patients classified as American Society of Anesthesiology class 1 (14 men, 10 women; median age, 56 years; range, 46-72 years). After minimally invasive UKA, patients documented their pain and oral medication use while at home for the first 5 days. Adverse events, medication adverse effects, and the amount of infused ropivacaine were recorded. Median pain scores for the first 3 days were 1, 2, and 2 (at rest) and 4, 5, and 3 (during physical therapy). Eighteen patients (75%) required less than 4 mg oral hydromorphone/d. Of the 18, 10 (42%) did not require supplemental oral opioids. The median catheter use was 3 days. Our results suggest that with careful patient selection and adequate teaching, continuous femoral nerve blocks may be used as part of a multimodal pain regimen to assist the delivery of outpatient UKA with high patient satisfaction.

Effect of Femoral Component Design on Patellofemoral Crepitance and Patella Clunk Syndrome After Posterior-Stabilized Total Knee Arthroplasty

Benjamin M. Frye, Mark W. Floyd, Dahn C. Pham, John J. Feldman, Brian R. Hamlin — 2012-01-30

Abstract: The purpose of this study was to determine if recent changes to the femoral component of a particular posterior-stabilized total knee prosthesis would affect the incidence of postoperative patellofemoral crepitance and patella clunk syndrome. One hundred eight total knee arthroplasties were performed with the conventional design; 136 were performed after the femoral component was changed. Complications were compared between the groups with an average follow-up of 17.7 months and 12.4 months, respectively. Thirteen knees with the conventional design (12%) were found to have patellofemoral complications; no complications were noted with the new design (P < .0001). Femoral components with a deep trochlear groove and smooth transition of the intercondylar box appear to better accommodate any peripatellar fibrous nodule that may form after total knee arthroplasty.

Increased Operating Room Time in Patients With Obesity During Primary Total Knee Arthroplasty: Conflicts for Scheduling

Naomi E. Gadinsky, Jacob B. Manuel, Stephen Lyman, Geoffrey H. Westrich — 2012-01-30

Abstract: Obesity is associated with increased complications related to total knee arthroplasty (TKA), but the relationship between body mass index (BMI) and operating room time during TKA is unknown. A total of 454 unilateral primary TKAs (2005-2009) were reviewed and categorized by BMI (normal weight, 18.5-25 kg/m2; overweight, 25-30 kg/m2; obese class I, 30-<35 kg/m2; class II, 35-40 kg/m2; class III, >40 kg/m2). Intraoperative time measurements (total room time, anesthesia induction time, tourniquet time, closing time, surgery time) were compared across the BMI groups. Comparing normal weight to obese class III, time differences were significant in total room time (24 minutes, P < .01), surgery time (16 minutes, P < .01), tourniquet time (7.5 minutes, P < .01), and closure time (8 minutes, P < .01). Armed with this information, BMI can be used to better allocate operating room time for TKA.

Meta-Analysis of Navigation vs Conventional Total Knee Arthroplasty

2012-02-15

Abstract: Navigated total knee arthroplasty (TKA) is promoted as a means to improve limb and prosthesis alignment. This study involved a systematic review and meta-analysis for all randomized controlled trials in the literature from 1986 to 2009 comparing alignment outcomes between navigated and conventional TKA. Alignment outcomes were pooled using a random-effects model, and heterogeneity was explored. Twenty-three randomized controlled trials were identified comparing navigated vs conventional TKA involving 2541 patients. Patients who underwent navigated TKA had a significantly lower risk of implant malalignment at more than 3° as well as more than 2°. In addition, the risk of malalignment was reduced for the coronal plane tibial and femoral components as well as femoral and tibial slope. This meta-analysis demonstrates that navigated TKA provides significant improvement in prosthesis alignment.

Temporal-Spatial Gait Adaptations During Stair Ascent and Descent in Patients With Knee Osteoarthritis

2012-03-05

Abstract: Knee osteoarthritis (OA) accounts for more functional disability of the lower extremity than any other disease. We recruited 18 patients with knee OA and 18 healthy age-, height-, mass-, and gender-matched control subjects to investigate the effects knee OA has on select spatial and temporal gait variables during a stair climbing task. No group-by-direction interaction was observed; however, significant effects did occur for group and direction. Specifically, patients with knee OA demonstrated less time in single support, greater time in double support, decreased step length, greater step width, less stride length, decreased total gait velocity, greater total time in support, and less total time in swing, compared with controls. Early-stage knee OA directly influences specific temporal and spatial gait characteristics during stair climbing.

Long-Term Follow-Up of Anatomic Graduated Component Total Knee Arthroplasty: A 15- to 20-Year Survival Analysis

2012-03-15

Abstract: The aims of this study were to determine survival rate, the clinical performance, and radiologic results of an Anatomic Graduated Component (AGC) total knee arthroplasty (TKA). Survival analysis was assessed by analyzing all hospital records of 211 AGC TKAs in 177 patients after 15 to 20 years. The survival rate was 87%, with failure defined as revision for any reason including infection. The main reasons for failure were infection and failure of the metal-backed patellar component. Clinical evaluation of 30 patients (33 TKAs) and questionnaires of 20 patients (23 TKAs) were taken, showing moderate to good results (mean Knee Society Score, 51; mean Western Ontario and McMaster Universities Osteoarthritis index, 82; mean University of California Los Angeles score, 4). Radiologic evaluation of 13 TKAs in 12 patients showed that none was suspect for loosening. Three knees showed significant medial wear but no clinical complaints. In conclusion, this is one of the first studies showing that AGC total knee prosthesis has good results 15 to 20 years after surgery.

In Vivo Kinematic Analysis of Cruciate-Retaining Total Knee Arthroplasty During Weight-Bearing and Non–Weight-Bearing Deep Knee Bending

2012-04-04

Abstract: The purpose of the present study was to evaluate the in vivo kinematics of the posterior cruciate ligament–retaining total knee arthroplasty during weight-bearing and non–weight-bearing deep knee bending and compare these 2 different conditions. We evaluated the in vivo kinematics of the knee using fluoroscopy and femorotibial translation relative to the tibia tray by 2-dimensional/3-dimensional registration. In the weight-bearing state, the femoral component showed central pivot and bicondylar posterior rollback pattern. During non–weight-bearing, the movement anteriorly occurred on both the medial and lateral side during early flexion, whereas bicondylar femoral component rollback occurred after that. During non–weight-bearing, both the medial and lateral condyle significantly moved anteriorly compared with the weight-bearing state during early flexion. However, bicondylar femoral rollback occurred under both these conditions.

Changes in Lower Extremity 3-Dimensional Load-Bearing Axes Before and After Mobile-Bearing Total Knee Arthroplasty

2012-02-10

Abstract: This study evaluated changes in the lower extremity 3-dimensional load-bearing mechanical axes in the anteroposterior and mediolateral directions before and at 3 weeks after mobile-bearing total knee arthroplasty. The effects of the degrees of anteroposterior constraint of the designs on the location of the load-bearing mechanical axis at the knee joint level were also assessed. We evaluated 151 knees from 134 patients with 74 knees receiving meniscal bearing-type and 77 knees receiving rotating platform-type prostheses. In the mediolateral direction, both designs showed significant improvements, whereas in the anteroposterior direction, they revealed no improvements postoperatively and were worsened significantly in meniscal bearing type. Differences in the degree of bone and soft tissue involvement for the correction of alignment may explain the findings.

Factors Affecting the Postoperative Limb Alignment and Clinical Outcome After Oxford Unicompartmental Knee Arthroplasty

Seung-Ju Kim, Ji-Hoon Bae, Hong Chul Lim — 2012-01-30

Abstract: We evaluated the postoperative mechanical axis deviation and clinical outcome according to bearing size, femoral component position, and tibial resection angle after unicompartmental knee arthroplasty (UKA). A total of 104 patients with 124 knees underwent Oxford phase 3 UKA. The overall changes in mechanical axis deviation and tibiofemoral angle were significantly different according to bearing size (P = .001 and < .001), but they were not significantly different according to the tibial resection angle and femoral component position. The postoperative mechanical axis fell into the zone C or zone 2 in 108 knees (87%) and into the zone 3 or zone 4 in 16 cases (13%). One hundred eight cases, which had the mechanical axis passing the zone C or zone 2, did not show any progression of arthritis. Limb alignment is a function of the thickness of the bearing rather than alignments of femoral and tibial implant.

Computed Tomographic Measurement of Gender Differences in Bowing of the Sagittal Femoral Shaft in Persons Older Than 50 Years

2012-02-27

Abstract: Surgeons do not give enough weight to the effects of bowing of the sagittal femoral shaft in total knee arthroplasty (TKA), which can result in damage to the cortex, fractures, or malalignment of the femoral component. To determine gender differences in bowing, we used spiral computed tomography to scan the femurs of 26 men and 47 women older than 50 years who required TKA. Skeletal extraction of the total sagittal femoral shaft from computed tomographic images was done by a matrix laboratory. The extracted curves were evenly divided into 3 sections. Comparison of the curvature on different sections of the same side of the femur showed that the distal third was significantly bowed. In addition, the curvature of the distal third was significantly larger in women than in men. Such morphological characteristics put forward new requirements in how intramedullary guide rods are used in TKA.

Acute Kidney Injury After Placement of an Antibiotic-Impregnated Cement Spacer During Revision Total Knee Arthroplasty

2012-02-10

Abstract: We performed a retrospective cohort study of 84 patients to determine the incidence and predictors of acute kidney injury after antibiotic-impregnated cement spacer (ACS) placement for infected total knee arthroplasties. Acute kidney injury was defined as a more than 50% rise in serum creatinine from a preoperative baseline to a level greater than 1.4 mg/dL within 90 days postoperatively. Total incidence was 17% (n = 14; 95% confidence interval [CI], 10%-26%), and acute kidney injury was significantly associated with ACS tobramycin dose as both a dichotomous variable (>4.8 g; odds ratio, 5.87; 95% CI, 1.43-24.19; P = .01) and linear variable (odds ratio, 1.24 for every 1-g increase; 95% CI, 1.00-1.52; P = .049). Routine monitoring of serum creatinine and measurement of serum aminoglycoside levels in response to a threshold creatinine rise may be warranted after the placement of an aminoglycoside-containing ACS.

Detection of Total Knee Prostheses at Airport Security Checkpoints

Qais Naziri, Aaron J. Johnson, Hasan A. Hooper, Said H. Sana, Michael A. Mont — 2012-02-27

Abstract: Airport security screening measures have changed substantially during the past decade, but few reports have examined how this affects patients who have undergone knee arthroplasties. The purpose of this study was to characterize the efficacy of airport metal detection of total knee prostheses, the delays faced, any inconvenience this may have caused, and the role of implant identification cards. Ninety-seven total knee arthroplasty recipients reported passing through an airport metal detector, with 70 triggering the alarm a mean of 3 times (range, 1-36). The presence of a single-knee prosthesis triggered airport security alarms more than 83% of the time and increased patient inconvenience. Patients should be informed about this chance and be prepared to present documentation of their prosthesis.

Multimodal Periarticular Injection Vs Continuous Femoral Nerve Block After Total Knee Arthroplasty: A Prospective, Crossover, Randomized Clinical Trial

Fu-Yuen Ng, Jacobus Kwok-Fu Ng, Kwong-Yuen Chiu, Chun-Hoi Yan, Chi-Wing Chan — 2012-02-10

Abstract: This study compares the efficacy of pain control using continuous femoral nerve block (FNB) and multimodal periarticular soft tissue injection. This is a randomized, crossover, clinical trial. Sixteen patients having bilateral osteoarthritis of the knee scheduled for staged total knee arthroplasty were randomized to receive either FNB (0.2% ropivacaine), via indwelling catheter for 72 hours, or multimodal periarticular soft tissue injection in the first stage. In the second stage, they received the opposite treatment. The primary outcome measure was morphine consumption by patient-controlled analgesia in the first 72 hours postoperatively. Cumulative morphine consumption as well as rest pain and motion pain in the first 72 hours was comparable between the 2 groups. The functional outcomes did not differ significantly. We conclude that multimodal periarticular soft tissue injection provides comparable analgesia to continuous FNB after total knee arthroplasty.

Revision Total Knee Arthroplasty: Infection Should Be Ruled Out in All Cases

2012-03-05

Abstract: We hypothesized that some aseptic revision total knee arthroplasty failures are indeed caused by occult infection. This prospective study recruited 65 patients undergoing revision total knee arthroplasty. The mean follow-up period was 19 months. Collected synovial fluid was analyzed by Ibis T5000 biosensor (Abbott Molecular Inc, Ill; a multiplex polymerase chain reaction technology). Cases were considered as infected or aseptic based on the surgeon's judgment and Ibis findings. Based on Ibis biosensor, 17 aseptic cases were indeed infected that had been missed. Of these 17 cases, 2 developed infection after the index revision. A considerable number of so-called aseptic failures seem to be occult infections that were not adequately investigated and/or miscategorized as aseptic failure. We recommend that all patients undergoing revision arthroplasty be investigated for periprosthetic joint infection.

The Knee Adduction Moment During Gait is Associated With the Adduction Angle Measured During Computer-Assisted Total Knee Arthroplasty

2012-04-05

Abstract: Computer-assisted surgery can be used to measure 3-dimensional knee function during arthroplasty surgery; however, it is unknown if the movement of the knee measured during surgery is related to the in vitro, dynamic state of the knee joint, specifically the knee adduction moment during gait, which has been related to implant migration. The purpose of this study was to determine if the preoperative adduction moment is correlated with the knee abduction/adduction angle measured intraoperatively. A statistically significant correlation was found between the mean (r2 = 0.59; P = .001) and peak (r2 = 0.53; P = .003) preoperative knee adduction moment and the mean abduction/adduction angle measured intraoperatively. The association found in this study suggests the potential for incorporating functional information that relates to surgical outcome into surgical decision making using computer-assisted surgery.

Removal of Trabecular Metal Osteonecrosis Intervention Implant and Conversion to Primary Total Hip Arthroplasty

2012-03-15

Abstract: Core decompression and placement of the Trabecular Metal Osteonecrosis Intervention Implant have shown to be initially successful in treating early osteonecrosis. When treatment fails, however, patients often undergo primary total hip arthroplasty (THA) requiring removal of a previously inserted trabecular metal implant. We describe a technical tip for removal of a well-ingrown trabecular metal screw. A metal-cutting trephine placed over the screw allows for removal in an efficient manner while minimizing additional dissection and bone loss during conversion to THA.

Alignment Changes Due to Incomplete Component Seating in Total Knee Arthroplasty

H. John Cooper — 2012-04-05

Abstract: Mechanical axis restoration remains a primary goal of total knee arthroplasty. Incomplete asymmetrical component seating, through intended or unintended alterations in surgical technique, changes the component alignment and, thus, the overall mechanical axis. Using a trigonometric analysis, it was determined that incomplete seating of 1 to 5 mm can alter the coronal alignment by 0.7° to 4.9°, depending on the amount of asymmetry as well as the size of the femoral or tibial component. This analysis quantifies the degree of changes surgeons should expect when incomplete component seating is encountered intraoperatively.

Squeaking in a Delta Ceramic-on-Ceramic Uncemented Total Hip Arthroplasty

Martin A. Buttaro, Gerardo Zanotti, Fernando M. Comba, Francisco Piccaluga — 2012-03-09

Abstract: Squeaking is one of the main concerns related to the use of ceramic-on-ceramic total hip arthroplasty. Although it has received much recent publicity, most of the previous reports on this complication have been related to the use of the second generation of alumina ceramics combined with a cup having an elevated metal rim to protect the ceramic liner from neck impingement. We report a patient with a third-generation Biolox Delta (CeramTec AG, Plochingen, Germany) ceramic-on-ceramic uncemented total hip arthroplasty without an elevated metal rim in the cup who presented with a squeaking hip at 23 months postoperative. Although this complication was mainly related to a specific design in the literature, this case demonstrates that newer generation ofceramics can also present squeaking.

Editorial board

2012-06-01

Masthead

2012-06-01

Inst to Authors

2012-06-01

Conflict of Interest

2012-06-01

The Journal of Arthroplasty

In-Hospital Patient Falls After Total Joint Arthroplasty: Incidence, Demographics, and Risk Factors in the United States

Proximal Femoral Allograft in Revision Hip Surgery With Severe Femoral Bone Loss: A Systematic Review and Meta-Analysis

Comparison of Total Hip and Knee Arthroplasty Cohorts and Short-Term Outcomes From a Single-Center Joint Registry

Design, Implementation, and Comparison of Methods for Collecting Implant Registry Data at Different Hospital Types

Effect of Immediate Postoperative Physical Therapy on Length of Stay for Total Joint Arthroplasty Patients

The Preoperative Prediction of Success Following Irrigation and Debridement With Polyethylene Exchange for Hip and Knee Prosthetic Joint Infections

Patient Perspective Survey of Total Hip vs Total Knee Arthroplasty Surgery

The Persistence of Staphylococcus aureus Decolonization After Mupirocin and Topical Chlorhexidine: Implications for Patients Requiring Multiple or Delayed Procedures

Periprosthetic Joint Infection: Are Patients With Multiple Prosthetic Joints at Risk?

Total Joint Arthroplasty in Patients With Rheumatoid Arthritis: A United States Experience From 1992 Through 2005

Outcomes of Total Hip and Knee Arthroplasty After Cardiac Transplantation

Ultrasound Screening of Periarticular Soft Tissue Abnormality Around Metal-on-Metal Bearings

The Optimal Skin Incision for Minimally Invasive Total Hip Arthroplasty Performed via the Anterolateral Approach

Squeaking After Third-Generation Ceramic-on-Ceramic Total Hip Arthroplasty

Anteversion of the Acetabular Component Aligned With the Transverse Acetabular Ligament in Total Hip Arthroplasty

Repeat 2-Stage Exchange for Infected Total Hip Arthroplasty: A Viable Option?

Long-Term Femoral Bone Remodeling After Cemented Hip Arthroplasty With the Müller Straight Stem in the Operated and Nonoperated Femora

Shortening Cemented Femoral Implants: An In Vitro Investigation to Quantify Exeter Femoral Implant Rotational Stability vs Simulated Implant Length

Change in Pelvic Tilt Angle 2 to 4 Years After Total Hip Arthroplasty

Anterior Pelvic Soft Tissue Thickness Influences Acetabular Cup Positioning with Imageless Navigation

The Effect of Hip Position on the Length of Trochanteric Muscles: Potential Implications for Early Postoperative Management of Hip Arthroplasty

Predicting Need for Allogeneic Transfusion After Total Knee Arthroplasty

Chinese Experience With Metal-on-Metal Hip Resurfacing

Large-Diameter Modular Metal-on-Metal Total Hip Arthroplasty: Incidence of Revision for Adverse Reaction to Metallic Debris

Are Hip Resurfacing Arthroplasties Meeting the Needs of Our Patients? A 2-Year Follow-Up Study

Cobalt and Chromium Ion Release After Large-Diameter Metal-on-Metal Total Hip Arthroplasty

Early Complications of Hip Resurfacing

Early Results of Total Hip Arthroplasty in Patients With Slipped Upper Femoral Epiphysis Compared With Patients With Osteoarthritis

Hip Squeaking: A 10-Year Follow-Up Study

Modern Proximally Tapered Uncemented Stems Can Be Safely Used in Dorr Type C Femoral Bone

Leg Length Change in Total Hip Arthroplasty With Subtrochanteric Femoral Shortening Osteotomy for Crowe Type IV Developmental Hip Dysplasia

Do Previous Operative Reports Provide the Critical Information Necessary for Revision Total Hip Arthroplasty?

Unplanned Admission to the Intensive Care Unit After Total Hip Arthroplasty

Retrospective Evaluation of Inpatient Celecoxib Use After Total Hip and Knee Arthroplasty at a Veterans Affairs Medical Center

Revision Total Hip Arthroplasty in Patients 80 Years or Older

Interobserver and Intraobserver Reliability and Validity of the Vancouver Classification System of Periprosthetic Femoral Fractures After Hip Arthroplasty

Recovery Room Radiographs After Total Hip Arthroplasty: Tradition vs Utility?

A Minimum of 10-Year Follow-Up of the Burch-Schneider Cage and Bulk Allografts for the Revision of Pelvic Discontinuity

Wear Analysis of First-Generation Highly Cross-Linked Polyethylene in Primary Total Hip Arthroplasty: An Average 9-Year Follow-Up

Imaging Periprosthetic Osteolysis Around Total Knee Arthroplasties Using a Human Cadaver Model

The Effect of Patellar Replacement Technique on Patellofemoral Complications and Anterior Knee Pain

Hi-Flexion and Gender-Specific Designs Fail to Provide Significant Increases in Range of Motion During Cruciate-Retaining Total Knee Arthroplasty

The Influence of Sterilization Method on Articular Surface Damage of Retrieved Cruciate-Retaining Tibial Inserts

Sagittal Flexion of the Femoral Component Affects Flexion Gap and Sizing in Total Knee Arthroplasty

Improvements in Knee Range and Symptomatic and Functional Behavior After Knee Arthroplasty Based on Preoperative Restriction in Range

Function and Quality of Life in Patients With Recurvatum Deformity After Primary Total Knee Arthroplasty: A Review of Our Joint Registry

Hybrid Component Fixation in Total Knee Arthroplasty: Minimum of 10-Year Follow-Up Study

Cutting Error of the Distal Femur in Total Knee Arthroplasty by Use of a Navigation System

A Comparison of Patellar Vascularity Between the Medial Parapatellar and Subvastus Approaches in Total Knee Arthroplasty

Incidence of Clinically Significant Venous Thromboembolic Events in Asian Patients Undergoing Total Knee Arthroplasty Without Anticoagulation

Unipolar vs Bipolar Hemostasis in Total Knee Arthroplasty: A Prospective Randomized Trial

Tibial Component Fixation with a Peri-Apatite Coating: Evaluation by Radiostereometric Analysis in a Canine Total Knee Arthroplasty Model

Custom-Fit Total Knee Arthroplasty: Our Initial Experience in 32 Knees

Changes in Posterior Condylar Offset After Total Knee Arthroplasty Cannot be Determined by Radiographic Measurements Alone

Outpatient Unicompartment Knee Arthroplasty With Indwelling Femoral Nerve Catheter

Effect of Femoral Component Design on Patellofemoral Crepitance and Patella Clunk Syndrome After Posterior-Stabilized Total Knee Arthroplasty

Increased Operating Room Time in Patients With Obesity During Primary Total Knee Arthroplasty: Conflicts for Scheduling

Meta-Analysis of Navigation vs Conventional Total Knee Arthroplasty

Temporal-Spatial Gait Adaptations During Stair Ascent and Descent in Patients With Knee Osteoarthritis

Long-Term Follow-Up of Anatomic Graduated Component Total Knee Arthroplasty: A 15- to 20-Year Survival Analysis

In Vivo Kinematic Analysis of Cruciate-Retaining Total Knee Arthroplasty During Weight-Bearing and Non–Weight-Bearing Deep Knee Bending

Changes in Lower Extremity 3-Dimensional Load-Bearing Axes Before and After Mobile-Bearing Total Knee Arthroplasty

Factors Affecting the Postoperative Limb Alignment and Clinical Outcome After Oxford Unicompartmental Knee Arthroplasty

Computed Tomographic Measurement of Gender Differences in Bowing of the Sagittal Femoral Shaft in Persons Older Than 50 Years

Acute Kidney Injury After Placement of an Antibiotic-Impregnated Cement Spacer During Revision Total Knee Arthroplasty

Detection of Total Knee Prostheses at Airport Security Checkpoints

Multimodal Periarticular Injection Vs Continuous Femoral Nerve Block After Total Knee Arthroplasty: A Prospective, Crossover, Randomized Clinical Trial

Revision Total Knee Arthroplasty: Infection Should Be Ruled Out in All Cases

The Knee Adduction Moment During Gait is Associated With the Adduction Angle Measured During Computer-Assisted Total Knee Arthroplasty

Removal of Trabecular Metal Osteonecrosis Intervention Implant and Conversion to Primary Total Hip Arthroplasty

Alignment Changes Due to Incomplete Component Seating in Total Knee Arthroplasty

Squeaking in a Delta Ceramic-on-Ceramic Uncemented Total Hip Arthroplasty

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