The Journal of Arthroplasty - Articles in Press

Validity of A Short-Term Quality of Life Questionnaire in Patients Undergoing Joint Replacement: The Quality of Recovery–40 - Corrected Proof

Stephane Poitras, Paul E. Beaule, Geoffrey F. Dervin — 2012-05-18

Abstract: One hundred thirty-two patients undergoing total hip or knee arthroplasty were evaluated before and after surgery with the Quality of Recovery–40 (QoR-40) and the Short Form 12 (SF-12) questionnaires seven times over a 4-month period, with the objective of comparing their psychometric properties. Physical dimensions of the QoR-40 and SF-12 were not related in the days after surgery but moderately related over the first month. Only the change in score for the physical independence dimension of the QoR-40 exceeded measurement error. Effect sizes were larger for the QoR-40 within the first month post-surgery and larger for the SF-12 past 1 month. Effect sizes were larger for the physical dimensions of both instruments compared to the psychological dimensions. Only the physical independence dimension of the QoR-40 appears useful to assess the quality of life in the first month following surgery.

The Importance of Bony Impingement in Restricting Flexion After Total Knee Arthroplasty: Computer Simulation Model With Clinical Correlation - Corrected Proof

2012-05-17

Abstract: We constructed patient-specific models from computed tomography data after total knee arthroplasty to predict knee flexion based on implant-bone impingement. The maximum flexion before impingement between the femur and the tibial insert was computed using a musculoskeletal modeling program (KneeSIM; LifeModeler, Inc, San Clemente, California) during a weight-bearing deep knee bend. Postoperative flexion was measured in a clinical cohort of 21 knees (low-flex group: 6 knees with <100° of flexion and high-flex group: 15 size-matched knees with >125° of flexion at 2 years). Average predicted flexion angles were within 2° of clinical measurements for the high-flex group. In the low-flex group, 4 cases had impingement involving the bone cut at the posterior condyle, and the average predicted knee flexion was 102° compared with 93° measured clinically. These results indicate that the level of the distal femoral resection should be carefully planned and that exposed bone proximal to the tips of the posterior condyles of the femoral component should be removed if there is risk of impingement.

Hip Resurfacing With the Biomet Hybrid ReCap-Magnum System: 7-Year Results - Corrected Proof

Thomas P. Gross, Fei Liu — 2012-05-17

Abstract: The purpose of this study was to report our clinical outcome of a large series of metal-on-metal hip resurfacing arthroplasty (HRA) using the hybrid Biomet ReCap-Magnum system. This is a single-designer surgeon series with an average of 5 ± 1 years. Seven hundred forty consecutive hybrid HRAs were performed in 653 patients. Kaplan-Meier survivorship with any revision as an end point was 96.4% at 7 years. Twenty-five (3.4%) cases were revised: 8 due to acetabular component loosening, 6 due to femoral neck facture, 4 due to failure of femoral component fixation, 2 due to deep infection, 2 due to adverse wear, 1 due to psoas tendonitis, 1 due to recurrent dislocation, and 1 due to unexplained pain. Biomet ReCap and Magnum HRA components with hybrid fixation methods showed excellent survivorship for a minimally selected young patient cohort at 7 years.

Biomechanical Analysis of Acetabular Revision Constructs: Is Pelvic Discontinuity Best Treated With Bicolumnar or Traditional Unicolumnar Fixation? - Corrected Proof

2012-05-17

Abstract: Pelvic discontinuity in revision total hip arthroplasty presents problems with component fixation and union. A construct was proposed based on bicolumnar fixation for transverse acetabular fractures. Each of 3 reconstructions was performed on 6 composite hemipelvises: (1) a cup-cage construct, (2) a posterior column plate construct, and (3) a bicolumnar construct (no. 2 plus an antegrade 4.5-mm anterior column screw). Bone-cup interface motions were measured, whereas cyclical loads were applied in both walking and descending stair simulations. The bicolumnar construct provided the most stable construct. Descending stair mode yielded more significant differences between constructs. The bicolumnar construct provided improved component stability. Placing an antegrade anterior column screw through a posterior approach is a novel method of providing anterior column support in this setting.

Two-Incision Minimally Invasive vs Standard Total Hip Arthroplasty: Comparison of Component Position and Hospital Costs - Corrected Proof

Sean Amman, Amy Cizik, Seth S. Leopold, Paul A. Manner — 2012-05-14

Abstract: Forty-nine patients undergoing 2-incision total hip arthroplasty were matched by age, gender, body mass index, and comorbidity to patients undergoing a standard lateral Hardinge approach. Hospital costs and charges were compared along with length of stay, component position, and complication rates. Component position and complication rates were identical for the 2 groups. However, hospital costs and charges were significantly lower for the 2-incision group, as was length of stay.

Assessing Readmission Databases: How Reliable Is the Information? - Corrected Proof

2012-05-14

Abstract: Databases are being used to shape health care policy. However, the reliability of coding information entered into the databases may be difficult to validate. In this study, we assess readmission data from an institutional database that identified 1515 readmissions (708 patients) after total hip or total knee arthroplasty during a 5-year interval. After exclusions, 223 readmissions (190 patients) underwent medical record review. Bleeding, wound-related, and arthroplasty-related complications constituted most (62.8%) of readmissions. Bleeding and wound complications were nearly 6 times more frequently associated with readmission than venous thromboembolism events. On secondary review, there was discordance between the diagnosis obtained by a surgeon reviewer and coding for diagnoses consistent with periprosthetic infection (996.66, 77, 78, and 998.59) in 70% of cases. The findings of our study raise questions regarding the validity of accepting information obtained from larger databases without closer scrutiny.

Uncemented Arthroplasty for Metastatic Disease of the Hip: Preliminary Clinical Experience - Corrected Proof

Ran Thein, Amir Herman, Ahron Chechik, Boaz Liberman — 2012-05-14

Abstract: Improved longevity among patients with metastatic bone disease led to increasing incidence of pathologic and impending fractures around the hip. Cemented hip arthroplasty is considered to be the standard of care for this condition. The purpose of this study is to evaluate the outcome of uncemented hip arthroplasty in those patients. We performed a retrospective review of clinical and radiologic data of 57 consecutive patients (60 hips) who underwent an uncemented hip arthroplasty due to metastatic hip disease. Mean follow-up was 18.6 months (range, 5-60 months); overall 1-year survival and mortality rates were 58.5% and 38.3%, respectively. Multiple myeloma and metastatic prostate carcinoma patients had better outcome over other metastasis origin. At last follow-up, no prosthesis failure or operation-related major complication has been recorded.

In Reply: - Corrected Proof

Morteza Meftah, Amar S. Ranawat, Chitranjan S. Ranawat — 2012-05-14

Thank you for your comments. As it is stated in the article, this is a concise report of a previously published article where the preoperative diagnoses, indications, and deformity are clearly stated . In severe cases of deformity and bone loss, where a metal back tibial component, a more constrained implant, and/or bone graft is required, all-poly tibia may not be a suitable option. Also, appropriate bony alignments and proper flexion and extension gap balance are required for long-term survivorship. The point of this study was to demonstrate that with proper technique and patient selection, all-poly tibia has excellent long-term outcomes in young and active patients.

Spontaneous Late Dissociation of the Tibial Insert After High-Flex Posterior-Stabilized Genesis II Total Knee Arthroplasty - Corrected Proof

Dae-Hee Lee, Tze Gin Lee, Sung-Joon Park, Seung-Beom Han — 2012-05-14

Abstract: We report a rare complication of spontaneous late dissociation of the tibial insert 2 years after total knee arthroplasty using a high-flex posterior-stabilized Genesis II prosthesis (Smith & Nephew, Memphis, Tenn). It appears that 2 factors may have contributed to dissociation, namely, incomplete seating of the insert and the design of the prosthesis, which involves a shallow anterior tab snap-fit locking mechanism and thin dovetail lips.

Posterior Femoral Neck Impingement Secondary to Excess Acetabular Anteversion in Hip Resurfacing Arthroplasty - Corrected Proof

Benan M. Dala-Ali, Matthew Welck, Ian Osborne, Sarah K. Muirhead-Allwood — 2012-05-07

Abstract: Component malposition in resurfacing arthroplasty can cause impingement, reduced range of motion, increased metal wear, and early failure. It is therefore important that any component malposition is recognized early and monitored carefully. We present a case of delayed diagnosis of excess acetabular component anteversion causing posterior femoral neck impingement and pain. We correlate the degree of damage found intraoperatively with the degree of component malposition on the radiographs. This is used as a platform to discuss the optimum positioning of hip resurfacing components and the radiographic methods used to determine component position postoperatively.

Internal Iliac Artery Injury and Total Hip Arthroplasty: Discovery After 10 Years - Corrected Proof

Emily L.M. Kong, Michael R. Knight — 2012-05-07

Abstract: Delayed presentation of iliac artery injury by acetabular screw. Screw removal at liner revision of a 10-year-old uncemented acetabular shell resulted in unexpected catastrophic blood loss. Replacing the screw prevented further hemorrhage, and investigation revealed internal iliac artery injury caused by the screw. This was treated successfully by bypass grafting. Careful review of preoperative imaging should aim to identify those at risk and requiring further imaging before undergoing revision surgery.

Diagnosis of Periprosthetic Joint Infection Using Synovial C-Reactive Protein - Corrected Proof

Javad Parvizi, James C. McKenzie, James P. Cashman — 2012-05-07

Abstract: The diagnosis of periprosthetic joint infection (PJI) is a considerable challenge. This study examines the quantification of C-reactive protein (CRP) in synovial fluid for diagnosis of PJI. Synovial fluid samples were collected prospectively from 63 patients undergoing revision or primary joint arthroplasty. All patients were divided into septic vs aseptic groups. There were 43 patients in the aseptic group and 20 patients in the septic group. There was a statistically significant difference in the mean synovial CRP between the septic cohort at 40 mg/L vs a mean of 2 mg/L for aseptic failure (P < .0001). The sensitivity was 85% with 95% specificity at a threshold of 9.5 mg/L. The area under the curve was 0.92. We believe that synovial CRP assay holds great promise as a diagnostic marker for PJI.

Total Knee Arthroplasty Has Higher Postoperative Morbidity Than Unicompartmental Knee Arthroplasty: A Multicenter Analysis - Corrected Proof

2012-05-07

Abstract: A total of 2235 primary total knee arthroplasties (TKAs) and 605 unicompartmental knee arthroplasties performed at 3 institutions over 5 years were reviewed to compare the incidence of postoperative complications between these groups. The overall risk of complications for patients undergoing TKA was 11.0%, compared with 4.3% for patients undergoing unicompartmental knee arthroplasty (P < .0001). Total knee arthroplasty was associated with increased rates of manipulation (odds ratio [OR], 13.0; P < .0001), transfusion (OR, 8.5; P = .036), intensive care unit admission (OR, 7.4; P = .049), discharge to a rehabilitation facility (OR, 5.2; P < .0001) and had longer hospital stays (mean, 3.3 vs 2.0 days; P < .0001). There was a trend toward an increased risk of deep infection (0.8% vs 0.2%, P = .13), readmission (4.2% vs 2.7%, P = .0795), thromboembolic events (1.0% vs 0.64%, P = .398), and any reoperation (1.4% vs 0.6%; P = .064). The increased risk of perioperative complications after TKA should be considered when counseling patients if they are an appropriate candidate for either procedure.

A Fluoroscopic Grid in Supine Total Hip Arthroplasty: Improving Cup Position, Limb Length, and Hip Offset - Corrected Proof

2012-05-07

Abstract: We hypothesized that use of a novel fluoroscopic grid would decrease operative time and component positioning variability during anterior supine total hip arthroplasty (THA). We reviewed 99 anterior supine THAs: 39 using a fluoroscopic grid, and 60 using fluoroscopy alone. Goals were cup abduction of 40° ± 10° and limb length and hip offset within 10 mm of the contralateral side. Surgical time was decreased in the study group (79 vs 94 minutes, P = .002). In the study group, more components met the goal for cup abduction (97% vs 83%, P = .046), limb length (100% vs 88%, P = .04), hip offset (85% vs 67%, P = .047), and all 3 combined (82% vs 52%, P = .002). We demonstrated decreased component positioning variability during anterior supine THA with assistance of a fluoroscopic grid.

How Do Frozen and Permanent Histopathologic Diagnoses Compare for Staged Revision After Periprosthetic Hip Infections? - Corrected Proof

D. Alex Stroh, Aaron J. Johnson, Qais Naziri, Michael A. Mont — 2012-05-07

Abstract: Histopathologic analysis of frozen tissue samples is used to aid the intraoperative diagnosis of periprosthetic hip infections, but there are concerns about reliability. The purposes of this study were to determine the rate of concordance between diagnoses of infection made with frozen and permanent sections and to assess how discrepancies affected patient outcomes. A total of 282 samples from 62 patients were collected for frozen and permanent section analysis. There was concordance in 274 samples (97%). In 1 case, discrepancies led to retention of components during persistent infection, and the patient required further revision and antibiotics until infection free. Otherwise, discrepancies did not affect patient outcomes. There is good concordance between frozen and permanent sections for diagnosing periprosthetic hip infection and rarely do these discrepancies affect management.

Intraoperative Soft Tissue Balance Reflects Minimum 5-Year Midterm Outcomes in Cruciate-Retaining and Posterior-Stabilized Total Knee Arthroplasty - Corrected Proof

2012-05-04

Abstract: With the use of an offset type tensor for total knee arthroplasties (TKAs), intraoperative soft tissue balance including the joint component gap and ligament balance was measured in 41 varus-type osteoarthritic patients (19 cruciate-retaining [CR] TKAs and 22 posterior-stabilized [PS] TKAs), and the correlations between the intraoperative values and the postoperative values assessed by stress radiographs at extension and flexion were examined at a minimum 5-year follow-up. In CR TKAs, the postoperative soft tissue balances at both angles were significantly correlated with the intraoperative values. In PS TKAs, the postoperative soft tissue balances at extension, not flexion, were significantly correlated with the intraoperative values. In conclusion, the intraoperative condition of the soft tissue balance reflected the postoperative values especially in CR TKAs even at 5-year midterm follow-ups.

Economic Burden of Periprosthetic Joint Infection in the United States - Corrected Proof

Steven M. Kurtz, Edmund Lau, Heather Watson, Jordana K. Schmier, Javad Parvizi — 2012-05-04

Abstract: This study characterizes the patient and clinical factors influencing the economic burden of periprosthetic joint infection (PJI) in the United States. The 2001-2009 Nationwide Inpatient Sample was used to identify total hip and knee arthroplasties using International Classification of Diseases, Ninth Revision, procedure codes. The relative incidence of PJI ranged between 2.0% and 2.4% of total hip arthroplasties and total knee arthroplasties and increased over time. The mean cost to treat hip PJIs was $5965 greater than the mean cost for knee PJIs. The annual cost of infected revisions to US hospitals increased from $320 million to $566 million during the study period and was projected to exceed $1.62 billion by 2020. As the demand for joint arthroplasty is expected to increase substantially over the coming decade, so too will the economic burden of prosthetic infections.

Total Knee Arthroplasty in Morbidly Obese Patients Treated With Bariatric Surgery: A Comparative Study - Corrected Proof

2012-05-04

Abstract: Our objective was to compare outcomes (anesthesia time, total operative time, tourniquet time, duration of hospital stay, 90-day complication rate, and transfusion rates) of patients with total knee arthroplasty (TKA) who underwent bariatric surgery before or after TKA. One hundred twenty-five patients were included: TKA before bariatric surgery (group 1; n = 39), TKA within 2 years of bariatric surgery (group 2; n = 25), and TKA more than 2 years after bariatric surgery (group 3; n = 61). Patients with TKA more than 2 years after bariatric surgery had shorter anesthesia and total operative and tourniquet times than other groups; differences were significant between groups. Ninety-day complication and transfusion rates approached but did not meet statistical significance. Ninety-day complication rates and duration of hospital stay did not differ significantly between the 3 groups. The level of evidence was level II (cohort study).

Ninety-day Mortality in Patients Undergoing Elective Total Hip or Total Knee Arthroplasty - Corrected Proof

Jasvinder A. Singh, David G. Lewallen — 2012-05-04

Abstract: Using an institutional joint registry, we studied frequency, trends and predictors of mortality after elective total hip or knee arthroplasty (THA/TKA). Of the 12 727 and 12 484 patients who underwent THA and TKA, respectively, all-cause mortality rates at 7-, 30-, and 90-days were as follows: THA, 0.1%, 0.2%, and 0.5%; TKA 0.1%. 0.2%, and 0.4%, respectively. Statistically significant downward time trend in 90-day mortality was noted after TKA (P = .02) but not after THA (P = .41). In multivariable-adjusted analyses of patients undergoing THA, older age, higher comorbidity index, and prior cardiac disease were significantly associated with higher 90-day mortality. In patients undergoing TKA, older age, male gender, a Society of Anesthesiologist class of III-IV, and higher comorbidity index were associated with higher 90-day all-cause mortality. Optimization of disease management may reduce postoperative mortality after THA/TKA.

Is Intra-Articular Multimodal Drug Injection Effective in Pain Management After Total Knee Arthroplasty? A Randomized, Double-Blinded, Prospective Study - Corrected Proof

Jong-Hwan Joo, Jang-Won Park, Jun-Shik Kim, Young-Hoo Kim — 2012-05-04

We appreciate Mr Alsawadi's comments regarding our article “Is Intra-Articular Multimodal Drug Injection Effective in Pain Management After Total Knee Arthroplasty? A Randomized, Double-Blinded, Prospective Study .”

Access to Arthroplasty in South Florida - Corrected Proof

Carlos J. Lavernia, Juan S. Contreras, Jose C. Alcerro — 2012-05-04

Abstract: Our objective was to compare the availability of hip and knee arthroplasty to an adult insured by Medicaid and by private insurance. All orthopedic surgeons' offices in a South Florida county were contacted by telephone and presented with a hypothetical patient that needed either a hip or a knee arthroplasty for end stage arthritis. Two scenarios were presented. The hypothetical patient was presented as either having private insurance or Medicaid. 14.3% of all offices contacted offered an appointment to patients with Medicaid coverage for hip and knee arthroplasty, respectively. All offices offered an appointment to patients with private insurance. The mean time until appointment was longer for patients with Medicaid when compared with private insurance. Adults insured with Medicaid currently have limited access to total joint arthroplasty within the studied community.

Metal-on-Metal Local Tissue Reaction Is Associated With Corrosion of the Head Taper Junction - Corrected Proof

Kevin B. Fricka, Henry Ho, William J. Peace, Charles A. Engh — 2012-05-04

Abstract: We evaluated taper corrosion in 36-mm diameter metal-on-metal (MOM) and metal-on-polyethylene (MOP) femoral heads from a single manufacturer retrieved for various reasons. Three reviewers visually graded taper corrosion with a 5-point scale on 19 MOM heads and 14 MOP heads. The MOM group had a higher corrosion score than the MOP group (mean, 3.5 vs 1.9; P < .001). There were 8 MOM heads (42%) and only 1 MOP head (7%) that demonstrated corrosion outside of the taper zone. Metal-on-metal patients revised secondary to adverse local tissue reactions (ALTRs) had greater scores than patients without ALTRs (mean, 4.36 vs 2.38; P < .01). Adverse local tissue reactions MOM patients were also likely to have corrosion outside of the taper junction. The corrosion score increased with implantation time, and at all time intervals, the corrosion score for the MOM group was greater. Because corrosion worsens with time, we are concerned that MOM ALTR failures will increase with longer follow-up.

All-Polyethylene Tibial Implant in Young, Active Patients - Corrected Proof

Raju Vaishya — 2012-05-03

We read with interest the article titled, “All-Polyethylene tibial implant in young, active patients” (2012;27(1):10-14). The authors have brought out a very important issue about the use of all-poly tibial component in young patients, as earlier reports have been reporting their use in elderly patients older than 60 years . However, the authors have failed to mention about the primary diagnosis of their patient population. This may have relevance in the choice of implant because we feel that patients with inflammatory arthritis with associated osteoporosis may not be suitable candidates for all-poly tibial implants. Moreover, the presence of bone defects in their cases has not been documented. The presence of a significant bone defect may restrict its use, especially if an associated bone grafting procedure or the use of stem is required. The cost saving is probably one of the driving forces for its use, especially in developing countries, but at present, the use of all-poly tibial implants still needs to be restricted in selecting patients (with good bone stock, without any significant bone loss, etc) until sufficient data from multicentric, randomized controlled trials are available.

Changes in Femoral Cortical Porosity After Reaming and Intramedullary Canal Preparation in a Canine Model - Corrected Proof

2012-05-02

Abstract: This study examined changes in femoral cortical porosity resulting from femoral canal preparation during cemented total hip arthroplasty (THA). Twenty-four canines were randomly assigned to 3 groups: (1) reaming only, (2) cementing without pressurization, and (3) cementing with pressurization. Femoral cortical porosity was measured from histologic samples of the femurs at 7 positions. Reaming during canal preparation significantly increased cortical porosity. Cementing further increased cortical porosity, whereas pressurization of cement helped to counteract the increase in cortical porosity caused by cementing alone. Cortical porosity was considered to be a marker for bone mineral density (BMD) during the early phase of peri-implant healing around cemented stems. To maximize bone mineral density after cemented total hip arthroplasty, we suggest using implants that do not require reaming and pressurizing cement appropriately.

Total Hip Arthroplasty for Crowe Type Ⅳ Developmental Dysplasia - Corrected Proof

Yukiharu Hasegawa, Toshiki Iwase, Toshiya Kanoh, Taisuke Seki, Atsushi Matsuoka — 2012-05-02

Abstract: The purposes of this study were to evaluate the midterm clinical and radiographic results of total hip arthroplasty (THA) in patients with Crowe type IV developmental dysplasia and to evaluate whether low back pain would improve after THA. Eighteen consecutive patients (20 hips) were included in this study. The average age at the time of surgery was 58.5 years. The average follow-up was 10.2 years. The socket was placed at the level of the true acetabulum, and a femoral shortening osteotomy was performed. The average Harris hip score before surgery was improved from 56 to 85 points at the final follow-up. Revision was performed in 4 hips due to loosening of the femoral component in 1 hip and osteolysis in 3 hips. The midterm outcomes of THA in patients with Crowe type IV developmental dysplasia were satisfactory. The severity of low back pain was significantly reduced after THA.

Arthroplasty Infection by Priopionibacterium granulosum Treated With Reimplantation Despite Ongoing Purulent-Appearing Fluid Collection - Corrected Proof

Lukas M. Nystrom, Casi M. Wyatt, Nicolas O. Noiseux — 2012-05-02

Abstract: We present the first case of infection in a native or prosthetic joint by Propionibacterium granulosum in which a patient developed symptoms of prosthetic hip infection 5 years after primary surgery. The patient required multiple operative debridements to eradicate the infection and was successfully reimplanted despite an ongoing purulent-appearing, although sterile, fluid collection at the time of reimplantation. There is no clinical or laboratory evidence of infection at 3 years post-reimplantation, and the patient has a well-functioning total hip arthroplasty. P granulosum is a low-virulence but highly-inflammatory organism. It seems to produce a large fluid collection that may require multiple debridements. To our knowledge, there are no reported cases of native or prosthetic joint infection from P granulosum. We present the first case here.

Clinical Outcomes of Primary Total Joint Arthroplasty Among Nonagenarian Patients - Corrected Proof

Danielle Petruccelli, Wael A. Rahman, Justin de Beer, Mitch Winemaker — 2012-05-02

Abstract: A retrospective cohort study and a comparative literature review were undertaken to determine outcomes and survival/mortality rates among nonagenarian patients who underwent total joint arthroplasty (TJA). Thirty-nine patients who underwent TJA (14 hips, 25 knees) aged 90+ years were identified from a database of 9817 primary TJA cases performed at one hospital between 1998 and 2010. Findings were compared to synthesized data from relevant published literature review (LR). The mean age was 91.3 (±1.4) years, 79.5% were rated by the American Society of Anesthetists as 3+. Medical complication rate was 25.6% vs 36.2% for LR cases (P = .219). Perioperative death rate was 2.6% vs 2.1% among LR cases (P = 1.000). At 3.8-year follow-up, mortality rate was 59% (LR, 58.2%; 5.1 years), with a mean age of 95.2 (±3.5) years at death (LR, 96.3 ± 3.4). Excellent clinical outcomes were achieved. Primary TJA remains a viable and effective procedure in nonagenarian patients.

Does Degree of the Pelvic Deformity Affect the Accuracy of Computed Tomography-Based Hip Navigation? - Corrected Proof

2012-05-02

Abstract: Although some navigation systems have been used for improvement of component positioning, there have been few reports regarding cases of severe pelvic deformity. We performed a retrospective review of 25 cases of total hip arthroplasty with a computed tomography-based navigation system in patients with severe pelvic deformities and estimated acetabular component position and angle between severe deformity group and mild dysplastic group as a control. There were no significant differences in accuracy of navigation system between 2 groups in terms of 3-dimensional component position or angle. Accuracy of computed tomography-based hip navigation does not depend on the degree of pelvic deformity, and this system is also useful to identify acetabular orientation and for precise component implantation in cases of pelvic deformity.

Are Gender, Comorbidity, and Obesity Risk Factors for Postoperative Periprosthetic Fractures After Primary Total Hip Arthroplasty? - Corrected Proof

Jasvinder A. Singh, Matthew R. Jensen, Scott W. Harmsen, David G. Lewallen — 2012-05-02

Abstract: We studied the frequency and patient risk factors for postoperative periprosthetic fractures after primary total hip arthroplasty (THA). With a mean follow-up of 6.3 years, 305 postoperative periprosthetic fractures occurred in 14 065 primary THAs. In multivariable-adjusted Cox regression analyses, female gender (hazard ratio [HR], 1.48; 95% confidence interval [CI], 1.17-1.88), Deyo-Charlson comorbidity score of 2 (HR, 1.74 for score of 2; 95% CI, 1.25-2.43) or 3 or higher (HR, 1.71; 95% CI, 1.26-2.32), and American Society of Anesthesiologist class of 2 (HR, 1.84; 95% CI, 0.90-3.76) or 3 (HR, 2.45; 95% CI, 1.18-5.1) or 4 or higher (HR, 2.68; 95% CI, 0.70-10.28) were significantly associated with higher risk/hazard, and cemented implant, with lower hazard (HR, 0.68; 95% CI, 0.54-0.87) of postoperative periprosthetic fractures. Interventions targeted at optimizing comorbidity management may decrease postoperative fractures after THA.

Periprosthetic Joint Infection Diagnosis: A Complete Understanding of White Blood Cell Count and Differential - Corrected Proof

2012-04-30

Abstract: Recent research has raised doubts regarding the utility of serum white blood cell count (WBC) for diagnosis of periprosthetic joint infection (PJI). As synovial WBC and neutrophil (PMN) percentage have been adopted as accurate markers of PJI, this study investigated the correlation of WBC in serum versus joint fluid and diagnostic value of all WBC levels for failed arthroplasty patients. 153 patients (73 PJI) undergoing revision knee arthroplasty were identified. Weak correlations between joint fluid and serum for WBC (R = 0.19), PMN count (R = 0.31), and lymphocyte count (R = −0.22) were observed. Diagnostic accuracy of PMN (93%) and WBC (93%) synovial count relative to serum was similar to synovial WBC (93%) and PMN% (95%) alone. Serum WBC analysis does little to improve the accurate diagnosis of PJI.

Periprosthetic Femoral Fracture Due to Biodegradable Cement Restrictor - Corrected Proof

Rohit Kumar Dhawan, David C. Mangham, Niall M. Graham — 2012-04-23

Abstract: Biodegradable materials are gaining popularity in orthopedics. Despite finding use in different areas of orthopedic surgery, they do not come without disadvantages such as foreign body reactions, granulomatous reactions, and sterile sinus formation in bone. We report a case of a patient who sustained a periprosthetic fracture seen at the tip of a cemented femoral stem approximately 5 years postsurgery, secondary to the use of a biodegradable cement restrictor. There was no evidence of trauma or fall on the affected hip. To our knowledge, there has been no previous report describing periprosthetic fracture at the tip of cemented femoral stem secondary to the use of a biodegradable cement restrictor. We suggest abandoning use of these materials while performing cemented hip arthroplasties.

Effect on Blood Loss and Cost-Effectiveness of Pain Cocktails, Platelet-Rich Plasma, or Fibrin Sealant After Total Knee Arthroplasty - Corrected Proof

2012-04-23

Abstract: This study evaluated the effect of periarticular pain cocktail, platelet-rich plasma, or fibrin sealant injections on blood loss, transfusion rate, and hospital costs after total knee arthroplasty. A retrospective review of 400 patients undergoing primary total knee arthroplasty with one of the different periarticular treatments as stated above was performed. Postoperative blood loss, hemoglobin levels, allogenic blood transfusion rates, and per-case hospital injection cost were reported. Although platelet-rich plasma and fibrin sealant decreased blood loss compared with the control group (P < .001), there was no significant difference in blood loss in the pain-cocktail group or in postoperative hemoglobin levels or transfusion rates between all groups. Significant efficacy and cost-effectiveness for these modalities could not be identified and have, therefore, been discontinued at our practice. Level of evidence: level III.

Juvenile Arthritis Patients Report Favorable Subjective Outcomes of Hip Arthroplasty Despite Poor Standard Outcome Scores - Corrected Proof

Brigitte M. Jolles, Earl R. Bogoch — 2012-04-23

Abstract: We evaluated midterm patient-reported outcomes and satisfaction with total hip arthroplasty in patients who had severe juvenile idiopathic arthritis. Thirty-one patients (49 hips), with a mean age of 29 years (range, 16-43 years), reported low hip pain and stiffness at follow-up (mean, 7 years; range, 3-17 years). Up to 92% were satisfied with their ability to perform various activities; 96% were satisfied with pain relief. A mean postoperative flexion arc of 96° was observed. Final 36-Item Short Form Health Survey, EuroQol in 5 dimensions, Western Ontario and McMaster Universities Arthritis Index, and Harris Hip scores were lower than reference populations, particularly for mobility, physical functioning, and social functioning subscores. Young adults with end-stage hip involvement and severe longstanding juvenile idiopathic arthritis expressed high satisfaction with total hip arthroplasty, which improved range of motion, pain, and stiffness, despite poor performance on widely used outcome measures.

The Distribution of Vascular Foramina at the Femoral Head/Neck Junction: Implications for Resurfacing Arthroplasty - Corrected Proof

Christopher J. Dy, Matthew T. Thompson, Molly M. Usrey, Philip C. Noble — 2012-04-23

Abstract: Reaming for resurfacing arthroplasty may endanger the blood supply at the head-neck junction, possibly predisposing to osteonecrosis and femoral neck fracture. The current study hypothesizes that reaming endangers femoral head vasculature. Vascular foramina were identified on 16 cadaveric femora and registered on computed tomographic models. Virtual reaming was performed after templating of resurfacing components. Almost half (41.8%) of foramina was located in the anterosuperior quadrant. Loss of foramina after reaming averaged 28% (P = .03), with up to 34.6% and 33.1% loss in the anterosuperior and posterosuperior quadrants, respectively. Reaming for resurfacing arthroplasty endangers a substantial number of vascular foramina. Notching or malpositioning of components may worsen injury to the vascular supply and could subsequently increase the risk of implant failure.

The Use of the Posterior Lesser Trochanter Line to Estimate Femoral Neck Version: An Analysis of Computed Tomography Measurements - Corrected Proof

2012-04-23

Abstract: We hypothesized that the lesser trochanter could be a useful guide for estimating femoral component version during total hip arthroplasty. We conducted a study of 88 patients to evaluate the relationship between the posterior lesser trochanter line (PLTL) and the femoral neck axis (FNA) using computed tomographic scans. The mean angle between the PLTL and the FNA was 17.4° ± 7.1° (range, −1.6° to 36.5°). The PLTL angle correlated (r2 = 0.67-0.72) with the FNA angle. Intraclass correlation coefficient values showed a high level of intraobserver and interobserver agreement in the angles between the PLTL and the FNA. We found a constant relationship between the lesser trochanter and the FNA, and femoral neck version can be estimated, using the PLTL, with reasonable reliability.

Anatomical Hip Range of Motion After Implantation During Total Hip Arthroplasty With a Large Change in Pelvic Inclination - Corrected Proof

Hidenobu Miki, Takayuki Kyo, Nobuhiko Sugano — 2012-04-23

Abstract: The supine functional pelvic plane is the recommended reference pelvic plane for acetabular cup planning in navigation-assisted total hip arthroplasty. However, it is unclear whether it can be used in patients with a large preoperative positional change in pelvic inclination (PC) from the supine to the standing position because it is unknown whether these patients have a different hip range of motion (ROM). We measured the anatomical hip ROM after implantation by computed tomography–based navigation in 91 patients and found it to be similar between those with a small PC (<10°) and those with a large PC (≥10°). There was no significant correlation between ROM and preoperative PC. The supine functional pelvic plane is adequate for cup planning whether the PC is small or large.

Pseudogout in the Early Postoperative Period After Total Knee Arthroplasty - Corrected Proof

Kengo Harato, Hiroki Yoshida — 2012-04-23

Abstract: Postoperative pseudogout after total knee arthroplasty is rare. If pseudogout attacks are misdiagnosed as periprosthetic sepsis, patients may undergo unnecessary surgical procedures. We report a case of pseudogout in the early postoperative period. The attack ensued shortly after a nonsteroidal antiinflammatory drug was discontinued. The diagnosis was confirmed by aspiration, and the patient improved after readministration of the nonsteroidal antiinflammatory drug. Although rare, pseudogout should be considered in the differential when approaching a suspected infection after total knee arthroplasty.

What Are Young Patients Doing After Hip Reconstruction? - Corrected Proof

2012-04-19

Abstract: We assessed primary hip arthroplasty patients younger than 50 years in terms of activity and function. We hypothesized that young patients are more active than previously thought. Physician activity recommendations were compared with patient-reported participation levels in activities. Sixty-one patients (65.3%) were reached by telephone. Average age was 43.18 years; body mass index, 29.46. “Recommended activities” increased by 33%. High-Activity Arthroplasty Score and University of California at Los Angeles scores were 11.69 and 6.87, respectively. Patients were 98% satisfied with their postoperative function, and 95% would redo the procedure. Activities stopped due to fear of injury (29%), physician recommendation (26%), hip pain (14%), early fatigue (17%), and decreased interest (14%). The average period to postoperative survey administration was 30.06 months (range, 10-81 months). Postoperative recommendations for the young total hip arthroplasty patient should be a balance between joint prosthesis preservation and regular activity participation.

Unicompartmental Knee Arthroplasties Revised to Total Knee Arthroplasties Compared With Primary Total Knee Arthroplasties - Corrected Proof

2012-04-16

Abstract: We studied the technical operative features and the subjective outcomes of 63 patients requiring a revision to a total knee arthroplasty (TKA) for failed Oxford medial unicompartmental knee arthroplasty. We compared this revision study group to a contemporary control cohort of 126 patients who underwent primary TKAs. The 2 groups from the same institution had a minimum follow-up of 2 years and were retrospectively matched 1:2 for age, sex, body mass index, and follow-up time. Length of stay and hemoglobin level drop were similar. Technically, the revision group required larger polyethylene inserts (P < .001) and longer tourniquet times (P < .001) with 15 of these patients needing augments, grafts, and/or stems. Subjectively, the revision group's mean total Western Ontario and McMaster Universities Arthritis Index score was 25.8 ± 20.2, thus less satisfactory compared with the control group (19.8 ± 15.3) at a mean follow-up of 3.1 years (P = .03). A revision unicompartmental knee arthroplasty to TKA is technically more difficult and functionally less satisfactory at last follow-up when compared with a primary TKA.

Are Prosthetic Spacers Safe to Use in 2-Stage Treatment for Infected Total Knee Arthroplasty? - Corrected Proof

Ho-Rim Choi, Henrik Malchau, Hany Bedair — 2012-04-16

Abstracts: This retrospective study compares treatment results of infected total knee arthroplasty with 2-stage exchange technique using 14 articulating spacers using metallic and polyethylene components (prosthetic group) and 33 static all-cement spacer (static group). For the prosthetic and static groups, treatment success rate was 71% and 67% at 58 months of follow-up, respectively, and not significantly different. The prosthetic group required less frequent extensile surgical approaches at the second-stage reimplantation. Range of motion was significantly improved in both groups, but there was no difference at latest follow-up between the groups. Of 14 in the prosthetic group, 4 (28%) did not undergo second-stage procedure. Antibiotic spacers consisting of prosthetic components can be a safe and effective treatment option for 2-stage revision total knee arthroplasty with equivalent infection control rates.

Two-stage Reimplantation in Infected Total Knee Arthroplasty Using a Re-sterilized Tibial Polyethylene Insert and Femoral Component - Corrected Proof

Jin Kyu Lee, Choong H. Choi — 2012-04-16

Abstract: Infection in total knee arthroplasty (TKA) is a challenging complication. We reviewed 20 cases of infected TKAs treated by two-stage reimplantation procedure involving the use of a temporary articulating system composed of autoclaved femoral component, low temperature hydrogen peroxide gas plasma sterilized polyethylene insert, and antibiotic-impregnated bone cement. The knee and functional score of the Knee Society scoring system at the last follow (average, 64.8 months) up was 86.2 points and 78.8 points. The success rate in terms of eradication of infection was 95% (19/20 knees). Use of a temporary articulating system composed of the re-sterilized components with antibiotic-impregnated bone cement was an effective therapy not only for the eradication of the infection but also for the recovery of soft tissue health and knee function.

Reliability of a PowerPoint Method for Wear Measurement After Total Hip Arthroplasty: A Retrieval Study Using 3-Dimensional Laser Scanning - Corrected Proof

Ho Hyun Yun, Won Yong Shon, Jung Ro Yoon, Jae-Hyuk Yang, Deuk-Soo Lim — 2012-04-13

Abstract: The purpose of this study was to evaluate the reliability of the PowerPoint (PP) (2007 Version; Microsoft, Redmond, Wash) method for measuring polyethylene liner wear after total hip arthroplasty. Seventeen retrieved polyethylene liners were included in this study. Wear volumes were calculated using the PP, the Dorr and Wan, and 3-dimensional (3D) laser scanning methods. Spearman correlation coefficients for wear volume results indicated strong correlations between the PP and 3D laser scanning methods (range, 0.89-0.93). On the other hand, Spearman correlation analysis revealed only moderate correlations between the Dorr and Wan and 3D laser scanning methods (range, 0.67-0.77). The PP method can be used to monitor linear wear after total hip arthroplasty and could serve as an alternative method when computerized methods are not available.

In Vitro Comparison of Fixed- and Mobile Meniscal–Bearing Unicondylar Knee Arthroplasties: Effect of Design, Kinematics, and Condylar Liftoff - Corrected Proof

Andrew Burton, Sophie Williams, Claire L. Brockett, John Fisher — 2012-04-13

Abstract: Unicondylar knee arthroplasty (UKA) has become a popular alternative to total knee arthroplasty or high tibial osteotomy for unicompartmental knee conditions. This study investigated the effects of kinematics and femoral liftoff on the wear of fixed and mobile versions of a UKA design. The fixed bearing had lower wear than the mobile bearing under all conditions. Wear was higher in lateral bearings than medial bearings, indicating that the increased sliding distance laterally had a greater effect than the greater loading medially. Femoral condylar liftoff resulted in increased wear in the medial UKAs but reduced wear in the lateral UKAs for both the bearing designs. The reduced wear rates observed for the fixed UKA bearings highlight the potential for a longer osteolysis-free clinical outcome for these devices.

Inflammatory Pseudotumor Causing Deep Vein Thrombosis After Metal-On-Metal Hip Resurfacing Arthroplasty - Corrected Proof

Adeel Rasool Memon, John G. Galbraith, James A. Harty, Rehan Gul — 2012-04-13

Abstract: Metal-on-metal hip resurfacings have recently been associated with a variety of complications resulting from adverse reaction to metal debris. We report a case of extensive soft tissue necrosis associated with a huge pelvic mass causing extensive deep vein thrombosis of the lower limb secondary to mechanical compression of the iliac vein. This is a rare and unusual cause of deep vein thrombosis after metal-on-metal hip resurfacing arthroplasty.

Computer-Assisted Total Knee Arthroplasty for Significant Tibial Deformities - Corrected Proof

Ritesh R. Shah, Ronak M. Patel, Lalit Puri — 2012-04-13

Abstract: Computer-assisted total knee arthroplasty has been demonstrated to provide reproducible limb mechanical alignment within 3° from the neutral mechanical axis. However, restoring proper implant and extremity alignment remains a significant challenge with proximal tibial deficiencies. In this prospective study, we describe the use of computer navigation to quantify the amount of bone loss on the medial or lateral tibial plateau and the use of these data to assess the need for augmentation with metallic tibial wedges. In this study, we demonstrate that computer-assisted total knee arthroplasty in patients with significant tibial deformities can accurately measure severe tibial deformities, predict tibial augment thickness, and provide excellent mechanical alignment and restore the joint line without excessive bony resection, repeated osteotomies, and repeated augment trialing.

Influence of Electron Beam Melting Manufactured Implants on Ingrowth and Shear Strength in an Ovine Model - Corrected Proof

Nicky Bertollo, Ruy Da Assuncao, Nicholas J. Hancock, Abe Lau, William R. Walsh — 2012-04-13

Abstract: Arthroplasty has evolved with the application of electron beam melting (EBM) in the manufacture of porous mediums for uncemented fixation. Osseointegration of EBM and plasma-sprayed titanium (Ti PS) implant dowels in adult sheep was assessed in graduated cancellous defects and under line-to-line fit in cortical bone. Shear strength and bony ingrowth (EBM) and ongrowth (Ti PS) were assessed after 4 and 12 weeks. Shear strength of EBM exceeded that for Ti PS at 12 weeks (P = .030). Ongrowth achieved by Ti PS in graduated cancellous defects followed a distinctive pattern that correlated to progressively decreasing radial distances between defect and implant, whereas cancellous ingrowth values at 12 weeks for the EBM were not different. Osteoconductive porous structures manufactured using EBM present a viable alternative to traditional surface treatments.

Incidence and Natural Course of Initial Polar Gaps in Birmingham Hip Resurfacing Cups - Corrected Proof

Satoshi Nakasone, Masaki Takao, Takashi Nishii, Takashi Sakai, Nobuhiko Sugano — 2012-04-13

Abstract: The purpose of this study was to retrospectively investigate the incidence of initial polar gaps and their effect on clinical results in Birmingham Hip Resurfacing cups. A total of 151 hips in 134 patients who underwent hip resurfacing at a mean age of 50 years were examined. The mean follow-up period was 7 years. A polar gap was identified in 47 hips (31%) with a mean width of 2.1 mm. Gaps of 2 mm or more were identified in 21 hips, 6 of which showed reductions in cup inclination during the initial 3 months. After 3 months, no progressive cup migration was observed. There was no cup revision. All gaps were filled with bone within 2 years of surgery. The initial polar gaps had no significant influence on the stability of hydroxyapatite-coated Porocast cobalt-chromium hemispherical monoblock cups (Midland Medical Technologies Ltd, Birmingham, UK), although gaps of 2 mm or more had a higher risk of early migration.

Practice Management Strategies Among Members of the American Association of Hip and Knee Surgeons - Corrected Proof

Jay R. Lieberman, Andrew A. Freiberg, Carlos Lavernia — 2012-04-13

Abstract: A survey was conducted at the 2011 Annual Meeting of the American Association of Hip and Knee Surgeons to determine current practice management strategies among its members. This article summarizes the audience responses to a number of different questions related to type of practice, use of physician extenders, potential sources of ancillary income, consulting activity, royalties, emergency department call, and the use of the electronic medical record.

To the Editor: - Corrected Proof

Abdulrahman Alsawadi — 2012-04-11

I read with interest the article by Joo et al (volume 26 [number 7]) of your journal. In this prospectively randomized controlled study, the senior author (Y.H.K.) performed 572 simultaneous bilateral sequential total knee arthroplasties in 286 consecutive patients, in an attempt to eliminate the issue of differences in the pain threshold between patients. The right or left knee was randomly allocated to local infiltration analgesia or the saline injection group. Two aliquots of a multimodal drug injection were injected into one knee, and a similar amount of normal saline was injected into the contralateral knee. All patients received patient-controlled epidural analgesia for 48 hours after the surgery. A visual analog scale was used for postoperative pain assessment and patient satisfactory. The authors reported no differences in the pain and satisfaction scores between the 2 groups, although this assessment is practically performed on 1 group only. Each patient is treated as 2 groups by having bilateral total knee arthroplasty, and it is not clear whether any pain or dissatisfaction originated from the knee treated with local infiltration analgesia or the saline-injected contralateral knee. Also, the significant amount of postoperative analgesia used might have masked the effect of the local infiltration. The epidural catheter was used for continuous pain relief for 48 hours after the surgery. Hospital stay, as another major outcome, very likely was masked as well by this practical mix-up of the groups. It is not possible to discharge one knee while the patient is still sore in the contralateral knee or he/she did not achieve full satisfactory progress in both knees. It is not clear whether the delay in discharge resulted from the “control knee” or the “trial knee.”

Differences Between Actual and Expected Leisure Activities After Total Knee Arthroplasty for Osteoarthritis - Corrected Proof

2012-04-05

Abstract: This prospective cohort study determined the type, frequency, intensity, and duration of actual vs expected leisure activity among a cohort undergoing total knee arthroplasty. Data on actual and expected participation in 36 leisure activities were collected preoperatively and at 12 months in 90 patients with knee osteoarthritis. Despite high expectations, there were statistically and clinically significant differences between actual and expected activity at 12 months suggesting that expectations may not have been fulfilled. The differences were equivalent to walking 14 less miles per week than expected, which is more than the amount of activity recommended in national physical activity guidelines. Perhaps an educational intervention could be implemented to help patients establish appropriate and realistic leisure activity expectations before surgery.