The Performance of Diagnostic Tests for Identifying Periprosthetic Joint Infection After Failed Partial Knee Arthroplasty



      Indications for unicompartmental knee arthroplasty (UKA) and patello-femoral arthroplasty are expanding. Despite the lower published infection rates for UKA and patello-femoral arthroplasty than total knee arthroplasty, periprosthetic joint infection (PJI) remains a devastating complication and diagnostic thresholds for commonly utilized tests have not been investigated recently. Thus, this study evaluated if diagnostic thresholds for PJI in patients who had a failed partial knee arthroplasty (PKA) align more closely with previously reported thresholds specific to UKA or the 2018 International Consensus Meeting on Musculoskeletal Infection.


      We identified 109 knees in 100 patients that underwent PKA with eventual conversion to total knee arthroplasty within a single healthcare system from 2000 to 2021. Synovial fluid nucleated cell count and synovial polymorphonuclear percentage in addition to preoperative serum erythrocyte sedimentation rate, serum C-reactive protein, and serum white blood cell count were compared with Student’s t-tests between septic and aseptic cases. Receiver operating characteristic curves and Youden’s index were used to assess diagnostic performance and the optimal cutoff point of each test.


      Synovial nucleated cell count, synovial polymorphonuclear percentage, and serum C-reactive protein demonstrated excellent discrimination for diagnosing PJI with an area under the curve of 0.97 and lower cutoff values than the previously determined UKA specific criteria. Serum erythrocyte sedimentation rateESR demonstrated good ability with an area under the curve of 0.89.


      Serum and synovial fluid diagnostic thresholds for PJI in PKAs align more closely with the thresholds established by the 2018 International Consensus Meeting as compared to previously proposed thresholds specific to UKA.

      Level of Evidence

      Level III, retrospective comparative study.


      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to The Journal of Arthroplasty
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Jennings J.M.
        • Kleeman-Forsthuber L.T.
        • Bolognesi M.P.
        Medial unicompartmental arthroplasty of the knee.
        J Am Acad Orthop Surg. 2019; 27: 166-176
        • Riddle D.L.
        • Jiranek W.A.
        • McGlynn F.J.
        Yearly incidence of unicompartmental knee arthroplasty in the United States.
        J Arthroplasty. 2008; 23: 408-412
        • Bolognesi M.P.
        • Greiner M.A.
        • Attarian D.E.
        • Watters T.S.
        • Wellman S.S.
        • Curtis L.H.
        • et al.
        Unicompartmental knee arthroplasty and total knee arthroplasty among Medicare beneficiaries, 2000 to 2009.
        J Bone Joint Surg Am. 2013; 95: e174
        • Kahlenberg C.A.
        • Richardson S.S.
        • Gruskay J.A.
        • Cross M.B.
        Trends in utilization of total and unicompartmental knee arthroplasty in the United States.
        J Knee Surg. 2021; 34: 1138-1141
        • Kozinn S.C.
        • Scott R.
        Unicondylar knee arthroplasty.
        J Bone Joint Surg Am. 1989; 71: 145-150
        • Cochrane N.
        • Belay E.
        • Wu M.
        • O'Donnell J.
        • Kim B.
        • Seyler T.
        An ACS-NSQIP analysis of unicompartmental knee arthroplasty trends from 2013 to 2018.
        J Knee Surg. 2022; ([Epub ahead of print])
        • Walton N.P.
        • Jahromi I.
        • Lewis P.L.
        • Dobson P.J.
        • Angel K.R.
        • Campbell D.G.
        Patient-perceived outcomes and return to sport and work: TKA versus mini-incision unicompartmental knee arthroplasty.
        J Knee Surg. 2006; 19: 112-116
        • Jeer P.J.
        • Cossey A.J.
        • Keene G.C.
        Haemoglobin levels following unicompartmental knee arthroplasty: influence of transfusion practice and surgical approach.
        Knee. 2005; 12: 358-361
        • Kleeblad L.J.
        • van der List J.P.
        • Zuiderbaan H.A.
        • Pearle A.D.
        Larger range of motion and increased return to activity, but higher revision rates following unicompartmental versus total knee arthroplasty in patients under 65: a systematic review.
        Knee Surg Sports Traumatol Arthrosc. 2018; 26: 1811-1822
        • Berger R.A.
        • Meneghini R.M.
        • Jacobs J.J.
        • Sheinkop M.B.
        • Della Valle C.J.
        • Rosenberg A.G.
        • et al.
        Results of unicompartmental knee arthroplasty at a minimum of ten years of follow-up.
        J Bone Joint Surg Am. 2005; 87: 999-1006
        • Foran J.R.
        • Brown N.M.
        • Della Valle C.J.
        • Berger R.A.
        • Galante J.O.
        Long-term survivorship and failure modes of unicompartmental knee arthroplasty.
        Clin Orthop Relat Res. 2013; 471: 102-108
        • Paul R.W.
        • Osman A.
        • Clements A.
        • Tjoumakaris F.P.
        • Lonner J.H.
        • Freedman K.B.
        What are the all-cause survivorship rates and functional outcomes in patients younger than 55 Years undergoing primary knee arthroplasty? A systematic review.
        Clin Orthop Relat Res. 2022; 480: 507-522
        • Li C.
        • Li Z.
        • Shi L.
        • Gao F.
        • Sun W.
        The short-term effectiveness and safety of second-generation patellofemoral arthroplasty and total knee arthroplasty on isolated patellofemoral osteoarthritis: a systematic review and meta-analysis.
        J Orthop Surg Res. 2021; 16: 358
        • Villa J.C.
        • Paoli A.R.
        • Nelson-Williams H.W.
        • Badr R.N.
        • Harper K.D.
        Onlay patellofemoral arthroplasty in patients with isolated patellofemoral arthritis: a systematic review.
        J Arthroplasty. 2021; 36: 2642-2649
        • Walter N.
        • Weber J.
        • Kerschbaum M.
        • Lau E.
        • Kurtz S.M.
        • Alt V.
        • et al.
        Revision arthroplasty after unicompartimental knee arthroplasty.
        J Orthop Surg Res. 2021; 16: 666
        • Yamagami R.
        • Inui H.
        • Jo T.
        • Kawata M.
        • Taketomi S.
        • Kono K.
        • et al.
        Unicompartmental knee arthroplasty is associated with lower proportions of surgical site infection compared with total knee arthroplasty: a retrospective nationwide database study.
        Knee. 2021; 28: 124-130
        • Lee C.S.
        • Su E.P.
        • Cross M.B.
        • Carli A.V.
        • Landy D.C.
        • Chalmers B.P.
        Unicompartmental knee arthroplasty is associated with a lower rate of periprosthetic joint infection compared to total knee arthroplasty.
        Arthroplast Today. 2021; 10: 117-120
        • Hansen E.N.
        • Ong K.L.
        • Lau E.
        • Kurtz S.M.
        • Lonner J.H.
        Unicondylar knee arthroplasty has fewer complications but higher revision rates than total knee arthroplasty in a study of large United States databases.
        J Arthroplasty. 2019; 34: 1617-1625
        • Hernandez N.M.
        • Petis S.M.
        • Hanssen A.D.
        • Sierra R.J.
        • Abdel M.P.
        • Pagnano M.W.
        Infection after unicompartmental knee arthroplasty: a high risk of subsequent complications.
        Clin Orthop Relat Res. 2019; 477: 70-77
        • Bendixen N.B.
        • Eskelund P.W.
        • Odgaard A.
        Failure modes of patellofemoral arthroplasty-registries vs. clinical studies: a systematic review.
        Acta Orthop. 2019; 90: 473-478
        • Labruyère C.
        • Zeller V.
        • Lhotellier L.
        • Desplaces N.
        • Léonard P.
        • Mamoudy P.
        • et al.
        Chronic infection of unicompartmental knee arthroplasty: one-stage conversion to total knee arthroplasty.
        Orthop Traumatol Surg Res. 2015; 101: 553-557
        • Vasso M.
        • Corona K.
        • D’Apolito R.
        • Mazzitelli G.
        • Panni A.S.
        Unicompartmental knee arthroplasty: modes of failure and conversion to total knee arthroplasty.
        Joints. 2017; 5: 44-50
        • Chalmers B.P.
        • Kapadia M.
        • Chiu Y.F.
        • Henry M.W.
        • Miller A.O.
        • Carli A.V.
        Treatment and outcome of periprosthetic joint infection in unicompartmental knee arthroplasty.
        J Arthroplasty. 2020; 35: 1917-1923
        • Parvizi J.
        • Tan T.L.
        • Goswami K.
        • Higuera C.
        • Della Valle C.
        • Chen A.F.
        • et al.
        The 2018 definition of periprosthetic Hip and knee infection: an evidence-based and validated criteria.
        J Arthroplasty. 2018; 33: 1309-1314
        • Amanatullah D.
        • Dennis D.
        • Oltra E.G.
        • Marcelino Gomes L.S.
        • Goodman S.B.
        • Hamlin B.
        • et al.
        Hip and knee section, diagnosis, definitions: proceedings of international consensus on orthopedic infections.
        J Arthroplasty. 2019; 34: S329-S337
        • Parvizi J.
        • Gehrke T.
        • Chen A.F.
        Proceedings of the international consensus on periprosthetic joint infection.
        Bone Joint J. 2013; 95-B: 1450-1452
        • Parvizi J.
        • Zmistowski B.
        • Berbari E.F.
        • Bauer T.W.
        • Springer B.D.
        • Della Valle C.J.
        • et al.
        New definition for periprosthetic joint infection: from the workgroup of the musculoskeletal infection society.
        Clin Orthop Relat Res. 2011; 469: 2992-2994
        • Education SoURaC
        Diagnosis of periprosthetic joint infection after unicompartmental knee arthroplasty.
        J Arthroplasty. 2012; 27: 46-50
        • Bedair H.
        • Ting N.
        • Jacovides C.
        • Saxena A.
        • Moric M.
        • Parvizi J.
        • et al.
        The Mark Coventry Award: diagnosis of early postoperative TKA infection using synovial fluid analysis.
        Clin Orthop Relat Res. 2011; 469: 34-40
        • Kim S.G.
        • Kim J.G.
        • Jang K.M.
        • Han S.B.
        • Lim H.C.
        • Bae J.H.
        Diagnostic value of synovial white blood cell count and serum C-reactive protein for acute periprosthetic joint infection after knee arthroplasty.
        J Arthroplasty. 2017; 32: 3724-3728
        • Abdelaziz H.
        • Rademacher K.
        • Suero E.M.
        • Gehrke T.
        • Lausmann C.
        • Salber J.
        • et al.
        The 2018 international consensus meeting minor criteria for chronic hip and knee periprosthetic joint infection: validation from a single center.
        J Arthroplasty. 2020; 35: 2200-2203
        • Bémer P.
        • Bourigault C.
        • Jolivet-Gougeon A.
        • Plouzeau-Jayle C.
        • Lemarie C.
        • Chenouard R.
        • et al.
        Assessment of a multiplex serological test for the diagnosis of prosthetic joint infection: a prospective multicentre study.
        J Bone Jt Infect. 2020; 5: 89-95
        • Plate A.
        • Anagnostopoulos A.
        • Glanzmann J.
        • Stadler L.
        • Weigelt L.
        • Sutter R.
        • et al.
        Synovial C-reactive protein features high negative predictive value but is not useful as a single diagnostic parameter in suspected periprosthetic joint infection (PJI).
        J Infect. 2019; 78: 439-444
        • Premkumar A.
        • Kolin D.A.
        • Farley K.X.
        • Wilson J.M.
        • McLawhorn A.S.
        • Cross M.B.
        • et al.
        Projected economic burden of periprosthetic joint infection of the hip and knee in the United States.
        J Arthroplasty. 2021; 36: 1484-1489
        • Parisi T.J.
        • Konopka J.F.
        • Bedair H.S.
        What is the long-term economic societal effect of periprosthetic infections after THA? A markov analysis.
        Clin Orthop Relat Res. 2017; 475: 1891-1900
        • Kim K.T.
        • Lee S.
        • Lee J.S.
        • Kang M.S.
        • Koo K.H.
        Long-term clinical results of unicompartmental knee arthroplasty in patients younger than 60 Years of age: minimum 10-year follow-up.
        Knee Surg Relat Res. 2018; 30: 28-33
        • Mannan A.
        • Pilling R.W.D.
        • Mason K.
        • Stirling P.
        • Duffy D.
        • London N.
        Excellent survival and outcomes with fixed-bearing medial UKA in young patients (≤ 60 years) at minimum 10-year follow-up.
        Knee Surg Sports Traumatol Arthrosc. 2020; 28: 3865-3870
        • Dwyer M.K.
        • Damsgaard C.
        • Wadibia J.
        • Wong G.
        • Lazar D.
        • Smith E.
        • et al.
        Laboratory tests for diagnosis of chronic periprosthetic joint infection can help predict outcomes of two-stage exchange.
        J Bone Joint Surg Am. 2018; 100: 1009-1015