A novel preoperative scoring system for the indication of unicompartmental knee arthroplasty, as predictor of clinical outcome and satisfaction

  • Alexander Antoniadis
  • Dimitris Dimitriou
  • Jean Pierre Canciani
  • Naeder Helmy
Knee Arthroplasty



Proper patient selection is a crucial factor for the outcome of the unicompartmental knee arthroplasty (UKA). However, there is still not a clear consensus on which patients could benefit the utmost from a UKA. The purpose of this prospective study was to introduce a novel, preoperative, predictive score (Unicompartmental Indication Score, UIS) to aid proper patient selection in UKA.

Materials and methods

A total of 152 patients with an average age of 68 years and a mean follow-up of 27 months were evaluated preoperatively with the UIS and postoperative at every follow-up. Correlation analysis was applied to identify potential relationships between the UIS, functional outcomes, pain relief, patient satisfaction, and range of motion. The ROC analysis was used to identify the best cutoff value of the UIS, which would have predicted an optimal outcome following UKA.


The majority of the patients (91%) were satisfied with the operation, with 61% reporting excellent and 30% good satisfaction. The UIS was positively correlated to the postoperative Knee Society Score (KSS) for both pain (r = 0.26, p < 0.001) and function (r = 0.31, p < 0.001). The UIS was also positively correlated to the patient satisfaction (p = 0.46, p < 0.001) and maximum postoperative flexion (r = 0.25, p < 0.001). The ROC analysis provided an ideal cutoff for UIS at 25 points (sensitivity: 75%, sensibility: 93%, area under the curve: 86%). At a mean follow-up of 27 months (range 24–37), we observed three revisions in 152 consecutive UKA with a mean UIS of 27 points (range 20–30).


The newly introduced UIS score might be a reliable preoperative scoring system to predict patients with excellent satisfaction, functional outcome, pain relief and possibly implant survivorship following UKA, and therefore, could help the proper patient selection and decision-making in UKA.


Prospective study, II.


Unicompartmental knee arthroplasty (UKA) Indication Clinical Outcome Patient-reported outcomes Predictive score Patient satisfaction Revision Scoring system 



There was no external funding source of funding in the current study.

Conflict of interest

The authors declare that they have no competing interests.


  1. 1.
    Centers for Disease C, Prevention (2009) Prevalence and most common causes of disability among adults–United States, 2005. MMWR Morb Mortal Wkly Rep 58(16):421–426Google Scholar
  2. 2.
    Ayis S, Dieppe P (2009) The natural history of disability and its determinants in adults with lower limb musculoskeletal pain. J Rheumatol 36(3):583–591. CrossRefPubMedGoogle Scholar
  3. 3.
    Dominick KL, Ahern FM, Gold CH, Heller DA (2004) Health-related quality of life and health service use among older adults with osteoarthritis. Arthritis Rheum 51(3):326–331. CrossRefPubMedGoogle Scholar
  4. 4.
    Morris MJ, Molli RG, Berend KR, Lombardi AV Jr (2013) Mortality and perioperative complications after unicompartmental knee arthroplasty. Knee 20(3):218–220. CrossRefPubMedGoogle Scholar
  5. 5.
    Patil S, Colwell CW Jr, Ezzet KA, D’Lima DD (2005) Can normal knee kinematics be restored with unicompartmental knee replacement? J Bone Jt Surg Am 87(2):332–338. CrossRefGoogle Scholar
  6. 6.
    Lyons MC, MacDonald SJ, Somerville LE, Naudie DD, McCalden RW (2012) Unicompartmental versus total knee arthroplasty database analysis: is there a winner? Clin Orthop Relat Res 470(1):84–90. CrossRefPubMedGoogle Scholar
  7. 7.
    Price AJ, Oppold PT, Murray DW, Zavatsky AB (2006) Simultaneous in vitro measurement of patellofemoral kinematics and forces following Oxford medial unicompartmental knee replacement. J Bone Jt Surg Br 88(12):1591–1595. CrossRefGoogle Scholar
  8. 8.
    Kozinn SC, Scott R (1989) Unicondylar knee arthroplasty. J Bone Jt Surg Am 71(1):145–150CrossRefGoogle Scholar
  9. 9.
    Vasso M, Corona K, D’Apolito R, Mazzitelli G, Panni AS (2017) Unicompartmental knee arthroplasty: modes of failure and conversion to total knee arthroplasty. Jt 5(01):044–050Google Scholar
  10. 10.
    Pennington DW, Swienckowski JJ, Lutes WB, Drake GN (2003) Unicompartmental knee arthroplasty in patients sixty years of age or younger. J Bone Jt Surg Am 85-A(10):1968–1973CrossRefGoogle Scholar
  11. 11.
    Tabor OB Jr, Tabor OB, Bernard M, Wan JY (2005) Unicompartmental knee arthroplasty: long-term success in middle-age and obese patients. J Surg Orthop Adv 14(2):59–63PubMedGoogle Scholar
  12. 12.
    Iacono F, Raspugli GF, Akkawi I, Bruni D, Filardo G, Budeyri A, Bragonzoni L, Presti ML, Bonanzinga T, Marcacci M (2016) Unicompartmental knee arthroplasty in patients over 75 years: a definitive solution? Arch Orthop Trauma Surg 136(1):117–123. CrossRefPubMedGoogle Scholar
  13. 13.
    Beard D, Pandit H, Ostlere S, Jenkins C, Dodd C, Murray D (2007) Pre-operative clinical and radiological assessment of the patellofemoral joint in unicompartmental knee replacement and its influence on outcome. Bone Jt J 89(12):1602–1607CrossRefGoogle Scholar
  14. 14.
    Engh GA, Ammeen DJ (2014) Unicondylar arthroplasty in knees with deficient anterior cruciate ligaments. Clin Orthop Relat Res 472(1):73–77. CrossRefPubMedGoogle Scholar
  15. 15.
    Mancuso F, Dodd CA, Murray DW, Pandit H (2016) Medial unicompartmental knee arthroplasty in the ACL-deficient knee. J Orthop Traumatol 17(3):267–275. CrossRefPubMedPubMedCentralGoogle Scholar
  16. 16.
    Rodriguez-Merchan EC (2016) Unicompartmental knee osteoarthritis (UKOA): unicompartmental knee arthroplasty (UKA) or high tibial osteotomy (HTO)? Arch Bone Jt Surg 4(4):307–313PubMedPubMedCentralGoogle Scholar
  17. 17.
    Luscombe KL, Lim J, Jones PW, White SH (2007) Minimally invasive Oxford medial unicompartmental knee arthroplasty. A note of caution! Int Orthop 31(3):321–324. CrossRefPubMedGoogle Scholar
  18. 18.
    Kang KT, Son J, Baek C, Kwon OR, Koh YG (2018) Femoral component alignment in unicompartmental knee arthroplasty leads to biomechanical change in contact stress and collateral ligament force in knee joint. Arch Orthop Trauma Surg 138(4):563–572. CrossRefPubMedGoogle Scholar
  19. 19.
    Liow MHL, Tsai T-Y, Dimitriou D, Li G, Kwon Y-M (2016) Does 3-dimensional in vivo component rotation affect clinical outcomes in unicompartmental knee arthroplasty? J Arthroplast 31(10):2167–2172CrossRefGoogle Scholar
  20. 20.
    Kuipers BM, Kollen BJ, Bots PCK, Burger BJ, van Raay JJ, Tulp NJ, Verheyen CC (2010) Factors associated with reduced early survival in the Oxford phase III medial unicompartment knee replacement. Knee 17(1):48–52CrossRefGoogle Scholar
  21. 21.
    Epinette JA, Brunschweiler B, Mertl P, Mole D, Cazenave A,, Knee (2012) French society for H. Unicompartmental knee arthroplasty modes of failure: wear is not the main reason for failure: a multicentre study of 418 failed knees. Orthop Traumatol Surg Res 98(6 Suppl):S124–S130. CrossRefPubMedGoogle Scholar
  22. 22.
    Kellgren JH, Lawrence JS (1957) Radiological assessment of osteo-arthrosis. Ann Rheum Dis 16(4):494–502CrossRefGoogle Scholar
  23. 23.
    Altman RD, Fries JF, Bloch DA, Carstens J, Mb D, Cooke T, Genant H, Gofton P, Groth H, Mcshane DJ (1987) Radiographic assessment of progression in osteoarthritis. Arthritis Rheumatol 30(11):1214–1225CrossRefGoogle Scholar
  24. 24.
    Scuderi GR, Bourne RB, Noble PC, Benjamin JB, Lonner JH, Scott WN (2012) The new knee society knee scoring system. Clin Orthop Relat Res 470(1):3–19. CrossRefPubMedGoogle Scholar
  25. 25.
    Argenson J-NA, Chevrol-Benkeddache Y, Aubaniac J-M (2002) Modern unicompartmental knee arthroplasty with cement: a three to ten-year follow-up study. JBJS 84(12):2235–2239CrossRefGoogle Scholar
  26. 26.
    Cantor SB, Kattan MW (2000) Determining the area under the ROC curve for a binary diagnostic test. Med Decis Mak 20(4):468–470. CrossRefGoogle Scholar
  27. 27.
    van Campen C, Sixma H, Friele RD, Kerssens JJ, Peters L (1995) Quality of care and patient satisfaction: a review of measuring instruments. Med Care Res Rev 52(1):109–133CrossRefGoogle Scholar
  28. 28.
    Von Keudell A, Sodha S, Collins J, Minas T, Fitz W, Gomoll A (2014) Patient satisfaction after primary total and unicompartmental knee arthroplasty: an age-dependent analysis. Knee 21(1):180–184CrossRefGoogle Scholar
  29. 29.
    Lee M, Huang Y, Chong HC, Ning Y, Lo NN, Yeo SJ (2016) Predicting satisfaction for unicompartmental knee arthroplasty patients in an Asian population. J Arthroplast 31(8):1706–1710CrossRefGoogle Scholar
  30. 30.
    Berger RA, Meneghini RM, Jacobs JJ, Sheinkop MB, Della Valle CJ, Rosenberg AG, Galante JO (2005) Results of unicompartmental knee arthroplasty at a minimum of ten years of follow-up. JBJS 87(5):999–1006CrossRefGoogle Scholar
  31. 31.
    Niinimäki T, Eskelinen A, Mäkelä K, Ohtonen P, Puhto A-P, Remes V (2014) Unicompartmental knee arthroplasty survivorship is lower than TKA survivorship: a 27-year finnish registry study. Clin Orthop Relat Res 472 (5):1496–1501CrossRefGoogle Scholar
  32. 32.
    van der List JP, Zuiderbaan HA, Pearle AD (2016) Why do medial unicompartmental knee arthroplasties fail today? J Arthroplast 31 (5):1016–1021CrossRefGoogle Scholar
  33. 33.
    35. Aleto TJ, Berend ME, Ritter MA, Faris PM, Meneghini RM (2008) Early failure of unicompartmental knee arthroplasty leading to revision. J Arthroplast 23 (2):159–163CrossRefGoogle Scholar
  34. 34.
    36. Berend KR, Lombardi AV Jr, Mallory TH, Adams JB, Groseth KL (2005) Early failure of minimally invasive unicompartmental knee arthroplasty is associated with obesity. Clin Orthop Relat Res 440:60–66CrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Department of Orthopaedics and TraumatologyBürgerspital SolothurnSolothurnSwitzerland
  2. 2.Centre Hospitalier Prive Saint GregoireSaint-GrégoireFrance

Personalised recommendations