Knee Surgery, Sports Traumatology, Arthroscopy

, Volume 21, Issue 11, pp 2453–2461 | Cite as

Improved accuracy in computer-assisted unicondylar knee arthroplasty: a meta-analysis

  • Patrick WeberEmail author
  • Alexander Crispin
  • Florian Schmidutz
  • Sandra Utzschneider
  • Matthias F. Pietschmann
  • Volkmar Jansson
  • Peter E. Müller



Inaccurate implantation rates of up to 30 % have been reported in cases using the conventional technique for implantation of a unicompartmental knee arthroplasty. Navigation should permit a more precise implantation, and several studies have investigated its role, albeit with a limited number of patients and inconsistent results. The aim of this meta-analysis was to compare risks of unsatisfactory outcomes in patients with navigated and conventional technique.


An electronic search was performed, and ten studies were eligible and included in the meta-analysis, with a total of 258 prostheses implanted with the navigated technique and 295 with the conventional one. The following items were analysed: radiological positioning of the femoral and the tibial component in the AP and lateral view, radiological analysis of the tibiofemoral mechanical axis and the difference in operating time between the two groups. Relative risks (RR) were calculated from the reported percentages of implants outside the optimal ranges defined by the manufacturers or the study groups. Natural logarithms of the relative risks were pooled by means of random effects models.


For all the analysed radiological parameters, the RR of measurements outside the optimal ranges were less than 1 in the navigation group suggesting a reduction in the risk of outliers with navigation. The average operating time in the navigated group was 15.4 min (95 % CI: 10.2–20.6) longer than in the conventional group.


The meta-analysis shows that the use of navigation systems in UKA leads to a more precise component position. Whether the more accurate position in UKA results in a better clinical outcome or long-term survival is yet unknown. Nevertheless, as a precise implant position appears to be beneficial, the use of navigation should be recommended for UKA. The limits defined by the manufacturers for an optimal positioning are not consistent.

Level of evidence

Therapeutic study (Systematic review of Level II/III studies), Level III.


Navigation Unicompartmental knee arthroplasty Component position Meta-analysis Accuracy 


Conflict of interest



  1. 1.
    The Swedish Knee Arthroplasty Register (2010) Annual Report 2010. Wallin & Dalholm, LundGoogle Scholar
  2. 2.
    Aldinger PR, Clarius M, Murray DW, Goodfellow JW, Breusch SJ (2004) Medial unicompartmental knee replacement using the “Oxford Uni” meniscal bearing knee. Orthopade 33:1277–1283PubMedCrossRefGoogle Scholar
  3. 3.
    Bauwens K, Matthes G, Wich M, Gebhard F, Hanson B, Ekkernkamp A, Stengel D (2007) Navigated total knee replacement. A meta-analysis. J Bone Jt Surg Am 89:261–269CrossRefGoogle Scholar
  4. 4.
    Brin YS, Nikolaou VS, Joseph L, Zukor DJ, Antoniou J (2011) Imageless computer assisted versus conventional total knee replacement. A Bayesian meta-analysis of 23 comparative studies. Int Orthop 35:331–339PubMedCrossRefGoogle Scholar
  5. 5.
    Browne JA, Cook C, Hofmann AA, Bolognesi MP (2010) Postoperative morbidity and mortality following total knee arthroplasty with computer navigation. Knee 17:152–156PubMedCrossRefGoogle Scholar
  6. 6.
    Buckup K, Linke LC, Hahne V (2007) Minimally invasive implantation and computer navigation for a unicondylar knee system. Orthopedics 30:66–69PubMedGoogle Scholar
  7. 7.
    Cheng T, Zhao S, Peng X, Zhang X (2012) Does computer-assisted surgery improve postoperative leg alignment and implant positioning following total knee arthroplasty? A meta-analysis of randomized controlled trials? Knee Surg Sports Traumatol Arthrosc 20:1307–1322PubMedCrossRefGoogle Scholar
  8. 8.
    Cossey AJ, Spriggins AJ (2005) The use of computer-assisted surgical navigation to prevent malalignment in unicompartmental knee arthroplasty. J Arthroplasty 20:29–34PubMedCrossRefGoogle Scholar
  9. 9.
    Czurda T, Fennema P, Baumgartner M, Ritschl P (2010) The association between component malalignment and post-operative pain following navigation-assisted total knee arthroplasty: results of a cohort/nested case-control study. Knee Surg Sports Traumatol Arthrosc 18:863–869PubMedCrossRefGoogle Scholar
  10. 10.
    Dalury DF, Fisher DA, Adams MJ, Gonzales RA (2009) Unicompartmental knee arthroplasty compares favorably to total knee arthroplasty in the same patient. Orthopedics 32.
  11. 11.
    Fu Y, Wang M, Liu Y, Fu Q (2012) Alignment outcomes in navigated total knee arthroplasty: a meta-analysis. Knee Surg Sports Traumatol Arthrosc 20:1075–1082PubMedCrossRefGoogle Scholar
  12. 12.
    Gulati A, Pandit H, Jenkins C, Chau R, Dodd CA, Murray DW (2009) The effect of leg alignment on the outcome of unicompartmental knee replacement. J Bone Jt Surg Br 91:469–474Google Scholar
  13. 13.
    Haaker RG, Wojciechowski M, Patzer P, Willburger RE, Senkal M, Engelhardt M (2006) Minimally invasive unicondylar knee replacement with computer navigation. Orthopade 35:1073–1079PubMedCrossRefGoogle Scholar
  14. 14.
    Hernigou P, Deschamps G (2004) Alignment influences wear in the knee after medial unicompartmental arthroplasty. Clin Orthop Relat Res 423:161–165PubMedCrossRefGoogle Scholar
  15. 15.
    Hernigou P, Deschamps G (2004) Posterior slope of the tibial implant and the outcome of unicompartmental knee arthroplasty. J Bone Jt Surg Am 86-A:506–511Google Scholar
  16. 16.
    Jadad AR, Moore RA, Carroll D, Jenkinson C, Reynolds DJ, Gavaghan DJ, McQuay HJ (1996) Assessing the quality of reports of randomized clinical trials: is blinding necessary? Control Clin Trials 17:1–12PubMedCrossRefGoogle Scholar
  17. 17.
    Jenny JY (2008) Unicompartmental knee replacement: a comparison of four techniques combining less invasive approach and navigation. Orthopedics 31.
  18. 18.
    Jenny JY, Boeri C (2003) Unicompartmental knee prosthesis implantation with a non-image-based navigation system: rationale, technique, case-control comparative study with a conventional instrumented implantation. Knee Surg Sports Traumatol Arthrosc 11:40–45PubMedGoogle Scholar
  19. 19.
    Jenny JY, Ciobanu E, Boeri C (2007) The rationale for navigated minimally invasive unicompartmental knee replacement. Clin Orthop Relat Res 463:58–62PubMedGoogle Scholar
  20. 20.
    Jenny JY, Muller PE, Weyer R, John M, Weber P, Ciobanu E, Schmitz A, Bacher T, Neumann W, Jansson V (2006) Navigated minimally invasive unicompartmental knee arthroplasty. Orthopedics 29:S117–S121PubMedGoogle Scholar
  21. 21.
    Jung KA, Kim SJ, Lee SC, Hwang SH, Ahn NK (2010) Accuracy of implantation during computer-assisted minimally invasive Oxford unicompartmental knee arthroplasty: a comparison with a conventional instrumented technique. Knee 17:387–391PubMedCrossRefGoogle Scholar
  22. 22.
    Keene G, Simpson D, Kalairajah Y (2006) Limb alignment in computer-assisted minimally-invasive unicompartmental knee replacement. J Bone Jt Surg Br 88:44–48Google Scholar
  23. 23.
    Kennedy WR, White RP (1987) Unicompartmental arthroplasty of the knee. Postoperative alignment and its influence on overall results. Clin Orthop Relat Res 221:278–285PubMedGoogle Scholar
  24. 24.
    Konyves A, Willis-Owen CA, Spriggins AJ (2010) The long-term benefit of computer-assisted surgical navigation in unicompartmental knee arthroplasty. J Orthop Surg Res 5:94PubMedCrossRefGoogle Scholar
  25. 25.
    Labek G, Sekyra K, Pawelka W, Janda W, Stockl B (2011) Outcome and reproducibility of data concerning the Oxford unicompartmental knee arthroplasty: a structured literature review including arthroplasty registry data. Acta Orthop 82:131–135PubMedCrossRefGoogle Scholar
  26. 26.
    Lim MH, Tallay A, Bartlett J (2009) Comparative study of the use of computer assisted navigation system for axial correction in medial unicompartmental knee arthroplasty. Knee Surg Sports Traumatol Arthrosc 17:341–346PubMedCrossRefGoogle Scholar
  27. 27.
    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 470:84–90PubMedCrossRefGoogle Scholar
  28. 28.
    Ma B, Rudan J, Chakravertty R, Grant H (2009) Computer-assisted FluoroGuide navigation of unicompartmental knee arthroplasty. Can J Surg 52:379–385PubMedGoogle Scholar
  29. 29.
    Mayman DJ, Rudan J, Watson D, Ellis R (2004) Computer-enhanced insertion of the Oxford unicompartmental arthroplasty: a fluoroguide technique. Comput Aided Surg 9:81–85PubMedGoogle Scholar
  30. 30.
    Mullaji AB, Shetty GM, Kanna R (2011) Postoperative limb alignment and its determinants after minimally invasive Oxford medial unicompartmental knee arthroplasty. J Arthroplasty 26:919–925PubMedCrossRefGoogle Scholar
  31. 31.
    Muller PE, Pellengahr C, Witt M, Kircher J, Refior HJ, Jansson V (2004) Influence of minimally invasive surgery on implant positioning and the functional outcome for medial unicompartmental knee arthroplasty. J Arthroplasty 19:296–301PubMedCrossRefGoogle Scholar
  32. 32.
    Pandit H, Jenkins C, Barker K, Dodd CA, Murray DW (2006) The Oxford medial unicompartmental knee replacement using a minimally-invasive approach. J Bone Jt Surg Br 88:54–60Google Scholar
  33. 33.
    Perlick L, Bathis H, Tingart M, Perlick C, Luring C, Grifka J (2004) Minimally invasive unicompartmental knee replacement with a nonimage-based navigation system. Int Orthop 28:193–197PubMedCrossRefGoogle Scholar
  34. 34.
    Price AJ, Svard U (2011) A second decade lifetable survival analysis of the Oxford unicompartmental knee arthroplasty. Clin Orthop Relat Res 469:174–179PubMedCrossRefGoogle Scholar
  35. 35.
    Rosenberger RE, Fink C, Quirbach S, Attal R, Tecklenburg K, Hoser C (2008) The immediate effect of navigation on implant accuracy in primary mini-invasive unicompartmental knee arthroplasty. Knee Surg Sports Traumatol Arthrosc 16:1133–1140PubMedCrossRefGoogle Scholar
  36. 36.
    Seon JK, Song EK, Park SJ, Yoon TR, Lee KB, Jung ST (2009) Comparison of minimally invasive unicompartmental knee arthroplasty with or without a navigation system. J Arthroplasty 24:351–357PubMedCrossRefGoogle Scholar
  37. 37.
    Voss F, Sheinkop MB, Galante JO, Barden RM, Rosenberg AG (1995) Miller-Galante unicompartmental knee arthroplasty at 2- to 5-year follow-up evaluations. J Arthroplasty 10:764–771PubMedCrossRefGoogle Scholar
  38. 38.
    Weber P, Schroder C, Utzschneider S, Schmidutz F, Jansson V, Muller PE (2012) Does increased tibial slope reduce the wear rate of unicompartmental knee prostheses? An in vitro investigation. Orthopade 41:298–302PubMedCrossRefGoogle Scholar
  39. 39.
    Weber P, Utzschneider S, Sadoghi P, Pietschmann MF, Ficklscherer A, Jansson V, Muller PE (2012) Navigation in minimally invasive unicompartmental knee arthroplasty has no advantage in comparison to a conventional minimally invasive implantation. Arch Orthop Trauma Surg 132:281–288PubMedCrossRefGoogle Scholar
  40. 40.
    Xie C, Liu K, Xiao L, Tang R (2012) Clinical outcomes after computer-assisted versus conventional total knee arthroplasty. Orthopedics 35:e647–e653PubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • Patrick Weber
    • 1
    • 2
    Email author
  • Alexander Crispin
    • 2
    • 3
  • Florian Schmidutz
    • 1
    • 2
  • Sandra Utzschneider
    • 1
    • 2
  • Matthias F. Pietschmann
    • 1
    • 2
  • Volkmar Jansson
    • 1
    • 2
  • Peter E. Müller
    • 1
    • 2
  1. 1.Department of Orthopedic SurgeryLudwig-Maximilians-University, University Hospital of Munich (LMU)MunichGermany
  2. 2.Department of StatisticsLudwig-Maximilians-UniversityMunichGermany
  3. 3.Institute of Medical Informatics, Biometry, and EpidemiologyLudwig-Maximilians-UniversityMunichGermany

Personalised recommendations