Master Techniques in Orthopedic Surgery Knee CH27

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PART V Alternatives to Total Knee Arthroplasty

Overresection of Tibia The original tibia cut must be carefully planned, because it is the main determinant of tibial slope and component thickness that will affect ligament balancing and alignment. An inadequate tibial resection can lead to overstuffing of the tibial component. In contrast, resecting too much tibia can cause weakness to the remaining tibial plateau and risk for fracture. 14,15 The level of resection of the tibia can be difficult to determine secondary to asymmetric wear in many patients undergoing OUKA. We recommend using the 2 + cutting guide to err on the side of caution with the tibial cut because more distal femur can be taken in subsequent steps to avoid overstuffing. COMPLICATIONS The complications of UKA are similar to those of total knee arthroplasty, including aseptic loosening, infection, periprosthetic fracture, soft-tissue pain, and polyethylene wear. However, the complication unique to OUKA is polyethylene bearing dislocation. 16-18 The complications associated with OUKA have been attributed to improper patient selection and inadequate surgeon experience. In a study where all patients had to meet strict operative criteria and a single surgeon with significant experience, the 10-year survival rate of OUKA was 98%. 16 RESULTS The overall survival of OUKA has continued to improve as the implants become more sophisticated and surgeon experience with this technique increases. Initially, reports from Swedish registry data for OUKA from Lewold et al showed overall survival at 6 years of 89%, and then Murray et al reported an overall survival at 10 years of 98%. 16 More recent series of 124 patients showed a 95% overall survival at 10 years 5 and in a large series of 564 knees between 91% and 96% at 10 years. 6 These data are comparable to results obtained from fixed-bearing UKA. 5 A known complication of OUKA or any mobile-bearing UKA is component dislocation, which is not seen in fixed-bearing UKA. This complication is rare, and it is avoided by appropriate surgical technique and rigid candidate selection criteria. The femur-first technique was initially proposed by Shakespeare et al to avoid problems typically associated with the OUKA, and their results showed adequate alignment of components and no evidence of bearing dislocations. 8 In summary, it is our opinion that in the appropriately selected candidates, the femur-first OUKA provides comparable long-term survival and complication rates as fixed-bearing UKA and OUKA via the standard technique. 1. Price AJ, Webb J, Topf H, Dodd CA, Goodfellow JW, Murray DW. Rapid recovery after oxford unicompartmental arthro- plasty through a short incision. J Arthroplasty . 2001;16(8):970. 2. Robertsson O, Borgquist L, Knutson K, Lewold S, Lidgren L. Use of unicompartmental instead of tricompartmental pros- theses for unicompartmental arthrosis in the knee is a cost-effective alternative. 15,437 primary tricompartmental prostheses were compared with 10,624 primary medial or lateral unicompartmental prostheses. Acta Orthop Scand . 1999;70(2):170. 3. Goodfellow J, O’Connor J. The anterior cruciate ligament in knee arthroplasty. A risk-factor with unconstrained meniscal prostheses. Clin Orthop Relat Res . 1992;(276):245. 4. White SH, Ludkowski PF, Goodfellow JW. Anteromedial osteoarthritis of the knee. J Bone Joint Surg Br . 1991;73(4):582. 5. Svard UC, Price AJ. Oxford medial unicompartmental knee arthroplasty. A survival analysis of an independent series. J Bone Joint Surg Br . 2001;83(2):191. 6. Price AJ, Dodd CA, Svard UG, Murray DW. Oxford medial unicompartmental knee arthroplasty in patients younger and older than 60 years of age. J Bone Joint Surg Br . 2005;87(11):1488. 7. Argenson JN, O’Connor JJ. Polyethylene wear in meniscal knee replacement. A one to nine-year retrieval analysis of the Oxford knee. J Bone Joint Surg Br . 1992;74(2):228. 8. Shakespeare D, Waite J. The Oxford Medial Partial Knee Replacement. The rationale for a femur first technique. Knee . 2012;19(6):927. 9. Skyrme AD, Mencia MM, Skinner PW. Early failure of the porous-coated anatomic cemented unicompartmental knee arthroplasty: a 5-to 9-year follow-up study. J Arthroplasty . 2002;17(2):201. 10. Bartley RE, Stulberg SD, Robb WJ III, Sweeney HJ. Polyethylene wear in unicompartmental knee arthroplasty. Clin Orthop Relat Res . 1994;(299):18. 11. Hamilton WG, Collier MB, Tarabee E, McAuley JP, Engh CA Jr, Engh GA. Incidence and reasons for reoperation after minimally invasive unicompartmental knee arthroplasty. J Arthroplasty . 2006;21(6 suppl 2):98. 12. Mariani EM, Bourne MH, Jackson RT, Jackson ST, Jones P. Early failure of unicompartmental knee arthroplasty. J Ar- throplasty . 2007;22(6 suppl 2):81. 13. Gulati A, Chau R, Simpson DJ, Dodd CA, Gill HS, Murray DW. Influence of component alignment on outcome for unicompartmental knee replacement. Knee . 2009;16(3):196. 14. Pandit H, Murray DW, Dodd CA, et al. Medial tibial plateau fracture and the Oxford unicompartmental knee. Orthopedics . 2007;30(5 suppl):28. REFERENCES