The Oxford unicompartmental knee prosthesis: a 2?14�year follow-up

Abstract

Our medium- and long-term results obtained with the Oxford unicompartmental knee prosthesis for unicompartmental knee osteoarthrosis are presented. Ninety-seven prostheses were evaluated (87 medial, 10 lateral) in 86 patients, with the Hospital for Special Surgery knee score after 2-14 years (mean follow-up: 6 years 9 months). Five prostheses were lost to follow-up. Eight patients died, not related to surgery; none had undergone a revision. Fourteen revisions (of which one bilateral UKP), 11 medial and three lateral, were performed. The mean HSS score of the 69 UKPs was 178.8 (80% excellent, 10% good, 4% fair, 6% poor). These findings confirm the good results reported in other studies, regarding proper patient selection and a consistent operative technique.

Reintervention after Mobile-bearing Oxford Unicompartmental Knee Arthroplasty

“…Our revision rate of 4.3% at a mean 42.6 months (range, 12-102 months) is comparable to rates in previous studies [3,5,9,10,12] and is consistent with the documented revision rates for UKA in Australia [1]. Some studies report higher rates of revision ranging between 12% and 15% [2][3][4]12]. An aspect of this study rarely reported in the literature is the revision of a UKA to a second UKA [5,7].…”

“…However, given that the median time from the index surgery to reintervention was 13 months, it is likely this underestimation of the reintervention rate is low. The revision rate for UKA is greater than for TKA [2,3,5,6,12], and recent Australian data show primary UKAs have a 5-year cumulative revision rate of 8.9%, whereas the 5-year cumulative revision rate for TKA is 3.6% [1]. Patients undergoing UKA generally have less marked disease than patients undergoing primary TKA, and as such, probably are less tolerant of imperfection, leading to complaints and intervention at an earlier stage.…”

“…For the Oxford 3 prosthesis, the cumulative revision rate at 5 years is 6.2% [1]. Failures usually are associated with progression of osteoarthritis to the lateral compartment, aseptic loosening, bearing dislocation, infection, and undiagnosed pain with the majority of patients having the UKA revised to a TKA [1,11,12].…”

“…Current literature provides little information regarding the nonrevision complications of UKA [8][9][10]12]. We were concerned that we had a group of patients who required reintervention for their arthroplasties; however, we had no data to advise them about the risk for this requirement or the success of such intervention.…”

Does Interlimb Knee Symmetry Exist After Unicompartmental Knee Arthroplasty?

“…It has been suggested that UKA should result in a more normal restoration of knee function compared with TKA because the procedure requires less soft tissue dissection and both cruciate ligaments are preserved [7,14]. However, studies on survival rates and clinical measures (eg, Knee Society scores) of UKA demonstrate mixed results [3,12,15,28,30], and some evidence of early failure rates has been reported [21]. Therefore, some surgeons are reluctant to use this procedure as a result of conflicting evidence of effectiveness [3,12,15,28,30].…”