Summary

Adjunct fixation with metaphyseal sleeves in revision total knee arthroplasty required no revision for aseptic loosening at mid-term follow up and showed similar functional outcomes to other revision implant systems.

Abstract

Introduction

Revision total knee arthroplasty (TKA) is increasing in the volume and in the complexity. Varus-valgus constrained (VVC) articulation is commonly used in revision TKAs. The purpose of this study is to evaluate the outcomes of a consecutive series of revision TKAs done using a mobile bearing VVC articulation and adjunct metaphyseal fixation using a sleeve.

Methods

This is an IRB-approved retrospective review of the experience at a single institution over 10 years using the same implant system. Minimum 2-year follow-up data were available in 112 consecutive patients. All patients received adjunct tibial metaphyseal fixation, and 30% also received adjunct femoral metaphyseal fixation. The mean age was 61 years. 63% were women. The mean BMI was 34.6 kg/m2.

Results

The mean follow-up was 56 months (24 to 144). The reasons for the revision included: aseptic loosening (70%), infection (18%), instability/stiffness/malposition (9%), and others (3%). The mean Knee Society Score was 56 (preop) and 85 (final). The mean functional score was 65 (preop) and 83 (final). The mean knee flexion was 960 at final follow-up. Radiographic evidence of spot-weld was seen around the sleeves in 24%, and reactive lines in 17%. The 5-year survival was 90% for any reoperations. The reasons for the reoperations included: infection (50%), stiffness/instability (45%), and wound dehiscence (5%).

Discussion And Conclusion

There were no complications specific to the implant design, to the mobile bearing, or the metaphyseal sleeve. The functional outcomes were similar to revision TKAs using other implant systems. There was no revision for aseptic fixation loosening at the mid-term. Longer term follow-up is needed to determine the efficacy and the durability of adjunct metaphyseal fixation.