Wrightington Hospital, UK
Title: Cruciate-retaining Total Knee Replacements for Valgus Deformity Secondary to Osteoarthritis: 5.5 years Follow-up Survival Study
Background: Clinical survival studies for cruciate-retaining TKR for valgus knees are very limited in literature. We present our series of valgus knees secondary to osteoarthritis treated with lateral soft tissue releases and CR-TKR.
Methods: A survival study of CR- TKR in knee OA with valgus deformity with functional MCL, has been performed by retrospective analysis of hospital data. Revision for any cause is considered the end point. 108 TKR in 102 patients with a minimum follow up of 1 year, who had a CR-TKR for knee arthritis with valgus deformity between December 2001 and November 2012 are included in the study.
Results: Mean follow up is 5.5 years (median 5 years, range 1 -14 years). Mean improvement in the valgus angle is 14.28 degrees +/- 2 degrees at 95% CI (Median 14, SD 9 degrees). Mean flexion is 105 degrees (Median 100, range 80-150). 10 patients have died due to non-orthopaedic causes. One patient has non-progressive lucency around the components and has not required revision. None of the tibio- femoral components have been revised so far. One patient had a fall and dislodged the Patellar Button which had to be removed. No instability has been noted in any of the patients during follow up. Two patients have persistent pain, but investigation has not shown any cause.
Conclusions: CR components for TKR for knee OA with valgus deformity has shown satisfactory survival at 5 years with low revision rate when adequate soft tissue balance is achieved at the time of implantation.
Implications: CR-TKR, which helps preserve femoral bone stock, can be successfully implanted in a valgus knees, as shown in our series, with 100% survival at an average of 5.5 years when the soft tissues are balanced at time of implantation. However, long term follow-up is required to ensure there are no late failures.