Early results of a domed tibia, mobile bearing lateral unicompartmental knee arthroplasty from an independent centre.

AIM: The aim of this study is to determine the short-term outcome of lateral unicompartmental knee arthroplasty (UKA) using a domed tibia, mobile bearing prosthesis. The primary outcome measure was revision due to bearing dislocation and the secondary measure was functional outcome.

METHODS

From 2005 to 2009, a total of 64 knees, in 58 patients, were identified as having the domed tibia, mobile bearing lateral UKA with a minimum 2-year follow-up. Forty-one females and 17 males with a mean age of 71years (range 44 to 92, median 72) were reviewed. The mean follow-up period was 38months (range 24 to 61, median 36). The primary outcome measure was re-operation and revision rate, particularly due to bearing dislocation. The secondary outcome assessed was a patient reported outcome measure (PROM) using the Oxford Knee Score (OKS) and compared using Student's Paired T-test.

RESULTS

There were four knees that underwent further surgery for any reason. Two patients required revision of the implant (3.1%). There were no cases of bearing dislocation in this series. The mean pre-operative OKS was 24 (range 9 to 36) and the mean post-operative score was 42 (range 23 to 48 p<0.0001).

CONCLUSION

This study from an independent centre, reporting on the short-term results of the domed tibia, mobile bearing lateral UKA supports the safety and efficacy of the procedure as a treatment option in the patients with lateral compartment osteoarthritis (OA) of the knee.

LEVEL OF EVIDENCE: This is a level 4; case series study.