Clinical outcomes of a 'patella-friendly' medial pivot total knee arthroplasty with and without patella resurfacing: A prospective randomised study

Abstract

Background

Advances in knee implant design brings new focus on the benefit of patella resurfacing in total knee arthroplasty (TKA). The “patella-friendly” medial pivot SAIPH™ knee was designed to provide a more optimal patella articular environment, potentially reducing the requirement for patella resurfacing. This study examined anterior knee pain and related clinical outcomes when patella resurfacing (PR) was randomised against retention of the native knee.

Methods

In a prospective study, fifty-one patients having a primary TKA were randomised to PR or non-RP prior to surgery. All patients received the same ‘patella-friendly’ implant using a standardized surgical technique. Patient demographics were recorded prior to surgery and intra-operative assessment of patella surface degeneration was conducted for all patients. Outcomes were evaluated at 4 weeks and one year. The primary outcome was the Kujala Anterior Knee Pain Score (KS), and secondary outcomes were the Patient Knee Implant Performance Score (PKIP), Oxford Knee Score (OKS) and Forgotten Joint Score (FJS). Complications requiring surgical management or mobility restriction treated with manipulation under anaesthesia (MUA) were recorded over the duration of the study.

Results

There was no significant difference between groups in baseline age (p = 0.67) or BMI (p = 0.97). Between-group differences in KS were not significant at 4 weeks (PR 55.3 Non-PR 53.6, p = 0.67) and 12 months (PR 78.4 Non-PR 77.6, p = 0.86). No significant between group differences were identified for the PKIP, OKS or FJS at both follow-up time points. The proportion of satisfied patients was not significantly different between groups (p = 0.14). No patients required revision surgery. Three patients in the non-PR group and one patient in the PR group required MUA (p = 0.32).

Conclusion

Patella resurfacing demonstrated no superiority compared to non-resurfacing in relation to clinical outcomes and post-operative complications when using a 'patella-friendly' implant.