Clinical outcomes of bilateral single-stage unicompartmental knee arthroplasty

Abstract

Background: Deciding whether to treat patients with bilateral arthritis with two-stage or bilateral single-stage arthroplasties is a cause of considerable debate in orthopaedic surgery.

Methods: A total of 394 cemented Unicompartmental Knee Arthroplasties (UKA) were performed in this unit between 2006 and 2010. A retrospective review identified 38 patients (76 knees) who underwent bilateral Single-Stage Sequential UKA, performed by a single surgeon.

Results: The mean BMI was 29.8 and the majority of patients were ASA grade 2. The mean duration of follow-up was 30 months. The mean total tourniquet time was 83 min. The mean post-operative haemoglobin was 11.8 and no patient required blood transfusion. The mean time to mobilisation was 18 h and the average length of stay was 3.5 days. This compares favourably with an institutional average length of stay of two days for a single UKA. There was a significant improvement in the mean pre- to post-operative OKS (from 14 to 34, p<0.0001). One patient required operative fixation of a tibial plateau fracture after sustaining a mechanical fall two months following surgery. There were no other major complications, including thrombo-embolic events or deep infections. Two patients required excision of a superficial suture granuloma.

Conclusions: Bilateral Single-Stage Sequential UKAs provide significant improvement in patient function and can be performed safely with a low complication rate. Patients can benefit from a single hospital admission and anaesthetic whilst the shorter total in-patient stay reduces costs incurred by the hospital.

Level of evidence: IV.

Keywords: Arthritis; Bilateral; Single-stage; Unicompartmental.