Manipulation under anaesthesia for stiffness following knee arthroplasty

Stiffness following knee arthroplasty is a frustrating complication and a significantly disabling problem. We present our experience of knee stiffness requiring manipulation under anaesthesia (MUA) as the first line of treatment following partial or total knee arthroplasty.

All stiff knees requiring MUA over a 6-month period from March to August 2007 were retrospectively analysed from theatre records and case notes. Data were collected regarding demographics, range of knee motion before and after manipulation and at subsequent follow-up. Complications of the procedure and outcomes were also analysed.

Twenty-one patients (11 female, 10 male) underwent MUA. The average age was 62 years (range, 56-80 years). Sixteen primary and 3 revision total knee replacements underwent manipulation, as did one medial unicompartmental replacement and one patellofemoral arthroplasty. General anaesthesia with good muscle relaxation was used in all but one patient. The mean duration between arthroplasty and MUA was 13.2 weeks (range, 6-32 weeks). The range of knee movement improved from a mean range of 10.4-71.2 degrees in the pre-MUA period to 2.1-94.0 degrees post-MUA and at follow-up was 2.3-91.9 degrees . The mean arc of motion improved from 60.2 degrees (range, 40-80 degrees ) pre-MUA to 91.9 degrees (range, 45-120 degrees ) post-MUA. The mean improvement in the arc of motion was 31.6 degrees (P < 0.001). At an average follow-up of 3 months (range, 6 weeks to 8 months), the mean arc of motion was 90.4 degrees (range, 40-120 degrees ). The mean improvement in knee movement from the pre-MUA at the follow-up was 30.2 degrees (P < 0.001). One patient failed to gain any improvement from MUA. There were no complications noted from the procedure.

MUA has a role in the treatment of early stiffness with excellent immediate outcomes. We advocate that MUA should be the first line of management for stiff knee arthroplasties after failed physiotherapy.