Introduction

Osteotomy is a recognised surgical option for the management of unicompartmental knee osteoarthritis. The effectiveness of the surgery is correlated with the accuracy of correction obtained. Overcorrection can potentially lead to excess load through the healthy cartilage resulting in accelerated wear and early failure of surgery. Despite this past studies report this accuracy to be as low as 20% in achieving planned corrections.

Aim

Assess the effectiveness of adopting modern osteotomy techniques in improving surgical accuracy.

Methodology

A prospective cohort study. Patients were identified who had undergone osteotomy surgery for unicompartmental knee OA using a standardised technique. The surgical techniques adopted to ensure accuracy included digital templating software (Orthoview), Precision saw(Stryker), bone wedge allograft and plate osteosynthesis (Tomofix).

Pre and post operative analysis of standardised long leg X-rays was performed and the intended (I) and achieved(A) corrections were calculated.

Results

A total of 94 (35F/59M) patients with a mean age of 52 years were identified who fulfilled the inclusion criteria for the study. 62 patients were treated with a tibial osteotomy, 21 with femoral and 11 with a double level osteotomy. Using a 10% acceptable range (AR) for error, in 89% of cases (84 of 94) the target Mikulicz point was achieved. Potential risk factors for overcorrection included female sex and osteotomy type, with a higher incidence of over correction observed with double level osteotomies (27%)

Conclusion

This study demonstrates that meticulous digital software planning and surgical technique ensures accurate surgical correction in periarticular knee osteotomy surgery.