Objective: To determine the success of 20 cases treated with TomoFix high tibial medial opening wedge osteotomy.

Study design: Retrospective review of 20 cases with 6 months of follow up including; indications for treatment, surgical technique, results, complications and patient satisfaction.

Background: High Tibial Osteotomy is an established technique for the treatment of unicompartmental osteoarthritis of the varus malaligned knee. Corrections are usually achieved by closed wedge osteotomy from a lateral exposure. This technique has associated risks of; peroneal nerve injuries, instability of the osteotomy and secondary loss of correction. Open wedge osteotomy of the medial side eliminates these risks. TomoFix allows stable fixation of the osteotomy without the need to fill the osteotomy gap with bone grafts.

Results: Full weight bearing after 6 weeks. No implant failures, delayed unions, nerve injuries or compartment syndromes. Complications included 1 infection, 1 over correction and 1 with metalwork pain.

Conclusions: TomoFix allows for early mobilisation and avoids loss of correction with reduced risk of nerve injuries and compartment syndrome.

Relevance: The surgical technique needs careful attention. Disorders of normal bone healing and inadequate axial correction may lead to failure of treatment. Early rehabilitation is possible and long term follow up is necessary.