gms | German Medical Science

Objective: Medial open wedge high tibial osteotomy (MOWHTO) is a well established method to treat unicompartimental osteoarthtritis of the knee joint. But there still is a controverse discussion about augmentation of the created tibial gap after osteotomy. The aim of the study is to examine the usefulness of synthetic bonegraft.

Methods: We performed a retrospective study on 57 consecutive MOWHTO in our department. Patients were divided into two groups: Group A with 20 knees in 19 patients and group B with 37 knees in 30 patients. In group A the augmentation of the opening gap after osteotomy was filled with a synthetic bonegraft (Actifuse, Baxter Deutschland GmbH, Unterschleissheim, Germany), in group B no augmentation was performed. In both groups the same surgical procedure was performed with using a Tomofix locking plate (Synthes GmbH, Solothurn, Switzerland). As an indicator for bone healing we investigated the non-union rate in our study population and compared the non-union-rate between the two groups.

Results and conclusion: In Group A - with synthetic augmentation - the non-union-rate was 25 % (five of 20 patients had to be revised), in Group B - without augmentation - the non-union rate was 5,4 % (2 of 37 patients had to be revised), which results in a statistically significant difference between the two groups.

Assessing the bone healing after MOWHTO we found no advantage of augmentation synthetic hydroxyapatite augmentation compared with no augmentation concerning the non-union-rate after surgery. Indeed we see a significant higher non-union rate after augmentation with synthetic hydroxyapatite.