Introduction: The knee arthritis is a very common seen chronic disease in an orthopaedic practice. It is mostly seen in patients after 6 decade of life and connected with a severe knee pain. In most of the cases the surgical intervention is indicated because of unicondylar arthritis changes. Because of the costs of the hemiarthroplasty we choose a high tibial osteotomy for tibial axis correction to prevent further gonarthrosis.

The aim of this study was to evaluate the late results after high tibial osteotomy in patients with unicondylar gonarthrosis.

Material and Methods: In our Institution during last 20 years 94 high tibial osteotomy were performed because of unicondylar, medial gonarthrosis. The mean age of the patient at the time of surgery was 56 years (from 19 to 72 years). The mean follow-up was 16 years. Only patients with arthritic changes on the medial compartment of the knee with a “good” lateral part of the knee were scheduled for this type of surgery. In every case the dome type of osteotomy was performed followed by 1cm resection of fibula. After surgery the limb was stabilized with plate in 16 cases, K-wires in 4 cases, Ilizarov frame in 43 cases, orthofix device in 8 cases and other type of external fixator in remaining 23 cases. In patients where external fixator was used the full weight bearing was recommended as soon as patient tolerated the pain. The external fixator was removed after an average period of 6 weeks when bone callus was diagnosed. To assess of the clinical results based on HSS score and radiological results were evaluated using the modified Dihlmann classification.

Results: In 88,8% of all cases the final result was graded as excellent and good, in 1,9% the final results was satisfactory and in 7.8% the final results was poor. From analyzed patients 46% was scheduled for TKR at an average time of 12 years after initial surgical procedure. In 28% after average 16 years after high tibial osteotomy the good shape of the knee joint was observed with good clinical function and radiographic appearance. Pain was reduced in 82% of all cases, increased range of the knee motion was observed in 65% and improved walking ability in 64% of all cases. The poor results were connected with not adequate patients selection for this type of surgery (patients after 7 decade of life) and with advanced arthritic knee changes before the surgery.

Conclusions : The high tibial osteotomy is a good method for preventing gonarthrosis. When early performed gives good long-lasting result. In our opinion is recommended for unicondylar gonarthrosis as an alternative to the knee hemiarthroplasty.