Intermediate follow-up of high tibial osteotomy: a comparison of two techniques.

Abstract

All high tibial osteotomies (HTOs) performed in the Royal Bournemouth Hospital from June 1987 to February 1995 were retrospectively analyzed looking at the preoperative and postoperative radiographs, preoperative and postoperative range of motion (ROM), alignment, and knee scores. Patient perception was also recorded. In all there were 68 high tibial osteotomies (HTOs), of which 40 were performed by Maquet's dome method and 28 were done by closing wedge osteotomy. Average follow up was 8.6 years (range: 5.2 to 13 years) and 16 (23.5%) cases went on to have total knee arthroplasty after an average interval of 3.7 years. The results of the two methods are compared. Average preoperative HTO alignment was a varus of 4.72 degrees and average postoperative HTO alignment was a valgus of 1.48 degrees. The average radiological grade of osteoarthritis and compartments affected was comparable in the two groups. Overall 35 (51.5%) patients were dissatisfied with their results. A larger percentage of people (57.5%) who had a Maquet's dome osteotomy were unhappy with their operation as compared to 42.9% of people who were unhappy following a closing wedge osteotomy. There was consistent undercorrection after dome osteotomy, with an average alignment of a varus of 1.45 degrees compared to a valgus of 5.67 degrees after a closing wedge procedure. The preoperative subluxation was greater in the patients with a relatively poor result, 3.86 mm compared to 2.03 mm in those with a good result. It is felt that the rather poor results following osteotomy in this series was due to insufficient correction obtained and the advanced stage of osteoarthritis resulting in subluxation. In this series the correction obtained with closing wedge method was better than with the dome method, although it was inadequate with both methods. Although the wedges appeared to do better than the domes, this was not statistically significant. Overall, there was no significant correlation of our results with post osteotomy alignment. Preoperative lateral tibial subluxation was, however, a poor prognosticator of results.