J Korean Knee Soc.
2008 Jun;20(1):38-43.
Conversion of Total Knee Arthroplasty after High Tibial Osteotomy
- Affiliations
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- 1Department of Orthopaedic Surgery, School of Medicine, Gyeongsang National University, Jinju, Korea. hscspine@nongae.gsnu.ac.kr
Abstract
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PURPOSE: We wanted to demonstrate the surgical techniques and report on the clinical and radiological outcomes of conversion to TKA after HTO.
MATERIALS AND METHODS
Eleven patients out of 147 patients who had HTO performed due to varus gonarthrosis and then they underwent conversion to TKA due to failure, from February 1993 to February 2002, were included in this study. The average follow-up duration was 3 years (range: 2 to 5.3 years). The average duration from HTO to TKA was 8.4 years (range: 4 to 10 years). The clinical outcomes with the Hospital for Special Surgery (HSS) score and the radiological studies with the Femoro-tibial angle, the Insall-salvati ratio and the distance between the lateral joint line and the fibular head were evaluated.
RESULTS
For the clinical evaluation, 7 cases were excellent, 4 cases were good and 1 case was fair. The average range of motion after TKA was 124 degrees (range: 115 to 130 degrees). We performed brisement force in one case, which underwent tibial tubercle osteotomy due to the difficulty of patellar eversion. For the radiological evaluation, the femoro-tibial angle at the postoperative state was 7.3 degrees valgus from 3.6 degrees in the preoperative state, and the Insall-Salvati ratio at the postoperative state was 0.96 from 0.94 in the preoperative state. The distance between the lateral joint line and the fibular head was 10.7 mm in the postoperative state from 11.2 mm in the preoperative state. Radiolucency of the femoral and tibial components didn't happen during the follow-up period.
CONCLUSION
Conversion TKA after HTO is a technically demanding surgery. However, the results of conversion to TKA are as good as that of primary TKA, if we follow the proper surgical principles.
