Abstract
BACKGROUND: High tibial osteotomy (HTO) for medial osteoarthritis of the knee is a well-established joint-saving surgical procedure that gives good clinical outcomes, but can give anatomical changes which may affect future total knee replacement. The primary purpose was to evaluate the obtained correction in patients who had a combined wedge osteotomy (CW) HTO compared to the lateral closing wedge (LCW) HTO technique. Secondary, the anatomical changes and patient reported outcomes measurements (PROMS) after one year were assessed. METHODS: In a non-blinded mono-center randomized controlled trial, patients eligible for HTO were randomized to CW or LCW HTO. Primary outcome was the achievement of an overcorrection of 4° valgus (2–6° was considered successful) one year after surgery. Secondary radiological outcomes were changes in tibial slope (Moore-Harvey), patellar height (Insall-Salvati and Caton Index) and difference in leg length (cm) one year after surgery. Other secondary outcomes were questionnaires to determine the pain severity, knee function and quality of life (visual analogue scale and Knee injury and Osteoarthritis Outcome Score) 1 year after surgery. RESULTS: A successful correction was obtained in 43% of the patients in the LCW group and in 52% of the patients in the CW group, which was not significantly different between groups (p = 0.373). No significant radiological differences were found, except for the leg length difference (0.28 cm shorter after LCW, 0.54 cm longer after CW, p = 0.006). This difference was clinically irrelevant (< 1.0 cm). All PROMS showed significant improvement after 1 year, without any differences between both groups. CONCLUSIONS: In this randomized controlled trial CW and LCW give similar accuracy of correction. Only 52 and 43% of the patients achieved the pre-planned correction, while both groups show comparable significant improvement of the clinical outcomes. Even though success rate of the achieved correction is relative low, these similar outcomes suggest that both CW and LCW HTO techniques can be used; where CW might be preferred to reduce bone loss at the proximal tibia. LEVEL OF EVIDENCE: Level 1, Randomized controlled trial. TRIAL REGISTRATION: The study was prospectively registered in the Dutch Trial Register on 27-3-2013 and is retrievable via www.onderzoekmetmensen.nl/en (NL43154.099.13).