Objective: To compare long term results of inverted-V shaped high tibial osteotomy (HTO) and wedged HTO for medial compartmental osteoarthritis.
Methods: One hundred and eight osteoarthritic knees treated with HTO were evaluated. Fifty two of those knees had been treated with inverted-V shaped HTO (Group V) . Their average age at surgery was 59.5 years old (range 43-75 years old), and their average follow-up period was 14.1 years (range 10-19 years) . The other 56 knees had been treated with wedged HTO according to Coventry (Group W) . Their average age at surgery was 59.8 years old (range 47-72 years old), and their average follow-up period was 12.0 years (range 10-17 years) in group W. There was no significant difference in preoperative clinical and radiological factors between group V and group W.
Results: Knee scores were improved by surgery from 58.1 ±8.1 to 85.1 ±9.7 in group V, and from 60.2 ±11.5 to 81.4±11.4 in group W. The percentage of patients evaluated as good (knee score more than 90 points) was significantly larger in group V (42% in group V versus 21% in group W) . The femorotibial angle (FTA) at final follow up in standing X-ray was 164.7 degrees in group V. In group W, FTA at final follow up in standing X-ray (171.0 degree) was significantly larger than in group V. Correction loss of more than 3 degrees within one year after surgery was observed in 7 % of group V.On the other hand, 29% of patients in group W had a change in tibial plateau angle of more than 3 degrees. This was statistically significant.
Conclusion: The present study showed that inverted-V shaped HTO decreased correction loss after surgery compared to wedge HTO. This result seems to confirm that patients treated with inverted-V shaped HTO have significantly better clinical results than patients with wedged HTO.
