Deterioration of long-term results following high tibial osteotomy in patients under 60 years of age.

We have investigated, in a prospective study, the outcome of a valgus osteotomy of the tibia in patients less than 60 years of age with arthrosis of the medial compartment and a varus angle of no more than 177.7 degrees . Included in the study were 44 high tibial osteotomies (HTO) performed in 42 patients from 1981 until 1996. There were 35 females (2 bilateral) and 7 males, with an average age of 51 years (range: 30-60 years). Only patients in the first three grades, according to Ahlback's classification, were included. During a mean follow-up period of 10 years (range: 5-17 years), all but 2 patients experienced pain relief. The average loss of postoperative correction at 10 years was 2.4 degrees . The average postoperative Hospital for Special Surgery Knee Rating System score (HSSK) for patients with excellent or good results was 83.5 points. Survivorship analysis showed a success rate of 80% and 66% at 10 and 15 years respectively, and over 52.8% at 17 years of follow-up. HTO results in redistribution of the main stresses towards normal levels, although normal values are never attained. This is probably the reason why patients experienced good results only in the medium term.