Long-term follow-up results of femoral varus osteotomy in the treatment of Perthes disease, and comparison of open-wedge and closed-wedge osteotomy techniques: A retrospective observational study

In this retrospective observational study, I aimed to report long-term follow-up results of femoral varus osteotomy in the treatment of Perthes disease patients who were between 6 and 8 years old at the onset of the disease with Herring B and C hip involvement. I also aimed to compare 2 different osteotomy techniques: open-wedge and closed-wedge femoral varus osteotomies. Patients with Perthes disease treated with femoral varus osteotomies were invited for final examination. Twenty two hips of 19 patients were evaluated. Mean follow-up period was 15.2 years. Patients were divided into 2 homogenous groups according to femoral osteotomy technique. In Group A (12 hips) open-wedge osteotomy, and in Group B (10 hips) closed-wedge osteotomy was performed. There were 15 male (78.9%) and 4 female (21.1%) patients. The median age at the onset of the disease was 7 years in Group A and B. The mean follow-up period was 16.2 years in Group A, and 11.4 years in Group B. According to Stulberg classification 5 hips (22.7%) were healed as Class I, 4 hips (18.2%) were healed as Class II, 12 hips (55.5%) were healed as Class III, and 1 hip (4.6%) was healed as Class IV. Also in Group A 4 hips (33.3%) were healed as Class I or II, 7 hips (58.3%) were healed as Class III, and 1 hip (8.3%) was healed as Class IV; in Group B 5 hips (50.0%) were healed as Class I or II, and 5 hips were healed as Class III (50.0%). There was no significant difference between the groups. According to Iowa scale, mean values were 92.6 in Group A and 92.4 in Group B. There was no significant difference between the groups. At the final follow-up mean center-edge angles of Group A and B were 16 and 22, the difference was significant. Long-term follow-up results showed that femoral varus osteotomy was an effective treatment method in Perthes disease patients who were between 6 and 8 years old with Herring B and C hip involvement at the onset of the disease. Hip joint congruency was obtained with femoral varus osteotomies, and closed-wedge osteotomy served more favorable center-edge angle results.