The acetabulum in healed Legg-Calvé-Perthes disease is cranially retroverted and associated with global reduction of femoral head coverage: a matched-cohort study

Does Acetabulum Remodel Following Varus Derotation Osteotomy for Perthes' Disease?

Objective  We investigated the effect of disease stage, patient's age and final contour of femoral head on acetabulum contour following varus derotation osteotomy of proximal femur (VDRO) in unilateral Perthes's disease. Methods  The study is a retrospective analysis of case records of 23 children aged ≥6 years with unilateral Perthes' disease who underwent primary VDRO procedure for containment. Acetabular index (AI) and center edge angle (CEA) were calculated bilaterally in preoperative and follow-up radiographs and compared statistically. Results  There were 15 boys and 8 girls. Six hips were in Ib, 8 in IIa and 9 in IIb modified Waldenström stage while undergoing VDRO. The mean age at surgical intervention was 8.7 years. The mean follow-up duration was 3.5 years. All femoral heads were healed at final follow-up and the final Stulberg grades were I = 3, II = 8, III = 7, IV = 5. A significant acetabular dysplasia on the affected side was present preoperatively. At follow-up, the patients operated had significantly raised AI and reduced CEA. There was no significant acetabular remodeling of the affected hips at follow-up even in children operated at younger age (< 8 years) or early stages (stage Ib or IIa). The acetabulum remodeling did not correspond to the final Stulberg grade as well. Conclusion  Acetabulum was found involved in early stages of Perthes' disease. Varus derotation femoral osteotomy for the diseased hip showed no significant improvement in acetabular dysplasia even when operated in early disease stages or younger age group. Residual acetabular changes were also noted even with favorable Stulberg grades.

How does former Salter innominate osteotomy in patients with Legg–Calvé–Perthes disease influence acetabular orientation? An MRI-based study

Salter innominate osteotomy (SIO) has been successfully used in the treatment of Legg–Calvé–Perthes disease (LCPD). Recent studies that have raised concerns about acetabular retroversion after SIO have been based on plain radiographs. In order to assess the true acetabular orientation, the present study uses a specific magnetic resonance imaging (MRI) technique. In addition, the association between acetabular morphology and clinical function as well as health-related quality of life was assessed. Twenty-three patients with 24 operated hips who underwent SIO for LCPD between January 2004 and November 2014 were included. Mean age was 8.5 ± 2.2 years at surgery and 18.5 ± 2.9 years at follow-up. MRIs were conducted at 1.5 T using radial sequences. The analysis included the acetabular version, acetabular sector angles (ASAs) and alpha angles. Plain radiographs were used in order to obtain the Stulberg classification. Patient-related outcome measures included the international Hip Outcome Tool and Euroqol-5 dimensions scores. In comparison to the non-operated side, the MRI of previously operated hips showed no difference of version at the center of the femoral head but significantly decreased version just below the roof level. As a marker for posterior acetabular coverage, the ASAs between 9 and 11 o’clock were significantly decreased when compared with non-operated hips. In hips with a mild acetabular retroversion (<15°), the function was significantly decreased when compared with non-retroverted hips. The SIO is an effective tool in order to restore acetabular containment in LCPD. When compared with the non-operated hips, our collective displays only moderate changes of acetabular orientation and coverage.

Bilateral femoral head reshaping and mosaicplasty in Legg-Calvé-Perthes disease residual deformity

Residual hip deformity secondary to Perthes disease may lead to early symptomatic joint degeneration. The altered anatomy results in biomechanical and biological problems that can be surgically addressed in adolescents or young adults with hip preservation procedures. This case report aims to demonstrate a customized surgical treatment performed on a 15-year-old male who developed painful hips with significant intra- and extra-articular impingement, secondary to bilateral Leg–Calvé–Perthes disease residual deformity. Intra-articular procedures were executed through a safe surgical dislocation of the hip, with a mosaicplasty using osteochondral autografts from the exceeding peripheral ipsilateral femoral head, a femoral head–neck osteochondroplasty and a labrum repair. A relative lengthening of the femoral neck was also carried out with a trochanteric advancement to solve the extra-articular issues. On follow-up, he referred to a substantial improvement in pain and function, being his radiographic studies satisfactory. At 4 and 5 years from surgery, the patient was able to exercise regularly with minimal complaints, with a Harris Hip Score of 85.85% and a Hip Outcome Score of 94.1% for activities of daily life and 86.1% for sports. In patients with hip deformity after healed Perthes disease, treatment strategies that address both the morphological disturbance of coxa magna, plana and breva, as well as the biological concerns arising from osteochondral injuries or labral tears, and mechanical dysfunctions lead to improvements in symptomatology, function and medium-term prognosis. Further procedures to address residual adaptative acetabular dysplasia would favor outcomes of conservative hip surgery in the sequelae of LCPD.