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

Figures

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  Fig. 1.. Pre-operative anteroposterior pelvic radiograph (A) and axial view of both hips (B). Widened, flattened and non-spherical femoral head, high-riding greater trochanter with negative articulo-trochanteric distance, short femoral neck and acetabulum under coverage. The extrusion index defined as the % of the femoral head (FH) width not covered by the acetabulum was 33.1 and 41.9% for the right and left hip, respectively. The Femoro-Epiphyseal Acetabular Roof (FEAR) index measured between the line of the acetabular roof and the central third of the physeal scar of the FH was −8° and 0.4°. The pelvis appears to be anteriorly rotated or anteverted due to the hip flexion contracture of the patient, which resulted in an apparent acetabular retroversion, inferred by the crossover sign and prominent ischial spines.

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  Fig. 2.. Preoperative CT scan of the pelvis. Coronal (A), axial (B), right (C) and left (D) sagittal sections and three-dimensional reconstruction (E). Dysmorphic femoral heads not well covered by the acetabulum, trochanteric overgrowth, normal acetabular anteversion and central osteochondral lesion. Measurements for right/left hip were: Lateral Center-Edge Angle (LCEA): 3.4°/4.6°; Tonnis roof angle: 22°/24.2°; Sharp angle: 47.5°/48.3°; Acetabular depth-width ratio calculated as depth (D)/width (W) × 1000: 250/216.7; Acetabular version: 13°/10.5°.

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  Fig. 3.. Surgical technique: (A) Delineation of the excess femoral head area. (B) Safe surgical dislocation of the hip and identification of the large central osteochondral lesion. (C) Removal of devitalized tissue and debridement up to stable cartilage. (D) Cylinder design at the recipient site, carved deep and perpendicular to the defect. (E) Graft obtention from the donor site with a tubular chisel. (F) Transplantation of the graft to the recipient site and introduction until the graft is at the same level as the surrounding cartilage. (G) Cylindrical graft transferred to the articular femoral head defect. (H) Cheilectomy and reshaping of the femoral head with a curved osteotome until obtaining a uniform femoral head-neck junction with the absence of impingement and a spherical femoral head. (I) Definitive result of the mosaicplasty and osteochondroplasty.

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  Fig. 4.. Anteroposterior (A) and axial (B) radiographs of both hips after the surgical procedures. Trochanteric osteotomies radiographically healed in a more distal position, femoral heads reshaped to achieve a more spherical morphology and a transitional head–neck junction and the osteochondral autografts appeared to be well incorporated.

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  Fig. 5.. Anteroposterior pelvic radiograph (A) and axial view of both hips (B) at the last follow-up at 4 and 5 years post-operatively. The findings are similar to the ones in previous radiographs but with all of the screws already extracted except for the left lower one. Radiological signs of healing of the osteochondral lesion are evident in the left hip, while in the right hip the central osteochondral lesion is still partially visible. Extrusion index has improved, as well as LCEA, however, there is residual adaptative acetabular dysplasia.