Intra-Capital Osteotomy

Severe deformities of femoral head and acetabulum after Perthes disease or Perthes-like deformities are prone to early degeneration. Surgical procedures with extracapsular approach can hardly change this prognosis. Application of detailed vascular knowledge has enabled an extension of intracapsular surgery including segmental resection of the femoral head, allowing direct correction of the deformity. This chapter describes indications, technical execution, as well as possible risk factors and complications of the procedure. Finally, it gives an overview of results. The femoral head has an asymmetric dual blood supply, coming primarily from the deep branch of the medial femoral circumflex artery (MFCA) and from the medial branch of the MFCA, each vessel running in a retinacular fold, which can be mobilized from the neck bone. While the supply from the deep branch can perfuse the entire epiphysis, the medial branch perfuses approximately the medial half of the head. Based on this blood distribution, a portion of the central head can be resected without circulatory consequences for both remaining parts. Because the medial portion rests connected with the neck, this retinacular flap does not need to be mobilized. The lateral portion of the head/neck is mobilized after preparation of the lateral flap and becomes reduced against the stable medial portion and fixed with 2(−3) screws. The resected portion can be a parallel segment, or an anterior- or posterior-based wedge. The mobile lateral portion can be rotated, abducted or adducted, and/or shifted in a cephalad or caudad direction, all within the limits of the retinacular tension. Ideally, the “new” head is close to spherical and has the size of the opposite head.