Knowledge of the vascular supply of the femoral head is crucial for hip-preserving surgical procedures. The critical area for reshaping cam deformity is at the retinacular vessel penetration, an area with ill-defined topographic anatomy. We performed a cadaver study of the extension of the lateral retinaculum near the head-neck junction, distribution of the arterial vascular foramina, and initial intracapital course of these vessels.
In 16 fresh proximal parts of the femur without head-neck deformities, the deep branch of the medial femoral circumflex artery was injected with gadolinium for magnetic resonance imaging (MRI) sequences to identify arterial structures.
We found a mean number of 4.5 arterial foramina, showing a predominance from 10 to 12 o’clock. The retinaculum extended 20 mm from 1 to 10 o’clock. The surface distance from the cartilage border to the vascular foramina under the synovial fold was 6.5 mm, and the depth from the same cartilage border to the initial intraosseous vessel pathways was 5.3 mm.
The data add further precision to the arterial topography at the retinacular foramina, an area that is crucial for the perfusion of the femoral head. It may overlap with the area of anterolateral cam deformity and plays a role in choosing the cuts for subcapital and intracapital osteotomies.
The information is taken from normal hips and may not be directly applicable to the deformed hip. Nevertheless, it is a prerequisite for a surgeon to understand the normal anatomy and use those boundaries to prevent mistakes during intra-articular joint-preserving hip surgical procedures.