The morphology and morphometry of the fovea capitis femoris.

BACKGROUND: There is little published information on the anatomy of the fovea capitis femoris (FCF), the distal attachment site of the ligament of the head of femur (LHF). This study investigates the morphology of the FCF on dry bones in an attempt to answer some of the debate around the functional significance of the LHF.

METHODS: The morphological and morphometric details of the FCF were analysed on 125 dry isolated femora (n = 125) from the Anatomy Museum, University of Otago, New Zealand.

RESULTS: All femora had a single distinct FCF. The proximal half of the foveal floor was rough indicating the attachment of the LHF, while the distal half or receptacle zone, was smooth. The long axis of most FCF (63.2%) was directed posteroinferiorly. The FCF measured 1.77 ± 0.4 cm (SD) in the longitudinal plane and 1.3 ± 0.32 cm (SD) in the transverse plane and occupied 17% of the surface area of the femoral head. The shape of the FCF was oval in 66%, circular in 28%, and triangular in 6%. In 123 of 125 bones, the FCF was located on the posteroinferior quadrant of the femoral head. Multiple vascular foramina were found in the ligament attachment zone in 76% of the bones and a quarter of the samples showed a shallow perifoveal groove (24%) or a deep perifoveal notch (26%) on the dry bones.

DISCUSSION: This study shows that the fovea consistently lies posteroinferior to the true centre of the femoral head and is usually oval in shape. Patent vascular foramina clustered within the LHF attachment site suggest that the ligament conveys some blood supply to the femoral head in adults.