Congenital Femoral Deficiency

Excerpt

Congenital femoral deficiency (CFD) is a rare inborn disability characterized by femoral underdevelopment or absence. The condition has a broad spectrum of presentations, ranging from the congenital short femur to severe proximal focal femoral deficiencies. Hip joint stability and mobility are often compromised, especially if associated with joint malorientation and soft tissue contractures. The affected limb's growth is inhibited, with severity depending on the presence of underlying conditions.

CFD patients usually present with coxa vara proximally and femoral valgus distally. The condition is generally associated with other skeletal abnormalities, with fibular hemimelia being the most common association. Caudal regression syndrome, caudal dysplasia, cruciate ligament deficiency, and lumbosacral spine deformities may also occur concomitantly with CFD.

Femoral Anatomy

The femur, the largest bone in the human body, is situated in the thigh and is a vital component of the lower limb's skeletal framework. The femur's proximal end articulates with the hip joint. The shaft is integral to the overall function and mobility of the lower limb, providing support, transmitting mechanical forces, protecting vital structures, and contributing to joint stability and alignment. The distal femur articulates with the tibia and patella, forming the knee joint.

The anterior compartment contains the quadriceps femoris muscle group, which includes 4 muscles: rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius. These muscles extend the knee joint. The femoral nerve, a branch of the lumbar plexus, innervates the quadriceps femoris.

The muscles in the medial compartment are primarily adductors and include the adductor longus, adductor brevis, magnus, pectineus, and gracilis. These muscles are responsible for adducting the thigh and assisting with hip flexion. Most of these muscles are innervated by the obturator nerve. The hamstring part of the adductor magnus is innervated by the tibial nerve, a branch of the sciatic nerve.

The posterior compartment contains the hamstring muscles, which include the biceps femoris, semitendinosus, and semimembranosus. These muscles flex the knee and extend the hip. The sciatic nerve innervates the muscles of the posterior compartment.

The femur receives its blood supply primarily from the femoral artery and its branches, including the deep femoral artery. The femoral vein accompanies the femoral artery.

The knee joint is typically aligned so that the femur and tibia form a straight line when viewed from the front or back. This alignment allows for efficient weight distribution and smooth knee movements during activities such as walking, running, and jumping. In CFD, the knee angulation may be affected due to femoral underdevelopment or absence.