Orthopedics - Oleksa A.P. 2006

Congenital and acquired deformities of the lower limb
Congenital and acquired deformities of the hip
Slipped capital femoral epiphysis

In 1894, Kocher considered adolescent epiphysiolysis to be a juvenile deformity of the Femur, but as this condition was studied further, it was classified as a distinct nosological entity.

Typically, this disorder occurs in children and adolescents with adiposogenital syndrome.

The exact Etiology of femoral neck deformity remains unclear, though prolonged microtrauma and excessive mechanical stress on the developing bone—particularly when altered by Rickets—are believed to play a significant role.

Through biochemical Blood analyses of patients with epiphysiolysis, E. A. Mandrikyan (1974) identified disturbances in carbohydrate, lipid, and Mineral METABOLISM in children and adolescents, alongside adrenal dysfunction (since Adrenal Hormones regulate metabolism within the cellular and fibrous structures of Connective Tissue). Against the backdrop of metabolic and endocrine disorders, small focal dystrophic changes develop in the Bone tissue of the paraepiphyseal region of the femoral neck, accompanied by the thinning of bone trabeculae, which reduces bone strength. However, due to relatively active bone repair, complete Separation of the epiphysis and the femoral neck typically does not occur; nevertheless, even minor sudden overloading (such as jumping over an obstacle or landing from a height) can trigger complete separation with displacement, which is considered a pathological traumatic epiphysiolysis. Under The Influence of static and dynamic loads, Varus deformity of the neck develops.

Clinically, the initial signs of adolescent epiphysiolysis manifest as pain in the groin or above the knee following prolonged walking or physical strain. Pain radiating to the knee frequently misleads physicians, causing them to examine the knee joint instead. Later on, pain leads to limping and antalgic Muscle contraction.

The most characteristic sign of adolescent epiphysiolysis is fixed external Rotation of the thigh with restricted internal rotation. The degree of restriction in rotational movement depends on the extent of posterior Displacement of the epiphysis. Thigh flexion remains normal for a long time, but supplementary extension is lost. In advanced cases with significant displacement resulting in an open posterior angle of the neck, the lower legs cross when sitting, and hip flexion is somewhat restricted.

Radiological examination is paramount in diagnosing adolescent epiphysiolysis. Radiographs of the hip joint and femoral neck must be taken in two projections (Fig. 160). An anteroposterior radiograph in the early stages reveals Osteoporosis with cortical thinning. The Structure of the neck adjacent to the growth Cartilage shows not only osteoporotic changes but occasionally small areas of osteosclerosis, creating a mottled appearance in the subepiphyseal region of the bone.

The epiphyseal plate appears somewhat uneven and tortuous, and often no pathological changes are detected on the anteroposterior radiograph because its planes are obscured by displacement.

The axis of the femoral neck relative to the HEAD is abnormal, and depending on the severity of the epiphysiolysis, the axes of the neck and head form a varus angle of varying magnitude.

More informative is the lateral radiograph performed using Lauenstein's method. It clearly demonstrates posterior angular displacement of the neck at the level of the epiphyseal cartilage, while the degree of displacement relative to the head varies (Fig. 160, b).

Adolescent epiphysiolysis must occasionally—though very rarely—be differentiated from dystrophic varus deformity of the femoral neck, which originates in early childhood. Dystrophic varus neck deformity occurs in younger children and typically presents without signs of obesity.

Parents consult a doctor complaining that their child or adolescent is limping, experiences mild pain in the hip joint, and tries to avoid running.

Upon examination, the majority of patients exhibit obesity. When walking, it is evident that the patient favors the affected leg and steps on it more cautiously. Assessment of the range of motion in the hip joint reveals marked restriction of external hip rotation.

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Fig. 160. Radiograph in two projections of proximal femoral epiphysiolysis.

Treatment for adolescent epiphysiolysis must be performed in a hospital Setting immediately after Diagnosis. The patient is placed in bed, and the affected limb is completely unloaded using Skin traction with internal rotation of the thigh, as the femoral neck tends to slip further at the growth cartilage level.

Cases with minimal epiphyseal displacement occasionally occur, where progressive displacement can be avoided if the leg is completely unloaded in a timely manner. However, children generally fail to follow the prescribed regimen, making it virtually practical to prevent slippage this way.

To prevent this and accelerate reparative processes, drilling of the neck with a Kirschner wire through the epiphyseal cartilage into the femoral head is employed. The wire is inserted from the subtrochanteric region—preferably under fluoroscopic guidance—into the head to create 5–6 channels, after which 2–3 wires are left in place, cutting off their ends protruding above the skin. It should be noted that wire ends traumatize soft Tissues and fail to provide secure fixation; therefore, screws are now driven in along a similar trajectory for minor displacements.

In acute cases of childhood or adolescent epiphysiolysis, we managed to reduce the displacement under anesthesia in the X-ray room in almost all cases. To achieve this, an assistant holds the patient's pelvis while the surgeon applies traction to the flexed thigh along its axis, rotates it internally, and abducts it. Afterward, the limb is straightened, and the accuracy of reduction is verified radiographically. A hip spica cast is then applied, including a pantaloon extension on the healthy thigh, with the affected limb in abduction and internal rotation.

For significant displacements of a slowly slipping neck in the epiphyseal region with marked external thigh rotation, corrective osteotomy of the neck in the paraepiphyseal zone is used, followed by fragment reposition and screw fixation. However, it should be noted that aseptic Necrosis of the epiphysis—and occasionally the head itself—sometimes occurs following such surgery. This complication is managed through prolonged (up to one year) complete unloading of the limb combined with a comprehensive regimen of drug therapy and physical/balneotherapy.

Weight-bearing on the leg is permitted only after reliable bone union and restoration of the Bone Structure are achieved.

Orthopedic surgeons occasionally perform intertrochanteric or subtrochanteric osteotomy to correct retroversion and varus deformity of the femoral neck. Such surgery carries no risk of complications.