Orthopedics - Oleksa A.P. 2006

Congenital and Acquired Deformities of the Lower Extremity
Congenital and Acquired Deformities of the Hip
Coxa Valga

Valgus deformity of the femoral neck is rare. It is believed to be caused by partial damage to the lateral part of the epiphyseal Cartilage beneath the femoral HEAD, as well as injury to the greater trochanter apophysis, as demonstrated experimentally by Laurent (1959). Coxa valga frequently develops during a child's growth As a result of untreated developmental Dysplasia of the hip (Fig. 152).

Furthermore, Bozdech and Kovanda (1961) observed the onset of coxa valga in children who underwent surgery for congenital hip dislocation when the greater trochanter apophyseal cartilage was damaged. The interdependence of these two growth plates is well known to ensure the normal development and growth of the proximal Femur.

At birth, the femoral Head and Neck present physiological valgus and retroversion. During a child's growth, these gradually change due to physiological torsion, so that in an adult the neck-shaft angle averages 127°, and the antetorsion angle is 8-10°. When the aforementioned epiphyseal cartilage disorders occur during childhood, this physiological process is disrupted, resulting in coxa valga.

In addition, valgus deformity can be "symptomatic" due to the predominance of hip adductor Muscles in Little's disease, post-polio syndrome, progressive muscular dystrophy, as well as tumors and exostoses that impair normal epiphyseal plate growth. Extremely rarely, valgus deformities occur following Rickets, improper management of femoral neck fractures, and untreated developmental dysplasia of the hip.

The mainstay in diagnosing coxa valga is radiographic examination, which must be performed with the limb in internal rotation, as lateral Rotation of the femur on a radiograph invariably exaggerates the valgus angle of the neck.

Clinically, valgus deformity may be asymptomatic in cases of bilateral involvement, whereas unilateral involvement can cause functional limb lengthening, thereby leading to a gait abnormality. Mild degrees of femoral neck valgus are difficult to detect clinically because hip joint function remains preserved.

Class="center">

Fig. 152. Radiograph of the hip joint showing coxa valga secondary to untreated developmental dysplasia of the hips.

As a rule, children with minor valgus deformities undergo conservative Treatment. Post-rickets deformities undergo self-correction as the child grows, which is also observed with proper management of children with developmental dysplasia of the hip when the femoral head is well-centered within the acetabulum.

Conservative treatment is also indicated for children with coxa valga resulting from growth plate injury. Since the condition has a protracted course, comprehensive treatment is administered in courses.

Surgical treatment (corrective varus subtrochanteric osteotomies) is performed when conservative management fails and the process in the epiphyseal cartilage has stabilized.

Prior to surgery, a properly executed radiograph is used to create a skiagram of the upper femur, from which the valgus angle, the osteotomy site, and the base width of the triangular wedge to be excised for deformity correction are calculated.

Surgical technique. The Procedure is performed under general anesthesia with anesthetic support. A lateral linear tissue incision is used to expose the intertrochanteric or subtrochanteric region of the femur, depending on The Nature of the valgus deformity. During dissection, it is crucial to avoid damaging the greater trochanter growth plate. The periosteum is incised linearly and stripped at the planned osteotomy site. Two Kirschner wires are inserted into the femur at the desired angle, and a control radiograph is obtained. Once the wires are correctly positioned, a triangular wedge is excised such that the bone resection lines meet on the Medial surface of the femur. Following wedge removal, the valgus deformity of the neck is corrected by abducting the femur, the bone interfaces are well-adapted, and the fragments are fixed with a metal L-shaped plate or percutaneous Kirschner wires, which are removed after three weeks. A repeat control radiograph is taken, after which the wound is closed in layers and drained for 24 hours. A hip spica cast is applied, shortened to the knee, and removed after 6 weeks once bone union is achieved.