Selected aspects of proximal femoral epiphysis fixation in children with early stages of slipped capital femoral epiphysis

BACKGROUND: Epiphyseodesis of the femoral head in the early stages of slipped capital femoral epiphysis using auto-, allografts, and synthetic implant may result in deformities of the femur leading cam-type femoroacetabular impingement and dysfunction of the gluteal muscles. Most surgeons refused this intervention and favor in situ fixation of the epiphysis with modern metal instrumentation and, in particular, cannulated screws with proximal threading. However, the number of screws that provide stable fixation and how to reduce their negative effect on the enchondral growth of the femur remain controversial.

AIM: To improve the results of surgical treatment in children with early stages of slipped capital femoral epiphysis.

MATERIALS AND METHODS: The radiological results of surgical treatment of 40 patients (80 affected joints) aged from 11 to 14 years with slipped capital femoral epiphysis of stage 1 in one joint and stage 2 in the other joint were analyzed. 20 children were divided into two groups. In each group, the epiphysis was fixed with a 7.0 mm cannulated screw. In the first group, the screw head was held on the cortical layer. In the second group, the screw head was held 5–10 millimeters away from the cortical layer. Long-term results were evaluated at the age of 17–18 years when no signs of enchondral and ecchondral growth of the proximal femur were noted. The obtained data were subjected to statistical analysis.

RESULTS: The fixation of the epiphysis was stable in all 80 joints. The shape of epimetaphysis in the joints of stage 2 did not change in most patients by the end of femoral growth. However, the correction recorded in 32.5% of cases was more often observed in children of the second group. The shape of epimetaphysis in all 40 joints with stage 1 of the disease remained normal. The mean length of the epimetaphysis was greater in the second group than in the first group by the end of growth regardless of the stage of the pathologic process during surgery.

CONCLUSIONS: The considered method of proximal femoral epiphysis fixation, which excludes the compressive effect of a cannulated screw with proximal threading on the epiphyseal growth cartilage, provides reliable epiphysis retention in the early stages of slipped capital femoral epiphysis. It has a less negative effect on the enchondral growth of the femoral component of the joint.