Gait outcomes of patients with severe slipped capital femoral epiphysis after treatment by flexion-rotation osteotomy.

BACKGROUND: Flexion-rotational osteotomy of the proximal femur is an accepted intervention in the management of severe deformity and femoral acetabular impingement secondary to slipped capital femoral epiphysis (SCFE). The impact of this surgical intervention on gait kinematics and kinetics, validated functional questionnaires, and patient outcomes has not been well studied. The purpose of this study was to analyze the changes in standard gait parameters of patients with moderate to severe SCFE who were treated with a flexion-rotational osteotomy. METHODS: This study is a retrospective review of 8 patients treated for a unilateral moderate and severe SCFE with a flexion-rotational osteotomy. All patients had 3-D computerized gait analysis studies completed preoperatively and 1-year postoperatively. Additional data analyzed preoperatively and postoperatively included: anterior/posterior hip radiographs, standard physical examination measures, and Pediatric Outcomes Data Collection Instrument (PODCI), completed by parents. RESULTS: The Gait Deviation Index, a composite of gait kinematics, showed a significant improvement from 64.9 to 88.0 (P<0.001). Radiographically, significant improvement toward normal values were found in the epiphyseal-shaft angle on the AP view from 123 to 139 degrees (P=0.005) and on the frog lateral view from 61 to 16 degrees (P=0.00001). Hip abduction range of motion on physical examination increased from 15 to 27 degrees and hip external rotation decreased from 51 to 25 degrees after surgery (P<0.05). The PODCI significantly improved in the categories of basic mobility, sports function, and global function (P<0.05). CONCLUSIONS: Longstanding deformity as a result of a severe SCFE may lead to osteoarthritis of the hip, disabling pain, and functional deficits. Although radiographic evidence of degenerative disease may take years to develop, changes in gait parameters can be immediately evident in this population. A flexion-rotation osteotomy in the adolescent and young adult population can improve gait kinematics, radiographic measures, range of motion, and short-term functional outcome scores. It is felt that normalization of these parameters may reduce the risk of long-term hip deterioration and its related sequelae. LEVEL OF EVIDENCE: Level IV.