BRUCE N. LE, D.O., Orthopaedic Resident
KIRK DABNEY, M.D., Attending Pediatric Orthopaedic Surgeon
April 12, 1996
CLINICAL CASE PRESENTATION
THE ALFRED I. DUPONT INSTITUTE
The patient is a 14 year old black male with a history of bilateral slipped capital femoral epiphysis (SCFE). He was initially diagnosed with left SCFE and pinned at an outside institution in 12/93. He had been doing well but then began unprotected weight bearing earlier than recommended. It was noted that his left cannulated hip screw had cut out of the femoral head and required removal in 2/94. The patient began to have right hip pain in 3/94 during a period of crutch walking. It was noted at that time that he also developed right sided SCFE. He underwent bilateral cannulated screw fixation of the SCFE lesions in-situ in 4/94. Avascular necrosis of the left femoral head with collapse had developed to where he began to have increased hip pain, particularly with ambulation.
The patient is a moderately obese 14 year old male at 105 kilograms. His systemic exams were all within normal limits. No palpable enlargement of the thyroid was noted. Bilateral hips with passive flexion to 75 degrees and abduction to 20 degrees on the left and 30 degrees on the right. Internal rotation was 0 degrees on the right and -15 on the left with external rotation 70 degrees, bilaterally. Knees extension was 0 with flexion to 110 degrees bilaterally. Upper extremities and bilateral legs and foot exams were all within normal limits. Neurological exams were grossly normal with 2+ DTR's. Labs were within normal ranges with evidence of thyroid nor other endocrine dysfunction.
Several hips and pelvis x-rays were taken through several months and revealed evidence of bilateral SCFE with in-situ screw fixations. One set of left hip films did reveal cut-out of the cannulated screw into the hip joint. There is evidence of left femoral head osteonecrosis with collapse and remodeling.
The patient underwent a corrective osteotomy to improve the surface contact area of the left hip. The area of osteonecrosis and collapse on the femoral head was located anteriorly and superiorly. A flexion-valgus osteotomy was performed to bring the diseased region of the femoral head out of the hip joint. This allowed the relatively disease free articular surface to articulate with the weight bearing region of the acetabular dome. This osteotomy was performed in the technique as described by Abraham et. al. The widest part of the wedge was placed anterolateral DIAGRAM, converging at a point in the posteromedial aspect of the femoral neck. Approximately 12 mm of bone was resected at the widest portion (AP view, LAT view). In this technique, cortex of the posterior neck was not violated and an osteoclysis was necessary to close the wedge (AP view, LAT view). The closing wedge was held reduced with two 7.3mm cannulated screws. No bone graft or cast was necessary. The patient was followed post operatively and at one month, is doing well. He ambulates with crutches and is touch-toe weight bearing to the left lower extremity.
The treatment for slipped capital femoral epiphysis is surgical(1,2). The underlying deformity for SCFE is the displacement of the femoral head posteriorly and inferiorly. Pinning of the slip in-situ has been found to have very good results when compared with attempted reduction using manipulation(1). Other options at treatment of SCFE have included bone graft epiphysiodesis, subcapital, intracapsular, extracapsular and trochanteric or subtrochanteric osteotomy(1,2,3,4).
The technique describe for this patient was originally designed for moderate and severe SCFE. It involves an extra-capsular basicervical osteotomy which flexes the head anteriorly and also brings it out laterally into valgus. This allows for the correction of the slipped femoral head and improves the Southwick angles. Abrahams series had an average varus slip to 112 degrees (normal 145) with a posterior tilt or retroversion of 60 degrees ( normal 10). After the osteotomy, they were able to improve the retroversion by 35 degrees and the varus deformity by 17 degrees. There were no cases of osteonecrosis and 3 cases of chondrolysis. Abraham et al. had good to excellent results in 90% of the cases with 10% being fair to poor. These results were comparable previously studied techniques including that of Southwick for his osteotomy. The benefit of this technique is that it is an extracapsular osteotomy which preserves the vital and already tenuous blood supply to the femoral head. Where the technique of Kramer is similar, Abraham's osteotomy does not violate the joint nor is the posterior cortex cut. Osteoclysis of the posterior cortex allows for a more stable osteotomy, minimizing displacement. Being extracapsular, this osteotomy is located in the relatively safe area of the femoral neck, away from the major blood supply in the posterosuperior aspect of the femoral neck(3).
Osteonecrosis(ON) of the femoral head following SCFE does occur, particularly in acute slips. Causes of ON were thought to have been caused by several factors, including the degree/severity of slip as well as iatrogenic in origin, particular a result of poor pin placement(6). Treatment of ON with SCFE have included some of the previously described osteotomies including the Sugioka technique. The Sugioka has been advocated by some for the treatment of ON, but the results have varied not to mention its technical difficulties. The technique described by Abraham is easier to perform and does allow for correction of the deformity, though not to the degree of the Sugioka.
The majority of the deformity in the previously described case patient was located in the anterolateral aspect of the femoral head. When this region directly articulate with the weight bearing region of the acetabular dome, pain and acetabular erosion ensues. In performing the osteotomy, the relatively disease free posteromedial surface of the femoral head is brought into the weight bearing region, thus relieving articular irritation and pain. The osteotomy, in giving more anteversion, allows for a greater degree of internal rotation. It has been previously noted that lack of internal rotation was a significant complaint of most patients, more so than pain. This corrective osteotomy should allow this patient to have better range of motion, to be more pain free and to prolong the need for joint replacement.