The incidence of bilaterality in slipped capital femoral epiphysis (SCFE) ranges, in the literature, from 19 per cent to 80 per cent. The role of contralateral pinning is to prevent late slipping of the femoral epiphysis and its complications. The purpose of this study is to assess the usefulness of routine preventive contralateral pinning in SCFE, and to evaluate its complications.
We reviewed retrospectively 74 consecutive patients treated for unilateral SCFE by associated routine preventive contralateral pinning. The age at surgery ranged from 10 years and 6 months to 16 years and 10 months. The osteosynthesis was achieved by a single cannulated holothreaded screw with a cross grooved head, with or without the use of washers.
An accidental pin penetration was noted in 4 cases. The epiphyseal position of the screw was satisfactory in 56 cases. The patient was allowed to walk the second or third day after surgery with the use of crutches. All our patients were reviewed after the end of squeletal growth. The follow-up ranged from 2 to 12 years and 8 months. The age at which the patient was last seen ranged from 15 years and 7 months to 27 years. Two major complications were noted: a femoral fracture at the level of the screw penetration in one case, and secondary slipping of the epiphysis after premature removal of the screw in two cases. The removal of the screw was considered to be very difficult in 10 cases. A relative overgrowth of the greater trochanter was noted in 8 cases, and was of no clinical significance. No infection was noted. At last follow-up, the shape of the femoral head and the function of the hip were normal in all cases except for one hip where severe coxa vara developed because of a secondary slip after premature removal of the screw.
There is a lot of controversy about the real necessity of routine preventive contralateral osteosynthesis in SCFE. In our experience this surgery succeeded in reducing the incidence of secondary contralateral slipping. The two cases in our series could have been prevented by an accurate timing of screw removal. The complications of this procedure are rare, and it could be done during the same operative time as the SCFE side's. The only case of femoral fracture was secondary to a violent car accident.
The routine prophylactic controlateral osteosyntheis in SCFE, using a single screw is a safe procedure and allows to reduce the incidence of bilaterality.