What are the risks of prophylactic pinning to prevent contralateral slipped capital femoral epiphysis?

BACKGROUND

Two decision analyses on managing the contralateral, unaffected hip after unilateral slipped capital femoral epiphysis (SCFE) have failed to yield consistent recommendations. Missing from both, however, are sufficient data on the risks associated with prophylactic pinning using modern surgical techniques.

QUESTIONS/PURPOSES: We determined the incidence and nature of complications after contemporary prophylactic fixation of the contralateral, unaffected hip in patients with a unilateral SCFE.

METHODS

We retrospectively identified and reviewed 99 children (mean age, 11 years; range, 8-15 years) who underwent prophylactic pinning of the contralateral hip after treatment of a unilateral SCFE at four tertiary-care children's hospitals from 2001 to 2010. Complications on the prophylactic side, such as avascular necrosis (AVN), chondrolysis, fractures, implant pain, and need for further surgery, were recorded. Minimum followup was 12 months (median, 26 months; range, 12-110 months).

RESULTS

On the prophylactic side, we found two cases of focal AVN (2%) and no cases of chondrolysis (0%). Two patients sustained periimplant femur fractures (2%). Three patients had symptomatic hardware (3%), two of whom required surgery for implant removal. In three patients (3%), growth occurred off the end of the prophylactic screw before physeal closure, but they did not require revision fixation. No patients developed a subsequent slip on the side of the prophylactic pinning.

CONCLUSIONS

While prophylactic pinning prevents SCFE, it is not an entirely benign procedure. The possibility of developing complications such as AVN and periimplant fracture should be considered when determining the best management for the contralateral hip in patients who present with unilateral SCFE.

LEVEL OF EVIDENCE: Level IV, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.