Early Breakage of All Proximal Locking Compression Screws under Non-weight-bearing Conditions after Derotational Femoral Osteotomy in a Child with Cerebral Palsy: A Case Report.

[INTRODUCTION] The locking compression plate (LCP) system for pediatric hips has improved fixation and angular stability. Herein, we report a rare case in which all proximal locking compression screws were broken before weight bearing in the early post-operative period after derotational femoral osteotomy in a child with spastic cerebral palsy (CP).

[CASE REPORT] Derotational femoral osteotomy was performed using a LCP system for a 9-year-old boy with spastic CP to correct excessive femoral anteversion, causing unstable toe-in gait. Proximal screw breakage was found 2 weeks postoperatively during hip-spica casting under non-weight-bearing conditions. Implant breakage was considered a result of the excessive spasticity of the lower limb. At the time of reoperation, shortening and varus correction of the femur and muscle tendon release were performed in addition to the refixation of the osteotomy. Intensive pain control was ensured, and anti-spastic medication and botulinum toxin injection were administered. Complete bone healing was successfully achieved 6 months after the second surgery.

[CONCLUSION] Surgeons need to consider the spasticity of the lower limb as a cause of implant failure. Management to reduce spasticity and mechanical load to the implant is important for preventing implant failures in patients with spastic CP.