Failure Modes of Screw Fixation in Slipped Capital Femoral Epiphysis: A Proposed Life-Cycle Classification

Screw fixation is the standard surgical treatment for slipped capital femoral epiphysis. Screw-related adverse events, including implant breakage, joint penetration, fixation failure, growth-mediated construct change, removal failure, and postremoval fracture, are inconsistently reported throughout the pediatric orthopaedic literature. In this current concept review, we propose a practical, life-cycle classification encompassing implant insertion, in vivo fixation, growth and remodeling, implant removal, and postremoval follow-up. Reported screw-related failures cluster into four practical evidence domains: placement-related risk, construct-longevity failure, mechanical implant failure, and removal/postremoval complications. These domains are organized into seven chronological life-cycle categories. A four-domain synthesis mapped to a seven-stage life-cycle classification provides a practical framework and shared vocabulary for preoperative counseling, implant selection, postoperative surveillance, removal planning, and standardized reporting. Key Concepts: (1)Screw-related failures after pediatric proximal femoral fixation are heterogeneous and can occur at any point in the implant life cycle, from insertion through long-term postremoval follow-up.(2)Reported failures can be grouped into four practical evidence domains: placement-related risk, construct-longevity failure, mechanical implant failure, and removal/postremoval complications, which map to seven chronological life-cycle categories.(3)Construct-level decisions, including single- versus two-screw fixation, screw-thread configuration, and implant material, entail different trade-offs across the insertion, fixation, growth, and removal stages.(4)Because pediatric proximal femoral fixation is performed in a growing skeleton, the relationship among the screw, physis, epiphysis, and femoral neck may change over time, warranting continued surveillance even after technically successful fixation.(5)Implant removal is a distinct failure window; removal-related and postremoval complications should be anticipated during preoperative counseling rather than assumed to be benign.