複雑な寛骨臼再建のための3Dプリント技術の活用：小児股関節外傷から個別化された現代的ソリューションまで

Revision total hip replacement (THR) in young patients is challenging due to higher functional demands, altered anatomy from prior pathology, and increased risk of implant failure. Severe acetabular bone loss, especially following childhood hip trauma and previous reconstruction, further complicates revision procedures. Advances in three-dimensional (3D) printing now enable patient-specific implants that improve implant fit, stability, and surgical precision.

A 36-year-old female with a history of childhood hip trauma and a left THR performed 4 years earlier presented with progressive hip pain and functional decline following a fall. Examination revealed Trendelenburg gait, painful global restriction of hip movements, joint line tenderness, and limb length discrepancy. Radiographs showed superior migration and failure of the acetabular component and metal augment. Metal artifact reduction system computed tomography (CT) demonstrated extensive superolateral and medial pelvic bone loss. A staged revision was planned. Stage one involved implant removal and placement of a cement spacer. Repeat 3D reconstruction CT was used to generate a patient-specific 3D pelvic model, guiding the design of a customized 3D-printed acetabular implant. Stage two involved implantation of the custom component with fluoroscopic guidance.

Postoperatively, weight-bearing was delayed, followed by structured rehabilitation. The patient showed a decrease in visual analog scale pain score from 8 to 3 and an improvement in Harris Hip Score from 30.45% to 60.65%. She remained complication-free but was lost to follow-up after 6 months.

Staged revision THR supported by advanced imaging and personalized 3D-printed implants offers a viable solution for managing complex acetabular defects in young patients. Early outcomes demonstrate improved stability and function, although long-term validation is needed.