Abstract
INTRODUCTION: Interference screws are commonly used implants, particularly in arthroscopic cruciate ligament reconstruction, where they achieve fixation by compression and friction rather than by threads. We report a case of a sunken interference screw, used as a stopper during core decompression and autologous adult live-cultured osteoblast (AALCO) injection for avascular necrosis (AVN) of the hip, which was successfully managed using a minimally invasive instrument-assisted retrieval technique. CASE REPORT: A 67-year-old male with bilateral hip AVN underwent bilateral core decompression and AALCO injection. After track preparation and drilling of the necrotic areas in the femoral head with an 8 mm reamer, an 8 mm interference screw was inserted before injection of the AALCO. The screw migrated into the femoral neck and became sunken, complicating retrieval. Using a combination of standard orthopedic operating room instruments, i.e., without specialised instruments for retained implant removal, the screw was retrieved without additional morbidity. The AALCO was injected as planned, and the patient had an uneventful post-operative recovery. CONCLUSION: A sunken interference screw in the proximal femur is a rare but challenging intraoperative complication. Our retrieval method using readily available instruments offers a safe and reproducible solution in such scenarios.