Incarcerated Cannulated Cancellous Screw Removal during Total Hip Arthroplasty with a Novel Trick: A Case Report

ABSTRACT

@#Salvage total hip arthroplasty (THA) may be required to manage femoral neck fracture implant failures, avascular necrosis and secondary hip arthritis. Cannulated cancellous screws can become stripped or incarcerated during the initial implantation and pose hardware removal issues. We present a novel technique for safe screw removal in a 62- year-old female patient with a painful right hip. She had undergone cancellous screw fixation for a fracture of the neck of femur ten years ago. There was avascular necrosis with screw cut out leading to secondary hip arthritis necessitating THA. Intra-operatively cannulated cancellous screw along the inferior femoral neck region was incarcerated. After posterior dislocation of the head, the neck was osteotomised, and the screw threads were exposed for possible extraction. However, the thickened femoral neck region with solid cortical bone prevented the screw disengagement in either direction. The screw along the femoral trochanter region was cut with a Harrington cutter and the remaining screw disengaged with careful removal of bony spicules and controlled anticlockwise rotations, to remove the screw in around fifteen minutes. Arthroplasty could be completed uneventfully thereafter. We could remove the screw while avoiding an iatrogenic fracture along the calcar region and excessive bone loss along the screw track. The femoral canal remained uncompromised. The anticipation of a difficult implant removal with a thorough understanding of the devices and techniques, is an invaluable asset to the operating surgeon. With a simple tool and novel technique in a difficult situation, we can save on operating time and minimise complications.