Abstract
Introduction: Metal-on-metal hip resurfacing arthroplasty is recommended for younger patients with advanced hip disease who are likely to outlive a conventional primary total hip arthroplasty and wish to be reasonably active. Intraoperative or immediate postoperative femoral neck fracture is a well described technical complication as a result of notching and stress shielding of the femoral head. We report two cases of femoral neck fracture incurred eight to fifteen months following the index operation.
Case 1: A 47 year old lady was admitted after sustaining a fall. Radiograph confirmed left femoral neck fracture with resurfacing prosthesis in situ. She underwent metal-on-metal surface hip replacement 15 months ago for advanced osteoarthritis. The periprosthetic fracture was treated by revising the femoral component, using Eurocone cormet modular endo head 44mm size. At one year follow up, she was able to mobilise unassisted and had a good range of movements.
Case 2: A 52 year old gentleman presented with a painful right hip. While walking in the supermarket, he suddenly felt a click in the right hip. Radiograph confirmed right femoral neck fracture with resurfacing prosthesis in place. The metal-on-metal surface hip replacement was performed 8 months previously for advanced avascular necrosis. His medical history was significant for epilepsy. The Femoral component was revised, using Eurocone cormet modular endo head 52mm. He made a satisfactory progress at 18 months follow up since his periprosthetic fracture.
Conclusion: We recommend that patient selection should be given prime importance before embarking on metal on metal surface hip replacement. The surgeons’ factors are meticulous technique in preventing neck notching and femoral head fixation in varus angulation. Revising femoral component, using large head and leaving resurfaced cups in place should be considered as mode of treatment. Large multicentric trials are needed to evaluate the exact incidence of periprosthetic fractures in metal on metal hip resurfacing
The abstracts were prepared by Mr Peter Kay, Editorial Secretary. Correspondence should be addressed to British Hip Society, The Hip Centre, Wrightington Hospital, Appley Bridge, Wigan, Lancashire WN6 9EP.
