Cobalt chrome alloy is commonly used in joint replacement surgery. However, it is recognised that some patients develop lymphocyte mediated delayed type hypersensitivity (DTH) responses to this material, which may result in extensive bone and soft tissue destruction.
A total of 606 DNA samples, from 397 males and 209 female patients, were typed. This included 176 from patients with failed prostheses, and 430 from asymptomatic patients at a mean of >10 years follow up. C-index and ROC(t) scores suggested a high degree of discrimination, whilst the IBS indicated good calibration and further backed up the indication of high discriminatory ability. At ten years, the weighted mean survival probability error was < 4%. At present, there are no tests in widespread clinical use which use a patient's genetic profile to guide implant selection or inform post-operative management. The algorithm described herein may address this issue and we suggest that the application may not be restricted to the field of MoM hip arthroplasty.
Resurfacing hip arthroplasty is a successful option for the treatment of the young and active patient with hip arthritis. However, it is complicated by femoral neck fracture and avascular necrosis, which result from devascularisation during surgery. Devascularisation maybe caused by thermal necrosis. Thermal necrosis of bone has been shown to occur in temperatures of 47°C and above. We investigated the temperatures generated during femoral head preparation to see if the temperatures reached were great enough to induce osteonecrosis.