Late Instability of Bilateral Metal on Metal Hip Resurfacings Due to Progressive Local Tissue Effects

Reports have emerged of local debris consisting of metal particles, with the development of pseudotumours, pelvic masses, lymphocytic perivascular infiltration of tissue around the implant and a neo-capsule tissue reaction in metal on metal (MoM) hip arthroplasty. Steeply-inclined acetabular components a large abduction angle of more than 55 degrees along with a combination of small size component are likely to give rise to higher levels of metal ions. This report describes a case of localised tissue destruction of abductor muscle probably due to the metal debris causing late onset subluxation/dislocation of a hip resurfacing. Late instability of hip resurfacing should raise concerns relating to possible local tissue reaction and muscle damage, and early revision may be recommended.