Femoral lysis after cemented hip arthroplasty.

The cause of femoral lysis after cemented total hip arthroplasty is unknown. Clinical aspects are poorly understood, and there have been only a few reports, with small numbers of cases, in the literature. The author analyzed common factors and clinical aspects in 51 cemented hip arthroplasties with lysis around the femoral component, in an effort to understand the cause of lysis. The process frequently starts where metal abuts against bone or where cement is deficient or fractured. Men are more commonly affected than women (4:1). Pain is the only symptom, but lysis can occur without pain. Lysis is progressive and always culminates in implant loosening. Progression is usually slow but can be alarmingly rapid. Twenty-six percent of cases in this series had associated acetabular loosening. After bilateral hip arthroplasty, lysis can be bilateral but usually is not. The major causative factor may be microfragmentation of any of the component parts of the artificial joint complex.