Clinical outcome of Bioball universal adapter in revision hip arthroplasty

Removal of a well-fixed uncemented femoral component in revision hip arthroplasty is challenging. A modular head-neck adapter provides an option to optimise the femoral offset and anteversion, avoiding the need for femoral stem revision.

To present the clinical results following revision arthroplasty with the Bioball head-neck adapter in the elderly American Society of Anaesthesiologists (ASA) Grade II, III & IV patients.

A retrospective review of our database was performed, and all patients classed as ASA grades II, III, & IV treated with the Bioball Universal Adapter (BUA) for 10 years were included. The indication for revision, stem retention, type of adapter, and head size were identified. Patients were contacted by a research nurse to assess the Forgotten Joint Score (FJS), the Oxford Hip Score (OHS), and any symptoms of instability at a minimum of one year post revision surgery.

Our study included 47 patients. 5 (10.6%) were ASA II, 19 (40.4%) were ASA III and 23 (49%) were ASA IV. The mean age was 74 years. The mean follow up was 52 months ± 28.4 SD. The median FJS was 86 ± 11.6 SD. The median OHS was 43 ± 6.2 SD. One patient (2.1%) developed recurrent dislocation following lumbar spinal fusion. None of the other patients experienced instability. The survival rate for the adapter was 98%.

The BUA gives good clinical outcomes with very low post revision instability. It is a valuable option for the elderly because it avoids the morbidity and risks associated with the removal of a well-fixed femoral stem.

Level IV.