Aims: To study clinical and radiological outcome of acetabular revision in THR with porous, hydroxyapatite-coated cups.

Methods: 50 acetabular revisions (48 patients) operated by single surgeon were reviewed. Uncemented, hydroxyapatite coated cup (Mallory/Head, Biomet) was used. Preoperative acetabular bone loss graded by Paprosky’s classification (grade 1: 12, grade 2a: 26, grade 2b: 8, 2c: 2, grade 3a: 2). Acetabulum alone was revised in 22 hips. Duration of follow up: 35 months (24–52). Clinical outcome assessment was done using Merle d’Aubigne and Postel score & QALY index questionnaire. Radiological assessment by standard X-rays taken at the latest review date. No case was lost to follow up.

Results: Merle d’Aubigne & Postel scores improved from 2.1, 2.7 and 2.4 (pre-operative) to 5.0, 4.3 and 4.5 (post-operative) respectively with significant improvement in QALYs scores. Radiological assessment showed no mechanical failures. Good trabecular formation between HA-coating and the bone seen in the majority. Non-progressive radiolucency < 1mm in 6 cases, superior migration > 2 mm in 3 cups where bone graft was used, and < 2mm migration in 9 cups was noted. 2 cases had rerevision for recurrent dislocation.

Conclusions: Hydroxyapatite coating on the implant may enhance bony ongrowth at bone-implant interface giving additional stability. Good midterm results obtained in our study using hydroxyapatite-coated components favour the use of this type of cup in acetabular revisions for moderate bone loss, but a long-term follow up is essential.