Abstract
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.
Theses abstracts were prepared by Mr Peter Kay. Correspondence should be address to him at The Hip Centre, Wrightington Hospital, Appley Bridge, Wigan, Lancashire WN6 9EP.
