HA-coated hip implants: A 10 year follow-up

Summary

We started using HA-coated hip prostheses on May 1997 and our personal experience reaches to date 2075 HA hips of which 1898 were primary hips. This study was based upon a consecutive series of 134 consecutive HA cases implanted from May '87 until December '88, at the Clinique Médico-Chirurgicale of Bruay-Labuissière, France. No patient was lost to follow up. 26 patients deceased and of the 104 remaining cases, 58 complete dossiers were available for addressing clinical and radiological scored results. Within the 58 over 10 year cases cohort, mean age was 56 years. Main aetiology was osteoarthritis in 81% and necrosis in 17%, 1 case was a revision one. Femoral component was HA Omnifit stem in all the cases, fitted with Arc 2f cup. No case of loosening nor any mechanical failure was observed within this over 10 yr of FU series, since 4 reoperations were related to 2 stiffnesses and 2 recurrent dislocations with neither retrieval of acetabular nor femoral component.

As regards radiographic findings, femoral lysis over 10 yr was none in 48%, limited to neck area in 28%, proximally extended in 24%, as no case of distal lysis was observed. 88% of cups had no lysis at 10 yr of FU. All our 58 “10 yr+” cases belonged to the “ingrowth confirmed” group. Mean values of HHS scores were preoperatively 33.34 ± 12.46 out of 100 pts preoperatively up to 97.6 pts at 10 year. Thus results were “excellent” in 86%, “good” in 9%, “fair” in 5%, and “poor” in 0%. Mean values according to Merle d'Aubigne score (MDA) were 7.98 ± 1.74 pts out of 18 preoperatively up to 16.90 pts at 10 yr, leading to 84% of “excellent”, 11% of “good”, 5% of “fair” and 0% of “poor” results.

When considering the cumulative survival analysis since 1987, the results at 10 year, based upon the 1922 primary cases reaches 0.9889 ± 0.0061 when considering all types of failures (Mechanical loosening + Clinical failure + Radiological failure). While considering a 10 year follow-up period as a major milestone in terms of hip results, the results of this series may look very encouraging and lead us to remain confident in bioactive coatings.