303. REVISION TOTAL HIP ARTHROPLASTY USING A NON-CEMENTED MODULAR STEM (PP): CLINICAL AND RADIOGRAPHIC OUTCOME AT MEAN NINE YEARS FOLLOW-UP

Abstract

Purpose of the study: We report the clinical and radiographic results of a series of revision total hip arthroplasties performed for aseptic loosening using a non-demented modular femoral implant (PP).

Material and methods: From 1991 to 2003, 146 revisions of total hip arthroplasty were performed using the same non-cemented modular femoral implant (PP). At mean nine years follow-up (3.5–17 years), 24 patients had died, 26 had insufficient data for review and 39 were lost to follow-up. The analysis thus included 54 cases. All revisions were performed for aseptic loosening. Mean age at surgery was 60 years. Preoperative bone damage, according to the Sofcot classification, was grade I and II (69%), grade III (26%), grade IV (5.5%). Clinical outcome was assessed with the Harris and Postel-Merle-d’Aubigné scores. The radiological review analysed stem anchoring, lucency and periprosthetic reconstruction.

Results: At mean nine years follow-up, the mean Harris score was 71 points, the mean PMA score 12.8 points. Patient satisfaction was 70%. There were five cases with deep infection (9%), five with dislocation and six intra-operative periprosthetic fractures. Trochanterotomy non-union was noted in 26% of patients. Mean impaction of the femoral stem was 5 mm (range 0–16 mm). There was a statistically significant association between the degree of bone damage and the quality of the bone reconstruction (p=0.012). Mean increase in cortical thickness in zones 1 and 2 (Gruen) was 1.1 mm and 1.6 mm respectively. In Gruen zones 2 and 6, the gain was 6 and 10 mm respectively. There were nine surgical revisions (17%) for deep infection (n=4), recurrent aseptic loosening and fracture of the femoral implant (n=1). The ten-year survival taking aseptic loosening as the endpoint was 90%.0

Discussion and Conclusion: Our work showed the good long-term results obtained with this implant for revision total hip arthroplasty. It allows clinical improvement, periprosthetic bone reconstruction and a low rate of surgical revision.