O2365 CEMENTLESS MALLORY HEAD HA-COATED FEMORAL PROSTHESIS IN PRIMARY TOTAL HIP ARTHROPLASTY: CLINICAL AND RADIOLOGICAL RESULTS OF A 5 TO 11 YEARS PROSPECTIVE STUDY

Aims: The results of the Mallory Head prosthesis were already described after 10 years. About the hydroxy-apatite coated Mallory Head prosthesis almost no literature is known. We chose a hydroxyapatite coating because of the sealing effect according to Soballe. Methods: In this þrst European study, we followed 152 consecutive primary hip replacements in 126 patients with a proximal hydroxyapatite coated femoral prosthesis for 5.2 to 11.1 years. Results: All but two prostheses showed osseointegration. No osteolysis was seen even in cases with PE-wear. The mean Harris Hip Score increased from 40 (16 Ð 48) to 92 (10 Ð 100). No or only mild pain reported 97%, limping reported 11% postoperatively (90% preop). There was a very low incidence in thigh pain: 3.2%. The morphology of positive bone remodeling depended on the stem þt in the medullary canal. The correlation between tight stem þt and symmetrical cortical thickening was signiþcant (p ≤ 0.001 chi-square test). The same correlation existed between non tight þt and cancellous densiþcations. There was no correlation between the clinical parameters and the radiological phenomena. The 11 year survival was 98.7 (±6.4)%. Conclusion: TheMallory Head hydroxyapatite coated femoral stem has a reliable long-term survival and clinical and radiological result. The hydroxyapatite coating has a protective effect against wear particle migration. The morphology of remodeling depends on stem þt.