HETEROTOPIC OSSIFICATIONS IN POSTEROLATERAL-APPROACH TOTAL HIP REPLACEMENT: INCIDENCE, RISK FACTORS AND CLINICAL RELEVANCE

Introduc on: Heterotopic ossi ca ons (HO) are infrequent in total hip re- placement and in a small amount of pa ents may cause pain and func onal loss. They can be linked to individual predisposi on, comorbidi es, previous hip fractures and surgical access. Preven on is possible with medica on or radiant therapy. Surgery is possible but there’s an high relapse percentage. Objec ves: In this prospec c study we evaluated incidence of HO, clinical signi cance, associated risk factors in an eterogeneous group of pa ents un- derwent total hip replacement. Methods: We evaluated 350 pa ents underwent total hip replacement in our Department between January 2010 to December 2012. All surgery were performed with posterolateral surgical access without any pharmacological or radiant therapy. Brooker Classi ca on was used. Pa ent age, sex, comor- bidi es and rate of revision surgery were evaluated in Brooker III and IV. Results: HO were present in 35% of pa ents. Brooker III and IV were 7,18% (6,4% group III, 1,14% group IV respec vely). Average follow-up was 13,4 months. Average age was 68,1 years. Comorbidi es in pa ents with Brooker III were: 2 colon diver culosis, 5 prosta c ipertrophy, 9 dyslipi- daemies, 2 reumatoid artrhi s, 1 pevious tuberculosis e 1 monoclonal gammopaty. Comorbidi es in group IV were 1 reumatoid artrhi s and hip fracture, 1 non Hodgkin linfoma, 1 mul ple sclerosis e 1 ulcera ve coli s. 5 pa ents with Brooker III presented pain at extreme hip mobiliza on, while 2 with Brooker IV pain and func onal limita on. 2 pa ents with Brooker IV underwent surgery to HO exeresis. Conclusions: Signi ca ve HO (Brooker III and IV) in posterolateral surgical access are rare but can be related to pain and func onal limita on. When performing a total hip replacement in pa ents with previous hip neck fractures or chronic in ammatory diseases should be useful a pharmacologi- cal or radiant prophylaxis regardless of sex and age