Abstract: Background: The study aims at providing Incidence rates with the use of posterior approach and the role of gender in development of HO after total hip arthroplasty in an Indian scenario.
Methods: 401 patients who had underwent total hip arthroplasty using posterior approach were studied retrospectively with the help of X-rays after a stipulated period of 12 weeks from the hospital database. The X-rays which were studied for any evidence of Hetertopic ossification and if present HO was classified using Brookers classification. The incidence rates were thus calculated along with incidence of each of the subtypes of HO with the use of posterior approach. The predisposition of sex for development of HO were noted.
Results: Evidence of HO was found in 32.9 percent of cases (132/401) with the incidence of type 1 - 24.4 % (98/401), type 2 - 6.4% (26/401), type 3 - 1.9% (8/401), type 4- Nil. The male to female ratio of total hip arthroplasty was found to be 65.08 % percent (261/401) males as compared to 34.92 percent females (140/401). Among males 35.63 % (93/261) percent of patients developed HO and among females 27.85 percent (39/140) of patients developed HO. Also out of the 401 hips replaced 370 were uncemented THRs and 31 were cemented THRS. 36.67 % (136/370) developed HO in uncemented implants and 29.03 % (9/31) developed HO in cemented implants.
Conclusion: The study demonstrated an incidence of 32.9% HO after primary THA in Indian population after using posterior approach with its incidence being higher in males.
