Table 1.

Summary of the most relevant finding in literature.

Author	Year	Results
Schmidt et al. [15]	1988	Indomethacin is especially recommended for patients who are at high risk for HO.
Wright et al. [16]	1994	The severity of HO did not correlate with the HHS; the relationship between HO and range of motion (ROM) indicates that the Brooker index is a valid measurement.
Fingeroth et al. [17]	1995	A single dose of 6 Gy of radiation given within the first 3 postoperative days provides effective prophylaxis against HO.
Seegenschmiedt et al. [18]	2001	Both preoperative (within 24 h) and postoperative RT (within 72 h) are effective in preventing HO after hip surgery.
Saudan et al. [13]	2007	Celecoxib was more effective than ibuprofen in preventing heterotopic bone formation after total hip replacement.
Xu et al. [11]	2014	Considering the side effects of nonselective NSAIDs, selective COX-2 inhibitors were recommend for the prevention of HO after THA.
Lavernia et al. [9]	2014	A short course of celecoxib for pain aids in the prevention of HO after primary THR.
Winkler et al. [8]	2016	Etoricoxib and diclofenac are equally effective for oral HO prophylaxis after primary cementless THA when given for nine peri-operative days.