Investigating the correlation between hip abductor muscle strength and width in anteroposterior pelvic radiographs in hip revision candidates following previous total hip arthroplasty: a cross-sectional study

The changes in strength of hip abductor muscles after total hip arthroplasty may depend on its anatomical parameters. In the present study the correlation between the strength of the hip abductor muscles before hip revision surgery and the diameter of the abductor muscles in the pelvic anterior posterior X-ray was investigated. METHODS: This cross-sectional study included the patients underwent hip arthroplasty and were candidates for revision surgery. The diameter of the hip abductor muscles on the affected and unaffected sides were calculated based on plain radiography. Patients were also clinically examined and their abductor muscle strength on both sides were determined based on Medical Research Council Manual Muscle Testing scale. RESULTS: A total of 51 patients were included in the study and after exiting 20 patients; finally 31 patients’ data were analyzed. Based on results there was a significant correlation between the ratios of muscle strength and muscle diameter in affected side to unaffected side (r=0.517, P=0.003). As indicated in Table 3, such significant association was revealed in men (r=0.719, P=0.001), but not in women (r=-0.092, P=0.754). Also, this relationship was found to be significant in patients older than 60 years (r=0.529, P=0.011), not in the younger. CONCLUSION: In patients undergoing total hip arthroplasty revision surgery, there is a strong association between the ratio of strength and diameter of the abductor muscles in the affected side to the unaffected side especially in men and older ages.