Brake Reaction Time After Hip Arthroscopy for Femoroacetabular Impingement and Labral Tear

Abstract

To determine if a difference exists in brake reaction time (BRT) before and after hip arthroscopyforfemoroacetabular impingement (FAI) and labral tear compared with age- and gender-matched controls. Consecutive adult subjects undergoing primary hip arthroscopy were eligible for this prospective investigation. Individuals with symptomatic FAI and labral tear that underwent hip arthroscopy with minimum 8weeks follow-up were included. BRT was measured using the RT-2S reaction time tester a maximum of 6weeks preoperatively and every 2weeks postoperatively for 8weeks. Sit-to-stand test (STST) was measured at each BRT testing session. An age- and gender-matched control group without hip or lower extremity symptoms were selected and completed both BRT and STST. Continuous pre- and postoperative BRT values were compared with Mann-Whitney and analyses of variance. Association of BRT and STST tests was performed with Spearman correlation. An a priori sample size calculation determined that minimally 18 subjects per group (surgery group vs control group) were necessary to detect, with 80% power (difference of 0.2seconds in BRT). Nineteen subjects (age 37.1 ± 12.7years, 10 women, 11 right hip) were analyzed. All subjects underwent arthroscopic labral repair and FAI correction. There was no difference between preoperative (604 ± 148milliseconds [ms]) and postoperative (608ms 2weeks; 566ms 4weeks; 559ms 6weeks; 595ms 8weeks) BRT. There was no difference between controls and subjects at any time point. There was a strong negative correlation between BRT and STST preoperatively and at 4 and 6weeks postoperatively and a moderate negative correlation at 2weeks postoperatively. After hip arthroscopy for FAI and labral tear, BRT is not different from preoperative values or that of controls. In addition, BRT had a significant correlation with STST in the first 6weeks after surgery. Level II, diagnostic, prospective.