Sex Differences in Outcome After an Acute Achilles Tendon Rupture

Abstract

Background: Tendon healing differs between the sexes. Comparisons in outcome between the sexes after an Achilles tendon rupture are often not possible because of the small cohort (<20%) of women. Purpose: To evaluate whether there are any differences in outcome between the sexes by combining the data from 2 large randomized controlled trials that used identical outcome measures. Study Design: Cohort study; Level of evidence, 3. Methods: Included in the evaluation were patients from 2 consecutive randomized controlled trials comparing surgical and nonsurgical treatment performed at our research laboratory. Patients who had a rerupture were excluded from analysis. A total of 182 patients (152 males, 30 females), with mean ± SD age of 40 ± 11 years, were included; 94 (76 males, 18 females) were treated with surgery and 88 (76 males, 12 females) nonsurgically. Patient-reported outcome was evaluated using the Achilles tendon Total Rupture Score (ATRS), and the functional outcome was measured with a heel-rise test (measurement of muscular endurance and heel-rise height) at 6 and 12 months after injury. Results: Male patients had a greater improvement in heel-rise height at 12 months ( P = .004). When each treatment group was analyzed separately, it was found that female patients had significantly ( P < .03) more symptoms after surgical treatment (mean ± SD ATRS, 59 ± 24) compared with males at 6 (73 ± 19) and 12 months (74 ± 27 vs 86.5 ± 17). This sex difference was not found in the nonsurgical treatment group. For the entire group, there were no significant differences between treatments on ATRS at 6 and 12 months. The surgical group had significantly better results compared with the nonsurgical group in heel-rise endurance at 6 and 12 months and in heel-rise height recovery at 6 months ( P < .03 for both). Conclusion: Sex differences were demonstrated, and female patients had a greater degree of deficit in heel-rise height as compared with males, irrespective of treatment. Females had more symptoms after surgery both at 6 and 12 months, but this difference was not found when treated nonsurgically. Clinical Relevance: Further research is needed to determine whether women will benefit more from nonsurgical compared with surgical treatment after an Achilles tendon rupture.