Women run a 4-8-fold greater risk of anterior cruciate ligament (ACL) tear than men, and especially during the pre-ovulation stage of their cycle. The main study objective was to describe the distribution of ACL lesions according to menstrual cycle in a large population of female recreational skiers.

A prospective study was conducted during the 2010–11 ski season on women sustaining ACL tear during skiing. Patients filled out a questionnaire during consultation with the mountain physician, including date of last menstrual period (LMP) and contraceptive method. Fifty-seven of the 229 patients with diagnosed ACL tear were excluded from analysis, 41 being post-menopausal (mean age, 47±9years), and 16 having irregular cycles or LMP>30days. One hundred and seventy-two patients (mean age, 34±8.7years) were thus included.

Fifty-eight women (33.72%) were in follicular phase, 63 (36.63%) in ovulatory phase and 51 (29.65%) in luteal phase; difference with respect to the theoretic distribution regardless of menstrual phase was highly significant: χ²=48.32; P=0.00001. Fifty-three of the 172 women (30.8%) were taking oral contraceptives. ACL tear was 2.4-fold more frequent in pre-ovulatory than post-ovulatory phase, whether in women using oral or other contraceptives: 85/119 (71.4%) vs. 36/53 (67.9%); P=0.64.

ACL tear risk in skiing in women is not constant over the menstrual cycle, being 2.4–fold more frequent in pre-ovulatory (follicular and ovulatory) than post-ovulatory phase (luteal). Oral contraception seems not to exert any protective effect.

Level IV. Retrospective cohort study.