Abstract
BACKGROUND: The incidence of anterior cruciate ligament (ACL) injuries is commonly reported as an annual incidence rate. There is relatively little information about the seasonal aspects of these injuries. The aim of the current study was to analyze the distribution of ACL injuries during the season in nonprofessional soccer, handball, and basketball based on a retrospective analysis of a hospital-based registry. HYPOTHESIS: ACL injuries in soccer, handball, and basketball were more common within the first 2 months of the season in comparison with the rest of the year. STUDY DESIGN: Case series. LEVEL OF EVIDENCE: Level 4. METHODS: Injury occurrence during the calendar year was divided into 6 periods of 2 months, with segment 1 (S1) representing the first 2 months of the season. For soccer, S1 corresponded to September and October. The season started 1 month later for handball and basketball, so S1 represented October and November. Chi-square tests were used to analyze the distribution of ACL injuries among segments according to gender, age, sports, and injury mechanism (contact/noncontact). RESULTS: A total of 371 ACL injuries were included (soccer, 258, handball, 56, basketball, 57). Overall, the distribution of ACL injuries was not uniform across the segments (P < 0.01). Almost one-third of the ACL injuries occurred in S1 (n = 104; 28%). Significant differences could be observed according to sports (P < 0.01). There were fewer ACL injuries in S2 for soccer compared with basketball (P < 0.05). In S5, there were significantly more ACL injuries in soccer compared with handball and basketball (P < 0.05). CONCLUSION: A high occurrence of ACL injuries was reported immediately within the first 2 months of the season in nonprofessional soccer, handball, and basketball sports. CLINICAL RELEVANCE: These findings indicate that ACL injury prevention programs should be started in the preseason period to allow for gradual increases of load.