ACL injury mechanism in elite and recreational handball players.

PURPOSE: Anterior cruciate ligament (ACL) injuries are among the most severe knee injuries in handball, often resulting in surgical reconstruction and prolonged rehabilitation. Research on specific ACL injury mechanisms remains limited, though essential for prevention. The aim of this study was to investigate ACL injury mechanism in handball players. METHODS: A registry-based study identified patients in the Danish National Patient Register with International Classification of Diseases (ICD) codes S835 (cruciate ligament lesion) and M235 (chronic knee instability) between 2000 and 2018. Players completed a questionnaire on ACL injury mechanism, and only handball-related cases were included. RESULTS: Of 90,608 registry-identified patients invited to participate, 40,691 responded (45%); 26,627 reported an ACL injury, of whom 4540 reported sustaining the injury while playing handball. Most injuries were non-contact (55%), frequently occurring during pivoting actions (25%) and single-leg landings (11%). Female players reported significantly more non-contact injuries (p = 0.011). Indirect contact not involving the injured knee accounted for 31% of injuries. Players were in ball possession in 80% of cases, mainly while feinting (32%) or shooting (30%). Most ACL injuries (86.1%) occurred on the opponent's half of the court during offensive play, particularly between the opponent's goal-area and free-throw lines (38.1%). Back-line players accounted for 61% of ACL injuries. Male players reported more injuries during counterattacks (p < 0.001). Players aged 40 years or older had more injuries as goalkeepers compared with other positions (p < 0.001). CONCLUSION: Non-contact movements were the most common ACL injury mechanism in handball, followed by indirect contact not involving the injured knee. Injuries predominantly occurred during ball possession, particularly while feinting or shooting. Most injuries occurred during offence and among back-line players. LEVEL OF EVIDENCE: Level II.