Second Anterior Cruciate Ligament Injuries After Anterior Cruciate Ligament Reconstruction in Professional Sumo Wrestlers: A Case Series

BACKGROUND: Anterior cruciate ligament (ACL) injury is one of the most common traumatic injuries in professional sumo wrestlers. Further, ipsilateral reinjuries or contralateral ACL injuries after ACL reconstruction can occur in sumo wrestlers. The incidence of ipsilateral reinjury and contralateral ACL injury after ACL reconstruction ranges from 3% to 13% in a healthy athletic population. PURPOSE: To investigate the current status of second ACL injuries after ACL reconstruction in sumo wrestlers. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Between 1988 and 2015, a total of 139 primary ACL reconstructions were performed in professional sumo wrestlers at our hospital. After exclusion of cases of multiple ligament knee reconstruction and patients in whom the contralateral ACL had been injured previously, 110 cases were included in this study. We investigated the number of second injuries, time from primary reconstruction to second injury, treatment method, and change in official sumo ranking after second injuries. The chi-square test, Student t test, and Fisher exact text were used for statistical analysis. RESULTS: Among 110 wrestlers who underwent ACL reconstruction, second injuries after primary ACL reconstruction occurred in 22 cases (20.0%). Among them, 14 cases (12.7%) entailed ipsilateral reinjury, 11 (10.0%) entailed contralateral injury, and 3 involved combined rerupture and contralateral injury. As for surgical treatment, 5 revision ACL reconstructions were performed for ipsilateral reinjury (35.7%), and 7 ACL reconstructions were performed for contralateral injury (63.6%). Surgical treatment was not performed for the remaining cases. Wrestlers who were treated by revision or contralateral ACL reconstruction after the second injury were demoted in rank for 3 to 4 tournaments but overtook the nonoperative treatment group in ranking by 2 years postoperatively; all athletes initially were demoted in rank after the second injury. CONCLUSION: This study is the first to investigate instances of ipsilateral reinjuries and contralateral ACL injuries after ACL reconstruction in professional athletes in heavyweight combat sports. The incidences of ipsilateral reinjury and contralateral ACL injury after ACL reconstruction in professional sumo wrestlers were relatively higher than those reported in previous studies.