15 Year Survival Of Endoscopic Anterior Cruciate Ligament Reconstruction In Patients Aged 18 Years And Under

OBJECTIVES: The incidence and risk factors for further anterior cruciate ligament (ACL) injury after ACL reconstruction have been examined in adults but not in juveniles. The aim of this study was to determine the long term survival of the ACL graft and the contralateral ACL (CACL) after primary reconstruction in those 18 years and under, and to identify the factors that increase the odds of subsequent ACL injury over the long term. METHODS: All patients having undergone primary ACL reconstruction at the age of 18 or less between January 1993 and December 1998 by a single surgeon in a single unit were considered. ACL reconstruction was performed using a single-incision endoscopic technique with either autologous bone-patellar tendon-bone graft (BPTB) or hamstring tendon graft (HT). Femoral tunnel drilling was performed via the anteromedial portal. Patients were contacted to complete a subjective interview by telephone or online questionnaire at a minimum of 15 years after the index surgery. RESULTS: A total of 288 juveniles met the inclusion criteria of which 237 (82%) were reviewed at a mean of 16.6 years after ACL reconstruction. The mean age at the time of surgery was 16 years (13-18). Subsequent ACL injury occurred in 29% of juveniles. 16% of suffered an ACL graft rupture, 19% suffered a CACL rupture and 5% ruptured both the graft and CACL. Expected survival of the ACL graft after reconstruction was 93%, 89%, 87% and 85% at 2, 5, 10 and 15 years, respectively. Expected survival of the CACL was 97%, 90%, 84% and 82%, respectively. Survival of the ACL graft was less favourable in those with a positive family history (73% versus 91%, p = .001). Survival of the CACL was less favourable in males than in females (77% versus 87%, p = .05). Graft source, age at surgery and graft diameter did not significantly increase the odds of graft or CACL rupture. The mean International Knee Documentation Committee (IKDC) subjective score at 15 years was 88. Return to preinjury sport level was reported in 69% of patients and 65% were still participating in strenuous or very strenuous activities at a mean 16 years post-reconstruction. CONCLUSION: After ACL reconstruction in those aged 18 years or less, further ACL injury occurred to 1 in 3 over 15 years. The expected 15 year survival of the ACL graft was 85% and expected 15 year survival of the CACL was 82%. Family history of ACL rupture significantly increased the odds of ACL graft rupture. CACL injury was more common in males than females. High subjective scores and continued participation in sports were maintained over the long term after ACL reconstruction in the juvenile population.