Dynamic Intraligamentary Stabilization (DIS) Repair for ACL Ruptures in Pediatric and Adolescent Patients: An Initial Pilot Study with Long-Term Follow Up

<b>Background/Objectives</b>: The aim of this study was to report first experiences with dynamic intraligamentary stabilization (DIS) technique for anterior cruciate ligament (ACL) rupture in children and adolescents. <b>Methods:</b> A case series of 22 children and adolescents with a mean age of 13.3 years underwent primary repair of an ACL rupture using the DIS technique as an off-label use in skeletally immature patients. Patients were evaluated for laxity, strength, range of motion (ROM), and functional tests, as well as Tegner, Lysholm, International Knee Documentation Committee (IKDC), and PedsQL scores after 3 years. A follow up after 11 years was conducted to analyze long-term results, rerupture rates and reinterventions. <b>Results</b>: Three years after surgery, there was no significant difference in laxity, strength, ROM, and in the functional tests comparing the injured to the contralateral knee. The Tegner Index after surgery showed a slight drop of 0.8 points, from 7.1 preoperatively to 6.3. Mean IKDC, Lysholm, and peds-QL scores were 91.17 (range 62.64-98.85, median 94.25), 88.27 (range 58-100, median 93), and 88.78 (range 58.15-100, median 91.30). Overall failure rate of the DIS-repaired knees was 55% (12 of 22 patients). In ten patients, reruptures happened at an average time of 3.2 years after initial surgery; additionally, two patients with chronic instability had to undergo revision ACL reconstruction. <b>Conclusions</b>: DIS repair might help ACL healing with satisfactory functional outcomes. However, given the high failure and reintervention rates, further studies need to show non-inferiority of the DIS technique in children and adolescents before being considered a valid treatment option.