All-inside, All-epiphyseal ACL Reconstruction in Skeletally Immature Athletes: Incidence of Second Surgery and Two-year Clinical Outcomes

Abstract

Objectives:Anterior cruciate ligament (ACL) injuries in skeletally immature athletes are increasing secondary to multiple factors that include increased participation and level of competition within sports, sports specialization and societal factors. Conservative treatment of these injuries has a poor natural history due to recurrent instability with meniscal and articular cartilage damage. The purpose of this study was to evaluate the 2 year clinical outcomes of an all-inside, all-epiphyseal ACL reconstruction in skeletally immature athletes with 3-6 years of remaining growth, with a focus upon return to play and the incidence of second surgery.Methods:Twenty-three skeletally immature athletes (mean chronologic age 11.8 yrs, [range 10-13]) were prospectively evaluated following an all-inside, all-epiphyseal ACL reconstruction utilizing hamstring autograft. The mean bone age (Greulich and Pyle method) was 12.1 years. There were 6 females and 17 males. Five athletes were involved in recreational sport and 18 participated competitively. Lacrosse (40%) and Soccer (27%) were the two most common sports associated with ACL injury in our cohort. All athletes were evaluated with a physical examination, KT-1000 arthrometry, isokinetic testing, and validated outcome scores including the International Knee Documentation Committee score (IKDC), the Lysholm score and Marx activity rating scale. Standing radiographs and SPGR MRI analysis was performed at 6, 12 and 24 months post-op depending upon skeletal age. A Return to Play performance analysis was also analyzed where symmetry, alignment control and the ability to decelerate were assessed during progressively challenging movement patterns encountered in sport.Results:At a minimum follow-up of 2 years (range 2-4.5), the mean IKDC score was 94.5 ± 5.4, the mean Lysholm score was 98.1 ± 4.1 and the mean Marx activity rating scale score was 12.8 ± 3.1. Lachman and pivot shift testing was negative in all patients. The mean side-to-side difference in the KT-1000 arthrometry was 1.0 ± 0.6 mm, with the maximum difference in the cohort being 2 mm. Isokinetic testing showed a mean deficit of 4.3% in extension torque and 9.1% in flexion torque at a repetition speed of 180 degrees per second. No angular deformities, significant leg length discrepancy or physeal disturbances were observed on postoperative radiographs or MRI. Two athletes (8.6%) required a second surgery: 1 (4.3%) had a traumatic graft disruption at 10 months and underwent revision ACLR and 1 (4.3%) required meniscectomy for an incompletely healed meniscal repair at 13 months. There were no contralateral injuries in this cohort of athletes. The mean time for return to unrestricted competitive activity after successful completion of the Return to Play analysis was 12.5 +/- 1.25 months from the time of surgery.Conclusion:An all-inside, all-epiphyseal ACL reconstruction technique using hamstring autograft demonstrates excellent subjective and objective clinical outcomes in skeletally immature athletes without growth disturbance. Return to Play assessment is an important tool to guide the young athlete and his or her family regarding resumption of competitive sports. In our experience, young athletes were on average released for full return to sport after 1 year from ACL reconstruction.