SEMITENDINOSUS AUTOGRAFT VERSUS COMBINED SEMITENDINOSUS AND GRACILIS AUTOGRAFT FOR ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION: A COMPARISON OF FUNCTIONAL AND SELF-REPORTED OUTCOMES IN ADOLESCENT PATIENTS

Autograft selection for anterior cruciate ligament (ACL) reconstruction in adolescents remains controversial. Hamstring tendon grafts are commonly used and depending on surgical technique, the semitendinosus tendon can be harvested and prepared as a quadrupled graft construct alone (ST) or in combination with the gracilis tendon (ST&G). The purpose of this study was to investigate differences in patient-reported knee outcome scores and objective knee functional outcome variables following ACL reconstruction in adolescent patients who received ST vs traditional ST&G autografts. A prospective cohort study of adolescent patients undergoing ACL reconstruction was used to perform a sub-group retrospective comparative cohort analysis. Either ST in a quadrupled all-inside approach or traditional ST&G autografts with suspensory and interference screw fixation were performed. Graft selection was made through shared decision making and hospital & tool availability. Post-operatively, after clearance for return to full activity, patients completed a series of single leg hoping tasks and a lower limb strength assessment. Demographic and clinical data were collected for all patients including sex, age, days from injury to reconstruction, Tanner stage and BMI. Postoperative objective knee functional outcome variables (drop vertical jump ground reaction forces (DVJ GRFs), isometric knee extension/flexion strength and single leg hop tests) were expressed as limb symmetry indices (LSIs; reconstructed limb/uninjured limb). Participants also completed self-reported knee outcome scores (IKDC and HSS Pedi-FABS). Twenty patients (ST: N=12, ST&G: N=8) were included in this study (Table 1). Patients with ST&G grafts were older (ST: 15.9 years (1.08); ST&G: 17.4 years (0.74), p<0.01), yet there were no significant differences in Tanner stages (ST: 4.75 (0.45); ST&G: 4.37 (0.74), p=0.31), days between surgery and follow up (ST: 272 (205); ST&G: 288 (154), p=0.88) or, importantly, graft diameters (ST: 8.42 mm (0.70); ST&G: 7.94 mm (0.94), p=0.21). There were no significant differences in LSIs between groups for the DVJ GRFs (p=0.87), knee extension/flexion strength (p= 0.83/0.30), hop tests (p>0.14), or subjective outcome scores (IKDC: p=0.48; Pedi-FABS: p=0.76). Mean LSIs for single leg hoping tasks were below 90% in two and three of the six tasks for ST&G and ST groups respectively. For adolescent patients undergoing ACL reconstruction, functional and self-reported outcome measures at return to activity are comparable between patients who received ST versus ST&G autografts. Important for any adolescent ACL reconstruction, the influence of graft and surgical technique remains controversial and poorly understood. Further work is required to improve our understanding of graft selection and technique, with a focus on both functional and patient-reported outcome scores. For any figures or tables, please contact the authors directly.