This is a phase II, randomized, double-blind, placebo-controlled, multicenter clinical study designed to evaluate the safety and tolerability profile of the absorbable oxandrolone implant as an adjuvant treatment in rehabilitation following anterior cruciate ligament (ACL) reconstruction surgery. The primary safety outcome will be the incidence of serious adverse events (SAEs) related do treatment collected through spontaneous reports and/or clinical findings over 24 weeks after randomization (subdermal insertion of the absorbable oxandrolone implant). The effectiveness of absorbable oxandrolone implants in the rehabilitation of patients after surgical ACL reconstruction will be evaluated in an exploratory manner, based on their effects on the recovery of muscle mass, muscle strength, and functional capacity.