Subdermal Implant-bioabsorbable Oxandrolone Pellet For Rehabilitation Following Anterior Cruciate Ligament (ACL) Surgical Reconstruction

Rehabilitation of knee stability and function after anterior cruciate ligament (ACL) reconstruction is slow and costly. The use of anabolic steroids, such as oxandrolone, may aid in the recovery of muscle mass and strength, as well as functional capacity. Oxandrolone, derived from dihydrotestosterone, has high anabolic activity and low androgenic activity (a 13:1 ratio), making it more effective in promoting weight gain with fewer side effects compared to other steroids. Registered by the FDA and previously by ANVISA, the National Health Surveillance Agency in Brazil, it is indicated for cases of post-trauma or post-surgery weight loss. The subdermal use of oxandrolone implants is proposed to release the drug directly into the bloodstream, improving efficacy and reducing issues related to oral administration. This study evaluates the safety and tolerability of the oxandrolone subdermal bioabsorbable implant for 24 weeks versus placebo implant in both men and women as an adjuvant treatment during rehabilitation following anterior cruciate ligament (ACL) surgical reconstruction. The serum and pharmacokinetic profile of the oxandrolone subdermal bioabsorbable implant will be monitored.

Inclusion Criteria: For male and female participants: * Ability to confirm voluntary participation and approve the Informed Consent Form; * Men and women aged 18 to 60 years (inclusive); * Body weight between 50-120 kg for men and 40-90 kg for women; * BMI ≤34.9 kg/m²; * Complete ACL rupture visualized by pre-operative magnetic resonance imaging (MRI); * Having undergone arthroscopic knee surgery for anterior cruciate ligament (ACL) coverage using an autologous hamstring tendon graft; * Presenting with an isolated ACL injury or combined with ligamentous, meniscal, or cartilage lesions visualized by MRI, provided they do not interfere with the rehabilitation protocol. * Classification as very active, active, or irregularly active type A according to the International Physical Activity Questionnaire (IPAQ), based on pre-ACL injury physical activity; Inclusion criteria assessed at the Randomization Visit (VR/V2): * Continue to meet all inclusion criteria verified during the Selection Visit (VS/V1) * Adherence to the rehabilitation protocol, having initiated postoperative physiotherapy treatment; * Functional range of motion from 0 to 120º and ability to ambulate without crutches; * Blood pressure in the seated position in the doctor's office \