Pilot, single-center, non-randomized, parallel-group clinical study designed to assess whether intraoperative application of autologous platelet-rich fibrin (PRF) at the bone-patellar tendon-bone (BPTB) donor site reduces postoperative anterior knee sensory deficit after anterior cruciate ligament (ACL) reconstruction in competitively active male athletes. Planned enrollment is 53 participants allocated to a PRF cohort or a standard-care cohort. The primary outcome is the proportion of participants without anterior knee sensory deficit at 12 months post-surgery.

Background: Sensory deficit around the BPTB donor site is a recognized complication after ACL reconstruction and may affect patient satisfaction and functional recovery. PRF is an autologous bioregenerative product with potential to support soft-tissue healing.

Objective: To determine whether PRF application at the donor site reduces anterior knee sensory deficit compared with standard surgical care.

Design and Participants: Single-center, prospective, pilot, non-randomized study with two parallel cohorts (PRF vs standard care). Competitively active male athletes meeting prespecified eligibility criteria are followed at 4, 8, and 12 months post-surgery. Recruitment window: January 2022 to January 2023.

Interventions: In the PRF cohort, PRF is prepared intraoperatively and applied to the donor site per manufacturer protocol; the comparator cohort receives standard closure without PRF.

Assessments:

Primary outcome: Proportion of participants without anterior knee sensory deficit at 12 months. Sensory testing is performed over a predefined 9-point area lateral to the surgical scar (eyes closed; contralateral knee used as reference if uncertain).

Secondary outcomes: Patient-reported knee function instruments (International Knee Documentation Committee [IKDC] Subjective Knee Form and Lysholm Knee Scoring Scale), each reported as total score (0-100; higher scores indicate better function) at 4, 8, and 12 months; optional MRI-based assessments of the donor site per protocol; safety monitoring of adverse events.

Analysis (planned): Group comparisons using appropriate categorical and non-parametric methods with prespecified approaches to handle multiplicity.

Inclusion Criteria:

• Age 18-40 years
• Isolated anterior cruciate ligament rupture confirmed by MRI and clinical examination
• Planned ACL reconstruction with BPTB autograft
• Written informed consent provided

Exclusion Criteria:

• Previous knee surgery on the affected knee
• Associated ligament injuries requiring additional reconstruction
• Significant cartilage damage (Outerbridge grade III-IV beyond donor site changes)
• Systemic disease affecting wound healing (e.g., diabetes mellitus, autoimmune disease)
• Active infection
• Refusal or inability to provide informed consent

Patients undergoing ACL reconstruction with bone-patellar tendon-bone (BPTB) autograft at the University Clinical Center of Serbia

Individual participant data (IPD) will not be shared due to privacy considerations and institutional regulations. Summary results will be published in peer-reviewed journals.