Micro-fragmented Adipose Tissue Enhances Graft-to-Bone Healing after Anterior Cruciate Ligament Reconstruction: A Non-blinded Randomised Controlled Trial

Abstract Objective Anterior cruciate ligament (ACL) reconstruction is widely used to treat ACL rupture, but graft-to-bone healing remains a key factor affecting graft maturation and postoperative stability. Micro-fragmented adipose tissue (MFAT) contains mesenchymal stem cells, extracellular matrix, and bioactive factors with anti-inflammatory and tissue-repair potential. This study aimed to evaluate the effect of local MFAT application on graft-to-bone healing, graft maturation, pain relief, and knee function after ACL reconstruction. Methods This prospective, single-centre, non-blinded randomised controlled trial included 40 patients with acute ACL injury. Patients were randomly assigned to a conventional ACL reconstruction group or an ACL reconstruction plus MFAT group, with 20 patients in each group. All patients underwent standard arthroscopic ACL reconstruction using a four-strand hamstring tendon graft. In the MFAT group, infrapatellar fat pad tissue was harvested, processed into MFAT, and injected around the femoral and tibial bone tunnel regions after graft fixation. Both groups followed the same postoperative rehabilitation protocol. The primary outcome was the MRI signal-to-noise quotient (SNQ) at 6 months postoperatively. Secondary outcomes included VAS pain scores, IKDC scores, and complications. Data were analysed using the Mann–Whitney U test, with P < 0.05 considered statistically significant. Results Baseline characteristics were comparable between the two groups. Operative time was longer in the MFAT group due to the additional MFAT procedure. At 6 months postoperatively, the MFAT group showed significantly lower SNQ values in ROI 1 and ROI 3 than the control group, indicating improved graft maturation and graft-to-bone healing. No significant difference was found in ROI 2. The MFAT group also had lower VAS pain scores at 3 months, while no significant difference was observed at 6 months. IKDC scores did not differ significantly between groups at 3 or 6 months. No severe complications, including infection, graft failure, or postoperative bleeding, occurred in either group. Conclusion Local MFAT application during ACL reconstruction may improve graft maturation and graft-to-bone healing in the femoral and tibial tunnel regions and reduce early postoperative pain, without increasing major complications. MFAT may be a promising adjunctive treatment for enhancing graft-to-bone healing after ACL reconstruction, although larger studies with longer follow-up are needed. Trial Registration Number: The Ethics Committee of Weifang People’s Hospital (approval number: KYLL20250105-5); Chinese Clinical Trial Registry (trial registration number: ChiCTR2500101018. Data of registration: 2025-04-18. Retrospectively registered).