Point-of-Care Procedure for Enhancement of Meniscal Healing in a Goat Model Utilizing Infrapatellar Fat Pad–Derived Stromal Vascular Fraction Cells Seeded in Photocrosslinkable Hydrogel Benjamin B. Rothrauff, * MD, PhD, Hiroshi Sasaki, * MD, PhD, Shinsuke Kihara, * MD, PhD, Kalon J. Overholt, * BS, Riccardo Gottardi, * PhD, Hang Lin, * PhD, Freddie H. Fu, * MD, DSc (Hon), DPs (Hon), Rocky S. Tuan, * y PhD, and Peter G. Alexander, * y PhD Investigation performed at the Center for Cellular and Molecular Engineering, Department of Orthopaedic Surgery, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA Background: Large radial tears of the meniscus involving the avascular region can compromise meniscal function and result in poor healing and subsequent osteochondral degeneration. Augmentation of surgical repairs with adipose-derived stromal vascular frac- tion (SVF), which contains mesenchymal stromal cells, may improve meniscal healing and preserve function (ie, chondroprotection). Purposes: (1) To develop a goat model of a radial meniscal tear with resulting osteoarthritis and (2) to explore the efficacy of a 1- step procedure utilizing infrapatellar fat pad–derived SVF cells seeded in a photocrosslinkable hydrogel to enhance meniscal healing and mitigate osteochondral degeneration. Study Design: Controlled laboratory study. Methods: A full-thickness radial tear spanning 90% of the medial meniscal width was made at the junction of the anterior and middle bodies of the goat stifle joint. Tears received 1 of 3 interventions (n = 4 per group): untreated, repair, or repair augmented with photo- crosslinkable methacrylated gelatin hydrogel containing 2.0 3 10 6 SVF cells/mL and 2.0 mg/mL of transforming growth factor b3. The contralateral (left) joint served as a healthy control. At 6 months, meniscal healing and joint health were evaluated by magnetic reso- nance imaging (MRI) and assessed by histological and macroscopic scoring. The Whole-Organ Magnetic Resonance Imaging Score and the presence of a residual tear, as evaluated with T2 MRI sequences, were determined by a single blinded orthopaedic surgeon. Results: When compared with tears left untreated or repaired with suture alone, augmented repairs demonstrated increased tis- sue formation in the meniscal tear site, as seen on MRI and macroscopically. Likewise, the neotissue of augmented repairs pos- sessed a histological appearance more similar, although still inferior, to healthy meniscus. Osteochondral degeneration in the medial compartment, as evaluated by the Whole-Organ Magnetic Resonance Imaging Score and Inoue (macroscopic) scale, revealed increased degeneration in the untreated and repair groups, which was mitigated in the augmented repair group. Histo- logical evaluation with a modified Mankin score showed a similar trend. In all measures of osteochondral degeneration, the aug- mented repair group did not differ significantly from the uninjured control. Conclusion: A radial tear spanning 90% of the medial meniscal width in a goat stifle joint showed poor healing potential and resulted in osteochondral degeneration by 6 months, even if suture repair was performed. Augmentation of the repair with a pho- tocrosslinkable hydrogel containing transforming growth factor b3 and SVF cells, isolated intraoperatively by rapid enzymatic digestion, improved meniscal healing and mitigated osteoarthritic changes. Clinical Relevance: Repair augmentation with an SVF cell–seeded hydrogel may support successful repair of meniscal tears pre- viously considered irreparable. Keywords: meniscus; adipose stem cell; mesenchymal stem cell; hydrogel; osteoarthritis; tissue engineering The menisci are integral to knee function, serving to dis- tribute tibiofemoral contact stresses during joint motion. 30,37 In 1948, Fairbank 19 reported progressive osteoarthritic changes after total meniscectomy, with The American Journal of Sports Medicine 1–10 DOI: 10.1177/0363546519880468 Ó 2019 The Author(s) 1