Arthroscopic Anterior Cruciate Ligament Transection for Osteoarthritis Induction in Rabbits: A Pilot Feasibility and Characterization Study.

Background and

Objectives

Traditional open anterior cruciate ligament transection (ACLT) surgical models performed through arthrotomy may introduce capsular trauma and postoperative inflammatory responses that can interfere with the interpretation of post-traumatic osteoarthritis (OA). This study aimed to evaluate the feasibility of a minimally invasive, arthroscopic ACLT rabbit model performed entirely under arthroscopic visualization, without arthrotomy, using a 2.4-mm arthroscope and 2.5-mm shaver, and to provide preliminary structural, histological, synovial, and systemic biochemical characterization of the model for future therapeutic testing. Materials and

Methods

Bilateral arthroscopic ACLT was performed in three skeletally mature New Zealand rabbits, followed by a supervised 12-week exercise protocol. Joint degeneration was evaluated macroscopically and histopathologically using the standardized Pritzker-Osteoarthritis Research Society International (OARSI) grading system. Collagen matrix remodeling was assessed via Picrosirius Red staining. Local intra-articular catabolism was quantified via Enzyme-Linked Immunosorbent Assay (ELISA) for matrix metallopeptidase 13 (MMP-13) and interleukin-1β (IL-1β) from synovial fluid. Systemic oxidative stress, including lipid peroxidation biomarkers, malondialdehyde (MDA), and nitric oxide (NO), was evaluated in serum.

Results

The arthroscopic approach induced osteoarthritic changes, with severity varying across the cohort. Histopathology revealed vertical matrix fissures and disruption of the normal columnar chondrocyte organization, yielding a median comprehensive Pritzker-OARSI score of 6 (range 6-10), with horizontal degradation restricted to stage 2. Synovial fluid analysis demonstrated measurable concentrations of MMP-13 (188.77 ± 93.87 ng/mL) and IL-1β (174.93 ± 95.51 pg/mL). Furthermore, serum oxidative stress parameters at the 12-week endpoint included lipid peroxidation (MDA: 1.01 ± 0.03 nmol/mL) and NO levels (82.72 ± 0.32 µmol/L), presented descriptively in the absence of a comparator group.

Conclusions

This study establishes the first multifaceted pathological baseline of a minimally invasive arthroscopic ACLT rabbit model before therapeutic intervention. The arthroscopic ACLT model produced structural cartilage degeneration alongside measurable intra-articular catabolic and systemic oxidative stress changes, establishing a baseline phenotype and a starting point for future therapeutic studies.