Developing an experimental model of early knee osteoarthritis after medial meniscus posterior root release: an in vivo study

Abstract

Purpose To develop a predictable and reproducible model of knee osteoarthritis after medial meniscus posterior root release. Methods Posteromedial meniscal root tears were created in 12 White New Zealand rabbit knees. The contralateral limbs were used as healthy controls. The animals were euthanized at 16 weeks postoperatively; tissue samples of femoral and tibial articular cartilage were collected and processed for macro and microscopic analyses to detect signs of early degeneration. Clinical evaluation of the weight-bearing status on the affected knee was conducted at 0-, 4-, 8-, and 16-weeks postoperatively. Results Early and severe osteoarthritic changes were the hallmark and the main findings after 16-weeks post-surgery. Macroscopically, extensive osteoarthritic changes were observed across the femoral condyle and tibial plateau. Microscopic finding included ulcerations, fissures, fibrillations, pitting, and loss of the superficial layer. Cellularity was diminished, the normal pattern of distribution in columns was lost, and subchondral bone exposure was also evident. Conclusions This study describes a novel model of knee osteoarthritis that may guide the development of tailored interventions to delay or prevent knee osteoarthritis. This knowledge could shift the current treatment paradigm toward more conservative and knee salvageable treatment options and increase surgeons’ awareness of this injury pattern. Such considerations may have a positive impact on clinical decision-making and subsequent patient-reported clinical outcomes. Design Controlled laboratory study. Level of evidence II.

Medial Meniscus Posterior Root Repair Reduces but Does Not Avoid Histologic Progression of Osteoarthritis: Randomized In Vivo Experimental Study in a Rabbit Model

“…Surgical destabilization of the meniscus root was conducted according to the previously described model. 18 The animals were euthanized at 16 weeks postoperatively; tissue samples of femoral and tibial articular cartilage were collected and processed for macro- and microscopic assessment to detect signs of early OA. The follow-up was set at 16 weeks as we considered this would be a proper timing to examine development of all relevant hallmark changes that are found in human OA, and based on previously published studies.…”

“…Large animal models remain a cornerstone to validate, improve, and aid early diagnosis of OA, providing a potential means to detect pathology at an earlier stage than is currently possible and to ascertain optimal future outcomes. 7,18,27,31,47 Rabbits are the most commonly used animal models, especially for knee OA. Over the past decades, multiple surgically induced instability models of OA in a rabbit have been reported to assess the therapeutic efficacy of compounds targeted for OA treatment because the procedure induces cartilage lesions similar to those observed in humans with OA.…”

Accurate tibial tunnel position in transtibial pullout repair for medial meniscus posterior root tears delays the progression of medial joint space narrowing

“…Regardless, MMPR repair does not completely prevent the progression of osteoarthritis and medial joint space (MJS) narrowing [2, 8, 14]. While many similar studies have reported on postoperative MM extrusion (MME) progression [19, 23, 29], a previous study reported that MMPR repair slowed the progression of osteoarthritis compared with conservative treatment or meniscectomy in a rabbit model [3]. Factors such as age, weight, quadriceps muscle strength, healing status of the repaired posterior roots and time from symptom onset to surgery have been reported to influence the progression of MJS, MME and osteoarthritis in the postoperative period after MMPR repair [7, 11, 24].…”