Enhancement of meniscal repair in the avascular zone using mesenchymal stem cells in a porcine model

Abstract

We hypothesised that meniscal tears treated with mesenchymal stem cells (MSCs) together with a conventional suturing technique would show improved healing compared with those treated by a conventional suturing technique alone. In a controlled laboratory study 28 adult pigs (56 knees) underwent meniscal procedures after the creation of a radial incision to represent a tear. Group 1 (n = 9) had a radial meniscal tear which was left untreated. In group 2 (n = 19) the incision was repaired with sutures and fibrin glue and in group 3, the experimental group (n = 28), treatment was by MSCs, suturing and fibrin glue. At eight weeks, macroscopic examination of group 1 showed no healing in any specimens. In group 2 no healing was found in 12 specimens and incomplete healing in seven. The experimental group 3 had 21 specimens with complete healing, five with incomplete healing and two with no healing. Between the experimental group and each of the control groups this difference was significant (p < 0.001). The histological and macroscopic findings showed that the repair of meniscal tears in the avascular zone was significantly improved with MSCs, but that the mechanical properties of the healed menisci remained reduced.

Stem Cell-Based Therapies for Osteoarthritis: From Pre-Clinical to Clinical Applications

“…The study on swine model confirmed the beneficial effect of MSC over the ACI [61,62]. Moreover, ovine MSCs have been isolated from bone marrow, expanded, characterized, and injected with transforming growth factor (TGF) b3 in a fibrin clot [63].…”

Animal Models of Meniscal Injury in Post-Traumatic Arthritis

“…Thus in the rabbit, the vascular region extends only 0.7-1 mm from the meniscosynovial junction, and 1.3 mm from this junction is considered to be in the avascular zone [ 21 ]. In the pig, the vascular pattern is similar to human [ 22 ], and in the dog, the peripheral 25 % of the meniscus is vascular [ 19 ]. Meniscal lesions in the vascularized zone have greater reparative ability than in the avascular zone, where lesions frequently fail to heal.…”

“…In pig, radial tears at the junction of the anterior horn and pars intermedia extending from the inner zone for two thirds of the width do not heal but development of PTA was not evaluated [ 22 ].…”

Advances in Meniscal Tissue Engineering

“…In another study on pigs, the authors were able to show substantial healing of torn avascular menisal tissue impregnated with mesenchymal stem cells compared to a control model where no healing was observed [35]. However, they noted that the me chanical properties of the healed meniscus were inferior to the normal native tissue.…”