Healing of a Surgically Created Partial Detachment of the Posterior Cruciate Ligament Using Marrow Stimulation: An Experimental Study in Dogs

ABSTRACT

The inability of intra-articular (cruciate) ligaments to generate a substantive reparative response may preclude the primary surgical repair of such lesions. A marrow stimulation technique that provides access to a fibrin scaffold, cytokines, and mesenchymal stem cells has been shown to be successful in generating a repair response in articular cartilage. We hypothesized that a similar approach may be effective in initiating and supporting a healing response in cruciate ligament injuries. The ability to treat cruciate ligament injuries by primary repair may have significant advantages over the more extensive reconstructive procedures currently advocated. Bilateral subtotal (75% of width) lacerations were made in the proximal aspect of the posterior cruciate ligament (PCL) in 10 adult mongrel dogs. A marrow stimulation technique in which small holes were made through the femoral origin of the PCL into the marrow cavity immediately adjacent to the lesion was performed in one limb. The contralateral limb served as the non-stimulated control. Twelve weeks after surgery the extent of healing and the histological character of the repair tissue in both groups were compared. Marrow stimulation resulted in a statistically significant (P < .05) improvement in the healing of subtotal lacerations made in the PCL. The marrow-stimulated repair tissue was more cellular and had a more organized extracellular matrix than the repair tissue in the non-stimulated group. Our hypothesis was confirmed. Marrow stimulation can induce a “healing response” in intra-articular (cruciate) ligaments. This technique may have clinical applications in primary surgical repair of these structures.