Treatment of MSI in dogs and certainly rotator cuff injuries in people has been quite controversial and is constantly evolving. However, there is general agreement that cases with partially torn ligaments are best treated with conservative, non-surgical management while cases with complete tears probably benefit from surgical reconstruction.
Following a thorough arthroscopic evaluation, conservative management includes intra-articular steroid injections, use of extracorporeal shock wave therapy (ESWT) (fig. 1) and shoulder immobilization. A shock wave is a very strong pressure wave in any elastic medium (such as air, water, or a solid), produced by supersonic craft, explosions, lightning, or other extreme phenomena that create sudden, huge changes in pressure.
Shock waves are characterized by an extremely rapid rise time and a slight negative pressure dip causing cavitation. The mechanical stresses on the cells cause a biological response involving the upregulation of specific proteins associated with a localized healing response, a reduction in inflammation, neovascularization and tissue proliferation. Following shock wave therapy, elbow hobbles (fig. 2) should be used during recovery. Ultimately, dogs undergoing conservative treatment should be rested for at least 2 months before slowly returning to normal.
Surgical treatment is indicated in complete tears of the MCL (fig. 3). Treatment involves arthroscopically assisted synthetic ligament replacement using similar materials and techniques employed in human rotator cuff injury and repair. The material currently used at CCO is fibertape also known as tightrope manufactured by Arthrex®. At CCO we have performed numerous surgical stabilizations including bilateral stabilization in a Colorado Springs Police dog. Shock wave therapy and elbow hobbles are used concurrently with surgical stabilization in most cases.
Overall, the prognosis in most cases of MSI is good. The critical issue in ensuring a good recovery is having a committed owner that understands the importance of strict rest and rehabilitation for as long as 3 to 4 months.