Treating Patellar Ligament Desmitis

Patellar ligament inflammation has been reported to follow tibial plateau leveling osteotomy (TPLO) procedures. While self-limiting, severe cases can result in marked lameness and prolonged recovery. Based on favorable results for shock wave therapy (SWT) of tendon and ligament injuries in other species, a clinical trial was conducted in dogs to determine if SWT would have a beneficial effect on patellar ligament inflammation following TPLO. Thirty large-breed dogs admitted for spontaneous unilateral rupture of the cranial cruciate ligament were included. The affected stifle was examined on radiographs and ultrasound preoperatively and at 4, 6, and 8 weeks after TPLO. Patellar ligament thickness on a lateral radiographic projection was measured at one-quarter, one-half, and three-quarters of the distance from origin to insertion. Although no dogs had obvious clinical signs of patellar desmitis, radiographic evidence was noted in 93% of the dogs based on 4-week postoperative radiographic measurements. At weeks 4 and 6, dogs in the treatment group (n = 19) were treated with SWT. A significant difference in thickness between groups at the distal point was reached at weeks 6 and 8 postoperatively. Ultrasound images evaluated for patellar ligament disruption and periligament edema showed no significant difference. Based on these findings, SWT can accelerate resolution of radiographic signs of patellar ligament desmitis and should be considered for treating patellar desmitis after TPLO.

CommentaryIt was interesting that SWT had no appreciable effect on the ultrasonographic appearance of the patellar ligament in this series. Constructing a potential rationale for the lack of difference, the authors referenced a study that showed tendon disruption and degraded collagen in normal ligaments of ponies following treatment. Based on these results, caution must be used before trying SWT routinely following TPLO. However, given the results of the radiographically measured thickness of the ligament in this study, the authors state that SWT should be considered in the treatment of patellar ligament desmitis.—Jonathan Miller, DVM, MS, DACVS

SourceThe effect of shock wave therapy on patellar ligament desmitis after tibial plateau leveling osteotomy. Gallagher A, Cross AR, Sepulveda G. VET SURG 41:482-485, 2012.