Long-term Outcome of Standing Medial Patellar Ligament Splitting to Manage Horses Exhibiting Delayed Patellar Release: 64 Horses

A standing surgical technique for splitting the medial patellar ligament is described, and the long-term (average 4.5-years) efficacy of the procedure in horses exhibiting delayed patellar release is reported. Medical records of 64 horses that underwent a standing medial patellar ligament splitting surgery performed to treat delayed patellar release were analyzed retrospectively. Horses were sedated in standing stocks. A number 15 scalpel blade was used to percutaneously split the medial patellar ligament from just proximal to its insertion on the tibial tuberosity to its attachment on the parapatellar fibrocartilage, with the goal of inducing a localized desmitis and subsequent thickening of the ligament. Aftercare consisted of oral antibiotics, 14 days stall rest with hand walking, light exercise for 14 days, and full work at 4 weeks. Follow-up information was obtained through telephone calls to owners and/or clinical evaluation by a veterinarian. Results showed that 89% of horses benefitted from the procedure, with complete resolution in 58% of horses and improvement in 31% of horses. A total of 73% of horses were able to perform at the desired level following the procedure; 63% of horses showed signs of improvement or resolution within 30 to 60 days. Two horses had complications following the procedure: 1 horse had an incisional infection, and 1 had a medial patellar ligament rupture. This study shows that standing medial patellar ligament splitting is a successful, long-term surgical option for treatment of delayed patellar release. The procedure has few complications and allows rapid return to desired performance.