Arthroscopic Removal of Traumatic Fractures of the Proximal Medial Trochlear Ridge of the Talus: A Retrospective Analysis of 18 Horses.

Objective:  The objectives of this study were (1) to evaluate the need for flexed radiographs of the proximal medial trochlear ridge (PMTR) after trauma involving medial tarsus; (2) to evaluate outcome following arthroscopic removal of traumatic osteochondral fragments (TOCF) resulting from direct injury to PMTR.

Methods:  Records of patients with wounds to the medial tarsus were searched and those with TOCF of the PMTR included. Patient history, fracture etiology, preoperative diagnostics, and intraoperative findings were documented. Postoperative performance data were collected using Thoroughbred Racing database or a telephone questionnaire.

Results:  All cases had wounds with concurrent synovial sepsis of the tarsocrural joint. Standard weight-bearing radiographs were performed preoperatively (n = 15), but most (n = 13) failed to identify PMTR pathology. When acquired (n = 8), flexed radiographs (including a uniquely described flexed plantaroproximolateral dorsodistomedial Pl30Pr45Lat-DoDiM oblique) identified PMTR lesions. PMTR TOCF were removed during the initial surgery (n = 15) or subsequent (n = 3) arthroscopy, performed due to unresolved synovial sepsis. Fifteen out of 16 horses with >6-month follow-up resumed full exercise.

Conclusion:  Flexed tarsal radiographs should be performed as part of a standard protocol for traumatic wounds involving the medial tarsus. Horses had excellent prognosis following arthroscopic removal of TOCF of the PMTR. Failure to recognize and remove TOCF resulted in refractory synovial sepsis for horses in this study.