Retrospective study of 24 cases of septic calcaneal bursitis in the horse

REASONS FOR PERFORMING STUDY: Wounds to the plantar aspect of the tarsus present a diagnostic and treatment challenge. This study was undertaken to describe specific features of traumatic wounds involving the calcaneal bursa, with a view to determining which clinical examination findings and diagnostic tests results could provide reliable indicators of prognosis. OBJECTIVES: To report clinical presentation, diagnostic findings, treatment and outcome of 24 cases of septic calcaneal bursitis; and to determine the importance of the involvement of specific anatomical structures in relation to the prognosis for survival and return to athletic function. METHODS: Records of 24 horses that had suffered traumatic wounds involving the calcaneal bursae were reviewed and divided into 3 groups, based on the bursa involved and presence or absence of involvement of the tuber calcanei. Clinical, diagnostic imaging and surgical findings were recorded for each case. Differences between groups and outcome were examined for significance with Chi-squared, Fisher's Exact or Kruskal-Wallis tests, as appropriate. RESULTS: Wounds involving only the subcutaneous bursa had an excellent prognosis for survival. Seventy-five percent of horses with wounds involving the intertendinous calcaneal bursa survived. Involvement of the tuber calcanei presented a fair to guarded prognosis, with only 44% of horses with involvement of this structure surviving. CONCLUSIONS: In contrast to other studies of septic synovial structures, the time between initial injury and referral did not affect the outcome. Correct identification of invasion of the calcaneal bursa(e) and/or tuber calcanei in wounds to the plantar aspect of the tarsus allows for more accurate pronostication. Damage to the tuber calcanei presents a poorer prognosis than for cases that involve only the soft tissue structures in the region. POTENTIAL RELEVANCE: This study demonstrates the importance of correct anatomical identification of structures involved in wounds in the region of the calcaneal bursa. The use of radiography, ultrasonography and synoviocentesis are essential in these cases to provide the most appropriate treatment for the horse and accurate prognosis for the owner.