Unusual osteochondral lesions of the talus in a horse

Fragmentation of the proximal tubercle of the talus in horses: 9 cases (2004-2010)

OBJECTIVE

To identify the prevalence of fragmentation of the proximal tubercle of the talus (FPTT) in a hospital population of horses, characterize the anatomic features of the affected area and fragments, and describe clinical findings, diagnosis, treatment, and outcome for horses with FPTT.

DESIGN

Retrospective case series.

ANIMALS

9 horses with FPTT.

PROCEDURES

2,543 radiographic views of the tarsal region of 1,526 horses that were evaluated between June 2004 and December 2010 were reviewed. Medical case records for horses with detectable FPTT were retrieved, and signalment, history, clinical signs, diagnostic methods, treatment, and outcome were recorded for assessment.

RESULTS

9 horses (median age, 5 years; age range, 1 to 12 years) with FPTT were identified. Seven horses were warmbloods. Diagnosis was made on the basis of radiographic findings, occasionally along with results of ultrasonography and CT. The only horse that was lame in the affected limb had a history of a prior traumatic event and resultant lateral tibial malleolus fracture. One horse underwent arthroscopy, but fragments were not found and were presumed to be extra-articular. Outcome was available for 7 horses; mean ± SD duration of stable radiographic and clinical examination findings was 3 ± 1 years (range, 1 to 4 years).

CONCLUSIONS AND CLINICAL RELEVANCE

FPTT appeared to occur more frequently in warmbloods and was not usually associated with lameness. Affected horses remained clinically and radiographically stable over time. These data have provided some information regarding the importance of FPTT for practitioners who perform radiographic screenings during prepurchase examinations.

Skeletal scintigraphy in the horse: Current indications and validity as a diagnostic test

Gamma scintigraphy is a well established imaging modality, which in equine practice is predominantly used in the investigation of lameness and suspected musculoskeletal problems. Whilst there is a growing literature on the indications for scintigraphy in the horse, there has been little emphasis so far on identifying the validity of scintigraphy as a diagnostic test. In particular, to what extent can the results of a scintigraphic examination be trusted? In this opinionated review the current indications for skeletal scintigraphy in the horse are considered and its validity as a diagnostic test reviewed. It is concluded that in the majority of published studies, inherent biases in study design make it difficult to assess accurately the validity of skeletal scintigraphy in the horse. Further well designed, prospective studies are required to assess the validity of skeletal scintigraphy as a diagnostic tool, particularly in horses with subtle alterations in radiopharmaceutical uptake.