A study of short tibia syndrome and its association with cranial cruciate ligament degeneration in dogs

The purpose of this study was to describe the radiological findings of short tibia syndrome and its possible association with cranial cruciate ligament degeneration in dogs. A retrospective study calculated limb length discrepancy, with a particular emphasis on the tibia, using entire hind limb radiographs taken from 84 dogs with long progressive ligamentous degeneration and subsequent rupture of the cranial cruciate ligament and a control group. The control group was subdivided into two groups; group A consisted of nine dogs that had a definite traumatic injury to the stifle before the rupture of the cranial cruciate ligament and had no histological evidence of ligament degeneration, and group B consisted of 22 healthy dogs which had no history, clinical or radiological evidence supporting a diagnosis of cranial cruciate ligament degeneration or rupture, but presented with other orthopaedic conditions that required radiographs of both hind limbs to be performed. In the study population group, all 84 dogs had a statistically significant total limb length discrepancy measurement because of significant underlying tibial asymmetry. Entire hind limbs radiographs showed one tibia appearing shorter than the other and different grades of stifle osteoarthritis. The radiographic investigation showed that 67% of the inter-observer inter-class correlation coefficients had high correlation and the remaining 33% had good correlation. Short tibia syndrome was consistently associated with stifle joint instability, cruciate ligament disease and progressive osteoarthritis. The radiographic investigation made by the three observers showed that tibial measurements were repeatable and reproducible, and the selected tibial measurement protocol had good to high correlation and was therefore dependable and reliable.