The patellar ligament angle (PLA) was assessed in 105 normal stifle joints of 79 dogs and 33 stifle joints of 26 dogs with a ruptured cranial cruciate ligament (CrCL). The PLA of stifles with complete CrCL rupture was significantly lower than that of normal stifles, particularly at a flexion angle of 60~80degrees in both plain and stress views. If the PLA was <90.55degrees on the stress view with a 60~80degrees flexion angle, the dog was diagnosed with a complete rupture of the CrCL with a sensitivity of 83.9% and specificity of 100%. In conclusion, measuring the PLA is a quantitative method for diagnosing complete CrCL rupture in canines.
Animals ; Anterior Cruciate Ligament/*injuries/radiography ; Dogs/*injuries ; Patellar Ligament/physiology/*radiography ; Radiography/*veterinary ; Retrospective Studies ; Rupture/veterinary