Stifle problems in larger dogs are not always cruciate ligament ruptures

I recently saw a case that was referred for a cranial cruciate ligament rupture. However, it did not have instability when the cranial drawer test was applied, and the amount of joint swelling was minimal. Careful palpation revealed that the tibial tuberosity was quite medial relative to the rest of the limb. Also, the patella could be palpated outside of its normal position in the trochlear groove. This patient had a grade 4 medial patella luxation.