[Treatment of a hip and patella luxation in a toy dog]

The present case report describes the surgical treatment of a traumatic craniodorsal luxation of the hip and a concomitant medial congenital luxation of the patella (3rd grade) in an 11-year-old Yorkshire Terrier. First the hip luxation was corrected with a cemented hip prosthesis. The femoral stem was inserted in slight anteversion (15°) with respect to the preoperative condition (5°), this contributed contrasting the medial traction of the femoral quadriceps on the patella, improving patellar luxation from 3rd to 2nd grade. However, the persistent patellar luxation and intermittent lameness reduced limb function and made a second intervention necessary. Four weeks after prosthetic surgery, a femoral trocleoplasty and lateral transposition of the tibial crest were performed to definitively re-establish a correct replacement of the patella in the femoral trochlea. No perioperative complications were found. At the final examination the patient did not show any lameness or pain that could be evoked when manipulating the surgically corrected limb. The surgical treatment allowed a restoration of the hip function and the alignment of the extensor mechanism of the femoral quadriceps and ensured a complete return to normal motor activities.