THE QUADRICEPS-ANGLE IN RADIOGRAPHY AND M AGNETIC-RESONANCE TOMOGRAPHY - A PARAMETER TO OBJECTIFY SOFT-TISSUE AND BONE DEFORMITIES ASSOCIATED WITH THE CONGENITAL DISLOCATION OF THE PATELLA

Diverse bone and soft tissue deformities found with congenital disloca tion of the patella in dogs provoke a lateral deviation of traction of the m. quadriceps femoris. That deviation of traction can be determin ed by measuring the quadriceps-angle (Q-angle) with radiographic techn iques. Magnetic resonance tomography verifies the radiographic Q-angle . The average Q-angle of the extended hind limb in healthy dogs is a m edial angle of 10 degrees. Angulatory deformities and rotatory instabi lities enlarge the Q-angle, i.e. the dislocation force of patella. Thu s, in condition with clinical examination, guidelines for diagnosis an d the following therapy and prognosis can be deduced.