Fig. 2From: Determination of reference values and frequency of occurrence of patella alta in German shepherd dogs: a retrospective studyMedio-lateral radiograph of the stifle joint. The lines show measurements of the patellar length (PL) and patellar ligament length according to Mostafa et al. [5] (PLLm). The measurements are used to calculate the Insall–Salvati ratio (PLLm/PL). The patellar ligament length is measured from the most distal part of the patella to the proximal extent of the tibial tuberosityBack to article page