Three-dimensional motion of the patella in French bulldogs with and without medial patellar luxation

Abstract

Background French bulldogs exhibit significantly larger femoral external rotation and abduction than other breeds. We were curious as to whether this peculiar leg kinematic affects patellar motion and/or might induce medial patellar subluxation (MPSL) or medial patellar permanent luxation (MPPL). We hypothesized that the more abducted leg posture during stance causes an unusual medial pull direction of the rectus femoris muscle during stance, and that this may facilitate the occurrence of MPSL or even MPPL during locomotion. To test our hypothesis, we analyzed existing stifle-joint X-ray-sequences collected during the treadmill walk and trot of seven adult female French bulldogs. We estimated 3D-patellar kinematics using Scientific Rotoscoping. Results The three-dimensional motion of the patella comprises rotations and translations. From the seven dogs analyzed, three exhibited MPSL and one MPPL during the gait cycle. Medial patellar luxation (MPL) occurred mostly around toe-off in both gaits studied. Patellar position was generally not gait-related at the analyzed timepoints. In dogs with MPL, the patella was placed significantly more distally (p = 0.037) at touch-down (TD) and at midswing (p = 0.024), and significantly more medial at midswing (p = 0.045) compared to dogs without MPL. Conclusions Medial patellar luxation seems to be the consequence of the far from parasagittal position of the stifle joint during stance due to a broad trunk, and a wide pelvis. This peculiar leg orientation leads to a medial sideway pull caused by the rectus femoris muscle and the quadriceps femoris and may initiate plastic deformation of the growing femur and tibia. Thus, a way to avoid MPL could be to control breeding by selecting dogs with lean bodies and narrow pelvis. Actual breeding control programs based on the orthopedic examination are susceptible to errors. Systematic errors arise from the fact that the grading system is highly dependent on the dog’s condition and the veterinarians’ ability to perform the palpation on the stifle. Based on our results, the position of the patella at TD, or even perhaps during stand might offer a possibility of an objective radioscopic diagnostic of the MPL.

Non-invasive methods to assess muscle function in dogs: A scoping review

“…Further, five out of six studies from Finland were from the same research group but applied different methods in the studies (6, 27,35,47,58). Accordingly, the included 12 studies from Germany were conducted by four research groups (59)(60)(61)(62)(63)(64)(65)(66)(67)(68)(69)(70). The German studies had a relatively high fraction of the objective, quantitative methods focusing on kinematics and kinetics e.g., six out of the nine studies applying a treadmill with force plates were German.…”

Three-dimensional printing educational anatomical model of the patellar luxation in dogs

“…In our study, the 3D model was able to simulate different grades of medial patella luxation. However, recent studies just analyzed three-dimensional kinematics of the patella in dogs during walk and trot [25] and, the influence of femoral varus deformities on patellar alignment using a computer model [26]. Physiologically, when the animal is growing, the patella is responsible for exerting retropatellar pressure in the femoral trochlea, leading to the development of a sulcus with depth and widths adequate for the correct slip of the patella.…”

Der vordere Kreuzbandriss – Pathogenese, OP-Methoden und postoperative Rehabilitation

“…Über das physiologische Ausmaß der Rotation der Hin tergliedmaßen des Hundes bestehen erst wenige Informationen [2], die aber sehr interessant sind. Whippets haben im Vergleich zu Bulldoggen deutlich weniger Rotationsbewegung zwischen Femur und Tibia.…”