Magnetic Resonance Measurements of the Deviation of the Angle of Force Generated by Contraction of the Quadriceps Muscle in Dogs with Congenital Patellar Luxation
To measure the quadriceps angle (Q-angle) in dogs with congenital patellar luxation using magnetic resonance (MR) methods. Study Design
Prospective clinical study. Animals
Thirty-eight client-owned dogs. Methods
Thirty-eight dogs were examined and placed into the following groups based on the degree of patellar instability: normal, grade I, grade II, and grade III. MR images of 37 pelvic limbs without patellar instability, 33 pelvic limbs with patellar luxation, and 6 limbs with cranial cruciate ligament (CrCL) rupture were made. The Q-angle was calculated using trigonometric methods based on MR images. Limbs with patellar luxation were compared with normal stifles and stifle with other disorders. Results
The average Q-angle of the normal group was 10.5° (24.9° to −2.0°). The grade I group had an average Q-angle of 12.2° (28.8° to 2°), the grade II group 24.3° (44.6° to 7.7°), and the grade III group 36.6° (51.4° to 15.6°). The average Q-angle of limbs with an isolated CrCL rupture was 19.3° (34.7° to 3.9°). Conclusion
MR images can be used to make exact calculations of the Q-angle. Clinical Relevance
MR images can be used to quantify the degree of patellar luxation.
©Copyright 2001 by The American College of Veterinary Surgeons
Document Type: Research Article
Affiliations: From the Department of Small Animals; Department of Radiology and Nuclear Medicine, Clinic Benjamin Franklin, Free University of Berlin; and Department of Anatomy, Tierärztliche Hochschule, Hanover, Germany.
Publication date: November 1, 2001