Computed tomographic morphometry of the biceps brachii muscle tendon of dogs affected by the medial coronoid disease

Abstract

The objective of this study was to measure the biceps brachii muscle (BBM) attachment to the medial coronoid process (MCP) using computed tomography images and to compare these data between clinically healthy and dogs affected by medial coronoid disease (MCD). Computed tomography was performed in MCD‐affected and healthy dogs. Multiplanar reconstruction views were obtained to measure distance (cm) of the BBM attachment point to the MCP. Results showed that the mean BBM attachment point‐to‐MCP was 1.42 ± 0.23 cm in MCD‐affected and 1.27 ± 0.20 cm in healthy dogs, respectively. In dogs with MCD, the BBM attachment point‐to‐MCP was significantly more abaxial than in clinically healthy dogs (p < .001). The results of this study support the hypothesis that the BBM attachment site is more abaxial to the MCP and therefore may contribute to supraphysiological overload leading to MCD. Albeit more research is necessary, this study proves a relationship between the BBM attachment point and the development of MCD.

Biomechanics of the Canine Elbow Joint

“…Furthermore, the elbow joint is more rapidly extended during the swing phase and kept in a more extended position during weight bearing [60]. This motion pattern aims to reduce the contact and pressure at the medial coronoid process, where most commonly lesions attributed to developmental elbow disease occur [90,103].…”

“…Absence of increased radio-ulnar rotational motion does not exclude an biomechanical overload along the lateral aspect of the medial coronoid process of the ulna caused by interaction with the radial head. An abaxial attachment of the tendon of the biceps brachii muscle at the ulna was detected in dogs with MCD [90]. The pull of the biceps brachii muscle on the ulna could potentially lead to increased pressure between the medial coronoid and the radial head without altering the kinematics.…”

“…Primary changes in the kinematics of the radius, ulna and humerus are assumed to play an role in the pathogenesis of MCD. Altered kinematics in the proximal radio-ulnar joint, were suggested by different researchers to be one potential factor influencing the development of MCD [76][77][78][79][80][81][82][83][84][85][86][87][88][89][90]. One proposed mechanism was an increased axial translation of the radius relative to the ulna leading to an dynamic radio-ulnar incongruence.…”

“…Especially in dogs without a measurable static incongruence, which account for 40% of all patients with MCD [76], the insufficient adaption to intra articular joint loads can lead to mechanical overload at one distinct joint compartment. Increased radio-ulnar rotation was proposed as another potential cause of mechanical overload along the radial incisure of the medial coronoid process and subsequent cartilage and bone damage [82,[87][88][89][90]. The only study comparing in vivo radio-ulnar rotational movement in healthy joints to joints with MCD showed no significant difference in the total amount of radial rotation and in the motion pattern of the radius [74].…”