Cartilage‐free areas in the elbow joint of young golden retrievers

Abstract

The present study describes cartilage-free areas on the ulnar trochlear notch and the humeral condyle of eight very young golden retrievers with otherwise healthy elbow joints. Remarkably, the youngest dog with fullthickness cartilage-free areas was only 8 weeks old. The younger dogs showed no macroscopic abnormalities on the locations that were affected in the older dogs. Two kinds of cartilage modifications were found. Cartilagefree areas at the edges of the articular cartilage layer were present on the humeral capitulum and on two locations of the ulna, (the medial and lateral at the base of the anconeal process, and the trochlear notch near the lateral coronoid process, which was fractured in two cases). Histological examination showed that these cartilage-free areas were filled with dense supportive tissue. Synovial cells covered this tissue as well as the surrounding hyaline cartilage. The synovial membrane covering the areas was macroscopically enlarged, but histological examination revealed no signs of inflammation. The second type of modification consisted of discoloration of the articular surface at the humeral trochlea. Histological examination revealed that in this area the articular surface was composed of fibrocartilage instead of hyaline cartilage. Apparently, there are locations within the elbow joint in which articular cartilage is not necessary for normal joint functioning. The presence of fibrocartilage on the articular surface of the humeral condyle is a surprising finding, for which no explanation has yet been found. Anat Rec Part A 275A: 990 -996, 2003.

Assessment of the geometry of the cubital (elbow) joint of dogs by use of magnetic resonance imaging

“…13 Histologic examination of the cartilage-free areas revealed no signs of inflammation, which suggests that cartilage alterations at these specific locations (ie, most commonly in the center of the trochlear notch or adjoining lateral areas) are not pathologic and do not interfere with joint function. 32 In the study reported here, various-sized cartilage-free areas in the center of the trochlear notch or adjoining lateral areas were evident in all joints of the large-breed dogs, whereas this was evident only at the site of the lateral coronoid process (if at all) in the other dogs. It is noteworthy that the specimens used in the study reported here were selected because of their normal anatomic appearance.…”

Curvature Radius Measurements From the Ulnar Trochlear Notch in Large Dogs

“…The cartilage distribution types observed in our study (type one and two) were the most frequently found by other authors (Probst et al, ). Some researchers believe that cartilage‐free areas in the UTN are not pathological and may represent a normal response to the absence of loading in these regions (Eckstein et al, ; Wolschrijn et al, ; Probst et al, ). These facts could be explained by the bicentric transmission of loads exhibited by some individuals reported in previous biomechanical studies (Preston et al, ).…”

Role of Elbow Incongruity in Canine Elbow Dysplasia: Advances in Diagnostics and Biomechanics

“…40 Histological examination of similar cartilage-free areas revealed no signs of inflammation, and so cartilage in these locations seemed unnecessary for normal joint functioning. 61 In humans, a lower degree of physiological incongruity in specimens with a continuous layer of the articular cartilage was observed when compared with those with a divided articular surface. 23…”