Radiological, vascular osteochondrosis occurs in the distal tarsus, and may cause osteoarthritis

Abstract

Background: Osteochondrosis occurs due to failure of the blood supply to growth cartilage. Osteochondrosis lesions have been identified in small tarsal bones and suggested to cause distal tarsal osteoarthritis, however; it has not been determined whether distal tarsal osteochondrosis lesions were the result of vascular failure. Objectives: To perform post-mortem arterial perfusion and micro-computed tomography (CT) of the central (CTB) and third tarsal bones (TIII) of foetuses and foals up to 5 months old, to describe tarsal development and any lesions detected. Study design: Descriptive, non-consecutive case series. Methods: Twenty-three animals that died or were euthanased from 228 days of gestation to 5 months old were collected, comprising 2 foetuses and 9 foals of miscellaneous breeds and 12 Icelandic Horse foals; a Accepted Article This article is protected by copyright. All rights reserved breed with high prevalence of distal tarsal osteoarthritis. One hindlimb from each foal was perfused arterially with barium, and the CTB and TIII were examined with micro-CT. Results: Perfusion yielded partial information from 41% of the animals. The CTB and TIII were supplied by nutrient arteries and perichondrial vessels with vertical, transverse and circumferential configurations. Fourteen of the 23 (61%) animals had focal defects in the ossification front, i.e. radiological osteochondrosis. The majority of lesions matched the configuration and development of vertical vessels. Additionally, full-thickness, cylindrical defects matched transverse vessels, and the long axes of some dorsal lesions matched circumferential vessels. Main limitations: Lack of histological validation. Conclusions: Post-mortem perfusion was poor for examination of the blood supply to the growth cartilage of the CTB and TIII. Radiological osteochondrosis lesions were compatible with vascular failure because they were focal, and because lesion geometry matched vessel configuration. The relationship between osteochondrosis and distal tarsal osteoarthritis warrants further investigation.

Osteochondrosis in the central and third tarsal bones of young horses

“…3b), 17,28 the cylindrical defects in case 6 were compatible with failure of transverse vessels (Fig. 5), 28 and the shelf and groove defects in case 13 represented failure of vessels entering canals at the dorsal perichondrium, and then turning to course vertically toward the distal articular cartilage (Fig. 6).…”

“…6,19,24 The cysts in cases 10 and 13 were compatible with failure of perpendicular (vertical) vessels entering growth cartilage from subchondral bone midway between the periphery and center (Fig. 3b), 17,28 the cylindrical defects in case 6 were compatible with failure of transverse vessels (Fig. 5), 28 and the shelf and groove defects in case 13 represented failure of vessels entering canals at the dorsal perichondrium, and then turning to course vertically toward the distal articular cartilage (Fig.…”

“…6). 24,28 In cases 6, 10, and 13, necrotic canals included eosinophilic streaks more commonly described in conjunction with physeal 22 than articular osteochondrosis. 6,24 Cartilage surrounding necrotic vessels in case 6 included areas of ischemic-necrotic cartilage, typical of articular osteochondrosis, 6,24 and retainedhypertrophic cartilage, typical of physeal osteochondrosis.…”

“…Previously, it was suggested that load dissipation might be altered superficial to an ossification front that is uneven due to indented osteochondrosis defects and protruding repair responses, and that this might produce local strain peaks leading to articular chondrocyte necrosis. 28 Articular chondrocyte necrosis is another change that has been proposed to represent early distal tarsal osteoarthritis. 4,12,13 In future, it would be ideal to detect vascular failure, chondrocyte necrosis, and retention and repair responses simultaneously by a modality that can be used longitudinally in vivo (eg, high-field MRI) 12 as this could enable monitoring of the proposed pathogenesis and sequelae of distal tarsal osteochondrosis, including osteoarthritis.…”

Allogeneic chondrogenic‐induced mesenchymal stem cells for the treatment of tarsometatarsal lameness in horses

“…No horses in either group were reported by owners to have experienced any detectable adverse reaction to treatment. First re-examination was 38 days (95% CI: 38-49), with no difference between groups: CIMSC 42 (35-45), control 34(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40)(41)(42), p = 0.11. All CIMSC horses and 79 controls F I G U R E 1 Violin plot showing the range of radiographic severity for the 67 horses treated with chondrocyte-induced mesenchymal stem cells (CIMSC) and 100 control horses treated with intra-articular corticosteroids.…”