Axial osteitis of the proximal sesamoid bones and desmitis of the intersesamoidean ligament in the hindlimb of Friesian horses: review of 12 cases (2002-2012) and post-mortem analysis of the bone-ligament interface

Abstract

BackgroundAxial osteitis of the proximal sesamoid bones and desmitis of the intersesamoidean ligament has been described in Friesian horses as well as in other breeds. The objectives of this study were to review the outcome of clinical cases of this disease in Friesian horses and analyse the pathology of the bone-ligament interface. Case records of Friesian horses diagnosed with axial osteitis of the proximal sesamoid bones and desmitis of the intersesamoidean ligament in the period 2002-2012 were retrospectively evaluated. Post-mortem examination was performed on horses that were euthanized (n = 3) and included macroscopic necropsy (n = 3), high-field (9.4 Tesla) magnetic resonance imaging (n = 1) and histopathology (n = 2).ResultsTwelve horses were included, aged 6.8 ± 2.7 years. The hindlimb was involved in all cases. Lameness was acute in onset and severe, with a mean duration of 1.9 ± 1.0 months. Three horses were euthanized after diagnosis; 9 horses underwent treatment. Two horses (22%) became sound for light riding purposes, 2 horses (22%) became pasture sound (comfortable at pasture, but not suitable for riding), 5 horses (56%) remained lame. In addition to bone resorption at the proximo-axial margin of the proximal sesamoid bones, magnetic resonance imaging and histopathology showed osteoporosis of the peripheral compact bone and spongious bone of the proximal sesamoid bones and chronic inflammation of the intersesamoidean ligament.ConclusionsAxial osteitis of the proximal sesamoid bones and desmitis of the intersesamoidean ligament in the hindlimb of Friesian horses carries a poor prognosis. Pathological characterization (inflammation, proximo-axial bone resorption and remodelling of the peripheral compact bone and spongious bone of the proximal sesamoid bones) may help in unravelling the aetiology of this disease.

Equine digital tendons show breed‐specific differences in their mechanical properties that may relate to athletic ability and predisposition to injury

“…In contrast, in dressage horses where WB horses dominate, suspensory ligament injuries in the hindlimbs are more common . There is also a reported increased risk of suspensory ligament injuries in FH , which besides the required ‘dressage’ movements, may also be amplified by the already hyperextended position of the metacarpophalangeal joints in FH . Although these studies report significant differences in tendon injuries related to their locomotor performance, none of the studies investigated differences in biomechanical tendon properties that could possibly lead to these injuries.…”

Clinical and low field magnetic resonance imaging features of osseous cyst‐like lesions of the proximal sesamoid bones in seven horses

“…Aseptic trauma at the attachment of the palmar/plantar (intersesamoidean) ligament has been proposed as a possible cause for osteitis of the axial border of the PSBs (Brommer et al . ; Vanderperren et al . ), and OCLLs in other regions have also been identified at the site of insertion of ligaments, suggesting that some may occur as a result of enthesiopathy (Dyson ; McDiarmid ; Dyson et al .…”

“…Osteitis of the axial border can affect one or both PSBs, and has been associated with sepsis of the metacarpo(tarso)phalangeal (fetlock) joint or digital flexor tendon sheath, or aseptic trauma at the attachment of the palmar/plantar (intersesamoidean) ligament (Brommer et al . ; Vanderperren et al . ).…”