Osteochondral fragments in the metacarpo- and metatarsophalangeal joint and their clinical importance

The radiographic evaluation of the fetlock joint as part of a lameness or prepurchase examination often reveals osteochondral fragmentation. These fragments can either be causing lameness or have no clinical importance at the time of examination. However, they can cause lameness at a later stage. An appropriate analysis of the situation requires a correct assessment of the fragment type and an up-to-date knowledge of their possible clinical importance. In this overview, the most common types of fetlock fragments, such as dorsoproximal first phalanx (PI) and proximal synovial pad fragments, as well as fragmentation on the proximal palmar/plantar border of PI and of the sesamoid bones are discussed. A few cases of uncommon large fragmentation on the abaxial borders of P1 are included. Fetlock fractures, obviously causing lameness, such as dorsofrontal fractures of the proximal phalanx, distal metacarpal/metatarsal and sesamoid bone fractures, are not dealt with in this review

Anatomy and imaging of the equine metacarpophalangeal/metatarsophalangeal joint

The metacarpo-/metatarsophalangeal joint is a high motion joint and is therefore prone to be injured. Lameness attributable to the metacarpo-/metatarsophalangeal joint is a frequent cause of early retirement from athletic activity in horses and should therefore be detected as early as possible. The basis of the examination for lameness remains the clinical examination, including a complete motion examination in which the lameness is unambiguously localized by means of local anesthesia. A combination of radiography and ultrasonography is often sufficient for visualizing the lesions. However, in the absence of clear radiological or ultrasonographical findings, more advanced imaging modalities, such as computed tomography (CT) or magnetic resonance imaging (MRI), are necessary. The choice of technique largely depends on the tissue characteristics of the expected lesion, the cost restraints of the owner, and the willingness to take the risk of general anesthesia

Equine allogeneic chondrogenic induced mesenchymal stem cells are an effective treatment for degenerative joint disease in horses

Degenerative joint disease is one of the main causes of equine early retirement from pleasure riding or a performance career. The disease is initially triggered by an abnormal loading of normal cartilage or a normal loading of abnormal cartilage. This primary insult is accompanied with joint inflammation, which leads to further progressive degeneration of the articular cartilage and changes in the surrounding tissues. Therefore, in search for an effective treatment, 75 adult horses with early signs of degenerative fetlock joint disease were enrolled in a randomized, multicenter, double-blinded, and placebo-controlled study. Fifty animals were injected intra-articularly with the investigational veterinary product (IVP) consisting of allogeneic chondrogenic induced mesenchymal stem cells (ciMSCs) with equine allogeneic plasma, and 25 horses were injected with 0.9% NaCl (saline) control product. From week 3 to 18 after treatment, lameness scores (P<0.001), flexion test responses (P<0.034), and joint effusion scores (P<0.001) were remarkably superior in IVP-treated horses. Besides nasal discharge in both treatment groups, no adverse events were observed during the entire study period. On long-term follow-up (1 year), significantly more investigational product-treated horses were working at training level or were returned to their previous level of work (P<0.001)