Soft Tissue Masses in the Fetlock Joint of Horses

Abstract

Eight cases of sessile, intra-articular soft tissue masses originating from the cranio-dorsal attachment of the capsule of the fetlock joint of horses are presented. In 4 of these cases an osteochondral fracture of the first phalanx was also present. Clinically the condition closely resembled villonodular synovitis; however the microscopic changes did not correspond to those reported. The clinical signs included lameness after exercise, joint effusion and pain on manipulation. The offending masses were surgically resected and their histology indicated a chronic proliferative synovitis. The results of these cases indicate that the condition carries a favourable prognosis.

Osteochondral Fragmentation in the Synovial Pad of the Fetlock in Warmblood Horses

“…Although its function is unknown, its position and structure suggest that the pad acts as a cushioning surface or contact interface between P1 and MC3 and MT3 during full extension of the joint 9 . The pathology most commonly described for the synovial pad is thickening and formation of large nodules of fibrous tissue that are associated with lameness, joint effusion, and remodeling of the dorsal surface of the MC3 9–13 . Presence of fragments in the synovial pad is also observed, but to our knowledge has never been described.…”

Diagnostic and surgical arthroscopy of the metacarpophalangeal and metatarsophalangeal joints

“…The condition initially designated as villonodular synovitis (Nickels et al 1976) and later described as chronic proliferative synovitis (van Veenendaal & Moffatt 1980, Kannegieter, 1990 is seen in the metacarpophalangeal joint. It involves a proliferative response from the synovial pad in the proximal dorsal aspect of the joint and, therefore, the term synovial pad fibrotic proliferation (Dabereiner et al 1996) is preferred.…”

Arthroscopic laser extirpation of metacarpophalangeal synovial pad proliferation in eleven horses

“…The condition in horses has been likened to pigmented villonodular synovitis in man (Van Veenendaal and Moffatt 1980;Rose 1988), from which its name is derived, although histologically the 2 conditions are quite distinct. Pigmented villonodular synovitis in man occurs in 3 forms, of which the localised form, characterised by solitary intra-articular nodules, most closely resembles the condition seen in horses (Moskovich and Parisien 1991;Rydholm 1998).…”

“…A ffected horses may respond initially to conservative treatment, such as rest and intra-articular injection of sodium hyaluronate and/or corticosteroids and atropine, but lameness frequently recurs when training is resumed (Barclay et al 1979;White 1990;Dabareiner et al 1996). It is now well recognised that surgical removal of the proliferative pad is the treatment of choice for optimal return to function (Barclay et al 1979;Van Veenendaal and Moffatt 1980;Kannegieter 1990;Dabareiner et al 1996). Various surgical techniques for removal of the fibrous masses have been described, including the use of sharp and electrosurgical excision via an arthrotomy (Barclay et al 1979;Van Veenendaal and Moffatt 1980;Jann et al 1986) and arthroscopic removal using a disposable knife, cutting basket forceps and/or a synovial resector (Kannegieter 1990;McIlwraith 1990;White 1990;Dabareiner et al 1996).…”