Objective—To determine clinical outcome following intrathecal injection of the podotrochlear (navicular) bursa for signs of foot pain in horses evaluated via magnetic resonance imaging (MRI) and evaluate efficacy of corticosteroids administered with or without hyaluronate.
Design—Retrospective case series.
Procedures—Data collected included signalment, history, intended use, duration and severity of lameness, results of diagnostic anesthesia, radiographic abnormalities, MRI abnormalities, and outcomes for return to use.
Results—MRI was conducted on 23 horses with lameness localized to the foot. Thirteen horses had bilateral forelimb lameness, and 10 had unilateral forelimb lameness. Mean duration of lameness was 10.5 months. Seventeen of 23 (74%) horses had excellent outcomes and returned to intended use within 2 to 4 weeks after navicular bursa injection. Hyaluronate treatment was not associated with outcome; however, horses receiving < 10 mg of trimacinolone had significantly worse outcomes than those treated with hyaluronate. Among horses with excellent outcomes, mean duration of soundness was 7.3 months. Seven of 8 horses with erosive lesions of the flexor surface of the distal sesamoid (navicular) bone diagnosed via MRI had a poor outcome. Horses with navicular bursitis responded optimally to injection, compared with horses with other problems.
Conclusions and Clinical Relevance—Results suggested that intrathecal injection of corticosteroid in horses with erosions of the flexor surface of the navicular bone associated with deep digital flexor tendon adhesions yielded a poor response. Treatment of horses with navicular bursitis via injection of the navicular bursa should be highly effective in alleviating lameness.
Objective—To investigate the relationship between inflammatory responses of the temporomandibular joint (TMJ) and the metacarpophalangeal (MCP) joint in clinically normal horses.
Animals—7 mature horses.
Procedures—In each horse, 1 TMJ and 1 MCP joint were injected with lipopolysaccharide (LPS; 0.0025 μg). The contralateral TMJ and MCP joint were injected with saline (0.9% NaCl) solution. Synovial fluid samples were collected from all 4 joints over 24 hours after injection. Concentrations of interleukin-6, tumor necrosis factor-α, transforming growth factor-β, and total protein were measured via immunoassay. Horses were assessed for clinical signs of joint inflammation at each time point.
Results—Concentrations of interleukin-6 were not significantly different between LPS-injected MCP joints and TMJs at any time point. Transforming growth factor-β concentrations were significantly increased in MCP joints, compared with concentrations in TMJs, at 12 and 24 hours after injection. Tumor necrosis factor-α concentrations were significantly higher in LPS-injected TMJs than in LPS-injected MCP joints at 1 and 6 hours after injection. Total protein concentration did not differ significantly between LPS-injected MCP joints and TMJs. Injection of LPS induced clinical inflammation at all time points; additionally, 2 MCP joints (but no TMJs) had an inflammatory response to injection of saline solution.
Conclusions and Clinical Relevance—The inflammatory response to LPS appeared to be attenuated more quickly in TMJs than in MCP joints of horses. The difference in response suggested that a lack of clinical osteoarthritis in the TMJ of horses could be attributable to a difference in cytokine response.
Objective—To assess the safety and efficacy of alcohol-facilitated ankylosis of the distal intertarsal (DIT) and tarsometatarsal (TMT) joints in horses with osteoarthritis (bone spavin).
Design—Prospective clinical trial.
Animals—21 horses with DIT or TMT joint-associated hind limb lameness and 5 nonlame horses.
Procedures—11 horses (group 1) underwent lameness, force-plate, and radiographic examinations; following intra-articular analgesia, lameness and force-plate examinations were repeated. Nonlame horses were used for force-plate data acquisition only. Following localization of lameness to the DIT and TMT joints, contrast arthrographic evaluation was performed; when communication with the tibiotarsal joint was not evident or suspected, 70% ethyl alcohol (3 mL) was injected. Group 1 horses underwent lameness, force-plate, and radiographic examinations every 3 months for 1 year. Ten other horses (group 2) underwent lameness and radiographic examinations followed by joint injection with alcohol; follow-up information was obtained from owners or via clinical examination.
Results—Significant postinjection reduction in lameness (after 3 days to 3 months) was evident for all treated horses. Twelve months after injection, 10 of 11 group 1 horses were not lame; lameness grade was 0.5 in 1 horse. Follow-up information was available for 9 of 10 group 2 horses; 7 were not lame, and 2 remained mildly lame (1 had a concurrent problem in the injected limb, and the other had DIT joint collapse that precluded needle entry).
Conclusions and Clinical Relevance—Intra-articular alcohol injection in horses with bone spavin resulted in a rapid (usually within 3 months) reduction in lameness and joint space collapse.