Alcohol-facilitated ankylosis of the distal intertarsal and tarsometatarsal joints in horses with osteoarthritis.

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.

Evaluation of ethyl alcohol for use in a minimally invasive technique for equine proximal interphalangeal joint arthrodesis.

OBJECTIVE: To determine whether intra-articular 70% ethyl alcohol alone (IAEA) or in combination with 2 percutaneously placed transarticular lag screws (EA-TLS) would result in arthrodesis of the equine proximal interphalangeal (PIP) joint. STUDY DESIGN: Experimental. ANIMALS: Healthy horses (n=6), aged 1.5-3 years, free of lameness, diagonally paired front and hind PIP joints. METHODS: Six milliliters 70% ethyl alcohol was injected into randomly selected diagonally paired front and hind PIP joints. Thirty days later, 2 parallel 5.5 mm cortical screws were inserted in lag fashion across the hind PIP joints and the limbs were cast. Horses were confined for 60 days after surgery before free exercise was permitted. Serial lameness examinations were performed at 1, 6, and 10 months. Radiographs of the PIP joints were obtained before injection with alcohol (front, hind PIP joints), at 6 and 10 months (front PIP joints) and 1, 3, 6, and 10 months (hind PIP joints). At 10 months, horses were euthanatized and gross and histopathologic examination of the treated joints was performed. RESULTS: Horses had variable cartilage thinning (more severe in hind PIP joints) and dorsal bone proliferation. One front and 1 hind PIP joint were fused 10 months after alcohol injection. CONCLUSIONS: Ethyl alcohol injected alone or in combination with percutaneously placed transarticular lag screws failed to reliably produce fusion of the PIP joint.

Arthrodesis of the equine proximal interphalangeal joint: a biomechanical comparison of two parallel headless, tapered, variable-pitched, titanium compression screws and two parallel 5.5 mm stainless-steel cortical screws.

OBJECTIVE: To compare the biomechanical characteristics, failure mode, and effects of side (left or right limb) and end (forelimb or hindlimb) of different screws in 2-screw, parallel-screw proximal interphalangeal joint arthrodesis constructs in horses. STUDY DESIGN: In vitro experimental study. SAMPLE POPULATION: Twenty limbs from 6 cadavers (4 complete limb sets, 2 partial sets-total of 4 forelimb and 6 hindlimb pairs). METHODS: Two parallel 5.5 mm cortical (AO) screws were inserted in lag fashion in 1 randomly allocated limb of a pair, and 2 parallel headless, tapered, variable-pitched, titanium compression screws (Acutrak-Plus) were inserted in the contralateral limb. Constructs were tested in 3-point bending in a dorsopalmar (plantar) direction using a materials-testing machine at a loading rate of 5.83 mm/s. Maximal bending moment at failure and composite stiffness were calculated from data generated on load-displacement curves. Data were analyzed using a Friedman 2-way analysis of variance and Wilcoxon's signed-rank tests. RESULTS: No significant difference was detected for bending moment or stiffness values in proximal interphalangeal joint arthrodesis constructs using 2 parallel Acutrak-Plus or AO screws for fixation. Mean stiffness values were significantly different between forelimb and hindlimb constructs. CONCLUSIONS: Performance of 2 parallel Acutrak-Plus screws was biomechanically comparable with 2 parallel AO 5.5 mm cortical screws in in vitro pastern arthrodesis constructs. CLINICAL RELEVANCE: Acutrak-Plus screws may provide an alternative means of fixation for proximal interphalangeal joint arthrodesis.