Utilização do álcool etílico 70% e cloreto de amônio 2% como agentes promotores da artrodese química das articulações interfalangeanas proximais de equinos hígidos

Abstract

Chemical arthrodesis is a relevant therapeutic procedure in veterinary medicine, used to alleviate pain and lameness associated with severe joint disease, with chronic and intractable pain from osteoarthritis being indications for arthrodesis. Given the significance of proximal interphalangeal joint lesions in equine orthopedics, this study aimed to evaluate the efficacy of intra-articular administration of 70% Ethanol and 2% Ammonium Chloride for chemical arthrodesis of the proximal interphalangeal joint in healthy horses. Four horses with healthy distal interphalangeal joints were used, which were inspected through specific clinical examination (sensitivity to palpation, flexion, and joint rotation) and radiological examination. Three treatments were applied, which differed in the content of the intra-articular injection: T1 (5 mL of 70% ethanol), T2 (5 mL of 0.9% NaCl saline solution), and T3 (5 mL of 2% ammonium chloride). Clinical examination assessed sensitivity to palpation, joint flexion, and rotation. Over time, up to 240 days after the injections, clinical and radiological examinations were performed, along with synovial fluid collection. All joints underwent macroscopic and histopathological examination of the proximal interphalangeal joint post-mortem. T1 resulted in greater pain sensitivity than T2 and T3, with T2 and T3 showing similar outcomes for this variable. No radiographic evidence of joint degeneration or osteoarticular remodeling was identified. Post-mortem examination revealed no fusion in any of the joints. Future studies are necessary, including equines with osteoarthritis, to reaffirm the effects of 70% ethanol and 2% ammonium chloride in accelerating the degenerative process. Arthrocentesis with ethanol and ammonium chloride in healthy horses was not effective in promoting reduction and collapse of the proximal interphalangeal joint. Ammonium chloride is not a drug capable of causing ankylosis.