Single transphyseal screws for the correction of moderate to severe angular limb deformities in 28 Thoroughbred foals

This study reports on the effective use of a single transphyseal screw for the treatment of moderate to severe angular limb deformities (ALDs) of the fetlocks and carpi of 28 young Thoroughbred foals. The objective was to evaluate the surgical management of foals with moderate to severe ALDs treated with single transphyseal screws. Evaluation of medical records of 28 Thoroughbred foals treated with single transphyseal screws placed across the distal radial, metacarpal and metatarsal physes was undertaken. The angle of joint deviation was measured prior to implantation and at removal of the implants, and the degree of improvement was calculated. A total of 39 screws were placed: 24 in the distal metacarpus or metatarsus and 15 in the distal radial physis. Varus or valgus deformities in the fetlock improved by 4-5 degrees over a period of 15-30days. Varus or valgus deformities in the carpi improved by 8-11 degrees in 11-56days. One case failed to improve adequately due to implant infection. Single transphyseal screws were effective in treating moderate to severe varus and valgus ALD of the fetlocks and carpi in young Thoroughbred foals. Further investigation into their use in the distal radius in young foals is needed. While single transphyseal screws are almost exclusively used by some clinics in the distal metatarsal and metacarpal physes, many clinicians do not use them in the distal radial physis of young foals due to fear of over-correction, physitis and metaphyseal collapse. This was not observed in any of our cases.