Outcome following repair of 63 sagittal fractures of the proximal phalanx in UK Thoroughbreds using either a triangular or linear screw configuration

Abstract

Background A triangular screw configuration has been suggested as preferable for repair of sagittal fractures of the proximal phalanx. Objective To assess the outcome of a triangular screw construct for repair of incomplete and complete minimally displaced proximal phalanx fractures under standing sedation in a population of Thoroughbred racehorses, compared with a cohort repaired using a linear screw configuration. Study design Retrospective cohort study. Methods Medical records and radiographs were accessed to garner clinical data. Date of return to racing was determined from http://www.racingpost.com. Survival data were compared using log‐rank test. Results Sixty‐two horses with one horse having two separate fractures. Fifty‐four fractures were repaired using triangular screw configuration, 10 with a linear screw configuration. 81% (43/53) of horses with triangular repair returned to racing at a median of 289 days (161‐482 days), 70% (7/10) horses with linear screws returned to racing at a median of 351 days (230‐815 days). Main limitations A limited number of horses underwent conventional (linear) screw placement. Conclusion A triangular screw configuration placed in the standing sedated horse is an effective way to repair incomplete and complete minimally displaced proximal phalanx fractures. The rate of return to racing was excellent with a low rate of complications.

Ex vivo comparison of standing and recumbent repair of incomplete parasagittal fractures of the first phalanx in horses

“…However, together with the median fracture gap width of R‐2 and unloaded R‐2 constructs, it supports previous conclusions of dynamic fracture gap instability in linear repairs 10 . Recent clinical evidence associating triangular as opposed to linear repairs with a faster return to racing echoes this conclusion 9 …”

“…Incomplete parasagittal P1 fractures provide an ideal opportunity to perform standing repairs because few implants are required and fracture gap instability is not a concern. Nevertheless, implants are best tightened with the leg unloaded to counteract the potential distraction with weight bearing 9,11,12 . While our results provide evidence of a clear absence of effect and that limb elevation is not required, aspects of study power and the closer clinical context must be considered in light of negative findings.…”

“…Because of this natural potential for fracture gap distraction during axial loading, perceived optimal screw insertion torques may be reached more rapidly and result in less lag compression when repairs are performed with horses standing rather than in recumbency. This may be of particular relevance with use of only one implant subjacent to the MCPJ and may validate recommendations to unload limbs for screw tightening and optimization of axial compression during standing repair 9,11,12 …”

“…Simple uniarticular fractures extending from the metatarsophalangeal joint or metacarpophalangeal joint (MCPJ) typically originate from the sagittal groove of P1 and extend distally for a variable length, resulting in short or long incomplete parasagittal P1 fractures. Incomplete parasagittal P1 fractures may be repaired with the horse sedated and weight bearing or recumbent under general anesthesia 7‐9 . Recently, linear, as opposed to triangular, cortical bone screw repair of simulated parasagittal P1 fractures has been associated with fracture gap distraction when cadaver limbs were loaded to forces normally encountered during slow walking 10 .…”

Experience in the treatment of horses with short incomplete sagittal fractures of the proximal phalanx

“…По данным мировых ученых, большинство лошадей с сагиттальными переломами проксимальной фаланги лечат с помощью фиксации стягивающими винтами [8]. Так указывается, что треугольное расположение винтов при скреплении неполных и полных сагиттальных переломов с минимальной репозицией костных отломков более эффективно, чем линейное.…”