Haywood L, Spike-Pierce D L, Barr B, Mathys D, Mollenkopf D
Rood and Riddle Equine Hospital, Lexington, Kentucky, USA.
Department of Veterinary Preventative Medicine, Ohio State University, Columbus, Ohio, USA.
Equine Vet J. 2018 Jan;50(1):29-33. doi: 10.1111/evj.12712. Epub 2017 Jul 20.
Incomplete ossification of the cuboidal bones of the carpus and tarsus in foals has the potential for significant consequences including chronic lameness and decreased athletic ability.
To determine if the degree of ossification of the cuboidal bones is associated with gestational length and if the diagnosis of incomplete ossification is a predictor of performance in Thoroughbred racehorses.
Retrospective cohort study.
The medical records of Thoroughbred foals less than 90 days of age from 1994 to 2011 were examined and records containing tarsal radiographs identified. Radiographs of the tarsus were examined for signs of incomplete ossification and those that were incompletely ossified graded on a scale of 1-4 using a modification of a previously reported index, with Grade 1 being the least ossified and Grade 4 being the most. Gestational length was determined by examining breeding records and foaling dates reported to the Jockey Club. Race records for 2- and 3-year-old affected foals and their maternal siblings were obtained and compared.
Foals with Grades 1 and 2 ossification were usually premature (gestation length <325 days), but Grades 3 and 4 were not. Foals with Grades 2 and 3 ossification were significantly less likely to race than their maternal siblings and Grades 1, 2, 3 and 4 foals earned less money.
A larger sample size of foals with Grade 1 ossification would increase the power of the study. Foals radiographed at an older age may have had lower ossification scores if radiographed earlier.
Incomplete ossification, especially Grades 1 and 2, is associated with a short gestation length. Foals with Grades 2 and 3 incomplete ossification were less likely to race and Grades 1, 2 and 3 earned around $30,000 less than their maternal siblings.
马驹腕骨和跗骨的立方体骨化不完全可能会产生严重后果，包括慢性跛行和运动能力下降。
确定立方体骨的骨化程度是否与妊娠期长度有关，以及不完全骨化的诊断是否是纯种赛马表现的预测指标。
回顾性队列研究。
检查了1994年至2011年90日龄以下纯种马驹的病历，并找出包含跗骨X光片的记录。检查跗骨X光片是否有不完全骨化的迹象，并使用先前报告的指数的修改版，将不完全骨化的跗骨按1-4级进行分级，1级骨化程度最低，4级骨化程度最高。通过检查向赛马俱乐部报告的繁殖记录和产驹日期来确定妊娠期长度。获取并比较了2岁和3岁受影响马驹及其母系同胞的比赛记录。
骨化程度为1级和2级的马驹通常早产（妊娠期长度<325天），但3级和4级则不然。骨化程度为2级和3级的马驹参赛的可能性明显低于其母系同胞，1级、2级、3级和4级马驹的收入也较低。
更大样本量的1级骨化马驹将增加研究的效力。如果在较早年龄进行X光检查，年龄较大的马驹可能骨化评分较低。
骨化不完全，尤其是1级和2级，与妊娠期短有关。骨化程度为2级和3级不完全的马驹参赛可能性较小，1级、2级和3级马驹的收入比其母系同胞少约3万美元。
