Fractures of the proximal phalanx: UK perspective

Fractures of the proximal phalanx are one of the most common long bone fractures of horses, and in the UK are seen most commonly in Thoroughbreds in flat training [1,2]. The following abstract is based on the author’s experiences in treating cases, and includes retrospective data from a case series from Newmarket Equine Hospital, some of which has been published elsewhere [3,4].

Epidemiology

Over a 5-year period, 121 cases (120 horses) with fractures of the proximal phalanx presented to Newmarket Equine Hospital for treatment. Long incomplete parasagittal fractures (LIPS) were the most common configuration (Table 1). There was no gender predisposition. Two-year-old horses were most frequently affected, and 88% of cases were either 2- or 3-years-old. Forelimbs were affected more frequently than hindlimbs (Table 1). One-hundred and eleven of 121 fractures (92%) occurred in horses in training or racing on the flat, whereas only 7 fractures (6%) occurred in horses training or racing under jump-racing rules. Only 5 fractures occurred whilst racing, whereas 116 occurred whilst training. Most fractures occurred between March and October (110/121; 91%). Aetiology Different mechanisms of fracture have been proposed. One of the earliest reports in the literature stated that fractures were of the fatigue type, occurring as a result of repeated stress [5]. Subsequently, accounts in the literature have favoured monotonic (supraphysiological) loading as the preferred pathoaetiological theory [6–9]. […]