Computed tomographic diagnosis of incomplete palmar cortical (fatigue) fracture of the third metacarpal bone in two young adult endurance horses

Bone stress injuries and fatigue fractures of the pelvis in endurance horses

BACKGROUND

Bone stress injuries and fatigue fractures of the pelvis are reported in only a small number of endurance horses.

OBJECTIVES

To describe bone stress injuries and fatigue fracture of the pelvis in endurance horses trained and competing on the deep sand surfaces.

STUDY DESIGN

Retrospective case series.

METHODS

Medical records of horses used for endurance and diagnosed with bone stress injuries and/or fatigue fractures of the pelvis by ultrasound were reviewed. The bone stress injuries and fatigue fractures were classified as affecting the iliac wing, the iliac shaft, the tuber ischiadicum, the rest of the ischium or the pubis and subdivided into four fracture configurations: isolated iliac fracture, isolated fracture of the floor of the pelvis, isolated tuber ischiadicum fracture and multiple fractures. Descriptive statistics were performed overall and on fracture configurations for age, sex, breed, level of activity, affected limbs, previous injuries, development of the injury, seasons in the UAE, physical and dynamic findings and outcome. For each fracture configuration and the outcome, multivariable logistic regression models were developed after univariable logistic regression and collinearity analyses. Significance was set at P ≤ .05.

RESULTS

Sixty endurance horses were included; 48% (95% CI: 36%-61%) had isolated iliac fracture, 17% (7%-26%) isolated fracture of the floor of the pelvis, 15% (6%-24%) isolated tuber ischiadicum fracture and 20% (10%-30%) had multiple fractures. Breed (OR, 4.42; 95%CI, 1.02-19.57) was significantly associated with isolated iliac fracture and asymmetry of bone landmarks (OR, 7.42; 95% CI, 1.47-37.45) with isolated tuber ischiadicum fracture. Degree of lameness (OR, 3.08; 95% CI, 1.07-8.9) and trotting on three tracks (OR, 8.62; 95% CI, 1.43-51.9) were significantly associated with the diagnosis of isolated fracture of the floor of the pelvis.

MAIN LIMITATIONS

Data acquired in a single country.

CONCLUSIONS

Bone stress injuries and fatigue fractures of the pelvis can affect endurance horses trained and competing on deep sand. Isolated bone stress injuries and/or fatigue fractures of the ileum were the commonest followed by multiple pelvic bones involvement. The presence of lameness and trotting on three tracks suggest the presence of bone stress injuries and/or fatigue fractures of the floor of the pelvis; asymmetry of bony landmarks is more commonly detected in horses with bone stress injuries and/or fatigue fractures of the tuber ischiadicum.

Type, prevalence, and risk factors for the development of orthopedic injuries in endurance horses during training and competition

OBJECTIVE

To report the type, prevalence, and risk factors for the development of orthopedic injuries in endurance horses.

ANIMALS

235 endurance horses.

PROCEDURES

Medical records of horses examined between January 2007 and December 2018 were reviewed. Recorded data were birth; breed; sex; dates of first and last examinations; presence of any conformation fault, lameness, positive flexion test result, and orthopedic injury; starts in endurance competitions; level of athletic activity; professional status of trainer or rider; and whether an orthopedic injury developed in > 1 limb or during or within 2 days after competition, lameness resolved after treatment, reinjury occurred, horse was eliminated from competition after treatment, and the horse required retirement from endurance competitions. Anatomic locations of injuries were classified as proximal portion of the metacarpal area, midportion of the metacarpal area, metacarpo- or metatarsophalangeal (fetlock) area, tarsus, or foot. For each outcome, multivariable logistic regression models were developed after bivariable logistic regression and collinearity analyses.

RESULTS

351 orthopedic injuries were detected in 76.6% of the horses, with 27.1% that affected the fetlock area, 21.4% the proximal portion of the metacarpal area, 21.1% the foot, 12.8% the tarsus, 9.1% the midportion of the metacarpal area, and 8.5% other sites. High suspensory disease (21.4%) was the most common condition, followed by arthropathy of the metacarpo- or metatarsophalangeal joint (19.4%) and solar pain (14%). Age at first examination (OR, 1.70; 95% CI, 1.37 to 2.11), months of observation (OR, 1.03; 95% CI, 1.01 to 1.05), conformation fault of forelimbs (OR, 4.08; 95% CI, 1.53 to 10.89), and amateur status (OR, 2.62; 95% CI, 1.86 to 7.99) remained significant in the final multivariable regression model for the development of orthopedic injuries.

CONCLUSIONS AND CLINICAL RELEVANCE

A large number of endurance horses developed ≥ 1 orthopedic injury during training or competition. Clinical and diagnostic examinations should be focused with particular attention to the metacarpophalangeal joints, proximal portion of the metacarpal area, and foot.