40
EQUINE VETERINARY EDUCATION / AE / JANUARY 2017
or bony lesions [acute or chronic]) were recorded. Data on treatment were recorded including: wound management (primary or secondary wound healing), synovial structure lavage (endoscopic or needle lavage, standing or under general anaesthesia, number of joint lavages), intra-articular and systemic antimicrobial treatment and systemic anti-inflammatory treatment. Hospitalisation time and complications, such as wound infection (defined as purulent discharge), suture dehiscence, exuberant granulation tissue and skin necrosis were noted. Additionally survival to discharge or euthanasia whilst hospitalised (short-term outcome) was retrieved from the medical records. Long-term outcomes were obtained through a follow-up
telephone interview with questionnaire, where owners were asked by one of the authors (N.B.) whether the formerly injured horse had survived, was sound and able to return to intended use or lame and unable to return to intended use, whether it showed increased post-injury stumbling and whether a coronation injury had recurred after hospital discharge. Long-term was defined as at least 6 months following hospital discharge.
Data analysis Statistical analyses were performed using Stata 10.1 Mean, s.d. and range were used to describe continuous variables and frequencies in percentages were used to describe categorical variables. All variables listed in Table 1 were tested for a univariable association with the following short- and long-term outcomes: (1) survival to discharge; (2) hospitalisation time; (3) long-term coronation specific mortality; (4) soundness and return to intended use; (5) increased post-injury stumbling; and (6) recurrence of coronation injury, using a Chi-squared test and/or univariable linear or logistic regression analysis, for continuous and categorical outcome variables, respectively. Exposure variables with P≤0.3 and potential confounding variables were considered for inclusion in multivariable linear or logistic regression models, which were constructed using a manual stepwise forwards and backwards procedure to test associations between exposure and outcome variables. Exposure variables were included in the model if they
significantly improved the model fit assessed using likelihood ratio test statistics (logistic regression) or adjusted r-squared (linear regression). Significance was set at P≤0.05. Linear regression diagnostics were performed, analysing Studentised residuals, the leverages to identify observations with potential great influence on regression coefficient estimates and overall measures of influence, specifically Cook’s D. Further, residuals were tested, for a normal distribution, homogeneity of variance and that there was a linear relationship between the outcome and exposure variables.
Results
Descriptive statistics Five horses were excluded due to missing information in the medical records. There were 138 with a mean age of
10.75 5.2 years (range 6 months to 27 years) that met the inclusion criteria for this study. Throughout the result section all percentages relate to this entire study population (n = 138) unless otherwise stated. The distributions of sex and breed in percentages are shown in Table 1. Under half of the horses (43.5%) sustained unilateral coronation injuries and 56.5%
© 2016 EVJ Ltd
sustained bilateral coronation injuries. When sustaining unilateral coronation injuries, the right limb was affected in 51.4% and the left limb in 48.6% of the horses. Coronation injuries occurred most frequently whilst trail
riding (59.4%), followed by paddock turn out (17.4%), showjumping (3.6%), carriage driving (2.9%) and other activities (16.7%). The mean duration between injury and
admission was 1.9 8.4 days (range 2 h–2.3 months). In 60.1% of the horses, treatment was administered prior to admission including wound debridement and cleansing (35.5%), systemic antimicrobial agents (29.7%), systemic anti- inflammatory agents (23.2%) and limb bandaging (37.7%). Primary closure of the coronation injury by the referring veterinarian was performed in 5.8% of the horses. Involvement of an extensor tendon was noted in 15.9% of
the horses and carpal joint involvement was diagnosed in 17.4%.
Carpal radiographs were obtained in 91.3% of the horses
(n = 126). Radiographic findings were noted as follows: radiopaque foreign material in 37% of the radiographed horses, acute bony injuries in 1.4% of the radiographed horses and chronic bony injuries in 10.9% of the radiographed horses.
Most horses (82.6%) were treated standing (of which 7.9%
of the horses had synovial structure involvement) and 16.7% were treated under general anaesthesia (of which 56.5% of the horses had synovial structure involvement). Treatment generally consisted of wound debridement, copious lavage of infected synovial structures (n = 24) via needles (n = 21) and via arthroscopy (n = 3). In 75.4% the coronation injury was sutured closed for primary intention healing with a drain implanted and in the remainder the wound was left open for secondary intention healing. In 94.2% of the horses a separate drainage opening distal to the injury was made and in the primary closed cases a drain was implanted (75.4%).
The drains were left in place for a mean of 3.46 1.75 days (range 1–14 days). At least one intra-articular antimicrobial treatment with amikacin was performed in 42%. In 94.2% of the horses, one surgery was required (standing or general anaesthesia) and, in 5.8% of the horses, more than one surgery was required. Post-operative treatment consisted of stabilisation using
splints or bandages for a mean duration of 22.6 10.4 days (range, 0–76 days) in 99.3% of the horses. In 6.3% of the horses
pressure sores associated with the splints or bandages were noted. The majority of horses received systemic antimicrobial
therapy (94.2%) for 6 5.1 days (range 0–42 days) and anti- inflammatory medication (96.4%) for 9.1 6.2 days (range 0– 34 days). The mean duration of hospitalisation was
15 8.6 days (range 1–61 days) with nearly 50% of horses having evidence of wound healing complications during this
time. The frequency of the different complications is presented in Table 1.
Outcomes A complete summary of the short- and long-term outcome data is included in Table 2. Almost all (n = 135) of the horses were successfully discharged from the hospital with three horses subjected to euthanasia during hospitalisation. Two weeks after hospital discharge one horse was
represented to the Equine Hospital due to complete dehiscence of the primary wound repair and 3 weeks following hospital discharge one horse was represented due
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72
