Hindlimb proximal suspensory desmopathy (PSD) is a common cause of lameness or poor performance in horses and may occur alone or together with other suspensory ligament (SL) injuries in forelimbs or hindlimbs. The aims of this retrospective case-control study (January 2009 to December 2018) were to describe the occurrence of, and identify risk factors for, concurrent SL injuries in horses with hindlimb PSD. Data concerning age, breed, sex, work discipline, height, bodyweight and work history were collected. Concurrent SL injuries were defined as forelimb proximal suspensory desmitis or SL branch injuries (≥grade 2 [0-3]) in any limb. Hindlimb PSD was graded mild, moderate or severe based on ultrasonography. Data were described, and multivariable logistic regression modelling was used to identify factors associated with concurrent SL injuries. Data were available for 923 horses with hindlimb PSD, 28.6% (n = 264) of which had concurrent SL injuries. Age category (≤5 years of age vs. ≥6 years of age; P = 0.008), bodyweight: height ratio (P = 0.001), breed (P = 0.05), symmetry vs. asymmetry of hindlimb PSD ultrasonography grade (P = 0.005) and asymmetry vs. symmetry of lameness grade (P = 0.02) were associated with concurrent SL injury in horses with hindlimb PSD. Compared with horses aged ≥ 6 years, younger horses (odds ratio [OR] 1.76; 95% confidence interval [CI] 1.2-2.7) were more likely to have concurrent SL injury. The risk for concurrent SL injuries increased for every unit increase in bodyweight:height ratio (OR 2.27; CI 1.4-3.7). Compared with Thoroughbred crosses, Warmblood crosses (OR 3.3, CI 1.4-7.8), Thoroughbreds (OR 2.9, CI 1.1-7.1) and Irish Draught Horses (OR 3.5, CI 1.3-9.9) were more likely to have concurrent SL injuries. Hindlimb PSD ultrasonography grade severity was not associated with concurrent SL injury. In conclusion, age, bodyweight:height ratio and breed influenced the risk for concurrent lesions of the SL ligament. Further prospective studies in young horses are warranted.

Background:In non-lame horses, the tubera sacrale (TS) are usually lower than or, less commonly, equal in height to the withers. Thoracolumbosacral, pelvic and hindlimb posture/conformation may be influenced by musculoskeletal pain, and development and function of epaxial, pelvic and abdominal muscles.Objectives: To investigate relationships between (1) conformation of the withers and pelvis and orthopaedic injuries; (2) tarsal angles and relative heights of the withers and TS. Study design:Retrospective cross-sectional clinical study.Methods: Horses (n = 193) presented for lameness or poor performance with a conclusive diagnosis based on abolition of clinical signs by diagnostic anaesthesia and imaging were included. Polystyrene hemispheres were adhered to the withers, TS and tubera ischiadica (TI). Lateral photographs were acquired with each horse standing squarely, with the head and neck in a neutral position, the metatarsal regions vertical, aligned with the TI. Relative heights of the withers and TS were determined using ImageJ. A line from the TS to the TI relative to the horizontal defined the pelvic angle. A line from the TS tangential to the lumbar region relative to the horizontal defined the lumbar angle.Measurements were compared across four injury groups consisting of hindlimb proximal suspensory desmopathy, primary sacroiliac joint region pain, a combination of both, and other causes of lameness. Results:The withers height was ≥TS in 138/193 (71.5%) horses; the withers were lower than the TS in 55/193 (28.5%) horses. Pelvic and lumbar angles ranged from 20.0-42.7° (mean 28.9°, SD 3.4°) and 6.3-18.7° (mean 12.2°, SD 2.3°), respectively. No association between measurements and injury groups was determined. Main limitations:There was a lack of non-lame control horses. It was not possible to differentiate between innate conformation versus acquired posture.Conclusions: Withers height was