Long‐term outcome and effect of diagnostic analgesia in horses undergoing interspinous ligament desmotomy for overriding dorsal spinous processes

Abstract

Objective To report the long‐term outcome of horses treated with interspinous ligament desmotomy (ISLD) for pain associated with overriding dorsal spinous processes (ORDSP) and determine the influence of preoperative diagnostic analgesia on long‐term outcome. Study design Retrospective study. Animals Eighteen horses. Methods Data were collected from horses presenting for ISLD to the University of Pennsylvania New Bolton Center between January 2013 and May 2018. Follow‐up of ≥3 months postsurgically was obtained from the owner, trainer, or referring veterinarian. Long‐term improvement was compared between horses that improved with diagnostic analgesia presurgically and horses that did not undergo diagnostic analgesia presurgically by using a χ2 test. Univariate logistic regression was used to test associations between long‐term improvement and independent variables. Results Clinical signs had improved in 13 of 18 horses at long‐term follow‐up (median, 14.5 months; range, 3‐57). Clinical signs improved in nine of 10 horses responding to diagnostic analgesia but only in four of eight horses that did not undergo diagnostic analgesia (χ2[1], N = 18) = 3.55; P = .06). Although the likelihood of long‐term improvement increased with prior diagnostic analgesia (odds ratio = 6.3; 95% confidence interval = 0.73, 55.0; P = .09), it did not reach statistical significance. Conclusion A higher proportion of horses experienced long‐term improvement in clinical signs after ISLD when horses responding to preoperative diagnostic analgesia were compared with horses that were not tested. Clinical significance This study provides some evidence to support the use of diagnostic analgesia in conjunction with clinical examination for identification of clinically relevant ORDSP.

Accelerometric Changes before and after Capacitive Resistive Electric Transfer Therapy in Horses with Thoracolumbar Pain Compared to a SHAM Procedure

“…A second limitation could be that diagnostic anesthesia was not pursued in order to confirm the radiological diagnosis. Overriding dorsal spinous processes is the most common radiographic finding in horses with thoracolumbar pain [5,40]. However, there are variable clinical signs associated with this disorder and a poor correlation between radiographic findings and clinical diseases has been described [5,20,41].…”

“…Overriding dorsal spinous processes is the most common radiographic finding in horses with thoracolumbar pain [5,40]. However, there are variable clinical signs associated with this disorder and a poor correlation between radiographic findings and clinical diseases has been described [5,20,41]. Consequently, many clinicians consider that diagnostic anesthesia is the most definitive method of identifying horses with pain attributable to thoracolumbar disease [5,20,41].…”

“…However, there are variable clinical signs associated with this disorder and a poor correlation between radiographic findings and clinical diseases has been described [5,20,41]. Consequently, many clinicians consider that diagnostic anesthesia is the most definitive method of identifying horses with pain attributable to thoracolumbar disease [5,20,41]. However, Holm et al [36] demonstrated that both the injection of a mepivacaine solution and sodium chloride in the back resulted in kinematic changes in asymptomatic horses, perhaps due to mechanical-neuromuscular changes in the musculature.…”

“…Thoracolumbar pain and associated neuromuscular dysfunction are common clinical entities in the athletic horse [1][2][3]. A great variety of specific disorders may cause thoracolumbar pain in horses, and affect several anatomical structures in the area, i.e., bones, muscles, joints and ligaments, although the most common disorders are the impingement of the dorsal spinous processes and osteoarthritis of the articular facets [4][5][6]. Regardless of the source/s of back pain, some authors have described the pathophysiological pattern of back pain in horses by extrapolating the knowledge and consequences of low back pain in human beings.…”

Implications of the neuroanatomy of the equine thoracolumbar vertebral column with regional anaesthesia and complications following desmotomy of the interspinous ligament

“…Using diagnostic analgesia to confirm or eliminate back pain as the cause of poor performance of horses has been strongly advocated by some clinicians, 16,56,57 but a standardised protocol has not been established. Some studies describe administering local anaesthetic adjacent to the impinging DSPs, whereas others describe administering the local anaesthetic into or adjacent to the interspinous spaces 12,16,57–59 . Some studies describe administering local anaesthetic on only one side of the back, whereas others advocate infiltrating local anaesthetic near to lesions detected during radiographic examination of the back.…”