Relationship of preoperative neurologic score with intervals to regaining micturition and ambulation following surgical treatment of thoracolumbar disk herniation in dogs

Thoracolumbar Intervertebral Disk Extrusion in Dogs: Do Onset of Clinical Signs, Time of Surgery, and Neurological Grade Matter?

OBJECTIVE

 The aim of this study was to determine the influence of time between the beginning of clinical signs, presentation and decompression, and combinations of several factors on the outcome and recovery of dogs undergoing surgery for thoracolumbar intervertebral disk extrusion (IVDE).

STUDY DESIGN

 In all, 433 client-owned dogs treated for IVDE between 2016 and 2020 were reviewed for signalment, neurological grade, rate of onset, duration of clinical signs, and surgical variables. Time from presentation to surgery was divided into three categories: S1 (0-12 hours), S2 (12-24 hours), and S3 (>24 hours). These variables were investigated to determine their influence on the return of pain sensation, urinary continence, ambulation and overall outcome.

RESULTS

 A significant association was found between an acute onset of clinical signs, worse neurological grade at presentation and poorer outcomes. There was a significant difference between S1, S2, and S3 in neurological grade at presentation (p < 0.001) and at discharge (p < 0.001); however, the latter was no longer significant when adjusted for the grade at presentation (p = 1,000). Disk fenestration was associated with a faster return to ambulation (p = 0.033). Duration of clinical signs and time of surgery did not correlate with the time to recovery and return of pain sensation, urinary continence, or ambulation.

CONCLUSION

 Dogs presented with severe neurological status and/or rapid onset of clinical signs were operated on more promptly, but their outcomes were also poorer. There was no significant evidence for a better outcome when surgery was not delayed.

Recovery of Spinal Walking in Paraplegic Dogs Using Physiotherapy and Supportive Devices to Maintain the Standing Position

Paraplegic patients have always been ideal candidates for physiotherapy due to their body's inability to recover on its own. Regardless of the cause that led to the onset of paraplegia (traumatic or degenerative), physiotherapy helps these patients with devices and methods designed to restore the proper functioning of their motility, as well as their quality of life. A total of 60 paraplegic dogs without deep pain in the hindlimbs caused by intervertebral disc extrusion or thoracolumbar fractures underwent physiotherapy sessions: manual therapy (massage), electrostimulation (10-20 min with possible repetition on the same day), ultrasound therapy, laser therapy, hydrotherapy, and assisted gait in supportive devices or on treadmills to stimulate and relearn walking, which was the main focus of the study. To maintain the standing position over time, we developed different devices adapted for each patient depending on the degree of damage and the possible associated pathologies: harnesses, trolleys, straps, exercise rollers, balancing platforms and mattresses, physio balls and rollers for recovery of proprioception. The main objective of our study was to demonstrate that physiotherapy and assisted gait in supportive devices to maintain the standing position may help paraplegic dogs to develop spinal walking. Concurrent pathologies (skin wounds, urinary infections, etc.) were managed concomitantly. Recovery of SW was evaluated by progression in regaining the reflectivity, nociception, gait score, and quality of life. After 125 to 320 physiotherapy sessions (25 to 64 weeks), 35 dogs (58.33%) developed spinal walking and were able to walk without falling or falling only sometimes in the case of a quick look (gait score 11.6 ± 1.57, with 14 considered normal), with a lack of coordination between the thoracic and pelvic limbs or difficulties in turning, especially when changing direction, but with the recovery of the quadrupedal position in less than 30 s. The majority of dogs recovering SW were of small size, with a median weight of 6.83 kg (range: 1.5-15.7), mixed breed (n = 9; 25.71%), Teckel (n = 4; 11.43%), Bichon (n = 5; 14.28%), Pekingese (n = 4; 11.43%), and Caniche (n = 2; 5.71%), while those who did not recover SW were larger in size, 15.59 kg (range: 5.5-45.2), and mixed breed (n = 16; 64%).

Does surgical timing affect the rapidity of recovery in deep pain-entire non-ambulatory dogs with thoracolumbar intervertebral disk extrusion?

OBJECTIVE

To investigate whether the delay between onset of neurological signs and spinal cord decompression affects the time to recovery in non-ambulatory paraparetic/paraplegic dogs with deep pain perception affected by thoracolumbar intervertebral disc extrusion.

MATERIALS AND METHODS

Data on non-ambulatory dogs with preserved deep pain perception in both hindlimbs and surgically treated for thoracolumbar intervertebral disc extrusion were prospectively collected from three referral hospitals. Cox proportional hazards regression was used to explore the relationship of time until restoration of independent ambulation with age, weight, preoperative use of anti-inflammatory drugs, delay between onset of inability to walk and arrival at the clinic, time between presentation and spinal surgery and surgery time.

RESULTS

One hundred and fifty-one dogs were included. Median time from admission to surgery, including imaging, was 180 (interquartile range, 65.4 to 240) minutes. All dogs were operated within 72 hours. Follow-up was available for all 151 dogs and ranged from 1 to 21 months. All but three dogs, which were all grade IV at presentation, recovered the ability to ambulate. In both univariable and multivariable models, only duration of surgery and neurological (Frankel) grade at presentation were significantly associated with the rapidity of recovery of ambulation.

CLINICAL SIGNIFICANCE

Delay between onset of clinical signs and presentation and time between presentation and spinal surgery was not associated with the rapidity of recovery of ambulation in dogs surgically treated for thoracolumbar intervertebral disc extrusion. These results should be evaluated in the context of a limited range of delay since only 14.5% dogs had a delay ≥6.5 hours. Duration of surgery and neurological grade at presentation were significantly associated with rapidity of recovery of ambulation.

ACVIM consensus statement on diagnosis and management of acute canine thoracolumbar intervertebral disc extrusion

Background

Thoracolumbar intervertebral disc extrusion (TL‐IVDE) is the most common cause of acute paraparesis and paraplegia in dogs; however, guidelines on management of the condition are lacking.

Objectives

To summarize the current literature as it relates to diagnosis and management of acute TL‐IVDE in dogs, and to formulate clinically relevant evidence‐based recommendations.

Animals

None.

Methods

A panel of 8 experts was convened to assess and summarize evidence from the peer‐reviewed literature in order to develop consensus clinical recommendations. Level of evidence available to support each recommendation was assessed and reported.

Results

The majority of available literature described observational studies. Most recommendations made by the panel were supported by a low or moderate level of evidence, and several areas of high need for further study were identified. These include better understanding of the ideal timing for surgical decompression, expected surgical vs medical outcomes for more mildly affected dogs, impact of durotomy on locomotor outcome and development of progressive myelomalacia, and refining of postoperative care, and genetic and preventative care studies.

Conclusions and Clinical Importance

Future efforts should build on current recommendations by conducting prospective studies and randomized controlled trials, where possible, to address identified gaps in knowledge and to develop cost effectiveness and number needed to treat studies supporting various aspects of diagnosis and treatment of TL‐IVDE.

Safety of early postoperative hydrotherapy in dogs undergoing thoracolumbar hemilaminectomy

OBJECTIVES

Hydrotherapy is a common part of the postoperative care after surgical treatment of thoracolumbar intervertebral disc extrusion in dogs. There are currently no guidelines on when to commence hydrotherapy after surgery. Early hydrotherapy may be associated with an increased risk of postoperative complications including surgical site infection and neurological deterioration. The goal of this study was to report the prevalence and types of postoperative complications in dogs receiving early hydrotherapy.

MATERIALS AND METHODS

Eighty-three dogs commencing hydrotherapy within 5 days after surgical treatment for thoracolumbar intervertebral disc extrusion were included in a retrospective descriptive study. All postoperative complications were recorded.

RESULTS

Ten minor and 16 major complications were recorded in a total of 26 dogs. The majority of recorded complications were unlikely, but not excluded to be, caused by the initiation time of hydrotherapy. One dog developed a surgical site infection and one dog had a confirmed further extrusion of the originally operated intervertebral disc, which may have been influenced by early initiation of hydrotherapy.

CLINICAL SIGNIFICANCE

Early hydrotherapy is possibly associated with occurrence of postoperative complications. Associations between the reported complications and early hydrotherapy, and possible benefits of early hydrotherapy, need to be further investigated before early initiation of hydrotherapy can be recommended.

Outcome in Cats with Acute Onset of Severe Thoracolumbar Spinal Cord Injury Following Physical Rehabilitation

The literature is lacking data concerning the prognosis in cats suffering from naturally occurring acute onset of thoracolumbar (TL) spinal cord injury that are undergoing rehabilitation therapy. Therefore, we investigated the effect of physical rehabilitation in cats suffering from naturally occurring TL spinal cord injury. The medical records of 36 cats with acute onset of TL spinal cord injury that were selected for rehabilitation treatment were reviewed. Twenty-nine cats underwent an intensive physical rehabilitation protocol in the clinic (group 1), whereas the owners of seven cats declined physical rehabilitation (group 2). In group 1, seven cats had pelvic limb deep pain perception (DPP), which was significantly associated with the functional recovery of voluntary ambulatory status (p = 0.010) and voluntary micturition (p < 0.001). Spinal walking was achieved in 10/22 (45%) of the cats without DPP, and none regained voluntary micturition. In group 2, no cats regained ambulatory status or voluntary micturition, although pelvic limb DPP was present in three patients. Treatment with a clinic-based rehabilitation program and the presence of a crossed extensor reflex were significantly associated with a higher possibility of regaining functional ambulatory status (p < 0.010), but there was no difference in the recovery of voluntary micturition between the groups. Thus, cats with severe, naturally occurring, acute onset of TL spinal cord injury may benefit from physical rehabilitation. In the case of the loss of DPP, the acquisition of spinal walking is possible, despite the high possibility of a persistent neurologically dysfunctional bladder.

Short-term clinical outcomes of 220 dogs with thoraco-lumbar disc disease treated by mini-hemilaminectomy

Thoraco-lumbar intervertebral disc extrusion is a common condition seen in veterinary practice. Although there are different surgical techniques described for decompression, most of these techniques are based on the surgeon’s preference or experience rather than clinical research. Our objective was to determine the clinical outcomes, using return to ambulation and micturition, as well as complication rates, in a large cohort of dogs by using a mini-hemilaminectomy for decompression of the thoraco-lumbar spinal cord with Hansen type I thoraco-lumbar intervertebral disc extrusions (IVDE). A retrospective study was performed on dogs presented for acute thoraco-lumbar IVDE undergoing surgical decompression. In total, 252 spinal decompression surgeries were performed. The recovery rates for patients graded with a modified Frankel score (MFS) of 5 to 0 were 100%, 99%, 100%, 96%, 86% and 64%, respectively. The mean days to micturition across all the MFS 5–0 were 1.5 (standard deviation [SD] ± 0.7), 1.8 (SD ± 1), 4.3 (SD ± 1.7), 6.4 (SD ± 2.2), 9.3 (SD 3) and 11.9 (SD ± 2.2), respectively. The mean days to ambulation across all the groups 5–0 were 2 (SD ± 0.7), 2.6 (SD ± 1), 7.6 (SD ± 4.4), 10.1 (SD ± 2.5), 16.1 (SD ± 2.9) and 19.3 (SD ± 2.6), respectively. Postoperative complications were seen in 32 of the surgeries, with a complication rate of 13%. Minor complications accounted for 38% of all complications, and major complications constituted 62% of all complications. In total, 15 dogs died or were euthanised as a direct result of thoraco-lumbar disc extrusion or the surgical procedure, with a mortality rate of 6% across all groups. A mini-hemilaminectomy provides similar clinical outcomes described in the literature for other methods of spinal cord decompressive surgery, and it also provides patients with similar short-term outcomes to other described decompressive surgical techniques in the dog, which have been described in the literature.

Classification of Intervertebral Disc Disease

Intervertebral disc disease (IVDD) has been recognized in dogs since the 1800s, when the first descriptions of extruded disc material within the vertebral canal were published. In the intervening time our understanding of intervertebral disc pathology in dogs and cats has increased dramatically, with many variations of IVDD described. Whilst the volume of literature and collective understanding of IVDD has expanded, there has also been scope for confusion as the definition of intervertebral disc disease, with its myriad different manifestations, becomes more complicated. A large volume of literature has aimed to combine the use of histopathology, diagnostic imaging and clinical findings to better understand the various ways in which IVDD can be classified. Much of this research has focused on the classification of mechanisms of intervertebral disc degeneration, centering around the differences between, and overlaps in, IVDD in chondrodystrophic and non-chondrodystrophic dog breeds. However, with the increasing availability of advanced imaging modalities allowing more accurate antemortem diagnosis, the concept of IVDD has expanded to include other clinical presentations that may not fit into traditional models of classification of IVDD. This review aims to provide an up to date overview of both historical and current systems of IVDD classification, highlighting the important findings and controversies underpinning them.