Caudal Cervical Spondylomyelopathy Research Articles

Clinical and epidemiological profiles and outcome of non-traumatic myelopathies in dogs

Myelopathies, the disorders affecting the spinal cord, are classified into traumatic or non-traumatic. In dogs, intervertebral disc disease (IVD) is the most common cause of spinal pain and neurological deficits. The aim of the current study is to present the prevalence, clinical presentation, diagnosis and outcome of non-traumatic myelopathies of various etiologies, in dogs. This was a retrospective study in dogs. The inclusion criteria for the dog population included complete clinical records of the cases (physical, neurological examination, clinicopathological and/or diagnostic imaging), therapy, outcome and re-examinations. A total of 618 dogs were included in the study with a mean age of 6 years and a mean body weight of 12Kg. The neurological deficits appeared acutely in 346 dogs (56%).Paraplegia (201/618, 32.5%), paraparesis (144/618, 23.3%) were the most frequent neurological deficits, followed by spinal pain (61/618, 9.9%). In the majority of cases the lesions (374/618, 60.5%) were localized in the thoracolumbar spinal cord segments. Degenerative disc disease was the predominant diagnosis in the study population (212 dogs, 62.5%), followed by neoplasia (10%), congenital anomalies (6.2%), myelitis (5.9%) and, less frequently, discospondylitis (4.1%), caudal cervical spondylomyelopathy (3.8%) and meningitis (3%). There were few cases with extradural synovial cysts (2.1%), congenital myelopathies (1.2%), Chiari like malformation (0.9%). Regarding outcome, 476/618 (77%) dogs were alive at the end of the study. From the 476 dogs that were still alive, 278/476 dogs (58.4%) improved neurologically, 120/476 dogs (25.2%) were neurologically stable, 22/476 dogs (4.6%) deteriorated. Degenerative disc disease was the most common diagnosis in dogs admitted with paraparesis/ paraplegia. Myelography could diagnose secondary spinal compression caused by disc protrusion/ extrusion or any other cause. Corticosteroids and non-steroidal anti-inflammatory drugs (NSAID) were used commonly by the referring veterinarian in case a compressive myelopathy was suspected. Prognosis in dogs with degenerative disc disease type II is favorable when therapy was started soon after the clinical sign’s onset and the deep pain sensation was intact.

Ex vivo study of the intradiskal pressure in the C6-7 intervertebral disk after experimental destabilization and distraction-fusion of the C5-C6 vertebrae in canine cadaveric specimens.

To evaluate intradiskal pressure (IDP) in the C6-7 intervertebral disk (IVD) after destabilization and distraction-fusion of the C5-C6 vertebrae. 7 cadaveric C4-T1 vertebral specimens with no evidence of IVD disease from large-breed dogs. Specimens were mounted in a custom-made 6 degrees of freedom spinal loading simulator so the C5-C6 and C6-C7 segments remained mobile. One specimen remained untreated and was used to assess the repeatability of the IDP measurement protocol. Six specimens underwent 3 sequential configurations (untreated, partial diskectomy of the C5-6 IVD, and distraction-fusion of the C5-C6 vertebrae). Each construct was biomechanically tested under neutral, flexion, extension, and right-lateral bending loads. The IDP was measured with a pressure transducer inserted into the C6-7 IVD and compared between the nucleus pulposus and annulus fibrosus and across all 3 constructs and 4 loads. Compared with untreated constructs, partial diskectomy and distraction-fusion of C5-C6 decreased the mean ± SD IDP in the C6-7 IVD by 1.3 ± 1.3% and 0.8 ± 1.3%, respectively. During motion, the IDP remained fairly constant in the annulus fibrosus and increased by 3.8 ± 3.0% in the nucleus pulposus. The increase in IDP within the nucleus pulposus was numerically greatest during flexion but did not differ significantly among loading conditions. Distraction-fusion of C5-C6 did not significantly alter the IDP of healthy C6-7 IVDs. Effects of vertebral distraction-fusion on the IDP of adjacent IVDs with degenerative changes, such as those in dogs with caudal cervical spondylomyelopathy, warrant investigation.

СОВРЕМЕННЫЕ МАТЕРИАЛЫ ДЛЯ ИМПЛАНТОВ, ПРИМЕНЯЕМЫЕ В ЛЕЧЕНИИ СОБАК С СИНДРОМОМ ВОББЛЕРА

Wobbler's syndrome or caudal cervical spondylomyelopathy is a disease of the cervical spine in dogs of large and giant breeds, characterized by dynamic or static compression of the cervical spinal cord and nerve roots, which leads to neurological deficits and neck pain. Currently, there are many materials for the manufacture of various implants, as well as prosthetic discs, which are successfully used in the treatment of dogs with Wobbler syndrome, but veterinary neurologists have certain dissatisfaction with the results of surgical treatment, as a result of which a number of postoperative complications are noted. This makes it necessary to use new materials for the manufacture of implants. Currently, the vast majority of veterinary specialists use only titanium and stainless steel alloys (304V and 316LVM) as a material for cages, screws and plates. However, a number of shortcomings of these materials indicate the need for a search new innovative materials with improved characteristics. Currently, the materials used for the manufacture of implants in human medicine are of great interest, but have not yet found application in veterinary medicine (with the exception of stainless steel and titanium alloys). Among such materials are polyether etherketone (PEEK), carbon fiber reinforced polyether etherketone (CFR-PEEK), cobalt-chromium alloys, nitinol, tantalum. The article reflects the characteristics of these materials for the manufacture of implants, their advantages and disadvantages.

Ex vivo Evaluation of the Dynamic Morphometry of the Caudal Cervical Intervertebral Disc Spaces of Small Dogs and Cats.

The objective of this study was to provide a morphometric description of the caudal cervical intervertebral disc (IVD) spaces of small-breed dogs and cats. Specimens consisting of C4 through C7 from five small-breed dogs and six cats were positioned in neutral, flexion, extension, and lateral bending positions; and CT images were acquired. Height and width of the cranial and caudal vertebral endplates (VEPs), angle between the VEPs (IVD wedge angle), and craniocaudal distance (IVD width) between VEPs for the four loading positions were measured and compared for three segments (C4–C5, C5–C6, and C6–C7). VEP size normalized to body weight from medium-sized dogs was retrieved from a previous study and compared with data from small dogs and cats. A linear mixed model was used to compare outcome measures. Significance was set to p < 0.05. VEP size normalized to body weight was the largest in small dogs compared with cats (p = 0.0422) and medium-sized dogs (p = 0.0064). Cats and medium-sized dogs were similar (p = 0.2763) in this regard. Flexion and extension induced a reduction of IVD width in the ventral portion of the IVD and the area of the nucleus. The dorsal part of the IVD remained unchanged throughout loading conditions. Unique morphometric characteristics of the caudal cervical IVD space of small dogs and cats were detected that are different from those described in sizes of dogs (medium-sized) typically affected by caudal cervical spondylomyelopathy (CSM). These findings may help to understand the different pathomechanisms in cervical spinal disease between small- and medium-sized dogs, including caudal CSM.

Extradural Synovial Cyst of the Cervical Spine in a Saint Bernard

Background: Extradural synovial cysts (ESC) originate from an extrusion of the synovium in unstable or degenerated joints. In the spine, this condition can cause neurological signs such as hyperesthesia, proprioceptive ataxia and paresis. Since extradural presentations of synovial cysts are unusual in dogs, the aim of this manuscript is to report a case of extradural synovial cyst of the cervical spine, as well as the clinical findings, diagnosis, surgical treatment and clinical evolution after therapy.Case: A 3-year-old spayed Saint Bernard weighing 60 kg was presented to a Veterinary Medical Teaching Hospital with a history of acute paraparesis that evolved to non-ambulatory tetraparesis five days after the appearance of the first clinical signs. Neurological examination revealed non-ambulatory tetraparesis, normal muscle tone and segmental spinal reflexes in the thoracic and pelvic limbs, as well as cervical pain associated with limited neck movement. According to the neurological examination, the likely lesion location was the C1-C5 spinal cord segment. The differential diagnosis list included intervertebral disc disease, caudal cervical spondylomyelopathy, neoplasm, infectious or noninfectious inflammatory disease, and cystic diseases. Complete blood (cell) count and serum biochemistry tests were within reference limits. The cerebrospinal fluid analysis revealed 35 mg/dL of protein (&lt; 30 mg/dL) and 27 cells (up to 5 cells/mm3) with a predominance of lymphocytes. In plain radiography, bone proliferations of the C4 (caudal) C5 (cranial) articular processes were observed and, in myelography, extradural spinal cord compression was evident between C4-C5 on the right side. The animal underwent dorsal laminectomy for spinal cord decompression. An extradural synovial cyst and proliferated articular processes were removed. At 1,281 days after surgery, the dog was clinically normal and presented no neurological deficits.Discussion: The etiology of synovial cysts has not been well established. However, it is believed that osteoarthritic degeneration associated with joint mobility could cause a rupture in the articular capsule, leading to a synovial membrane protrusion, which would fill with synovial fluid and compress spinal structures. ESC in the cervical region have been reported, often associated with cervical neoplasm. The case we report had no evidence of bone or intervertebral disc compression in myelographic and radiographic exams, abnormalities that would appear in cervical neoplasm. The patient underwent dorsal laminectomy to confirm the presumptive diagnosis and decompress the spine. In the histopathological exam, the cystic material consisted of connective fibrous tissue with a synovial cell lining layer, compatible with synovial cysts. The fluid drained during surgery was also analyzed, showing similarities to synovial fluid drained from other conventional joints. Cerebrospinal fluid analysis revealed mononuclear pleocytosis, a common finding in ESC. The ESC should be included in the differential diagnosis of dogs with cervical myelopathy, especially in young animals and large breeds. A myelographic exam is an important but not definitive auxiliary tool for diagnosis and the therapeutic plan. Dorsal laminectomy is an effective technique for treating ESC.

Instrumented cervical fusion in nine dogs with caudal cervical spondylomyelopathy.

ObjectiveTo report the long‐term outcome of nine dogs treated for caudal cervical spondylomyelopathy (CCSM) with surgical spinal fusion.Study designShort case series.AnimalsNine large‐breed dogs.MethodsMedical records of dogs treated for disc‐associated CCSM (2013‐2016) were reviewed. The surgery objective was spinal distraction by implantation of a SynCage and fixation with two Unilock plates. Follow‐up included the Helsinki pain score questionnaire, neurological grading, radiography, computed tomography (CT), and micro‐CT (μCT) with subsequent histopathology (two dogs).ResultsClinical follow‐up was obtained between 9 and 51 months (27.4 ± 13.4 months). The Helsinki pain score and neurological Griffith score improved (P < .01) in all dogs and in eight of nine dogs, respectively. According to CT, the volume of bone (mean ± SD) through the cage was 79.5% ± 14.3%, including compact bone (53.0% ± 23.4%). Subsidence was seen in one of nine dogs. Implant failure was evident in four dogs, and plates were removed in two dogs. In seven of nine dogs, infraclinical pathology was observed in adjacent segment, associated with implants engaging adjacent intervertebral discs. Radiographic evidence of bony fusion between vertebral bodies was noted in all dogs. Spinal fusion was confirmed by μCT and histopathology in two cervical spine segments that became available at 22 and 40 months postoperatively.ConclusionInstrumented spinal fusion in dogs with disc‐associated CCSM resulted in owner satisfaction and radiographic evidence of interbody spinal fusion in all dogs.Clinical significanceThe fusion distraction technique reported here can be used to achieve spinal fusion with a good long‐term outcome.

Cervical Laminectomy for the Treatment of Chronic Caudal Cervical Spondylomyelopathy in a Dog

Background: Cervical spondylomyelopathy (CSM) is a common disease of the cervical spine, and causes neurogenic disorders commonly diagnosed in large and giant breeds dogs. There are many surgical procedures proposed for the treat­ment of CSM. Although many authors report a high success rate (between 70% and 90%) after surgical procedures, the high number of techniques described reflects the difficulty in treating this disorder. The objective of this paper is to report a case of CSM with chronic ventral compression (intervertebral disc extrusion) that was treated with dorsal decompres­sion, and to demonstrate the effectiveness of the decompressive technique through pre- and post-operative myelograms.Case: A 9-year-old Doberman Pinscher dog weighing 41.8 kg presented due to a history of tetraparesis. Neurological exami­nation did not reveal any alteration in mental status. There was absence of conscious proprioception on the four limbs; the pelvic limbs were more severely affected. Bilateral patellar hyperreflexia and normal flexor withdrawal reflex were observed on the hind limbs. There was decreased flexor withdrawal reflex and increased extensor tone on the forelimbs. The patient exhibited pain during caudal cervical palpation, and no alterations were seen on the cutaneous trunci reflex. Superficial pain was absent in the hind limbs; forelimbs exhibited presence of motor function with severe paresis. Survey radiographs revealed intervertebral disc space narrowing between C6-C7. A myelogram revealed ventral and dorsal compressions of the spinal cord in the C6-C7 area. Surgical treatment was elected, and laminectomy of the sixth and seventh cervical vertebrae was performed. Improvements were progressive on evaluations made on the seventh, eighteenth, forty-fifth, and sixtieth days after surgery. On the forty-fifth day after surgery, the patient was able to walk with the aid of a support sling, but was incapable of standing and walking without help. Muscle atrophy and paresis progressively improved up to the sixtieth day after surgery, but such improvement was not enough for the patient to get up and walk without the aid of the sling. In view of the evolution of the clinical signs during the post-operative period, another myelogram was performed to check if the extruded intervertebral disc, which was not removed during laminectomy, was still causing spinal cord compression. In comparison to the first myelogram, the compression was significantly attenuated by the surgical procedure. In this examination, the contrast medium columns were minimally compromised by the presence of herniated material; because of that, we opted not to perform a second surgical intervention for removal of herniated disc content.Discussion: Cervical laminectomy is indicated primarily for cases of dorsal compression associated with osteoarthritic changes of facet joints, malformation of the dorsal lamina, or ligamentum flavum hypertrophy however, this technique has also been used to treat ventral compressions, especially if they are multiple. There are no reports of direct comparison between laminectomy and other surgical techniques for the treatment of chronic ventral compressions; consequently, the choice of the technique depends on the surgeon’s experience and preference. Some authors argue that cervical laminec­tomy is not enough to attenuate the compression caused by the disc because this technique does not allow removal of the herniated disc material located ventrally. However, in the case reported here, a comparison between pre- and postopera­tive myelograms revealed that even though the herniated material was not removed, dorsal decompression allowed dorsal dislocation of the spinal cord and, consequently, promoted considerable attenuation of ventral compression.Keywords: Wobbler syndrome, nervous system, spinal cord, cervical vertebrae.

Distraction-stabilisation of two adjacent intervertebral spaces in a Dalmatian dog with caudal cervical spondylomyelopathy

A 4-year-old, 40-kg, male, entire Dalmatian was presented for evaluation of chronic neck pain and pelvic limb ataxia. Myelography revealed ventrodorsal (hourglass) extradural compression over the intervertebral space between the 5th and 6th cervical vertebra and ventral extradural compression between the 6th and 7th cervical vertebra. Cranial compression disappeared and caudal compression markedly diminished after performing cervical traction. MRI scan confirmed protrusion of intervertebral discs and spinal cord compression in previously mentioned intervertebral spaces. Surgical distraction-stabilization of both intervertebral spaces was performed using threaded pins and polymethylmethacrylate. The convalescence from surgery was uneventful and the dog was walking without any signs of paresis until 5 months after surgery when radiography revealed implants loosening. The dog recovered fully of the implant removal and remained asymptomatic for more than 30 months.

Myelographic diagnosis and results of surgical treatment of caudal cervical spondylomyelopathy in dogs: a retrospective study (2000–2010)

The outcomes of six different surgical techniques of caudal cervical spondylomyelopathy treatment in dogs with static and dynamic spinal cord compressions were assessed. Out of 425 dogs with cervical spine diseases, caudal cervical spondylomyelopathy was diagnosed in 69 dogs. Dynamic myelographic study was performed in 48 of them as a diagnostic method necessary for choosing the appropriate technique of surgical treatment. Twenty-five out of the 48 dogs underwent surgery. The best results of the surgical treatment of static compression were achieved with a ventral slot (89% of the nine surgical interventions) with partial improvement 48 h after surgery and marked improvement 8 weeks after surgery. For dynamic compressions, vertebral traction and stabilization with intervertebral washer plus vertebral body screws and polymethylmethacrylate bridge was found to be the most successful surgical treatment with significant improvement in 62% of the thirteen surgical interventions 8 weeks after surgery. In 5 dogs (20%), two intervertebral spaces with caudal cervical spondylomyelopathy were surgically treated. Recurrence was observed in 6 dogs (24%) after the mean period of 20 months (5 to 44 months) after surgery. Direct ventral slot decompression could be recommended for clinical cases of the caudal cervical spondylomyelopathy with static compression, and intervertebral washer plus vertebral body screws and polymethylmethacrylate bridge for dogs with dynamic compression, respectively. Our findings refer to the results of surgical treatment in a relatively large number of dogs with caudal cervical spondylomyelopathy and can help surgeons to choose an effective surgical method of treatment in dogs with wobbler syndrome based on dynamic myelographic study findings.

Distraction–Fusion for Caudal Cervical Spondylomyelopathy Using an Intervertebral Cage and Locking Plates in 14 Dogs

To evaluate clinical and radiographic outcome in dogs with caudal cervical spondylomyelopathy (CCSM) treated with an intervertebral fusion cage and locking plates. Prospective clinical study. Large breed dogs (n=14) with CCSM. Dogs had single level cervical spine distraction/fusion performed using an intervertebral cage with a hollow center filled with cancellous autograft and 2 ventrally applied locking plates. Outcome was measured using neurologic scores and radiographic interpretation 6 weeks, 6 months, and 12 months postoperatively. The surgical procedure was well tolerated in all dogs. Final outcome at 12 months was available in 9 dogs. Five dogs were judged excellent, 1 dog was good, 2 dogs were satisfactory, and 2 dogs were poor because of adjacent segment disease. Four dogs died for reasons unrelated to the procedure. Radiographically, implants remained stable over the entire follow-up period. The disc space continued to fill with an immature pattern of new bone, which showed progressive increase in opacity and quantity. Subsidence of the cage (median 2 m) was detected in 9 dogs at 6 weeks and remained unchanged in those that could be followed further. Distraction-fusion of single level CCSM in dogs with a combination of intervertebral cage and ventral locking plates is clinically effective and results in successful bony fusion.

Radiographic vertebral canal and vertebral body ratios in Doberman Pinschers with and without clinical signs of caudal cervical spondylomyelopathy

To determine radiographic vertebral ratio values representing vertebral canal stenosis in Doberman Pinschers with and without clinical signs of caudal cervical spondylomyelopathy (CCSM). Doberman Pinschers with (n = 81) and without (39) signs of CCSM. All dogs underwent lateral survey radiography of the cervical vertebral column. Five specific measurements were made at C3 through C7, and from those data, 3 ratios were calculated and analyzed for use in diagnosis of CSSM: canal height-to-vertebral body height ratio (CBHR), canal height-to-vertebral body length ratio (CBLR), and caudal vertebral canal height-to-cranial vertebral canal height ratio (CCHR). The CBHR and CBLR were considered indicators of vertebral canal stenosis, and CCHR described vertebral canal shape. Compared with Doberman Pinschers without CCSM, mean CBHR and CBLR values were significantly smaller for Doberman Pinschers with CCSM; for CBHR, this difference was evident at each assessed vertebra. The CCHR value for C7 was significantly larger in dogs with CCSM. Receiver operating characteristic statistics did not identify a threshold point that had combined high sensitivity and specificity sufficient to differentiate between Doberman Pinschers with and without CCSM. Doberman Pinschers with CCSM had vertebral canal stenosis combined with a funnel-shaped vertebral canal at C7 significantly more often than did Doberman Pinschers without CCSM. Despite these significant differences, no reliable threshold ratio values were identified to differentiate groups of dogs.

Bicortical Implant Insertion in Caudal Cervical Spondylomyelopathy: A Computed Tomography Simulation in Affected Doberman Pinschers

To evaluate the safety of the angle of insertion of bicortical implants in Doberman Pinschers affected by caudal cervical spondylomyelopathy (CCSM) using simulation on computed tomography (CT) images. Doberman Pinschers (n=9) with dynamic spinal compression attributed to CCSM. Dogs had CT evaluation of the cervical vertebral column. Digital images were used to evaluate the safety of bicortical implant insertion from the midline at 30, 35, and 40 degrees inclination by drawing a line simulating implant position. Correct surgical positioning of dogs was evaluated by measuring the degree of rotation of the spine along the longitudinal axis. Insertion of an implant at 30, 35, and 40 degrees inclination was considered safe in 42%, 59%, and 67% of selected sites. Rotation of the spine from 9 degrees counter clockwise to 10 degrees clockwise along the longitudinal axis occurred in 53% of the areas considered. These results suggest that bicortical implants in the caudal cervical area in Doberman Pinschers affected by CCSM carry a high risk of vertebral canal and intervertebral foramina violation. Bicortical implants inserted at 30 and 35 degrees in the caudal cervical area in Doberman Pinschers affected by CCSM carry a high risk of vertebral canal and intervertebral foramina violation. CT planning for individual dogs can facilitate selection of the appropriate insertion plane and vertebral column rotation needs to be considered in surgical planning.

In Vitro Biomechanical Comparison of Cervical Disk Arthroplasty, Ventral Slot Procedure, and Smooth Pins with Polymethylmethacrylate Fixation at Treated and Adjacent Canine Cervical Motion Units

To compare the biomechanical properties of cervical arthroplasty to a ventral slot procedure and pin-polymethylmethacrylate (pin-PMMA) fixation. Fresh cadaveric cervical (C2-T1) spines from 6 large dogs. Four spinal conditions were studied in each spinal specimen: intact, disk arthroplasty, ventral slot, and fixation with smooth pin-PMMA at C5-C6 intervertebral space. Axial compression, torsion, flexion-extension, and lateral bending moments were sequentially tested on each specimen for the 4 spinal conditions. Data from the C3-C4, C4-C5, C5-C6, and C6-C7 vertebral motion units (VMUs) were compared among treatments. In axial compression and torsion, the ventral slot procedure allowed significantly less motion than intact, pin-PMMA, and arthroplasty groups at C5-C6. In lateral bending and flexion-extension, pin-PMMA had the least motion of C5-C6, followed by the arthroplasty group, intact spine, and ventral slot, all of which were significantly different from each other. Overall, the artificial disk was better able to mimic the behavior of the intact specimens compared with the ventral slot and pin-PMMA, producing similar displacements in axial compression and rotation in torsion, but more limited motion than intact in flexion-extension and in lateral bending. Cervical spine specimens with an implanted prosthesis have biomechanical behaviors more similar to an intact spine compared with spinal specimens with ventral slot and pin-PMMA procedures. Cervical arthroplasty may then preserve some of the motion in the affected area after neural decompression while providing distraction. Cervical arthroplasty should be further investigated in vivo to determine if it is a viable alternative to the ventral slot or pin-PMMA procedures for surgical treatment of cervical diseases in dogs and in particular for treatment of disk-associated caudal cervical spondylomyelopathy.

Use of the ComPact UniLock System for ventral stabilization procedures of the cervical spine

This study evaluates clinical application of the ComPact UniLock system for ventral stabilization of the cervical spine. Patient material included 13 consecutive cases, 12 dogs and one cat, with cervical spinal instabilities secondary to disc-associated wobbler syndrome (six dogs), traumatic, iatrogenic, and disc-associated cervical spinal instability of small dogs (four cases), cervical spinal fractures (one dog and one cat), and congenital atlantoaxial instability (one dog). The 2.0 system was used in smaller patients and the 2.4 system was applied in large dogs. Implant failure was observed on follow-up radiographs in one dog with a healed C2 fracture and screw pullout occurred in one dog with caudal cervical spondylomyelopathy, necessitating revision surgery. Implants remained stable throughout the follow-up period in the other cases. 'Good' or 'excellent' clinical outcome was achieved in 12 patients, including the dog with revision surgery. One dog had to be euthanatized due to postoperative deterioration of neurological status and development of pneumonia. The ComPact UniLock system was found to be a suitable implant for treating cervical instabilities of different origin in both small and large patients with lesions from C1/C2 to C6/C7. Some problems were encountered in the dogs with disc-associated Wobbler syndrome, such as lack or slow rate of vertebral fusion and partial collapse of the distracted intervertebral space on follow-up radiographs. A lack of adequate fusion was most likely related to grafting techniques used.

A Modified Lateral Approach to the Canine Cervical Spine: Procedural Description and Clinical Application in 16 Dogs with Lateralized Compressive Myelopathy or Radiculopathy

To describe a modified lateral surgical approach to the cervical spine in dogs and evaluate clinical outcomes of dogs with neurologic disorders treated with this technique. Retrospective study. Sixteen dogs with lesions involving the cervical spine. Medical records (1998-2002) of dogs that had a modified lateral approach to the cervical spine were reviewed. To reduce procedural morbidity, the surgical approach was modified from original descriptions of the technique by minimizing disruption of epaxial and extrinsic thoracic limb musculature and limiting the size of the operative field to the affected vertebral segment. Signalment, neurologic status on admission; onset, progression, and duration of clinical signs; diagnostic testing, etiologic diagnosis, surgical site(s), intra- and postoperative complications, hospitalization, time to optimum recovery, neurologic status at discharge, final neurologic status, and outcome were recorded. Neurologic status (0-5) was scored preoperatively, 1 day postoperatively, at discharge, and at recheck examination (8 dogs). Telephone interviews were used to obtain additional follow-up information. None of the dogs had postoperative deterioration in neurologic status. Outcomes were good or excellent in dogs with intervertebral disc disease, 3/4 dogs with caudal cervical spondylomyelopathy, 1/2 dogs with spinal neoplasia, and in 1 dog with the vascular anomaly; long-term outcomes were unknown in 2 dogs. Intraoperative complications occurred in 3 dogs and included controllable venous plexus hemorrhage (2) and incorrect lesion localization (1). One dog was euthanatized because of postoperative complications. Hospitalization, time to optimal recovery, and overall outcome were not different from previously reported results using other surgical approaches to treat analogous neurologic conditions. A modified lateral approach to the cervical spine is viable for surgical treatment of cervical myelopathic or radiculopathic lesions when exposure to foraminal and lateralized lesions of the vertebral canal involving the C2-C7 vertebral articulations is desirable. A modified lateral approach to the cervical spine can be successfully used in dogs of all sizes to treat caudal cervical spondylomyelopathy, other anomalous conditions of the cervical spine, intervertebral disc disease, and spinal neoplasms. Although long-term follow-up was not available for all patients, outcomes were generally favorable.

Dorsal laminectomy for caudal cervical spondylomyelopathy: postoperative recovery and long-term follow-up in 20 dogs.

To evaluate the postoperative morbidity and long-term outcome of dogs after dorsal laminectomy for caudal cervical spondylomyelopathy (CCSM). Retrospective study. Twenty dogs with CCSM. Medical records of dogs treated by dorsal laminectomy for CCSM at North Carolina State University and Colorado State University between 1989 and 1999 were reviewed. Information on signalment, onset, progression and duration of clinical signs, diagnostic testing, sites of dorsal laminectomy, postoperative complications, length of hospitalization, and the ambulatory status on discharge was recorded. A minimum follow-up of 7 months was required for inclusion in the study. Neurologic status was graded (0 to 5) preoperatively, 2 days after surgery, and at the time of the study (final score). Improvement or worsening of the neurologic status was assessed by comparison of different scores for each dog. Additional follow-up information was obtained by means of a detailed telephone questionnaire directed at both the owner and referring veterinarian. Mean duration of clinical signs before surgery was 4.9 months. At admission, 15 dogs were ambulatory and 5 were nonambulatory. Neurologic status worsened in 70% of dogs 2 days after surgery but improved in all but 1 dog over the long term. Mean time to optimal recovery was 3.6 months. Long-term follow-up ranged from 7 months to 9 years (mean +/- SD, 3.2 +/- 2.4 years). Four dogs had confirmed recurrence; 2 other dogs may have had recurrence. Dorsal cervical laminectomy is an effective treatment for CCSM in those dogs with dorsal compression or multiple sites of involvement. Although most dogs' neurologic status transiently worsened after surgery, long-term outcome and recurrence rates were comparable to those seen with other surgical techniques for CCSM.

Comparison of two surgical techniques for the management of cervical spondylomyelopathy in dobermanns

A study was undertaken to compare the efficacy of two surgical techniques for the treatment of caudal cervical spondylomyelopathy (CCSM): ventral decompression (slot) and vertebral distraction and stabilisation with a screw and washer (screw/washer). Twenty-eight dobermanns managed surgically for disc-associated CCSM during a four-year period were studied retrospectively. The maximum postoperative period was 40 months. Cases were excluded if a minimum follow-up of 24 months after surgery could not be made. A 'slot' took a longer time to perform and had a higher rate of immediate postoperative deterioration. Duration of hospital stay was similar for both procedures. At six months after surgery the two techniques were comparable; 12/14 (screw/washer) and 13/14 (slot) patients were deemed to have a satisfactory outcome. Recurrence of cervical spinal cord disease was higher in the screw/washer dogs. At one year after surgery the recurrence rate was zero (slot) and 5/14 (screw/washer), respectively. At two years after surgery 4/14 of the slot dogs had deteriorated compared to 7/14 of the screw/washer dogs. Where investigated, the cause of deterioration was either a domino disc lesion or vertebral endplate collapse and dorsal displacement of the screw and washer.

Surgical conditions of the cervical spine.

This article reviews the four most common surgical conditions of the cervical spinal cord other than vertebral fractures including atlantoaxial instability, cervical disc disease, caudal cervical spondylomyelopathy, and spinal cord tumors. Each disease is reviewed by signalment, history, neurological examination, differential diagnosis, pertinent diagnostic testing, treatment, postoperative care, and prognosis.

Abstract of Current Literature

Modified Distraction‐Stabilization Technique Using an Interbody Polymethyl Methacrylate Plug in Dogs With Caudal Cervical Spondylomyelopathy by Dixon BC, et al

Modified distraction-stabilization technique using an interbody polymethyl methacrylate plug in dogs with caudal cervical spondylomyelopathy

Modified distraction-stabilization technique using an interbody polymethyl methacrylate plug in dogs with caudal cervical spondylomyelopathy