RADIOGRAPHIC SENSITIVITY AND NEGATIVE PREDICTIVE VALUE FOR ACUTE CANINE SPINAL TRAUMA

A Case Series of Four Dogs Presenting with Neurological Deficits Due to Suspected Nutritional Secondary Hyperparathyroidism after Being Fed an Exclusive Diet of Raw Meat

Nutritional secondary hyperparathyroidism (NSH) in dogs is a condition that develops in response to a vitamin D deficiency or an imbalanced calcium-to-phosphorus ratio in dog food. Puppies of large-breed dogs exclusively fed a non-supplemented, boneless raw meat diet are especially susceptible to developing NSH due to their elevated calcium requirement. Reports on NSH in companion animals have been sparse in the last decades due to dog owners having easy access to commercially balanced dog foods. However, with the rising popularity of meat-based raw feeding, this condition has re-emerged. In this case series, four large-breed puppies fed exclusively non-supplemented, boneless raw meat diets presented with complaints of acute onset of pain and paresis. Radiographs and/or computed tomography (CT) scans showed reduced radio density of the skeleton in all four puppies. Two of the dogs had pathological fractures, and these two puppies were euthanized. One was subjected to a post mortem examination, which revealed cortical bone resorption and hypertrophy of the parathyroid glands. The remaining two puppies rapidly improved after receiving pain medication and a commercial, balanced diet. This case series demonstrates a risk of young dogs developing severe neurological deficits when fed a non-supplemented, boneless raw meat diet.

Spinal Neuronavigation for Lumbar Plate Fixation in Miniature Breed Dogs

OBJECTIVE

 The main aim of this pilot study was to assess the feasibility of spinal neuronavigation for plate fixation of lumbar vertebrae in miniature breed dogs using a surgical navigation system in combination with a custom-made reference array.

STUDY DESIGN

 This was an experimental cadaveric study in five miniature breed dogs.

METHODS

 A 4-hole locking plate with four 2.0-mm locking screws was placed on two adjacent lumbar vertebrae using a neuronavigation system consisting of a mobile cone beam computed tomography linked to a navigation system. The procedure was performed by a novice surgeon. The plate and screw positions were assessed for surgical safety using predefined criteria. Surgical accuracy was determined by the deviation of entry and exit points between pre- and postoperative images.

RESULTS

 A total of five plates and 20 screws were placed. In 85% (17/20), screws were placed appropriately. The median entry point deviation was 1.8 mm (range: 0.3-3.7) and the median exit point deviation was 1.6 mm (range: 0.6-5).

CONCLUSION

 Achievement of surgical accuracy in the placement of screws for fixation of lumbar vertebral plates in small breed dogs using neuronavigation with a custom-made reference array by a novice surgeon resulted in surgical safe plate placement in four of the five cadavers. Therefore, we judge the method as promising, however, further studies are necessary to allow the transfer of image-guided navigation for lumbar plate fixation into the clinic.

Case report: Traumatic hemorrhagic cervical myelopathy in a dog

A 1.5-year-old female entire French bulldog was referred for neurological evaluation, further diagnostic tests, and treatment 24 h after a road traffic accident. Initial emergency treatment, diagnostic tests, and stabilization had been performed by the referring veterinarian. Neurological examination revealed severe spastic non-ambulatory tetraparesis and was consistent with a C1-5 myelopathy. A magnetic resonance imaging (MRI) study revealed an irregular to elongated ovoid intramedullary lesion centered over the body of C2. The lesion showed marked signal heterogeneity with a central T2W and T2* hyperintense region, surrounded by a hypointense rim on both sequences. The lesion appeared heterogeneously T1W hypointense. The lesion was asymmetric (right-sided), affecting both white and gray matter. The C2-3 intervertebral disk appeared moderately degenerate with a Pfirrmann grade of 3. No evidence of vertebral fracture or luxation was found on radiographs or MRI of the vertebral column. Additional soft tissue abnormalities in the area of the right brachial plexus were suggestive of brachial plexus and muscle injury. A diagnosis of traumatic hemorrhagic myelopathy at the level of C2 and concurrent brachial plexus injury was formed. Conservative treatment was elected and consisted of physiotherapy, bladder care with an indwelling urinary catheter, repeated IV methadone based on pain scoring (0.2 mg/kg), oral meloxicam 0.1 mg/kg q24h, and oral gabapentin 10 mg/kg q8h. The dog was discharged after 4 days, with an indwelling urinary catheter and oral medication as described. The catheter was replaced two times by the referring veterinarian and finally removed after 10 days. Thereafter, voluntary urination was seen. During the 2 months after the road traffic accident, slow recovery of motor function was seen. The right thoracic limb recovery progressed more slowly than the left limb, also showing some lower motor neuron signs during follow-up. This was judged to be consistent with a right-sided brachial plexus injury. The dog was reported ambulatory with mild residual ataxia and residual monoparesis of the right thoracic limb at the last follow-up 3 months post-injury. This case report highlights the MRI-based diagnosis of traumatic hemorrhagic myelopathy in a dog. A fair short-term outcome was achieved with conservative treatment in this case.

Diagnostic and Treatment of Spinal Fracture and Luxation in Italian Wolves (Canis lupus italicus)

The medical records of 14 Italian wolves (Canis lupus italicus) with a vertebral fracture or luxation (SFL) between C1 and L7 treated at Ospedale Veterinario San Michele from 2017 and 2022 were reviewed. The most common cause of SFL was “road traffic accident”. Neurological signs were graded from 0 to 6 using a modified Frankel scale. Spinal fractures occurred in C1–C5 in 1 case, in T3–L3 in 11 cases and in L4–L7 in 2 cases. Six wolves were euthanized without treatment because they presented paraplegia without deep pain perception (DPP). Two animals with motor function were treated conservatively, and later on one of them was euthanized because of neurological impairment. Six wolves were surgically treated. Seven wolves had good neurological recovery, and six of them were released into the wild. Our results suggest that wolves with DPP before surgery may have a good functional recovery.

Long-Term Follow-Up of Dogs and Cats after Stabilization of Thoracolumbar Instability Using 2-0 UniLock Implants

Traumatic vertebral fracture or luxation often results in spinal instability requiring surgical stabilization. This study describes the long-term outcome of spinal stabilization using a unilateral 5-hole 2-0 UniLock implant in eight dogs and two cats with trauma-induced thoracolumbar vertebral luxation/subluxation and presumed instability, as assessed by a combination of preoperative radiographs and MRI using a 3-compartment method. The UniLock plate was secured with four monocortical locking screws in adjacent vertebral bodies. Additional pins and facet screws were used in several patients. Postoperative radiographs and MRI studies showed restoration of the main spinal axis in all patients and satisfactory implantation of the screws in the vertebral bodies, with no intrusion in the vertebral canal or in the adjacent intervertebral disc spaces. Neurological status improved in nine patients six weeks postoperatively. Partial implant failure was detected in three patients with no long-term consequences. After 12 months, seven patients reached full recovery with no neurological deficit, two patients were euthanized (including one owing to an unrelated condition), and one remained paraparetic. The results of this study demonstrate that using a 2-0 UniLock implant to stabilize the thoracolumbar spine results in satisfactory long-term recovery in most dogs and cats with traumatic spinal luxation/subluxation and presumed instability. Complications may occur but do not require revision surgery and do not affect clinical outcomes.

Dystocia and cesarean section in a free-ranging ocelot (Leopardus pardalis) after traumatic spinal cord injury resulting from dog (Canis familiaris) attack

Background:

Ex situ breeding programs are essential to establish genetic resource banks and produce offspring to strengthen the in situ conservation of endangered species. However, many programs fail to maintain viable ex situ populations due to reproductive problems, including dystocia in pregnant females. Dystocia encompasses different emergency obstetric situations for the lives of dams and fetuses that require urgent intervention. This condition has been studied in domesticated species but published records in wildlife, specifically in felines species, are scarce.

Case Description:

An adult female ocelot (Leopardus pardalis) was referred to the wildlife hospital of the Universidad San Francisco de Quito after being attacked by dogs (Canis familiaris). Neurological tests revealed traumatic spinal cord injury at a thoracolumbar level. Complementary tests (laboratory exams, radiographs, and ultrasound) revealed a full-term pregnancy, failure in the labor progress, and critical fetal stress. A cesarean section was performed, and the newborns received resuscitation care after assessing their viability using the Apgar score system. The neonate with the lowest Apgar score died within the first hour after birth, while the second one showed an increase in Apgar score after resuscitation care and survived the procedure.

Conclusion:

We provide new obstetric data that could be relevant to save the lives of dams and newborns in related cases for ocelots and other species of wild felids. Furthermore, this study confirms the adverse effects that domestic dogs have on wildlife species.

Deer Rescue in Tuscany: Retrospective Analysis and Assessment of Radiography Diagnoses

Simple Summary

Animal-vehicle collisions are the major cause of rescue and need for hospitalization in wildlife referral centers. Radiography is used to assess the traumatized animal and is a rapid means to evaluate various traumatic pathologies. Clinicians can exploit radiography when making rapid decisions about whether to euthanize or treat an animal. We evaluated data (reasons for rescue, diagnosed lesions, and outcome) from a population of hospitalized wildlife ungulates and we investigated the benefits of using radiography as a diagnostic tool.

Abstract

Animal-vehicle collisions are the major cause of rescue and need for hospitalization in wildlife referral centers. Clinicians need easy-to-use tools to make rapid decisions about whether to euthanize or treat injured animals. The aim of the study was to evaluate the data (reasons for rescue, diagnosed lesions, and outcome) from a hospitalized population of wildlife ungulates and investigate the benefits of using radiography as a diagnostic tool. Data were collected from three wildlife referral centers in Tuscany (Italy). The following information was collected for each animal: reason for hospitalization, clinical examination, radiographic examination, definitive diagnosis, and outcome. A chi-squared test was used to assess the benefits of radiography in detecting different traumatic lesions. Prevalence was reported according to the reason for hospitalization, definitive diagnosis, radiographic diagnosis, and outcome. The main reason for hospitalization was traumatic lesions due to vehicle collisions and 71.1% of the animals did not survive. Radiography was more useful in patients with traumatic axial skeletal lesions and/or multiple traumas with respect to traumatic appendicular skeleton lesions. Our results show that radiography is a useful diagnostic technique for assessing wildlife emergencies and it could help the clinician in making medical decisions.

Pedicle screws implantation in polymethylmethacrylate construct to stabilise sixth lumbar vertebral body fracture in dogs: 5 cases (2015-2018)

OBJECTIVES

To assess the feasibility and outcome of pedicle screw implantation on sixth lumbar vertebral body fractures.

MATERIALS AND METHODS

Dogs with sixth lumbar vertebral body fractures stabilised using L6 and L7 (±L5) pedicular implantation via a dorsal approach preferentially and conventional vertebral body implantation otherwise were reviewed. Coaptation was made with bone cement. Complete neurological examination, pre and postoperative imaging consistent with L6 body fracture (radiographs ± CT scan) and follow up including clinical examination and radiographs 3 to 5 weeks post-operatively were required as inclusion criteria. When available, owner interview and/or clinical examination and imaging (radiographs ± CT scan) at least 1 year after surgery were reported.

RESULTS

Five dogs met the inclusion criteria. Dorsal pedicle screws implantation was feasible in all L7 vertebrae and in four L6 vertebrae. Adequate implantation was observed in all of the post-operative radiographs and on all of the three CT scans available. At 3 to 6 weeks after surgery, neurological status and locomotion were normal in four dogs, while one dog suffering from severe sciatic neuropathy did not regain normal locomotion. At least 1 year after surgery, clinical outcome was excellent for four dogs and imaging by radiography and CT scan were available for three dogs and showed complete healing of the fracture and correct positioning of the implants. The dog suffering from sciatic neuropathy had a further trauma and was euthanased 7 weeks after the surgery.

CLINICAL SIGNIFICANCE

In this case series, pedicle screw implantation achieved stabilisation of L6 vertebral body fractures, with full recovery observed in four out of five dogs. Further studies are required to confirm the safety and the effectiveness of this intervention.

Diagnostic Imaging in Intervertebral Disc Disease

Imaging is integral in the diagnosis of canine intervertebral disc disease (IVDD) and in differentiating subtypes of intervertebral disc herniation (IVDH). These include intervertebral disc extrusion (IVDE), intervertebral disc protrusion (IVDP) and more recently recognized forms such as acute non-compressive nucleus pulposus extrusion (ANNPE), hydrated nucleus pulposus extrusion (HNPE), and intradural/intramedullary intervertebral disc extrusion (IIVDE). Many imaging techniques have been described in dogs with roles for survey radiographs, myelography, computed tomography (CT), and magnetic resonance imaging (MRI). Given how common IVDH is in dogs, a thorough understanding of the indications and limitations for each imaging modality to aid in diagnosis, treatment planning and prognosis is essential to successful case management. While radiographs can provide useful information, especially for identifying intervertebral disc degeneration or calcification, there are notable limitations. Myelography addresses some of the constraints of survey radiographs but has largely been supplanted by cross-sectional imaging. Computed tomography with or without myelography and MRI is currently utilized most widely and have become the focus of most contemporary studies on this subject. Novel advanced imaging applications are being explored in dogs but are not yet routinely performed in clinical patients. The following review will provide a comprehensive overview on common imaging modalities reported to aid in the diagnosis of IVDH including IVDE, IVDP, ANNPE, HNPE, and IIVDE. The review focuses primarily on canine IVDH due to its frequency and vast literature as opposed to feline IVDH.

MRI has limited agreement with CT in the evaluation of vertebral fractures of the canine trauma patient

Complete assessment of vertebral trauma in dogs currently requires CT and MRI for evaluation of the osseous and soft tissue structures that contribute to vertebral stability. Some studies in people have suggested that MRI may be sensitive and specific at detecting vertebral fractures making this potentially a single modality that could be used in spinal trauma evaluation. This study aimed to assess the ability for observers to evaluate vertebral fractures using MRI when compared to CT, which was used as the reference standard. Twenty-nine dogs with previously diagnosed acute vertebral fractures and four dogs with no vertebral fracture that had undergone sequential CT and MRI were included into the study. One hundred twenty-eight vertebrae were evaluated for the presence of fractures. Imaging studies were read by two observers blinded to the history. While both observers had similarly high sensitivity and specificity for simple detection of any fractured vertebrae, interobserver agreement was only moderate (κ = 0.584). When evaluations were specifically limited to detection of structurally unstable fractured vertebrae both observers showed improved specificity and interobserver agreement became substantial (κ = 0.650). Complete agreement for exact fracture location between MRI and CT results was only achieved in 14.3-32.6% of fractured vertebra with up to 79% of fractures being missed in some vertebral structures. This suggests that although MRI may be able to detect the presence of fractured vertebrae, it is not able to replace CT for the complete evaluation of the traumatized spine and documentation of fracture morphology.

Traumatic atlantoaxial subluxation in dogs: 8 cases (2009-2016)

OBJECTIVE

To demonstrate the utility of advanced imaging in dogs with traumatic atlantoaxial subluxation (TAAS), and to report the presentation, treatment, and outcome for these dogs.

DESIGN

Retrospective study (2009-2016).

SETTING

University teaching hospital.

ANIMALS

Eight dogs diagnosed with TAAS with magnetic resonance imaging (MRI), computed tomography (CT), or both.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Eight dogs met criteria for inclusion. Of these, 6 were male, median age was 4 years (range, 1.5-11 years), and median body weight was 4.9 kg (range, 3.0-25.0 kg). On presentation, 6/8 (75%) dogs were nonambulatory tetraparetic and the most common injury was trauma inflicted by another animal 5/8 (62.5%). Diagnosis of TAAS was made using a combination of imaging modalities including vertebral column radiographs in 7/8 (87.5%) (of which 71.4% were suspicious for TAAS), CT in 7/8 (87.5%), and MRI in 7/8 (87.5%). In 7/8 (87.5%) dogs, CT and/or MRI offered additional information regarding the extent of injuries. Vertebral fractures were identified in 62.5% (5/8) of dogs. The majority of dogs underwent surgical repair (7/8 [87.5%]). The most common complication was aspiration pneumonia (3/8 [37.5%]). All 8 dogs survived to discharge. At the time of discharge, 4/8 (50%) were ambulatory tetraparetic. The 4 dogs that were nonambulatory tetraparetic at discharge progressed to being ambulatory within 2 months of surgery.

CONCLUSIONS

Although TAAS is an uncommon occurrence it should be considered a differential for any trauma patient that is presenting with signs of a cranial cervical myelopathy. CT and MRI have been shown to be useful to identify the extent of injuries and to facilitate surgical planning. With appropriate care, these dogs can have an excellent prognosis.

Estabilização vertebral segmentar modificada no tratamento de trauma medular em ouriço-cacheiro (Coendou spinosus): relato de caso

RESUMO Uma fêmea, adulta, de ouriço-cacheiro (Coendou spinosus, F. Cuvier, 1823), foi atendida com histórico de trauma medular. No exame neurológico, foi constatada paraplegia com nocicepção preservada e sinais compatíveis com choque espinhal. Exame radiográfico e mielografia apontaram presença de fratura e luxação vertebral torácica entre T10-11. O paciente foi submetido à técnica de estabilização vertebral segmentar modificada, com pinos de Steinmann e fios de cerclagem. A técnica utilizada mostrou-se eficaz na estabilização da fratura/luxação vertebral e na recuperação dos sinais neurológicos. O paciente apresentou recuperação progressiva da deambulação. Para o conhecimento dos autores, este é o primeiro relato utilizando estabilização vertebral segmentar modificada para o tratamento de fratura/luxação vertebral torácica em Coendou spinosus.

Percutaneous transilial pinning for treatment of seventh lumbar vertebral body fracture

Objective: To evaluate outcomes after percutaneous application of transilial pinning in dogs with seventh lumbar vertebral body fracture with concurrent lumbosacral luxation.

Methods: We reviewed the medical records of dogs with seventh lumbar vertebral body fracture stabilized with percutaneous transilial pinning that were treated at our hospital between January 2000 and March 2014. Radiographic measurements were used for comparing craniocaudal and ventrodorsal displacement pre- and postoperatively.

Results: Seventeen dogs met the inclusion criteria. The neurological status of the majority of treated dogs improved quickly, with immediate pain reduction after surgery. Implants were well tolerated throughout the application period and were removed at a mean time of 54.4 ± 9.2 days. One dog experienced a major complication (implant failure) and required surgical revision a week after the initial procedure. Minor complications included pin-tract inflammation, signs of back pain lasting five weeks and acute lameness after implant removal. Postoperative radiographic measurements showed shortening of the vertebral body and residual dorsoventral dislocation. Otherwise, functional recovery was good (5 of 17 dogs) to excellent (10 of 17 dogs) in the majority of the patients.

Clinical relevance: The use of two percutaneous transilial pins can be considered as treatment for the management of seventh lumbar fracture-luxation in dogs. Our modified stabilization technique is relatively easy to perform; less invasive on the soft tissues; and uses implants that are versatile, modifiable, and easily removable.

Acute Herniation of Nondegenerate Nucleus Pulposus: Acute Noncompressive Nucleus Pulposus Extrusion and Compressive Hydrated Nucleus Pulposus Extrusion

Acute herniation of nondegenerate nucleus pulposus material is an important and relative common cause of acute spinal cord dysfunction in dogs. Two types of herniation of nondegenerate or hydrated nucleus pulposus have been recognized: acute noncompressive nucleus pulposus extrusion (ANNPE) and acute compressive hydrated nucleus pulposus extrusion (HNPE). Spinal cord contusion plays an important role in the pathophysiology of both conditions. Sustained spinal cord compression is not present in ANNPE, whereas varying degrees of compression are present in HNPE. Although affected animals often present with severe neurologic signs, good outcomes can be achieved with appropriate treatment.

Usefulness of multidetector computed tomography in the evaluation of spinal neuro-musculoskeletal injuries

Spinal trauma is commonly diagnosed in small animal practice. Although the first approach to the patient with spinal trauma includes survey spinal radiographs, an accurate evaluation of the injury often requires advanced imaging. Multidetector computed tomography has revolutionized computed tomography technology, providing near-isotropic volumetric representation of the complete body with exquisite anatomical detail in a brief scan time. This review aims to discuss the technical background, indications, and limitations of multidetector computed tomography in the assessment of spinal trauma with particular reference to skeletal, muscular and nervous spinal components.

Updates in the management of the small animal patient with neurologic trauma

Neurologic trauma, encompassing traumatic brain injury (TBI) and acute spinal cord injury (SCI), is a cause of significant morbidity and mortality in veterinary patients. Acute SCIs occurring secondary to trauma are also common. Essential to the management of TBI and SCI is a thorough understanding of the pathophysiology of the primary and secondary injury that occurs following trauma. This article reviews the pathophysiology of this primary and secondary injury, as well as recommendations regarding clinical assessment, diagnostics, pharmacologic and nonpharmacologic therapy, and prognosis.

Mechanisms of injury and emergency care of acute spinal cord injury in dogs and cats

OBJECTIVES

To review the literature in regards to the pathophysiology of acute spinal cord injury, and to describe current concepts in regards to patient assessment, diagnostic, and therapeutic measures with a special emphasis on emergency and critical care considerations.

ETIOLOGY

Acute spinal cord injury occurs in 2 phases. The primary injury occurs at the time of initial injury and may include intervertebral disk herniation, vertebral fracture or luxation, penetrating injury, and vascular anomalies such as fibrocartilaginous embolic myelopathy. Secondary injury occurs following primary injury and is multifactorial encompassing numerous biochemical and vascular events that result in progression of injury.

DIAGNOSIS

The diagnosis is based on history and physical examination findings. A neurologic examination should be performed following initial patient assessment and stabilization. Further diagnostics to characterize acute spinal injury include radiographs and advanced imaging modalities such as myelography, computed tomography, or magnetic resonance imaging.

THERAPY

Initial treatment should focus on addressing the patient's cardiovascular and respiratory system. Supportive measures to support systemic perfusion are vital to minimizing secondary injury. Specific therapy toward minimizing secondary injury in veterinary medicine remains controversial, especially in regards to the utilization of methylprednisolone. Other therapies are either in need of additional research or have failed to document clinical difference.

PROGNOSIS

The prognosis for acute spinal injury is varied and is dependent upon the presence of concurrent trauma, location, and type of primary injury sustained, and extent of neurologic impairment at the time of initial presentation. The etiology of the underlying trauma is of great importance in determining prognosis and outcome. Loss of deep pain is generally accepted as a poor prognostic indicator; however, even these patients can recover depending on their response to treatment.

Acute Spinal Cord Injury in the Cat: Causes, Treatment and Prognosis

Practical relevance Acute spinal conditions are a common emergency presentation in general veterinary practice and have the potential to cause devastating spinal cord injury (SCI) and consequent severe neurological deficits. SCI can be divided into two subgroups: exogenous SCI (vertebral fracture and/or luxation/subluxation) and endogenous SCI (intervertebral disc extrusion and ischaemic myelopathy).

Clinical challenges The majority of cats with SCI have concurrent injuries. The clinician must perform a thorough physical examination and prioritise and then stabilise the life-threatening problems before focusing on the neurological examination. The possibility of multiple sites of SCI and spinal shock can make interpretation of the neurological examination challenging. While plain radiographs or myelography are usually diagnostic, they do not give direct information about the integrity of the spinal cord parenchyma or the severity of any damage. If facilities or experienced staff capable of performing the necessary surgery are not available, or advanced imaging is indicated, referral to a specialist veterinary institution should be considered.

Audience This review is aimed at clinicians dealing with feline SCI in the emergency setting or at first-opinion level, and discusses causes, initial management, specific treatment and prognosis.

Patient group While any cat may potentially be affected by SCI, there is a tendency for exogenous SCI to be more common in younger individuals and, in the authors' experience, pure-breed cats are very rarely presented. Endogenous SCI can be seen in any breed and is typically a condition of adult cats.

Diagnosis and surgical management of a fractured atlas in a cat

A 6-month-old male-castrated domestic shorthair cat was presented shortly after being bitten on the neck by a large breed dog. On presentation the cat was non-ambulatory tetraparetic with preserved deep pain perception. Plain radiographs of the neck did not show any abnormalities. Computed tomography was performed and showed a right-sided depressed fracture of the dorsal lamina of the atlas. A partial dorsal laminectomy was performed to alleviate the spinal cord compression. The cat made a full recovery within 12 weeks of surgery.

Accuracy of conventional radiography and computed tomography in predicting implant position in relation to the vertebral canal in dogs

OBJECTIVE

To compare the accuracy of radiography and computed tomography (CT) in predicting implant position in relation to the vertebral canal in the cervical and thoracolumbar vertebral column.

STUDY DESIGN

In vitro imaging and anatomic study.

ANIMALS

Medium-sized canine cadaver vertebral columns (n=12).

METHODS

Steinmann pins were inserted into cervical and thoracolumbar vertebrae based on established landmarks but without predetermination of vertebral canal violation. Radiographs and CT images were obtained and evaluated by 6 individuals. A random subset of pins was evaluated for ability to distinguish left from right pins on radiographs. The ability to correctly identify vertebral canal penetration for all pins was assessed both on radiographs and CT. Spines were then anatomically prepared and visual examination of pin penetration into the canal served as the gold standard.

RESULTS

Left/right accuracy was 93.1%. Overall sensitivity of radiographs and CT to detect vertebral canal penetration by an implant were significantly different and estimated as 50.7% and 93.4%, respectively (P<.0001). Sensitivity was significantly higher for complete versus partial penetration and for radiologists compared with nonradiologists for both imaging modalities. Overall specificity of radiographs and CT to detect vertebral canal penetration was 82.9% and 86.4%, respectively (P=.049).

CONCLUSIONS

CT was superior to radiographic assessment and is the recommended imaging modality to assess penetration into the vertebral canal.

CLINICAL RELEVANCE

CT is significantly more accurate in identifying vertebral canal violation by Steinmann pins and should be performed postoperatively to assess implant position.