CT diagnosis of occipital condyle fracture in a dog presented for severe cervical hyperesthesia.

A 9-month-old male entire Doberman Pinscher presented with acute onset of severe cervical hyperesthesia after a fall. Neurological examination revealed a normal gait with low head carriage and severe cervical hyperesthesia. A CT scan of the cervical vertebral column revealed the presence of a comminuted fracture at the dorsomedial aspect of the right occipital condyle and sclerosis of the underlying bone. Medical management was initiated consisting of an external bandage, strict rest, and pain medication. Due to the lack of clinical improvement, the dog was euthanized 2 months after diagnosis. Histopathology of the lesion was compatible with a healing fracture.

Application of a bilateral temporal fascia free graft in a dog with multifragmented frontal sinus and nasal bone fracture.

OBJECTIVE: To describe the use of temporal fascia free grafts to treat dorsal open comminuted frontal sinus and nasal fractures. ANIMAL: One Belgian shepherd dog. STUDY DESIGN: Case report METHODS: A 5-year-old spayed female Belgian shepherd was admitted with severe facial deformation due to trauma. A deep, 3 cm wide wound was present between the nose and the frontal sinus. No abnormalities were detected on neurological examination. On computed tomographic examination, comminuted open fractures of the frontal and nasal bones were associated with a severe depression of the dorsal wall and presence of bone fragments in the sinus cavities. Bone fragments were apposed with polydioxanone monofilament suture. Bilateral temporal fascia grafts were placed over the bone fragments. RESULTS: The integrity of the frontal and nasal cavities, and the facial profile of the dog were restored. No short-term or long-term complications were observed after 4 months follow up. CONCLUSION: The innovative combination of suture apposition of bone fragments and a temporal fascia free graft resulted in very satisfying long-term outcomes in a dog with open sinus and nasal bone fractures.

Traumatic skull fractures in dogs and cats: A comparative analysis of neurological and computed tomographic features.

BACKGROUND: Traumatic skull fractures (TSF) are relatively frequent in dogs and cats, but little information is available regarding their clinical and imaging features. HYPOTHESIS/OBJECTIVES: To describe the neurological and computed tomographic (CT) features of a large cohort of dogs and cats with TSF. ANIMALS: Ninety-one dogs and 95 cats with TSF identified on CT. METHODS: Multicenter retrospective comparative study. Signalment, cause of trauma, fracture locations and characteristics, presence of neurological deficits, and 1-week survival were recorded. Fractures were classified according to the extent of fragmentation and displacement. RESULTS: The cranial vault was affected more frequently in dogs (P = .003), whereas the face and base of the cranium more often was affected in cats (P < .001). Cats presented with multiple fractures more frequently (P < .001). All animals with TSF in the cranial vault were more likely to develop neurological signs (P = .02), especially when depressed fractures were present (95% confidence interval [CI], 1.7-8.2; P = .001). Animals with TSF located only in the facial region were less likely to have neurological signs (odds ratio with Mantel-Haenszel's method [ORMH ], 0.2; 95% CI, 0.1-0.6; P = .004). Most affected animals (84.9%) survived the first week post-trauma. Death was more likely with fractures of the cranial vault (P = .003), especially when fragmented (P = .007) and displaced (P = .004). CONCLUSIONS AND CLINICAL IMPORTANCE: Traumatic skull fracture distribution and patterns are different between dogs and cats. Cranial vault fractures were associated with neurological deficits and worse survival. The presence of TSF alone should not be considered a negative prognostic factor because most affected animals survived the first week.

Intrasinus bolstering of traumatic maxillary sinus fractures by using Foley catheter balloons in two foals.

OBJECTIVE: To describe the repair of unstable facial fractures by using Foley catheter balloons as intrasinus bolsters. STUDY DESIGN: Case report ANIMALS: Two weanling foals with unilateral fractures of the sinus and orbit secondary to kick injuries. Preoperative imaging that included positive contrast dacrocystorhinography and computed tomography confirmed severe comminution of facial fractures and nasolacrimal duct disruption in both foals. METHODS: Small bone fragments were surgically removed, and large fragments were retained even when denuded of periosteum. Repair procedures included nasolacrimal canaliculosinusotomy and suturing fracture fragments together with polydioxanone sutures. After fixation, the fracture fragments could be depressed into the sinus with manual pressure, so two intrasinus Foley catheters were placed to bolster the sinus wall, with the tubing exiting through a frontal sinus trephine. The skin was completely closed over the fractures. Catheters and nasolacrimal stenting were maintained in place during fracture healing. RESULTS: One foal prematurely dislodged catheters and nasolacrimal stent 11 days after fixation. The catheters and stenting were removed as planned 4 weeks after surgery in the second foal. Wound, fracture healing, and overall cosmesis was good in both foals, and epiphora resolved. Surgical site infection, sinusitis, and sequestration did not occur. Both foals became high-level performance horses with acceptable cosmetic outcome and good bilateral nasal airflow. CONCLUSION: Foley catheter balloons supported sinus fracture repair and maintained stability of the surgical reconstruction during convalescence. CLINICAL SIGNIFICANCE: Suture repair of comminuted sinus fractures can be supported by using Foley catheters, which are readily available.

Avian Skull Orthopedics.

Because the avian skull is the reflection of the wide biodiversity of birds, many anatomic, morphologic, and functional variations are encountered. The main objectives of this article are to review the surgical considerations associated with the functional anatomy of the avian jaw apparatus and its variation among species, and to describe the general medical and surgical management of head traumatic and developmental disorders in birds.

The prevalence of temporal bone fractures is high in horses with severe temporohyoid osteoarthropathy.

Temporohyoid osteoarthropathy is a well-recognized cause of equine neurologic disease. Temporal bone fractures associated with temporohyoid osteoarthropathy have been recognized with CT, however, little information is available regarding these fractures. The aims of this retrospective analytical study were to assess the prevalence of these fractures and to describe the specific configurations and associated imaging and clinical features. Fracture of the temporal bone was identified with CT in 16 of 39 included horses. All fractures were unilateral, minimally displaced and extended through the temporal bone in a rostrodorsal to caudoventral orientation. Two fracture configurations were identified: in nine cases, the fracture extended the full width of the petrous pyramid into the cranial vault and in seven cases, the fracture only extended through the lateral part of the petrous temporal bone, not involving the cranial vault. Fusion of the temporohyoid joint was present in 13 of the 16 fracture cases. Quarter Horses were over-represented in the fractured population (14/16). All horses with fractures had ipsilateral neurologic deficits. Patient outcomes were not significantly different between temporohyoid osteoarthropathy horses with and without temporal bone fractures (P = 0.68). However, six of the nine patients with cranial vault involvement did not return to their previous use. Findings support previous studies indicating that temporal bones should be carefully assessed for concurrent fractures when temporohyoid osteoarthropathy is identified in CT images, especially when there is fusion of the temporohyoid joint. An improved awareness of specific fracture configurations will help with detection of these fractures.

Feline head trauma: a CT analysis of skull fractures and their management in 75 cats.

OBJECTIVES: The aim of this study was to describe and evaluate the configurations and management of feline skull fractures and concurrent injuries following head trauma. METHODS: Medical records and CT images were reviewed for cats with skull fractures confirmed by CT that were managed conservatively or with surgery. Details of signalment, presentation, skull fracture configuration, management, re-examination, and complications or mortality were recorded and analysed. RESULTS: Seventy-five cats (53 males, 22 females) with a mean age of 4.8 ± 3 years met the inclusion criteria. Eighty-nine percent of cats had fractures in multiple bones of the skull, with the mandible, upper jaw (maxilla, incisive and nasal bones) and craniofacial regions most commonly affected. Temporomandibular joint injury occurred in 56% of cats. Road traffic accidents (RTAs) were the most common cause of skull fractures, occurring in 89% of cats, and caused fractures of multiple regions of the skull. RTAs were also associated with high levels of concurrent injuries, particularly ophthalmic, neurological and thoracic injuries. A more limited distribution of injuries was seen in non-RTA cats. Equal numbers of cats were managed conservatively or surgically (47%). Mortality rate was 8% and complications were reported in 22% of cats. Increasing age at presentation and presence of internal upper jaw fractures were risk factors for development of complications. No risk factors were identified for mortality. CONCLUSIONS AND RELEVANCE: RTAs were the most common cause of feline skull fractures and resulted in fractures in multiple regions of the skull and concurrent injuries occurred frequently. Problems with dental occlusion were uncommon post-treatment. An increased risk of implant loosening and malocclusion was seen with palatine and pterygoid bone fractures and hard palate injuries. This study provides useful additional information regarding feline skull fractures, concurrent injuries and management techniques following head trauma.

Treatment of calvarial defects by resorbable and non-resorbable sonic activated polymer pins and mouldable titanium mesh in two dogs: a case report.

BACKGROUND: To date, calvarial defects in dogs have traditionally been addressed with different types of implants including bone allograft, polymethylmethacrylate and titanium mesh secured with conventional metallic fixation methods. This report describes the use of an absorbable and non absorbable novel polymer fixation method, Bonewelding® technology, in combination with titanium mesh for the repair of calvarial defects in two dogs. The clinical outcomes and comparative complication using resorbable and non-resorbable thermoplastic pins were compared. CASE PRESENTATION: This report of two cases documents the repair of a traumatic calvarial fracture in an adult male Greyhound and a cranioplasty following frontal bone tumor resection in an adult female Cavalier King Charles Spaniel with the use of a commercially available titanium mesh secured with an innovative thermoplastic polymer screw system (Bonewelding®). The treatment combination aimed to restore cranial structure, sinus integrity and cosmetic appearance. A mouldable titanium mesh was cut to fit the bone defect of the frontal bone and secured with either resorbable or non-resorbable polymer pins using Bonewelding® technology. Gentamycin-impregnated collagen sponge was used intraoperatively to assist with sealing of the frontal sinuses. Calvarial fracture and post-operative implant positioning were advised using computed tomography. A satisfactory restoration of skull integrity and cosmetic result was achieved, and long term clinical outcome was deemed clinically adequate with good patient quality of life. Postoperative complications including rostral mesh uplift with minor associated clinical signs were encountered when resorbable pins were used. No postoperative complications were experienced in non-resorbable pins at 7 months follow-up, by contrast mesh uplift was noted 3 weeks post-procedure in the case treated using absorbable pins. CONCLUSIONS: The report demonstrates the innovative use of sonic-activated polymer pins (Bonewelding® technology) alongside titanium mesh is a suitable alternative technique for skull defect repair in dogs. The use of Bonewelding® may offer advantages in reduction of surgical time. Further, ultrasonic pin application may be less invasive than alternative metallic fixation and potentially reduces bone trauma. Polymer systems may offer enhanced mesh-bone integration when compared to traditional metallic implants. The use of polymer pins demonstrates initial potential as a fixation method in cranioplasty. Initial findings in a single case comparison indicate a possible advantage in the use of non-absorbable over the absorbable systems to circumvent complications associated with variable polymer degradation, further long term studies with higher patient numbers are required before reliable conclusions can be made.

Validation of a portable pneumatic captive bolt device as a one-step method of euthanasia for use in depopulation of feedlot cattle.

OBJECTIVE: To validate the effectiveness of a penetrating captive bolt device with a built-in low-pressure air channel pithing mechanism (PCBD) as a 1-step method for euthanasia of cattle. DESIGN: Clinical trial. ANIMALS: 66 feedlot steers and heifers (weight, 227 to 500 kg [500 to 1,100 lb]) that were not expected to survive or finish the feeding period with their cohorts. PROCEDURES: Cattle were transported to a university facility and euthanized with the PCBD. For each calf, clinical variables were monitored and recorded immediately before and for at least 10 minutes after application of the PCBD. Following euthanasia, the head of each calf was removed and trauma to the brain and skull was assessed and scored. RESULTS: Death was successfully achieved with the PCBD without application of an ancillary technique in all 66 cattle; however, 4 (6%) cattle required a second or third shot from the PCBD because of technical errors in its placement. All shots from the PCBD that entered the cranial vault successfully rendered cattle unconscious without a return to sensibility. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that the PCBD was an effective 1-step method of euthanasia for use in mass depopulation of feedlot cattle.

Transmylohyoid orotracheal intubation in surgical management of canine maxillofacial fractures: an alternative to pharyngotomy endotracheal intubation.

OBJECTIVE: To describe the surgical technique of transmylohyoid orotracheal intubation in surgical management of maxillofacial fractures in dogs. STUDY DESIGN: Case series. ANIMALS: Dogs (n = 4) with maxillofacial fractures. METHODS: Transmylohyoid orotracheal intubation was used for airway management of dogs undergoing surgical repair of maxillofacial trauma. A stoma was surgically created by an incision through the skin, subcutaneous tissue, and mylohyoideus muscle immediately medial to the lingual cortex of the mandible at the level of the mandibular 1st molar tooth, so that an endotracheal tube could exit the oral cavity between the mandibular bodies bypassing the dentition. RESULTS: Transmylohyoid orotracheal intubation allowed excellent surgical visibility of the oral cavity and intraoperative control of occlusion during surgery. No complications were encountered during the procedure and the stoma healed without complication. CONCLUSIONS: Transmylohyoid orotracheal intubation is a safe, simple, and effective technique for bypassing the rostral oral cavity and dentition during surgical management of maxillofacial fractures.

Effectiveness of a nonpenetrating captive bolt for euthanasia of 3 kg to 9 kg pigs.

The objective of this study was to determine the effectiveness of a nonpenetrating captive bolt, Zephyr-E, for euthanasia of suckling and weaned pigs from 3 to 9 kg (5-49 d of age) using signs of insensibility and death as well as postmortem assessment of traumatic brain injury (TBI). The Zephyr-E was used by 15 stock people to euthanize 150 compromised pigs from 4 farrowing and nursery units from commercial farms and 2 research stations. Brainstem reflexes, convulsions, and heartbeat were used to assess insensibility, time of brain death, and cardiac arrest following Zephyr-E application. Skull fracture displacement (FD) was quantified from computed tomography (CT) scans (n = 24), macroscopic scoring was used to assess brain hemorrhage and skull fracture severity (n = 150), and microscopic scoring was used to assess subdural hemorrhage (SDH) and parenchymal hemorrhage within specific brain regions that are responsible for consciousness and vital function (n = 32). The Zephyr-E caused immediate, sustained insensibility until death in 98.6% of pigs. On average, clonic convulsions (CC) ceased in 82.2 s (± 3.4 SE), brain death was achieved in 144.9 s (± 5.4 SE), and cardiac arrest occurred in 226.5 s (± 8.7 SE). Time of brain death and cardiac arrest differed significantly among stock people (P = 0.0225 and P = 0.0369). Age was positively related to the duration of CC (P = 0.0092), time of brain death (P = 0.0025), and cardiac arrest (P = 0.0068) with shorter durations seen in younger pigs. Average FD was 8.3 mm (± 1.0 SE). Macroscopic scores were significantly different among weight classes for subcutaneous (P = 0.0402) and subdural-ventral (P = 0.0037) hemorrhage with the lowest severity hemorrhage found in the 9-kg weight category. Microscopic scores differed among brain sections (P = 0.0070) for SDH with lower scores found in the brainstem compared to the cerebral cortex and midbrain. Parenchymal hemorrhage differed among brain sections (P = 0.0052) and weight categories (P = 0.0128) with the lowest scores in the midbrain and brainstem and the 7- and 9-kg weight categories. The Zephyr-E was highly effective for the euthanasia of pigs up to 9 kg (49 d) based on immediate insensibility sustained until death. Postmortem results confirmed that severe skull fracture and widespread brain hemorrhage were caused by the Zephyr-E nonpenetrating captive bolt.

Growing skull fracture in a red-tailed hawk (Buteo jamaicensis).

Growing skull fractures have been reported in humans for many years, usually resulting from injury to the soft skull during the rapid growth period of an infant's life. Nestling raptors have thin, fragile skulls, a rapid growth rate, and compete aggressively for food items. Skull trauma may occur, which may lead to the development of a growing skull fracture. Growing skull fractures may be under-diagnosed in raptor rehabilitation facilities that do not have access to advanced technologic equipment. Three-dimensional (3-D) computed tomography was used to diagnose a growing skull fracture in a red-tailed hawk (Buteo jamaicensis). The lesion was surgically repaired and the animal was eventually returned to the wild. This is the first report of a growing skull fracture in an animal. In this case, 3-D computed topographic imaging was utilized to diagnose a growing skull fracture in a red-tailed hawk, surgical repair was performed, and the bird recovered completely and was ultimately released.

Intradiploic hematoma of the frontal bone with secondary exophthalmos in a mare.

A 13-year-old cob mare was presented with exophthalmos and periocular swelling of the left eye. The diagnostic work-up included ocular ultrasound, sonographic examination through the thinned frontal bone, radiography, standing computed tomography of the skull and exploratory osteoplastic surgery. Histopathology was consistent with an organized hematoma. An intradiploic hematoma of the frontal bone was diagnosed 5 years after head trauma, with progressive expansion and deformation of the skull resulting in exophthalmos. Exophthalmos with facial bone deformation was the only clinical finding of intradiploic hematoma. Standing computed tomography (CT) aided the diagnosis to differentiate intradiploic hematoma from other, more common causes of facial bone distortion associated with paranasal sinus diseases. Intradiploic hematoma of possible traumatic origin is a differential diagnosis for sinonasal disease and exophthalmos in the horse.

Traumatic tympanic bulla fracture.

A Pekingese dog was presented for evaluation of head trauma with ventral head and neck swelling, puncture wounds, palpable mandibular fractures, and loss of menace, severe miosis, and loss of palpebral reflex of the right eye. Computed tomography confirmed multiple mandibular and zygomatic fractures, a right ear canal avulsion, and a complete right tympanic bulla fracture with ventral displacement. The tympanic bulla fracture was managed conservatively. Topical lubrication and antibiotic ointment was prescribed for the right eye. A subtotal hemimandibulectomy was performed to address the mandibular fractures. A temporary oesophagostomy feeding tube was placed. No short-term complications developed as a result of the fractured bulla and avulsed ear canal being left in situ, and no complications were reported 18 months after the injury. To the authors' knowledge this is the first report of a traumatic tympanic bulla fracture in the dog.

Pneumocephalus in five horses.

Pneumocephalus is occasionally encountered in horses but poorly described in the literature. The study aimed to describe historical, clinical and diagnostic imaging findings and outcome in horses to increase the awareness and recognition of the condition amongst equine practitioners, allowing appropriate management of these cases. Cases of pneumocephalus from 4 participating institutions were identified and case details extracted from the medical records. Five cases of pneumocephalus were identified. Head trauma with suspected or confirmed fractures of the sinuses was the underlying cause in 4 cases, while the remaining horse was thought to have developed pneumocephalus secondary to sinusitis or trauma. Diagnosis was established radiographically in 4 cases and by computed tomography in a fifth. Gas was noted between the cranial vault and the brain, in the lateral ventricles, in the brain parenchyma and within the cranial cervical canal. The gas accumulation resolved gradually in all horses and did not appear independently to result in neurological compromise. Long-term outcome was available for 3 cases, 2 of which were ultimately subjected to euthanasia due to neurological deficits. Pneumocephalus is a possible consequence of head trauma or sinusitis in horses; although the finding is frequently incidental, it has the potential to develop into a life-threatening complication. Imaging the complete skull and cranial cervical spine is important to allow identification and appropriate management of these cases. The use of computed tomography enables easier identification and localisation of the gas accumulation within the central nervous system.

Fatal skull trauma in caged layer chickens associated with a moving feed hopper: diagnosis based on autopsy examination, forensic computed tomography and farm visit.

Investigation of unexpected mortality in caged layer chickens led to the discovery of a consistent traumatic injury to the heads of affected hens. Initial post-mortem examination found linear skin lacerations and associated fractures in the dorsal cranium of all birds examined, and 5 to 10 mm deep trauma in the underlying brain tissue. Post-mortem multidetector computed tomography (CT) scanning of two affected birds demonstrated similar obliquely orientated, linear, depressed fractures of the skulls consistent with a single, severe impact force to the head. Both skull fractures had a pattern of rounded, rostral expansion measuring approximately 3 mm in width. On inspection of the cages during a farm visit, this CT pattern corresponded with the size and shape of sheet metal lugs holding feed troughs onto the cages (on which blood stains were subsequently observed). Based on this analysis and hypothesizing that hunger was a triggering factor, a recommendation was made to reverse the shed "lights on" and feed hopper operation times with instant reduction in mortality. This case highlights the value of post-mortem CT imaging in bird death investigation where trauma is a postulated cause.

Head trauma in the cat: 1. assessment and management of craniofacial injury.

PRACTICAL RELEVANCE: Feline trauma is commonly seen in general practice and frequently involves damage to the head. CLINICAL CHALLENGES: While craniofacial injuries following trauma vary widely in severity, affected cats can often be severely compromised in terms of their neurological, respiratory and cardiovascular status, and their management can be challenging in both the short and long term. They need prompt stabilisation and careful monitoring in the initial period to maximise prospects of a successful outcome. Many cats with severe facial trauma will require surgery to stabilise skull fractures or address injuries to the eyes, with its inherent issues surrounding pain management, ensuring adequate nutrition and the necessity for ongoing hospitalisation. DIAGNOSTICS: Cats with head trauma benefit from imaging of the injured areas as well as thoracic radiography. Imaging the skull can be challenging and is best performed under general anaesthesia. In unstable patients this can be delayed to prevent any associated morbidity. EVIDENCE BASE: The clinical evidence base relating to injury to the feline head is limited, despite its relative frequency in general practice. This review focuses on the initial approach to craniofacial (in particular, ocular and jaw) trauma, and outlines simple techniques for management of soft tissue and bone injuries. Much of the information is based on the authors' clinical experience, as there is a paucity of well-described clinical case material.