Vertebral Osteosarcoma in Two Cats-Diagnosis, Treatment, and Outcome.

In this case report, we describe the diagnosis, treatment, and outcome of two feline cases of vertebral osteosarcoma. Case 1: A 6-year-old female neutered domestic longhaired cat was presented with progressive paraparesis, ataxia, and spinal hyperesthesia. MRI of the thoracolumbar spinal cord and vertebral column revealed a strongly contrast-enhancing mass lesion originating from the dorsal lamina and spinous process of T13. The lesion caused extradural compression of the spinal cord. Surgical debulking was performed, and the histopathological evaluation of surgical biopsies was consistent with vertebral osteosarcoma. The cat was paraplegic with intact nociception post-surgery. Subsequently, the cat recovered ambulation while remaining mildly ataxic and paraparetic at long-term follow-up. Post-operative chemotherapy was started with doxorubicin. CT scans at 2, 4, 9, 13, and 20 months post-surgery showed no signs of local recurrence or metastasis. Case 2: A 15.5-year-old male neutered domestic shorthaired cat was presented with progressive paraparesis, tail paresis, and spinal hyperesthesia. Radiographs and CT scan of the lumbar vertebral column showed a large mass originating from the dorsal lamina and spinous process of L6, suggestive of neoplasia, with severe compression of the spinal cord. Surgical debulking was performed, and the histopathological evaluation was consistent with vertebral osteosarcoma. Post-operative chemotherapy was started with doxorubicin. Seven months post-surgery, the patient was neurologically normal with no signs of metastatic disease. This case report highlights the possibility of good outcomes after the surgical treatment of feline vertebral osteosarcoma supplemented with post-surgical chemotherapy.

Determination of Isometric Points in the Stifle of a Dog Using a 3D Model.

OBJECTIVE: The aim of this study was to develop a three-dimensional (3D) model to identify the isometric component of the cranial cruciate ligament (CCL) in dogs. METHODS: A static 3D model of the specimen was generated from a computed tomography scan of the stifle of a dog and a kinematic model was generated from data collected, every 5 degrees from full extension (131 degrees) through 80 degrees of stifle flexion, from four sensors attached to the tibia. Kinematic data were superimposed on the static model by aligning the points of interest, which were defined for both models. This allowed the tibia to rotate and translate relative to the femur based on the kinematic data. The contours of the distal femur and proximal tibia were converted into point clouds and the distance between each point in the femoral point cloud and all the points in the tibial point cloud were measured at each of the 15 positions. The difference between the maximum and minimum distances for each pair of points was calculated, and when it was less than 0.2 mm, points were illustrated as two red dots connected by a line at their locations on the femur and tibia. RESULTS: A total of 3,681 pairs of isometric points were identified and were located at the origin and insertion of the CCL and on the lateral aspect of the stifle. CONCLUSION: Isometric areas are present at the origin and insertion of the CCL and lateral aspect of the stifle. Better understanding of these locations may lead to refinements in techniques to replace the ruptured CCL.

The effect of joint orientation on passive movement of the dog's stifle.

Introduction: The cranial cruciate ligament (CCL) is one of numerous structures which determine the path of the tibia relative to the femur when passively flexing/extending the stifle of the dog. The effect of cutting the CCL on passive motion with the hind limb in different orientations, is unknown. The aim of this study was to describe passive movement of the tibia relative to the femur in dogs, with the hind limb in three different orientations, and with CCL intact and cut. Methods: Ten cadaveric hind limbs were obtained from dogs weighing between 20 kg and 25 kg and prepared for testing in a custom-built joint testing machine. Each hind limb was tested in three different orientations with data collected, using an electromagnetic tracking system, during 2 cycles of flexion/extension with the CCL intact and cut. Each cycle was initiated with the stifle in full extension (0°) and data was collected at 0°, 20°, 30°, 40°, 45°, and 55° of stifle flexion/extension. Results: Flexion of the stifle resulted in caudal translation and internal rotation of the tibia relative to the femur, with cranial translation and external rotation occurring during extension along the identical path. Cutting the cranial cruciate ligament did not result in significant differences in translation or rotation when the stifle was orientated to approximated the standing position of a dog. Discussion: Isometric points at the origin and insertion of the CCL can potentially be identified in CCL deficient stifles using a technique based on passive motion of an intact stifle.

Surgical and medical management in the treatment of proximal tibial metaphyseal fracture in immature dogs.

The purpose of this study was to report approaches to surgical and medical management of proximal tibial metaphyseal fractures (PTMF) and short-term case outcome. Medical records of immature dogs with PTMF were reviewed and data were collected including history, signalment and side affected. Data pertaining to surgical and medical management including radiographic evaluation and short-term complications were recorded. Forty-five dogs with a total of 47 PTMF identified and treated between 2007-2019 were included in this study. Six cases were managed with external coaptation alone. Forty-one cases were treated surgically with constructs including K-wires in different configurations, bone plate and screws, and external skeletal fixation. Of the cases managed conservatively, 4 developed complications, including bandage sores, diffuse osteopenia of the tarsus/metatarsus, and angular limb deformities. Surgical complications including pin migration necessitating removal, osteopenia, and screw placement in the proximal tibial growth plate or into the stifle joint were found in 16 cases. PTMF treated with surgery had a subjectively more predictable outcome compared to those treated with external coaptation alone. Conservative management may result in complications including development of excessive tibial plateau angle (TPA) as well as distal tibial valgus.

Evaluation of post-operative complications, outcome, and long-term owner satisfaction of elbow arthrodesis (EA) in 22 dogs.

The objective of this study was to report post-operative complications and outcomes in canines undergoing elbow arthrodesis (EA) with fixation techniques including bone plate fixation with a non-locking dynamic compression plate (DCP), bone plate fixation with a locking plate (LCP), and external skeletal fixator (ESF). Medical records of twenty-two cases that underwent EA between January 2009-December 2019 from 8 referral hospitals including both private practice and academic institutions were reviewed. Post-operative complications were classified as either minor or major, surgical evaluations were performed 8 weeks post operatively, and a follow-up questionnaire was sent to owners. Of the total 22 cases that met inclusion criteria, a total of 19/22 cases had complications, 12 major and 7 minor. Complications reported in 8/9, 7/9, and 4/4, for the DCP, LCP, and ESF fixation groups, respectively. Mild to moderate mechanical lameness was identified at surgical evaluation in 16/22 cases. Complete radiographic bone healing was achieved after 9 weeks in 19/22 cases. Long term owner follow up was available in 14/22 cases. Owners reported a good to normal quality of life in 13/14 cases and poor in one case. The majority of owners (11/14) reported good to excellent satisfaction with the outcome irrespective of persistent lameness. This study demonstrates that successful EA can be achieved using a variety of fixation methods, but persistent lameness is expected and complication rate is high.

Stance and weight distribution after tibial plateau leveling osteotomy in fore limb and hind limb amputee dogs.

BACKGROUND: Little is known about the weight distribution to the remaining limbs for amputee dogs that undergo orthopedic surgery. The objective of the paper was to describe stance and weight distribution after tibial plateau leveling osteotomy (TPLO) in forelimb and in hind limb amputees (AmpTPLO) and to compare them to four-legged TPLO patients (4LTPLO) and amputees without TPLO (Amp). Weight bearing distribution at a stance was compared between groups. Joint angles of forelimb and hind limb joints in a sagittal plane, hind limb orientation in a frontal plane, and pelvic orientation in a transverse plane (pelvic tilt) were measured and compared between groups. RESULTS: Joint angles, hind limb abduction, and pelvic tilt of AmpTPLO and Amp did not differ statistically. Mean weight bearing in the operated hind limb was higher for AmpTPLO than 4LTPLO. Mean weight bearing for thoracic limbs of AmpTPLO and 4LTPLO did not differ statistically. Weight bearing of the hind limb of AmpTPLO and Amp did not differ statistically. CONCLUSIONS: The position of the center of mass and posture of AmpTPLO and Amp does not differ. The weight distribution and posture of Amp is not impacted negatively by TPLO.

Use of computed tomography (CT) for the diagnosis of mechanical gastrointestinal obstruction in canines and felines.

The objective of this study was to describe the use of computed tomography (CT) for diagnosis of mechanical gastrointestinal (GIT) obstruction in canines and felines. Medical records of 130 canines and felines that underwent an abdominal CT scan between 2013 and 2015 at a specialty referral hospital for suspected gastrointestinal tract (GIT) obstruction were reviewed. Images were evaluated by a single board-certified radiologist for the presence of foreign material, evidence of obstruction, and location of foreign material present. Confirmation of CT findings was based on surgical exploration or medical management if surgery was not indicated. Of the 97 patients that met the inclusion criteria, 48 (49.48%) had evidence of foreign material present within the GIT and 49 (50.52%) did not. Forty-one patients had evidence of mechanical gastrointestinal obstruction. Thirty-nine of these patients had an obstruction due to foreign material; one had an intussusception with no foreign material, and another had obstruction secondary to mucosal thickening. Forty-five patients underwent exploratory laparotomy, and CT findings were confirmed in all patients. The presence of a GIT obstruction was confirmed intra-operatively in 37 patients and lack of obstruction was confirmed in the remaining eight. Non-surgical medical management was pursued for the remaining patients. Based on follow-up client interviews, clinical signs resolved in all of these patients. In conclusion, computed tomography appears to be useful for the diagnosis of GIT obstruction in canines and felines and is a helpful tool for guiding the recommendation for surgical intervention.

The use of bidirectional barbed suture in the treatment of a complete common calcanean tendon rupture in a dog: Long-term clinical and ultrasonographic evaluation.

The canine common calcanean tendon can be repaired successfully using a modified Kessler knotless barbed technique. A long-term ultrasound follow-up showed improved and increased normal tendon fibrillar echotexture and homogeneity.

Fibular osteotomy to facilitate proximal tibial rotation during tibial plateau leveling osteotomy.

OBJECTIVE: To identify factors that restrict proximal tibial rotation during tibial plateau leveling osteotomy (TPLO) and report on the outcome of concurrent fibular osteotomy (TPLO-FO). STUDY DESIGN: Retrospective case-control study. ANIMALS: Dogs undergoing TPLO-FO (n = 23) and dogs undergoing routine TPLO (n = 49). METHODS: Medical records and radiographs of dogs that had undergone TPLO-FO were reviewed. Data that were collected included signalment, preoperative tibial plateau angle (TPA), mechanical medial proximal tibial angle (mMPTA), postoperative and recheck TPA and mMPTA, ratio of fibular width to tibial width (FW:TW), presence of tibiofibular synostosis, tibial osteotomy location, and use of additional implants. RESULTS: The odds of exhibiting rotational constraints requiring FO during TPLO were 62-fold greater in dogs with tibiofibular synostosis than in dogs without synostosis. Dogs with FW:TW greater than 0.24 were 7.8-fold more likely to exhibit rotational constraints. After TPLO-FO, the postoperative increase in TPA was greater after single-plate fixation (mean, 5.4 ° ± 4.5 °) compared with fixation with 2 plates (mean, 1.4 ° ± 0.6 °). CONCLUSION: Proximal tibiofibular synostosis and a relatively wide fibula restricted tibial plateau rotation. In these dogs, concurrent fibular osteotomy allowed adequate rotation. Adjunct plate fixation limited loss of rotation after TPLO-FO. CLINICAL SIGNIFICANCE: Successful TPLO relies on adequate rotation of the proximal tibial segment. Fibular osteotomy and adjunct plate fixation are recommended to achieve and maintain adequate rotation of the osteotomized tibia in dogs with rotational constraints.

Evaluating Stiffness of Fibreglass and Thermoplastic Splint Materials and Inter-fragmentary Motion in a Canine Tibial Fracture Model.

OBJECTIVES: Various materials are used to construct splints for mid-diaphyseal tibial fracture stabilization. The objective of this study was to compare construct stiffness and inter-fragmentary bone motion when fibreglass (FG) or thermoplastic (TP) splints are applied to either the lateral or cranial aspect of the tibia in a mid-diaphyseal fracture model. METHODS: A coaptation bandage was applied to eight cadaveric canine pelvic limbs, with a custom-formed splint made of either FG or TP material applied to either the lateral or cranial aspect of the osteotomized tibia. Four-point bending tests were performed to evaluate construct stiffness and inter-fragmentary motion in both frontal and sagittal planes. RESULTS: For a given material, FG or TP, construct stiffness was not affected by splint location. Construct stiffness was significantly greater with cranial FG splints than with cranial TP splints (p < 0.05), but this difference was not significant when comparing splints applied laterally (p = 0.15). Inter-fragmentary motions in the sagittal and frontal planes were similar across splint types for cranial splints, but for lateral splints there was a 64% reduction in frontal plane motion when FG was used as the splint material (p = 0.03). CLINICAL SIGNIFICANCE: FG produces a stiffer construct, but the difference is not reflected in a reduction in inter-fragmentary motion. For lateral splints, FG splints are associated with reduced inter-fragmentary motion as compared with TP and may therefore have slight superiority for this application.

Proximal tibial metaphyseal fractures in immature dogs.

OBJECTIVE: To describe proximal tibial metaphyseal fractures in immature dogs. MATERIALS AND METHODS: Medical records of immature dogs with metaphyseal fractures of the proximal tibia were reviewed and data were collected on signalment and history of trauma. Craniocaudal and mediolateral radiographs were evaluated for the determination of the bones fractured, location of the fracture within the bone, fracture configuration, and the presence of fracture segment displacement and angulation. RESULTS: Eighteen dogs with 22 proximal tibial metaphyseal fractures fulfilled the inclusion criteria. All fractures had a curvilinear, complete fracture of the proximal tibial metaphysis. Displacement was identified in 16 fractures and angulation in 15 fractures. All affected breeds were terrier or small breed dogs less than six months of age. The majority of dogs weighed less than or equal to 5 kg at the time of injury. The most common type of trauma that occurred was a jump or fall from a short distance. CLINICAL SIGNIFICANCE: Proximal tibial metaphyseal fractures are an uncommon injury that occur in skeletally immature dogs from minimal trauma. Proximal tibial metaphyseal fractures have a characteristic curvilinear fracture configuration that affects mainly small breed dogs with a predominance for terrier breeds.

Intraperitoneal bilirubin administration decreases infarct area in a rat coronary ischemia/reperfusion model.

Bilirubin was previously considered a toxin byproduct of heme catabolism. However, a mounting body of evidence suggests that at physiological doses, bilirubin is a powerful antioxidant and anti-atherosclerotic agent. Recent clinical studies have shown that human beings with genetically-induced hyperbilirubinemia (Gilbert Syndrome) are protected against coronary heart disease. The purpose of this study was to investigate whether administration of exogenous bilirubin to normal rats would convey similar protective effects in an experimental model of coronary ischemia. We hypothesized that intraperitoneal bilirubin administration 1 h before injury would decrease infarct area and preserve left ventricular (LV) systolic function when compared to non-treated rats. Coronary ischemia was induced by temporary (30 min) ligation of the left anterior descending coronary artery in control or bilirubin treated rats, followed by a 1-h period of reperfusion. LV function was estimated by measurements of fractional shortening (FS) and fractional area shortening using echocardiography. LV function decreased in both experimental groups after ischemia and reperfusion, although in bilirubin-treated rats FS was less depressed during the period of ischemia (18.8 vs. 25.8%, p = 0.034). Infarct size was significantly reduced in the bilirubin treated group compared to the non-treated group (13.34 vs. 25.5%, p = 0.0067). Based on the results of this study, bilirubin supplementation appears to provide significant decrease in infarct size although protective effects on LV function were noted only during the period of ischemia. This result also suggests that lipid soluble antioxidant bilirubin prevents the oxidation of cardiolipin and decreases the infarct size in the heart during ischemia.

Endoscopic diagnosis of a pylorogastric intussusception with spontaneous resolution.

A 7 mo old intact female golden retriever was evaluated for acute vomiting. Abdominal radiographs revealed a possible gastric foreign body. Upper gastrointestinal endoscopy revealed an edematous, tubular antral mass, which on further evaluation was determined to be a pylorogastric intussusception based on radiographic, endoscopic, and surgical findings. Spontaneous resolution of the intussusception occurred upon surgical exploration of the abdomen. Histopathology of a full-thickness gastric biopsy revealed vascular congestion consistent with an intussusception, but did not indicate the primary cause. The dog recovered uneventfully from surgery and had no further vomiting during the 6 mo follow-up period. This case was significant as it was the first report of pylorogastric intussusception diagnosed using endoscopy. This description of the unique endoscopic appearance of pylorogastric intussusception will be useful for the veterinary endoscopist.

Magnet ingestion in dogs: two cases.

Two dogs that had ingested foreign bodies were presented with vomiting. The foreign bodies appeared as metal and dense on abdominal radiographs. Abdominal exploratory identified intestinal perforation in one case and gastrointestinal tissue trapped between the two foreign bodies adhered to each other in the second case. The foreign bodies were identified as magnets in one case and magnets and other metallic foreign bodies in the second case. Both dogs had excellent outcomes following surgical intervention. These cases demonstrate the danger of tissue entrapment between the foreign bodies as a result of the magnetic attraction between two objects. Dogs that are presented with a history of or are suspect for ingesting multiple magnets or a magnet and metal foreign bodies should be treated with surgical intervention because of the risk of gastrointestinal perforation as a result of magnetic attraction between the foreign bodies.

The use of vacuum-assisted closure therapy for the treatment of distal extremity wounds in 15 dogs.

OBJECTIVE: To evaluate clinical outcome after vacuum-assisted closure (VAC) therapy in dogs with traumatic wounds located in the distal extremities and report our early experience with VAC. STUDY DESIGN: Retrospective study. ANIMALS: Dogs (n=15) with traumatic distal extremity wounds. METHODS: Medical records (1999-2003) of dogs with traumatic injuries to the distal extremities managed by VAC were evaluated. Data included signalment, location of wound, time until surgical intervention, wound reconstruction methods, orthopedic procedures, outcome, complications associated with VAC, and length of hospitalization. RESULTS: The mean number of days until reconstruction was 4.6 days (range, 2-7 days). Reconstructive surgery was successful in all cases. Mean hospitalization was 9.7 days (range, 6-16 days). Complications included dermatitis at the wound margin and loss of vacuum causing wound desiccation. CONCLUSION: VAC therapy can be used to achieve adequate management of traumatic distal extremity wounds. VAC provides an effective method of securing skin grafts over the wound bed. CLINICAL RELEVANCE: VAC therapy can be used as an ancillary treatment for distal extremity wounds in dogs before surgical repair as well as a method for securing skin grafts to the wound bed.