Veterinary and Comparative Orthopaedics and Traumatology (VCOT) Veterinary and Comparative Orthopaedics and Traumatology (VCOT) vcot de-de Mon, 29 May 17 15:22:30 +0200 2017 VOS Abstracts 27559 2017-05-22 13:38:33 Ahead of print: Three-dimensional kinematics of the equine metacarpophalangeal joint using x-ray... X-ray reconstruction of moving morphology (XROMM) uses biplanar videoradiography and computed tomography (CT) scanning to capture three-dimensional (3D) bone motion. In XROMM, morphologically accurate 3D bone models derived from CT are animated with motion from videoradiography, yielding a highly accurate and precise reconstruction of skeletal kinematics. We employ this motion analysis technique to characterize metacarpophalangeal joint (MCPJ) motion in the absence and presence of protective legwear in a healthy pony. Our in vivo marker tracking precision was 0.09 mm for walk and trot, and 0.10 mm during jump down exercises. We report MCPJ maximum extension (walk: –27.70 ± 2.78° [standard deviation]; trot: –33.84 ± 4.94°), abduction/adduction (walk: 0.04 ± 0.24°; trot: –0.23 ± 0.35°) and external/internal rotations (walk: 0.30 ± 0.32°; trot: –0.49 ± 1.05°) indicating that the MCPJ in this pony is a stable hinge joint with negligible extra-sagittal rotations. No substantial change in MCPJ maximum extension angles or vertical ground reaction forces (GRFv) were observed upon application of legwear during jump down exercise. Neoprene boot application yielded –65.20 ± 2.06° extension (GRFv = 11.97 ± 0.67 N/kg) and fleece polo wrap application yielded –64.23 ± 1.68° extension (GRFv = 11.36 ± 1.66 N/kg), when compared to naked control (-66.11 ± 0.96°; GRFv = 12.02 ± 0.53 N/kg). Collectively, this proof of concept study illustrates the benefits and practical limitations of using XROMM to document equine MCPJ kinematics in the presence and absence of legwear.... B. A. Childs (1), B. R. Pugliese (1), C. T. Carballo (1), D. L. Miranda (2), E. L. Brainerd (3), C. A. Kirker-Head (1) 27495 2017-05-05 13:02:03 Pelvic limb alignment measured by computed tomography in purebred English Bulldogs with medial... Objectives: The aim of the study was to describe the differences in pelvic limb alignment between healthy purebred English Bulldogs and those with medial patellar luxation through the measurement of femoral and tibial angles on computed tomography images in multiplanar reconstruction modality (MPR-CT). Methods: Twenty-one purebred English Bulldogs were included and divided into two groups: one including healthy dogs (15 limbs) and the other including those with medial patellar luxation (24 limbs). Three different observers used MPR-CT to measure the following angles: anatomical lateral proximal femoral angle (aLPFA), anatomical lateral distal femoral angle (aLDFA), mechanical lateral proximal femoral angle (mLPFA), mechanical lateral distal femoral angle (mLDFA), angle of inclination of the femoral neck (AI), angle of anteversion (AA), mechanical medial proximal tibial angle (mMPTA), mechanical medial distal tibial angle (mMDTA), mechanical caudal distal tibial angle (mCdDTA), mechanical caudal proximal tibial angle (mCdPTA), and the tibial torsion angle (TTA). A Mann-Whitney U test was used to compare each variable in both groups. Results: The values for aLDFA and mLDFA in the medial patellar luxation population were significantly increased compared to healthy subjects (p <0.05). No significant differences were observed for the other variables. Clinical significance: In our population, an increased distal femoral varus was associated with medial patellar luxation. Our results could be useful to determine whether or not angular deformity of the femur is present and help determine the degree of correction necessary to restore alignment.... F. Lusetti (1), A. Bonardi (1), C. Eid (1), A. Brandstetter de Belesini (1), F. M. Martini (1, 2) 27494 2017-05-05 13:00:15 Ahead of print: 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.... L. Deahl (1), R. Ben-Amotz (1), A. V. Caceres (2), K. A. Agnello (2) 27409 2017-04-10 13:06:06 Surgical stabilization of concomitant canine medial patellar luxation and cranial cruciate ligament... Objectives: To compare complication rates and outcomes between cases of concomitant cranial cruciate ligament (CrCL) disease and medial patellar luxation (MPL) treated using extracapsular stabilization and tibial tuberosity transposition (ECS+TTT) and tibial tuberosity transposition and advancement (TTTA). Methods: In a multicentre retrospective study, records from four referral hospitals were reviewed for dogs with concomitant CrCL pathology and MPL treated using ECS+TTT or TTTA. Data retrieved included signalment, partial/complete CrCL tear, MPL grade, treatment performed, occurrence of postoperative complications, and postoperative outcome grade. Associations between surgical procedure and risk of complication and surgical procedure and outcome were investigated using univariable logistic regression and proportional odds logistic regression respectively. Multiple logistic regression was used to explore confounding factors. Results: A total of 72 stifles were evaluated in 66 dogs; 32 stifles were stabilized using ECS+TTT and 40 using TTTA. Overall complications were 2.7 times more frequent in the ECS+TTT group and major complications occurred only in this group. The TTTA group was less likely to suffer complications (17.5%) compared to the ECS+TTT group (46.9%) (p = 0.009) and TTTA cases had lower odds of a poorer clinical outcome (p = 0.047). Clinical significance: Stifles stabilized using ECS+TTT are more likely to suffer from postoperative complications and a poorer clinical outcome when compared to TTTA.... A. H. Fauron (1), M. Bruce (2), D. R. James (3), M. A. Owen (4), K. L. Perry (1) 27408 2017-04-10 13:05:13 Computed tomographic evaluation of femoral and tibial conformation in English Staffordshire Bull... Objective: To compare hindlimb conformation of English Staffordshire Bull Terriers with and without medial patellar luxation using computed tomography. Methods: Hindlimb computed tomography (CT) was performed on six English Staffordshire Bull Terriers with grade II or III medial patellar luxation, and six without medial patellar luxation. Inclination angle, femoral condyle trochanteric angle, anteversion angle (AA), distal anteversion angle (DAA), proximal anteversion angle (PAA), femoral varus angle (FVA), tibial valgus angle (TVA), and tibial torsion angle (TTA) were measured. Student’s T-test was conducted to compare normal limbs to limbs with medial patellar luxation, all limbs of dogs with medial patellar luxation to limbs of the control group, and medial patellar luxation affected limbs (normal limbs of unilaterally affected dogs excluded) to the control group. P-values less than 0.05 were considered significant. Results: Two dogs with medial patellar luxation were only affected unilaterally. Limbs of English Staffordshire Bull Terriers with medial patellar luxation had significantly diminished AA and DAA, in addition to decreased TVA. These differences were similar regardless of how the unaffected limbs from affected dogs were treated in our analysis. Discussion and conclusion: Medial patellar luxation in this population of English Staffordshire Bull Terriers was characterized by a decrease in femoral anteversion, external rotation of the femoral diaphysis, and decreased tibial valgus. These findings may help inform clinical decision making when performing osteotomy for treatment of medial patellar luxation in this breed.... M. Newman (1, 2), K. Voss (1, 3) 27351 2017-03-23 09:15:31 Single cycle to failure in bending of three titanium polyaxial locking plates Objective: Evaluation of the bending properties in one direction of three titanium polyaxial locking plate systems. Materials and methods: The Polyaxial Advanced Locking System (PAX®) straight plate (PAX SP), the PAX® reconstruction plate (PAX RP), and the VetLOX reconstruction plates (VetLOX) were evaluated individually and as constructs applied to a bone model simulating a fracture gap and compared using a two-way analysis of variance and Tukey post-hoc analysis. Results: The PAX SP had the highest values of bending stiffness, bending structural stiffness and bending strength. When tested as plates alone, the PAX RP and VetLOX showed no differences with regard to bending stiffness and bending structural stiffness, whilst the PAX RP had significantly higher strength. The PAX RP construct had significantly higher bending stiffness, bending structural stiffness and bending strength than the VetLOX construct. Clinical relevance: The PAX RP and VetLOX reconstruction plates are much more likely to fail when used as bridging implants, thus adjunct support is needed. The lower bending strength of the VetLOX reconstruction plates suggests it should not be used in fractures under high loads.... C. Eid (1), F. M. Martini (1, 2), A. Bonardi (1), F. Lusetti (1), A. Brandstetter de Belesini (1), G. Nicoletto (3) 27350 2017-03-23 09:14:33 Bilateral shoulder arthrodesis in a Pekinese using three-dimensional printed patient-specific... Objective: To report the use of computer-aided design software for virtual surgical planning and design of three-dimensional printed patient-specific osteotomy and reduction guides for facilitation of bilateral shoulder arthrodesis in a dog. Methods: A three-year-old male entire Pekinese was presented unable to walk due to bilateral severe medial shoulder instability. Computed tomographic data was processed to yield three-dimensional mesh representations of the humeri and scapulae which could be manipulated in computer-aided design software. Key virtual surgical planning steps included joint realignment, osteotomies of the glenoid and humeral head, and reduction. Virtual osteotomy and reduction guides were designed, three-dimensionally printed, and used intra-operatively. Results: Appropriate alignment, reduction and fixation of the humeri and scapulae were achieved bilaterally. The patient regained the ability to walk unassisted after two weeks and was subsequently able to exercise normally without lameness. Clinical significance: Patient-specific, three-dimensional printed osteotomy and reduction guides facilitated accurate bilateral shoulder arthrodeses.... B. Oxley (1) 27349 2017-03-23 09:13:49 Conformation of the proximal tibia and cranial cruciate ligament disease in small breed dogs Objectives: To investigate the conformation of the proximal tibia in small breed dogs with and without cranial cruciate ligament disease (CCLD) and to identify morphologic abnormalities that may predispose to development of CCLD. Methods: Mediolateral radiographs of the entire tibia of dogs J. Janovec (1), M. Kyllar (2), D. Midgley (1), M. Owen (3) 27348 2017-03-23 09:13:02 Cranial thoracic vertebral canal stenosis in three juvenile large-breed brachycephalic dogs treated... Objective: To describe the surgical treatment and outcome for juvenile dogs with cranial thoracic vertebral canal stenosis treated by unilateral hemilaminectomy. Study design: Case series. Animals: Three large-breed brachycephalic dogs of various breeds (Dogue de Bordeaux, Australian Bulldog, Boerboel) with neurological signs consistent with a myelopathy of the third thoracic (T) to third lumbar (L) spinal cord segment. Methods: Information on clinical presentation, diagnostic imaging, surgical procedures, postoperative complications, recovery and outcome is described. Results: Neurological signs were present and progressive for two to four weeks prior to surgery and ranged from mild ataxia to paralysis. Cranial thoracic vertebral canal stenosis was diagnosed with computed tomography imaging. Lateral and dorsolateral spinal cord compression was present at multiple sites between T2 and T6. Alternating left and right-sided compressions were common. Surgical treatment was by unilateral, continuous hemilaminectomy over three to six vertebral spaces. Postoperative morbidity was minimal and return of independent ambulation was rapid (median: 13.5 days, range: 2–29 days). Neurological status in one dog worsened four months after surgery due to reoccurrence of osseous compression; unilateral hemilaminectomy was repeated in this dog. Long-term follow-up ranged from six to 10 months; neurological signs had completely resolved in one dog and substantially improved in the other two dogs. Clinical significance: Unilateral hemilaminectomy was associated with rapid return of independent ambulation and substantial improvement in neurological scores.... A. Miller (1), A. Marchevsky (1) 27347 2017-03-23 09:12:22 Donald L. Piermattei 27335 2017-03-20 09:13:10 Navicular disease...remembrance of things past M. Stewart 27334 2017-03-20 09:09:16 Distal border synovial invaginations of the equine distal sesamoid bone communicate with the distal... Objectives: Macroscopic studies have suggested a link between distal border synovial invaginations of the navicular bone and the distal interphalangeal joint. However, many practitioners consider that these invaginations are directly and solely related to navicular disease. The objective was to investigate the communication pattern of these synovial invaginations with the synovial compartments of the distal interphalangeal joint and the navicular bursa, using minimally invasive imaging techniques. Methods: In a prospective observational study, 10 cadaveric limbs with radiographically evident distal border synovial invaginations were randomly assigned to computed tomography arthrography or bursography groups, using iopamidol. Results: In 5/5 limbs, contrast medium filled the invaginations following distal interphalangeal arthrography. In the other five limbs, no contrast medium filled the invaginations following bursography. Clinical significance: Contrary to existing beliefs, these invaginations are more likely associated with distal interphalangeal joint synovitis and may not be directly linked to primary navicular bone pathology, but might reflect distal interphalangeal arthropathy. Therefore, the rationale for assessment of these invaginations in stallion selection or pre-purchase examinations as a predictive sign for navicular disease is questionable. Nonetheless, comorbidities are frequent in the equine distal limb. Enlarged synovial invaginations may also be seen in limbs with concomitant primary navicular disease. Further studies are needed to elucidate possible inter-related pathological processes.... J. Olive (1), M. Videau (1) 27192 2017-02-16 13:28:21 The effect of valgus and varus femoral osteotomies on measures of anteversion in the dog Objective: To determine whether femoral osteotomies that change frontal plane alignment without affecting torsion influence anteversion and inclination. Methods: Femurs without deformity were scanned to create three-dimensional reconstructions. The femoral head-neck axis was identified by placement of a virtual intramedullary pin. A proximal osteotomy was simulated to create three conditions while keeping torsion constant: Normal, Coxa Valga (neck-shaft angle increased by 12°), and Coxa Vara (neck-shaft angle decreased by 12°). Femoral anteversion was measured from an axial image in all three conditions. Femoral inclination was calculated for all conditions using the neck-shaft and anteversion angles. Changes in anteversion and inclination were calculated and compared using a one-way repeated measures analysis of variance. Distal femoral osteotomies were then simulated with the native femurs, inducing 18° of distal varus with no change to torsion. Changes in anteversion and inclination for the Normal and Distal Varus conditions were calculated and compared by a paired t-test. Results: Version changed by a mean of 13.9° (± 1.5; p... R. W. Adams (1), B. Gilleland (2), F. Monibi (3), S. P. Franklin (1) 27098 2017-01-27 08:14:21 An anatomical and histological study of the equine proximal manica flexoria Objectives: The main aim was to describe the gross and histological appearance of the equine manica flexoria and to identify any differences between the forelimbs and hindlimbs. An additional aim was to relate the findings to diagnostic and surgical anatomy of the manica flexoria. Methods: Measurements of the manica flexoria were made on cadaveric limbs from horses free from pathology within the digital flexor tendon sheath. Histological sections, stained with haematoxylin and eosin and alcian- periodic acid schiff, were evaluated based on three micro-anatomical zones from dorsal to palmar or plantar. The prevalent tenocyte morphology, number, and distribution of blood vessels and nerves were described in each zone. Forelimb and hindlimb measurements were compared using a Students T-test. Results: Proximally, the manica flexoria attaches to the digital flexor tendon sheath via a reflection of areolar tissue. The fibrous manica flexoria is longer in the forelimb (32.0 ± 4.2 mm) than the hindlimb (29.4 ± 3.8 mm) (p = 0.04), with the areolar portion longer in the hindlimb (22.9 ± 5.3 mm) compared to the forelimb (16.7 ± 4.3 mm) limb (p = 0.0005). Histologically, degenerate blood vessels were prevalent in the palmar/plantar regions and were associated with chondrocyte-like tenocytes, indicative of fibrocartilagenous metaplasia. Clinical significance: The study has provided a detailed anatomical description of the manica flexoria relevant for interpretation of diagnostic and surgical evaluation. Fibrocartilaginous metaplasia occurs on the palmar/plantar surfaces of the manica flexoria.... J. A. Findley (1), E. E. Ricci (2), E. E. Singer (3) 27097 2017-01-27 08:13:23 Erratum to: Augmentation of diaphyseal fractures of the radius and ulna in toy breed dogs using a... 27096 2017-01-27 07:54:24 Ultrasound-guided approach to the cervical articular process joints in horses: a validation of the... Objectives: To compare accuracy of the ultrasound-guided craniodorsal (CrD) approach with the dorsal (D) approach to the cervical articular process joints, and to evaluate the effect of the transducer, needle gauge, and operator experience. Methods: Cervical articular process joints from 14 cadaveric neck specimens were injected using either a D or CrD approach, a linear (13 MHx) or microconvex transducer (10 MHz), and an 18 or 20 gauge needle, by an experienced or inexperienced operator. Injectate consisted of an iodinated contrast material solution. Time taken for injection, number of redirects, and retrieval of synovial fluid were recorded. Accuracy was assessed using a scoring system for contrast seen on computed tomography (CT). Results: The successful performance of intra-articular injections of contrast detected by CT using the D (61/68) and CrD (57/64) approaches was comparable. No significant effect of approach, transducer or needle gauge was observed on injection accuracy, time taken to perform injection, or number of redirects. The 18 gauge needle had a positive correlation with retrieval of synovial fluid. A positive learning curve was observed for the inexperienced operator. Clinical relevance: Both approaches to the cervical articular process joints were highly accurate. Ultrasound-guided injection of the cervical articular process joints is an easily-learnt technique for an inexperienced veterinarian. Either approach may be employed in the field with a high level of accuracy, using widely available equipment.... J. Purefoy Johnson (1), J. D. Stack (1), C. Rowan (1), I. Handel (2), J. M. O'Leary (1) 27057 2017-01-17 10:14:19 Comparative anatomy and biomechanical properties of atlantoaxial ligaments in equine, bovine, and... Objectives: Atlantoaxial instability has been reported in humans, dogs, equids and ruminants. The functional role of the atlantoaxial ligaments has only been described rudimentarily in equids and ruminants. The goal of the present cadaveric study was to compare the anatomy between the different species and to comparatively assess the role of the stabilizing ligaments of the atlantoaxial joint under sagittal shear loading in canine, equine, and bovine cervical spines. Methods: Three equine, bovine, and canine cadaveric specimens were investigated. Biomechanical testing was performed using a purpose built shear‐testing device driven by a uniaxial servo-hydraulic testing machine. Three cycles in a dorsoventral direction with a constant quasi-static velocity of 0.2 mm/s up to a limiting force of 50 N (canine) or 250 N (bovine, equine), respectively, were performed for each specimen tested. Load and linear displacement were measured by the displacement sensor and load cell of the testing system at a sampling rate of 20 Hz. Tests were performed and the range of motion determined with both intact and transected atlantoaxial ligaments. Results: The range of motion was significantly increased after transection of the ligaments only in the canine specimens. The bovine atlantoaxial joint was biomechanically more stable than in equids. Clinical significance: Species-specific anatomical and biomechanical differences of the atlantoaxial ligaments in canines, equids, and bovines were detected. The significance of these differences and their impact on the pathogenesis of atlantoaxial subluxations and subsequent treatment remain open questions.... F. Forterre (1), M. H. Stoffel (2), C. Koch (3), C. Precht (4), M. Waschk (4), A. Bürki (5) 27056 2017-01-17 10:13:08 Asymmetrical lumbosacral transitional vertebrae in dogs may promote asymmetrical hip joint... Objectives: This study examines the relationship between the morphology of the lumbosacral transitional vertebra (LTV) and asymmetrical development of the hip joints in dogs. Methods: A total of 4000 dogs which had been consecutively scored for canine hip dysplasia were checked for the presence of a LTV. A LTV was noted in 138 dogs and classified depending on the morphology of the transverse processes and the degree of contact with the ilium. Results: In dogs with an asymmetrical LTV, the hip joint was significantly more predisposed to subluxation and malformation on the side of the intermediate or sacral-like transverse process (p <0.01), on the side of the elevated pelvis (p <0.01), or when an asymmetrical LTV resulted in pelvic rotation on its long axis (p <0.01), whereas hip joint conformation was less affected on the side featuring a free transverse process (p <0.01). Clinical significance: The results support our hypothesis that an asymmetrical LTV favours pelvic rotation over its long axis, resulting in inadequate femoral head coverage by the acetabulum on one side. Inadequate coverage of the femoral head favours subluxation, malformation of the hip joint, and secondary osteoarthritis. Asymmetrical hip conformation may therefore be the sequela of a LTV and mask or aggravate genetically induced canine hip dysplasia.... M. A. Flückiger (1), F. Steffen (2), M. Hässig (3), J. P. Morgan (4) 27055 2017-01-17 10:07:36 Evaluation of the optimal plate position for the fixation of supraglenoid tubercle fractures in... Objectives: To determine scapular cortex thickness, distal scapular bone density and describe the exact suprascapular nerve course to evaluate the best plate position for the fixation of supraglenoid tubercle fractures in horses. Methods: Twelve equine cadaveric shoulders were examined with computed tomography. Computed tomography morphometry and density measurements (Hounsfield units [HU]) of the scapula were recorded. Statistical comparisons were made between the cranial and caudal aspects of the scapula. Dissection of each shoulder was performed and the suprascapular nerve course was described morphometrically and morphologically. Results: The suprascapular nerve was found on the periosteum and embedded in connective tissue at the cranial aspect of the scapula. It ramified proximally and distally into the supraspinatus muscle, coursed caudolaterally at a median of 2 cm (1–2 cm) distal to the scapular spine and ramified proximally and distally into the infraspinatus muscle. The scapular cortex measurements (HU) cranially were significantly larger than caudally at most levels of the scapula. The bone density of the distal scapula cranially (651.3 ± 104.2) was significantly lower than caudally (745.7 ± 179.1). Clinical significance: For surgical access to the supraglenoid tubercle, knowledge of the anatomy is important. It is easiest to avoid the suprascapular nerve at the most cranial aspect of the scapula, where it has not yet ramified. For a stable fixation, knowledge of the characteristics of the equine scapula, such as scapular cortex thickness, is important.... S. Frei (1), H. Geyer (2), S. Hoey (3, 4), A. E. Fuerst (1), A. S. Bischofberger (1) 27054 2017-01-17 10:06:39 Predicting the need for trochleoplasty in canine patellar luxation using pre- and intra-operative... Objectives: To evaluate the repeatability and reproducibility of ultrasonographic femoral trochlear depth measurements and to compare ultrasonographic and intra-operative evaluations of femoral trochlear depth for predictive value in selecting trochleoplasty. Methods: Repeatability and reproducibility of an ultrasonographic protocol were tested in a preclinical cadaveric study. Clinical patients undergoing corrective surgery for patellar luxation were evaluated preoperatively with ultrasound and intra-operatively using a depth gauge. Measurements were assessed for equivalence using linear regression, and agreement between decisions made based on these measurements assessed using Cohen’s kappa. Results: Although ultrasonographic and intra-operative measurements were in broad agreement, the prediction interval was too wide for clinical use. There was no significant agreement between predictions of the need for trochleoplasty using various cut-off values for the two measurements, nor between these and the surgeon’s decision. Clinical significance: Based on our observations, use of ultrasound for evaluation of the femoral trochlea remains a largely qualitative assessment. A simpler and more direct objective measure of femoral trochlear adequacy is required for intra-operative use.... J. S. O. Hansen (1), K. Lindeblad (2), L. Buelund (3), J. Miles (3) 27053 2017-01-17 10:05:28 Outcome of nonunion fractures in dogs treated with fixation, compression resistant matrix, and... Objectives: To report the use of compression resistant matrix (CRM) infused with recombinant human bone morphogenetic protein (rhBMP-2) prospectively in the healing of nonunion long-bone fractures in dogs. Methods: A longitudinal cohort of dogs that were presented with nonunion fractures were classified and treated with CRM soaked with rhBMP-2 and fracture fixation. They were followed with serial radiographs and evaluated for healing times and complications according to the time frame and definitions previously established for orthopaedic clinical cases. Results: Eleven nonunion fractures in nine dogs were included. Median healing time was 10 weeks (range: 7–20 weeks). Major perioperative complications due to bandage morbidity were encountered in two of 11 limbs and resolved. All other complications were minor. They occurred perioperatively in eight of 11 limbs. Minor follow-up complications included short-term in one of two limbs, mid-term in one of three, and long-term in four of five limbs. Nine limbs returned to full function and two limbs returned to acceptable function at the last follow-up. Clinical significance: Nonunion fractures given a poor prognosis via standard-of-care treatment were successfully repaired using CRM with rhBMP-2 accompanying fixation. These dogs, previously at high risk of failure, returned to full or acceptable function.... A. M. Massie (1), A. S. Kapatkin (2), M. C. Fuller (2, 3), F. J. M. Verstraete (2), B. Arzi (2) 27052 2017-01-17 10:04:33 Ex vivo torsional properties of a 2.5 mm veterinary interlocking nail system in canine femurs Objective: To evaluate the torsional properties of the Targon® Vet Nail System (TVS) in small canine femurs and to compare these properties to those of the 2.4 mm LC-DCP® plates. Methods: Thirty-six cadaveric femurs were allocated to three groups (n = 12). In all bones, points just distal to the lesser trochanter and just proximal to the fabellae were marked and a midshaft transverse osteotomy was performed. Group 1: bones were fixed with the 2.5 mm TVS with the bolts applied at the pre-identified marks. Group 2: A TVS system with 25% shorter inter-bolt distance was used. Group 3: A 7-hole 2.4 mm LC-DCP® plates were applied. All constructs were tested non-destructively for 10 cycles, followed by an acute torsion to failure. Results: Torque at yield was 0.806 ± 0.183 and 0.805 ± 0.093 Nm for groups 1 and 2 and 1.737 ± 0.461 Nm for group 3. Stiffness was 0.05 ± 0.01, 0.05 ± 0.007, and 0.14 ± 0.015 Nm/° for groups 1 to 3 respectively. Maximal angular displacement under cyclic loading was 16.6° ± 2.5°, 15.6° ± 2.1°, and 7.8° ± 1.06° respectively. There was no significant difference for any of the parameters between groups 1 and 2. Both torque at yield and stiffness were significantly greater between group 3 and groups 1 and 2. Clinical significance: The TVS had approximately half the torsional strength and approximately 1/3 of the stiffness of the 2.4 mm bone plate. Slippage of the locking mechanism was probably the cause of the early failure. The system should be considered as a low-strength and low-stiffness system when compared to bone plates.... A. S. Macedo (1), N. M. M. Moens (2), J. Runciman (3), T. W. G. Gibson (2), B. W. Minto (1) 27051 2017-01-17 10:03:35 Biomechanical evaluation of simulated feline patellar fracture repairs Objective: To investigate four techniques for stabilization of feline patellar fracture. Methods: Feline cadaveric stifles with simulated patellar fracture were stabilized with one of four techniques: Group A - circumferential wire, group B - figure-of-eight wire, group C - combined figure-of-eight and circumferential wire, group D - pin and tension band wire. All repairs were subjected to a period of cyclic loading prior to load to failure testing. Experiments were recorded by video capture to determine load at failure and failure mode. Failure was defined as an opening of the fracture gap of 3 mm. Results: Mean fracture gap opening (±SD) during peak loading after 1000 cycles was: group A with 1.66 mm (± 0.69), group B with 1.01 mm (± 0.45), group C with 0.81 mm (± 0.58), and group D with 0.65 mm (± 0.54). Groups C and D had significantly lower mean fracture gap opening after 1000 cycles when compared to group A (p M. Longley (1), S. Langley-Hobbs (1), J. Tarlton (1) 27050 2017-01-17 10:02:26 Repeatability and accuracy testing of a weight distribution platform and comparison to a pressure... Objective: To evaluate the accuracy and repeatability of measurements collected using a weight distribution platform and a pressure sensitive walkway using an inanimate object with known weight distribution. Methods: A custom-built jig with a range of weights was applied in a random order. Measurements were collected on both devices and compared to each other and to the known weight distribution. Results: Weight distribution platform and pressure sensitive walkway measurements were highly correlated to each other (Pearson’s correlation coefficient R = 0.98) and to actual weights (R = 0.99 for the weight distribution platform; 0.98 for the pressure sensitive walkway). Repeatability from day to day for both devices was greater than 0.99. For the weight distribution platform, the 95% confidence interval was ± 2.5% from the true percentage and ± 3.3% for the pressure sensitive walkway. The coefficient of variation (COV) was highest for both devices at the lightest weights (weight distribution platform 11.28%, pressure sensitive walkway 16.91%) and lowest with the heaviest weights (weight distribution platform 3.71%, pressure sensitive walkway 5.86%). Conclusion: Both the weight distribution platform and the pressure sensitive walkway provided accurate and consistent measures of weight distribution with no significant difference between devices. The rounded standard error was three percent for the weight distribution platform, and four percent for the pressure sensitive walkway. The higher variability when measuring the smallest weight suggests less accuracy at lower weights with both devices. Clinical significance: The weight distribution platform is a repeatable and accessible device to measure static weight distribution, and if proven the same in a clinical setting, it will be a valuable addition to current objective measures of limb use.... G. Bosscher (1), A. Tomas (1), S. C. Roe (1), D. J. Marcellin-Little (1), B. D. X. Lascelles (1) 27049 2017-01-17 10:01:25