Veterinary and Comparative Orthopaedics and Traumatology (VCOT) Veterinary and Comparative Orthopaedics and Traumatology (VCOT) vcot de-de Mon, 27 Feb 17 21:25:10 +0100 Ahead of print: Distal border synovial invaginations of the equine distal sesamoid bone communicate... 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 Ahead of print: The effect of valgus and varus femoral osteotomies on measures of anteversion in the... 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 <0.0001) from the Coxa Valga to Coxa Vara conditions while inclination changed by a mean of 1.3° (± 0.39; p <0.01). Version changed by a mean of 6.6° (± 0.7; p <0.0001) between the Distal Varus and Normal conditions while inclination changed by a mean of –3.8° (± 0.75; p <0.001). Clinical significance: Femoral version changes with changing frontal plane alignment even when torsion is constant. This should be considered when correcting femoral deformities.... R. W. Adams (1), B. Gilleland (2), F. Monibi (3), S. P. Franklin (1) 27098 2017-01-27 08:14:21 Ahead of print: 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 Ahead of print: Erratum to: Augmentation of diaphyseal fractures of the radius and ulna in toy breed... 27096 2017-01-27 07:54:24 Ahead of print: Ultrasound-guided approach to the cervical articular process joints in horses: a... 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 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. P. Johnson (1), J. D. Stack (1), C. Rowan (1), I. Handel (2), J. M. O'Leary (1) 27057 2017-01-17 10:14:19 Ahead of print: Comparative anatomy and biomechanical properties of atlantoaxial ligaments in... 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 Ahead of print: Asymmetrical lumbosacral transitional vertebrae in dogs may promote asymmetrical hip... 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 Ahead of print: Evaluation of the optimal plate position for the fixation of supraglenoid tubercle... 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 Ahead of print: Predicting the need for trochleoplasty in canine patellar luxation using pre- and... 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 Ahead of print: Outcome of nonunion fractures in dogs treated with fixation, compression resistant... 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 Ahead of print: Ex vivo torsional properties of a 2.5 mm veterinary interlocking nail system in... 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: TVS system with 25% shorter inter-bolt distance was used. Group 3: 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 Ahead of print: 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 Ahead of print: Repeatability and accuracy testing of a weight distribution platform and comparison... 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 Ahead of print: Postoperative computed tomography and low-field magnetic resonance imaging findings... Objectives: To describe postoperative computed tomography (CT) and magnetic resonance imaging (MRI) findings in dogs with degenerative lumbosacral stenosis (DLSS) treated by dorsal laminectomy and partial discectomy. Methods: Prospective clinical case study of dogs diagnosed with and treated for DLSS. Surgical and clinical findings were described. Computed tomography and low field MRI findings pre- and postoperatively were described and graded. Clinical, CT and MRI examinations were performed four to 18 months after surgery. Results: Eleven of 13 dogs were clinically improved and two dogs had unchanged clinical status postoperatively despite imaging signs of neural compression. Vacuum phenomenon, spondylosis, sclerosis of the seventh lumbar (L7) and first sacral (S1) vertebrae endplates and lumbosacral intervertebral joint osteoarthritis became more frequent in postoperative CT images. Postoperative MRI showed mild disc extrusions in five cases, and in all cases contrast enhancing non-discal tissue was present. All cases showed contrast enhancement of the L7 spinal nerves both pre- and postoperatively and seven had contrast enhancement of the lumbosacral intervertebral joints and paraspinal tissue postoperatively. Articular process fractures or fissures were noted in four dogs. Clinical significance: The study indicates that imaging signs of neural compression are common after DLSS surgery, even in dogs that have clinical improvement. Contrast enhancement of spinal nerves and soft tissues around the region of disc herniation is common both pre- and postoperatively and thus are unreliable criteria for identifying complications of the DLSS surgery.... M. Rapp (1), C. J. Ley (2), K. Hansson (2), L. Sjöström (1) 27048 2017-01-17 10:00:31 Ahead of print: Evaluation of proximal and distal motor nerve conduction using the electrical root... Objectives: This study aimed to investigate the adaptability of the electrical root stimulation technique by achieving normative data from the obturator and femoral nerves of healthy dogs. Methods: For this purpose, two stimulations and recordings were performed on both the obturator and femoral nerves in 40 dogs (22 males and 18 females). Electrical root stimulation was applied via monopolar needle electrodes between the sixth to seventh and fifth to sixth lumbar interarcuate spaces to the obturator and femoral nerves, respectively. Muscle waves were recorded from the gracilis and sartorius muscles of the left and right pelvic limb. Results: The proximal motor nerve conduction velocity was 60.89 ± 3.93 m/s and 59.87 ± 4.83 m/s in the obturator and femoral nerves, respectively. Clinical significance: Our results showed that electrical root stimulation could be a useful method to test the integrity of the roots of obturator and femoral nerves and their proximal parts. C. Ünsal (1), E. Turan (2), Ö. G. Dilek (3), S. S. Sabancı (4), M. Sarıerler (5) 27047 2017-01-17 09:59:34 Updated Instructions to Authors K. Johnson 27046 2017-01-16 09:44:02 2016 Resident Publication Award 27045 2017-01-16 09:41:40 Surgical management of dorsal scapular luxation in three dogs Scapular luxation is an uncommon cause of forelimb lameness in dogs and cats. Traumatic rupture of the serratus ventralis muscle allows the scapula to displace dorsally during weight-bearing. Specific documentation regarding clinical presentation and surgical techniques is limited, with no medium- to long-term results of surgical intervention in dogs described. Presented here are three cases of scapular luxation in dogs, treated with a modified surgical technique. Clinical outcome was considered good to excellent, with resolution of lameness and abnormal scapular motion in all three dogs. Medium- and long-term outcomes were assessed in two of the dogs, with an excellent outcome in both cases. S. C. Jones (1, 2), S. Tinga (1), E. G. Porter (1), D. Lewis (1) 27013 2016-12-15 14:01:02 The effect of limb amputation on standing weight distribution in the remaining three limbs in dogs Despite the fact that limb amputation is a commonly performed procedure in veterinary medicine, quantitative data regarding outcomes are lacking. The intention of this study was to evaluate the effect of limb amputation on weight distribution to the remaining three limbs at a stance in dogs. Ten dogs with a prior forelimb amputation and ten dogs with a prior hindlimb amputation; all of which had no history of orthopaedic or neural disease in the remaining three limbs were included in the study. Standing weight bearing was evaluated with a commercial stance analyzer in all dogs. Five valid trials were obtained and a mean percentage of weight bearing was calculated for each remaining limb. The dogs with a previous forelimb amputation, and also those with a previous hindlimb amputation, had the largest mean increase in weight bearing in the contralateral forelimb. In conclusion, proactive monitoring of orthopaedic disease in the contralateral forelimb may be advisable in dogs with a previous limb amputation. In addition, when determining candidacy for a limb amputation, disease of the contralateral forelimb should be thoroughly evaluated.... G. L. Cole (1), D. L. Millis (2) 27012 2016-12-15 14:00:16 A response to: Traumatic fracture of the medial coronoid process in 24 dogs D. K. Tan (1), S. O. Canapp Jr. (1), C. S. Leasure (1), D. L. Dycus (1), E. O'Donnell (1) 26995 2016-12-09 13:14:07 Comparison of osteotomy technique and jig type in completion of distal femoral osteotomies for... Objectives: Femoral osteotomies are frequently completed to correct malalignment associated with patellar luxation. The objectives of this study were to compare the use of: 1) two different types of jig; and 2) different types of osteotomy in the realignment of canine femoral bone models which possessed various iterations of angular deformity. Methods: Models of canine femora possessing distal varus, external torsion and a combination of varus and torsion underwent correction utilizing two alignment jigs (Slocum jig and Deformity Reduction Device) and either a closing wedge ostectomy (CWO) or an opening wedge osteotomy (OWO). Post-correctional alignment was evaluated by radiographic assessment and compared between groups. Results: The use of the Slocum jig resulted in frontal plane overcorrection when used with CWO in models of femoral varus, and when used with OWO in models of femoral varus and external torsion when compared to other techniques. The Deformity Reduction Device tended to realign the frontal plane closer to the post-correction target value in all angulation types. The use of both jigs resulted in undercorrection in the transverse plane in models with varus and torsion. Clinical significance: Jig selection and osteotomy type may lead to different post-correctional alignment results when performing distal femoral osteotomies. Whereas OWO allows accurate correction when used with either jig to address frontal plane deformities, the Deformity Reduction Device can be utilized with both CWO and OWO to correct torsion-angulation femoral deformities to optimize frontal plane alignment.... M. Olimpo (1), L. A. Piras (1), B. Peirone (1), D. B. Fox (2) 26994 2016-12-09 13:13:03 Distal femoral lateral closing wedge osteotomy as a component of comprehensive treatment of medial... Objective: To describe a cohort of dogs with medial patellar luxation managed with a distal femoral lateral closing wedge ostectomy (DFO) as a component of comprehensive treatment, and to report radiographic and long-term clinical outcome of this technique. Methods: Medical records of dogs that had a lateral closing wedge DFO as part of management of medial patellar luxation at three veterinary teaching hospitals were reviewed. Surgical reports as well as the preoperative, postoperative, and follow-up radiographs were reviewed. The anatomical lateral distal femoral angle (aLDFA) was determined. Long-term clinical outcome was assessed by telephone interview with the owner. Results: A lateral closing wedge DFO was performed on 66 limbs. The mean pre- and postoperative aLDFA was 107.6° ± 5.8° and 94.1° ± 4.2°, respectively. Cranial cruciate ligament disease was identified in 28/66 affected limbs. Tibial angular deformity, torsional deformity, or both was identified in nine of the 66 limbs. Ostectomy healing was confirmed radiographically in 51/66 limbs. The mean time to union was 73 ± 37 days. All patellae were in the normal position and stable. Complications included infection (2/51), fixation failure (1/51), delayed healing (2/51), and persistent lameness (1/51). Clinical significance: In this cohort of cases, DFO was a highly successful and repeatable component of surgical treatment for dogs with medial patellar luxation associated with femoral varus. This study also provides more evidence of the high rate of concurrent cranial cruciate ligament disease in cases of medial patellar luxation complicated by femoral varus, and supports an association between stifle instability and medial patellar luxation.... B. E. Brower (1), M. P. Kowaleski (2), A. M. Peruski (3), A. Pozzi (4), J. Dyce (5), K. A. Johnson (6), R. J. Boudrieau (2) 26993 2016-12-09 13:12:06 Preoperative low level laser therapy in dogs undergoing tibial plateau levelling osteotomy: A... Objectives: To evaluate the influence of preoperative low-level laser therapy (LLLT) on therapeutic outcomes of dogs undergoing tibial plateau levelling osteotomy (TPLO). Methods: Healthy dogs undergoing TPLO were randomly assigned to receive either a single preoperative LLLT treatment (800–900 nm dual wavelength, 6 W, 3.5 J/cm2, 100 cm2 area) or a sham treatment. Lameness assessment and response to manipulation, as well as force plate analysis, were performed preoperatively, then again at 24 hours, two weeks, and eight weeks postoperatively. Radiographic signs of healing of the osteo-tomy were assessed at eight weeks postoperatively. Results: Twenty-seven dogs (27 stifles) were included and no major complications occurred. At eight weeks postoperatively, a significant difference in peak vertical force analysis was noted between the LLLT (39.6% ± 4.7%) and sham groups (28.9% ± 2.6%), (p  C. P. Rogatko (1, 2), W. I. Baltzer (1), R. Tennant (3) 26992 2016-12-09 13:10:36 Farewell from the Publishers Geoffrey Sumner-Smith 1928-2016 D. Bergemann, A. Schürg, L. Lenz, E. Switzer 26897 2016-11-23 11:56:04 A Tribute to Professor Geoffrey Sumner-Smith 1928 – 2016 Kenneth A. Johnson 26896 2016-11-23 11:54:16