Veterinary and Comparative Orthopaedics and Traumatology (VCOT) Veterinary and Comparative Orthopaedics and Traumatology (VCOT) vcot de-de Mon, 25 May 15 13:20:31 +0200 Ahead of print: Histological and immunohistological analysis of degenerative changes in the cranial... Objective: To create a canine model of excessive tibial plateau angle (eTPA) and assess the chondroid metaplasia and extracellular matrix alteration in the cranial cruciate ligament. Methods: Seven mature female Beagles were included. Cylindrical osteotomy was performed bilaterally in the proximal tibia. The TPA was increased to approximately 40° in the left tibia (eTPA stifle) and left unchanged in the right tibia (control stifle). Exercise stress was started at three months postoperatively, and at 12 months postoperatively the dogs were euthanatized and the cranial cruciate ligaments were collected. The specimens were subjected to haematoxylin and eosin staining to assess the ligamentocyte morphology and immunostaining to assess the type I (COLI), type II (COLII), and type III (COLIII) collagen, and the sry-type HMG box 9 (SOX9) staining. Results: Macroscopic cranial cruciate ligament injury was absent in six dogs but present in the eTPA stifle of one dog, which was excluded from the analysis. The ligamentocyte density decreased and the percentage of round ligamentocytes increased in the eTPA stifles. The COLII, COLIII, and SOX9 staining increased significantly and COLI deposition decreased in the eTPA stifles compared to the control stifle. Clinical significance: The extracellular matrix changed, COLI deposition decreased, and COLIII and SOX9 staining increased in the cranial cruciate ligament of the eTPA stifles. SOX9 may contribute to COLII synthesis in the extracellular matrix of the cranial cruciate ligament in eTPA stifles, and eTPA may promote chondroid metaplasia and extracellular matrix alteration.... T. Ichinohe (1), N. Kanno (1), Y. Harada (1), T. Yogo (1), M. Tagawa (1), Y. Hara (1) 24398 2015-05-22 10:42:49 Ahead of print: In vitro biomechanical testing of different configurations of acrylic external... Objective: To evaluate the in vitro biomechanical properties of four different configurations of acrylic external skeletal fixator constructs. Materials and methods: Simulated bone constructs were prepared using 2 segments of 20 mm ultra-high-density polyethylene rods with a gap of 5 mm. The full pins (1.5 mm) were passed through the proximal and distal segments of ultra-high-density polyethylene rods, in the same plane, parallel to each other in configuration U, and were crossed in the M1, M2 and C configurations at a 90° angle to each other. Configuration U was a single bilateral uniplanar construct, M1 was a double orthogonal bilateral construct, M2 was a double orthogonal bilateral construct with proximal and distal connecting articulations, and C was a double orthogonal bilateral construct with proximal and distal circumferential articulations. Temporary scaffolds of different external skeletal fixator configurations were constructed using commercially available polyvinyl chloride pipes (20 mm) connected and secured to the fixation pins at a fixed distance from the rods. Acrylic powder (polymer) mixed with liquid (monomer) was poured into the pipes and allowed to solidify to form the side bars and rings. The external skeletal fixator constructs were then subjected to axial compression, cranio-caudal three-point bending and torsion (n = 4 each) using a universal testing machine. Mechanical parameters, namely stress, strain, modulus of elasticity, stiffness and bending moment of fixator constructs, were determined from load-displacement curves. Results: Configuration U was the weakest and configuration C was the strongest under all the testing modes. Under compression,the M1, M2 and C configurations were similar. Under bending, a significant difference was observed among the uniplanar, multiplanar and circular configurations with no difference between M1 and M2. However, under torsion, all the external skeletal fixator configurations differed significantly. Clinical significance: The freeform external skeletal fixator using acrylic as a replacement for a metallic bar may be useful to treat bone fractures and luxations in small animals, as it is mechanically strong, lightweight, economical, and pins can be passed from any direction depending upon the clinical situation.... S. K. Tyagi (1), H. P. Aithal (1), P. Kinjavdekar (1), Amarpal (1), A. M. Pawde (1), T. Srivastava (1), J. Singh (1), D. N. Madhu (1) 24397 2015-05-22 10:40:48 Veterinary Orthopedic Society - 42nd Annual Conference 24353 2015-05-12 16:28:51 Promotion of Bone Regeneration K. A. Johnson 24352 2015-05-12 14:54:22 Comparison of autogenous cancellous bone grafting and extracorporeal shock wave therapy on osteotomy... Objectives: To compare optical values in the osteotomy gap created after a tibial tuberosity advancement (TTA) treated with autogenous cancellous bone graft, extracorporeal shock wave therapy, a combination of autogenous cancellous bone graft and extracorporeal shock wave therapy, and absence of both autogenous cancellous bone graft and extracorporeal shock wave therapy using densitometry. Methods: Dogs that were presented for surgical repair of a cranial cruciate ligament rupture were randomly assigned to one of four groups: TTA with autogenous cancellous bone graft (TTA-G), TTA with autogenous cancellous bone graft and extracorporeal shock wave therapy (TTA-GS), TTA with extracorporeal shock wave therapy (TTA-S), and TTA with no additional therapy (TTA-O). Mediolateral radiographs at zero, four and eight weeks after surgery were evaluated to compare healing of the osteotomy gap via densitometry. An analysis of variance was used to compare the densitometric values between groups. Results: At four weeks after surgery, a significant difference in osteotomy gap density was noted between TTA-GS (8.4 millimetres of aluminium equivalent [mmAleq]) and TTA-S (6.1 mmAleq), and between TTA-GS (8.4 mmAleq) and TTA-O (6.4 mmAleq). There were no significant differences noted between any groups at the eight week re-evaluation. Clinical significance: There were no significant differences in the osteotomy gap density at eight weeks after surgery regardless of the treatment modality used. The combination of autogenous cancellous bone graft and extracorporeal shock wave therapy may lead to increased radiographic density of the osteotomy gap in the first four weeks after surgery. Densitometry using an aluminium step wedge is a feasible method for comparison of bone density after TTA in dogs.... K. Barnes (1), O. Lanz (1), S. Werre (1), K. Clapp (1), R. Gilley (1) 24274 2015-04-22 13:11:36 Ahead of print: Distal tibial tuberosity translation using TTA implants for the treatment of patella... Introduction: Medial patellar luxation frequently occurs in dogs resulting in lameness with increasing incidence in large breed dogs. Patella alta has been defined as a patellar ligament length to patellar length ratio that is greater than two and may predispose to patellar luxation. Objective: To describe the surgical technique for stabilization of the distal translation of the tibial tuberosity using tibial tuberosity advancement plates and the clinical outcomes with follow-up for clinical cases of dogs. Methods: Dogs that were presented with the complaint of patellar luxation and that were concurrently diagnosed with patella alta and were greater than 20 kg in body weight underwent surgery using a tibial tuberosity advancement plate to stabilize the osteotomy. Radiographic assessment of A:PL (the ratio of the proximal aspect of the patella to the femoral condyle [A] to the patellar length [PL]) distance, L:P ratio (ratio of the length of the patellar ligament to the diagonal length of the patella), and owner assessment were obtained. Results: Eleven stifles in nine dogs underwent surgical correction with a mean preoperative L:P ratio of 2.47. There were no complications and the lameness resolved clinically. The mean A:PL ratios preoperatively (2.6 ± 0.22) and postoperatively (2.1 ± 0.25) were significantly different (p = 0.0003). All owners were satisfied with the outcome and all dogs had a resolution of lameness with no recurrence of patellar luxation. Clinical significance: Stabilization of distal translation of the tibial tuberosity using tibial tuberosity advancement implants to correct patella alta in large breed dogs was feasible and resulted in good clinical outcome.... L. C. Pugliese (1), F. S. Pike (2), S. W. Aiken (2) 24273 2015-04-22 12:58:01 Single-stage bilateral tibial tuberosity advancement for treatment of bilateral canine cranial... Objective: To report complications in dogs with naturally occurring cranial cruciate ligament rupture following single-stage bilateral tibial tuberosity advancement (SS-BTTA) procedures, and to compare these complications to a population of dogs undergoing unilateral tibial tuberosity advancement (UTTA). Methods: Medical records and radiographs of client-owned dogs treated with tibial tuberosity advancement between August 2008 and December 2011 were reviewed. Forty-four client-owned dogs with bilateral cranial cruciate ligament rupture that underwent SS-BTTA procedures and 82 client-owned dogs that underwent UTTA procedures were randomly selected from our hospital population. Complications were recorded and analysed. Major complications were defined as fractures or any complication requiring a second surgery. Minor complications were any problem identified that did not require surgical management. Results: Incidence for major and minor complications in the UTTA group was 2.3% and 24.4%, respectively. Incidence for major and minor complications in the SS-BTTA group was 12.5% and 26.1%, respectively. Single-stage bilateral tibial tuberosity advancement procedures had a four- to five-fold increase in odds of a major complication (p... J. E. Kiefer (1), A. Langenbach (1), J. Boim (2), S. Gordon (1), D. J. Marcellin-Little (3) 24272 2015-04-22 12:57:57 Evaluation of a distractor to increase joint space of the stifle joint in dogs: a cadaveric study Objective: To evaluate the technical feasibility and efficacy of a joint distraction technique to increase the stifle joint space and assess potential soft tissue damage due to the distraction. Methods: Twenty stifle joints of twelve canine cadavers without evidence of disease were radiographically evaluated by medio-lateral, cranio-caudal and varus-valgus stressed projections. Joint distraction was applied with loads from 40 N up to 200 N, and the joint space achieved was measured on radiographic images. Distraction plus distension with saline was subsequently applied and measured. Varus-valgus stressed projections were repeated after distraction to evaluate a potential increase in joint laxity. Results: Distraction produced a significant increase of the joint space for most of the evaluated loads. Distraction plus distension produced a significant increase for most of the loads compared to the distraction alone. No ensuing joint laxity could be inferred from the post-distraction radiographic evaluation. Clinical significance: Stifle distraction produces an increase of the joint space, which is wider when intra-articular saline is injected. This may be potentially useful for improving joint structure visualization and facilitating arthroscopic procedures, thus reducing the potential for iatrogenic damage to intra-articular structures. No soft tissue damage could be inferred by radiographic pre- and post-procedure comparison. Further clinical studies are required to evaluate potential neurovascular complications.... G. L. Rovesti (1), V. Devesa-Garcia (2), P. G. Urrutia (3), F. San Roman (2), J. Rodriguez-Quiros (2) 24271 2015-04-22 12:57:50 Reconstruction of chronic triceps tendon avulsion using synthetic mesh graft in a dog Avulsion of the triceps tendon insertion was diagnosed in a two-year-old Poodle mixed breed dog 10 weeks after traumatic injury. Diagnosis was confirmed with clinical examination and magnetic resonance imaging (MRI). The tendon was reconstructed using tension-relieving sutures augmented with a synthetic degradable porous polyurethane urea onlay mesh graft. The repair was immobilized using a transarticular external skeletal fixator with staged increases in elbow flexion. Treatment was successful, with signs of healing confirmed by MRI and normal clinical function one year after surgery. The successful outcome in this case suggests that surgical repair of a chronic triceps tendon injury using a synthetic mesh augmentation may be successful in similar cases. L. Ambrosius (1), C. Arnoldy (2), K. R. Waller III (2), J. P. Little (3), J. A. Bleedorn (2) 24191 2015-03-25 10:24:30 Radiographic and computed tomographic assessment of the development of the antebrachia and elbow... Objectives: To compare the development, monitored by radiography and computed tomography, of the antebrachia and elbow joints in seven Labrador Retrievers with healthy elbow joints and in seven Labrador Retrievers that developed medial coronoid disease (MCD), in order to determine whether disturbances in the development of the antebrachia and elbow joints, between the age of six and 17 weeks may lead to medial coronoid disease. Methods: A prospective study of 14 Labrador Retrievers in their active growth stage was performed. The development of the antebrachia and elbow joints was assessed between six and 17 weeks of age using radiography and computed tomography determining the development of secondary ossification centres, radioulnar length ratio, radial angulation, and inter-relationship between the humerus, ulna and radius. Results: For the parameters of ossification of secondary ossification centres, radioulnar length ratio, radial angulation, and joint congruence evaluation, there was no significant difference in the development of the antebrachia and elbow joints of seven Labrador Retrievers positive and seven Labrador Retrievers negative for MCD at the age of six to 17 weeks. Clinical significance: These findings demonstrate that the development of MCD in the Labrador Retrievers in our study was not related to any disturbance in the development of the antebrachia and elbow joints during the rapid growth phase.... S. F. Lau (1, 2), H. A. W. Hazewinkel (3), G. Voorhout (1) 24190 2015-03-25 10:23:09 Ahead of print: Repair of chronic rupture of the insertion of the gastrocnemius tendon in the dog... Objectives: Chronic degeneration of the gastrocnemius tendon results in scar tissue formation at the insertion of the tendon, and detachment from the calcaneus. In severe cases, excision of this tissue makes repositioning of the tendon to the calcaneus extremely difficult. A polyethylene terephthalate implant, used to aide repair by bridging gaps and allowing tissue ingrowth, was evaluated. Methods: In this retrospective study, clinical records were evaluated to assess long-term outcomes and complications. The surgical technique is also described. The implant was sutured proximally into the gastrocnemius at the myotendinous junction, and secured into the calcaneus using an interference screw. Results: The implant was used in 10 patients; of which seven returned to full function. Major complications, due to infection, were identified in two of the 10 patients. Minor complications occurred in five of the 10 patients. These were associated with external coaptation in three of the patients in the immediate postoperative period. One minor infection was reported. These all resolved without further complication. Long-term outcome was available in eight patients, with six of these eight dogs returning to normal exercise. Clinical significance: This implant may be suitable for use in canine patients with severe gastrocnemius tendon degeneration. Ongoing evaluation is warranted.... M. A. Morton (1), D. G. Thomson (1), R. M. Rayward (1, 2), M. Jiménez-Peláez (1), R. G. Whitelock (1) 24189 2015-03-25 10:21:45 A comparison of anatomical lateral distal femoral angles obtained with four femoral axis methods in... Objectives: To report the repeatability and reproducibility of four different anatomical proximal femoral axis (a-PFA) methods for measuring anatomical lateral distal femoral angle (a-LDFA), and to compare a-LDFA values produced by each method at three different femoral elevation angles. Methods: Digital radiographs were obtained of seven dry canine femora at 0°, 12.5° and 25° elevations. Using image analysis software, landmarks defining four different a-PFA and the condylar axis were identified by two independent observers on two separate occasions. Corresponding a-LDFA were calculated for each femur, elevation and a-PFA. Repeatability and reproducibility parameters were calculated and compared statistically, along with the effect of technique and elevation on a-LDFA value. Results: Interobserver repeatability coefficients were subjectively better for three of the a-PFA methods at 2° compared to the fourth at 3.1°. Median a-LDFA increased significantly (p ≤0.002) with increasing femoral elevation for all a-PFA methods, with a median increase of 3.3°. The median difference in a-LDFA between a-PFA methods yielding the highest and lowest measurements was 2.6° over all three elevations. Clinical significance: The combined effects of a-PFA choice, femoral elevation and measurement reproducibility may produce typical errors of ± 2.6°, which could have implications for the selection of candidates for corrective osteotomies. Clinicians need to be aware that values obtained with one method and femoral elevation may not be equivalent to values obtained with other methods or elevations.... J. E. Miles (1), M. Mortensen (1), E. L. Svalastoga (1), T. Eriksen (1) 24188 2015-03-25 10:20:44 Treatment of a diaphyseal long-bone defect with autologous bone grafts and platelet-rich plasma in a... Introduction: Large bone defects are a therapeutic challenge to surgeons and are often associated with a high morbidity. The use of autologous cancellous bone graft represents an essential therapeutic option and is considered the gold standard. However, the use of platelet-rich plasma (PRP) for improving bone defect healing has been discussed controversially. The aim of this study was to evaluate the treatment of a diaphyseal long-bone defect in a rabbit model with a combination of PRP and autologous cancellous bone. Material and methods: A monocortical long-bone defect in the radial diaphysis of 24 New Zealand white rabbits was filled either with autologous cancellous graft as a control group or with autologous cancellous graft combined with autologous PRP. Histomorphometrical and radiological analysis as well as quantification of platelets and growth factors were performed. The animals were euthanatized after three and six weeks according to the study arms. Results: A significant improvement in bone healing was observed histomorphometrically in the PRP group in the central area of the defect zone (p <0.01) as well as the cortical defect zone (p <0.01). The radiological findings were in accordance with the histomorphometrical results. Comparing native blood and PRP, an enrichment of growth factors and platelets was detectable in the PRP. Conclusion: Within this animal study, the combination of PRP and autologous cancellous bone grafts improved bone healing significantly compared to the sole application of autologous bone. Therefore, further efforts should be initiated to establish the composite of PRP and autologous bone for bone healing disorders in clinical use.... J. Schneppendahl (1), P. Jungbluth (1), T. T. Lögters (1), M. Sager (2), M. Wild (1), M. Hakimi (1), J. Windolf (1), J. P. Grassmann (1) 24187 2015-03-25 10:19:37 Effect of locally injected autologous platelet-rich plasma on second intention wound healing of... Objectives: Second intention wound healing may be impaired by wound and host factors and thus more advanced therapies are required for a fast and satisfactory outcome. Platelet-rich plasma (PRP), rich in growth factors and cytokines essential for tissue repair, could improve wound healing. The purpose of this experimental study was to evaluate the effect of locally injected autologous PRP on second intention healing of acute full-thickness skin defects in dogs. Methods: Three 2x2 cm full-thickness skin defects were created bilaterally on the dorsolateral area of the trunk of six Beagle dogs. The wounds of one randomly selected side received PRP treatment, whereas the contralateral wounds were left untreated (controls). Wound healing was evaluated by planimetry, laser-Doppler flowmetry measurements of tissue perfusion, and histologically. Results: The rate of wound healing did not differ significantly between the two groups. Tissue perfusion was significantly higher in the PRP-treated group (p = 0.008) compared to controls on day 10. Histological evaluation revealed a trend towards greater collagen production and a significantly better collagen orientation (p = 0.019) in PRP-treated wounds on day 20. Clinical significance: Locally injected autologous PRP does not accelerate the healing process, but increases tissue perfusion and may promote the formation of organized collagen bundles in acute full-thickness skin defects in dogs.... M. Karayannopoulou (1), D. Psalla (2), G. Kazakos (1), P. Loukopoulos (2), N. Giannakas (1), I. Savvas (1), M. Kritsepi-Konstantinou (3), A. Chantes (4), L. G. Papazoglou (1) 24186 2015-03-25 10:17:26 Veterinary Orthopedic Society - 42nd Annual Conference 24151 2015-03-17 10:11:57 Prior Publication of Papers K. A. Johnson 24150 2015-03-17 09:33:09 Perioperative risk factors for surgical site infection in tibial tuberosity advancement: 224 stifles Objective: To examine perioperative factors affecting surgical site infection (SSI) rate following tibial tuberosity advancement (TTA). Study design: Retrospective case series. Sample population: 224 stifles in 186 dogs. Methods: Medical records of dogs that underwent TTA in a single institution were reviewed. Information on signalment, anaesthetic and surgical parameters, as well as occurrence of SSI was recorded. Dogs were followed for a minimum of three months postoperatively. The association between perioperative factors and SSI was assessed using Chi-squared tests and binary logistic regression. Results: The prevalence of SSI was 5.3% (12/224 TTA). Surgical time (p = 0.02) and anaesthesia time (p = 0.03) were significantly associated with SSI. For every minute increase in surgical time and anaesthesia time, the likelihood of developing SSI increased by seven percent and four percent respectively. The use of postoperative antimicrobial therapy was not significantly associated with lower SSI (p = 0.719). Implants were removed in 1.3% of cases (3/224 TTA). Conclusions: The findings of this study suggest that increased surgical and anaesthesia times are significant risk factors for SSI in TTA, and that there is no evidence that postoperative prophylactic antimicrobial therapy is associated with SSI rate.... F. W. Yap (1), I. Calvo (1), K. D. Smith (1), T. Parkin (1) 24115 2015-03-11 08:39:35 Evaluation of the diagnostic accuracy of four-view radiography and conventional computed tomography... Objective: The purpose of our study was (1) to determine whether four-view radiography of the pelvis is as reliable and accurate as computed tomography (CT) in diagnosing sacral and pelvic fractures, in addition to coxofemoral and sacroiliac joint subluxation or luxation, and (2) to evaluate the effect of the amount of training in reading diagnostic imaging studies on the accuracy of diagnosing sacral and pelvic fractures in dogs. Methods: Sacral and pelvic fractures were created in 11 canine cadavers using a lateral impactor. In all cadavers, frog-legged ventro-dorsal, lateral, right and left ventro-45°-medial to dorsolateral oblique frog leg (“rollover 45-degree view”) radiographs and a CT of the pelvis were obtained. Two radiologists, two surgeons and two veterinary students classified fractures using a confidence scale and noted the duration of evaluation for each imaging modality and case. The imaging results were compared to gross dissection. Results: All evaluators required significantly more time to analyse CT images compared to radiographic images. Sacral and pelvic fractures, specifically those of the sacral body, ischiatic table, and the pubic bone, were more accurately diagnosed using CT compared to radiography. Fractures of the acetabulum and iliac body were diagnosed with similar accuracy (at least 86%) using either modality. Clinical significance: Computed tomography is a better method for detecting canine sacral and some pelvic fractures compared to radiography. Computed tomography provided an accuracy of close to 100% in persons trained in evaluating CT images.... S. M. Stieger-Vanegas (1), S. K. J. Senthirajah (1), S. Nemanic (1), W. Baltzer (1), J. Warnock (1), G. Bobe (2, 3) 24114 2015-03-11 08:38:55 The potential tyranny of statistical power J. K. Roush (1) 24113 2015-03-11 08:37:52 Augmentation of diaphyseal fractures of the radius and ulna in toy breed dogs using a free... Objectives: Evaluation of the short-term outcome, duration of bone healing, and complications following bone plate fixation in dogs weighing ≤6 kg, with and without the use of a free autogenous greater omental graft (OG). Materials and methods: A retrospective clinical study reviewed the medical records of 25 dogs of body weight <6 kg with mid to distal diaphyseal fractures of the radius and ulna (29 fractures) treated with open reduction bone plate fixation. Thirteen out of 29 fractures were implanted with an additional 2–3 cm³ OG lateral, cranial, and medial to the fracture site, adjacent to the bone plate. Results: Median time to radiographic healing in OG fractures (n = 11) was 70 days (range 28–98) compared to 106 days (range: 56–144) in non-OG grafted fractures (n = 14). The OG dogs had no major complications; minor complications included oedema, erythema, and mild osteopenia. Six of the eight non-OG dogs for which follow-up could be obtained developed osteopenia necessitating implant removal, four of which re-fractured the radius one to five months after implant removal, with one dog re-fracturing the limb a second time and resulting in amputation. Telephone follow-up of owners of OG dogs (n = 11) three to 15 months (median 10) post-surgery did not identify any signs of lameness or other complications. Owners of the non-OG dogs (n = 8) reported that there were not any signs of lameness six to 48 months (median 36) post-surgery. Clinical relevance: Free autogenous omental grafting of diaphyseal fractures of the radius and ulna was associated with radial and ulnar healing with minimal complications in dogs weighing less than 6 kg.... W. I. Baltzer (1), S. Cooley (2), J. J. Warnock (1), S. Nemanic (1), S. M. Stieger-Vanagas (1) 24045 2015-02-23 08:54:26 Mechanical performance in axial compression of a titanium polyaxial locking plate system in a... Objective: To evaluate the bending strength of the VetLOX® polyaxial locking plate system. Materials and methods: Thirty-five 3.5 mm 12-hole titanium VetLOX® plates were used to stabilize seven different construct designs in a 1 cm fracture gap simulation model. Each construct was subjected to axial compression. Mean bending stiffness (BS) and yield load (YL) of each construct design were analysed using a one-way ANOVA and Tukey post-hoc analysis. Screw angulation was measured on reconstructed computed tomography (CT) images. Results: Reducing plate working length for fixed-angle constructs significantly increased BS (p A. W. Tomlinson (1), E. J. Comerford (1, 2), R. S. Birch (3), J. F. Innes (4), M. B. Walton (4) 24044 2015-02-23 08:53:31 Femoral nerve entrapment in a dog with diffuse idiopathic skeletal hyperostosis Objective: To report femoral neuropathy caused by nerve entrapment associated with diffuse idiopathic skeletal hyperostosis (DISH). Study Design: Case report. Animal: Seven-year-old female spayed Boxer dog. Results: Entrapment of the right femoral nerve due to DISH caused a femoral nerve deficit and atrophy of muscle groups associated with the affected nerve. A combination of computed tomography and magnetic resonance imaging was performed to provide a diagnosis. Amputation of the right transverse process of the sixth lumbar vertebra at the level of nerve entrapment relieved the neurological abnormality. Conclusions: Nerve entrapment leading to neurapraxia may occur concurrently with DISH and surgery in this case was successful in restoring function. Clinical relevance: Peripheral neuropathy from nerve entrapment should be considered in patients with DISH. Surgical amputation of impinging osseous structures may be indicated for relief of femoral neuropathy. A. Lai (1), J. Culvenor (1), C. Bailey (1), S. Davies (2) 23964 2015-02-04 14:53:04 Bilateral cervical ribs in a Dobermann Pinscher An 11-year-old intact female Doberman Pinscher was presented with the complaint of non-ambulatory tetraparesis. Clinical and neurological examination revealed a caudal cervical spinal cord disfunction (C6-T2 spinal cord segments). Magnetic resonance imaging and computed tomographic (CT) findings of the cervical spine were consistent with caudal cervical spondylomyelopathy (CSM). During the diagnostic work-up for the cervical spine, bilateral bone anomalies involving the seventh cervical vertebra and the first ribs were found on radiographs and CT examination. The rib anomalies found in this dog appear similar to cervical ribs widely described in human medicine. In people, cervical ribs are associated with a high rate of stillbirth, early childhood cancer, and can cause the thoracic outlet syndrome, characterized by neurovascular compression at level of superior aperture of the chest. In dogs, only some sporadic anatomopathological descriptions of cervical ribs exist. In this report the radiographic and CT findings of these particular vertebral and rib anomalies along with their relationships with adjacent vasculature and musculature are shown intravitam in a dog. Specific radiographic and CT findings described in this report may help in reaching a presumptive diagnosis of this anomaly. Finally, their clinical and evolutionary significance are discussed.... M. Ricciardi (1), A. De Simone (1), F. Gernone (1), P. Giannuzzi (1) 23963 2015-02-04 14:52:23 Patellar groove replacement in patellar luxation with severe femoro-patellar osteoarthritis Objective: To report a novel method of treating femoro-patellar instability in association with severe femoro-patellar osteoarthritis, by substituting the femoral trochlear with a patellar groove replacement prosthesis. Study design: Retrospective case series. Methods: Preoperative lameness was scored from 0–4, and radiographic studies including standard positions for patellar luxation were obtained for evidence of malalignment and femoro-patellar osteoarthritis. Cases with or without previous surgeries were included. The size of trochlear implant was determined by transparent templates and confirmed intra-operatively with trials. Radiographic images, together with clinical examinations, were reviewed immediately and at three months postoperatively and at longer term when available. Results: Thirty-five cases of patellar luxation ranging from grades II to IV were included. Eleven of these cases had prior surgical interventions which failed to stabilize the patella. Fourteen dogs required additional surgical procedures in conjunction with patellar groove replacement. Complications occurred in six patients, of which three required revision. Complete resolution of subjectively-assessed lameness was evident in 24/35 cases by the third month and in another seven of 35 patients on the longer term re-evaluations. Clinical significance: Use of a patellar groove replacement prosthesis has the potential to decrease the lameness associated with severe femoro-patellar arthritis, to improve patellar stability, and to correct the alignment of the extensor mechanism.... Z. Dokic (1), D. Lorinson (1), J. P. Weigel (2), A. Vezzoni (3) 23962 2015-02-04 14:51:36 Impact of fixation method on postoperative complication rates following surgical stabilization of... Objectives: To compare the complication rate between open reduction and internal fixation (ORIF) and external skeletal fixation (ESF) for feline diaphyseal tibial fractures. Methods: In a retrospective study spanning a 10 year period, 57 feline tibial fractures stabilized via ESF or ORIF were included for analysis and complication rates were compared between the two methods. Results: In the overall study population, 23 (40.4%) cases suffered complications (9 major, 20 minor, 6 with both major and minor). All of the major complications occurred in the ESF group. Complications were more common in cats with ESF (50.0%) while only one (7.7%) of the ORIF cases suffered complications (OR 12.0 [CI: 2.09; 228.10], p = 0.02). Use of postoperative antibiotic medications was identified as a confounder. After adjusting for confounding, stabilization using ESF remained associated with a higher risk of complications (OR = 13.71 [CI: 2.18; 274.25], p = 0.02). Cats with ESF had a longer duration of follow-up (15.6 weeks; 95% CI: 13.0; 18.3) compared to ORIF (9.5 weeks; 95% CI: 6.4; 12.7) (p = 0.003), and a higher number of revisits (mean 3.0; 95% CI: 2.4; 3.6) than the ORIF group (mean 1.6; 95% CI: 0.9; 2.3) (p = 0.002). Clinical significance: This study demonstrates a significant difference in complication rates between the methods of stabilization, with ESF resulting in a significantly higher complication rate compared to ORIF. Based on these results, it may be prudent to select ORIF for stabilization of feline tibial fractures wherever practical.... K. L. Perry (1), M. Bruce (2) 23961 2015-02-04 14:50:50