Veterinary and Comparative Orthopaedics and Traumatology (VCOT) Veterinary and Comparative Orthopaedics and Traumatology (VCOT) vcot de-de Sat, 29 Oct 16 01:22:18 +0200 Ahead of print: Inter- and intra-observer variability of radiography and computed tomography for... Objective: To evaluate the inter- and intra-observer variability in measurement of the angle of lateral opening (ALO) and version angle measurement using digital radiography and computed tomography (CT). Methods: Each hemipelvis was implanted with a cementless acetabular cup. Ventrodorsal and mediolateral radiographs were made of each pelvis, followed by CT imaging. After removal of the first cup, the pelves were implanted with an acetabular cup in the contralateral acetabulum and imaging was repeated. Three surgeons measured the ALO and version angles three times for each cup from the mediolateral radiographic projection. The same measurements were made using three-dimensional multiplanar reconstructions from CT images. Two anatomical axes were used to measure pelvic inclination in the sagittal plane, resulting in six measurements per cup. Two-way repeated measures analysis of variance evaluated inter- and intra-observer repeatability for radiographic and CT-based measurements. Results: Version angle based on radiographic measurement did not differ within surgeons (p = 0.433), but differed between surgeons (p <0.001). Radiographic measurement of ALO differed within surgeons (p = 0.006) but not between surgeons (p = 0.989). The ALO and version angle measured on CT images did not differ with or between surgeons. Clinical significance: Assessment of inter- and intra-observer measurement of ALO and version angle was more reproducible using CT images than conventional mediolateral radiography for a Zurich cementless acetabular cup.... J. O. Leasure (1), J. N. Peck (1), A. Villamil (1), K. L. Fiore (1), C. A. Tano (1) 26741 2016-10-25 11:13:47 Ahead of print: Effect of monocortical and bicortical screw numbers on the properties of a locking... Objectives: To evaluate the effect of varying the number and configuration of locking bicortical and monocortical screws on a plate-rod construct using a mid-diaphyseal femoral ostectomy model. Methods: Thirty Greyhound femurs were assigned to six groups (A-F). An intramedullary pin was placed in each bone following which a 3.5 mm locking plate was applied with six differing locking screw configurations. Groups A to C had one bicortical screw in the most proximal and distal plate holes and one to three monocortical locking screws in the proximal and distal fragments. Groups D to F had no bicortical screws placed and two to four monocortical locking screws in proximal and distal fragments. Each construct was axially loaded at 4 Hz from a preload of 10 Newtons (N) to 72 N, increasing to 144 N and 216 N, each of 6000 cycles with a further 45,000 cycles at 216 N to simulate a three to six week postoperative convalescence period. Constructs were then loaded to failure. Results: No construct suffered screw loosening or a significant change in construct stiffness during cyclic loading. There was no significant difference in load to failure of any construct (p = 0.34), however, less variation was seen with monocortical constructs. All constructs failed at greater than 2.5 times physiological load, and failure was by bending of the intramedullary pin and plate rather than screw loosening or pull-out. Clinical significance: Axially loaded locking monocortical plate-rod constructs applied to the canine femur may confer no difference biomechanically to those employing locking bicortical screws.... E. J. Field (1), K. Parsons (1), J. A. Etches (2), K. Hamilton (3), N. J. Burton (1) 26740 2016-10-25 11:11:31 Ahead of print: One-stage revision of an infected cementless total hip replacement A two-year-old, 44 kg dog with a right Helica cementless total hip replacement (THR) was radiographically diagnosed with implant loosening eight months after the index total hip replacement procedure. Subsequent synoviocentesis and synovial fluid culture revealed a methicillin-resistant coagulase-negative Staphylococcus spp infection of the right THR. A one-stage revision using a hybrid BFX cementless acetabular cup and CFX cemented femoral stem was performed. Vancomycin and micro-silver antimicrobial powder impregnated cement were used in the revision. At re-evaluation 27 months following the revision procedure, the patient did not exhibit any signs of lameness. Radiographic images confirmed stable implants, with bone ingrowth into the cup and no signs of implant loosening. Our report demonstrates the success of a one-stage THR revision when faced with a multi-drug resistant periprosthetic infection, when combined with the use of micro-silver antimicrobial powder and culture-based antibiotic impregnated cement therapy.... M. G. Ficklin (1), M. P. Kowaleski (2), K. A. R. Kunkel (1), J. T. Suber (1) 26725 2016-10-20 10:11:52 Ahead of print: Evaluation of inertial measurement units as a novel method for kinematic gait... Objective: To evaluate the use of inertial measurement units (IMU) for quantification of canine limb kinematics. Methods: Sixteen clinically healthy, medium-sized dogs were enrolled. Baseline kinematic data were acquired using an optical motion capture system. Following this baseline data acquisition, a harness system was used for attachment of IMU to the animals. Optical kinematic data of dogs with and without the harness were compared to evaluate the influence of the harness on gait parameters. Sagittal plane joint kinematics acquired simultaneously with IMU and the optical system were compared for the carpal, tarsal, stifle and hip joints. Comparisons of data were made using the concordance correlation coefficient (CCC) test and evaluation of root mean squared errors (RMSE). Results: No significant differences were demonstrated in stance duration, swing duration or stride length between dogs instrumented with or without the harness, however, mean RMSE values ranged from 4.90° to 14.10° across the various joints. When comparing simultaneously acquired optical and IMU kinematic data, strong correlations were found for all four joints evaluated (CCC: carpus = 0.98, hock = 0.95, stifle = 0.98, hip = 0.96) and median RMSE values were similar across the joints ranging from 2.51° to 3.52°. Conclusions and Clinical relevance: Canine sagittal plane motion data acquisition with IMU is feasible, and optically acquired and IMU acquired sagittal plane kinematics had good correlation. This technology allows data acquisition outside the gait laboratory and may provide an alternative to optical kinematic gait analysis for the carpal, tarsal, stifle, and hip joints in the dog. Further investigation into this technology is indicated.... F. M. Duerr (1), A. Pauls (1), C. Kawcak (2), K. Haussler (2), G. Bertocci (3), V. Moorman (2), M. King (2) 26724 2016-10-20 10:06:05 Ahead of print: Evaluation of an overlapping pubic and ischiatic osteotomy for the improvement of... Objectives: To assess the potential of a new single-session surgical procedure, the overlapping pubic and ischiatic osteotomy (OPIO) for modification of bilateral hip conformation. We hypothesized that OPIO would be simple to perform with currently available surgical equipment, through a single surgical approach, with minimal potential morbidity, and that it would allow adequate simultaneous bilateral improvement of coxofemoral joint conformation in patients at risk of canine hip dysplasia. Methods: The OPIO procedure was performed in the pelves of five large breed canine cadavers. Computed tomography images of each cadaver were compared by measurement of the dorsal acetabular rim angle (DARA), acetabular angle (AA), dorso-ventral sacroiliac ratio (SR) and pubic inlet area before and after OPIO. Results: Coxofemoral joint conformation was improved after OPIO. Postoperative DARA was significantly decreased (mean: –5.09°) and AA was significantly increased (mean: 3.54°) after OPIO. The SR was not significantly different after OPIO, indicating minimal impact on the sacro-illiac joints by the procedure. Pubic inlet dimensions and area were significantly decreased after OPIO, but the overall effect on pelvic inlet area was clinically insignificant. Clinical significance: An OPIO allows some improvement of coxofemoral joint conformation in canine cadavers.... J. A. Gervais (1), J. K. Roush (1), D. S. Biller (1) 26723 2016-10-20 10:05:13 Ahead of print: Combined tibial plateau levelling osteotomy and tibial tuberosity transposition for... Objectives: To describe the surgical technique and report short-term outcome for combined tibial plateau levelling osteotomy and tibial tuberosity transposition (TPLO-TTT) as an option in the treatment of cranial cruciate ligament insufficiency with concomitant medial patellar luxation. Methods: Medical records were reviewed (2011–2013) of dogs that underwent a standard tibial plateau levelling osteotomy followed by a tibial tuberosity transposition in the frontal plane and stabilized with pin and tension-band wire fixation as a component of surgical treatment for combined cranial cruciate ligament insufficiency and medial patellar luxation. Signalment, fixation method together with any ancillary procedures, function at the in-hospital follow-up examinations, and any complications were recorded. Healing was assessed retrospectively based on the grading criteria of the International Society Of Limb Salvage. Results: Fifteen stifle joints in 11 dogs were identified; 13 stifles were available for in-hospital follow-up. All 13 achieved union (3 with grade III/IV and 10 with grade IV/IV radiographic healing scores); mean time to healing was 10.6 (±2.9) weeks. Patellar ligament thickening was also identified radiographically in seven of the 13 of stifle joints. All dogs were reported to have mild or no lameness at their last follow-up examination. No catastrophic or major postoperative complications occurred that required additional surgery. Patellar re-luxation did not occur in any of the 13 stifles available for in-hospital follow-up. Clinical significance: The TPLO-TTT was found to be a reliable and effective technique when used as a part of the treatment of combined cranial cruciate ligament insufficiency with concomitant medial patellar luxation in this series of dogs.... K. C. Leonard (1), M. P. Kowaleski (1), W. B. Saunders (2), R. J. McCarthy (1), R. J. Boudrieau (1) 26694 2016-10-14 11:26:16 Ahead of print: Clinical evaluation of a mini locking plate system for fracture repair of the radius... Objectives: To retrospectively evaluate the effectiveness of a novel 1.2 mm mini locking plate system in treating fractures of the radius and ulna in miniature breed dogs. Methods: Medical records and radiographs of miniature breed dogs with fractures treated with a 1.2 mm mini locking plate system were reviewed. The inclusion criteria were: body weight of 2.5 kg or less, transverse or short oblique fracture of the radius and ulna, and treatment with mini locking plate system as the sole method of fixation. For each patient, data including signalment, time to radiographic union, use of bone graft or other agents, and previous repair attempts were recorded. The outcome and complications were determined from clinical and radiographic follow-up examinations. Results: Fourteen cases with a mean radial width of 4.5 mm (± 0.8 mm) were included into this study. The fractures healed without failure of fixation in all cases. Mean time to adequate radiographic union was 8.4 weeks (± 2.6 weeks). Major complications were not seen in any of the cases, and minor complications occurred in three of the cases. Limb function was graded as ‘normal’ in 10 cases and ‘occasional lameness’ in four cases. Clinical significance: The mini locking system evaluated in this study was an effective treatment method for radial and ulnar fractures in miniature breed dogs with a radial width smaller than 5.5 mm.... B.-J. Kang (1), H.-H. Ryu (2), S. Park (3), Y. Kim (4), O.-K. Kweon (4), K. Hayashi (5) 26693 2016-10-14 11:23:20 Ahead of print: Evaluation of the relationship of tibiofemoral kinematics before and after total... Objective: To investigate the relationship between tibiofemoral kinematics before and after total knee replacement (TKR) in vitro. Animals: Eight canine hemipelves. Methods: A modified Oxford Knee Rig was used to place cadaveric limbs through a range of passive motion allowing the kinematics of the stifle to be evaluated. Four measurements were performed: a control stage, followed by a cranial cruciate transection stage, then following TKR with the musculature intact stage, and finally TKR with removal of limb musculature stage. Joint angles and translations of the femur relative to the tibia, including flexion-extension versus adduction-abduction, flexion-extension versus internal-external rotation, as well as flexion-extension versus each translation (cranial-caudal and lateral-medial) were calculated. Results: Significant differences were identified in kinematic data from limbs following TKR implantation as compared to the unaltered stifle. The TKR resulted in significant decreases in external rotation of the stifle during flexion-extension compared to the limb prior to any intervention, as well as increasing the abduction. The TKR significantly increased the caudal translation of the femur relative to the tibia compared to the unaltered limb. When compared with the cranial cruciate ligament-transection stage, TKR significantly decreased the ratio of the external rotation to flexion. Discussion: All three test periods showed significant differences from the unaltered stifle. The TKR did not completely restore the normal kinematics of the stifle.... R. N. Howie (1), T. L. Foutz (1), C. C. Cathcart (2), J. S. Burmeister (3), S. C. Budsberg (2) 26692 2016-10-14 11:22:43 Ahead of print: Clinical, radiographic, and magnetic resonance imaging findings of gastrocnemius... Objectives: To describe clinical, radiographic, and magnetic resonance imaging (MRI) findings in 16 dogs diagnosed with gastrocnemius musculotendinopathy. Methods: Retrospective evaluation of medical records, radiographs, and MRI results, as well as follow-up completed by telephone questionnaire. Results: Most dogs had chronic hindlimb lameness with no history of trauma or athletic activities. Clinical examination revealed signs of pain on palpation without stifle joint instability. Seven dogs had radiographic signs of osteophyte formation on the lateral fabella. Magnetic resonance imaging revealed T2 hyperintensity and uptake of contrast agent in the region of the origin of the gastrocnemius muscle. Changes were found in the lateral and medial heads of the gastrocnemius. Conservative treatment resulted in return to full function in 11 dogs. Two dogs showed partial restoration of normal function, one dog showed no improvement. Two dogs were lost to follow-up. Clinical significance: Gastrocnemius musculotendinopathy is a potential cause of chronic hindlimb lameness in medium to large breed dogs. A history of athletic activity must not necessarily be present. Magnetic resonance imaging shows signal changes and uptake of contrast agent in the region of the origin of the gastrocnemius muscle. A combination of T1 pre- and post-contrast administration and T2 weighted sequences completed by a fat-suppressed sequence in the sagittal plane are well-suited for diagnosis. Conservative treatment generally results in return to normal function.... S. M. Kaiser (1), O. Harms (2, 3), M. Konar (4), A. Staudacher (1), A. Langer (3), C. Thiel (1), M. Kramer (1), S. Schaub (1), K. H. von Pückler (1) 26691 2016-10-14 11:21:28 Ahead of print: Evaluation of an intra-articular synthetic ligament for treatment of cranial... Objective: Evaluate the short-term outcomes of a novel synthetic ligament for treatment of naturally occurring canine cranial cruciate ligament disease. Study design: Prospective clinical study. Animals: Dogs with unilateral cranial cruciate ligament disease (n = 50). Methods: Patient parameters evaluated included a five-point lameness score, evaluation of craniocaudal stifle instability and radiographic findings over 24 weeks. Any postoperative complications were recorded. Results: Thirty-four out of 42 dogs experienced significant improvements in lameness between the preoperative and 24 week time points. Lameness scores in those dogs improved significantly at all measured time intervals after postoperative week 2. Recurrence of stifle instability increased significantly over the study period from immediate postoperative measurements. Cranial drawer recurred in seven out of 42 of dogs by week 4 and 18/42 by week 24. Implant changes were not noted between the immediate and six-month postoperative radiographs except where complications occurred. Overall, 25 dogs experienced a total of 32 complications (22 major and 10 minor). Sixteen dogs had major complications, and nine had minor complications. Conclusion: The procedure was generally effective at improving lameness scores, but did not consistently maintain postoperative stifle stability and had an unacceptably high complication rate. This synthetic ligament procedure cannot be recommended for use in its current form.... M. D. Barnhart (1), K. Maritato (2), K. Schankereli (3), H. Wotton (4), S. Naber (5) 26665 2016-10-06 09:10:41 Ahead of print: Tibial plateau levelling osteotomy in eleven cats with cranial cruciate ligament... Objective: To report the surgical procedure, intra- and postoperative complications, and short-term follow-up of tibial plateau levelling osteotomy (TPLO) in feline patients with cranial cruciate ligament (CrCL) rupture using a 2.0 or 2.4 mm Synthes® TPLO plate. Study design: Prospective study. Material and methods: Eleven cats with a CrCL rupture were included in the study. Inspection of intra-articular structures was carried out via arthroscopy or arthrotomy. Each patient was re-examined one and 10 days after surgery. Orthopaedic examination and follow-up radiographs were obtained four to 12 weeks postoperatively. Results: Two meniscopathies and one partial CrCL rupture were detected. Minor intra-operative complications occurred in five cats (suboptimal positioning of the plate [n = 3], proximal fibular fracture [n = 1], a visible osteotomy gap [n = 1]). Postoperatively, minor complications were detected in three cats (mild patellar desmitis [n = 2], superficial wound infection [n = 1]). No additional surgical reintervention, graded as major complication, was necessary. Four to eight weeks postoperatively, all cats showed no to mild intermittent lameness. Complete bone union was apparent within four to 12 weeks. Owners reported a high level of comfort and mobility during the last follow-up. Conclusion: The preliminary results of this study support the use of TPLO in cats, but larger case numbers are needed to evaluate its practicability, as well as long-term outcome (>1 year), especially evaluating the development and the clinical relevance of osteoarthritis.... J. K. Mindner (1), M. J. Bielecki (1), S. Scharvogel (1), D. Meiler (1) 26664 2016-10-06 09:09:50 Ahead of print: Pullout strength of monocortical and bicortical screws in metaphyseal and diaphyseal... Objective: Monocortical screws are commonly employed in locking plate fixation, but specific recommendations for their placement are lacking and use of short monocortical screws in metaphyseal bone may be contraindicated. Objectives of this study were to evaluate axial pullout strength of two different lengths of monocortical screws placed in various regions of the canine humerus compared to bicortical screws and to derive cortical thickness and bone density values for those regions using quantitative computed tomography analysis (QCT). Methods: The QCT analysis was performed on 36 cadaveric canine humeri for six regions of interest (ROI). A bicortical, short monocortical, or 50% transcortical 3.5 mm screw was implanted in each ROI and an axial pullout testing was performed. Results: Bicortical screws were stronger than monocortical screws in all ROI except the lateral epicondylar crest. Short monocortical metaphyseal screws were weaker than those placed in other regions. The 50% transcortical screws were stronger than the short monocortical screws in the condyle. A linear relationship between screw length and pullout strength was observed. Clinical significance: Cortical thickness and bone density measurements were obtained from multiple regions of the canine humerus using QCT. Use of short monocortical screws may contribute to failure of locking plate fixation of humeral fractures, especially when placed in the condyle. When bicortical screw placement is not possible, maximizing monocortical screw length may optimize fixation stability for distal humeral fractures.... D. P. Vaughn (1), J. A. Syrcle (1), J. E. Ball (2), S. H. Elder (3), J. M. Gambino (1), R. L. Griffin (4), R. M. McLaughlin (1) 26663 2016-10-06 09:09:00 Ahead of print: The effect of intramedullary pin size and plate working length on plate strain in... Objective: To investigate the effect of intramedullary pin size and plate working length on plate strain in locking compression plate-rod constructs. Methods: A synthetic bone model with a 40 mm fracture gap was used. Locking compression plates with monocortical locking screws were tested with no pin (LCP-Mono) and intramedullary pins of 20% (LCPR-20), 30% (LCPR-30) and 40% (LCPR-40) of intramedullary diameter. Two screws per fragment modelled a long (8-hole) and short (4-hole) plate working length. Strain responses to axial compression were recorded at six regions of the plate via three-dimensional digital image correlation. Results: The addition of a pin of any size provided a significant decrease in plate strain. For the long working length, LCPR-30 and LCPR-40 had significantly lower strain than the LCPR-20 and plate strain was significantly higher adjacent to the screw closest to the fracture site. For the short working length, there was no significant difference in strain across any LCPR constructs or at any region of the plate. Plate strain was significantly lower for the short working length compared to the long working length for the LCP-Mono and LCPR-20 constructs but not for the LCPR-30 and LCPR-40 constructs. Clinical significance: The increase in plate strain encountered with a long working length can be overcome by the use of a pin of 30–40% intramedullary diameter. Where placement of a large diameter pin is not possible, screws should be placed as close to the fracture gap as possible to minimize plate strain and distribute it more evenly over the plate.... T. Pearson (1), M. R. Glyde (1), R. E. Day (2), G. L. Hosgood (1) 26662 2016-10-06 09:08:14 Human error and surgical complications K. Johnson 26589 2016-09-20 16:17:01 A response to: “Evaluation of pain” L. J. Beever (1), E. R. Kulendra (1), R. L. Meeson (1) 26261 2016-08-05 08:36:06 Surgical correction of bilateral metacarpophalangeal valgus with curved osteotomies and type II... Objective: To report the successful surgical correction of severe bilateral metacarpophalangeal valgus angular limb deformities in a seven-month-old intact male alpaca cria using curved osteotomies stabilized with type II external skeletal fixation. Methods: Using a 21 mm crescentic shaped oscillating saw blade, bilateral osteotomies were performed in the distal metaphyses of the fused third and fourth metacarpal bones to correct valgus angular limb deformity of the metacarpophalangeal joints. Axial alignment of each limb was achieved by medially rotating the distal metacarpus in the frontal plane along the curved osteotomies. The osteotomies were stabilized using type II external skeletal fixators. Results: The alpaca was immediately weight-bearing following the surgical procedure and no to minimal lameness was observed during healing of the osteotomies. Evaluation at five and 10 months following the surgery demonstrated acceptable axial alignment in the left forelimb while moderate to severe varus deformity (overcorrection) was observed in the right. Clinical significance: Curved osteotomy of the distal metacarpus stabilized with type II external skeletal fixation can provide a favourable outcome in older alpaca crias affected with metacarpophalangeal angular limb deformities. Placement of the distal transfixation pins relative to the metacarpal physes should be carefully evaluated as overcorrection is possible, especially if growthpotential remains in only one physis of the fused third and fourth metacarpal bones.... M. J. Schoonover (1), C. T. Whitfield (1), M. C. Rochat (2), R. N. Streeter (1), K. Sippel (3) 26125 2016-07-29 10:31:26 Biomechanical evaluation of polymethyl methacrylate with the addition of various doses of cefazolin,... Objectives: Numerous studies have examined the biomechanics of polymethyl methacrylate (PMMA) with added antibiotics, but direct comparison between studies is difficult. Our purpose was to evaluate the effects of the addition of antibiotic drugs and silver on compressive and bending strength of PMMA. Our null hypothesis was that there would be no significant difference in the compressive strength or bending strength of PMMA with the addition of silver or varying amounts of antibiotic drugs. Methods: Polymethyl methacrylate was mixed with cefazolin, gentamicin, vancomycin, or silver; the control was PMMA alone. Antibiotic groups contained 20 g PMMA and 0.5 g, 1 g, 2 g, or 3 g of antibiotic. Silver groups had 0.25 g silver powder alone added to 20 g PMMA or silver with PMMA and 0, 0.5 g or 1 g of antibiotic. Samples underwent four-point bending and compression testing in air at room temperature and prevailing humidity. Pairwise comparisons between groups and to the ASTM and ISO standards were performed. Results: Compression: All antibiotic and silver groups were weaker than the control. Samples with cefazolin tended to be stronger than other antibiotic groups with equivalent doses of antibiotic. All groups were above the ASTM standard, except 3 g vancomycin. Four-point bending: The addition of antibiotics did not significantly affect bending strength in groups with lower doses of antibiotics. The silver + PMMA group was weaker than the control. No groups were significantly below the ISO standard except the 3 g vancomycin group. Clinical significance: The addition of antibiotic or silver decreased the biomechanical strength in all samples, but not below the ASTM or ISO standard for most groups. The addition of cefazolin appears to affect strength the least, while high doses of vancomycin alter strength the most.... M. G. Ficklin (1), K. A. R. Kunkel (1), J. T. Suber (1), P. D. Gerard (2), M. P. Kowaleski (3) 26124 2016-07-29 08:41:38 Bone morphogenetic protein 2 stimulates chondrogenesis of equine synovial membrane-derived... Objectives: Bone morphogenetic protein 2 (BMP-2) is critical for skeletal and cartilage development, homeostasis and repair. This study was conducted to clone and characterize equine BMP-2, develop expression constructs for equine BMP-2, and to determine whether BMP-2 can stimulate chondrogenesis of equine synovial membrane-derived progenitor cells (SMPC). Methods: Equine BMP-2 cDNA was amplified from chondrocyte RNA, and then transferred into an expression plasmid and adenoviral vector. Effective expression of equine BMP-2 was confirmed using a BMP reporter cell line. SMPC were isolated from synovium, expanded through two passages and transferred to chondrogenic cultures, with recombinant human (rh) transforming growth factor beta 1 (TGF-β1) or rhBMP-2. Chondrogenesis was assessed by up-regulation of collagen types II and X, and aggrecan mRNA, secretion of collagen type II protein and sulfated glycosaminoglycans (sGAG), and by alkaline phosphatase induction. Chondrogenic stimulation of SMPC by the equine BMP-2 adenovirus was assessed by sGAG secretion and histology. Results: The mature equine BMP-2 peptide is identical to human and murine peptides. Recombinant human BMP-2 and TGF-β1 stimulated equivalent amounts of collagen type II protein in SMPC pellets, but sGAG secretion was doubled by BMP-2. Neither factor stimulated hypertrophic marker expression. The equine BMP-2 adenoviral vector induced chondrogenesis comparably to rhBMP-2 protein, with no indication of hypertrophy. Clinical significance: Bone morphogenetic protein 2 is a potent inducer of SMPC non-hypertrophic chondrogenesis, supporting the use of this combination for articular cartilage repair applications.... Y. Chen (1, 2), E. Caporali (1, 3), M. Stewart (1) 26123 2016-07-29 08:40:55 Analysis of risk factors for elbow dysplasia in giant breed dogs Objective: Identify radiographic risk factors for development of elbow dysplasia in giant breed dogs less than one year of age. Methods: Twenty-five giant breed puppies (Bernese Mountain dogs, English Mastiff, and Newfoundland) were studied. Both elbows of each dog were radiographed monthly from two to six months of age, then every other month until radial and ulnar physeal closure, followed two months later by bilateral elbow computed tomography. Radiographic parameters measured included the presence or absence of a separate centre of ossification of the anconeal process (SCOAP), medial coronoid disease (MCD), ununited anconeal process, humeral osteochondrosis, elbow incongruity, as well as the length of the radius and ulna, radius-to-ulna ratio, and date of closure of the radial and ulnar physes. Results: Fifteen dogs completed the study. Two Bernese Mountain dogs were diagnosed with MCD. Risk factors significantly associated with medial coronoid disease included dyssynchronous physeal closure and a decreased radius-to-ulna ratio, both detected between eight to 11 months of age. A separate centre of ossification of the anconeal process was present in 60% of the dogs, and was not a risk factor for development of elbow dysplasia. Clinical significance: Transient, dyssynchronous growth of the radius and ulna may be a risk factor for development of MCD in Bernese Mountain dogs. Dyssynchronous physeal closure or decreased radius-to-ulna ratio prior to radiographic closure of the distal ulnar and radial physes warrants further study in Bernese Mountain dogs and other breeds subject to MCD development.... S. Nemanic (1), B. K. Nixon (2), W. Baltzer (1) 26122 2016-07-29 08:40:09 Video-assisted removal of metal pellet fragments from the vertebral canal following gunshot injury... Objective: To describe the surgical management and long-term outcome of a spinal gunshot injury in a cat. Clinical report: A two‐year‐old, 4.2 kg castrated European Shorthair male cat was referred for evaluation of bilateral acute hindlimb paralysis with loss of deep pain perception in the right hindlimb associated with a perforating gunshot wound in the left side of the flank. Based on the clinical findings, the injury was localized to the fourth lumbar-first sacral spinal cord segment. The orthogonal spinal radiographs and computed tomography examination showed several metal pellet fragments within the vertebral canal of the sixth lumbar vertebra. A left mini-hemilaminectomy of the sixth lumbar vertebra pedicle combined with a mini dorsal laminectomy over the sixth to seventh lumbar vertebrae disc space were performed. A 2.4 mm 30° arthroscope was then introduced within the spinal canal to improve visibility and help with the fragment extraction. The cat was discharged from the hospital five days after surgery and the owners were encouraged to continue passive and active physiotherapy movements. Results: The cat was ambulatory with a plantigrade stance eight weeks following surgery. At the last follow-up examination (24 months postoperatively), the cat was able to jump on chairs, although intermittent urinary and faecal incontinence, proprioceptive deficits, and plantigrade stance were still present. Clinical significance: Decompressive surgery may promote neurological status improvement following spinal gunshot injury.... L. Matres-Lorenzo (1), A. Bernardé (1), F. Bernard (1) 26121 2016-07-29 08:39:08 Distal femoral osteotomy using a novel deformity reduction device Distal femoral osteotomy is a surgical procedure used to correct patellar luxation, secondary to a femoral deformity. A distal femoral osteotomy using the tibial plateau levelling osteotomy-jig to temporarily provide stability of the distal femoral osteotomy, maintaining limb alignment in the frontal and axial planes prior to internal plate fixation of the osteotomy, has been described. This report describes a novel jig named Deformity Reduction Device (DRD). This device was developed with the specific aim of increasing precision and predictability during corrective osteotomy execution in order to be consistent with the preoperative planning. The distal femoral osteotomy DRD-assisted procedure is described in detail, discussing the theoretical and practical principles of the application. E. Panichi (1), F. Cappellari (1), M. Olimpo (2), L. A. Piras (2), R. Radasch (3), A. Ferretti (4), B. Peirone (2) 26120 2016-07-29 08:38:17 Comparison of two ultrasound-guided injection techniques targeting the sacroiliac joint region in... Objectives: To compare the accuracy and distribution of injectate for cranial (CR) and caudomedial (CM) ultrasound-guided injections of equine sacroiliac joints. Methods: Both sacroiliac joints from 10 lumbosacropelvic specimens were injected using cranial parasagittal (CR; curved 18 gauge, 25 cm spinal needles) and caudomedial (CM; straight 18 gauge, 15 cm spinal needles) ultrasound-guided approaches. Injectate consisted of 4 ml iodinated contrast and 2 ml methylene blue. Computed tomographical (CT) scans were performed before and after injections. Time for needle guidance and repositioning attempts were recorded. The CT sequences were analysed for accuracy and distribution of contrast. Results: Intra-articular contrast was detected in sacroiliac joints following 15/40 injections. The CR and CM approaches deposited injectate ≤2 cm from sacroiliac joint margins following 17/20 and 20/20 injections, respectively. Median distance of closest contrast to the sacroiliac joint was 0.4 cm (interquartile range [IQR]: 1.5 cm) for CR approaches and 0.6 cm (IQR: 0.95 cm) for CM approaches. Cranial injections resulted in injectate contacting lumbosacral intertransverse joints 15/20 times. Caudomedial injections were perivascular 16/20 times. Limitations: Safety and efficacy could not be established. Clinical relevance: Cranial and CM ultrasound-guided injections targeting sacroiliac joints were very accurate for periarticular injection, but accuracy was poor for intra-articular injection. Injectate was frequently found in contact with interosseous sacroiliac ligaments, as well as neurovascular and synovial structures in close vicinity of sacroiliac joints.... J. D. Stack (1), C. Bergamino (2), R. Sanders (3), U. Fogarty (4), A. Puggioni (2), C. Kearney (1), F. David (5) 26119 2016-07-29 08:36:42 Biomechanical comparison of 3.0 mm headless compression screw and 3.5 mm cortical bone screw in a... Objective: To compare the biomechanical properties of simulated humeral condylar fractures reduced with one of two screw fixation methods: 3.0 mm headless compression screw (HCS) or 3.5 mm cortical bone screw (CBS) placed in lag fashion. Methods: Bilateral humeri were collected from nine canine cadavers. Standardized osteotomies were stabilized with 3.0 mm HCS in one limb and 3.5 mm CBS in the contralateral limb. Condylar fragments were loaded to walk, trot, and failure loads while measuring construct properties and condylar fragment motion. Results: The 3.5 mm CBS-stabilized constructs were 36% stiffer than 3.0 mm HCS-stabilized constructs, but differences were not apparent in quality of fracture reduction nor in yield loads, which exceeded expected physiological loads during rehabilitation. Small residual fragment displacements were not different between CBS and HCS screws. Small fragment rotation was not significantly different between screws, but was weakly correlated with moment arm length (R² = 0.25). Clinical significance: A CBS screw placed in lag fashion provides stiffer fixation than an HCS screw, although both screws provide similar anatomical reduction and yield strength to condylar fracture fixation in adult canine humeri.... M. N. Gonsalves (1), D. A. Jankovits (1), M. L. Huber (1), A. M. Strom (1), T. C. Garcia (2), S. M. Stover (2) 26094 2016-07-21 11:30:40 Complex angular and torsional deformities (distal femoral malunions) Objective: To describe the surgical technique of complex distal femoral deformity correction with the aid of stereolithography apparatus (SLA) biomodels, stabilized with locking plate fixation. Methods: Full-size replica epoxy bone biomodels of the affected femurs (4 dogs/ 5 limbs) were used as templates for surgical planning. A rehearsal procedure was performed on the biomodels aided by a guide wire technique and stabilized with locking plate fixation. Surgery performed in all dogs was guided by the rehearsal procedure. All pre-contoured implants were subsequently used in the definitive surgical procedure with minimal modification. Results: All dogs had markedly improved, with near normal functional outcomes; all but one had a mild persistent lameness at the final in-hospital follow-up examination (mean: 54.4 weeks; range: 24–113 weeks after surgery). All femurs healed without complications (mean: 34 weeks, median: 12 weeks; range: 8–12 weeks for closing osteotomies, and 26–113 weeks for opening wedge osteotomies). Long-term follow-up examination (mean: 28.6 months; range: 5–42 months) revealed all but one owner to be highly satisfied with the outcome. Complications were observed in two dogs: prolonged tibiotarsal joint decreased flexion that resolved with physical therapy. In one of these dogs, iatrogenic transection of the long digital extensor tendon was repaired, and the other had a peroneal nerve neurapraxia. Clinical significance: Stereolithography apparatus biomodels and rehearsal surgery simplified the definitive surgical corrections of complex femoral malunions and resulted in good functional outcomes.... M. D. DeTora (1), R. J. Boudrieau (1) 26093 2016-07-21 11:29:56 Ankylosis and pseudoankylosis of the temporomandibular joint in 10 dogs (1993–2015) Objective: To describe the clinical features and results of treatment of true ankylosis and pseudoankylosis of the temporomandibular joint in dogs. Methods: This study was a retrospective case series. Ten client-owned dogs that were presented for inability to open the mouth or a severely decreased range of motion of the temporomandibular joint were included. Information on the surgical procedures performed and the perioperative complications were documented. Three-dimensional printing of the skull was performed in four dogs. Results: Two dogs were diagnosed with temporomandibular joint ankylosis and seven dogs with pseudoankylosis. One dog had evidence of combined temporomandibular joint ankylosis and pseudoankylosis. Of the seven dogs with pseudoankylosis, six had an osseous fusion involving the zygomatic arch and mandible. Surgical treatment was performed in nine dogs and a revision surgery was needed in one dog. Follow-up ranged from five months to eight years (mean: 48.6 months). Eight out of nine dogs that were treated surgically regained the ability to open their mouth, but six dogs never regained a fully normal temporomandibular joint range of motion. Clinical significance: Temporomandibular joint ankylosis and pseudoankylosis are uncommon in the dog. Surgical treatment for temporomandibular joint ankylosis or pseudoankylosis in dogs is a successful option and carries a prognosis dependent on patient-specific abnormalities. Computed tomography complemented with three-dimensional printing is valuable for understanding the extent of abnormalities and for preoperative planning.... P. C. Strøm (1), B. Arzi (2), D. D. Cissell (2), F. J. M. Verstraete (2) 26092 2016-07-21 11:29:05