Veterinary and Comparative Orthopaedics and Traumatology (VCOT) Veterinary and Comparative Orthopaedics and Traumatology (VCOT) vcot de-de Wed, 17 Sep 14 17:34:07 +0200 Veterinary Orthopaedics and Traumatology on New Frontiers K. A. Johnson 23375 2014-09-12 10:27:20 Arthroscopy of the normal cadaveric ovine femorotibial joint: a systematic approach to the cranial... Objectives: Preclinical studies using large animal models play an intergral part in translational research. For this study, our objectives were: to develop and validate arthroscopic approaches to four compartments of the stifle joint as determined via the gross and arthroscopic anatomy of the cranial and caudal aspects of the joint. Methods: Cadaveric hindlimbs (n = 39) were harvested from mature ewes. The anatomy was examined by tissue dissection (n = 6), transverse sections (n = 4), and computed tomography (n = 4). The joint was arthroscopically explored in 25 hindlimbs. Results: A cranio-medial portal was created medial to the patellar ligament. The cranio-lateral portal was made medial to the extensor digitorum longus tendon. The medial femoral condyle was visible, as well as the cranial cruciate ligament, caudal cruciate ligament and both menisci with the intermeniscal ligament. Valgus stress improved visibility of the caudal horn of the medial meniscus and tibial plateau. To explore the caudal compartments, a portal was created 1 cm proximal to the most caudal aspect of the tibial condyle. Both femoral condyles, menisci, caudal cruciate ligament, the popliteal tendon and the menisco-femoral ligament were visible. The common peroneal nerve and popliteal artery and vein are vulnerable structures to injury during arthroscopy. Clinical significance: The arthroscopic approach developed in this research is ideal to evaluate the ovine stifle joint.... R. B. Modesto (1), K. A. Mansmann (2), T. P. Schaer (3) 22387 2014-08-27 14:03:36 Effect of tibial plateau levelling osteotomy on patellar tendon angle: A prospective clinical study Objective: To evaluate the effect of the tibial plateau levelling osteotomy (TPLO) procedure on the patellar tendon angle (PTA) in dogs with naturally occurring cranial cruciate ligament rupture. Study design: Prospective observational clinical study. Animals: Dogs with naturally occurring CrCL rupture that had a TPLO performed (n = 40). Methods: Preoperative tibial plateau angle (TPA) and PTA were measured on radiographic images of affected stifle joints at 90° and standing angle (135°) respectively. The TPA and PTA were measured after TPLO was performed. Regression analysis was performed to evaluate the effect of preoperative TPA and PTA and postoperative TPA on postoperative PTA. Linear regression analysis was performed to evaluate the correlation between postoperative TPA and PTA. Results: The mean (± SD) preoperative TPA and PTA were 26.5 ± 3.8° and 105.7 ± 3.8° respectively. The postoperative TPA and PTA values were 7.6 ± 3.3° and 91.4 ± 5.5°, respectively. Regression analysis showed that higher preoperative PTA and postoperative TPA are associated with a larger difference between the postoperative PTA and 90°. There was a positive correlation between postoperative TPA and PTA. Conclusion: The TPLO procedure alters the PTA to 90° in dogs with cranial cruciate ligament rupture similar to tibial tuberosity advancement (TTA). Clinical significance: The TPLO may provide dynamic stability to the cranial cruciate deficient stifle by altering the TPA relative to the patellar tendon and creating a PTA of 90°. The biomechanical principle and mechanism of action of TPLO may be similar to TTA.... S. Sathya (1), P. Gilbert (1, 2), A. Sharma (3), S. Hendrick (4) 22386 2014-08-27 13:56:43 Ahead of print: Unilateral or single-session bilateral surgery for correction of medial patellar... Objective: To compare complication rates as well as the short and long-term function of surgical limbs in small dogs with bilateral medial patellar luxation (MPL) undergoing unilateral or single-session bilateral surgery. Methods: Dogs weighing less than 12 kg with bilateral MPL that underwent unilateral (group U) or single-session bilateral surgery (group B) were retrospectively analysed. Data analysed included signalment, grades of luxation, surgical procedures, duration of surgery and anaesthesia, use of antibiotic medications, hospitalization time, complications, function at short-term follow-up, bone healing, and long-term assessment of function by means of a questionnaire. Results: Twenty-four dogs were included in group U and 27 in group B. Groups were similar in signalment and procedures performed. No significant difference was found in overall, minor, and major complication rates between Group U and Group B, nor in the short and long-term function of surgical limbs. Nine out of 21 dogs developed clinical signs on the contralateral stifle in Group U, of which only three underwent corrective surgery. Clinical significance: Single-session bilateral surgery could be offered for dogs with bilateral MPL with complication rates and function of operated limbs similar to unilateral surgery.... P. Clerfond (1), L. Huneault (1), J. Dupuis (1), M. Moreau (2), J. Auger (1) 22384 2014-08-27 12:57:20 Lumbosacral foraminal ratios and areas using MRI in medium-sized dogs Objective: To examine conventional magnetic resonance imaging planes of the lumbosacral foramina to obtain objective measurements of foraminal size in medium-sized (20–28 kg) normal dogs. Method: Ten canine cadavers were evaluated using magnetic resonance imaging in neutral, flexed and extended position. Foraminal ratios, areas and lumbosacral angles were calculated and their relationship to body weight was evaluated. Results: Foraminal ratios were found to be independent of body weight in medium sized dogs (p >0.42). Foraminal areas were dependent on body weight (p D. Reynolds (1), R. L. Tucker (2), N. Fitzpatrick (3) 22383 2014-08-27 12:57:04 Is anaesthesia of the deep branch of the lateral plantar nerve specific for the diagnosis of... Objectives: To investigate the specificity of anaesthesia of the deep branch of the lateral plantar nerve (DB-LPN). Methods: Twenty horses had DB-LPN anaesthesia performed by a single injection technique as part of a lameness investigation. The mechanical nociceptive threshold (NT) was measured using a handheld force meter at six points on the lateral aspect of the limb: before diagnostic anaesthesia (T0), and at 15 (T15) and 30 (T30) minutes post anaesthesia. Paired t-tests were performed and significance was set at p G. Hinnigan (1), P. Milner (2), A. Talbot (3), E. Singer (2) 22382 2014-08-27 12:16:57 Morphologic and morphometric features of the calcaneal insertions of the superficial digital flexor... Introduction: Accurate description of the calcaneal insertions of the superficial digital flexor tendon (SDFT) is lacking and inconsistent. The aim of this study was to undertake morphologic and morphometic evaluations of these structures to assist in elucidating their functional and pathogenic roles in displacement of the SDFT from the calcaneal tuber. Method: Dissections were performed on 10 normal cadaveric hindlimbs. The anatomy was photographed to allow measurements at repeatable locations and differences in SDFT dimensions at the various locations were compared using a paired student t-test. Results: This study demonstrated that the calcaneal insertions of the SDFT are independent from the overlying tarsal insertions of the biceps femoris and semitendinosus, which blend into the plantar surface of the fibrocartilaginous cap (FCC) of the SDFT before inserting dorsal to the insertion of the SDFT on the calcaneal tuber. The lateral insertion of the SDFT is larger in cross-sectional area (median: 219 mm²) at its origin from the FCC than its medial counterpart (median: 159 mm², p = 0.004) and has a more complex fibre alignment. The lateral site of attachment of the SDFT on the calcaneal tuber is dorsolateral to the insertion of the gastrocnemius tendon and is larger (median: 525 mm²) than the medial insertion (median: 428 mm², p = 0.036), which inserts distal to the insertion of the gastrocnemius tendon. Conclusion: The features identified in this study suggest that the calcaneal insertions of the SDFT are complex and their morphological and morphometric differences are likely to contribute to clinical lesions identified at this site.... W. H. J. Barker (1), I. M. Wright (1) 22242 2014-08-04 13:52:05 Locally injected autologous platelet-rich plasma enhanced tissue perfusion and improved survival of... Objectives: Distal flap necrosis remains a major complication in subdermal plexus (random) skin flaps. Platelet-rich plasma (PRP) has been shown to improve the survival of ischemic random skin flaps in rats. The objective of this study was to evaluate the effect of locally injected autologous PRP on the survival of long (5:1 length-to-width ratio) subdermal plexus skin flaps in dogs. Methods: A 2x10 cm subdermal plexus skin flap was created bilaterally on the abdominal wall of six Beagle dogs. One randomly selected side received 2.5 ml of fresh auto-logous PRP injected evenly between sutures underneath the flap, whereas the other side was left untreated (control). Skin flap survival was evaluated macroscopically, histologically and by laser-Doppler flowmetry measurements of tissue perfusion. Results: Flap percentage survival on day 10 (96.3% versus 74.5%; p = 0.046) and tissue perfusion (p M. Karayannopoulou (1), L. G. Papazoglou (1), P. Loukopoulos (2), G. Kazakos (1), A. Chantes (3), N. Giannakas (1), I. Savvas (1), D. Psalla (2), M. Kritsepi-Konstantinou (4), D. Dionyssiou (3) 22241 2014-08-04 13:51:07 Bacteriostatic effect of equine pure platelet-rich plasma and other blood products against... Objectives: 1) To evaluate the bacteriostatic in vitro effect of pure platelet-rich plasma (P-PRP), pure platelet-rich gel (P-PRG), leukocyte-poor gel (LPG), platelet-poor plasma (PPP), and heat inactivated plasma (IP) against methicillin-sensitive Staphylococcus aureus (MSSA) over a period of 24 hours. 2) To determine the degradation of platelet factor-4 (PF-4), transforming growth factor beta 1 (TGF-β1), and platelet-derived growth factor isoform BB (PDGF-BB) in these equine blood components. 3) To establish correlations between platelet and leukocyte counts, PF-4 concentrations, and MSSA growth. Methods: Fourteen horses were used. Blood components were obtained by a manual protocol. Every blood component was mixed with MSSA and Müller-Hinton Broth and cultured at 37°C for 24 hours. Samples for the determination of bacterial growth (colony-forming units) and PF-4, TGF-β1 and PDGF-BB concentrations were taken at one, four, eight, 12 and 24 hours. Results: The bacterial growth was significantly (p = 0.01) inhibited for P-PRP, P-PRG, LPG and PPP in comparison with IP and, the positive control group during the first 12 hours. The P-PRG had higher and sustained TGF-β1 and PDGF-BB concentrations over time in comparison with the other blood components. Clinical significance: The plasma complement could be one of the most responsible components of the in vitro bacteriostatic effect of P-PRP, P-PRG, LPG and PPP against MSSA. Additionally, P-PRG was the better biomaterial because it had an acceptable bacteriostatic effect and the highest concentration of growth factors.... C. López (1), J. U. Carmona (1), C. E. Giraldo (1), M. E. Álvarez (1) 22240 2014-08-04 13:49:47 Surgical repair of a severely comminuted maxillary fracture in a dog with a titanium locking plate... A four-year old male Labrador Retriever was admitted with head trauma after being hit by a car. The dog had sustained multiple nasal, maxillary, and frontal bone fractures that resulted in separation of the maxilla from the base of the skull. A severely comminuted left zygomatic arch fracture was also present. These fractures were all repaired using a point contact, locking titanium plate system, in a single procedure that resulted in excellent postoperative occlusion and immediate function. Healing was uneventful. Full function and excellent cosmetic appearance were evident 13 months after surgery. This case illustrates the ease of repair and the success of treatment of severely comminuted maxillofacial fractures by conforming to basic biomechanical principles taken directly from the human experience and successfully applied to the dog; these included multiple plate application along the buttresses and trusses of the facial skeleton. The plate fixation was applied to bridge the multiple fractures along the most appropriate lines of stress. The small size of the plates, and the ability to easily contour them to adapt to the bone surface in three-dimensions, allowed their placement in the most appropriate positions to achieve sufficient rigidity and lead to uncomplicated healing without any postoperative complications.... E. Illukka (1), R. J. Boudrieau (1) 22239 2014-08-04 13:46:00 Bi-institutional retrospective cohort study evaluating the incidence of osteosarcoma following... Objectives: To evaluate the incidence and risk factors for occurrence of osteosarcoma (OSA) following tibial plateau levelling osteotomy (TPLO). Methods: Medical records of client-owned dogs that underwent consecutive TPLO procedures at two institutions were retrospectively reviewed. Referring veterinarians and owners were contacted for follow-up. Each institutional cohort was assessed separately, and the incidence density rate and median time to occurrence of OSA at the TPLO site and at other sites were calculated. Marginal Cox regression was used to calculate hazard ratios and 95% confidence intervals for potential risk factors for occurrence of OSA. Results: There were 472 CLINIC A (Colorado State University Veterinary Teaching Hospital) and 1992 CLINIC B (SAGE Centers for Veterinary Specialty and Emergency Care) TPLO cases with over one year of follow-up available. There were five and six dogs within the cohorts that developed OSA at the site of TPLO, and seven and 22 dogs that developed OSA at other anatomical sites, respectively. The incidence density rates of OSA at the TPLO site were 30.4 and 10.2 per 10,000 dog-years at risk, and other sites were 42.6 and 37.5 per 10,000 dog-years at risk. The median time to occurrence of OSA of TPLO site OSA was 4.6 and 4.4 years, which was longer than that of other site OSA of 2.9 and 3.4 years. Clinical significance: There is a low incidence of OSA following TPLO surgery. The longer time to occurrence for TPLO site OSA is similar to that for fracture-associated sarcoma, and could indicate a similar underlying pathophysiology rather than spontaneous OSA occurrence.... A. J. Sartor (1), S. D. Ryan (2, 3), T. Sellmeyer (1), S. J. Withrow (3), L. E. Selmic (3) 21785 2014-07-31 11:08:48 Comparison of healing in forelimb and hindlimb surgically induced core lesions of the equine... Objective: Even though equine multi-limb tendinopathy models have been reported, it is unknown if fore- and hindlimb tendon healing behave similarly. The aim of this study was to compare the healing process of surgically induced superficial digital flexor tendon (SDFT) core lesions of fore- and hindlimbs in horses. Methods: Tendon core lesions were surgically induced in the SDFT of both fore- and hindlimbs in eight horses. One randomly assigned forelimb and one randomly assigned hindlimb were injected with saline one and two weeks post-surgery. The healing process was monitored clinically and ultrasonographically. After 24 weeks, the tendons were harvested and biochemical, biomechanical and histological parameters were evaluated. Results: Twenty-four weeks post-surgery, the forelimb SDFT lesions had a significantly higher colour Doppler ultrasound vascularization score (p = 0.02) and glycosaminoglycan concentration (p = 0.04) and a significantly lower hydroxylysylpyridinoline content (p = 0.03). Clinical relevance: Our results indicate that fore- and hindlimb SDFT surgically induced lesions exhibit significant differences in several important parameters of tendon healing 24 weeks post-surgery. These differences create significant challenges in using all four limbs and accurately interpreting the results that one might generate. Therefore these findings do not support the use of four-limb models for study of tendon injury until the reasons for these differences are much better understood.... R. J. Estrada (1, 2), P. R. van Weeren (3), C. H. A. van de Lest (3, 4), J. Boere (3), M. Reyes (5), J. C. Ionita (6), M. Estrada (2), C. J. Lischer (1) 21784 2014-07-31 11:07:57 Combined prevalence of inherited skeletal disorders in dog breeds in Belgium Canine hip dysplasia (CHD), canine elbow dysplasia (CED), and humeral head osteochondrosis (HHOC) are inherited traits with uneven incidence in dog breeds. Knowledge of the combined prevalence of these three disorders is necessary to estimate the effect of the currently applied breeding strategies, in order to improve the genetic health of the population. Official screening results of the Belgian National Committee for Inherited Skeletal Disorders (NCSID) revealed that an average of 31.8% (CHD, CED, or both; n = 1273 dogs) and 47.2% (CHD, CED, HHOC, or a combination of these three diseases; n = 250 dogs) of dogs are mildly to severely affected by at least one skeletal disorder. According to the current breeding recommendations in some dog breeds in Belgium, these animals should be restricted (mild signs) or excluded (moderate to severe signs) from breeding. The introduction of genetic parameters, such as estimated breeding values, might create a better approach to gradually reduce the incidence of these complex inherited joint disorders, without compromising genetic population health.... F. Coopman (1, 2, 3), B. Broeckx (4), E. Verelst (2), D. Deforce (4), J. Saunders (3), L. Duchateau (5), G. Verhoeven (3) 21783 2014-07-31 11:06:40 Surgical management and follow-up of triceps tendon avulsion after repeated local infiltration of... Disruption of the triceps tendon insertion is an uncommon injury, with only a few reports of traumatic triceps tendon avulsion in dogs or cats present in the veterinary literature. Although this injury has been previously described in two dogs that had received a local injection of corticosteroids for the treatment of soft tissue injuries, reports with long term clinical follow-up and outcome in working dogs are lacking. This report describes two surgically treated cases of complete triceps tendon avulsion rupture in Malinois police dogs. These two dogs had a history of repeated local infiltration of a corticosteroid preparation used to treat adventitial bursitis. The clinical features, surgical treatment, long-term management and outcome are reported. A modified triple locking loop pattern was used to suture the tendons. The long-term outcome was considered excellent with both dogs resuming work. Although it is an uncommon condition in small animals, avulsion of the triceps tendon should remain on the differential diagnosis list for acute onset forelimb lameness, particularly if there is a history of local infiltration with corticosteroids. The diagnosis should be based on clinical, radiographic and ultrasonographic examination.... P. García-Fernández (1), P. Quero Martín (1), A. Mayenco (1), M. Gardoqui (1), I. Calvo (2) 21782 2014-07-31 11:04:21 4th World Veterinary Orthopaedic Congress & 41st Veterinary Orthopedic Society Conference Abstracts 21751 2014-07-21 11:08:00 Veterinary journal editors meet in Croatia Veterinary Journal Editors Meet in Croatia K. A. Johnson (1) 21749 2014-07-21 11:05:44 Erratum to: Radiographic and ultrasonographic changes of the patellar ligament following tibial... 21750 2014-07-21 11:05:44 Assessment of the medial collateral ligament as an intra-operative anatomical landmark for tibial... Objectives: To determine whether the medial collateral ligament can be a reliable intra-operative anatomical landmark for rotation of the tibial plateau in the tibial plateau levelling osteotomy (TPLO) procedure, thus providing a tibial plateau rotation equal to that obtained using standard preoperative measurements. Methods: Tibial plateau levelling osteotomy procedures were performed on pelvic limbs (n = 42) from canine cadavers with or without a history of cranial cruciate ligament deficiency. The rotation of the proximal fragment was performed such that the orientation of the fibres of the medial collateral ligament were aligned parallel to the caudal tibial cortex at the location of the osteotomy. Statistical analysis was performed to evaluate the difference between calculated rotation to achieve a postoperative tibial plateau angle of five degrees and the actual rotation achieved by aligning the medial collateral ligament and caudal tibial cortex. Results: The rotation performed by alignment of the medial collateral ligament fibres with the caudal tibial cortex resulted in a significantly greater rotation than the calculated movement required to achieve a postoperative angle of five degrees. The mean over-rotation was 2.1 ± 1.73 mm. Clinical significance: Use of the medial collateral ligament alignment with the caudal tibial cortex will reliably result in over-rotation of the tibial plateau and should not be used as an intra-operative guideline for tibial plateau rotation during TPLO procedures.... B. Ley (1), B. Daubs (2), J. Bader (3), E. Silverman (1) 21374 2014-07-07 10:53:42 Treatment of antebrachial and crural septic nonunion fractures in dogs using circular external... Objective: To evaluate the outcome of treatment of antebrachial and crural septic non-union fractures in dogs using circular external skeletal fixation (CESF), and to document the type and frequency of complications associated with this technique. Methods: The medical records of all dogs with infected antebrachial and crural non-union fractures treated using the methods of Ilizarov at the Department of Animal Pathology of the University of Turin between 2006 and 2011 were retrospectively reviewed. Only dogs in which radiographic and clinical assessment were available at the time of CESF removal were included in the study. Results: Twenty-three dogs met the inclusion criteria. Twenty nonunion fractures treated with CESF healed and three did not. The latter three cases underwent amputation of the affected limb. In the 20 dogs that achieved bone union, six had minor complications and five had major complications. The mid-term outcome was judged to be excellent (n = 11), good (n = 6), fair (n = 2), or poor (n = 4). Conclusions: The results of this study support the use of CESF for the management of antebrachial and crural septic nonunion fractures in dogs. Union was achieved in the majority of dogs and the complication rate was acceptable, considering the severity of the nonunion fractures that were managed in this fashion.... F. Cappellari (1), L. Piras (2), E. Panichi (1), A. Ferretti (3), B. Peirone (2) 21373 2014-07-07 10:51:25 Treatment of bicondylar femoral fractures complicated by concurrent ligament or tendon injuries in... Objective: Retrospective case series describing the surgical treatment and outcome in dogs with bicondylar femoral fractures complicated by ligament or tendon injuries. Methods: Medical records were reviewed for three immature and one mature dog with traumatic bicondylar fractures of the distal femur and concurrent ligament or tendon injury treated surgically. Data retrieved included physical examination, imaging, and treatment. Long-term follow-up and return to function was assessed by owner feedback, physical examination, radiology, and force plate analysis. The immediate, four-week, and two-year postoperative outcomes were described. Results: All four dogs were presented with injuries to either the cranial or caudal cruciate ligament. Only two dogs underwent surgical repair of the caudal cruciate ligament. Anatomical reduction and rigid internal fixation of the distal femoral fractures was performed using a combination of lag screws, Kirschner wires, and bone plates. At the long-term follow-up, all cases had good to excellent return to function, as assessed by force plate analysis and owner assessment of quality of life and satisfaction. Radiographs revealed evidence of complete fracture healing, with moderate to severe osteoarthritis of the stifle. Clinical significance: Bicondylar femoral fractures can be associated with ligament or tendon injuries. Anatomical reduction and internal fixation of bicondylar femoral fractures is recommended and may offer a good to excellent return function, with or without repair of associated caudal cruciate ligament injuries.... G. H. Frydman (1), L. C. Cuddy (1), S. E. Kim (1), A. Pozzi (1) 21366 2014-07-03 15:31:43 Tibial tuberosity transposition-advancement for lateralization of the tibial tuberosity: An ex vivo... Objectives: To evaluate the degree of lateralization achievable and strength of tibial tuberosity transposition and advancement (TTTA) relative to pin and tension band wiring (PTBW) for lateral tibial tuberosity transposition. Methods: Six pairs of cadaveric tibiae were used. Tibial tuberosity position was determined with computed tomography (CT); bones were then randomly assigned into TTTA and PTBW groups. The PTBW group had a tibial tuberosity osteotomy and fixation with pin and tension band wiring. The TTTA group had a tibial tuberosity advancement performed with lateralization of the tibial tuberosity by 50% of cage depth, using spacers on the cranial cage screw. Postoperative CT images showed lateralization and craniocaudal deviation. Single axial distractive loading was applied to the patella at 90˚ to the tibial plateau, and peak load, energy, and stiffness were calculated. Results: There were significant differences in lateralization (PTBW: 67.92 ± 5.1 %; TTTA: 88.51 ± 5.5 %) (p = 0.0173) and craniocaudal deviation (PTBW: –8.30 ± 1.4 %; TTTA: 6.83 ± 0.6) (p = 0.0001). There were no significant differences in peak load to failure (N) (PTBW: 1448 ± 121; TTTA: 1597 ± 43) (p = 0.4541), energy to failure (N/mm) (PTBW: 15013 ± 2719; TTTA: 17314 ± 887) (p = 0.646), or stiffness (N/mm)(PTBW: 102.8 ± 4.7; TTTA: 92.9 ± 4.8) (p = 0.2716). Clinical significance: The TTTA was more effective at lateralization of the tibial tuberosity, and of comparable strength to PTBW. Greater support of the osteotomized fragment with TTTA may resist cyclic loading, and requires evaluation.... M. Newman (1), N. Bertollo (2), W. Walsh (2), K. Voss (1) 21365 2014-07-03 15:14:14 Tibial displacement with stifle joint flexion and cranial cruciate ligament transection in the dog Objective: The aim of this study was to investigate the biomechanical effects of cranial cruciate ligament (CrCL) transection on stifle stability at three different stifle joint flexion angles using a robotic system. Methods: This was an ex vivo biomechanical study. Stifles (n = 6) were collected from the cadavers of Beagles weighing 10.5–12.0 kg. Six stifle joints were dissected, potted, and secured to the manipulator arms of a robotic simulator. With the stifle joint angle maintained at either hyperextension (151°), 135° or 90°, stability was assessed by application of a 50 N load in either the cranial-caudal (CrCd test) or proximal-distal (PD test) directions. The stifle was given a cranial-caudal load of 50 N (CrCd test). A proximal-distal compression load of 50 N was then administered by the manipulator (proximal-distal test: PD test). The change in three-dimensional kinematics of the intact and the CrCL-transected stifles was compared between hyperextension, and 135° and 90° flexion for the CrCd and PD load conditions. A value of p ... N. Kanno (1), Y. Hara (1), S. Fukano (1), H. Fujie (1), H. Ochi (1), Y. Fujita (1), H. Yasuji (1), Y. Nezu (1), T. Yogo (1), M. Tagawa (1) 21364 2014-07-03 15:13:20 The relevance of threaded external skeletal fixation pin insertion speed in canine bone with and... Objectives: The effects of insertion speed in revolutions per minute (RPM) and pilot hole predrilling for placement of threaded external skeletal fixation pins on temperature and morphological damage in cortical bone were evaluated. The null hypothesis states that insertion speed and predrilling will have no significant effect on temperature and morphological damage. Methods: Fixation pins were inserted into cadaveric canine femurs at speeds of 700 RPM and 150 RPM, with and without pre-drilling. Temperature was measured at each cortex 0.5 mm and 3.0 mm from each insertion site. Samples were examined grossly and by scanning electron microscopy for evidence of morphological damage. Data were analysed for maximum temperature, temperature increase, sites above thermal necrosis thresholds, microcracks, thread quality and gross damage. Results: Predrilling had a significant effect on maximum temperature, temperature increase, sites exceeding necrosis thresholds, microcracks, thread quality and gross damage. Speed of insertion had no significant effect on any of the measured parameters following predrilling, but had a significant effect on thread quality without predrilling. Clinical significance: Our results fail to reject the null hypothesis concerning insertion speed, which had no significant effect on thermal damage, and minimal effect on morphological damage, which was negated by predrilling. Our results reject the null hypothesis concerning predrilling and support the practice of predrilling fixation pin insertion sites.... J. T. Walker (1), M. C. Rochat (1), T. A. Snider (1), M. E. Payton (2) 21363 2014-07-03 15:12:40 Severity of spinal cord dysfunction and pain associated with hydrated nucleus pulposus extrusion in... Objective: To identify the severity of neurological deficits, presence of signs of cervical pain, and the site of intervertebral disc space extrusion in 21 dogs diagnosed via magnetic resonance imaging (MRI) with a hydrated nucleus pulposus extrusion (HNPE) and compare those findings to dogs with other compressive cervical myelopathies. Methods: Medical records and MRI findings were reviewed in dogs that were presented to two veterinary hospitals between 2006 and 2012 and subsequently diagnosed by MRI to have a HNPE (n = 21) or other compressive cervical myelopathies originating from the intervertebral disc (n = 174). Information obtained included signalment, severity of neurological deficits, presence of signs of neck pain, and site of HNPE. The severity of clinical neurological spinal cord dysfunction was determined for each dog in both groups using the Frankel scoring system (0–4). The MRI were reviewed for confirmation of diagnosis and site of HNPE. An ANOVA was used to compare age between groups and a Mann-Whitney test for pairwise comparisons of the Frankel score between groups. Values of p... T. Hamilton (1), E. Glass (2), K. Drobatz (1), K. A. Agnello (1) 21362 2014-07-03 15:11:42 Ganglion cyst arising from the composite occipito-atlanto-axial joint cavity in a cat A four-year-old, female spayed Domestic Longhaired cat was referred for evaluation with a two month history of initial inability to jump progressing to ambulatory tetraparesis. Magnetic resonance imaging studies demonstrated a cystic lesion arising from the composite occipito-atlanto-axial joint cavity and extending to the region of the occipital bone and the axis. The lesion surrounded the spinal canal, causing moderate dorsal spinal cord compression at the atlanto-occipital joint. A dynamic myelographic study demonstrated attenuation of the dorsal contrast column at the atlanto-occipital joint when the cervical spine was positioned in extension. Partial excision of the cyst capsule by a ventral approach resulted in long-term (64 months) resolution of clinical signs. Histological evaluation was consistent with a ganglion cyst. An intra-spinal ganglion cyst arising from the composite occipito-atlanto-axial joint cavity may be considered as an uncommon differential diagnosis for cats with cervical myelopathy.... T. Aikawa (1, 2), S. Sadahiro (1), M. Nishimura (1), Y. Miyazaki (1), M. Shibata (1) 21361 2014-07-03 15:10:45