Veterinary and Comparative Orthopaedics and Traumatology (VCOT) Veterinary and Comparative Orthopaedics and Traumatology (VCOT) vcot de-de Sat, 22 Nov 14 03:42:31 +0100 Healing Large Bone Defects K. A. Johnson 23704 2014-11-18 10:17:47 Ahead of print: Arthrodesis of the proximal interphalangeal joints of a hindlimb in a heifer A two-year-old Braunvieh heifer was presented with a traumatic luxation of the second phalanx of the medial digit and concurrent subluxation of the second phalanx of the lateral digit of the right hindlimb. Closed reduction of both luxations was possible. Surgical arthrodesis was achieved using one narrow 4.5 mm three-hole equine locking compression plate for each joint. Placement of the bone plates resulted in stable arthrodesis of both proximal interphalangeal joints of the right hindlimb but there was persistent residual lameness. The heifer delivered a healthy calf but was slaughtered eight months after surgery because of varus deformity of the contralateral limb. Radiographs taken post-mortem revealed pronounced periosteal reactions involving both proximal interphalangeal joints and only partial bony bridging of the joint spaces. E. Muggli (1), E. Weidmann (1), A. Bruderer (1), K. Nuss (1) 23690 2014-11-14 08:57:28 Ahead of print: Risk factors for loosening of cementless threaded femoral implants in canine total... Objective: To determine the incidence and potential risk factors of femoral implant loosening in the canine Helica® total hip replacement (THR) system. Method: Sixteen dogs with a Helica THR were included. Medical records were reviewed for signalment and size of implants. Stem angle, stem collar to lateral cortex distance, tip to cortex distance, stem collar to lateral cortex distance at a stem angle of 150°, lever arm distance, and the distance on the diaphysis measurements were calculated from the one year postoperative radiographs. Three ratios were determined from these measurements to take into account the size of the femur in relation to the size of the implant. Femoral implant loosening was identified by radiographic and clinical signs, and confirmed at the time of surgical explantation. Differences in the successful and femoral stem failure groups were compared using either a students t-test or a Mann Whitney test. Significance was set at p <0.003. Results: Six of the 16 dogs had loosening of the femoral prostheses within one year post-implantation. One dog had evidence of a septic cause for loosening. No significant risk factors could be identified in this group of dogs with Helica stem loosening. Clinical significance: Helica femoral stem loosening was a common complication within one year post-implantation in this group of dogs. No risk factors were identified to potentially decrease the incidence of loosening. Therefore, due to this unacceptably high complication rate, the authors do not recommend this model of the Helica THR.... K. A. Agnello (1), D. Cimino Brown (1), K. Aoki (2), S. Franklin (3), K. Hayashi (4) 23689 2014-11-14 08:56:24 Ahead of print: Ex vivo kinematic studies of a canine unlinked semi-constrained hybrid total elbow... Objectives: Introduction of the Sirius® canine total elbow arthroplasty system, and presentation of the results of a passive range-of-motion analysis based on ex vivo kinematic studies pre-and post-implantation. Materials and methods: Thoracic limbs (n = 4) of medium sized dogs were harvested by forequarter amputation. Plain orthogonal radiographs of each limb were obtained pre- and post-implantation. Limbs were prepared by placement of external fixator pins and Kirschner wires into the humerus and radius. Each limb was secured into a custom-made box frame and retro-reflective markers were placed on the exposed ends of the pins and wires. Each elbow was manually moved through five ranges-of-motion manoeuvres. Data collected included six trials of i) full extension to full flexion and ii) pronation and supination in 90° flexion; a three-dimensional motion capture system was used to collect and analyse the data. The Sirius elbow prosthesis was subsequently implanted and the same measurements were repeated. Data sets were tested for normality. Paired t-tests were used for comparison of pre- and post-implantation motion parameters. Results: Kinematic analysis showed that the range-of-motion (mean and SD) for flexion and extension pre-implantation was 115° ± 6 (range: 25° to 140°). The range-of-motion in the sagittal plane post-implantation was 90° ± 4 (range: 36° to 130°) and this reduction was significant (p = 0.0001). The ranges-of-motion (mean and SD) for supination and pronation at 90° were 50° ± 5, whereas the corresponding mean ranges-of-motion post-implantation were 38° ± 6 (p = 0.0188). Conclusion: Compared to a normal elbow the range-of-motion was reduced. Post-implantation, supination and pronation range-of-motion was significantly reduced at 90° over pre-implantation values. Clinical relevance: These results provide valuable information regarding the effect of the Sirius system on ex vivo kinematics of the normal canine elbow joint. Further, this particular ex vivo model allowed for satisfactory and repeatable kinematic analysis.... N. D. Lorenz (1), S. Channon (2), R. Pettitt (1), P. Smirthwaite (3), J. F. Innes (1, 4) 23688 2014-11-14 08:55:26 Ahead of print: Erosion of the medial compartment of the canine elbow: occurrence, diagnosis and... Erosion of the medial compartment of the elbow joint refers to full thickness cartilage loss with exposure of the subchondral bone (modified Outerbridge grades 4–5) of the medial part of the humeral condyle (MHC) and the corresponding ulnar contact area. This finding may appear in the absence of an osteochondral fragment or a cartilage flap, or in combination with fragmentation of the medial coronoid process (MCP) or osteochondritis dissecans (OCD) of the MHC. With regard to the prognosis, it is important to diagnose these severe erosions. Imaging of cartilage lesions by means of radiography, ultrasonography, computed tomography or magnetic resonance imaging is challenging in dogs. In contrast, direct arthroscopic inspection provides detailed information about the cartilage. The treatment of these severe erosions is difficult because of the limited regenerative capacity of cartilage and presumed mechanical or physical triggering factors. Several conservative and surgical treatment methods have been proposed to treat elbows with severe cartilage defects. However, due to irreversible loss of cartilage, the prognosis in these cases remains guarded.... E. Coppieters (1), I. Gielen (1), G. Verhoeven (1), D. Van Vynckt (1), B. Van Ryssen (1) 23687 2014-11-14 08:54:30 Ahead of print: Revision of a loose cementless short-stem threaded femoral component using a... A Helica short-stemmed femoral prosthesis that was identified as being loose one year after implantation was revised with a standard long stem cementless BFX femoral prosthesis. A double pelvic osteotomy was also performed to improve the orientation of the stable acetabular cup. Despite complete resorption of the femoral neck, and a large perforation of the lateral femoral cortex, the revision stem did not subside or rotate. The prosthetic joint did not dislocate. At re-evaluation two years after revision surgery, the prosthetic components were stable. Signs of bone ingrowth into the stem and cup were evident on radiographs. The dog had a seven percent greater thigh muscle girth in the limb implanted with the hip prosthesis compared to the contralateral limb, and was very active with no lameness. S. C. Roe (1), D. J. Marcellin-Little (1), B. D. X. Lascelles (1) 23686 2014-11-14 08:52:55 A comparison of conventional compression plates and locking compression plates using cantilever... Objectives: The purpose of this study was to compare the stiffness, yield load, ultimate load at failure, displacement at failure, and mode of failure in cantilever bending of locking compression plates (LCP) and dynamic compression plates (DCP) in an acute failure ilial fracture model. Our hypothesis was that the LCP would be superior to the DCP for all of these biomechanical properties. Methods: Ten pelves were harvested from healthy dogs euthanatized for reasons unrelated to this study and divided into two groups. A transverse osteotomy was performed and stabilized with either a 6-hole DCP applied in compression or a 6-hole LCP. Pelves were tested in cantilever bending at 20 mm/min to failure and construct stiffness, yield load, ultimate load at failure, displacement at failure, and mode of failure were compared. Results: The mean stiffness of DCP constructs (193 N/mm [95% CI 121 – 264]) and of LCP constructs (224 N/mm [95% CI 152 – 295]) was not significantly different. Mean yield load of DCP constructs (900 N [95% CI 649 –1151]) and of LCP constructs (984 N [95% CI 733 –1235]) was not significantly different. No significant differences were found between the DCP and LCP constructs with respect to mode of failure, displacement at failure, or ultimate load at failure. Clinical significance: Our study did not demonstrate any differences between DCP and LCP construct performance in acute failure testing in vitro.... C. W. Bruce (1), T. W. G. Gibson (2), R. J. Runciman (3) 23615 2014-10-27 08:48:08 Kinematic gait analysis of the canine thoracic limb using a six degrees of freedom marker set Objectives: To determine if the use of a six degrees of freedom marker set would allow new kinematic data of the canine thoracic limbs to be calculated. To identify any significant differences in thoracic limb gait patterns in all planes of motion, between the normal canine population and patients with confirmed medial coronoid disease (MCD). Method: Two groups of dogs were selected representing the normal Labrador Retriever population (n = 13) and Labrador Retrievers with confirmed MCD (n = 13). Normal dogs had “normal” hip and elbow radiographic scores in line with the International Elbow Working Group and British Veterinary Association guidelines. Medial coronoid disease was confirmed using arthroscopy after kinematic analysis was performed with a six degrees of freedom marker set. Results: The diseased elbow was nine degrees more extended between 43%-55% of the gait cycle and 16° more supinated prior, early during and after foot strike. The antebrachium was nine degrees more supinated during foot strike and three degrees more abducted during early stance. None of the other parameters were significantly different. Clinical significance: The use of a six degrees of freedom marker set made it possible for the elbow and antebrachium to be reliably tracked in more than one plane of motion. Significant differences were identified between the normal canine population and those affected by MCD. These data may help elucidate biomechanical factors contributing to aetiopathogenesis of MCD.... A. Caron (1), A. Caley (2), M. Farrell (1), N. Fitzpatrick (1) 23614 2014-10-27 08:46:47 Treatment of canine cranial cruciate ligament disease Objective: To describe veterinarians’ treatment recommendations and decision-making factors for dogs with cranial cruciate ligament disease (CCLD). Methods: An online survey of American College of Veterinary Surgeons (ACVS)-Diplomates (surgeon group) and primary care veterinarians (practitioner group) was performed. The survey included questions on treatment recommendations for common case scenarios (small or large breed dog with complete or partial CCLD), treatment decision factors, non-surgical treatment options, and actual treatment, if any, provided for a client-owned dog as well as one owned by their family or close friend. Results: The response rate was 42% for the surgeon group (n = 305/723) and four percent for the practitioner group (n = 1145/ 27,771). Extracapsular stabilization (ES) was the most common treatment recommendation for CCLD in small (9.1 kg) breed dogs amongst surgeons and practitioners. Tibial plateau levelling osteotomy (TPLO) was the most common treatment recommendation for CCLD in large (27.2 kg) breed dogs amongst both groups. The two most important treatment decision factors were dog size (78% of practitioners, 69% of surgeons) and activity level (63% of practitioners, 52% of surgeons). The most common treatment provided for a dog of their own or close relation in the surgeon group was TPLO (64%) followed by ES (15%), whereas in the practitioner group it was ES (38%) followed by TPLO (30%). Clinical significance: Extracapsular stabilization and TPLO are the most commonly employed surgical procedures in the surveyed population; dog size and activity level (but not age) are the major factors influencing treatment decisions.... F. M. Duerr (1), K. W. Martin (1), M. Rishniw (2), R. H. Palmer (1), L. E. Selmic (1) 23607 2014-10-20 10:52:37 Medullary cavity diameter of metacarpal and metatarsal bones in cats Objectives: To compare radiography and computed tomography (CT) for the evaluation of medullary cavity diameters of metacarpal and metatarsal bones in cats and to analyse their correlation with intramedullary pin size. Methods: Radiography and CT were performed in cadavers (n = 12). The mid-diaphysis was determined and the medullary cavity diameter was measured by two observers. Each bone was osteotomized at the mid-diaphysis, Kirschner wires were inserted, and pin size was documented. Intra- and interobserver variability was evaluated (hierarchical analysis of variance). Radiography and CT were compared (correlation analysis, a t-test for dependent samples, a Bland-Altman analysis) and pin size, radiography and CT were compared (regression and correlation analysis). Results: Intra-observer variability was low for radiographs and CT, with an estimated median variation of 0.10 mm for radiographs and 0.12 mm for CT. Inter-observer variability was low, with a median variation of 0.03 mm for radiographs and 0.21 mm for CT. There was a high correlation between radiography and CT for the assessment of the medullary cavity diameter. A high correlation was found between pin size and measurement on radiographs, and between pin size and measurements on CT. In two cats, pin insertion was difficult or impossible. Clinical significance: Mid-diaphyseal meas-urements are applicable methods for the assessment of the medullary cavity diameter in feline metacarpal and metatarsal bones regarding intramedullary pins. In some cats the medullary cavity diameter may be too small for intramedullary pinning techniques, which can be identified preoperatively on radiographs.... M. Kornmayer (1), K. Amort (1), K. Failing (2), M. Kramer (1) 23606 2014-10-20 10:50:16 Lameness associated with tarsal haemarthrosis as the sole clinical sign of idiopathic... A four-year-old, male Cocker Spaniel was presented for investigation of pelvic limb stiffness. There was palpable effusion of both tarsi, and analysis of synovial fluid from these joints indicated previous haemorrhage. After further investigation a diagnosis of idiopathic immune-mediated thrombocytopenia was made. The dog responded to treatment with prednisolone and azathioprine. To the authors’ knowledge, this is the first reported case of confirmed haemarthrosis as the sole presenting clinical sign for canine idiopathic immune-mediated thrombocytopenia. M. B. Walton (1), E. Mardell (2), M. Spoor (3), J. Innes (1) 23605 2014-10-20 10:28:01 Kinetic and kinematic evaluation of compensatory movements of the head, pelvis and thoracolumbar... Objectives: To determine ground reaction forces, head and pelvis vertical motion (HVM and PVM, respectively), and thoraco-lumbar lateral angular motion (LAM) of the spine using kinematic gait analysis in dogs with mild asymmetric weight-bearing of the pelvic limbs while trotting. Methods: Twenty-seven hound-type dogs were fitted with reflective markers placed on the sagittal crest of the skull, the ischiatic tuberosity, and thoracolumbar spine of dogs to track motion while trotting. Kinetic and kinematic data were used to characterize asymmetry between the left and right pelvic limbs, and to describe HVM, PVM and thoraco-lumbar LAM. Maximum and minimum position and total motion values were determined for each measured variable. Results: Dogs with asymmetric weight bearing of the pelvic limbs had greater PVM on the side with a greater peak vertical force (PVF), and greater thoraco-lumbar LAM toward the side with a lower PVF while trotting. No differences in mean HVM were detected, and there were no significant correlations between the magnitude of HVM, PVM and thoraco-lumbar LAM and the degree of asymmetric weight bearing. Clinical significance: Dogs with subtle asymmetric weight bearing of a pelvic limb had patterns of body motion that may be useful in identifying subtle lameness in dogs; greater PVM on the side with greater weight bearing and greater thoraco-lumbar LAM toward the side with less weight bearing while trotting. Description of these compensatory movements is valuable when evaluating dogs with subtle weight bearing asymmetry in the pelvic limbs and may improve the sensitivity of lameness detection during subjective clinical lameness examination.... D. A. Hicks (1), D. L. Millis (2) 23604 2014-10-20 10:27:09 Effect of tibial subluxation on the measurements for tibial tuberosity advancement in dogs with... Objectives: The main objectives were to evaluate the impact of femorotibial subluxation on the preoperative measurements for tibial tuberosity advancement (TTA) by defining radiographic landmarks and testing the repeatability for assessing cranial tibial subluxation (CTS). Also, we aimed at developing a formula to calculate the necessary adjustment in measurement of TTA in stifles with CTS. Methods: Forty stifles were used to examine the influence of CTS on preoperative TTA measurements before and after transection of the cranial cruciate ligament. Mediolateral radiographs were obtained and measurements performed by three investigators. The observed variabilities were assessed by inter- and intra-observer differences. Results: Measurements of CTS and preoperative TTA showed a good to excellent inter- and intra-observer correlation. We found a significant influence of CTS on TTA measurements and developed a formula to calculate the necessary adjustment in measurement of TTA in stifles with CTS. Conclusion: We found a correlation between the tibial subluxation and the measurements for TTA, with the latter decreasing with increasing subluxation. This has to be taken into account when measuring the advancement in stifles with complete rupture of the cranial cruciate ligament. We provided a formula to calculate the necessary addition to the measured advancement.... M. J. Bielecki (1), C. S. Schwandt (1), S. Scharvogel (1) 23603 2014-10-20 10:26:09 Computed tomography assisted determination of optimal insertion points and bone corridors for... Objective: Describe optimal corridors for mediolateral or lateromedial implant placement in the feline tarsus and base of the metatarsus. Methods: Computed tomographic images of 20 cadaveric tarsi were used to define optimal talocalcaneal, centroquartal, distal tarsal, and metatarsal corridors characterized by medial and lateral insertion points (IP), mean height, width, length and optimal dorsomedial-plantarolateral implantation angle (OIA). Results: Talocalcaneal level: The IP were at the head of the talus and plantar to the peroneal tubercle of the calcaneus and OIA was 22.7° ± 0.3. Centroquartal level: The IP were at the centre of the medial surface of the central tarsal bone and dorsoproximal to the tuberosity of the fourth tarsal bone and OIA was 5.9° ± 0.06. Distal tarsal level: The IP were at the centre of the medial surface of the tarsal bone II and dorsodistal to the tuberosity of the fourth tarsal bone and OIA was 5.4° ± 0.14. Metatarsal level: The IP were at the dorsomedial surface of the proximal end of the metatarsal bone II and at the dorsolateral surface of metatarsal bone V and OIA was 0.5° ± 0.06. Significant positive correlation was found between body weight and the length of each corridor. Clinical significance: Most of the corridors obtained in this study had a diameter between 1.5 mm and 2 mm with a length of 15 mm to 18 mm, which stresses the importance of their accurate placement.... M. Benlloch-Gonzalez (1), M. Grapperon-Mathis (1), B. Bouvy (2) 23602 2014-10-20 10:25:10 BMP-2 delivered from a self-crosslinkable CaP/hydrogel construct promotes bone regeneration in a... Objectives: To determine whether the addition of recombinant human bone morphogenetic protein (rhBMP-2) to a self-crosslinkable cellulosic hydrogel/biphasic calcium phosphate (BCP) granules construct promotes bone healing in critical-size ulnar defects in dogs. Methods: A standardized 2 cm long ulnar ostectomy was performed bilaterally in five dogs to compare bone healing with hydrogel/BCP constructs associated with or without rhBMP-2. Cancellous-bone autografts were used as positive controls in unilateral ulnar defects in five additional dogs. Radiographically, bone healing was evaluated at four, eight, 12, 16 and 20 weeks postoperatively. Histological qualitative analysis with microCT imaging and light and scanning electron microscopy were performed 20 weeks after implantation. Results: All rhBMP-2-loaded constructs induced the formation of well-differentiated mineralized lamellar bone surrounding the BCP granules and bridging bone/implant interfaces as early as eight weeks after surgery. Bone regeneration appeared to develop earlier with the rhBMP-2 constructs than with the cancellous-bone autografts while similar results were obtained at 20 weeks. Constructs without any rhBMP-2 showed osteoconductive properties limited to the bone junctions and a lack of osteoinduction without bone ingrowth within the implantation site. In one dog, the leakage of the hydrogel loaded with rhBMP-2 induced an extensive heterotopic bone formation. Clinical significance: The addition of rhBMP-2 to a self-crosslinkable hydrogel/BCP construct could promote bone regeneration in a critical-size-defect model with similar performance to autologous bone grafts.... K. Minier (1, 2), A. Touré (3), M. Fusellier (1, 3), B. Fellah (1), B. Bouvy (2), P. Weiss (3), O. Gauthier (1, 3) 23601 2014-10-20 10:23:57 Biomechanical comparison of mono- and bicortical screws in an experimentally induced gap fracture Objectives: To compare the bending and torsional mechanical properties of mono- and bicortical locking screws in a canine cadaveric tibial gap ostectomy bridged by a locking compression plate (LCP). Methods: A 10-hole 3.5 mm LCP was applied medially to the tibia with a gap ostectomy using locking screws in the two proximal and distal plate holes. One tibia of each pair was randomly assigned monocortical screws and the other bicortical screws. Constructs were tested non-destructively in mediolateral and caudocranial four-point bending and torsion, and then to failure in four-point bending. Stiffness, yield and failure variables were compared between screw lengths and load conditions using analysis of variance. Results: Caudocranial and mediolateral four-point bending stiffnesses were not different between screw constructs. Torsional stiffness was greater and neutral zone smaller for bicortical constructs. Constructs were stiffer and stronger in caudocranial bending than in mediolateral bending. In caudocranial bending, bicortical constructs failed by bone fracture and monocortical constructs by screw loosening. Conclusion: Bicortical constructs were stiffer than monocortical constructs in torsion but not bending. Bicortical screw constructs failed by bone fracture under the applied loads whereas monocortical screw constructs failed at the bone-screw interface. Clinical relevance: Bicortical screw placement may be a safer clinical alternative than monocortical screw placement for minimally invasive percutaneous osteosynthesis LCP-plated canine tibiae with comminuted diaphyseal fractures.... D. Demner (1), T. C. Garcia (2), M. G. Serdy (1), K. Hayashi (3), B.-A. Nir (1), S. M. Stover (4) 23600 2014-10-20 10:22:42 Barbed versus smooth poly-propylene three-loop pulley sutures for repair of canine gastrocnemius... Objective: To compare the ultimate tensile strength (UTS) and load to 1 and 3 mm gap formation of smooth (3-metric) and knotless barbed (4-metric) polypropylene sutures placed in a three-loop pulley pattern for canine gastrocnemius tendon repair. Study design: In vitro. Sample size: Thirty-three paired bone-tendon units with one of each pair assigned to each suture type. Barbed suture size was based on previously published materials testing results. Methods: Each unit was placed in a servo-hydraulic testing machine and tested under single cycle tensile loading until repair failure. Results: There was a significantly higher UTS for smooth polypropylene compared to the barbed polypropylene repairs. The loads resulting in 1 and 3 mm gaps for the barbed repairs were consistently significantly less than the corresponding smooth polypropylene repair values. Conclusion: The knotted smooth polypropylene repair was consistently stronger than the knotless barbed polypropylene repair when placed in a three-loop pulley pattern for gastrocnemius repair. Clinical significance: Knotless barbed polypropylene suture should not be considered equivalent to knotted smooth polypropylene of comparable tensile strength when placed in a three-loop pulley pattern for canine gastrocnemius tendon repair. The low failure loads of the barbed repair are probably due to failure of the barbs to anchor consistently throughout the tendon in the knotless configuration.... B. S. Perry (1), T. A. Harper (1), M. A. Mitchell (1), M. S. McFadden (2), B. Heggem Perry (1) 23599 2014-10-20 10:21:46 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 Unilateral or single-session bilateral surgery for correction of medial patellar luxation in small... 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