Characteristics, surgical treatment, and outcomes of injuries involving the tarsus in greyhounds.

Objective: The first objective of this study was to describe the type of tarsal injuries sustained, surgery performed, and postoperative complications in greyhounds presenting to a single veterinary hospital. An additional objective of the study was to determine the surgical site infection (SSI) and explantation rate, and if any variables were associated with an increased risk of SSI and/or explantation. Animals: 116 greyhounds receiving surgical intervention for a tarsal injury. Proceures: Medical records from a single veterinary referral hospital were reviewed retrospectively. Data retrieved included signalment, details regarding the injury, surgical intervention, concurrent castration, surgical/anesthesia times, postoperative management, time to healing, and postoperative complications. In cases that underwent explantation, cause, time from initial surgery, and risk factors were evaluated. Results: The most frequently diagnosed tarsal injuries were fracture of the central tarsal bone (CTB; 57.8%), calcaneal fracture (56.9%) and proximal intertarsal subluxation (34.5%). The most common injury combination was a CTB fracture with a calcaneal fracture (31.9%). In total 115 (99.1%) survived to discharge. Of these, 46 (40.0%) were diagnosed with an SSI and 59 (51.3%) underwent explantation. The most common indication for explantation was SSI. Concurrent medial and lateral surgical approaches was found to be associated with an increased likelihood of SSI and explantation. Clinical relevance: Practitioners performing surgical intervention for tarsal injuries in greyhounds should be aware of the high SSI rate and likelihood that explantation will be required. This risk is elevated for injuries requiring a bilateral surgical approach.

Case factors for selection of femoral component type in canine hip arthroplasty using a modular system.

OBJECTIVE: To describe a femoral stem selection process based on case features in dogs treated with total hip replacement (THR) by an expert surgeon, compare complications between implant types, and develop an algorithm for stem type selection. STUDY DESIGN: Retrospective study. ANIMALS: 128 dogs, 135 THR. METHODS: Data collected included breed, age, weight, canal flare index (CFI), and implant type: cementless (BFX), cementless with a collared stem (BFX-C), hybrid (cementless acetabular component with cemented stem), and cemented (CFX). RESULTS: Of the 135 THRs, 69 BFX, 47 hybrid, and 18 BFX-C were performed. Dogs receiving hybrid (mean 5.5 years) were older than those receiving BFX (2.5 years, p < .0001) and BFX-C implants (2.5 years, p = .0014). The mean weights of dogs with hybrid, BFX, and BFX-C implants were 40.0, 31.0, and 35.3 kg, respectively, with dogs receiving hybrid heavier than those receiving BFX (p < .0001). Mean CFI for hybrid (1.52) was lower than for BFX (1.79, p < .0001) and BFX-C (1.76, p = .0021). Total complication rate was 14.0% with catastrophic complications in 1.5% and no association between implant type and risk of complications (p = .36). Femur fractures occurred in 2.9% of all cases and 1.1% of cementless THR cases. CONCLUSIONS: Dogs receiving hybrid THR were older with lower CFI than dogs receiving BFX and BFX-C and heavier than dogs receiving BFX. There was no difference in complications between groups. Catastrophic complications and femur fractures occurred less frequently compared to recent studies of BFX THR. CLINICAL SIGNIFICANCE: Careful preoperative assessment and implant selection can reduce complications of canine THR.

Total hip replacement in dogs with contralateral pelvic limb amputation: A retrospective evaluation of 13 cases.

OBJECTIVE: To report the clinical characteristics, surgical management, and medium-term outcomes of total hip replacement (THR) performed in dogs with previous contralateral pelvic limb amputation. ANIMALS: Thirteen client-owned dogs. STUDY DESIGN: Multi-institutional retrospective clinical study. METHODS: Data recorded from medical records included signalment, indication for amputation and THR, and surgical complications. Implant positioning and complications were assessed on radiographs. Clinical outcomes were evaluated during follow-up examinations by one of the authors and through a mobility- and lifestyle-based questionnaire completed by owners. RESULTS: All 13 dogs had satisfactory clinical results at follow-up a median of 3 months (range, 2-36) after THR. No postoperative luxation was recorded. Four dogs had minor complications that did not require additional treatment. The only major complication was one failure of osseointegration of a cementless acetabular cup, and it was successfully revised. CONCLUSION: Total hip replacement resulted in satisfactory clinical results and acceptable morbidity in this population. CLINICAL SIGNIFICANCE: Total hip replacement should be considered in dogs with severe coxofemoral joint disease and contralateral pelvic limb amputation.

Total hip arthroplasty to address chronic hip luxation with pseudoacetabulum formation in seven dogs.

OBJECTIVE: To compare the outcome of dogs treated with total hip arthroplasty (THA) for chronic hip luxation and pseudoacetabulum formation to that of dogs with simple hip dysplasia and secondary osteoarthritis. STUDY DESIGN: Retrospective, case-controlled study. ANIMALS: Seven dogs with pseudoacetabulum (group 1) and 21 matched control dogs (group 2). METHODS: Each dog in group 1 was matched with three control dogs, primarily according to similarity of THA implant type and size. Patterns of radiographic pathology were characterized in each dog. Outcome measures included operative time, acetabular cup position/orientation (inclination angle, angle of lateral opening, version angle) complications, and long-term outcomes. Outcome measures were compared between groups using linear regression (P = .05). RESULTS: The presence of a pseudoacetabulum was associated with ilial remodeling and heterotopic bone formation concentric to the luxated femoral head. Exposing the native acetabulum and reducing the prosthesis were surgically challenging. The mean (SD) operative time of dogs in group 1 (96 [18] minutes) was longer than that of dogs in group 2 (63 [14] minutes; P = .00002). Cup position/orientation was not different between dogs in group 1 and group 2. One intraoperative complication and two minor postoperative complications occurred in group 1 dogs. All dogs had good long-term outcomes. CONCLUSION: Total hip arthroplasty in dogs with a pseudoacetabulum was more challenging than in control dogs. However, the procedure provided good to excellent long-term clinical outcomes in all dogs. CLINICAL SIGNIFICANCE: Surgeons should be prepared for the specific surgical challenges associated with THA in dogs with pseudoacetabulum formation.

Fibular osteotomy to facilitate proximal tibial rotation during tibial plateau leveling osteotomy.

OBJECTIVE: To identify factors that restrict proximal tibial rotation during tibial plateau leveling osteotomy (TPLO) and report on the outcome of concurrent fibular osteotomy (TPLO-FO). STUDY DESIGN: Retrospective case-control study. ANIMALS: Dogs undergoing TPLO-FO (n = 23) and dogs undergoing routine TPLO (n = 49). METHODS: Medical records and radiographs of dogs that had undergone TPLO-FO were reviewed. Data that were collected included signalment, preoperative tibial plateau angle (TPA), mechanical medial proximal tibial angle (mMPTA), postoperative and recheck TPA and mMPTA, ratio of fibular width to tibial width (FW:TW), presence of tibiofibular synostosis, tibial osteotomy location, and use of additional implants. RESULTS: The odds of exhibiting rotational constraints requiring FO during TPLO were 62-fold greater in dogs with tibiofibular synostosis than in dogs without synostosis. Dogs with FW:TW greater than 0.24 were 7.8-fold more likely to exhibit rotational constraints. After TPLO-FO, the postoperative increase in TPA was greater after single-plate fixation (mean, 5.4 ° ± 4.5 °) compared with fixation with 2 plates (mean, 1.4 ° ± 0.6 °). CONCLUSION: Proximal tibiofibular synostosis and a relatively wide fibula restricted tibial plateau rotation. In these dogs, concurrent fibular osteotomy allowed adequate rotation. Adjunct plate fixation limited loss of rotation after TPLO-FO. CLINICAL SIGNIFICANCE: Successful TPLO relies on adequate rotation of the proximal tibial segment. Fibular osteotomy and adjunct plate fixation are recommended to achieve and maintain adequate rotation of the osteotomized tibia in dogs with rotational constraints.

Pharmacokinetics and pharmacodynamics after oral administration of tapentadol hydrochloride in dogs.

OBJECTIVE To evaluate pharmacokinetic and pharmacodynamic characteristics of 3 doses of tapentadol hydrochloride orally administered in dogs. ANIMALS 6 healthy adult mixed-breed dogs. PROCEDURES In a prospective, randomized crossover study, dogs were assigned to receive each of 3 doses of tapentadol (10, 20, and 30 mg/kg, PO); there was a 1-week washout period between subsequent administrations. Plasma concentrations and physiologic variables were measured for 24 hours. Samples were analyzed by use of high-performance liquid chromatography-tandem mass spectrometry. RESULTS Tapentadol was rapidly absorbed after oral administration. Mean maximum plasma concentrations after 10, 20, and 30 mg/kg were 10.2, 19.7, and 31 ng/mL, respectively. Geometric mean plasma half-life of the terminal phase after tapentadol administration at 10, 20, and 30 mg/kg was 3.5 hours (range, 2.7 to 4.5 hours), 3.7 hours (range, 3.1 to 4.0 hours), and 3.7 hours (range, 2.8 to 6.5 hours), respectively. Tapentadol and its 3 quantified metabolites (tapentadol sulfate, tapentadol-O-glucuronide, and desmethyltapentadol) were detected in all dogs and constituted 0.16%, 2.8%, 97%, and 0.04% of the total area under the concentration-time curve (AUC), respectively. Plasma AUCs for tapentadol, tapentadol sulfate, and tapentadol-O-glucuronide increased in a dose-dependent manner. Desmethyltapentadol AUC did not increase in a linear manner at the 30-mg/kg dose. Sedation scores and heart and respiratory rates were not significantly affected by dose or time after administration. CONCLUSIONS AND CLINICAL RELEVANCE Oral administration of tapentadol was tolerated well, and the drug was rapidly absorbed. Adverse events were not apparent in any dogs at any doses in this study.

Distal femoral lateral closing wedge osteotomy as a component of comprehensive treatment of medial patellar luxation and distal femoral varus in dogs.

OBJECTIVE: To describe a cohort of dogs with medial patellar luxation managed with a distal femoral lateral closing wedge ostectomy (DFO) as a component of comprehensive treatment, and to report radiographic and long-term clinical outcome of this technique. METHODS: Medical records of dogs that had a lateral closing wedge DFO as part of management of medial patellar luxation at three veterinary teaching hospitals were reviewed. Surgical reports as well as the preoperative, postoperative, and follow-up radiographs were reviewed. The anatomical lateral distal femoral angle (aLDFA) was determined. Long-term clinical outcome was assessed by telephone interview with the owner. RESULTS: A lateral closing wedge DFO was performed on 66 limbs. The mean pre- and postoperative aLDFA was 107.6° ± 5.8° and 94.1° ± 4.2°, respectively. Cranial cruciate ligament disease was identified in 28/66 affected limbs. Tibial angular deformity, torsional deformity, or both was identified in nine of the 66 limbs. Ostectomy healing was confirmed radiographically in 51/66 limbs. The mean time to union was 73 ± 37 days. All patellae were in the normal position and stable. Complications included infection (2/51), fixation failure (1/51), delayed healing (2/51), and persistent lameness (1/51). CLINICAL SIGNIFICANCE: In this cohort of cases, DFO was a highly successful and repeatable component of surgical treatment for dogs with medial patellar luxation associated with femoral varus. This study also provides more evidence of the high rate of concurrent cranial cruciate ligament disease in cases of medial patellar luxation complicated by femoral varus, and supports an association between stifle instability and medial patellar luxation.

The effect of dorsal rim loss on the initial stability of the BioMedtrix cementless acetabular cup.

BACKGROUND: Loss of dorsal acetabular rim (DAR) is a common sequela to canine hip dysplasia. The purpose of this study is to evaluate the effect of DAR loss on the initial stability of the cementless (BFX) acetabular cup. BFX cups were implanted into foam blocks reamed to resemble acetabulae with simulated 0, 25, 50, and 75% DAR loss. Models were tested in edge loading of the lateral surface of the cup with an indenter, and in centered loading with an articulated femoral prosthesis. Additionally, cups were implanted into paired cadaveric canine hemipelves with either no DAR depletion, or removal of 50% of the DAR, and acutely loaded to failure with an articulated femoral prosthesis. RESULTS: Mean load measured at 1 mm cup displacement during edge loading was not significantly different in foam blocks with loss of 0, 25, 50, and 75% DAR (360 ± 124 N, 352 ± 42 N, 330 ± 81 N, 288 ± 43 N, respectively; P = 0.425). Mean load to failure with centered loads was greatest in blocks with 0% DAR loss (2828 ± 208 N; P < 0.001), but was not significantly different between 25, 50, and 75% DAR loss (2270 ± 301 N, 1924 ± 157 N, 1745 ± 118 N). In cadaveric testing, neither mean load to failure (P = 0.067), stiffness (P = 0.707), nor energy (P = 0.228) were significantly different in control hemipelves and those with 50% depletion of the DAR. Failure in all acetabulae occurred due to acetabular bone fracture at forces in supraphysiologic ranges. CONCLUSIONS: BFX cup stability under normal physiologic loads does not appear to be compromised in acetabulae with up to 50% DAR loss.

Postoperative comparison of four perioperative analgesia protocols in dogs undergoing stifle joint surgery.

OBJECTIVE: To compare 4 analgesic protocols in dogs undergoing stifle joint surgery. DESIGN: Randomized, blinded, prospective clinical trial. Animals-48 client-owned dogs that underwent stifle joint surgery. PROCEDURES: Dogs undergoing tibial plateau leveling osteotomy were randomly assigned to receive a constant rate infusion of a combination of morphine, lidocaine, and ketamine; a lumbosacral epidural with morphine and ropivacaine; both treatments (ie, constant rate infusion and lumbosacral epidural); or only IM premedication with morphine. Indices of cardiorespiratory function and isoflurane requirement were recorded at 5-minute intervals during anesthesia. A validated sedation scoring system and the modified Glasgow composite measure pain score were used to assess comfort and sedation after surgery and anesthesia once the swallowing reflex returned and a body temperature of ≥ 36.7°C (98.1°F) was attained. Pain and sedation scores were acquired at 60-minute intervals for 4 hours, then at 4-hour intervals for 24 hours. Dogs with a postoperative pain score > 5 of 24 were given morphine as rescue analgesia. RESULTS: No differences in heart rate, respiratory rate, systolic arterial blood pressure, end-tidal Pco2, end-tidal isoflurane concentration, and vaporizer setting were detected among groups. No differences in pain score, sedation score, rescue analgesia requirement, or time to first rescue analgesia after surgery were detected. CONCLUSIONS AND CLINICAL RELEVANCE: Pain scores were similar among groups, and all 4 groups had similar rescue analgesia requirements and similar times to first administration of rescue analgesia. All 4 analgesic protocols provided acceptable analgesia for 24 hours after stifle joint surgery.

Epidemiological profiling of methicillin-resistant Staphylococcus aureus-positive dogs arriving at a veterinary teaching hospital.

Methicillin-resistant Staphylococcus aureus (MRSA) has emerged as an important zoonotic and nosocomial pathogen in veterinary settings. Even though human risk factors for MRSA infection and colonization are well known, this information in animals is lacking. The objective of this study was to identify risk factors associated with MRSA carrier dogs on their arrival at a veterinary teaching hospital. A total of 435 dogs were enrolled in the MRSA active surveillance program at The Ohio State University-Veterinary Medical Center over a 1-year period. Dogs were screened for MRSA on arrival, regardless of health status, sex, breed, or age. In addition, an epidemiological survey and medical history were obtained for each dog to identify potential risk factors up to 1 year prior to the appointment. Of 435 dogs included in the study, 25 (5.7%) were MRSA positive, with 86.5% of the isolates classified staphylococcal chromosome cassette mec (SCCmec) type II and USA100. Four of the 25 MRSA carrier dogs were healthy, 20 had health issues unrelated to MRSA, and 1 had an active MRSA infection. MRSA was detected in the nares (72%, 18/25), skin lesions (24%, 6/25), and the perianal area (16%, 4/25). Except for previous surgery <90 days (odds ratio [OR]=4.9; 95% confidence interval [CI] 1.4-17.6; p value 0.01), none of the variables related to the previous medical history, dog's management, home environment, and other potential exposures were associated with the MRSA carrier status. However, the profession of the owner was significantly associated, and dogs owned by veterinary students were 20.5 times (95% CI 4.5-93.6; p value≤0.01) more likely to be MRSA positive than dogs owned by clients with different occupations. MRSA-positive dogs were dispersed in different categories, preventing the creation of an epidemiological profile that would allow their early recognition upon arrival to a veterinary hospital. However, the association between veterinary students with MRSA-positive dogs is a concern that deserves further evaluation.

Presence, distribution, and molecular epidemiology of methicillin-resistant Staphylococcus aureus in a small animal teaching hospital: a year-long active surveillance targeting dogs and their environment.

Methicillin-resistant Staphylococcus aureus (MRSA) is known to be present in small animal veterinary clinical environments. However, a better understanding of the ecology and dynamics of MRSA in these environments is necessary for the development of effective infectious disease prevention and control programs. To achieve this goal, a yearlong active MRSA surveillance program was established at The Ohio State University (OSU) Veterinary Medical Center to describe the spatial and molecular epidemiology of this bacterium in the small animal hospital. Antimicrobial susceptibility testing, staphylococcal chromosomal cassette mec (SCCmec) typing, pulsed-field gel electrophoresis (PFGE) typing, and dendrogram analysis were used to characterize and analyze the 81 environmental and 37 canine-origin MRSA isolates obtained during monthly sampling events. Overall, 13.5% of surfaces were contaminated with MRSA at 1 or more sampling times throughout the year. The majority of the environmental and canine isolates were SCCmec type II (93.8% and 86.5%, respectively) and USA100 (90.1% and 86.5%, respectively). By PFGE analysis, these isolates were found to be closely related, which reflects a low diversity of MRSA strains circulating in the hospital. For 5 consecutive months, 1 unique pulsotype was the most prevalent across the medical services and was recovered from a variety of surfaces and hospital locations. Carts/gurneys, doors, and examination tables/floors were the most frequently contaminated surfaces. Some surfaces maintained the same pulsotypes for 3 consecutive months. Molecular analysis found that incoming MRSA-positive dogs were capable of introducing a new pulsotype into the hospital environment during the surveillance period. Our results suggest that once a MRSA strain is introduced into the hospital environment, it can be maintained and spread for extended periods of time. These findings can aid in the development of biosecurity and biocontainment protocols aimed at reducing environmental contamination and potential exposures to MRSA in veterinary hospital staff, clients, and patients.

Retrospective evaluation of the effectiveness of epsilon aminocaproic acid for the prevention of postamputation bleeding in retired racing Greyhounds with appendicular bone tumors: 46 cases (2003-2008).

OBJECTIVES: To determine the frequency of delayed postoperative bleeding in retired racing Greyhounds with appendicular bone tumors undergoing limb amputations. To identify if administration of epsilon-aminocaproic acid (EACA) was effective on the prevention of postoperative bleeding. DESIGN: Retrospective study from December 2003 to December 2008. SETTING: Veterinary university teaching hospital. ANIMALS: Forty-six retired racing Greyhounds (RRGs) diagnosed with primary appendicular bone tumors that underwent limb amputation were included in the study. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Thirteen of 46 RRGs (28%) included in the study had delayed postoperative bleeding starting 48-72 h after surgery. Bleeding episodes included cutaneous, subcutaneous, and external bleeding that extended from the area of the surgical site that became widespread within hours, and that required administration of blood components. A paired t-test suggests that there was a significant decrease in PCV postoperatively for both dogs that bled and dogs that did not bleed (P < 0.0001). Forty of 46 RRGs (86%) received either fresh frozen plasma (FFP) or EACA or both, for the prevention of postoperative bleeding. A logistic regression model determined that dogs that did not receive EACA were 5.7 times more likely to bleed than dogs that did receive EACA, when controlling for whether or not they received FFP (95% CI: 1.02-32.15, P = 0.047). CONCLUSION: This retrospective study suggests that preemptive postoperative administration of EACA appears to be efficacious in decreasing the frequency of bleeding in RRGs undergoing limb amputation; however, a prospective study is warranted to corroborate its effectiveness.

Comparison of the effects of two screw insertion patterns on bone fragment translocation in a 3.5 mm dynamic compression plate and a 3.5 mm limited-contact dynamic compression plate.

OBJECTIVE: To compare the effects of screw insertion pattern, plate type, application of bone reduction forceps, and additional load screw insertion in an 8-hole 3.5 mm dynamic compression plate (DCP) and limited-contact dynamic compression plate (LC-DCP) on bone fragment translocation (BFT) in a fracture gap model. STUDY DESIGN: In vitro mechanical study. METHODS: Two screw insertion patterns were tested in the DCP and newly redesigned LC-DCP using gap model synthetic bone constructs. In Pattern 1, screws were first inserted into the holes at each end of the plate, then screws were inserted into the holes adjacent to the fracture gap. In Pattern 2, screws were only inserted into the holes adjacent to the fracture gap. The effects of tight or loose bone forceps securing the plate, loosening a neutral screw in Pattern 1, and inserting up to 4 additional load screws with each pattern were tested. Changes in the fracture gap were measured after insertion of all neutral screws and after each load screw. RESULTS: Pattern 2 BFT was significantly greater than Pattern 1 BFT when bone forceps were loose with both plates (P < .001). In the DCP, the BFT was significantly increased by loosening the bone forceps with Pattern 2 (P < .001) and by loosening 1 neutral screw in Pattern 1 (P < .001). The BFT for each additional load screw inserted was significantly less than 1.0 mm. CONCLUSIONS: A tight neutral screw in the same bone fragment as the load screw or bone clamps that tightly secure the plate to the bone can limit BFT.

Detectable reporter gene expression following transduction of adenovirus and adeno-associated virus serotype 2 vectors within full-thickness osteoarthritic and unaffected canine cartilage in vitro and unaffected guinea pig cartilage in vivo.

This study quantified and compared the transduction efficiencies of adenoviral (Ad), Arg-Gly-Asp (RGD)-modified Ad, adeno-associated viral serotype 2 (AAV2), and self-complementary AAV2 (scAAV2) vectors within full-thickness osteoarthritic (OA) and unaffected canine cartilage explants in vitro. Intraarticular administration of Ad and scAAV2 vectors was performed to determine the ability of these vectors to transduce unaffected guinea pig cartilage in vivo. Following explant exposure to vector treatment or control, the onset and surface distribution of reporter gene expression was monitored daily with fluorescent microscopy. At termination, explants were divided: one half was digested for analysis using flow cytometry; the remaining portion was used for histology and immunohistochemistry (IHC). Intact articular joints were collected for real-time RT-PCR and IHC to detect reporter gene expression following injection of selected vectors. Ad vector transduced focal areas along the perimeters of explants; the remaining vectors transduced chondrocytes across 100% of the surface. Greater mean transduction efficiencies were found with both AAV2 vectors as compared to the Ad vector (p < or = 0.026). Ad and Ad-RGD vectors transduced only superficial chondrocytes of OA and unaffected cartilage. Uniform reporter gene expression from AAV2 and scAAV2 was detected in the tangential and transitional zones of OA cartilage, but not deeper zones. AAV2 and scAAV2 vectors achieved partial and full-thickness transduction of unaffected cartilage. In vivo work revealed that scAAV2 vector, but not Ad vector, transduced deeper zones of cartilage and menisci. This study demonstrates that AAV2 and scAAV2 are reliable vectors for use in cartilage in vitro and in vivo.

Cementless total hip replacement in an alpaca.

OBJECTIVE: To report management of a chronic slipped capital femoral epiphysis (SCFE) in an alpaca using cementless total hip replacement (THR). STUDY DESIGN: Case report. ANIMAL: An 18-month-old, 47 kg alpaca male. METHODS: Cementless THR was performed in an alpaca with a chronic, right SCFE, and secondary osteoarthritis. Force plate gait analysis was performed before and 8 weeks after surgery. Outcome was determined through clinical evaluation, radiography, and force plate gait analysis. RESULTS: Cementless THR resulted in marked improvement in the alpaca's comfort level, degree of lameness, and range of motion. On preoperative force plate gait analysis there was decreased contact time (P=.01) and vertical impulse (P<.01) of the affected limb, whereas at 8 weeks postoperatively significant differences in gait analysis between pelvic limbs were not apparent. CONCLUSION: THR using a BioMedtrix canine cementless modular prosthesis restored hip function in an alpaca with coxofemoral osteoarthritis from chronic SCFE. CLINICAL RELEVANCE: THR may be an appropriate treatment for selected traumatic and degenerative conditions of the coxofemoral joint in alpacas.

Computed tomographic arthrography of the stifle for detection of cranial and caudal cruciate ligament and meniscal tears in dogs.

The purpose of this study was to evaluate the utility of single-detector computed tomographic arthrography (CT arthrography) for the diagnosis of cranial and caudal cruciate ligament and meniscal lesions in the dog stifle. Four normal and 25 abnormal stifle joints, determined to have lesions related to intra-articular ligamentous insufficiency based on clinical history, orthopedic examination, and survey orthogonal radiographs, were imaged using a previously developed CT arthrography protocol. Surgery was performed immediately following the CT procedure. Three board-certified radiologists inexperienced at interpreting CT stifle arthrograms reviewed all CT studies independently, and then as a group, without knowledge of surgical or necropsy findings. Sensitivity, specificity, positive predictive value, and negative predictive value for determination of cranial and caudal cruciate and meniscal tears were calculated for each individual reviewer and based on group consensus. All reviewers identified the normal canine stifle joints imaged correctly. Reviewers did well in discriminating normal from torn cranial cruciate ligaments, with sensitivities of 96-100% and specificities of 75-100%. No reviewer correctly identified the solitary caudal cruciate ligament tear and specificity ranged from 89.3% to 100%. Reviewers were less adept at discriminating normal from torn meniscal fibrocartilage, with sensitivities of 13.3-73.3% and specificities of 57.1-100%. Interpretive accuracy improved slightly when consensus scores were compared with surgical findings. Single-detector CT arthrography may be useful for identifying pathology of the canine cruciate ligaments but is of limited value for assessing the menisci.

Risk factors for ventral luxation in canine total hip replacement.

OBJECTIVE: To identify risk factors associated with ventral luxation (VL) of canine total hip replacement (THR), and outcome. STUDY DESIGN: Retrospective study. ANIMALS: Dogs (n=602) that had THR (563 cemented, 35 cementless, 4 hybrid). METHODS: Dogs (1999-2004) with VL after THR were compared with dogs with uncomplicated THR. Data included signalment, body weight, diagnosis, implant size, acetabular cup orientation, and femoral displacement ratio (FDR). RESULTS: VL was diagnosed in 11 (1.8%) dogs after primary THR. Including 2 other dogs that had VL after the study period, 10 (77%) of 13 dogs had VL within 7 days of surgery. Risk factors for VL included Saint Bernard-type dogs (P=.0001), short neck extension (P=.0005), and high angle of lateral opening in other breeds (P=.018). There were trends toward higher risk of VL with lower FDR in Saint Bernard types (P=.060), and with cementless implants (P=.061). Twelve dogs had revision arthroplasty that was successful in all cementless and 2 cemented VL cases. Five dogs had recurrent VL and a poor outcome. CONCLUSION: VL is generally an early complication of THR, with no single common risk factor identified. CLINICAL RELEVANCE: Saint Bernard types and short neck extensions are associated with increased risk of VL. Poor cup orientation is a determining factor for VL in some dogs, but a protective orientation of the acetabular cup was not found. Revision is successful in most dogs, but recurrent VL merits a guarded prognosis.

Relationship of tibial plateau slope to limb function in dogs treated with a lateral suture technique for stabilization of cranial cruciate ligament deficient stifles.

OBJECTIVE: To evaluate the effect of a lateral suture technique (LST) on tibial plateau angle (TPA) measurement and to compare TPA with functional outcome in dogs treated for cranial cruciate ligament (CrCL) rupture with LST. STUDY DESIGN: Prospective clinical study. SAMPLE POPULATION: Dogs (n=34) with unilateral CrCL instability. METHODS: All dogs had lameness examination, survey stifle radiographs, and force plate analysis before and at 6, 12, 24, and 48 weeks after surgery. Radiographic osteoarthritis (OA) scores and lameness scores were assigned using previously reported methods. Preoperative radiographs were performed in all dogs, and postoperative serial radiographs were performed in 6 dogs for measurement of TPA. Differences in TPA measurements were evaluated with a random effects repeated measures model. The significance of LST on TPA measurement was established in 6 dogs and the effect of TPA on vertical impulse, peak vertical force, progression of radiographic scores, and lameness score were analyzed by general linear models in all dogs. Differences were considered significant if P<.05. RESULTS: Significant differences were not noted between pre- and serial postoperative measurements of TPA. A significant correlation was not established between TPA and postoperative vertical impulse, peak vertical force, lameness score, or radiographic OA scores. CONCLUSIONS: TPA values were unchanged after LST and TPA does not affect outcome measures in dogs treated with LST. CLINICAL RELEVANCE: TPA has no predictive value on clinical outcome in dogs treated with LST for stabilization of CrCL deficient stifles.