Real-Time Feedback to Enhance the Teaching of Wire Tying.

Teaching the art of wire tying is difficult because the instructor is not able to gauge the effectiveness of the final product. The impact of an incorrect technique is usually not evident. Also, the instructor does not have a way to demonstrate the different levels of tension generated by different wire knotting techniques, nor their differing abilities to resist a load that a patient may apply. In this paper, a device is described that can provide real-time feedback on wire tension generated during knot tying, and how particular knots resist an applied distraction. This device has been used to deliver a live demonstration to reinforce lecture material, and in small group teaching exercises, where real-time feedback enhances skills and understanding. A stepwise training schedule for surgery residents structured as an entrustable professional activity is proposed.

Double-loop cerclage resists greater loads for more cycles than twist and single-loop cerclage.

OBJECTIVE: To compare the mechanical performance of cerclage secured with twist, single-loop, and double-loop knots subjected to cyclic loading. STUDY DESIGN: In vitro biomechanical study. SAMPLE POPULATION: Twist, single-loop and double-loop cerclage configurations of 1.0 mm wire. METHODS: The peak load resisted by each cerclage type was determined (n = 6). Cerclage were loaded cyclically to 80%, 60%, 40%, or 20% of its peak load (n = 8 per load level). The number of cycles until each cerclage loosened (residual tension <10 N) was recorded. RESULTS: All wires that failed did so by loosening. Twist cerclage cycled to 390 N and 290 N loosened within the first 10 cycles, and, when cycled to 100 N, they loosened by 250 cycles. All twist knots loosened by untwisting. Single-loop cerclage cycled to 320 N loosened within 10 cycles. At 240 N, 5 single-loop cerclage resisted 250 cycles before loosening. At 160 N, 2 of the 8 single-loop cerclage did not loosen by 100 000 cycles. When cycled to 640 N, one of the double-loop cerclage did not loosen following 500 000 cycles. When cycled to 480 N, 3 of the 8 wires did not loosen. CONCLUSION: Double-loop cerclage will be tighter and are better able to resist cycling than twist or single-loop cerclage. CLINICAL SIGNIFICANCE: Use of double-loop cerclage to stabilize bone fragments or prevent fissure propagation can be expected to provide greater resistance to loosening than twist or single-loop cerclage, both initially and with repeated loading.

Defining the rate of, and factors influencing, radiographic progression of osteoarthritis of the canine hip joint.

BACKGROUND: This study aimed to define the rate of progression of radiographic osteoarthritis (OA) of the canine hip joint and to describe factors affecting this progression. METHODS: Dogs that underwent unilateral total hip replacement (THR) were reviewed for the evaluation of radiographic appearance of the non-operated hip joint over time. Standard extended ventrodorsal hip radiographs were taken preoperatively and postoperatively. All images were anonymized, randomized and scored using three different methods. The mean daily change between evaluations was calculated in each individual dog, and the effect of sex, age, body weight, open/closed status of the proximal femoral physis, preoperative severity of OA, time after surgery and their interactions, were investigated as potential influencing factors. RESULTS: After reviewing the medical records, 163 dogs (468 images) met the inclusion criteria. Consistent across the three scoring systems, radiographic progression of OA was greater in younger (open physis) and spayed female dogs. A subset of seven patients (4.3%) had a faster progression of OA and was considered outliers. No dog was rated as outlier by all three scoring systems. CONCLUSION: The rate of progression of radiographically assessed coxofemoral OA varies greatly, but is faster in younger, spayed female dogs. Unusually fast progression occasionally occurs.

Use of Top Hat Audience Response Software in a Third-Year Veterinary Medicine and Surgery Course.

Audience response devices are useful tools that can improve student engagement and learning during instructional sessions. The purpose of this article is to describe our experience with a new cloud-based application known as Top Hat, which includes audience response tools in its application suite. The software was used in a multi-specialty, multi-instructor medicine and surgery course in the third year of a veterinary curriculum. In addition to standard multiple-choice and short-answer questions, Top Hat has several unique question types and methods of displaying the responses given. These include displaying free-text responses in a word cloud format and a "click-on-target" question type that allows students to indicate their response by clicking on a location within an image. Responses for this latter question type are displayed in a heat map format. A discussion tool is also available, which allows students to respond, read other students' responses in real time, and then reply again if warranted. This feature also supports drawing-based responses. The variety of question types was very useful in keeping students engaged during teaching sessions, giving this application several advantages over systems that are limited to multiple-choice questions only. In addition, the application allowed rapid identification of areas of student knowledge and misunderstandings, which facilitated the direction of further discussion and clarification of important learning issues.

Influence of wire configuration on resistance to fragment distraction of tension bands placed in a greater trochanteric osteotomy model.

OBJECTIVE: To determine the influence of wiring configurations on initial tension and resistance to tensile loads in tension band constructs without the contributions of Kirschner-wire stabilization. STUDY DESIGN: Experimental study. SAMPLE POPULATION: A solid brass femur model manufactured on the basis of computed tomography of a normal right femur of a 30-kg dog modified by transection of the greater trochanter and placement of two pins that did not cross the simulated osteotomy. METHODS: Four tension band configurations were applied to the metal trochanteric osteotomy model: figure-of-eight with one twist (OT), figure-of-eight with two twists (TT), dual interlocking single loop, and double loop (DL). Configurations were tested under both monotonic loading (n = 8 per configuration) and incremental cyclic loading (n = 8 per configuration). Initial tension after tying, residual tension remaining after each cycle, and failure load at 2 mm of displacement (considered equivalent to clinical failure) were compared between configurations. RESULTS: The initial tension and the load to 2 mm of displacement were lower for OT wires compared with TT wires. The DL was the strongest and most stable configuration, generating 2.3 to 3.5 times greater initial tension, maintaining a greater percentage of residual tension under incremental cyclic loads, and resisting 2.0 to 2.4 times greater load before failure at 2 mm. Failure load was highly correlated with initial tension. CONCLUSION: Wire configurations reaching greater initial tension, such as the DL, allowed constructs to resist higher tensile loads. CLINICAL IMPACT: Wire configurations allowing higher initial tension may be warranted when tension bands are expected to sustain high tensile loads.

Influence of Radiographic Positioning on Canine Sacroiliac and Lumbosacral Angle Measurements.

OBJECTIVES: To evaluate the influence of radiographic malpositioning on canine sacroiliac and lumbosacral inclination angles. METHODS: Using canine cadavers, lateral pelvic radiographs were acquired with the radiographic beam in a neutral position and then rotated 5, 10 and 15° to mimic rotational malpositioning. The focal point of the beam was then focused over the abdomen and again over mid-diaphysis of the femur to mimic an abdominal or femoral radiographic study. RESULTS: Five degrees of rotational malpositioning did not influence measurements of sacroiliac or lumbosacral inclination, but malpositioning by more than 5° led to a significant decrease in both sacroiliac and lumbosacral angles. Moving the focal point to the femur significantly decreased the measured lumbosacral angle. Abdominally centred radiographs had no effect on lumbosacral and sacroiliac angle measurements. CLINICAL SIGNIFICANCE: When evaluating canine lumbosacral and sacroiliac angles radiographically, pelvic rotation of more than 5° should be avoided as should the use of lateral radiographs centred over the femur.

Repeatability and accuracy testing of a weight distribution platform and comparison to a pressure sensitive walkway to assess static weight distribution.

OBJECTIVE: To evaluate the accuracy and repeatability of measurements collected using a weight distribution platform and a pressure sensitive walkway using an inanimate object with known weight distribution. METHODS: A custom-built jig with a range of weights was applied in a random order. Measurements were collected on both devices and compared to each other and to the known weight distribution. RESULTS: Weight distribution platform and pressure sensitive walkway measurements were highly correlated to each other (Pearson's correlation coefficient R = 0.98) and to actual weights (R = 0.99 for the weight distribution platform; 0.98 for the pressure sensitive walkway). Repeatability from day to day for both devices was greater than 0.99. For the weight distribution platform, the 95% confidence interval was ± 2.5% from the true percentage and ± 3.3% for the pressure sensitive walkway. The coefficient of variation (COV) was highest for both devices at the lightest weights (weight distribution platform 11.28%, pressure sensitive walkway 16.91%) and lowest with the heaviest weights (weight distribution platform 3.71%, pressure sensitive walkway 5.86%). CONCLUSION: Both the weight distribution platform and the pressure sensitive walkway provided accurate and consistent measures of weight distribution with no significant difference between devices. The rounded standard error was three percent for the weight distribution platform, and four percent for the pressure sensitive walkway. The higher variability when measuring the smallest weight suggests less accuracy at lower weights with both devices. CLINICAL SIGNIFICANCE: The weight distribution platform is a repeatable and accessible device to measure static weight distribution, and if proven the same in a clinical setting, it will be a valuable addition to current objective measures of limb use.

Assessment of an implant-skin interface scoring system for external skeletal fixation of dogs.

OBJECTIVE To assess intraobserver repeatability and interobserver and in vivo versus photographic agreement of a scoring system for the implant-skin interface (ISI) of external skeletal fixation (ESF). SAMPLE 42 photographs of ISIs from 18 dogs for interobserver agreement and intraobserver repeatability and 27 photographs of ISIs from 6 dogs for in vivo versus photograph agreement. PROCEDURES An ISI inflammation scoring system was developed. It included scales for 6 metrics (erythema, drainage amount, drainage type, swelling, hair loss or lack of hair regrowth, and granulation tissue). Photographs of the ISI of ESF were obtained by use of a standard protocol and evaluated to determine intraobserver repeatability and interobserver agreement (Cronbach α; 4 raters) of the ISI score. Agreement between in vivo and photographic ISI scores (2 raters) and correlation between median scores across metrics were evaluated. RESULTS 42 photographs met the inclusion criteria. Overall intraclass correlation coefficients ranged from 0.922 to 0.975. Interobserver overall Cronbach α ranged from 0.835 to 0.943. For in vivo versus photographic assessment, 27 ISIs in 6 dogs and their photographs were evaluated. The Cronbach α for both raters ranged from 0.614 to 0.938. Overall, the Cronbach α ranged from 0.725 to 0.932. Mean photographic scores were greater than mean in vivo scores for each metric. Pearson correlation coefficients ranged from 0.221 to 0.923. Erythema, swelling, and granulation were correlated with all other metrics. CONCLUSIONS AND CLINICAL RELEVANCE In this study, an ISI scoring system used in this study had high repeatability and agreement and may therefore be considered for use in clinical situations. Photographic scores were not equivalent to in vivo scores and should not be used interchangeably.

Tibial Plateau Leveling Osteotomy Plate Contouring and Proximal Load Screw Angulation Affect Osteotomy Compression.

OBJECTIVE: To evaluate the effect of contouring a tibial plateau leveling osteotomy (TPLO) plate, the associated angulation of the dynamic compression plate (DCP) hole relative to the long axis of the tibia, and angulation of the screw relative to the DCP hole on the osteotomy compression generated by load screws in a TPLO model. STUDY DESIGN: In vitro biomechanical study. STUDY POPULATION: Polyoxymethylene (POM) rod and synthetic cortical bone substitute model (n = 9). METHODS: The distal portion of a Slocum TPLO plate was attached to a horizontally positioned POM rod that was connected to a load cell. A segment of synthetic cortical bone substitute was attached to the end mount of the testing frame and adjusted to conform to the angle of the proximal portion of the TPLO plate. A 3.5 mm cortical bone screw was inserted in the proximal DCP hole and tightened to 1.5 Nm. The peak longitudinal load (N) was recorded. Screw insertion and data collection were repeated for proximal plate angles of 0-40° at 5° increments. RESULTS: A significant increase in the compression generated was observed as the plate angle was increased from 0° to 10°. The compression ceased to significantly increase until the plate was bent more than 20°, after which a significant decrease in compression was noted. A marked reduction in the compression generated occurred at plate angles greater than 30°. CONCLUSION: Angulation of the DCP hole and screw insertion angle can have deleterious effects on the magnitude of osteotomy compression.

Use of trazodone to facilitate postsurgical confinement in dogs.

OBJECTIVE: To investigate the safety and efficacy of oral administration of the serotonin antagonist and reuptake inhibitor trazodone hydrochloride to facilitate confinement and calming after orthopedic surgery in dogs. DESIGN: Prospective open-label clinical trial. ANIMALS: 36 client-owned dogs that underwent orthopedic surgery. PROCEDURES: Starting the day after surgery, dogs were administered trazodone (approx 3.5 mg/kg [1.6 mg/lb], PO, q 12 h) with tramadol (4 to 6 mg/kg [1.8 to 2.7 mg/lb], PO, q 8 to 12 h) for pain management. After 3 days, administration of tramadol was discontinued, and the trazodone dosage was increased (approx 7 mg/kg [3.2 mg/lb], PO, q 12 h) and maintained for at least 4 weeks. If needed, trazodone dosage was increased (7 to 10 mg/kg [3.2 to 4.5 mg/lb], PO, q 8 h). Owners completed electronic surveys rating their dogs' confinement tolerance, calmness or hyperactivity level, and responses to specific provocative situations prior to surgery and 1, 2, 3, and 4 weeks after surgery and at the postsurgery evaluation (at 8 to 12 weeks). RESULTS: Most (32/36 [89%]) of owners reported that their dogs, when given trazodone during the 8 to 12 weeks following orthopedic surgery, improved moderately or extremely with regard to confinement tolerance and calmness. Trazodone was well tolerated, even in combination with NSAIDs, antimicrobials, and other medications; no dogs were withdrawn from the study because of adverse reactions. Owner-reported median onset of action of trazodone was 31 to 45 minutes, and median duration of action was ≥ 4 hours. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that oral administration of trazodone was safe and efficacious and may be used to facilitate confinement and enhance behavioral calmness of dogs during the critical recovery period following orthopedic surgery.

Relationship between mechanical thresholds and limb use in dogs with coxofemoral joint oa-associated pain and the modulating effects of pain alleviation from total hip replacement on mechanical thresholds.

OBJECTIVES: To compare von Frey mechanical quantitative sensory thresholds (mQSTvF ) between pelvic limbs in dogs before unilateral total hip replacement (THR) surgery; to correlate ground reaction forces (GRF) with mQSTvF ; to assess changes in mQSTvF after THR surgery. STUDY DESIGN: Prospective clinical study. ANIMALS: Dogs (n = 44). METHODS: mQSTvF and GRF measured using a pressure sensitive walkway were evaluated before, and 3, 6, and 12 months after, unilateral THR. Measurements were recorded from the affected (operated) pelvic limb (APL) and the non-operated pelvic limb (NPL). Random effects analysis and forwards stepwise linear regression models were used to evaluate the influence of time since surgery and patient factors on mQSTvF thresholds. RESULTS: There were no significant correlations between mQSTvF data and age, bodyweight or the GRF variables. Preoperative mQSTvF measured at the APL and NPL did not differ (P = .909). mQSTvF thresholds increased significantly after 12 months in NPL (P = .047) and APL (P = .001). In addition to time, APL mQSTvF values were significantly affected by sex (higher in males, P = .010) and body condition score (higher in leaner dogs, P = .035) and NPL mQSTvF values by sex (P = .038). CONCLUSION: Successful unilateral THR results in decreased central sensitization after 12 months.

Biomechanical evaluation of the influence of an intramedullary pin on the stability of a feline ilial fracture model stabilized with a bone plate.

OBJECTIVE: To compare the mechanical properties of feline ilial fractures stabilized with either a plate (P), or a plate and IM pin (P + P). STUDY DESIGN: Mechanical study. SAMPLE POPULATION: Cadaveric cat pelvii (n = 10). METHODS: Feline ilial fractures (n = 20) stabilized with either P or P + P were subjected to 100 nondestructive load cycles, then loaded to failure. Deformation after cycling, yield load and displacement, stiffness and load at 2 mm of displacement were compared between groups. RESULTS: There were no significant differences between groups for any of the parameters. Variability of data was much larger for the P + P group. CONCLUSIONS: No biomechanical advantage was demonstrated. The P + P constructs were not significantly stronger than plates alone in this acutely loaded cadaveric model.