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Abstract

Studies in human medicine indicate that between 22,000 and 400,000 people die every year as a direct result of medical errors. In veterinary medicine, 42% of human-caused incidents caused harm to the patient, including 5% resulting in death. In a university veterinary teaching hospital, there were 5.3 errors/1,000 patient visits, and 4 of these resulted in death. Veterinary medicine falls far behind other safety-critical industries in adopting a culture of patient safety. Organizations should respond in a just and effective way when errors occur. Psychological safety for team members to identify and speak up about areas of concern must be created and the results of improvements made based on these concerns shared within the professional group. If veterinary medicine is going to embrace patient safety culture, it needs to be included in the curriculum. Accrediting and licensing bodies need to require the teaching and application of principles of patient safety culture. Faculty must be trained to deliver patient safety–oriented care. Experts in human systems engineering should be brought in to educate veterinarians on how the systems we work in impact patient outcomes. If we are going to fulfill the promise of the Veterinarian’s Oath, we must embrace patient safety culture and all the difficult changes it requires of our professional culture.

Open access
in Journal of the American Veterinary Medical Association

Department of Industrial and Systems Engineering as partial fulfillment of the requirements for a Doctor of Philosophy degree. Supported by the Leonard X. Bosack & Betty M. Kruger Charitable Foundation. The authors declare that there were no conflicts of

Full access
in American Journal of Veterinary Research

Abstract

Objective—To design and manufacture custom titanium bone plates and a custom cutting and drill guide by use of free-form fabrication methods and to compare variables and mechanical properties of 2 canine tibial plateau leveling methods with each other and with historical control values.

Sample Population—10 canine tibial replicas created by rapid prototyping methods.

Procedures—Application time, accuracy of correction of the tibial plateau slope (TPS), presence and magnitude of rotational and angular deformation, and replica axial stiffness for 2 chevron wedge osteotomy (CWO) methods were assessed. One involved use of freehand CWO (FHCWO) and screw hole drilling, whereas the other used jig-guided CWO (JGCWO) and screw hole drilling.

Results—Replicas used for FHCWO and JGCWO methods had similar stiffness. Although JGCWO and FHCWO did not weaken the replicas, mean axial stiffness of replicas after JGCWO was higher than after FHCWO. The JGCWO method was faster than the FHCWO method. Mean ± SD TPS after osteotomy was lower for FHCWO (4.4 ± 1.1°) than for JGCWO (9.5 ± 0.4°), and JGCWO was more accurate (target TPS, 8.9°). Slight varus was evident after FHCWO but not after JGCWO. Mean postoperative rotation after JGCWO and FHCWO did not differ from the target value or between methods.

Conclusions and Clinical Relevance—The JGCWO method was more accurate and more rapid and resulted in more stability than the FHCWO method. Use of custom drill guides could enhance the speed, accuracy, and stability of corrective osteotomies in dogs.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To design and fabricate fiberglass-reinforced composite (FRC) replicas of a canine radius and compare their mechanical properties with those of radii from dog cadavers.

Sample—Replicas based on 3 FRC formulations with 33%, 50%, or 60% short-length discontinuous fiberglass by weight (7 replicas/group) and 5 radii from large (> 30-kg) dog cadavers.

Procedures—Bones and FRC replicas underwent nondestructive mechanical testing including 4-point bending, axial loading, and torsion and destructive testing to failure during 4-point bending. Axial, internal and external torsional, and bending stiffnesses were calculated. Axial pullout loads for bone screws placed in the replicas and cadaveric radii were also assessed.

Results—Axial, internal and external torsional, and 4-point bending stiffnesses of FRC replicas increased significantly with increasing fiberglass content. The 4-point bending stiffness of 33% and 50% FRC replicas and axial and internal torsional stiffnesses of 33% FRC replicas were equivalent to the cadaveric bone stiffnesses. Ultimate 4-point bending loads did not differ significantly between FRC replicas and bones. Ultimate screw pullout loads did not differ significantly between 33% or 50% FRC replicas and bones. Mechanical property variability (coefficient of variation) of cadaveric radii was approximately 2 to 19 times that of FRC replicas, depending on loading protocols.

Conclusions and Clinical Relevance—Within the range of properties tested, FRC replicas had mechanical properties equivalent to and mechanical property variability less than those of radii from dog cadavers. Results indicated that FRC replicas may be a useful alternative to cadaveric bones for biomechanical testing of canine bone constructs.

Full access
in American Journal of Veterinary Research

Abstract

OBJECTIVE To assess the repeatability and accuracy of polymer replicas of small, medium, and large long bones of small animals fabricated by use of 2 low-end and 2 high-end 3-D printers.

SAMPLE Polymer replicas of a cat femur, dog radius, and dog tibia were fabricated in triplicate by use of each of four 3-D printing methods.

PROCEDURES 3-D renderings of the 3 bones reconstructed from CT images were prepared, and length, width of the proximal aspect, and width of the distal aspect of each CT image were measured in triplicate. Polymer replicas were fabricated by use of a high-end system that relied on jetting of curable liquid photopolymer, a high-end system that relied on polymer extrusion, a triple-nozzle polymer extrusion low-end system, and a dual-nozzle polymer extrusion low-end system. Polymer replicas were scanned by use of a laser-based coordinate measurement machine. Length, width of the proximal aspect, and width of the distal aspect of the scans of replicas were measured and compared with measurements for the 3-D renderings.

RESULTS 129 measurements were collected for 34 replicas (fabrication of 1 large long-bone replica was unsuccessful on each of the 2 low-end printers). Replicas were highly repeatable for all 3-D printers. The 3-D printers overestimated dimensions of large replicas by approximately 1%.

CONCLUSIONS AND CLINICAL RELEVANCE Low-end and high-end 3-D printers fabricated CT-derived replicas of bones of small animals with high repeatability. Replicas were slightly larger than the original bones.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To compare an electron beam melting-processed (EBMP) low-modulus titanium alloy mesh stem with a commercial cobalt-chromium (CC) stem in a canine cadaver model.

Sample Population—9 pairs of cadaver femora.

Procedures—EBMP stems of 3 sizes were placed in randomly chosen sides of femora (left or right) and CC stems in opposite sides. Stem impaction distances were recorded. Five strain gauges were attached to the femoral surface to record transverse tensile (hoop) strains in the femur during axial loading. Constructs were axially loaded 4 times to 800 N and 4 times to 1,600 N in a materials testing machine. Axial stiffness of constructs and bone surface strains were compared between EBMP and CC constructs.

Results—Stems were impacted without creating femoral fissures or fractures. Stem impaction distances were larger for EBMP stems than for CC stems. Mean axial stiffness of EBMP constructs was lower than mean axial stiffness of CC constructs. Subsidence did not differ between groups. Bone strains varied among strain gauge positions and were largest at the distal aspect of the stems. At a load of 1,600 N, bones strains were higher in CC constructs than in EBMP constructs for 2 of 4 medial strain gauges.

Conclusions and Clinical Relevance—EBMP stems were successfully impacted and stable and led to a focal decrease in bone strain; this may represent an acceptable option for conventional or custom joint replacement. (Am J Vet Res 2010;71:1089–1095)

Although cemented hip stems have been used successfully as part of total hip replacements in humans, their success rate has been reportedly lower in younger patients than in older patients. The longterm success of hip stems is affected by aseptic implant loosening, implant wear, and stress-mediated bone resorption (stress shielding). Cementless hip stems were originally developed in part because polymethylmethacrylate bone cement was considered to be a contributing factor to aseptic loosening of cemented hip stems. A portion of a cementless stem is textured or coated with porous surfaces for bone ongrowth and ingrowth. Stem stability relies on initial press fit and long-term bone ingrowth into the porous portions of the stems. Cementless stems are large and have a high

Full access
in American Journal of Veterinary Research

Abstract

OBJECTIVE To assess 3-D geometry of the humerus of dogs and determine whether the craniocaudal canal flare index (CFI) is associated with specific geometric features.

SAMPLE CT images (n = 40) and radiographs (38) for 2 groups of skeletally mature nonchondrodystrophic dogs.

PROCEDURES General dimensions (length, CFI, cortical thickness, and humeral head offset), curvature (shaft, humeral head, and glenoid cavity), version (humeral head and greater tubercle), and torsion were evaluated on CT images. Dogs were allocated into 3 groups on the basis of the craniocaudal CFI, and results were compared among these 3 groups. The CT measurements were compared with radiographic measurements obtained for another group of dogs.

RESULTS Mean ± SD humeral head version was −75.9 ± 9.6° (range, −100.7° to −59.4°). Mean mechanical lateral distal humeral angle, mechanical caudal proximal humeral angle, and mechanical cranial distal humeral angle were 89.5 ± 3.5°, 50.2 ± 4.5°, and 72.9 ± 7.8°, respectively, and did not differ from corresponding radiographic measurements. Mean humeral curvature was 20.4 ± 4.4° (range, 9.6° to 30.5°). Mean craniocaudal CFI was 1.74 ± 0.18 (range, 1.37 to 2.10). Dogs with a high craniocaudal CFI had thicker cranial and medial cortices than dogs with a low craniocaudal CFI. Increased body weight was associated with a lower craniocaudal CFI. Radiographic and CT measurements of craniocaudal CFI and curvature differed significantly.

CONCLUSIONS AND CLINICAL RELEVANCE CT-based 3-D reconstructions allowed the assessment of shaft angulation, torsion, and CFI. Radiographic and CT measurements of shaft curvature and CFI may differ.

Full access
in American Journal of Veterinary Research

Abstract

OBJECTIVES

To evaluate suturing skills of veterinary students using 3 common performance assessments (PAs) and to compare findings to data obtained by an electromyographic armband.

SAMPLE

16 second-year veterinary students.

PROCEDURES

Students performed 4 suturing tasks on synthetic tissue models 1, 3, and 5 weeks after a surgical skills course. Digital videos were scored by 4 expert surgeons using 3 PAs (an Objective Structured Clinical Examination [OSCE]- style surgical binary checklist, an Objective Structured Assessment of Technical Skill [OSATS] checklist, and a surgical Global Rating Scale [GRS]). Surface electromyography (sEMG) data collected from the dominant forearm were input to machine learning algorithms. Performance assessment scores were compared between experts and correlated to task completion times and sEMG data. Inter-rater reliability was calculated using the intraclass correlation coefficient (ICC). Inter-rater agreement was calculated using percent agreement with varying levels of tolerance.

RESULTS

Reliability was moderate for the OSCE and OSATS checklists and poor for the GRS. Agreement was achieved for the checklists when moderate tolerance was applied but remained poor for the GRS. sEMG signals did not correlate well with checklist scores or task times, but features extracted from signals permitted task differentiation by routine statistical comparison and correct task classification using machine learning algorithms.

CLINICAL RELEVANCE

Reliability and agreement of an OSCE-style checklist, OSATS checklist, and surgical GRS assessment were insufficient to characterize suturing skills of veterinary students. To avoid subjectivity associated with PA by raters, further study of kinematics and EMG data is warranted in the surgical skills evaluation of veterinary students.

Open access
in American Journal of Veterinary Research

Abstract

Objective—To compare a sensor-based accelerometer-gyroscopic (A-G) system with a video-based motion analysis system (VMAS) technique for detection and quantification of lameness in horses.

Animals—8 adult horses.

Procedure—2 horses were evaluated once, 2 had navicular disease and were evaluated before and after nerve blocks, and 4 had 2 levels of shoe-induced lameness, alternatively, in each of 4 limbs. Horses were instrumented with an accelerometer transducer on the head and pelvis, a gyroscopic transducer on the right forelimb and hind feet, and a receiver-transmitter. Signals from the A-G system were collected simultaneously with those from the VMAS for collection of head, pelvis, and right feet positions with horses trotting on a treadmill. Lameness was detected with an algorithm that quantified lameness as asymmetry of head and pelvic movements. Comparisons between the A-G and VMAS systems were made by use of correlation and agreement (κ value) analyses.

Results—Correlation between the A-G and VMAS systems for quantification of lameness was linear and high ( r 2 = 0.9544 and 0.8235 for forelimb and hind limb, respectively). Quantification of hind limb lameness with the A-G system was higher than measured via VMAS. Agreement between the 2 methods for detection of lameness was excellent (κ = 0.76) for the forelimb and good (κ = 0.56) for the hind limb.

Conclusions and Clinical Relevance—The A-G system detected and quantified forelimb and hind limb lameness in horses trotting on the treadmill. Because the data are collected wirelessly, this system might be used to objectively evaluate lameness in the field. ( Am J Vet Res 2004;65:665–670)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To design and manufacture free-form biodegradable polycaprolactone (PCL) bone plates and to compare mechanical properties of femoral constructs with a distal physeal fracture repaired by use of 5 stabilization methods.

Sample Population—40 canine femoral replicas created by use of additive manufacturing and rapid tooling.

Procedures—Surgery duration, mediolateral and craniocaudal bending stiffness, and torsional stiffness of femoral physeal fracture repair constructs made by use of 5 stabilization methods were assessed. The implants included 2 Kirschner wires inserted medially and 2 inserted laterally (4KW), a commercial stainless steel plate (CSP), a custom free-form titanium plate (CTP), thin (2-mm-thick) biodegradable PCL plates (TNP) placed medially and laterally, and thick (4-mm-thick) PCL plates (TKP) placed medially and laterally.

Results—Surgical placement of 4KW was more rapid than placement of other implants The mean caudal cantilever bending stiffness of CTP and CSP constructs was greater than that for TNP TKP and 4KW constructs, and the mean caudal cantilever bending stiffness of TNP and TKP constructs was greater than that for 4KW constructs. The mean lateral cantilever bending stiffness of TKP constructs was greater than that for 4KW constructs. Differences among construct types were not significant in yield strength, ultimate strength, yield torque, and ultimate torque.

Conclusions and Clinical Relevance—The mechanical properties of fracture repair constructs made from free-form PCL biodegradable plates compared favorably with those of constructs made from Kirschner wires. The impact of PCL plates on musculoskeletal soft tissues, bone healing, and bone growth should be evaluated before clinical use.

Full access
in American Journal of Veterinary Research