Comparison of three-dimensional printed patient-specific guides versus freehand approach for radial osteotomies in normal dogs: Ex vivo model.

OBJECTIVE To compare the accuracy of three-dimensional (3D) printed patient-specific guide (PSG) with a freehand (FH) approach for radial osteotomies in ex vivo normal dogs. STUDY DESIGN Experimental study. ANIMALS Twenty four ex vivo thoracic limb pairs from normal beagle dogs. METHODS Computed tomography (CT) images were collected preoperatively and postoperatively. Three osteotomies tested (n = 8/group) were: (1) uniplanar 30° frontal plane wedge ostectomy, (2) oblique plane (30° frontal, 15° sagittal) wedge ostectomy, and (3) single oblique plane osteotomy (SOO, 30° frontal, 15° sagittal, and 30° external). Limb pairs were randomized to a 3D PSG or FH approach. The resultant osteotomies were compared with virtual target osteotomies by surface shape-matching postoperative to the preoperative radii. RESULTS The mean ± standard deviation osteotomy angle deviation for all 3D PSG osteotomies (2.8 ± 2.8°, range 0.11-14.1°) was less than for the FH osteotomies (6.4 ± 6.0°, range 0.03-29.7°). No differences were found for osteotomy location in any group. In total, 84% of 3D PSG osteotomies were within 5° deviance from the target compared to 50% of freehand osteotomies. CONCLUSION Three-dimensional PSG improved FH accuracy of osteotomy angle in select planes and the most complex osteotomy orientation in a normal ex vivo radial model. CLINICAL SIGNIFICANCE Three-dimensional PSGs provided more consistent accuracy, which was most notable in complex radial osteotomies. Future work is needed to investigate guided osteotomies in dogs with antebrachial bone deformities

Accuracy of pin placement in the canine thoracolumbar spine using a free-hand probing technique versus 3D-printed patient-specific drill guides: An ex-vivo study.

OBJECTIVE To compare pin placement accuracy, intraoperative technique deviations, and duration of pin placement for pins placed by free-hand probing (FHP) or 3D-printed drill guide (3DPG) technique. SAMPLE POPULATION Four greyhound cadavers. METHODS Computed tomography (CT) examinations from T6-sacrum were obtained for determination of optimal pin placement and 3DPG creation. Two 3.2/2.4-mm positive profile pins were inserted per vertebra, one left and one right from T7-L7 (FHP [n = 56]; 3DPG [n = 56]) by one surgeon and removed for repeat CT. Duration of pin placement and intraoperative deviations (unanticipated deviations from planned technique) were recorded. Pin tracts were graded by two blinded observers using modified Zdichavsky classification. Descriptive statistics were used. RESULTS A total of 54/56 pins placed with 3DPGs were assigned grade I (optimal placement) compared with 49/56 pins using the FHP technique. A total of 2/56 pins placed with 3DPGs and 3/56 pins using the FHP technique were assigned grade IIa (partial medial violation). A total of 4/56 pins placed using the FHP technique were assigned grade IIIa (partial lateral violation). No pins were assigned grade IIb (full medial violation). Intraoperative technique deviations occurred with 6/56 pins placed using the FHP technique and no pins with 3DPGs. Overall, pins were placed faster (mean ± SD 2.6 [1.3] vs. 4.5 [1.8] min) with 3DPGs. CONCLUSIONS Both techniques were accurate for placement of spinal fixation pins. The 3DPG technique may decrease intraoperative deviations and duration of pin placement. CLINICAL RELEVANCE Both techniques allow accurate pin placement in the canine thoracolumbar spine. The FHP technique requires specific training and has learning curve, whereas 3DPG technique requires specific software and 3D printers

Feasibility and accuracy of intraosseous endoscopy for inspection of thoracolumbar and lumbar pedicle drill tracts in a canine large-breed cadaveric model.

OBJECTIVE To evaluate the feasibility of endoscopic inspection of thoracolumbar and lumbar pedicle tracts in a canine large-breed model and its accuracy for the detection of breached versus nonbreached tracts. ANIMALS 2 greyhound cadavers. METHODS CT scans of 2 greyhound cadavers from the sixth thoracic vertebra to the sacrum were obtained. Fifty-six pedicles were randomized to have drill tracts with different modified Zdichavsky grades (nonbreached, partial/full medial breach, or partial/full lateral breach) using 3-D-printed guides. Endoscopy was performed on a single occasion from October 9 to 10, 2023, using a 1.9-mm 0-degree needle arthroscope in a randomized blinded fashion. The grading of drill tracts was performed on postoperative CT. Specificity, sensitivity, positive and negative predictive values, and time to assign endoscopic grade were investigated. RESULTS Postoperative CT confirmed 43 nonbreached tracts, 7 medial breaches (partial/full), and 5 lateral breaches (partial/full). One tract was excluded because of guide misplacement. Intraosseous endoscopy was successfully performed in the remaining 55 drill tracts. Sensitivity to detect medial and lateral breaches was 71.4% and 60.0%. Negative predictive value was 93.1%. Specificity was 94.2%. Positive predictive value for detection of medial and lateral breaches was 83.3% and 54.5%. Median (range) time to assign an endoscopic grade was 118 (30 to 486) seconds. CLINICAL RELEVANCE Intraosseous endoscopy of pedicle drill tracts may be a useful adjunct technique during pedicle screw/pin placement in dogs

Contralateral Cruciate Survival in Dogs with Unilateral Non-Contact Cranial Cruciate Ligament Rupture

BACKGROUND: Non-contact cranial cruciate ligament rupture (CrCLR) is an important cause of lameness in client-owned dogs and typically occurs without obvious injury. There is a high incidence of bilateral rupture at presentation or subsequent contralateral rupture in affected dogs. Although stifle synovitis increases risk of contralateral CrCLR, relatively little is known about risk factors for subsequent contralateral rupture, or whether therapeutic intervention may modify this risk. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a longitudinal study examining survival of the contralateral CrCL in client-owned dogs with unilateral CrCLR in a large baseline control population (n = 380), and a group of dogs that received disease-modifying therapy with arthroscopic lavage, intra-articular hyaluronic acid and oral doxycycline (n = 16), and were followed for one year. Follow-up in treated dogs included analysis of mobility, radiographic evaluation of stifle effusion and arthritis, and quantification of biomarkers of synovial inflammation. We found that median survival of the contralateral CrCL was 947 days. Increasing tibial plateau angle decreased contralateral ligament survival, whereas increasing age at diagnosis increased survival. Contralateral ligament survival was reduced in neutered dogs. Our disease-modifying therapy did not significantly influence contralateral ligament survival. Correlative analysis of clinical and biomarker variables with development of subsequent contralateral rupture revealed few significant results. However, increased expression of T lymphocyte-associated genes in the index unstable stifle at diagnosis was significantly related to development of subsequent non-contact contralateral CrCLR. CONCLUSION: Subsequent contralateral CrCLR is common in client-owned dogs, with a median ligament survival time of 947 days. In this naturally occurring model of non-contact cruciate ligament rupture, cranial tibial translation is preceded by development of synovial inflammation. However, treatment with arthroscopic lavage, intra-articular hyaluronic acid and oral doxycycline does not significantly influence contralateral CrCL survival

Effect of analgesic therapy on clinical outcome measures in a randomized controlled trial using client-owned dogs with hip osteoarthritis

BACKGROUND: Pain and impaired mobility because of osteoarthritis (OA) is common in dogs and humans. Efficacy studies of analgesic drug treatment of dogs with naturally occurring OA may be challenging, as a caregiver placebo effect is typically evident. However, little is known about effect sizes of common outcome-measures in canine clinical trials evaluating treatment of OA pain. Forty-nine client-owned dogs with hip OA were enrolled in a randomized, double-blinded placebo-controlled prospective trial. After a 1 week baseline period, dogs were randomly assigned to a treatment (ABT-116 – transient receptor potential vanilloid 1 (TRPV1) antagonist, Carprofen – non-steroidal anti-inflammatory drug (NSAID), Tramadol - synthetic opiate, or Placebo) for 2 weeks. Outcome-measures included physical examination parameters, owner questionnaire, activity monitoring, gait analysis, and use of rescue medication. RESULTS: Acute hyperthermia developed after ABT-116 treatment (P < 0.001). Treatment with carprofen (P ≤ 0.01) and tramadol (P ≤ 0.001) led to improved mobility assessed by owner questionnaire. Nighttime activity was increased after ABT-116 treatment (P = 0.01). Kinetic gait analysis did not reveal significant treatment effects. Use of rescue treatment decreased with treatment in the ABT-116 and Carprofen groups (P < 0.001). Questionnaire score and activity count at the end of treatment were correlated with age, clinical severity at trial entry, and outcome measure baseline status (S(R) ≥ ±0.40, P ≤ 0.005). Placebo treatment effects were evident with all variables studied. CONCLUSION: Treatment of hip OA in client-owned dogs is associated with a placebo effect for all variables that are commonly used for efficacy studies of analgesic drugs. This likely reflects caregiver bias or the phenomenon of regression to the mean. In the present study, outcome measures with significant effects also varied between groups, highlighting the value of using multiple outcome measures, as well as an a priori analysis of effect size associated with each measure. Effect size data from the present study could be used to inform design of future trials studying analgesic treatment of canine OA. Our results suggest that analgesic treatment with ABT-116 is not as effective as carprofen or tramadol for treatment of hip arthritis pain in client-owned dogs

Teaching and proficiency assessment for arthroscopy in veterinary surgery: A 2017 survey of diplomates and residents of the American and European College of Veterinary Surgeons

OBJECTIVE: To determine current methods of arthroscopic skills training and proficiency assessment, identify skills considered fundamental to arthroscopy, and evaluate desire for a formal training and assessment program. STUDY DESIGN: Anonymized electronic survey. SAMPLE POPULATION: Diplomates and residents of the American College of Veterinary Surgeons (ACVS) and European College of Veterinary Surgeons (ECVS). METHODS: An electronic survey was distributed in commercial software (Qualtrics, Provo, Utah). Questions were divided into 4 categories: (1) demographics, (2) arthroscopy experience, (3) teaching, and (4) proficiency assessment. Descriptive statistical analysis was performed. Comparisons between groups were performed by using χ , t tests, and 1-way ANOVA (P ≤ .05). RESULTS: In total, 429 diplomates and 149 residents responded (response rate 28%). Overall, 80% of respondents trained using clinical cases. Barriers to simulator training included cadaver/simulator availability and time. Skills deemed most fundamental included anatomic knowledge, precise portal placement, triangulation, and image orientation. Overall, 90% of respondents supported a formal training program with requirement to demonstrate proficiency; 80% believed this should be part of standard ACVS/ECVS residency training. CONCLUSION: Arthroscopic skills are taught by using clinical cases, with subjective proficiency assessment. Fundamental skills are those that may be taught using simulators. There is enthusiasm for formal arthroscopic skills training and assessment. CLINICAL SIGNIFICANCE: Improved acquisition and assessment of fundamental arthroscopic skills is indicated. A validated methodology for formal training using simulators, minimizing morbidity, and facilitating objective evaluation is warranted. This is the first phase of a project to develop and validate a simulator program

Accuracy and safety of three‐dimensionally printed animal‐specific drill guides for thoracolumbar vertebral column instrumentation in dogs: Bilateral and unilateral designs

Objective: To evaluate the safety and accuracy of a unilateral three-dimensionally printed animal-specific drill guide (3DASDG) design for unilateral stabilization in the thoracolumbar vertebral column of dogs compared to a bilateral design. Study design: Cadaveric study. Sample population: Fifty-two corridors in one canine cadaver. Methods: Two 3DASDG designs with 2 drilling tubes each were created from T8 to L7 vertebrae. Fifty-two corridors were drilled on the right and the left sides by using unilateral and bilateral designs, respectively. Planned and postoperative trajectories (entry point, exit point, angle) were compared to establish the accuracy. Statistical analysis was used for accuracy comparison between designs. Safety was evaluated by using Zdichavsky classification. Results: Unilateral and bilateral drill guide designs were not different for entry point and angle deviations; however, they were different for the exit point deviations. Two corridors breached outside the vertebra. For all guides, mean entry and exit point deviations were less than 1 and 2 mm, respectively. The maximum entry or exit point deviation in both groups was 4.7 mm. The mean angle deviation was <3.5°, and the maximum angle deviation was 9.3°. Conclusion: No difference was detected in accuracy of entry points and angle deviations between drill guide designs tested in normal vertebrae. The technique was classified as highly safe. Clinical significance: A unilateral drill guide design may be a safe alternative to bilateral guides for unilateral stabilization of the thoracolumbar vertebral column in dogs

Statistical shape modeling of the geometric morphology of the canine femur, tibia, and patella

Bone morphometry varies among dogs of different sizes and breeds. Studying these differences may help understand the predisposition of certain breeds for specific orthopedic pathologies. This study aimed to develop a statistical shape model (SSM) of the femur, patella, and tibia of dogs without any clinical orthopeadic abnormalities to analyze and compare morphological variations based on body weight and breed. A total of 97 CT scans were collected from different facilities and divided based on breed and body weight. The 3D models of the bones were obtained and aligned to a coordinate system. The SSM was created using principal component analysis (PCA) to analyze shape variations. The study found that the first few modes of variation accounted for a significant percentage of the total variation, with size/scale being the most prominent factor. The results provide valuable insights into normal anatomical variations and can be used for future research in understanding pathological bone morphologies and developing 3D imaging algorithms in veterinary medicine

Summary of two-way ANOVA results for load-induced periosteal bone formation in CGRPα and CGRPβ wildtype and knockout mice.

<p><b>Note</b>: NS - not significant. <i>P</i> values<0.15 are also reported. Treatments were Sham, Load, or Block + Load.</p><p>Summary of two-way ANOVA results for load-induced periosteal bone formation in CGRPα and CGRPβ wildtype and knockout mice.</p

Role of Calcitonin Gene-Related Peptide in Functional Adaptation of the Skeleton

<div><p>Peptidergic sensory nerve fibers innervating bone and periosteum are rich in calcitonin gene-related peptide (CGRP), an osteoanabolic neurotransmitter. There are two CGRP isoforms, CGRPα and CGRPβ. Sensory fibers are a potential means by which the nervous system may detect and respond to loading events within the skeleton. However, the functional role of the nervous system in the response of bone to mechanical loading is unclear. We used the ulna end-loading model to induce an adaptive modeling response in CGRPα and CGRPβ knockout mouse lines and their respective wildtype controls. For each knockout mouse line, groups of mice were treated with cyclic loading or sham-loading of the right ulna. A third group of mice received brachial plexus anesthesia (BPA) of the loaded limb before mechanical loading. Fluorochrome labels were administered at the time of loading and 7 days later. Ten days after loading, bone responses were quantified morphometrically. We hypothesized that CGRP signaling is required for normal mechanosensing and associated load-induced bone formation. We found that mechanically-induced activation of periosteal mineralizing surface in mice and associated blocking with BPA were eliminated by knockout of CGRPα signaling. This effect was not evident in CGRPβ knockout mice. We also found that mineral apposition responses to mechanical loading and associated BPA blocking were retained with CGRPα deletion. We conclude that activation of periosteal mineralizing surfaces in response to mechanical loading of bone is CGRPα-dependent <i>in</i><i>vivo</i>. This suggests that release of CGRP from sensory peptidergic fibers in periosteum and bone has a functional role in load-induced bone formation.</p></div