ObjectiveTo report geometric methods to assess femoral transverse bone morphology and develop a virtual method to guide the surgical correction of femoral torsional deformities.Study designObservational study.Sample populationSixteen client‐owned dogs comprising 14 normal femurs and 14 femurs with angulation‐rotation bone deformities.MethodsFemoral torsion angle was measured with computed tomographic (CT) three‐dimensional (3D) multiplanar reconstruction. Distal femoral transverse morphology was estimated with geometric methods and compared to direct measurements to span a target 20° angle on 3D reconstructions. A virtual correction of 20° was performed, and 3D‐printed bone models were created. Femoral torsion of corrected bone models was compared to precorrection.ResultsGeometric estimates with an arc and chord of the metaphyseal area and chord of a best fit circle did not differ from direct measurement of femoral cortical length along the cranial cortex. Femoral torsion differed between normal femurs (25.8° ± 6°) and those with deformity (36.9° ± 8.4°, P < .001). Torsion that was measured on corrected 3D bone models did not differ from the expected torsion (preoperative +20°).ConclusionGeometric methods provided an accurate estimate of distal femoral transverse bone morphology. Rotation of the distal femur based on geometric methods resulted in an accurate correction of torsion.Clinical significanceFemoral bone diameter can be measured on a CT cross‐section, and rotation distance can be calculated to achieve a desired correction of torsion. This approach provides a simple and accurate method to guide the correction of femoral torsion.

Objective: To determine the influence of barbed epitendinous sutures (ES) on the biomechanical properties and gap formation of repaired canine tendons. Study design: Ex vivo, experimental study. Sample population: Eighty (n = 16/group) canine superficial digital flexor tendons (SDFT). Methods: After transection, SDFT were repaired with a locking-loop (LL) pattern alone (group 1), an LL + smooth ES with monofilament suture (group 2), an LL + V-loc-ES (group 3), an LL + Quill-ES (group 4), or an LL + Stratafix-ES (group 5). All core LL repairs were performed with 0 USP polypropylene, and all ES were placed with 2-0 USP equivalent. Constructs were preloaded and tested to failure. Yield, peak, and failure loads; occurrence of gap formation; and failure modes were compared. Results: Yield loads were greater for groups 2 and 5 (P < .0001). Peak and failure loads were greater when an ES was used (P < .005), especially for groups 2 and 5 (P < .0001). Groups with an ES required higher loads to generate 1and 3-mm gaps compared with specimens without an ES (P < .002). Force to create 1-and 3-mm gaps was greater for group 5 (P < .0001) and groups 2 and 5 (P < .0001), respectively. Failure mechanism did not differ (P = .092) between ES groups, consisting of suture breakage in 51 of 64 constructs compared with pull-through in seven of 16 group 1 constructs. Conclusion: Epitendinous suture placement improved the biomechanical properties of repaired tendons. Stratafix barbed suture performed better as an ES compared with other barbed sutures and similarly to monofilament suture. Clinical significance: Stratafix barbed suture eliminates the requirement for knot tying and seems to be equivalent to smooth monofilament suture when used as an ES in this pattern. [Corrections updated on Aug 29, 2020 after online publication]

Objectives: (1) To report internal measurements of thoracic vertebral bone morphology and (2) identify safe and clinically applicable surgical implant corridors in the T7-T9 thoracic vertebrae of French Bulldogs. Study Design: Observational, cross‐sectional, descriptive study. Sample Population: Seven client-owned French Bulldogs with normal thoracic vertebrae. Methods: Computed tomographic (CT) studies of normal French Bulldogs were reviewed. Multiplanar reconstruction of the CT images was used to determine thoracic vertebral corridors. Corridor measurements included the width, length, insertion distance off midline, and angle off midline (sagittal) for each thoracic vertebra. One‐way analysis of variance was used to detect differences between groups. Results: Measurements of vertebral corridor width (p>0.9848), length (p>0.8113), implant center (p>0.9282) and angle (p>0.3609) did not differ between each vertebra. The average vertebral corridor width was 4.5 ± 0.7 mm. The average corridor length was 17.2 ± 2.5 mm. The average corridor angle was 22.3 ± 1.9 °. The mean distance the proposed implant center was from the vertebral midline was 8.2 ± 1.1 mm. Inter-observer agreement of corridor length and implant center was good but poor for corridor angle and width. Conclusion: Based on average corridor width and length, commercially available cortical screws or pins can be utilized for implants in this region of the thoracic spine. The angle of corridor trajectory from a dorsal approach seems most applicable for T7-T9. Clinical Significance: Vertebral corridors can be measured using CT-MPR, and implant specifications and angles derived. Surgical guides can also be created to guide implant placement. This approach provides a simple and accurate method to guide the placement of thoracic vertebral implants.

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