Quiz Question
In Israel 2022 et al., on cerclage wire in THR, what is a biomechanical benefit of cerclage application around the proximal femur?
🔍 Key Findings
- No proximal femoral fractures occurred in any of the 184 hips with cerclage wire placement
- Cerclage wire was well tolerated, with no failures or complications related to the wire
- Application of a single cerclage wire took <10 minutes, was cost-effective, and required minimal instrumentation
- 3 postoperative complications (1 fissure, 2 fractures) occurred distal to the cerclage site, near the stem tip, requiring plate/screw fixation
- All dogs returned to normal activity, and all owners were satisfied with the outcome
- Cerclage placement location is critical—must be proximal to the lesser trochanter and close to the calcar to resist hoop strain
- Biomechanical evidence supports that cerclage wires improve resistance to hoop strain and subsidence of cementless stems
- Press-fit cementless stems may settle, but when supported by cerclage, this does not result in fractures even in undersized implants
Veterinary Surgery
2
2022
Outcome of canine cementless collared stem total hip replacement with proximal femoral periprosthetic cerclage application: 184 consecutive cases
2022-2-VS-israel-5
In Perez Neto 2025 et al., on hip resurfacing arthroplasty, which biomechanical variables were NOT significantly different between prosthetic and intact femurs?
🔍 Key Findings
- In an ex vivo study of 20 canine femur pairs, implantation of a novel hip resurfacing arthroplasty (HRA) prosthesis reduced maximum load (ML) by 22% and load at collapse (LC) by 27% vs. intact controls (p ≤ 0.05).
- Displacement at maximum load (DML), displacement at collapse (DC), and stiffness (k) were not significantly different between prosthesis and control groups.
- Both groups showed similar failure patterns, with 92% failing at the femoral neck.
- All prosthetic femurs still withstood ~6.2× body weight — exceeding estimated in vivo peak loads (~1.64× BW).
- Prosthesis positioning (neutral vs valgus) had no significant effect on biomechanical outcomes.
- Implant design preserved more metaphyseal bone stock than total hip replacement, possibly explaining the smaller load reduction compared to other short-stem prostheses.
- The press-fit cobalt–chromium design with conical stem allowed full contact and stress distribution over the femoral head/neck.
- Authors conclude the device has adequate immediate biomechanical strength for clinical use, though long-term in vivo studies are needed.
Veterinary and Comparative Orthopaedics and Traumatology
4
2025
Biomechanical Evaluation of a Femoral Implant for Hip Resurfacing Arthroplasty in Dogs: An Ex Vivo Study
2025-4-VCOT-perezneto-2
In Lu 2025 et al., on SOP constructs, what mechanical outcome was observed across **all test constructs**, regardless of tee presence?
🔍 Key Findings
- Bending tees significantly increased mediolateral bending stiffness, but not craniocaudal stiffness, in plate-bone constructs.
- Mean mediolateral stiffness was 43.2 N/mm with tees vs. 41.1 N/mm without (p = 0.0042), though the absolute difference was small.
- No significant differences were found in craniocaudal bending stiffness between constructs with or without tees (p = 0.89).
- Plastic deformation occurred in all constructs; no screw pull-out or implant breakage was observed.
- SOP nodes may resist compressive but not tensile deformation, suggesting variable mechanical contributions depending on loading direction.
- Craniocaudal bending had greater stiffness than mediolateral due to higher area moment of inertia along the node diameter.
- Clinical relevance of added stiffness from tees remains unclear, warranting further in vivo and cyclic testing.
- This was the first study to directly test SOP constructs with/without tees over a fracture gap in multiple planes.
Veterinary and Comparative Orthopaedics and Traumatology
2
2025
Comparison of Bending Stiffness between String of Pearls Plate-Bone Substitute Constructs with and without Bending Tees in a Fracture Gap Model
2025-2-VCOT-lu-3
In Trefny 2025 et al., on plate length and stiffness, which biomechanical testing method was used to measure stiffness and strain?
🔍 Key Findings
- 12-hole LCPs (80% plate–bone ratio) showed significantly higher construct stiffness than 6-, 8-, or 10-hole plates in both compression and tension bending.
- Strain on the plate was significantly lower in 12-hole vs 6-hole plates at all regions of interest (ROIs), especially around the fracture gap.
- No incremental increases in stiffness or decreases in strain were observed between 6-, 8-, and 10-hole plates—only when comparing to 12-hole plates.
- Bone model strain adjacent to the plate end was significantly lower for 10- and 12-hole plates vs 6-hole plates under both loading conditions.
- The threshold effect suggests biomechanical benefits only emerge beyond a plate–bone ratio of ~80%.
- Working length increased from 9.4 mm (6-hole) to 13 mm (others), potentially influencing strain/stiffness differences.
- Four-point bending was used, as it replicates the most biomechanically relevant force on plated long bones.
- Clinical implication: Longer plates may reduce plate strain and peri-implant bone strain, potentially lowering risk of fatigue failure or stress risers.
Veterinary and Comparative Orthopaedics and Traumatology
2
2025
Effect of Plate Length on Construct Stiffness and Strain in a Synthetic Short-Fragment Fracture Gap Model Stabilized with a 3.5-mm Locking Compression Plate
2025-2-VCOT-trefny-4
In De Moya 2025 et al., on antebrachial deformity correction, what percentage of the recorded distraction translated to actual radial lengthening?
🔍 Key Findings
- CESF with distraction osteogenesis restored elbow congruity and normalized aLDRA in skeletally immature dogs with PCDRP.
- Radial head subluxation was eliminated in all dogs, and elbow incongruity reduced significantly (from 6.1 mm to 0.3 mm, p <.01).
- Mean radial lengthening of 22.6 mm (∼11% of normal length) was achieved, but only 80% of recorded distraction translated to length gain.
- Major complications occurred in 2/12 dogs: one with permanent carpal contracture, one with radial fracture at wire tract.
- Minor complications (e.g., carpal pain, restricted extension, synostosis, pin tract issues) were noted in 10/12 dogs but generally resolved.
- Owner surveys (8/12 dogs) reported good to excellent long-term function, even up to 6 years post-op.
- Radial valgus deformities were moderate (mean 15°) and less severe than deformities from ulnar physeal closure.
- Surgical strategy included staged distraction, with radial or combined radius/ulna distraction guided by fluoroscopy and adjusted per case.
Veterinary Surgery
6
2025
Treatment of antebrachial deformities secondary to premature closure of the distal radial physis using circular external skeletal fixation and distraction osteogenesis in skeletally immature dogs
2025-6-VS-demoya-2
In Sisk 2024 et al., on intramedullary nails, what biomechanical property is most affected by increasing nail diameter?
🔍 Key Findings Summary
- IMN provides relative stability, resists bending/torsion due to central axis alignment
- Larger diameter nails = exponentially greater stiffness (∝ D⁴)
- Trade-off: Larger interlocking holes weaken fatigue strength of the nail
- Reaming increases contact/stability but has pros/cons:
- Improves outcomes in closed fractures
- May reduce endosteal blood flow in thin-walled bones (e.g., cats)
- Design advances:
- Angle-stable IMN reduce rotational slack
- Expandable nails simplify insertion but may compromise removal or compressive load resistance
- Precontoured nails match bone curvature but lack consistent clinical superiority
- Material debates continue (e.g., titanium vs. stainless steel vs. magnesium)
Veterinary and Comparative Orthopedics and Traumatology
6
2024
Biomechanical Principles of Intramedullary Nails in Veterinary and Human Medicine
2024-6-VCOT-sisk-1
In Hawker 2025 et al., on locking head inserts, what was the impact of LHI on plate strain in a fracture-gap model?
🔍 Key Findings
- Adding Locking Head Inserts (LHI) to a 3.5-mm LCP had no effect on plate strain, stiffness, or deformation in an open fracture gap model.
- Peak strain consistently occurred at the Combi-hole over the fracture gap, with values up to ~1837 µε.
- No significant difference in strain was found across configurations with 0, 3, or 9 LHI (p = 0.847).
- Construct stiffness and compressive displacement also remained unchanged regardless of LHI count (p = 0.311 and 0.069 respectively).
- Study contradicted the hypothesis that LHI would reduce strain and increase stiffness under biologic loading.
- Combi-hole design may limit the efficacy of LHI, as LHI only fill the locking portion, not the compression side where strain peaks.
- Implant fatigue risk remains highest over unfilled screw holes, especially over fracture sites—confirming previous failure patterns.
- Surgeons should consider alternative methods to reduce strain when facing high implant load scenarios.
Veterinary and Comparative Orthopaedics and Traumatology
4
2025
The Effect of Locking Head Inserts on the Biomechanical Properties of a 3.5-mm Broad Locking Compression Plate When Used in an Open Fracture-Gap Model
2025-4-VCOT-hawker-1
In Townsend 2024 et al., on 3D osteotomy accuracy, which osteotomy type showed the most significant time reduction using PSG versus freehand?
🔍 Key Findings:
- Design: Ex vivo study with 24 paired limbs from normal beagle dogs.
- Osteotomy types (3 groups):
- 30° uniplanar frontal wedge
- Oblique (30° frontal, 15° sagittal)
- Single oblique (30° frontal, 15° sagittal, 30° external rotation)
- Comparison: 3D PSG vs Freehand (FH)
- Main Outcomes:
- PSG accuracy: Mean angular deviation = 2.8° vs 6.4° in FH (p < .001).
- 84% of PSG osteotomies were within 5° of target vs 50% of FH.
- Significant improvements with PSG in:
- Group 1 (uniplanar frontal) proximal and distal frontal planes (p < .001, .006)
- Group 3 (SOO) frontal and sagittal planes (p = .002, .043)
- Time: PSG faster in complex SOO group (84s vs 162s, p < .001); no difference in others.
- No difference in osteotomy location (mm) between methods.
- Clinical relevance: PSG more consistent and accurate, especially for complex cuts.
Veterinary Surgery
2
2024
Comparison of three-dimensional printed patient-specific guides versus freehand approach for radial osteotomies in normal dogs: Ex vivo model
2024-2-VS-townsend-3
In Buote 2023 et al., on 3D-printed cannulas in feline laparoscopy, what was the estimated cost of a single 3D printed autoclavable cannula?
🔍 Key Findings
- 3D-printed cannulas (3DPCs) reduced mean surgical time significantly in cadaveric procedures (125.6 vs 95.2 min, p = 0.03).
- Cannula pullout events decreased from a mean of 10 to 2.2 per procedure when using only 3DPCs (p = 0.03).
- Instrument collisions were significantly fewer with 3DPCs (6.8 vs 2.6 collisions, p = 0.03).
- Live patients experienced no postoperative complications, including no incision site infections or discomfort.
- Initial versions of 3DPCs had minor issues, including valve leakage and looser trocar fit, requiring surgical workarounds.
- Customization of cannula shaft length (3 cm vs standard 5–8.3 cm) improved working space and reduced instrument interference.
- Production cost was under $5 per cannula, suggesting 3DPCs may be a cost-effective and reusable alternative for small patients.
- Study supports broader use of 3DPCs in laparoscopic procedures requiring long-jawed instruments or intricate tissue handling.
Veterinary Surgery
6
2023
3D printed cannulas for use in laparoscopic surgery in feline patients: A cadaveric study and case series
2023-6-VS-buote-5
In Lu 2025 et al., on SOP constructs, what was the **mean mediolateral bending stiffness** of SOP constructs **with** bending tees?
🔍 Key Findings
- Bending tees significantly increased mediolateral bending stiffness, but not craniocaudal stiffness, in plate-bone constructs.
- Mean mediolateral stiffness was 43.2 N/mm with tees vs. 41.1 N/mm without (p = 0.0042), though the absolute difference was small.
- No significant differences were found in craniocaudal bending stiffness between constructs with or without tees (p = 0.89).
- Plastic deformation occurred in all constructs; no screw pull-out or implant breakage was observed.
- SOP nodes may resist compressive but not tensile deformation, suggesting variable mechanical contributions depending on loading direction.
- Craniocaudal bending had greater stiffness than mediolateral due to higher area moment of inertia along the node diameter.
- Clinical relevance of added stiffness from tees remains unclear, warranting further in vivo and cyclic testing.
- This was the first study to directly test SOP constructs with/without tees over a fracture gap in multiple planes.
Veterinary and Comparative Orthopaedics and Traumatology
2
2025
Comparison of Bending Stiffness between String of Pearls Plate-Bone Substitute Constructs with and without Bending Tees in a Fracture Gap Model
2025-2-VCOT-lu-2
Quiz Results
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Key Findings