Veterinary and Comparative Orthopaedics and Traumatology最新文献

Objective:  The aim of this study was to determine the effect of double pelvic osteotomy (DPO) on dorsolateral subluxation (DLS) of the femoral head in a weight-bearing position.

Study design:  Retrospective observational study with treatment effect analysis. Twenty-four client-owned dogs that underwent DPO due to hip dysplasia.

Methods:  Computed tomography (CT) studies were performed on 24 dogs that underwent a DPO between 2015 and 2021. The patients were positioned with the femora in a weight-bearing position. The DLS score was measured pre-DPO, immediately post-DPO, and at follow-up to determine if DPO resulted in an increase in the DLS score.

Results:  A total of 21 dogs underwent single-stage bilateral DPO and 3 dogs underwent unilateral DPO resulting in 45 hip joints available for analysis. Follow-up CT was available for 29 of these at a median of 51 days (range: 35-482 days). The mean DLS score was 36.1% ± 14.6 preoperatively, 71.4% ± 12.5 post-DPO, and 70.0% ± 15.3 at follow-up. The increase between the pre- and postoperative measurement was significant (p < 0.001).

Conclusion:  DPO results in reduced subluxation of the femoral head in a weight-bearing position.

Clinical significance:  The in vivo results suggest that DPO will result in reduced femoral subluxation during weight-bearing.

Objective:  The aim of this study was to assess if the level of osteotomy (50 or 75% the length of the humerus), osteotomy angle (5, 10, or 20 degrees), direction of bone alteration (external rotational or medial opening wedge osteotomies), or orientation of osteotomy (perpendicular to the humeral long axis or perpendicular to the weight-bearing axis of the limb) affect pressure through the medial compartment of the elbow.

Study design:  Humeral osteotomies were performed at 50 and 75% the length of the humerus on 12 canine cadaver thoracic limbs and patient-specific three-dimensional (3D) printed plates applied to induce the desired alteration. Sensors were placed into the medial and lateral aspects of the elbow joint and the limb compressed to 90 N in a universal testing system.

Results:  Increasing the angle of the induced change had a significant effect on the decreased load through the medial compartment. Performing the osteotomy at 75% of humeral length from proximal was significantly more effective at reducing the medial elbow load than performing it at 50%. Opening wedge osteotomies were more effective than external rotational osteotomies, but both were effective. Changing the direction of the osteotomy (comparing transverse to oblique) did not significantly affect the load reduction through the medial compartment.

Conclusion:  Performing an osteotomy at a more distal location along the humerus and increasing the angle of the induced change increased the effectiveness of load-shifting humeral osteotomies.

Introduction:  Arthroscopy is a well-established diagnostic modality for various orthopaedic conditions in veterinary medicine. The aim of this study was to describe the relationship of canine shoulder arthroscopy portals to major muscular, ligamentous, and neurovascular structures for anatomical and safety considerations.

Materials and methods:  Arthroscopic exploration of 20 adult canine cadaver shoulders was performed. Each shoulder region was dissected layer by layer to the level of the joint. Musculotendinous, ligamentous, and cartilaginous lesions were documented. The distance was measured from each portal to neurovascular structures encountered.

Results:  Muscular lesions included the deltoideus, cleidobrachialis, omotransversarius, supraspinatus, infraspinatus, and teres minor muscles. The neurovascular structures identified were the omobrachial vein, the caudal circumflex humeral artery, axillobrachial vein, and branches of the axillary nerve. Lesions to the lateral glenohumeral ligament were noted from the caudal instrument portal and the middle arthroscope portal. Iatrogenic articular cartilage injuries were identified on the caudal humeral head and the glenoid.

Conclusion:  This study supports the safety of lateral shoulder arthroscopy in dogs. Most local neurovascular structures are unaffected with traditional scope portal positions. Musculotendinous lesions are unavoidable due to the extensive muscling surrounding the shoulder but are unlikely to cause severe complications postoperatively.

Objective:  The aim of this study was to report postoperative complications and long-term outcomes following transcondylar screw placement for humeral intracondylar fissure (HIF).

Study design:  It was a retrospective single-centre case series. Medical records (2018-2022) were reviewed for dogs with HIF treated with transcondylar screw placement. Data collected included signalment, concurrent orthopaedic disease, partial or complete HIF, surgeon, surgical approach, surgical technique and implant type, transcondylar screw angulation, postoperative complications and outcomes. Long-term outcome was assessed with owner questionnaire, orthopaedic examination and follow-up radiography. Statistical analysis was performed to identify risk factors predisposing to a complication or a poor outcome.

Results:  Forty-seven dogs (57 elbows) met the inclusion criteria; long-term follow-up was available in 41 dogs (50 elbows). Minor and major medical complications were noted in seven and three elbows respectively. The total complication rate was 17.5%. Increasing age was significantly associated with a reduced risk of postoperative complications (p = 0.0051). No other risk factors were identified. A postoperative complication was not associated with a less than full outcome (p = 0.5698).

Conclusion:  Transcondylar screw placement for HIF is associated with a low complication rate and good outcome.

Objective:  The aim of this study was to compare stiffness and strain of an in vitro fracture-gap model secured with a primary 3.5-mm locking compression plate (LCP) at three primary plate working lengths without and with an orthogonal 2.7-mm LCP.

Study design:  Primary plate screw configurations modeled short working length (SWL), medium working length (MWL), and long working length (LWL) constructs. Construct stiffness with and without an orthogonal plate during nondestructive four-point bending and torsion, and plate surface strain measured during bending, was analyzed.

Results:  Single plate construct stiffness was significantly, incrementally, lower in four-point bending and torsion as working length was extended. Addition of an orthogonal plate resulted in significantly higher bending stiffness for SWL, MWL, and LWL (p < 0.05) and torsional stiffness for MWL and LWL (p < 0.05). Single plate construct strain was significantly, incrementally, higher as working length was extended. Addition of an orthogonal plate significantly lowered strain for SWL, MWL, and LWL constructs (p < 0.01).

Conclusion:  Orthogonal plate application resulted in higher bending and torsional construct stiffness and lower strain over the primary plate in bending in this in vitro model. Working length had an inverse relationship with construct stiffness in bending and torsion and a direct relationship with strain. The inverse effect of working length on construct stiffness was completely mitigated by the application of an orthogonal plate in bending and modified in torsion.

Objective:  The aim of this study was to perform gait analysis using a pressure-sensitive walkway in dogs submitted to high (total) or low amputation (partial) of one forelimb or hindlimb.

Study design:  A total of 39 dogs met the inclusion criteria. The reasons for the amputations were motor vehicle accidents in 38 dogs and possible limb malformation in 1 dog. The amputee dogs were divided into four groups: G1 (n = 10)-high forelimb; G2 (n = 10)-low forelimb; G3 (n = 9)-high hindlimb; and G4 (n = 10)-low hindlimb. For kinetic evaluation, the dogs were walked across a pressure-sensitive walkway.

Results:  In dogs with forelimb amputation, the percentage of body weight (%BW) distribution on the contralateral forelimb was 50.7% in cases of high amputation and 55.5% in cases of low amputation, while the %BW distribution on the hindlimbs, mainly in the ipsilateral hindlimb, was 27.9% in cases of high amputation and 27.1% in cases of low amputation. In cases of high amputation of the hindlimb, the %BW distribution was 71.5% on the forelimbs and 29.7% on the contralateral hindlimb, while in cases of low amputation, the distribution was mainly for the contralateral hindlimb and ipsilateral forelimb. No statistical difference was noted between the amputation levels, except for the contralateral limb in cases of low and high amputation of the hindlimbs concerning the overload percentage and %BW distribution.

Conclusion:  The amputation level of one forelimb did not influence the %BW distribution; however, in the hindlimb, this was higher for the contralateral limb in dogs submitted to high amputation.

Objectives:  The first objective of this study was to compare the mechanical performance of a straight and contoured rod for the sliding on pivot-locking clamp (SOP-LC) system. The second objective was to compare single-cycle bending and torsion of the SOP-LC rod-bone constructs to a bone gap model between two clamp configurations.

Study design:  First experiment, 5 mm diameter rods from the 3.5 mm SOP-LC system, 4 straight and 4 bent rods were mechanically compared in four-point bending. The second experiment, 8 constructs with clamps on a single side of the rod and 8 constructs with clamps on alternating sides were compared in four-point bending and torsion. A torque limiting screwdriver at 2.5N was used for all constructs.

Results:  There were not significant differences between the noncontoured versus contoured rods. Constructs with clamps on a single side had a significantly higher yield load, yield displacement and bending strength, but the constructs with alternating clamps had a significantly higher initial torsional stiffness. There were no other significant differences. Mild clamp slippage and mild screw bending were noted in all the torsion tested constructs graphically with multiple stiffness slopes and visually on the post-tested constructs.

Conclusion:  Torque applied to initial screw placement may play a role in reducing clamp slippage. Although bending yield load, bending yield displacement, bending strength and torsional stiffness were improved by different clamp placement, clinically this will depend on fracture type. Further studies are needed for clinical significance.

Objectives:  The aim of this study was to evaluate and characterize different methods to achieve interfragmentary compression during tibial plateau levelling osteotomy (TPLO).

Study design:  TPLO was performed in 20 canine tibia models (Sawbones, Vashon, Washington, United States) using 3D-printed guides for standardization. Interfragmentary compression was assessed using pressure-sensitive films (Prescale, Fujifilm, Atherstone, United Kingdom). Seven compression methods were tested: (1) Kern bone holding forceps clamping the craniodistal aspect of the TPLO plate to the caudal aspect of the tibia (K); (2) using the distal TPLO plate dynamic compression hole (P); (3) pointed bone reduction forceps engaging the caudal aspect of the proximal bone fragment and the cranial aspect of the tibial crest (F); (4) K + P; (5) K + F; (6) F + P; and (7) K + F + P. Five measurements were obtained for each method, and each bone model was used for two measurements (single method, ± plate). The interfragmentary surface was digitalized and divided into quadrants for standardization and pixel density calculation: Q1, craniomedial; Q2, craniolateral; Q3, caudomedial; and Q4, caudolateral. One-way analysis of variance (ANOVA) and post hoc tests were used for statistical analysis.

Results:  Mean pressures per quadrant differed significantly between methods (p < 0.001). Methods K, F, and P produced more craniomedial, craniolateral, and caudal compression, respectively. Method K resulted in loss of caudal compression (p < 0.001). Method F + P provided the most even distribution of high interfragmentary compression forces. The addition of method K to this construct (K + F + P) marginally increased cranial compression (p = 0.189 for Q1; p < 0.001 for Q2), but reduced compression caudally (p < 0.001).

Conclusion:  Method F + P provided more even interfragmentary compression. If method K were used, then combined use with method F + P would be recommended.