Long-term survivors of craniospinal irradiation have an increased risk for stroke which increases with radiation dose and follow-up time. Radiotherapy induces structural changes of the cerebral vasculature, affecting both, large, and small vessels. It is unknown how these structural changes affect functional mechanisms of cerebral blood flow regulation such as cerebral autoregulation and neurovascular coupling.

Using the transcranial Doppler, we compared dynamic cerebral autoregulation and neurovascular coupling of 12 patients after long-term survival of craniospinal irradiation due to a malignant pediatric brain tumor of the posterior fossa and 12 age- and sex-matched healthy patients. Mean arterial blood pressure and cerebral blood flow velocities in the middle and posterior cerebral artery were recorded at rest during normal breathing to assess cerebral autoregulation (transfer function parameters phase and gain, as well as the correlation coefficient indices Mx, Sx, and Dx), and during 10 cycles of a visual task to assess neurovascular coupling (parameters time delay, natural frequency, gain, attenuation, and rate time).

Parameters of cerebral autoregulation showed a consistent trend toward reduced cerebral autoregulation in patients that did not reach statistical significance. Neurovascular coupling was not altered after craniospinal irradiation.

In this pilot study, we demonstrated a trend toward reduced cerebral autoregulation, and no alteration of neurovascular coupling after irradiation in long-term survivors of malignant pediatric brain tumors of the posterior fossa.

In this pilot study, we demonstrated a trend toward reduced cerebral autoregulation, and no alteration of neurovascular coupling after irradiation in long-term survivors of malignant pediatric brain tumors of the posterior fossa.

 The aim of this study was to report the prevalence and risk factors of bilateral meniscal tears during a tibial plateau levelling osteotomy (TPLO).

 Data from 362 dogs that underwent staged or simultaneous TPLO between January 2006 and April 2019 were retrospectively collected. Variables such as breed, sex, weight change and intervals between surgeries were analysed with logistic regression. Preoperative tibial plateau angle, age, cranial cruciate ligament status and body weight were analysed with a generalized linear mixed model. All analyses were performed to assess the likelihood of bilateral meniscal tears versus unilateral tears and no tears. Correlation of meniscal tears between stifles was assessed with Cohen’s kappa coefficient.

 Prevalence of bilateral meniscal tears was 48.0% (95% confidence interval [CI] 43.0-53.0%). There was moderate agreement of the presence of meniscal tears between stifles (Cohen’s kappa coefficient = 0.41, 95% CI 0.31-0.51).The odds for bilateral meniscal tears were higher for Rottweilers (odds ratio [OR] 4.5 [95% CI 1.1-30.3],

 = 0.033), older dogs (OR 1.2 [95% CI 1.1-1.4 per year],

 < 0.0001), smaller dogs (OR 0.98 [95% CI 0.97-0.99 per 0.45-kg],

 = 0.001), stifles with complete cranial cruciate ligament tears (OR 21.1 [95% CI 7.1-62.4],

 < 0.0001).

 Contralateral meniscal tears, breed, older age, lower patient weight and complete cranial cruciate ligament tear were significant risk factors for bilateral meniscal tears. Surgeons can use these results to determine prognoses and propensities for meniscal tears in at-risk dogs.

 Contralateral meniscal tears, breed, older age, lower patient weight and complete cranial cruciate ligament tear were significant risk factors for bilateral meniscal tears. Floxuridine RNA Synthesis inhibitor Surgeons can use these results to determine prognoses and propensities for meniscal tears in at-risk dogs.

 The aim of this study was to determine the effect of insertion torque and angulation on the push-out strength of screws in Atraumatic Rigid Fixation (ARIX) system.

 

mechanical tests of the ARIX system were conducted. Screw plate constructs (

 = 120) were tested using five different insertion torques at four different angles relative to the perpendicular axis of the plate. Before the push-out test, screws were locked into the plates, and the push-out force of the screw was measured by applying a load parallel to the screw axis.

 Implant failure was observed at 0.8 Nm at an insertion angle of 15 degrees, and at 1 Nm at 0 degree, 5 degrees and 10 degrees. Two types of failures were observed cold welding and plate deformation. An insertion torque of 0.8 Nm produced a significantly higher push-out force compared with 0.2 Nm. Non-angled specimens with 0.8 Nm insertion torque exhibited significantly higher screw push-out forces compared with other tested specimens and insertion angles. Insertion angle did not affect screw push-out force at insertion torques of 0, 0.2, 0.4 and 0.6 Nm.

 The ARIX locking system is much more sensitive to insertion torque than angle. An effect of insertion angle was observed only at an insertion torque of 0.8 Nm, under which all angles significantly decreased push-out force relative to zero degrees of angulation. In addition, low insertion torques can result in screws loosening over time, while greater insertion torques than 1 Nm can result in screw head stripping and plate hole deformation.

 The ARIX locking system is much more sensitive to insertion torque than angle. An effect of insertion angle was observed only at an insertion torque of 0.8 Nm, under which all angles significantly decreased push-out force relative to zero degrees of angulation. In addition, low insertion torques can result in screws loosening over time, while greater insertion torques than 1 Nm can result in screw head stripping and plate hole deformation.

 Successful stabilization of comminuted supracondylar humeral fractures is challenging, and biomechanical studies are scarce. This study compares double-plate (DB-PLATE) and linear external fixator with an intramedullary pin tie-in (ESF-IMP) fixation techniques in a cadaveric gap model. The hypothesis was the DB-PLATE construct would be stiffer, stronger and more resistant to repeated loading than the ESF-IMP construct in both cyclic and load-to-failure axial compression testing.

 A 2 cm ostectomy was performed on 10 pairs of canine cadaveric humeri proximal to the supratrochlear foramen. Stabilization was with DB-PLATE (

 = 10) or ESF-IMP (

 = 10). Cyclic testing was performed by applying a 200 N load at 2 Hz for 63,000 cycles. Axial compressive load to failure testing followed. Data analysed included dynamic stiffness, stiffness and yield load.

 No constructs failed during cyclic testing or lost stiffness over time. Mean dynamic stiffness over the final 100 cycles was greater for DB-PLATE compared with ESF-IMP.