Automated rodent in situ muscle contraction assay and myofiber organization analysis in sarcopenia animal models

Age-related sarcopenia results in frailty and decreased mobility, which are associated with increased falls and long-term disability in the elderly. Given the global increase in lifespan, sarcopenia is a growing, unmet medical need. This report aims to systematically characterize muscle aging in preclinical models, which may facilitate the development of sarcopenia therapies. Naïve rats and mice were subjected to noninvasive micro X-ray computed tomography (micro-CT) imaging, terminal in situ muscle function characterizations, and ATPase-based myofiber analysis. We developed a Definiens (Parsippany, NJ)-based algorithm to automate micro-CT image analysis, which facilitates longitudinal in vivo muscle mass analysis. We report development and characterization of translational in situ skeletal muscle performance assay systems in rat and mouse. The systems incorporate a custom-designed animal assay stage, resulting in enhanced force measurement precision, and LabVIEW (National Instruments, Austin, TX)-based algorithms to support automated data acquisition and data analysis. We used ATPase-staining techniques for myofibers to characterize fiber subtypes and distribution. Major parameters contributing to muscle performance were identified using data mining and integration, enabled by Labmatrix (BioFortis, Columbia, MD). These technologies enabled the systemic and accurate monitoring of muscle aging from a large number of animals. The data indicated that longitudinal muscle cross-sectional area measurement effectively monitors change of muscle mass and function during aging. Furthermore, the data showed that muscle performance during aging is also modulated by myofiber remodeling factors, such as changes in myofiber distribution patterns and changes in fiber shape, which affect myofiber interaction. This in vivo muscle assay platform has been applied to support identification and validation of novel targets for the treatment of sarcopenia.

Operative treatment of isthmic spondylolisthesis with posterior stabilization and ALIF. Cages versus autogenous bone grafts

In the following study the use of cages and autogenous bone grafts were compared in the operative treatment of isthmic spondylolisthesis with the posterior stabilization and Anterior Lumbosacral Interbody Fusion (ALIF). 55 patients were divided into two groups. Autogenous bone grafts were used in the first group (34 patients) and titanium interbody implants (cages) in the second group (21 patients). The mean follow up period in the first group was 8.6 years and 3.4 years in the second group. The radiological outcome was based upon the evaluation of the degree of spondylolisthesis, the angle of the lumbar lordosis, the height of the interbody space and intervertebral foramen and the evaluation of the spinal fusion. The objective clinical outcome assessment was based on Oswestry Disability Index. Subjective clinical evaluation was performed with the use of Visual Analog Pain Score (VAS) and the two questions concerning the evaluation of success of the operative treatment and a possible agreement to the following operation if necessary. The use of autogenous bone grafts alone in ALIF was related to the significant loss of achieved segmental spine anatomy restoration. The implantation of the cages prevented the loss of slippage correction, permanently reconstructed the anatomical conditions in the area of the operated spinal segment.

Secondary scoliosis after thoracotomy in patients with aortic coarctation and patent ductus arteriosus

The aim of this study was to determine the influence of lateral thoracotomy on the development of scoliosis in subjects undergoing repair of coarctation of the aorta (CoAo) and patent ductus arteriosus (PDA). A group of 133 patients with CoAo and PDA was evaluated. Forty-five patients with CoAo and 38 with PDA were operated on using lateral thoracotomy (operative group) while 12 patients with CoAo and 31 with PDA were treated using balloon dilatation and stent or coil implantation (non-operative group). Clinical examination and the evaluation of spinal roentgenograms were performed. Among the operated patients 46.6% of those with CoAo and 39.5% of those with PDA had clinical scoliosis. In the non-operated patients scoliosis was present in only 16.6% of those with CoAo and 12.9% of those with PDA. Scoliosis ranged between 10° and 42° and it was mild in the majority of cases. In 90.4% of the operated scoliotic patients with CoAo and 73.3% of those with PDA the curve was thoracic and in 47.6% of the CoAo group and 53,3% of the PDA group the curve was left sided. All curves were right sided in non-operated subjects. Scoliosis in the operated group was higher in males than in females (63.3% versus 60% in CoAo and 68.2% versus 37.5% in PDA). The prevalence of scoliosis after thoracotomy was significantly higher than after non-surgical methods of treatment of both CoAo and PDA as well as in the general population. The rate of single thoracic and the rate of left thoracic curves in patients after thoracotomy is higher than in patients treated non-surgically or in idiopathic scoliosis. The rate of scoliosis after thoracotomy is higher in males than females especially following thoracotomy for PDA.

Intraoperative Neurophysiologic Monitoring (INM) in scoliosis surgery

Even among skilled spinal deformity surgeons, neurologic deficits are inherent potential complications of spine surgery. The aim was to assess the meaning of changes and to evaluate the critical rates of Somatosensory Evoked Potentials (SEP) and Motor Evoked Potentials (MEP) for Neurologic Deficit (ND) occurrence associated with scoliosis surgery. A Group of 30 patients with idiopathic scoliosis treated surgically by posterior correction and stabilisation were included. Patients were matched by age, sex, aetiology, Cobb angle, and surgical criteria. Data on three planar scoliosis correction and concomitant (INM) alarms were compared. Radiographic assessment was performed from radiographs taken before surgery and just after it. The (INM) was performed with the use of ISSIS (Inomed) in every patients the same fashion. The average thoracic curve correction was 69.7% and lumbar 69.8%. The average preoperative Apical Vertebral Rotation was 23.5° for thoracic and 27.9° for lumbar curves and postoperatively 10.9° and 14.3° respectively. There was a significant variability of SEP during surgery with only 7 (23%) patients with stable SEP. 15(50%) patients had a decrease of SEP below 50% and 8(27%) had severe decrease of SEP below 50% what caused us to stop surgery or to decrease correction of curves. There was a MEP decrease in 11(37%) patients and in 6 (20%) directly after correction up to 50% of normal value. In 5 of 30 (17%) patients there was a significant decrease of MEP below 50% and we immediately released the implant. The SEP decrease up to 50% without any MEP change did not influenced the outcome. There was no correlation between flexibility and correction of the curve and SEP and MEP decrease. The safe level for MEP was not determined but its meaning for the outcome was more important than SEP value. The need of (INM) during scoliosis surgery to avoid (ND) was confirmed.