Motion preservation surgery for scoliosis with a vertebral body tethering system: a biomechanical study

Purpose There is a paucity of studies on new vertebral body tethering (VBT) surgical constructs especially regarding their potentially motion-preserving ability. This study analyses their effects on the ROM of the spine. Methods Human spines (T10-L3) were tested under pure moment in four different conditions: (1) native, (2) instrumented with one tether continuously connected in all vertebrae from T10 to L3, (3) additional instrumented with a second tether continuously connected in all vertebrae from T11 to L3, and (4) instrumented with one tether and one titanium rod (hybrid) attached to T12, L1 and L2. The instrumentation was inserted in the left lateral side. The intersegmental ROM was evaluated using a magnetic tracking system, and the medians were analysed. Please check and confirm the author names and initials are correct. Also, kindly confirm the details in the metadata are correct. The mentioned information is correct Results Compared to the native spine, the instrumented spine presented a reduction of less than 13% in global ROM considering flexion–extension and axial rotation. For left lateral bending, the median global ROM of the native spine (100%) significantly reduced to 74.6%, 66.4%, and 68.1% after testing one tether, two tethers and the hybrid construction, respectively. In these cases, the L1-L2 ROM was reduced to 68.3%, 58.5%, and 38.3%, respectively. In right lateral bending, the normalized global ROM of the spine with one tether, two tethers and the hybrid construction was 58.9%, 54.0%, and 56.6%, respectively. Considering the same order, the normalized L1-L2 ROM was 64.3%, 49.9%, and 35.3%, respectively. Conclusion The investigated VBT techniques preserved global ROM of the spine in flexion–extension and axial rotation while reduced the ROM in lateral bending.

Dynamic properties of hybrid machine tool body – Theoretical and experimental investigation

The article presents theoretical and experimental investigation in order to obtain dynamic properties of hybrid machine tool body in comparison with cast iron body. For this purpose, the theoretical and experimental modal analyses were carried out. The influence of the mineral cast material for filling voids on the dynamic properties of the machine tool body was discussed. During the analysis, the modes and frequencies of free vibrations, the amplitude values and the damping ratios were compared. Despite lowering the free vibration frequency of the hybrid construction, compared to the cast iron body, in some cases, the dynamic properties were affected. This could be determined on the basis of decreasing the amplitude value of the transfer function (from 12.16% to 58.66%) and the increasing the vibration damping coefficient ratio (from 12.22% to 75.24%) in the case of a hybrid body as compared to a cast iron body. The final conclusions were drawn about the application of mineral casts in the construction of machine tools and its impact on the dynamic properties of the structure.

Anterior Hybrid Construction of Multilevel Cervical Disc Disease and Spondylotic Spinal Stenosis: Surgical Results and Factors Affecting Adjacent Segment Problems

Objective: We aimed to evaluate reliability, radiological outcomes and the impacts of anterior cervical hybrid construction on the adjacent segments for the multilevel cervical degenerative disc disease (mCDDD) and spondylotic spinal stenosis (SSS).Methods: A retrospective analysis was performed using data extracted from the medical files of 195 patients (105 males, 90 females; mean age: 47.7 years). From 2008 to 2018, these patients underwent anterior cervical hybrid construction for symptomatic contiguous at least 2-level cervical degenerative disc diseases and cervical spondylosis. Clinical and radiological data including Neck Disability Index (NDI), Visual Analogue Scale (VAS), local cervical degenerative disk disease in adjacent segments on magnetic resonance imaging (MRI) views and complications were reviewed. Results: The mean clinical and radiological follow-up was 45.2 months (range: 24 to 102). Radiculopathy and/or myelopathy were the main clinical problems in all patients. The mean VAS scores of HC for arm pain were 7.4±0.8 preoperatively; 2.8±0.6, 1 month after surgery; 2.3±0.6, 6 months after surgery; 1.8±0.6, 12 month after surgery; and 1.6±0.6, 24 months after surgery. The mean NDI scores (mean±SD) of HC significantly improved after surgery (on admission, 57.2±5.5%; 1 month after surgery, 27.35±5.3%; 6 month after surgery, 21.43±2.8%; 12 months after surgery, 21.9±2.3%; 24 months after surgery, 20.6±2.6%, p=0.006). Hoarseness and dysphagia were the most common complications and osteophyte formation was the most frequent radiographic change.Conclusion: Anterior cervical hybrid construction appears to be an acceptable option in the management of multilevel cervical degenerative disc diseases and spondylotic spinal stenosis.

Legal regulation of the hygienic issues on the interaction of built-in healthcare institutions and residential part of the building

Objective: We analysed the regulatory framework on the design of healthcare facilities built in the residential buildings, studied the conditions of their location and developed sanitary-and-antiepidemic requirements for them. Materials and methods: In the work, we used bibliosemantic (for the analysis of the use of legal regulation), theoretical (retrospective use of research data) and analytical methods. Results: According to the reform of the healthcare sector of Ukraine, at the primary level of medical care, the number of healthcare institutions is growing, in particular outpatient ones (outpatient clinics, family doctors’ offices, etc.), which are located in built-in (attached) non-residential premises of ground, first, and basement floors of multistory residential buildings. The authors of the article propose sanitary-and-hygienic and antiepidemic requirements for the location of built-in healthcare institutions at the hybrid type of the construction of residential and public part of the building, using parametric and target (object-by-object) methods. Conclusions: Taking into account that the outpatient healthcare institutions are the primary link in healthcare and make up the bulk of the entire healthcare institutions network, as well as the shortage of land for the construction of outpatient clinics in a separate building, the built-in healthcare institutions have become widespread and are located mainly in non-residential premises and residential buildings (ground, first, and basement floors), which is the element of hybrid construction. Developed sanitary-and-hygienic and antiepidemic measures for built-in healthcare institutionswill help to increase their epidemic safety, to prevent occupational diseases of medical staff.

Laser measurement system dedicated to the determination of rails deformation of a hybrid electromagnetic launcher

The growing applications area of an electromagnetic launcher lead to numerous researches on new constructions and analyzes of existing and novel solutions of this type of device. The typical solutions with a coil or rail drive (named coil-gun and rail-gun) as well as a new hybrid construction which is a combination of these two types of drives are known. The paper presents the construction and mathematical model of the hybrid electromagnetic launcher (containing coil-gun and rail-gun module) with pneumatic assists, but the main purpose of this paper is to present measurement and simulation results of rails deformation for an electromagnetic launcher with rails (rail-gun module). The computer simulations were made using Inventor Professional software. In the measurement system the laser displacement sensor was used.