Rigid Stabilization Research Articles

Rigid stabilizers and local prosolubility for boundary-transitive actions on tree

Abstract Let 𝐺 be a group acting 2-transitively on the boundary of a locally finite tree, and exclude the situation (which is a genuine exception) where 𝐺 has both P ⁢ Γ ⁢ L 3 ⁢ ( 4 ) \mathrm{P}\Gamma\mathrm{L}_{3}(4) and P ⁢ Γ ⁢ L 3 ⁢ ( 5 ) \mathrm{P}\Gamma\mathrm{L}_{3}(5) as local actions. We show that, for each half-tree T a T_{a} , the local action of the rigid stabilizer of T a T_{a} at the root of T a T_{a} contains the soluble residual of the point stabilizer of the local action of 𝐺. In particular, 𝐺 is locally prosoluble if and only if its local actions have soluble point stabilizers; if 𝐺 is not locally prosoluble, then it has micro-supported action on the boundary. We also prove some strong restrictions on the local actions of end stabilizers in 𝐺. These results are partly inspired by Radu’s classification of groups acting boundary-2-transitively on trees with local action containing the alternating group, and partly based on the author’s recent classification of finite permutation groups that preserve an equivalence relation, act faithfully on blocks and act transitively on pairs of points from different blocks.

One-Stage Posterior Only Corpectomy AndFusionInTheTreatment Of Metastatic Spinal Disease WithoutNeurologic Deficit: A Case Presentation

Introduction The treatment of lumbar metastatic burst fractures without neurologic deficit can be approached using a one-stageposterior-only corpectomy and fusion technique. This technique involves the removal of the af ected vertebral bodyand its replacement with an expandable titanium cage to provide stability and promote fusion. Case Report We describe our initial experience with the case of a 36-year-old female who presented with spinal nervecompression symptoms with radiological features of a solitary metastatic disease of the second lumbar vertebraewith a background history of missed unilateral breast tumour. She had a one-staged L2 posterior corpectomy, insertion of an expandable cage and stabilization with pedicle screws and rods. She subsequently did well withnoneurological deficit. Subsequently, she had a full assessment for breast cancer which revealed a left breast malignant tumour and had a radical mastectomy done and followed up with chemotherapy. Discussion Lumber corpectomy combines a posterior approach for instrumentation with an anterior approach for corpectomy and reconstruction of the anterior column. This combined approach is usually associated with high morbidity, long operative time, more blood loss, long hospital stay, protracted rehabilitation period and an access surgeon. In our case, a single approach was done to achieve posterior rigid stabilization, 360° neural decompression, and anterior column reconstruction without exposing the patient to the morbidity associated with the combined approach or the possible vascular complication of an anterior surgery. Conclusion This case shows that a one-stage posterior only corpectomy and fusion can be done safely with good outcome in a poor resource setting

FUNCTIONAL OUTCOMES OF DORSAL BRIDGE PLATING FOR LISFRANC INJURIES WITH ROUTINE METALWORK RETENTION: A MAJOR TRAUMA CENTRE EXPERIENCE

BackgroundAnatomical reduction of unstable Lisfranc injuries is crucial. Evidence as to the best methods of surgical stabilization remains sparse, with small patient numbers a particular issue. Dorsal bridge plating offers rigid stability and joint preservation.The primary aim of this study was to assess the medium-term functional outcomes for patients treated with this technique at our centre. Additionally, we review for risk factors that influence outcomes.Methods85 patients who underwent open reduction and dorsal bridge plate fixation of unstable Lisfranc injuries between January 2014 and January 2019 were identified. Metalwork was not routinely removed. A retrospective review of case notes was conducted. The Manchester-Oxford Foot Questionnaire summary index (MOXFQ-Index) was the primary outcome measure, collected at final follow-up, with a minimum follow-up of 24 months. The American Orthopedic Foot and Ankle Society (AOFAS) midfoot scale, complications, and all-cause re-operation rates were secondary outcome measures. Univariate and multivariate analyses were used to identify risk factors associated with poorer outcomes.ResultsMean follow-up 40.8 months (24–72). Mean MOXFQ-Index 27.0 (SD 7.1). Mean AOFAS score 72.6 (SD 11.6). 48/85 patients had injury patterns that included an intra-articular fracture and this was associated with poorer outcomes, with worse MOXFQ and AOFAS scores (both p < 0.001). 18 patients (21%) required the removal of metalwork for either prominence or stiffness. Female patients were more likely to require metalwork removal (OR 3.89, 95% CI 1.27 to 12.0, p = 0.02). Eight patients (9%) required secondary arthrodesis.ConclusionsThis is the largest series of Lisfranc injuries treated with dorsal bridge plate fixation reported to date and the only to routinely retain metalwork. The technique is safe and effective. The presence of an intraarticular fracture is a poor prognostic indicator. Metalwork removal is more likely to be needed in female patients but routine removal may not be essential.

Can Dynamic Spinal Stabilization Be an Alternative to Fusion Surgery in Adult Spinal Deformity Cases?

Rigid stabilization and fusion surgery are widely used for the correction of spinal sagittal and coronal imbalance (SCI). However, instrument failure, pseudoarthrosis, and adjacent segment disease are frequent complications of rigid stabilization and fusion surgery in elderly patients. In this study, we present the results of dynamic stabilization and 2-stage dynamic stabilization surgery for the treatment of spinal SCI. The advantages and disadvantages are discussed, especially as an alternative to fusion surgery. In our study, spinal, sagittal, and coronal deformities were corrected with dynamic stabilization performed in a single session in patients with good bone quality (without osteopenia and osteoporosis), while 2-stage surgery was performed in patients with poor bone quality (first stage: percutaneous placement of screws; second stage: placement of dynamic rods and correction of spinal SCI 4-6 months after the first stage). One-stage dynamic spinal instrumentation was applied to 20 of 25 patients with spinal SCI, and 2-stage dynamic spinal instrumentation was applied to the remaining 5 patients. Spinal SCI was corrected with these stabilization systems. At 2-year follow-up, no significant loss was observed in the instrumentation system, while no significant loss of correction was observed in sagittal and coronal deformities. In adult patients with spinal SCI, single or 2-stage dynamic stabilization is a viable alternative to fusion surgery due to the very low rate of instrument failure. This study questions the use of dynamic stabilization systems for the treatment of adult degenerative deformities.

Use of Dynamic Spinal Instruments (Dynesys) in Adult Spinal Deformities According to Silva-Lenke and Berjano-Lamartina Classifications.

Adult spinal deformities (ASD) present complex challenges in spine surgery. The diverse nature of these deformities requires a comprehensive understanding of their classification and treatment options. Traditional approaches, such as fusion and rigid stabilization are associated with complications, including screw loosening, breakage, proximal junctional kyphosis (PJK), and pseudoarthrosis. Dynamic stabilization techniques have emerged as promising alternatives, to reduce these complications and preserve spinal motion. This study investigated the effectiveness of dynamic stabilization using the Dynesys system in the surgical treatment of adult degenerative spinal deformities, with a particular emphasis on their classification. ASDs were classified according to the Berjano-Lamartina (BL) and Silva-Lenke (SL) classifications. We analyzed the efficacy of the Dynesys system in enhancing sagittal balance, radiological parameters, and clinical outcomes in this context. Dynamic stabilization of patients with ASDs using the Dynesys system significantly improved the visual analog scale and Oswestry Disability Index scores and decreased the complication rates. Patients with BL types 2, 3, and 4 experienced a significant improvement in sagittal balance followed by sagittal vertical axis measurements (p = 0.045, p = 0.015, and p < 0.0001, respectively). The SL and BL classifications, which were originally developed for rigid spinal stabilization, can be applied in dynamic stabilization. Furthermore, dynamic stabilization using the Dynesys system can be used as an alternative to rigid stabilization in SL levels 2 and 3, and BL types 1, 2, and 3, and in some patients with type 4 ASDs.

Partial Vertebrectomy in Neglected Spondyloptosis at the T10–11 Level: A Case Report

Our objective was to document the surgical results from a case and conduct a retrospective analysis of partial vertebrectomy in neglected spondyloptosis at the T10–11 level. Traumatic spondyloptosis is a severe and rare spinal cord injury. In spondyloptosis, there is a traumatic subluxation of adjacent vertebral bodies that exceeds the normal anatomical limits. The thoracic vertebrae possess a rigid skeleton, and the sternum also contributes to maintaining stability in the upper-middle chest area. Therefore, instances of spondyloptosis in the thoracic spine are exceedingly rare. Thoracic spondyloptosis typically results in neurological deficits. A 45-year-old man presented to the neurosurgery outpatient clinic complaining of weakness of lower extremities, back pain, headache, and vomiting. The patient was hospitalized for 7 days, and he was diagnosed with neglected spondyloptosis based on a computed tomography scan. The patient was treated using laminectomy decompression, bilateral facetectomy, partial vertebrectomy, and posterior stabilization. Management in cases of spondyloptosis has the aim of reduction, alignment, and stabilization. Early surgery with reduction and rigid stabilization is preferable to conservative treatment in most cases. The surgical approach can be anterior, posterior, or combined, without significant differences. Vertebrectomy is performed to remove part of the vertebral body to reduce spinal cord pressure. Thoracic spondyloptosis is a very rare but severe type of spinal cord injury. Neurological deficits are common in patients with this condition. Early management involving reduction and stabilization is generally recommended to obtain a better outcome.

Modular Knee Arthrodesis as Definitive Treatment for Periprosthetic Infection, Bone Loss, and Failure of the Extensor Mechanism After Total Knee Arthroplasty

BackgroundPeriprosthetic joint infection (PJI) after total knee arthroplasty (TKA) can result in bone and soft-tissue loss, leg length discrepancies, and dysfunctional extensor mechanisms. While above-knee amputation (AKA) is an established salvage treatment, modular knee arthrodesis (MKA) is a viable option that provides rigid stability and maintains leg length even in patients with severe bone and soft-tissue loss. We sought to report the outcomes of patients with an MKA as the definitive treatment. MethodsWe retrospectively reviewed 8 patients implanted with an MKA at 2 institutions between 2016 and 2022. The mean age was 69.63 years, and 50.0% of patients were women. All patients were indicated for conversion to an MKA as the definitive treatment in the setting of treated chronic PJI after TKA, severe bone loss, and failure of the extensor mechanism not amenable to repair. Medical records and radiographs were reviewed. ResultsNo patients required incision and drainage or exchange of their MKA for PJI at mean 2-year follow-up. One patient required 2 revisions for mechanical failure of his implant at 5.0 and 6.4 years postoperatively. ConclusionsMKA is a viable permanent alternative to AKA for patients with treated chronic PJI and dysfunctional extensor mechanism after TKA. The procedure restores leg lengths in the setting of severe bone and soft-tissue loss, therefore allowing patients to ambulate independently. Still, surgeons should be aware of the potential for mechanical failure requiring revision.

Reverse Dynamization Accelerates Regenerate Bone Formation and Remodeling in a Goat Distraction Osteogenesis Model.

This article was updated on December 20, 2023, because of previous errors, which were discovered after the preliminary version of the article was posted online. Figure 4 has been replaced with a figure that presents different p values. Also, on page 1943, the text that had read: "Quantitative microCT confirmed that the total volume of the regenerate in the RD group was much smaller compared with the SF (p = 0.06) and DF (p = 0.007) groups, although it was significantly smaller only compared with the DF group (Fig. 4-A). The total volume of the intact bone (contralateral tibia) was significantly smaller in the RD group compared with the other groups, but the RD group had values closest to those for the intact tibia. Similarly, the RD group had less bone volume compared with the SF and DF groups, and this value was significantly different from the DF group (p = 0.034; Fig. 4-B). Of the 3 groups, the RD group had vBMD that was the closest to that of intact bone. It also had significantly higher vBMD compared with the SF and DF groups (p < 0.0001 for both; Fig. 4-C).The results of torsional testing (Fig. 4-D) confirmed that the regenerate bone formed under conditions of RD was significantly stronger than that formed under SF or DF (p < 0.001 versus SF group, and p = 0.0493 versus DF group)."now reads: "Quantitative microCT confirmed that the total volume of the regenerate in the RD group was significantly smaller compared with the SF and DF groups (p < 0.01 for both groups; Fig. 4-A). The total volume of the intact bone (contralateral tibia) was significantly smaller compared with the SF and DF groups (p < 0.0001 for both). The RD group had values closest to those for the intact tibia, and this difference was not significant (Fig. 4-A). Similarly, the RD group had less bone volume compared with the SF and DF groups, and this value was significantly different from the DF group (p < 0.01; Fig. 4-B). Of the 3 groups, the RD group had vBMD that was the closest to that of intact bone, but the intact bone was significantly different compared with all of the other groups (p < 0.0001 for all groups). The RD group had significantly higher vBMD compared with the SF and DF groups (p = 0.042 and p = 0.046, respectively; Fig. 4-C).The results of torsional testing (Fig. 4-D) confirmed that the regenerate bone formed under conditions of RD was significantly stronger than that formed under SF or DF (p < 0.0001 versus SF group, and p = 0.0493 versus DF group). The intact group was significantly different compared with the SF group (p < 0.0001)."

Transdiscal Screw Fixation in L5-S1 Adult Spondylolisthesis: Technical Note and Midterm Outcomes of a Case Series

Spondylolisthesis changes the pelvic morphology and sagittal spinopelvic alignment with abnormality compared to individuals with similar pelvic morphology. There are many treatment options including a combination of decompression and fusion. In spondylolisthesis patients with high-grade spondylolisthesis, bone to bone contact (closed intradiscal space), and high-grade disc degeneration with disc collapse, fusion is challenging. From 2011 through 2020, an analysis of L5-S1 spondylolisthesis patients who had L5-S1 transdiscal screw fixation with a minimum follow-up of 2 years was performed. Radiological evaluation and clinical measures were compared preoperatively and postoperatively. Postoperative complications were analyzed. Also, L5-S1 degree fusion was analyzed using a CT scan. 8 patients of L5-S1 spondylolisthesis with a mean follow-up of 69 (25-122) months. All patients were female, the average age was 58 (43-78) years. 4 patients presented with high-grade spondylolisthesis (Meyerding grade III). Among the patients, three patients were undergoing revision surgery. Only 5 patients had interbody fusion for their adjacent levels. In the postoperative follow-up, none of the patients had a neurological deficits. Radiological evaluations of L5-S1 level showed fusion in all patients. Only one patient had rod failure and was advised for revision surgery. L5-S1 transdiscal screw fixation may provide a satisfactory rigid fixation and fusion at the L5-S1 level in cases of spondylolisthesis. This technique requires a surgeon's experience. Despite the challenge of this technique, it can provide a safe option for acquiring rigid stabilization.

Biomechanical analysis of lumbar nonfusion dynamic stabilization using a pedicle screw-based dynamic stabilizer or an interspinous process spacer.

This study aimed to investigate and compare the effects of two widely used nonfusion posterior dynamic stabilization (NPDS) devices, pedicle screw-based dynamic stabilizer (PSDS) and interspinous process spacer (IPS), on biomechanics of the implanted lumbar spine under static and vibration loadings. The finite element model of healthy human lumbosacral segment was modified to incorporate NPDS device insertion at L4-L5 segment. Bioflex and DIAM were used as PSDS-based and IPS-based NPDS devices, respectively. As a comparison, lumbar interbody fusion with rigid stabilization was also simulated at L4-L5. For static loading, segmental range of motion (ROM) of the models under moments of four physiological motions was computed using hybrid testing protocol. For vibration loading, resonant modes and dynamic stress of the models under vertical excitation were extracted through random response analysis. The results showed that compared with the rigid fusion model, ROM of the nonfusion models was higher at L4-L5 level but lower at adjacent levels (L1- L2, L2-L3, L3-L4, L5-S1). Compared with the Bioflex model, the DIAM model produced higher ROM at L4-L5 level but lower ROM at adjacent levels, especially under lateral bending and axial rotation; resonant frequency of the DIAM model was slightly lower; dynamic response of nucleus stress at L4-L5 level was slightly higher for the DIAM model, and the dynamic stress at adjacent levels was no obvious difference between the nonfusion models. This study reveals biomechanical differences between the Bioflex and DIAM systems, which may provide references for selecting surgical approaches in clinical practice.

Comprehensive analysis of the results of surgical treatment of patients with degenerative diseases of the lumbar spine using rigid fixation systems

Introduction. According to the literature, the development of adjacent-level syndrome 10 years after posterior rigid stabilization is noted in 6.7–80 % of patients, of which 24 % require revision surgery.The aim: to conduct a comprehensive analysis of the results of surgical treatment of patients with degenerative diseases of the lumbar spine using rigid fixation systems.Materials and methods. A multicenter retrospective study of the results of surgical treatment of 268 patients with degenerative-dystrophic diseases of the lumbar spine, who underwent mono- or bisegmental decompression-stabilizing intervention with the implementation of the TLIF (Transforaminal Lumbar Interbody Fusion) technique and open transpedicular rigid fixation, was conducted. The study included radiography, MRI and CT (in 2-energy mode) of intervertebral discs and isolated facet degeneration of the upper adjacent level.Results and discussion. The combination of the initial degeneration of the adjacent spinal motion segment in the form of disc degeneration of grade III and higher according to Pfirrmann with threshold values of the density of the outer cartilaginous plate from 161.7 ± 18.8 to 164.8 ± 14.2 HU, the density of the outer facet – from 702.43 ± 12.3 to 713.65 ± 13.6 HU and the density of the inner facet – from 580.5 ± 11.6 to 582.1 ± 15.1 HU, as well as with signs of segmental instability of the adjacent segment can be considered as risk factors for the development of its degeneration. With the progression of degeneration of the upper intervertebral disc, revision interventions were performed within 12–60 months after surgery.Conclusion. Bisegmental stabilization with signs of initial degeneration in the intervertebral disc and facet joints in the upper segment has proven its clinical and instrumental effectiveness in the period of 36 months and reduces the risks of developing degenerative disease of the adjacent disc.

“Flexible nature of fixation” in syndesmotic stabilization of the inferior tibiofibular joint affects the radiological reduction outcome

PurposeFibular mobility after suture button stabilization (SBS) of inferior tibiofibular joint (syndesmosis) injuries has been described. This effect is called the “flexible nature of fixation (FNF).” In this study, we aimed to quantify FNF in syndesmotic stabilization.MethodsPostoperative bilateral computed tomography (CT) of ankle fractures with syndesmosis stabilization by SBS or syndesmotic screw (SYS) was retrospectively analyzed. The transverse offset (TO) and vertical offset (VO) were defined by evaluating the drill channels. The reduction outcome was evaluated by the side-to-side difference between the clear space and the anterior tibiofibular distance (antTFD). The calculated anterior tibiofibular distance (cal-antTFD) was calculated by subtracting the TO from the validated antTFD. Subsequently, a reevaluation of the reduction outcomes after SYS or SBS stabilization was performed using cal-antTFD.ResultsSixty patients (44 with SBS and 16 with SYS stabilization) were analyzed. The intra-rater and inter-rater reliabilities for TO and VO were excellent (α > 0.92). SYS stabilization showed lower mean TO (− 0.02 mm; SD 0.14) and VO (0.11 mm; SD, 0.29 mm) than SBS stabilization (TO 1.16 mm, SD 1.4 mm; VO 0.2 mm, SD 0.8 mm; p = 0.001). The rate of malreduction according to cal-antTFD was higher than that of antFTD (p = 0.033).ConclusionThe presented method, which evaluates the position of the tibial to the fibular drill channel, allowed the quantification of the “FNF.” The often described difference in the dynamic stabilization of SBS compared to the rigid stabilization by SYS could be objectified. Considering cal-antTFD illustrates that FNF potentially reduces the rate of malreduction in SBS stabilization.

Treatment options in non-unions of the pelvis: A retrospective analysis of a single center experience over 12 years

BackgroundNon-unions and chronic instability of the pelvis remain rare complications after complex high velocity injuries with vertical and rotational instability of the pelvis. Treatment options are insufficiently supported by data evidence due to the rareness of this condition. Patients and methodswe conducted a single center, retrospective study of all non-unions and pelvic instabilities between 1.1.2008 and 1.1.2019, excluding fragility fractures. Patients’ characteristics, fracture patterns, procedures and outcomes with regard to developing treatment options and successful union in the follow-up were obtained. Results26 patients were included in this retrospective analysis. The mean age was 55 years (range 34–78 years). Seventy-seven percent of the patients were male. The standard procedure consisted of radical debridement of the non-union, interposition of autologous bone graft and rigid stabilization systems. Three patients were lost to follow up. In the remaining n = 23 patients (88%) consolidation of the non-union was achieved. The mean follow up was 31.3 months (range 6–144). Follow up showed that an iliolumbar fixation seems to be favorable regarding outcome and complications. DiscussionNon-union and remaining instability of the pelvic ring represent a rare complication after high grade pelvic trauma. There are only limited data regarding the incidence and the treatment regimen is based on small study populations only. Based on our findings we recommend to combine autologous bone grafts with rigid fixation systems especially for non-union of the pelvis to restore the posterior sacroiliac arch.

What is the Effectiveness of Premaxilla Surgical Repositioning and its Stabilization Methods in Mixed Dentition Patients With Bilateral Cleft Lip and Palate?

Verify the effectiveness of surgical repositioning of the premaxilla and its stabilization methods in patients with bilateral cleft lip and palate during mixed dentition. Systematic review. The search was conducted in 7 databases (eg, Medline via PubMed; Scopus; Central Cochrane; LILACS; Embase, Web of Science; and Sigle via OpenGrey until August 2021), using the descriptors "premaxilla", "cleft Palate", and "bone transplantation". Clinical trials and observational studies that have patients with bilateral cleft who had a need for superior/posterior repositioning of the premaxilla on mixed dentition; Studies in any language was evaluted whitout time restriction of publication. From 5572 records, 6 studies were included in the review with a total sample of 212 patients. Regarding the type of stabilization used in the premaxilla, the hybrid method (rigid and complementary semi-rigid stabilization) predominated, being observed in 184 patients (86.8%). A total of 17 failures were identified related to the surgical repositioning of the premaxilla, corresponding to 8% of the total number of surgeries. A meta-analysis of prevalence was performed, only with the retrospective studies. It was observed that the effectiveness rate of premaxilla repositioning was 92%, with a CI between 0.04 and 0.13, with all included studies showing a similar failure rate (0.08-0.09). The included studies also showed great homogeneity in this analysis (I2 = 0%; P = .75). Although there are several alternatives and techniques for repositioning and stabilizing the premaxilla, the statistical result did not differ between the different techniques.

Morphological, mechanical, and physical properties of ground rubber tire thermoplastic elastomer/rubberwood sawdust composites: Effects of composition contents and rubber types

Waste tire disposal is a growing challenge among major cities worldwide because each year, a huge number of end-of-life tires is generated. The current study aimed to evaluate the potential of ground rubber tire (GRT) and waste rubberwood sawdust (RWS) as materials for developing wood-polymer composites (WPCs). The effects of the compositions’ contents and rubber types on the mechanical and physical properties, as well as the morphology of the thermoplastic elastomer (TPE)/RWS composites were investigated. The results revealed that the addition of about 30–60 wt% of RWS improved the modulus of elasticity, compressive modulus, and hardness of the TPE composites based on both the GRT and natural rubber (NR). With the same RWS content and rubber type, the TPE/RWS composites with rubber/plastic blends of a 30/70 ratio clearly yielded better mechanical and physical properties than those blends with a 40/60 ratio. The addition of about 2–4 wt% of maleic anhydride-grafted polypropylene (MAPP) improved all the properties of the TPE/RWS composites. Overall, the composites based on the GRT gave superior strength, rigidity, and dimensional stability than that based on NR. It is therefore suggested that the eco-friendly TPE composites made from GRT and waste rubberwood could be a suitable replacement for the inorganic filler-natural rubber composites for saving costs and the environment.

Long Cervicothoracolumbal Rigid Bracing Stabilization on Incomplete Spinal Cord Injury of Post-Operated Multi-Focal Upper Cervical-Thoracic Spinal Tuberculosis: A Unique Case Report

Background and aim: Spinal tuberculosis (STB) is a hazardous type of bone tuberculosis that could affect the entire spine, with predilection towards the lower thoracic level. Upper cervical spondylitis occurred only at 0.3 – 1% of all STB cases, but this rare type leads to severe consequences, including tetraplegia, autonomic dysfunction, and respiratory impairment. This case reported long CTLSO rigid external stabilisation reasoning to boost protection whilst recovering tuberculosis despite stable internal stabilisation. Methods: A 34-year-old male came with one year of worsening low-back pain, unintentional weight loss, and gradual loss of power and sensation of both feet within a month. Physical examination showed kyphotic deformity, tenderness, key-muscle-strength 3, and sensory impairment for lower extremities, with no autonomic disturbances. Laboratory works showed chronic ongoing infection. Whole-spine MRI showed multiple spondylodiscitis with multi-focal paravertebral abscesses at C3 – C5, C7 – T3, T9 – T12, L1, severe canal stenosis and anterior segment destruction of T12. Results: The patient was diagnosed with SCI AIS D with a neurological level of L3 secondary to T12 vertebra destruction from STB. He underwent abscess evacuation, debridement, and posterior stabilisation at T10 – L3 and debridement of abscess at C3 – C5 without the need for stabilisation. After procedures, the spine was further stabilised by a CTSLO brace with flexion, extension, lateral flexion, rotation stop. Inward rehabilitation includes incremental mobilisation, upper-limb-extensor-group-strengthening-programme, balance-exercise with ambulation training. Patient discharged with status: ambulate independently with a walker. To date, the patient has returned to work with independent ambulation. Conclusion: Type-III STB was indicated for surgical procedures. Instability of upper cervical prevented patient to performed loadbearing activity thus lowering patient functional outcomes. CTLSO supplementation was given to compensate for 3 lesion sites, the upper cervical, mid-thoracic, and lower-thoracic. For the C3 – C5 lesion, there was no internal stabilisation, so a proper external mode of stabilisation should be given. However, for the thoracic level, CTLSO was given due to (1) incomplete SCI lesion in the absence of deteriorating neurological deficit,c(2) porous nature of STB, and (3) good prognostic recovery of STB with anti-TB medication leading to the reversible neurological deficit.

Economic Operation and Management of Microgrid System Using Deep Reinforcement Learning

The paper presents an adaptive Backstepping sliding mode control (BSMC) management method based on deep reinforcement learning to manage and stabilize DC/DC boost converter with constant power loads (CPLs) in Microgrids market. To perform the BSMC, the system's zero dynamic stability with diverse output functions has been presented via applying the input/output precise feedback linearization. The suggested layout has been modeled in Brunovsky's canonical model to solve the nonlinear issue resulting from the CPLs and the non-minimum phase problem. In this offered controller, the gains of the switching have been considered to being the adjustable controller coefficients that are chosen adaptively via the DRL method by online learning. This topology makes sure the rigid stability of the power electronic system by simultaneous adaptively tuning the gains. Eventually, the results prove the suggested control method owns stronger robustness efficiency and better dynamic regulation in comparison to the nonlinear control strategies.

Short and long term follow up of humeral condylar fracture type II treated by lag screw and anti-rotational pin associated to olecranon osteotomy

Humeral condylar fractures are relatively common in dogs and are most often associated with low-energy trauma, mainly affecting young animals. Anatomical reduction and rigid stabilization are mandatory to correct these types of articular fractures and achieve the main goals as early return of limb function, pain-free elbow movement, and prevent or at least reduce degenerative joint disease. Even with optimal anatomic reduction, surgical outcome complications associated to this type of fractures may be very common, giving this kind of osteosynthesis a reserve prognosis and making it challenging to the surgeon. In the case report, an adult mixed-breed dog, 3,9 kg, has fractured the lateral condylar portion of the left humerus after a 4 meters fall. Corrective osteosynthesis was performed using an association of a transcondylar lag screw and an anti-rotational pin through an olecranon osteotomy access. Monthly clinical and radiographic follow up were carried out with the intent to show bone healing evolution. Within 45 days consolidation of the fracture could already be seen. And after 180 days follow up, no signals of osteoarthrosis were found in the elbow joint, and the dog is fine, painless, has good weight bearing and optimal limb function.

Velocity-Free State Feedback Fault-Tolerant Control for Satellite with Actuator and Sensor Faults

A velocity-free state feedback fault-tolerant control approach is proposed for the rigid satellite attitude stabilization problem subject to velocity-free measurements and actuator and sensor faults. First, multiplicative faults and additive faults are considered in the actuator and the sensor. The faults and system states are extended into a new augmented vector. Then, an improved sliding mode observer based on the augmented vector is presented to estimate unknown system states and actuator and sensor faults simultaneously. Next, a velocity-free state feedback attitude controller is designed based on the information from the observer. The controller compensates for the effects of actuator and sensor faults and asymptotically stabilizes the attitude. Finally, simulation results demonstrate the effectiveness of the proposed scheme.

Functional Outcomes of Dorsal Bridge Plating for Lisfranc Injuries with Routine Metalwork Retention: A Major Trauma Centre Experience

Category:Midfoot/Forefoot; TraumaIntroduction/Purpose:Lisfranc injuries represent a significant disruption to the complex articulations of the midfoot. Many of these injuries are unstable with displacement and articular incongruity. This necessitates surgical intervention with the primary goals of anatomic reduction and midfoot stability. Evidence around surgical treatments for Lisfranc complex injuries is limited by heterogeneity in outcome measures and small patient numbers. Dorsal bridge plating is a well-recognized surgical technique with the benefits of rigid stability and joint preservation. The primary aim of this study is to assess the midterm functional outcomes for patients treated with this technique at our major trauma centre. Additionally, we assess the complication profile and review for risk factors that influence the functional outcome.Methods:Eighty-five adult patients were identified as undergoing open reduction and dorsal bridge plate fixation for displaced, unstable Lisfranc injuries at our major trauma centre between January 2014 and January 2018. Supplemental Kirschner wire stabilization was used for the lateral column if necessitated by the injury pattern. Importantly, metalwork was not routinely removed. A retrospective review of case notes and imaging was conducted in order to collate demographic data including co- morbidities and smoking status. Patient-reported outcome measures were collected at final follow-up, with a minimum follow-up of 24 months. The Manchester-Oxford Foot Questionnaire summary index (MOXFQ-Index) was the primary patient-reported outcome. The American Orthopaedic Foot & Ankle Society (AOFAS) midfoot scale, complications, and all-cause re-operation rates were secondary outcome measures. Univariate and multivariate analyses were used to identify risk factors associated with poorer functional outcomes.Results:The mean follow-up in this study was 40.8 months (24 - 72). 61/85 patients (72%) had high-energy or crush mechanisms of injury. The mean MOXFQ-Index was 27.0 (SD 7.1). The mean AOFAS score was 72.6 (SD 11.6). 48/85 patients (56%) had injury patterns that included an intra-articular fracture and this was associated with poorer outcomes, with worse MOXFQ and AOFAS scores (both p<0.001). There were trends towards poorer outcomes in diabetic patients (p=0.07), those patients needing supplementary Lisfranc or intercuneiform screws (p= 0.39 and 0.45 respectively), and as a greater number of tarsometatarsal joints were stabilized (p=0.12). Overall, eighteen patients (21%) underwent removal of metalwork for either prominence or stiffness. Female patients were more likely to require metalwork removal (OR 3.89, 95% CI 1.27 to 12.0, p=0.02). Eight patients (9%) required secondary arthrodesis for post-traumatic osteoarthritis.Conclusion:This is the largest series of Lisfranc injuries treated with dorsal bridge plate fixation reported to-date. Bridge plating is safe and effective in stabilizing this complex midfoot injury. The presence of an intraarticular fracture is a poor prognostic indicator. This is the first study to report on outcomes with routine retention of bridge plates. 21% of patients required removal of metalwork and this was more likely in female patients. Patient-reported outcomes and secondary arthrodesis rates were comparable to the existing literature in which bridge plates are routinely explanted. This suggests that routine removal may not be a necessity.