Search Results (307)

To address the pronounced asymmetric deformation of roadway-surrounding rock under deep multi-dynamic pressure, the N8003 tailgate of the Wuyang Mine was adopted as the engineering background, and the deformation–failure characteristics of the roadway sidewalls and the evolution of deviatoric stress under dynamic loading were analyzed. Based on numerical simulation, the maximum principal deviatoric stress S₁ was employed as the core indicator for evaluating pressure-relief effectiveness, upon which a three–dimensional Pressure Relief Efficiency Index (PREI) considering strength, range, and position was developed. The key parameters of large-diameter hydraulic cavitation pressure–relief boreholes were optimized, and the evolution patterns of deviatoric stress under static and dynamic conditions were further revealed. To overcome the limitations of conventional high-strength bolt–cable combined support in controlling large deformation, a layered support–relief collaborative control technology featuring “external reinforcement fixation (ERF), near-surface modification and grouting (NSMG), and deep targeted destressing (DTD)” was proposed. Field tests demonstrated that this technology can significantly suppress sidewall deformation, maintain support system stability, and exhibit strong adaptability and application potential in deep roadways influenced by multi-dynamic pressure. Full article

Background: Syndesmotic screw breakage is a well-recognized mechanical complication following ankle fracture fixation. Although several studies have investigated patient-related and technical factors associated with screw breakage, the temporal pattern of screw failure and implant survival remains less clearly defined. Therefore, this study aimed to evaluate one-year syndesmotic screw survival using time-to-event analysis and to identify factors associated with screw breakage. Materials and Methods: A total of 132 patients with unstable AO-Weber 44-B/C ankle fractures treated with syndesmotic screw fixation were retrospectively analyzed. Patients were followed for a minimum of 12 months or until screw breakage occurred. Screw survival was evaluated using Kaplan–Meier analysis and Cox proportional hazards regression was performed to identify factors associated with screw breakage. Demographic variables, fracture type, and screw-related parameters were analyzed. Receiver operating characteristic (ROC) analysis was used to assess the discriminative ability of age. Results: Screw breakage occurred in 31 patients (23.5%) during follow-up. Kaplan–Meier analysis demonstrated significantly lower screw survival in Weber C fractures compared with Weber B fractures (log-rank p < 0.001). Cox regression analysis identified younger age (HR: 0.965, 95% CI: 0.937–0.993, p = 0.016) and Weber C fracture type (HR: 1.811, 95% CI: 1.260–2.602, p = 0.001) as independent predictors of screw breakage. ROC analysis showed that age had moderate discriminative ability (AUC: 0.719, 95% CI: 0.612–0.816), with a cut-off value of 35.5 years. Conclusions: Younger age and Weber C fracture type are associated with an increased risk of syndesmotic screw breakage and Weber C fractures also demonstrating reduced screw survival. These findings may assist in patient counseling; however, the clinical implications of screw breakage remain uncertain. Full article

Background/Objectives: Twiddler’s syndrome is an uncommon but clinically important complication of implantable cardiac devices, in which generator rotation within the pocket results in lead torsion, lead retraction, and device malfunction. Recurrence can necessitate repeated surgical intervention and may be preventable through early risk identification and procedural strategies. Methods: We describe a single-centre case series of three female patients with pacemaker-associated Twiddler’s syndrome. Clinical presentation, timing of lead retraction, management strategies (including pocket location and fixation approach), recurrence, and follow-up outcomes were reviewed. Results: All patients were older women and developed symptomatic device failure early after implantation, with radiographic confirmation of lead retraction and coiling occurring within three weeks in all cases. Recurrence was observed when enhanced preventive measures were not employed. Notably, in one patient, recurrence occurred after an initial revision in a second prepectoral pocket, prompting subsequent reimplantation in a subpectoral location with reinforced fixation and structured patient and family counselling, after which no further recurrence occurred at one year. In the remaining cases, revision with reinforced generator fixation and counselling was associated with stable lead position and satisfactory device function during follow-up. Conclusions: Twiddler’s syndrome most commonly presents in the first weeks following implantation. Proactive identification of at-risk patients and consideration of reinforced fixation and pocket strategies at the index procedure may reduce recurrence and avoid repeat interventions. Full article

Background and Objectives: To provide a systematic narrative review of published literature on atypical hangman’s fractures focusing on pathophysiology, treatment options and clinical outcomes. Materials and Methods: A systematic review was performed according to PRISMA guidelines. MEDLINE (PubMed), EMBASE, Scopus, and Cochrane Library were searched until March 2025. Studies reporting outcomes of atypical hangman’s fractures treated conservatively or surgically were included. Data on demographics, mechanism of injury, treatment modality, outcomes, and complications were extracted and analyzed. Results: Thirteen studies with a total of 275 patients were included. The average age was 54.36 years. High-energy trauma was the predominant mechanism of injury. Conservative treatment was performed in 210 patients, with 204 (97.14%) achieving fusion and 6 (2.86%) converted to surgical treatment. Surgical fixation was performed in 71 patients, most commonly via a posterior approach. Failure of surgical treatment occurred in 5 patients, all treated with isolated anterior fusion. Neurologic injury was reported in 21 patients (7.63%), with full recovery in 14 (66%). Conclusions: Atypical hangman’s fractures represent a distinct subgroup of C2 fractures with diverse morphology and stability. Most fractures are stable and may be managed conservatively. Surgical fixation should be reserved for unstable patterns. If surgery is pursued, posterior fixation is recommended. Outcomes are generally favorable for both conservative and surgical treatment. Full article

Electrochemical biosensors integrated into wearable devices have revolutionized the technology in terms of health monitoring and diagnostic systems. However, when it comes to moving the devices from the laboratory to real-world environments, a critical problem emerges with the interface. The problem, in essence, is that biorecognition elements tend to lose their activity, delaminate, and drift when exposed to various environmental stresses. The traditional methods for the immobilization of the biorecognition elements result in receptors with random orientations, hydrolytically unstable bonds, and batch-to-batch variability, regardless of the method, including physisorption or non-selective covalent attachment, like using EDC/NHS. This review is organized around a comparative question: which limitations of classical immobilization strategies (physisorption, self-assembled monolayers used as passive anchoring platforms, and EDC/NHS coupling) can be resolved by click chemistry, which can be resolved by mechanistic features? Accordingly, CuAAC, SPAAC, IEDDA, and thiol-ene/yne photoclick reactions are discussed, not as an isolated catalog of ligations, but as complementary solutions to specific interfacial failure modes, including random bioreceptor orientation, hydrolytically vulnerable attachment, poor batch reproducibility, catalyst sensitivity, and the difficulty of functionalizing soft polymeric or textile substrates. In this framework, click chemistry is treated as a deterministic interface-engineering strategy that enables defined covalent fixation, programmable probe density, and improved mechanical and electrochemical robustness under wearable operating conditions. Full article

Rotator cuff suture anchors have traditionally been inserted at the 45° “deadman” angle, but this recommendation was largely derived from single-row constructs and may not reflect the biomechanics of contemporary double-row suture bridge repairs. This study compared the biomechanical performance and stress distribution of medial row anchors inserted at 45° versus 90° in a double-row suture bridge construct. Sixteen ovine humeri with intact infraspinatus tendons were randomized to 45° or 90° medial anchor insertion (n = 8 each), and double-row suture bridge repair was performed using 3.5 mm metallic and PEEK anchors. Specimens underwent uniaxial tensile testing (10-N preload, 5 mm/min) to failure, measuring yield load, failure load, displacement, stiffness, and energy absorption; additionally, a CT-based finite element model of the human humerus assessed von Mises stress, strain, and deformation under 200 N loading. Mean failure load was 161.96 ± 50.99 N for 45° and 185.61 ± 60.97 N for 90° (p = 0.447), and stiffness was 31.63 ± 8.18 N/mm versus 36.79 ± 9.26 N/mm (p = 0.291). Displacement at failure was greater with 90° insertion (8.11 ± 0.51 mm vs. 6.65 ± 0.83 mm; p = 0.002), while energy absorption was higher but not significantly different (p = 0.255). Finite element analysis demonstrated lower bone von Mises stress with 90° insertion (14.03 MPa) compared with 45° (24.77 MPa), with similar deformation. In double-row suture bridge repair, 90° medial anchor insertion provides comparable fixation strength to that at 45° while reducing bone stress, suggesting a biomechanical advantage. Full article

Background and Objectives: Complicated osteoporotic thoracolumbar fractures represent a major surgical challenge because compromised bone quality predisposes to progressive deformity, neurological deterioration, and fixation failure. This study aimed to evaluate the clinical and radiological outcomes of hybrid stabilization in patients with severe osteoporotic fractures classified as AO Spine-DGOU OF4–OF5. Materials and Methods: This single-center retrospective observational cohort study included 87 consecutively treated patients with complicated osteoporotic thoracolumbar fractures who underwent surgical treatment between 2012 and 2022. Clinical outcomes were assessed using the Visual Analog Scale (VAS) and Oswestry Disability Index (ODI). Radiological outcomes included the regional kyphotic angle (RKA) and interbody fusion graded according to the Bridwell classification. Imaging was reviewed preoperatively, immediately postoperatively, and at follow-up, with 12-month outcomes used for the principal analysis. Additionally, a retrospective comparative analysis was undertaken between the two largest fixation subgroups within the cohort to explore outcome differences across the most representative construct patterns. Results: At 12 months, complete interbody fusion (Bridwell grade I) was achieved in 75.9% of patients. Mean RKA improved from 29.4° ± 14.1° preoperatively to 7.9° ± 8.0° immediately after surgery, with only minimal loss of correction during follow-up. Mean VAS improved from 7.0 ± 1.8 to 2.1 ± 1.2, while mean ODI decreased from 61.3% ± 6.8% to 9.8% ± 1.2% (both p < 0.001). Reoperation for implant-related mechanical failure was required in three patients (3.4%). Conclusions: Hybrid stabilization with cement augmentation was associated with marked improvement in pain, functional disability, and sagittal alignment, as well as a high rate of interbody fusion at 12 months, in patients with complicated osteoporotic thoracolumbar fractures. Given the retrospective observational design, these findings should be interpreted as associations within the treated cohort. Prospective comparative studies are warranted to further validate these results. Full article

Radial and ulnar fractures in toy-breed dogs are associated with a high risk of complications due to limited bone stock and soft tissue coverage. The aim of this retrospective study was to evaluate the postoperative clinical and radiographic outcomes in dogs undergoing radial and ulnar fracture stabilization with a titanium locking mini-plate system. Medical records and radiographs of toy-breed dogs weighing ≤5 kg treated between 2020 and 2025 were reviewed. Twenty-six dogs met the inclusion criteria. Radiographic union after primary fixation was observed in 92.9% of fractures. Implant failure occurred in 7.1% of cases and was successfully addressed with revision surgery, after which fracture healing was achieved. At final follow-up, limb function was graded as excellent in all dogs, including those requiring revision surgery. A shorter distal fragment length was significantly associated with implant failure, whereas implant length and proximal fragment length showed no significant association. These findings indicate that titanium locking mini-plates were associated with favorable clinical and radiographic outcomes. Distal fragment dimensions may influence the risk of implant failure and should be considered during surgical planning. However, the small number of implant failure events limits the robustness of statistical inferences, and the absence of a control group prevents direct comparison with alternative fixation techniques. Full article

Background: To describe an aortic arch incision and closure technique (AICT) for proximal fixation of a frozen elephant trunk (FET) and to report early outcomes. Methods: We retrospectively reviewed 15 consecutive patients who underwent distal arch repair with an FET using AICT (mean age 77 ± 7 years; 14 men). Indications were distal arch aneurysm (n = 12), acute Stanford type B dissection (n = 2), and distal arch enlargement after thoracic endovascular aortic repair (n = 1). Under circulatory arrest, an oblique arch aortotomy was created, the FET was deployed antegrade, trimmed, and sutured to the native aortic wall during simultaneous closure, allowing extended posterior fixation. Clinical outcomes and postoperative computed tomography were assessed. Results: No ischemic complications related to graft kinking or thrombosis, reoperation for bleeding, stroke, spinal cord ischemia, or organ failure occurred. One patient died of pneumonia on postoperative day 47 (6.7%). Cervical branch reconstruction was required in 12 patients (80%), whereas two patients with type III arch morphology and acute angulation were treated without debranching via a Zone 3 aortotomy. At a median follow-up of 29 months, no proximal endoleak was observed; one distal endoleak occurred without reintervention. Coronary bypass grafts remained patent in all patients with concomitant or prior CABG. Conclusions: AICT provided secure proximal FET fixation and arch closure while preserving the ascending aorta, offering an alternative to total arch replacement in selected distal arch pathologies. Full article

Background/Objectives: Transphyseal fracture of the distal humerus (TFDH) is a rare but clinically important pediatric elbow injury that predominantly affects children under 3 years of age. Due to the radiolucent nature of the cartilaginous distal humeral epiphysis in this age group, TFDH is often misdiagnosed as elbow dislocation, supracondylar fracture, or lateral/medial condyle fracture. Time pressures, limited pediatric musculoskeletal expertise, and incomplete clinical histories in emergency settings further compound this diagnostic challenge. Despite the importance of early and accurate diagnosis to prevent complications such as cubitus varus, systematic studies on diagnostic pitfalls and strategies for improving recognition remain scarce. We therefore aim to characterize misclassification patterns, standardize radiographic cues, and evaluate management outcomes. Methods: We conducted a single-center retrospective review of 25 pediatric patients with TFDH who were misdiagnosed at initial presentation between 2012 and 2022. Clinical records, radiographic features, treatment modalities, and complications were analyzed over a minimum follow-up period of 24 months. Results: All 25 cases were initially misdiagnosed. The most common misdiagnoses were supracondylar and lateral condyle fractures (each 6/25, 24%), followed by elbow dislocation (4/25, 16%). Misclassification was primarily attributed to failure to assess global forearm–humerus alignment and misinterpretation of the radiocapitellar line. All patients underwent emergency management, with 18/25 (72%) receiving closed reduction and percutaneous K-wire fixation, and 7/25 (28%) undergoing closed reduction and cast immobilization. Cubitus varus developed in 5/25 (20%) overall and was more frequent after closed reduction with cast immobilization (3/7, 43%) than after K-wire fixation (2/18, 11%). Overall, 92% achieved excellent functional outcomes according to the Mayo Elbow Performance Index (MEPI). The implementation of a targeted curriculum improved diagnostic accuracy among trainees from 70% to 100%. Conclusions: TFDH poses substantial cognitive and radiographic diagnostic challenges. A structured radiographic assessment, early senior review, and targeted education may improve recognition and outcomes. These findings offer actionable insights to enhance diagnostic accuracy and optimize care for this vulnerable patient population. Full article

Infiltrative lipomas involving the upper cervical spine present a significant surgical challenge, as the extensive muscular resection required for tumor control often leads to severe structural instability. This report describes the surgical treatment of an infiltrative lipoma that extensively invaded the cervical area in a 9-year-old dog. Following wide surgical debulking, a dual-plane stabilization strategy was employed. Ventral stabilization was attempted using standard C1–C2 transarticular screw fixation, while a modified dorsal stabilization technique anchored the occipital protuberance to the C2 spinous process using an ultra-high molecular weight polyethylene (UHMWPE) suture construct, combined with nuchal ligament reconstruction. Follow-up at 78 days revealed failure of the ventral implants, characterized by immediate improper positioning of the right screw and subsequent migration of the left screw. Despite these complications and confirmed tumor recurrence, the patient maintained normal neurological function and clinical cervical stability. This clinical course was suggestive of fibrous or early osseous union at the atlantoaxial joint. These findings suggest that the modified dorsal stabilization technique provided critical biomechanical support, effectively compensating for the compromised ventral fixation, and may represent a potential surgical option for managing extensive occipito-cervical instability in dogs. Full article

Background: Kyphotic deformity following osteoporotic vertebral fracture (KDOVF) often requires corrective surgery to restore sagittal alignment; however, mechanical complications, such as proximal junctional failure (PJF) and distal junctional failure (DJF), remain major concerns. Selection of the lower instrumented vertebra (LIV) plays a critical role in balancing mechanical stability and functional preservation; however, the optimal criteria for LIV selection have not been fully established. Methods: This multicenter retrospective cohort study included 52 patients who underwent corrective surgery for KDOVF, with a minimum 1-year follow-up. The patients were classified into a long-fixation group with pelvic fixation (n = 27) and a short-fixation group with lumbar LIV fixation (n = 25). Mechanical complications, radiographic parameters, patient-reported outcomes, and paraspinal muscle fatty degeneration were compared between groups. Subgroup analysis was performed within the short-fixation group to identify the factors associated with DJF. Results: The incidence of PJF was significantly higher in the long-fixation group than in the short-fixation group (37% vs. 8%, p < 0.01), whereas DJF was observed only in the short-fixation group (24%). Within the short-fixation group, patients who developed DJF demonstrated significantly greater preoperative sagittal malalignment, a lower rate of cement-augmented pedicle screw, and more advanced fatty degeneration of the paraspinal muscles. The short-fixation group also showed better postoperative lumbar function. Conclusions: LIV selection in KDOVF surgery is associated with distinct patterns of junctional mechanical complications. Short fixation may be feasible in carefully selected patients who demonstrate preserved compensatory capacity. Full article

Background and Objectives: Pelvic ring injuries with symphyseal disruption are classically associated with high-energy mechanisms such as motor vehicle collisions. Recently, waterslides have emerged as an underrecognized but distinct source of severe pelvic trauma. Waterslide-related pelvic trauma represents a distinct biomechanical entity characterized by a supine or semi-supine body position at splashdown, extreme forced hip abduction, asymmetric lower-limb positioning, and abrupt hydrodynamic deceleration. The high descent velocity, abrupt hydrodynamic deceleration, and forced hip abduction at water entry may combine to generate open-book-type pelvic injuries. Evidence guiding diagnosis and surgical management in this setting remains scarce. Materials and Methods: We retrospectively analyzed a consecutive series of adult patients sustaining waterslide-related anterior–posterior compression type II (APC2) pelvic ring injuries. Demographic data and the body mass index (BMI), fracture classification, surgical strategy, complications, and functional outcomes were reviewed. Only patients with complete imaging, operative records, and follow-up were included. Results: Four patients (38–72 years) met the inclusion criteria. All sustained rotationally unstable open-book pelvic injuries and were classified as APC2; three were AO/OTA 61B2.3 and one 61B3.3. All patients were overweight or obese (BMI 27.2–31.2). Pelvic binders provided an effective acute reduction in symphyseal diastasis; however, in one bilateral injury, CT imaging obtained with the binder in situ masked posterior ligamentous instability. Definitive surgical fixation was performed in all cases. Early mechanical failure occurred in two patients treated with short anterior symphyseal plate constructs. In the bilateral injury, isolated anterior fixation failed repeatedly until posterior sacroiliac stabilization was added. No deep infections or thromboembolic events occurred. Although two patients required short observational ICU stays, none were admitted for hemodynamic instability or pelvic bleeding. Conclusions: At 12-month follow-up, three patients achieved pain-free ambulation without assistive devices, while one patient required intermittent use of a single crutch; all patients regained independence in daily activities. Waterslide accidents represent a high-energy injury mechanism capable of producing severe APC2 pelvic disruptions, particularly in patients with an elevated BMI. Awareness of this mechanism and meticulous assessment of posterior stability are essential to avoid under-treatment and mechanical failure. Full article