Unplanned reoperations (UROs) following corrective surgery for adult spinal deformity (ASD) present significant challenges for both patients and surgeons. Understanding the specific UROs types is crucial for improving patient outcomes and refining surgical strategies in ASD correction. This retrospective analysis utilized data from the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database spanning from 2017 to 2021. Patient information was extracted using specific CPT codes related to posterior pedicle fixation.Introduction
Method
Most western countries have implemented fast-track hip fracture aiming at surgery within 24 hours, since the mortality rate hereafter rises markedly. In Greenland, it is not achievable to operate within 24 hours. Arctic people live in sparsely populated areas and Greenland's population is scattered along the vast coastline. All patients must be chartered to Nuuk by airplane which can take up till several days to weeks, due to logistics and the Arctic weather. This presents a challenge regarding adhering to western guidelines. The operative delay may be acceptable though, as it is the impression that the Greenlandic population survives and endures better than patients of western populations. However, as data are lacking, we aimed to describe mortality among hip fracture patients in Greenland taking frailty and comorbidities into account. All patients with ICD-10 codes DS720, DS721 and DS722 from 2018-2022 were identified as 261 patients diagnosed with hip fractures. Variables including time of diagnosis, time to operation, reasons for delay, ASA-score, Charlson Comorbidity index, time of death, and other possible confounding variables were analyzed. Primary outcome was mortality rates at 30-day post-OP and 1-year post-OP.Introduction
Method
Immunomodulation represents a novel strategy to improve bone healing in combination with low doses of bone morphogenetic growth factors like BMP-2. This study aims to investigate the effect and timing of monoclonal anti-IL-1ß antibody administration with 1μg BMP-2 on bone healing over 14 weeks in a rat femur segmental defect model. 2 mm femoral defects were created in 22-27 weeks-old female Fischer F344 rats, internally fixed with a plate (animal license: GR/19/2022) using established protocols for analgesia and anesthesia. Animals (n=4/group) received either a collagen sponge, a collagen sponge+1μg BMP-2 (InductOs, Medtronic) or a collagen sponge+1μg BMP-2 with a monoclonal anti-IL-1ß antibody (BioXCell, 10 mg/ml), administered intravenously under anesthesia every third day until day 15, from day 0 or 3. Introduction
Method
Many patients with obesity experience knee pain. Excess body weight is a modifiable risk factor for osteoarthritis (OA) and weight loss is encouraged in patients with OA. Bariatric surgery could improve or limit the progression of these conditions through significant weight loss. The Oxford Knee Score (OKS) is a validated tool in the assessment of knee replacement surgery for OA. We present a novel application of the OKS to assess knee pain & function after weight loss surgery. The primary aim of this study was to assess whether there was a significant difference in mean OKS before and 24 months after weight loss surgery. Eighteen female participants were included in this study. They underwent sleeve gastrectomy or Roux-en-Y gastric bypass. Patient demographics, body mass index (BMI) and OKS were collected pre- and 24 months post operatively.Introduction
Method
Recently, a new dynamic high-strength round suture dynacord (DC) was introduced featuring a salt-infused silicone core attracting water in a fluid environment to preserve tissue approximation which is also available in tape form (DT). Study aims: (1) assess the influence of securing knot number on knot security of two double-stranded knot configurations (Cow-hitch and Nice-knot) tied with either dynamic (DC and DT) or conventional round sutures fiberwire (FW) and conventional suture tapes (ST), (2) compare the ultimate force and knot slippage of (a) Cow-hitch and Nice-knot and (b) DC and DT versus FW and FT at their minimal number of needed securing knots. Seven specimens of each FW, ST, DC and DT were considered for tying with Cow-hitch or Nice-knots. The base of these Cow-hitch and Nice-knots were secured with surgeons’ knots using 1-3 alternating throws. Tensile tests were conducted under physiologic conditions to evaluate knot slippage, ultimate force at rupture, and minimum number of knots ensuring 100% knot securityIntroduction
Method
Healthy tendons are mainly composed of aligned collagen hierarchically organized from collagen fibrils to fiber bundles with a scarce cellular population mainly composed of tenocytes and tendon stem/progenitor cells. However, injured tendon acquires a fibrotic state characterized by a loss of ECM alignment and increased cellularization. The lack of reliable 3D models that recreate the organization and microenvironment of healthy and diseased tendons is one of the main obstacles faced by the scientific community. To recreate the architecture of healthy and diseased tendons, electrospun nanofiber scaffolds with anisotropic and isotropic nanotopography were developed. These scaffolds were coated with a shell consisting of cell-laden hydrogels encapsulating human adipose-derived stem cells (hASCs) to include the living component. To show the versatility of the system, extracellular vesicles (EVs) were encapsulated in the hydrogel as biological cues. The living fibers were characterized by microscopy and morphological analysis. The morphology and phenotype of cells was evaluated using microscopy, gene expression analysis and immunostainings for tendon markers.Introduction
Method
The incidences of fragility fractures, often because of osteoporosis, are increasing. Research has moved towards bioresorbable scaffolds that provide temporary mechanical stability and promote osteogenesis. This research aims to fabricate a 3D printed composite Poly (l-lactic-co-glycolic acid)-strontium doped tricalcium phosphate (PLGA-SrTCP) scaffold and evaluate in an in vitro co culture study containing osteoporotic donor cells. PLGA, PLGA TCP, and PLGA SrTCP scaffolds were produced using Fused Filament Fabrication (FFF). A four-group 35-day cell culture study was carried out using human bone marrow derived mesenchymal stem cells (hMSCs) from osteoporotic and control donors (monoculture) and hMSCs & human monocytes (hMCs) (Co culture). Outcome measures were biochemical assays, PCR, and cell imaging. Cells were cultured on scaffolds that had been pre-degraded for six weeks at 47°C prior to drying and gamma sterilisation.Introduction
Method
Osteoarthritis (OA) occurs due to a multi-scale degradation of articular cartilage (AC) surface which aggravates the disease condition. Investigating the micro-scale structural alterations and mechano-tribological properties facilitates comprehension of disease-mechanisms to improve future injectable-therapies. This study aims to analyze these properties using various experimental and analytical methods to establish correlations between their morpho-physiological features. In this study, Raman-spectroscopy was used to investigate microscale changes in AC constituents and categorize OA damage regions in knee-joint samples from joint replacement patients (Samples = 5 and Regions = 40). Following, microscale indentation and sliding tests were performed on these regions to evaluate variations in aggregate-modulus (AM) and elastic-modulus (EM), with coefficient of friction (COF). Finally, scanning electron microscopy (SEM) was employed to analyze these morphological variations.Introduction
Method
Endochondral ossification (EO) is the process of bone development via a cartilage template. It involves multiple stages, including chondrogenesis, mineralisation and angiogenesis. Importantly, how cartilage mineralisation affects angiogenesis during EO is not fully understood. Here we aimed to develop a new in vitro co-culture model to recapitulate and study the interaction between mineralised cartilage generated from human mesenchymal stromal cells (hMSCs) and microvascular networks. Chondrogenic hMSC pellets were generated by culture with transforming growth factor (TGF)-β3. For mineralised pellets, β-glycerophosphate (BGP) was added from day 7 and TGF-β3 was withdrawn on day 14. Conditioned medium (CM) from the pellets was used to evaluate the effect on human umbilical vein endothelial cells (HUVECs) in migration, proliferation and tube formation assays. To perform direct co-cultures, pellets were embedded in fibrin hydrogels containing vessel-forming cells (HUVECs, adipose stromal cells) for 10 days with BGP to induce mineralisation. The pellets and hydrogels were characterised by immunohistochemistry and confocal imaging.Introduction
Method
Analogous to articular cartilage, changes in spatial chondrocyte organisation have been proposed to be a strong indicator for local tissue degeneration and destruction in the intervertebral disc (IVD). While a progressive structural and functional degradation of the extracellular (ECM) and pericellular (PCM) matrix occurs in osteoarthritic cartilage, these processes have not yet been biomechanically elucidated in the IVD. We aimed to evaluate the local stiffness of the ECM and PCM in the anulus fibrosus of the IVD on the basis of local cellular spatial organisation. Using atomic force microscopy, we measured the elastic modulus of the local ECM and PCM in human disc samples using the spatial chondrocyte patterns as an image-based biomarker.Introduction
Method
Osteoarthritis (OA) often results from joint misloading, which affects chondrocyte calcium signaling through mechano-sensitive receptors such as Piezo1, -2, and TRPV4. Activation of Piezo1, especially under inflammatory conditions, can trigger premature chondrocyte apoptosis. Intra-articular glucocorticoid therapy, while beneficial against inflammation and pain in osteoarthritis, may induce oxidative stress and chondrotoxicity at higher doses. This study aims to assess the effects of glucocorticoids, particularly triamcinolone, on chondrocyte elasticity and mechanosignaling. Chondrocytes isolated from articular condyles obtained from patients undergoing knee replacement surgery (n= 5) were cultured for 7 days in triamcinolone acetonide (TA) at different concentrations (0.2µM – 2mM). Cytoskeletal changes were assessed by F-actin labeling. Cell elasticity was measured using atomic force microscopy (AFM). Labeling cells (n=6 patients) with the calcium-sensitive dye (Fluo-4) enabled monitoring changes in intracellular calcium fluorescence intensity during guided single-cell mechanical indentation (500 nN) by AFM.Introduction
Method
Piezo1 is a mechanosensitive Ca2+ ion channel that has been shown to transduce hyper-physiologic mechanical loads in chondrocytes. In osteoarthritic cartilage, Piezo1 expression was shown to be upregulated by interleukin-1 alpha (IL-1α) and resulted in altered calcium dynamics and actin cytoskeleton rarefication. Together these studies highlight the importance of Piezo1 channels during joint injury. However, the mechanism by which Piezo1 regulates chondrocyte physiology and mechanotransduction during homeostasis is still largely unknown. In this study, we investigate the impact of Piezo1 activation on nuclear mechanics and chromatin methylation state. Porcine chondrocytes (n=3-5 pigs) were treated with Yoda1, a Piezo1-specific agonist, for either 2, 5, 15 or 180 minutes. To characterize chromatin state, we monitored the abundance of a chromatin methylation marker (H3K9Me3) using immunofluorescence (IF). Atomic force microscopy (AFM, 25 nm cantilever) was employed to quantify the nuclear elastic modulus (NEM) of individual cell nuclei. To explore the interplay between cytoskeletal dynamics and nuclear mechanics, chondrocytes were treated with Latrunculin A (LatA), an actin polymerization inhibitor.Introduction
Methods
Functional Spine Units (FSUs) play a vital role in understanding biomechanical characteristics of the spine, particularly bone fracture risk assessment. While established models focus on simulating axial compression of individual bones to assess fracture load, recent models underscore the importance of understanding fracture load within FSUs, offering a better representation of physiological conditions. Despite the limited number of FSU fracture studies, they predominantly rely on a linear material model with an annulus fibrosus Young's modulus set at 500 MPa, significantly higher than stiffness values (ca. 4 MPa) utilized in other FSU and spine section biomechanical models. Thus, this study aims to study the effect of varying annulus fibrosus stiffness on FSU fracture load, aiming to identify physiologically relevant biomechanical parameters. Subject-specific geometry and material properties of bones were derived from computed tomography (CT) image data of five human cadaveric FSU specimens. The annulus fibrosus and nucleus pulposus were manually recreated and assigned linear elastic material properties. By subjecting the model to axial compression, the fracture load of the FSU was deduced from the peak of the force-displacement graph. To explore the effect of stiffness of the annulus fibrosus on simulated fracture load, we conducted a parameter study, varying stiffness values from the high 500 MPa to a more physiologically relevant 25 MPa, aiming to approximate values applied in FSU kinematic models while achieving bone fracture.Introduction
Method
Bernese periacetabular osteotomy (PAO) repositions the acetabulum to increase femoral head coverage (FHC) in hip dysplasia. Currently, there is a paucity of objective peri-operative metrics to plan for optimal acetabular fragment repositioning. The MSk Lab Hip 3D Planner (MSkL-HP) measures acetabular morphology and simulates PAO cuts to achieve optimal FHC. We evaluated how adjusting location and orientation of cutting planes can alter FHC. MSkL-HP simulated 274 feasible PAOs on four dysplastic hips. Femoroacetabular anatomy was landmarked to simulate cutting planes. Posterior column and ischial cuts were standardised, whilst iliac and pubic cut combinations varied. The slope of the iliac cut was either neutral (aligned to pelvis), exit point 5mm above the entry point (+5), or 5mm below (-5). The slope of the pubic cut was either 90°, 50°, or 70° (medial-to-lateral). Iliac and pubic cuts were simulated 0, 5 and 15mm - distal and medial – to a classic cut. Outcome measures were achieved LCEA, Tönnis, FHC and % bone overlap at the pubic cut. Targets were LCEA >30°, Tönnis angle <10°, and FHC >70% and minimum bone overlap ≥10%.Introduction
Method
The ACTIVE(Advanced Cartilage Treatment with Injectable-hydrogel Validation of the Effect) study investigates safety and performance of a novel dextran-tyramine hydrogel implant for treatment of small cartilage defects in the knee (0.5-2.0cm2). The hydrogel is composed of a mixture of natural polymer conjugates that are mixed intra-operatively and which cross-link in situ through a mild enzymatic reaction, providing a cell-free scaffold for cartilage repair. The ACTIVE study is split into a safety (n=10) and a performance cohort (n=36). The Knee Injury and Osteoarthritis Outcome Score (KOOS), pain (numeric rating scale, NRS), Short-Form Health Survey (SF-36) were compared at baseline and 3, 6, and 12 months after surgery. The primary performance hypothesis is an average change in the KOOS from baseline to 12 months (ΔKOOS) greater than a minimal clinically important change (MIC) of 10. No statistical tests were performed as these are preliminary data on a smaller portion of the total study.Introduction
Method
The management of pathologic fractures (PF) following osteomyelitis (especially acute subtype) has not been widely investigated. This is challenging due to the infection-induced destructive process causing bone architecture defects. Therefore, this study aims to assess a stepwise treatment plan for the acute incidence of PF in long bone following pediatric acute Hematogenous osteomyelitis(AHO) (the most common mechanism in children). This case series was conducted in a tertiary pediatric center. Patients with fracture incidence within the first 10 days after AHO diagnosis were included. Patients’ characteristics were retrospectively reviewed.Introduction
Method
We aimed to study the rates of both surgical and medical complications associated with femoral diaphysis fracture fixation with intramedullary nailing including all fracture mechanisms. Additionally, we investigated whether the trauma energy has an impact on the complication risk. In this retrospective cohort study, the health records of 491 patients with 503 femoral fractures, who underwent surgery between May 2007 and May 2022 in Tampere University Hospital, were reviewed. Patients who underwent a primary operation with a reamed rigid intramedullary nail for a diaphyseal femoral fracture and whose follow-ups were organized at the same hospital district, were included. Based on those criteria, 57.5% were included for analysis (279 patients with 289 fractures). The complications were then recorded by chart review. To investigate the impact of trauma energy on complication risk, we compared complication proportions in high- and low-energy groups and calculated odds ratios.Introduction
Method
Osteoarthritis (OA) is a predominant chronic degenerative disease exerting a deep impact on quality of life and healthcare systems. Recent evidences suggest that pyroptosis, a programmed cell death characterized by inflammatory cytokine release, may play a significant role in modulating OA pain. The aim of the study is to investigate the potential role of extracellular vesicles derived from umbilical cord Wharton's jelly (WJ-MSC EVs) in the attenuation of the pyroptotic process on human chondrocytes (hOAC) pre-treated with synovial fluid in a 3D in vitro model. EVs isolated by tangential filtration of the conditioned medium of WJ-MSCs were characterized for: morphology by TEM, surface markers by WB and size by NTA. Confocal microscopy was used to identify PKH26-labelled EVs and monitor their incorporation into hOACs. The hOACs from surgical waste material of patients undergoing knee replacement, expanded, encapsulated in alginate beads were pre-treated with synovial fluid for 24 h (SF) and subsequently co-incubated with WJ-MSC EVs. We examined viability (CCK-8), metabolic activity (MTT), nitrite production (Griess) activation of the pyroptotis (IF), DNA quantification (PicoGreen) and gene expression levels of extracellular matrix (ECM) components (qPCR). One-way ANOVA analysis was used to compare the groups under exam and data were expressed as mean ± S.DIntroduction
Method
Treatment strategies for irreparable Massive Rotator Cuff Tears (MRCTs) are debatable, especially for younger, active patients. Superior Capsular Reconstruction (SCR) acts as a static stabilizer, while Lower Trapezius Transfer (LTT) serves as a dynamic stabilizer. This study compares the biomechanical effectiveness of SCR and LTT, hypothesizing that their combination will enhance shoulder kinematics. Eight human shoulders from donors aged 55-75 (mean = 63.75 years), balanced for gender, averaging 219.5 lbs, were used. Rotator cuff and deltoid tendons were connected to force sensors through a pulley system, with the deltoid linked to a servohydraulic motor for dynamic force measurement.Introduction
Methods
Tendinopathies represent a significant health burden, causing inflammation, pain, and reducing quality of life. The pivotal role of macrophages (Mφ) characterized by their ability to differentiate into proinflammatory (M1) or anti-inflammatory (M2) phenotypes depending on the microenvironment, has gained significant interest in tissue inflammation research. Additionally, existing literature states that the interplay between tenocytes and immune cells during inflammation involves unidentified soluble factors (SF). This study aimed to investigate the effect of extracellular vesicles (EVs) and SF derived from polarized Mφ on tendon cells to provide deeper insights of their potential therapeutic applications in the context of inflammation. Human monocytes were isolated from blood donor buffy coats and differentiated into M1, M2, and hybrid M1/M2 phenotypes. Subsequently, EVs were isolated from the conditioned media from polarized Mφ and comprehensively characterized. In parallel, the elution media containing SF was collected. Furthermore, the EVs and SF were released independently onto tenocytes from human donors, previously induced with IL-1β to simulate an inflammatory environment. Finally, mRNA levels of tendon-related markers were evaluated by qPCR after the exposure to these EVs and SF.Introduction
Method
