Bone Surface Research Articles

Intraoperative cartilage analysis of the first carpometacarpal joint - comparison with conventional staging according to Eaton and Littler

IntroductionOsteoarthritis of the first carpometacarpal joint is a common pathology of the hand, which may show an increasing prevalence in Germany due to the demographic development. In recent years, not only the current gold standard - the resection arthroplasty of the thumb saddle joint - has been used, but also therapeutic thumb saddle joint arthroscopy. In addition to the patient’s clinical complaints, radiographic diagnostics have been used to decide on treatment, although it has not been proven whether there is a correlation between imaging and clinical complaints.Materials and methodsBetween 2020 and 2022, 20 articular surfaces of the thumb saddle joint undergoing resection arthroplasty for symptomatic basal thumb osteoarthritis were prospectively examined, mapped and compared with preoperative conventional radiographs.ResultsThe evaluation of the corresponding articular surfaces showed a higher cartilage destruction at the articular surfaces of the trapezium compared to the first metacarpal. No correlation was found between the stage of osteoarthritis and the Eaton-Littler classification.ConclusionsOverall, there is a patient-specific heterogeneity of the cartilage damage of the articular surface of the trapezium bone, as well in the metacarpal bone I base in relation to the radiographic diagnosis. Furthermore, an inhomogeneity of the radiographic stage of osteoarthritis of the carpometacarpal joint according to Eaton and Littler in relation to the intraoperatively assessed cartilage damage. The statistical significance of the surgically assessed cartilage damage in relation to the conventional radiographs could not be demonstrated. Thus, the treatment of symptomatic osteoarthritis of the carpometacarpal joint should primarily address the patient’s individual complaints. The radiographic classification according to Eaton and Littler can be used as an additional factor to decide on the surgical procedure but should not delay the therapeutic treatment.Level of evidenceIII.

Utility of ultrasound imaging in monitoring fracture healing in rat femur: Comparison with other imaging modalities

ObjectiveFractures are common injuries and various imaging modalities are employed to diagnose and monitor bone union. However, the follow-up of fracture healing using ultrasound imaging (US) remains a topic of debate. In this study, we analyzed of fracture healing process and compared US and radiological analyses with histological analyses to clarify the characteristics and limitations of each modality. MethodsAn osteotomy model was created using the femur of Wistar rats, and US, radiological (radiography and micro-computed tomography (micro-CT)), and histological analyses were performed. Radiological assessments were conducted for the evaluation of calcified tissue. The gap between the bony callus and cartilaginous callus was measured. ResultsUS effectively captured changes on the fracture surface, potentially reflecting the early healing processes. Both US and radiographic findings showed strong correlation in terms of the decrease in the bony callus gap. US was unable to distinguish cartilaginous callus from the surrounding soft tissue. During the remodeling stage, micro-CT offered a detailed assessment of the internal fracture surface, whereas US was limited to evaluating the outer bone surface and lacked accuracy in visualizing the entire fracture site. Radiography provided a general overview of the fractures. The decrease in the bony callus gap measured using US correlated with the reduction in cartilaginous callus observed histologically. ConclusionThis study demonstrated that US could be a valuable tool for evaluating fracture healing. Combining fracture management with US and radiological examinations may provide a more accurate assessment of healing progress.

Factors affecting distribution of dose in horizontal direction during irradiation

Recording and managing the dose of x-rays in an x-ray machine is an important part of the data. In addition, recording and managing radiation dose data in x-ray devices plays an important role in providing transparency of radiation dose to medical staff and patients by quantifying the radiation dose data. Four mobile diagnostic X-ray units were used to analyze the dose by spatial location. The dose distribution by location was analyzed by identifying and analyzing the dose by angle for both image intensifier and flat panel detector types. The three-dimensional space of the radiation area consisted of 27 sides, and the structure of the space was assumed to be horizontal X, Y, and Z sides and vertical A, B, and C sides, and the dose analysis was performed at the assumed position. On the longitudinal side, the highest dose tissue (highest μSv/min) is B_Center : (R.B.M, Colon, Lung, Stomach, Breasts, Remainder of body) - 330.404 μSv/min, and the lowest dose tissue (lowest μSv/min) is 0.002 μSv/min on the (Skin, Bone surface, Salivary glands, Brain) side at C_270°. The findings from diagnostic X-ray devices have emphasized the importance of managing radiation exposure when using the devices and may raise questions about the management of radiation protection measures to protect the health of healthcare personnel and patients. This can be expected to advance the organization of the use of radiation devices in a safe healthcare environment. A system for managing data will be useful as an indicator to guide medical staff using the equipment and patients participating in procedures and surgeries where they can minimize their dose and avoid harm.

Living in a coast–grassland ecotone: Zooarchaeology of a late Holocene shell midden in the Uruguayan Atlantic Coast

La Esmeralda is a group of Donax hanleyanus shell middens (A, B, and C) located on the Uruguayan Atlantic coast dating to the late Holocene. This paper analyzes the vertebrate remains recovered during the excavation of shell midden A. The remains were taxonomically and anatomically identified, and quantified using NISP (number of identified specimens), MNI (minimum number of individuals), MNE (minimum number of elements), and MAU (minimum animal units). Additionally, bone surfaces were examined to identify anthropogenic and natural modifications. Several vertebrate species, including marine (pinnipeds, birds, fish) and terrestrial (deer, armadillos), were captured, processed, and consumed at the site. La Esmeralda can be chronologically linked to other coastal and inland sites located near the coast, which together reflect diverse forms of landscape occupation and various economic, domestic, and ritual activities. Collectively, these settlements show a sustained use of the Atlantic coast–grassland ecotone during the late Holocene, possibly within a coastal–inland mobility circuit. The significance of coastal and continental resources in this region has been discussed for over two decades. Although isotopic studies of human remains suggests that marine resources did not play a significant role in the diet, the material record shows the simultaneous exploitation of both types of resources. This work provides new information to continue enriching this discussion.

Targeting Death Receptor 5 (DR5) for the imaging and treatment of primary bone and soft tissue tumors: an update of the literature.

Death Receptor 5 (DR5) is expressed on the surface of primary bone and soft tissue sarcoma cells, and its activation induces cell death primarily through apoptosis. The combination of DR5 agonists and commonly used chemotherapeutic agents, such as doxorubicin, can promote cell death. Currently, clinical trials are investigating the effectiveness of DR5 activation using new biological agents, such as bi-specific or tetravalent antibodies, in improving the survival of patients with relapsed or refractory cancers. Furthermore, investigations continue into the use of novel combination therapies to enhance DR5 response, for example, with inhibitor of apoptosis protein (IAP) antagonist agents [such as the second mitochondria-derived activator of caspase (SMAC) mimetics] and with immune checkpoint inhibitor anti-programmed death-ligand 1 (anti-PD-L1) or anti-programmed cell death-1 (anti-PD-1) antibodies. Other therapies include nanoparticle-mediated delivery of TRAIL plasmid DNA or TRAIL mRNA and stem cells as a vehicle for the targeted delivery of anti-cancer agents, such as TRAIL, to the tumor. Scoping review of the literature from November 2017 to March 2024, utilizing PubMed and Google Scholar. New agents under investigation include nanoTRAIL, anti-Kv10.1, multimeric IgM, and humanized tetravalent antibodies. Developments have been made to test novel agents, and imaging has been used to detect DR5 in preclinical models and patients. The models include 3D spheroids, genetically modified mouse models, a novel jaw osteosarcoma model, and patient-derived xenograft (PDX) animal models. There are currently two ongoing clinical trials focusing on the activation of DR5, namely, IGM-8444 and INBRX-109, which have progressed to phase 2. Further modifications of TRAIL delivery with fusion to single-chain variable fragments (scFv-TRAIL), directed against tumor-associated antigens (TAAs), and in the use of stem cells focus on targeted TRAIL delivery to cancer cells using bi-functional strategies. In vitro, in vivo, and clinical trials, as well as advances in imaging and theranostics, indicate that targeting DR5 remains a valid strategy in the treatment of some relapsed and refractory cancers.

An Upper Paleolithic horse mandible with an embedded lithic projectile: Insights into 16,500 cal BP hunting strategies through a unique case of bone injury from Cantabrian Spain

AbstractEmbedded artifacts in osteoarchaeological remains may be key to approaching hunting strategies and other behavioral‐related issues such as technological development. However, that kind of evidence is not common within the archaeological record and often not well‐characterized, especially for faunal remains from prehistoric sites. Here, we present and discuss a unique case of a horse (Equus caballus) mandible with an embedded lithic remains from the Upper Paleolithic (ca. 17,300–16,200 cal BP) from La Garma cave in Cantabria, Spain. Our macro‐ and microscopic faunal and lithic integrated analysis suggests that the case presented here is a potential perimortem hunting lesion, representing an uncommon hunting strategy during the Magdalenian period. Furthermore, this study, representing the first case of its kind in the Iberian Peninsula, emphasizes the importance of the taphonomic analysis of bone surfaces to approach the understanding of past human behaviors.

The identification, research and implications of human tooth-marks on bone surface in prehistoric archaeology

The identification, research and implications of human tooth-marks on bone surface in prehistoric archaeology

Wave mode variation of multi-wavelength photoacoustic guided waves in cortical bone

Abstract Photoacoustic guided waves (PAGWs), excited based on the optical-thermo-mechanical coupling mechanism, have the potential to non-invasion assess the optical properties which associates tissue composition of bones. This study investigates the wave mode variation of PAGWs with the optical transmissivity in a 2mm-thick cortical bone plate. Multi-wavelength PAGWs were generated by lasers of different wavelength with a tunable pulsed laser system; Two piezoelectric transducers with the centre frequency of 500 kHz, symmetrically sticked on the bone surfaces, were used to acquire the signals. The symmetric (S) mode and anti-symmetric (A) mode were extracted by adding and subtracting the signals received by different transducers, respectively. The relative amplitude ratio of A mode and S mode was found to have an inverse relationship with the optical transmissivity of the bone. For the 750 nm laser with high transmissivity, the waves are mainly S mode; the relative amplitude of A mode wave increases with the laser wavelength. The amplitude ratio of A- and S- modes is in exponential attenuation with the transmissivity. The research results suggest that the wave mode variation in signal amplitude is suitable for evaluating the optical properties of bones, which is benefit for the development of quantitative ultrasound assessment of long cortical bone.

Combined use of PRPP, diode laser and piezosurgery device improves reparative osteogenesis previously to dental implants placement

ObjectiveCurrent study evaluated whether use of the platelet-rich powder (PRPP), piezosurgery device and diode laser after removal of jawbones cysts and benign bone formations and extraction of impacted tooth could enhance bone regeneration before dental implantation. MethodsA study was conducted among 200 patients with post-surgical cavities (not exceeding 1.5 cm upon cystectomy, benign bone tumor removal and impacted tooth extraction) who underwent plasma powder, autograft, allograft, xenograft or beta-tricalcium phosphate augmentation procedures. ResultsPRPP implantation in combination with irradiation of bone cavity by diode laser led to the formation of 15.40 % ± 2.1 of new bone. The activity of reparative osteogenesis on the bone surface was BB = 6.71 ± 1.3, which is 3 and 3.5 times higher than the mean value in comparison group after augmentation of xenograft and beta-tricalcium phosphate. The value of bone tissue resorption for main group patients was less pronounced (Ra.Oc = 25.20 % ± 2.1).The ratio between pro- and anti-inflammatory cytokines in the main group after 1, 7 and 30 days since surgical procedure was lower than the ratio of the corresponding cytokines in the comparison groups. ConclusionThe examination of computed tomograms, histological and morphometric analysis of bone tissue after trepanobiopsy, cytological analysis of swabs and enzyme immunoassay to determine local immunity indicated that the proposed method of treatment with the use of PRPP, the piezosurgery device and the diode laser has a positive effect: it helped to optimize reparative osteogenesis after filling post-surgical cavities and restore bone volume.

The deterioration of microstructure and biochemical components in cancellous bone characterizing by the photoacoustic microscopy imaging

Abstract Background/Objective: Osteoporosis is mainly characterized by a deterioration of microstructure and a loss of biochemical components in bone tissues. Developing an imaging technique for measuring bone tissue microstructure and the biochemical components is of great significance for the early diagnosis of osteoporosis. Photoacoustic microscopy (PAM) has the advantage of high optical resolution and the potential to diagnose osteoporosis. In this study, we investigated the feasibility of the photoacoustic microscopy (PAM) technique for bone tissue imaging, and the deterioration of microstructure and biochemical components in cancellous bone was characterized by the PAM. Statement of Contribution/Methods: We performed the optical-resolution photoacoustic microscopy (OR-PAM) for bone tissue imaging and the trabecular microstructure and hydroxyapatite (HAP) were degraded by immersion in JYBL-I solution. The PAM imaging method was developed for the measurement of the surface and subsurface of cancellous bone with a high resolution. Specifically, a 532 nm pulse laser was used to excite the PA signal from the bone. The PA signal sampling frequency was 80 MHz. A motor rotated a 15 MHz central frequency transducer to receive 1000 × 1000 × 250 points data. The envelope of the signal was obtained using the Hilbert transform for reconstruction. Then, the JYBL-I solution was used to reduce the HAP component in the bone. The PAM imaging was performed after different immersion times, (i.e., at 0, 5, and 10 mins). In the PAM measurement of the cancellous bone, the imaging area was a cylinder with an 8 mm diameter and an 8 μm/pixel resolution. Results/Discussion: The results showed that the trabecular microstructure could be imaged with a relatively high quality using the PAM technique. With the different extent of HAP degradation by immersion in JYBL-I solution, some trabecular bone disappeared corresponding with PA signals decreased significantly in amplitude. Conclusion: These results indicate that the PA technique has potential application in the characterization of bone microstructure and biochemical components with a high resolution.

Synthetic cartilage implant vs. first metatarsophalangeal arthrodesis for the treatment of hallux rigidus

BackgroundThis study evaluated the outcome of the Cartiva synthetic cartilage implant (SCI) in the treatment of hallux rigidus.MethodsIn the present retrospective matched case-control study, we compared 18 patients with Cartiva SCI (mean follow-up: 17.7 months) to 18 patients with metatarsophalangeal joint arthrodesis (mean follow-up: 20 months) using multiple function measures, along with four specified visual analog subscales for pain. Pre- and postoperative radiographs were compared, and radiographic abnormalities were documented.ResultsWe observed no significant differences in function measures between groups. While both groups experienced significant pain reduction, the arthrodesis group reported significantly lower exertion pain than the Cartiva SCI group (p = 0.004). Radiographic abnormalities, including implant site enlargement (6/18, 33.3%), erosive changes of the metatarsal bone (11/18, 61.1%) or articular surfaces (10/18, 55.6%), and bright sclerotic margins (12/18, 66.7%), occurred in the Cartiva SCI group.ConclusionThe present study showed good functional results and a high satisfaction rate after MTP joint arthrodesis, which is considered the gold standard surgical treatment for higher grade hallux rigidus. While the Cartiva SCI group did not show significant differences from the arthrodesis in most aspects of function and clinical scores, the arthrodesis group tended to have better results in terms of satisfaction, residual pain, and revision rate. Even after the short follow-up period, there were some remarkable radiographic findings in the Cartiva SCI group, the long-term effects of which are not yet evident, but which may lead to implant loss. Cartiva SCI has advantages for patients who prioritize postoperative mobility, but the potential risks should be considered in the patient’s informed consent. Therefore, the present study highlights the importance of MTP joint arthrodesis for the treatment of hallux rigidus.Level of evidenceLevel IV – Retrospective matched case-control study.

Multirod posterior occipitocervical instrumentation constructs: a biomechanical analysis and initial case series of 10 patients with complex craniocervical pathology

BACKGROUND CONTEXTStabilization of the occipitocervical (OC) junction with posterior instrumentation plays a vital role in addressing a spectrum of pathologies. Due to limited bone surfaces of the occiput and C1 lamina, achieving union across the OC junction is challenging. PURPOSETo explore the biomechanics and a clinical series of patients treated with multirod constructs across the OC junction using a novel occipital plate with single- and dual-headed, modular tulip heads. STUDY DESIGN/SETTINGBiomechanical analysis and retrospective case series. PATIENT SAMPLEAdults at a single institution who underwent posterior cervical multirod constructs across the OC junction. OUTCOME MEASURESOC–C4 range of motion (ROM), maximum von Mises stress on the rods, and adjacent segment ROMs and intradiscal parameters. Patient demographics, revision operations, rod breakages, wound complications. METHODSA validated occiput-cervical finite element (FE) model was used to simulate OC–C4 cervical fixation under multidirectional pure moment loading. A total of 4 rod configurations were simulated: (A) 2-rod-Ti (4.0 mm titanium rods); (B) 2-rod-CoCr (3.5 mm cobalt chrome rods); (C) 3-rods (4.0 mm titanium rods); (D) 4-rods (4.0 mm titanium rods). The aforementioned measures were compared. A retrospective analysis was also performed of adults at a single institution who underwent posterior cervical multirod constructs across the OC junction. RESULTSBiomechanically, lowest primary rod stresses were observed for 3- and 4-rod constructs. Compared to 2-rod-Ti (121.8 MPa), 2-rod-CoCr showed a 43.2% stress increase in the rods, while 3- and 4-rods experienced rod stress reductions of 20% and 23.2%, respectively. No appreciable differences in OC–C4 ROM, C4–5 ROM, and C4–5 discal stresses were found between multirod and 2-rod constructs. Maximum occipital and C4 screw stresses were decreased in multirod constructs compared to 2-rods, with least stresses noted in the 4-rod construct. Maximum plate stresses were slightly increased in the 4-rod construct compared to 2- and 3-rod fixation, though the forces were largely similar among the constructs. Ten patients (average age 66.4±10.6 years; 8 males) were assessed clinically. Nine of the ten operations were for primary stabilization of pathological fractures and associated craniocervical and/or atlantoaxial instability using 4-rods across the OC junction. At an average follow-up time of 1.58±0.5 years (range, 1–2.3 years), there were no instrumentation failures, no adjacent segment failures, and no wound complications. CONCLUSIONSIn this proof-of-concept investigation, multiple rods (3- and 4-rods) across the OC junction using a novel occipital plate with single- and dual-headed, modular tulips was safe and effective in stabilizing the OC junction. Accompanying FE analysis demonstrated that multirod constructs decreased primary rod stresses and had lower stresses on occipital and C4 screws compared to 2-rod constructs, while occipital plate stresses were largely similar. Additional clinical studies are needed to confirm these findings and to determine the ultimate utility of multirod constructs across the OC junction.

Relationship between interincisal angles and TMJ morphology/position and trabecular structure: a retrospective study

BackgroundTMJ morphology/position and trabecular structure are influenced by various factors. The role of the interincisal angle, an indicator of the anterior occlusal relationship, on TMJ remains unclear. This study aims to investigate the morphology, trabecular bone structure, and position of the condyle, as well as the glenoid fossa’s morphology in skeletal class II populations with different interincisal angles.Materials and methodsA total of 150 adult patients with normodivergent facial types and skeletal class II malocclusions were selected and divided into three groups based on their interincisal angles: normal, small, and large angle groups. The indexes of TMJ were measured using cone-beam computed tomography (CBCT) data and analyzed using Dolphin Imaging, Mimics, and ImageJ.ResultsThe small angle group had the smallest anteroposterior diameter (APD), while the large angle group had a greater mediolateral diameter (MLD). The large angle group exhibited significantly the largest maximum axial area, bone surface area, and bone volume (P < 0.05). Small and large angle groups exhibited greater bone trabeculae (Tb. N) and thinner trabecular thickness (Tb. Th). Compared to the normal angle group, the small angle group exhibited a larger horizontal condylar angle and smaller bilateral condylar angles on the axial plane, while the large angle group showed the opposite trend. Small and large angle groups showed a reduced vertical condyle angle on the coronal plane, with the largest reduction observed in the large angle group (P < 0.05). Small and large angle groups had higher heights of the glenoid fossa (GFH). The large angle group exhibited the greatest GFH and width of the glenoid fossa (GFW) (P < 0.05).ConclusionThe large angle group had elongated oval and large condyles, and deeper glenoid fossae, while a flattened-oval and smaller condyle, and wider and shallower glenoid fossae were observed in the small angle group. Small and large interincisal angle affects the structure of condylar trabeculae, resulting in thinner Tb. Th and greater Th. N. In the condylar position, small and large angle groups exhibit condylar rotation in the axial and coronal planes. Therefore, the interincisal angle affects the morphology, position, and trabecular structure of the TMJ. This implies that we must pay attention to the impact of the interincisal angle on TMJ, and it is crucial to restore the normal interincisal angle during orthodontic treatment.

Human exposure to uranium through drinking water and its detrimental impact on the human body organs.

Human exposure to high concentrations of uranium is a major concern due to the risk of developing numerous internal organ malignancies over time. In addition to the numerous attributes of uranium in the nuclear power industry, the radiological characteristics and chemical toxicity of uranium present a substantial risk to human health. This study aims to evaluate potential negative health impacts associated with the ingestion of uranium through drinking water in the Noida and Greater Noida region within the Gautam Buddha districts of Uttar Pradesh (India), due to extreme industrial revolution in this geological location. The mean concentration of uranium in drinking water of the examined area was estimated to range from 0.23 to 78.21µgl-1. The hair compartment biokinetic model is used to estimate the retention and radiological doses of uranium in distinct organs and tissues. Studies on time-dependent factors revealed variations in uranium retention, with lower levels observed in the Gastrointestinal Tract (GIT) region and higher levels on cortical bone surfaces causes the skeletal deformities. The kidney, liver, and other soft tissues (OST) exhibited a non-saturation pattern in the retention of uranium via exposure of drinking water. The age-wise non-carcinogenic and carcinogenic doses were estimated for the health hazards studies. The outcome of this study will be useful for water resource management authorities to supply safe potable water to the local residents.

Characterization of Trabecular Bone Microarchitecture and Mechanical Properties Using Bone Surface Curvature Distributions.

Understanding bone surface curvatures is crucial for the advancement of bone material design, as these curvatures play a significant role in the mechanical behavior and functionality of bone structures. Previous studies have demonstrated that bone surface curvature distributions could be used to characterize bone geometry and have been proposed as key parameters for biomimetic microstructure design and optimization. However, understanding of how bone surface curvature distributions correlate with bone microstructure and mechanical properties remains limited. This study hypothesized that bone surface curvature distributions could be used to predict the microstructure as well as mechanical properties of trabecular bone. To test the hypothesis, a convolutional neural network (CNN) model was trained and validated to predict the histomorphometric parameters (e.g., BV/TV, BS, Tb.Th, DA, Conn.D, and SMI), geometric parameters (e.g., plate area PA, plate thickness PT, rod length RL, rod diameter RD, plate-to-plate nearest neighbor distance NNDPP, rod-to-rod nearest neighbor distance NNDRR, plate number PN, and rod number RN), as well as the apparent stiffness tensor of trabecular bone using various bone surface curvature distributions, including maximum principal curvature distribution, minimum principal curvature distribution, Gaussian curvature distribution, and mean curvature distribution. The results showed that the surface curvature distribution-based deep learning model achieved high fidelity in predicting the major histomorphometric parameters and geometric parameters as well as the stiffness tenor of trabecular bone, thus supporting the hypothesis of this study. The findings of this study underscore the importance of incorporating bone surface curvature analysis in the design of synthetic bone materials and implants.

The periosteum provides a stromal defence against cancer invasion into the bone.

The periosteum is the layer of cells that covers nearly the entire surface of every bone. Upon infection, injury or malignancy the bone surface undergoes new growth-the periosteal reaction-but the mechanism and physiological role of this process remain unknown1,2. Here we show that the periosteal reaction protects against cancer invasion into the bone. Histological analyses of human lesions of head and neck squamous cell carcinomas (HNSCCs) show that periosteal thickening occurs in proximity to the tumour. We developed a genetically dissectible mouse model of HNSCC and demonstrate that inducible depletion of periosteal cells accelerates cancerous invasion of the bone. Single-cell RNA sequencing reveals that expression of the gene encoding the protease inhibitor TIMP1 is markedly increased in the periosteum at the pre-invasive stage. This increase is due to upregulation of HIF1α expression in the tumour microenvironment, and increased TIMP1 inactivates matrix-degrading proteases, promoting periosteal thickening to inhibit cancer invasion. Genetic deletion of Timp1 impairs periosteal expansion, exacerbating bone invasion and decreasing survival in tumour-bearing mice. Together, these data show that the periosteal reaction may act as a functional stromal barrier against tumour progression, representing a unique example of tissue immunity mediated by stromal cells.

Investigation of periodontal tissue regeneration using octacalcium phosphate and collagen composite

ObjectiveThis study aimed to investigate periodontal tissue regenerative potential of octacalcium phosphate (OCP) and collagen composite (OCPcol), recognized as excellent bone-regenerative materials, in artificial bone defect models using beagle dogs. This study specifically assessed the efficacy of OCPcol in periodontal soft-tissue regeneration. MethodsOCPcol was implanted in bone defects adjacent to the roots of the left mandibular third and fourth premolars in six beagle dogs (OCP group), while five dogs did not receive OCPcol (control group). The dogs were observed for 3 months. The specimens were evaluated radiologically and histologically. ResultsMicrocomputed tomography revealed bone regeneration originating from the lateral cortical bone surface adjacent to the created defect. The superficial layer of the regenerated bone was cortical bone-like and continuous with the upper and lower alveolar bone. The bone was regenerated by maintaining a continuous void in the periodontal ligament space above and below the dentinal defect. Dental defects of roots were not regenerated. The control group did not exhibit sufficient bone regeneration. Histologically, in the OCP group, formation of new cementum was observed on the outer surface of the root dentin, with connective tissue attachment and an oblique-running periodontal ligament in the space between the new bone and dentin. However, the dentinal defects were not regenerated． ConclusionsAlveolar bone and periodontal ligament regenerated when OCPcol was implanted into a bone and dentinal defect created around a natural tooth root. These results suggest that OCPcol effectively regenerates periodontal tissue, without ankylosis.

Application of the Modified RUST Score in Tibial Bone Transport and Factors Associated with Docking Site Complications.

Reconstruction of segmental bone defects with bone transport is a well-established treatment. Mechanical complications at the docking site after frame removal are common. These complications include malunion, non-union, axial deviation and refracture. A simple tool to assess the healing of the docking site is currently lacking. The aim of this study is to evaluate the use of the modified RUST (mRUST) score in the setting of bone transport and to identify factors associated with an increased risk of docking site complications. This retrospective study was conducted at a single tertiary centre in South Africa, included 24 patients with a tibial bone defect treated with bone transport and a circular frame between 2014 and 2023. Demographic data, clinical and bone transport characteristics were recorded. Mechanical complications, such as fracture, non-union, any angulation >5°, shortening >5 mm, or any other complication requiring reoperation, were recorded. The mRUST was adapted as a ratio for the purpose of this study to overcome the common occurrence of cortices being obscured by the frame. The mRUST ratio was applied before and after frame removal for each patient by three appraisers. Comparison between the groups with and without complications was performed regarding bone transport characteristics, docking site configuration and mRUST ratio. The correlation of the score between radiographs before and after frame removal was assessed. The inter-rater reliability of the mRUST was analysed using Fleiss Kappa statistics for each cortex individually and the intraclass correlation coefficient (ICC) for the mRUST ratio. In this study, 20 men and 4 women with a median age of 26 years were included. The overall rate of mechanical complications after frame removal was 21.7%. Complications were all related to the docking site, with two angulations, two fractures and one non-union. Demographics, bone transport characteristics and mRUST ratio before and after frame removal were similar between the two groups. Regarding the configuration of the docking site, an angle of 45° or more between the bone surfaces was associated with the occurrence of mechanical complications (p < 0.001). The correlation of the mean mRUST ratio before and after frame removal showed a moderate relationship, with a Spearman correlation coefficient of 0.50 (p-value 0.13). The inter-rater reliability of the mRUST was "fair" (kappa 0.21-0.40) for the scoring of individual cortices, except for one score which was "slight" (kappa 0.00-0.20). The ICC of the mRUST ratio was 0.662 on radiographs with the frame, and 0.759 after frame removal. This study did not find the mRUST or mRUST ratio useful in assessing the healing of the docking site to decide on the best time to remove the frame. However, a notable finding was that the shape and orientation of the bone ends meeting at the docking site might well be relevant to decrease complication rates. If the angle between the bony surfaces is 45° or more, it may be associated with an increased risk of complications. It may be worthwhile considering reshaping these bone ends at the time of debridement or formal docking procedure to be more collinear, in order to reduce the potential for mechanical complications such as non-union, axial deviation or refracture at the docking site. Kummer A, Nieuwoudt L, Marais LC. Application of the Modified RUST Score in Tibial Bone Transport and Factors Associated with Docking Site Complications. Strategies Trauma Limb Reconstr 2024;19(2):73-81.

Assessment of Novel Surgical Procedures Using Bone Morphogenic Protein-7 Infused Into Decellularised Muscle and Bioactive Ceramic: A Histological Analysis.

Reconstruction of critical bone defects is considered a challenge due to vascular reperfusion injury that may occur. The present study hypothesized that the use of decellularized muscle scaffold (DMS) and bone morphogenic protein-7 (BMP-7), along with resorbable bioactive ceramic silica calcium phosphate cement (SCPC) seeded with human bone marrow stromal cells, can expedite bone formation and maturation. Surgical bone defects were created in 20 nude transgenic mice. In experimental group 1 (n = 10), a critical-size (4mm) calvarial defect was made and grafted with DMS-BMP-7/SCPC. In situ human bone marrow stromal cells [human mesenchymal stromal cells (hMSC)] were seeded thereafter. As a control, group 2 (n = 10) was treated with DMS/SCPC seeded with hMSCs. After 8 weeks, bone regeneration was evaluated using histology and histomorphometry for both groups. Histological examination showed bone regeneration crossing the gap (experimental group 1), bone regeneration was noted at the defect periphery, and scattered islands of bone at the canters of the defects (control group 2). New bone formation and maturation were superior in the groups treated with the DMS/BMP-7/SCPC/hMSC constructs. The quantitative histological assessment revealed that the average bone surface area was 255 ± 25mm2, which was 1.5 times the surface area of group 2, which was reported at 170 ± 35mm2. The reported difference was considered statistically significant (P < 0.05). The DMS-BMP-7/SCPC scaffold induced bone regeneration and neovascularization in critical-size defects.

Preventing periprosthetic osteolysis in aging populations through lymphatic activation and stem cell-associated secretory phenotype inhibition

With increases in life expectancy, the number of patients requiring joint replacement therapy and experiencing periprosthetic osteolysis, the most common complication leading to implant failure, is growing or underestimated. In this study, we found that osteolysis progression and osteoclast differentiation in the surface of the skull bone of adult mice were accompanied by significant expansion of lymphatic vessels within bones. Using recombinant VEGF-C protein to activate VEGFR3 and promote proliferation of lymphatic vessels in bone, we counteracted excessive differentiation of osteoclasts and osteolysis caused by titanium alloy particles or inflammatory cytokines LPS/TNF-α. However, this effect was not observed in aged mice because adipogenically differentiated mesenchymal stem cells (MSCs) inhibited the response of lymphatic endothelial cells to agonist proteins. The addition of the JAK inhibitor ruxolitinib restored the response of lymphatic vessels to external stimuli in aged mice to protect against osteolysis progression. These findings suggest that inhibiting SASP secretion by adipogenically differentiated MSCs while activating lymphatic vessels in bone offers a new method to prevent periprosthetic osteolysis during joint replacement follow-up.