The effects of mechanical instability on PDGF mediated inflammatory response at early stage of fracture healing under diabetic condition

Advances in computational modeling of cytokine and growth factor dynamics in bone healing: a scoping review

Bone healing is a complex process regulated by intricate biological and mechanical factors and spatially varied regions over time. This scoping review synthesizes current computational models that incorporate cytokines and growth factors, examining their role in bone healing. Through a systematic analysis of 71 studies, this review identifies and categorizes the modeling methodologies used, including mathematical, finite element, agent-based, mechanobiological, pharmacobiological, and hybrid approaches. The findings highlight the predominant use of mathematical models while noting a recent shift toward more sophisticated techniques like finite element and agent-based models. Key cytokines and growth factors, such as TGF-β, RANK-RANKL-OPG, and PTH, are repeatedly used, underscoring their essential roles in regulating cellular processes. This review also analyzes parameter selection and validation strategies, identifying gaps in current practices and emphasizing the need for high-quality experimental validation to improve model reliability. Some bibliometric analyses provide insights into citation networks and keyword co-occurrence, illustrating influential studies in the field and central themes. The findings offer a foundation for future research to enhance model accuracy, aiming toward more predictive and clinically relevant models accounting for biology and mechanics in bone healing.

Autologous and Heterologous Minor and Major Bone Regeneration with Platelet-Derived Growth Factors

AIM

This review aims to explore the clinical applications, biological mechanisms, and potential benefits of concentrated growth factors (CGFs), autologous materials, and xenografts in bone regeneration, particularly in dental treatments such as alveolar ridge preservation, mandibular osteonecrosis, and peri-implantitis.

MATERIALS AND METHODS

A systematic literature search was conducted using databases like PubMed, Scopus, and Web of Science, with keywords such as "bone regeneration" and "CGF" from 2014 to 2024. Only English-language clinical studies involving human subjects were included. A total of 10 studies were selected for qualitative analysis. Data were processed through multiple stages, including title and abstract screening and full-text evaluation.

CONCLUSION

The findings of the reviewed studies underscore the potential of the CGF in enhancing bone regeneration through stimulating cell proliferation, angiogenesis, and extracellular matrix mineralization. Autologous materials have also demonstrated promising results due to their biocompatibility and capacity for seamless integration with natural bone tissue. When combined with xenografts, these materials show synergistic effects in improving bone quantity and quality, which are crucial for dental implant success. Future research should focus on direct comparisons of different techniques, the optimization of protocols, and broader applications beyond dental medicine. The integration of CGFs and autologous materials into routine clinical practice represents a significant advancement in regenerative dental medicine, with the potential for improved patient outcomes and satisfaction.

Can concentrated growth factor prevent postoperative complications of impacted third molar surgery? A split-mouth randomized double-blind trial

OBJECTIVES

The purpose of the present study was to evaluate the effect of concentrated growth factor (CGF) on prevention of postoperative complications in the impacted third molar extraction.

MATERIALS AND METHODS

A total of 25 healthy patients with symmetrical bilaterally impacted third molars (50 extraction sites) were enrolled in this split-mouth, randomized, double-blind clinical trial. Third molar extractions were performed in both sites of the mandible at the same appointment. Randomization was performed using a coin toss to choose the test and control sites. CGF was placed in the extraction socket and the socket was sutured (test group), while the contralateral socket was only sutured (control group). Each patient acted as their own control. The primary outcome were pain assessed by visual analog scale (VAS) and facial swelling on the1st, 3rd and 7th postoperative days. The secondary outcomes were bone healing in extraction sockets through alveolar bone height (ABH) and alveolar bone density (ABD) evaluated by cone beam computed tomography (CBCT) immediately after extraction and in the 3rd and 6th months.

RESULTS

Twenty-five patients (12 female, 13 male; mean age 29.17) with bilateral impacted third molars participated in the study. A statistically significant reduction in pain was determined on the 3rd and 7th postoperative days in the CGF sites compared to the control sites while no statistically significant difference was found between the groups on the 1st postoperative day (3rd day, p = 0.009; 7th day, p = 0.039). There were no statistically significant differences in facial swelling and bone healing between the test and control groups at different time intervals, although the data obtained were slightly favoring the CGF group (p > 0.05). There were no serious adverse effects such as infection, alveolitis, paraesthesia, fracture through the follow-up period in all of the cases.

CONCLUSION

The study has demonstrated the effect of CGF on relieving the severity of pain after the third molar extraction.

CLINICAL RELEVANCE

Placement of CGF in the extraction socket could relieve postoperative pain and reduce patient discomfort after the third molar extraction. CGF is recommended during the third molar extraction due to its good biological effects, low cost and simple preparation procedures.

TRIAL REGISTRATION NUMBER

ChiCTR2300077819.

The impact of osteoporosis and diabetes on fracture healing under different loading conditions

BACKGROUND

Osteoporosis and diabetes are two prevalent conditions among the elderly population. Each of these conditions can profoundly influence the fracture healing process by disturbing the associated inflammatory process. However, the combined effects of osteoporosis and diabetes on fracture healing remain unclear. Therefore, the purpose of the present study is to investigate the role of osteoporosis and diabetes in fracture healing and the underlying mechanisms by developing numerical models.

METHOD

This study introduces a numerical model that consists of a three-dimensional model of a tibia fracture stabilized by a Locking Compression Plate (LCP), coupled with a two-dimensional axisymmetric model which illustrates the transport and reactions of cells and cytokines throughout the inflammatory phase in early fracture healing. First, the model parameters were calibrated using available experimental data. The model was then implemented to predict the healing outcomes of fractures under five varied conditions, consisting of both osteoporotic and non-osteoporotic bones, each subjected to different physiological loads.

RESULTS

The instability of the fracture callus can significantly escalate in osteoporotic fractures (e.g., when a 150 N physiological load is applied, the unstable region of the osteoporotic fracture callus can reach 26 %, in contrast to 12 % in non-osteoporotic fractures). Additionally, the mesenchymal stem cells (MSCs) proliferation and differentiation can be disrupted in osteoporotic fracture compared to non-osteoporotic fractures (e.g., on the 10th day post-fracture, the decrease in the concentration of MSCs, osteoblasts, and chondrocytes in osteoporotic fractures is nearly double that in non-osteoporotic fractures under a 150 N). Finally, the healing process of fractures can suffer significant impairment when osteoporosis coexists with diabetes (e.g., the concentration of MSCs can be drastically reduced by nearly 37 % in osteoporotic fractures under diabetic conditions when subjected to a load of 200 N) CONCLUSIONS: Fracture calluses destabilized by osteoporosis can negatively affect the fracture healing process by disrupting the proliferation and differentiation of mesenchymal stem cells (MSCs). Moreover, when osteoporosis coexists with diabetes, the fracture healing process can severely impair the fracture healing outcomes.

Depth camera-based model for studying the effects of muscle loading on distal radius fracture healing

BACKGROUND

Distal radius fractures (DRFs) treated with volar locking plates (VLPs) allows early rehabilitation exercises favourable to fracture recovery. However, the role of rehabilitation exercises induced muscle forces on the biomechanical microenvironment at the fracture site remains to be fully explored. The purpose of this study is to investigate the effects of muscle forces on DRF healing by developing a depth camera-based fracture healing model.

METHOD

First, the rehabilitation-related hand motions were captured by a depth camera system. A macro-musculoskeletal model is then developed to analyse the data captured by the system for estimating hand muscle and joint reaction forces which are used as inputs for our previously developed DRF model to predict the tissue differentiation patterns at the fracture site. Finally, the effect of different wrist motions (e.g., from 60° of extension to 60° of flexion) on the DRF healing outcomes will be studied.

RESULTS

Muscle and joint reaction forces in hands which are highly dependent on hand motions could significantly affect DRF healing through imposed compressive and bending forces at the fracture site. There is an optimal range of wrist motion (i.e., between 40° of extension and 40° of flexion) which could promote mechanical stimuli governed healing while mitigating the risk of bony non-union due to excessive movement at the fracture site.

CONCLUSION

The developed depth camera-based fracture healing model can accurately predict the influence of muscle loading induced by rehabilitation exercises in distal radius fracture healing outcomes. The outcomes from this study could potentially assist osteopathic surgeons in designing effective post-operative rehabilitation strategies for DRF patients.