Cortical bone drilling is integral to orthopedic and dental surgeries, yet challenges such as thermal necrosis persist. Previous finite element (FE) models may overlook critical parameters, impacting accuracy. This study aims to integrate experimental and computational approaches to predict essential parameters-initial temperature, point angle, and spindle speed-enhancing precision in cortical bone drilling. Bovine cortical samples were utilized to systematically investigate the impact of four independent parameters on maximum temperature (MT) and maximum thrust force (MTF). Parameters included drill bit initial temperature (IT), diameter, point angle, and spindle speed (225-2700 rpm, feed rate 0.5-3 mm/s). Experimental procedures involved an orthopedic handpiece with titanium drill bits. DEFORM-3D V6.02 facilitated FE simulation, with the validated model developed for the second stage of the drilling process. The validated model highlighted the significant impact of drill bit IT on MT, predicting a 26.14 % decrease in final bone temperature as IT decreased from 25 to 5 °C. Increasing the point angle from 70 to 120° resulted in a 13.1 % MT increase and a 26.9 % decrease in MTF. Spindle speed variations exhibited a 48.3 % temperature increase and an 82.8 % MTF decrease. Integrating experimental validation and computational modeling offers a comprehensive approach to predict drilling parameters. Precision in cortical bone drilling can be optimized by selecting specific parameters, including lower drill bit IT, smaller point angles, and controlled spindle speeds. This optimization reduces the risk of bone necrosis and thermal damage, thereby enhancing surgical outcomes.

Flatfoot is a very common condition that alters gait mechanics and is usually accompanied by pain. In this current study, two types of custom-made insoles using polyethylene and silicon, respectively, were designed to help alleviate this condition. Such insoles are tested for their functionality using advanced 3D printing and finite element analysis. Tests were conducted at body weights of 60, 80, 100, and 120 kg. Results indicated that silicone insoles outperformed the others by effecting a better redistribution of pressure with higher magnitudes of strain and stress. Specifically, silicon had strain values between 1.44 × 10 ⁻⁷ and 2.88 × 10 ⁻⁷ , much lower than polyethylene’s 5.92 × 10 ⁻⁵ –1.18 × 10 ⁻⁴ . Whereby, silicon would withstand stress levels to about 47,058 Pa, while polyethylene would do so at 31,932 Pa, making it more resilient under higher loads. Further validation through kinematic analysis proved that silicon insoles enhance the symmetry of walk and disperses the concentration of pressures of the feet, therefore providing more comfort and support during locomotion. These results suggest that silicon insoles offer significant benefits for managing flatfoot, paving the way for future innovations in personalized orthopedic footwear.

This study investigates the influence of intervertebral disc (IVD) height on thoracic spine biomechanics using finite element analysis (FEA) at the T11-T12 segment. A three-dimensional model, derived from CT imaging, was used to compare normal and doubled IVD thickness. In the normal model, stress was uniformly distributed with a maximum von Mises stress of 0.6 MPa in the IVD and 30 MPa overall, ensuring structural integrity. However, the thicker IVD model exhibited heightened stress levels, with von Mises stresses increasing to 4.5 MPa in the IVD and 55.52 MPa in the whole model, a 7.5- and two-fold rise, respectively. Displacement in the thicker IVD model also increased significantly, particularly in the sagittal and frontal planes, indicating reduced spinal stability. These findings demonstrate that excessive IVD thickness disrupts load distribution, increases stress concentration, and impairs stability, exacerbating the risk of herniation and degeneration. The results align with prior studies and highlight the importance of maintaining optimal IVD height for spinal health. This research contributes valuable insights for clinical applications, such as artificial disc design, emphasizing the critical balance between mobility and stability.

Background: Cryo-neurolysis has been proposed as an adjunct for postoperative pain management in total knee arthroplasty (TKA) to reduce opioid consumption and enhance functional recovery. However, its long-term efficacy remains underexplored. This study evaluates pain reduction trajectories, opioid use, and mobility outcomes over a six-month period. Methods: A retrospective cohort study was conducted on 34 patients who underwent TKA with intraoperative cryo-neurolysis. Pain scores were assessed using the Visual Analog Scale (VAS) at seven time points from postoperative Day 1 to Month 6. Opioid consumption and time to unaided ambulation were recorded. Statistical analyses included the Friedman test for pain trends, the Mann-Whitney U test for group comparisons, and Kaplan-Meier survival analysis for time to pain resolution. Results: Median pain scores declined from 2 (Day 1) to 0 (Month 3, p < 0.00001), with all patients achieving complete pain resolution by Month 6. Bilateral procedures demonstrated slightly greater pain reduction at Month 3 (p = 0.048). The median time to VAS = 0 was 90 days (95% CI: 84.2–95.8 days). Opioid use data were inconsistently recorded, limiting conclusive analysis of consumption patterns. No significant associations were found between pain reduction and age, BMI, or comorbidities (p > 0.05). Conclusion: Intraoperative cryo-neurolysis significantly reduced postoperative pain and was associated with early pain resolution in TKA patients. These findings suggest it could be a valuable addition to multimodal pain management strategies in TKA. Further randomized trials are warranted to validate these results and assess its impact on opioid use and functional recovery.