Study Design: Microstructural investigation of compression-induced herniation of a lumbar disc held in a concordant complex posture.
Objective: To explore the significance of loading rate in a highly asymmetric concordant posture, comparing the mechanisms of failure to an earlier study using a nonconcordant complex posture.
Summary Of Background Data: A recent study with a nonconcordant complex posture (turning in the opposite direction to that which the load is applied) demonstrated the vulnerability of the disc to loading that is borne by one set of oblique-counter oblique fiber sets in the alternating lamellae of the annulus, and aggravated by an elevated loading rate. Given the strain rate-dependent properties of the disc it might be expected that the outcome differs if the posture is reversed.
Methods: Forty-one motion segments from ovine 16 spines were split into two cohorts; adopting the previously employed low rate (40 mm/min) and surprise rate (400 mm/min) of loading. Both groups of damaged discs were then analyzed microstructurally.
Results: With the lower rate loading the concordant posture significantly reduced the load required to cause disc failure than earlier described for nonconcordant posture (6.9 vs. 8.4 kN), with more direct tears and alternate lamella damage extending to the anterior disc. Contrary to this result, with a surprise rate, the load at failure was significantly increased with the concordant posture (8.08 vs. 6.96 kN), although remaining significantly less than that from a simple flexed posture (9.6 kN). Analysis of the damage modes and postures suggest facet engagement plays a significant role.
Conclusion: This study confirms that adding shear to the posture lowers the load at failure, and causes alternate lamella rupture. Load at failure in a complex posture is not determined by loading rate alone. Rather, the strain rate-dependent properties of the disc influence which elements of the system are brought into play.
Level Of Evidence: N/A.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1097/BRS.0000000000002652 | DOI Listing |
Int J Biol Macromol
January 2025
School of Food Science and Technology, South China Agricultural University, Guangzhou 510642, China; School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; State Key Laboratory of Food Science and Resources, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China. Electronic address:
In this paper, zein-carboxymethyl starch (CMS) nanoparticles were prepared by antisolvent precipitation method to improve the stability of rutin (RT). The encapsulation efficiency, loading capacity, oxidation resistance, structural properties were evaluated. The results showed that electrostatic, hydrogen bond and hydrophobic interaction were the main driving forces for the formation of nanoparticles.
View Article and Find Full Text PDFJ Stomatol Oral Maxillofac Surg
January 2025
Department of Prosthodontics and Gerostomatology, Poznan University of Medical Sciences, 60-792 Poznan, Poland.
Background: Tooth agenesis, particularly the absence of upper lateral incisors, presents substantial challenges for clinicians due to the associated bone atrophy, which limits the use of traditional implant solutions. Current options, such as endosseous implants combined with guided bone regeneration (GBR), often fail due to insufficient osseointegration in atrophic bone. This study aims to evaluate the effectiveness of custom-made, additively manufactured subperiosteal implants in addressing these challenges METHODS: This retrospective study assessed 16 custom-made subperiosteal implants used in 12 patients (10 females, 2 males; mean age 25 ± 2.
View Article and Find Full Text PDFAppl Radiat Isot
January 2025
Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81300, Skudai, Johor, Malaysia.
Dealing with radioactive waste, particularly from various industrial processes, poses significant challenges. This paper explores the use of lithium aluminate borate (Li-Al-B) glass matrix as an alternative method for immobilizing radioactive waste, focusing specifically on waste generated in tin smelting industries, known as tin slag. The study primarily concentrates on transforming tin slag, a byproduct abundant in Natural Occurring Radioactive Material (NORM), into a stable and safe form for disposal.
View Article and Find Full Text PDFACS Appl Bio Mater
January 2025
College of Chemical and Biological Engineering, Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology, Zhejiang University, Hangzhou 310027, China.
Traditional drug-delivery methods are limited by low bioavailability and nonspecific drug distribution, resulting in poor therapeutic efficacy and potential risks of toxicity. Mesoporous silica nanoparticles (MSNs) have attracted wide attention as drug-delivery carriers due to their large specific surface area, adjustable pore size, good mechanical strength, good biocompatibility, and rich hydroxyl groups on their surface. In this paper, MSNs were synthesized by a template method, and the morphology and pore structure were regulated.
View Article and Find Full Text PDFHernia
January 2025
Centro de Patología Herniaria Argentina, Cerviño 4449, 1425, Buenos Aires, Argentina.
Purpose: This article critically examines long-standing groin pain (LSGP) in physically active adults related to sports overload by analyzing terminology, pathophysiology, and treatment.
Method: This review is based on data from over 10,000 patients managed through a multidisciplinary algorithm. (LSGP) has been variably labeled, using terms that have led to inconsistencies in understanding its origin and management.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!