RESUMO
The applicability of a polyether ether ketone locking compression plate (PEEK LCP) fabricated using FDM (fused deposition modeling)-based 3D printing to treat actual patients was studied. Three different tests-bending, axial compression, and axial torsion-were conducted on tibial non-osteoporotic comminuted diaphyseal fracture samples fixed with the commercial titanium alloy LCP and 3D-printed PEEK LCP. Comparing the outcomes of these tests revealed that the commercial titanium alloy LCP underwent plastic deformation in the bending and axial torsion tests, though the LCP did not fail even when an external force greater than the maximum allowable load of the tibia fixture of the LCP was applied. Elastic deformation occurred in the 3D-printed PEEK LCP in the bending and axial torsion tests. However, deformation occurred even under a small external force, and its stiffness was 10% compared to commercial titanium alloy LCP. Thus, 3D-printed PEEK LCP can be applied to the fracture conditions in non-weight-bearing regions. The experimental results reveal detailed insights into the treatment of actual patients by considering the stiffness and high toughness of 3D-printed PEEK LCP.
RESUMO
Purpose: We evaluated the feasibility of a juxta-articular-type volar distal radius plate for the surgical treatment of marginal distal radius fractures. Materials and methods: Twenty marginal distal radius fractures, defined by the location of the fracture line within 10 mm of the joint line of the lunate fossa, were retrospectively reviewed between July 2020 and July 2022. The fractures were fixed using a juxta-articular-type volar plate (ARIX Wrist System). The characteristics of the implant and surgical technique, radiologic, and clinical outcomes, and related complications were evaluated. Results: Bony union was achieved in all patients within six months. Acceptable radiological alignment was achieved with no significant differences between the fractured and the normal sides. The clinical outcomes were favorable, with satisfactory functional outcomes. There was one case of post-traumatic arthritis and two cases of carpal tunnel syndrome. No implant-related complications including flexor tendon problems were observed. Conclusion: The juxta-articular distal radius plate of the Arix Wrist system is feasible for treating marginal distal radius fractures and achieves favorable clinical outcomes without implant-related complications in East Asian patients.
RESUMO
The indication for the surgical treatment of ankle fractures that involve a posterior malleolar fragment remains controversial. This cadaver study assessed the biomechanical results of rotation stiffness of Haraguchi type 1 posterior malleolar fragments with or without cannulated screw fixation. Twelve anatomic lower-extremity specimens from 6 cadavers were tested. Six right legs were subjected to posterior malleolus osteotomy (Haraguchi type I) followed with (group A; n = 3) or without (group B; n = 3) fixation using a cannulated screw. Ankle joint stability was measured under both external rotation force and axial loading, and the passive resistive torque was measured in both groups. The mean torque value in group A was 0.1093 Nm/º, while that in group B was 0.0537 Nm/º. There was a significant intergroup difference (p = .004). In group B, the torque value was further increased in the latter rotation period (about 40-60 degrees). Group A proved more stable under experimental conditions than group B. Fixation in type I posterior malleolar fragments produced improved stability in ankle rotation, even for posterior malleolar fragments involving <25% of the articular surface, and has been considered an effective aid in treatment.
