0000000000263875
AUTHOR
Nieves Saiz-sapena
showing 6 related works from this author
ADDISC lumbar disc prosthesis: Analytical and FEA testing of novel implants
2023
The intact intervertebral disc is a six-freedom degree elastic deformation structure with shock absorption. 'Ball-and-socket' TDR do not reproduce these properties inducing zygapophyseal joint overload. Elastomeric TDRs reproduce better normal disc kinematics, but repeated core deformation causes its degeneration. We aimed to create a new TDR (ADDISC) reproducing healthy disc features. We designed TDR, analyzed (Finite Element Analysis), and measured every 500,000 cycles for 10 million cycles of the flexion-extension, lateral bending, and axial rotation cyclic compression bench-testing. In the inlay case, we weighted it and measured its deformation. ADDISC has two semi-spherical articular s…
Selective T3–T4 sympathicotomy versus gray ramicotomy on outcome and quality of life in hyperhidrosis patients: a randomized clinical trial
2021
Abstract Background: compensatory hyperhidrosis is the leading cause of patients' dissatisfaction after thoracic sympathicotomy.Objective: to reduce compensatory hyperhidrosis to increase patients' satisfaction. Patients and methods: a prospective randomized study on palmar hyperhidrosis, May 2016-September, 2019. Twenty-one patients T3-T4 sympathicotomy and 21 T3-T4 gray ramicotomy. Data prospectively collected. Analysis at study's end. Focus on the sweating, temperature, quality of life baseline and postoperatively, compensatory hyperhidrosis, hand dryness, patients' satisfaction, and if they would undergo the procedure again and would recommend it.Results: No baseline differences between…
Bionate Lumbar Disc Nucleus Prosthesis: Biomechanical Studies in Cadaveric Human Spines.
2022
Design: cadaveric spine nucleus replacement study. Objective: determining Bionate 80A nucleus replacement biomechanics in cadaveric spines. Methods: in cold preserved spines, with ligaments and discs intact, and no muscles, L3-L4, L4-L5, and L5-S1 nucleus implantation was done. Differences between customized and overdimensioned implants were compared. Flexion, extension, lateral bending, and torsion were measured in the intact spine, nucleotomy, and nucleus implantation specimens. Increasing load or bending moment was applied four times at 2, 4, 6, and 8 Nm, twice in increasing mode and twice in decreasing mode. Spine motion was recorded using stereophotogrammetry. Expulsion tests: cyclic c…
Barbed Dental Ti6Al4V Alloy Screw : Design and Bench Testing
2023
Background context. Dental implants are designed to replace a missing tooth. Implant stability is vital to achieving osseointegration and successful implantation. Although there are many implants available on the market, there is room for improvement. Purpose. We describe a new dental implant with improved primary stability features. Study design. Lab bench test studies. Methods. We evaluated the new implant using static and flexion–compression fatigue tests with compression loads, 35 Ncm tightening torque, displacement control, 0.01 mm/s actuator movement speed, and 9–10 Hz load application frequency, obtaining a cyclic load diagram. We applied variable cyclic loadings of prede…
Nucleus disc replacement : designs and material selection FEA analysis
2022
Study Design. We selected the materials and implant design and performed Finite Element Analysis (FEA) studies. Background. Nucleus disc replacements, implanted since 1960, have undergone continuous evolution in materials and designs, but subsidence, extrusion, and in vivo degradation limit widespread use. Aim. The aim of this study is to create a new nucleus disc replacement that avoids the abovementioned drawbacks. Material and Methods. We created eighteen designs with varied materials and analyzed them with FEA in compression and shear tests in a lumbar spine model programmed in Ansys Parametric Design Language. Results. Bionate® 80A had the closest mechanical characteristics to the inta…
High frequency of lumbar fusion in patients denied surgical treatment of the sacroiliac joint.
2019
Purpose: Effective treatment of medical conditions relies on proper diagnosis. Clinical trials show the safety and effectiveness of sacroiliac joint (SIJ) fusion in patients with chronic SI joint dysfunction. To what extent is the condition under recognised? Objective: To determine whether under recognition of SIJ pain affects healthcare trajectories in Spanish patients with low back pain. Methods: Retrospective study of characteristics and consequences of 189 patients with persistent SIJ pain seen in an outpatient neurosurgery clinic. Results: Patients with SIJ pain who were denied surgical treatment had a longer pain duration, higher likelihood of prior lumbar fusion, and a high rate (63%…