1. Pedicle Screw System May Not Control Severe Spinal Rotational Instability
- Author
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Permsak Paholpak, Winai Sirichativapee, Yuichi Kasai, Takaya Kato, Taweechok Wisanuyotin, Tetsutaro Mizuno, Weerachai Kosuwon, and Kriengkrai Nabudda
- Subjects
Joint Instability ,Male ,musculoskeletal diseases ,Rotation ,medicine.medical_treatment ,Instability ,03 medical and health sciences ,0302 clinical medicine ,Lumbar ,Pedicle Screws ,Functional spinal unit ,Cadaver ,Animals ,Humans ,Medicine ,Orthopedics and Sports Medicine ,Range of Motion, Articular ,Pedicle screw ,Aged ,Aged, 80 and over ,Human cadaver ,030222 orthopedics ,Lumbar Vertebrae ,business.industry ,Deer ,Anatomy ,Middle Aged ,musculoskeletal system ,Biomechanical Phenomena ,Spinal Fusion ,Facetectomy ,Female ,Neurology (clinical) ,Cadaveric spasm ,business ,Range of motion ,030217 neurology & neurosurgery - Abstract
Study design An in vitro biomechanical study. Objective The purpose of this study is to discuss whether pedicle screw systems can control spinal rotational instability in a functional spinal unit of lumbar spine on human cadaver. Summary of background data Rotational experiments using deer lumbar cadaveric models showed that rotational range of motion (ROM) of the model fixed by a pedicle screw system with crosslinking after total facetectomy for both the sides was larger than that in the intact model, and stated that spinal rotational instability could not be controlled using a pedicle screw system. Methods A rotation experiment using 10 functional spinal units (L3-4) of lumbar spine on human cadavers was performed by preparing the four models (intact model, damaged model, pedicle screw model, and crosslink (CL) model) in stages, then calculating and comparing rotational ROM among the four models. Results Rotational ROM in the CL model was still larger than that of the intact model in all the samples. And, rotational ROM decreased in the order of damaged model >> pedicle screw model > CL model > intact model. Statistical analysis revealed significant differences between all models (P Conclusions Pedicle screw systems may not control severe spinal rotational instability in human lumbar cadaveric models with total facetectomy on both the sides. This may represent a major biomechanical drawback to the pedicle screw system. Level of evidence N/A.
- Published
- 2020
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