19 Harley St, London, W1G 9QJ, UK

Comparative biomechanical investigation of a modular dynamic lumbar stabilization system and the Dynesys system

The goal of non-fusion stabilization is to reduce the mobility of the spine segment to less than that of the intact spine specimen, while retaining some residual motion. Several in vitro studies have been conducted on a dynamic system currently available for clinical use (Dynesys). Under pure moment loading, a dependency of the biomechanical performance on spacer length has been demonstrated; this variability in implant properties is removed with a modular concept incorporating a discrete flexible element. An in vitro study was performed to compare the kinematic and stabilizing properties of a modular dynamic lumbar stabilization system with those of Dynesys, under the influence of an axial preload. Six human cadaver spine specimens (L1-S1) were tested in a spine loading apparatus. Flexibility measurements were performed by applying pure bending moments of 8 Nm, about each of the three principal anatomical axes, with a simultaneously applied axial preload of 400 N. Specimens were tested intact, and following creation of a defect at L3-L4, with the Dynesys implant, with the modular implant and, after removal of the hardware, the injury state. Segmental range of motion (ROM) was reduced for flexion-extension and lateral bending with both implants. Motion in flexion was reduced to less than 20% of the intact level, in extension to approximately 40% and in lateral bending a motion reduction to less than 40% was measured. In torsion, the total ROM was not significantly different from that of the intact level. The expectations for a flexible posterior stabilizing implant are not fulfilled. The assumption that a device which is particularly compliant in bending allows substantial intersegmental motion cannot be fully supported when one considers that such devices are placed at a location far removed from the natural rotation center of the intervertebral joint

Keywords : Aged,anatomy & histology,Biomechanical Phenomena,Cadaver,diagnostic imaging,Equipment Design,Equipment Failure Analysis,Humans,injuries,instrumentation,Internal Fixators,Joint Instability,Lumbar Vertebrae,Motion,Movement,physiology,physiopathology,Prostheses and Implants,Radiography,Range of Motion,Articular,Rotation,Spinal Fusion,Spine,Spondylosis,standards,surgery,Switzerland,Universities,Weight-Bearing,Zygapophyseal Joint,, Biomechanical,Investigation,Modular, botox leg injections side effects

Date of Publication : 2009 Oct

Authors : Gedet P;Haschtmann D;Thistlethwaite PA;Ferguson SJ;

Organisation : Institute for Surgical Technology and Biomechanics, University of Bern, Stauffacherstrasse 78, 3014, Bern, Switzerland

Journal of Publication : Eur Spine J

Pubmed Link : https://www.ncbi.nlm.nih.gov/pubmed/19565278

The London Spine Unit : Harley Street UK. Specialists in Cutting Edge Technologies for Spinal Surgery

Make an Appointment 

Trustpilot Reviews
Doctify Reviews
Top Doctor Reviews

Comparative biomechanical investigation of a modular dynamic lumbar stabilization system and the Dynesys system | Nerve pain groin

What our patients say ...

Consultant Spine Surgeon
Consultant Spine Surgeon
Consultant Spine Surgeon

This surgical technique consists of a percutaneous approach for the treatment of small to medium size hernias of the intervertebral disc by laser energy. The main objective is to reduce the intradiscal pressure in the nucleus pulposus

Laser Disc Surgery can be performed under local anaesthetic as a day case at our centre on the prestigious Harley Street.
What is London spine unit and How it Works

The London Spine Unit was established in 2005 and has successfully treated over 5000 patients. All conditions are treated.

treatment of all spinal disorders

The London Spine Unit specialises in Minimally Invasive Treatments allowing rapid recovery and return to normal function

Trusted by patients worldwide

The London Spine Unit provides the highest quality care to all patients and has VIP services for those seeking exceptional services

If you have any emergency Doctor’s need, simply call our 24 hour emergency

Your personal case manager will ensure that you receive the best possible care.

Call Now 

+44 844 589 2020
+44 203 973 8810