Lumbar Dynamic Segmental Restabilization: The Dynesys® Experience 1999-2009

Read printer friendly
 Subscribe in a reader

Share with others

 

HJ Leu PD DR.MED
President Ismiss 2008-2011
Bethania Spine Base, Orthopaedic Spinal Surgery
Klinikum Bethanien

Address:
Z®rich
Switzerland

Citation: H. Leu : Lumbar Dynamic Segmental Restabilization: The Dynesys® Experience 1999-2009. The Internet Journal of Minimally Invasive Spinal Technology. 2009 Supplement II - to IJMIST Vol III No 4

Abstract

In modern western societies, degenerative disc disease is an increasing therapeutic and economic problem in modern societies and afflicts over 80% op population at least once in lifetime. The reasons ground in changed live stile with more sitting working position, long sitting schooling periods in decisive adolescent skeletal maturation phase of life. Beside changes in physical behavior also some nutritional aspects in post-agricultural societies may play a relevant role. While in an early stage lumbar disc failures as protrusion and herniation prevails, in a later stage segmental instability deserves our diagnostic and therapeutic interest. Segmental instability has become a controversially defined and treated vertebral pathology with considerable impact also on tt costs. From asymptomatic hypermobility up to instability covers a larger field of different combined pathologies that need well differentiated treatments. In cases without neurologic implication a physical therapy with isometric circumferential stabilization remains the golden standard. Where this fails, treatment options are to consider following the structures to treat. For diagnostics, beside clinical examination various imaging techniques help to determine the concerned level. First is conventional functional x-ray, the classic lumbar functional myelography and where available dynamic MR-imaging. This newest technique nevertheless has its methodical limits in symptomatic patients due to up to unbearable pain with motion-artifacts during still relatively long exposure time. In cases with isolated mono- or bisegmental instability of the ventral pillar including alsp posterior facet disease, interbody restabilization with fusion or total disc replacement (TDR) are available; in cases with isolated inborn defects of the posterior facet pillar - such as spondylolysis ® an interbody fusion (PLIF) remains the golden standard. TDR is fine in cases with untreatable dysfunction of the disc with intact mid/posterior pillar structures. Due to persisting facet problems where preoperatively present and potential problems due to its anterior operative approach (e.g. lesions of the plexus hyposgastricus with potential sexual dysfunctions), its indication remains narrow and its outcome controversial. Where instability is due to spondylolysis, local isthmic repair hardly brings reproducible results in larger series. In degenerative facet disease without pseudolisthesis less then grade II, a dynamic restabilization with pedicular anchorage (e.g. DYNESYS® developed by Dubois in France 1994)) is our treatment of choice since its clinical introduction in 1999. In mayor pseudolisthesis segmental instrumented fusion remains the tt of choice. Interspinal implants can be a favorable option in an elderly patient without considerable all-day demands and restricted systemic options for mayor surgery. In an younger active patient, beside lost of correction due to spinal process arrosion and other risks as their limited lateral bending stability can maintain facet irritation symptoms. As degenerative instability is often combined with soft (ligamentary) stenosis, combined treatment is mandatory and deserves our individual evaluation for specific operative adaptations. Since 1999 to 2007 over 572 cases with lumbar posterior facet disease and lumbar soft stenosis were treated with a combination of interlaminar decompression in combination with a pedicular based posterior bilateral dynamic stabilization device. A selscted group of 224 cases with over 5 year decourse and some specific problems as screw-loosening, spontaneous interfacet fusion and seldom reported late infection of its textile cable components are presented. The clinical overall outcome reached a score of 7.6 while a control group of 100 cases with conventional fusion reached 6.8 in the Balgrist-score. As the indications of Dynesys involve less advanced pathologies, the slightly better score is not significant. The same is to consider for the slightly lower rate of adjacent level degeneration over 5 years. The main advantages remain its less invasive operative procedure and the easier muscular rehabilitation

This article was last modified on Fri, 03 Jul 09 14:16:48 -0500

This page was generated on Fri, 20 Nov 09 21:42:07 -0600, and may be cached.