A systematic review to assess whether dynamic stabilisation provides any improvement in validated clinical outcome measures in adult patients with degenerative lumbar spondylolisthesis

Introduction Dynamic stabilization in degenerative spondylolisthesis is a relatively new concept and has been designed to overcome the negative effects of spinal fusion, i.e. increase in spine stiffness, chronic back pain and acceleration of degenerative process at the adjacent levels. To our knowledge and to date, this is the first systematic review presenting the results of an evaluation of the clinical effectiveness of dynamic stabilization devices in patients with degenerative lumbar spondylolisthesis as the sole diagnosis. Materials and methods A detailed search was conducted through several databases (up to February 2013): MEDLINE, CINAHL, AMED, British Nursing Index, SPORTDiscus, EMBASE and Journals@Ovid; an extensive handsearch, including grey literature and reference lists of the articles was conducted. The methodological assessment was performed by two reviewers using the McMaster University framework. Results The search identified a total of 493 titles. Ten studies were included in the final review of which only one was a randomized controlled trial. The reported validated clinical outcome measures were: Oswestry Disability Index, Short Form 36, Visual Analogue Score for back and leg pain and Patient Satisfaction Index. Each study reported a statistically significant improvement of the outcome measures. Conclusion Although the results of dynamic stabilization in degenerative spondylolisthesis are encouraging, the authors cannot safely recommend the use of these devices to the general population as yet due to the moderate methodological quality of the included primary papers. The authors recommend that future research should include properly designed randomized controlled studies, preferably multi-centred, demonstrating solid methodology. Introduction Description of the Condition Degenerative lumbar spondylolisthesis is a condition which occurs when a lumbar vertebra displaces forward in relation to the vertebra situated one level below, due to degeneration of the spinal structures1 (Figure 1). There are three main symptoms associated with degenerative spondylolisthesis: neurogenic claudication, radicular pain and low back pain. The prevalence of degenerative lumbar spondylolisthesis increases from the fifth to the eighth decade2. This condition is three times more common in females than males2 and it mainly affects the level between the fourth and the fifth lumbar vertebrae3. First line treatment for the degenerative lumbar spondylolisthesis is non-operative (analgesia, sacral epidural injections and physical therapy in the form of bracing, electrical stimulation, exercises or ultrasound) but surgery is indicated if conservative measures fail to offer any improvement of symptoms and quality of life is severely impaired. It is important to understand the biomechanics of degenerative lumbar spondylolisthesis because the principles of dynamic stabilization devices are to limit this abnormal motion and restore the loading pattern of the affected segment but at the same time to preserve the mobility of the adjacent level4. Description of the Intervention Treatment options for degenerative lumbar spondylolisthesis are non-operative (analgesia, sacral epidural injections, bracing, electrical stimulation, exercises or ultrasound) and operative (decompression, fusion or dynamic stabilization). The main disadvantages of fusion surgery are related to an increase in spine stiffness, chronic back pain and acceleration of degenerative processes at the adjacent levels5,6. Dynamic stabilization systems have been designed to address the complications associated with spinal fusion and can be described as systems which improve the mobility of a spinal segment by providing stability, but also preventing fusion at the operated level1. The main advantages of dynamic stabilization systems are considered to be: protection of the adjacent levels, preservation of normal posture whilst the patient is sitting and protection of rotatory stress to the sacroiliac joints8. How the Intervention Might Work Two classes of dynamic stabilizers have been designed: *Corresponding author Email: razvantrn@gmail.com 1 Wansbeck General Hospital, Northumbria Healthcare NHS Trust, UK 2 Teesside University, Middlesbrough, UK