Biological Treatment for Intervertebral Disc Degeneration to Preserve Motion โ€“ Reality or Fantasy?

Vivian Tam, Victor Leung, Kenneth MC Cheung
European Musculoskeletal Review, 2012;7(1):49-53
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Abstract

Intervertebral disc (IVD) degeneration and its associated low back pain affects a large proportion of the worldwide population and is characterised by biochemical changes in the IVD, such as loss of proteoglycans and water, which leads to structural and functional changes of the IVD. The majority of conventional treatments for IVD degeneration aim to reduce the clinical symptoms associated with this condition, yet few commonly used treatments address the underlying biological causes of IVD degeneration. Recently, there has been an increase in the study of biological therapeutics to counter IVD degeneration. The rationale behind this is that by addressing the underlying biological causes of IVD degeneration, the structure, integrity and function of the degenerated IVD could improve. Several approaches including that of the application of growth factors, gene therapy and cellular therapy have been taken and we review here the latest updates in their potential as treatments for IVD degeneration.
Keywords
Intervertebral disc degeneration, biological therapeutics, gene therapy, mesenchymal stem cell therapy, growth factors, stem cell therapy, regenerative medicine
Disclosure The authors have no conflicts of interest to declare.
Received: November 22, 2011 Accepted January 03, 2012
Correspondence: Kenneth MC Cheung, Clinical Professor and Deputy Chief, Division of Spine Surgery, Department of Orthopaedics and Traumatology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Pokfulam, Hong Kong. E: ken-cheung@hku.hk

Intervertebral disc (IVD) degeneration and its associated low back pain (LBP) is a potentially debilitating condition that will affect up to two-thirds of the worldโ€™s population at some stage in their lives.1,2 The aetiology of IVD degeneration is multi-factorial and is characterised most prominently by a decrease in water, proteoglycan and collagen content from the nucleus pulposus (NP),3,4 which leads to morphological and structural changes in the IVD, ultimately affecting IVD function. The resulting effect of these changes, such as a decrease in disc height and instability of the spine/spinal segment, can cause LBP in patients with IVD degeneration. While LBP is commonly associated with IVD degeneration, some patients with IVD degeneration remain asymptomatic.5 IVD degeneration and associated LBP accounts for a large proportion of medical consultations due to its prevalence. The costs associated with medical treatment in addition to loss of work hours and care result in a large economic burden to society, with reported costs in the UK and Australia exceeding ยฃ12 billion and AUS$9 billion per annum, respectively.6,7

Conventional therapies for the treatment of IVD degeneration and associated LBP have targeted the relief of pain for the improvement of quality of life of the affected patient. Such treatments include the use of medication for pain; however, when non-surgical treatment has little or no effect on pain caused by IVD degeneration, surgical intervention is used as an alternative. One of the popular surgical treatments for IVD degeneration and associated LBP is spinal fusion. Spinal fusion was first reported over 60 years ago for this indication8,9 and to this day remains the gold standard of surgical treatment for lumbar IVD degeneration in symptomatic patients. Originally utilising bone autografts, other materials subsequently used in spinal fusion also include bone allografts, demineralised bone matrices, ceramics and putty.10 The use of ceramics and other materials in comparison with bone autografts is advantageous as there is no donor site morbidity, which occurs with autografts and there is an abundant source on demand. The application of both growth factors such as bone morphogenetic proteins (BMP) as well as cells has also been reported to increase the healing and success rate of spinal fusion.10โ€“12

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