Researchers at King's College London have identified a gene linked to age-related degeneration of the intervertebral discs, a common cause of lower back pain.
Back pain costs the United Kingdom an estimated £7billion ($11 billion in US dollars) a year due to sick leave and treatment costs. Lumbar disc degeneration (LDD) is inherited in 65%-80% of people with the condition, suggesting that genes play a key role. Until now, the genetic cause of lower back pain associated with LDD was unknown, says King's.
For this study, scientists compared MRI images of the spine in 4,600 individuals with genome-wide association data, which mapped the genes of all the volunteers. They identified that the gene PARK2 was implicated in people with degenerate discs and could affect the speed at which they deteriorate.
The researchers say the results show that the gene may be switched off in people with LDD. Although it is still unclear how this might happen, it is thought that environmental factors, such as lifestyle and diet, could trigger this switch by making changes known as epigenetic modifications to the gene.
The study
was published online September 19 in Annals of Rheumatic Diseases.
The Myth of the Disc as the Cause of Low Back Pain
Another commonly accepted and often repeated myth is that degeneration of the intervertebral disc is a major source of low back pain," The degenerated disc is not now, nor ever has been the cause of idiopathic low back pain. This is another perennial, persistent and pervasive attempt to establish a non-existent relationship.
Holt (14, 15), who also found that degeneration of the disc is common and commonly found in subjects with no history of back pain, concluded that pain production is not necessarily an indication of an abnormal disc. Savage stated that 47% of those who had experienced low back pain had normal lumbar spines.(16)
In 1992, Shaw reported on 1000 consecutive cases of low back pain using changes in apparent leg length and movement of the pelvis from asymmetry to symmetry to correctly identify and treat the dysfunction of the sacroiliac joints (17). He found that 98% of all patients had at least some degree of dysfunction of the sacroiliac joint (SIJD) and his surgical incidence for herniated discs dropped to 0.2%. (17) The improvement of 50 consecutive cases of sacroiliac dysfunction of 96% in Murikami’s study is nearly equal to an incidence of 98% in Shaw's study, substantiating Shaw's study. (13)
The frequency and level of degeneration is of greater interest as the prevalence of disc degeneration at L4/5 and L5/S1 reported was three times greater than that at L3/L4 and above. With a dysfunction of the sacroiliac joints in anterior rotation the lumbosacral angle will be increased and the iliolumbar ligaments will be loosened, destabilizing the lower lumbar vertebra and increasing shear and torsion shear to the disks. This is probably the most likely cause of pathological disk disease at L4/5 and L5/S1 and of spondylolisthesis. (18,19, 20) Practitioners who use the traditional side-lying method of manipulation, pulling the shoulder back and shoving the hip anteriorly and caudad hard enough to cause cavitation, are at considerable risk of increasing shear and joint instability.
Nachemson (21) observed that "Even though in elective, carefully selected lumbar disc surgery, 90% of the patients will enjoy the relief of leg pain, as many as 60-70% may continue to have some low back pain. If a relationship existed between the disc and low back pain, then the low back pain should be relieved with the repair of the disc.
Posted by Richard DonTigny, PT
on 10/2/2012 4:28 PM