Almond-sized device to ease chronic back pain

AN IMPLANT the size of an almond is being used to treat chronic lower back pain. The device, which takes just 20 minutes to insert near the bottom of the spine, is packed with donated bone cells.

These seep out over weeks and months to form healthy, strong bone that stabilises the sacroiliac joints — among the largest in the body, linking the pelvis to the spine. Their job is to provide stability and act as a shock absorber for the back and pelvis.

But almost one in three cases of chronic lower back pain in the UK is due to excess movement — or destabilisation — in these joints.

This is usually the result of inflammation arising from injury, or wear and tear from the joint disease osteoarthritis.

With the new implant, healthy bone cells fuse with the damaged joint, creating strong new bone that restores stability and soothes pain.

The sacroiliac joints connect the hip bones to the sacrum at the bottom of the spine. Reinforced with strong ligaments, they bear the load of the upper body when you stand, sit, walk or jump and also help with forward and backward bending.

If one or both of the joints become hypermobile (where the degree of movement is greater than it should be) or hypomobile (when there is too little movement), this can lead to chronic pain.

Hypermobility causes inflammation that affects the joint and surrounding nerves, while in hypomobility — often caused by osteoarthritis — the bones in the hip and sacrum rub against one another, triggering pain.

Current treatments include steroid injections ( to dampen inflammation), physiotherapy and painkillers. In severe cases, surgeons fuse the sacrum and the hip together with metal implants to restrict excess movement.

However, it can be several weeks before patients can even stand up properly after the operation.

The tiny LINQ Fusion System device, tested at Rush University in Chicago, U.S., could be a simpler and more effective alternative.

Doctors apply a local anaesthetic to the lower back and make a halfinch incision to insert a thin ‘loading tube’ into the sacroiliac joint. The device is then fixed in place before the tube is withdrawn.

The results of a recent study published in the Journal of pain Research, involving 159 patients aged 21 to 70 with chronic lower back pain, showed that one year after implantation, pain levels had dropped by more than 80 per cent in roughly a third of patients. many others experienced a 50 per cent reduction in pain.

And their mobility also improved. at the start of the study, 82 per cent were severely disabled or bedbound. after the trial, none was bedbound and there was a three-fold drop in the number suffering from severe disability.

Commenting on the research, mike McNicholas, a consultant orthopaedic surgeon at liverpool University Hospitals, said: ‘lower back pain due to sacroiliac joint pathology is a massive burden on society.

‘ This promising, minimally invasive approach offers great hope to those suffering the problem and their carers and family who are also severely affected.’