The XStop helps prevent a patient from bending too far backwards and causing compression of the spinal nerves where spinal stenosis exists. The implant allows forward bending (flexion) however, and does not unduly restrict the rotation of the spine, making it less rigid than after spinal fusion and laminectomy. Patients who are unable to have an extensive surgical procedure under general anaesthetic can experience some degree of relief from the insertion of the X-Stop device and it may allow them to delay or remove the need for further surgery.
The relief that many patients with spinal stenosis experience from simply bending forward, or when in a bike-riding position, can be achieved by the X-Stop as the patient is standing or sitting. The device essentially opens up (decompresses) the lumbar spine to remove the pressure on the spinal nerves, with varying degrees of success. That there is no necessity for extensive tissue removal, the use of pedicle screws or metal plates, and that muscles and ligaments are not severed, makes this an attractive procedure for many where significantly, and permanently, affecting the structure of the spine could facilitate further degeneration.
Clinical Trial Evidence
The evidence from clinical trials that the FDA took into account prior to approving the device for general use found that two years after implantation there was an 84% maintenance rate in terms of the decompression of the spine. In 96% of cases the implant experienced no dislodging, and 94% of patients suffered no incidence of complications connected to the device itself. The vast majority of patients having the X-Stop implant inserted did not go on to require, or desire, additional back surgery at the two-year follow-up, although 7% did opt to have the device removed with some going on to have a laminectomy.
Risk of Complications
The risk of complication from the X-Stop procedure is relatively small, and the short duration of the operation and recovery period make it an attractive option for many patients with mild to moderate lumbar spinal stenosis. Pain reduction, improved function and mobility, and better quality of life are amongst the benefits of the X-Stop procedure, with relief from symptoms comparing very favourably against non-operative treatment for spinal stenosis at the follow-up mark of 1-4 years. Long-term data confirming the continued benefits of the X-Stop is lacking due to the relative youth of the device, but patient satisfaction has been suggested to be between 50-78% up to four years after the procedure.
Patients with pre-existing spondylolisthesis are considerably less likely to have continued success with the X-Stop procedure as their condition will most likely degenerate and necessitate further, more invasive surgery. Pain relief achieved with the X-Stop for spondylolisthesis sufferers may only occur in around half of those treated, making it a less attractive option than other surgeries such as TLIF or decompressive laminectomy. Discussing surgical outcomes of previous patients with the clinic or hospital under consideration is desirable as there may be an alternative procedure that has worked well for patients with a similar condition.