Interspinous process implantation for the treatment of neurogenic intermittent claudication.

BACKGROUND

Lumbar spinal stenosis (LSS) is a disabling medical condition in which narrowing of the spinal canal compresses the spinal cord and nerves causing a condition called neurogenic intermittent claudication (NIC). Decompressive spine surgery is the standard of care for patients who fail to improve with conservative management. However, oftentimes, patients who suffer from LSS are elderly individuals with multiple co-morbidities who cannot withstand the risks of decompressive surgery. X-Stop, a novel and minimally invasive FDA approved interspinous process implant, has come into the scene as an alternative to decompressive surgery, and can be inserted under local anesthetic with minimal blood loss.

OBJECTIVE

Despite its growing support in medical literature as an effective and conservative treatment of NIC, X-Stop remains a fairly new form of treatment. The aim of this study is to assess the clinical efficacy of its use.

METHODS

Fifty consecutive patients with at least two-year follow-up had a confirmed diagnosis of NIC secondary to LSS by computed tomography or magnetic resonance imaging (MRI) and subsequently received an X-Stop implant. Subjects' ages ranged from 64 to 95 with a mean age of 79, while the gender distribution comprised of 23 males and 27 females. Zurich Claudication Questionnaire (ZCQ) was used to assess patient outcome measures in three domains: physical function (PF), patient satisfaction (PS), and symptom severity (SS). The visual analog scale (VAS) was used to assess trends in pain with a scale from 0-10, with 0 defined as "pain-free" and 10 designated as "the worst pain imaginable".

RESULTS

Compared to pre-op scores, PF, SS, and VAS scores for back, buttock and leg pain had a significant mean decrease at 6, 12, 24 months post-op (P < 0.05). Based on the ZCQ and VAS scores, a success rate of 79% (27.34), 78% (30.38) and 74% (17.23) were achieved at six months, 12 months, and 24 months respectively.

CONCLUSIONS

X-Stop is a safe and effective treatment for NIC that provides marked relief of symptoms with sustained beneficial outcomes at up to two years of follow-up. In addition, X-Stop permits implantation under local anesthetic with minimal blood loss".