Clinical trial: Feasibility Study of NL-Prow Interspinous Spacer to Treat Lumbar Spinal Stenosis (NCT01053364)

Eligibility criteria:
Inclusion Criteria:

          -  Men and women ≥50 years of age.

          -  Symptoms of leg/buttock/groin pain, with or without back pain, that are exacerbated by
             lumbar extension and relieved in flexion.

          -  Diagnosis of neurogenic intermittent claudication (NIC) (defined as a feeling of
             paresthesia and/or discomfort and/or pain and/or weakness in the leg(s) during walking
             or standing) secondary to lumbar spinal canal stenosis at 1-2 lumbar levels (between
             L1 and L5), confirmed by dynamic X-Ray (showing sagital instability or rocking), and
             CT and/or MRI (showing central spinal canal narrowing and/or foraminal narrowing).

          -  Has completed at least 6 months of conservative therapy, which may include but is not
             limited to, epidural steroid injections, oral steroids, NSAIDS, analgesics, physical
             therapy, spinal manipulation, bracing.

          -  Appropriate candidate for lumbar surgical treatment using posterior approach.

          -  Subject can walk independently 15 meters or more.

          -  Subject is able to understand the risks and benefits of participating in the study.

          -  Subject understands and has signed the study informed consent form.

          -  Subject is physically and mentally willing and able to comply with the requirements of
             the study procedure and scheduled follow-up visits and testing.

        Exclusion Criteria:

          -  Severe symptomatic lumbar spinal stenosis at ≥2 level, requiring surgical
             intervention.

          -  Prior lumbar spine surgery at any level.

          -  Unremitting pain in any spinal position or axial back pain only without
             leg/buttock/groin pain.

          -  Evidence that subject's symptoms are due to vascular claudication OR has significant
             peripheral vascular disease.

          -  Significant instability of the lumbar spine at any level OR defined as translation of
             more than 3mm or 10 degrees of angular motion between flexion and extension on upright
             lateral radiographs.

          -  Subject has an ankylosed segment at the affected level.

          -  Significant scoliosis, defined as Cobb angle >25°.

          -  Cauda equina syndrome.

          -  Fixed motor deficit or known peripheral neuropathy demonstrated clinically.

          -  Subject has degenerative neurologic disease.

          -  Subject has any mass lesions.

          -  Any evidence of spinal or systemic infection.

          -  Subject has a history of spinous process fracture or pars interarticularis fractures
             or pathologic fractures of the vertebrae or multiple fractures of the vertebrae and/or
             hips

          -  Subject has history or radiographic evidence of 1 or more osteoporotic fractures in
             the spine.

          -  Subject has severe osteoporosis of the spine, defined as bone mineral density (BMD) in
             the spine more than 2.5 SD below the mean of adult normals.

          -  Subject is paraparetic.

          -  Subject has a bleeding disorder.

          -  Active systemic disease such as HIV, hepatitis, etc.

          -  Subject is immunologically suppressed, or has received or is receiving 7.5 milligrams
             prednisone (or equivalent) daily for more than six months immediately prior to
             enrollment.

          -  Extreme morbid obesity, defined as BMI >35 kg/m2.

          -  Diagnosis of lumbar spinal stenosis which requires a direct neural decompression or
             surgical intervention other than those required to implant the experimental device.

          -  Subject is not able to undergo MRI or tolerate closed MRI scan.

          -  Known or suspected history of alcohol and/or drug abuse.

          -  Life expectancy less than one year.

          -  Active rheumatoid arthritis.
No condition on gender to be admitted to the trial.
No healthy subjects accepted to join the trial.
Subject must be at least 50 Years old.


Patient description (medical language): A 57-year-old man comes to the emergency department due to constipation.  His last bowel movement was 2 days ago. He complains of spending about 30 minutes once attempting to defecate. He also has lower back pain.  There is no history of trauma. The pain is not relieved with over-the-counter pain medications.  His vital signs are within normal limits.  Examination shows low back pain that is worse with back flexion and raising of the legs; it radiates into his left leg.  Pinprick in the perianal area does not cause rapid contraction of the anal sphincter.  The rest of the neurologic examination is normal. He is suspected of Cauda Equina syndrome and referred to a spinal MRI.

Patient description (patient's own words): I'm a 57 year-old-man, and I had to go to the ER because I couldn't go defecate. My last trip to the toilet was 2 days ago, and I tried too many times, during 30 min, to get my poop to get out. I also have terrible lower back pain. The doctor did not notice any trauma. I tried to get the pain away using over-the-counter medications, but it simply did not work! Back in the ER my vitals were normal. My pain was even more intense with back flexion, and when I raised my legs, it radiated into my left leg. The doctor did an anus exam where he had to pinch it and it was not reacting! However the rest of my neurologic exam was normal. The doctor suspects a Cauda Equina syndrome and referred me to a spinal MRI.

Does the patient match the trial criteria? Contradiction