A clinical trial being conducted at Hospital for Special Surgery (HSS) offers patients with a common degenerative spinal condition a nonfusion treatment for their condition. The trial tests the implantation of the LimiFlex Paraspinous Tension Band (Empirical Spine Inc.) after surgical decompression for a condition called degenerative lumbar spondylolisthesis with spinal stenosis.

"The FDA has allowed us to do this trial without randomizing. There are about 20 centers involved in this clinical trial; some are designated as experimental and others as control. At HSS, all patients who decide to enter the trial will get the new investigational treatment," said Harvinder Sandhu, MD, a spine surgeon who is leading the trial at HSS in New York City.

Degenerative spondylolisthesis with spinal stenosis is one of the most common problems that occurs in lumbar spine. "It affects primarily adults over the age of 40 and presents as a combination of back pain and pain that goes down the legs with activities," said trial investigator Sheeraz Qureshi, MD, spine surgeon at HSS. "We are always looking for nonfusion alternatives for everything we do, and LimiFlex is an exciting nonfusion option. This trial will help us determine if it is a long term solution."

Degenerative spondylolisthesis is diagnosed when one vertebra slips forward over the one below it. The condition is a disease of aging in which the bones, joints and ligaments in the spine become weak and less able to hold the spinal column in alignment. Degenerative spondylolisthesis most commonly occurs in the L4-L5 level of the lower spine, but can also occur at the L3-L4 level. Females are three times as likely to be diagnosed with the condition than males.

"Degenerative spondylolisthesis results from arthritis in the joints, which then ultimately leads to some abnormal movement of the vertebrae, which then results in this closing up of the nerve channel, the stenosis," said Dr. Qureshi. "The most common treatment is to do a decompression to get rid of the stenosis to open up the nerve channel, and to do a fusion to prevent the spondylolisthesis from getting worse."

The LimiFlex Clinical Trial will evaluate the safety and effectiveness of decompression and stabilization with the LimiFlex Paraspinous Tension Band, compared with the standard treatment, decompression and transforaminal lumbar interbody fusion with concomitant posterolateral fusion for the treatment of lumbar degenerative spondylolisthesis (Grade I per Meyerding classification) with spinal stenosis. LimiFlex is designed to stabilize the spine without fusing it. The device is made of two spring-like titanium rods that are wrapped around the back of two spine segments, allowing the spine to move in a controlled manner. Clinical trial investigators will collect data from all trial sites and compare clinical outcomes of patients receiving LimiFlex with patients who receive the conventional treatment.

"We are going to use standardize measures for those outcomes. We also want to see how many patients may require future surgery or have problems at other levels of the spine," said Dr. Sandhu. "There is an ongoing theory that one of the downsides of fusion is that it puts additional stresses on other levels of the spine. With the LimiFlex, in theory, if you don’t actually completely join the vertebrae together and fuse them, allowing some degree of motion, that puts less stress on other levels. The hypothesis is that these patients will be less likely in need of future surgery." The trial will help answer this question.

To be eligible for the trial, patients must be between the ages of 25 and 80 and have lumbar degenerative spondyloslisthesis (grade I per Meyerding classification), at one level from L1 to S1, with radiographic confirmation using X-Ray. Exclusion criteria includes morbid obesity (BMI >40), history of cancer in last five years, involvement in litigation because of spinal condition, and planned hip or knee replacement surgery.