Five-year durability of stand-alone interspinous process decompression for lumbar spinal stenosis

Within the next decade, it is estimated that around 64 million older adults will be affected by lumbar spinal stenosis, making it the most common reason for spine surgery in individuals aged over 65. The increasing number of patients demands a wider range of treatment options, especially for elderly patients who may not be suitable candidates for open surgical procedures and the associated risks of general anesthesia. Interspinous process decompression (IPD) is a minimally invasive procedure that can be performed under monitored anesthesia care in an ambulatory surgery center. It has been proven to provide similar clinical results to decompressive laminectomy for managing symptoms of spinal stenosis.

Neurogenic claudication, characterized by leg pain during walking or standing that is relieved by sitting or flexing the lumbar spine, is the primary symptom of lumbar spinal stenosis. This condition limits a patient’s mobility and significantly affects their quality of life. The compression and constriction of nerves in the lumbar spine contribute to the development of these symptoms. IPD utilizes a stand-alone spacer to prevent the compression of neural elements, particularly in the lateral recess and foramina. Importantly, the spacer is inserted percutaneously without the need for surgical removal of adjacent tissue, thus minimizing the risks associated with invasive procedures.

This article presents the 5-year clinical outcomes of patients with moderate lumbar spinal stenosis treated with the IPD device. The data was obtained from the Superion® treatment arm of a randomized controlled trial comparing two interspinous spacers. The study evaluated the use of stand-alone IPD in subjects aged 45 and older with moderate symptoms of intermittent neurogenic claudication. The results show that IPD with the stand-alone spacer provides sustained clinical benefits. At the 5-year follow-up, 84% of patients demonstrated clinical success on at least two of the three Zurich Claudication Questionnaire (ZCQ) domains. The success rates for individual ZCQ domains were 75%, 81%, and 90% for symptom severity, physical function, and patient satisfaction, respectively. Additionally, there were significant improvements in leg and back pain severity, as well as the Oswestry Disability Index.

The study also reports that 75% of spacer patients remained free of reoperation, revision, or supplemental fixation at the index level after 5 years. The rate of reoperation decreased over time, with most revisions occurring within the first 2 years of observation. Spacer patients who demonstrated early clinical improvement maintained the benefit over time, suggesting the long-term effectiveness of IPD in managing lumbar spinal stenosis.

In conclusion, IPD with a stand-alone spacer provides sustained clinical benefits for patients with moderate lumbar spinal stenosis. With its minimally invasive nature, rapid patient recovery, and low surgical risk of complications, IPD remains a viable treatment option for these patients.

This study contributes valuable insights into the long-term durability of IPD and its ability to provide symptom relief and improve patients’ quality of life.