Surgical Treatment in Degenerative Lumbar Spinal Canal Stenosis: Results on Four Relevant Aspects from a Spine Surgeon’s Perspective

Degenerative lumbar spinal stenosis (DLSS) is a progressive condition that leads to enlargement of the facet joints and thickening of the ligamentum flavum as a result of intervertebral disc degeneration. It ultimately causes stenosis in the spinal canal, which subsequently compresses neurovascular structures. These physiological changes are predominately age related and can lead to leg numbness and weakness, buttock pain, and discomfort in the lower extremities. Patients who suffer from DLSS are frequently forced to take periodic breaks when walking due to leg aches or discomfort. As such, DLSS can fundamentally undermine an individual’s quality of life. DLSS impacts people throughout the world. Due to the global aging population, it is anticipated that its prevalence will rise from 9%-47% (1) (2). In Switzerland alone, the prevalence of DLSS among people over the age of 65 will increase from 18% in 2015 to 22.8% by 2030, and among those over the age of 80, it will increase from 5% to 7.2% during this time period (3). In recent decades, more and more people have undergone spinal surgery due to DLSS (4). In Zurich, for example, the number of people who underwent spinal surgery increased from 430 in 2011 to over 1750 in 2015 (5). Lumbar spinal stenosis represents one of the most frequent indications for spinal surgery, with members of the population who are over 65 being the most frequently affected (6) (7). The North American Spine Society (NASS) describes DLSS as ‘‘a clinical syndrome of buttock or lower extremity pain, which may occur with or without back pain, associated with diminished space available for the neural and vascular elements in the lumbar spine’’ (1). A formal DLSS diagnosis is based on a multifaceted combination of dynamics, which include the patient’s personal history, an examination of his or her physical condition, and magnet resonance imaging (MRI) of the lumbar spine. Imaging diagnostics of this nature typically find that the impacted patient has more than one 4 stenotic level (8). In such cases, it can be difficult to arrive at a conclusive judgment as to how many levels of stenosis are required, and there is currently a lack of overall agreement between spinal surgeons on the optimal approach. Furthermore, an additional MRI irregularity is frequently observed among DLSS patients: a displacement of the adjacent vertebral caused by facet joint arthrosis. This vertebra shift, which is also referred to as degenerative spondylolisthesis, can lead to progressive instability as a result of the handling of spinal elements during operations (9) (10). A large number of spinal experts argue that this instability represents a basic indication for fusion surgery as a means of averting the onward development of symptoms and further vertebra slippage. However, this is not the universal view. Other spine surgeons argue that simple decompression for DLSS can be sufficient to enhance the quality of life of the patient involved and reduce claudication symptoms. The New England Journal of Medicine recently published the findings of two randomized trials, which reached contradictory conclusions in terms of the extent to which fusion is advantageous for patients who have DLSS and additional degenerative spondylolisthesis (11, 12). This habilitation presents an overview of four different papers that have a) examined the extent to which spinal surgery is beneficial for patients aged over 80, b) reviewed the debates surrounding the two common surgical options that are employed to treat DLSS patients, c) considered the influence single-level versus multilevel decompression has on the results of multisegmental lumbar spinal stenosis, and d) considered the extent to which preoperative degenerative spondylolisthesis has an impact on the decompression of degenerative lumbar spinal stenosis cases. The analysis presented in this habilitation was based on data acquired from the Lumbar Stenosis Outcome Study (LSOS). The LSOS was performed as a prospective cohort study at eight medical centers in a region of Switzerland that serves approximately two million 5 inhabitants. It is anticipated that the outcomes of the four papers will inform the ongoing efforts of scientists, spine surgeons, and other health care providers to deliver more targeted care through which they enhance the outcomes of DLSS-patients