Postural Imbalance Amongst Elderly Patients With Symptomatic Lumbar Spinal Stenosis Before and After Decompressive Surgery

Disease Background:

While lumbar spinal stenosis (LSS) is one of the most common degenerative diseases of the spinal column, there is no universally accepted definition of LSS, and no accepted radiologic diagnostic criteria. LSS most often refers to a narrowing in the central canal of the vertebrae, the lateral recess, or the neural foramen. Changes to these can occur due to acquired degenerative spondylosis or spondylolisthesis, or more rarely due to conditions such as ankylosing spondylitis and space-occupying lesions, or congenital abnormalities. LSS can be classified according to anatomical location, etiology or severity of narrowing, though no validated classification has been published.

The lack of concrete definition has caused difficulties in estimating the prevalence of LSS. Studies using community-based sampling has shown a prevalence of acquired LSS, defined as a narrowing of the central canal to ≤ 10mm in the anterior-posterior direction, of 7.3%. The prevalence has been shown to rise with age, from 4.0% affected at < 40 years of age, to 14.3% amongst patients ≥ 60. No significant differences have been observed in overall prevalence according to gender, although there seems to be a slightly higher prevalence amongst elderly females than males.

Although LSS is often asymptomatic, common symptoms of LSS include low back pain, which worsens with prolonged ambulation, lumbar extension and standing, and which is relieved by rest and forward flexion, as well as lumbar radiculopathy. Patients may also complain of poor balance, and physical examination findings may include a wide-based gait and abnormal Romberg results. Symptoms are thought to occur due to compression of microvascular structures in the nerves, allowing for neural ischemia and defects in nerve conduction, and venous pooling resulting in inadequate oxygenation and metabolite accumulation.

Current treatment options for LSS range across both conservative and surgical management strategies. Conservative management has traditionally been regarded as first-line treatment, with a combination approach of physical therapy and pharmacological treatment with NSAIDs and analgesics. Epidural steroid injections have been used for symptom management, though with limited short and long-term benefits. Surgical management is often indicated in patients with ongoing pain despite attempts at conservative management for 3-6 months. Choice of surgical strategy to relieve the pressure on the neural structures depends on the anatomical location of stenosis and number of stenotic segments, as well as the intraoperative assessment of stability.