Introduction
Patients with lumbar spinal stenosis (LSS) may complain of poor balance, decreased physical function and problems maintaining physical activity levels due to radiculopathy on ambulation1–3. Decompressive surgery is often indicated if conservative management fails to achieve a satisfactory clinical outcome4,5. While surgical management has proven effective at treating radiculopathy, and patients report increased physical function post-operatively, knowledge about the effect on postural control and physical activity is sparse6. We present preliminary data and the protocol for an ongoing trial which aims to investigate the effects of decompressive surgery on the balance and activity levels of elderly with LSS.
Methods
This is a 24-month, multi-centre, pre-post intervention trial, with the included participants acting as their own controls. Patients ≥ 65 years of age with magnetic resonance imaging verified symptomatic LSS are recruited from two separate centers, with pre-operative baseline data collected up to 3 months before surgery, and follow-up data collected 3, 6, 12 and 24-months post-operatively. An inclusion period of one year is planned. Postural control measurements are performed using the Wii Balance Board, mini–Balance Evaluation Systems Test (mini-BESTest) and Tandem test, and data concerning physical activity levels are collected using ActiGraph wGT3X-BT accelerometers. Patient reported outcomes regarding quality of life and physical function are collected from the EuroQol-5D, 36-Item Short Form Health Survey and Zurich Claudication Questionnaire. The primary outcomes are change in sway area of centre of pressure (COP) and change in time spent in moderate-vigorous physical activity (MVPA) per week from baseline to follow-up at 24-months. A sample size of 80 participants has been calculated. Study inclusion began in September 2023 and the trial is expected to be completed by August 2026.
Results
As of writing, three participants have been included. Preliminary pre-operative data has shown a mean sway area of COP of 17.35 cm2, compared to 0.33 cm2 for a young, healthy control without LSS in the eyes open configuration, and 22.55 cm2 compared to 1.02 cm2 in the eyes closed configuration (figure 1). Mean mini-BESTest and Tandem test score was 17.67 and 25.67 respectively. Physical activity data varied, with only one participant achieving a minimum of 150 minutes of MVPA over the course of a week, as recommended by the World Health Organisation. Preliminary post-operative data is expected by January 2024.
Discussion
This trial seeks to quantify the effect of decompressive surgery for the purpose of maintaining physical function and preventing falls amongst elderly suffering from LSS. It is expected that the study will be able to definitively ascertain whether surgical management of LSS leads to improved postural control and increased levels of physical activity. Knowledge from this study can be used to guide future rehabilitative interventions and choice of management strategy concerning elderly patients with symptomatic LSS, to help strengthen balance and physical function in this patient group.
Figure 1:
Figure 1: Schematic of the postural control investigation test setup and preliminary pre-operative results compared to a young, healthy control. COM; centre of mass, BOS; base of support, COP; centre of pressure.