Prediction of walking ability following posterior decompression for lumbar spinal stenosis

Following surgery for lumbar spinal stenosis (LSS) up to 40% of people report persistent walking disability. This study aimed to identify pre-operative factors that are predictive of walking ability post-surgery for LSS.

An observational cohort study was conducted using data from the British Spine Registry (2017-2018) of adults (≥ 50 years) with LSS, who underwent ≤ 2 level posterior lumbar decompression. Patients receiving fixation or who had previous lumbar surgery were excluded. Walking ability was assessed by a single item on the Oswestry Disability Index and dichotomised into poor/good outcome. Multivariable regression models were performed.

14,485 patients were identified. Pre-operatively 30% patients reported poor walking ability, this decreased to 8% at 12 months follow-up. Predictors associated with poor walking ability at 12 months were: increasing age (≥ 75 years OR 1.54, 95% CI 1.07, 2.18), BMI ≥ 35 kg/m² (OR 1.52, 95% CI 1.00, 2.30), severity of leg pain (OR 1.10, CI 95% 1.01, 1.21), disability (OR 1.01, 95% CI 1.01, 1.02) and quality of life (OR 0.72, 95% CI 0.56, 0.89). Pre-operative maximum walking distance (OR 1.10, 95% CI 1.05, 1.25) and higher education (OR 0.90, 95% CI 0.80, 0.96) were associated with reduced risk of poor walking ability at 12 months; p < 0.05. Depression, fear of movement and symptom duration were not associated with risk of poor outcome.

Older age, obesity, greater pre-operative pain and disability and lower quality of life are associated with risk of poor walking ability post-operatively. Greater pre-operative walking and higher education are associated with reduced risk of poor walking ability post-operatively. Patients should be counselled on their risk of poor outcome and considered for rehabilitation so that walking and surgical outcomes may be optimised.