Older adults with back pain and spinal morning stiffness longer than 30 minutes are more at risk of developing long-term physical functioning limitations

Abstract

Purpose: Spinal osteoarthritis (OA) is related to various signs and symptoms such as back pain, spinal morning stiffness, restricted/painful spinal range of motion (ROM) and lumbar disc degeneration (LDD). However, it is not known if patients with these signs and symptoms experience more limitations in physical functioning, and if these features are prognostic for long-term physical functioning limitations. Therefore, the aims of this study were to assess the following associations in older patients with back pain: 1) Morning stiffness, spinal ROM, and radiographic LDD with physical functioning at baseline, and 2) Morning stiffness, spinal ROM, and radiographic LDD with physical functioning after 1 year. Methods: For this prospective observational study data from the BACE cohort was used. Patients aged >55 years visiting a general practitioner with a new episode of back pain were included. Presence and duration of spinal morning stiffness were assessed with single-item patient-reported questions. Low back ROM was investigated through physical examination by an experienced research assistant, evaluating limitations and pain during lateroflexion, rotations and anteflexion of the spine. Osteophytes and disc space narrowing were considered LDD features, and they were investigated with lumbar lateral X-rays. The 4-grade Lane Atlas classification was used (i.e. grade 0= none, grade 1= mild, grade 2= moderate, grade 3= severe); osteophytes grade 2 or higher at two or more levels for L1-2 to L5-S1 and disc space narrowing grade 1 or higher at two or more levels from L1-2 to L5-S1 were defined as LDD presence. Outcomes were physical functioning limitations at baseline and physical functioning limitations at 1-year follow-up; physical functioning was measured with the Roland Morris Disability Questionnaire (RMDQ, range 0-24, 0 = no physical functioning limitation, 24 = maximum physical functioning limitation). The associations between morning stiffness, spinal ROM and radiographic features of LDD and back-related physical functioning at baseline and 1-year follow-up were assessed with multivariable linear regression models. Adjustments were made for age, sex, BMI, back pain severity, recent episodes of back pain, kinesiophobia and depressive symptoms. Results: This study included 543 patients, with mean age 67 years (SD 8), and 59% female. In multivariable adjusted analyses, presence of spinal morning stiffness (β=1.78, 95%CI 0.93-2.63), morning stiffness longer than 30 minutes (β=1.04, 95%CI 0.04-2.02), and pain during anteflexion (β=1.54, 95%CI 0.71-2.37) were independently associated with worse physical functioning at baseline. Morning stiffness longer than 30 minutes (β=1.54, 95%CI 0.22-2.86) was the only spinal OA feature independently associated with worse physical functioning at 1-year follow-up. Conclusions: Presence of morning stiffness, morning stiffness longer than 30 minutes and pain with anteflexion are associated with the level of physical functioning. Additionally, morning stiffness longer than 30 minutes is a prognostic factor for worse physical functioning at 1 year follow-up, independently of other already known prognostic factors (e.g. previous back pain episodes, physical functioning at baseline, and depression). Hence, older patients with back pain and spinal morning stiffness longer than 30 minutes are more at risk of having future back-related physical activity limitations.