Is restricted range of motion one of the signs of lumbar disc degeneration in older adults with low back pain?

Abstract

Purpose: Low back pain (LBP) is the most prevalent musculoskeletal complaint throughout the world, causing burden to heath care systems and society. Lumbar disc degeneration (LDD) is a feature of spinal osteoarthritis and it is associated with LBP and spinal morning stiffness. However, it is unknown which signs and symptoms related to LDD could help to distinguish patients with LBP and LDD-related symptoms from other patients with LBP. For classifying symptomatic degeneration of the hip and/or knee, the ACR criteria are commonly used, but similar clinical criteria for spinal osteoarthritis do not exist. Besides pain and morning stiffness, one of the other components of the ACR criteria is limited (or painful) range of motion (ROM); however, it is unknown if ROM is related to LDD in patients with LBP. Therefore, the goal of this study was to assess the association between low back ROM and LDD. Methods: This study used the baseline data of the BACE cohort study, including 675 patients aged >55 years visiting a general practitioner with a new episode of non-specific LBP. Low back ROM was investigated through physical examination by a medical doctor evaluating ROM and pain during lateroflexion, rotation, and anteflexion. Restricted lateroflexion was defined as not able to bend sideways further then the knee. For anteflexion the distance between finger tops and the floor was measured, performing maximal anteflexion. The presence of LDD features was evaluated with the four grade Lane Atlas classification (i.e. grade 0= none, grade 1= mild, grade 2= moderate, grade 3= severe) for osteophytes and disc space narrowing. The following definitions of LDD presence were used: osteophytes of grade 2 or higher at two or more levels for L1-2 to L5-S1, or disc space narrowing grade 1 or higher at two or more levels from L1-2 to L5-S1. The association between ROM and LDD was assessed with logistic regression models, and adjustments were made for BMI, age and gender. Results: Six-hundred sixty-one patients with LBP (60% female) were included. Mean age was 66 (SD 8) years, 63% reported spinal morning stiffness. 37% were classified as having the LDD definition of osteophytes and 73% the LDD definition of disc space narrowing. Restricted lateroflexion was strongly associated with the osteophytes LDD definition, grade 2 disc space narrowing (as compared to grade 0) and the disc space narrowing LDD definition (Table 1). Pain during lateroflexion was associated with disc space narrowing grade 2 or 3 (when compared to grade 0), disc space narrowing grade 3 (compared to grade 0), and the LDD definition of disc space narrowing (Table 1). Pain during rotation was associated with narrowing grade 3 (if compared to grade 0, Table 1), but asymmetry or pain in rotation were not associated to any other LDD feature. Restricted or painful anteflexion was not associated with any LDD feature, with the sole exception of anteflexion <10 cm with the LDD definition of disc space narrowing (OR= 1.5, 95% CI 1.0-2.1). Conclusions: This study found multiple associations between restricted or painful low back lateroflexion and LDD, particularly with disc space narrowing (Table 1), in older adults with LBP. Almost no associations were found between LDD features and altered (or painful) rotation and anteflexion ROM. These results imply that assessing low back ROM in lateroflexion may help to identify LDD in patients with LBP.