Dynamic Thoracolumbar Fascial Integrity in Chronic Low Back Pain – an Ultrasonographic Study

Introduction/Background Segmental dysfunction at the thoracolumbar junction is a cause of chronic low back pain (cLBP) [1]. The thoracolumbar fascia (TLF) can be pathologically altered in patients with cLBP [2]. While reliable quantitative ultrasound techniques exist using static images at low lumbar levels [3], little is known about the relationship between chronic pain and dynamic ultrasound images [4]. We therefore compared dynamic US imaging of the thoracolumbar junction fascia in patients with and without cLBP. Methods This two-arm cross-sectional cohort study assessed participants with and without cLBP. Assessment included demographics, back pain (0-10), and lower extremity strength during prone straight leg raise (SLR; 0-10). Fascial organization and resting tensional integrity (fascial pathology) of the posterior layer of the TLF and aponeurosis of the erector spinae were assessed using an adapted published 4-point scale (0-1 points “mild fascial pathology”; ≥ 2 points “moderate fascial pathology”). [5] Participants were assessed while prone with B mode sonographic palpation bilaterally at the T11, T12, and L1 spinous processes. T-tests compared strength and UFPRS (Ultrasound Fascial Pathology Rating Scale) scores between participants with and without cLBP. Results We assessed 50 cLBP participants (male, 48%; 52.5±14.1 years, median pain duration 4.3 years, at-rest pain severity 3.8±2.3 points, with exercise 6.0±2.4 points); and 50 Control participants without cLBP (male, 46%; age 51.3±14.1 years). There were no between-group baseline differences in age, sex, height and weight. Compared with Controls, cLBP participants had significantly weaker SLR (Left 7.0±1.3 vs 7.58±1.1, p=0.018; Right 6.8±1.3 vs 7.66±1.2). p=0.002). Those with moderate fascial pathology were significantly weaker on SLR regardless of the presence or absence of back pain (Left 7.2±1.2 vs 7.8±1.4, p = .042; Right 7.1±1.3 vs 8.0±1.3, p =.010). Moderate fascial pathology was common in both groups, but more common in those with low back pain (44/50 vs 36/50, p = .009). Conclusion cLBP patients had a weaker prone SLR and more thoracolumbar fascial pathology on dynamic ultrasound, suggesting further evaluation of this technique toward potential inclusion in cLBP examination is warranted. Altered fascial integrity was common with or without cLBP.