Background: Low back pain and lumbar intervertebral disc degeneration (IDD) are common findings. Valid data on correlation between clinical pain scores and grades of IDD are not available.
Objective: To investigate the correlation of intervertebral disc degeneration (IDD) at lumbar levels L4/5 and L5/S1 and the Oswestry Disability Index (ODI).
Methods: The lumbar discs L4/5 and L5/S1 of 591 patients were evaluated according to the 5-point (Grade I to Grade V) grading system as published by Pfirrmann et al. Functional status was assessed using the Oswestry Disability Index. Spearman's coefficient of rank correlation was used for statistical analysis (p < 0.05).
Results: The majority of patients revealed lumbar discs with Pfirrmann grade II to grade IV changes (93.3% at level L4/5; 89.8% at level L5/S1), while a relatively low percentage of lumbar discs presented with grade I (level L4/5: 1.5%; level L5/S1: 2.0%) or grade V (level L4/5: 5.1%; level L5/S1: 8.1%) changes, respectively. Patients' ODI scores ranged between 0 and 91.11% (arithmetic mean of 32.77% ± 17.02%). The largest group of patients (48.39%) had moderate functional disability (ODI score between 21 and 40%). There was a weak, but statistically significant positive correlation between IDD and ODI for both evaluated lumbar levels.
Conclusions: Increased lumbar IDD in MRI goes along with an increased ODI. Thus, MRI is a strong indicator of a patient's clinical appearance. However, low back pain cannot be explained by imaging alone. Clinical correlation is imperative for an adequate diagnostic advance in patients with low back pain.
Keywords: Lumbar spine; Oswestry Disability Index; intervertebral disc degeneration; low back pain; magnetic resonance imaging.