Role of magnetic resonance imaging in lumbar spondylosis

To assess the frequency of various MRI findings in patients with lumbar spondylosis and determine their association with symptoms of patients.

Cross-sectional analytical study.

Radiology Department,The Aga Khan University Hospital, Karachi, from January to December, 2002.

The study included 120 patients who presented with low back and leg pain. Segmental classification system was used to classify the pain distribution. All patients underwent lumbar MRI using 1.5 T-scanner. MRI scans was evaluated for magnitude and location of nerve compression, disc extrusion and the nature of nerve and thecal sac deformation in the central canal, lateral recess and intervertebral foramen at each spinal level. Statistical analysis was performed using computer program SPSS (Version; 10). Chi-square test was also used to determine significance of association between degree of compression, duration of symptoms, site of pain and presence of weakness and numbness. Independent samples test (Levenes test) and Chi-square test were used to determine the significance of associations between age, gender, chronicity of symptoms and MRI findings. A p-value of <0.05 was considered to indicate statistically significant association.

The study included 120 patients, the age range was 22 to 88 years (mean 47 years). Twenty-three patients had acute pain of less than 2 months, 40 patients had recurrence of previous symptoms within past 2 months and 57 patients had chronic pain. Disc herniation was most frequent finding seen in 107 patients (89%). Eighty-eight patients (73%) had MRI evidence showing some degree of nerve or thecal sac compression. Severe nerve compression was present in 48 patients (40%). Disc extrusion was present in 22 patients (18%). There was no significant association between segmental distribution of symptoms and presence of anatomic impairment. However, severe nerve compression and disc extrusion were significantly associated with pain distal to the knees.

The presence of disc extrusion or ipsilateral severe nerve compression at one or multiple side is strongly associated with distal leg pain. There should be a correlation between patient symptoms and signs of sciatica and imaging demonstration of nerve root compression before invasive therapy is undertaken.