Chapter 5. Results

Table of Contents
5.1. Baseline characteristics of the patients
5.2. Correlations of symptoms and signs to MRI findings (I)
5.3. Evaluation of patients with the Trp2 and Trp3 alleles (II and III)
5.4. Clinical efficacy of periradicular infiltration. Intention-to-treat analysis (IV)
5.5. Clinical efficacy of periradicular infiltration. Subgroup analysis (V)
5.6. Cost-effectiveness of the treatments in subgroups (V)

5.1. Baseline characteristics of the patients

A total of 277 trial candidates were contacted by the principal author from January 1997 to May 1998. Of the 171 eligible patients, 8 refused to take participate. None specified the reason for refusal. Of the remaining 163 patients, 3 were withdrawn by the radiologist (envelopes unsealed) because typical neurograms were not produced. Of the final study population (160 patients), 97 were men and 63 women. The mean age of the patients was 43.7 years (range 19–78 years), and the mean duration of symptoms 2.5 months. Their clinical signs and symptoms are presented in Table 1.

Five patients had L4, 89 had L5, and 66 had S1 radiculopathy. MRI identified a disc herniation corresponding to the symptoms in 131 (82 %) patients, as well as nerve root enhancement in 3 patients with a non-herniated symptomatic disc. The degree of disc displacement was graded bulge (or normal) in 29 (18%), as contained herniation in 50 (31%), as noncontained herniation in 68 (43%) and as sequester in 13 (8%) patients.

Table 1. Baseline characteristics of 160 patients with sciatica randomly assigned to receive periradicular infiltration either with methylprednisolone-bupivacaine or saline.*

CharacteristicMethylprednisolone- bupivacaine (n = 80)Saline (n = 80)Total (n = 160)
Age (year)43.81343.71343.713
Male gender (%)645861
High school graduates (%)151616
Work-related features
Employed (%)737875
Retired (%)111111
Others (unemployed, students)161114
Duration of sciatica (months)2.41.52.61.52.51.5
First or second episode of sciatica (%)594753
Level affected on MRI (%)
L3-L4 354
L4-L5614051
L5-S1365545
MRI-classification of the symptomatic disc (%)
Bulge or normal 221418
Contained herniation303231
Extrusion485451
Leg pain intensity (100-mm VAS)71 1875 1973 18
Back pain intensity (100-mm VAS)53 2560 2556 25
Oswestry score (%)43 1644 1543 15
Nottingham Health Profile§
Dimension of energy21 2817 2519 27
Dimension of emotional reactions11 1510 1310 14
Dimension of sleep28 3231 3129 31
Dimension of pain66 2672 2569 26
Dimension of mobility33 1934 1734 18
Dimension of social isolation 4 9 2 8 3 8
Mean duration of sick leave (days)14 1822 2618 23
Physical measures
Straight leg raising test (°) 58 1860 1959 19
Lumbar flexion (cm) 4.81.54.91.54.81.5
Motor deficit (% )242022
* Mean SD values shown unless otherwise stated. § The scores of the Nottingham Health Profile range from 0 to 100, with higher scores indicating worse health-related quality in each dimension.Measured by the modified Schober method (the difference between a 15-cm distance marked on the back of the patient in a standing position and distance with the patient in full flexion).