Abstract
Background: The perception of back pain subjective is hard for physicians to measure. For this
reason, questionnaires are an important instrument to evaluate the pain [1]. The main point of this study was to verify differentiation of pain symptoms in
patients with different pain mechanisms. The most important parameter was the PainDetect
questionnaire, which can differentiate between nociceptive and neuropathic pain. Additional
parameters were measured before and after surgery to characterise pain symptoms in
detail.
Material and Methods: We selected patients with diagnosed vertebral compression fracture, herniated disc
or with spinal cord compression. To characterise the preoperative condition on admittance,
we collected the data from the physical examination, as well as clinical data, including
X-ray, CT and MRI. To characterise the pain, we used the painDetect questionnaire,
the Oswestry Index questionnaire (ODI) and the visual analogue scale (VAS). Depending
on the diagnosis, patients were treated by surgery (radiofrequency kyphoplasty, nucleotomy,
spondylodesis). At 2 to 3 days and 6 months after surgery, we repeated the questionnaire
and compared the results with those before the operation. Data on patient satisfaction
and adverse events were also collected.
Results: This study included 62 patients with vertebral compression fracture (group 1: VBF,
89 % female, mean age 71 years) and 77 patients with herniated disc or spinal cord
compression (group 2: non-VBF, 55 % female, mean age 53 years). There was no difference
between both groups in preoperative pain intensity (acute, maximum, average): median
ordinal scale 0 to 10; group 1: 6, 8, 7; group 2: 6, 9, 7. The total score in the
painDetect questionnaire differed significantly between the two groups (median group
1 = 9, group 2 = 17; effect size r = 0.5; p = 0.000). The existence of neuropathic
pain was presumed (> 90 %) in 3 % of the patients in group 1 and in 13 % of patients
it was not excluded. In contrast, in group 2 it was presumed (> 90 %) in 43 % of patients
and in 30 % of patients it could not be excluded. Patients with vertebral compression
fracture had greater pain intensity (VAS 71) than patients from group 2 (VAS 53).
There was no difference in the total score of the Oswestry questionnaire between the
two groups (56 % vs. 58 %). Pain intensity was significantly reduced in both groups
after the operations. Six months postoperatively, pain intensity (median ordinal scale
0 to 10; acute, maximum, average) was 2, 5, 3 in group 1 and 2, 4, 2 in group 2. Moreover,
the final scores of the painDetect questionnaires were significantly lower in both
groups after the operations (4 in both groups). The median score of the ODI was reduced
in both groups, with an effect size of 0.6. 98 % of the patients in group 1 and 94 %
in group 2 were satisfied with the outcome of the operation.
Conclusion: The preoperative pain characteristics of patients with vertebral compression fracture
is different from those of patients with herniated disc or with spinal cord compression.
43 % of patients in group 2 exhibited a neuropathic pain component and in 30 % this
could not be excluded. In contrast, in group 1 only 3 % of the patients exhibited
a neuropathic pain component. Postoperatively, pain symptoms were significant reduced
in both groups, so that the risk of chronic pain was considerably less.
Key words
painDetect questionnaires - neuropathic pain - vertebral compression fracture - herniated
disc - spinal cord compression
