engleski

Provocative discography screening improves surgical outcome

INTRODUCTION Lumbar back pain is extremely common, but most cases are self-limiting with no functional deficit. Newerthless, even when diagnostic imaging reveals only degenerative changes, some people become seriously debilitated in the absence of any serious pathology or instability. Is there a specific „pain generator“ responsible for these symptoms? A lordotic reconfiguration of the lumbar spine during rhe course of human evolution was an atecendent of the freeing of human hands for creative work and for the consequent brain development. A price that the human beings have to pay is a degenerative disc disease (DDD) of the lumbar spine. For the treatment of DDD there are at least two hundred treatment options. The Evidence based medicine exactly validated only few of them. Some clinical trials in which surgical techniques were tested had ill defined preoperative patient's status, inclusion and excluison criteria. In the treatment of the patients suffering from a low back pain a specific diagnosis is essential for satisfactory postoperative results. In order to clarify the operation indication, to simplify demanding decision-making process and to improve quality of clinical trials a few classification systems of degenerative disc disease were introduced during last decade. Weaknesses of proposed classification systems were omitting of a degree of intradiscal disruption and degenerative changes of the posterior structures of vertebrae. Provocative discography has assumed the role of identifying the pain generator with the aim of directing specific treatment, which has not been without its cntroversies. Lindblom introduced and popularized provocative discography in 1940s. Although the diagnostic method has resisted test of the time competing with new more sophisticated and noninvasive diagnostic tests its usefulness in preoperative workout is controversal. In 2004 the North America Spine Society have introduced a new classification system that included a provocative discography although some papers denied usefulness of the provocative discography in the treatment of low back pain. The objective of the study was comparison of surgical outcomes of patinets operated on without discography and patients that underwent discography. METHODS Study was designed as a randomized controlled trial. According to power analysis study comprised 310 patients divided in the experimental (No=207) and the control (No=103) groups. Inclusion criteria were low back pain resisitant to the nonsurgical treatment for more than 6 months and conventional radiological findings showing degenerative changes without clear generator of the pain. Exclusion criteria were red flags. After standard radiological diagnostic imaging (standard radiograms in AP and LL projections, CT and MR) patients filled in Oswestry Disability Index (ODI) , SF36, Zung and MSPQ Questioners. Depending on radiological findings and statistical test results patients were indicated to randomisation. The analysed group had 207 patients and controled group 103 patients. The second author performed discography and the first author CT's post discography and analyzed questioners and radiological findings. At 1-year follow-up examination patients filled in ODI, SF-36, Likert scale analyzing satisfaction with procedure and answer to the question would he / she repeat discography if it would be necessary. RESULTS At first enrollment included 356 patients but 46 were excluded because they refused to participated in study. 310 patients were randomised (M-131, F-179, average age 49, 5 age) between 2003 and 2009. The analysed group had 207 patients and controled group 103 patients. 10 patients from analysed group had high depression (Zung more than 33) and somatisation (MSPQ more than 12 in patients with Zung results between 18 and 33) in 10 patients so they were excluded from study. We performed discography on 197 patients. In 39 cases the findings were negative, their pain were discordant so they were excluded. The surgery was performed on 158 patients in analysed group and 103 patients in controlled group. In patients with D group by Thalgott on one segment we performed noninstrumented fusion. In cases on D changes on more segments (mostly two) we performed transpedicular fixation. In cases with E and F grop by Thalgott we performed cirkumferential – posterolateral and intercorporal fixation. During 1-year follow-up 2 patients didn’t came on control. In analysed group 72 patients had DDD and 84 had degenerative changes on facet joints, discopathy with sagital or coronal plane deformity or some other generator of the pain. That group we classified as group with other indications. In controlled group DDD had 57 patients and group with other indications 46 patients. In control group without discography in patients with DDD preoperative ODI were 41.95% and postoperative ODI were 18.88. Difference between both ODI was 22.07%, or 11 points. In discography group with DDD preoperative ODI were 42.46% and postoperative ODI were 7.42%. Difference between both ODI was 35.04%, or 17.5 points. In control group, in patients with other indications preoperative ODI were 46.78% and postoperative ODI were 20.65%. Difference between both ODI was 26.13% or 13 points. In discography group patients with other indications have preoperative ODI 47.02% and postoperative ODI 18.60%. Difference between both ODI was 28, 42% or 14, 5 points. CONCLUSIONS DDD treated surgically without discography didn't reach clinically significant improvement of 15 ODI points as recommended by FDA for the patients treated with fusion. Provocative discography screening with psychological testing in the trial group made improvement following fusion clinically significant. For other degenerative generators of the pain discography didn't prove useful diagnostic tool. As there were no post discography spondilodiscitis and patients are willing to repeat procedure if it would be necesssary, our results suggest discography use in preoperative workput of patients with DDD.

Provocative discography; MR; DDD

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