The impact of discography on the surgical decision in patients with chronic low back pain

Background context: A reduced frequency of discographies might be the result of increasing concern with long-term effects of discography such as disc degeneration. More knowledge is needed in what patient discography is most likely to influence the surgical decision.

Purpose: This study was aimed at highlighting how discography affects surgical decisions when performed on one of four different indications in a complicated subgroup of patients with chronic low back pain assumed to be associated with degenerative disc disease (DDD).

Study design: Prospective before-after study to analyze how frequently a prediscography preliminary decision was changed and in what direction by adding information from discography in a subgroup of patients with DDD.

Patient sample: One hundred thirty-eight patients admitted to a spine clinic more than 4 years with the DDD diagnosis (15% of all) were referred for discography because it was considered that medical history, clinical findings, and magnetic resonance imaging (MRI) were insufficient to make a final assessment on whether to propose surgery/recommend against surgery or what segments to operate on.

Outcome measures: These were the recorded changes to prediscography preliminary decisions after information was added from discography.

Methods: Before these patients were referred to provocative discography, the surgeon had to select one of four alternative questions/indications being the reason for the discography and choose what decision would have been made if discography would not have been available. The questions/indications were as follows: surgery decided discography to establish whether to treat adjacent segment as well (n=17); several segments degenerated on MRI, pain likely to be discogenic, discography to evaluate what segments to treat (n=56); uncertainty whether pain is discogenic but one suspected segment on MRI (n=38); uncertainty whether pain is discogenic and several segments degenerated in MRI (n=27); the decision after discography was then compared with the prediscography decision and the changes affected by the result of the discography were analyzed.

Results: Changes were made to the prediscography decision in 71% of the patients in total. When the surgeon was assured that the pain was discogenic, one segment was added or subtracted in 58% of the patients compared with original prediscography decision. When the surgeon was uncertain if pain was discogenic, the final decision changed from surgery to no surgery in 8%, from no surgery to surgery in 42%, and in cases that were planned for surgery prediscography, one segment was added or subtracted in 17% of the patients. The more certain the surgeon was before discography that the patient's pain was indeed discogenic, the fewer changes between surgical treatment and no surgical treatment took place. The more uncertain the surgeon was before discography that the patient's pain was discogenic, the fewer changes in segments to treat took place in patients who went on to surgery. Changes of involved segments were made to all the 27 patients with a preliminary decision for surgical treatment of the L5-S1 segment solely. The corresponding figure for L4-L5 and L4-L5-S1 was 70% and 53%, respectively.

Conclusions: A high frequency of decisions was altered in this group of surgeons when using discography as an additional examination in patients where uncertainty remains in how to treat after clinical examination, questioning, and MRI.