Results of surgery for discogenic low back pain: a randomized study using discography versus discoblock for diagnosis.
METHODS
Randomized, controlled study.


OBJECTIVE
To evaluate the diagnosis of discogenic low back pain (LBP) with discography and discoblock.


BACKGROUND
Discogenic LBP is usually diagnosed by magnetic resonance imaging and discography. However, the reliability of discography is controversial. Previously, we reported the usefulness of discoblock with bupivacaine for diagnosis, and discoblock improved the results of anterior interbody fusion surgery. However, that study was not a randomized, controlled study. Therefore, the purpose of the current study was to compare the results of surgery after diagnosis of LBP by discography and discoblock.


METHODS
Patients (n = 42) with severe LBP showing L4-L5 or L5-S1 disc degeneration on magnetic resonance imaging were evaluated by discography (1.5 mL of contrast medium) or discoblock (intradisc injection of 0.75 mL of 0.5% bupivacaine). We randomized the patients in turn. Anterior discectomy and interbody fusion were performed in patients who responded to the diagnostic procedures. The visual analogue scale score (0, no pain; 100, worst pain), Japanese Orthopedic Association Score (0, worst pain; 3, no pain), Oswestry Disability Index, and patient satisfaction before and 3 years after surgery were recorded and compared between groups.


RESULTS
Twelve patients did not show pain provocation by discography or pain relief by discoblock and were excluded. Fifteen patients who showed pain provocation by discography and 15 patients who experienced pain relief with discoblock were evaluated. Rates of improvement in the visual analogue scale score, Japanese Orthopedic Association Score, and Oswestry Disability Index score in the discoblock group were significantly higher than those in the discography group (P < 0.05) from baseline to 3 years after surgery. Three patients were dissatisfied with surgery after discography compared with one patient after discoblock.


CONCLUSIONS
Pain relief after injection of a small amount of bupivacaine into the painful disc was a useful tool for the diagnosis of discogenic LBP compared with discography.
Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan. sohtori@faculty.chiba-u.jp
Seiji
S
Ohtori
Tomoaki
T
Kinoshita
Masaomi
M
Yamashita
Gen
G
Inoue
Kazuyo
K
Yamauchi
Takana
T
Koshi
Munetaka
M
Suzuki
Sumihisa
S
Orita
Yawara
Y
Eguchi
Shinichiro
S
Nakamura
Masatsune
M
Yamagata
Masashi
M
Takaso
Nobuyasu
N
Ochiai
Shunji
S
Kishida
Yasuchika
Y
Aoki
Kazuhisa
K
Takahashi
D000293:Adolescent; D000328:Adult; D000779:Anesthetics, Local / Q000008:administration & dosage; D002045:Bupivacaine / Q000008:administration & dosage; D017586:Diskectomy / Q000379:methods; D005260:Female; D006801:Humans; D007403:Intervertebral Disc / Q000000981:diagnostic imaging / Q000473:pathology*; D007405:Intervertebral Disc Displacement / Q000150:complications / Q000175:diagnosis / Q000601:surgery*; D017116:Low Back Pain / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D008159:Lumbar Vertebrae; D008279:Magnetic Resonance Imaging; D008297:Male; D010147:Pain Measurement / Q000379:methods; D011859:Radiography; D013123:Spinal Fusion / Q000379:methods; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
D000779:Anesthetics, Local; D002045:Bupivacaine