Effectiveness of L2 spinal nerve infiltration for selective discogenic low back pain patients.
BACKGROUND
It has been reported that rat L5/6 lumbar discs are innervated mainly by L2 dorsal root ganglion neurons. We previously reported that L2 spinal nerve infiltration was effective for discogenic low back pain (DLBP) patients, although the diagnosis was based only on the results of physical examination, plain films, and magnetic resonance imaging (MRI). The purpose of the current study was to evaluate L2 spinal nerve block for DLBP patients retrospectively based on MRI findings and surgical results.


METHODS
A total of 62 patients with only LBP and no accompanying radicular pain were investigated. Patients had only one level of disc degeneration on MRI. When pain was provoked during discography, we performed surgery at the next stage (40 patients). In all, 22 patients were excluded owing to negative discography results. Of the 40 patients, we evaluated 25 strictly selected patients suffering from DLBP. DLBP was diagnosed when the patient experienced pain relief at least 2 years after anterior lumbar interbody fusion. Fifteen patients who did not show pain relief after surgery were used for the non-DLBP group. L2 spinal nerve infiltration using 1.5 ml of lidocaine was performed in all 40 patients before surgery. The visual analogue scale (VAS) score after L2 spinal nerve infiltration was recorded, and an association of L2 spinal nerve infiltration and DLBP was explored.


RESULTS
Low back pain scores assessed using the VAS score, the Japanese Orthopedic Association score, and the Oswestry Disability Index score in the two groups were not significantly different. L 2 spinal nerve infiltration was effective for 27 patients but not effective for 13 patients; the VAS score after 15 min and 2 h improved in the DLBP group compared with that of the non-DLBP group (P < 0. 05). L2 spinal nerve infiltration was more effective in DLBP patients (21 patients, 84%) than in the non-DLBP group (6 patients, 40%) (P < 0.05).


CONCLUSIONS
In the current study, L2 spinal nerve infiltration was effective in 84% of selected DLBP patients and is thought to be a useful tool for diagnosing DLBP. However, we should take into consideration that the L2 spinal nerve infiltration was effective in 40% of non-DLBP patients as well.
Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan.
Seiji
S
Ohtori
Shinichiro
S
Nakamura
Takana
T
Koshi
Masaomi
M
Yamashita
Kazuyo
K
Yamauchi
Gen
G
Inoue
Sumihisa
S
Orita
Yawara
Y
Eguchi
Munetaka
M
Suzuki
Nobuyasu
N
Ochiai
Shunji
S
Kishida
Masashi
M
Takaso
Yasuchika
Y
Aoki
Kazuki
K
Kuniyoshi
Junichi
J
Nakamura
Tetsuhiro
T
Ishikawa
Gen
G
Arai
Masayuki
M
Miyagi
Hiroto
H
Kamoda
Miyako
M
Suzuki
Yuzuru
Y
Takahashi
Tomoaki
T
Toyone
Masatsune
M
Yamagata
Kazuhisa
K
Takahashi
D000293:Adolescent; D000328:Adult; D000772:Anesthesia, Local; D000779:Anesthetics, Local / Q000008:administration & dosage*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D055959:Intervertebral Disc Degeneration / Q000150:complications* / Q000473:pathology / Q000628:therapy; D008012:Lidocaine / Q000008:administration & dosage*; D017116:Low Back Pain / Q000209:etiology / Q000473:pathology / Q000628:therapy*; D008159:Lumbar Vertebrae; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D012189:Retrospective Studies; D013123:Spinal Fusion; D016896:Treatment Outcome; D055815:Young Adult
D000779:Anesthetics, Local; D008012:Lidocaine