Does a small size needle puncture cause intervertebral disc changes?
OBJECTIVE
Small size needles have been regularly used for intradiscal injection of innocuous/potential therapeutic compounds in experimental conditions, but also in clinic procedures, such as discography. Our aim was to investigate if a 30-gauge needle could trigger observable changes on intact intervertebral discs. We compared these effects to those induced by a large size needle (21-gauge), a well-known intervertebral disc degenerative model based on needle puncture.


METHODS
Coccygeal intervertebral discs (Co8-9) of adult male Wistar rats were punctured with a 21-gauge needle, while the coccygeal levels Co7-8 and Co9-10 remained intact. The 30-gauge needle was used to inject a safe volume of saline (2 µl) on both intact (Co9-10) and punctured (Co8-9) discs. MRI and histological score were performed at 2, 15 and 42 days after procedure.


RESULTS
MRI analyses revealed significant reduction on signal intensity of 21-gauge punctured discs. Intact discs which received a saline injection through a 30-gauge needle also revealed significant alterations in the MRI signal when compared with control discs. No histological changes were observed in the intact saline injected discs at any time analyzed.


CONCLUSIONS
Since significant intervertebral image changes were observed with a 30-gauge needle, cautious interpretation of the pharmacological inoculation findings is required.
Dental School of Ribeirao Preto, Universidade de São Paulo, BR.
Ana Carolina
AC
Issy
Medical School of Ribeirao Preto, USP, BR.
Vitor
V
Castania
FMRP, USP, Ribeirão Preto, SP, BR.
Joao Walter
JW
Silveira
Department of Internal Medicine, FMRP, USP, Ribeirão Preto, SP, BR.
Marcello Henrique
MH
Nogueira-Barbosa
Department of Physics, Faculty of Philosophy and Science Ribeirao Preto, USP, BR.
Carlos Ernesto Garrido
CE
Salmon
Dental School of Ribeirao Preto, NAPNA, USP, BR.
Elaine
E
Del-Bel
FMRP, USP, Ribeirão Preto, SP, BR.
Helton Luis Aparecido
HL
Defino
D000818:Animals; D004195:Disease Models, Animal; D004867:Equipment Design; D007403:Intervertebral Disc / Q000293:injuries / Q000473:pathology*; D055959:Intervertebral Disc Degeneration / Q000209:etiology / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D009339:Needles / Q000009:adverse effects*; D011677:Punctures / Q000009:adverse effects* / Q000295:instrumentation*; D017208:Rats, Wistar; D012445:Sacrococcygeal Region; D013997:Time Factors