Quantitative sensory testing in painful osteoarthritis: a systematic review and meta-analysis.
OBJECTIVE
To systematically review the use of quantitative sensory testing (QST) in pain characterisation (phenotyping) in osteoarthritis (OA).


METHODS
Six bibliographic databases (Medline, Embase, Amed, Cinahl, PubMed, Web of Science) were searched to identify studies published before May 2011. Data were extracted based on the primary site of OA, QST modalities, outcome measures and test sites. Standardised mean difference (SMD) and 95% confidence intervals (CIs) were calculated if possible. Publication bias was determined using funnel plot and Egger's test. Heterogeneity was examined using Cochran Q test and I2 statistic. Random effects model was used to pool the results.


RESULTS
Of 41 studies (2281 participants) included, 23 were case control studies, 15 case only studies, two randomised controlled trials, and one uncontrolled trial. The majority of studies examined pressure pain with smaller numbers using electrical and/or thermal stimuli. QST was more often applied to the affected joint than distal and remote sites. Of 20 studies comparing people with OA and healthy controls, seven provided sufficient information for meta-analysis. Compared with controls, people with OA had lower pressure pain thresholds (PPTs) both at the affected joint (SMD = -1.24, 95% CI -1.54, -0.93) and at remote sites (SMD = -0.88, 95% CI -1.11, -0.65).


CONCLUSIONS
QST of PPTs demonstrated good ability to differentiate between people with OA and healthy controls. Lower PPTs in people with OA in affected sites may suggest peripheral, and in remote sites central, sensitisation. PPT measurement merits further evaluation as a tool for phenotyping OA pain.
Arthritis Research UK Pain Centre, University of Nottingham, UK. anu.suokas@nottingham.ac.uk
A K
AK
Suokas
D A
DA
Walsh
D F
DF
McWilliams
L
L
Condon
B
B
Moreton
V
V
Wylde
L
L
Arendt-Nielsen
W
W
Zhang
D005260:Female; D006801:Humans; D007596:Joints / Q000473:pathology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology*; D010146:Pain / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology*; D010147:Pain Measurement / Q000379:methods*; D017288:Pain Threshold / Q000502:physiology*; D010812:Physical Stimulation; D016032:Randomized Controlled Trials as Topic