Ultrasound guidance allows accurate needle placement and aspiration from small joints in patients with early inflammatory arthritis.
OBJECTIVE
To compare the accuracy of palpation-guided and high frequency ultrasound-guided needle placement in small joints and to develop a technique to obtain synovial fluid from these joints for diagnosis and research.


METHODS
The accuracy of needle placement during palpation-guided proximal interphalangeal (PIP) or metacarpophalangeal (MCP) joint injection was assessed. This was compared with the accuracy of ultrasound-guided needle placement. A joint lavage technique was developed to obtain synovial fluid from these joints.


RESULTS
Needle positioning was intra-articular in 59% of palpation-guided injections (6/12 PIP and 4/5 MCP joints). No fluid could be aspirated prior to injection. With ultrasound guidance, initial needle placement was intra-articular in 96% of cases (24/26 PIP and 27/27 MCP joints). Synovial fluid cells were lavaged from 63% of joints (19/25 PIP and 14/27 MCP joints). In only one case was a large effusion seen and this was aspirated directly.


CONCLUSIONS
The use of high frequency ultrasound to guide needle placement within a small joint allows for significantly greater accuracy than a palpation-guided approach. When followed by lavage, synovial fluid cells and diluted synovial fluid can be obtained from the majority of small joints. This has important clinical and research implications.
Raza
K
K
MRC Centre for Immune Regulation, Division of Immunity and Infection, The University of Birmingham, Birmingham B15 2TT, UK. k.raza@bham.ac.uk
Lee
C Y
CY
Pilling
D
D
Heaton
S
S
Situnayake
R D
RD
Carruthers
D M
DM
Buckley
C D
CD
Gordon
C
C
Salmon
M
M
D001168:Arthritis / Q000175:diagnosis*; D001707:Biopsy, Needle / Q000379:methods; D006801:Humans; D010173:Palpation; D013582:Synovial Fluid / Q000276:immunology*; D007507:Therapeutic Irrigation; D014463:Ultrasonography