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.
MRC Centre for Immune Regulation, Division of Immunity and Infection, The University of Birmingham, Birmingham B15 2TT, UK. k.raza@bham.ac.uk
K
K
Raza
C Y
CY
Lee
D
D
Pilling
S
S
Heaton
R D
RD
Situnayake
D M
DM
Carruthers
C D
CD
Buckley
C
C
Gordon
M
M
Salmon
D001168:Arthritis / Q000175:diagnosis*; D001707:Biopsy, Needle / Q000379:methods; D006801:Humans; D010173:Palpation; D013582:Synovial Fluid / Q000276:immunology*; D007507:Therapeutic Irrigation; D014463:Ultrasonography