A simple technique for injecting the small joints of the fingers and thumb using finger traps for traction

Background

Injection of steroids for pain relief into the small joints of the fingers and thumb is a well known treatment method. It is not easy to insert the needle accurately into the joint. We have used finger traps to distract the joint for injections.

Technique

Under image intensifier guidance, after ring block anaesthesia, the finger trap is applied distally (Fig 1). With an assistant applying traction, a 25G injection needle is inserted into the joint under fluoroscopy and the steroid injected (Figs 2 and 3). We have found a point just dorsal to the midlateral position where it is safe and easy to enter the joint.

Figure 1.

Finger trap applied to the finger for traction

Figure 2.

Fluoroscopy image before traction

Figure 3.

Fluoroscopy image showing needle in the proximal interphalangeal joint after traction

Discussion

It is not easy to inject small joints of the hand owing to the narrow joint space, which can be reduced further by the arthritic process, the shape of the joint, associated osteophytes and calcification of ligaments. Intra-articular injections can be given inaccurately if sufficient precautions are not taken.¹ Distraction of the joint by finger trap is a useful method to create space for injections. It may be possible to apply excessive traction: use of fluoroscopy would avoid this happening.

We have used this technique in 12 joints in 7 different patients. Only once did we fail to inject into the joint. We recommend the use of finger traps for distraction of small joints of the hand for injection (under fluoroscopic guidance) and not to over distract them.