Metacarpal neck fracture reduction
General principles of fracture reduction involve axially distracting or pulling on a fracture fragment and pushing the piece back into anatomical alignment. This can be seen in the video above (automatically starts at 2:25 for the actual procedure). What if this approach doesn't work? The fracture fragment remains immobile despite your best efforts.
Image from AO Foundation
Trick of the Trade:
Jahss reduction technique
This technique, also known as the 90-90 approach, involves flexing the patient's MCP and PIP 90 degrees. Dorsal force is applied to metacarpal head by through dorsal pressure on the proximal phalanx. The 90-90 positioning also stretches the collateral ligaments of the MCP joint, which further optimizes the reduction technique.
Although this cool animation below was intended for patient education, it nicely illustrates how the Jahss technique works.
See the Paucis Verbis card on Metacarpal Fractures.
The Jahss reduction technique resulted in unacceptable complications of flexed IP joints and skin necrosis, if splinted in that way. If not splinted in that way, it will not hold. A randomized trial of 5th MC neck fractures (McKerrell et al. J Trauma 27(5):486-490, 1987) showed better outcomes with no reduction (except derotation) because even if you reduce these, they cannot be held in place unless you use the dangerous Jahss method.
ReplyDeletehttp://www.sciencedirect.com/science/article/pii/0020138386902378
http://www.sciencedirect.com/science/article/pii/002013839190103L
In fact, you don't even have to splint these: http://link.springer.com/article/10.1007%2Fs00402-003-0580-2?LI=true
Steve Smith
Thanks for the comments and clarification, Steve.
Delete1. Thanks for clarifying: The Jahss manuever does NOT mean to splint in the Jahss position. Splinting in this position has some serious complications. Use the usual ulnar gutter splint approach.
2. As for reducing vs not reducing significantly angulated metacarpal neck fractures, that's controversial. The studies you cite are a bit older (1986, 1991) and the second study enrolled metacarpal neck fractures of all angulations, which all underwent reduction with a mean angulation pre-reduction of 41 degrees. This study may be the crux as to why 5th metacarpal neck fractures are allowed up to 40-45 degrees of angulation before considering an attempted reduction in the ED.
3. Agreed, splinting of most metacarpal neck fractures probably fare the same between splinting vs pressure bandage if fracture fragment not manipulated.
The balance is: Do I attempt an ED reduction of a severely angulated metacarpal neck fracture, which will likely need operative repair, knowing that some may be unstable and fail to maintain alignment upon follow-up with the orthopedist? I think it's worth the attempt because some reductions may be effectively stable after closed ED reduction and may help the patient avoid an operation.