Conventional Plaster Versus Thermoplastic Splint for the Treatment of a Pediatric Metacarpal Neck Fracture: a Randomized Trial

Nearly all Boxer's fractures are treated without surgery using a splint to keep part or all of the hand from moving (immobilization). There are several acceptable methods of immobilization used by hand surgeons, using splints of different sizes and materials for variable periods of time(1-6).

A recent systematic review from The Cochrane Collaboration found the current data to be inconclusive with regards to the optimal immobilization technique and highlighted the need for further studies(2). Specifically, it was recommended that future studies include functional outcome measures, timing of return to work, complications, pain scores, and an economic analysis.

The current practice at the investigators' institution is for patients to be splinted in a plaster ulnar gutter splint, in the Emergency Department and referred to the next available plastic surgery clinic. If needed, a closed reduction would be performed in clinic, if there was a significant angulation (greater than 45 degrees) or any clinical rotation deformity. The most common method of immobilization involves placing the wrist, ring finger and little finger all the way from the fingertips to the mid-forearm in molded plaster called an ulnar gutter splint. The splint is left on 24 hours a day for 3 to 4 weeks and then removed in the clinic.

Many patients find it difficult to keep the splint on for the full 3 to 4 weeks for a number of reasons. The plaster needs to stay dry, making it awkward to bathe. The splint can also get loose and rub as the swelling around the fracture gets better. The splint can also start to smell because sweat builds up under it. Some patients find the plaster material heavy, making it difficult to wear. Finally, many patients are self-conscious about the appearance of the splint and remove it for this reason alone. In the investigators' experience, up to 1 out of 5 patients will remove the splint on their own against doctor's orders for one reason or another. When patients do follow instructions and keep the splint on 24 hours a day for 3 to 4 weeks, this can lead to joint stiffness when the splint is removed. Some patients may even require physiotherapy to regain their normal finger movement and grip strength.

It is unknown if the ulnar gutter splint is really the best way to immobilize the hand after a Boxer's fracture. It is unknown what material is best for making the splint, whether it is truly necessary to keep the entirety of the wrist and ring and little fingers still, and for how long the hand and fingers should be kept still. Most surgeons recommend patients wear a splint for 3 to 4 weeks.