How to Size a Mallet Splint.

Mallet splints are great for treating injuries to the final joint of the finger.  So if you have an extensor tendon strain or similar finger injury, read on to make sure you get a splint that fits correctly.

The most common form of purpose-made mallet splint is a type sometimes called a stax splint. This is the type of mallet splint we sell, and this blog post explains how to choose the correct size. The stax splint is simple and effective – it semi-encloses the end of the finger in a rigid, plastic shell to hold it straight in a good healing position and protect it from further damage (as pictured.) There are ventilation holes in the shell to keep it breathable and help prevent skin maceration.

Sizing Instructions

1) Mallet splints need to fit fairly precisely, so you must measure the injured finger. Do not guess. You need to measure around the part of your finger known as the distal interphalangeal joint, or DIP joint. This is the final joint before your fingertip. See picture:

2) It is difficult to measure around your own finger, because you’ll be working one-handed. Therefore, it is best if you get someone to help. A good tool for the job is a flexible tape measure of the type found in most sewing kits. If you don’t have one, you can use a piece a string instead: wrap it around the DIP joint, mark it with a pen and measure off against a rule.

3) Once you have measured the circumference of the DIP joint, find that measurement in the following table and read off the corresponding size number. This is the size of mallet splint you need to order.

4) Mallet splints fit closely, so if you fall between two sizes it is best to order the larger of the two. If necessary you can “pack out” the splint slightly by wrapping a turn or two of zinc oxide tape around your finger. (Or use foam underwrap  for greater thickness.)

5) If you feel the mallet splint might slip off, you can lightly tape it on. Around the top part of the splint, between the finger joints, is the best place to do this. Use zinc oxide tape or micropore.

6) That’s it. But we offer one note of caution. Mallet splints are suitable for all manner of injuries to the end of the finger. However, if you suspect you have a case of actual mallet finger (i.e. an injury that prevents you from fully straightening the final joint of the finger unassisted) then you should also see a doctor at your earliest possible convenience. Mallet finger can lead to permanent loss of function if not properly and carefully treated – your finger will need to be held straight at all times.