Fractures of the metacarpal neck, or "Boxer's Fractures", are incredibly common. A significant amount of angulation (up to 40°-70°*) is acceptable in fractures at the neck. A smaller amount of angulation (around 15°*) can be tolerated in fractures of the shaft. Patients tend to feel the knuckle 'disappears' and will often have an extensor lag. When the angle of a little finger metacarpal neck fracture is greater than 30° grip strength is reduced*.
Boxer's fractures are challenging to fix as there is very little bone distal to the break, which makes fixation difficult. I tend to avoid plates in the hand if possible, as I find the extensor tendons stick to them, resulting in significant stiffness (the rate of moderate complications in metacarpal plating is 36% overall, with stiffness in 76%*). My preference for fractures of the metacarpal shaft (that require operation) is an intramedullary K-wire, which corrects the deformity and allows early mobilisation. In my practice, this technique works very well, but it is less effective in boxer's fractures.
A technique that is gaining popularity is a retrograde intramedullary screw. I was initially hesitant to try this procedure as the screw goes through the articular surface of the knuckle, but the evidence is growing that this doesn't cause a problem. The Xrays and video here show my first case using this technique. I reduced the fracture closed and inserted the screw through a stab incision directly over the knuckle.
Followup Xrays at two weeks show that the fracture is well on the way to being healed.
This patient only had one therapy session immediately post-op to show her how to do gentle range of motion. The video is at two weeks, and she already has a full pain free range of motion.
Overall both the patient and I are delighted with the results of this technique.
Published with patient permission.
*Metacarpal fractures: treatment and complications. KM Kollitz, WC Hammert, NB Vedder, and JI Huang. Hand (N Y). 2014 Mar; 9(1): 16–23.
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