Mallet finger is a condition where the tip of the finger cannot be straightened due to a tendon injury.
Mallet finger describes an injury to the extensor tendon at the point where it attaches to the bone at the very tip of the finger. The injury disrupts the tendon's ability to straighten the fingertip, sometimes with a small fragment of bone pulled away along with the tendon.
The result is a fingertip that droops and cannot be actively straightened, though it can usually still be passively straightened by the other hand. It is a common injury, particularly in ball sports.
Mallet finger typically follows a direct blow to the tip of an extended finger, most often from a ball striking the fingertip during sport. Catching or fielding a ball awkwardly is a particularly common scenario, though the injury can also occur from everyday activities such as tucking in a sheet or bumping the fingertip against a hard surface.
The characteristic feature of mallet finger is:
The drooping fingertip is usually obvious and is the key feature that prompts assessment.
Assessment includes examination of the fingertip and an X-ray to check for an associated bone fragment and assess the joint.
Most cases are treated non-surgically with continuous splinting of the fingertip joint in a straight position, worn full-time for six to eight weeks, followed by a period of night-time splinting. Consistency is important, as the tendon needs to heal in a shortened position, and even brief unsplinted bending can set healing back.
Surgery is considered in a minority of cases: where there is a large bone fragment involved, where the joint is unstable or has shifted out of position, or where splinting alone has not been successful.
The outlook with consistent splinting is generally good, with most people regaining a straight or near-straight fingertip. A mild residual extension lag, meaning the fingertip does not sit perfectly straight, can occur even with good treatment adherence, and is usually a minor cosmetic issue rather than a functional problem. Interrupting the splinting schedule partway through treatment can mean starting the healing process again from the beginning.
Mallet finger is a common, generally straightforward finger injury that responds well to consistent splinting in most cases. Prompt treatment and, importantly, sticking with the splinting schedule give the best chance of a good outcome. A fingertip that will not straighten after a knock or jam deserves early assessment.
