Mallet thumb is a rare clinical entity and little consensus exists as to operative versus non operative treatment. It is also unclear what surgical methods are optimal, as both suture repair and bony anchor are reported, or if conservative management is planned, what sort of splint should be used, either immobilising just the IPJ or using a hand based splint
We report a series of 4 cases of closed mallet thumb injury. Two of these were managed operatively, and two non-operatively. Our patients ranged in age from 30-48, with three male and one female. The injured thumb was on the dominant hand in two (one operative and one non operative). All were acute injuries.
All patients were diagnosed clinically by inability to extend the thumb at the IPJ, and two underwent confirmatory USS. All patients were reported to have intact EPL at the level of the anatomical snuffbox with the ability to retropulse the thumb.
Both the patients treated non operatively were managed in a mallet splint with immobilisation of the IPJ only. At 8 weeks, one patient had normal extension and the other a 5 degree extensor lag. Flexion was good in both cases, to around 45 degrees.
Both patients treated operatively were managed with a suture repair to remnant tendon distally, at a range of 1-7 days post injury. At 7-8 weeks follow up, the first patient had an intact extensor with minimal movement of the IPJ, and the second had a range of movement of 0-25 degrees.
The case series shows non operative management is an effective treatment for a closed mallet thumb injury, and indeed may be superior to operative management with better range of movement at the 8 week mark seen in those who were managed in a splint.