Monday, May 25, 2020

Distal Phalanx Fractures


Injuries of the distal phalanx can be a fingertip injury, which will be a different topic by itself. Fracture of the distal phalanx is the most common phalangeal fracture, and it can occur from a crushing injury that produces major soft tissue injury. It can involve the tuft, the shaft, or the base of the phalanx. If it involves the tuft, then it is usually a crush injury and may be associated with a nail bed injury. Usually it is associated with subungual hematoma. If the hematoma involves more than 25% of the nail, especially if there is a fracture, then you need to remove the nail, as well as explore and suture the nail bed. Most of the time the fracture is comminuted and probably will need a splint. In some cases, the fracture may need k-wire fixation. The fracture may fail to unite. Fracture of the distal phalanx shaft is usually stable and can be treated conservatively by a splint or buddy taping, and surgery is rarely needed. Distal phalanx nonunion, if symptomatic and painful, do reduction and internal fixation with bone graft. With fracture of the distal phalanx base, there are two types jersey finger and mallet finger. The patient that is unable to flex the DIP joint is the patient that has a Jersey finger, or volar base fracture. The patient with a mallet finger, or dorsal base fracture, is unable to extend the DIP joint. If the fracture is large, there may be a volar subluxation of the distal phalanx. Be aware of avulsion fracture at the base of the distal phalanx, because it must be evaluated thoroughly. It could be an avulsion of the insertion of the flexor or the extensor tendon, and the fracture appearing small and benign. If the fragment is large or if there is volar subluxation of the joint, then this can be treated by different techniques. K-wire utilization is a very common technique. The goal is to keep the DIP extended until the bone or the tendon heals. Some orthopaedic surgeons will continue to treat this injury by closed means (splint), even if there is a volar subluxation of the joint. The rationale is that a stiff finger that is treated by closed means is better than a stiff finger that is treated by surgery. When the tendon is avulsed with a bony fragment, the tendon with a piece of bone could be retracted at different levels, and it can be seen in the x-ray. In general, if the tendon is retracted to the palm, then the blood supply could be affected and surgery should be done within 10 days. If the fragment is large, then usually the retraction is limited to the DIP. The finger lies in extension relative to the other fingers, and the patient will not be able to do active DIP flexion. Seymour fracture is an epiphyseal fracture of the distal phalanx. It is a flexion injury that leads to physeal separation between the extensor tendon dorsally and the flexor digitorum profundus volarly. This flexion injury causes an avulsion of the nail from the nail fold with disruption of the nail matrix. The patient’s finger will appear flexed, which looks like a mallet finger, and the nail appears to be larger compared to the nail on the other side. This injury is really an open fracture and needs to be treated by antibiotics, removal of the nail, irrigation and debridement of the fracture, reduction and pinning of the fracture and nail bed repair.