Sports injuries of the fingers are common. Sports involving catching and throwing present a particular vulnerability to the fingers. Many adults live with the residual effects of these injuries that were not treated or, treatment was delayed. The goal in managing these injuries, particularly in the young athlete, is to obtain prompt diagnosis and treatment to avoid any long-term consequences.
The ubiquitous nature of the athlete with the “jammed” finger makes it difficult to discern the true nature of the injury at first glance. There is significant variability in severity and outcome. Injuries included under this heading could include simple dislocations, fractures, and complex variations of these two.
The treatment depends on the exact pathology; which cannot be entirely determined by physical examination alone.
The purpose of this paper is to address common finger injuries encountered in sports; and thereby raise awareness of players and trainers of the nature of these conditions. The goal is to avoid the situation where the player is treated with temporizing measures to allow return to play, but does not seek additional follow-up.
Common injuries that occur under this heading include, phalangeal fractures, Extensor tendon avulsions (mallet and boutonneire deformities), Proximal interphalangeal joint (PIP) fracture dislocations, simple dislocations, and flexor tendon avulsions (Jersey finger).
Phalangeal fractures may have an innocuous appearance or significant deformity. Direct blows to the finger, axial loading, and twisting can produce characteristic fracture patterns. This may be accompanied by a rotational deformity of the finger where it appears to overlap the neighboring digit. There may be a significant angular deformity where the finger appears to be grossly malaligned. Many phalangeal fracures present with mild swelling and no apparent deformity. Radiographic exam (X-ray) is required when any of the signs and symptoms are present.
Recognizing these injuries early offers many advantages. Primarily, the ability to reduce (re-align) the fracture appropriately is greatly enhanced. Malunited fractures can result in permanent rotational or angular deformity. Functionally this will result in reduced grip strength, dexterity, and ultimately decreased performance. Intra-articular fractures are of particular concern. Disruption of the smooth gliding surface of the joint can lead to chronic pain and early post-traumatic arthritis.
Treatment varies based on the severity and location of the injury. Diaphyseal (shaft) fractures that are stable can be treated with splinting and early motion.. Unstable or displaced injuries may require reduction and surgical stabilization. Intra-articular injuries are the most problematic and may require surgical stabilization and early motion with dynamic external fixation. The key is correct initial diagnosis and elimination of a delay in care.
Dislocation of the PIP joint occurs frequently , varying in severity and complexity. Commonly these injuries are reduced by the athlete themselves and sometimes the trainer. The majority of these injuries are straight forward and do well without significant intervention. A short period of splinting followed by buddytaping with early motion is usually sufficient. However, it is the unrecognized collateral ligament tears, tendon ruptures, and fractures which can leave an athlete with a potentially debilitating injury.
All of these injuries warrant radiographic examination in the acute phase. There are many varieties of dislocation; volar , dorsal, radial/ ulnar and rotatory. Dislocations that are difficult to reduce or result in a digit with some residual deformity must be followed with immediate imaging to rule out associated injury. Occasionally, interposed soft tissue will not allow adequate reduction and may require surgical intervention. This can include interposition of the collateral ligaments , volar plate and occasionally flexor or extensor tendons.
Avulsion of the flexor tendon from the distal phalanx is commonly referred to as a jersey finger. This nomenclature relates the injury to a football tackle but it can occur in other scenarios. The mechanism of the avulsion injury occurs when the athlete grabs the jersey of a player that is running away. This applies an eccentric load to the finger that is attempting to maximally flex. In this manner the tendon is literally avulsed from the bone.
These injuries often present in a delayed manner, which is extremely problematic. The player complains of pain and inability to flex the distal interphalangeal (DIP) joint. There may be a palpable lump in the finger or palm which represents the level of tendon retraction. The player may not seek immediate attention because the finger can actively flex at the PIP joint because the sublimis tendon is still intact.
The level of retraction becomes a key component of treating this injury. Treatment is always surgical and requires reattachment of the tendon to the bone. This is sometimes facilitated by and associated avulsion fracture which limits tendon retraction. In general, immediate repair is necessary.
There is a 2 week window in which these injuries can be repaired successfully without undue complications. This depends on the level of tendon retraction. Injuries presenting at 4-6 weeks are generally not repairable. There are many variables that govern the success of the repair. The overriding principle is that these must be recognized and treated immediately.
Avulsion of the terminal tendon of the distal phalanx (mallet finger), and avulsion of the central slip from the middle phalanx (boutonneire) are both injuries associated with axial loading of the finger. The avulsion of the terminal extensor tendon from its insertion site on the distal phalanx creates and extensor lag, or droopy finger. Left untreated, this imbalance can lead to a deformity in which the PIP joint hyperextends as well (swan neck deformity). The avulsion of the central slip from the middle phalanx causes an inability to extend the PIP joint. This leads to the charactersistic boutonneire deformity in which the PIP joint is hyperflexed and the DIP joint is extended.
The mainstay of treatment of mallet finger is full time extension splinting of the DIP joint. This regimen applies whether or not this injury presents in the acute or subacute setting. Treatment consists of full time splinting for 6 weeks or until the integrity of the extensor mechanism is regained. Surgical treatment has limited indications. One clear indication for surgical treatment of a mallet finger is when there is an associated avulsion fracture of the distal phalanx (bony mallet). Treatment includes closed reduction and pinning and occasionally open reduction and internal fixation. Normal DIP joint motion and finger extension are dependent on properreduction and fixation of the avulsion fragment. Radiographic examination is required to differentiate between these injuries.
Treatment of central slip injuries is somewhat complicated by the propensity of the PIP joint to develop contractures. Injuries that present early are splinted with the PIP in full extension and the DIP is allowed to flex to accomplish rebalancing of the extensor mechanism. Patients with delayed presentation are usually found to have a PIP flexion contracture , this adds significant difficulty to treatment. In these cases the contracture must be corrected first prior to addressing the tendon injury.
This review has addressed some of the most common manifestations of the “jammed finger”. Of course there are many subsets of these injuries and additional findings that can be further explored. The take home message is that these injuries can present in a benign fashion, but can lead to significant disability if not treated appropriately in the acute phase. Any persistent swelling, deformity, or decreased motion after such an event warrants a radiologic exam and appropriate physical exam by an orthopaedic specialist. In this way we can avoid permanent disability and facilitate a return to play.