16-Year-Old With Painful Ring Finger After Football Injury

A 16-year-old football player complains of increasing pain in the ring finger of his right hand. It began 2 days earlier, when he tried to tackle a running back by grabbing the player's jersey; he felt immediate pain and was unable to continue holding on to the jersey. The pain is largely confined to the palmar surface of the distal part of his ring finger, from the proximal interphalangeal (PIP) joint to the distal interphalangeal (DIP) joint. In addition, he has noticed a lump surrounded by swelling in his palm near the metacarpophalangeal (MCP) joint, and he feels the grip of his right hand to be weaker than that of his left.

Immediately after the injury, the patient's hand was iced and he was taken to the emergency department for evaluation. A radiograph showed no abnormalities. His finger was splinted, and he was told not to play football for a week. He wants to return to play sooner and seeks your advice. The patient is otherwise healthy.

What is your presumptive diagnosis at this point?A. Torn extensor tendon of the DIP joint.
B. Torn extensor tendon of the PIP joint.
C. Injured volar plate of the PIP joint.
D. Torn flexor tendon of the DIP joint.

THE CONSULTANT'S CHOICE

The description of the mechanism of this patient's injury makes a torn deep flexor tendon (D) the most likely choice. Forced extension of the DIP joint while it is in active flexion produces a full or partial tear of the deep flexor tendon (Figure 1). Grabbing the jersey of a person attempting to escape your grasp can cause this injury.

Forced extension of the PIP joint typically occurs when an object, such as a ball, forces that joint into extension. This mechanism results in injury to the volar plate of the PIP (C).

An extensor tendon is usually injured when it is in active extension and an object, such as a ball, strikes the finger distal to the PIP or DIP joint, creating forced flexion. Injury of the extensor tendon of the DIP joint occurs when the distal phalanx is forced into flexion at the same time that the DIP joint is actively extended. Injury to the extensor tendon of the PIP joint occurs with simultaneous forced flexion of the PIP joint and active PIP extension.

Which test will help confirm the diagnosis?A. The test shown in Figure 2.B. The test shown in Figure 3.C. The test shown in Figure 4.D. The test shown in Figure 5.

THE CONSULTANT'S CHOICE

The test shown in Figure 4 (C) is the most appropriate choice because it specifically tests DIP flexion. Inability to flex the DIP joint when force is applied to the palmar side of the extended finger indicates weakness or a tear of the DIP flexor.

The test shown in Figure 2 (A) evaluates the ability of the DIP joint to extend against a counterforce. Inability to extend the distal phalanx when force is applied to the dorsal side of the flexed fingertip indicates weakness or tears of the extensors of the DIP joint.

The test shown in Figure 3 (B) evaluates the ability of the PIP joint to extend against a counterforce. Force is applied to the dorsal side of the second phalanx of the finger while the PIP joint is in a flexed position. Inability to extend the PIP joint against this force indicates weakness or a tear of the extensor of the PIP joint.

The test shown in Figure 5 (D), in which force is applied to the palmar side of a fully extended finger while the patient attempts to flex it, tests the ability of both the deep flexor of the DIP joint and the superficial flexor of the PIP joint to flex these joints. However, ability to flex the finger does not necessarily mean that flexion is intact in both joints. If the deep flexor is torn, the finger can still be flexed at the PIP joint because the superficial flexor provides flexion at that joint. Thus, it is important to observe carefully how the patient flexes the finger and to determine whether flexion occurs at both or only 1 of the 2 joints. Figure 1 shows how the deep and superficial flexors are attached to the DIP and PIP joints. Note that the deep flexor tendon travels through the superficial flexor tendon and inserts at the DIP joint.

In this patient, the test shown in Figure 5 shows intact flexion in the injured finger in the PIP joint only. The test shown in Figure 4 confirms inability to flex the finger at the DIP joint. In addition, there is tenderness over the DIP and PIP joints, and a tender lump is detected in the palm near the MCP joint.

The patient has an avulsion of the deep flexor tendon of his ring finger. This type of injury is most commonly seen in boys and young men who play football or rugby. It occurs when an athlete grabs the jersey of a player on the opposing team. For this reason, the injury is often called "jersey finger."

Jersey finger has been reported in all fingers, including the thumb; however, the ring finger is involved in 75% of these injuries. The ring finger is most susceptible because it is the longest finger when the hand is in a grasping position (Figure 6).

Which treatment would you recommend?A. Splint the DIP joint in 30 degrees of flexion for 8 weeks.
B. Splint the DIP joint in 45 degrees of flexion for 4 weeks.
C. Refer the patient to a hand surgeon for immediate surgery.
D. Refer the patient to a hand surgeon in the next week or two, after all pain and swelling have subsided.

THE CONSULTANT'S CHOICE

Because extensor tendons in the hand do not usually retract after they are torn, injuries to these tendons can often be managed nonsurgically with splints. Splinting in hyperextension facilitates approximation of the torn ends of the tendons.

Unlike extensor tendons, however, the deep flexor tendons in the hand will retract if torn. Thus, splinting (A and B) has no place in the care of tears of the deep flexor tendon of the DIP joint. Surgical reattachment (C) is the only appropriate treatment. Although prompt surgical repair is usually recommended, the urgency of surgical treatment depends on specific features of the injury.

Classification of deep flexor tendon injuries. Jersey finger injuries are classified based on the level of tendon retraction and on whether a bony fragment is present:

• In a type 1 injury, the tendon retracts into the palm. Disruption of the vincula compromises the blood supply to the tendon. Type 1 injuries are especially worrisome because loss of the blood supply can result in delayed healing or tendon death. If surgery is delayed beyond 5 to 7 days, a retracted tendon with minimal or no blood supply will probably not be viable.
• In a type 2 injury, the tendon retracts to the PIP joint. However, the tendon remains in its sheath, the long vinculum remains intact, and the blood supply is thus maintained. Occasionally in type 2 injuries, a small fleck of bone may be seen on radiographs at the level of the PIP joint.
• In a type 3 injury, a more considerable bony fragment typically prevents retraction past the A4 pulley (a connective tissue band between the DIP and PIP joints). Tendon length is preserved in type 3 injuries, and the intact vincula maintain vascular supply.

A few authorities believe that surgery can be delayed if the tendon is not retracted. However, this decision is best left to the hand surgeon.

This patient has a type 1 jersey injury. The lump in his palm is the retracted tendon. All or part of the blood supply to the tendon may be cut off, and there may be an avulsed bone fragment with the tendon. Thus, for treatment to be successful, time is of the essence. The sooner surgery can be performed, the greater the likelihood of reinsertion, healing, and tendon survival. For the greatest likelihood of successful tendon reinsertion, a window of no more than 7 days is recommended.

Outcome of this case. This patient was referred to a hand surgeon and had surgery the next day. He did very well and was able to return to playing football the next season.

References:

FOR MORE INFORMATION:

• Hong E. Hand injuries in sports medicine. Prim Care. 2005;32:91-103.m Leddy JP, Packer JW. Avulsion of the profundus tendon insertion in athletes. J Hand Surg Am. 1977;2:66-69.
• Mastey RD, Weiss AP, Akelman E. Primary care of hand and wrist athletic injuries. Clin Sports Med. 1997;16:705-724.