On-Site Treatment of PIP Joint Dislocations
CAPT Edward R. McDevitt, MD
Department Editor: William O. Roberts, MD
THE PHYSICIAN AND SPORTSMEDICINE - VOL 26 - NO. 8 - AUGUST 2021
An athlete, in obvious distress, runs off the field during a game and seeks your help. "Doc, my finger, I jammed it, pull it out! Now, Doc! Come on, hurry up, I've got to get back."
You take a look at your player. The finger is indeed injured; it looks malaligned. Is it fractured? Is it dislocated? You are tempted to pull on the finger quickly, "pop" it back in place, apply a little tape, and send the player back in.
But wait a minute. Take your time. Calmly assess the situation. A careful approach will take little extra time and may prevent mistakes that could cause delayed healing or residual problems. Tell the player you are going to help him, but firmly walk him over to the bench where you both sit down.
Ask the player what exactly happened; you may gather invaluable clues regarding the mechanism of injury (the mechanism in many digital dislocations is jamming of the extended finger). Ask about past injuries to the hand and fingers. Was the injured digit normal before this injury? If a digit has been crooked for the last few years from a previous untreated injury, it probably is not going to straighten out if you pull on it on the sidelines.
Look carefully at the injured digit. Are there signs of a fracture or dislocation? Look for ecchymosis, edema, and midshaft angulation and rotation, which are suggestive of a fracture. Which joint is affected? Dislocations of the proximal interphalangeal (PIP) joint differ from those of the metacarpophalangeal (MCP) joint, which differ from those of the distal interphalangeal joint. Because PIP joint dislocations are the most common finger dislocations in most sports, they are the focus here.
A dislocation is named according to the position of the distal segment in relation to the proximal segment. Regardless of the joint involved, most dislocations of the digits are dorsal (figure 1). Volar dislocations (figure 2) are far less common.
Do a careful physical exam. It is very important to distinguish a dorsal dislocation from a volar dislocation, because the two require different reduction maneuvers and splinting. The type of dislocation is usually obvious from the abnormal PIP joint angulation. Other physical signs should be checked:
If the injury is a PIP joint dislocation (dorsal or volar) that has just occurred, it can probably be gently reduced without anesthesia. Tell the player you are going to attempt to reduce the dislocation. It is safer for the player to be seated.
Dorsal dislocations. For a dorsal dislocation, flexing the wrist and the metacarpophalangeal joint will relax the digit flexors and make reduction easier. Use one hand to stabilize the proximal segment while the other hand firmly grasps the distal, displaced segment. Direct traction is the initial and most important reduction force. While maintaining distal distraction, apply a gentle volar (palmar) pressure to the distal segment while simultaneously lifting the proximal segment dorsally (figure 1). If you apply too much pressure to the joint and the segments are not distracted sufficiently, you can cause a fracture. Reduction will usually be obvious.
After reduction, make sure that the patient can move the joint. The finger can be buddy-taped and the player allowed to return to participation (though the player should be reexamined after the game). Since dorsal PIP dislocations are most often caused by hyperextension of the PIP joint, a 15° dorsal splint over the joint may be used for a week to prevent hyperextension.
Volar dislocations. For the middle phalanx to be displaced volarly, the central slip—the portion of the extensor tendon that inserts on the proximal dorsal aspect of the middle phalanx—must be torn. As with a dorsal dislocation, distal traction is the critical reduction force. But, in contrast to the approach for reducing a dorsal dislocation, you direct a dorsal force to the distal segment and a volar force to the proximal segment. The wrist and the MCP joint should be in neutral or slight extension. Successful reduction usually is obvious.
After the reduction, it is critical to hold the PIP joint in full extension. This will allow the torn central slip to heal close to its anatomic attachment site. The approach used for dorsal dislocations—buddy taping in slight flexion—should not be used. Continuous splinting is needed for 4 to 6 weeks (1). Because it is difficult for athletes to play when their finger is fully extended, they usually cannot return to play until splinting is discontinued.
Difficult reduction. If the dislocation does not reduce readily, it is time to reassess. Sometimes the pain of the injury calls for a local anesthetic block. (Some team physicians always block the finger with lidocaine to facilitate the reduction.) But most simple dislocations, if seen acutely, can be reduced humanely without anesthesia. If the dislocation resists reduction even with anesthesia, open reduction may be necessary.
All dislocations should be reevaluated after the game. It is important to obtain radiographs to rule out a fracture or incomplete reduction. In a landmark article, McCue et al (2) wrote of the necessity of proper postreduction care of "coach's finger." In the early days of sports medicine, the coach was often the person to reduce finger "dislocations," and many serious injuries to the digits were missed when the player was not adequately evaluated after the injury. McCue et al emphasized that not all "dislocations" are simple dislocations. They stressed that many players have significant residual problems from undiagnosed and poorly treated fractures, fracture-dislocations, and complex ligamentous injuries of the joint. Don't forget the postgame reevaluation.
Dr McDevitt is chief of orthopedics and sports medicine at the US Naval Academy in Annapolis, Maryland. He serves on the Council of Delegates of the American Orthopaedic Society for Sports Medicine and is an instructor in arthroscopy for the Arthroscopy Association of North America. Dr Roberts is a family physician at MinnHealth SportsCare in White Bear Lake, Minnesota, medical director of the Twin Cities Marathon, and an editorial board member of The Physician and Sportsmedicine.
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