Finger Injuries

Specific Finger Injuries

Boutiniere (Central Slip tendon rupture)
Chainring pinch
Dislocation
Fingernail avulsion
Fracture
Mallet (baseball) finger
Sprain
Volar Plate Injury

Scenario:
You're dodging the aspens on the downhill and -- yikes -- you overshoot the turn, smacking your knuckles against an aspen as they grip the handlebar. (You should have invested in bar ends.)

Description:
The central portion of the extensor tendon is pinched over the middle knuckle (proximal interphalangeal joint or PIPJ), and tears apart. There's swelling and tenderness over the top of the joint, and it's painful to straighten the finger fully.

Concerns:
A ruptured tendon won't heal properly unless managed by the doctor. Even minor tendon injuries can result in tendinitis and long-term pain. The deformity seen in this photo may not occur until several weeks after the accident.

See the doctor for an injured finger if:
    there's significant swelling or deformity
    there's pain when the finger is resting (after the first hour)
    you can't move the joint fully
    there's severe pain with motion of the finger
    there's numbness or weakness

Immediate care:
Rest, Ice, Compress, and Elevate. Immediately elevate the injured part and apply an ice bag. Go see the doctor for an x-ray.

This biker (riding without bar ends), veered into an aspen. The index finger was hit directly over the middle knuckle (PIPJ). He's trying to straighten the finger, but the middle knuckle keeps popping up. This is a rupture of the central slip of the extensor tendon.

Chainring pinch

Scenario:
Your buddy is helping you tune your derailleur. Oops! You just sucked his finger right into the cassette, where it got mangled between the teeth of the sprocket and the chain.

Description:
In most cases, this injury is BAD. The break in the skin is usually thoroughly contaminated with dirt and grease. More than half the time, the bone is broken underneath the fingernail, and often the bone has torn out through the surface underneath the fingernail.

Concerns:
This is an extremely infection-prone wound, and the exposed bone means the infection could be very serious. If everything isn't put back together properly, the fingertip could be permanently deformed.

Immediate care:
Unless you're sure the injury is trivial, this finger should be seen by the doctor. While biking out to civilization, use a bandaid or tape to hold the fingertip in place. (It's often a near-amputation.) Start on the palm side of the finger, run the tape down to the tip of the finger, then overtop the nail and back down the top. A second band circumferentially around the first helps keep it from falling off as it soaks with blood.

Typical chainring pinch. The dark color under the nail is a bursting laceration, with exposure of the bone.

Dislocation

Scenario:
Most dislocations occur during a forward or sideways fall. The biker puts his hand out and lands "fingers first." As the fingers bend back, the base of the more distant bone slides over the curved end of the closer bone, ending up on the top side of the joint.

Description:
A dislocation means that the joint has been forced apart, and the bones are still out of position. Inevitably, there is tearing of the ligaments alongside the joint (third-degree sprain). Most finger dislocations occur at the end knuckle (distal interphalangeal joint or DIPJ).

Concerns:
There may be a fracture accompanying the dislocation.

Immediate care:
Normally, doctors disapprove of patients trying to correct deformities on their own. But if you've got several miles to ride, it makes sense to correct the dislocation at the scene. (It's not safe to ride with a hand that doesn't work. So if you know what you're doing, you can give it a shot.)

Relocating a dislocated PIPJ in the woods. Grab the victim's wrist with one hand (left hand if you're a right-hander). Using your dominant hand, slide your index finger under the bone just upstream from the dislocated knuckle. Put the tip of your thumb opposite the index finger, just past the "bump" on the top of the knuckle. Trap the finger at the distant knuckle (DIPJ) by curling your middle and ring fingers firmly around it, with the victim's finger slightly bent. Pull back towards you with your hand (while holding the victim's hand still with the other hand). While pulling, push upward with your index finger and flex your thumb sharply down and back towards you.

I'm NOT recommending you try this, unless it's the only way you can safely get back to civilization:

Rest, Ice, Compress, and Elevate. Immediately elevate the injured part and apply an ice bag. Go to the doctor, unless you're absolutely certain that there isn't a significant injury.

After relocation of the joint, see the doctor for a dislocated finger if:
    there's significant swelling or deformity
    there's pain when the finger is resting (after the first hour)
    you can't move the joint fully
    there's severe pain with motion of the finger
    there's numbness or weakness

Ongoing care:
For the first 48 hours, repeat ice and elevation 1/4 of the time (for example, 30 minutes of ice every two hours). Continue splinting for a few days. As the pain subsides, return to activities. Often you can protect the injured finger by "buddy taping," taping it to an adjacent bigger stronger finger. It will take about three weeks for the sprain to heal. As you resume sports, remember the rule: "If it hurts, don't do it." If the finger becomes increasingly swollen, or remains weak or painful in routine use, go to the doctor.

Finger rehab:
After the first few days of splinting, start range of motion exercises.
Range of motion: Warm the finger for 10 minutes (heating pad or sink of warm water). Gently bend the finger until it begins to feel uncomfortable, then hold the stretch for 30 seconds. Rest for a minute, then do it again. Repeat 10 times. Now straighten the finger and hold for 30 seconds, rest a minute, and repeat 10 times. If the finger has increased discomfort after the exercises, ice the wrist for 20 minutes after the exercises. Do the exercises twice a day.

Watch for:
If the injured area doesn't improve promptly, see the doctor.

Sprained Finger

Scenario:
Sprained fingers are usually the result of landing on the hands, but with the wrist too straight. This puts the initial force on the fingers, bending them back too far.

Description:
A sprain is a stretching of ligaments -- the tissues that hold two bones together. In the finger, you have these ligaments on the inner and outer sides of each joint, and on the underside of each joint. When an accident bends the joint in a direction it's not supposed to go (most commonly, bending backwards), it injures the ligament. Ligament injuries come in three degrees of seriousness: 1st degree = stretching, 2nd degree = partial tear, and 3rd degree = complete rupture.

Concerns:
The same forces that sprain a finger can also cause dislocation, tendon rupture, fracture, or volar plate injury. So you should assess careful for the signs of serious injury. Only if the injury seems trivial should you self-diagnose a sprain.

Immediate care:
Rest, Ice, Compress, and Elevate. Immediately elevate the injured part and apply an ice bag. Splint the finger in its most comfortable position. Usually, the most comfortable position is very slightly bent.

Often you can protect the injured finger by "buddy taping," taping it to an adjacent bigger stronger finger. It will take about three weeks for the sprain to heal. As you resume sports, remember the rule: "If it hurts, don't do it." If the finger becomes increasingly swollen, or remains weak or painful in routine use, go to the doctor.

Buddy tape: The normal finger can protect the injured finger from stress while it heals.

Watch for:
If the injured area doesn't improve promptly, see the doctor.

Mallet Finger

Scenario:
You're eyeballing the upcoming "rock garden," and being the naturally cautious type, you find yourself slowing down to a crawl. So when your front tire bumps the first rock (while your cautious fingers still have a grip on the front brake lever), it's ENDO time. And as you land on hands and knees, you drive your middle finger straight into the dirt.

Typical bent-down position of the last finger joint with mallet finger.

Description:
Mallet finger, also known as baseball finger, is a tear of the extensor tendon where it attaches to the top of the distal phalanx (that's the top of the knuckle just upstream from your fingernail). The joint bends downward, and can't be fully straightened.

Concerns:
You get ONE -- and only one -- chance for the mallet finger to heal properly. If you mess up, you're looking at surgery or a permanent deformity! Get medical help.

Immediate care:
Rest, Ice, Compress, and Elevate. Immediately elevate the injured part and apply an ice bag. Go to the doctor.

Volar Plate Injury

Scenario:
Volar plate injury most commonly results from landing on the hands, but with the wrist too straight. This puts the initial force on the fingers, bending them back too far. When the ligament on the underside of the middle knuckle (proximal interphalangeal joint or PIPJ) gets too tight, it may rupture, or may pull off a chunk of the bone.

Description:
A volar plate injury may be a sprain (a stretching of ligaments -- the tissues that hold two bones together), or it may be much more serious. For example, a large avulsion fracture, where the ligament pulled off a piece of bone more than 1/3 of the joint surface, usually requires surgery. When only the ligament is injured, there are three degrees of seriousness: 1st degree = stretching, 2nd degree = partial tear, and 3rd degree = complete rupture.

Concerns:
If there's a fracture, the treatment may be very different. So you should assess careful for the signs of serious injury. Only if the injury seems trivial should you self-diagnose a sprain.