What is Flexor Digitorum Profundus Rupture
The flexor digitorum profundus (FDP) is a muscle attached to a bone (ulna) in the forearm. The FDP muscle helps to bend the four fingers of the hand. The FDP works together with bands of fibrous tissue (tendons) that attach to the finger joints.
The tendons start at the wrist and cross the palm, and then spread out to the fingers. A tear (rupture) in the FDP means that a tendon has been separated from a finger joint. If this happens, you will not be able to bend the injured finger.
An FDP rupture may occur in one or more fingers. It is most common in the ring finger. There are three types of FDP ruptures:
- Type I causes the tip of the tendon to draw back (retract) into the palm.
- Type II causes the tip of the tendon to retract to the finger joint.
- Type III happens when the rupture tears away a piece of the bone that the tendon is attached to (avulsion fracture).
What are the causes?
FDP rupture is usually caused by a forceful straightening (extension) of the finger while the FDP muscle is tightened (contracted). This may result from:
- Grabbing someone’s clothing while playing a sport and having it pulled away (jersey finger).
- Getting a strong pull on a rope or leash that you are holding tightly.
- Starting a lawn mower or other engine with a pull cord.
What increases the risk?
The following factors may make you more likely to develop this condition:
- Playing contact sports.
- Having poor hand strength and flexibility.
- Having injured a finger tendon in the past.
- Having rheumatoid arthritis.
What are the signs or symptoms?
Symptoms of this condition may include:
- Feeling a “pop” or a rip in the finger at the time of injury.
- Pain when moving the finger.
- Inability to bend the finger on its own. When you bend the finger with assistance, it may be able to bend all the way. This is referred to as having full passive range of motion.
- Bruising. This may take up to 48 hours after the time of injury to develop.
- A lump in the palm of the hand. This may be a symptom of a type I rupture.
- Numbness in the fingers. This may be a sign that a nerve near the tendon is damaged.
How is this diagnosed?
This condition will be diagnosed based on your symptoms, and your history of recent injuries. You will also have a physical exam, in which your health care provider may:
- Ask you to bend and extend your fingers.
- Test your finger strength.
- Check your fingers for numbness.
- Feel your hand for a retracted tendon.
You may have tests to check for an avulsion fracture, such as:
- X-rays.
- CT scan.
- MRI.
How is this treated?
This condition is treated with surgery. It is best to have surgery within 10 days of injury. Before surgery, treatment may include:
- A hand splint.
- Medicines to help reduce pain and swelling.
- Keeping your hand raised above the level of your heart (elevated) to reduce swelling.
The goal of surgery depends on the type of rupture you have. Surgery usually involves reattaching the tendon to the bone. After surgery, treatment includes:
- A hand splint.
- Physical therapy to improve finger strength and range of motion.
Follow these instructions at home:
If you have a splint:
- Do notput pressure on any part of the splint until it is fully hardened. This may take several hours.
- Wear it as told by your health care provider. Remove it only as told by your health care provider.
- Loosen the splint if your fingers tingle, become numb, or turn cold and blue.
- Do
notlet your splint get wet if it is not waterproof.
- Do nottake baths, swim, or use a hot tub until your health care provider approves. Ask your health care provider if you can take showers. You may only be allowed to take sponge baths for bathing.
- If your splint is not waterproof, cover it with a watertight plastic bag when you take a bath or shower.
- Keep the splint clean.
Managing pain, stiffness, and swelling
- If
directed, apply ice to the injured area.
- Put ice in a plastic bag.
- Place a towel between your splint and the bag.
- Leave the ice on for 20 minutes, 2–3 times per day.
- Move your fingers often to avoid stiffness and to lessen swelling.
- Elevate your injured hand while you are sitting or lying down.
Driving
- Do notdrive or operate heavy machinery while taking prescription pain medicine.
- Do notdrive if you have a splint on your hand.
Activity
- Return to your normal activities as told by your health care provider. Ask your health care provider what activities are safe for you.
- Do physical therapy exercises as told by your health care provider.
- Do notparticipate in sports activities until your health care provider approves.
General instructions
- Do notuse any tobacco products, such as cigarettes, chewing tobacco, or e-cigarettes. Tobacco can delay bone healing. If you need help quitting, ask your health care provider.
- Take over-the-counter and prescription medicines only as told by your health care provider.
- Keep all follow-up visits as told by your health care provider. This is important.
Contact a health care provider if:
- You have pain that gets worse or does not get better with medicine.
- You have more swelling or numbness in your hand or fingers.
- Your hand or fingers turn cold, pale, or blue.
- Your splint becomes loose or damaged.
