The hand consists of five bones called metacarpal bones for all the five fingers. The knuckles at the back of the hand are formed by the end of the metacarpal bones, which also assist or support the hand. Metacarpal fracture occurs when one of the long bones get injured. This could happen by performing certain activities like punch or direct impact to the hand due to which stress is placed on the metacarpal bones. As this kind of stress could be traumatic and beyond what the bone can withstand, an injury or a break in one or more metacarpals occurs. Thus the condition is called as metacarpal fracture. In other words, metacarpal fracture can be termed as broken hand.
Fifth metacarpal fracture is the most common type of fracture though other four metacarpal fractures can also occur from punching such as in boxing. This type of fracture is known as a boxer's fracture.
A boxer's fracture is a fracture in which the fifth metacarpal bone of the hand that is located at the metacarpal neck damages and breaks. The fifth metacarpal is the bone connected with the little finger. Boxer's fracture often is displaced or angulated abnormally requiring reduction and sometimes surgical repair.
Causes and Risk Factors of Boxer's Fracture
- The neck of the fifth metacarpal bone is generally the most vulnerable area mostly at its weakest point, which is where most of the fractures occur. This type of phenomenon is most commonly seen in sports such as boxing hence this is known as boxer's fracture.
- As stated earlier, boxer's fracture is caused due to punching an object with a closed unprotected fist. This is frequently experienced in the course of fist fights or punching hard objects such as a wall. These fractures can also occur when the hand is not clenched while striking a hard object.
Signs and Symptoms Boxer's Fracture
- Sudden pain and swelling in the hand.
- Tenderness on touching the hand.
- Pain while attempting movement of the hand, especially the last two fingers.
- Development of bruising and discoloration around the injured area.
- Knuckles and the broken bones may get deformed.
- Abnormal movements of the broken bone fragments.
- Pain on holding the finger that attaches to the fracture metacarpal bone and pushing it inwards toward the broken bone.
- Malalignment of the connected finger when making a fist with an injured hand.
- Another common sign is a cut on the hand in the injured area. A cut may indicate a more severe type of boxer's fracture.
Treatment for Boxer's Fracture
- Generally, conservative route suffices for treatment of boxer's fracture where there is no significant displacement or rotational deformity. Conservative measures include closed reduction under local anesthesia and then casting or splinting of hand and small finger. Some digital motion may be allowed while casting for improved results depending upon the severity of the fracture. Fracture may require at least six to ten weeks for complete healing, which includes period of immobilization for about six weeks followed by protective splinting for another six weeks.
- Surgery may be recommended in some severe cases where there are multiple fractures or open wound. Two factors play a major role in determining if surgery is warranted.
- Length: If the digit gets shortened or decreases in length due to fracture, surgery is recommended to restore the digit to its usual size.
- Rotation: In cases where the digit gets rotated due to the fracture, surgery is recommended to correct the deformity and restore the digit to its usual position.
- Metal implants such as plates, wires, and screws are used to fix the broken fragments of bone depending upon the nature and type of the fracture.
- Some of the high level athletes may go for open reduction and internal fixation in an effort to return to sports earlier.
- The surgical procedure carries a risk of infection, bleeding, damage to neurovascular structures, and failure of hardware.
Exercises for Boxer's Fracture
Stretching and strengthening exercises are required in the recovery phase to attain full motion of the finger.
Stretching Exercises for Boxer's Fracture
- Flexion: This is done by bending the wrist forward until a pain-free stretch is sensed. This position need to be held for 5 seconds and should be performed in 2 sets of 15.
- Extension: This is done by bending the wrist backwards until a pain-free stretch is sensed. This position need to be held for about 5 seconds and should be performed in 2 sets of 15.
- Side to Side: This is done by moving the wrist from side to side until a pain-free stretch is sensed. This position need to be held for about 5 seconds in each direction and should be performed in 2 sets of 15.
Strengthening Exercises for Boxer's Fracture
- Opposition Stretch: This is done by resting the hand on the table and palm in the upward direction. Then join the tip of the thumb with the tip of the small finger. Hold this position for 6 seconds. Repeat for 10 times.
- Wrist Flexion: This is done by holding a hammer handle or soup can in the hand with palm facing the ceiling. Then bend the wrist in the upward direction. Gradually decrease the weight and come back to the starting posture. Perform 2 sets of 15. Slowly increase the weight of the object.
- Wrist Extension: This is done by holding a hammer handle or a soup can in hands with the palm facing downwards. The wrist is then bent slowly in the upward direction. The weight needs to be decreased gradually when coming back to the starting posture. This needs to be performed in 2 sets of 15. Over time, the weight should be increased.
- Grip Strengthening: This is done by holding a tennis ball in the hand and squeezing it in the hardest possible manner without aggravating pain. It should be held for about 5 seconds and then released. It should be repeated about 5 to 10 times making sure there is no aggravation of symptoms.
- Finger Spring: This is done by wearing a rubber band around the outer surface of fingers, including thumb and stretching the rubber band by stretching the fingers. This should be performed in 2 sets of 15.
Investigations for Boxer's Fracture
A complete subjective and physical examination is necessary to diagnose a metacarpal fracture. A thorough neurovascular examination of the hand and the digits is performed to assess for injuries to the nerves and vessels. Typically an x-ray is required for confirming the severity.
Other Diagnostic Tests May Include
- CT scan.