The hand has 19 small bones. The thumb has 2 phalanges, the 4 fingers have 3 phalanges. The hand also consists of 5 metacarpal bones (the pasterns). The word ‘metacarpal bone’ is also used to refer to the set of metacarpal bones. Together with tendons and muscles, they allow us to perform very complicated and precise movements.
Trauma is an injury that is unexpected, unavoidable, or sustained in an accident, such as a fracture, dislocation or sprain.
Each injury requires specific treatment and follow-up. A fracture may or may not be displaced, depending on whether the fragments of the fracture are properly aligned or not. The distinction is extremely important for treatment. Displaced fractures more often need to be treated surgically, while an undisplaced fracture is usually treated with a splint or cast.
Fractures
Hand
The “Boxer’s fracture” is a common fracture, at the level of the fifth metacarpal, just below the little finger. The fracture is typically caused by punching a hard surface, causing the neck of the bone to fracture. The joint looks loose and a protrusion on the back of the hand is sometimes felt. A simultaneous fracture of several metacarpals is possible. The diagnosis is made by an x-ray (x-ray). The treatment consists of the placement of a cast, after the realignment of the bone fragments by a specialist. For quick healing, the wrists and other joints are placed at the correct angle. After the plaster has been laid, an additional x-ray is often taken to check that everything is in place.
The fractures in the middle of the metacarpal are usually oblique or transverse fractures. Bone fragments are often moved relative to each other, frequently (but not always) requiring an operation. The patient is in a cast for about four weeks. A short week after the fracture, we check whether the bone fragments are still properly aligned.
The fractures at the base of the metacarpals are rare. Treatment of an undisplaced fracture consists of wearing a plaster splint for 4 weeks. In the event of a displaced fracture, an operation is sometimes necessary.
The thumb fractures fall into two types:
- Rolando’s fracture is a fracture in the lower part of the metacarpal bone of the thumb, in the joint. The bottom of the bone is often crushed.
- Benett’s fracture is also a fracture in the lower part of the metacarpal bone of the thumb, but with displacement of the thumb and most of the metacarpal bone. The thumb is sore and may turn blue. It is no longer possible to join the tip of the index finger and the tip of the thumb (thumb-index clamp).
In both types of fractures, the bone fragments are aligned and then immobilized with a cast for 4 weeks. As the fracture affects the joint, the thumb is often very stiff after healing.
Fingers
Most finger fractures are actually cracks. The fracture is said to be “stable” when the two bone fragments are not moved and cannot move. In the case of a displaced fracture, and therefore “unstable”, the finger is abnormally bent, twisted or shortened. The doctor first tries to collect the bone fragments without surgery. Under local anesthesia, he gently pulls the fingertip so as to realign the fragments. If this attempt is unsuccessful, an operation must be performed.
For the treatment of a finger fracture, the broken finger is often plastered with the neighboring finger (s). These fingers serve as a splint. A short week after the fracture, the doctor can take an additional x-ray to check that everything is in place.
Dislocations
Dislocations interphalangeal are frequent. A typical cause is the landing of a balloon on an outstretched finger. The joint between two phalanges is sensitive to pressure and can be deformed. It is no longer possible to stretch or bend the finger. An experienced doctor will push the phalanges back into place with a gentle pull. Then, when it is again possible to stretch and flex the finger, a splint will be put on for a period of time. If this treatment fails, surgery may be necessary. This is usually the case when the end of the phalanx is stuck in the extensor tendon (“buttonhole finger”). An x-ray should then confirm that the finger is well healed.
In the case of a dislocation between the phalanges and metacarpals, the base of the phalanx is moved up or down relative to the metacarpal. This dislocation is clearly visible. The phalanx usually snaps back into place with a slight pull of the finger. If this manipulation fails, the tendon is probably affected. In this case, surgery is required.
Sprains
Skier thumb
the “Skier’s thumb” corresponds to a sprain or a tear of the ligaments at the level of the base of the thumb. The joint which allows movement of the thumb in relation to the hand is shaped like a saddle and is bordered on both sides by strong ligaments which hold the joint in place. A “skier’s thumb” often goes hand in hand with a contusion of ligaments and, in some cases, with a tear in the ligaments. The typical cause of the injury is a forced separation of the thumb from the hand, for example during a ski fall. The thumb is sore at the lesion and there may be an effusion of blood. The diagnosis is made by physical examination and x-ray, which may reveal that a bone fragment has come off. The stability of this joint is very important because it allows you to take something firmly. A lesion in this area must therefore be treated properly. If the ligament is completely torn, repair surgery should be done within two weeks of the injury. Wearing a splint for 3 to 4 weeks is sufficient in the case of a sprain or partial tear of the ligament.
Mallet finger
The tendons attached to the back of the phalanges with the fingertips allow us to stretch the fingers. Sometimes one of these tendons is torn, often after a shock, such as the direct contact of a balloon on an outstretched finger. The fingertip is literally hanging from the joint. This is what we denote by mallet or hammer finger. It is no longer possible to straighten the tip of the finger. The doctor makes the diagnosis on the basis of an x-ray. Left untreated, the extensor tendon can form scar tissue and permanently prevent straightening of the fingertip. In many cases, it is sufficient to wear a splint for 6 to 8 weeks (up to 3 months), sometimes longer, to keep the finger straight. The finger should remain stretched throughout the treatment, including when replacing a splint. If this treatment fails, intervention is sometimes necessary (at the earliest after 12 months). The operation is more often necessary in case of a mallet finger with a fracture, in which a bone fragment has come loose.
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