Hand Fractures and Dislocations

A Bennetts’s fracture is an intra-articular fracture at the base of the thumb, with a dislocation or subluxation of the carpometacarpal (CMC) joint. Because it involves the joint surface, it is often significantly displaced and is very unstable. This type of fracture is often seen in sports such as football.

When the bone breaks, there is bleeding from the ends of the bone, which can cause swelling and subsequent stiffness – particularly in the fingers and thumbs.

If not properly diagnosed, a Bennett’s fracture can develop an uneven joint surface at the base of the thumb and create an environment favorable for late onset arthritis in the joint.

Treatment
The primary treatment option for this type of fracture is reduction, which is pulling bones back into place. This may be done either open or closed in the operating room. A closed reduction does not require an incision, but will utilize a splint. An open reduction entails an incision in order to directly reposition the bones. They are then held in place with internal fixation, screws and/or wires.

Metacarpal fractures are common injuries – accounting for nearly 40 percent of all hand fractures. The fracture may occur at the base, shaft, head or neck of the metacarpal as a result of a direct blow, a fall onto the hand, or from the force of punching with a closed fist.

While the outer fingers and thumb are the most commonly affected, fractures at the neck of the little finger metacarpal – also known as boxer’s fractures – are among the most common types of injuries to the hand.

Metacarpal fractures are most often seen in boys and young men. In both the very young as well as the older age groups, metacarpal fractures generally result from a trauma such as a fall.

These types of fractures are classified according to the location of the break. The neck and shaft are the most common fracture sites for the second through fifth metacarpals. Most thumb metacarpal fractures occur at the base – though are treated differently, because of the biomechanics of the thumb.

Treatment
While treatment depends on the severity of the fracture, most metacarpal fractures are minimally displaced (slightly out of alignment) and without rotational deformity, so closed reduction (pulling of bones back into place without an open incision) and short period of casting or splinting is all that is indicated.

Unstable or inadequately reduced fractures may require surgery and internal fixation, in order to ensure rigid immobilization and allow for early motion.

Thumb Dislocation

Since the thumb has only two phalanges, only two joints can potentially dislocate – the interphalangeal (IP) joint or the metacarpophalangeal (MCP) joint. Dislocations of the MCP joint of the thumb are fairly common, but can be complex injuries and difficult to reduce. They most often occur when a fall produces a forceful hyperextension of the thumb on an extended hand.

Pain may be mild to moderate, and swelling may be evident.

Dislocations of the thumb are generally best corrected with open reduction in order to directly reposition the tissue and bone. Failure to sufficiently correct the dislocation of a thumb could result in instability, chronic joint stiffness, an inability to flex and extend the thumb in a normal way – and eventually arthritis.

Thumb Fracture

When a fracture is involved in a thumb injury it becomes a more serious problem – as it hinders the ability to grasp items in the hand and increases the risk of arthritis later in life.

Thumb fractures generally occur when they are placed under direct stress such as in a fall or injuries incurred in some ball sports. Though, some may be caused indirectly by an unusual twisting and muscle contraction. Those involved in contact sports as well as those with a history of bone disease or calcium deficiency are at particular risk.

Fractures are named based on the type and location of the break. Those involving joints are always more difficult to treat and are at greater risk for complications.

Symptoms include severe pain, swelling, reduced thumb movement, and sensitivity.

Treatment

Prompt and proper treatment of joint injuries to the hands reduces the risk of other conditions. Initially, rest, cold compression, and elevation are advised. A splint to help maintain the thumb in position is also encouraged until appropriate treatment is determined.

If treating a fracture that is not displaced, a thumb spica cast may be all that is indicated to realign the bones. For more severe fractures of the thumb, surgical treatment and internal fixation may be required.

The triquetrum is one of the eight wrist bones. Triquetral fractures are common in falls on an outstretched hand.

Swelling may be minimal, but the area is usually very tender. Radiographic imaging of various wrist positions will confirm diagnosis and determine if any other fractures or tissue damage resulted from the fall.

Treatment
Because of the rich blood supply to the area, triquetral fractures generally heal very well and require little more than short-arm casting until union is achieved – approximately three to six weeks.