Fracture-dislocation of the base of the first metacarpal

Introduction of the first metacarpal base fracture and dislocation The first metacarpal basal fracture and dislocation, also known as Bennett fracture dislocation, is a very unstable fracture. The carpometacarpal joint is a saddle-shaped joint composed of the first metacarpal and the multi-corner bone. It is flexible and stable. When the first metacarpal is in a slightly flexed position and is subjected to an external force on the longitudinal axis, a base is produced at the base of the first metacarpal. The fracture line consists of an intra-articular fracture from the inside to the lower side, forming a triangular bone at the medial base. The bone mass is generally less than 1/3 of the articular surface of the base. Due to the attachment of the collateral collateral ligament, it will continue to maintain a positional relationship with the large angle bone; the distal segment of the fracture, that is, the first metacarpal bone, is due to the abductor of the thumb. Pulling causes dislocation to the temporal and dorsal sides. basic knowledge The proportion of illness: 0.02% Susceptible people: no special people Mode of infection: non-infectious Complications: fracture

The cause of fracture and dislocation of the first metacarpal base

Violence (45%):

Mostly caused by axial violence from the fingertips. The first metacarpal base fracture and dislocation (Bennett fracture dislocation) The traumatic mechanism is similar to the basal fracture, mostly caused by axial violence transmitted from the fingertip, but there is a fracture of the joint at the proximal end of the first metacarpal, palm (triangle) The joint is a saddle joint, and the basal articular surface of the first metacarpal and the articular surface of the most metacarpal are saddle-shaped, and the two are diagonally interlocked. For example, the two hands are enlarged and inserted, allowing pre-, post-, left, and right four-way activities. After the anterior internal angle of the metacarpal base is broken, the metacarpal bone is dislocated laterally to the proximal side (displaced outward and downward), and the broken triangular bone piece is fixed by the ligament on the ligament connected to the large angle bone and the second metacarpal bone. Without resetting, the base of the metacarpal bone is prominent, local pain and tenderness, the first palm joint movement is limited, the thumb is abducted, and the Zhang Dahu mouth and palm function are affected.

Prevention of fracture and dislocation of the first metacarpal base

Avoid the occurrence of violent incidents. Take first aid measures when a violent incident causes the disease.

1. Have the patient sit down and fold the clean gauze or handkerchief over the injured hand.

2. Place the injured forearm on the chest and suspend the injured forearm with a bandage or bandage. A bandage or bandage can be placed around the patient's chest, knotted on the healthy side, and a padded cushion is placed between the knot and the body.

3. After the dressing is over, check the patient's blood circulation.

4. Patients should be seated when they are taken to the hospital.

Complications of the first metacarpal base fracture and dislocation Complications

The first metacarpal base fracture and dislocation, also known as Bennett fracture and dislocation, is a very unstable fracture. The thumb and wrist joint is a saddle joint composed of the first metacarpal and the large angle bone. It is flexible and stable. The disease is mainly traumatic. Caused by it, it can lead to nerve, muscle, blood vessel, tendon injury, such as local bleeding and swelling, nerve damage caused by muscle numbness, fatigue, acupuncture and so on.

The first metacarpal base fracture and dislocation symptoms common symptoms joint pain simple fracture

The clinical manifestations were pain, swelling of the carpometacarpal joint, obvious bulging of the dorsal aspect of the ankle, local tenderness, mild flexion and adduction of the thumb, thumb adduction, limited abduction and palm function, X-ray film display 1 ulnar fracture of the metacarpal base of the metacarpal, with dislocation or subluxation of the carpometacarpal joint.

Although the fracture of the first metacarpal can occur in all parts of the metacarpal, the basal fracture is more common. The basal fracture can be divided into two types: intra-articular and extra-articular (Fig. 2). The former includes Bennett fracture and Rolando fracture. The axial violence transmitted from the fingertips.

Examination of the first metacarpal base fracture and dislocation

X-ray film can clearly show the fracture and dislocation of the base of the first metacarpal.

Diagnosis and diagnosis of fracture and dislocation of the first metacarpal base

diagnosis:

Clear history of trauma, swelling of the base of the thumb of the hand, pain, tenderness and conduction pain, and dysfunction, X-ray film to confirm the diagnosis.

Differential diagnosis:

1. Metacarpal neck fracture: The performance of this disease is similar to that of the first metacarpal base fracture and dislocation. It is usually caused by violent injury, and it is characterized by pain and limited activity. X-ray film inspection can be performed for identification.

2. The metacarpal shaft fracture: the mechanism of the attack is also dislocated with the fracture of the base of the first metacarpal. The clinical manifestations are mainly pain, limited mobility and swelling. Line X-ray examination can be clear.

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