Carpal bones

The bones of the wrist. general information

The bones of the wrist forms a set of 8 small cancellous bone, which are arranged in two rows, each of which is 4 seeds.  The bones of the wrist of man

The first or proximal row disposed closer to the forearm consists of the following bone submitted in order, starting with the thumb:

  • navicular or os scaphoideum;
  • lunate or os lunatum;
  • triangular or os triquetrum;
  • pisiform or os pisiforme.

The connection of the first three bones forming elliptical articular surface, which is articulated wrist and the distal end of the radius. Pisiform bone of the wrist, which is usually attributed to the sesamoid bone, in turn, is connected to the triangular bone.

The second row of carpal bones - distal - formed following bones:

  • trapezoid or os trapezium;
  • trapezoidal or os trapezoideum;
  • capitate or os capitation;
  • hamate or os hamatum.

The surface of each bone is provided with a special articular facets that help connect bones to bones closest. Also on the palmar surface of the row of carpal bones are arranged tubercles, which are attached to the ligaments and muscles. These bones include the scaphoid, trapezium, hamate.

General view of the carpal bones form a set, the convex part of which is located on the back of the hand, the concave - in the palm.

Almost all the 8 carpal bones have six surfaces (except the pisiform). At the same time, without exception, all of the bones belong to articulate: the lower their surface forms the glenoid fossa and the upper - joint head. Between the side surfaces of the bones also have a joint connecting the carpal bones with each other.

Damage wrist bones

Among the most common wrist injuries - sprains and fractures:

  • dislocations of the wrist bones .  Dislocations are different options depending on the bone involved in the injury .  The most common dislocations of the lunate bone, a little less - scaphoid, rarely - pisiform .  Dislocation of the lunate bone is quite difficult to detect even with the help of X-ray inspection .  However, the main symptoms are the following: the presence of the protrusion in the center of the palm side of the wrist and depressions on the back, the sensation of pain when straightening the fingers, which often take the form of fixed or bent .  Furthermore, the wrist joint swells palm movements painful .  It reduces a dislocated by protivotyagi, pull or push method Belair .  Dislocation of the scaphoid fracture is often accompanied .  Diagnosing it is possible only with the help of X-ray examination .  So reduce a dislocation under general anesthesia or local anesthesia by means of traction, then the bandage is assigned special exercises, physiotherapy .  Dislocation pisiform carpal bones usually does not adversely affect the functioning of the hand and wrist .  Appointed surgery in which bone is filed in its place, and ligaments are closed with stitches;  Fracture of the carpal bones
  • fractures of the wrist - a rare phenomenon, but the most susceptible scaphoid .  In more rare cases (as with sprains), and possible fractures of the lunate bone pisiform .  Fractures of other wrist bones - exceptional cases .  Scaphoid fracture is possible in situations involving a fall on a bent arm, punched on a hard surface or a direct blow to the palm .  In most cases, the scaphoid is broken into two parts .  Symptoms of a fracture include: sore wrist, aggravated by stress on the fingers I or II, the inability to compress brushes in a fist because of the pain .  Diagnosis is made by means of X-ray examination, treatment involves immobilization for a period of 1 to 6 months .  If the fracture of the wrist is not accompanied by a shift, it is recommended to apply a plaster cast for about 3 months .  In the presence of bias carried out osteosynthesis of bone fragments with screws .  The time for the immobilization is increased up to 2 months .  Lunate bone fracture occurs when you fall on the wrist or as a result of a direct blow .  After the damage is noted joint swelling, pain, aggravated by extension brush in the back side .  Treatment involves the imposition of plaster splints, wearing a period which varies from 1, 5 to 2 months .  Typically, the bone has healed complications are not marked .  The most rare type of bone fractures of the wrist - fracture pisiform bone, which becomes a cause of injury blows to damage or blow edge brush on a hard surface .  Symptoms include pain in the area of ​​the wrist joint of the little finger side that increases the compressive hand into a fist or trying to bend a little finger .  Treatment involves immobilizing lasting at least 1 month .