Joints of the bones of the hand

The articular joint (art mediocarpea) is formed by the articulating articular surfaces of the bones of the first and second rows of the wrist. This is a complex joint, block-shaped in shape. His articular fissure is S-shaped. The joint capsule is thin, especially on the back, attached to the edges of the articular surfaces. The articular joint is functionally associated with the wrist joint.

Intervertebral joints (artt., Intercarpeae) are inactive, formed by adjacent bones of the wrist. Joint capsules are attached along the edges of the articulating surfaces. Joint arteries of the intervertebral joints communicate with the cavity of the articular joint.

Mid-wrist and inter-wrist joints are strengthened by many ligaments. The most pronounced radial ligament of the wrist (lig. Carpii radiatum), representing fan-shaped fibrous bundles, running on the palmar surface from the head bone to the adjacent bones. Nearby located bones of the wrist connect palmar and dorsal intercostal ligaments (ligg. Intercarpale palmaria et dorsalia). Some wrist bones are connected by intra-articular interosseous inter-vertebral ligaments (ligg. Intercarpalia interossea).

The joint of the pea-bones (art. Ossis pisiformis), formed by pea-like and trihedral bones and fortifications of pea-metacarpal (lig. Pisometacarpale) and pea-hook-like ligament (lig. Piso-hamatum), is also referred to intercostal joints. These ligaments are a continuation of the tendon of the muscle - the elbow flexor of the wrist.

The wrist joints (artt. Carpometacarpeae) are formed by the articular surfaces of the bones of the second wrist row and the bases of the metacarpal bones. Pony-metacarpal joints (II-V metacarpal bones) are flat in shape, they share a joint joint. The joint capsule is thin, attached to the edges of the articular surfaces and tightly taut. The articular cavity of the carpometacarpal joints is usually communicated with the articular cavities of the middle-wrist and inter-articular joints. The capsule is strengthened by the back and palm carpally-metacarpal ligaments (ligg. Carpometatacarpea dorsalia and palmaria). Mobility in carpometacarpal joints of II-V metacarpal bones is minimal.

The carpometal joint of the thumb (art. Carpometacarpea pollicis) is different from the rest. It is formed by the saddle joint surface of the polygonal bone (bone-trapezium) and the base of the first metacarpal bone. The wrist joint of the big toe, isolated from the rest of the carpometacarpal joints, has great mobility. Around the frontal axis, passing not strictly transversely (at an angle to the frontal plane), the opposition of the thumb to the others (oppositio) is realized. The return of the thumb to its original position is called repositio. Around the sagittal axis, the reduction and removal of the thumb relative to the second finger is performed. Circular motion is the result of combined movements with respect to the frontal and sagittal axes.

Inter-articular joints (artt., Intermetacarpeae) are formed by adjacent lateral surfaces of the bases of II-V metacarpal bones. The joint capsule in the joints and carpometacarpal joints is common. The wrist joints are strengthened by transverse dorsal and palmar ligament ligament (ligg. Metacarpea dorsalia and palmaria), as well as intercostal metacarpal ligament (ligg. Metacarpea interossea). The interosseous metacarpal ligaments are intraarticular, they connect the facing surfaces of metacarpal bones.

Pseudo-phalangeal joints (artt. Metacarpophalangeae) are formed by the bases of proximal phalanges of the fingers and the articular surfaces of the metacarpophalangeal heads. The articular heads are round in shape, the articular cavities on the phalanges are ellipsoidal. Joint capsules are free, attached to the edges of articular surfaces, strengthened with ligaments. On the palmar side, the capsule is thickened by the palmar ligament (ligg. Palmaria), on the sides - by collateral ligaments (ligg. Collateralia). Between the heads II-V of metacarpal bones in the transverse direction are deep transverse metacarpal ligament (ligg. Metacarpea transversa profunda).

The movements in the metacarpophalangeal joints are performed around two axes - frontal (flexion and extension) and sagittal (pulling the finger in one or the other direction).

Interphalangeal joints (artt., Interphalangea) are formed by the heads and bases of neighboring phalanges of the brush. This block-shaped joints. The joint capsules are loose, attached to the edges of the articular cartilage. Capsules are strengthened in front and laterally with palmar and collateral ligaments (ligg. Collateralia).

In the movements of the hand relative to the forearm, many joints are involved, which in the clinic are conveniently called carpal joints.

In the metacarpophalangeal joints, it is possible to move around two axes. Around the frontal axis, bending is performed - extension up to a total of 90 °. With reference to the sagittal axis, the removal and reduction within limited limits are performed. In the metacarpophalangeal joints, a circular motion is possible. In the interphalangeal joints of movement (flexion and extension) are made relative to the frontal axis. The total amount of flexion - extension in these joints is about 90 °.

[1], [2]