The interphalangeal joints of the hand are the pivot joints between the phalanges of the fingers that give flexion towards the palm of the hand.
There are two sets in each finger (aside from in the thumb, which has just a single joint):
"proximal interphalangeal joints" (PIJ or PIP), those between the first (likewise called proximal) and second (middle) phalanges
"distal interphalangeal joints" (DIJ or DIP), those between the second (middle of the road) and third (distal) phalanges
Anatomically, the proximal and distal interphalangeal joints are fundamentally the same as. There are some minor contrasts in how the palmar plates are appended proximally and in the division of the flexor ligament sheath, however the significant contrasts are the littler measurement and diminished portability of the distal joint.
Palmar tendon:
The palmar tendon is more slender and increasingly adaptable in its focal proximal part. On the two sides it is strengthened by the supposed check rein tendons. The extra guarantee tendons (ACL) begin at the proximal phalanx and are embedded distally at the base of the center phalanx underneath the security tendons.
The extra tendon and the proximal edge of the palmar plate are adaptable and overlap back upon themselves amid flexion. The flexor ligament sheaths are immovably appended to the proximal and center phalanges by annular pulleys A2 and A4, while the A3 pulley and the proximal filaments of the C1 tendon connect the sheaths to the versatile volar tendon at the PIP joint. Amid flexion this course of action delivers a space at the neck of the proximal phalanx which is filled by the collapsing palmar plate.
The palmar plate is upheld by a tendon on either side of the joint called the insurance tendons, which keep deviation of the joint from side to side. The tendons can mostly or completely tear and can separate with a little break part when the finger is constrained in reverse into hyperextension. This is known as a "palmar plate, or volar plate damage".
The palmar plate frames a semi-inflexible floor and the insurance tendons the dividers in a portable box which moves together with the distal piece of the joint and gives strength to the joint amid its whole scope of movement. Since the palmar plate clings to the flexor digitorum superficialis close to the distal connection of the muscle, it likewise expands the snapshot of flexor activity. In the PIP joint, augmentation is progressively restricted in view of the two supposed registration tendons, which connect the palmar plate to the proximal phalanx.
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