Human hand, or distal part upper limb, has a special meaning. With the help of hands and fine motor skills, movements of all fingers, people learn about the world and interact with it. The hand and fingers are the main tools in any work. A decrease in their functionality largely leads to a decrease in working capacity and to a limitation of human capabilities.
Joints and bones of the hand
The anatomy of the human hand is distinguished by the presence of small bones articulated by joints various types. There are three components of the hand: the wrist, the metacarpal part, and the phalanges of the fingers. The wrist in common parlance is called the wrist joint, but from an anatomical point of view it is the proximal part of the hand. It consists of 8 bones arranged in two rows.
The first proximal row consists of three bones connected by fixed joints. Adjacent to it on the outer side is a pisiform bone, inherited from distant ancestors and used to enhance muscle strength (one of the sesamoid bones). The bony surface of the first row, facing the bones of the forearm, forms a single articular surface for connection with radius.
Bones of the hand
The second row of bones is represented by four bones that connect distally to the metacarpus. The carpal part is shaped like a small boat, where the palmar surface is its concave part. The space between the bones is filled with articular cartilage, connective tissue, nerves and blood vessels. Movements in the wrist itself and movement of its bones relative to each other are almost impossible. But thanks to the presence of a joint between the carpal part and the radius, a person can rotate the hand, adduct it and abduct it.
The metacarpal part consists of five tubular bones. Their proximal part is connected to the wrist by fixed joints, and the distal part is connected to the proximal phalanges of the fingers by movable joints. The metacarpophalangeal joints are ball-and-socket joints. They enable flexion and extension and rotational movements.
Joint thumb has a saddle shape and provides only extension and flexion. Each finger is represented by three phalanges, connected through movable trochlear joints. They perform flexion and extension of the fingers. All hand joints have durable articular capsules. Sometimes the capsule can unite 2-3 joints. To strengthen the osteoarticular frame, there is a ligamentous apparatus.
Ligaments of the hand
The joints of the human hand are held and protected by a whole complex of ligaments. They have increased elasticity and at the same time strength due to very dense fibers made from connective tissue. Their function is to provide movement in the joints no more physiological norm, protect them from injury. In cases of increased physical effort (falls, heavy lifting), the ligaments of the hand can still be stretched; cases of rupture are very rare.
The ligamentous apparatus of the hand is represented by numerous ligaments: interarticular, dorsal, palmar, collateral. The palmar part of the hand is covered by the flexor retinaculum. It forms a single channel through which the tendons of the digital flexor muscle pass. The palmar ligaments run in different directions, creating a thick fibrous layer; there are fewer dorsal ligaments.
The metacarpophalangeal and interphalangeal joints are strengthened by lateral collateral ligaments and also have additional ones on the palmar surface. The flexor retinaculum on the palm and the extensor retinaculum on the dorsum are involved in creating fibrous sheaths for these muscles. Thanks to them and the synovial spaces, the tendons are protected from external influences.
Muscles of the hand
When studying the anatomy of the human hand, one cannot help but pay attention to the perfection of the structure of its muscular apparatus. All the smallest and precise movements of the fingers would be impossible without the coordinated work of all the wrist muscles. All of them are located only on the palm; the extensor tendon runs on the back side. According to their location, the muscles of the hand can be divided into three groups: the muscles of the thumb, the middle group and the small finger.
The middle group is represented by interosseous muscles that connect the bones of the metacarpal part, and worm-shaped muscles that are attached to the phalanges. The interosseous muscles bring and spread the fingers, and the lumbrical muscles bend them at the metacarpophalangeal joints. The muscle group of the thumb makes up the so-called thenar, the eminence of the thumb. They bend and unbend, abduct and adduct.
The hypotenar, or eminence of the lesser finger (little finger), is located on the other side of the palm. The muscle group of the small finger opposes, abducts and adducts, flexes and extends. Movement of the hand in the wrist joint is provided by the muscles located on the forearm due to the attachment of their tendons to the bones of the hand.
Blood supply and innervation of the hand
The bones and joints, muscles and ligaments of the hand are literally riddled with blood vessels. The blood supply is very well developed, which ensures high differentiation of movements and rapid tissue regeneration. Two arteries, the ulnar and the radial, approach the hand from the forearm, and, passing through special channels through the wrist joint, they end up between the muscles and bones of the hand. Here an anastomosis (connection) is formed between them in the form of a deep and superficial arc.
Smaller arteries extend from the arches to the fingers; each finger is supplied with blood by four vessels. These arteries also connect with each other, forming a network. This branched type of vessels helps with injuries when, if any branch is damaged, the blood supply to the fingers suffers slightly.
The ulnar, radial and median nerves, passing through all elements of the hand, end on the pads of the fingers a huge amount receptors. Their function is to provide tactile, temperature and pain sensitivity.
Coordinated and harmonious work of the hand is possible only if the functionality of all its parts is preserved. components. A healthy hand is essential for full life person, maintaining his ability to work.
Among all bone fractures, the data is 5%.
Fractures of the second finger are more common, with the fifth finger in second place.
In almost 20% of cases, multiple fractures of the phalanges of various fingers are observed.
Damage to the main phalanges most often occurs, then to the nail and rarely to the middle phalanges.
Four of the five fingers of the hand consist of three phalanges - the proximal (upper) phalanx, the middle and the distal (lower).
The thumb is formed by a proximal and distal phalanx.
The distal phalanges are the shortest, the proximal ones are the longest.
Each phalanx has a body, as well as a proximal and distal end. For articulation with neighboring bones, the phalanges have articular surfaces (cartilage).
Causes
Fractures occur at the level of the diaphysis, metaphysis and epiphysis.
They are available without offset or with offset, open and closed.
Observations show that almost half of phalangeal fractures are intra-articular.
They condition functional disorders brushes Therefore, phalangeal fractures should be considered as a severe injury in a functional sense, the treatment of which must be approached with the utmost seriousness.
The mechanism of fractures is predominantly direct. They occur more often in adults. The blows fall on the back surface of the fingers.
Symptoms
Throbbing pain, deformation of the phalanges, and in case of non-displaced fractures - deformation due to swelling, which spreads to the entire finger and even the back of the hand.
Displacements of fragments are often angular, with lateral deviation from the axis of the finger.
Typical for a phalangeal fracture is the inability to fully extend the finger.
If you place both hands with your palms on the table, then only the broken finger does not adhere to the plane of the table. With displacements along the length, shortening of the finger and phalanx is noted.
For fractures of the nail phalanges
Subungual hematomas occur. Active and passive movements of the fingers are significantly limited due to exacerbation of pain, which radiates to the tip of the finger and is often pulsating.
The severity of the pain corresponds to the site of the phalanx fracture.
Not only the function of the fingers is impaired, but also the grasping function of the hand.
When the dorsal edge of the nail phalanx is torn off
When the dorsal edge of the nail phalanx is torn off (Bush fracture) with the extensor tendon, the nail phalanx is bent and the victim cannot actively straighten it.
Intra-articular fractures cause deformation of the interphalangeal joints with axial deviations of the phalanges.
Axial pressure on the finger aggravates the pain at the site of the phalanx fracture. In fractures with displaced fragments, pathological mobility is always a positive symptom.
Diagnostics
X-ray examination clarifies the level and nature of the fracture.
First aid
Any fracture requires temporary fixation before medical intervention, so as not to aggravate the injury.
If the phalanges of the hand are fractured, two or three ordinary sticks can be used for fixation.
They need to be placed around the finger and wrapped with a bandage or any other cloth.
As a last resort, you can bandage the damaged finger to a healthy one. If a painkiller tablet is available, give it to the victim to reduce pain.
Ring on injured finger provokes an increase in edema and tissue necrosis, so it must be removed in the first seconds after the injury.
In the case of an open fracture, it is prohibited to set the bones yourself. If there are disinfectants, you need to treat the wound and carefully apply a splint.
Treatment
No offset
Fractures without displacement are subject to conservative treatment plaster immobilization.
Displaced fractures with a transverse or close to it plane are subject to closed, one-step comparison of fragments (after anesthesia) with plaster immobilization for a period of 2-3 weeks.
Working capacity is restored after 1.5-2 months.
With an oblique fracture plane
Treatment with skeletal traction or special compression-distraction devices for the fingers is indicated.
For intra-articular fractures
Intra-articular fractures, in which it is not possible not only to eliminate the displacement, but also to restore the congruence of the articular surfaces, are subject to surgical treatment, which is carried out with open reduction with osteosynthesis of fragments, and early rehabilitation.
Must be remembered that treatment of all phalangeal fractures should be carried out in the physiological position of the fingers (half-bent at the joints).
Rehabilitation
Rehabilitation for finger fractures is one of the components complex treatment, and it has an important place in restoring finger function.
On the second day after the injury, the patient begins to move the healthy fingers of the injured hand. The exercise can be performed synchronously with a healthy hand.
The damaged finger, which is accustomed to being immobile, will not be able to freely bend and straighten immediately after the immobilization is removed. To develop it, the doctor prescribes physiotherapeutic treatment, electrophoresis, UHF, magnetic therapy, and physical therapy.
rice. 127 Bones of the upper limb ( ossa membri superioris) right; front view.Finger bones (phalanges), ossa digitorum (phalanges) (see Fig. , , , , ), are presented phalanges, phalanges, related in shape to long bones. The first, thumb, finger has two phalanges: proximal, phalanx proximalis, And distal, phalanx distalis. The remaining fingers still have middle phalanx, phalanx media. Each phalanx has a body and two epiphyses - proximal and distal.
Body, corpus, each phalanx is flattened on the anterior (palmar) side. The surface of the body of the phalanx is limited on the sides by small scallops. On it is nutrient opening, continuing to distally directed nutrient channel.
The superior, proximal, end of the phalanx, or base, basis phalangis, thickened and has articular surfaces. The proximal phalanges articulate with the bones of the metacarpus, and the middle and distal phalanges are connected to each other.
The lower, distal, end of the 1st and 2nd phalanges has head of the phalanx, caput phalangis.
At the lower end of the distal phalanx, with back side, there is a slight roughness – tuberosity of the distal phalanx, tuberositas phalangis distalis.
In the area of the metacarpophalangeal joints of the 1st, 2nd and 4th fingers and the interphalangeal joint of the 1st finger on the palmar surface, in the thickness of the muscle tendons, there are sesamoid bones, ossa sesamoidea.
rice. 151. Bones of the hand, right (x-ray). 1 - radius; 2 - styloid process of the radius; 3 - lunate bone; 4 - scaphoid bone; 5 - trapezium bone; 6 - trapezoid bone; 7-1 metacarpal bone; 8 -sesamoid bone; 9 - proximal phalanx of the thumb; 10 - distal phalanx of the thumb; 11 - II metacarpal bone; 12 - proximal phalanx index finger; 13 - base of the middle phalanx of the index finger; 14 - distal phalanx of the index finger; 15 - capitate bone; 16 - hook of the hamate; 17 - hamate bone; 18 - pisiform bone; 19 - triangular bone; 20 - styloid process ulna; 21 - head of the ulna. Fractures distal phalanges divided into extra-articular (longitudinal, transverse and comminuted) and intra-articular. Knowledge of the anatomy of the distal phalanx is important for the diagnosis and treatment of these types of injuries. As shown in the figure, fibrous bridges are stretched between the bone and skin to help stabilize the distal phalanx fracture.
In the space between these jumpers, a traumatic hematoma, causing severe pain due to increased pressure inside this enclosed space.
TO distal phalanges of fingers II-V two tendons are attached. As shown in the figure, the deep flexor tendon is attached to the palmar surface, and the terminal portion of the extensor tendon is attached to the dorsal surface. If too much force is applied, these tendons can tear off. Clinically, there is a loss of function, and radiologically, minor avulsion fractures at the base of the phalanx can be detected. These fractures are considered intra-articular.
Mechanism of damage in all cases there is a direct blow to the distal one. The force of the impact determines the severity of the fracture. The most typical fracture is a comminuted fracture.
At inspection Usually there is tenderness and swelling of the distal phalanx of the finger. Subungual hematomas are often observed, indicating a rupture of the nail bed.
IN diagnostics fracture and possible displacement, images in both direct and lateral projections are equally informative.
As mentioned earlier, it is often observed subungual hematomas and nail bed tears. Often, in combination with a transverse fracture of the distal phalanx, incomplete separation of the nail is observed.
Hairpin type splint used for distal phalanx fractures
Treatment of extra-articular fractures of the distal phalanges of the fingers
Class A: Type I (longitudinal), Type II (transverse), Type III (comminuted). These fractures are treated with a protective splint, elevating the limb to reduce swelling, and analgesics. A simple palmar splint or a hairpin splint is recommended. Both allow for some degree of tissue expansion due to edema.
Subungual hematomas should be drained by drilling out the nail plate using a hot paper clip. These fractures require protective splinting for 3-4 weeks. Comminuted fractures may remain painful for several months.
Draining a subungual hematoma with a paper clip
Class A: Type IV (with displacement). Transverse fractures with angular deformation or width displacement may be difficult to reduce because soft tissue interposition between the fragments is likely. If left uncorrected, this fracture may be complicated by nonunion.
Reposition often perform traction in the dorsal direction for the distal fragment, followed by immobilization with a palmar splint and control radiography to confirm the correctness of the reposition. If unsuccessful, the patient is referred to an orthopedist for surgical treatment.
Class A (open fractures with nail bed rupture). Fractures of the distal phalanges in combination with tears of the nail plate should be considered as open fractures and treated in the operating room. The treatment for these fractures is described below.
1. For anesthesia, a regional block of the wrist or intermetacarpal spaces should be used. Then the brush is processed and covered with sterile material.
2. The nail plate is bluntly separated from the bed (using a spoon or probe) and the matrix.
3. Once the nail plate is removed, the nail bed can be raised and repositioned. The nail bed is then closed with a No. 5-0 Dexon ligature using a minimal number of sutures.
4. Xeroform gauze is placed under the roof of the matrix, separating it from the root. This prevents the development of synechiae, which can lead to deformation of the nail plate.
5. The entire finger is bandaged and splinted for protection. The outer bandage is changed as needed, but the adaptation layer separating the root from the matrix roof must remain in place for 10 days.
6. To confirm the correctness of the reposition, control radiographs are shown. If the bone fragments remain unmatched, osteosynthesis can be performed with a wire.
A. Treatment technique for an open fracture of the distal phalanx. B. The nail is removed and the nail bed is sutured with an absorbable suture.
B. Simply suturing the nail bed results in good matching. bone fragments phalanx.
D. The nail bed is covered with a small strip of xeroform-soaked gauze, which is placed over the nail bed and under the eponychium fold.
Complications of extra-articular fractures of the distal phalanges of the fingers
Fractures of the distal phalanges There may be several serious complications associated with it.
1. Open fractures often complicated by osteomyelitis. Open fractures include fractures associated with a nail bed rupture and fractures with a drained subungual hematoma.
2. Nonunion usually results from interposition of the nail bed between the fragments.
3. With comminuted fractures, as a rule, delayed healing is observed.
Try not using your hands for a while. Difficult? Not difficult, but almost impossible! The main function of the hands, especially small, subtle movements, is provided by the fingers. The absence of such a small organ compared to the size of the entire body even imposes restrictions on the performance of certain types of work. Thus, the absence of a thumb or part of it may be a contraindication to driving.
Description
Our limbs end with fingers. A person normally has 5 fingers on his hand: a separate thumb, opposed to the rest, and the index, middle, ring and little fingers arranged in a row.
Man received this separate arrangement of the thumb during evolution. Scientists believe that it was the opposable finger and the associated well-developed grasping reflex that led to a global evolutionary leap. In humans, the thumb is located in this way only on the hands (unlike primates). In addition, only a human can connect the thumb with the ring and little fingers and has the ability to both have a strong grip and small movements.
Functions
Thanks to the variety of movements in which the fingers are involved, we can:
- grasp and hold objects of varying sizes, shapes and weights;
- perform small precise manipulations;
- write;
- gesticulate (the lack of ability to speak led to the intensive development of sign language).
The skin of the fingertips has folds and stripes that form a unique pattern. This ability is actively used to identify a person by law enforcement agencies or the security system of employers.
Structure
- The basis of the fingers is the bony skeleton. The fingers consist of phalanges: the smallest, nail or distal, middle phalanx and proximal phalanx (all fingers except the thumb). The phalanges of the fingers are small tubular bones- hollow inside. Each phalanx has a head and a base. The middle thinnest part of the bone is called the body of the phalanx. The nail phalanx is the smallest and ends at the distal phalangeal tubercle.
- The connection of the head and base of adjacent phalangeal bones forms the interphalangeal joints - distal (located further from the body) and proximal (located closer to the body). The thumb has one interphalangeal joint. Interphalangeal joints belong to typical axial joints. Movements in them occur in the same plane - flexion and extension.
- The finger joints are secured by palmar and collateral ligaments, running from the heads of the phalangeal bones to the base of other bones or to the palmar surface of an adjacent bone.
- The muscular system of the fingers is just part of the muscles of the hand. The fingers themselves have practically no muscles. The tendons of the hand muscles, which are responsible for the mobility of the fingers, are attached to the phalanges of the fingers. The lateral group of muscles of the palmar surface of the hand provides movements of the thumb - its flexion, abduction, adduction, opposition. The medial group is responsible for the movements of the little finger. Movements of 2–4 fingers are provided by muscle contraction middle group. The flexor tendons are attached to proximal phalanges fingers. Extension of the fingers is ensured by the finger extensor muscles located on the back of the hand. Their long tendons are attached to the distal and middle phalanges of the fingers.
- The tendons of the hand muscles are located in peculiar synovial sheaths that extend from the hand to the fingers and reach the distal phalanges.
- The fingers are supplied with blood from the radial and ulnar arteries, which form arterial arches and multiple anastomoses on the hand. The arteries that supply the tissues of the finger are located along the lateral surfaces of the phalanges, along with the nerves. The venous network of the hand originates from the fingertips.
- The space between internal structures finger is filled with fatty tissue. The outside of the fingers, like most of our body, is covered with skin. On the dorsal surface of the distal phalanges of the fingers in the nail bed there is a nail.
Finger injuries
By doing various types work injury to the fingers is the most common. This is due to the fact that it is with the help of our fingers that we do the bulk of the work. Conventionally, finger injuries can be divided into several groups:
- soft tissue injury - cut, bruise, compression,
- injury to a bone or joint - fracture, dislocation, sprain,
- thermal injuries - frostbite, burns,
- traumatic amputations,
- damage to nerves and tendons.
Symptoms vary depending on the type of injury, but all injuries have common general signs- pain of varying intensity, tissue swelling, hemorrhage or bleeding during open injury, impaired movement of the injured finger.
Little finger
The smallest, medially located finger. Carry the most minimal functional load. The meaning of the word little finger in Russian is younger brother, younger son.
Ring finger
Located between the little finger and middle finger - it is practically not used independently, which is explained by the commonality of the tendons of adjacent fingers. Bears independent load when playing keyboard instruments or typing. There was a belief that from this finger a vein went straight to the heart, which explains the tradition of wearing wedding rings exactly on this finger.
Middle finger
Its name speaks for itself - it is located in the middle of the finger row. The longest finger of the hand is more mobile than the ring finger. In sign language, the middle finger is used to make an offensive gesture.
Forefinger
One of the most functional fingers on the hand. This finger is able to move independently of the others. This is the finger we point most often.
Thumb
The thickest, free-standing finger. It has only 2 phalanges, opposed to the rest, which ensures perfect grasping ability of the hand. The thumb is actively used in gesture communication. The width of the thumb was formerly used as a measurement unit equal to 1 centimeter, and the inch was originally defined as the length of the nail phalanx of the thumb.
