1.General information
Each joint, that is, a movable articulation of two bone structures, has a certain “degree of freedom” - and only within these limits are natural rotational, flexion-extension and other movements possible for a person.
If the head of one of the bones goes beyond the boundaries of the anatomical bed allocated to it by nature and cannot return on its own, this situation is called a dislocation or subluxation. The difference between one and the other can often be established only during instrumental examination (for example, x-ray): a complete dislocation is accompanied by destruction of the ligamentous apparatus; with subluxation, the ligaments can be stretched, but not torn. Another criterion is the presence or absence of contact of the articular surfaces: with subluxation they touch at least partially, with complete dislocation there is no contact.
Symptomatically, dislocation and subluxation are very similar - the joint turns red and swells, the limb is in an unnatural position, its mobility is sharply limited (with concomitant nerve damage, tactile sensitivity may also be impaired), the victim usually experiences severe pain.
It seems quite logical, from a mechanical and anatomical point of view, a trend long known to traumatologists: the more complex the joint, the more complex, diverse and dangerous its dislocations.
Shoulder dislocations lead in trauma statistics. Dislocations and subluxations of the forearm are in second place in terms of frequency of occurrence (20-25% of all recorded traumatic dislocations). According to some data, the gender and age structure of victims is dominated by males aged 10-30 years and females over 50 years old.
A dislocation (subluxation) of the forearm that has not been reduced in a closed manner for two weeks or more is considered old.
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Clinical picture and diagnostic methods
The manifestations of posterior and anterior dislocations of the forearm bones will be slightly different. A posterior dislocation makes itself felt by a sharp pain in the elbow. The joint increases in volume and becomes deformed due to the protruding olecranon process. Movement in it is impossible, since the victim feels springy resistance when trying to move his hand.
Anterior dislocation of the forearm bones is quite rare. It occurs as a result of a blow to the arm bent at the elbow. Unlike a posterior dislocation, where the forearm is shortened, in this case it is, on the contrary, lengthened. A depression will be palpable in the projection of the olecranon process. A feeling of sharp pain accompanies the moment of injury. The function of the elbow joint, of course, will be limited, but to a lesser extent than with the posterior version of the dislocation.
As a rule, the clinical picture is clear, so the correct diagnosis can be made based on symptoms alone. However, due to possible fractures and other complications, radiography in two projections is necessary.
2. Reasons
The causes of (sub)luxation of the ulna and radius are as varied as the causes of dislocations in general. Absolute leadership belongs to traumatic mechanical impacts: a blow, a fall on a straight or half-bent arm, an attempt to hold an impossible load, etc. However, the topic of the article is not acute, but chronic dislocation of the forearm, and it is no coincidence that such an injury is identified as a special problem for traumatology. The fact is that with an old dislocation, intensive degenerative-dystrophic processes begin in the periarticular tissues, the so-called, within two to four weeks. Ossification: muscle and other elastic tissues are replaced by rapidly growing and ossifying scar tissue (in some cases, cartilage). Thus, a characteristic feature of chronic dislocation of the forearm is the impossibility (in the vast majority of cases) of its reduction using a closed method.
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First aid
Before the victim, who is believed to have suffered a dislocated joint, gets to the trauma center, it is necessary to carry out pre-medical measures:
- Call an ambulance.
- Examine the hand, if there is no bleeding, try to position it motionless so that the hand is level with the heart.
- If there is damage to the skin, wash the wound with an antiseptic solution (hydrogen peroxide) and cover with a sterile cloth.
- Carefully apply a cold object to your elbow (cloth soaked in cold water, chilled foods) for 10-15 minutes. This measure will reduce the lumen of the blood vessels, which will reduce pain and reduce the likelihood of swelling spreading.
- Baralgin, Ketorol, Ketanov can be taken as painkillers.
When providing first aid, you should not move the patient’s arm or try to straighten the dislocation yourself. It should be borne in mind that the disease can be complicated by a fracture, which can be determined using hardware testing.
3. Symptoms and diagnosis
The clinical picture of chronic forearm dislocation is very diverse; it is determined, first of all, by the direction of the displacement. Up to 90% of such cases are posterior dislocations - with this option, the forearm appears unnaturally short, and the shoulder, on the contrary, appears disproportionately long. The opposite picture occurs when the forearm is dislocated anteriorly; in this case, severe tendon damage and muscle ruptures often occur. Displacements outward or inward, as well as divergent dislocation (divergence of the radius and ulna in any plane) are very rare and, as a rule, have the character of a combined fracture-dislocation.
The intensity of pain, limitation of mobility, severity of swelling and hematoma depend on the degree of displacement of the articular surfaces and damage to the ligamentous apparatus; in the most severe cases, ligaments and muscles are torn off, and conductive nerves and blood vessels are also damaged.
From a diagnostic point of view, dislocations and subluxations of the forearm are usually not particularly difficult. However, to clarify the situation, an X-ray examination is required, both before reduction (which often makes it possible to diagnose fractures, cracks or other complications), and after - to monitor the anatomical correctness of the joint.
One of the most informative techniques is an X-ray contrast study with the introduction of a contrast agent into the joint space.
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Forearm dislocations
Forearm dislocations rank second in frequency among all dislocations (18-27%).
Classification
- both bones of the forearm - posteriorly, inwardly, outwardly, anteriorly, divergent dislocation;
- one radius - anteriorly, posteriorly, outwardly;
- one ulna.
The most common are posterior dislocations of both forearm bones (up to 90% of all elbow dislocations). Dislocations of the forearm can be complete or incomplete. With incomplete dislocations, partial contact of the articular surfaces is maintained.
Mechanism of injury. Dislocations can occur due to both direct and indirect trauma. Under the influence of the acting force, the forearm moves in one direction or another. Both bones, tightly connected to each other by the annular ligament and the interosseous membrane, are usually displaced together; dislocation of one bone occurs relatively rarely. Dislocations can be complicated, in addition to separation of the coronoid process (more often with posterior dislocations of the forearm), also by fractures of the ulna and radius, condyles and separations of the epicondyles of the humerus.
Dislocations of both bones of the forearm posteriorly
Mechanism of injury - this most common type of dislocation occurs mainly when a fall on the palmar surface (indirect injury) of the arm extended at the elbow joint. Due to a sharp hyperextension, the olecranon process rests against the olecranon fossa, the anterior part of the joint capsule is torn, the lower part of the shoulder is pushed forward, and the forearm is pulled posteriorly due to contraction of the triceps muscle.
Symptoms and Recognition: Pain in the elbow joint and usually support the forearm with the unaffected hand. The area of the elbow joint is deformed, and there is significant swelling and hemorrhage. the forearm is in a position of incomplete fixed extension (120-140°) and slightly pronated. The shoulder appears elongated and the forearm appears shortened. the axis of the forearm is shifted inward or outward from the axis of the shoulder. the olecranon process protrudes sharply posteriorly; In most cases, an arcuate depression is visible between the extensor surface of the lower shoulder and the olecranon. the head of the radius protrudes posteriorly and externally. Above and in front of the elbow bend, more medially, a protrusion is visible, corresponding to the lower end of the shoulder that has shifted forward. the mentioned protrusions, corresponding to the displaced olecranon, the head of the radius and the condyles of the humerus, are well defined by palpation. the length of the circumference at the level of the elbow and the olecranon on the side of the dislocation is increased compared to the healthy arm due to the lengthening of its anteroposterior diameter. The apex of the olecranon process stands 2-3 cm above the condyles of the shoulder, while if there is no dislocation, it is at the same level. active and passive movements are impossible. When trying to reproduce movements in the elbow joint, the symptom of spring resistance is determined.
Reduction technique.
The patient is injected under the skin with 1 ml of a 1% morphine solution. Reduction can be done under general anesthesia or local anesthesia. 20 ml of 2% or 30 ml of 1% novocaine solution is injected into the joint above the protruding olecranon and head of the radius. The patient is placed on the table, the shoulder is abducted to a right angle. The surgeon stands behind the abducted arm and with both hands covers the shoulder above the elbow joint so that the first finger of one hand lies on the displaced olecranon, and the first finger of the other on the head of the radius. The assistant covers the lower third of the forearm with one hand, and the hand with the other. The surgeon and assistant smoothly and strongly stretch the patient's arm, bending it at the elbow joint. At the same time, the surgeon uses his thumbs to move the olecranon protruding posteriorly and the head of the radius. Usually, in this way, the dislocation is easily reduced in the early stages and the patient can freely make movements in the elbow joint. X-ray control is required before and after reduction of the dislocation.
Follow-up treatment. After reduction of the dislocation, the elbow joint should be fixed with a plaster splint at a right angle; the forearm is placed in a supinated position. This bandage is applied for 5-10 days, depending on the degree of damage to the ligamentous apparatus and the tendency to re-dislocation. From the 2nd day, therapeutic exercises begin - movements in the fingers and shoulder joint. After removing the plaster cast, movements in the elbow joint are prescribed, gradually increasing in strength and volume: flexion, extension, pronation and supination. Massage of the elbow joint and passive movements are contraindicated, since ossifying processes easily develop in the tissues surrounding the joint and in the muscles, which sharply limit the function of the elbow joint.
Dislocation of the forearm medially
is rare. The axis of the forearm is shifted medially, the degree of displacement varies greatly. In most cases, medial dislocation is incomplete. It is usually accompanied by severe damage to soft tissues, the bursa and the ligamentous apparatus. The elbow joint is expanded in the transverse direction. The external condyle can be easily felt.
Reduction. One assistant holds the shoulder, the other performs traction along the axis of the displaced forearm. With continued traction, the surgeon applies pressure in opposite directions on the lateral surfaces of the humeral condyles and the upper part of the forearm. A click is heard when adjusting. The forearm is placed in a flexion position and fixed in this position.
Dislocation of the forearm outwards
It is rare, the surrounding soft tissues, the bursa and ligaments of the joint are severely damaged, the axis of the forearm is deviated outward, the internal condyle of the shoulder can be easily felt. The elbow joint is expanded in the transverse direction. Dislocations can be complete or incomplete and are often accompanied by separation of the condyle.
Reduction. The assistant holds the patient's shoulder firmly. The surgeon applies traction to the forearm with one hand, and with the other, first applies pressure on the upper part of the forearm downwards, outwards and backwards, then supinates the forearm and pushes the upper part of it around the external condyle of the shoulder. The forearm is bent at the elbow joint to a position that can be achieved without squeezing the swollen soft tissue. In this position, a plaster splint is applied.
Anterior dislocation of both forearm bones
sometimes accompanied by a fracture of the olecranon, the forearm appears elongated, a ledge-like depression is determined under the condyles of the shoulder, and the soft tissues in the elbow bend are severely damaged.
Reduction. Assistants perform counter-traction on the shoulder. The surgeon pulls the forearm along its axis with one hand, and with the other puts pressure on the upper part of the forearm down and back and bends it at the elbow joint. When repositioning, a clicking sound is heard. A hand with the forearm bent at the elbow joint at an angle of 135°.
Divergent dislocation of the bones of the forearm
is extremely rare.
Dislocation of the radial head
Isolated, rare, the radial head may move anteriorly, posteriorly, or outwardly, but it usually moves anteriorly. When the radial bone is dislocated, the radial nerve, most often its branch, can be damaged. Anterior dislocation of one radius is often accompanied by a fracture of the ulna in the upper third or avulsion of the lateral condyle of the humerus. When the head is displaced anteriorly, movements in the elbow joint are possible, but flexion is limited; pronation and supination are possible, but limited and painful.
Symptoms and recognition: in the area of the elbow, on the anterior outer surface, a protrusion corresponding to the head of the radius is felt; the head moves with flexion and extension at the elbow joint, as well as with pronation and supination. when one radius is dislocated posteriorly, the arm is in a bent position. The olecranon process is not displaced and is well contoured. The head of the radius is palpated posteriorly; the skin over it is stretched.
Reduction of an anterior isolated dislocation of the radius anteriorly is performed as follows. One assistant holds the shoulder, the other pulls the forearm straight at the elbow joint, pronates and adducts it at the elbow joint. At this time, the surgeon puts pressure on the head of the radius in a posterior direction and pushes it until it is reduced to its normal position. The forearm is supinated and flexed at the elbow joint. In this position, the arm is fixed with a plaster splint. Reduction of the dislocated head of the radial bone outwards and backwards is carried out in the same way. Pressure on the head is applied in the direction opposite to the displacement.
4.Treatment
In the acute period of dislocation or subluxation of the forearm, the method of choice is almost always closed reduction, the specific technique of which is determined by the clinical picture. This is especially true for pediatric and young patients, when the priority solution is minimal invasiveness and preservation of the integrity of the joint and periarticular tissues. This reduction is carried out either under local anesthesia or general anesthesia (depending on a number of individual factors).
Of course, the minimum condition for this is a timely visit to a doctor (attempts to straighten the joint on your own usually end in serious complications). The deadline is usually 21-28 days from the moment of dislocation - after which ossification makes conservative reduction impossible, i.e. It is no longer possible to do without surgery. However, in some cases, when an elderly or senile person with a chronic dislocation/subluxation of the forearm has no pain, and the functioning of the arm is preserved to a degree acceptable to the patient, surgery is also considered undesirable.
In all other cases, with chronic dislocation of the forearm, surgical intervention with arthroplasty is performed - reduction and restoration of the normal anatomy of the elbow joint. Hinge-distraction devices are used according to indications.
A common consequence of such a dislocation or subluxation is a significant decrease in strength in the injured limb.
Treatment for subluxation of the radial head
Reduction of subluxation of the radial head on the 1st day is usually easy (without prior anesthesia).
Reduction technique. subluxation of the head of the radial bone in children: The shoulder is fixed in the area of the elbow joint with one hand, the first finger is placed in the projection of the head of the radial bone. With the other hand, carefully bend the forearm at the elbow joint at a right angle while simultaneously supinating and pressing the surgeon’s finger on the head. All movements are performed smoothly, but without interruption and with some force. At the moment of reduction during the transition to supination, a click is felt. The child screams, then quickly calms down, and after a few minutes free active movements are restored. In some cases, reduction is not immediately successful, and this technique must be repeated several times. Failure usually occurs from improper fixation and insufficient flexion of the arm or from incomplete supination. After reduction, immobilization is not necessary. You just need to explain to parents the mechanism of damage in order to avoid frequent relapses. It is advisable to recommend the use of “reins” when walking with toddlers. After the manipulation, the arm is suspended on a scarf for 3-5 days.
Prevention
To prevent injuries, it is enough to follow safety rules on the road, in a work environment, and during sports training. To prevent forearm dislocation, it is important to wear comfortable shoes and engage in light sports to train the muscles and coordination. If you are involved in extreme sports, use protective equipment to soften the impact of a possible fall. If injury cannot be avoided, an immediate visit to the doctor is necessary for diagnosis and effective treatment.
Diagnosis and treatment
An orthopedic traumatologist determines the type and extent of damage. The diagnosis is made based on clinical symptoms and details of the injury. To confirm the assumptions, radiography is prescribed. The image shows not only bone displacements, but also a violation of their integrity. After confirming the diagnosis, the doctor determines the method of reduction.
The procedure for restoring the anatomically correct location of bones in the joint is carried out in stationary conditions. Under local or general anesthesia, closed reduction is performed by a doctor and an assistant. Depending on the type of dislocation, a flexion movement is performed with the injured arm while simultaneously pressing on the head of the ulna or humerus.
A click and restoration of movement function confirms a successful outcome. To consolidate the positive result, a rigid immobilizing bandage made of plaster or polymer bandages is applied. In case of old or complicated dislocation of the forearm, surgery is prescribed.
The joint remains immobile for two to three weeks, after which restorative treatment is carried out. Throughout the entire treatment, painkillers are prescribed to relieve unpleasant symptoms - Ketoprofen, Indomethacin, Ketorol.
Further rehabilitation consists of the use of physiotherapeutic procedures, massage and physical therapy. After completing a full course of rehabilitation measures, blood circulation and innervation of the elbow joint are restored. Regular exercise therapy sessions restore movement function to the maximum extent.