The glenoid cavity or rosette of the scapula is a depression in the bony structure of the scapula in which the ball-shaped head of the humerus is located. The shoulder has three joints. One of these joints (the shoulder) is formed by the glenoid cavity and the head of the humerus. This joint allows free rotation of the head of the humerus. The joint and complex of tendons and muscles allow the upper limb to perform various movements such as lifting, pushing, pulling. Therefore, damage to the glenoid cavity sharply reduces the range of motion in the shoulder. While the head and rosette of joints such as the hip joint can support weight bearing, the shoulder joint has less strength but a greater range of motion. Increased mobility in the shoulder joint is due to thinner tendons and ligaments in the shoulder. In addition, the head of the humerus is proportionally much larger than the glenoid cavity, which significantly increases the risk of dislocations.
Both the glenoid cavity and the head of the humerus are covered with cartilage, which allows movement in the joint with virtually no friction. Cartilage also helps strengthen the small joint cavity. In the shoulder joint, the cartilage covering the head of the humerus is thicker at the point where it enters the center of the cavity. In addition, the glenoid cavity has a cartilaginous collar, which is called the lip. The labrum curves around the thickened part of the head of the humerus, which also enhances the stability of the joint.
The most common injuries to the socket are cracks (fractures) of the socket, damage to the labrum, or dislocation of the joint. A glenoid fracture results in pain and swelling, causing the patient to avoid raising the arm or straightening the arm. Pain and a sharp decrease in range of motion also occur with shoulder dislocation, but this type of injury is quite well determined visually.
Causes
Indirect trauma can lead to rosette fracture and occurs when the load is transmitted vectorially through the outstretched arm.
Direct injury occurs from a blow or fall.
Traction injuries occur when there is excessive traction on muscles and ligaments, which can also cause a fracture of the glenoid cavity (for example, when trying to lift a heavy object suddenly).
Types of glenoid fractures
The existing classification of glenoid fractures distinguishes 6 types of fractures:
IA - Anterior rim failure; IB – Rear rim failure; II - the fracture line passes through the glenoid cavity and extends along the lateral border of the scapula; III – the fracture line passes through the glenoid fossa and extends to the upper edge of the scapula; IV - the fracture line passes through the glenoid fossa and extends to the medial edge of the scapula; VA - combination of types II and IV; VB - combination of types III and IV; VC - combination of types II, III, IV and VI - comminuted fracture
Damage to the articular notch of the scapula
It is this connection that facilitates circular movements of the head of the humerus. The joint and tendon-muscular complex allow the hand to perform movements such as lifting, pulling, and also allows it to push. It is because of this that when injury occurs in this joint, the ability to perform such movements is sharply reduced.
A similar articulation is present in the lower extremities. This is the connection between the hip and pelvis. But this joint is capable of supporting quite a lot of weight, and the connection of the shoulder to the shoulder blade has little strength, but at the same time it performs many more types of movement. This property is associated with a less powerful tendon-ligament apparatus. The head of the humerus bone is much larger than the socket in the scapula. This is why the risk of displacement in this joint increases.
The socket for the joint in the shoulder blade and the head of the humerus bone are covered with cartilage, so movements are carried out without friction. The cartilage that covers the head of the humerus bone is thicker where it ends up in the center of the notch. In addition, the depression in the scapula has a “lip” (this is a cartilaginous layer surrounding the depression). It is this “lip” that increases stability in this joint.
The most common damage to this recess: cracks, tears or other injuries to the “lip”, dislocations. Due to a fracture of the joint cavity, pain and swelling appear. This forces the patient not to raise or straighten his arm. Pain and inability to move also cause shoulder dislocations. This damage is clearly visible to the eye.
Causes
A fracture of the glenoid cavity is carried out by impact on the elongated upper limb. This is also called indirect trauma.
True damage is possible from impact or falling.
Traction injuries occur when excessive traction forces are applied to the musculo-ligamentous system. Because of this, there is a possibility of a fracture of the articular notch.
Fracture options
There is a classification of damage to the articular recess, where there are 6 options:
1A - frontal damage to the rim;
1B - posterior damage to the rim; 2 - the contour of the damage passes through the notch of the joint and exits along the lateral part of the scapula;
3- the contour passes through the notch of the joint and extends to the upper part of the scapula;
4- the contour passes through the notch of the joint and goes to the median edge;
5A - combination of 2 and 4 options;
5B - combination of options 3 and 4;
5B - combination of 2,3,4 options;
6-shrapnel damage;
Symptoms
The symptom complex is: pain when trying to lift the upper limb, clicking in the joint, blocking, decreased range of motion, decreased strength.
Diagnostics
When there is pain and the fact of injury, doctors suspect an injury to the joint notch. The characteristics of pain and their relationship with movements are of great value. X-ray diagnostics is an integral part in recognizing injuries. Detection of soft tissue injuries is carried out using tomography, using contrast. This makes it possible to detect even minor damage to the cartilage and ligamentous-muscular apparatus. Arthroscopy is often performed, which allows the eye to see what damage there is.
The tear can be much higher than the medial line of the glenoid cavity and, on the contrary, much lower.
With SLAP injury (Superior Labrum Anterior Posterior), there is a tearing of the cartilaginous surroundings above the midline of the recess. There is a possibility of injury to the tendon fibers of the biceps brachii muscle.
Underruptures of the cartilaginous environment below the joint notch, which are accompanied by injury to the lower ligamentous apparatus, are called Bankart injuries.
Underruptures of the cartilaginous environment surrounding the articular cavity can also occur in various injuries. Most often, such injuries occur when the humerus is displaced, which is called a complete or partial dislocation.
Treatment
After the diagnosis is made, a doctor specializing in traumatology, judging by the nature of the injury, prescribes the necessary treatment. The decision to prescribe the necessary type of treatment must occur as soon as possible, otherwise, after more than 6 hours have passed since the moment of injury, the wrong method can lead to life-threatening complications. This complication is considered to be traumatic shock. In addition, the underlying tissues may lose their elasticity, which leads to the most difficult comparison of fragments and damaged tissues.
Conservative treatment is often used for minor injuries to the articular notch. It involves immobilizing and preventing movement in the injured area, taking non-steroidal anti-inflammatory drugs and applying ice to the injured area. But often with these types of injuries it is necessary to resort to surgical intervention. At the moment, small, low-traumatic arthroscopic operations have found use, which, with a small risk of complications in the postoperative period, make it possible to completely compare and fix damaged tissues. At the same time, the full range of movements is restored.
Rehabilitation
It does not matter what treatment method was used, medicinal or surgical, fixation and prevention of active movements in the damaged joint should last at least a month. But at the same time, in order to prevent the shoulder muscles from atrophying, it is necessary to perform passive motor activity every day.
After this period, it is necessary to resort to physical therapy in order for the muscles to develop.
After one and a half months from the moment of injury, it is allowed to resort to load-bearing exercises. Full functioning of the shoulder joint occurs in three to four months. Author: K.M.N., Academician of the Russian Academy of Medical Sciences M.A. Bobyr
Diagnostics
If you have shoulder pain and a previous injury, your doctor may suspect a fracture of the glenoid cavity. The nature of the pain and its connection with the movement of the arm also matters, and therefore the doctor conducts functional tests. In addition to the examination, the doctor prescribes x-rays to visualize changes in the bone tissue of the shoulder. But if there is a suspicion of soft tissue damage, then an MRI or CT scan is prescribed. In both cases, it is better to conduct the examination with contrast, which will allow diagnosing even minor damage, both in cartilage tissue and in muscles and ligaments. Sometimes it is necessary to perform diagnostic arthroscopy and visually assess the existing damage.
The tears can be located both above the middle of the articular rosette and below it.
With a SLAP injury, there is a rupture of the cartilage ring above the middle of the rosette, which may be accompanied by damage to the biceps tendon.
A tear of the cartilaginous ring below the glenoid cavity, accompanied by damage to the inferior humeral ligament, is called a Bankart injury.
Tears of the cartilaginous ring around the articular rosette also occur with other injuries, especially with shoulder dislocations (complete or partial dislocation).
Shoulder impingement syndrome
Impingement (impeachment) - shoulder syndrome is characterized by pain and decreased motor activity in the shoulder joint. The cause of this condition is damage to the rotator cuff, formed by muscle tendons, due to friction against the acromion process, acromial joint and coracoacromial ligament.
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Impingement syndrome can occur not only in the elderly, but also in young people against the background of the following conditions of the acromion process and its articulation:
- excessively bent forward configuration of the acromion;
- thickening of the coracoacromial ligament and joint deformation in chronic injuries and arthrosis.
Thus, damage to the rotator cuff may be a complication of untimely or inadequate treatment of injuries and diseases of the acromion process. A timely visit to a doctor at the first signs of damage to the area of the acromioclavicular joint will help to significantly reduce the risk of such a complication.
Treatment
After making a diagnosis, the traumatologist prescribes treatment, depending on the nature of the injury. The decision on choosing a treatment method must be made quickly enough, since 6 hours after a fracture, inadequate treatment can lead to the development of complications such as traumatic shock. In addition, many fabrics lose elasticity and it is more difficult to match torn fabrics. Conservative treatment is possible for minor damage to the glenoid fossa and consists of immobilization, taking NSAIDs, and applying cold to the shoulder area. But in most cases, a fracture of the glenoid cavity requires surgical treatment. Currently, minimally invasive atroscopic techniques are used, which make it possible to restore the integrity of both the bony structures of the shoulder and soft tissues with minimal risk of postoperative complications.
Rehabilitation
After a fracture, both with conservative treatment and after surgery, immobilization in a splint is necessary for 3-4 weeks. But it is imperative to carry out passive (painless) movements in the shoulder during this period of time so that the “frozen” shoulder syndrome does not develop. After removing the splint, it is necessary to begin therapeutic exercises to develop the joint. You can begin weight-bearing exercises 6 weeks after the injury. Full restoration of the function of the joint and shoulder usually requires 3-4 months.
Anatomy
The acromion has an almost triangular shape, its upper surface is convex and rough, and its lower surface is smooth and concave. The upper part of the acromion, which projects laterally, is the highest point of the human shoulder.
The deltoid muscle is attached to the upper part of the acromion process, but its large area is covered not by muscles, but by the skin of the shoulder girdle.
The deltoid muscle is also attached to the inner part of the lower surface of the acromial protrusion with its tendons, and its outer part is the place for attachment of the trapezius muscle bundles.
At the highest point of the acromion process there is a small smooth surface - the place of the acromioclavicular joint connecting the scapula and the clavicle. Under the acromion, on the outer side of the scapula, there is its glenoid cavity - the junction of the scapula with the humerus.
The acromion and acromial joint perform the following functions:
- protective;
- holding;
- coordinating movements;
- shock-absorbing
The acromial protrusion, as well as the coracoacromial (coracoid-acromial) ligament, connecting the acromial and coracoid processes, hanging over the shoulder joint, protect the joint and the surrounding muscles and their tendons from external mechanical influences.
The acromioclavicular joint is a flat, shallow-radius joint in which the clavicle and acromion protrusion are connected by the joint capsule and the acromioclavicular ligament. This is a fairly rigid connection; in addition, the mobility of the clavicle is limited by the coracoclavicular ligament, which fixes the clavicle to the coracoid process of the scapula. Therefore, the range of motion in this joint is limited, and the joint itself has a supporting and coordinating function, ensuring the normal position of the scapula, collarbone and shoulder relative to each other and controlling their coordinated movement.
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The acromioclavicular joint also softens (shock absorbs) the increased load on the shoulder joint due to the high degree of mobility of the latter.