Arthroscopic Science II – Shoulder Joint Injury
What is arthroscopic surgery?
An arthroscope is a “chopstick” tube containing a set of optical fibers that transmit light into the joint and a lens that transmits images from inside the joint. Outside the joint, the optical fibers are connected to the cold light generator through a fiber optic cable, and the lens is connected to the monitor through a cable with a photoelectric conversion device. With this system, the cold light illuminates the inside of the joint, and the doctor can view the various tissues inside the joint through the monitor, just like watching a live TV broadcast. This system of cold light source, fiber optic cable, lens, cable and monitor is the arthroscope.
During an arthroscopic procedure, the surgeon makes a small incision about 5-10 mm long in the joint space to insert the arthroscope into your joint so that the surgeon can get a good view of the condition inside your joint. In addition, a small incision is made in another location to insert additional instruments to identify the lesion and treat the damage.
How do you perform an arthroscopic procedure?
Before the procedure, your surgeon or anesthesiologist will discuss the choice of anesthesia with you, and your informed consent is required.
Once the anesthesia has taken effect, your surgeon will sterilize your joint and place a sterile sheet. With muscle relaxation after anesthesia, your surgeon will examine your joint again to further confirm the diagnosis.
When your surgical site is numb or you have fallen asleep, your surgeon uses the bony anatomical landmarks on the surface of your joint to select the correct location for the arthroscopic procedure. Several small 5-10mm incisions are then made in your joint area, and through these access points, the surgeon begins the procedure for you. During the procedure, the surgeon will look at your joint on a monitor, identify the lesion, treat the damage, and repair or even reconstruct it. Some joints include multiple chambers, and a full examination and thorough cleaning may require more than three small incisions.
After the arthroscopic procedure is completed, several small incisions are closed and dressed with a dressing. Because the incisions are small, they usually heal in about a week.
After the procedure your joint may be braced, too high, and sometimes ice packs are placed on the joint to reduce pain and prevent joint swelling.
What are the advantages of arthroscopic surgery?
1. Clear observation. Arthroscopy allows dynamic observation of the lesions in the joint in a near physiological state, and certain diseases must be diagnosed under arthroscopy.
2. Fine surgery, which can preserve the physiological tissue structure intact and limit the joint trauma to a minimum by targeted surgery.
3.It is minimally invasive surgery, with small skin incision and surgical incision, and the ligaments, joint capsule and cutaneous nerve around the joint are not damaged.
4.Less pain, small skin scars and beautiful.
5.Little surgical damage, less bleeding, less pain for the patient, and fast recovery after surgery.
6.Faster recovery of joint function after surgery, early activity on the ground, and less complications.
7.Short hospital stay, reduced medical costs, 2-3 days after surgery, you can get up and move around and resume work early.
Composition of the shoulder joint
The shoulder joint is composed of six joints, divided into the acromioclavicular joint, glenohumeral joint, acromioclavicular joint, sternoclavicular joint, rostraloclavicular joint, and interscapular thoracic wall joint. Because the humeral head is large and spherical, the glenoid is shallow and small, encasing only 1/3 of the humeral head, and the joint capsule is thin and flaccid, the shoulder joint is the joint with the largest range of motion and the most flexibility in the human body, allowing for forward flexion, back extension, abduction, adduction, internal rotation, external rotation, and circular rotation. However, although this structural feature of the shoulder joint ensures its flexibility, it is less stable than other joints and is the most structurally unstable of the large joints in the body. The most common is anterior and inferior dislocation of the shoulder joint, because the acromion, rostral process and the rostro-capital ligament, which is attached to the shoulder joint, prevent upward dislocation of the humeral head. The anterior, posterior and upper parts of the shoulder joint are healed by muscles and tendons with the fibrous layer of the joint capsule, which enhances its firmness. And only the anterior lower part of the joint capsule is not reinforced by muscles and tendons, which is a weak area of the shoulder joint. Therefore, when the upper limb is abducted, under the action of external force or when it falls, such as when the upper limb is abducted and externally rotated and then extended to the ground, the humeral head can break through the weak zone below the front of the joint capsule and move out to the front of the scapula, resulting in anterior dislocation of the shoulder joint. The affected shoulder collapses and loses its rounded contour, resulting in a so-called “square shoulder”.
What procedures can be performed with shoulder arthroscopy?
1.Diagnostic examination of shoulder joint: including examination of shoulder joint disorders with unclear clinical diagnosis, biopsy of intra-articular lesions, and diagnostic confirmation before open surgery, in order to obtain visual information about the condition.
2. acromioclavicular impingement, acromioplasty decompression.
3, repair of glenoid labral injury in shoulder instability.
4, rotator cuff tears, rotator cuff repair.
5, biceps tendon inflammation, biceps tendon severing and refixation
6, joint capsule release surgery.
7.Resetting and internal fixation of intra-articular fractures.
Shoulder joint diseases
(I) Shoulder impingement
In the upper outer part of the shoulder, the rostral shoulder arch consists of the acromion, rostral process and rostral shoulder ligament. On the lateral side of the humeral head, there is a cap-like structure composed of four tendons, including the subscapularis, supraspinatus, infraspinatus and teres minor, which is the rotator cuff. The gap between the rostro-capital arch and the rotator cuff is filled with bursae and is divided into two bursal gaps by the rostro-humeral ligament, namely the subacromial gap between the anterior border of the acromion, the rostro-capital ligament and the humeral head; and the subacromial gap between the rostral process and the tuberosity.
The subacromial space contains the supraspinatus tendon, also known as the “supraspinatus outlet”, which travels from the inside out. Under normal conditions, there is no contact between the rotator cuff, bursa and other structures and the rostro-capital arch during movement. When the head of the humerus impacts the anterior border of the acromion and the rostral shoulder ligament, which make up the rostral shoulder arch, the bursa and supraspinatus tendon are damaged, which is called subacromial impingement.
According to statistics, subacromial impingement is one of the most common causes of shoulder pain in middle-aged and elderly people, far exceeding the traditional term “frozen shoulder”.
Symptoms: Shoulder pain, which may even radiate from the shoulder to the neck or to the upper arm and forearm, complaining of pain at night, waking up in pain and disturbing sleep. Patients have difficulty pinpointing the exact location of the pain. Patients often complain of difficulty raising their hands above their heads due to the inability to fully abduct the shoulder.
Physical examination: Active or passive shoulder abduction mobility is significantly limited and may be accompanied by some degree of shoulder internal rotation restriction. Shoulder abduction, external rotation and internal rotation muscle strength are basically normal
Symptom provocation test: Neer’s sign and Hawkins’ sign are positive, while they disappear after subacromial closure
X-Ray: Orthopantomogram of shoulder joint: basically normal, possibly with increased density of humeral greater tuberosity, osteosclerosis manifestation, etc. Supraspinatus exit film: it can detect the hyperplastic bone of the acromion
MRI or ultrasound: It can evaluate whether there is any damage to the acromion bone superfluity and rotator cuff.
Diagnosis: Combining symptoms, physical examination and imaging tests, the diagnosis is not difficult. The key is that prior knowledge of the disease should be available before this diagnosis is considered. For patients who clearly have subacromial impingement, it is important to exclude possible rotator cuff injury, and if rotator cuff injury affects function, the focus is on treatment of the injured rotator cuff.
Treatment: Subacromial impingement can first be treated by trial closure. The key to local closure is to accurately inject the medication into the “subacromial space”. There is a need to clarify that there is no inevitable connection between the subacromial bones and the degree of pain of subacromial impingement, so the purpose of treatment for subacromial impingement is to relieve pain. The results are satisfactory.
(2) Rotator cuff tear
The rotator cuff is composed of four groups of tendons attached to the humeral head, and its function is to maintain the stability of the humeral head. Rotator cuff tears can be caused by acute trauma, such as falls, upper limb pulling, sudden exertion, etc., or by repeated strain, which in turn causes a parenchymal rotator cuff tear. The most common type of rotator cuff tear in middle-aged and elderly people with shoulder joint pain is caused by rotator cuff degeneration and brittle texture.
Symptoms.
1. recurrent or persistent shoulder pain, especially with overhead movements.
2. nighttime pain, especially the inability to sleep to the affected side
3, loss of muscle strength, especially when trying to lift the upper arm.
4. a ringing sound can be heard in the joint when the shoulder joint is moved.
5.The mobility of the joint can be limited.
6.It often occurs in the dominant shoulder (it is more likely to occur in the left shoulder in people who are used to using the left hand and in the right shoulder in people who are used to using the right hand).
7.It can be aggravated or triggered by a sudden event.
Risk factors.
1.Repeated overhead movements, such as swimming (except breaststroke), baseball, tennis, painting ceilings, painting, construction work, writing on blackboards, etc.
2, carrying heavy objects, such as baggage handlers, porters.
3, traumatic injuries, such as falls, impact on the shoulder.
4, Age-induced degeneration with a concomitant decrease in blood supply to the rotator cuff.
5, Narrowing of the rotator cuff space between the clavicle and the acromion.
6. instability of the shoulder joint.
Diagnosis: In addition to the complaints in the medical history, the physician can obtain a general diagnosis through careful physical examination. x-rays can help identify the presence of tumors, narrowing of the subacromial space, and other bony lesions. For a full rotator cuff tear, MRI and ultrasound can make a relatively accurate diagnosis, but for a partial rotator cuff tear, MRI imaging may be required to obtain a definitive diagnosis.
Treatment: Rotator cuff tears can be divided into complete tears and incomplete tears (partial tears). Regardless of the type of tear, conservative treatment should be started, including rest, anti-inflammatory and analgesic medication, rehabilitation exercises, and elimination of disease-causing risk factors. Local closure can help reduce pain, but should not be used multiple times, as multiple applications can cause the rotator cuff to become brittle and aggravate the tear.
When conservative treatment is ineffective, surgery is required, which includes.
1) Removal of risk factors, such as subacromial plasty to widen the subacromial space.
2) scraping or suturing of a partial tear.
3) suturing of the full tear (arthroscopic or small incision)
Prognosis: With proper treatment, more than 90% of patients can achieve pain relief, while the recovery of shoulder mobility and strength requires longer rehabilitation exercises to achieve satisfactory results.
(C) Shoulder dislocation
Shoulder dislocation is a very old injury, described in the murals of the Egyptian tomb as early as 3000 B.C.; and the famous Western medical pioneer “Hippocrates” invented the reset method, which is still widely used in clinical practice.
According to the direction of dislocation, shoulder dislocation can be divided into anterior dislocation, posterior dislocation and inferior dislocation, of which more than 95% are anterior dislocation, about 4% are posterior dislocation and only 0.5% are inferior dislocation. According to statistics, shoulder dislocations are more common in young men aged 20 to 30 years old and older women aged 61 to 80 years old.
Dislocation of the shoulder joint can lead to avulsion of the joint capsule from the humeral head, or the detachment of the joint capsule attached to the labrum of the scapular glenoid. In order to allow adequate self-repair of the injured tissue, the conservative treatment of 3 to 6 weeks of immobilization in the internal shoulder position after repositioning was mostly used in the past.
However, whether you are a sports medicine, orthopedic, or emergency medicine physician, or a layperson, you have seen cases of recurrent shoulder dislocation/habitual shoulder dislocation, where the shoulder joint is repeatedly re-dislocated under minor external forces following the first shoulder dislocation, which seriously affects the patient’s life. Some patients are even afraid to engage in the corresponding activities because of the intense fear and worry about dislocation. Some complain that when they pull the handrail on the bus, they may dislocate when they are not careful.
It has been studied that young patients with shoulder dislocations still have a high recurrence rate, regardless of how effective the fixation is. It has been reported that patients younger than 25 years of age have a 60% to 94% chance of re-dislocation after their first shoulder dislocation. It is even believed that young people have a 100% chance of re-dislocation.
Therefore, more and more scholars advocate that surgical treatment should be considered at the first shoulder dislocation visit for young patients, especially those who enjoy sports, or professional athletes, rather than trying conservative treatment.
The goal of surgical treatment is to suture the avulsed joint capsule and glenoid labrum. There are two types of surgical methods: open surgery and arthroscopic surgery. Arthroscopic surgery is less invasive, has faster postoperative recovery, and is functionally satisfactory. However, for patients with chronic recurrent shoulder dislocation, there is a certain percentage of re-dislocation after surgery, regardless of whether it is open surgery or arthroscopic surgery. Therefore, we advocate that young patients with shoulder dislocations should be treated as early as possible and undergo arthroscopic surgery to repair the damaged tissue and avoid re-dislocation. As for recurrent shoulder dislocation/habitual shoulder dislocation, if conservative treatment is ineffective, arthroscopic or open surgery is recommended.