The shoulder joint (glenohumeral joint) is a structure consisting of the bullet-shaped head of the humerus and the glenoid cavity of the scapula. Normally, the contact surfaces of the bones are covered by the articular cartilage, which in the case of the shoulder is about 3 cm thick.
With aging, the articular space is getting narrower and the head of the humerus becomes irregularly shaped due to the formation of osteophytes. Unlike the other large spheroidal structure of the body, the hip joint, the head of the humerus is larger than the shoulder blade, which allows for even greater range of movement in daily and athletic activities.
As in other joints, articular cartilage between the bones in contact reduces friction and allows for unobstructed movement. Shoulder radiographs show a cartilage thickness of about 3 cm, as mentioned above. In addition, the shoulder joint is stabilized by the ligaments and muscles. The rotator cuff muscles and tendons stabilize the joint and aid in shoulder movement.
A normal shoulder joint allows for painless and unobstructed movement in daily and sports activities. However, arthritic lesions may develop after injury or due to the normal process of degeneration and other concomitant diseases.
“ARTHRITIS” – WHAT IS ARTHRITIS?
According to the US Centers for Disease Control and Prevention, it is estimated that 50 million people suffer from some type of arthritis (osteoarthritis, rheumatoid arthritis, post-traumatic arthritis, etc.).
In other words, one in five adults suffers from some type of arthritis, while at age 65 and over, the proportion of patients is up to 50%. In 2004, 400,000 total knee arthroplasty surgeries, 230,000 total hip arthroplasty surgeries and 40,000 total shoulder arthroplasty surgeries were reported in the US alone, and the number is expected to increase in the coming years. The relatively smaller number of shoulder surgeries is probably due to the ability of patients to tolerate much more the symptoms of arthritic shoulder lesions much more than the hip or knee since it is not a weight-loaded joint. Patients usually visit the orthopedist when the pain significantly limits the patient’s sleep time and quality of life.
There are three main types of arthritis: osteoarthritis, rheumatoid arthritis and post-traumatic arthritis.
- Osteoarthritis is the most common type of arthritis in the shoulder. It is a degenerative type of disease that occurs mainly in people over 50 years of age.
In osteoarthritis, the cartilage of the shoulder surfaces gets gradually degenerated. As the cartilage collapses, the bones begin to come into contact with each other. The procedure is accompanied by hardening of the bony surfaces beneath the cartilage, development of new bone and cartilage at the edges of the joint (osteophytes) as well as synovial fibrosis. Frequently, it has no other systemic manifestations, but – locally – signs of inflammation may be observed.
- Post-traumatic arthritis develops after a shoulder injury. For example, a fracture involving the joint (intra-articular fracture) can cause irreparable damage to the cartilage covering the knee articular surfaces, and consequently lead to chronic arthritic lesions.
- Rheumatoid arthritis is a chronic inflammatory disease that simultaneously affects many joints in the human body including the shoulder. It is manifested as symmetrical polyarthritis, which means it affects the same joint both ways.
In rheumatoid arthritis, the synovial membrane begins to inflame, swell and lead to shoulder pain and stiffness. It is an autoimmune disorder. This means that the immune system, through the inflammatory response, damages normal tissues (cartilage, ligaments and bone).
Other Causes: Arthritic lesions can occur after surgery and in particular the use of anchors to repair instability after poor positioning.
Among the other and rarer causes of shoulder arthritis is aseptic necrosis, a pathological condition in which blood flow is interrupted, leading to necrosis and deformity of the humeral head. Postoperative arthritis is due to a wrong suturing technique of the bursa, which pushes the head back toward the glenoid cavity and asymmetrically loads the joint, leading to arthritic lesions. Chondrolysis is another pathological condition characterized by rapid degeneration and loss of articular cartilage in the shoulder. It has been linked to the use of intraarticular pain channels and medical history of infection, use of absorbable anchors etc. It affects new patients and causes major functional problems of the joint.
SYMPTOMATOLOGY
The stages of the progression of shoulder arthritis are not fully known. It seems that the majority of patients tolerate the symptoms for a long time, perhaps due to the fact that the shoulder joint is not fully loaded with body weight as is the case with hip and knee joints. Probably, this is the reason that the total number of shoulder arthroplasty surgeries is smaller than those performed on the hip and knee, as mentioned above. However, the increase in the number of shoulder arthroplasty surgeries is significant, as the rate of increase from 1993 to 2007 in the US reached 39%.
Initially, symptoms include mild pain associated with articular movements, and usually have a gradual development over time. Most patients then experience movement limitation or stiffness in their daily activities, and in some cases, concomitant cracking. The weakness is due to pain-related inhibition and progressively it leads to years of pain during rest and sleep.
DIAGNOSIS
The progressive loss of range of motion and the gradual increase in pain that affect patients’ work and daily life are some of the most commonly reported symptoms. Also, waking up at night with pain and feeling cramped can be some of the complaints of the patient. The weakness is usually due to pain and is recognized during clinical examination.
In addition, clinical examination will reveal stiffness and loss of range of motion during active and passive joint movement as a result of deformity and arthritic lesions in general. Strength is affected by pain and therefore no real weakness can be observed during the examination.
Radiological Examination: Anterior and axillary X-ray depiction is usually performed.
Magnetic Resonance Imaging and Computed Tomography: Additional imaging methods include Computed tomography and more rarely magnetic resonance imaging. Many surgeons use Computed tomography for pre-operative planning, while MRI helps not only in describing the symptoms of arthritis but in evaluating the condition of the rotator cuff.
TREATMENT
CONSERVATIVE TREATMENT
The conservative treatment may be effective for some patients or may temporarily relieve them until shoulder arthroplasty is performed and includes:
– Modification of activities: One of the first steps in treatment must include total rest and avoiding weight lifting.
– Physiotherapy: It can be effective if the shoulder range of motion is restored. However, if the joint has significant arthritic lesions it can worsen the symptoms.
– Anti-inflammatory drugs: Non-steroidal anti-inflammatory drugs (NSAIDs) can be effective in some patients. Today a large number of different medications are available and are administered for a few days as appropriate. Side effects such as stomach and gastrointestinal disorders, etc., need attention.
– Glucosamine / Chondroitin: Glucosamine is found naturally in the body and stimulates the formation and regeneration of articular surfaces. Some supplements are of animal origin. Chondroitin sulfate is another natural substance (glycosaminoglycan) found in the human body. The effect of chondroitin sulfate in patients with osteoarthritis is probably due to some of its properties, including: its anti-inflammatory action, stimulation of proteoglycan and hyaluronic acid synthesis and inhibition of catabolic activity. The type of medical supplements available in health food stores and pharmacies are of animal origin.
– Corticosteroids (more commonly known as cortisone) are potent anti-inflammatory agents administered intra-articularly (within the joint). These injections provide relief to the patient’s symptoms. However, the results do not last indefinitely. Usually, three or four injections per year are recommended, mainly because of possible side effects. In some cases, pain and edema can worsen after injection, and there may be long-term damage to the joint or infection (infection). Frequent, repeated intra-articular injections can accelerate the lesions rather than reduce them, and can damage the myotenodial rotator cuff.
In addition to cortisone, intra-articular therapy may include substances of high viscosity (thickness), such as hyaluronic acid, which is able to relieve the patient. During this procedure, if there is edema in the shoulder, it is treated before the injection of hyaluronic acid. Following infusion, a local reaction with edema, pain and redness may be observed.
SURGICAL TREATMENT
Extensive articular destruction with increasing intensity of pain that does not subside with conservative treatment requires surgery. Usually, patients decide to have surgery when the symptoms are so severe that they are unable to sleep due to pain and shoulder function has deteriorated to such an extent that they cannot enjoy their daily activities. In addition, some questions about pain and how the patient would describe it on a scale may be helpful. To the question “How would you score your shoulder’s functionality, if 100% is considered normal?” the answer from suffering patients is usually 25%.
There are various methods of surgery; depending on several factors, it is determined which one is most appropriate. Thus, depending on the age of the patient, the location of the arthritic lesions (humerus or scapula) and the position of the rotator cuff, the Orthopedist recommends the type of surgery. As with all surgeries, there are certain risks and potential complications that the orthopedic surgeon must explain to the patient. These risks include infection, bleeding, nerve or artery injury, chronic post-operative pain and failure of the implanted material, with the need for second surgery.
In general, younger patients undergo surgery, in which the anatomical elements of the joint are preserved (arthroscopic washout, etc.). In particular, arthroscopic washout helps to remove various chemical and mechanical factors of inflammation that help reduce pain. However, the success of arthroscopic washout is neither guaranteed, nor predictable and largely depends on the patient.
Total Shoulder Arthroplasty
In patients with chronic pain and severe arthritic lesions, arthroplasty is a valid treatment option. In particular, it is indicated for patients with severe osteoarthritis who are not relieved by conservative treatment.
There are three different types of prostheses and procedures that can be used and include the semi-arthroplasty or semi-total arthroplasty in which only the head of the humerus is replaced, the total shoulder arthroplasty, in which the head of the humerus and the glenoid cavity of the scapula are replaced and finally, the reversed shoulder arthroplasty, which is used in patients with a large functional rotator cuff’s deficit.
There are many different companies that manufacture shoulder arthroplasty implants, and while they differ in many characteristics, they all serve the same purpose: to relieve pain and restore joint function. This is achieved by the use of implants of different orientation and size allowing the correct placement and application of the prosthesis, despite the anatomical variations of each patient. So far, there is no evidence that one design is better than another or that one material is more durable than the other.
Semi-arthroplasty or Semi-total shoulder arthroplasty
Depending on the case, the orthopedist may choose to only replace the head of the humerus, with an implant similar to that used in a total shoulder arthroplasty. Most surgeons recommend semi-arthroplasty when the head of the humerus is severely fractured, but the scapula is intact and with no major lesions. Other indications for semi-arthroplasty include:
– Osteoarthritis that has affected only the head of the humerus, while the glenoid cavity of the scapula does not bear any particular arthritic lesions.
– Severe bone defect of the scapula.
Occasionally, a choice can be made between semi-arthroplasty and total shoulder arthroplasty during surgery.
Studies have shown that patients with osteoarthritis undergoing total shoulder arthroplasty report greater pain relief than those undergoing semi-arthroplasty.
SHOULDER SURFACE SEMI-ARTHROPLASTY
Shoulder surface semi-arthroplasty involves the replacement of the articular surface of the humerus without the use of a stem, and offers an alternative option to other techniques.
Indications of the shoulder surface semi-arthroplasty include:
– The articular surface of the scapula should not be damaged.
– No fracture of the head of the humerus.
– Desire to maintain much of the humerus
For patients who are young and active, shoulder surface semi-arthroplasty avoids the risk of material failure and loosening. Due to the preservation of the humeral bone, it can be more easily converted to total shoulder arthroplasty if needed at a later stage.
2nd Case: 19-year-old engineer with limited range of motion due to severe deformation caused by previous surgery. Four years after a shoulder surface semi-arthroplasty, he works in the same job without painful symptoms.
TOTAL SHOULDER ARTHROPLASTY
Total shoulder arthroplasty is a procedure that can relieve pain and greatly improve the functionality of the patient’s joint. Several studies have shown excellent clinical results and long-term durability of materials in patients undergoing total arthroplasty. Specifically, in terms of durability of the prosthesis, 85% of patients undergoing total shoulder arthroplasty did not need replacement surgery (revision) even after 20 years (Torchia et al.).
Although semi-total shoulder arthroplasty may be a good treatment option, total arthroplasty offers more consistent and predictable results.
Total arthroplasty is indicated for patients with severe shoulder osteoarthritis and normal functionality of the rotator cuff, as well as lesions on the glenoid cavity of the scapula. J Shoulder Elbow Surg. 1997 Nov-Dec; 6 (6): 495-505.
PREDICTION – WHAT ARE THE REALISTIC EXPECTATIONS FOR RETURN TO SPORTS AFTER SHOULDER ARTHROPLASTY?
Patients undergoing shoulder arthroplasty can return to their daily activities and do most of what they did with the exception of high-risk contact sports. Activities such as skiing are permitted despite the fact that they increase the risk of fracture and loosening of the implant after a fall. In conclusion, patients should determine the value of each activity and the degree of risk it has for their lives.
<h4style=”font-size: 20px;” >DISCUSSION – CONCLUSIONS
The current view that semi-arthroplasty offers the patient more freedom of movement and activities than total arthroplasty is no longer valid. Patients undergoing total arthroplasty report better movement and less pain than those undergoing semi-arthroplasty.
COMPLICATIONS
Nerve and vessel injury in the anatomical area of the shoulder joint is a rare complication in arthroplasty, and in the vast majority of cases it is observed postoperatively.
Arthroplasty infection is a complication that may be superficial to the trauma or implant and develop during hospitalization or long after discharge. In the case of wound infection, oral antibiotics are sufficient, while in the case of material infection, it must be removed and replaced by a temporary antibiotic-infused spacer until the responsible microorganism is considered to have disappeared. Only then can the patient undergo replacement with a new implant (prosthesis). Any incision or surgery and dental surgery can become the cause of infection.
Although the materials of the prostheses are made of increasingly durable materials, they can wear out and loosen. Excessive wear and tear may require revision surgery.
Finally, stiffness is a complication that causes progressive loss of range of motion, despite physiotherapy.