Shoulder Surgery | Shoulder Pain
Osteoarthritis of the shoulder | Instability of the shoulder joint | Rotator cuff tears | The inverse prosthesis | Biceps tendon | Impingement syndrome | Fracture of the head of the humerus
Omarthrosis refers to abrasion of the cartilage in the shoulder joint. In this form of osteoarthritis, there is wearing of thecartilage on the head of the humerus and/or of the shoulder joint socket (glenoid cavity). Differentiation is made between primary (no discernible cause) and secondary osteoarthritis (resulting from accidents). Impairment of the joint cartilage commonly occurs as a result of a substantial rotator cuff lesion, leading eventually to a "cuff tear arthropathy". Put simply: Joint abrasion as a result of a major defect of the rotator cuff (a sleeve of tendons around the joint head).
If the cartilage is degraded, the bones of the head of the humerus (ball) and glenoid cavity (socket) rub against each other without the protective, shock-absorbing joint cartilage. This leads to pain and restricted movement. As people have been living longer in our culture over the last century thanks to improved medicine and good nutrition, we are increasingly confronted with the consequences of this ageing. Osteoarthritis of the joints and their treatment options are thus becoming ever more important. Prosthetic joint replacement (shoulder prosthesis) is already a standard procedure and maintains the quality of life in many cases.
When is the right time for a shoulder prosthesis?
The most important thing about the shoulder is not the joint itself, but the movable soft tissue covering, the rotator cuff. When only the joint is replaced, it is often unsatisfactory. The primary goal may indeed be pain relief, but most patients also want to restore mobility and strength. In advanced osteoarthritis, it is therefore not uncommon that the soft tissue components of the rotator cuff are in such poor condition or even absent that full mobility and strength are matters of chance. Despite intensive strength training after the operation, these wishes and goals are not always achieved. This supports the idea that a joint replacement operation should not be delayed until all the structures are destroyed, but should be performed when the burden is indeed substantial, but when the degenerative changes are not yet too advanced.
What types of prostheses are available?
Various prosthetic procedures exist for osteoarthritis of the shoulder. Total endoprosthesis, i.e. replacement of the head of the humerus and glenoid cavity, is currently only performed in younger patients with good soft tissue, namely a mostly intact rotator cuff. These prostheses are designed so that they can later be converted into an inverse prosthesis, called a reversed joint, if required.
The once very common replacement of the head of the humerus (without replacement of the glenoid cavity) is now only performed rarely, primarily for comminuted fractures. Primary implantation of the inverse prosthesis is increasingly recommended in elderly patients, where the rotator cuff is usually also impaired. The cup prosthesis (replacement of the surface of the head of the humerus only) has supporters and opponents. The supporters hold that the osteoarthritis receives optimum treatment and, furthermore, that a rupture of the rotator cuff can be solidly repaired without problems and without needing to replace the socket. Moreover, almost no bone needs to be sacrificed, whereby the patient still has all options open in future. Opponents believe that, in the event of any later need to replace components of the socket, the operation and the implantation of the socket become very difficult, hence primary implantation of the socket is to be recommended.
Which prosthesis is best in your case must be investigated as part of a thorough clinical examination. Your medical history, lifestyle and quality of life are of great importance for this.
The shoulder joint is essentially only stabilised by the muscles and joint capsule. Other stabilisers include the rim of cartilage around the glenoid cavity (called the glenoid labrum or limbus), a mild vacuum within the joint and the bony structure. It must also be noted that the glenoid cavity is relatively small and the head of the humerus large. The shoulder is therefore the joint with the widest range of motion in the human body, but it is highly susceptible to instabilities.
What makes the shoulder unstable?
Trauma is responsible for shoulder dislocation in most patients, frequently an event that was so dramatic that the patient can remember it clearly years later. The trauma (e.g. a fall) can injure the stabilisers. This is called "traumatic shoulder instability". This usually leads to a lesion (tear) of the anterior rim of cartilage around the glenoid cavity, known as a Bankart lesion. The anterior lower shoulder joint capsule and associated ligaments also frequently tear with it. Depending on age and other factors, this often leads to repeated dislocations owing to the stabilisers injured in the initial trauma; these can usually no longer heal spontaneously. "Arbitrary dislocations" are seen in rare cases. In this form, the patients can perform a dislocation at will, then reposition the arm independently. This is often performed many times in a row.
However, the shoulder stabilisers may also be congenitally too weak, as shown in soft tissues of the capsule/ligament apparatus that are too weak and too elastic. Even minor injuries are sufficient to dislocate the shoulder in such patients. These non-traumatic instabilities are usually congenital. Excessively elastic capsule ligaments give the arm too much movement within the glenoid cavity and even small manipulations can lead to a partial or complete dislocation.
How is shoulder instability diagnosed?
Initially, a conventional X-ray examination is performed on the shoulder at various levels. In acute cases, the hypothetical direction of the dislocation can be determined. A fracture to the head of the humerus or socket can also be ruled out. The next step requires an ultrasound examination to be able to assess the soft tissues (e.g. rotator cuff). Magnetic resonance imaging (MRI) is performed for relapsing (recurrent) dislocations or for persistent pain, so as to be able to image any injuries to the limbus (joint labrum), cartilage or tendons. However, in the beginning, the clinical examination is always essential for the assessment of the grade and direction of the instability.
How is shoulder instability treated?
Non-surgical, conservative treatment of shoulder instabilities
Immediate repositioning is the primary goal for acute shoulder dislocations. An X-ray is taken beforehand to rule out a fracture. If repositioning is not possible in an alert patient owing to muscle tension, it must be performed under short-term anaesthetic. After repositioning, the shoulder is immobilised for a few days in a sling or vest, then followed up with the aid of physiotherapy. Immediate surgery is not required in most cases. It is only urgent for fractures that cannot be treated conservatively and for patients who require an extremely resilient shoulder (e.g. professional sportspeople).
Patients who can perform arbitrary dislocations should cease doing so. The prognosis for spontaneous healing even after several years is good. Indications for surgery owing to arbitrary dislocation rarely lead to the desired success.
In chronic shoulder instability, surgery can potentially be avoided with physiotherapeutic guidance and a targeted muscle strength-building programme, compensating for the injuries to the limbus and capsular ligaments through strengthening of the dynamic stabilisers (muscles). However, this will not lead to healing of the injured structures. In the event of persistent pain despite conservative therapy, the only option remaining is stabilising surgery.
The younger the patient with an initial dislocation (e.g. 18 to 30 years), the more likely surgical stabilisation will be recommended, as the probability of a renewed dislocation is around 90%. The older the patient (above 50 years), the more likely an initial wait-and-see approach and conservative therapy will be recommended, provided the tendon/muscle apparatus is intact. However, surgery is indicated in the event of a concurrent rotator cuff injury.
Surgical therapy of shoulder instabilities
A differentiation is made here between arthroscopic and open stabilisation surgery. For arthroscopic shoulder stabilisations, an arthroscope and a surgical instrument are inserted through two to four small, roughly 0.5 to 1 cm long incisions. Arthroscopic surgery is usually performed with the patient lying on their side or back.
The Bankart operation is an arthroscopic procedure where the torn-off limbus is reattached to the bone and the over-stretched capsular ligaments are tightened. This uses special suture anchors which are fixed into the bone of the glenoid cavity. In specific cases, an additional remplissage ("filling") is performed. The tendon of the infraspinatus muscle is sutured into the Hill-Sachs lesion found on the upper posterior head of the humerus.
The Bankart operation can also be performed open and is a classic procedure for attaching the torn-off limbus to the anterior rim of the glenoid cavity, using openly placed suture anchors or bioresorbable screws. If larger bony injuries are present at the rim of the glenoid cavity, these must be attached with screws in the classic procedure.
If the bony injury to the rim of the glenoid cavity is too large, or the detached bony fragment is too small for screwing or has already healed in an abnormal position, a method is selected whereby a bone block must be transferred. For example, a bone block can be taken from the iliac crest of the hip and implanted in the bony defect at the rim of the glenoid cavity (J bone) to restore the natural contour of the joint socket. Alternatively, the coracoid process (a bony protuberance on the scapula) can be detached and transferred with the attached biceps tendon as static and dynamic stabilisation. This stabilisation technique is often known as an open Latarjet procedure. Long-term results of this procedure show up to 98 percent of patients are highly satisfied, with a redislocation rate of no more than 3 percent.
Why/when does surgery make sense?
- Recurring dislocations are extremely painful.
- At each dislocation the axillary nerve can be pinched, then damaged through pressure and tension during the dislocation event or the manoeuvre. This can become associated with palsy and/or sensory disorders.
- Each dislocation can lead to further structural damage to the cartilage, limbus, capsule and bones of the glenoid cavity and head of humerus. The consequence would be early osteoarthritis.
What does follow-up consist of?
The appropriate follow-up is just as important as the actual procedure. The shoulder is immobilised for the first two weeks using an orthopaedic vest. The patient then wears a sling during the day for a further two weeks. A specially trained physiotherapy team leads a rehabilitation programme, starting the day after the surgery. The shoulder joint is inspected and carefully mobilised to prevent adhesions of the gliding surfaces. The arm must not be rotated beyond 0 degrees externally for the first six weeks. A continuous increase in movement and load bearing with muscular stabilisation exercises under physiotherapeutic guidance follows this initial rehabilitation phase. Gentler physical and sporting activities can be restarted from this time.
Contact sports, such as handball, football, martial arts, etc. can be restarted after 6 to 9 months.
The precise measures and recommendations depend on the relevant procedure and surgical method.
The rotator cuff is the grouping of tendons of the shoulder joint. This surrounds the head of the humerus like a cap and binds the upper arm with the shoulder girdle musculature. Tears to the rotator cuff before the age of 40 usually occur owing to accidents and after the age of 40 owing to prior degenerative damage.
What are the symptoms of a rotator cuff tear?
In the case of chronic ruptures, the primary symptoms are night- and load-dependent pains, but also a significant loss of strength, especially when working overhead. A sudden tear of the rotator cuff is usually accompanied with considerable loss of function in the arm. Although the mobility can be normalised thanks to the extraordinary ability of the remaining shoulder girdle musculature to compensate, it is usually the persistent pain and loss of strength that drive patients to consult a shoulder specialist. Quality of life is severely restricted, especially by nocturnal pain. This is easily explained. During the day, the arm is drawn slightly downwards by gravity, which for the rotator cuff represents a relieving expansion of the space beneath the acromion. When lying down at night, the pull of gravity is ineffective, hence the muscle tone of the remaining shoulder girdle musculature draws the head of the humerus upwards, pinching the injured cuff beneath the acromion.
How is a rotator cuff tear diagnosed?
A rotator cuff rupture can be investigated clinically, using ultrasound and, most reliably, arthro-MRI. Earlier, such injuries were rarely operated on as the results after the surgery were inadequate. Today, though, the attitude of shoulder specialists regarding the treatment of these injuries has changed. We now know that a tear cannot heal spontaneously. Waiting too long extends the lesion, making it eventually develop into a difficult to nearly impossible problem. Today treating the tear with surgery as soon as possible is recommended, provided the tissue condition is still good and the reconstruction promises a good result. The larger the defect to be treated, the more difficult the procedure and the ability to predict the result. However, reconstruction of the rotator cuff requires a certified, thoroughly knowledgeable shoulder surgery specialist to provide the patient with the prospect of a good result with reliable security.
How is the rotator cuff reconstructed?
The rotator cuff is mobilised and newly reinserted into the bone at an early stage. This means increasingly more tension in the recently operated tissue, explaining why more pain occurs immediately and for a short time after surgery. An abduction splint cushion must be worn for relief. Likewise, the AC joint is abraded to avoid pain after surgery from this small shoulder joint. This expansion of the "subacromial space" is required to provide the newly reconstructed rotator cuff sufficient space and to prevent renewed chafing of the cuff. The remainder of the bursa between the acromion and rotator cuff is also normally removed. Firstly, the bursa is usually also injured during the tear lesion. Secondly, with intensive movement therapy after surgery, it spontaneously regenerates within half a year.
If a rotator cuff rupture (tear) has existed for some time, even for years, or the tissue retracts rapidly after the tear lesion, a defect can arise which can no longer be repaired with normal methods. During this long time, the body has learned to get used to the defect and how to compensate for the loss. This means that the patient may be able to move their arm to some extent for quite some time even for considerable defects. In the event of a minor trauma, however, subsequent tearing of the cuff can decompensate the balance attained. The situation then arises that the arm can suddenly no longer be lifted, similar to a palsy. This is always a memorable event that greatly disconcerts the patients. Provided the tendon apparatus can be repaired, it must be reconstructed.
What if the rotator cuff cannot be reconstructed?
If the tendon defect is too large or the head of the joint is definitively attached beneath the acromion and the joint surfaces on the head of the humerus and glenoid cavity are already deformed and destroyed (defect arthropathy), joint replacement surgery must be considered. Joint replacement surgery in such a case cannot be performed with a standard joint replacement prosthesis as the good function of such a prosthesis would be equally dependent on the good function of the rotator cuff. If the rotator cuff is missing as the centralising force in the joint, the prosthesis must take over this function from the rotator cuff. This is only possible with an inverse prosthesis. This means that the centre of rotation must be set through the prosthesis itself, as in the hip joint.
The principle of the inverse prosthesis is that the centre of rotation of the joint is no longer maintained by the rotator cuff, but by the prosthesis itself. In reality, this prosthesis is not a joint replacement, rather a replacement for the missing rotator cuff. This prosthesis is therefore reserved for shoulders that no longer have a functional rotator cuff, where the joint can no longer centre itself. If the rotator cuff is absent and impossible to repair, implantation of such a prosthesis is a quantum leap in improving the quality of life. This is independent of whether loosening or degradation is likely later (10 years or more afterwards). We may indeed expect that in 10 years science and technology will make further substantial advances and will provide improved possibilities and new solution approaches even for such cases.
The long and short biceps tendons begin in the shoulder, pass along the anterior portion of the humerus in the well-known muscle belly and come together at the radial tuberosity. The main action of the biceps is flexion of the elbow. The effect on the shoulder joint itself is not primary. However, what is interesting and important for the shoulder joint is the origin of the long biceps tendon on the upper rim of the glenoid cavity at or near the limbus (meniscus). During rotations of the upper arm, the long biceps tendon, guided by a complex ligament apparatus, is tensed over the head of the humerus, thus gaining a centralising effect on the shoulder joint itself, primarily with the humerus in the external rotation position. Damage to the long biceps tendon can therefore arise when over-stressing the flexor muscles of the elbow. This injury can either occur at the meniscus near the insertion with fraying of the tendon, or as the detachment of the meniscus with the biceps tendon attached. Such injuries to the biceps tendons lead to inflammation with strong pain along the course of the tendon, radiating into the upper arm.
However, an injury to the biceps tendon can also occur through a sudden tearing event (e.g. when trying to stop a load from falling), not only through repetitive movements. When the damaged tendon is stretched, it can then tear and the stump of the tendon can slide down. The patient recognises this partly through a reduction in the pain as well as by the belly of the biceps muscle "slipping down".
The meniscus forms a cartilaginous ring around the rim of the glenoid cavity and provides better grip for the head of the humerus as well as increasing the joint surface area by around one third. An injury, in particular the detachment of the meniscus from the rim of the glenoid cavity always means a loss of stability of the shoulder joint. Such a loss of stability can lead to subsequent damages, in that, for example, the head of the humerus is no longer centred within the glenoid cavity when raising the arm. and deviates upwards. This places the rotator cuff under pressure and it can rub on the acromion. The result is "impingement syndrome", or in less medical terms, pinching. This leads to various severities of injury or changes to the meniscus.
How are injuries to the biceps tendon and impingement syndrome treated?
Most diseases or injuries to the meniscus or biceps tendon can be treated arthroscopically. This means that even the surrounding soft tissues are protected. However, a torn or injured biceps tendon usually cannot be reconstructed. It is separated from the origin of the biceps, at the transition to the meniscus, and reattached in the tendon groove on the head of the humerus. The meniscus, detached from the upper edge of the joint, can then be reattached arthroscopically. In most cases, though, two to three months of rehabilitation are to be expected.
The classical fracture of the head of the humerus is a consequence of a fall onto the outstretched arm; this is common in the elderly. It can be very painful and substantially impairs mobility in the shoulder joint, similar to a severe dislocation. The fracture can be beneath the joint, but can also pass into the joint.
How is a fracture of the head of the humerus treated?
Depending on the displacement of the fragments and on the type of fracture, healing without consequences is possible with immobilisation alone. In many cases, however, there is significant displacement of the fracture fragments as the attached rotator cuff pulls on them. Impingement events beneath the acromion with extensive, painful movement restrictions therefore occur following healing. Most of these complex fractures can still be provided with a satisfactory result with skilful, well-planned surgical treatments. For comminuted fractures that can longer be reconstructed, an artificial head of humerus (prosthesis) may sometimes be implanted. For comminuted fractures with concurrent dislocation of the shoulder joint or excessive displacement of the fragments, there is increasing interest in primary implantation of an inverse prosthesis.
Osteosynthesis with plate and screws has become the current standard in emergency shoulder surgery. Too often, however, the attention of the surgeon is directed solely to the bones and their reconstruction. As it is precisely these injuries in which the soft tissue cuff is also affected, every reconstruction demands attention also be paid to this. Many postoperative results are only unsatisfactory for the reason that overall shoulder function with all tissues involved receives too little consideration. Certain fractures of the head of the humerus near the joint behave like rotator cuff injuries as the tendons of the rotator cuff are attached to these bone fragments.
Conservative, non-surgical treatment of these complex fractures often leads to the disabling of this area, such that surgery is usually to be preferred, even when taking incomplete, although painless movement of the shoulder joint into consideration.
What does follow-up consist of?
Rehabilitation is dependent on the reconstruction performed, on the stability and on the condition of the surrounding soft tissues. Surgical care of even very difficult injuries should always target being able to move the arm as soon as possible, even during the healing phase.
Author: Assoc. Lect. Dr. med. K. Modaressi