Introduction
Impingement syndrome of the shoulder results in a narrowing of the space between the acromion and the head of the humerus. Due to this narrowing, the structures and soft tissues that run in this space, such as tendons, muscles or bursae, become trapped, which leads to severe pain and significant movement restrictions in the shoulder joint. The terms shoulder bottleneck syndrome or shoulder-arm syndrome are also used synonymously for the disease. In the field of hip joint surgery, the term impingement syndrome is also used, whereby it is a narrowing of the space between the socket of the hip joint and the head or neck of the femur.
When do I need an operation?
In the early stages of the disease it is often sufficient to spare the affected shoulder, avoid overhead work and avoid lifting heavy objects. At the same time, conservative treatment methods in the form of painkilling and anti-inflammatory medications (ointments, injections or tablets), physiotherapy, cold therapy and electrotherapy as well as targeted muscle training can help to improve the symptoms. An operation is necessary if the pain and the movement restrictions in the arm and shoulder, despite conservative therapy, persist or increase over several months.
Due to the lack of relief of the constricted structures and soft tissues, further damage and inflammation of the shoulder joint occurs. In the worst case, muscles or tendons of the shoulder-stabilizing muscle group (rotator cuff) can tear and thus make surgery urgently necessary. Further information on this topic:
- Therapy of the impingement syndrome
- Physiotherapy for impingement syndrome
Surgical therapy
The treating physician differentiates between stage I and II of the disease, in which after about half a year to one year of conservative forms of therapy the treatment must be classified as unsuccessful and a lesion of the tendon caused by the so-called acromion spur is present, and stage III, the stage of incomplete rupture. The surgical procedure for a subacromial bottleneck syndrome, as the impingement syndrome is also called, is called subacromial decompression (decompression = extension). With regard to this decompression, there are – depending on the underlying cause – different approaches to surgery.
The aim is to eliminate constrictions in the shoulder joint so that tendon material or soft tissue is no longer trapped. A distinction is made in the surgical field between:
- Acromioplasty according to Neer (= défilé – expansion) In principle, this is understood to be the expansion of the subacromial space through decompression of the supraspinatus tendon. The aim is to create more space for the soft tissues below the acromion to move.
To achieve this, a small amount of bone is removed from the lower part of the acromion. Under certain circumstances, acromioplasty can be performed arthroscopically. An acromioplasty can be performed for both a rotator cuff lesion and an intact rotator cuff.
Further below you will find more detailed explanations of this procedure.
- A corrective operation that may become necessary after a fracture of the humeral head has healed in a malposition.
- Surgical removal of calcifications on the rotator cuff (tendinitis calcarea). In this procedure, a thickened and inflamed bursa located on the rotator cuff is completely or partially removed. This is usually done in conjunction with acromioplasty (see above).
Subacromial decompression is discussed below.
The acromion consists of two parts, the posterior bony part, called acromion, and the anterior ligament part, the ligamentum coraco-acromiale. The tendons and soft tissue of the rotator cuff are located in the subacromial space, which forms a tunnel-like space in the shoulder joint. This “tunnel” is too narrow in a subacromial bottleneck syndrome and must be widened.
The distance between the head of humerus and the acromion subsurface is known medically as the acromio-humeral distance. Under normal circumstances, a minimum distance of 10 mm must be guaranteed. This space can be increased by removing the downward pointing “bone nose” on the acromion.
Whereas in the past, the anterior ligament part of the acromion was usually removed, this is generally not done today.If the so-called “abutment”, the front part of the ligament, is completely missing, the humeral head can slide upwards. The surgical procedure can be performed using either arthroscopic (arthroscopic subacromial decompression, also known as ASD) or open technique (OSD = open subacromial decompression). Arthroscopic subacromial decompression – ASD – is performed as part of the simultaneous endoscopy of the shoulder joint.
As a rule, only 2 – 3 small skin incisions of about 1 cm in length are required, into which special instruments are inserted. This allows the surgeon to insert a camera into the joint, which enables him to directly identify and remove bony structures that lead to constrictions. A shaver, a rotating special instrument, is used to mill off a part of the acromion undersurface.
For more pronounced clinical pictures, open therapy is usually preferable. In this case, larger bone spurs can be removed and any existing adhesions removed at the same time. If necessary, the surgeon can also remove parts of the joint (bone parts, tendons or parts of bursae) and/or smooth joint surfaces.
Open subacromial decompression – OSD – is performed through a skin incision of approximately 5 cm. Due to the higher stress for the patient, this procedure is accompanied by a longer hospital stay. If it is possible to differentiate between the two types of surgery, ASD is generally preferable to OSD.
The advantage of the ASD is mainly the lower invasiveness. With this variant, the operation can normally be performed on an outpatient basis, i.e. the patient can leave the hospital on the day of the operation. After each type of operation, extensive physiotherapy is prescribed, whereby it is important to find a good middle ground between overloading the joint too early and immobilising it for too long, both of which can have a long-term negative effect on the healing process.
The more extensive the intervention, the slower mobilisation of the joint should be started and the longer it usually takes to regain completely normal mobility and freedom from pain in the affected shoulder. More detailed information is provided in the chapter: Subacromial decompression spur before surgery Illustration of a special X-ray image (outlet view) in which a constricting spur can be seen under the acromion. After surgery Same X-ray image after arthroscopic surgery, after the spur has been removed.
If surgery is necessary, it is usually performed under general anesthesia. In the meantime, the patient is positioned in a sitting position (“beach-chair position”) and does not notice anything of the operation. Consciousness and pain sensation are completely eliminated with this method of anaesthesia and the patient is not responsive during the procedure.
In rare cases, local or regional anesthesia (scalenus block or plexus anesthesia) can be used. In this case, nerve fiber bundles in the area of the neck and armpits are injected with an anesthetic. The patient is conscious and responsive at all times.
In most cases this form of anaesthesia is used in combination with general anaesthesia or for temporary pain elimination. General information on general anesthesia can be found here: General anesthesia – procedure, risks and side effectsThe operation usually takes 30-45 minutes. In the case of open surgery and complex preparation of the shoulder joint, for example in the case of pronounced adhesions in the joint, the surgery time can increase to several hours.
The operation is performed under general anesthesia. For the treatment as a whole, at least one day should be planned, since the anesthesia is usually followed by an observation period. If the patient is admitted to hospital, 2-4 days should be expected.
If the operation is performed under general anesthesia, the patient does not feel any pain during this time and is not conscious. In the initial period after the operation, painkilling medication is used to enable almost painless mobility of the shoulder. Early movement is very important in order to prevent adhesions or renewed, space-consuming adhesions.
After a few days, the pain should have subsided to such an extent that it is no longer necessary to take painkillers. This topic might also be of interest to you: Exercises against muscle shortening in impingement syndromeThe operation for impingement syndrome can be performed as an inpatient or outpatient procedure.An outpatient operation is only planned with a hospital stay for the day of the operation, the hospital can be left the same day. Should complications arise, a stay beyond the day of surgery can be recommended.
Outpatient treatment should only be considered if someone is available after discharge to support daily activities and there is a certain degree of mobility to come to the hospital for follow-up examinations or in case of complications that occur later. An inpatient operation is usually scheduled for 2 nights for this treatment. An operation in general always involves certain risks.
The general anesthesia is not equally well tolerated by all people and complications may occur during the operation. However, these are not specific, but apply to every surgical procedure and are discussed with the doctor before the operation. Inflammation of the surgical wounds may occur after the operation.
Since only small incisions are made during the impingement syndrome surgery, the risk of developing an infection is low. A risk that should not be neglected is that despite the operation the tendon damage remains and tears are formed. Likewise, despite surgery, a renewed impingement syndrome can occur, among other things due to a thickened bursa or other inflammatory thickened structures in the shoulder area. After surgery, the increased risk of thrombosis should be taken into account during immobilization, but this can be prevented by medication if immobilized for a longer period of time.
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