Open subacromial decompression (OSD)
The second possibility of a surgical intervention is open subacromial decompression, which was the only possibility of surgical extension surgery before the standardized use of ASD.In contrast to ASD, a larger skin incision (about 5 cm in size) must be made to allow access to the surgical area. While in the ASD a reflection of the area to be operated is made, in the OSD the direct operation is started. The operation itself consists of two parts in the classical manner.
In the first part of the operation, the band connections between the acromion and the coracoid are removed. This loosening of the band connections can be done in different ways depending on the individual. It is not always necessary to remove all band connections.
Sometimes band connections are also reattached later. Following the first step of the OSD, the second step involves the removal of the bony wedge on the underside of the acromion. A reduced distance between the acromion and the humeral head should be increased to allow the rotator cuff sufficient freedom of movement.
Now the first step of the OSD takes place: The band connections between acromion and coracoid are removed. Subsequently, the 2nd step, the removal of the bony wedge, takes place. In the context of the OSD, a chisel is required for this instead of a shaver (see ASD).
Operative accesses
The procedure consists of 2 parts in the classical way:
- Remove the ligament connection between acromion and coracoid (ligamentum coraco-acromiale).
- Removal of a bone wedge of a certain size from the anterior and posterior surface of the acromion
Risks of decompression
The risks of subacromial decompression depend on various factors. Despite surgery, the severity of the impingement syndrome has an effect on the chances of recovery and improvement after surgery. The two different surgical procedures also entail different risks.
In general, the arthroscopic procedure is very low-risk. Nevertheless, all potential consequential damages and side effects of anesthesia and surgery itself must be explained before the operation. Since subacromial decompression is usually performed under general anesthesia, the first risks can already occur during anesthesia.
In addition to intolerances and allergies to the anaesthetic, irritations can also occur through the breathing tube in the trachea. This can result in hoarseness and sore throat. The risks of the actual operation include accidental injury to the structures being operated on.
In the case of unstable joints, special care must be taken during the operation, as cutting through ligament structures can aggravate the instability. In addition, there is a risk of injury to the muscle and bone structures of the shoulder joint, as well as to cartilage surfaces and joint components. This can lead to bruising in the area of the operation.
Under certain circumstances, there is a risk that the surgery performed will cause little or no improvement. In all invasive procedures, whether minimally invasive or open surgery, there is a risk of infection by pathogens. By cutting through the skin barrier and opening up the surgical site, pathogens can penetrate if hygiene is inadequate and can inflame the shoulder region, muscles, wound area and skin. This is one of the reasons why the patient has to spend a few days in hospital even after a positive outcome of the operation.
