The shoulder is the third most common place of artificial joint implementation, following the hip and the knee. We can differentiate among several types of shoulder prostheses. Shoulder prostheses can be divided into three groups:
a. partial prostheses
b. total prostheses
c. reverse prostheses
A partial shoulder prosthesis (shoulder hemiarthroplasty) is the one in which only the upper part (head) of the upper arm bone (humerus) is replaced, but the part of the shoulder-blade (glenoid) is not replaced (Fig. 1).
In case of a total shoulder prosthesis, apart from the upper arm part of the bone, the glenoid of the shoulder-blade is also replaced (Fig. 2).
The third prosthesis type is called reverse shoulder prosthesis due to the reverse relationships of supportive surfaces. The head of prosthesis is on the shoulder-blade and the cup is on the upper arm bone (Fig. 3). Unlike conventional prostheses, function of which is based on the rotator cuff muscles, the reverse prosthesis is based on the deltoid muscle function only.
The indications for the implementation of a shoulder prosthesis is a shoulder joint destruction due to arthrosis (Fig. 4), rheumatoid arthritis, fracture, poorly treated fracture, (treated either conservatively or surgically), (Fig. 5 and 6), humeral head necrosis, etc. One of the reasons for the implementation of a shoulder prosthesis is a shoulder arthropathy, as a result of massive rupture of the rotator cuff tendons, which is a shoulder particularity (Fig.7 and 8).
A reverse shoulder prosthesis is used as a revision prosthesis after an unsuccessful partial or total shoulder prosthesis (Fig. 9).
General risks encountered in all artificial joint replacement procedures. In general, risks of a shoulder prosthesis implantation are extremely rare. The risks include infection and prosthesis dislocation. Other complications, such as thrombosis or nerve injuries in the shoulder area are extremely rare.
Rehabilitation depends on the type of the prosthesis implanted and the condition of the shoulder joint, especially the rotator cuff muscles. Generally, after the surgery the patient needs to wear an arm sling. The sling is worn four weeks, and after that period the patient has the sling removed and passively stretches the arm according to the surgeon’s and physiotherapist’s instructions. Patients start to lift the arm actively 6 weeks after the surgery, and muscle strengthening occurs 2 months after the surgery.