SHOULDER PROSTHESIS
For proper functioning, the shoulder requires integrity of the bony surfaces as well as good function of the deltoid muscle (which gives the shoulder its contour) and the muscles of the rotator cuff that attach to the tuberosities of the humerus. The placement of a shoulder prosthesis may be necessary in cases of significant cartilage wear (osteoarthritis), complex shoulder fractures, or severe and irreparable damage to the rotator cuff tendons.
BONE SURFACE WEAR (OSTEOARTHRITIS) :
Shoulder osteoarthritis is less common than in the hip or knee, but it can be highly disabling, causing pain and limited shoulder movement. Sometimes, only the humeral head is affected, as in the case of osteonecrosis.
FRACTURES :
In the case of certain complex shoulder fractures, the blood supply to the humeral head is compromised (interrupted blood flow to the humeral head). In such cases, shoulder replacement surgery may be recommended along with the reconstruction of the tuberosities to which the rotator cuff muscles attach.
MASSIVE ROTATOR CUFF TEAR :
It most often occurs in elderly individuals and is accompanied by an upward displacement of the humeral head under the acromion, resulting in an inability to raise the arm. If the rotator cuff tear is not repairable, then total reverse shoulder replacement surgery may be considered.
Additional tests are necessary to support the diagnosis. This typically involves shoulder X-rays and a shoulder CT scan (sometimes a CT scan with contrast injection: arthrogram).
Medical treatment is always indicated (except in cases of fracture) and involves rehabilitation to maintain shoulder mobility and muscle strength, taking painkillers or anti-inflammatories, and possibly receiving injections. If unsuccessful, surgical treatment is then considered.
Total shoulder replacement involves replacing the worn joint surfaces with prosthetic components. The goal of this intervention is to provide lasting pain relief and restore strength and mobility to the shoulder. There are two main types of shoulder prostheses: anatomical and reverse prostheses.
ANATOMIC PROSTHESIS :
This type of prosthesis is used in cases of shoulder arthritis or osteonecrosis of the humeral head.
In this case, the rotator cuff tendons are intact, and the intervention aims to replicate the anatomy by placing a metal sphere to replace the humeral head and a polyethylene cup to replace the glenoid of the scapula.
TOTAL REVERSE PROSTHESIS :
This prosthesis is called “reverse” because the spherical part of the prosthesis is positioned on the scapula and the concave part on the humerus. This type of prosthesis is used in cases of significant and non-repairable rotator cuff tears, or in cases of prosthesis revision (prosthesis replacement), or when the glenoid of the scapula is severely deformed. For this type of surgery, a hospital stay of 1 to 2 days is required.
Postoperatively, the arm is immobilized in a splint for a period of 4 to 6 weeks, but rehabilitation begins the day after the operation. This rehabilitation involves self-rehabilitation movements that the patient performs alone at home and conventional physiotherapy sessions.
For this type of procedure, hospitalization for 1 to 2 days is necessary. Postoperatively, the arm is immobilized in a splint for a period of 4 to 6 weeks, but rehabilitation begins the day after the operation.
This rehabilitation program is based on self-rehabilitation movements that the patient performs independently at home, as well as conventional physiotherapy sessions.
