- See: Brachial Plexus Injury
- Indications:
- shoulder paralysis:
- may include paralytic dislocation or combined rotator cuff / deltoid paralysis (in which case shoulder arthroplasty would be contra-indicated);
- as a requirement for shoulder fusion, the muscles of forearm and hand need to be functional as do the serratus anterior and trapezius;
- the later muscles need to be strong inorder to control scapulothoracic motion after the fusion;
- degenerative or rheumatoid arthritis;
- Functional Position:
- fusion should allow the patient to reach the face as well as the back pocket;
- when trapezius and serratus anterior function is acceptable, position in:
- abduction:
- recommendations have ranged from 15 deg to 45 deg;
- historically recommended positions for shoulder fusion have ranged from 30-45 deg;
- abduction beyond 45 deg may be associated with pain and winging of the scapula;
- when serratus anterior is paralyzed, the shoulder should be fused in no more than 30 deg of abduction;
- otherwise, the weight of the arm may depress the lateral part of the scapula and overstretch and weaken the trapezius;
- flexion: less than 10-30 deg;
- internal rotation: 20-45 deg;
- allows patient to reach contra-lateral should, belt, and mouth;
- deg of rotation can be the most important factor determining extremity function;
- references:
- A functional analysis of shoulder fusions.
- Re-evaluation of the position of the arm in arthrodesis of the shoulder in the adult.
- Technical Considerations:
- incision: begin at the scapular spine, continue across the anterior aspect of the acromion, and down the anterior aspect of the proximal part of the humeral shaft;
- deltoid is detached from the anterior aspect of the acromion, and the fibers are split distally;
- rotator cuff is excised, the articular surfaces of the glenoid and humeral head are removed, and the undersurface of the acromion is decorticated;
- attempt both intra-articular fusion (glenohumeral) and extra-articular fusion (acromio-humeral) fusion;
- if glenohumeral contact is inadequate w/ the superior placement of the humeral head, a partial osteotomy of the acromion can be performed at the junction with the scapular spine;
- acromion is then displaced downward, hinging at the AC joint;
- plate is contoured against the scapular spine, over the acromion, and against the proximal humerus;
- Post Op Evaluation:
- motion of scapula then compensates for the lack of motion in joint;
- single most important cause of complications following shoulder arthrodesis is malposition, either too much flexion or too much abduction, which results in periscapular pain;
- Arthrodesis in Children:
- indicatioins:
- children w/ paralysis of shoulder girdle muscles w/ subluxation or dislocation (as might occur in Polio) inorder to stabilize the flail shoulder;
- prerequisites for procedure:
- functional results are related to neurologic status of distal arm & hand, & therefore normal function of forearm & hand is a prerequisite;
- strong trapezius & serratus anterior muscles are required in order to allow for increased scapulothoracic movement;
- optimal age is controversial;
- since it is difficult to predict the final position, some delay shoulder arthrodesis until skeletal maturity;
- pseudoarthrosis: may occur in 20%;
- solid fusion is technically difficult to achieve in children because of the amount of cartilage in pediatric humeral head;
- care must be taken to preserve the proximal humeral growth plate in skeletally immature patient;
- optimal position of arthrodesis:
- abduction: 15 deg (but 45 deg as been recommended historically);
- excessive abduction should be avoided, because excessive scapular winging can result;
- there may be loss of 10-20 degrees of abduction during first 12 months in young children;
- flexion: 25 deg;
- internal rotation: 25 deg
A functional analysis of shoulder fusions.
Glenohumeral arthrodesis. Operative and long-term functional results.
Early arthrodesis for a flail shoulder in young children.
A simplified compression arthrodesis of the shoulder.
Shoulder arthrodesis using a pelvic-reconstruction plate. A report of eleven cases.
Arthrodesis of the shoulder in children
Treatment of Complications of Shoulder Arthrodesis.
A simple method of shoulder arthrodesis.