肩部关节固定术 - 肩部稳定手术 - 肩部专家

                               
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The techniques of shoulder arthrodesis have evolved extensively over the past century. The procedure was originally performed to treat complications related to poliomyelitis and infection  and it involved extra-articular bone grafting of decordicated gleno-humeral surfaces. Due to its overwhelming success, the indications grew to include disabling arthritis and rotator cuff tears. Later, external fixation was designed to improve compression resulting in a more stable construct. After 6 weeks of external fixation, a spica cast was applied for an additional 3 months. Although this technique resulted in successful fusion, it could not reliably maintain stable fusion. In addition, external fixators proved extremely cumbersome and inconvenient for the patients.

Therefore, internal fixation constructs were developed to improve the stabilization of fixed glenohumeral components. The improved stability led to a higher fusion rates and also eliminated the need for casts, braces and splints.

Most current techniques in shoulder arthrodesis utilize internal fixation with screws or plates. Screw fixation alone utilize up to 3 screws into the acromial head and if necessary, up to 3 screws on the greater tuberosity into the glenoid. Evidence suggests that a higher non-union rate with screw fixation.

External fixation has a limited role when there is extensive soft-tissue loss or an underlying infection. The AO group described a double-plating technique in which one plate can be placed in line with the scapular spine and bent inferiorly to contour with the proximal humerus. A second plate is applied posteriorly across the joint spanning from the proximal humerus to the posterior glenoid neck. Although excellent stability is obtained, the need for symptomatic hardware removal is relatively common. To avoid this problem, along with the difficulty in contouring, a malleable reconstruction plate to fuse the glenohumeral joint in a similar fashion. Excellent fixation has been achieved without the need for plate removal in several studies. The malleable reconstruction plate has become the most commonly used shoulder arthrodesis technique.  

The current indications for shoulder arthrodesis include:

- Paralytic disorders
- Irreparable rotator cuff tears
- Rotator cuff and deltoid insufficiency
- Failed shoulder arthroplasty
- Contraindication to shoulder arthroplasty
- End-stage instability
- Neoplastic lesions

In shoulder specialist Peter Millett, MD's practice, the most common indication for shoulder arthrodesis is end-stage shoulder instability in young patients.

The prefered method is an anterolateral approach. The axillary nerve is identified and protected with a vessel loop. After the deltoid is split, the superior rotator cuff tendons are resected and cartilage from the articular surfaces of the humeral head and glenoid are removed. The humeral head, greater tuberosity, glenoid and under-surface of the acromium are decordicated so that a gleno-acromioal humeral arthrodesis can occur.

A 12-hole malleable reconstruction plate is contoured and applied over the scapular spine extending over the aromium and bending inferiorly down the shaft of the humerus. The plate is passed underneath the previously dissected axillary nerve.

The humerus is positioned in 20 degrees of abduction and 30 degrees of forward flexion and 40 degrees of internal rotation. Too much abduction can lead to excessive strain on the pari-scapular muscles and winging of the scapula. After a range of motion test, corticocancellous bone graft is then packed around the bone fusion sites to promote fusion across decordicated genoid humeral and acromo humeral surfaces. The deltoid is then repaired and the wound is closed.

Shoulder arthrodesis should only be performed in select cases with the appropriate indications. In this case example, the 22 year old patients had Ehlers-Danlos syndrome who had previously undergone failed stabilization procedures. The patient was willing to sacrifice shoulder motion for stability. Shoulder specialist Dr. Peter Millett performed a shoulder arthrodesis.

Shoulder specialist Dr. Peter Millett has performed 5 shoulder arthrodesis procedures that all successfully fused with no episodes of instability and significant decrease in pain with improvement in function, although one patient had mild postoperative residual tenderness.

Overall, shoulder arthrodesis with plate fixation provides predictable outcomes with low complication rates. This is considered a salvage procedure and our most common indication being young patients with end-stage instability with multiple failed stability procedures. Most patients are able to adequately perform ADLs and significant decrease in pain and improved functional range of motion.