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A. APOIL
Hôpital Saint-Antoine - F-75571 Paris Cedex 12
The technique of covering large tears of the rotator cuff with a flap of deltoid muscle has been used regularly at Saint-Antoine for more than ten years; the first clinical results were reported to the French College of Surgeons on 27th March, 1985.
The original idea was to construct a continuous muscle bridge between the distal deltoid and the proximal part of the tendons of the torn cuff (supraspinatus and infraspinatus), with a view to restoring a cuff that could keep the humeral head in its anatomical position and prevent it migrating upwards. This was achieved by means of a muscle flap taken from the anterior fascicle of the middle deltoid and swung into the defect in the cuff.
- Patient positioning The patient is supine, with a pad placed between the medial border of the scapula and the spine, and the arm in slight extension and resting on an armboard placed along the table; the head end of the table is raised. The patient may also be placed in a sitting or semi-sitting position. The entire arm is prepped and draped free for ease of manipulation.
- Incision The superolateral approach is used. The incision begins at the acromioclavicular joint, follows the anterior edge of the acromion and is then angled and continued distally from the tip of the acromion for a distance of 4 cm (Fig. 1). The anterior fascicle of the middle deltoid is released from the anterior border of the acromion, and the fibres are then divided in the line of the skin incision (Fig. 2) (the axillary nerve runs 3 cm distally). Care should be taken to separate the plane of the deltoid insertion from that of the origin of the coracoacromial ligament.
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| Fig. 1 : Superolateral approach : line of incision. | Fig. 2 : Superolateral approach : deltoid flap. |
- Anterior superior decompression and debridement The whole of the coracoacromial ligament is resected, together with the fibrous arch which extends it from the tip of the coracoid process towards the conjoined tendon; a limited acromioplasty is performed to remove the anteroinferior part of the acromion (Fig. 3), together with any neo-articulation in a Stage 0 arthritis resulting from subluxation of the humeral head. This debridement provides ample access to the rotator cuff.
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| Fig. 3 : Large rotator cuff tear (6 cm x 5 cm). Preliminary acromioplasty. |
- Preparation of the cuff The bursa or bursal remnants are excised, together with any remnants of the cuff on the greater tuberosity and any osteophytes; this will reveal a large defect, usually more than 5 cm long, extending from the subscapularis anteriorly to the teres minor posteriorly; medially, the proximal stump of the supraspinatus is easily identified at the apex of the glenoid, while the infraspinatus is more difficult to locate behind the neo-articulation on the acromion. The edges of the tear are debrided very sparingly. Sutures are then placed every 5 mm and held in forceps; posteriorly, the teres minor is often completely displaced downwards behind the head of the humerus and the sutures have to be passed progressively from distal to proximal, starting at the insertion on the greater tuberosity (which is the only accessible site), "bringing up" the posterior edge one suture at a time.
- Deltoid flap repair Starting with the part of the deltoid muscle used for the approach (inverted L-shape), a flap is formed for the repair by anterior division in the line of the muscle fibres, starting at the acromioclavicular joint and continuing for a distance of 3 cm. This distally based flap is then swung into the defect. The sutures previously placed in the edges of the tear are passed through the flap edges using an intestinal Reverdin needle, and the knots tied one at a time, spreading the flap out over the head of the humerus, which will then be separated from the arch of the acromion by this sheet of muscle (Fig. 4).
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| Fig. 4 : Flap with sutures S.SCAP = SUBSC. S.E. = SUPSPIN SS.E = INFSPIN Pt.ROND = TM |
- Wound closure The defect in the anterior fascicle of the middle deltoid is left open, with no attempt being made to reapproximate the edges; the subcutaneous and cutaneous layers are closed over a suction drain.
- Postoperative care A plaster shoulder splint is applied while the patient is still under anaesthesia, maintaining the arm in 70° of abduction, 30° of forward flexion, and neutral rotation. The final shoulder spica is fitted in the same position after 24 hours; it is bivalved in the arm section to allow active-assisted exercises in the scapular plane with the patient supine, which are started after 36 hours (Fig. 5); the shoulder spica is removed 30 to 45 days later, and replaced with a simple abduction cushion for a fortnight. Exercises are continued daily for three months, and then at intervals over a long period; the final result will be assessed at one year.
We have been performing this procedure for several years; during that time, our ideas on the mechanics and role of the flap have developed, along with the technique itself.
Technically,
- it became apparent that the deltoid should not be split anteriorly, starting at the acromioclavicular joint, for a distance of more than 25 to 30 mm (while posteriorly, from the tip of the acromion, the split could be continued for a distance of 50 mm); the anterior part of the flap is partly vascularised by branches of the thoracoacromial artery, which has to be preserved in order to prevent necrosis of the anterior part of the flap.- While it is always easy to locate the proximal stump of the supraspinatus at the apex of the glenoid, the infraspinatus is usually in a higher position, as a result of the superior migration of the humeral head, and has to be mobilised from the undersurface of the acromion, behind the neo-articulation.
- If the tear goes backwards a long way, the tendon of the teres minor should be identified at the level of the greater tuberosity, with tag sutures placed from lateral to medial in order to "bring up" the posterior edge of the tear.
- If the deltoid is very thick, it is possible to create an anteromedial impingement at the tip of the coracoid process when suturing the anterior edge of the flap to the subscapularis, and care should always be taken to avoid this pitfall.
With regard to the mechanical role of the flap, it has not always been possible to achieve in practice the ideal theoretical result of a continuous muscle unit that provides a dynamic head depressor: Some flaps do effectively take over the head depressing function of the cuff, and will restore the humeral head to its correct position (when the MRI image will show a continuous structure, with no fatty degeneration of the rotator cuff) (Figs. 6, 7 and 8); however, all too often the flap acts merely as a well-vascularised living spacer between the head and the acromial arch, rather than actively depressing the head. At several reoperations following flap repairs, we have found that the muscle may split into a superficial plane, reinserting itself on the underside of the acromion, and a deep plane reconstituting the cuff; in some of the failures, the latter was found to be torn.
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| Fig. 5 : Postoperative exercise physiotherapy | Fig. 6 : Check MRI scan of a deltoid flap at 8 years (coronal view) |
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| Fig. 7 : Check MRI scan of a deltoid flap at 2 years. Suture zone in horizontal section. | Fig. 8 : Check arthrography after flap repair |
Between September 1984 and December 1995, 248 deltoid flap repairs were performed in our department; the patients were reviewed by Dr Chilot, Dr Dumontier, and Dr Sautet. Since 1990, we have been performing between 25 and 30 flap repairs a year; this relative decrease has resulted from better education of the referring doctors, who now send us their patients earlier; from the development of alternative techniques (such as arthroscopic procedures in some indications); and from a greater awareness of the limitations of the technique.
The mean age of the female patients was 55 ± 9 years (range 32-73 years), while the mean age of the male patients was 56 ± 8 years (range 38-74 years).
In 30% of these cases, the main part of the tear was situated in the supraspinatus. Slightly more than 50% of patients presented a tear of both the supraspinatus and infraspinatus, with the tendons retracted to the glenoid. The remaining patients had more extensive tears. The biceps tendon was sound in 44% of patients, inflamed in 25%, displaced in 6%, and absent or torn in 24%.
The preoperative Constant score without measurement of power was 25 ± 13 out of a possible maximum score of 75. In 95% of patients, the operated shoulder was on the dominant side. Scores were similar irrespective of whether the right or the left shoulder had been operated on.
Mean hospital stay was 18 days (range 3-54 days). The following complications were observed: haematoma (5%), infection (6%), reflex sympathetic dystrophy (9%), and compression of the ulnar nerve at the elbow (5%).
The functional result obtained took one year to stabilise (Diagram 1). After this time there was no further change in global function as measured by the Constant score, although imaging might show some thinning of the flap. At a mean follow-up of 3 years (range 1-11 years), the Constant score was found to have risen to 53.2/75 points.
Patients were satisfied with the absence of pain (score rising from 4.2 to 10.8 on the Constant scale) and by the improvement in function. Abduction improved from 90° preoperatively to 135° at the final visit (Diagram 2). Power, which was not measured routinely before surgery, remained poor, with a mean value of 3 kg at the longest follow-up (6.6/25 points).
In our series, tear size appeared to make no difference to the result, either in the short term or the long term; however, there were very few patients with either small or very large tears (Diagram 3).
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| 3 mos 6 mos 1 Yr 2 Yrs Max Diagram 1 : Change in Constant score over time |
Pain x 10 Abd Pre-op 3 mos 6 mos 1 Yr 2 Yrs Max Diagram 2 : Change in pain over time (x10) and active abduction |
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1 tendon 2 tendons 3 tendons 6 mos 1 Yr 2 Yrs Max Diagram 3 : Change in Constant score as a function of the number of tendons torn |
Healthy Inflamed Damaged 6 mos 1 Yr 2 Yrs Max Diagram 4 : Change in Constant score over time as a function of the condition of the biceps tendon |
Biceps tendon pathology carried a poor prognosis, affecting mobility and the global Constant score. In the group of patients who had two tendon tears, patients with a dislocated or torn biceps tendon had a poor initial result, which did not change (Diagram 4). At the longest follow-up, forward flexion and abduction were 150° when the biceps tendon was healthy or inflamed, but only 100° when it was torn.
Thirty-six per cent. of the patients suffered a secondary flap tear (anterior tear in 10%, posterior tear in 5%, and complete tear in 20% of cases). Revision surgery was required in 13% of patients.
In conclusion, the deltoid flap repair improves shoulder function and regularly gives patients freedom from pain and good mobility, even in large tears. The improvement is durable, but the functional improvement obtained is rarely sufficient to allow patients to resume work requiring strength and endurance.
Indications and limitations
The indication for the deltoid flap repair is a large tear of the rotator cuff involving the supraspinatus and infraspinatus; it may also occasionally be used as a patch flap in smaller tears.
It should, however, be borne in mind that good results cannot be achieved without careful patient selection.
- A history of damage to the axillary nerve, even where there has been a clinical recovery. Preoperative deltoid electromyography is essential if there is any doubt at all on this point.- Severe wasting of the deltoid, either after prolonged corticosteroid therapy, or from long-standing disuse; in this condition, ultrasonography or MRI will show that the muscle is less than 4 mm thick, and there would be no prospect of effecting a sound deltoid flap repair.
- Long-standing subluxation of the humeral head. It will be possible to achieve a good position for the humeral head only if it is possible to reposition the head while the arm is passively abducted (a radiograph is essential), confirming that there is no inferior capsulitis, in which a flap would not work (Fig. 9).
- Complete tears of the rotator cuff involving not only the supraspinatus and infraspinatus, but also the upper half of the subscapularis anteriorly and the teres minor posteriorly, when the biceps is absent.
Although it is technically possible to create a flap in most of these cases, there would be many failures as the flap would be stretched too tightly over the top of the humeral head, and the sutures would be of very poor quality.
- Stage I arthritis resulting from subluxation of the humeral head, when the flap should be combined with an unconstrained arthroplasty (Fig. 10).
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| Fig. 9 : Restoration of humeral head position by a dynamic flap : Pre- and post-operative views of acromiohumeral distance in abduction against resistance (Leclercq test). | Fig. 10 : Stage I glenohumeral arthritis with displaced head: flap repair not appropriate. |
- A tear of the tendons of the supraspinatus and infraspinatus, where both the anterior and posterior dynamic restraints of the cuff are preserved -
1. anteriorly, the subscapularis, which should not present any lesions extending over more than the superior quarter of the tendon (common in the event of gaping of the rotator interval).2. posteriorly, the teres minor, which should be intact, or better still, stabilised by a strip of infraspinatus, so that it does not become displaced behind the head below the centre of rotation of the shoulder.
- A biceps tendon which can be preserved: This structure is very effective in protecting the flap from any tendency for the head to migrate upwards and forwards.
- A supple shoulder, with a humeral head that can be recentred in passive abduction (Fig.11).
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| Fig. 11 : Recentring of the humeral head in passive abduction. |
- Anteriorly, a tear involving the entire superior half of the subscapularis and the supraspinatus can be treated by a flap, provided that the infraspinatus is intact. When the flap is swung into place, it only has to be brought further forwards; in contrast, if there is a complete tear of the subscapularis, the flap repair has to be combined with a transposition of the clavicular head of the pectoralis major.- Posteriorly, the same applies: It is possible to treat a tear involving both the teres minor and the infraspinatus, provided that at least the anterior two-thirds of the supraspinatus is intact; in this case, the flap is positioned more posteriorly.
- Mini-flaps or partial flaps.
Mini-flaps can be used to cover a biceps tendon which has been exposed by a small tear of the supraspinatus, and they contribute to the blood supply to the cuff repair. They make it possible to avoid restricting the joint capacity by direct suturing or a reinsertion of the infraspinatus, and they preserve maximum mobility, particularly in the form of rotation.
Thus, if after debridement of the edges, the biceps tendon is exposed by a small tear of the supraspinatus (20 to 30 mm wide, with the humeral head in its correct position) we would not routinely resect the tendon. Instead, we would excise the edges of the tear, and cover the tendon with a patch flap, which provides both blood supply and substance.
- A combination of a deltoid flap and an unconstrained prosthesis.
This type of procedure is intended for Stage I cuff-tear arthropathy, and to arthritis without humeral head displacement but with a cuff tear, where direct reconstruction is impossible.
In arthritis where the humeral head is still in the correct position, the results are usually similar to those for prostheses with a dynamic cuff (Fig. 12).
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| Fig. 12 : Stage 0 glenohumeral arthritis with displaced head: possible indication for flap repair. |
In Stage I cuff-tear arthropathy, the correct indication is the same as for a flap, i.e. a small tear of the supraspinatus and infraspinatus only, with a sound subscapularis in front (+++) and a usable teres minor behind. If the tear is more extensive, it is better to do a bipolar arthroplasty with subacromial centring.