Background
After severe brachial palsy involving the shoulder, secondary operations are sometimes
required to restore function. These include shoulder artrhodesis, rotational osteotomy,
muscle transfer or a combination of these techniques.
For paralysis of the deltoid and supraspinatus muscle many different muscle transfers
have been advocated to restore movement and stability of the shoulder. These include
transfer of the trapezius, pectoralis major and teres major, latissimus dorsi, and
combined biceps and triceps.
In a classic monograph; Saha [[1]] gave details of his experience with transfer of the trapezius, using a modification
of the technique originally described by Bateman [[2]]. However, the absence of clear indications for the operation and expecting too
much for this transfer alone has led to its infrequent use.
We have evaluated the results of the trapezius transfer for flail shoulder after brachial
plexus injury.
Methods
We treated 10 patients, 8 males and 2 females, by transfer of the trapezius to the
proximal humerus. In 6 patients the C5 and C6 roots had been injured; in one C5, C6
and C7 roots; and in 3 there were complete brachial plexus injuries. Eight of the
10 had had neurosurgical repairs before muscle transfer.
Their average age was 28.3 years (range 17 to 41), and the average follow-up was 17.5
months (range 6 to 52). The mean delay between injury and transfer was 3.1 years (range
14 months to 6.3 years).
All patients had elbow flexion (2 had had previous Steindler flexorplasties) and 6
patients had good ipsilateral hand function.
Evaluation included physical and radiographic examinations. The active abduction/flexion
shoulder motion was recorded (power between 3 to 5 grades according to MRC scale).
Shoulder abduction was measured as the angle between the trunk and the arm. The pre-operative
average was 3.1° (range 0° to 30°). The average shoulder forward flexion was 4.5°
(range 0° to 45°). In all patients, the deltoid, supraspinatus, teres minor, infraspinatus
and subscapularis were paralysed and the trapezius, levator scapulae were preserved.
The rhomboids were affected in 2 patients. Paralysis of deltoid and supraspinatus
was confirmed by EMG. All patients were unemployed at the time of trapezius transfer.
Radiological subluxation of the shoulder was present in all cases. The subjective
assessment of the patients was not considered.
Surgery can be considered if the patient presents flail shoulder at more than one
year after the accident without spontaneous recovery or when it is clear that recovery
following neurosurgical repair is not progressing any more. A simple trapezius transfer
is compatible with the later return of some function to other shoulder girdle muscles.
Passive shoulder abduction of 80° is an important pre-requisite before transfer. The
only contra-indication is advanced degeneration of the shoulder.
A modification of Mayer’s [[3]] transfer of the trapezius muscle was performed in which a portion of the acromion
is removed to allow for a more straight-line pull. The lateral aspect of the acromion
and its attached trapezius is removed, and its undersurface is roughened with a rasp.
Fixation with one or two screws secures the acromion and trapezius transfer to the
proximal part of the humeral shaft.
The principal goal of this work was to evaluate the results of the trapezius transfer
for flail shoulder after brachial plexus injury.
Surgical technique
The patient is placed supine with a sand-bag under the shoulder. The shoulder, the
neck, and the whole arm are prepared and free.
A saber-cut incision is made from the inferior border of the anterior axillary fold
over the anterior aspect of the shoulder to a point a few centimetres lateral to the
medial border of the scapula and just distal to the scapular spine. The deltoid origin
is then cut from the lateral third of the clavicle, the acromion, and the lateral
half of the spine of the scapula.
A Gigli wire saw is used to transect the root of the acromion, and then the lateral
clavicle, so as to separate the lateral 1 cm of the clavicle with the acromion. The
remaining insertions of the trapezius are elevated from the clavicle and the scapular
spine to 2 cm from the vertebral border of the scapula. Careful dissection is needed
to define the interval between the trapezius and the supraspinatus. Special attention
is needed to preserve the neurovascular bundle of the spinal accessory nerve and transverse
cervical artery, which courses from deep to superficial through the trapezius.
The partly detached deltoid is split longitudinally to expose the proximal humerus,
which is scored with an osteotome. The arm is then abducted to 90°, and the acromiocalvicular
fragment with its trapezius insertion is fixed to the humerus with two screws, ensuring
firm bone-to-bone. The wound is thoroughly irrigated with saline solution, and the
deltoid is sutured on top of the new trapezius insertion. The skin is closed in two
layers over suction drains a shoulder spica applied with the shoulder in 90° of abduction.
Postoperative management. Drains are removed on the second or third day. The spica
is worn for six weeks or until union is seen between the acromion fragment and the
humerus. The arm is then allowed to adduct progressively and a vigorous physical therapy
programme is started. As strength improves, more resisted muscle strengthening exercises
are added.
Results
The transfer improved function of the shoulder ([Figure 1]). Postoperatively, the average gain in shoulder abduction was 46.2° (p < 0.001,
Fisher exact test); the gain in shoulder flexion average 37.4° (p < 0.001). All patients
had stable shoulders (no subluxation of the humeral head on radiographs, [Figure 2]).
Figure 1
A 18-year-old man 16 months after trapezius transfer on the left side, showing 90°
of abduction.
Figure 2
The radiograph shows that there is not downward subluxation of the humeral head.
Surgical time averaged 2 hours (range 1 to 4), and the estimated mean blood loss was
200 ml. There were no postoperative complications.
Discussion
Severe injuries to the brachial plexus cannot always be successfully repaired; even
failures are seen after the best repair. Unsatisfactory or incomplete results affect
abduction, external rotation and forward projection of the humerus at shoulder level.
Flail shoulder secondary to a brachial plexus injury is difficult to treat. After
neurosurgical treatment and adequate physiotherapy, reconstructive surgery may be
needed to improve the stability and function of the shoulder.
Deltoid and supraspinatus paralysis may be managed by shoulder fusion [[4],[5],[6]] or muscle transfer [[7]]. Shoulder arthordesis has been considered the procedure of choice in patients with
flail shoulder after brachial plexus palsy, but is irreversible and has a high complication
rate. Cofield and Briggs [[8]] pointed out the disadvantages of arthrodesis (24% incidence of fractures, 25% had
no improvement and 15% had aggravation of pain).
Trapezius, levator scapulae and rhomboid muscles remain healthy or recover in 96%
of cases, therefore are available for transposition.
Several muscle transfers have been advocated to restore movement and stability of
the shoulder after poliomyelitis [[7],[9],[10]], and, more recently, the use of these procedures after brachial plexus palsy has
been reported. [[11],[12],[13],[14]]
Aziz, Singer and Wolff [[12]] discuss trapezius transfer for flail shoulder after brachial plexus palsy, finding
it a simple procedure with minimal blood loss, which provided functional improvement.
Passive shoulder abduction of 80° is an important pre-requisite, and requires intensive
physiotherapy before transfer. If 80° is not obtained, shoulder arthrodesis is recommended
[[13]].
Trapezius transfer to treat flail shoulder after a brachial plexus injury will allow
the patient to position the arm much better, even when functional recovery is not
adequately strong to keep the shoulder stable. The procedure is relatively simple
with minimal blood loss and the only contraindication is advanced degeneration of
the shoulder. Trapezius transfer can be used combined with other transfers to achieve
optimal use of the upper limb.
Conclusion
Trapezius transfer can provide satisfactory functional improvement and it is better
than arthrodesis for paralysis of the shoulder after brachial plexus injury.
