**9. Soft-tissue surgeries**

Children with residual brachial plexus birth palsy frequently end up with incomplete spontaneous recovery of shoulder abduction and external rotation strength. It leads to the development of contracture of shoulder internal rotators. Progressive reduction in passive shoulder external rotation with the arm adducted is the key examination point. Studies show that the reduction of passive external rotation below neutral is associated with glenoid retroversion and humeral head posterior subluxation. Further increase in internal rotation contracture leads to flattening of humeral head and formation of biconvex glenoid, which is termed as 'false glenoid'. The aim of shoulder balancing treatment is to prevent this structural change in glenohumeral joint. Soft-tissue release to correct internal rotation contracture and tendon transfer surgeries to balance shoulder joint are possible when glenohumeral joint is congruent (Waters I–III). Once it turns non-congruent (Waters IV and V), bony procedures are offered to redirect the extremity in functional position.

#### **9.1. Role of Botulinum toxin-A (BTX-A)**

Injection of BTX-A in shoulder internal rotators temporarily denervates them while the neuronal recovery is evolving in shoulder abductors and external rotators. It is postulated that the temporary relaxation of internal rotators will help in keeping the subluxating humeral head reduced with adjunctive treatments like physiotherapy and splinting [56]. Botulinum toxin injection has also been used to treat biceps-triceps co-contraction in children with recovered palsy. Authors reported successful treatment in six patients for 18 months, where they required to inject triceps muscle twice or thrice [16, 20, 57].

#### **9.2. Role of soft-tissue release**

AMS ≥ 5. Single-fascicle transfer resulted in elbow flexion of AMS ≥ 6 and supination of AMS

To restore elbow extension, one possible solution is to reinnervate motor branches of radial nerve to the triceps muscle. Depending on the severity and extent of brachial plexus lesion, the radial nerve can be neurotized by means of intercostal nerves when the palsy involves the whole brachial plexus (thus, inferior roots are damaged), while in upper two or three radicular palsy, the use of fascicles of the ulnar nerve (modified Oberlin's procedure) is advisable [53].

One or two branches to the pectoralis major can be taken for the transfer so that some pectoralis major supply can be preserved and a direct repair without intervening graft can be performed to the MCN [54] or nerve to biceps [55], in the distal axilla. Intercostal nerves are an extraplexus source. They can be cut 1 cm distal to the mammary line and their stumps can

Children with residual brachial plexus birth palsy frequently end up with incomplete spontaneous recovery of shoulder abduction and external rotation strength. It leads to the development of contracture of shoulder internal rotators. Progressive reduction in passive shoulder external rotation with the arm adducted is the key examination point. Studies show that the reduction of passive external rotation below neutral is associated with glenoid retroversion and humeral head posterior subluxation. Further increase in internal rotation contracture leads to flattening of humeral head and formation of biconvex glenoid, which is termed as 'false glenoid'. The aim of shoulder balancing treatment is to prevent this structural change in glenohumeral joint. Soft-tissue release to correct internal rotation contracture and tendon transfer surgeries to balance shoulder joint are possible when glenohumeral joint is congruent (Waters I–III). Once it turns non-congruent (Waters IV and V), bony procedures are offered to

Injection of BTX-A in shoulder internal rotators temporarily denervates them while the neuronal recovery is evolving in shoulder abductors and external rotators. It is postulated that the temporary relaxation of internal rotators will help in keeping the subluxating humeral head reduced with adjunctive treatments like physiotherapy and splinting [56]. Botulinum toxin injection has also been used to treat biceps-triceps co-contraction in children with recovered palsy. Authors reported successful treatment in six patients for 18 months, where they

grades 2–5. Thus, the combined transfer achieved better function.

*8.2.6. Nerve transfer for elbow extension*

be coapted directly to the MCN in the axilla.

redirect the extremity in functional position.

required to inject triceps muscle twice or thrice [16, 20, 57].

**9.1. Role of Botulinum toxin-A (BTX-A)**

*8.2.7. Extraplexus transfer*

90 Treatment of Brachial Plexus Injuries

**9. Soft-tissue surgeries**

Subscapularis is considered as the main element responsible for shoulder internal rotation contracture. Different methods of subscapularis lengthening are described in various studies with their positive and negative aspects. Gilbert reported that isolated subscapularis lengthening was enough to balance the shoulder joint in about 50% patients in their study [21, 58]. Thus, he recommended performing tendon transfer surgery in the second stage if required.

#### *9.2.1. Open subscapularis slide from the lateral border of scapula*

Subscapularis slide was introduced by Caroliz and Brahimi [58]. It involves an incision along the lateral border of scapula, approaching scapular ridge through the interval between Teres major and Teres minor. Recurrence rate was 50–70% when it was done in isolation [21, 22, 58–60]. Grossman et al. reported no recurrence when it was coupled with tendon transfer surgery [23]. Reports of ischemic necrosis of subscapularis after lateral slide pose question of safety of artery to subscapularis owing to its vicinity to the entry point for release [24, 61].

#### *9.2.2. Minimally invasive subscapularis release*

Since 2013, we have started performing subscapularis slide from the medial border of scapula through a centimeter incision placed at the junction of the upper one-third and lower twothirds. The arm is internally rotated and the shoulder is pressed backward to make the medial border of scapula prominent (**Figure 1**). Artery forceps are advanced to make a plane between rhomboids (**Figure 2**). A small periosteal elevator is introduced in the submuscular and extra periosteal space, and subscapularis slide is done in a clockwise fashion (**Figure 3**). A larger periosteal elevator is then introduced to release stronger muscle attachments at supero-medial and inferior angle of scapula. The arm is externally rotated to achieve 90° external rotation (**Figure 4**). Conventional conjoined tendon transfer surgery was performed after minimally invasive subscapularis release (MISR). Thirty-five patients with congruent glenohumeral joint constructed the study group and were followed up for a minimum of 18 months. Improvements

**Figure 1.** The arm is internally rotated to make the medial border of scapula prominent.

in Modified Mallet scores and axial MRI parameters were comparable to the open subscapularis lengthening from insertion and arthroscopic release of subscapularis. MISR was found to have the advantage of minimal learning curve, no need of arthroscopic setup, lengthening of

Current Concept in the Management of Brachial Plexus Birth Palsy

http://dx.doi.org/10.5772/intechopen.76109

93

Partial lengthening or z-plasty of subscapularis through anterior incision has been described. Van der Juis reported that excessive release of muscle from insertion leads to external rotation contracture and anterior shoulder instability. A subset of patients in their series required

Pearl et al. reported results of arthroscopic soft-tissue release with the help of a 2.7-mm arthroscope [64]. Children younger than 4 years received the release of tendinous part of subscapularis and capsulo-ligamentous structures, while the older children also had lattissimus dorsi transfer. Four of the 19 patients who received only soft-tissue release required tendon transfer surgery later. Three out of these four children had pseudoglenoid on preoperative imaging. The major issue related to arthroscopic release was the loss of internal rotation range [27].

L'Episcopo primarily reported muscle transfers for residual brachial plexus palsy patients in 1934 [28]. It was sub-sequentially altered by Hoffer [65]. Latissimus dorsi and teres major transfer to rotator cuff along with the release of pectoralis major has demonstrated enhanced

Waters et al. reported halting of glenohumeral deformity from progression after these transfers with extraarticular soft-tissue release [67]. Greenhill et al. compared a combined conjoined tendon transfer to isolated Teres major transfer. They found similar improvements in external rotation in both transfers but the incidence of limited midline function was found more in combined transfers. They recommended isolated Teres major transfer where preop-

Cheung et al. proposed the theory of co-contraction between agonist and antagonist muscles while they are recovering, leading to the restriction of particular movement across the shoulder joint. They advocated lateral trans-positioning of clavicular part of pectoralis major along with Teres major transfer to infraspinatus. The authors reported the average gain in abduction of 77° in their cohort [69, 70]. Improvement in abduction has been reported in patients where conjoined teres major and lattissimus dorsi tendons were transferred to infraspinatus without

active external rotation of 45° and abduction of 64° at 2–8 years of follow-up [66].

the muscle without weakening it and the safety of the procedure [25, 62].

*9.2.3. Subscapularis lengthening from insertion*

secondary internal rotation osteotomy [26, 63].

*9.2.4. Arthroscopic subscapularis and soft-tissue release*

**9.3. Tendon transfer surgery to improve external rotation**

erative midline function was in question [68].

pectoralis major trans-positioning [31].

**9.4. Tendon transfer surgery to improve shoulder abduction**

**Figure 2.** Rhomboids and trapezius are bluntly dissected with artery forceps.

**Figure 3.** Periosteal elevator is inserted through the wound.

**Figure 4.** Shoulder is externally rotated to 90°.

in Modified Mallet scores and axial MRI parameters were comparable to the open subscapularis lengthening from insertion and arthroscopic release of subscapularis. MISR was found to have the advantage of minimal learning curve, no need of arthroscopic setup, lengthening of the muscle without weakening it and the safety of the procedure [25, 62].

#### *9.2.3. Subscapularis lengthening from insertion*

**Figure 2.** Rhomboids and trapezius are bluntly dissected with artery forceps.

92 Treatment of Brachial Plexus Injuries

**Figure 3.** Periosteal elevator is inserted through the wound.

**Figure 4.** Shoulder is externally rotated to 90°.

Partial lengthening or z-plasty of subscapularis through anterior incision has been described. Van der Juis reported that excessive release of muscle from insertion leads to external rotation contracture and anterior shoulder instability. A subset of patients in their series required secondary internal rotation osteotomy [26, 63].

#### *9.2.4. Arthroscopic subscapularis and soft-tissue release*

Pearl et al. reported results of arthroscopic soft-tissue release with the help of a 2.7-mm arthroscope [64]. Children younger than 4 years received the release of tendinous part of subscapularis and capsulo-ligamentous structures, while the older children also had lattissimus dorsi transfer. Four of the 19 patients who received only soft-tissue release required tendon transfer surgery later. Three out of these four children had pseudoglenoid on preoperative imaging. The major issue related to arthroscopic release was the loss of internal rotation range [27].

#### **9.3. Tendon transfer surgery to improve external rotation**

L'Episcopo primarily reported muscle transfers for residual brachial plexus palsy patients in 1934 [28]. It was sub-sequentially altered by Hoffer [65]. Latissimus dorsi and teres major transfer to rotator cuff along with the release of pectoralis major has demonstrated enhanced active external rotation of 45° and abduction of 64° at 2–8 years of follow-up [66].

Waters et al. reported halting of glenohumeral deformity from progression after these transfers with extraarticular soft-tissue release [67]. Greenhill et al. compared a combined conjoined tendon transfer to isolated Teres major transfer. They found similar improvements in external rotation in both transfers but the incidence of limited midline function was found more in combined transfers. They recommended isolated Teres major transfer where preoperative midline function was in question [68].

#### **9.4. Tendon transfer surgery to improve shoulder abduction**

Cheung et al. proposed the theory of co-contraction between agonist and antagonist muscles while they are recovering, leading to the restriction of particular movement across the shoulder joint. They advocated lateral trans-positioning of clavicular part of pectoralis major along with Teres major transfer to infraspinatus. The authors reported the average gain in abduction of 77° in their cohort [69, 70]. Improvement in abduction has been reported in patients where conjoined teres major and lattissimus dorsi tendons were transferred to infraspinatus without pectoralis major trans-positioning [31].
