Brachial Plexus Shoulder: Joint Reduction, Tendon Transfers, Humeral and Glenoid Osteotomies

Andrea S. Bauer

Tendon Transfer—Lengthening and Joint Reduction

Pectoralis major musculotendinous lengthening
Subscapularis partial lengthening or slide, open or arthroscopic
Latissimus dorsi (LD) and teres major (TM) tendon transfer
Open anterior-inferior capsulotomy and glenohumeral joint reduction
Posterior capsular reefing

Operative Indications

Internal rotation (IR) contracture unresponsive to aggressive therapy (Figure 10.1)
External rotation weakness despite sufficient neural recovery time
Subluxated or dislocated humeral with glenohumeral deformity on MRI scan (Figure 10.2)
Age range can be as young as 6 to 12 months when there is rare infantile dislocation
Operative age usually 18 months to 3 years in a dysplastic shoulder which is unresponsive to therapy
Surgery tailored to each patient in terms of releases, lengthenings, transfers, and joint reduction

Final Decision on Extent of Reconstruction Made During Operative Care

Examination Under Anesthesia

Before positioning in lateral decubitus, check passive range of motion

Adduction (ADD), external rotation (ER)

Usually <0° (normal >60°)

Figure 10-1 ▪ Child with an internal rotation contracture of the right shoulder. (Courtesy of Shriners Hospitals for Children, Northern California and Children’s Orthopaedic Surgery Foundation.)

Figure 10-2 ▪ Axial MRI image demonstrating a normal right glenohumeral joint and a dysplastic left glenohumeral joint. (Courtesy of Children’s Orthopaedic Surgery Foundation.)

Abduction (ABD), ER
- Usually <90° (normal >120°)
Scapulohumeral angle
- Usually <135° (normal >150°)
- Check for glenohumeral joint dislocation, instability, or reducibility
These measurements will be repeated throughout stepwise surgery to determine extent of releases, lengthenings, and joint reduction and stability with each step

Positioning

Lateral decubitus position with the affected side up
Care taken to protect all bony prominences and neurovascular structures including:
- Peroneal nerves (especially downside)
- Unaffected downside brachial plexus
- Cervical nerve roots with padded head position without tension
Entire affected arm, axillae, shoulder girdle including entire scapula prepped
Entire scapula must be visible in operative field to allow accurate assessment of scapulothoracic versus glenohumeral motion

Surgical Approach (

Video)

Techniques in Steps

Axillary Exposure and Pectoralis Major Lengthening (Figure 10.3A and B)

Transaxillary from edge of anterior pectoralis major to posterior extent axillary crease
- Incision carefully placed in axillary line for aesthetic result
- Can be modified to 2 incisions: small anterior and larger posterior incisions if joint reduction not required
Elevate skin and subcutaneous flaps protecting intercostobrachial nerve branches in midline of incision

Identify pectoralis major anterior edge and dissect underneath tendon to insertion site

Separate pectoralis major from underlying coracobrachialis, pectoralis minor, and short head of biceps inserting into coracoid
Protect musculocutaneous nerve deep

Figure 10-3 ▪ A, Illustration of the relevant anterior anatomy in a typical shoulder versus a dysplastic shoulder. B, Open subscapularis release with latissimus dorsi and teres major transfer. C, Arthroscopic subscapularis release. MGHL, middle glenohumeral ligament. (Courtesy of Children’s Orthopaedic Surgery Foundation.)

Identify and palpate tight, thickened tendon
Release sharply with knife or cautery only the tight, thickened tendon near insertion
- Preserve pectoralis major muscle
- Visualize slide of musculotendinous junction
- Reassess ABD-ER ROM, which improves beyond vertical as desired
- ADD-ER may improve but usually not
- Humeral head may now be reducible but usually not

Posterior Exposure and LD-TM Transfer

Dissect carefully in axillae to expose LD and TM muscle insertion
- Protect brachial plexus anterior to latissimus tendon
- Protect axillary nerve underneath tendons as it transverses quadrilateral space
D and TM tendons are more posterior than triceps tendon, but can be confused especially for the uninitiated surgeon not used to operative exposure of shoulder through axillae in sidelying position with arm elevated and abducted for exposure
- Triceps tendon heads to infraglenoid tubercle
- D and TM tendons head to humeral shaft and lie anterior to triceps
- IR positioning of humerus aids in exposure
Release LD and TM tendons from humeral insertion periosteum
- LD and TM often conjoint in young and often transferred together
- Takedown of insertion needs to be very close to periosteum
  - Protects underlying axillary nerve and circumflex vessels
  - Maintains sufficient tendon length for secure transfer insertion
Fully mobilize LD and TM tendons and muscles back to NV pedicle
- Carefully release adjacent fascia while protecting all vessels and nerves
- Place inverted nonabsorbable horizontal mattress sutures in tendons
- Maximize excursion of LD and TM for transfer including release of overlying skin and fascia
Retest passive range of motion (ROM) for ABD-ER and ADD-ER as well as joint stability
- If ABD-ER >110° (20° beyond vertical) and ADD-ER >40° with light 2-finger testing; and glenohumeral joint reduced and stable
  - Extra-articular tendon transfer sufficient and proceed to tendon transfer beneath deltoid into greater tuberosity region
- If ADD-ER <20° and joint is not reduced and stable
  - Proceed to joint capsulotomy, reduction, and subscapularis partial lengthening

Subscapularis Partial Lengthening and Joint Capsulotomy and Reduction

Very, very important NOT to overlengthen subscapularis or overrelease joint

This leads to external rotation posture and loss of IR power
This will become very problematic later if the child cannot reach midline with strength to do buttons, zippers, and other important self-care activities

Subscapularis Mobilization and Lengthening

After release and mobilization of LD and TM, carefully dissect down to subscapularis and glenohumeral joint while protecting brachial plexus
Subscapularis insertion into lesser tuberosity of humerus traversing across anterior and inferior glenohumeral joint can be carefully identified
Elevate subscapularis of glenohumeral joint capsule
- This interval is hard to distinguish
- Requires use of elevator into interval without entering capsule
Subscapularis mobilization including musculotendinous junction
- This can improve ADD-ER > 40° with a reduced and stable joint and if so,
- We can progress to LD-TM tendon transfer insertion
If subscapularis mobilization is not sufficient to improve passive ROM, proceed to partial subscapularis musculotendinous lengthening and capsulotomy to reduce humeral head centered on dysplastic glenoid
- Again do not overrelease subscapularis

Anterior-Inferior Glenohumeral Joint Release and Reduction

If ADD-ER contracture persists with dislocated humeral head
Elevate subscapularis mobilization off capsule
Start sequential capsular release while testing reduction and motion
- Be careful not to injure labrum or articular cartilage
Again be careful not to overrelease anterior-inferior capsule that results in ER posture and IR weakness
Once 2-finger testing of ADD-ER exceeds 60° and joint is reduced, progress to tendon transfer insertion