DEFINITION

Refractory disorders of the scapulothoracic articulation have been reported to result in debilitating pain and dysfunction that may require surgical management.

The most common clinical presentation, scapular winging, was first reported in the published literature in 1723, and several etiologies for scapular winging have been documented since then.14

Soft tissue operations (eg, pectoralis major tendon transfer) have had reported success in stabilizing the dyskinetic scapula in appropriate patients.

Despite successful clinical outcomes, a population of patients experience recurrent symptomatic scapular winging even after pectoralis major transfer.6,10,14

Several authors report that arthrodesis is the treatment of choice for these failed muscle transfers.5,7,10,14 For failed pectoralis transfer or significant (ie, irreducible) fixed winging, scapulothoracic arthrodesis can be a successful salvage operation for these patients.13

 

 

ANATOMY

 

The scapula is positioned over the posterolateral aspect of the rib cage, overlying ribs one to seven. It is suspended from the sternum by the clavicle anteriorly and plays an important role in positioning the upper extremity for proper function.

 

The lateral scapula includes the glenoid fossa for articulation with the humeral head.

 

The scapula provides an attachment for 16 muscles, which help maintain it in functional positions. It articulates on the thoracic cavity, allowing for elevation/depression, protraction/retraction, medial/lateral rotation, and anterior/posterior tilting.

 

A thin bursal layer separates the scapula from the underlying ribs.

 

PATHOGENESIS

 

 

Dysfunction of the scapulothoracic articulation has been well documented in the peer-reviewed literature. The most common manifestation of scapulothoracic dysfunction is symptomatic scapular winging7,14 (FIG 1).

 

Traumatic injuries to the serratus anterior muscle or the long thoracic nerve have been reported to cause symptomatic winging.7,8,11,14,19,20

 

Atraumatic etiologies, such as neuralgic amyotrophy, polio, and the muscular dystrophies, also may produce disabling scapular winging.1,2,4,5,8,10,15,16

 

Intolerable winging also has been demonstrated in association with other bony abnormalities (eg, rib or scapular osteochondromas and malunited scapular fractures) or soft tissue lesions (eg, scapular-stabilizing muscle contractures, muscle avulsions, and scapulothoracic bursitis).3,11,14

 

Recent authors have reported a significant incidence of scapular winging secondary to glenohumeral joint lesions such as rotator cuff tears and glenohumeral instability (especially posterior and multidirectional

instability).18

 

The scapulothoracic articulation also is a potential source of debilitating pain in the shoulder girdle.

 

 

Several authors have documented the incidence of painful scapulothoracic crepitus (“snapping scapula” syndrome) and scapulothoracic bursitis.9,12,17,18

 

Painful crepitus can be due to interposed muscle, fibrous and granulomatous lesions, or bony incongruity associated with osteochondromata, fractures, scoliosis, or kyphosis.12

NATURAL HISTORY

 

Most patients who present with symptomatic scapular winging, scapulothoracic pain, or crepitus respond to nonoperative measures.

 

A subset of this patient population, however, experiences complex scapulothoracic dysfunction or pain refractory to conservative measures.

 

PATIENT HISTORY AND PHYSICAL FINDINGS

 

Patients presenting with scapulothoracic disorders typically complain of debilitating pain, shoulder dysfunction, or scapulothoracic crepitus.

 

Physical findings commonly include scapular winging, crepitus, alterations in normal scapulohumeral rhythm, or neurologic deficits.

 

Physical examination should focus on the resting posture of the scapula as well as its dynamic position.

 

 

Both scapulae should be observed and palpated while the arms are elevated or while the patient performs a wall push-up. These dynamic tests may make subtle winging more obvious.

 

 

 

FIG 1 • A. Moderate dynamic scapular winging demonstrated with slow forward elevation of the arms in the frontal plane. B. The same patient demonstrating marked medial winging with the resisted elevation at 30 degrees.

 

 

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The pattern of winging distinguishes between serratus anterior dysfunction (long thoracic nerve) or trapezius palsy (spinal accessory nerve).

 

The more common medial winging is consistent with serratus anterior dysfunction, whereas lateral winging is observed in trapezius palsy.

 

Further assessment includes the scapula stabilization test, which is critical in order to assess for fixed or reducible/correctable winging. It demonstrates the amount of discomfort the patient has and indicates the extent to which reduction of the scapula will relieve that discomfort.

 

Painful crepitus localized to the scapulothoracic region is verified by diagnostic injection in which 1% lidocaine is injected beneath the medial border of the scapula into the scapulothoracic bursa. Improvement in pain may be noted in the examination room, further supporting the diagnosis.

 

IMAGING AND OTHER DIAGNOSTIC STUDIES

 

Standard plain radiographs of the shoulder, including anteroposterior views in internal and external rotation, axillary lateral views, and scapular Y views are obtained to evaluate the status of the clavicle, acromioclavicular joint, glenohumeral joint, and bony contour of the scapula.

 

Computed tomography (CT) scans, including axial images and reformatted coronal and sagittal images, provide further detail and may be required to assess scapular morphology and for the presence of exostoses or bony deformity.

 

Electromyography and nerve conduction velocity are important to verify neurologic dysfunction of the long thoracic or spinal accessory nerves.

 

DIFFERENTIAL DIAGNOSIS

 

Long thoracic nerve palsy Spinal accessory nerve palsy

Glenohumeral joint derangement with secondary scapular winging Scapulothoracic bursitis

Snapping scapula

Scapular exostosis or osteochondroma

 

 

NONOPERATIVE MANAGEMENT

 

Nonoperative treatment is the cornerstone of management of scapulothoracic dysfunction.

 

Therapeutic modalities involve supervised scapular-stabilizer and glenohumeral stretching and strengthening, the judicious use of oral anti-inflammatory medications, and selective cortisone injections.

 

SURGICAL MANAGEMENT

 

 

Patients who have failed an extensive nonoperative course are candidates for surgical treatment. Surgical options for scapulothoracic dysfunction include the following:

 

 

Arthroscopic or open decompression and bursectomy or medial border scapulectomy for painful crepitus Split pectoralis major tendon transfer for dynamic winging

 

Scapulothoracic arthrodesis

 

Surgical indications for scapulothoracic arthrodesis include the following clinical situations:

 

 

For patients with a history of failed resection of the superomedial border of the scapula with continued disabling pain associated with crepitus

 

For patients with disabling pain associated with fixed scapular winging or failed pectoralis transfer, indications for fusion include the following:

 

 

Significant winging

 

Difficulty in reducing the scapula with the “scapular stabilization test”

 

Significant pain relief (>75%) that substantially improved function during a scapular stabilization test

 

Preoperative Planning

 

Preoperative anesthesia consultation is recommended. We use general anesthesia with a double-lumen endotracheal tube to allow for selective deflation of the ipsilateral lung during wire passage.

 

Positioning

 

 

Patients are placed in the prone position. Care is taken to pad all bony prominences.

 

The entire involved arm, scapula, and ipsilateral posterior iliac crest are prepped and draped to the midline of the spine (FIG 2).

 

 

It is essential that the entire arm be prepped and draped in the surgical field to allow for appropriate manipulation of the scapula and accurate placement of the scapula on the rib cage for fusion.

Approach

 

A direct approach to the scapulothoracic articulation along the medial border of the scapula is used. This approach allows excellent exposure of the underlying ribs and undersurface of the scapula. The superficial location of the scapula makes this approach relatively straightforward.

 

 

 

 

FIG 2 • Patient in the prone position. The surgical preparation must include the entire arm and the back, extending medially past the midline of the spine and inferiorly to include the posterior superior iliac crest.

 

 

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TECHNIQUES

• Exposure

The incision is placed along the medial border of the scapula from just superior to the scapular spine to the inferior angle.

 

 

The superficial fascia is incised, and the trapezius muscle is identified and retracted medially (TECH FIG 1A). The rhomboid muscles are incised off the medial edge of the scapula and are tagged for reattachment before closure (TECH FIG 1B).

 

 

 

TECH FIG 1 • A. Superficial dissection proceeds down to the trapezial fascia, and the trapezius is retracted medially. B. The rhomboids are released from the medial border of the scapula and tagged for later repair. C. A retractor is positioned on the medial border of the scapula, and the scapula is elevated, allowing for dissection of the scapulothoracic articulation and underlying ribs. D. Following dissection of one-third of the serratus anterior and subscapularis musculature, a wide fusion bed is visualized overlying the ribs.

 

 

With the rhomboid muscles elevated, a rake retractor can be placed on the anterior surface of the medial scapular border to retract the medial scapula away from the rib cage (TECH FIG 1C).

 

About one-third of the musculature of the serratus anterior and the subscapularis is resected from medial to lateral off the anterior surface of the scapula to allow for a wide fusion surface (TECH FIG 1D).

 

Care must be taken to avoid resecting the subscapularis beyond the midline of the scapula to prevent denervation.

• Bony Preparation

   

  The anterior surface of the scapula is now roughened slightly with a burr (TECH FIG 2A). Care must be taken during this maneuver to avoid thinning the medial border excessively because that could lead to fracture during hardware fixation.

   

  Next, the scapula is reduced to the rib cage in approximately 20 to 25 degrees of external rotation from the midline to maximize subsequent shoulder range of motion (most notably elevation and external rotation).

   

  If patients demonstrated concomitant multidirectional glenohumeral instability with a symptomatic inferior component, the scapula is rotated externally 35 to 40 degrees from the midline to use the inferior glenoid rim to buttress against inferior translation.

   

  The ribs corresponding to the decorticated anterior surface of the scapula are identified, and the scapula is again retracted to allow for rib preparation.

   

  Depending on the size and configuration of the scapula, three or four ribs typically will be used in the fusion (usually the third to sixth ribs).

   

   

  The periosteum is incised carefully in a longitudinal direction and stripped off each rib (TECH FIG 2B,C). The ribs are minimally roughened with a burr down to bleeding bone.

   

  It is essential to remove all areas of soft tissue between the scapula and rib cage to permit maximum bony contact between the anterior surface of the scapula and the ribs (TECH FIG 2D).

   

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  TECH FIG 2 • A. The anterior surface of the scapula is lightly decorticated with a motorized oval burr. B. The first rib has been prepared with the periosteum incised and stripped off of the rib, ready for light decortication. C. Rib preparation continues, exposing the bony surface of the ribs corresponding to the undersurface of the scapula. This typically involves three to four ribs. D. Appearance of the rib surface after light decortication to a bleeding bony surface. Note that in this case, three ribs were prepared for the fusion surface.

• Wire Passage and Placement of Semitubular Plate

   

  The involved lung is then deflated before cerclage wires are passed around the ribs to minimize trauma to the lung fields.

   

  Using rib and periosteal dissectors, cerclage wires with a minimum diameter of 1.5 mm are passed carefully around each of the exposed ribs at the level where the medial border of the scapula will be placed on the rib cage (TECH FIG 3A,B). We prefer the use of closed loop “Luque” or similar wires.

   

   

   

  TECH FIG 3 • A. The 1.5-mm cerclage wires are passed around the rib using rib and periosteal elevators. The lung is deflated by the anesthesia team before the wires are passed to minimize damage to the underlying pleura. B. Wires are passed around each of the ribs to be involved in the fusion construct. C. A one-third semitubular plate (typically with five or six holes) is positioned over the medial border of the scapula. D. Holes are drilled in the scapula, corresponding to the plate, with a 3-mm motorized burr. A skid retractor is placed beneath the scapula to protect the underlying thoracic cavity.

   

   

  After passage of the cerclage wires, a one-third semitubular plate (usually with five or six holes, depending on the size of the scapula) is lined up on the posterior aspect of the medial border of the scapula (the thickest part of the scapula; TECH FIG 3C).

   

   

  A 3-mm burr is used to make holes through the scapula corresponding to the holes in the semitubular plate (TECH FIG 3D).

   

• Reduction and Plate Fixation

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Cancellous bone is now harvested from the posterior iliac crest in routine fashion through a separate incision paralleling the path of the cluneal nerves.

 

If more bone graft is desired, either allograft cancellous chips or a synthetic bone graft substitute can be added.

 

The wires are now passed through the scapula and semitubular plate (TECH FIG 4A), and the bone graft is placed between the scapula and ribs.

 

 

 

TECH FIG 4 • A. The previously placed wires are then passed through the scapula and plate in the appropriate position. B. The scapula is reduced into the predetermined position overlying the ribs and held in place before wire tightening. C,D. The wires are tightened sequentially, applying uniform tension on the plate and compressing the scapula against the ribs. E. The final position of the scapula after fixation with the wires. Note the autologous bone graft seen along the medial border. F. Illustration of the final construct. G. The wires are then cut, and attention is turned to wound closure.

 

 

The scapula is reduced to the underlying ribs (TECH FIG 4B), and the wires are sequentially tightened with the scapula held in 20 to 25 degrees of external rotation from the midline (TECH FIG 4C,D).

 

The semitubular plate allows uniform stress distribution once the wires are tightened (TECH FIG 4E,F).

 

The wires are cut, and attention is turned to closure of the wound (TECH FIG 4G).

 

 

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Wound Closure and Chest Tube Placement

 

The lung is reinflated, and irrigation is used to assess for a pneumothorax, which may be present.

 

The rhomboids are then reattached to the medial aspect of the scapula (TECH FIG 5), and the subcutaneous tissue and skin are closed in the usual fashion.

A thoracostomy tube is inserted if necessary, both to treat any associated pneumothorax and to drain any reactive pleural effusion that may develop postoperatively.

 

TECH FIG 5 • The rhomboids are repaired securely to the medial border of the scapula. This provides adequate coverage of the hardware.

 

 

PEARLS AND PITFALLS
	Avoiding pulmonary ▪ Use double-lumen tube and deflate lung. complications ▪ Meticulous subperiosteal passage of rib cerclage wires Thoracostomy tube when necessary     Avoiding hardware ▪ Minimum size for wire is 1.50 mm. complications and ▪ Use posterior iliac crest autograft. nonunion ▪ Use cancellous autograft. Immobilize in gunslinger or similar brace     Avoiding neurologic ▪ Prevention of intercostal neuralgia by minimizing trauma to intercostal complications nerves is the best method to reduce neurologic complications.     Avoiding wound ▪ Infection is rare, but surgeons must maintain vigilance. complications

 

 

 

 

POSTOPERATIVE CARE

 

The patient is placed in a “gunslinger” brace, immobilizing the arm in neutral rotation (FIG 3), and a postoperative chest radiograph is obtained to document any hemothorax and/or pneumothorax.

 

 

 

 

FIG 3 • Gunslinger brace with the arm positioned in neutral rotation.

 

 

If a chest tube has been placed, it is removed 1 or 2 days postoperatively, depending on chest tube outputs and pulmonary status.

 

Patients are immobilized in the brace for 12 weeks.

 

Rehabilitation is commenced at 12 weeks with a gentle passive range-of-motion program that emphasizes forward elevation and external rotation.

 

Three weeks later, the patient is progressed to an active range-of-motion program.

 

A strengthening program involving resisted exercises is begun 6 weeks after the gunslinger brace is removed.

OUTCOMES

Despite the significant complication rate (nearly 50%) that accompanies scapulothoracic arthrodesis, this operation has been documented to provide improvements in both pain and functional disability.

A high level of patient satisfaction when patients are chosen appropriately and expert surgical technique is used can make this operation rewarding for both patient and surgeon.

 

In one series of 23 patients undergoing scapulothoracic fusion, mean American Shoulder and Elbow Surgeons (ASES)

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scores improved from 35.8 to 40.1. Postoperative pain scores decreased from mean 5.5 to 4.7. Mean patient satisfaction was 9.5 out of 10 for the surgical procedure, and 91% of patients reported that they would undergo the procedure again.13

 

 

COMPLICATIONS

Complications are not uncommon with this procedure and have been reported to be as high as 50% in some series.13

The most commonly cited complications associated with this procedure include the following: Pneumothorax

Hemothorax

Hardware complications, including wire breakage, nonunion, and pseudarthrosis Neurologic complications, including intercostal neuralgia

Wound complications, including infection or wound dehiscence

 

 

REFERENCES

1. Bunch WH, Siegel IM. Scapulothoracic arthrodesis in fascioscapulohumeral muscular dystrophy. Review of seventeen procedures with three to twenty-one-year follow-up. J Bone Joint Surg Am 1993;75(3):372-376.

    

    

2. Connor PM, Yamaguchi K, Manifold SG, et al. Split pectoralis major for serratus anterior palsy. Clin Orthop Relat Res 1997;341:134-142.

    

    

3. Cooley LH, Torg JS. “Pseudowinging” of the scapula secondary to subscapular osteochondroma. Clin Orthop Relat Res 1982;(162): 119-124.

    

    

4. Fery A. Results of treatment of anterior serratus paralysis. In: Post M, Morrey BF, Hawkins RJ, eds. Surgery of the Shoulder. Philadelphia: Mosby, 1990:325-329.

    

    

5. Foo CL, Swann M. Isolated paralysis of the serratus anterior. A report of 20 cases. J Bone Joint Surg Br 1983;65(5):552-556.

    

    

6. Freedman L, Munro RR. Abduction of the arm in the scapular plane: scapular and glenohumeral movements. J Bone Joint Surg Am 1966;48(8):1503-1510.

    

    

7. Gozna ER, Harris WR. Traumatic winging of the scapula. J Bone Joint Surg Am 1979;61(8):1230-1233.

    

    

8. Gregg JR, LaBosky D, Harty M, et al. Serratus anterior paralysis in the young athlete. J Bone Joint Surg Am 1979;61(6A):825-832.

    

    

9. Harper GD, McIlroy S, Bayley JI, et al. Arthroscopic partial resection of the scapula for snapping scapula: a new technique. J Shoulder Elbow Surg 1999;8:53-57.

    

    

10. Hawkins RJ, Willis RB, Litchfield RB. Scapulothoracic arthrodesis for scapular winging. In: Post M, Morrey BF, Hawkins RJ, eds. Surgery of the Shoulder. Philadelphia: Mosby, 1990:340-349.

     

     

11. Hayes JM, Zehr DJ. Traumatic muscle avulsion causing winging of the scapula. J Bone Joint Surg Am 1981;63(3):495-497.

     

     

12. Krishnan SG, Hawkins RJ, Michelotti JD, et al. Scapulothoracic arthrodesis: indications, technique, and results. Clin Orthop Relat Res 2005;435:126-133.

     

     

13. Kuhn JE, Plancher KD, Hawkins RJ. Scapular winging. J Am Acad Orthop Surg 1995;3:319-325.

     

     

14. Kuhn JE, Plancher KD, Hawkins RJ. Symptomatic scapulothoracic crepitus and bursitis. J Am Acad Orthop Surg 1998;6:267-273.

     

     

15. Marmor L, Bechtol CO. Paralysis of the serratus anterior due to electric shock relieved by transplantation of the pectoralis major muscle: a case report. J Bone Joint Surg Am 1963;45:156-160.

     

     

16. Perlmutter GS, Leffert RD. Results of transfer of the pectoralis major tendon to treat paralysis of the serratus anterior muscle. J Bone Joint Surg Am 1999;81(3):377-384.

     

     

17. Richards RR, McKee MD. Treatment of painful scapulothoracic crepitus by resection of the superomedial angle of the scapula. Clin Orthop Relat Res 1989;(247):111-116.

     

     

18. Strizak AM, Cowen MH. The snapping scapula syndrome. J Bone Joint Surg Am 1982;64(6):941-942.

     

     

19. Warner JJ, Navarro RA. Serratus anterior dysfunction. Recognition and treatment. Clin Orthop Relat Res 1998;349:139-148.

     

     

20. Wiater JM, Flatow EL. Long thoracic nerve injury. Clin Orthop Relat Res 1999;(368):17-27.