Evaluation and Management of Scapular Winging due to long thoracic nerve palsy

The Problem

Scapular winging is a rare condition that results in abnormal scapular motion, causing pain and decreased functionality of the upper extremity. The diagnosis can be missed, leading to unnecessary surgery, although a thorough physical examination and proper diagnostic studies can lead to the correct diagnosis as well as elucidating the underlying etiology.

Causes for this condition are usually neurological with or without trauma. Regardless of the etiology, the consequence may be significant functional impairment, pain and even instability of the glenohumeral joint.

The most common type of scapular winging is medial winging due to a long thoracic nerve (LTN) palsy leading to a dysfunctional serratus anterior muscle. This weakness of the serratus causes the scapula to move away from the ribs with flexion of the arm. Consequently the glenoid tilts downward and the arm cannot be raised into full flexion.

The presentation, exam findings and treatment plans can vary based on the individual etiology responsible for the winging, however, this chapter will focus on LTN palsy leading to winging from a dysfunctional serratus anterior muscle.

Clinical Presentation

A young patient (typically 2nd – 6th decade) presents with a complaint of loss of shoulder motion and pain. They may or may not have the sense of instability as well. They will report difficulties with activities of daily living or decreased athletic ability. They can complain of asymmetry of their shoulder blades and posterior pain when their back is against hard surfaces. Patients may have a recent or remote history of blunt trauma, or previous viral illness that can be responsible for a nerve palsy leading to winging.

Diagnostic Workup

Physical examination reveals inability to reach full forward flexion (FF) with posterior winging of the scapula evident if viewed from the side or posterior aspect. Both scapulae should be viewed from the posterior aspect during elevation of the arm in order to detect asymmetry (Figure 1). Specific testing of the serratus anterior is performed by having the patient push-up off of the wall from a standing position and observing asymmetric winging of the scapula. Alternatively, resisted flexion with the arm below the horizontal will place the serratus under maximum resistance and will demonstrate winging.

The scapular compression test requires the clinician to apply an anterior-directed force on the posterior aspect of the scapula with one hand while stabilizing the patient on the anterior chest wall with the other hand and then having the patient again attempt FF. This should result in greater motion and less pain as this compression stabilizes the scapula during arm flexion and offsets serratus anterior weakness.

Plain films are commonly normal, although subtle differences in scapular position may be detected.

A CT scan can be performed to better elucidate bony abnormalities and rule out scapular masses only if the patient has mechanical symptoms to suggest such deformities.

An EMG evaluation is required to confirm the diagnosis of LTN dysfunction but should not be performed until at least 6 weeks after onset of symptoms.

Non–Operative Management

Non-operative management is the appropriate treatment for winging due to LTN palsy as most cases will ultimately recover, sometimes taking 1 – 2 years. With this type of winging, physical therapy is usually not effective and, moreover, may aggravate the problem by stressing the long thoracic nerve. While bracing might seem to be helpful it is usually not well tolerated by most patients.

Indications for Surgery

Surgery is generally reserved for a case in which winging continues to affect function significantly after a period of at least 1 year.

Surgical Technique

Surgery for medial winging consists of a transfer of the entire pectoralis major tendon (direct procedure) or the sternal portion (indirect procedure). While some attempt this transfer without any additional tissue extension to lengthen the tendon, most surgeons prefer to augment the transfer using either autograft or allograft tissue.

We prefer a transfer of the sternal head of the pectoralis major with augmentation with autograft hamstring (both tendons).

Standard equipment is utilized, although a tendon stripper and a burr are needed, and a bean bag and an arm-positioner can be helpful.

Set up:

The patient is placed in a supine position for the initiation of general anesthesia. An endotracheal tube is needed as complete paralysis is required for this procedure. After induction of anesthesia, the patient is placed in position of slight flexion at the waist and lateral tilt to the contralateral side in order to allow access to the front and back of the shoulder (Figure 2). The entire scapula should be exposed with the shoulder girdle freely mobile. An arm holder is placed on the ipsilateral side, oriented so as to be able to place the arm in a position for harvesting of the pectoralis major and also for the actual transfer of the tendon. The operative arm and hemithorax, as well as the ipsilateral leg are prepped and draped in the usual sterile fashion.

Figure 2.

Hamstring tendon harvesting:

A sterile tourniquet is routinely used during the tendon harvesting portion of the procedure. The hamstring tendons are harvested according to standard technique and then prepared on the back table while the tourniquet is deflated, hemostasis is achieved and the wound closed and dressed.

Tendon graft preparation:

The tendon is freed of soft tissue with Metzenbaum scissors and then sewn from the midpoint of the tendon to each end with a running whipstitch of #2 non-absorbable suture. The smaller end of the tendon, which is the proximal part, was tubularized with a wrapping technique using #2 non-absorbable suture. The tendon is then placed into a moistened sponge until it was required.

Harvesting of pectoralis major:

An approximately 8 cm incision is made from the coracoid process distally in the skin crease lines of the anterior axillary fold. Sharp dissection is employed down to the fascia overlying the deltoid and the pectoralis major. The upper and lower border of the pectoralis major is exposed and the deltopectoral interval dissected. The interval between the sternal and clavicular heads of the pectoralis major is identified and a Penrose drain is passed around the sternal portion of the muscle. The sternal head is then dissected free from the clavicular head from medial to lateral defining the tendon insertion into the lateral lip of the bicipital groove. To facilitate this, the arm is internally rotated. The short and long heads of the biceps are protected while a 15 blade is used to transect the sternal head tendon attachment to the humerus. The clavicular attachment is preserved. #2 non-absorbable sutures are placed in a modified Mason-Allen configuration to the end of the tendon.

The previously harvested graft is then woven through the pectoralis major in a Pulvertaft fashion so that the tendon end is lengthened by about 8 cm. This is done by weaving the tendon, with one short limb to the level of the pectoralis major tendon and the longer limb projecting forward. #2 non-absorbable sutures are then used to sew the graft into the pectoralis major tendon so that a funnel shape is created, tubularizing the end of the tendon so it could slide through the soft tissue tunnel when transferred (Figure 3). Once the tubularization is completed, the tendon is placed back into the incision with a moistened sponge placed over it while the exposure of the inferior border of the scapula is started.

Figure 3.

Scapular exposure and tendon transfer:

The arm is then placed in a position of flexion and abduction, which brings the inferior angle forward.

A 5 cm incision is made in the skin crease lines over the inferior border of the scapula and sharp dissection employed through the subcutaneous tissues down to the latissimus dorsi. The latissimus dorsi is then split in line with its fibers, first with electrocautery and then with a Cobb elevator until the inferior border of the scapula and the teres major is clearly identified. Electrocautery is then used to divide the soft tissue off the lateral inferior border of the scapula. This plane is developed with a Cobb elevator and electrocautery medially on the external and the deep surface of the scapula, thus clearing away the soft tissues. The thickened lateral ridge of the scapula should then be visible with a thinner body medial to it. Cobra retractors are placed behind the scapula and an oval burr is used to create a hole through the inferomedial border of the scapula just medial to the lateral thickened ridge. This must be of a large enough diameter to allow passage of the graft. A right angle clamp is then used to pass a suture loop through the created hole in the scapula.

A soft tissue tunnel along the chest wall is then created first from inferior to superior and then from superior to inferior so as to fully dilate the tunnel along the chest wall through which the tendon will be transferred. This is done entirely bluntly, with no sharp dissection needed. A clamp placed from the distal aspect of the tunnel can then retrieve the sutures in the end of the hamstring tendons and pull them distally to the incision made over the inferior border of the scapula. The tendon should be seen to freely slide along the chest wall and to have full excursion without being tethered. The suture loop previously placed through the hole in the scapula is then used to transfer the hamstring tendons through the hole in the scapula (Figure 4). The scapula is pushed forward along the chest wall as this is done.

Figure 4.

The pectoralis major tendon is then advanced until the native pectoralis major tendon touches the deep surface of the scapula, and then fixed in place by sewing the sutures already through the graft to itself with a free needle and then using a #2 non-absorbable suture in a stirrup fashion to sew the graft to itself. Usually eight such sutures are utilized to secure this. At this point, it should be verified that the graft is securely fixed and the scapula is held forward in its proper position with excellent tension in the pectoralis major. After irrigation, the latissimus split is closed with interrupted #2 non-absorbable suture and the incision is then closed in layers in a routine fashion (Figure 5). A drain is not routinely used. The patient is then placed in a shoulder immobilizer.

Figure 5.

Pearls and Pitfalls of Technique

Pearls

• Set up must allow entire area of scapula to be accessible once the area is draped and patient must be tilted slightly to the contralateral side to allow this.

• It can take several adjustments of the penrose drain to ensure the entire sternal head of the pectoralis major is identified, do not dissect too deeply through the pectoralis major until this plane is clearly established.

• The attachment of the native sternal head of the pectoralis major to the graft must be tubularized to permit easy passage through the soft tissue tunnel.

Pitfalls

• If the deltopectoral incision is made too lateral, it will lead to difficulty in identifying the separate heads of the pectoralis major.

• If the long and short head of the biceps are not protected and visualized, they may be inadvertently tenotomized when performing the release of the sternal head of the pectoralis major.

• Before suturing the tendon to itself, the scapula must be reduced anteriorly to allow correction of the winging.

Potential Complications

Seroma, hematoma, infection and painful neuroma can all occur at the site of hamstring harvest.

Deep infection can occur at the site of the tendon transfer which may necessitate graft removal. Residual winging can occur if the scapula is not pushed anteriorly while suturing the graft to itself. Intra-operative or post-operative fracture of the scapula could theoretically occur if the tunnel is malpositioned.

Post–operative Rehabilitation

Postoperative care consists of sling immobilization for 4-6 weeks to allow for healing, although early passive ROM is allowed to permit passage of the tendon in the soft tissue tunnel. Active ROM can then be initiated at the 4-6 week mark. Strengthening against resistance should not begin until after 12 weeks which can then progress to resumption of normal activities.

Lifting more than 20 pounds with the surgically treated arm or contact and collision sports are prohibited for 1 year after surgery.

After 2 months a biofeedback program is instituted to help the patient train the tendon transfer to actively stabilize the scapula during shoulder flexion. It is the authors’ impression that the speed of recovery of scapular stabilization is better with this technique than with other methods of muscle training. The biofeedback program is done using surface electrodes placed over the transferred pectoralis muscle. The biofeedback unit gives visual and audible feedback from electromyographic activity occurring with muscle contraction. The threshold level initially is set low and is increased as the patient is able to maintain muscle activity more consistently during shoulder flexion. Biofeedback training is performed initially with the patient in a side lying position to eliminate the effects of gravity. The patient is asked to adduct the flexed arm against resistance to promote contraction of the pectoralis major. This resistance is maintained for 5 seconds for five to 10 repetitions to allow the patient to become familiar with the biofeedback signal. The patient then attempts to flex the shoulder anterior to the plane of the scapula while maintaining the pectoralis muscle contraction by maximizing the biofeedback audible and visible signals. If the patient has difficulty maintaining pectoralis contraction during flexion, the therapist provides some concomitant resistance to adduction during flexion.

Once the patient is able to maximize pectoralis contraction consistently without gravity, he or she is asked to sit up and attempt flexion. Usually two to four sessions are required to produce this effect.

Outcomes/Evidence in the Literature

Post, M. “Pectoralis major transfer for winging of the scapula”. J Shoulder Elbow Surg. vol. 4. 1995. pp. 1-9. (Eight patients with painful, chronic winging of the scapula had an indirect transfer of the pectoralis major with fascia lata autograft. Preoperative duration of symptoms averaged 20.9 months (range, 12 – 35 months). Surgery was performed in the lateral decubitus position with the torso tilted backward 35 degrees. A 5 x 20 cm section of the fascia lata was harvested and twisted into a tubular graft. One long incision was made to harvest the sternal portion of the pectoralis major tendon as well as transfer the graft to the inferior scapula. Patients were followed for an average of 27.1 months (range, 12 – 57 months). One patient had continued pain, and one patient did not regain full motion. Three of four patients had their previous multi-directional instability resolve post-operatively, while one underwent a capsular shift procedure. Two patients had a seroma or hematoma at the graft harvest site requiring aspiration.)

Connor, PM, Yamaguchi, K, Manifold, SG, Pollock, RG, Flatow, EL, Bigliani, LU. “Split pectoralis major transfer for serratus anterior palsy”. Clin Orthop Relat Res. 1997. pp. 134-42. (Eleven patients with symptomatic scapular winging with duration of symptoms from 12 – 60 months underwent a transfer of the sternal portion of the pectoralis major tendon reinforced with fascia lata autograft. Surgery was performed in a modified beach chair position with a 20 cm incision in the axillary skin crease for both tendon harvest and transfer. A 4 x 10 cm fascia lata graft was harvested and tubularized and used to reinforce but not be interposed between the pectoralis major and scapula. Patients were followed for an average of 41 months. Ten of the eleven patients had satisfactory results with improvement in function and reduction of pain with no winging. One patient had a full recurrence of winging.)

Warner, JJ, Navarro, RA. “Serratus anterior dysfunction. Recognition and treatment”. Clin Orthop Relat Res. 1998. pp. 139-48. (Eight patients with scapular winging due to LTN palsy underwent an indirect pectoralis major tendon transfer with autograft hamstrings through a two-incision technique on the shoulder and a separate incision for graft harvest on the ipsilateral leg. Patients had experienced symptoms for an average of 40 months (range 12 – 86 months). Surgery was performed in the manner described above in the surgical technique portion of this paper. Patients were followed for an average of 32 months (range 24 – 40 months) post-operatively. There was one patient who reportedly had a deep infection treated at another institution and was lost to follow-up. FF improved to an average of 150 degrees (range, 120-165 degrees), compared with the preoperative average of 97 degrees (range, 80-120 degrees). All patients were satisfied with the cosmesis of their incisions.)

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. vol. 81. 1999. pp. 377-84. (Sixteen patients with scapular winging underwent pectoralis major transfer with fascia lata autograft. Surgery was originally performed with individual strips of fascia lata and then later changed to a rectangular graft that was sewn into a tubular configuration. Surgery was performed in the lateral decubitus position and the entire pectoralis major tendon was used for transfer. Patients were followed for an average of 4 years and 3 months (range 2 years and 1 month to 9 years). Results were graded as excellent in eight patients, good for five and fair for one. The two remaining patients both had failures attributed to using individual, small strips of fascia lata graft and were revised to scapulothoracic fusions.)

Povacz, P, Resch, H. “Dynamic stabilization of winging scapula by direct split pectoralis major transfer: a technical note”. J Shoulder Elbow Surg. vol. 9. 2000. pp. 76-8. (This is an anatomic study performed on 40 cadaver shoulders to measure the size of the pectoralis major muscle and its sternal portion. This study was designed to answer whether the length of the pectoralis major muscle would permit a direct transfixation of the split sternal portion to the inferior pole of the scapula. The distance from the origin of the sternal portion of the pectoralis major muscle to its insertion on the humeral shaft was measured and then repeated in abduction of 45 and 90 degrees. This length of the sternal portion was then compared to the distance from its origin to the inferior angle of the scapula. At 45 degrees of abduction, the lengths of both these measures are near equal, leading the authors to recommend direct transfer of the sternal head without graft.)

Noerdlinger, MA, Cole, BJ, Stewart, M, Post, M. “Results of pectoralis major transfer with fascia lata autograft augmentation for scapula winging”. J Shoulder Elbow Surg. vol. 11. 2002. pp. 345-50. (Fifteen patients with scapular winging, weakness of arm abduction and fatigue with overhead activities underwent pectoralis major transfer with fascia lata autograft after an average of 25 months of symptoms (range 3-72 months). Details on the surgery were not provided. Patients were followed for an average of 64 months (range 33-118 months). According to Rowe’s criteria, two patients had excellent results, five had good results, four had fair results and four had poor results. Pain decreased with 11 patients, but no patients were pain-free with all activities. Two patients had persistent adhesive capsulitis, one patient had persistent muscle bulging on the lateral aspect of her thigh and one patient required chronic narcotics for pain. A correlation was found with post-operative limited external rotation (ER) and significantly lower outcome scores.)

Steinmann, SP, Wood, MB. “Pectoralis major transfer for serratus anterior paralysis”. J Shoulder Elbow Surg. vol. 12. 2003. pp. 555-60. (Nine patients with LTN paralysis with symptoms for an average of 34 months were followed after indirect pectoralis major tendon transfer with fascia lata autograft. Surgery was performed in the lateral decubitus position with the head of the table elevated to 20 degrees. The entire pectoralis major was detached and a 5 x 15 cm portion of fascia lata was harvested and sutured to the stump of the pectoralis major tendon to augment the graft. Five patients were placed in a shoulder spica cast post-operatively. Follow-up averaged 70 months (range 12 – 168 months). There were three complications post-operatively with two cases of adhesive capsulitis and a thigh seroma from the fascia lata graft. Five patients had biomechanical analysis performed post-operatively which demonstrated mean isometric strength compared to the contralateral side at adduction – 59%, ER – 62%, abduction – 69% and internal rotation – 73%.)

Tauber, M, Moursy, M, Koller, H, Schwartz, M, Resch, H. “Direct pectoralis major muscle transfer for dynamic stabilization of scapular winging”. J Shoulder Elbow Surg. vol. 17. 2008. pp. 29S-34S. (Direct transfer of the pectoralis major tendon in the lateral decubitus position was performed on twelve patients with LTN palsy that had symptoms for an average of 24 months. The entire tendon was detached with a cortical flake of bone and then the sternal head was transferred to the scapula while the clavicular head was reattached to the insertion. Patients were followed for an average of 92.5 months (range 60-136). The average Constant score improved to 95% of the uninjured side, all patients stated they would have the surgery again and average satisfaction on the VAS score was 9.2 (range 8-10). One patient had a rupture of the tendon transfer during a fall, resulting in continued winging and underwent a revision. Final results based on Steinmann’s criteria were rated as excellent in 10 and good in 2 patients.)

Galano, GJ, Bigliani, LU, Ahmad, CS, Levine, WN. “Surgical treatment of winged scapula”. Clin Orthop Relat Res. vol. 466. 2008. pp. 652-60. (Ten patients with LTN palsy resulting in scapular winging underwent a direct transfer of the sternal head of the pectoralis major tendon without graft. Symptoms had been present for an average of 6 years. Sternal head transfer was performed in the lateral decubitus position with a two-incision technique and no graft with sutures passed in mattress fashion through drill holes in the scapula to reduce the length of tendon needed. Patients were followed for an average of 44 months post-operatively. The patients all had an improvement in FF, ASES scores, VAS pain scores and were satisfied with the procedure. Two patients had superficial infections treated with subsequent surgery, one patient had loosening of the split pectoralis major transfer and was converted to a scapulothoracic fusion.)

Streit, JJ, Lenarz, CJ, Shishani, Y, McCrum, C, Wanner, JP, Nowinski, RJ, Warner, JJ, Gobezie, R. “Pectoralis major tendon transfer for the treatment of scapular winging due to long thoracic nerve palsy”. J Shoulder Elbow Surg. vol. 21. 2012. pp. 685-90. (A multi-center retrospective review was performed of 26 patients who underwent direct (n=4) or indirect (n=22) transfer of the pectoralis major tendon for EMG confirmed LTN palsy resulting in scapular winging. The direct transfer was performed with the entirety of the pectoralis major tendon with a thin wafer of bone, fixed to the inferior aspect of the scapula through drill holes. The indirect transfer was performed with the sternal head and interposed autograft hamstring in the fashion of Warner & Navarro, 1998. Patients were followed for an average of 21.8 months (range, 3-62 months). Statistically significant improvements were made in active FF, ER, mean ASES score and VAS pain score. Five patients with indirect transfer had five complications, with three having numbness in the anterior leg, medial arm neuritis in one patient and post-operative hematoma that self-resolved in one patient. There were no differences in outcomes when stratified by length of follow-up.)

Summary

Scapular winging is a cause of shoulder pain that is often overlooked, leading to unnecessary surgical procedures. Careful physical examination and appropriate diagnostic workup can verify the diagnosis, which is most commonly due to a long thoracic nerve palsy. Most patients benefit from a trial of conservative therapy focusing on periscapular strengthening with or without bracing. Surgery may be indicated for those patients who do not improve with conservative therapy and consists of transfer of all, or a portion of the pectoralis major tendon either with or without graft. In our preferred technique, the sternal head of the pectoralis major tendon is transferred to the inferior scapula through a two-incision technique, augmented by autograft hamstring. This reproducible procedure can lead to significantly improved results in pain as well as function, with a low complication rate in experienced surgeons.

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