Evaluation and Management of Scapular Winging due to Facioscapulohumeral dystrophy (FSH)

The Problem

Facioscapulohumeral muscular dystrophy (FSH) is an autosomal dominant condition with frequent sporadic cases that is the third most common dystrophy. First described in 1884, it has a prevalence estimated at 1:20,000. Although it has a wide-ranging clinical spectrum, there is a high penetrance, so greater than 95% of patients will have clinical symptoms by age 20. The most common presenting symptom is an inability to reach above the shoulder level. This almost always progresses at a slow but steady rate which causes symptoms to increase, although the exact pathophysiological mechanisms are unknown.

Usually the upper trapezius is spared, giving an examination profile slightly different from other causes of scapular winging. There may also be a constellation of other physical exam findings including facial, truncal and other extremity deficiencies.

Clinical Presentation

The presentation is typically a young patient in their 2nd – 3rd decade presents with an inability to forward flex their arm above their shoulder or complaints of generalized weakness of their shoulder. They may complain of weakness that causes them difficulty with activities of daily living that require their arms above their head, such as grooming or washing their hair. They may also complain of winging that causes pain when their shoulders are up against a hard surface.

History of similar complaints of family members should be queried to determine if any familial pattern is evident. Patients might also have other complaints that indicate other manifestations of FSH such as truncal weakness or facial weakness.

Diagnostic Workup

Physical examination can reveal several key findings that help differentiate FSH from other causes of scapular winging. When viewed from the front, there will be a forward sloping and rounding of the shoulders. There is involvement of the biceps and triceps with sparing of the deltoid and forearm giving a unique appearance to the arm.

When the patient forward flexes the arm, there is prominent posterior winging as well as cranial motion of the scapula due to the sparing of the upper trapezius. When viewed from the back, there is lateral displacement of the medial border of the scapula due to the weakened rhomboids with any abduction or flexion.

There can be other systemic findings including drooping of the lower facial muscles, causing a relative lack of expression. There can be lumbar lordosis with a protuberant abdomen reflecting the involvement of the abdominal musculature. Anterior leg muscles can be affected, leading to a foot drop.

Routine radiographs, computed-tomography (CT) or magnetic resonance imaging (MRI) are not normally diagnostic, although based on the chronicity, there may be decreased muscle quantity on axial CT or MRI.

EMG should be performed to rule out any neurogenic or myotonic pathologies. Molecular diagnostic testing is confirmatory of FSH.

Non–Operative Management

Due to the progressive nature of this condition, there is no therapy treatment that will stop progression or reverse weakness or atrophy. Pain management is a large part of non-operative treatment. There can be a short-term benefit with physical therapy, although no long-term studies have shown this to have a lasting effect. No role for shoulder bracing has been shown for patients with FSH.

Indications for Surgery

Surgery is indicated for those patients with a painful, weakened shoulder who no longer have the ability to raise their arm above shoulder level. There is controversy over which patients may not benefit from surgical intervention. The senior author (JJW) uses the scapular compression test (similar to the Horowitz maneuver) to provide an external support keeping the scapula in position to test the patient’s shoulder motion. It is likely that if they have increased motion with the scapula held in place during this exam, that they will benefit from the fusion. Those patients with no improvement with this maneuver or those that have lost deltoid function, may have less increase in motion post-operatively, however this is not necessarily a contraindication to the procedure.

Surgical Technique

Surgery for patients with FSH in our practice entails a scapulothoracic fusion. There have been several different methods proposed for this; the technique listed below is the one utilized by the senior author (JJW).

Necessary Equipment/ Instrumentation:

5-hole limited-contact, dynamic compression plate (LC-DCP)

18 gauge wire

Iliac crest autograft harvest

Allograft

Set Up:

After the induction of general anesthesia, the patient is placed prone on a Jackson table or similar. Care is taken to ensure that there is no pressure on the eyes, genitals of male patients or the breasts of female patients. The operative side arm is allowed to be completely free of any restriction as it will be moved between being placed in a position of forward elevation and external rotation on an arm board and then moved posteriorly and resting in internal rotation on the lumbar area during the surgery (Figure 1). The entire arm of the operative side as well as the hemithorax is then prepped and draped in a sterile fashion. The arm is wrapped and then covered with an elastic bandage. Antibiotic-impregnated adhesive drapes are then applied to completely cover the exposed skin. Preoperative antibiotics are given.

Figure 1.

Approach:

The spinous processes as well as the bony anatomy of the scapula are then outlined, and local anesthetic with epinephrine is given to aid in hemostasis along the planned incision. The dissection starts with the arm supported on an arm board in a position of 90 degrees of elevation and 90 degrees of external rotation. A longitudinal incision is made halfway between the lateral border of the spinous processes and the scapula. Sharp dissection is employed through the subcutaneous tissues down to the fascia overlying the trapezius until its upper and lower borders are visible. The trapezius is then detached from the medial scapula with electrocautery and tagging sutures used for traction to complete the separation from the underlying rhomboids (Figure 2). The rhomboids are exposed and also released from the medial border of the scapula with electrocautery (Figure 3).

Figure 2.

Figure 3.

At this point the arm is internally rotated behind the back which allows the scapula to wing away from the chest wall, placing the serratus anterior under stretch. The underlying bursa is excised with electrocautery and the serratus anterior is then detached from the medial border of the scapula and the plane between it and the subscapularis is divided. The serratus is then resected as far laterally as possible.

The subscapularis is dissected from its fossa using electrocautery and a Cobb elevator. Tagging sutures are also used so that the medial two-thirds can be carefully reflected, exposing the ribs.

The arm is now transiently brought back into the starting position to check that the scapula can be placed on the chest wall directly on the ribs with no interposed muscle medially. The arm is then placed back in internal rotation.

Preparation of ribs:

Needle-tip electrocautery and a Cobb elevator are then used to remove the soft tissue off the third through sixth rib. Prominent intercostal muscle mass is resected, as is a small amount of the paraspinal musculature medially. A motorized burr is then used to lightly decorticate the exposed ribs as well as the undersurface of the scapula. 18-gauge wires are then passed carefully around the ribs 3, 4 and 5 as well as 6 using a Penfield elevator to create a small space both above and below each rib and then placing the wire through that track. These wires are then clamped and placed aside.

Sterile saline is then used to fill the wound so that the ribs are completely covered. At this point, the anesthesiologist is asked to create a positive pressure ventilation several times in order to ensure that no bubbles are visualized and therefore no penetration of the pleura has occurred.

A moist lap sponge is placed in the wound and attention is directed to bone graft harvesting.

Iliac crest bone graft harvesting:

A longitudinal incision is then made over the posterior iliac crest and sharp dissection used through the subcutaneous tissues down to the outer table of the iliac crest. A half-inch curved osteotome is used to osteotomize strips of cortical bone and then the outer table is removed. At this point, a curette or gouge can be used to harvest the cancellous strips of bone. The wound is then irrigated and thrombin-soaked gelfoam is inserted. The incision is then closed in layers and reinforced with a skin sealant.

Plating and bone grafting:

Allograft chips or croutons can be used, or a femoral head can be morselized into appropriate sized pieces to augment the autograft obtained.

The infraspinatus and supraspinatus are elevated out of their fossa from medial to lateral, far enough to place a 5-hole LC-DCP just lateral to the medial border of the scapula. Using the plate as a guide, small holes are created with the burr in the scapula, as well as an additional hole superior to the plate. The arm is then placed in elevation and external rotation on the arm board into a physiologic position that allows the best fit of the scapula along the prepared ribs; this is often in a more lateralized position than the native scapula. This position usually creates a 15 – 20 degree angle between the medial border of the scapula and the vertical line of the spinous processes. The pre-positioned wires are then brought through their respective holes in the scapula as well as the plate, so that there is a bridge of the plate between each two wires that will be tightened together. Before the wires are tightened, the allograft is placed as far laterally as possible under the scapula along the exposed ribs and the autograft is placed directly over the ribs that will be in contact with the scapula medially. We believe that this gives the best chance of producing a solid arthrodesis.

The wires are then tightened together with a jet wire-tightener starting proximally first to set the height of the scapula and then working from distal to central. The wires are tightened until the scapula is securely compressed against the abraded surface of the ribs (Figure 4). The excess wire is then cut with a wire cutter and the tails of the wires are bent over the scapula to decrease their prominence. Any additional autograft bone is then packed over the medial border of the scapula and ribs. Demineralized bone matrix can also be added. The arm is then moved to ensure that the scapula is securely fixed to the ribs with no motion.

Figure 4.

Closing:

A sponge is placed over the bone graft and suction used over the sponge so as not to remove any graft. The soft tissue layers are then repaired to provide cushion over the plate and wires by first repairing the rhomboids in a pants-over-vest fashion and then the trapezius. A drain can be placed based on the appearance of the wound. The subcutaneous and skin layer is then closed in layers. After a dressing is applied, an immobilizer and cryotherapy cuff are placed and the patient is transferred back to the gurney and awakened from anesthesia.

Pearls and Pitfalls of Technique

Pearls

• Set up must allow free motion of the involved arm as it will move from a position of flexion and abduction to a position of extension and internal rotation throughout the case.

• The use of tagging sutures in the muscle layers helps place traction on them which allows a more careful dissection between layers, decreasing operative time and improving hemostasis.

• Don’t try to position the scapula solely according to the number of the rib, place the scapula where it has the best fit along the rib for a more secure compression.

Pitfalls

• If a careful plane is not established under the rib, a pneumothorax can be created or bleeding may occur due to violation of the intercostal vessels directly on the inferior aspect of each rib.

• Do not over tighten the 18 gauge wire, especially after deformation of the wire occurs, as this will lead to weakening or even breakage of the wire.

• Not resecting the muscle layers laterally enough will interpose a soft tissue layer between the scapula and the exposed ribs, preventing fusion from taking place.

Potential Complications

The most serious complication can be perforation of the pleura; this is why the inter-operative positive pressure ventilation check with the wound filled with irrigation is critical. If a violation has occurred, then a chest tube is mandatory. A small pneumothorax that is recognized post-operatively may be able to be managed without further intervention.

Seroma, hematoma, infection are possible which can result in the need for an irrigation and debridement, effectively removing all bone graft.

Neurologic stretch injuries to the brachial plexus can occur, some of which will be permanent. As the scapula is effectively lateralized with this procedure, upper trunk injuries are especially at risk.

Nonunion can occur which will lead to hardware failure. Hardware failure can occur even when nonunion is not detected and patients can remain asymptomatic. If careful soft tissue coverage is not provided, there can be hardware irritation when the patient leans back against a hard surface.

Post–operative Rehabilitation

Postoperative care consists of a sling and immobilizer for 6 weeks, during which time elbow, wrist and hand motion are permitted. After six weeks, gentle passive motion of the glenohumeral joint is allowed with the restriction of 90 degree of forward elevation. No active motion is allowed until radiographs at 3 months show signs of bony union with no hardware failure (Figure 5).

Figure 5.

Outcomes/Evidence in the Literature

Bunch, WH, Siegel, IM. “Scapulothoracic arthrodesis in facioscapulohumeral muscular dystrophy. Review of seventeen procedures with three to twenty-one-year follow-up”. J Bone Joint Surg Am. vol. 75. 1993. pp. 372-6. (Twelve patients with FSH underwent seventeen scapulothoracic arthrodeses. The patients were age 17-48. The arthrodeses were performed with autograft iliac crest and two 1.0 mm wires placed around each exposed rib and then through drill holes in the scapula. The undersurface of the scapula was not decorticated. Patients were managed post-operatively in a figure of 8 dressing if at least four ribs were included in the fixation, and were otherwise placed into a shoulder spica cast until radiographic union. All patients achieved solid fusion and all but one was capable of forward flexion and abduction to 90 degrees or more. Follow-up ranged from 3 to 21 years. There was a complication of a brachial plexus palsy that resolved and one patient who developed adhesive capsulitis.)

Twyman, RS, Harper, GD, Edgar, MA. “Thoracoscapular fusion in facioscapulohumeral dystrophy: clinical review of a new surgical method”. J Shoulder Elbow Surg. vol. 5. 1996. pp. 201-5. (Six patients with FSH had bilateral procedures performed at an average age of 30 years (range, 17-44 years). The average follow-up was 49 months (range 1 – 7 years). A double strand of 18-gauge wire was used and passed through holes in the scapula as well as ribs 2 through 6 or 7. No plate was used. Cancellous posterior iliac crest was utilized. Active ROM was allowed on post-operative day 2 and a sling was used for 6 weeks. All patients showed increases in flexion and abduction and all patients were happy with the cosmetic result. Pulmonary function tests were performed pre- and post-operatively and demonstrated a small diminution of respiratory function. There was a complication of a puncture of the pleura that was recognized intra-operatively and a chest tube was placed, one patient later had an upper trunk brachial plexus traction injury that did not resolve and one patient had a symptomatic nonunion. There were broken wires in three patients and a rib stress fracture in another.)

Andrews, CT, Taylor, TC, Patterson, VH. “Scapulothoracic arthrodesis for patients with facioscapulohumeral muscular dystrophy”. Neuromuscul Disord. vol. 8. 1998. pp. 580-4. (Six patients with FSH had 10 scapulothoracic arthrodesis procedures. Age ranged from 17-33 years and follow-up ranged from 28-120 months. The authors used an L-shaped incision and exposed three ribs for the fusion. Two wires were passed along each exposed rib and passed through the scapula and autograft iliac crest was utilized as well. Post-operatively, patients were immobilized in a shoulder spica cast for 12 weeks. Post-operatively, patients were able to perform many ADLs that they were previously unable to do, however carrying strength was not improved, and one patient had a subsequent decrease in motion after 1 year. No differences were found on pre- and post-operative pulmonary function tests. There was one pneumothorax that resolved without intervention and one patient that had a broken drain that needed to be surgically removed. One patient developed a lung infection and one a pleural effusion. Almost all patients developed at least one broken wire and one patient broke three out of five wires on each side, but still went on to bony union.)

Krishnan, SG, Hawkins, RJ, Michelotti, JD, Litchfield, R, Willis, RB, Kim, YK. “Scapulothoracic arthrodesis: indications, technique, and results”. Clin Orthop Relat Res. 2005. pp. 126-33. (Twenty-two patients, of which five had FSH underwent 24 scapulothoracic arthrodeses. The patients with FSH made up the largest group of those with primary scapular winging and 11 patients had secondary winging after multiple previous surgeries. The mean age was 32 years (range, 18 – 53 years) and follow-up was at a minimum of 2 years (range 2 – 9.5 years). The fusion was performed using a semi-tubular plate to tie wires over three or four ribs after passing wires through the scapula as well. A routine chest tube was inserted in all patients to drain the pleural space and removed in 1-2 days post-operatively. Post-operative immobilization was done in a gunslinger brace for 12 weeks. Ninety-one percent of patients were pleased and stated they would have the surgery again. There were 11 patients with complications including six with a pneumothorax and five with reactive pleural effusions. Two patients required transfusions and four patients had pain and numbness in an intercostals nerve dermatomal distribution. One patient had a superficial infection and one had broken wires. Two patients had painful nonunions that required revision surgery. Seven patients developed a pseudarthrosis.)

Diab, M, Darras, BT, Shapiro, F. “Scapulothoracic fusion for facioscapulohumeral muscular dystrophy”. J Bone Joint Surg Am. vol. 87. 2005. pp. 2267-75. (Eight patients with FSH underwent 11 scapulothoracic arthrodeses at an average age of 17 years (range 11 – 21 years) with a mean follow-up of 6 years (range 2 – 10 years). The procedure was performed slightly differently by passing a 16-gauge wire around each rib (usually ribs 3 – 8), twisting the wire on itself and then passing one limb through the scapula and plate or washers and then securing it to the other end of the wire. Autograft posterior iliac crest was utilized. Immobilization was performed for 4 weeks with a sling and swathe and then sling only for an additional 4 weeks. Unrestricted activity was allowed between 3-4 months post-operatively. There were six excellent, three good and two fair results based on motion, pain and satisfaction. All patients had relief of pain and were satisfied with the cosmetic result. Two complications of prominent wires were revised. No other complications were reported.)

Tawil, R, Van Der Maarel, SM. “Facioscapulohumeral muscular dystrophy”. Muscle Nerve. vol. 34. 2006. pp. 1-15. (While this paper does not report any surgical outcomes, it is an excellent review of FSH. It provides detailed description of the genetics as well as clinical manifestation, pathophysiology, diagnosis and treatment options. As the orthopaedic surgeon may be the clinician to establish the diagnosis of FSH, a thorough understanding of this condition is needed as well as an appropriate diagnostic plan.)

Rhee, YG, Ha, JH. “Long-term results of scapulothoracic arthrodesis of facioscapulohumeral muscular dystrophy”. J Shoulder Elbow Surg. vol. 15. 2006. pp. 445-50. (Six patients with FSH underwent 9 modified scapulothoracic arthrodeses. The mean age of patients was 25 years (range, 15-37 years). A 5 or 6 hole pelvic reconstruction plate and 18 gauge wire and autograft was used. This procedure is considered modified by the authors as only a limited soft tissue dissection is performed and only a medial-based fusion is sought. Patients were immobilized for 3 months. Pain score, satisfaction and UCLA scores were all improved significantly. One patient complained of pain and was unhappy with the cosmesis. Post-operative ROM declined from 1 year to 4 years after surgery. One patient had a pleural effusion treated with repeated aspirations and steroid injections.

Giannini, S, Ceccarelli, F, Faldini, C, Pagkrati, S, Merlini, L. “Scapulopexy of winged scapula secondary to facioscapulohumeral muscular dystrophy”. Clin Orthop Relat Res. vol. 449. 2006. pp. 288-94. (Nine patients with FSH each underwent bilateral scapulothoracic fixation without arthrodesis. The average age was 25 years (range 15 – 35 years) and average follow-up was 9.9 years (range 3 – 16 years). The surgical method differed from others in that the scapula was tethered to the underlying four ribs through holes and wires, but no preparation of the bones was performed and no bone graft was used on either side. On the dominant side, the wires were tightened securely, compressing the scapula to the ribs. However, on the non-dominant side, the wires were only loosely secured, tethering the scapula, but not compressing it to the ribs. Physical therapy was started immediately as tolerated in a figure-eight brace. All patients showed improvement in active ROM and strength. Two patients had wires break at the 3 year and 7 year mark respectively, however the position of the scapula was maintained. One patient had a pneumothorax that spontaneously resolved in 48 hours.)

Giannini, S, Faldini, C, Pagkrati, S, Grandi, G, Digennaro, V, Luciani, D, Merlini, L. “Fixation of winged scapula in facioscapulohumeral muscular dystrophy”. Clin Med Res. vol. 5. 2007. pp. 155-62. (In this second report by the authors, they included an additional four patients to the ones listed above to now have follow-up on thirteen patients with FSH with bilateral scapulothoracic fixation without arthrodesis. Again, they demonstrated a stable and long-lasting scapulopexy with limited complications by performing their described procedure which consists of different methods of fixation for the right versus the left scapula. Again the figure-eight brace was worn for a total of 6 weeks, but immediate motion was allowed. No further complications were reported.)

Van Tongel, A, Atoun, E, Narvani, A, Sforza, G, Copeland, S, Levy, O. “Medium to long-term outcome of thoracoscapular arthrodesis with screw fixation for facioscapulohumeral muscular dystrophy”. J Bone Joint Surg Am. vol. 95. 2013. pp. 1404-8. (Twenty-four patients with FSH underwent 35 scapulothoracic arthrodeses and were followed for a minimum of 24 months (range, 24 – 174 months, mean 88 months). The mean age was 26 years (range, 16 – 62 years). Fixation between the scapula and the first three to four ribs was achieved with a 4.5mm screw and washer. Autograft posterior iliac crest was utilized. Three patients were lost to follow-up, two who had unsatisfactory outcomes. Active arm elevation, Constant score, pain levels and patient satisfaction all improved significantly. Short term complications revealed one pneumothorax that resolved spontaneously, one superficial wound infection that was treated with oral antibiotics and four patients with signs of early failure. Three of those patients were revised. Long term complications consisted of one fractured scapula and pullout of screws after a fall that underwent revision, one painful nonunion that was revised at another institution, one patient had rapid deterioration of all upper and lower-limb muscle function several months after surgery and one cardiac death a year after surgery.)

Summary

Patients with scapular winging due to FSH can be initially diagnosed by the treating orthopaedic surgeon, therefore a careful history as well as focused examination is necessary, as well as referral for appropriate further testing to confirm the diagnosis. Conservative treatment consisting of pain management and physical therapy can be beneficial in the short-term. As this condition is progressive, ultimately many patients will be indicated for surgical consideration. Surgery consists of a scapulothoracic fusion with deliberate attention to preparation of the surfaces to achieve a bony union utilizing auto- and allograft. In our experience this preparation, combined with a LC-DCP and a conservative post-operative protocol, can lead to scapulothoracic fusion and an improved quality of life for the patient. Although a high complication rate has been reported in the literature, many of these complications resolve without the need for revision surgical intervention and do not appear to affect the final outcome.

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