Open Pectoralis Major Repair: Endobutton Fixation

Abstract

Background:

Rupture of the pectoralis major is most commonly seen with eccentric contraction mechanisms, and surgical options in the setting of acute tear include direct repair, endocortical buttons, suture anchors, and transosseous tunnel fixation. This technique video will detail repair using a unicortical endobutton fixation construct.

Indications:

Surgical repair is indicated for acute, complete pectoralis major tears; incomplete tears involving rupture of the sternal head with intact clavicular head; and tears in the young, active, high-demand demographic. Delay in diagnosis increases the risk of tendon retraction and fatty atrophy. Recent literature has shown that acute repair is superior to chronic repair in functional outcome, pain relief, and overall cosmesis.

Technique Description:

A beach-chair position and a deltopectoral approach are used to identify and mobilize the torn and retracted sternal head of the pectoralis major. A No. 2 SutureTape is then passed through the disrupted sternal head in a Krackow fashion to allow for a 6-strand repair. Two of the suture strands are then shuttled through the endocortical button. A drill is used to create a corticectomy for endobutton placement, which is secured into place by sequentially tightening each limb. Two additional endobuttons are placed in a similar fashion to complete the construct.

Results:

Outcomes studies regarding patients with pectoralis major tendon ruptures who underwent endocortical button fixation reveal that 83% of patients had good or excellent outcomes in a recent systematic review. Another study showed no significant difference in functional outcomes, return to activity, or complication rate with endocortical button fixation compared with other mechanisms of fixation.

Discussion/Conclusion:

Unicortical endobutton fixation can provide another fixation strategy for acute pectoralis major tears in young, active high-demand individuals.

Patient Consent Disclosure Statement:

The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Graphical Abstract

This is a visual representation of the abstract.

Video Transcript

This video illustrates the surgical technique associated with using a unicoritcal endobutton fixation construct to repair a pectoralis major tear as described by the senior author (B.C.W.).

The authors’ financial and professional disclosures can be seen here.

Background

This video will first aim to provide pertinent information regarding the natural history of a pectoralis major tendon rupture, and we will discuss the indication for surgery and repair modalities. We will then provide our patient’s presentation and their clinical examination as well as relevant imaging findings from the case. We will then address the operative plan and detail our technique. Finally, we will illustrate the rehabilitation course and finish with discussing existing literature regarding pec tendon repair with various modalities of repair and their outcomes.

Regarding the anatomy of the pectoralis major muscle, it comprises 2 heads: the sternal head and the clavicular head. ⁷ Among these, the sternal head is most frequently torn, with a classic mechanism of rupture seen with eccentric contraction. These injuries are often seen in isolation, and clinical examination with confirmation on magnetic resonance imaging is used to make the diagnosis. Evaluation and management are time sensitive as a delay in diagnosis increases the risk of tendon retraction and atrophy. Improved outcomes are seen in patients who undergo an acute repair. ²

Indications

Surgical treatment can be beneficial in both the acute and chronic settings, albeit with different surgical techniques used. Acute pec tendon repair options for fixation include direct repair, endocortical button fixation, or suture anchor fixation. Chronic tears require reconstructive augments and allografts to address the retracted nature of the tendon. Acute repair is superior to chronic repair in functional outcomes, pain relief, and cosmesis. With regards to endocortical button fixation specifically, indications include full-thickness tears of the pectoralis major muscle or incomplete tears that involve the sternal head in a young, high-demand patient.^1,3,4,6,9,10 Proximal tears that involve the myotendinous junction or intramuscular tears are not amenable to this fixation strategy, and therefore careful and thorough review of the preoperative magnetic resonance imaging is critical to planning for a successful intervention.^3,7

This case focuses on a 23-year-old man who reports an acute pop in his right chest wall while bench pressing, with an immediate feeling of weakness in his right pectoral area. Clinical appearance of a similar patient is included here. Physical examination reveals bruising of the right proximal arm with effacement of the pectoral outline, as shown here in the image on the right. ⁷ Range of motion is equivalent to the uninjured side, but strength is markedly diminished on the right, with a palpable defect in the lateral chest wall and tenderness noted over the pectoral muscle. Resisted adduction of the humerus can reveal an obvious difference relative to the contralateral extremity, which is shown here in the figure on the right. ⁷ The patient was neurovascularly intact at time of presentation.

Magnetic resonance imaging was obtained to confirm the diagnosis. Imaging shown on the left is from a patient with a rupture of the attachment of the pectoralis major to the humerus, displayed along with tendon retraction and edema shown in the emphasized area. A corresponding normal axial magnetic resonance imaging is shown on the right detailing the normal course and insertion of the pectoralis major tendon on the humerus.

Technique Description

Given the acuity of the injury and the patient’s baseline level of activity, the joint decision was made to proceed with surgical management.^1,3,4,6,9,10 The plan was to perform an outpatient surgical procedure using general anesthesia and a regional nerve block as a potential adjunct in the form of an interscalene and truncal block. The senior author prefers beach-chair positioning. The planned operative technique was to perform a deltopectoral approach and open pectoralis major repair with endocortical button fixation.

The incision is marked in the deltopectoral groove in the usual manner, staying lateral to the coracoid. In the acute setting, placement of the skin incision is made over the least traumatized tissue while also allowing for medial exposure to access the interval between the sternal and clavicular head of the pectoralis major if necessary.

Superficial incision is made using a No. 15 blade. Superficial dissection is performed with a combination of electrocautery and dissecting scissors. The cephalic vein and the deltopectoral interval are identified and can be seen here. Visualization of the deltopectoral groove is critical to ensure that the surgeon is in the correct plane to access the sternal and clavicular head. Care should be taken during this step to avoid iatrogenic injury to the cephalic vein.

The sternal head and the clavicular head of the pectoralis major are identified, with acute rupture and retraction shown of the sternal head. Here we can see the ruptured sternal head in the Alice clamp and the intact clavicular head. In the setting of significant retraction of the sternal head, dissection should be conducted medially to identify the sternal head as it dives below the medial border of the clavicular head.

Finger dissection is used here to further mobilize the disrupted sternal head.

Here we can see the mobilization of the retracted sternal head after it has been freed of all adhesions. In this clip, we can see the required path of the sternal head under the clavicular head to its attachment point on the humerus as indicated here.

Attention is then turned to preparation of the bony humeral insertion. The biceps groove is identified and exposed, as shown here with lateral retraction of the deltoid and medial retraction of the clavicular head of the pectoralis major. Here we can see the bicipital groove being defined by the tonsil. The biceps tendon within the groove is retracted medially.

The lateral surface of the groove is prepared using a burr, as shown here. The location of the sternal head insertion should be just proximal to the superior border of the intact clavicular head insertion, which can be used as a landmark if there is a complete avulsion of the sternal head tendon. This relationship is demonstrated on the model here with the intact clavicular head footprint identified in red and the ruptured sternal head footprint shown in white.

A No. 2 SutureTape (Arthrex) is then passed through the disrupted sternal head in a Krackow fashion to allow for a 6-strand repair. It is important during mobilization and suturing to preserve and incorporate the fascia surrounding the pectoralis; in particular, the deep fascia tends to be more robust and allow for improved suture security. ⁸ Here you can see the final Krackow configuration.

The planned sites of 3 endobuttons for fixation are marked with the bovie approximately 1 cm apart in a superior to inferior fashion in the anatomic location of the pectoralis major insertion. This distance of separation between drill holes is critical to allow the endobutton to successfully deploy. The location for these proposed drill holes should be staggered in the anterior to posterior direction on the footprint of the tendon insertion to avoid the creation of a linear stress riser. A drill is used as shown here to perform a unicortical corticotomy. This is a critical step as failure to angle the drill toward the intermedullary canal can result in a drill hole that skives through cortical bone, which would not accommodate the endobutton. Similarly, it is critical that a unicortical hole is placed as a bicortical hole may result in the endobutton being positioned outside the far cortex. The biceps tendon should be identified and protected during drilling to avoid iatrogenic injury.

The SutureTape is then shuttled through the endobutton, which is shown here. The first limb of the suture is passed from the distal hole of the button on the inserter to the proximal hole so that it enters and exits on the underside of the button. The second limb of the suture is passed proximally on the button to the distal end in a similar fashion so the limb enters and exits on the underside of the button.

The endobutton is then inserted. The authors suggest aiming the endobutton slightly distally within the hole and maintaining tension as it is inserted. The 2 limbs are sequentially tightened only a few millimeters at a time to encourage the button to properly seat within the canal, and the sutures are tied under tension. Second and third endobuttons are placed in similar fashion as shown.

The final repair construct with all endobuttons tightened is visualized here.

Results and Discussion

Postoperatively, the patient is placed in a sling with instructions to immobilize when not doing range of motion exercises. The rehabilitation protocol focuses on maintaining range of motion while protecting the repair with sling immobilization until 6 weeks postoperatively. Following 6 weeks, there is guided return to full range of motion and weightbearing with initial avoidance of internal rotation and adduction. Progressive strength training is not allowed until 12 weeks postoperatively.

The authors’ experience with this procedure reveals the following pearls and pitfalls that can be summarized here. The upper/proximal border of the clavicular head of the pectoralis major tendon can be used as a landmark for the reattachment site of a fully ruptured sternal head. We recommend burring to decorticate the area prior to repair. When placing repair stitches through the ruptured sternal head of the pectoralis major, take care to grab the deep fascia as it provides more robust fixation. Drill holes for the endobutton should be placed in a “zigzag” fashion to avoid a stress riser, and placing drill holes at least 1 cm apart will aid in allowing the endobutton to successfully deploy.

For successful endobutton deployment, we recommend maintaining tension on the button inserter during placement and angling the button inferiorly/distally during placement. The order of button placement should be distal to proximal to allow for appropriate tensioning, and finally the sutures through the buttons should be slowly alternated to allow for the button to successfully deploy.

One systematic review consolidated 265 cases of patients with pectoralis major tendon ruptures who underwent fixation with suture anchors, transosseous suture fixation, and unicortical button fixation. For patients who underwent endocortical button fixation, 83% had good or excellent outcomes in this systematic review. ⁵ This figure may be negatively skewed by the addition of 1 case series that showed multiple fair or poor outcomes associated with cosmesis. There did not appear to be statistical difference in outcomes measures associated with one fixation strategy versus another.

Our references are listed here.

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