Quadruple Disruption of Superior Shoulder Suspensory Complex With Proximal Humerus Open Fracture-Dislocation

Abstract

Case:

A 34-year-old man was a restrained passenger involved in a high-speed rollover motor vehicle crash. The patient sustained a type 5 AC joint separation, severely comminuted intra-articular glenoid fracture with extension to the coracoid process base, displaced open scapular body fracture, a posterior shoulder dislocation of the glenohumeral joint, and a 2-part proximal humerus fracture.

Conclusion:

To our knowledge, this is the first report describing this injury pattern involving the superior shoulder suspensory complex with an associated open proximal humerus fracture-dislocation.

The functional unit of the upper extremity provides a stable biomechanical construct to allow efficient transfer of force from the hand to the axial spine. The shoulder girdle is simply suspended in space by 2 struts, the middle third of the clavicle and the lateral border of the scapula. These struts are interconnected by the superior shoulder suspensory complex (SSSC) that provides a stable base for the head of the humerus to abut the glenoid fossa and allow the upper extremity to be suspended in space¹. The SSSC is a functional stable ring composed of both bony and soft tissue components including the clavicle, coracoclavicular ligaments, coracoid, glenoid, spine of the scapula, acromion, and acromioclavicular (AC) ligament that provides stability to the glenohumeral (GH) joint and connects this complex to the axial skeleton¹. When two or more aspects of the ring are disrupted, the SSSC is no longer a stable complex. Furthermore, the GH joint is no longer considered connected to the axial skeleton as 1 functional unit, and operative fixation is indicated to restore that stable relationship. In this study, we present a case report of a patient with an open quadruple disruption of the SSSC with associated proximal humerus fracture-dislocation requiring a 3-stage reconstruction of the glenoid, scapula, proximal humerus, and AC joint complex.

The patient was informed that data concerning the case would be submitted for publication, and he provided consent.

Case Presentation

Clinical Presentation and Imaging Findings

A 34-year-old man was a restrained passenger involved in a high-speed rollover motor vehicle crash and presented to a Level 1 trauma center with severe left shoulder pain. Physical examination revealed a large laceration over the left posterior shoulder with exposed bone and an obvious AC joint deformity. The patient had intact brachial and radial pulses, along with normal motor and sensory function in the median, ulnar, and radial nerve distributions.

From the orthopedic standpoint, the patient sustained a complex left upper extremity injury.

The injury included a type 5 AC joint separation, severely comminuted intra-articular glenoid fracture with extension to the coracoid process base, displaced open scapular body fracture (Fig. 1), a posterior shoulder dislocation of the glenohumeral joint (Figs. 2 and 3), and a 2-part proximal humerus fracture (Fig. 4).

Fig. 1.

Preoperative anterior to posterior (Fig. 1-A) and Y-view (Fig. 1-B) radiographs of the left scapula demonstrating a comminuted scapular fracture involving the bony glenoid. 3D CT scans (Figs. 1-C and 1-D) showing the scapular anterior/posterior, respectively, body fractures extending into the coracoid process, intra-articular glenoid fracture, and acromioclavicular separation. The arrows represent the 4 areas of disruption of the SSSC. CT = computed tomography, and SSSC = superior shoulder suspensory complex.

Fig. 2.

Preoperative anterior to posterior radiographs of the shoulder with internal rotation (Fig. 2-A) and external rotation (Fig. 2-B) demonstrating posterior dislocation of the glenohumeral joint.

Fig. 3.

Axial CT scan showing posterior dislocation of the humeral head. CT = computed tomography.

Fig. 4.

Preoperative posterior to anterior (Fig. 4-A) and lateral (Fig. 4-B) radiographs of the left upper extremity demonstrating a displaced, angulated humeral neck fracture.

Surgical Procedures

A treatment plan was devised with sequence of fixation strategies as follows: first, reduction of the dislocated glenohumeral joint and fixation of the proximal humerus to simplify the overall injury to a double disruption of the SSSC; then, glenoid fixation to aid intra-articular stabilization and enhance scapular flexibility for independent articular reduction; and finally, neutralization of the AC separation with a hook plate.

The patient's proximal humerus was definitively fixed with a proximal humerus locking plate. We encountered severely disrupted soft tissue at the level of the pectoralis major insertion with some significant stripping of the deltoid insertion; however, the traditional landmarks of the conjoined tendon were not disrupted and provided landmarks for the deltopectoral exposure. The rotator cuff was intact, but the long head of the biceps was severely deformed with a need to mobilize the biceps to offer reduction of the humeral head. We used a rotator interval window to clear obstructions to the humeral head reduction and used sutures in the subscapularis to pull the humeral head into reduction (Fig. 5).

Fig. 5.

Intraoperative fixation of the scapular body (Fig. 5-A) and proximal humerus (Fig. 5-B).

We then turned to the fractures in the glenoid fossa and scapular body (Fig. 5). We aimed to use a posterior arthrotomy to visualize and reduce the glenoid surface first, as we thought this was the most important factor in stabilization of the glenohumeral component. Once we achieved anatomic reduction of the articular surface, we used lag screw fixation to secure articular surface reduction. Then we chose to anatomically reduce the glenoid neck using an L-shaped plate which resulted in restoration of the glenopolar angle². At this point, the medial border was reduced adequately to not require additional fixation.

Once the glenoid was reduced, the proximal humerus appeared to be stable. We did not feel the need to perform a capsulorrhaphy or a labral repair at the time as the posterior dislocation closure adequately provided soft tissue stability, and an extensive soft tissue procedure could result in capsular tightness. The humeral head cartilage, evaluated intraoperatively, was not significantly injured. We placed a distal clavicle plate along the lateral border of the scapula to hold fixation over the reduced scapular body fracture and repaired the deltoid muscle primarily by attaching it to the humeral plate. We then closed the posterior incision primarily to conclude the procedure.

Three days later, we returned to the operating room for repair of the AC joint with a hook plate fixation to provide adequate strength of fixation. Independent fixation of the coracoid would have been difficult given the comminution, so hook plate fixation would serve the purpose of securing the coracoid as well. We placed the hook plate across the joint, with 8-cortices of fixation on the distal clavicle. Adequate fixation was necessary given the likely stress across the hook plate that will entail due to the weight of the scapula and soft tissue disruption produced by the injury at the shoulder region (Fig. 6). The plan was to ultimately remove the hook plate 1 month after the standard time of 3 months to allow for cortical healing.

Fig. 6.

Intraoperative fluoroscopy showing repair of the acromioclavicular joint with a hook plate.

Follow-up and Outcomes

The patient is doing well postoperatively and can complete all his functions as an electrician. His range of motion at his 2-month visit was 0 to 40° with active abduction and forward flexion, active external rotation to 20°, and internal rotation to L3 (Fig. 7). Seven months postoperatively, the hook plate was removed (Fig. 8). One month later, he could forward flex to 85°, externally rotate to 10°, and internally rotate to the spine of the scapula. At almost 3 years postoperatively, his ASES score is 98, with nearly full range of motion, as shown in Fig. 9.

Fig. 7.

Postoperative left shoulder radiographs at 1 (Fig. 7-A) and 2 (Fig. 7-B) weeks of follow-up demonstrating satisfactory alignment and no evidence of hardware complications.

Fig. 8.

Postoperative left shoulder radiographs at 8-month follow-up demonstrating interim hook-plate removal, satisfactory alignment, and no evidence of hardware complications.

Fig. 9.

Postoperative range of motion images at almost 3 years of follow-up demonstrating (Fig. 9-A) abduction, (Fig. 9-B) internal rotation, (Fig. 9-C) forward flexion, and (Fig. 9-D) side view of forward flexion.

Discussion

SSSC double disruption injuries are not quite as rare as originally perceived^3-5. A review of the literature for the even rarer triple or quadruple disruptions of the SSSC yields 3 reports of triple disruptions^6-8, 1 report of open quadruple disruption⁹ and a 10-year prospective case series of 180 operative scapula fractures, of which 15 were considered triple or quadruple disruptions¹⁰. None of these cases describe the inclusion of a proximal humerus fracture-dislocation as seen in the case described in this study. These injuries can be associated with significant morbidity, especially when combined with a scapula fracture as they have a high rate of associated injuries¹⁰.

Treatment paradigms of complex SSSC injuries have not been well defined in the past, given prior controversies over nonoperative vs. operative management of the double disruption of the SSSC^11-14. Although nonoperative treatment has been shown to have acceptable outcomes¹², the decision to treat operatively is still largely determined by the degree of displacement of disrupted SSSC components. In a normal functioning shoulder, the clavicle connected to the SSSC puts the scapula in a more retracted position and allows a favorable and efficient scapular position for functional shoulder movement^15-17. If the chain of force transmission from the GH joint to SC joint becomes disrupted as seen in SSSC disruption, unopposed muscular forces acting on the scapula can alter the scapular position toward a more protracted position with internal rotation and anterior tilt causing disruption in the kinematics of the shoulder movement¹⁸.

Although the injury of an open quadruple disruption of the SSSC with an associated proximal humerus fracture-dislocation is not described to our knowledge, we ultimately elected to perform operative fixation of the type 5 AC joint separation, scapular body, intra-articular glenoid fracture, and proximal humerus to restore the correct anatomic positioning of the shoulder girdle for optimal functioning given his age and functional status as well as prevent glenohumeral osteoarthritis. Operative fixation of these injuries would allow for earlier shoulder mobilization, which would aid in his ability to undergo physical therapy and prevent further morbidity with shoulder stiffness and pain. We elected to place a hook plate over the AC joint rather than a suspensory device or perform an allograft CC ligament reconstruction due to the strength of the plate and its ability to properly hold the scapula in a more superiorly translated position next to the distal clavicle. This position allows for less stress to be put on the plates and screws being used to hold the reduced fractures in the glenoid and scapular bodies.

Conclusion

Quadruple disruptions of the SSSC may represent significant morbidity given their association with polytrauma, affecting the ability to recover postoperatively. We present the first documented case of a patient with a quadruple disruption coupled with a proximal humeral fracture-dislocation. Despite the patient's complicated injury pattern, our treatment regimen led to a successful outcome with no complications.