Open reduction internal fixation with mesh plating and suture fixation for scapulothoracic dissociation: a case report and discussion of surgical methods

Abstract

Scapulothoracic dissociation (STD) is a rare, limb-threating injury that typically results from high-energy trauma to the shoulder girdle. Outcomes of STD can be devastating with flail limb developing in up to 50% of patients, 11 amputation required in up to 20% of patients, and an overall mortality rate of 11%. 2 STD is often missed on initial examination when patients present with polytrauma, leading to delayed diagnosis and treatment and ultimately increased morbidity and mortality. Originally described by Oreck in 1984, 18 there have been further variations of STD described to date. The most common injury pattern consists of a laterally displaced scapula, disruption of the brachial plexus and subclavian vessels, and a distracted clavicle fracture. 4 Other patterns include sternoclavicular joint (SCJ) disruption, acromioclavicular joint (ACJ) disruption, as well as incomplete injuries to the ipsilateral subclavian or axillary vessels and the brachial plexus. When this injury occurs in conjunction with severe neurovascular damage, it is likened to a “closed” forequarter amputation. 11 The treatment of the musculoskeletal aspect of STD by orthopedic surgeons is controversial and there are no current universal treatment algorithms. Potential advantages of open reduction and internal fixation (ORIF) of STD are to protect neurovascular structures from further damage as well as to provide a stable shoulder girdle for early rehabilitation. 5 , 6 Previous reports of STD ORIF include fixation of the clavicle fracture and any adjacent joints that display separation. 13 , 17 Fixation constructs vary widely from plates to tension band wiring. In contrast, an early above-elbow amputation has been recommended when there is complete brachial plexus avulsion due to a flail extremity. 3 Early above-elbow amputation minimizes the risk of metabolic derangement, myoglobinuria, and thrombosis associated with crush injuries. It has been shown that some patients recover and return to work quicker with an early amputation. However, many patients struggle to accept the social and cosmetic aspects of traumatic amputations, 3 , 5 , 7 which can increase rates of anxiety and depression and negatively affect quality of life. 2 , 16 There is no widely agreed upon algorithm for the musculoskeletal management of STD. Due to the low incidence of STD, decisions regarding the optimal treatment are often based on case reports and a clinician’s judgment. Here, we describe a successful case with a treatment approach to STD with ORIF of a concomitant clavicle fracture, SCJ dislocation, and coracoclavicular (CC) ligament injury using an approach involving traditional fixation techniques and a combination of various suture fixation devices. Case Injury A 28-year-old, right-hand dominant male who works as a tractor-trailer mechanic was involved in a motorcycle accident. He presented to the emergency department by ambulance unable to move his right upper extremity, with a splint on his right lower extremity. His Glasgow Coma Scale score was 15 and there were facial abrasions across his forehead and nose. There was an obvious deformity of the right lower extremity, with cyanosis of the toes, and an absent dorsalis pedis artery pulse even with Doppler. Postreduction of the lower extremity fracture, perfusion, and signal were returned. The right shoulder had diffuse swelling with superficial abrasions, and the right upper extremity was pulseless with soft compartments and complete loss of motor function and sensation of the C5-T1 dermatomes. Radiographs of his right lower extremity revealed a comminuted distal third tibial shaft fracture. Radiographs and computed tomography (CT) imaging with 3-dimensional reconstruction was obtained of his right upper extremity to characterize the extent of bony injury, including fracture pattern and joint congruency. These revealed a scapular body fracture with lateral displacement of the scapula, a displaced distal clavicle fracture, and a SCJ dislocation (Figure 1, Figure 2, Figure 3). A CT angiogram was also performed on his right upper extremity given his pulseless extremity, which identified a right subclavian and proximal axillary artery occlusion and disruption. Magnetic resonance imaging of the brachial plexus was sought to better characterize injury to nerves prior to surgery, but this was initially unable to be obtained due to the patient’s size. The injury was classified as a Zelle type 4 and Damschen type 3 STD based on radiographic findings as well as complete loss of neurologic function in the right upper extremity. 7 , 12 Figure 1 AP radiograph of right shoulder at time of presentation demonstrating a displaced distal clavicle fracture. AP, anteroposterior. Figure 2 3-dimensional (3D) CT reconstruction demonstrating a comminuted right scapula fracture, distal clavicle fracture, sternoclavicular joint disassociations, as well as severe lateral displacement of the scapula. CT, computed tomography. Figure 3 3D CT reconstructions further demonstrating the scapula fracture, clavicle fracture, and sternoclavicular joint disassociations. (A) Anterior view. (B) Cranial view. (C) Posterior view. 3D, 3-dimensional; CT, computed tomography. Surgical technique Initial stabilization Treatment of the vascular injuries was prioritized and performed on the night of presentation by the vascular surgery team via endovascular repair of the right subclavian and axillary arteries with a Viabahn 8 mm × 15 cm stent (W. L. Gore and Associates, Flagstaff, AZ, USA). The following morning, intramedullary nailing of the right tibial shaft fracture and fasciotomies of the right arm and forearm were performed by the orthopedic service during the same procedure. Fasciotomies were prophylactically performed due to the patient’s increased risk for developing compartment syndrome status post endovascular repair the previous day. The fasciotomy wounds were loosely closed at the end of the procedure to decrease chance of nosocomial infection while in the intensive care unit. Shoulder ORIF Following vascular repair and stabilization of long bone injury, the patient returned to the operating room for surgical stabilization of the STD on hospital day 3. The patient was positioned supine on a reversed cantilever-type table with a radiolucent extension and plexiglass arm board. The patient’s cross-matched blood was available and a vascular surgeon was on call during the entirety of the procedure. Prior to incision, fluoroscopy was used to localize the sternal notch, SCJ, and ACJ. A single incision was then made that extended from the midbody of the sternum to the lateral border of the acromion to ensure these three landmarks were incorporated in the approach. The fracture of the distal clavicle was noted to be 1.4 cm medial to the ACJ; however, the ACJ ligaments and capsule appeared to be intact. There was lateral translation of both the scapula and distal fragment of the clavicle. Medially directed reduction force was used through the lateral arm to medialize the scapula and decrease the fracture gap. Two orthogonal, modified pointed reduction clamps were placed through drill holes in the clavicle to directly reduce and compress the transverse fracture of the distal clavicle. A DePuy Synthes 3.5 mm Locking Compression Plate (LCP) oblique T-plate (DePuy Synthes, Raynham, MA, USA) was utilized to stabilize the distal clavicle fracture (Fig. 4, A). The T portion of the plate provided adequate fixation into the acromion and the shaft of the plate allowed for fixation across the fracture into the clavicle. Kirschner (K) wires were used for provisional fixation of the plate and 4 unicortical locking screws were placed into the acromion to provide fixed-angle fixation and minimize irritation of the underlying rotator cuff muscles. The plate positioning allowed for a single screw hole of fixation into the lateral aspect of the clavicle with a 3.5 mm cortical screw. To generate further compression, 2 cortical screws were placed in the medial aspect of the plate after eccentric drilling. One additional locking screw was placed in the medial aspect of the plate. Figure 4 Intraoperative fluoroscopic images demonstrating: (A) Reduction of the clavicle fracture using modified clamps and plate application, (B) Drill placement through the plate/clavicle and coracoid to allow insertion of suture button device, (C) T-plate applied spanning the acromioclavicular joint for fixation of the distal clavicle fracture following clamp removal, (D) application of a mesh plate and internal brace for fixation of the sternoclavicular joint. The CC ligaments were confirmed to be completely disrupted, therefore we elected to reconstruct the CC ligaments using a TightRope (Arthrex, Naples, FL, USA) suture button device to further secure the scapula to the clavicle and reinforce the overall construct stability. Both fluoroscopy and tactile feedback were used to localize the coracoid. Manufacturer guidelines were followed to place a guidewire, cannulated drill, and insert the suture button through the plate, clavicle, and coracoid (Fig. 4, B). The TightRope construct was maximally tensioned and secured (Fig. 4, C). A fracture-dislocation of the first rib at the sternocostal junction was present along with the SC dislocation, but the costoclavicular ligaments were noted to be intact. The fracture gap was able to be reduced with a medially directed force along the shoulder and compression was achieved with a modified clamp placed through drill holes in the first rib and sternum. Direct visualization as well as fluoroscopic imaging showed appropriate reduction of the SCJ and first rib. No capsular or ligamentous tissue was amenable for direct repair, therefore a dual Internal Brace (Arthrex, Naples, FL, USA) construct, each consisting of two 3.5-mm SwiveLock anchors (Arthrex, Naples, FL, USA) and FiberTape (Arthrex, Naples, FL, USA) was utilized. The thickness of bony structures was preoperatively measured from CT imaging, which ensured that drilling holes for the suture anchors did not extend deeper than bone and damage the underlying neurovascular structures (Fig. 5). The first internal brace was placed over the cranial portion of the SCJ and the second over the caudal aspect while exercising extreme care. Figure 5 Preoperative planning on CT images in order to plan safe placement of suture anchors. Since the anchors are a predetermined length, it is recommended to understand if the intended area of insertion is deep enough or if slight angulation if needed to avoid violating the far cortex and risk neurovascular injury which could be catastrophic in the region of the sternoclavicular joint. (A) Axial view of medial clavicle showing appropriate depth for drill and anchor insertion 10 mm lateral to the joint. (B) Axial view of the sternum showing that moving 20 mm from the joint is necessary for appropriate depth. (C) Coronal view used for localization of appropriate axial measurements for (A and B). CT, computed tomography. Additional fixation was felt to be necessary due to the tremendous stress across the SCJ as this is the main connection between the appendicular and axial skeleton for this extremely unstable upper extremity combined with the patient’s obesity and complete lack of motor function. A Synthes 2.4/2.7-mm VA-LCP mesh plate (DePuy Synthes, Raynham, MA, USA) was cut and contoured to allow placement across the SCJ (Fig. 4, D). The plate bridged from the medial aspect of the clavicle to the proximal aspect of the sternum and secured with unicortical locking screws into the sternum and both locking and cortical screws into the clavicle. Final imaging confirmed appropriate reduction and safe implant placement at all points of fixation (Fig. 6). There were no intraoperative or postoperative complications. Figure 6 Immediate postoperative AP radiographs (A and B) of right shoulder demonstrating the final construct and reduction. Clavicle is anatomically aligned, and the normal alignment of the CC and SC joints has been restored. AP, anteroposterior; CC, coracoclavicular; SC, sternoclavicular. Recovery and follow-up Postoperatively, the patient was placed in a sling to provide additional security to the arm, prevent further traction neuropraxia, and protect the construct. He was instructed to avoid passive motion of the right shoulder but was approved to perform passive range of motion (ROM) of the elbow and wrist with formal physical therapy. The patient discharged to a post-acute rehab facility on post-injury day 14. A dedicated brachial plexus magnetic resonance imaging obtained prior to discharge showed no evidence of nerve root avulsion. Postoperative radiographs at 6 weeks and at clinic follow-ups thereafter showed stable implants with no signs of loss of fixation or failure. The patient had no incisional complications and pulses were 2+ with good limb perfusion. The patient was referred to an upper extremity specialist with a brachial plexus focus on an outpatient basis where neurologic function continues to be assessed for possible brachial plexus exploration. Electromyography was performed two months following the injury, which corroborated a right pan-brachial plexopathy. He has been gradually allowed to increase use of his right arm as tolerated but has not recovered any neurologic function as shown by continued presence of a flail right upper extremity. Patient had complaints of neuropathic pain throughout the right extremity but has not regained sensation. Postoperative imaging at 8 months (Fig. 7) showed no signs of implant failure despite nearly complete inferior glenohumeral joint subluxation due to muscle paralysis. He has developed slight contractures throughout the upper extremity but has maintained normal vascular function. Figure 7 8-month postoperative AP radiograph of right shoulder. The CC and SC joints remain well aligned and the clavicle fracture has united with no loss of reduction at any location when compared to initial postoperative radiographs. There are no signs of implant failure despite the stress on the construct by a flail limb as evidenced by chronic glenohumeral subluxation due to no muscle recovery. AP, anteroposterior; CC, coracoclavicular; SC, sternoclavicular. Discussion In this case of STD following a high-energy trauma, a patient was successfully treated with ORIF of the distal clavicle utilizing an ACJ-spanning plate, CC ligament reconstruction utilizing an Arthrex TightRope system, and SCJ reconstruction and internal fixation utilizing an Arthrex Internal Brace, and a Synthes mesh plate. Preoperative planning considered both the patient’s body habitus and the stability believed to be required to prevent further neurovascular injury. This patient had complete loss of neurologic function of his right upper extremity due to severe brachial plexus injury and consequently had no muscular support of his right shoulder. ORIF was chosen to provide the patient the best chance at recovering neurologic function by preventing further damage of the neurovascular structures because the patient was not able to control his limb for protection. Injury severity Because STD often occurs in a patient with polytrauma, not only is the classification of STD important, but the swift identification of any injuries that may lead to further complication such as sepsis, limb loss, and even death is imperative. Severity level of an injury is often a good predictor of patient outcomes and is used for guiding treatment decisions. For STD injuries, often two main score categories are used, one to determine the extent and type of STD and one to determine limb survival. In combination, these two scores are utilized for predicting a patient’s prognosis. The Damschen classification and the Zelle classification, a modification of the prior, are often utilized for categorization of the extent and type of STD injury. 4 , 6 , 24 In the Zelle classification, the injury is divided into 4 types depending on the presence of musculoskeletal, vascular, and neurologic injury. The patient described above was categorized as a Zelle type 4 which has been shown to result in poor patient outcomes. The Mangled Extremity Severity Score (MESS) has often been used to identify injured limbs that may require amputation. 9 , 14 The value of the MESS has come into question accompanied by a call for further identification of predictors of amputation because of the treatment advances that have developed since 1990 when the MESS was developed. Further research into optimal classifications of STD injuries and the treatment options available is needed. Treatment modality Choice of treatment modality for STD must consider the vascular, neurological, and musculoskeletal injuries and the possibility for patient recovery. Oftentimes due to the concomitant presence of polytrauma, neurologic injuries have delayed management in favor of treating vascular injuries first. The ideal timing for orthopedic intervention has not been well-defined, 15 but stabilizing the shoulder girdle may assist in preventing further injury to repaired vascular structures and it may be beneficial to treat orthopedic injuries immediately following vascular repair. 5 , 6 The choice of ORIF or amputation is controversial and the main discussion point since STD has been defined. There have been cases reporting treatment with both modalities with varied success. McCague et al 15 suggest that when a patient presents with both brachial plexus avulsion and severely compromised vasculature, amputation is a safer route as there are fewer existing guidelines for fixation or nonsurgical management. On the contrary, Sampson et al 17 reviewed 11 cases of STD with complete subclavian and brachial artery occlusion and found equivocal evidence for revascularization. Six of their patients were revascularized and five were not; all limbs in both groups remained viable, but none regained function. 20 In the last decade, evidence in the literature has supported ORIF for cases of STD (Table I). 1 , 10 , 12 , 13 , 15 , 17 , 19 , 23 Lal et al reported the case of a 32-year-old male who sustained a Zelle 2B STD following a motor vehicle accident. They performed ORIF with successful recovery of a nearly full ROM in the shoulder postoperatively. 13 Nanno et al described ORIF in a 38-year-old male who sustained fractures of the clavicle, scapular neck, and coracoid process after a motorcycle accident. They performed clavicle ORIF but not scapular neck or coracoid process fixation; at 14-month follow-up, the patient was pain-free with recovery of limited ROM. 17 Others have endorsed ORIF to avoid delayed union or nonunion, to protect neurovascular structures for rehabilitation, and to restore shoulder girdle stability. 8 , 11 , 22 Table I Overview of scapulothoracic dissociation case reports published in the last decade (2011-2021). Author, y Age (y) Sex Cause of injury Injury type Orthopedic/Neurologic treatment Outcome (F/u time) McCague et al, 2012 15 25 F MV accident Type IV Amputation at level of humeral deltoid insertion Survival; requires full care at skilled nursing facility (NA) Nanno et al, 2012 17 38 M MV accident NA Open reduction internal fixation Pain-free, has diminished motor function (14 mo) Lal et al, 2014 13 32 M MV accident Type IIB Open reduction internal fixation Nearly full range of motion, uneventful f/u (NA) Ozeki et al, 2015 19 20 M MV accident Type IIB Reduction, stabilization Complete recovery of suprascapular and axillary nerves (1 yr) Anbarasan et al, 2018 1 21 M Industrial accident NA Forequarter amputation Wound healed (1 mo) Jordan et al, 2019 10 “Young” M Shotgun blast NA Nonsurgical management Slow return of elbow and wrist flexion/extension and diminished grip strength (NA) Labrum et al, 2019 12 28 M MV accident Type IV Nonsurgical management; then performed glenohumeral amputation Developed necrosis after preservation; uneventful f/u after amputation, severe phantom limb pain (4 yrs) Vega Peña et al, 2020 23 24 M MV accident NA Fasciotomy, nonsurgical management Partial functional recovery of proximal third of the arm (1 yr) F, female; M, male; MV, motor vehicle; mo, months; y, years; f/u, follow-up; NA, not available. Limited guidance exists on the ideal order of fixation during ORIF of STD, largely due to the variability of concomitant injuries. In our case, we elected to stabilize the clavicle first to protect the patient’s arterial repair and to prevent further traction injury to the brachial plexus, however, we recommend approaching the order of injuries on a case-by-case basis. Following ORIF, it is important to perform repeat neurovascular evaluations if there is concern for damage intraoperatively. Electromyography and nerve conduction studies are helpful in localizing nerve injury and monitoring the injury status, but they should not be performed sooner than 3 weeks after injury. 20 It is also important to provide realistic postoperative expectations with patients. Approximately 52% of patients with STD will have complete loss of motor and sensory functions in the affected extremity. 1 , 10 Since STD is rare, it is difficult to create a treatment algorithm that fully captures and appropriately weighs all possible factors. However, improved decision-making aids are needed, as clinicians have voiced concerns that singular factors, such as MESS scores, are inadequate for choosing treatment and predicting outcomes. 21 By building resources for well-informed treatment decisions, we may come closer to clarifying/quantifying the best paths forward in ambiguous cases and improving patient outcomes. Conclusion In this case of STD, we present unique surgical techniques to address both the associated bony and soft tissue injuries. This case emphasizes that both the bone and soft tissues need to be addressed to adequately stabilize the flaccid upper extremity to allow for protection of the neurovascular structures. This case report joins a growing body of evidence that supports ORIF for mid-level injury severity. In the future, a universal resource of treatment considerations to predict optimal patient outcomes is needed to improve and support clinician judgment. Acknowledgment The authors acknowledge Superior Medical Experts for assistance with drafting and Samuel Stegelman for assistance with editing. Disclaimers: Funding: No funding was disclosed by the authors. Conflicts of interest: The authors, their immediate families, and any research foundation with which they are affiliated have not received any financial payments or other benefits from any commercial entity related to the subject of this article. Patient consent: Obtained.