The shoulder girdle is highly mobile and complex joint made up of the clavicle with the sternoclavicular and acromioclavicular joints, the scapula and glenohumeral joint and their ligamentous attachments to each other. It forms the only functional link between the axial skeleton and the upper limb suspending its entire weight. The term “floating shoulder” was first described by Ganz and Noesberger in 1975 as an ipsilateral fracture of the middle third of clavicle and glenoid neck ^[1]. The definition was later expanded to as double disruption of the superior shoulder suspension complex (SSSC) by Goss ^[2]. SSSC is essentially a bone and soft tissue stable ring made up of clavicular-acromioclavicular strut, the three-process scapular body junction and the clavicular-coracoclavicular ligamentous-coracoid (C-4) linkage. When the biomechanical integrity of SSSC is disturbed at two sites the weight of the arm along with the musculature around the shoulder girdle pulls it anteriorly, medially and inferiorly which, when left untreated, results in sequelae, such as nonunion, malunion, drooping shoulder, weakness and muscle fatigue causing dyskinesia, rotator cuff dysfunction causing early degenerative joint disease, chronic brachial plexopathy [2-5]. Due to paucity of literature on standard protocol in management of floating shoulder there are no definitive guidelines. Studies have shown conservative treatment with aggressive physiotherapy after a few weeks to benefit with good outcome for these injuries but are possibly best reserved for undisplaced or minimally displaced fractures ^[6]. According to Goss significant displacement of the scapular neck constituted of >10 mm of translation and >40° in sagittal and/or coronal planes ^[2]. Hardegger et al. [3,7] postulated that, in floating shoulders, disruption at any one site of the SSSC complex makes the other site even more unstable in a vicious cycle altering the functional anatomy and muscular forces. The Glenopolar angle (GPA) can also be used to measure the severity of displacement of scapula neck, was first described by et al. ^[8]. Normal values range between 30 and 45°. et al. ^[9] reported a GPA of <20° to be associated with poor functional outcome. The glenoid offset is the distance between medial border of distal clavicle and the line drawn tangential to the greater tuberosity of humerus. et al. ^[10] said that >25 mm of medialization produces abductor weakness predisposing to joint wear in the long term. Early surgical fixation within 10 days eases the rehabilitation of the patient, especially important in cases of polytrauma patients resulting in improved functional results. The present study aims to assess the functional outcome of surgical fixation of both glenoid neck/spinal pillar fractures and clavicle in unstable floating shoulder injuries (FSI).

An interventional observational study was conducted in level 1 trauma care center in Nagpur, India between May 2019 and May 2023 on 18 patients with significantly displaced (GPA <20°, medialization/lateralization >25 mm, clavicular shortening >20 mm) unstable floating shoulders. The study was approved by the ethical committee of the Ggovernment medical college and hospital, Nagpur, India. The selected participants were visited, and a questionnaire was administered after a written informed consent was obtained. All patients were willing to visit for post-operative follow-up visits. Standard antero-posterior, Grashey and lateral view radiographs were taken both pre- and post-operatively. A pre-operative computed tomography (CT) scan with 3D reconstruction was obtained in all patients for accurate assessment of fracture configuration and measurements of parameters of displacement. The orthopedic trauma association/arbeitsgemeinschaft fur osteosynthesefragen classification system was used to classify both clavicle and scapula. Patients eligible for the study were skeletally mature patients >18 years of age, fresh (injuries within 14 days of presentation) double disruption of the SSSC which met the criteria for significant displacement. Exclusion criteria included minimally displaced floating shoulder, associated neurovascular injury, previously operated shoulder, previous malunion and/or nonunion. Operative indications for ipsilateral fractures comprised of GPA <20°, medialization of >25 mm, open fractures, clavicular shortening of >20 mm or displacement >10 mm with no cortical contact/comminution. Distances and angles were calculated using picture archiving and communication system or by manual methods using protractors. The GPA is measured on 3D CT reconstruction by the angle created by two lines- line 1 extending from the superior glenoid pole to inferior glenoid pole and line 2 connecting the superior glenoid pole to the inferior most pole of inferior pole of scapula. Medialization/lateralization displacement is measured similarly by determining the distance between the vertical planes drawn at the lateral most edge of both scapular fragments (Fig. 1). All patients were operated in floppy lateral decubitus with shoulder girdle and the whole upper limb prepared and draped. Clavicle fracture was fixed first in all cases with an anatomical 3.5 mm clavicle plate using standard direct approach. Brodsky’s direct lateral column approach was taken to fix the scapula which utilizes the plane between infraspinatus and teres minor. 3.5 reconstruction plates, molded to match anatomy, were used for fixing the lateral pillar. Reduction and fixation of clavicle first allows for ease of reduction of the scapular segment; both fixations were carried out in the same seating (Fig. 2 and 3). The shoulder was kept in a universal shoulder immobilizer for up to one week depending upon the associated injuries, following which gentle pendulum exercises with passive movements for the shoulder girdle were initiated. Full range of movements compatible with activities of daily living was started at 2 months. Patients were evaluated clinically with Herscovici and American shoulder and Elbow score (ASES) scoring system and imaged at regular intervals of 2, 6 and 12 weeks in AP, lateral, Grashey views. Additional follow-up for any complication including but not limited to plate prominence, poor range of motion, persistent pain for a period of 18 months (Fig. 4).

The mean age at the time of injury was 34.11 years. High energy mechanism was the cause of all the cases which included motorcycle and automobile accidents. There were 6 (33.33%) females and 12 (66.66%) males. The mean delay in surgery was 4.3 days. Mean stay in hospital was for 13.2 days. Details about patient demographic and injury characteristics are tabulated in Table 1. Associated injuries in the form of rib fractures, ipsilateral fractures, hemothorax and/or pneumothorax, head injury, blunt trauma abdomen are documents in Table 2 along with injury parameters. Tables 3 and 4 document functional outcome. The mean time for signs of radiological union to be seen in clavicle was 13.55 weeks and for scapula it was seen to be 8.5 weeks. Cases with blunt trauma chest presented with hemothorax and/or pneumothorax were managed with an intercostal drain insertion for 5 days till breath sounds were equal bilaterally. Patients with head injury who had multiple hemorrhagic contusions on CT Head; was managed conservatively. No patient in our series had head injury which warranted surgery. 2 patients with Femur shaft fractures were managed femur interlock nailing on day 3 following injury, which was followed by scapula and clavicle plating after 2 days for optimizing physiologic reserve. One case of blunt trauma abdomen having grade 1 liver laceration was kept under observation for 7 days following which he was operated for floating shoulder after general surgical clearance. One patient developed early post-operative surgical site infection at the site of clavicular plating on day 3. He was immediately taken up for debridement and given antibiotic coverage for 6 weeks. The wound eventually healed well with the patient with a Herscovici score of 7 and ASES score of 62% at 13 months of follow-up.

“Floating shoulder injuries” are rare with complex fracture patterns [1,2]. This type of double disruptions of SSSC is usually the result of high energy trauma can cause associated injury to the thorax, abdomen, head or limb fractures. et al. ^[11], in a cadaveric study, reported that he glenoid becomes unstable when both the coracoacromial and the coraco-clavicular ligaments are cut. Thus, the term floating shoulder is used when the bony and/or the ligamentous continuity of the girdle is disturbed as described by ^[4]. It is imperative to mobilize such polytrauma patients as early as possible for physical and psychologic benefits. et al. ^[12] reported that unstable shoulder girdle injuries should undergo surgery for fixation as early as possible, so that they could be undergo functional rehabilitation at the earliest. The surgical techniques have become popular with the advent of new implants and technology. These new techniques provide objective indications as to what constitutes as an acceptable displacement and angulation, thereby improving results with surgical fixation. Good reduction equalizes the length and tension of the muscles around the shoulder girdle restoring the normal leverage of rotator cuff which in-turn enables for early exercise of shoulder. et al. ^[13] suggested the most important factor for determining shoulder function is the degree of displacement of the glenoid. There are studies which advocate that fixation of only the clavicle indirectly reduces the scapula by means of the intact ligaments and muscle pull. et al. ^[14] reported on 7 cases had excellent results after fixing only the clavicle but two patients had severe drooping of shoulder which could not undergo operative management later due to severity of injuries. Similar studies by . [9, 15] postulate that scapula fixation is not necessary in double disruptions as some degree of malunion is tolerated. However, we feel this may lead to delayed rehabilitation which is needed for the overall health of a polytrauma patient. Furthermore, in FSI the ligament complex might not be intact to indirectly reduce and align the scapula. MRI may not always be advisable in such cases, so we have to rely on parameters, such as GPA, medialization, and glenoid offset to assess the integrity of the C4 linkage and in case of doubt it is always advisable to fix both in the same seating. As a rule of thumb, it is generally recommended to fix the clavicle first with a plate, as a nail or any other elastic form much not provide much torsional stability required. With the now clavicle stable, the motion at the lateral pillar of scapula is negated and it is easy to reduce and fix it. Our study showed excellent to good Herscovici scores in 72.2% and ASES score of 50–100 in 61% of the patients. However, being a single center study with a small cohort of patients our results are difficult to generalize. Furthermore, our study group only comprised of patients managed surgically and was compared to the contralateral side which was assumed to be normal. Another limitation was that more than one surgeon operated but a single surgical approach was used for both the fixation.

Open reduction and internal fixation of unstable FSIs, especially in polytrauma patients, results in early opportunity for rehabilitation with a good clinical outcome. Surgical fixation should ideally be down within the 1^st 10 days to maximize the outcome; fixation of clavicle first eases reduction of the scapula.

FSIs represent complex disruption in the soft tissue and bony attachment between the axial and appendicular skeleton, often associated with high energy trauma. Early surgical fixation of scapula and clavicle allows effective mobilization required for optimization the overall health of a polytraumatized patient.