Intrathoracic scapular dislocation following radical surgical chondrosarcoma resection from chest wall

Abstract

Locked scapula or intrathoracic scapular dislocation is an extremely rare entity encountered in the emergency department, with very few cases reported in literature. Conservative vs surgical approach in treating intrathoracic scapular dislocation is not well defined in literature. In this case report, we present a rare case of intrathoracic scapular dislocation, following multiple ribs resection due to malignant bone tumour, which was treated by closed manipulation reduction technique.

Introduction

Locked scapula or intrathoracic scapular dislocation is an extremely rare entity encountered in the emergency department, with very few cases reported in literature.^1–9 An invasive procedure affecting the congruity of the ribcage such as thoracotomy or ribs resection is almost always present as a predisposing factor. When the scapula becomes trapped inside the ribcage, it compromises the lung expansion space and alters the intrathoracic pressure potentially affecting the hemodynamic stability of the patient. Thus, it requires a prompt intervention to reduce the dislocated scapula out of the intrathoracic space.

In this case report, we present a rare case of intrathoracic scapular dislocation, following multiple ribs resection due to malignant bone tumour, which was treated by closed manipulation reduction technique.

Case report

A 41-years-old man who in 2014 underwent radical surgical resection of chest wall chondrosarcoma mass and the removal of third, fourth right ribs and intercostals muscle surrounding the mass with 4 cm margins (medially and laterally), presented at the emergency department with a debilitating pain in right shoulder region after his 5-years-old daughter jumped on his upper back while lying in prone position. Clinical exam revealed hyper-protracted scapula with an absent scapular skin footprint from upper right back, an intact glenohumeral congruency – no gap sign, and intact neurovascular exam at distal right limb (Figure 1). On X-ray, the scapula silhouette was displaced anteriorly (Figure 2). Computed tomography demonstrated a dislocated scapula into the intrathoracic space through the ribcage wall defect (Figure 3). No clinical sign of patient’s hemodynamic instability was noted. Vital signs including blood pressure, heartbeat and air room oxygenation saturation were within normal limits.

Figure 1.

Absence of scapular skin footprint.

Figure 2.

Plain radiography of the scapula silhouette displaced anteriorly.

Figure 3.

Computed tomography demonstrating a dislocated scapula inside the intrathoracic space through the ribcage wall defect.

The patient was initially treated by analgesics in the emergency room. Later, the patient was taken to the operating room and placed in supine position under general anaesthesia.

The preoperative planning in coordination with cardiothoracic surgeon included, initially, an attempt of closed reduction of the scapula, with option for thoracotomy with chest wall reconstruction and mesh insertion to prevent recurrence.

Under general anaesthesia, the patient’s shoulder was brought to 90 degrees of abduction and 90 degrees of external rotation (horn blower position), a slide of the scapula was felt and reduced scapula footprint on the upper right back was noted (Figure 4). Post close reduction of the scapula, the patient was clinically and radiologically, employing intra-operative C arm scapular Y and true anterior–posterior views (Figure 5), evaluated by senior orthopaedic and cardiothoracic surgeons to confirm the reduction of the scapula with no farther imaging indicated. Stress dislocation test was conducted to assess scapular stability and evaluate the need for further immediate invasive procedure with posterior chest wall reconstruction. Scapular instability was noted at 45° body supination with concurrent excessive axial load on right shoulder. Due to sufficient relative scapular stability and the fact that this is the first occurrence 6 years after his major operation, a conservative approach was favoured. At the end of the operation, the arm was placed in 90 degrees sling. Post-operative neurovascular exam of the limb was intact. The patient was admitted for overnight observation and later followed for 6 months in out-patient clinic with non-recurrence of scapular instability. In addition, the patient was instructed to engage in long-term peri-scapular muscles rehabilitation program.

Figure 4.

Close reduction manipulation.

Figure 5.

Post close reduction scapular Y view of the scapula.

Discussion

Intrathoracic scapular dislocation is seldom reported in literature, and it is most likely concomitant with an invasive procedure deforming the congruity of the ribcage, such as ribs resection or open thoracotomy due to metastatic bone disease. When reviewing previously reported case reports of scapular intrathoracic dislocation in literature, it appears that a minimum of two resected ribs are needed to predispose the scapula for instability episode. Conservative vs surgical approach in treating intrathoracic scapular dislocation is not well defined in literature. However, in previously reported cases, conservative approach was favoured in cases of simple scapular dislocation with no supervened complication, and surgical approach in those experiencing multiple scapular dislocation recurrences or concurrent complication.

Ward et al. and Fowler et al. presented cases of scapular dislocation which were treated by close reduction with good outcomes.^1,2 On the contrary, Tomita et al. presented a case of scapular dislocation complicated by local infection, which required a redo surgery to repair the ribcage defect. ³ Eguchi et al., presented a case of intrathoracic scapular dislocation supervened by haemorrhagic shock, which was treated by surgical reconstruction of ribcage, and Palissery et al. initially adopting conservative approach redeemed to surgical treatment due to low scapular stability.^4,5

Invasive surgical treatment to restore chest wall congruity and rigidity aids to minimize dead space, preserve pulmonary mechanic, protect intrathoracic organs, and prevent future occurrence of intrathoracic scapular dislocation or intra-thoracic organs herniation.^10–12 A method commonly employed by cardiothoracic surgeons to reconstruct the chest wall is filling the gap with synthetic material such as titanium plates or methyl methacrylate mesh. Other suggested invasive surgical treatments described in literature to prevent intrathoracic scapular dislocation include resecting the inferior pole of the scapula and scapulothoracic arthrodesis in impaired shoulder function patients.^9,13

In this case conservative approach was adopted, reducing the dislocated scapula by close reduction technique with no further ribcage reconstruction, due to relatively good clinical intraoperative scapular stability, first-time dislocation occurrence, long time interval from primary thoracic surgery, young age and no clear history of radio/chemotherapy or steroids treatment which could potentially weaken the muscle layer around the right shoulder girdle predisposing for scapular dislocation as was noted by Gould et al. ⁶

In conclusion, we suggest the following treatment algorithm in the management of intrathoracic scapular dislocation (Figure 6). In this case, a conservative approach in treating intrathoracic scapular dislocation was adopted with favourable results due to patient’s haemodynamical stability and first-time occurrence. However, due to the nature of this rare dislocation, orthopaedic surgeons treating such pathology should consider the possibility of open reduction and invasive surgical treatment. Thus, coordination with a cardiothoracic surgeon and preparing an adequate chest wall reconstruction device on standby are advised.

Figure 6.

Intrathoracic scapular dislocation treatment algorithm.

Ethical Review and Patient Consent

Ethical approval to report this case was obtained from the medical centre institutional review board. Written informed consent was obtained from the patient for his anonymized information to be published in this article.