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Q1: What is the diagnosis?
The patient has sustained a posterior fracture dislocation of the left sternoclavicular joint with compression of the upper mediastinal structures, including the oesophagus. The fracture dislocation can be visualised on the computed tomogram (fig 1; see p357) where the difference between the left and right sternoclavicular joints can be clearly seen. It is also possible the patient suffered from a transient brachial plexus palsy after injury.
Q2: What do the angiograms demonstrate?
Arteriography when performed with the limb in the resting position (fig 2; see p357) demonstrates a patent subclavian artery but with the limb in the abducted positions (fig 3; see p XXX) virtual occlusion of the subclavian artery can be seen. Venography demonstrated similar positional compression of the subclavian vein. The vascular compression accounts for the limb colour changes and lack of pulses during abduction and for the symptoms when working overhead.
Q3: How should be injury have been managed upon initial presentation?
This patient presented after a fall onto his shoulder with pain and swelling in his neck and left medial end of clavicle, symptoms and signs of neurovascular compromise of his left upper limb, and asymmetry between the medial end of his clavicles. This history strongly suggests posterior sternoclavicular joint dislocation with mediastinal structure compromise, but this diagnosis was not made post-injury as the plain radiographs appeared normal. This injury is often not demonstrated by plain radiographs and therefore computed tomography should have been performed at initial presentation, and would have demonstrated the injury. The fracture dislocation should then have been reduced, thereby resolving symptoms both from the dislocation and from compression of nearby structures. It is important not to miss posterior sternoclavicular joint dislocations as injury to the upper mediastinal structures can cause serious complications including death.
Q4: What are the management options nine years after injury?
The options available to the patient are to live with his disability or to undergo surgery to prevent the medial clavicle compressing mediastinal structures.
The patient chose to proceed to surgery due to the severity of his symptoms. At operation a fracture dislocation of the clavicle 1 cm from the medial end was noted and as reconstruction of the fracture-dislocation was not possible the medial 2 cm of the clavicle was resected subperiosteally leaving the costoclavicular ligament intact. At review six weeks postoperatively symptoms had resolved, the medial clavicle was stable and he had returned to work. At six and 12 months postoperatively the patient felt that both his upper limbs were normal and on examination his shoulders and upper limbs were functionally normal with full power, normal range of joint movements and normal pulses in all limb positions.
Posterior sternoclavicular dislocation is a rare injury.1 It is nearly always a result of trauma and is rare after the age of 25 years.2 It can result in significant morbidity or death due to the proximity of the superior mediastinal contents, which may be compressed or injured by the medial end of the clavicle.3
Early diagnosis can often be difficult due to extensive local swelling and bruising,4 difficulties in assessment using plain radiographs,5 and as this injury is rare it is often overlooked. Computed tomography is the best method of demonstrating the anatomy of the sternoclavicular joint and its surroundings structures.5 In most cases the dislocation can be reduced by closed methods within 48 hours of injury and after 48 hours open reduction is more likely to be required.2 It is therefore important to maintain a high level of suspicion of this injury as early diagnosis improves the success of closed treatment and reduces complications. Our patient’s injury was missed due to poor awareness and inadequate imaging after the injury. At presentation nine years later, the diagnosis was confirmed using computed tomography and angiography.
Our patient suffered from dysphagia due to compression of the oesophagus, which is the most common mediastinal symptom from posterior sternoclavicular joint dislocation.4 The positional vascular symptoms experienced by our patient are rare.6
Due to the length of time that had elapsed since the fracture, scarring between the medial end of clavicle and the great vessels was anticipated and therefore the operation was performed jointly by orthopaedic and vascular surgeons. Fortunately, the medial end of clavicle was mobilised easily, without damage to the great vessels.
There is conflicting advice from previous authors regarding the surgical approach for chronic posterior sternoclavicular dislocation. Rockwood et al recommend resection of the medial clavicle and retention of the costoclavicular ligament for support.7 Other authors suggest that reconstruction of the joint provides better results.8,9 In this patient reconstruction would not have produced normal joint function due to the degree of joint damage and thus resection was performed.
Medical practitioners should maintain a high index of suspicion of posterior sternoclavicular joint dislocation in patients complaining of pain near the joint after direct or indirect trauma to the neck or shoulder as this injury is easily missed. Also radiographs should not be relied upon to exclude sternoclavicular dislocation and further imaging, usually a computed tomogram, is indicated.
Posterior fracture dislocation of the left sternoclavicular joint with compression of the upper mediastinal structures.