CT Case 086
An 18-year-old male presents following after a high-speed motorbike accident (MBA) in which he was thrown into a pole at whilst wearing a helmet.
On arrival he was haemodynamically stable with a GCS of 14. He has extensive grazes to his left shoulder and marked left upper arm swelling.
Following the primary survey it was noted that he had an absent left radial and brachial pulse. Bedside doppler could detect left upper limb pulses and the hand was warm. However there was minimal motor function in the left upper limb.
A CXR and Left shoulder X-ray were taken in the resuscitation bay
The patient is subsequently taken for CT.
Describe and interpret the CT scans
Underlying the clavicle fracture there is abrupt cut-off of the left subclavian artery as it passes over the 1st rib with distal reformation of the axillary artery.
Other fractures revealed on CT include a fracture of the left acromion and widening of the left AC joint. There is also a fracture of the scapula, involving the coracoid process and extending into the anterior aspect of the glenoid. There is extensive haematoma associated with these shoulder girdle injuries.
Clinical Pearls
This complex of injuries is suspicious for scapulothoracic dissociation.
This injury occurs as a result of a high velocity traction injury to the arm.
Severe neurological sequelae with injury to the brachial plexus and or nerve root avulsion may occur.
The left subclavian artery occlusion seen on CT was thought to be secondary to thrombus with likely underlying small dissection. Extrinsic compression secondary to haematoma was thought to also contribute. This was managed with aspirin, and decompression of the haematoma intra-operatively.
MRI imaging was consistent with a complete brachial plexus injury, which has left him with permanent neurological deficit of his left arm.
He had ORIF with plates to his clavicular and humeral fractures.
References
- Kani KK, Chew FS. Scapulothoracic dissociation. Br J Radiol. 2019 Sep;92(1101):20190090.
- Heiman EM, Jankowski JM, Yoon RS, Feldman JJ. Scapulothoracic Dissociation: A Review of an Orthopedic Emergency. Orthop Clin North Am. 2022 Jan;53(1):77-81
- Choo AM, Schottel PC, Burgess AR. Scapulothoracic Dissociation: Evaluation and Management. J Am Acad Orthop Surg. 2017 May;25(5):339-347.
TOP 100 CT SERIES
Provisional fellow in emergency radiology, Liverpool hospital, Sydney. Other areas of interest include paediatric and cardiac imaging.
Emergency Medicine Education Fellow at Liverpool Hospital NSW. MBBS (Hons) Monash University. Interests in indigenous health and medical education. When not in the emergency department, can most likely be found running up some mountain training for the next ultramarathon.
Dr Leon Lam FRANZCR MBBS BSci(Med). Clinical Radiologist and Senior Staff Specialist at Liverpool Hospital, Sydney
Sydney-based Emergency Physician (MBBS, FACEM) working at Liverpool Hospital. Passionate about education, trainees and travel. Special interests include radiology, orthopaedics and trauma. Creator of the Sydney Emergency XRay interpretation day (SEXI).