Pelvic Ring Injury
Classification systems
- Descriptive of anterior and posterior ring involvement
Mechanism
High-energy trauma: a lateral impact from a vehicle, an anteroposterior crush such as a motorcyclist or a pedestrian, or a vertical shear from a fall from height. In the elderly, a simple fall can produce a fragility fracture of the pelvis with an intact-looking ring but genuine posterior insufficiency. The clinical priority is haemorrhage — the posterior venous plexus and branches of the internal iliac artery bleed into a pelvis that has lost its containment.
Age considerations
- Paediatric
- The elastic paediatric pelvis can deform and spring back, so single-break patterns are more common and the triradiate cartilage may be injured with later acetabular dysplasia. Significant visceral injury may accompany a deceptively mild-looking radiograph.
- Young adult
- High-energy injury demanding a systematic trauma approach: haemorrhage control, exclusion of urogenital and bowel injury, and definitive fixation of an unstable ring once resuscitated.
- Elderly
- Fragility fractures of the pelvis present with inability to mobilise after a modest fall. Cross-sectional imaging reveals posterior ring involvement not visible on plain films; treatment focuses on analgesia and early mobilisation, with percutaneous fixation for those who cannot mobilise.
Management options
Resuscitation with a pelvic binder and haemorrhage controlshowhide
Indication
Every haemodynamically abnormal patient with a suspected unstable pelvic ring injury.
Implant design notes
A circumferential pelvic binder applied at the level of the greater trochanters, reducing pelvic volume and tamponading venous bleeding. It is a resuscitation device, not a definitive treatment, and prolonged application causes pressure necrosis.
Approach
Non-operative resuscitative measure alongside transfusion protocols, angioembolisation or pelvic packing.
Steps overview
- Apply the binder at the level of the greater trochanters, not the iliac crests
- Follow the major haemorrhage protocol with blood products rather than crystalloid
- Examine for urogenital injury: blood at the meatus, scrotal or perineal bruising, and a high-riding prostate
- Do not spring or rock the pelvis repeatedly — one gentle assessment at most
- Obtain cross-sectional imaging with contrast when stable enough, and involve interventional radiology for arterial bleeding
- Consider pre-peritoneal packing and external fixation in the persistently unstable patient
- Remove or loosen the binder as soon as it is safe to prevent skin necrosis
Notes
Do not pass a urinary catheter blindly if a urethral injury is suspected; involve urology. Rocking the pelvis to test stability displaces clot and worsens bleeding.
Resident summary compiled from standard orthopaedic trauma teaching; verify against your departmental protocol.
External fixation or anterior pelvic bridgingshowhide
Indication
Damage control stabilisation of the unstable ring, particularly with an open abdominal wound, and as an adjunct while the patient is resuscitated.
Implant design notes
Supra-acetabular or iliac crest pins connected anteriorly, controlling rotational instability. It controls the anterior ring only and does not stabilise a vertically unstable posterior ring, for which posterior fixation is required.
Approach
Percutaneous pin insertion under fluoroscopic control, taking care with the lateral femoral cutaneous nerve.
Steps overview
- Choose pin sites — supra-acetabular pins give better mechanical control than iliac crest pins
- Insert pins under fluoroscopy, confirming they are within the bony corridor
- Reduce the rotational deformity and lock the frame with clearance for the abdomen
- Recognise that vertical instability still needs posterior fixation
- Continue resuscitation and reassess for ongoing bleeding
- Plan definitive fixation once physiology allows
Notes
A frame is not definitive treatment for a vertically unstable injury; say so explicitly in a viva.
Resident summary compiled from standard orthopaedic trauma teaching; verify against your departmental protocol.
Definitive internal fixation of the ringshowhide
Indication
Rotationally or vertically unstable ring injuries in a resuscitated patient, and displaced injuries that will not tolerate mobilisation.
Implant design notes
Anterior plating of the symphysis with a multi-hole plate, and posterior stabilisation with percutaneous iliosacral screws along the safe osseous corridor, or plating of the posterior ring. Percutaneous techniques minimise soft tissue insult in a region where wound problems are catastrophic.
Approach
Pfannenstiel or modified Stoppa approach for the symphysis and anterior column, percutaneous posterior approach for iliosacral screws with high-quality imaging.
Steps overview
- Confirm the patient is physiologically ready and the deformity is fully characterised on cross-sectional imaging
- Reduce the posterior ring first in most patterns, since it determines overall alignment
- Insert iliosacral screws under precise fluoroscopic control using inlet, outlet and lateral views
- Verify screw position within the corridor before advancing — the nerve roots and vessels are adjacent
- Address the anterior ring with symphyseal plating or an anterior subcutaneous internal fixator
- Confirm the reduction of the whole ring, then plan progressive weight bearing
Notes
Iliosacral screw placement demands excellent imaging and understanding of the safe corridor; a malpositioned screw injures the L5 or S1 nerve root.
Resident summary compiled from standard orthopaedic trauma teaching; verify against your departmental protocol.
Viva pearls
- Start every answer with resuscitation and haemorrhage control, not with classification.
- Apply the binder at the greater trochanters — at the iliac crests it does not reduce pelvic volume.
- Examine for urogenital and rectal injury and document it; a missed urethral injury is a serious omission.
- Do not repeatedly spring the pelvis; one gentle assessment, then imaging.
- An anterior external fixator does not control vertical instability — the posterior ring needs fixation.
- In the elderly, inability to mobilise after a minor fall with normal plain films means cross-sectional imaging for a fragility fracture of the pelvis.
Sources for further reading
- Rockwood and Green's Fractures in Adults — pelvic ring injuries
- Standard operative orthopaedics textbook — pelvic and acetabular trauma
- Advanced trauma life support principles and national major trauma guidance
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Resident-authored study summary in original wording, not reproduced from copyrighted source text.