Summary Pelvic ring fractures are high energy fractures of the pelvic ring which typically occur due to blunt trauma. Diagnosis is made radiographically with pelvic radiographs and further characterized with CT scan. Treatment is typically operative fixation depending on degree of pelvis instability, fracture displacement and patient activity demands. Etiology Associated injuries orthopaedics chest injury in up to 63% long bone fractures in 50% spine fractures in 25% non-orthopaedic urogenital login to view 1 more bullet head and abdominal injury in 40% Pediatric pelvic ring fractures children with open triradiate cartilage have different fracture patterns than do children whose triradiate cartilage has closed if triradiate cartilage is open the iliac wing is weaker than the elastic pelvic ligaments, resulting in bone failure before pelvic ring disruption for this reason fractures usually involve the pubic rami and iliac wings and rarely require surgical treatment Anatomy Osteology ring structure made up of the sacrum and two innominate bones stability dependent on strong surrounding ligamentous structures displacement can only occur with disruption of the ring in two places neurovascular structures intimately associated with posterior pelvic ligaments high index of suspicion for injury of internal iliac vessels or lumbosacral plexus Ligaments anterior symphyseal ligaments login to view 1 more bullet pelvic floor sacrospinous ligaments login to view 1 more bullet sacrotuberous ligaments login to view 1 more bullet posterior sacroiliac complex (posterior tension band) strongest ligaments in the body more important than anterior structures for pelvic ring stability anterior sacroiliac ligaments login to view 1 more bullet interosseous sacroiliac login to view 1 more bullet posterior sacroiliac login to view 1 more bullet iliolumbar login to view 1 more bullet Vascular common iliac system begins near L4 at bifurcation of abdominal aorta external iliac artery courses anteriorly along pelvic brim and emerges as the common femoral artery distal to the inguinal ligament internal iliac artery dives posteriorly near SI joint and divides in the posterior division (giving of superiior gluteal artery) and anterior division (becoming obturator artery) corona mortis is a connection between the obturator and and external iliac systems mean distance of 6.2cm from the pubic symphysis venous plexus in posterior pelvis accounts for 90% of the hemorrhage associated with pelvic ring injuries Neurologic Lumbosacral trunk crosses anterior sacral ala and SI joint L5 nerve root exits below L5 TP a courses over sacral ala 2cm medial to SI joint Classification Tile classification Tile classification A: Stable A1: fracture not involving the ring (avulsion or iliac wing fracture) A2: stable or minimally displaced fracture of the ring A3: transverse sacral fracture (Denis zone III sacral fracture) B: Rotationally unstable, vertically stable B1: open book injury (external rotation) B2: lateral compression injury (internal rotation) B2-1: with anterior ring rotation/displacement through ipsilateral rami B2-2-with anterior ring rotation/displacement through contralateral rami (bucket-handle injury) B3: bilateral C: Rotationally and vertically unstable C1: unilateral C1-1: iliac fracture C1-2: sacroiliac fracture-dislocation C1-3: sacral fracture C2: bilateral with one side type B and one side type C C3: bilateral with both sides type C Young-Burgess Classification Anterior Posterior Compression (APC) APC I Symphysis widening < 2.5 cm APC II Symphysis widening > 2.5 cm. Anterior SI joint diastasis. Posterior SI ligaments are intact. Disruption of sacrospinous and sacrotuberous ligaments. APC III Disruption of anterior and posterior SI ligaments (SI dislocation). Disruption of sacrospinous and sacrotuberous ligaments. APCIII associated with vascular injury Lateral Compression (LC) LC I Oblique or transverse ramus fracture and ipsilateral anterior sacral ala compression fracture. LC II Rami fracture and ipsilateral posterior ilium fracture dislocation (crescent fracture). LC III Ipsilateral lateral compression and contralateral APC (windswept pelvis). Common mechanism is rollover vehicle accident or pedestrian vs auto. Vertical Shear (VS) Vertical shear Posterior and superior directed force. Associated with the highest risk of hypovolemic shock (63%); mortality rate up to 25% Physical Exam Symptoms pain & inability to bear weight Physical exam inspection test stability by placing gentle rotational force on each iliac crest login to view 2 more bullets look for abnormal lower extremity positioning login to view 2 more bullets skin scrotal, labial or perineal hematoma, swelling or ecchymosis flank hematoma lacerations of perineum degloving injuries (Morel-Lavallee lesion) neurologic exam rule out lumbosacral plexus injuries (L5 and S1 are most common) rectal exam to evaluate sphincter tone and perirectal sensation up to 10-15% of patients will sustain neurologic injury urogenital exam most common finding is gross hematuria more common in males (21% in males, 8% in females) vaginal and rectal examinations mandatory to rule out occult open fracture Imaging Radiographs recommended views AP login to view 3 more bullets inlet login to view 7 more bullets outlet login to view 6 more bullets Single-leg stance AP pelvis ("flamingo views") login to view 4 more bullets findings radiographic signs of instability login to view 3 more bullets CT routine part of pelvic ring injury evaluation better characterization of posterior ring injuries helps define comminution and fragment rotation visualize position of fracture lines relative to sacral foramina radiographic signs of sacral dysmorphism: anterior up-sloping upper sacral ala irregular, non-circular, sacral nerve root tunnels residual S1 disk tongue-and-groove SI joint Studies Serum labs hgb serum lactate base excess Initial Management & Resusitation Bleeding Source intraabdominal (present in up to 40% of cases) intrathoracic retroperitoneal extremity (thigh compartments) pelvic common sources of hemorrhage login to view 4 more bullets uncommon sources of hemorrhage login to view 4 more bullets Treatment resuscitation PRBC:FFP:Platelets ideally should be transfused 1:1:1 this ratio shown to improve mortality in patients requiring massive transfusion pelvic binder/sheet indications login to view 2 more bullets contraindications login to view 2 more bullets pitfalls login to view 2 more bullets external fixation indications login to view 3 more bullets contraindications login to view 2 more bullets angiography / embolization indications login to view 3 more bullets contraindications login to view 1 more bullet technique login to view 5 more bullets Definitive Treatment Overview by Classification Definitive treatment of Anterior Posterior Compression (APC) injuries APC I Non-operative. Protected weight bearing APC II Anterior symphyseal plate or external fixator +/- posterior fixation APC III Anterior symphyseal multi-hole plate or external fixator and posterior stabilization with SI screws or plate/screws Definitive treatment of Lateral Compression (LC) injuries LC I Majority non-operative.-Protected weight bearing (complete, comminuted sacral component.-Weight bearing as tolerated (simple, incomplete sacral fracture) -Posterior stabilization in unstable fractures results in decreased short-term pain LC II Open reduction and internal fixation of ilium LC III Posterior stabilization with plate or SI screws as needed. Percutaneous or open based on injury pattern and surgeon preference. Definitive treatment of Vertical Shear (VS) injuries Vertical Shear Posterior stabilization with plate or SI screws as needed. Percutaneous or open based on injury pattern and surgeon preference. Nonoperative weight bearing as tolerated indications login to view 8 more bullets Operative ORIF indications login to view 6 more bullets technique login to view 1 more bullet anterior subcutaneous pelvic fixator (INFIX) indications login to view 1 more bullet complications login to view 1 more bullet diverting colostomy indications login to view 2 more bullets Techniques Pelvic Binding technique centered over greater trochanters to effect indirect reduction do not place over iliac crest/abdomen login to view 1 more bullet may augment with internal rotation of lower extremities and taping at ankles transition to alternative fixation as soon as possible login to view 1 more bullet working portals may be cut in sheet to place percutaneous fixation early pelvic binding and CT have been associated with underestimation of pelvic ring instability fluroscopic exam under anesthesia can be used to assess stability in these circumstances External fixation theoretically works by decreasing pelvic volume stability of bleeding bone surfaces and venous plexus in order to form clot pins inserted into ilium supra-acetabular pin insertion single pin in column of supracetabular bone from AIIS towards PSIS login to view 8 more bullets superior iliac crest pin insertion multiple half pins in the superior iliac crest login to view 2 more bullets ORIF anterior ring stabilization single superior plate login to view 2 more bullets posterior ring stabilization anterior SI plating login to view 1 more bullet iliosacral screws (percutaneous) login to view 8 more bullets posterior SI "tension" plating login to view 1 more bullet anterior and posterior ring stabilization necessary in vertically unstable injuries ipsilateral acetabular and pelvic ring fractures in general, reduction and fixation of the pelvic ring should be performed first Rehabilitation stable fractures treated nonsurgically patients may mobilize immediately with protected weight bearing after stable fracture pattern in confirmed (may require post-mobilization views to confirm stability) unstable fractures treated surgically patient mobility and weight bearing depend on the location of the posterior pelvic ring fracture mobility includes weight-of-limb weight bearing ipsilateral to the posterior pelvic injury with full weight bearing on contralateral side patients with bilateral posterior pelvic ring injuries limited to bed-to-chair transfers only when radiographic healing has occured weight bearing can be gradually advanced Complications Urogenital Injuries present in 12-20% of patients with pelvic fractures higher incidence in males (21%) includes posterior urethral tear login to view 1 more bullet bladder rupture login to view 2 more bullets diagnosis made with retrograde urethrocystogram indications for retrograde urethrocystogram include login to view 3 more bullets treatment suprapubic catheter placement login to view 1 more bullet surgical repair login to view 1 more bullet complications long-term complications common (up to 35%) login to view 5 more bullets Neurologic injury L5 nerve root runs over sacral ala joint may be injured if SI screw is placed to anterior anterior subcutaneous pelvic fixator may give rise to LFCN injury (most common) or femoral nerve injury DVT and PE DVT in ~ 60%, PE in ~ 27%, fatal PE in 2% prophylaxis essential mechanical compression pharmacologic prevention (LMWH or Lovenox) vena caval filters (closed head injury) Chronic instability rare complication; can be seen in nonoperative cases presents with subjective instability and mechanical symptoms diagnosed with alternating single-leg-stance pelvic radiographs (flamingo views) Infection risk factors include: obesity diabetes prolonged operation time prolonged ICU stay larger amount of packed red blood cell transfusions, associated genitourinary and abdominal trauma open fractures preoperative angioembolization is controversial Prognosis High prevalence of poor functional outcome due to chronic pain and/or sexual dysfunction Poor outcome associated with SI joint incongruity of > 1 cm high degree initial displacement malunion or residual displacement leg length discrepancy > 2 cm nonunion neurologic injury urethral injury Mortality rate 1-15% for closed fractures, as much as 50% for open fractures hemorrhage is leading cause of death overall closed head injury is the most common for lateral compression injuries increased mortality associated with systolic BP <90 on presentation age >60 years increased Injury Severity Score (ISS) or Revised Trauma Score (RTS) need for transfusion > 4 units APC III injury