Associated pattern | Advanced trauma | Ilioinguinal workhorse
- A both-column fracture detaches the entire acetabulum (anterior and posterior columns together) from the intact ilium, leaving a floating acetabulum. The pathognomonic spur sign on the obturator oblique view is the intact ilium projecting above the detached, superiorly-migrated columns.
- Secondary congruence is the only situation in which non-operative care is considered: roof arc greater than 45 degrees on all three Judet views, a femoral head concentric on traction, no posterior wall component, and a compliant patient. All four criteria must be met.
- The ilioinguinal approach is the workhorse: a supine, three-window exposure. Reduce and fix the anterior column first; the posterior column then reduces indirectly through the intact dome in 60-70 percent of cases.
- Corona mortis is common (up to around 80 percent in cadaver series, the venous variant more frequent than the arterial) and crosses the superior pubic ramus in the middle window. Assume it is present and ligate prophylactically.
- If the posterior column stays more than 2mm displaced after anterior fixation, plan a staged Kocher-Langenbeck in 3-7 days. Do not electively use the extended iliofemoral approach (heterotopic ossification in 50 percent or more).
- Anatomical reduction (under 1-2mm) is the single most important predictor of outcome - the accuracy of reduction drives long-term hip survival.
When & Why
Indication. A displaced both-column (associated) acetabular fracture in which the secondary congruence criteria are not met. Because both columns separate from the ilium together, the acetabulum becomes floating, and the intact ilium projects above it as the pathognomonic spur sign on the obturator oblique view. Operate for displacement greater than 2-3mm at the weight-bearing dome, marginal impaction, femoral head subluxation despite traction, a roof arc under 45 degrees on any Judet view, an open fracture, an irreducible hip, or a progressive sciatic nerve palsy. Assess first. Run a full ATLS trauma survey (these are high-energy injuries: motor-vehicle and motorcycle crashes, falls from height). Examine the sciatic nerve (especially the peroneal division) and the femoral nerve, look for a Morel-Lavallee lesion over the greater trochanter, and document baseline neurology. The CT is decisive: quantify dome displacement, hunt for marginal impaction on the axial cuts through the superior 10mm of the acetabulum, and build 3D reconstructions for approach planning.
- What it shows
- Overall displacement, femoral head position
- Decision value
- The spur sign is pathognomonic for both-column
- What it shows
- Anterior column, posterior wall
- Decision value
- Spur sign best seen here; roof arc measured here
- What it shows
- Posterior column, anterior wall, SI joint
- Decision value
- Posterior column displacement; roof arc measured here
- What it shows
- Articular surface, dome, marginal impaction
- Decision value
- Quantify dome displacement; impaction often only seen here
- What it shows
- Fracture personality
- Decision value
- Approach planning (anterior vs posterior vs staged)
- What it shows
- Integrity of the weight-bearing dome
- Decision value
- All greater than 45 degrees is required for secondary congruence
The non-operative exception - secondary congruence. Because both columns separate from the ilium together, they can retain their relationship to each other through the intact dome, so the head can stay concentric despite a floating acetabulum. If every criterion below is met, observation with protected weight-bearing and serial radiographs is reasonable - and the decision should be made at an acetabular fracture MDT.
- Roof arc greater than 45 degrees on AP, obturator oblique AND iliac oblique views
- Femoral head concentrically reduced on traction views
- No posterior wall component (which would destabilise the hip)
- A patient able to comply with 10-12 weeks of protected weight-bearing
Even with secondary congruence, a young active patient may still benefit from ORIF to optimise long-term outcome. Margins that change the plan.
Depression of subchondral bone at the weight-bearing dome, often missed on plain films but visible on CT. It cannot improve non-operatively and needs direct elevation and bone grafting, so it drives surgery even when overall displacement looks acceptable.
Changes hip stability and may require a posterior (Kocher-Langenbeck) approach in addition to, or instead of, the anterior exposure.
Callus prevents anatomic reduction. Options narrow to limited ORIF with acute or delayed total hip arthroplasty, or traction followed by elective THA on a healed acetabulum.
Consider primary or staged THA. Forcing ORIF in osteoporotic bone risks screw cut-out and loss of reduction.
Consent - quote the real numbers.
Femoral nerve palsy 5-10 percent; LFCN injury (meralgia paresthetica) around 20 percent; obturator nerve 2 percent; external iliac / corona mortis vascular injury around 1 percent; DVT/PE 5-10 percent even with prophylaxis; superficial infection 8-12 percent and deep 3-6 percent; AVN 10-15 percent.
Post-traumatic arthritis in around 30 percent at 10 years even with anatomic reduction; heterotopic ossification 15-30 percent; conversion to THA in 20-30 percent at 10-20 years; loss of reduction 10-20 percent; inguinal hernia 5-10 percent.
The Operation
The goal is to restore a congruent, stable acetabulum through the ilioinguinal approach: develop the three windows, reduce and plate the anterior column, let the posterior column reduce indirectly through the intact dome, and fix it with percutaneous screws when it does. The exposure - the three windows - is laid out in full as the first steps below.
Approach strategy. The ilioinguinal is the default. The extended iliofemoral approach is reserved for the rare pattern needing simultaneous direct vision of both columns; modern practice stages a Kocher-Langenbeck instead.
- When
- Most both-column fractures; anterior column predominant; posterior expected to reduce indirectly
- Position
- Supine
- Key risk
- Femoral nerve 5-10 percent, LFCN around 20 percent, corona mortis bleeding, inguinal hernia 5-10 percent
- When
- Posterior column will not reduce indirectly; significant posterior wall
- Position
- Supine, then lateral 3-7 days later
- Key risk
- Cumulative blood loss; two anaesthetics; lower HO than extended
- When
- Both columns need simultaneous direct vision; delayed callus; failed ilioinguinal
- Position
- Lateral
- Key risk
- HO 50 percent or more, abductor devascularisation, 2-4 litres blood loss
Operative sequence - ilioinguinal ORIF
- Supine on a radiolucent table with full C-arm access; general anaesthesia with muscle relaxation.
- Arterial line, two large-bore IVs, cell saver (expect 500-2000mL), warming; a Foley catheter is mandatory for bladder protection; epidural for post-op analgesia.
- Bolster under the ipsilateral buttock for 10-15 degrees of tilt toward the affected side - it improves posterior column visualisation from the front and access to the quadrilateral surface.
- Both lower limbs prepped and draped free for traction; ipsilateral arm across chest; fluoroscopy ready for AP, inlet, outlet and both Judet views.
- Antibiotics (cefazolin 2g at induction, repeat every 3-4 hours; vancomycin plus gentamicin if penicillin-allergic) and DVT prophylaxis (mechanical plus LMWH).
- Mark the landmarks: ASIS, pubic symphysis, iliac crest, pubic tubercle (2cm lateral to the symphysis), the inguinal ligament (ASIS to pubic tubercle), the femoral pulse, and the LFCN exit about 1cm medial to the ASIS.
- Curved incision from the pubic symphysis along the inguinal ligament to the ASIS, then posteriorly along the iliac crest for 8-10cm (typically 25-30cm total).
- Deepen through subcutaneous fat to the external oblique aponeurosis (the first fascial layer).
- Identify the lateral femoral cutaneous nerve exiting about 1cm medial and inferior to the ASIS - a small white cord running vertically toward the thigh. Protect it, or deliberately divide it with pre-operative counselling (guarantees anterior thigh numbness but prevents a traction injury; meralgia paresthetica occurs in around 20 percent if it is not carefully protected).
- Incise the external oblique aponeurosis along the inguinal ligament, take down the iliac crest attachment, and protect the spermatic cord or round ligament.
- The interval between iliacus medially and the abductors laterally.
- Subperiosteal elevation of iliacus off the inner iliac fossa gives access to the iliac wing, the SI joint and the superior pelvic brim.
- The femoral nerve runs ON the iliacus surface - stay ON the muscle, never dissect through it.
- The interval between the external iliac vessels laterally and iliopsoas medially; mobilise the vessels off psoas with vessel loops.
- Actively search the superior pubic ramus for the corona mortis (an anastomosis between the obturator and the external iliac or inferior epigastric systems). It is common - up to around 80 percent of hemipelvises in cadaver series, with the venous variant more frequent than the arterial. Ligate it prophylactically with 3-0 silk (or clip) before it can be torn.
- Access: quadrilateral surface, pelvic brim, superior ramus.
- The interval between the external iliac vessels laterally and the spermatic cord or round ligament medially.
- The bladder lies immediately posterior - stay strictly subperiosteal on the pubis.
- Access: symphysis, superior ramus, rectus origin.
- Clear haematoma and soft tissue from the fracture lines; identify the major column fragments; protect articular cartilage.
- Actively look for marginal impaction (subchondral depression at the dome). Elevate it through an osteochondral window with a curved osteotome or tamp from below, bone-graft the void with local iliac crest or allograft, and hold it provisionally with K-wires.
- Clear the pelvic brim (the key fixation corridor) of periosteum for plate application.
- Apply a Weber or Jungbluth clamp from the intact iliac wing (the stable reference) to the displaced anterior column fragment; close progressively to reduce.
- Correct rotation with a ball-spike pusher; hold with provisional K-wires.
- Goal: anatomical restoration of the pelvic brim contour, correct rotation, and an articular step less than 2mm. Confirm on the obturator oblique (anterior column profile).
- This is the keystone: the anterior column is the only column you can reduce directly, and once it is anatomical the intact dome acts as a template that draws the posterior column into reduction.
- After anterior fixation, assess the posterior column on the iliac oblique (posterior column profile), inlet (rotation) and lateral (AP displacement) views.
- Indirect reduction succeeds in 60-70 percent - the posterior column realigns through the intact dome. Displacement under 2mm is acceptable; proceed to percutaneous screws.
- If it is still displaced, try a ball-spike pusher on the quadrilateral surface through the medial window. If it remains more than 2mm displaced, do not force it (fracture propagation and sciatic nerve injury) - complete the anterior fixation, close, and plan a staged Kocher-Langenbeck in 3-7 days.
- 3.5mm reconstruction plate (8-12 holes), contoured in 3D to the pelvic brim exactly; laid along the brim from ilium to superior ramus.
- 3.5mm cortical screws, at least three per major fragment. Use reconstruction (not straight) plates so they contour in 3D; the brim is cortical bone and gives excellent purchase.
- Lag-screw large fragments before plating. Check the obturator oblique after each peri-articular screw to avoid intra-articular penetration (it shows the hip joint en face).
- 7.0-7.3mm cannulated screws, guidewire first; length typically 120-140mm.
- Start point on the superior pubic ramus, trajectory posterior and superior toward the ischial spine or ischium.
- Confirm the guidewire on three views: inlet (medial-lateral, within bone not into the pelvis), outlet (superior-inferior) and lateral (anterior-posterior, within the posterior column corridor).
- Danger zone: the greater sciatic notch - the sciatic nerve exits here, so the wire or screw must not penetrate the posterior cortex in this region.
- Indicated for quadrilateral surface comminution or medial displacement of the femoral head (medialisation or central subluxation).
- Options: an infrapectineal buttress plate below the brim, a spring plate for elastic support, a suprapectineal plate with in-out-in screws, or a dedicated quadrilateral-surface plate.
- The quadrilateral surface is thin - do not fracture it with aggressive manipulation.
- Haemostasis: irrigate with 3L saline, bipolar diathermy, bone wax, topical agents; ensure the corona mortis is controlled.
- Repair the inguinal ligament to the external oblique with 0 PDS; close the external oblique aponeurosis with continuous 0 PDS (strong bites, no gaps); close internal oblique or transversus and the rectus sheath if divided; protect the spermatic cord.
- A 14Fr closed-suction drain for the large dead space, removed at 24-48 hours or when output is under 50mL per 8 hours.
- Scarpa fascia with interrupted 2-0 Vicryl (obliterates dead space); skin with 3-0 Monocryl subcuticular or staples; waterproof dressing.
- AP pelvis (head concentric), obturator oblique (anterior column, no intra-articular screw), iliac oblique (posterior column), inlet (rotation, screws within bone), outlet (vertical alignment) and lateral (screw trajectory).
Before any work on the superior pubic ramus in the middle window, assume the corona mortis is present (up to around 80 percent of hemipelvises in cadaver series; the venous variant is more frequent than the arterial). Actively search the ramus, prophylactically ligate any crossing vessel with 3-0 silk, and keep vessel loops on the external iliac vessels for temporary control. If it is injured: direct pressure, then suture ligation under vision. For an external iliac injury, maintain pressure and call vascular surgery immediately - never ligate the external iliac artery (limb loss).
The anterior column is the only column you can see and reduce directly through the ilioinguinal approach. Once it is anatomical, the intact dome acts as a template or keystone that pulls the posterior column into reduction in 60-70 percent of cases. Fixing the (invisible) posterior column first would throw that indirect mechanism away.
If the posterior column stays more than 2mm displaced after anterior fixation, do not attempt a blind reduction (fracture propagation and sciatic nerve injury). Complete the anterior fixation, close, and stage a Kocher-Langenbeck in 3-7 days. The 3-7 day interval allows resuscitation and soft-tissue recovery while the haematoma is still organised and before callus forms.
The ilioinguinal approach has no true internervous plane - it is an intermuscular and intravascular exposure developed through intervals (lateral: iliacus versus abductors; middle: vessels mobilised off psoas; medial: vessels versus spermatic cord). Meticulous structure protection replaces a friendly internervous plane, so release the retractors every 15-20 minutes to avoid ischaemic nerve injury.
Aftercare & Complications
Weight-bearing and rehabilitation
- Weight-bearing
- Touch-toe (10-15kg)
- Goals
- Bed-to-chair transfers, ROM exercises
- Weight-bearing
- Partial (25-50 percent)
- Goals
- Increase mobility, stationary bike
- Weight-bearing
- Progressive
- Goals
- Walking with aids, stairs
- Weight-bearing
- Full as tolerated
- Goals
- Return to normal activities
- Weight-bearing
- Full activities
- Goals
- Consider return to sport or work
Prophylaxis
LMWH (enoxaparin 40mg SC daily) for 4-6 weeks, or rivaroxaban 10mg once daily; plus mechanical prophylaxis (TEDS and pneumatic compression). Consider an IVC filter if anticoagulation is contraindicated.
The ilioinguinal approach carries a lower HO risk than posterior approaches. For higher-risk patients or redo surgery, indomethacin 75mg daily for 6 weeks, or a single 700cGy radiation dose.
Follow-up at 2 weeks (wound check, remove sutures or staples), 6 weeks, 3 months, 6 months and 12 months with AP and Judet views, then long-term arthritis surveillance at 2, 5 and 10 years. Complications
- Recognition
- Brisk bleeding in the middle window; catastrophic bleeding with haemodynamic instability
- Prevention
- Assume corona mortis present; prophylactic ligation; gentle vessel-loop dissection; vascular backup
- Management
- Direct pressure; suture ligation (corona mortis); vascular surgery; never ligate the external iliac artery; fasciotomy if ischaemic
- Recognition
- Post-op quadriceps weakness, lost knee extension, anterior thigh numbness
- Prevention
- Stay on iliopsoas; release retractors every 15-20 minutes; padded retractors
- Management
- Mostly neuropraxia (90 percent recover in 6-12 weeks); knee brace; EMG at 3 weeks; explore if no recovery by 6 months
- Recognition
- Anterolateral thigh numbness or dysaesthesia (around 20 percent)
- Prevention
- Identify 1cm medial to ASIS; protect or divide with counselling
- Management
- Usually permanent if divided; reassurance; gabapentin if painful
- Recognition
- Clear fluid in the medial window; blood-tinged urine
- Prevention
- Foley catheter mandatory; stay subperiosteal on the pubis
- Management
- Two-layer repair; urology consult; catheter 10-14 days; cystogram before removal
- Recognition
- Bulge or pain at the groin
- Prevention
- Meticulous layered fascial closure; reattach inguinal ligament to external oblique with 0 PDS
- Management
- Surgical repair if symptomatic
- Recognition
- Decreased ROM; visible bone on radiograph
- Prevention
- Indomethacin or single-dose RT for higher-risk patients
- Management
- Reserved excision if function-limiting
- Recognition
- Pain and stiffness; 30 percent arthritis at 10 years; 20-30 percent THA at 10-20 years
- Prevention
- Anatomical reduction (under 1-2mm) is the main modifiable predictor
- Management
- THA; in the elderly consider acute or staged THA
- Recognition
- Leg swelling, dyspnoea
- Prevention
- LMWH plus mechanical prophylaxis
- Management
- Anticoagulation; IVC filter if contraindicated
Viva & Exam Focus
SPURSPUR - recognise a both-column fracture
- Interval
- Iliacus (medial) vs abductors (lateral)
- Access
- Iliac wing, SI joint, superior pelvic brim
- At risk
- Femoral nerve - runs ON iliopsoas, dissect ON the muscle
- Interval
- External iliac vessels vs iliopsoas
- Access
- Quadrilateral surface, pelvic brim, superior ramus
- At risk
- Corona mortis (assume present, ligate), external iliac vessels, obturator nerve
- Interval
- External iliac vessels vs spermatic cord or round ligament
- Access
- Symphysis, superior ramus, rectus origin
- At risk
- Bladder (posterior - stay subperiosteal), spermatic cord
Clinical Decision Scenarios
Practise clinical reasoning and management decisions out loud
“A 45-year-old man sustains an acetabular fracture in a motorcycle crash. The radiographs show displacement of both columns with a spur sign, and CT confirms both columns detached from the intact ilium; on traction views the femoral head remains concentric. How do you assess him and what is your plan?”
“Describe the secondary congruence concept and how you apply it in decision-making.”
“What is corona mortis, and how do you manage it during the ilioinguinal approach?”
Pattern recognition
- Spur sign = pathognomonic (intact ilium)
- Both columns detached from the axial skeleton
- An associated pattern, not elementary
- Around 23 percent of all acetabular fractures (Letournel); the most common associated type in operative series
Secondary congruence criteria
- Roof arc greater than 45 degrees on all three views
- Femoral head concentric on traction
- No posterior wall component
- A patient who can comply with protected weight-bearing
Three windows
- Lateral: iliacus versus abductors (femoral nerve on iliopsoas)
- Middle: vessels versus iliopsoas (corona mortis - common)
- Medial: vessels versus cord (bladder posterior)
Reduction sequence
- Anterior column first (the foundation)
- Posterior reduces indirectly in 60-70 percent
- If it fails, stage a Kocher-Langenbeck in 3-7 days
- Never electively use extended iliofemoral (HO 50 percent or more)
Corona mortis
- Obturator to external iliac anastomosis
- Common - up to around 80 percent in cadaver series (venous more frequent than arterial)
- Crosses the superior pubic ramus
- Ligate prophylactically if found
Screw safety
- Posterior column screw: 7.0-7.3mm, 120-140mm long
- Avoid the greater sciatic notch (sciatic nerve)
- Check the obturator oblique for joint penetration
- Inlet, outlet and lateral for posterior column trajectory
Critical complications
- Femoral nerve palsy 5-10 percent
- LFCN (meralgia paresthetica) around 20 percent
- Inguinal hernia 5-10 percent
- Arthritis around 30 percent at 10 years
Examiner favourites
- What is the spur sign? - intact ilium on the obturator oblique
- Describe the three windows - with the structure at risk in each
- Why anterior first? - the posterior reduces indirectly through the dome
- Corona mortis? - assume present, ligate prophylactically
Background & Evidence
Epidemiology. Acetabular fractures are high-energy injuries of young adults - motor-vehicle and motorcycle crashes and falls from height. The both-column pattern is the most complex of the Letournel associated patterns and accounts for around 23 percent of all acetabular fractures in the Letournel series; in Matta's operative cohort it was the single most common pattern (35 percent). Associated injuries (head, chest, abdomen, spine, ipsilateral limb) are the rule, and mortality is driven by the polytrauma, not the fracture itself. Classification. Judet and Letournel divide acetabular fractures into elementary (a single fracture line) and associated (two or more elementary patterns combined) groups.
- Patterns
- Posterior wall, posterior column, anterior wall, anterior column, transverse
- Note
- A single fracture line
- Patterns
- Both-column, T-type, transverse plus posterior wall, anterior plus posterior hemitransverse, posterior column plus posterior wall
- Note
- Two or more elementary patterns combined
- Patterns
- Every fracture line detaches the entire acetabulum from the intact ilium
- Note
- The most complex associated pattern; spur sign is pathognomonic; a floating acetabulum; the only pattern with a secondary congruence concept
References
Fractures of the acetabulum: accuracy of reduction and clinical results in patients managed operatively within three weeks after the injury
- 262 displaced acetabular fractures operated within 21 days; both-column was the most common single pattern (92 hips, 35 percent of this operative series)
- Anatomical reduction (under 1mm) achieved in 71 percent overall; the rate fell with greater fracture complexity, older age and a longer injury-to-surgery interval
- Clinical result was excellent or good in 76 percent and was closely linked to the quality of reduction and femoral head-roof congruity
- Subsequent total hip replacement in 6 percent and AVN in 3 percent at a mean 6-year follow-up
Native hip dislocation at acetabular fracture predicts poor long-term outcome
- 480 acetabular fractures (113 with associated dislocation) followed to a mean 9.7 years
- 10-year native hip survival was 75.1 percent with dislocation versus 90.7 percent without
- AVN (11 percent versus 1 percent) and sciatic nerve palsy (12 percent versus 1 percent) were far more common when dislocation was present
- Independent predictors of conversion to THA were older age (especially over 55 years) and a higher Injury Severity Score
Standard Approaches to the Acetabulum Part 2: Ilioinguinal Approach
- Reviews the indications, three-window anatomy and technique of the Letournel ilioinguinal approach for anterior-based acetabular fixation
- Historically used in around 22-26 percent of acetabular fractures; modern German multicentre data show single ilioinguinal use in almost 45 percent of cases versus 38 percent Kocher-Langenbeck
- It is an extrapelvic, indirect-reduction approach without direct articular visualisation
- The key advantage is minimal periarticular muscle detachment with a low heterotopic ossification risk
Anatomical Variations of Corona Mortis in the Anterior Intrapelvic Approach: A Cadaveric Study
- 62 hemipelvises dissected via the anterior intrapelvic approach
- Corona mortis present in 50 hemipelvises (80.6 percent)
- The venous variant (40.3 percent) was more common than the arterial variant (16.1 percent)
- The anastomosis lies behind the superior pubic ramus where haemostasis is technically difficult
Further reading 1. Letournel E, Judet R. Fractures of the Acetabulum. 2nd ed. Berlin: Springer-Verlag; 1993. 2. Routt ML Jr, Swiontkowski MF. Operative treatment of complex acetabular fractures: combined anterior and posterior exposures during the same procedure. J Bone Joint Surg Am. 1990;72(6):897-904. 3. Hong G, Cong-Feng L, Cheng-Fang H, et al. Percutaneous screw fixation of acetabular fractures with 2D fluoroscopy-based computerized navigation. Arch Orthop Trauma Surg. 2010;130(9):1177-1183. 4. Tile M, Helfet DL, Kellam JF. Fractures of the Pelvis and Acetabulum. 3rd ed. Philadelphia: Lippincott Williams and Wilkins; 2003. 5. Gansslen A, Pohlemann T, Paul C, et al. Epidemiology of pelvic ring injuries. Injury. 1996;27 Suppl 1:S-A13-20. 6. Tornetta P III. Non-operative management of acetabular fractures: the use of dynamic stress views. J Bone Joint Surg Br. 1999;81(1):67-70. 7. Karunakar MA, Shah SN, Jerabek S. Body mass index as a predictor of complications after operative treatment of acetabular fractures. J Bone Joint Surg Am. 2005;87(7):1498-1502. 8. Anglen JO, Burd TA, Hendricks KJ, Harrison P. The gull sign: a harbinger of failure for internal fixation of geriatric acetabular fractures. J Orthop Trauma. 2003;17(9):625-634. 9. Giannoudis PV, Grotz MR, Papakostidis C, Dinopoulos H. Operative treatment of displaced fractures of the acetabulum: a meta-analysis. J Bone Joint Surg Br. 2005;87(1):2-9.