Pelvic and Acetabular Fractures

Pelvic Anatomy - Ring Fundamentals

• Bones: Ilium, ischium, pubis (form acetabulum); sacrum, coccyx. Pelvis = 2 innominate bones + sacrum.
• Key Ligaments:
  • Sacrospinous, sacrotuberous (resist external rotation & vertical shear).
  • Anterior & Posterior Sacroiliac (SI) ligaments.
  • Pubic symphysis.
• Neurovascular:
  • Sciatic nerve (L4-S3), lumbosacral plexus.
  • Internal iliac artery branches (📌 'I Like Going Places In My Very Own Underwear'). Key: Superior/Inferior gluteal, Obturator artery/nerve.
• Stability: Posterior ring integrity (SI joints, sacrum, iliac wings & ligaments) is crucial.

⭐ The posterior sacroiliac ligament complex is the strongest in the pelvis and crucial for vertical stability.

Pelvic Fractures - Stability Showdown

Stability by Young & Burgess (Y&B), Tile. 📌 Y&B: APC ('Open Book'), LC ('Closed Book'), VS.

⭐ APC Type III ("open book") highest hemorrhage risk.

Acetabular Fractures - Column Conundrums

• Anatomy: Two columns, anterior (iliopubic) & posterior (ilioischial), are key to stability. Also includes walls (anterior, posterior), roof (dome), and quadrilateral plate. Femoral head blood supply primarily via Medial Circumflex Femoral Artery.
• Judet & Letournel Classification: Divides fractures into 5 elementary and 5 associated types, crucial for surgical planning.

  Elementary Types	Associated Types
  Posterior Wall	T-shaped
  Posterior Column	Posterior Column + Posterior Wall
  Anterior Wall	Transverse + Posterior Wall
  Anterior Column	Ant. Column/Wall + Post. Hemitransverse
  Transverse	Both Columns

• Imaging: Radiographs: AP Pelvis. Judet views: 📌 Iliac Oblique = I see Posterior column, Anterior wall; Obturator Oblique = I see Anterior column, Posterior wall. CT scan is gold standard for detailed assessment.

⭐ The posterior wall is the most frequently fractured component of the acetabulum.

Definitive Management - Fixation Focus

Pelvic Fractures:

• Non-operative: Stable (e.g., Tile A, LC-I).
• Operative Indications: Hemodynamic instability, open Fx, symphyseal diastasis >2.5cm, vertical shear, displaced sacral Fx >1cm.
• Fixation Methods: External fixation, anterior ORIF (symphysis/rami), posterior percutaneous SI screws/ORIF.

Acetabular Fractures:

• Non-operative: Undisplaced/minimally displaced (<2mm), congruent joint, roof arc angle >45°.
• Operative Indications: Displacement >2mm, incongruity, posterior wall instability >40-50%, intra-articular fragments, irreducible dislocation.
  • Surgical Approaches: Kocher-Langenbeck (posterior), Ilioinguinal (anterior), Stoppa.
• Goals (Both): Anatomical reduction, stable fixation, early mobilization.

⭐ Anatomic reduction of the weight-bearing dome of the acetabulum is paramount for preventing post-traumatic arthritis.

Complications - Damage Control

• Early:
  • Hemorrhage (pelvic venous plexus; sup. gluteal a., int. pudendal a.)
  • Urogenital injury (urethral/bladder)
  • Neurologic: Sciatic nerve (peroneal div. common), L5/S1 roots
  • DVT/PE, Infection, Morel-Lavallée lesion
• Late:
  • Post-traumatic Osteoarthritis (PTOA)
  • Malunion/Nonunion
  • Heterotopic Ossification (HO); Prophylaxis: Indomethacin 25mg TID or 75mg SR OD
  • AVN femoral head, Chronic pain, Sexual dysfunction

⭐ Sciatic nerve injury occurs in up to 20% of acetabular fractures, particularly with posterior dislocations or posterior column/wall fractures, often affecting the peroneal division.

High‑Yield Points - ⚡ Biggest Takeaways

• Young-Burgess classification (APC, LC, VS, CM) guides pelvic ring injury management by mechanism.
• Tile classification (A, B, C) assesses pelvic stability, crucial for surgical decisions.
• Letournel-Judet classification for acetabular fractures uses iliac/obturator oblique (Judet) views.
• Prioritize hemodynamic resuscitation for pelvic hemorrhage; use pelvic binders/ex-fix early.
• High risk of sciatic nerve injury (especially posterior acetabular wall) and urogenital trauma.
• Watch for Morel-Lavallée lesions (closed degloving) with pelvic trauma; can complicate recovery.