nerve injury

Anatomy

Pelvis is a true ring

- any anterior fracture must have a posterior injury as well

- integrity of the posterior sacroiliac complex is key

Bony Anatomy

2 innominate bones + sacrum

Symphysis pubis < 5mm

SI joint 2-4 mm

Bristow

Concept

Non-anatomical bony block 

- transfer of coracoid process through subscapularis

- dynamic anteroinferior musculotendinous sling

- provides subscapularis tenodesis

- preventing lower portion from displacing proximally as arm abducted

- when shoulder in vulnerable position abduction and ER

Epidemiology

Primary THR 1%

Revision THR 3%

DDH  5%

Sciatic nerve 90% of nerve palsy

Other

- femoral nerve

- CPN

- ulna / radial nerve from positioning

Aetiology

Direct 

Laceration

- exposure / sciatic and superior gluteal nerve

- drill reamer / obturator nerve

- spike of cement / obturator nerve

Indication

Diagnostic

Pain / Stiffness / Locking

Instability

- exclude OCD

Assess syndesmosis

Therapeutic

Synovitis

Osseous lesions / Tibiotalar impingement spurs

Osteochondral defects