background

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

Anatomy

Size

2 x as strong as ACL

About the same length as ACL 38 mm

Cross sectional area 150% of ACL

13 mm diameter (thicker) 

2 Bundles

1.  Anterolateral

- most important

- double the size of the posteromedial

- tight in flexion

- try to reconstruct this bundle

Definition

Non-traumatic or traumatic condition of femoral head with bone death

Epidemiology

20 - 50 yo (average 38)

- M: F 4:1

NHx  

70-80% with AVN will progress within 1 year

Definition

Full thickness tear (FTT)

- variable amount retraction from insertion

Partial thickness tear (PTT)

- incomplete

- bursal or articular sided

Definition

Osteochondritis Dissecans

- separation of avascular fragment of bone & cartilage

Epidemiology

M : F = 2:1

Mean age 18 years

- can present as young as 9

4:1000

Issues

Templating

Approach

Fixation

Bearing Surface

Head Size

Offset

Indications

Disabling hip pain

Severe functional impairment

Failed non operative management

Not Indicated 

Painless deformity

Definition

Abnormal posteriorly directed sagittal plane curve of spine

Scoliosis Research Society 

Thoracic

Normal range thoracic kyphosis is 20-40° 

- measured over T1 to T12 by Cobb method

- upper limit of normal thoracic kyphosis < 45°

Cervical & Lumbar

- lordosis is normal

- any kyphosis (>5°) considered abnormal