surgical techniques

Incidence

5-15% of posterior dislocations

Aetiology

Posterior hip dislocation

Pipkin Classification

Type I - head fracture below fovea

Undisplaced

- non operative

Displaced

- excise fragment if small

- ORIF fragment if large (can contribute to instability)

1.  Arthroscopic Posterior Bankart Repair +/- Capsular Plication

Technique

Posterior Portal

- make slightly inferior and lateral compare to normal

- inspect joint

Biomechanics

Able to achieve relatively high level of function after STJ fusion

- previously believed that isolated STJ fusion should not be performed

- believed that triple arthrodesis was operation of choice for hindfoot

- STJ fusion has superior result with less stress on AJ

Average loss of DF 30% / PF 10%

Position of hindfoot determines flexibility of transverse tarsal (CCJ & TNJ) joints

- imperative that fusion be positioned in ~ 5^o valgus 

Radial Head Fracture

Mechanism

FOOSH

- axial load with a valgus force

Biomechanics

1.  Provides Valgus stability

- especially if MCL deficient

2.  Longitudinal stability

- aided by interosseous membrane

3.  Load Transfer

- 60% of load at elbow

Concept

THR in dysplastic hips has a higher failure rate

- due to anatomic abnormalities

- due to generally younger age

Aim

Restore normal biomechanics and preserve bone stock

Issues

Soft tissues

Definition

Chronic instability due to rupture of one or more parts of the lateral ligament

Anatomy

Progressive injury

1. Anterolateral capsule

2. ATFL

3. CFL

NHx

Can lead to ankle OA over time