instability

LC-1:  pubic rami fracture with sacral fracture

Complications

Subscapularis failure

Rotator cuff failure

Instability

Infection

Periprosthetic fracture

Aseptic loosening

Neurological injury

Parada et al. J Should Elbow Surg 2021

- 2224 aTSA complication rate 11%, revision rate 5.6%

3 types

1. Posterior Arch

Mechanism

- axial compression with hyperextension

Associations

- 50% incidence other C1/2 fracture

- i.e. ondontoid fracture

Management

- stable

- soft / philadelphia collar

2. Isolated lateral mass fracture

Mechanism

- asymmetrical axial compression / lateral bend

General

- haemarthrosis

- DVT

- infection

Septic Arthritis

Incidence

1.  Infection

Peters et al J Arthroplasty 2009

Types of Instability

1.  AP Instability

2.  Varus Valgus Instability

3.  Global Instability

4. Frank Dislocation

Definition

Repeated dislocation of patella with minimal trauma

- 15-20% of paediatric acute patella dislocations

- more common girls 

- often bilateral

Dislocation occurs unexpectedly when quadriceps contracted with knee in flexion 

Direction

1.  Arthroscopic Posterior Bankart Repair +/- Capsular Plication

Technique

Posterior Portal

- make slightly inferior and lateral compare to normal

- inspect joint

Non-operative

Results

90% respond 

- very important

- 6 - 12 months minimum before offering surgery

Physiotherapy

1.  Stretches

- quads stretches

- ITB

- lateral retinaculum

AP / Long Leg Views

Quantify Valgus Malalignment

Lateral Xray

1.  Assess Patella Alta

30^o flexion