injury

Etiology

Ankle sprain

- eversion / external rotation

Ankle fractures

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

Classification Leffert "OCRO"

I Open

II Closed

A  Supraclavicular 

- Preganglionic / Avulsion of Roots

- Postganglionic / Rupture of Trunks

B Infraclavicular

- cords & branches

C.  Post anaesthetic

III Radiation / Other

Tumour

Definition

Present with pain but not instability

Types

Traumatic

Degenerative

Different treatment algorithms for each

History

Ulna side wrist pain

- may be worse with rotation

- opening doors and jars

History of trauma

Examination

Local tenderness DRUJ

Definition

Dorsal Intercalated Segmental Instability / CID

Anatomy

Scapholunate joint

- C shaped

- 2-3 mm thick dorsally with transverse fibres

- thin palmar

Dorsal extrinsic ligaments

- V shaped, onto trapezium

Anatomy

Terminal branch of the posterior cord

- lateral to radial nerve

- behind axillary artery

- runs over inferolateral border of SSC

- enters quadrangular space

Quadrangular space

- SSC superiorly anterior

- T major inferior

- T minor superiorly posterior

- long head triceps and humerus

Divides into anterior and posterior branches

Anatomy

3 primary stabilizers (plus posterolateral capsule)

LCL / Popliteus / Popliteofibular ligament

Laprade et al. AJSM 2003

https://pubmed.ncbi.nlm.nih.gov/14623649/

1.  Lateral collateral ligament

Femoral attachment

Anatomy

1. Seebacher's 3 layers of the medial knee

Layer 1

- sartorius and sartorius fascia

Layer 2

- superficial MCL

- posterior oblique ligament

- semimembranosus

Layer 3

- deep MCL (meniscofemoral and meniscotibial ligament)

- posteromedial capsule 

2. MCL

Superficial MCL

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