diagnosis

Internal snapping hip

Cause

 

Movement of iliopsoas tendon over femoral head / iliofemoral ridge / iliofemoral ligament

 

Can be seen following THA with cup impingement

 

Symptoms

 

Audible or palpable snap in the groin

 

Hip moves

- from flexed / abducted / externally rotated position

- to extended / internally rotated position

 

Incidence

 

10% of the population - usually painless

Patella Baja

Patella Baja

 

Aetiology

 

Congenital

 

Acquired

- trauma

- post ACL reconstruction / TKR

- chronic quadriceps rupture

 

Issues

 

Decreases ROM

Associated with early OA of the PFJ

 

Diagnosis

 

Blackburne-Peel ratio at 30 degrees flexion

 

Cuboid Fractures

Types

 

1.  Capsular avulsions

 

2.  Body / Nutcracker fracture

 

Nutcracker fracture

 

Epidemiology

- rare

 

Mechanism

- forced eversion / abduction of forefoot

- cuboid crushed between 4th and 5th MT and calaneum

 

Pathology

- displaced cuboid fracture with subluxation of tarsus

DIC

Definition

 

Disseminated Intravascular Coagulation

 

Pathology

 

Results from excessive activation of either extrinsic or intrinsic coagulation pathway

- multiple small clots 

- consumptive coagulopathy

 

1.  Excessive Extrinsic Activation

 

Secondary to extensive cellular destruction

- thromboplastins +++ released into circulation

Necrotising Fasciitis

Definition

 

Infection of skin and subcutaneous tissue

- spreads across fascial planes

- many microbes can be responsible

 

Types

 

Type 1 Polymicrobial

 

Type 2 Monomicrobial

 

Aetiology

 

Group A Beta Hemolytic Strep (S. pyogenes)

- most common cause monomicrobial

 

S. Aureus / MRSA

 

Vibrio

Paget's Disease

Definition

 

Chronic, non metabolic bone disorder

Characterised by increased bone resorption, bone formation and remodelling

 

Epidemiology

 

Rare < 40

1 – 3 % population over 60

M > F

 

Aetiology

 

Unknown

 

Paramyxovirus implicated

- measles

- RSV

- canine distemper virus

 

Electron Microscope

Syndesmotic Injuries

Definition

 

High ankle sprain

 

Epidemiology

 

Uncommon

- often unrecognised or misdiagnosed as lateral ligament injuries

- seen in ice hockey

 

1-15% of ankle sprains involve the syndesmosis

 

Mechanism Injury

 

Hyperdorsiflexion and forced external rotation

 

Anatomy

 

Structures

- anterior inferior tibiofibular ligament (AITFL)

Background

Aim 

 

The identification of skeletal metastasis & fixation prior to fracture

 

Incidence

 

50% of new cancer cases have metastasis

- 1% have pathological fracture

- increasing with more aggressive palliative care

 

Mass Behind Knee

DDxPosterior knee mass

 

Baker's Cyst

Popliteal Anerysm

Soft tissue sarcoma

Osteosarcoma / Parosteal OS

Hemangioma / AVM

 

Note:

 

Always do xray for calcification

A Bakers cyst / aneurysm can be calcified

 

 

 

Basic Science

Pathogenesis

 

Virchow's Triad

1. Venous stasis

2. Hypercoagulability

3. Endothelial damage

 

Starts as platelet nidus at valves

- thrombogenic materials elaborated by platelets

- leads to development of fibrin thrombus

- thrombus grows

 

Thrombus may 

- detach as embolus

- be completely dissolved / recanalise

- organise with valve incompetence