ultrasound

Non Union

Definition

 

Non-union

- arrest of progression to union at fracture site 

- > 6-9 /12

- no visible progressive signs of healing for at least three consecutive months

- individualise for each fracture

- when the surgeon believes the fracture has little or no chance to heal

 

Delayed union

- failure of fracture to unite within expected time

- still may spontaneously unite

 

Tibial Nonunion

Definitions

 

Delayed union

- difficult to define

 

Nonunion

- US FDA

- 9/12 since injury

- 3 consecutive months with no signs union

- when the fracture has not healed in what you would expect to be a normal time period

 

Types

 

A.  Hypertrophic

- abundant callous

- adequate blood supply, insufficient stability

 

Ultrasound

Physics

 

Very high frequency sound waves

- 3 - 15 MHz

 

Production

 

Piezoelectric effect

- run electric current through a crystal

- produces ultrasound waves

 

Theory

 

Density of substance determines velocity of the US

- reflected back to the probe at different velocities

- converted into 2D image on monitor

 

 

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

Calcific Tendonitis

Definition

 

Mid-substance calcification of the rotator cuff

- part of a metaplasia secondary to hypoxia

 

Supraspinatous CalciumSupaspinatous Large Deposits

 

Aetiology

 

2 groups of patients

 

Compartment Syndrome Exertional,

DefinitionCompartment Release

 

Increased pressure within a closed fibro-osseous space

 

Aetiology

 

Seen in athletes, associated with repetitive exertion

 

Anatomy

 

Leg

 

1.  Anterior compartment

- anterior tibial artery

- deep peroneal nerve

Infected THR

Risk factors

 

Patient 

 

Advanced age

Immunosuppression - steroids / Rheumatoid / DM

Malnutrition - Lymphocyte count / Transferrin / Albumin

Vascular disease

Obesity

Poor skin i.e. psoriasis

Previous infection in joint

Infection elsewhere - i.e. UTi

Prolonged hospital admission

Revision surgery

 

Operative Factors

 

Preoperative

Achilles Tendon Rupture

AnatomyAchilles tendon anatomy

 

Gastrocnemius tendon 10-25 cm long

- soleus 3-10 cm

- inserts superior calcaneal tuberosity

- fibres spiral 90°

- fibres that lie medially in proximal portion become posterior distally

- allows elastic recoil & energy storage

 

Plantaris present in 90% population

- medial to T Achilles

 

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