fracture

 Os peroneum

Location

Sesamoid in peroneus longus

- at level calcaneo-cuboid joint

- articulates with cuboid

Incidence

5 - 30% population

60% bilateral

Anatomy

Posterolateral & Posteromedial tubercles

- separated by sulcus for FHL

- lateral larger than medial 

PL tubercle

- size variable

Epidemiology

< 10% of all talus fractures

Rare and often missed

Types

Definition

Spinous process avulsion

- typically C7

- can be seen in thoracic spine

Mechanism

Spinous process avulsion secondary to ligamentum nuchae

Sudden single overload 

Complications

Subscapularis failure

Rotator cuff failure

Instability

Infection

Periprosthetic fracture

Aseptic loosening

Neurological injury

Incidence

Parada et al. J Should Elbow Surg 2021

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

Indications

RA 

OA 

AVN 

Distal Tibial Fractures

Definition

Metaphyseal

Extra-articular

Intra-articular Extension

Issues

Femur

Multiplanar deformity

- worsend by previous surgery

- may require osteotomy

Acetabulum

Dysplasia often present

- not as severe as in DDH

LLD

Can be significant

Abductors

Have been short for long time

- difficult to restore length

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

Mechanism

Direct blow

- most common

Indirect

- forced knee flexion with foot fixed / maximally contracted quadriceps

Types

1.  Vertical

2.  Transverse