prognosis

Epidemiology

Most common pattern cord injury

Hyper-extension injury in middle aged man with osteoarthritic spine

Usually C3/4 and C4/5

Mechanism

Most common type / in older patient with pre-existing spondylosis / OPLL

- hyperextension injury

- compression of the cord

- anteriorly by osteophytes

- posteriorly by infolded ligamentum flavum

Definition

Isolated posterior ligament injuries

- PLL / Posterior interspinous ligament / Paraspinal muscles

Excludes fracture / dislocation / HNP

Aetiology

MVA

Sport

Hyperflexion injuries

Symptoms

Large spectrum clinical presentation

- neck ache 

- nausea & vomiting 

- headache 

- visual symptoms

Epidemiology

Most common site for skeletal TB

- usually haematogenous spread

- can be direct from lung

3 patterns

1.  Peridiscal (50%) - originating in metaphyseal region

2.  Central - high incidence of vertebral collapse

3.  Anterior - instability less common with less bony destruction

Pathology

Affects multiple contiguous vertebrae

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

Definition

Idiopathic condition of the immature femoral capital epiphysis involving varying degrees of osteonecrosis

AKA

- Legg-Calve-Perthes disease

- coxa plana

Described in separate publications in 1912 by

- Legg (Boston)

- Calve (France)

- Perthes (Germany)

Epidemiology

M: F    4:1

1 in 740 males

Epidemiology

4th most common STS

- 10-35% of STS

Peak age 3rd-4th decade

- rare in children

Pathology

Cellular characteristics suggest tumour arises from primitive synovial cells

- rarely actually occurs within joint

Characteristic

Occasionally metastasis to lymph nodes (5-7%) 

- like Epitheloid Sarcoma 

Definition

Malignant tumour of striated muscle

Juvenile variety arises from mesenchyme

Epidemiology

Most common malignant ST Tumour in children (< 15 years)

Definition

STS composed of malignant lipoblasts

Epidemiology

Common 

- 10% of STS

- second only to MFH

Occurs almost exclusively in adults

Males age 40-60

Can be multiple origin -> examine patient

Rarely arise from lipoma

Definition

Malignant Fibrous Histiocytoma

Characterised by heterogenous population of pleomorphic spindle cells

- organised in a characteristic storiform or "starry night" pattern

Cell of origin unknown 

- primitive mesenchymal cell

- allowing both features of a macrophage (hence histiocyte)

- and collagen producing cell (hence fibroblast)

Epidemiology