Previously we discussed basics of orthopedics, in this part, we will discuss quickly on Anatomy of an Immature long bone and Anatomy of Joints.
Anatomy of Immature Long Bone
A bone consists of four parts: Epiphysis, Growth plate in between epiphysis and metaphysis, Metaphysis and Diaphysis. We will discuss in detail the following:
Functional Classification of Epiphysis
Pressure Epiphysis
It is an intra-articular weight bearing epiphysis
Traction Epiphysis
It is an extra-articular epiphysis for Traction or Pull or Attachment to soft tissues, mainly tendons
Atavistic Epiphysis
E.g. – Coracoid process of scapula
Aberrant Epiphysis
Occasional epiphysis, e.g. – Head of first metacarpal
Layers of Growth plate (Physis)
The mnemonic for layers of Growth plate or Physis is as follows:
Real People Have Carrier Options
- Reserve Zone / Resting Zone- contains chondrocytes that store glycogen or lipids
- Proliferative Zone- determines height and width of bone
- Hypertrophic Zone / Maturation Zone
- Zone of Calcification
- Zone of Ossification
Key points to remember
Reserve zone
- Gaucher’s disease
Proliferative zone
- Achondroplasia (dwarfism)
- Gigantism
- Laron’s syndrome- Hereditary dwarfism and Truncal obesity
Hypertrophic zone
- Cartilage converted to bone
- Maturation occurs with Calcium incorporation
- Most common layer for trauma or injury
Zone of Calcification
- Rickets
Zone of Ossification
- Vascularity (metaphyseal vascular invasion)
Metaphysis
- Special bone- Spongy, Soft or Cancellous
- Highly vascular
- Vessels dilated, Tortuous and End arteries
- Hair pin loop of vessels
- Most common site for acute hematogenous osteomyelitis
Anatomy of Joint
Functional classification of Joint:
- Fibrous joint- Synarthrosis- Non-motile
- Cartilaginous joint- Amphiarthrosis- Somewhat motile
- Synovial joint- Diarthrosis- Highly motile
| Feature | Fibrous Joint | Cartilaginous Joint | Synovial joint |
| Other name | Synarthrosis | Amphiarthrosis | Diarthrosis |
| Types | Suture
E.g. – Cranial vault skull Syndesmosis E.g. – Inferior tibio-fibular joint Gomphosis E.g. – Tooth and socket joint |
1st degree- Synchondrosis or Syncedrosis
E.g. – Costochondral joint 2nd degree- Symphysis E.g. – Pubic symphysis |
Hinge joint
E.g. – Elbow joint Ellipsoid joint E.g. – Wrist joint Condylar joint E.g. – Knee joint and temporomandibular joint Ball and socket joint E.g. – Hip and shoulder joint Pivot joint E.g. – Atlantoaxial joint Saddle joint E.g. – 1st carpo-metacarpal joint Gliding joint E.g. – Inter-carpal joint |