Trauma_lecture_2.pdf
- 1. Introduction to Orthopedic Anatomy Traumatology RHS 231 Dr. Einas Al-Eisa Lecture 2
- 2. Types of Joints Synovial Diarthroidal Freely movable Cartilagenous Amphiarthroidal Slightly movable Fibrous Synarthroidal Immovable
- 4. Synchodroses = Fibrocatilagenous joint that allows very slight movement
- 6. Syndesmosis = bones held together by strong ligaments that allow minimal movement Inferior tibiofibular joint
- 8. Characteristics of Synovial Joints • Articular end plate = a thin layer of compact bone over the spongy bone (covering the ends of the bones) • Articular (hyaline) cartilage for shock absorption, stability, improved fit for the surfaces, lubrication Covered by:
- 9. Characteristics of Synovial Joints • Joint capsule = a fibrous connective tissue that surround the bony ends forming the joint • Synovial membrane = loose, vascularized connective tissue that secretes synovial fluid into the joint cavity for lubrication Lined with:
- 10. Synovial joint
- 11. Characteristics of Synovial Joints • Where additional support is needed, the joint capsule is thickened to form tough, non-elastic ligaments to provide additional support. • Stability of a synovial joint is provided by: the capsule, ligaments, muscles & tendons spanning the joint, and the congruency of the bone surfaces.
- 13. Types of synovial joints 1) Plane (gliding) joint: consists of two flat surfaces that glide over each other. Example: carpals & tarsals
- 15. Types of synovial joints 2) Hinge joint: allow movement in one plane (flexion / extension). Example: interphalangeal joints (hand), ulnohumeral joint (elbow)
- 16. Hinge Joint
- 17. Types of synovial joints 3) Pivot Joint: allows a rotational movement around a long axis. Example: superior & inferior radioulnar joint (pronation / supination), atlantoaxial joint at the base of the skull (rotation)
- 18. Pivot Joint
- 19. Types of synovial joints 4) Condyloid joint: allows movement in two planes (flexion / extension and abduction /adduction) without rotation. Example: metacarpophalangeal joints
- 20. Condyloid Joint
- 21. Types of synovial joints 5) Saddle joint: allows two planes of movement (flexion / extension, abduction / adduction). Example: only found at the carpometacarpal joint of the thumb.
- 22. Saddle Joint
- 23. Types of synovial joints 6) Ball-and-socket joint: allows movement in all three planes (flexion/extension, abduction/adduction, & rotation) Example: the hip and shoulder joints.
- 25. Architecture of bone (osseous tissue) 1. Cortical (compact) bone: – the exterior dense layer of the bone – consists of hollow tubes called lamellae (collagen fibers that are arranged in layers and run in different directions) – A series of lamellae form an osteon or haversian system (weight-bearing pillars) – Provides strength for weight bearing & stiffness in response to muscle tension
- 26. Osteon
- 27. Architecture of bone (osseous tissue) 2. Cancellous (spongy) bone : – interior to cortical bone – consists of flat pieces of bone called trabeculae (collagen runs along the axis of the trabeculae) – Provides energy absorption & stress distribution in response to loads – Not as strong as cortical bone (risk of fracture in the elderly)
- 28. Types of Bones
- 29. Long Bones
- 30. Long Bones • Consist of a shaft called diaphysis (made of compact bone), which broadens out into the epiphysis (made up of spongy bone inside a thin layer of compact bone) • Offer support and leverage • Example: humerus, radius, ulna, femur, tibia, fibula, metacarpals, metatarsals
- 31. Flat Bones
- 32. Flat Bones • Consist of two layers of compact bone with spongy bone in between • Protect internal structures and offer broad surfaces for muscle attachments • Example: ribs, illium, sternum, scapula
- 34. Short Bones • Consist of spongy bone covered with a thin layer of compact bone • Play an important role in shock absorption and transmission of forces • Example: carpals of the hand and the tarsals of the foot
- 37. Irregular Bones • Consist of spongy bone and thin exterior layer of compact bone • Specialized functions such as supporting the weight, protecting the spinal cord, dissipating loads • Example: vertebrae, ischium, pubis
- 39. Sesamoid Bones • Short type of bone embedded in a tendon or joint capsule • Alter the angle of muscle insertion to increase its mechanical advantage • Example: the patella embedded in the quadriceps tendon, sesamoid bones within the flexor tendons of the great toe & thumb
- 40. Accessory ossicles • Occur as variants of normal (only in few individuals, in addition to the normal bones). • Can be mistaken as fractures, but are harmless. • Example: the os trigonum behind the talus, the accessory navicular.
- 44. Growth of bone • Long bones grow from the epiphyseal plate (growth plate) at each end. • Both ends grow, but generally one end will grow faster than the other. • Example: distal epiphysis of the femur & proximal epiphysis of the tibia contribute roughly 60% of limb length, but proximal epiphysis of the humerus contribute 80% of humeral length.
- 45. Muscles • Agonists and antagonists oppose each other, but still work as balanced groups. • Muscles are contained within Fascial Compartments. • Swelling compartment pressure ischaemic pain
- 46. Forearm compartments • Ventral compartment: ¾median & ulnar nerves ¾Radial & ulnar arteries • Dorsal compartment: ¾Less common and less serious ¾Posterior interosseous nerve
- 48. Lower limb compartments • Anterior (tibial) compartment: ¾Deep peroneal nerve ¾Anterior tibial artery • Lateral (peroneal) compartment: ¾Superficial peroneal nerve ¾Rarely affected by compression
- 49. Lower limb compartments • Superficial posterior compartment: ¾Gastrocnemius & soleus muscles ¾No important nerves or vessels • Deep posterior compartment: ¾Posterior tibial vessels and nerves ¾Peroneal artery ¾Serious consequences if damaged
- 50. Tendons • Muscle action depends on the direction of its tendon. • Tendons do not tolerate friction protected by bursae or synovial sheets
- 52. Nerves Root lesions (e.g., disc prolapse, spinal injury) Peripheral nerves (e.g., ulnar neuritis, median nerve compression)
- 53. Vulnerable peripheral nerves Upper limb • Median nerve ¾Most common: compression at the wrist (carpal tunnel) ¾Fluid retention in pregnancy ¾Repetitive movement (flexor tenosynovitis) ¾Sensory distribution: thumb, index, and middle fingers, half the ring finger
- 54. Vulnerable peripheral nerves Upper limb • Ulnar nerve: ¾Most common: irritation at the elbow ¾Sensory distribution: little finger & ulnar half of the ring finger • Radial nerve: ¾Vulnerable in the medial side of the upper arm (e.g., axillary crutches) ¾Drop wrist (few sensory symptoms)
- 55. Vulnerable peripheral nerves Lower limb • Sciatic nerve: ¾Posterior dislocation of the hip • Common peroneal nerve: ¾Trauma causing lesion as the nerve crosses the neck of fibula • Lumbar nerve roots ¾Prolapsed intervertebral discs