1. Joints

2. Joints (Articulations)
Weakest parts of the skeleton
Articulation – site where two or more bones meet
Functions of joints
Give the skeleton mobility
Hold the skeleton together

3. Classification of Joints
Joints are classified based on:
Structure
Fibrous
Cartilaginous
Synovial
Function
Synarthroses – immovable
Amphiarthroses – slightly movable
Diarthroses – freely movable
Fibrous/Synarthroses

4. Classification of Joints: Structural
Structural classification focuses on the material binding bones together and whether or not a joint cavity is present
The three structural classifications are:
Fibrous
Cartilaginous
Synovial

5. Classification of Joints: Functional
Functional classification is based on the amount of movement allowed by the joint
The three functional classes of joints are:
Synarthroses – immovable
Amphiarthroses – slightly movable
Diarthroses – freely movable

6. Classification of Joints: Structural

7. Fibrous Structural Joints
The bones are joined by fibrous tissues
There is no joint cavity
Most are immovable
There are three types – sutures, syndesmoses, and gomphoses

8. Fibrous Structural Joints: Sutures
Occur between the bones of the skull
Comprised of interlocking junctions completely filled with connective tissue fibers
Bind bones tightly together, but allow for growth during youth
In middle age, skull bones fuse and are called synostoses

9. Fibrous Structural Joints: Syndesmoses
Bones are connected by a fibrous tissue ligament
Movement varies from immovable to slightly variable
Examples include the connection between the tibia and fibula, and the radius and ulna

10. Fibrous Structural Joints: Gomphoses
The peg-in-socket fibrous joint between a tooth and its alveolar socket
The fibrous connection is the periodontal ligament

11. Cartilaginous Joints Articulating bones are united by cartilage
Lack a joint cavity
Two types – synchondroses and symphyses

12. Cartilaginous Joints: Synchondroses
A bar or plate of hyaline cartilage unites the bones
All synchondroses are synarthrotic
Examples include:
Epiphyseal plates of children
Joint between the costal cartilage of the first rib and the sternum

13. Cartilaginous Joints: Symphyses
Hyaline cartilage covers the articulating surface of the bone and is fused to an intervening pad of fibrocartilage
Amphiarthrotic joints designed for strength and flexibility
Examples include intervertebral joints and the pubic symphysis of the pelvis

14. Synovial Joints
Those joints in which the articulating bones are separated by a fluid-containing joint cavity
All are freely movable diarthroses
Examples – all limb joints, and most joints of the body

15. Synovial Joints

16. Synovial Joints: General Structure
Synovial joints all have the following
Articular cartilage
Joint (synovial) cavity
Articular capsule
Synovial fluid
Reinforcing ligaments

17. Synovial Joints: Friction-Reducing Structures
Bursae – flattened, fibrous sacs lined with synovial membranes and containing synovial fluid
Common where ligaments, muscles, skin, tendons, or bones rub together
Tendon sheath – elongated bursa that wraps completely around a tendon

18. Synovial Joints: Stability
Stability is determined by:
Articular surfaces – shape determines what movements are possible
Ligaments – unite bones and prevent excessive or undesirable motion

19. Synovial Joints: Range of Motion
Nonaxial – slipping movements only
Uniaxial – movement in one plane
Biaxial – movement in two planes
Multiaxial – movement in or around all three planes

20. Gliding Movements
One flat bone surface glides or slips over another similar surface
Examples – intercarpal and intertarsal joints, and between the flat articular processes of the vertebrae

21. Angular Movement
Flexion — bending movement that decreases the angle of the joint
Extension — reverse of flexion; joint angle is increased
Dorsiflexion and plantar flexion — up and down movement of the foot
Abduction — movement away from the midline
Adduction — movement toward the midline
Circumduction — movement describes a cone in space

22. Gliding Movement

23. Angular Movement

24. Angular Movement

25. Rotation The turning of a bone around its own long axis Examples
Between first two vertebrae
Hip and shoulder joints

26. Angular Movement

27. Special Movements Supination and pronation Inversion and eversion
Protraction and retraction
Elevation and depression
Opposition

28. Special Movements

29. Special Movements

30. Special Movements

31. Special Movements

32. Special Movements

33. Synovial Joints: Knee Largest and most complex joint of the body
Allows flexion, extension, and some rotation
Three joints in one surrounded by a single joint cavity
Femoropatellar
Lateral and medial tibiofemoral joints

34. Synovial Joints: Knee Ligaments and Tendons – Anterior View
Tendon of the quadriceps femoris muscle
Lateral and medial patellar retinacula
Fibular and tibial collateral ligaments
Patellar ligament

35. Synovial Joints: Knee – Other Supporting Structures
Anterior cruciate ligament
Posterior cruciate ligament
Medial meniscus (semilunar cartilage)
Lateral meniscus

36. Synovial Joints: Knee – Other Supporting Structures

37. Synovial Joints: Knee – Posterior Superficial View
Adductor magnus tendon
Articular capsule
Oblique popliteal ligament
Arcuate popliteal ligament
Semimembranosus tendon

38. Synovial Joints: Shoulder (Glenohumeral)
Ball-and-socket joint in which stability is sacrificed to obtain greater freedom of movement
Head of humerus articulates with the glenoid fossa of the scapula

39. Synovial Joints: Shoulder Stability
Weak stability is maintained by:
Thin, loose joint capsule
Four ligaments – coracohumeral, and three glenohumeral
Tendon of the long head of biceps, which travels through the intertubercular groove and secures the humerus to the glenoid cavity
Rotator cuff (four tendons) that encircles the shoulder joint and blends with the articular capsule

40. Synovial Joints: Shoulder Stability

41. Synovial Joints: Shoulder Stability

42. Synovial Joints: Hip (Coxal) Joint
Ball-and-socket joint
Head of the femur articulates with the acetabulum
Good range of motion, but limited by the deep socket and strong ligaments

43. Synovial Joints: Hip Stability
Acetabular labrum
Iliofemoral ligament
Pubofemoral ligament
Ischiofemoral ligament
Ligamentum teres

44. Synovial Joints: Hip Stability

45. Synovial Joints: Elbow
Hinge joint that allows flexion and extension only
Radius and ulna articulate with the humerus

46. Synovial Joints: Elbow Stability
Annular ligament
Ulnar collateral ligament
Radial collateral ligament

47. Synovial Joints: Elbow Stability

48. Injuries Sprains Cartilage Injuries Dislocations Bursitis Tendonitis
Arthritis
Osteoarthritis (OA)
Rheumatoid Arthritis (RA)
Gouty Arthritis

49. Sprains The ligaments reinforcing a joint are stretched or torn
Partially torn ligaments slowly repair themselves
Completely torn ligaments require prompt surgical repair

50. Cartilage Injuries The snap and pop of overstressed cartilage
Common aerobics injury
Repaired with arthroscopic surgery

51. Dislocations Occur when bones are forced out of alignment
Usually accompanied by sprains, inflammation, and joint immobilization
Caused by serious falls and are common sports injuries
Subluxation – partial dislocation of a joint

52. Inflammatory and Degenerative Conditions
Bursitis
An inflammation of a bursa, usually caused by a blow or friction
Symptoms are pain and swelling
Treated with anti-inflammatory drugs; excessive fluid may be aspirated
Tendonitis
Inflammation of tendon sheaths typically caused by overuse
Symptoms and treatment are similar to bursitis

53. Arthritis
More than 100 different types of inflammatory or degenerative diseases that damage the joints
Most widespread crippling disease in the U.S.
Symptoms – pain, stiffness, and swelling of a joint
Acute forms are caused by bacteria and are treated with antibiotics
Chronic forms include osteoarthritis, rheumatoid arthritis, and gouty arthritis

54. Osteoarthritis (OA)
Most common chronic arthritis; often called “wear-and-tear” arthritis
Affects women more than men
85% of all Americans develop OA
More prevalent in the aged, and is probably related to the normal aging process

55. Osteoarthritis: Course
OA reflects the years of abrasion and compression causing increased production of metalloproteinase enzymes that break down cartilage
As one ages, cartilage is destroyed more quickly than it is replaced
The exposed bone ends thicken, enlarge, form bone spurs, and restrict movement
Joints most affected are the cervical and lumbar spine, fingers, knuckles, knees, and hips

56. Osteoarthritis: Treatments
OA is slow and irreversible
Treatments include:
Mild pain relievers, along with moderate activity
Magnetic therapy
Glucosamine sulfate decreases pain and inflammation

57. Rheumatoid Arthritis (RA)
Chronic, inflammatory, autoimmune disease of unknown cause, with an insidious onset
Usually arises between the ages of 40 to 50, but may occur at any age
Signs and symptoms include joint tenderness, anemia, osteoporosis, muscle atrophy, and cardiovascular problems
The course of RA is marked with exacerbations and remissions

58. Rheumatoid Arthritis: Course
RA begins with synovitis of the affected joint
Inflammatory chemicals are inappropriately released
Inflammatory blood cells migrate to the joint, causing swelling
Inflamed synovial membrane thickens into a pannus
Pannus erodes cartilage, scar tissue forms, articulating bone ends connect
The end result, ankylosis, produces bent, deformed fingers

59. Rheumatoid Arthritis: Course
RA begins with synovitis of the affected joint
Inflammatory chemicals are inappropriately released
Inflammatory blood cells migrate to the joint, causing swelling
Inflamed synovial membrane thickens into a pannus
Pannus erodes cartilage, scar tissue forms, articulating bone ends connect
The end result, ankylosis, produces bent, deformed fingers

60. Rheumatoid Arthritis: Treatment
Conservative therapy – aspirin, long-term use of antibiotics, and physical therapy
Progressive treatment – anti-inflammatory drugs or immunosuppressants
The drug Enbrel, a biological response modifier, neutralizes the harmful properties of inflammatory chemicals

61. Gouty Arthritis
Deposition of uric acid crystals in joints and soft tissues, followed by an inflammation response
Typically, gouty arthritis affects the joint at the base of the great toe
In untreated gouty arthritis, the bone ends fuse and immobilize the joint
Treatment – colchicine, nonsteroidal anti-inflammatory drugs, and glucocorticoids