THE MUSCULAR SYSTEM: Diseases of Joints and Muscles

Rheumatoid Arthritis

INFLAMMATORY JOINT DISEASE:

• chronic progressive inflammatory autoimmune disease mainly affecting peripheral synovial joints

Rheumatoid Arthritis

RISK FACTORS:

• Age (Elderly) — increases with age

• Sex — premenopausal women are 3x more often than men

• Genetic Risk — strong familial link

peripheral synovial joints (hands and feet)

what rheumatoid arthritis affects

Spondylitis

inflammation of the vertebra

Ankylosing spondylitis

INFLAMMATORY JOINT DISEASE:

• Calcification of the intervertebral joints and laying down of new bone lead to reduced spinal flexibility

• occurs in young adults

joints of the vertebral column

what ankylosing spondylitis affects

Psoriatic Arthritis

INFLAMMATORY JOINT DISEASE:

• occurs in a proportion of people who suffer from psoriasis, especially if nails are involved (nail pitting)

joints of the fingers and toes

what psoriatic arthritis affects

Reiter’s Syndrome

INFLAMMATORY JOINT DISEASE:

• also known as Reactive Arthritis or Polyarthritis with Urethritis and Conjunctivitis

• sexually transmitted and is caused by Chlamydia trachomatis infection

• also associated with an immune response to enteric or genitourinary (Shigella, Salmonella, Yersinia) organisms

joints of the lower limb (knees, ankles, feet)

what reactive arthritis affects

Conjunctivitis

associated with discharge, erythema, burning, photophobia in the eyes

Urethritis

associated with dysuria, urgency, frequency, discharge in the urethra

Rheumatic Fever

INFLAMMATORY JOINT DISEASE:

• diffuse inflammatory condition that affects many connective tissues (systemic illness/widespread infection)

• polyarthritis

• manifest in the cardiovascular system (can damage the valves of the heart)

• type of arthritis that can usually resolves spontaneously without complications except the cardiac effects

joints of the wrists, elbows, knees, and ankles

what rheumatic fever affects

Infective Arthritis

INFLAMMATORY JOINT DISEASE:

• Joint infection (Septic arthritis )usually results from a blood-borne systemic infection (sepsis, mainly staphylococcal)

• also results from a penetrating joint injury

• monoarthritis (only one joint is involved) which becomes acutely inflamed

• complete resolution/healing is possible if treatment is prompt but may result in permanent joint disease

Ostheoarthritis

degenerative, non-inflammatory disease that results in pain and restrictive movement of affected joints which usually develops in late middle ages

Osteoarthritis

RISK FACTORS:

• Increasing age (people > 65 y/o)

• Female

• Excessive repetitive use of the affected joints

• Obesity

• Heredity

Degenerative

TYPE OF DISEASE: Osteoarthritis

Inflammatory and Autoimmune

TYPE OF DISEASE: Rheumatoid Arthritis

Articular cartilage

TISSUE AFFECTED: Osteoarthritis

Synovial membrane

TISSUE AFFECTED: Rheumatoid Arthritis

Late middle age

AGE OF ONSET: Osteoarthritis

Any age, mainly 30-55 y/o, occasionally children

AGE OF ONSET: Rheumatoid Arthritis

weight bearing (hip, knee, joint of the cervical and lower lumbar spine); only a single joint

JOINTS AFFECTED: Osteoarthritis

Small (hands, feet); many joints

JOINTS AFFECTED: Rheumatoid Arthritis

Sprain

TRAUMATIC INJURY TO JOINTS:

• a traumatic stretch or tear of a ligament

Strain

TRAUMATIC INJURY TO JOINTS:

• excessive stretching of a muscle/tendon, often leading to a tear

Dislocation

TRAUMATIC INJURY TO JOINTS:

• complete displacement of the bones at a joint such that the articular surfaces of the bones are no longer in contact

Penetrating Injuries

TRAUMATIC INJURY TO JOINTS:

• caused by a compound fracture of one of the articulating bones or by trauma

• healing may be uneventful or delayed because of:

  • presence of fragments of damaged/torn joint tissue

  • infection

• can lead to permanent degenerative changes in the joint

Gout

caused by the deposition of sodium urate crystals in joints and tendons, provoking an acute inflammatory response (red, hot, extremely painful); monoarthritis

Gout

RISK FACTORS:

• Male

• Obesity

• Heredity

• Hyperuricemia

• High alcohol intake

metatarsophalangeal joints of the big toe and the ankle, knee, wrist, and elbow joints

example of gout

Connective Tissue Diseases

group of chronic autoimmune disorders that has common features:

• affect many organ systems of the body (joints, skin, subcutaneous tissues)

• occur in early adult life

• affect more females than males

• Systemic lupus erythematosus (SLE)

• Systemic sclerosis (scleroderma)

• Rheumatoid arthritis (RA)

• Ankylosing Spondylitis

• Reiter’s Syndrome

examples of connective tissue diseases

Carpal Tunnel Syndrome

• occurs when the median nerve is compressed in the wrist as it passes through the carpal tunnel

• commonly occurs in women in the ages of 30 - 50 y/o

• characterized by pain and numbness in the hand and wrist affecting the thumb, index and middle fingers, and half of the ring finger

Carpal Tunnel Syndrome

causes:

• many cases are idiopathic

• secondary to other conditions (RA, diabetes mellitus, acromegaly, hypothyroidism

• repetitive flexion and extension of the wrist joint (keyboarding)

use of wrist splint

conservative management for Carpal Tunnel Syndrome is the ________________ to immobilize the wrist in a neutral position

Laboratory Studies for Joints

Laboratory Studies/Imaging Studies/Pharmacologic Treatment/Non-Pharmacologic Treatment?

• Complete Blood Count (CBC)

• Rheumatoid factor (RF)

• Human Leukocyte Antigen (HLA-B27)

• Erythrocyte Sedimentation Rate (ESR)

• C-Reactive Protein (CRP)

• Antinuclear Antibody (ANA)

• Anti-citrullinated peptide antibody (ACPA)

• Synovial fluid analysis

Imaging Studies for Joints

Laboratory Studies/Imaging Studies/Pharmacologic Treatment/Non-Pharmacologic Treatment?

• X-Ray

• MRI

• CT Scan

• Ultrasound

Pharmacologic Treatment for Joints

Laboratory Studies/Imaging Studies/Pharmacologic Treatment/Non-Pharmacologic Treatment?

• NSAIDs (Non-Steroidal Anti-Inflammatory Drugs)

• COX-2 inhibitors

• Glucocorticoids

• DMARDs (Disease Modifying Anti-Rheumatic Drugs)

• TNF-a (Tumor Necrosis Factor alpha) inhibitors

Non-Pharmacologic Treatment for Joints

Laboratory Studies/Imaging Studies/Pharmacologic Treatment/Non-Pharmacologic Treatment?

• Immobilization (with splints, casts, or bandages)

• Physical and occupational therapy

• Hot or cold packs for pain management

• R-I-C-E Approach (Rest-Ice-Compression-Elevation) during sprains and strains.

• Dietary and lifestyle modifications

• Surgery is necessary if extensive joint damage is present

Human Leukocyte Antigen (HLA-B27)

laboratory studies for joint disorders that is used as a marker for spondylitis

Erythrocyte Sedimentation Rate (ESR)

laboratory studies for joint disorders that is used as a nonspecific inflammatory factor from the red blood cell

C-Reactive Protein (CRP)

laboratory studies for joint disorders that is used as a nonspecific inflammatory factor produced by the liver

Antinuclear Antibody (ANA)

laboratory studies for joint disorders that is used as a marker for autoimmune disease

Anti-citrullinated peptide antibody (ACPA)

laboratory studies for joint disorders that is used as a marker for rheumatoid arthritis

Myasthenia gravis

• autoimmune condition of unknown origin affects more women than men, usually aged between 20 - 40 years old

• antibodies are produced that bind to and block the acetylcholine receptors of the neuromuscular junction, blocking the nerve impulses to muscle fibers, causing progressive and extensive muscle weakness

• PATTERN OF MUSCLE WEAKNESS: upper to lower

  • extrinsic and eyelid muscle (ptosis — drooping of eyelids and diplopia (double vision)

  • neck (chewing, swallowing, speech)

  • Limbs

Duchenne muscular dystrophy

• sign and symptoms may not appear until 5 y/o

• PATTERN OF MUSCLE WEAKNESS: lower — higher

  • lower limbs

  • upper limbs

• death occurs in adolescence from:

  • respiratory failure

  • cardiac arrhythmias or cardiomyopathy

• muscles enlarge with fat and connective tissue while the muscle fibers degenerate

Facioscapulohumeral dystrophy

• affects both sexes

• usually begins in adolescence, and the younger the age of onset, the more rapidly it progresses

• muscles of the face and shoulders are affected first

• chronic condition that progresses slowly, life expectancy is normal

Myotonic dystrophy

• pattern: Upper — lower

  • tongue

  • face

  • limbs

• associated with:

  • cataracts

  • atrophy of gonads

  • cardiomyopathy

  • glucose intolerance

• disease progresses without remission and with increasing disability

• death occurs in middle age from respiratory or cardiac failure

Edrophonium Test (Tensilon Test)

used to diagnose myasthenia gravis before antibody testing became the common method

Laboratory Studies for Muscles

Laboratory Studies/Imaging Studies/Pharmacologic Treatment/Non-Pharmacologic Treatment?

• Creatine kinase

• Genetic analysis (gene mutations)

• Muscle biopsy

• Antibody testing

• Electromyography (EMG)

• Edrophonium Test (Tensilon Test)

Imaging Studies for Muscles

Laboratory Studies/Imaging Studies/Pharmacologic Treatment/Non-Pharmacologic Treatment?

• X-Ray

• MRI

• CT Scan

• Ultrasound

Pharmacologic Treatment for Muscles

Laboratory Studies/Imaging Studies/Pharmacologic Treatment/Non-Pharmacologic Treatment?

• IV Immunoglobulins

• Plasmapheresis

• Glucocorticoids

• Skeletal Muscle Relaxants

Non-Pharmacologic Treatment for Muscles

Laboratory Studies/Imaging Studies/Pharmacologic Treatment/Non-Pharmacologic Treatment?

• Breathing assistance (ventilatory support)

• Physiotherapy

• Orthopedic assistive devices

• Psychological support

• If necessary, surgical treatment