Ch. 13 Introduction to Pathology of the Musculoskeletal System - Student 2024 - Tagged 2

Chapter 13: Introduction to Pathology of the Musculoskeletal System

Instructor

• Mrs. Giomara McBee, PTA, MS, ASDI

• Institution: Keiser University

Objectives

• Review biological response to trauma

• Orientation to diseases affecting the musculoskeletal system

Biological Response to Trauma

• Immediate Response: Generalized inflammatory reaction characterized by vascular, chemical, and cellular events aimed at preparing the area for repair.

  • 1. Vasoconstriction:

    • Initiates in response to injury.

    • Margination: White blood cells (WBCs) migrate to the periphery of the vessel.

    • Pavementing: WBCs adhere to the walls of damaged capillaries.

  • 2. Vasodilation: Increased permeability of blood vessels.

    • Mediated by histamine, serotonin, and bradykinins.

  • 3. Diapedesis:

    • WBCs squeeze through the blood vessel walls and increase fluid to the area.

  • 4. Chemotaxis:

    • WBCs are guided to the site of injury.

  • 5. Phagocytosis:

    • WBCs (neutrophils, monocytes, macrophages) clean up the area by engulfing and digesting debris, necrotic tissue, and red blood cells.

Cellular Response for Inflammatory Reaction

• Mast Cells: Release inflammatory chemicals.

• Chemotaxis: Draws WBCs to the site of injury.

• Increased Permeability: Allows proteins and fluids to pass into tissues.

Sarcopenia

• Definition: Age-related loss in muscle mass, strength, and endurance, accompanied by changes in metabolic quality of skeletal muscle.

• Occurrence: Common among older adults but can begin earlier.

• Characteristics:

  • Low muscle strength

  • Low muscle quantity and quality

  • Poor performance in physical strength

Etiology

• Factors contributing to sarcopenia include:

  • Changes in muscle metabolism

  • Endocrine system changes

  • Nutritional deficiencies

  • Mitochondrial and genetic factors.

• Uncertainty remains if age-related loss of muscle function is inevitable due to aging, nutrition, or dysregulation of homeostasis.

Pathogenesis

• Decreased motor neuron capacity to innervate regenerating fibers.

• Decline in muscle mass related to ineffective protein utilization and hormonal changes.

• Impacts include:

  • Decreased muscle fibers and size

  • Impaired excitation-contraction

  • Mitochondrial dysfunction.

Classification of Sarcopenia

• Primary: Age-related with no additional factors.

• Secondary: Associated with systemic diseases, physical inactivity, or malnutrition.

• Acute Sarcopenia: Less than 6 months; ties to acute illness or injury.

• Chronic Sarcopenia: More than 6 months; related to progressive illnesses and comorbidities.

Risk Factors for Sarcopenia

• Obesity

• Physical inactivity

• Malnutrition (particularly protein)

• Cigarette smoking

• Extreme sleep duration

• Reduced growth hormone levels

• Insulin resistance

• Reduction in Type II muscle fibers.

Related Chronic Diseases & Factors

• Chronic Obstructive Pulmonary Disease (COPD)

• Cancer

• Congestive Heart Failure

• Chronic Kidney Disease

• Diabetes Mellitus

• HIV

• Osteoporosis

• Anemia

• Aging

Effects of Sarcopenia

• Loss of muscle mass leading to functional decline and muscle weakness.

• Impact on Activities of Daily Living (ADLs):

  • Increased risk of vertebral fractures

  • Slower gait speed

  • Impaired balance

• Longer recovery times and potential for additional comorbidities.

Related Consequences

• Increased mortality

• Hospitalization

• Functional decline leading to issues like osteoporosis, fractures, falls, cognitive impairments, dysphagia, diabetes, depression, and hypertension.

Patient Profile

• Frailty: Low grip strength, low energy, slowed walking speed, low physical activity.

• Cachexia: Low muscle strength, weight loss, low energy and appetite, and inflammation due to illness (also called wasting syndrome).

Patient Assessment

• Measures:

  • Hand grip strength

  • 30-second chair stand test

  • Calf circumference measurement

  • Age, hospitalization history, and weight

• Subjective Assessment: Activity level of the patient.

• Diagnosis: Confirmed via CT scan, MRI, or Bioelectric Impedance Analysis.

• Severity: Assessed by gait speed, Timed Up & Go, and 400m walk tests.

Clinical Measurements

• Posture: Check for excessive kyphosis or lordosis.

• Joint Range of Motion (ROM): Focus on cervical/thoracic spine and ribs.

• Muscle strength/performance: Emphasis on core strength and respiratory muscle performance.

• Gait Assessment: Employ dynamic gait index and functional gait assessment.

• Functional Movements: Bed mobility and transition movements along with ADLs.

• Breathing Assessment: Spirometry and evaluation of diaphragmatic breathing and positional influences.

• Balance/Function: Evaluate through Single Leg Stance (SLS), Single Leg balance/squat, Berg, and Tinetti tests.

Exercise & Sarcopenia

• Role of Exercise: Appropriate exercise can alter, slow, or partially reverse age-related physiologic changes.

• Types:

  • Progressive resistive training or high-intensity training recommended.

  • Strength training has proven to improve muscle strength and function, reduce fall risks, and enhance independence.

• Educational Role: Therapists should educate older adults about the importance of strength and endurance training.

Joint & Connective Tissue

• Aging effects include increased stiffness and decreased flexibility.

• Articular Cartilage: Cushions subchondral bone and provides a low-friction surface; prone to breakdown with aging, contributing to osteoarthritis (OA).

• Tendons: Experience a decrease in tensile strength and loss of joint integrity as they age.

Bone Health

• Bone Functions: Main storage for calcium, phosphate, sodium, and magnesium; hosts hemopoietic bone marrow.

• Aging Effect: Quality of bone matrix declines; increased bone resorption and accelerated calcium release without sufficient new bone formation.

Muscle Fiber Types

• Type I (Aerobic): Slow-oxidative, fatigue-resistant, utilized for aerobic activities.

• Type IIa: Fast-oxidative, fatigue-resistant, used for long-term anaerobic activities.

• Type IIb: Fast-twitch, easily fatigued, utilized for short-term anaerobic activities.

Medical Terminology

Combining Forms

• Ankyl/o - Stiff joint

• Chondr/o - Cartilage

• Arthr/o - Joint

• Eryth/o - Red

• Burs/o - Bursa

• Orth/o - Straight

• Cost/o - Rib

• Sarc/o - Flesh

• Kyph/o - Hump

• Lord/o - Bent backward

• Oste/o - Bone

• Ped/o - Child; foot

• Prosthet/o - Addition

• Scoli/o - Crooked

• Spondyl/o - Vertebra

Prefixes

• Sub- - Under

• Ex- - Outward

• Dis- - Apart

• Inter- - Between

• Non- - Not

• Per- - Through

• Pre- - Before

Suffixes

• -algia - Pain

• -centesis - Puncture to withdraw fluid

• -clasia - Surgically break

• -desis - To fuse

• -ectomy - Surgically remove

• -genic - Producing

• -gram - Record

• -itis - Inflammation

• -listhesis - Slipping

• -malacia - Softening

• -oma - Tumor

• -osis - Abnormal condition

• -plasty - Surgical repair

• -porosis - Porous

• -iatry - Medical treatment

Medical Specialties

Chiropractic

• Concerned with diagnosis and treatment of malalignment conditions of spine and musculoskeletal system.

Orthopedics

• Specializes in diagnosis and treatment of musculoskeletal conditions; originally focused on straightening deformities in children.

Orthotics

• Involves making orthopedic appliances like braces and splints.

Prosthetics

• Focuses on creating artificial body parts.

Rheumatology

• Diagnosis and treatment of musculoskeletal and autoimmune conditions affecting joints, muscles, and bones.

Signs & Symptoms

• Arthralgia: Pain in the joint.

• Chondromalacia: Abnormal softening of cartilage.

• Crepitation: Noise made when bones or cartilage rub together.

• Osteoalgia: Pain in the bone.

• Osteoporosis: Thinning and weakening of bones, leading to fractures.

• Ankylosing spondylitis: Inflammatory condition that causes stiffness and fusion of vertebrae.

• Spondylolisthesis: Slipping of vertebrae.

Diagnostic Procedures

• Arthrogram: X-ray record of a joint.

• Myelogram: X-ray of the spinal column.

Surgical Procedures

• Amputation: Partial or complete removal of limb.

• Arthrodesis: Fusion of bones at a joint.

• Laminectomy: Removal of posterior part of vertebra to relieve pressure.

• Spinal fusion: Surgical immobilization of vertebrae.

• Arthroscopic surgery: Minimally invasive surgery to inspect or operate on a joint.

• Fixation: Stabilization of fractured bones during healing.

• Reduction: Realignment of fractured bones, either closed or open.

Pharmacology

• Bone Reabsorption Inhibitors: Used for osteoporosis and Paget's disease. Examples: Alendronate (Fosamax), Ibandronate (Boniva).

• Calcium and Vitamin D Therapy: Maintains bone density; treats osteomalacia and osteoporosis.

• Corticosteroids: Anti-inflammatory medications for conditions like rheumatoid arthritis. Examples: Prednisone, Methylprednisolone.

• NSAIDs: Provide mild pain relief and anti-inflammatory benefits. Examples: Ibuprofen (Advil), Aspirin (Bayer).

References

• Goodman, C., Fuller, K., & Marshall, C. (2017). Pathology for the Physical Therapist Assistant (2nd Ed.). St. Louis, MO: Saunders.

• Fremgen, B. F., & Frucht, S. S. (2019). Medical Terminology: A Living Language (7th ed.). Pearson Education.

• Goodman, C., Fuller, K., & Marshall, C. (2024). Pathology for the Physical Therapist Assistant (3rd Ed.). Elsevier.