Musculoskeletal System

1. Anatomy & Physiology

The musculoskeletal system is composed of bones, muscles, joints, cartilage, tendons, ligaments, and bursae.

Bones

• Spongy (cancellous) bone — located in the ends of long bones & center of flat/irregular bones
• Dense (cortical) bone — covers the spongy bone

Types of Bones

• Long bones (femur, humerus): diaphysis (shaft, compact bone) + epiphysis (ends, cancellous) + metaphysis (growth plate / epiphyseal plate)
• Short bones (carpals, tarsals): cancellous covered by thin compact bone
• Flat bones (skull, ribs): two compact layers sandwiching cancellous bone
• Irregular bones (vertebrae, mandible): varying size and shape

Cartilage

• Cushioning effect; inflammation = chondritis
• Degeneration of articular cartilage → osteoarthritis

Joints

• Freely movable (diarthrosis) — ball & socket, hinge, pivot
• Partially movable (amphiarthrosis) — pivot (skull rotation on atlas), hinge (elbow, knee)
• Immovable (synarthrosis) — skull sutures
• Apophyseal joint — between vertebrae

Muscles

• Involuntary: smooth (intestine wall), cardiac
• Voluntary: striated skeletal muscles
• Compartments: each limb has compartments separated by fascia, each with its own nerve and blood supply

Tendons, Ligaments & Meniscus

• Tendons: attach bone to muscle
• Ligaments: attach bone to bone
• Meniscus: thin cartilage layer between bones at a joint

2. Diagnostic Tests & Lab Values

Bone Scan

• Fluoroscopic X-ray after IV radioisotope (Technetium, Gallium)
• Indications: bone tumors, osteomyelitis
• Pre-op: informed consent, hold fluids 4 hr before, drink 4 cups water after injection
• Posttest: encourage oral fluids; no radiation precautions needed

Bone Density Test (DEXA Scan)

• Measures bone mass; indicated for osteoporosis

Arthroscopy

• Fiberoptic endoscope into joint → biopsy, removal of loose bodies, surgery
• Pre: NPO 8–12 hr, informed consent, prepare for crutch walking if lower extremity
• Post: activity limitation 2–4 days, ambulation without weight bearing once sensation returns

Arthrocentesis

• Aspiration of synovial fluid; post: elastic compression bandage, rest joint 8–24 hr

Myelography

• Fluoroscopic exam of spinal cord after CSF withdrawn & replaced with radiopaque dye
• Pre: NPO, informed consent, withhold anticoagulants 48 hr before & 24 hr after
• Post: seizure precautions; oil-based dye → flat 8–12 hr; water-based dye → HOB elevated 15–30° for 8 hr

Electromyography (EMG)

• Measures electrical activity of skeletal muscle; needles into muscle (some discomfort)
• Indication: distinguish muscle disease from neuromuscular disease

Key Lab Values

3. Orthopedic Interventions

Weight-Bearing Terminology

• NWB — Non Weight Bearing
• PWB — Partial Weight Bearing
• WBAT — Weight Bearing As Tolerated
• FWB — Full Weight Bearing

Range of Motion (ROM) Exercises

• Active: client performs independently
• Passive: caregiver performs for client
• Active assistive: client moves as far as possible, nurse/therapist completes
• Active resistive: contraction against opposing force → ↑ muscle size & strength
• Isometric: ↑ tension for seconds then relax; maintains strength during casting or acute RA
• Isotonic: flexion & extension; includes ROM exercises

Assistive Devices

Cane

• Hold in hand opposite affected limb
• Advance cane at same time as affected leg
• Elbow flexed 15–30°
• Nurse stands at affected side

Walker

• Hold upper bars; move walker forward, step into it
• Stand adjacent to affected side

Crutches

• Top of crutch 2–3 inches below axilla; weight NOT borne by axilla
• Tip 6 inches in front & to side of feet
• Elbows slightly flexed on hand grip
• When ambulating, stand on affected side
• 4-point: Rt crutch → Lt foot → Lt crutch → Rt foot (both WB allowed)
• 3-point: Both crutches + affected extremity → unaffected (one NWB)
• Swing-to / Swing-through: for paralysis of both lower extremities or bilateral amputation
• Climb stairs: good leg first; descend: bad leg first

Casts

Cast Care — Nursing

• Don't cover until dry; use palms (not fingertips) to support
• Support on rubber/plastic-protected pillows; turn q1h
• Neurovascular checks distal to cast — 6 Ps: Pain, Pallor, Pulselessness, Paresthesia, Paralysis, Poikilothermia
• Instruct wiggle toes/fingers; elevate above heart; isometric exercises when cleared
• Apply ice bags if ordered; don't get cast wet
• Don't scratch under cast — use cool blow dryer air for itching
• Petaling cast edges; bivalve if circulatory impairment suspected
• No powder, cream, or lotion near cast

Traction

• Pulling force on bones; weights provide traction, body weight provides counter-traction
• Continuous vs. intermittent; Skin vs. Skeletal
• Purposes: reduce/immobilize fractures, reduce muscle spasm, correct/prevent deformities

Types of Traction

Traction Nursing Care

• Ropes aligned, weights hanging freely; don't rest limb against foot of bed
• Don't remove/lift weights without order
• Place knots in rope to prevent slipping; line of traction within long axis of bone
• Prevent foot drop (high-top sneakers, boots, sandbag, splint)
• Prevent DVT; pad ring of Thomas splint, pad popliteal space in Russell's
• In cervical traction: pad chin area, protect ears
• For skeletal traction: surgical site care with NS, H₂O₂ or Betadine; observe for redness, odor, drainage
• Provide overhead trapeze for mobility

4. Fractures

Definition: Break in continuity of bone.

Types

• Closed (simple): no break in skin
• Open (compound): break in skin ± protrusion of bone
• Comminuted: broken/splintered into fragments
• Greenstick: one side broken, one bent (children)
• Impacted (telescoped): opposite sides compressed together
• Avulsion: bone fragment & soft tissue pulled away
• Colle's: distal radius within 1 inch of articular surface
• Pott's: tibia & fibula near ankle joint
• Supracondylar: distal humerus just above elbow

Stages of Bone Healing

1. Hematoma — blood clot forms at fracture site
2. Cellular proliferation — granulation tissue forms
3. Callus formation — cartilage and bone matrix deposited
4. Ossification — new bone cells (osteoblasts) form
5. Consolidation & remodeling — bone reshaped to original form

Findings

• Pain aggravated by motion, tenderness, loss of motion
• Ecchymosis, crepitus

Management

• Reduction: closed (manual) or open (ORIF with pins, wires, plates, external fixator)
• Cast, traction

Complications

• Fat emboli: begins 24–72 hr; mental disturbance, fever, petechial rash on chest/neck, respiratory distress, shock
• Compartment syndrome
• Osteomyelitis
• Arrested bone growth (epiphyseal plate fracture)
• Renal calculi, DVT, mal-union

Nursing Care

• Neurovascular checks
• Diet high in protein & vitamins, moderate calcium/phosphorus/sodium
• Encourage fluids

5. Compartment Syndrome

Increased pressure within one or more muscle compartments causing neurovascular impairment. Irreversible damage if not relieved in 4–6 hours.

Causes

• Fractures, crush injuries
• Cast, traction
• Circumferential burns of extremities

Findings (6 Ps)

• Pain unrelieved even with narcotics
• Pain on passive motion
• Pulselessness
• Paresthesia
• Paralysis
• Poikilothermia (coldness)

Volkmann's Ischemic Contracture

• Seen with distal humerus fracture or elbow trauma
• Vascular injury → permanent flexion contracture of hand/fingers/wrist
• Medical emergency; more common in children
• Treatment: immediate removal of occlusive dressings/cast, surgery as needed

6. Osteomyelitis

Infection of bone and surrounding tissues; frequent complication of open fracture or surgery.

Findings

• Pain & tenderness of bone, redness, swelling
• Difficulty with weight bearing, possible drainage

Diagnosis

• Elevated WBC & ESR; C&S for organism

Management

• Prolonged antibiotic therapy; pain management
• Surgery: I&D of bone abscess, sequestrectomy (remove dead bone), bone grafting, amputation
• Nursing: psychological support, diversional activities

7. Hip Fracture

May involve head, neck (intracapsular) or trochanter (extracapsular). Most frequent in elderly women; common complication of osteoporosis.

Findings

• Pain in affected limb; limb appears shorter with external rotation

Management

• Buck's or Russell's traction (temporary) to reduce spasm
• Surgery: ORIF with pins/nails/plates; hemiarthroplasty (Austin-Moore prosthesis) if healing difficult

Nursing Care

• Monitor for disorientation in elderly
• Neurovascular checks; encourage trapeze use
• Check dressings for bleeding; empty JP/hemovac drain — keep compressed
• Avoid over-sedating elderly
• Turn q2h to unoperative side only; pillow between legs when turning
• DVT precautions: antiembolic stockings, sequential compression devices, foot exercises, anticoagulants
• Quadriceps & gluteal setting exercises
• OOB usually day 1–2 post-op; pivot/lift into chair; move to unaffected side when transferring
• Avoid weight bearing until allowed

8. Joint Replacement (Hip & Knee)

Total Hip Replacement (THR)

Replacement of both femoral head and acetabulum with prosthesis. Indicated for advanced OA, RA, non-union hip fracture.

Post-Op Care

• Maintain abduction at all times with abduction splint, wedge, or 2 pillows
• Monitor for ↑ pain → may indicate dislocation of prosthesis
• Prevent external rotation with trochanter rolls
• Prevent hip flexion: keep HOB flat (may raise to 45° for meals); turn only to unoperative side with abduction pillow
• OOB usually day 2; avoid weight bearing until allowed
• Avoid adduction & hip flexion: don't use low chair, don't cross legs, use raised toilet seat, don't bend to put on shoes/socks

Knee Replacement (Knee Arthroplasty)

Replacement of weight-bearing surfaces of knee joint with metal/plastic devices. Indicated for OA, RA, trauma.

Post-Op Care

• Pain management; CPM (Continuous Passive Motion) machine
• Crutch walking / walker

9. Rheumatoid Arthritis & Osteoarthritis

RA — Stages of Deterioration

1. Synovitis
2. Pannus formation (abnormal granulation tissue)
3. Fibrous ankylosis
4. Bony ankylosis

RA — Management

• NSAIDs, DMARDs (gold compounds, TNF inhibitors, Methotrexate, Sulfasalazine, Hydroxychloroquine)
• Corticosteroids (intra-articular initially, systemic if other drugs fail)
• Physical therapy, heat treatments (warm bath, paraffin wax, whirlpool)
• Surgery to replace damaged joints

RA — Nursing Management

• ROM exercises several times/day; isometric during acute inflammation
• Frequent position changes; balance rest & activity
• Bed rest if ordered: firm mattress, avoid pillows under knees, prone ½ hr twice daily
• Emotional support, realistic goal-setting
• Discharge: ADL devices, balanced diet, avoid excessive physical/emotional stress

OA — Management

• Heat application, NSAIDs, intra-articular corticosteroids
• Herbal: ginger concentrate, capsaicin
• Nursing: rest periods, assistive devices, proper posture, weight reduction, ROM & isometric exercises

10. Gout (Hyperuricemia)

Disorder of purine metabolism → high uric acid → precipitation of urate crystals in joints. More common in men.

Findings

• Joint pain (frequently foot/ankle); redness, heat, swelling
• Tophi in outer ear, hands, feet
• Headache, malaise, anorexia, tachycardia, fever
• Renal stones

Diagnosis

Elevated serum uric acid.

Management

• Acute attack: Colchicine (S/E: diarrhea), NSAIDs
• Prophylactic: Uricosurics (Probenecid, Sulfinpyrazone) — excrete uric acid; Allopurinol (Zyloprim) — prevent uric acid formation
• Low purine diet: avoid shellfish, sardines, anchovies, mussel, oatmeal, peas, nuts, gravy, glandular meats (liver, kidney, brain)
• Joint rest, heat treatment
• Nursing: bed rest & joint immobilization, ↑ fluids 2000–3000 mL/day, weight reduction, limit alcohol, regular exercise

11. Osteoporosis

Metabolic bone disease characterized by decreased bone mass and density, leading to increased fracture risk.

Risk Factors

• Postmenopausal women, advanced age, family history
• Low calcium/vitamin D intake, sedentary lifestyle, smoking, excessive alcohol
• Prolonged corticosteroid use

Diagnosis

• DEXA scan (T-score ≤ −2.5 indicates osteoporosis)

Management

• Bisphosphonates: Alendronate (Fosamax), Risedronate (Actonel), Ibandronate (Boniva) — take on empty stomach with full water, remain upright for 30 min after
• Calcium & Vitamin D supplements
• Weight-bearing exercise, fall prevention
• Calcitonin (Miacalcin) for pain management

12. Herniated Nucleus Pulposus

Protrusion of the central part of intervertebral disc into spinal canal → compression of spinal nerve roots. More frequent in men.

Risk Factors

• Heavy lifting, pulling, trauma

Findings (by level)

• Lumbosacral: back pain radiating to leg (sciatica), weakness of leg/foot, numbness/tingling, positive straight leg raise (Laseague's sign), depressed/absent Achilles reflex, muscle spasm
• Cervical: shoulder pain radiating to arm/hand, weakness, sensory disturbances

Diagnosis

CT, MRI, Myelogram.

Management

• Non-surgical: bed rest, traction, muscle relaxants (Cyclobenzaprine/Flexeril), heat, brace/corset, cervical collar, epidural corticosteroids
• Surgical: laminectomy with/without spinal fusion

Nursing Care — Laminectomy

• Pre-op: teach log rolling, bedpan use
• Post-op: position based on level (lower spinal → flat; cervical → slight HOB elevation)
• Avoid neck flexion with cervical surgery; monitor sensory/motor function q2–4h
• Monitor difficulty swallowing/coughing (cervical); keep suction & tracheostomy set available
• Monitor dressing for hemorrhage, CSF leak, infection
• OOB day after surgery; apply brace/corset if ordered; straight back chair, feet flat

13. Systemic Lupus Erythematosus (SLE)

Chronic connective tissue disease involving multiple organ systems; characterized by remission and exacerbation. More frequent in young women, higher risk in African-Americans, Hispanics, Asians, and Native Americans.

Findings

• Arthritis: morning stiffness, joint pain
• Systemic: fatigue, fever, anorexia, weight loss
• Skin: butterfly rash over bridge of nose/cheeks, photosensitivity, alopecia
• Renal: proteinuria, hematuria, renal failure
• Neurologic: peripheral neuritis, organic brain syndrome, psychosis, seizures
• Cardiopulmonary: pleurisy, pericarditis
• Hematologic: pancytopenia → weakness, oral/nasopharyngeal ulcers, bleeding, DVT

Diagnosis

• ↑ESR, pancytopenia, ANA+, LE cells+, anti-DNA+

Management

• NSAIDs, corticosteroids, immunosuppressants (Cyclosporine, Azathioprine, Cyclophosphamide, Hydroxychloroquine)
• Plasmapheresis to remove circulating antibodies
• Nursing: seizure precautions, psychological support, avoid stress, avoid infection, adequate rest, avoid direct sunlight

14. Key Medications

NSAIDs

• Aspirin, Ibuprofen (Motrin), Indomethacin (Indocin), Naproxen (Naprosyn), Piroxicam (Feldene), Sulindac (Clinoril)
• Used for pain, inflammation; monitor GI bleeding risk, renal function

DMARDs (Disease-Modifying Antirheumatic Drugs)

• Gold compounds: IM (Myochrysine, Solganal) — deep IM, small gauge; takes 3–6 months; S/E proteinuria, aplastic anemia. Oral: Auranofin (Ridaura) — causes diarrhea
• TNF inhibitors: Adalimumab (Humira), Infliximab (Remicade), Etanercept (Enbrel) — SQ, anti-inflammatory/immunosuppressive
• Methotrexate (Rheumatrex), Sulfasalazine, Hydroxychloroquine (Plaquenil)

Corticosteroids

• Intra-articular injections (initial); systemic when other drugs ineffective
• Monitor for immunosuppression, hyperglycemia, bone loss, adrenal suppression

Bisphosphonates

• Alendronate (Fosamax), Risedronate (Actonel), Ibandronate (Boniva)
• Take on empty stomach with 8 oz water, remain upright 30 min; monitor for esophagitis, osteonecrosis of jaw

Muscle Relaxants

• Cyclobenzaprine (Flexeril), Carisoprodol (Soma), Baclofen, Tizanidine (Zanaflex)
• Monitor for sedation, dizziness; avoid alcohol

Gout Medications

• Acute: Colchicine (S/E: diarrhea), NSAIDs
• Prophylactic: Probenecid (uricosuric), Allopurinol (decreases uric acid production)

15. NCLEX Priorities

• Neurovascular checks (6 Ps) are the #1 priority after casting, traction, or fracture surgery — report changes immediately
• Compartment syndrome = surgical emergency (fasciotomy within 4–6 hr); hallmark = pain on passive motion + pain unrelieved by narcotics
• Fat embolism syndrome: earliest signs are respiratory distress + petechiae on chest/neck + mental status change (24–72 hr post-fracture)
• THR precautions: never adduct past midline, never flex hip > 90°, never cross legs; use abduction pillow, raised toilet seat
• Crutch walking: climb with good leg first, descend with bad leg first; weight on hands, NOT axillae
• Cane: hold in hand opposite affected leg, advance with affected leg
• Buck's traction: never reposition side to side; foot of bed elevated for counter-traction
• Osteomyelitis: prolonged IV antibiotics; wound precautions; monitor for sepsis
• Gout: avoid high-purine foods; push fluids 2000–3000 mL/day; allopurinol for prophylaxis
• RA: isometric exercises during acute flare, ROM during remission; balance rest & activity
• Osteoporosis: bisphosphonate administration (empty stomach, upright 30 min); fall prevention; calcium + vitamin D
• Hip fracture in elderly: high risk for confusion, DVT, pneumonia, pressure ulcers; turn q2h to unoperative side; DVT prophylaxis
• Cast care: don't cover wet cast, use palms to support, petal edges, never insert objects under cast