Bone and joint disorders and injuries

Parathyroid hormone - function

increases serum calcium by stimulating osteoclasts and enhancing renal reabsorption.

• does this by breaking down bone

Calcitonin - function

Secreted by the thyroid gland; lowers blood calcium by inhibiting osteoclast activity

vitamin D - function

Essential for calcium absorption in the intestines; increases calcium and phosphate levels in the blood.

Osteoporosis - def and types

• an imbalance between bone resorption and formation

• primary and secondary types

Osteoporosis - primary

type 1: postmenopausal - decreases estrogen → loses bone density

type 2: age-related - >greater than 70 years old in both genders = slower bone remodeling

Osteoporosis - secondary

Due to disease or drugs
• e.g., corticosteroids, excess thyroid hormone)

Osteoporosis - osteoclast, osteoblast, and estrogen activity

• Osteoclast activity → excessive bone loss
• ↓ Osteoblast activity → reduced bone formation
• ↓ Estrogen post-menopause → ↑ osteoclast activation

Osteoporosis - non-modifable causes

• age, gender, fam history, ethnicity

• increases with age women more prone

Osteoporosis - modifiable causes

smoking, alcohol, body weight, diet, activity, medications

• S: impaires formation, A: bone loss, BW: low increases risk, steroids 

Osteoporosis - signs and symptoms 

• asymptomatic until fracture

• fracture: 

• wrist: lower mobility after fall - hip: can’t put weight on it, - vertebral: acute back pain (worsens with movement)

• loss of height, KYPHOSIS (round back), decreases activity level from fear of falls, fatigue 

osteoporosis diagnositcs

DEXA SCAN - gold standard - measures bone density at hip & lumbar spine

t-score - less than -2.5 (so -3.3) is osteoporosi

osteoporosis - labs and imaging

calcium - normal

Bone Turnover Markers: Alk phosphatase (increased), → assess bone metabolism

imaging: x-ray or MRI

Osteoporosis - pharm treatment

1. Bisphosphonates (alendronate)

2. SERMs (raloxifene)

3. Recombinant PTH analog (teriparatide)

4. Rank-L inhibtor MAB (denosumab)

5. calcitonin

6. calcium (1000) and vit D (800-1000)

Osteoporosis - non-pharm treatment

lifestyle:

• increase calcium (leafy greens and dairy), vitamin D (fortified foods, fish)

• exercise: weight-bearing and strength training

prevention:

• screening: DEXA for at-risk groups

• fall prevention (get glasses)

Osteopenia - def and causes

def: A condition characterized by lower-than- normal bone density, indicating increased risk for osteoporosis.

causes: Aging, hormonal changes, sedentary lifestyle, poor nutrition (low calcium or vitamin D)

Osteopenia - signs and testing

• Typically asymptomatic; may lead to increased fracture risk

• DEXA scan showing bone density between -1.0 and -2.5

Osteopenia - treatment

Lifestyle changes (diet and exercise)
• Calcium and vitamin D supplementation
• Monitoring bone density.

hip fractures - def and causes

def: Fractures of the femur near the hip joint, often due to falls or osteoporosis.

causes: Age, osteoporosis, low vision, and balance disorders

hip fractures - signs and testing

• Severe hip or groin pain, inability to bear weight, external rotation and shortening present

• X-ray and MRI to confirm fracture

hip fractures - treatment

Surgical intervention (e.g., hip replacement or fixation) and rehabilitation

Osteomalacia - def and labs

def: Soft, poorly mineralized bone → usually from vitamin D deficiency

labs: ↓ Ca, ↓ Phos, ↑ Alk Phos, ↓ Vit D

Osteomalacia - causes

↓ Vitamin D (primary cause) #1
• Malabsorption (celiac, GI disorders)
• Medications; renal insufficiency

Osteomalacia - symptoms

Bone pain (hips, low back)
• Muscle weakness, fatigue
• Fragility fractures (weight-bearing bones)

Osteomalacia - treatment 

Vitamin D (ergocalciferol/cholecalciferol)
• Calcium supplementation
• ↑ Dietary intake; safe sun exposure

calcium overview (role in bone, sources, daily intake, deficiency effects)

role: major component of bone tissue - for bone strength 

sources: leafy greens, dairy products

daily: 1,000 - 1,200 daily

deficiency: can lead to osteopenia - pororsis, and increased fracture risk

Vitamin D - overview (role, sources, daily, deficiency effects)

role: promotes calcium absorption in gut

sources: sunlight exposure, dietary sources (fatty fish, fortified foods)

daily: 600-800 daily

deficiency: can lead to osteomalacia and contribute to osteoporosis

bone pharm treatment types and goal

• Anti-resorptives → ↓ osteoclast activity
• Anabolic agents → ↑ osteoblast activity
• Goal → maintain or ↑ BMD → prevent fractures

Bisphosphonates and SERMs MOA

B: decreases osteoclast activity - deceases bone resportion (CAN CAUSE ESOPHAGUS PROBLEMS!!)

S: estrogen agonist on bone - decreases bone resorption

PTH analog and Rank-L inhibitor MOA

P: Intermittent PTH → increases osteoblast activity for bone formation

• given first and then R

• for mod to severe osteoporosis

R: Blocks Rank-L → decreases osteoclast formation to lower bone resorption

Paget’s disease (osteitis deformans) - def and causes

def: Chronic bone remodeling disorder → excessive breakdown and abnormal regrowth of bone, causing enlargement, deformity, and pain

causes: Likely genetic and viral origins -also Age > 50

Paget’s disease (osteitis deformans) -  symptoms, complications

S: Deep, aching bone pain (worse with activity) → Bowed legs, enlarged skull
• Warmth over affected areas

C: Fractures of weight-bearing bones | Rarely osteosarcoma

Paget’s disease (osteitis deformans) - diagnostics

x-ray: bone thickening/deformity

bone scan: increases metabolic activity

labs: increased alkaline phosphatase

Paget’s disease (osteitis deformans) - treatment

Bisphosphonates ( alendronate)
• Pain control: NSAIDs, calcitonin
• Surgery: For severe fractures or deformities (e.g., joint replacement)

Gout arthritis - def and labs

Inflammatory arthritis from uric acid crystal deposition.

↑ Serum uric acid > 6.8 mg/dl

Gout arthritis - causes

high-purine diet - red/processed meats, shellfish, alcohol, legumes)

obesity, meds, kidney dysfunction, dehydration

Gout arthritis - signs

• sudden severe joint pain (usually one joint)
  • Redness, swelling
  • Classic: big toe involvement (podagra)

Gout arthritis - treatment

colchicine and allopurinol

osteomyelitis - def and causes

def: Infection of bone → usually S. aureus

causes:

-Diabetes → ↓ perfusion
• Trauma/surgery → direct inoculation
• IV drug use → hematogenous spread
• PAD → poor healing

osteomyelitis - signs

• deep bone pain → constant
  • Fever → systemic infection
  • Swelling → warmth → redness → local inflammation
  • ↓ mobility

osteomyelitis - labs and treatments

labs: MRI and bone biopsy - will have increased WBC

treatments: IV antibiotics (vanco) (4-6 weeks) 

• if necrosis - surgery

multiple myeloma - def and causes

def: cancer of plasma cells that disrupt bone marrow function

causes: age, family history, environmental exposures

multiple myeloma - signs and testing

signs: Bone pain, anemia, fatigue, renal dysfunction

testing: bone marrow biopsy

multiple myeloma - treatment

• chemotherapy and immunotherapy and steroids to manage

• stem cell transplant 

• Bisphosphonates for bone health 

Rheum. arth - def and how it happens

def: Chronic autoimmune inflammation → joint pain, swelling, damage

causes: Genetics + environmental triggers (infection, smoking)

Rheum. arth - signs and labs

signs: joint → symmetrical pain → morning stiffness >30 min → swelling/deformity
• Systemic → fatigue → low-grade fever → weight loss

labs:

Rheumatoid factor is ↑
• ESR/CRP ↑ inflammation
• X-ray → joint erosions

Rheum. arth - treatments

• DMARDS - methotrexate - to slow progression

• NSAIDS - for pain

• biologics - TNF-A inhibits for inflammation

• non-pharm - exercise and anti-inflamm diet 

Osteoarthritis (OA) - def and how it happens

def: Degenerative joint disease → cartilage erosion → pain, stiffness (<30 min AM), ↓ mobility

how it happens: Age → obesity → prior joint injury → genetics → mechanical wear/tear

Osteoarthritis (OA) - signs

joint pain → worse with activity
• Stiffness → improves with movement
• Crepitus → grating with motion
• ↓ ROM → limited movement

Osteoarthritis (OA) - treatment 

NSAIDs and PT/exercise → naproxen for pain and for strength 
• Corticosteroid injections → ↓ inflammation
• Hyaluronic acid injections → ↑ lubrication/function
• Surgery → joint replacement for severe disease

musculoskeletal injuries - def and types

def: Damage to bones, muscles, ligaments, tendons → trauma, overuse, degeneration

types: fractures, sprins, strains, dislocations

musculoskeletal injuries - fractures types 

-closed → break w/o skin opening
• Open → bone through skin → ↑ infection risk
• Comminuted → bone in multiple pieces → often needs surgery
• Greenstick → incomplete bend/break in children

• transverse: horizonal

• oblique: angle

• sprial: twisting force - spiral pattern - sign of abuse

• nondisplaced - bone ends aligned

• displaced - misaligned bone ends

musculoskeletal injuries - sprain and strains types

sprain:

Definition → ligament stretch/tear
• Symptoms → swelling → bruising → severe pain with movement

strains:

Definition → muscle/tendon stretch/tear
• Symptoms → sudden pain → spasms → ↓ mobility

musculoskeletal injuries - dislocations types

Definition → bone displaced from joint
• Common sites → shoulder, knee, fingers
• Key point → needs prompt reduction

bone fracture - classification - causes and location * go over

cause: traumatic (direct injury), pathologic (disease), stress (overuse)

location: 

Epidural → outer bone layer
• Intramedullary → medullary cavity
• Articular → joint surface
• Shaft → long bone shaft

bone fracture - classification - grade

Grade I → minimal damage; stable; non-displaced; usually closed
• Grade II → moderate damage; slight displacement; minimal soft-tissue injury
• Grade III → severe damage; major displacement; extensive soft-tissue injury; often open

types of fractures

colles: FOOSH (fall on outstretched hand)

scaphoid: FOOSH - necrosis risk

humerus:  surgical neck

hip: femoral neck  - increases fall risk and death

smith’s: on flexed wrist

navicular: necrosis risk

fractur complications

• infections, Compartment syndrome, delayed healing, heals misaligned, DVT/PE, Neuro injury (claw hand), arthritis - chronic pain

Compartment syndrome - def and what causes it 

fracture complication

↑ pressure within a closed muscle compartment → ↓ capillary perfusion → tissue ischemia → potential permanent nerve/muscle damage - (blocks blood flow)

risk factors: tibia/fibula fractures, tight casts, burns

Compartment syndrome - signs 6 P’s

• Pain: severe, out of proportion, unrelieved by opioids
• Paresthesia: tingling or numbness (early sign)
• Pallor/coolness: impaired circulation
• Pulses: very late, indicates arterial compromise
• Paralysis: late, indicates nerve damage
•pressure is greater than 30

Compartment syndrome - treatment

STAT fasciotomy to decompress compartment
• Loosen/remove tight cast/dressing immediately
• Keep limb at heart level (NOT elevated above, which ↓ perfusion

Avascular Necrosis (AVN) - def and what causes it

def: loss of blood supply to bone → bone ischemia (disruption of blood flow)
• → bone collapse & Joint dysfunction if untreated

risk: fractures: scaphoid, navicular, femoral head
• Chronic corticosteroids
• Alcohol Use Disorder, Sickle cell disease; Lupus; Trauma/Dislocations

Avascular Necrosis (AVN) -signs and tests

Deep, persistent pain
• Pain with weight-bearing or gripping
• ↓ ROM and stiffness
• Delayed or non-union in fracture healing

MRI - most sensitive, X-ray for late findings shows crescent sign (subchondral collapse)

Avascular Necrosis (AVN) - treatment

Immobilize/protect joint early
• Surgical options: core decompression, ORIF, or bone grafting
• Joint replacement for advanced collapse

Fat Embolus Syndrome (FES) - def and risk factors

def: fat droplets enter bloodstream after long-bone/pelvis trauma → lodge in lungs/brain → acute respiratory + neuro compromise

risk factors: femur/pelvis fracture, multiple fractors, ortho surg

Fat Embolus Syndrome (FES) - signs and lab

Triad:
• Resp: dyspnea, tachypnea, hypoxia
• Neuro: confusion, agitation
• Skin: petechiae (axilla/chest/conjunctiva)

Lab: hypoemia, and chest x-ray shows snowstorm

Fat Embolus Syndrome (FES) - treatment

High-flow O₂
• Stabilize fracture early
• IV fluids
• Monitor resp + neuro status

treatment of fractures

• stabilize

• swelling: delay casting till it decreases

• splints: initial immobilization

• slings: for upper-extremity fractures

• weight-bearing restrictions: canes/crutches

• surgical: ORIF - open reduction and internal fixation