t30 - bone and degenerative disorders

osteoarthritis

-aka degenerative joint disease

-most common arthritis world wide

-leading cause of disability in older adults

-affects knees, hips, hands (DIP, PIP, CMC) and spine

osteoarthritis patho

-progressive degradation of articular cartilage with attempted repairs mechanism > imbalance between cartilage breakdown and synthesis by chondrocytes > mechanical stress and biochemical changes create cycle of joint destruction

-subchondral bone changes

-synovial inflammation

-joint space narrowing as cartilage is lost

osteoarthritis etiology

Primary

-idiopathic

-biomechanical factors can contribute to disease

Secondary

-previous injury

-previous septic arthritis

-hemochromatosis

-acromegaly

-gout

osteoarthritis RF

-increasing age

-females

-postmenopausal

-african americans

-obesity

-mechanical stress

osteoarthritis sx

-joint pain: gradual onset, worse with activity, improve with rest

-morning stiffness lasting less than 30 min

-joint stiffness goes away after activity slowly

-may lock or give away

-NO systemic sx

-tenderness to palpation along joint lines

-effusion, muscle atrophy, crepitus

-Heberden node (DIP), Bouchard node (PIP), square hand deformity

-varus or valgus deformity in knees

-limited internal rotation, pain with flexion

osteoarthritis dx

-clinical

Imaging

-Xray weight bearing: Asymmetric joint space narrowing

-subchondral sclerosis, osteophytes, subchondral cysts

If effusion present

-synovial fluid analysis: noninflammatory (<2000), clear/yellow, high viscosity

osteoarthritis tx

Nonpharm

-weight loss

-Refer all patients to PT

Pharm

-first line: acetaminophen

-topical diclofenac gel for hands and knees

-NSAIDs: test for GI bleed risk

-duloxetine: SNRI for chronic pain

-tramadol: if NSAID contraindicated

Surgery

-document failed conservative first

-intraarticular corticosteroid injection

-arthroscopy, osteotomy, joint replacement

osteoporosis

-skeletal disease characterized by low bone mass and microarchitectural deterioration

-caucasian and asian

-women postmenopausal

-affects hip, vertebral body, distal radius

osteoporosis patho

-bone resorption exceeds bone formation > decreased bone mass and deterioration of bone microarchitecture > increased bone fragility and fracture risk

-trabecular bone affects more severely

osteoporosis types

-postmenopausal osteoporosis: estrogen deficiency leads to increased osteoclast activity

-age related osteoporosis: decreased osteoblast function, decreased calcium absorption

-secondary osteoporosis: underlying disease or medication causing bone loss

osteoporosis etiology

Primary

-postmenopausal (type I)

-age related (type II)

Secondary

-hyperthyroidism, hyperparathyroidism, Cushings, hypogonadism, DM

-glucocorticoids, heparin, PPI, SSRI

-celiac disease, IBD

-CKD

osteoporosis RF

-advanced age

-female

-small body stature

-early menopause

-sedentary lifestyle

-cigarette smoking

-eating disorder

osteoporosis sx

-asymptomatic until fracture

-fragility fracture = fracture from fall from standing height

-loss of height

-kyphosis

-decreased rib to pelvis ratio

osteoporosis dx

Gold standard = DEXA scan

T score

-normal: >-1

-osteopenia: -1.0 to -2.5

-osteoporosis: <-2.5

Labs

-BMP: calcium, creatinine

-Vit D levels

FRAX score

-estimate 10 year probability of major fracture

-should be calculated for all osteoporotic pts

Imaging

-used to identify fractures

Screening Q1-2 years

-all women >65, postmenopausal women <65 with RF

-men >70 or younger with RF

osteoporosis tx

Nonpharm

-calcium intake 1000-2000 mg QD

-Vit D 800-1000 IU QD, goal >30

-exercise, fall prevention

Pharm

-indications: T score <-2.5, hx of fragility fracture, T score -1 to -.25 + FRAX score >20%

-first line: alendronate or risedronate

-denosumab SQ if bisphosphonates not tolerated

-anabolic agents reserved for high risk

-hormone replacement therapy

osteogenesis imperfecta

-genetic disorder of collagen synthesis causing bone fragility

-autosomal dominant or recessive

-due to COL1A1 or COL1A2 gene

-type 1: mildest and most common

osteogenesis imperfecta patho

-genetic mutations affect quantity or structure of type I collagen > leads to decreased bone mass and abnormal bone architecture > bone are fragile and prone to fractures with minimal trauma

osteogenesis imperfecta etiology

-primarily genetic disorder with autosomal dominant or recessive

-90% are due to COL1A1 or COL1A2 mutation

osteogenesis imperfecta sx

-multiple fractures throughout life with minimal or no trauma

-bone pain

-short stature and growth delay

-easy bruiding, excessive sweating

-dental problems

-blue or gray sclera

-bone deformities, hearing loss, triangular facies

-type 1: normal stature, blue sclera, hearing loss

osteogenesis imperfecta dx

-clinical

Labs

-usually normal

-genetic testing = confirmatory

Imaging

-Xray: generalized osteopenia, multiple fractures, thin cortices, bowing deformities, codfish vertebrae

-DEXA scan: show decreased BMD

osteogenesis imperfecta tx

Nonpharm

-fracture prevention, PT, OT

-adequate calcium and vit D

Pharm

-bisphosphonates: pamidronate IV or zoledronic acid IV

osteomalacia and rickets

Osteomalacia: defective bone mineralization in adults

Rickets: defective bone mineralization in children

-MCC = vit D deficiency

osteomalacia and rickets patho

Inadequate mineralization of bone matrix due to vitamin D

-Osteomalacia: new bone formed during remodeling remains unmineralized > fracture, bone pain

-Rickets: growth plate cartilage fails to mineralize properly > widening, irregular growth plates

osteomalacia and rickets etiology

-MCC = vitamin D deficiency

-phenytoin or phenobarbital

-phosphate deficiency

-genetic defects

osteomalacia and rickets RF

-limited sun exposure

-darker skin

-elderly age

-exclusive breastfeeding

-strict vegetarian diet

-CKD

osteomalacia and rickets sx

Osteomalacia

-diffuse bone pain in hip, pelvis, lower back

-muscle weakness, waddling gait

-fragility with minimal trauma

-tenderness over bones

Rickets

-delayed motor milestones

-bone pain in legs and spine

-growth delay, dental problems

-seizures, tetany

-craniofacial deformities, rachitic rosary, harrison groove, widening wrist

osteomalacia and rickets dx

-clinical

Labs

-25-hydroxyvitamin D level = low <20

-calcium and phosphate = low

-alkaline and PTH = elevated

-renal function test, LFT

Imaging

-Rickets Xray: widening, irregular, frayed growth plates, bowing deformity

-Osteomalacia Xray: looser zone, generalized osteopenia, fractures

-bone biopsy = gold standard

osteomalacia and rickets tx

Mainstay = vitamin D and calcium supplementation

-ergocalciferol or cholecalciferol 2000-6000 IU QD

-monitor levels after 3 months

-goal >30

Prevention

-exclusively breastfed infants should receive 400 IU QD

paget's disease

-chronic localized disorder of bone remodeling

-localized to specific bones, does not spread to other bones

-second most common bone disorder

-men

-70-80 yo

paget's disease patho

Excessive, disorganized bone remodeling at focal sites

Lytic phase: excessive osteoclastic bone resorption

Mixed phase: compensatory osteoblastic bone formation

Sclerotic phase: sclerosis formation

paget's disease etiology

-unknown

-genetics

-mutation in SQSTM1 gene

paget's disease RF

-advanced age

-family hx of paget's

-anglo-saxon

-male

paget's disease sx

-asymptomatic

-deep, aching, worse at night bone pain

-enlarged skull, bowing of legs, kyposis

-warmth over affected bone

-bone tenderness to palpation

paget's disease dx

Labs

-alkaline phosphatase = elevated

-calcium, phosphate, PTH = normal

Imaging

-often incidental finding

-Xray: lytic lesions, slcerotic lesions, bone enlargement and deformity

-bone scan: increased uptake in affected bone

-bone biopsy: mosaic pattern

paget's disease tx

Nonpharm

-observation of asymptomatic

-pain management

-adequate calcium intake

Pharm

-first line: zoledronic acid 5mg IV once

-calcitonin