Osteoarthritis

Question 1

Epidemiology

Answer 1

Most common joint d/o (21 million pts in US); prevalence increase greatly >40y

Question 2

Risk factors

Answer 2

Age, obesity, trauma, repetitive use, female, genetics/FHx, neuropathy, pseudogout, bleeding dyscrasias (->hemarthrosis)

Question 3

Pathophysiology

Answer 3

Slow, progressive loss of articular cartilage assoc w/hypertrophy (osteophytes) & sclerosis of nearby bone; usually 1 degree? (idiopathic) bu may also be 2/2 trauma, deformity, inflammatory process; thought to represent a heterogenous group of disease

Question 4

Affected joints

Answer 4

Typically hands (DIP, thumb base, 1st MTP), feet, knees, hips, spine (C5, T8, L3), shoulders; ankles, elbows, wrists less commonly involved

Question 5

Ddx

Answer 5

RA, gout/pseudogout, septic joints (acute onset, fevers, leukocytosis, severely decrease ROM), bursitis, referred back/hip pain, avascular necrosis, spondyloarthropathies (typically assoc w/other systemic sx IE IBD)

Question 6

History

Answer 6

Highly variable and depends on affected joint(s); pain worsened by activity, relieved by rest; gelling/stiffness w/inactivity; slowly progressive; morning stiffness that resolves in <30min; joints locking, popping, or instability; may report trauma/repetitive injury

Question 7

Noninflammatory OA

Answer 7

Pain/disability is primary sx as compared to joint swelling; prolonged morning pain, effusion, night pain seen in inflammatory OA

Question 8

Patterns of presentation

Answer 8

Monoarticular (young adults0, pauciarticular/large joint, polyarticular, rapidly progressive, trauma-related

Question 9

Exam

Answer 9

Depends on joint; generally, swelling (+/- tenderness) around joint line; crepitus; decrease ROM w/pain at end of range, typically w/o warmth; periarticular muscle weakness/wasting or bursitis/tendinitis that may explain sx

Question 10

Workup

Answer 10

Imaging (esp CT or MRI) is rarely necessary unless suspicion for alt dx (meniscal injury in the knee); plain radiography may confirm dx (eg joint space narrowing w/osteophytes and sclerosis) but late finding

Question 11

Labs

Answer 11

(eg ANA, RF, anti-CCP, Lyme serology) should not be initiated unless suspicion for alt dx exists; CRP may be slightly increased

Question 12

Prognosis

Answer 12

Slowly progressive, cases may stabilize, w/risk factor reduction, exercise

Question 13

Nonpharmacologic treatment

Answer 13

Pt education, exercise (esp non wt-bearing like swimming), resting affect joint for brief periods (<12h), wt loss, PT/OT, joint braces/splints, stretching, massage, heat, hparaffin wax; unloading of joint wt w/ a cane/walker; soft shoes/insoles; TENS controversial

Question 14

Pharmacologic

Answer 14

APAP
NSAIDS
Opiods
Intracticular injections
Glucosamine and chondroitin
Topicals
Colchicine

Question 15

Noninflammatory OA

Pharmacologic

Answer 15

APAP prn -> standing -> NSAIDs (if persistent pain)

Question 16

Inflammatory

Pharmacologic

Answer 16

NSAIDs prn -> standing (if persistent pain)

Question 17

Opiods

Answer 17

Use cautiously; may be indicated for acute increase in pain; tramadol may be synergistic w/ APAP; other opiod use not recommended by American College of Rheumatology

Question 18

NSAIDs

Answer 18

Start at lowest dose and uptitrate; may take 2-4 wks for maximal pain control; do not combine NSAIDs; contraindicated in PUD ant pts w/ ASA sensitivity; May increase risk of bleeding w/warfarin; use cautiously in pts w/ CKD, CHF, cirrhosis, on diuretics due to risk of AKI; may worsen htn; NSAIDs + PPI/misoprostol may decrease PUD risk; IBU, naproxen inhibit PLT function

Question 19

Nabumetone

Answer 19

NSAID, decreases renal toxicity, decreases antiplatelet activity

Question 20

Sulindac

Answer 20

NSAID, decreases renal toxicity, contraindicated in cirrhosis/liver disease (hepatic metabolism)

Question 21

Diflunisal

Answer 21

NSAID, decreases risk of PUD, decreases antiplatelet activity

Question 22

Cox-2 inhibitors

Answer 22

Celecoxib, NSAIDs, may increase CV risk as much as Ibuprofen, no effect on plt function

Question 23

Intraarticular injections

Answer 23

Short-term pain relief w/glucocorticoids (1-2 mos) or hyaluronans (approx. 4 months); consider in pts w/pain refractory to NSAIDs

Question 24

Glucosamine and Chondroitin

Answer 24

Decrease pain in some studies; consider in mod-severe knee OA but should be discontinued if no improvement by 3-6 mos; glucosamine contraindicated in pts with shellfish allergy

Question 25

Topicals

Answer 25

Capsaicin and NSAIDs

Question 26

Colchicine

Answer 26

Consider in pts w/inflammatory OA unresponsive to NSAIDs

Question 27

Surgery

Answer 27

Consider joint replacement in pts w/ severe hip/knee OA who fail medical RX; timing of surgery balanced btw limited hardware lifespan
(15-20 y) and functional loss, muscle atrophy; improved outcomes for surgeons w/increase volume; no benefit for arthroscopic debridement/irrigation of knee