OSTEOARTHRITIS/HIP REPLACEMENT
| OSTEOARTHRITIS: PATHOGENESIS, DIAGNOSIS, AND MANAGE-MENT —Carlos J. Lozada, MD, Associate
Professor of Medicine, Division of Rheumatology and Immunology, University of Miami Miller School of Medicine
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| Basic features of osteoarthritis (OA): 80% of those >75 yr of age have x-ray evidence of OA; clinical symptoms of OA
range from <0.1% at 25 to 34 yr of age to 20% at 65 to 74 yr of age; symptoms and signs—pain (related to use; worsens
during day); morning stiffness (if >45 to 60 min, more likely rheumatoid arthritis [RA]); difficulty moving after inactivity
(gelling); decreased range of motion; joint instability; bony enlargement; crepitus; swelling possible
(inflammatory component); risk factors—advanced age; female sex; obesity; heredity; trauma; neuromuscular dysfunction;
metabolic disorders
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| Distribution in primary OA: cervical and lumbar spine; proximal and distal interphalangeal joints; hips; knees; how RA
differs—absent in lumbar spine and distal interphalangeal joints; prominent in wrist, shoulder, and metacarpal joints
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| Disease process: progressive loss of articular cartilage; new bone formation in subchondral trabeculae; new cartilage formation
(attempt at repair); new bone at joint margins (osteophytes); evidence of inflammation—effusions (usually <10,000
leukocytes/mm3 ; <200/mm3 normal); often low-grade localized synovitis on arthroscopy; evidence on x-ray—joint
space narrowing; marginal osteophytes; subchondral cysts; bony sclerosis; in later stage, eg, knee, valgus (swinging outward)
and varus (swinging inward) deformity; how RA differs on x-ray—evidence of periarticular osteopenia and joint
erosions
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| Potential disease-modifying strategy: how cartilage destroyed—mechanical forces cause cartilage breakdown; particles
in synovial fluid provoke release of inflammatory cytokines by synovial macrophages (interleukin [IL]-1, tumor
necrosis factor [TNF]), causing chondrocytes to produce and release IL-1 and enzymes (collagenases) that degrade cartilage
matrix; potential targets—IL-1; TNF; collagenases
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| Evaluating benefits of therapy: preservation of cartilage assessed by measuring changes in joint space of knee over time
with periodic x-rays (semi-flexed anteroposterior view)
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| Potential disease-modifying interventions:
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 | Nonpharmacologic: benefits demonstrated; exercise—eg, strengthening quadriceps muscles protects knee; weight
loss—reduces symptoms and progression in hip and knee; excess weight early in life (eg, teenage years) associated
with propensity to develop OA, even if weight subsequently lost
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| Pharmacologic: enzyme inhibitors; nutriceuticals (eg, glucosamine); anti-inflammatory cytokines; cytokine blockade;
gene therapy (eg, introducing gene for collagenase inhibitors)
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| Tetracyclines: inhibit collagenase; National Institutes of Health (NIH) study found daily doxycycline over ≈2 yr preserved
fraction of millimeter of cartilage in knee; minocycline and doxycycline currently used in RA
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| Glucosamine: present in glycoproteins and cartilage; may stimulate glycosaminoglycan synthesis; small and short studies
found pain relief (eg, equal to 1200 mg of ibuprofen); disease modifying effect—shown in 2 European trials in knee;
followed 200 patients for 3 yr; results in doubt because of failure to use now-standard x-ray positioning; NIH study under
way using correct x-ray positioning; standardization lacking—product may not contain specified amount
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| Current management: nonpharmacologic—patient education; weight loss; exercise; heat and cold modalities; cane
(unloads ≈50% of weight on knee and hip); modifications in activities of daily living; medical—nonopioid analgesics;
topical agents; intra-articular agents; opioid analgesics; nonsteroidal anti-inflammatory drugs (NSAIDS)/cyclooxygenase
(COX)-2 inhibitors
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| Acetaminophen: pain relief with 4-g dose (1 g qid) equivalent to full-dose ibuprofen (but less effective for rest pain);
NSAIDs tend to be more effective in patients with moderate-to-severe pain and inflammation; side effects—hepatic toxicity;
mild gastrointestinal (GI) problems (may require prophylactic therapy); combining with NSAIDs increases GI risks;
recent finding—acetaminophen inhibits COX-3 (similar to COX-1)
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| Topical agents: local cold or heat; capsaicin (effective in clinical trials in knee and hand; avoid eye contact)
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| Intra-articular therapy: does not modify disease; steroid injections—good pain relief; limited to 3 or 4 injections per
joint in 1 yr; study showed symptomatic relief when patients with knee OA received injections every 3 mo for 2 yr; hyaluronic
acid injections—relieve pain for few months in some patients
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| Tramadol: inhibits transport of norepinephrine and serotonin; weak opioid agonist; dose, 1 to 2 tablets qid; can be combined
with NSAID, selective COX inhibitor, or with acetaminophen; side effects—dizziness; somnolence; orthostatic hypotension;
increased seizure risk in patients taking medications that lower seizure threshold or who have history of seizures
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| Opioids: act centrally and peripherally; effective in most patients; side effects—more likely in elderly; constipation; sedation;
nausea; respiratory depression (unlikely at doses used for OA); addiction (unlikely but mention to patient)
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| NSAID therapy: eventually used in most patients; GI side effects—lead to ≤100,000 annual hospitalizations and
≈16,000 deaths; side effects range from dyspepsia and nausea to bleeding, perforation, and obstruction; 58% to 81% of
patients asymptomatic before serious complications; need to know risk factors—advanced age; history of ulcer or GI
complications; higher dose or multiple NSAIDs; concomitant corticosteroid use; major illness (eg, heart disease, diabetes);
concomitant anticoagulant use
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| Reducing risk: misoprostol—prostaglandin agent found to reduce GI events by ≈40%; potential for diarrhea with qid
dose; prevent diarrhea by using bid or using misoprostol/diclofenac combination product (Arthrotec); proton pump
inhibitors—shown to reduce endoscopic ulcers 75% and, therefore, likely to reduce events; COX-2 inhibitors—
reduced GI events ≈50% in clinical trials; COX-3 inhibition—acetaminophen
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| COX-2 inhibitors: reduced rate of GI events ≈50% in patients not taking aspirin, leaving platelets (COX-1 system) untouched;
emergence of cardiac problems thought to result from unopposed COX-2 inhibition, or from some aspect of
COX-2 molecule itself; rofecoxib (Vioxx) study—3-yr trial in patients at risk for polyps of colon stopped at 18 mo due
to approximate doubling of risk of myocardial infarction and stroke; drug withdrawn from market; valdecoxib (Bextra)
study—trial of oral valdecoxib and injectable version (parecoxib) in high-risk patients after coronary artery bypass
graft (CABG) surgery found increased risk of cardiovascular events; meanwhile, meta-analysis of available trials found
no difference in rate of events; celecoxib—National Cancer Institute (NCI) adenoma prevention trial found increased
cardiovascular risk after patients had taken 400 mg or 800 mg daily for almost 3 yr; number of events limited (20 in 700
patients; 6 in 700 for placebo); increased relative risk (2.5 at 400-mg dose; 3.4 at 800-mg dose); other findings—
another NCI trial using celecoxib “monitored by the same board and using very similar conditions did not show an
increased risk”; trial also found patients taking over-the-counter dose of naproxen had 50% increase in cardiovascular
events; trial involved patients with Alzheimer’s disease; concluding comment—“we still need a lot of information
to look at the reasons and what’s happening here very, very closely”; patient and physicians now somewhat confused;
Food and Drug Administration (FDA) recommends careful use of agents, especially COX-2 inhibitors (FDA expected
to offer firmer recommendations)
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| Summary of OA management: make appropriate diagnosis; first, try weight loss, exercise, topical therapy; weigh use of
acetaminophen vs NSAIDs/COX-2 inhibitors based on risk profile; second-line therapy, intra-articular agents, opioids;
third line, surgery (total joint replacement for knee and hip); ideal approach similar to that for RA, combining medications
for symptom relief and for slowing disease progression
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| WHAT INTERNISTS NEED TO KNOW ABOUT TOTAL HIP REPLACEMENT —Simon C. Mears, MD, Assistant
Professor, Department of Orthopaedic Surgery, Johns Hopkins University School of Medicine, and Johns Hopkins Bayview
Medical Center, Baltimore
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| Underlying disease process: older patients—osteoarthritic degeneration (genetic predisposition of cartilage; subtle
congenital anatomic variation); younger patients—slipped capital femoral epiphysis (often seen in young teenaged
boys); Perthes disease; hip dysplasia (may present as hip pain in patient 20-39 yr of age; may benefit from periacetabular
osteotomy to realign joint); RA and its variations; osteonecrosis of femoral head (associated with corticosteroid use
and some antiviral medications)
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| Preoperative considerations: referred pain—arthritis of hip may cause pain in knee, no pain in hip; confused with hip
pain—trochanteric bursitis (painful at night; weight loss and back and abdominal strengthening advised); actual hip
pain—often in groin; examination—with patient in prone position, flex hip, checking stiffness, external and internal
rotation; when to operate—when pain and its impact on patient’s quality of life reaches point that benefits outweigh
risk of complications; benefits of total hip arthroplasty (THA)—excellent pain reduction; improved function; long
lasting (90% working well at 10 yr); preoperative “clearance”—to avoid perioperative complications of elective surgery;
cardiovascular evaluation; treatment of infections, eg, dental
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| Complications of THA: deep venous thrombosis (DVT)—without prophylaxis, develops in ≤40% of patients; postsurgical
prophylaxis (mechanical; warfarin; low molecular weight heparin [LMWH]); 2-wk duration; warfarin continued 6
wk in patients at high risk, eg, with personal or family history of DVT, cancer, or lack of mobility; monitor patients for
potential complications); other medical—myocardial infarction; cardiac stents (patients on clopidogrel [Plavix]);
death (0.5% in Mayo Clinic study of 10,000 patients); leg-length discrepancy—arthritic hip may be lengthened during
surgery; overcorrection may require heel lift on opposite side; persistent limp—eliminating preoperative limp requires
adequate abductor strengthening and use of cane; dislocation—smaller femoral head used on implants may pop out of
acetabular cup during awkward maneuver, eg, getting off toilet seat; painful and requires emergency attention for reduction;
implant that continues to dislocate may require revision; risk low (≈1%); nerve damage—to femoral or sciatic
nerve; rare; arterial damage—rare; check for nonpalpable pulses (evaluation by vascular surgeon indicated before
THA); wear and component loosening—wear releases polyethylene particles that activate macrophages that attack
bone; osteolysis leads to loosening and risk of fracture; to avoid potentially catastrophic problems, x-ray joint at ≈2-yr
intervals or when it becomes painful; may require surgery; infection—risk ≈0.5% in healthy patients; increased by diabetes,
smoking; perioperative prevention (antibiotics 60 min before incision and for 24 hr after surgery; sterile technique);
postoperative prevention (risk of hematogenous spread greatest in first 2 yr; prompt treatment of infections;
dental prophylaxis (including cleaning) for first 2 yr, continuing for major dental procedures; speaker recommends prophylaxis
prior to colonoscopy for first 2 yr)
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| Composition of components: stem—goes into proximal femur; cemented (used since THA began; bone filled with cement,
which hardens after stem inserted; excellent track record; failure rate higher in more active patients; uncemented
stem (roughened surface for bone ingrowth; after bone prepared, stem press-fit, allowing early weight bearing); cup—
uncemented today, with surface designed for bone ingrowth after cup forced into reamed acetabulum; modular plastic
cup liners provide better fit and easier revision; bearing surfaces—highly cross-linked polyethylene (undergoes hardening
process; used in cup liners; most commonly used and least expensive implant; laboratory results indicate minimal
wear rates; in use for only 5 yr; another 15 yr before long-term results known; ceramic on ceramic—excellent wear;
fracture risk (low; potentially catastrophic); expensive; metal on metal—excellent wear; metal particles released from
wear (potential toxicity troubling to patients); larger head reduces risk of dislocation; expensive
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| Surgical approaches: varied ways to put in hip (from front, back, or side); anterolateral—large incision; good exposure;
low dislocation rate; harmful to abductor muscle (risk of limp); posterolateral—good exposure without damaging
abductor; limp less likely; dislocation rate slightly higher
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| Minimally invasive surgery (MIS): subject of much hype and advertising; MIS may refer to—smaller incision; less
damage to muscles and tendons; removal of less bone; faster recovery; most important considerations in THA today—
long-term outcomes; functional results; rate of recovery (importance increased by insurance limitations and caregiver
demands); mini-posterior incision results—decreased hospital stay; patient satisfaction with small scar; acquiring surgical
skills involves long learning curve; 2-incision approach—used by speaker; no need to cut muscles; requires fluoroscopy
during surgery; 5- to 6-cm incision in groin (for cup); smaller incision in buttock (for stem); results—Berger
reported last 200 patients went home day of surgery (patients carefully selected); speaker’s experience (≈140 patients;
goal of enabling patients to go home); Medicare to eliminate eligibility for rehabilitation; hospital stay associated with
iatrogenic infections and medication errors; patients able to walk and negotiate stairs before release (may be next day;
usually 2 days, others in 3 or 4 days, or after stay in rehabilitation center); MIS based on better anesthesia—regional
nerve blocks; fewer narcotics and side effects
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Educational Objectives
| The goal of this program is to educate internists about osteoarthritis (OA) and total hip replacement. After hearing
and assimilating this program, the clinician will be better able to:
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| Diagnose OA.
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| Employ strategies aimed at preventing and slowing the development of OA.
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| Select medications for OA pain, including nonsteroidal anti-inflammatory drugs and agents for the prevention
and treatment of gastrointestinal side effects.
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| Counsel patients considering total hip arthroplasty (THA).
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| Avoid and detect potential complications in patients who have undergone THA.
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Discussed on This Program
Acetaminophen (several trade names)
Aspirin (acetylsalicylic acid; ASA) [several trade names]
Celecoxib [Celebrex]
Diclofenac sodium and misoprostol {Arthrotec]
Doxycycline (several trade names)
Glucosamine
Ibuprofen (several trade names)
Minocycline HCl (minomycin) [Arestin, Dynacin, Minocin, Minocin IV]
Parecoxib (not available in United States)
Rofecoxib [Vioxx] (withdrawn from market 09/30/04)
Valdecoxib [Bextra]
Suggested Reading
Baker CL Jr et al: Future treatment of osteoarthritis. Orthopedics 28:s227, 2005; Berger RA et al: Rapid rehabilitation
and recovery with minimally invasive total hip arthroplasty. Clin Orthop Relat Res:239, 2004; Berger RA: Minimally
invasive THR using two incisions. Orthopedics 27:382, 2004; Birrell F et al: Predictors of hip joint
replacement in new attenders in primary care with hip pain. Br J Gen Pract 53:26, 2003; Fajardo M et al: Disease-
modifying therapies for osteoarthritis : current status. Drugs Aging22:141, 2005; Goldberg SH et al: Pharmacologic
therapy for osteoarthritis. Am J Orthop 31:673, 2002; Gossec L et al: Predictive factors of total hip replacement due
to primary osteoarthritis: a prospective 2 year study of 505 patients. Ann Rheum Dis 64:1028, 2005; McCarthy JC:
Hip arthroscopy: when it is and when it is not indicated. Instr Course Lect53:615, 2004; Sarzi-Puttini P et al: Osteoarthritis:
an overview of the disease and its treatment strategies. Semin Arthritis Rheum 35:1, 2005; Scheiman J et
al: Agents used in the prevention and treatment of nonsteroidal anti-inflammatory drug-associated symptoms and ulcers.
Am J Med 105:32S, 1998; Scheiman JM et al: A randomized, controlled comparison of ibuprofen at the maximal
over-the-counter dose compared with prescription-dose celecoxib on upper gastrointestinal mucosal injury. Clin
Gastroenterol Hepatol 2:290, 2004; Scheiman JM et al: Practical approaches to minimizing gastrointestinal and cardiovascular
safety concerns with COX-2 inhibitors and NSAIDs. Arthritis Res Ther7 Suppl 4:S23, 2005; Scheiman
JM: Gastroduodenal safety of cyclooxygenase-2 inhibitors. Curr Pharm Des9:2197, 2003; Sculco TP et al: Minimally
invasive total hip arthroplasty: the Hospital for Special Surgery experience. Orthop Clin North Am 35:137,
2004;; Sculco TP: Minimally invasive total hip arthroplasty: in the affirmative. J Arthroplasty 19:78, 2004;; Shorr
RI et al: Concurrent use of nonsteroidal anti-inflammatory drugs and oral anticoagulants places elderly persons at
high risk for hemorrhagic peptic ulcer disease. Arch Intern Med 153:1665, 1993; Siggeirsdottir K et al: Short hospital
stay augmented with education and home-based rehabilitation improves function and quality of life after hip replacement:
randomized study of 50 patients with 6 months of follow-up. Acta Orthop 76:555, 2005; Silverstein FE et
al: Misoprostol reduces serious gastrointestinal complications in patients with rheumatoid arthritis receiving nonsteroidal
anti-inflammatory drugs. A randomized, double-blind, placebo-controlled trial. Ann Intern Med 123:241,
1995; Singh G et al: Gastrointestinal tract complications of nonsteroidal anti-inflammatory drug treatment in rheumatoid
arthritis. A prospective observational cohort study. Arch Intern Med 156:1530, 1996; Towheed TE et al: Glucosamine
therapy for treating osteoarthritis. Cochrane Database Syst Rev:CD002946, 2005; Uthman I et al: Intra-
articular therapy in osteoarthritis. Postgrad Med J 79:449, 2003; Wolfe MM et al: Gastrointestinal toxicity of nonsteroidal
antiinflammatory drugs. N Engl J Med 340:1888, 1999; Wu CW et al: New developments in osteoarthritis.
Clin Geriatr Med 21:589, 2005.
Faculty Disclosure
In adherence to ACCME guidelines, the Audio-Digest Foundation requests all lecturers to disclose any significant financial
relationship with the manufacturer or provider of any commercial product or service discussed. The following
has been disclosed: Dr Mears—Zimmer, Inc. (consultant)
Dr. Lozada was recorded at Internal Medicine Update 2005, sponsored the University of Miami Miller School of
Medicine and held January 30 to February 4, 2205, in Miami Beach, Florida; Dr. Mears, at the 50th Annual Topics in
Clinical Medicine, sponsored by Johns Hopkins University School of Medicine, and held May 2-6, 2005, in Baltimore.
The Audio-Digest Foundation thanks the speakers and the sponsors for their cooperation in the production of
this program.
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