Antecedentes: proyecto piloto

Approximately 40 million Americans of all ages are affected by osteoarthritis and 70 to 90 percent of Ameri- cans older than 75 years have at least one involved joint. The prevalence of osteoarthritis ranges from 30 to 90 percent.

Clinical Features of Osteoarthritis Symptoms

Joint pain

Morning stiffness lasting less than 30 minutes Joint instability or buckling Loss of function

Pattern of joint involve- ment

Axial: cervical and lumbar

spine

Peripheral: distal

interphalangeal joint proxi- mal interphalangeal joint first carpometacarpal joints,

knees, hips

Signs

Bony enlargement at af- fected joints

Limitation of range of mo- tion

Crepitus on motion Pain with motion Malalignment and/or joint deformity

I. Clinical evaluation

A. Pathogenesis. Osteoarthritis is caused by a

combination of mechanical, cellular, and biochemi- cal processes leading to changes in the composi- tion and mechanical properties of the articular cartilage and degenerative changes and an abnor- mal repair response.

B. The typical patient with osteoarthritis is mid-

dle-aged or elderly and complains of pain in the knee, hip, hand or spine. The usual presenting symptom is pain involving one or only a few joints. Joint involvement is usually symmetric. The patient usually has pain, stiffness, and some limitation of function. Pain typically worsens with use of the affected joint and is alleviated with rest. Morning stiffness lasting less than 30 minutes is common. (morning stiffness in rheumatoid arthritis lasts longer than 45 minutes.)

C. Patients with osteoarthritis of the hip may complain

of pain in the buttock, groin, thigh or knee. Hip stiffness is common, particularly after inactivity. Involvement of the apophyseal or facet joints of the lower cervical spine may cause neck symptoms, and involvement of the lumbar spine may cause pain in the lower back. Patients may have radicular symptoms, including pain, weakness and numb- ness.

D. The physical examination should include an as-

sessment of the affected joints, surrounding soft tissue and bursal areas. Joint enlargement may become evident. Crepitus, or a grating sensation in the joint, is a late manifestation.

E. Laboratory work may include erythrocyte sedimen-

tation rate and rheumatoid factor. Synovial fluid analysis may be conducted to help exclude other diagnoses.

F. Radiographic findings consistent with osteoarthritis

include presence of joint space narrowing, osteophyte formation, pseudocyst in subchondral bone, and increased density of subchondral bone. The absence of radiographic changes does not exclude the diagnosis of osteoarthritis. Radio- graphs are recommended for patients with trauma, joint pain at night, progressive joint pain, significant family history of inflammatory arthritis, and children younger than 18 years.

II. Treatment of osteoarthritis

A. Exercise. The goals of an exercise program are to

maintain range of motion, muscle strength and general health.

Management of Osteoarthritis of the Knee

1. Patient education, exercise, weight loss, joint protection 2. Acetaminophen (Tylenol), up to 4 g per day. 3. Add topical capsaicin cream (eg ArthriCare) applied four

times daily if needed.

4. If joint effusion is present consider aspiration and intra-articular injection of triamcinolone (Aristocort) 40 mg.

5. If more pain or symptom control is needed add an NSAID, 400 mg of ibuprofen (eg Advil) taken four times daily or a nonacetylated salicylate such as choline mag- nesium trisalicylate (Trilisate), 500-1500 mg bid, or salsalate (Disalcid), 500-1000 mg tid.

6. If more pain or symptom control is needed use the full dosage of an NSAID plus misoprostol (Cytotec) or a proton pump inhibitor if the patient is at risk for upper gastrointestinal tract bleeding or ulcer disease, or sub- stitute a cyclo-oxygenase-2 inhibitor for the NSAID; some patients may benefit from intra-articular injections of a hyaluronic acid-like product.

7. If the response is inadequate, consider joint lavage, arthroscopic debridement osteotomy, or joint replace- ment.

Risk Factors for Ulcer Complications Induced by Nonsteroidal Anti-inflammatory Drugs Definite risk factors

Patient older than 65 years of age

Previous ulcer disease or upper gastrointestinal tract bleeding

Use of a high dosage of one of these drugs Concomitant oral corticosteroid therapy Concomitant anticoagulant therapy

Duration of therapy (risk is higher in first three months of treatment)

Possible risk factors

Female gender Smoking Alcohol consumption Helicobacter pylori infec- tion

B. The risk of NSAID-induced renal and hepatic

toxicity is increased in older patients and in pa- tients with preexisting renal or hepatic insuffi- ciency. Thus, it is important to monitor renal and liver function. Choline magnesium trisalicylate (Trilisate) and salsalate (Disalcid) cause less renal toxicity. Liver function tests and serum hemoglo- bin, creatinine and potassium measurements should be performed before NSAID therapy is initiated and again after six months of treatment.

C. Cyclooxygenase-2 (COX-2) inhibitors 1. Celecoxib (Celebrex) is a COX-2 inhibitor

labeled for treatment of osteoarthritis and rheu- matoid arthritis. Celecoxib effectively alleviates pain and reduces inflammation, but it does not cause gastric ulcers or affect platelet function (two toxic effects associated with COX-1 inhibi- tors). The most common side effects of celecoxib are dyspepsia, diarrhea and abdomi- nal pain. The FDA has labeled celecoxib, 100 mg twice daily and 200 mg once daily, for the treatment of osteoarthritis. This drug is also labeled, in a dosage of 100 to 200 mg twice daily, for the treatment of rheumatoid arthritis in adults.

2. Rofecoxib (Vioxx) is also given once daily for

the treatment of osteoarthritis and acute pain. The FDA has labeled rofecoxib for the treatment of primary dysmenorrhea, acute pain, and osteoarthritis. For osteoarthritis, the recom- mended dosage of rofecoxib is 12.5 to 25 mg once daily. For acute pain and primary dysmenorrhea, the dosage is 50 mg once daily.

3. Meloxicam (Mobic) has been labeled by the

FDA for the treatment of osteoarthritis. The starting and maintenance dosage is 7.5 mg per day.

4. Valdecoxib (Bextra) is an COX-2 inhibitor for

Costs of Some Common Nonsteroidal Anti-inflammatory Drugs

Drug Usual dosage

for adults Formulations Acetic acids Diclofenac po- tassium (Cataflam) 100 to 200 mg daily 50 mg Diclofenac so- dium Immedi- ate-release (Voltaren) 100 to 200 mg daily 25, 50, 75 mg De- layed-release (Voltaren XR) 100 to 200 mg daily 100 mg With misoprostol (Arthrotec) 50 mg three times daily 50 mg three or four times daily for rheumatoid arthritis 50 mg diclofenac sodium with 200 :g misoprostol 75 mg diclofenac sodium with 200 :g misoprostol Etodolac Immedi- ate-release (Lodine) 600 to 1,000 mg daily given in two divided doses 200 mg 300 mg 400 mg 500 mg Ex- tended-release (Lodine XL) 400 to 1,000 mg daily 400 mg500 mg 600 mg Sulindac (Clinoril) 150 mg twice daily (maximum dosage: 400 mg daily) 150, 200 mg Propionic acids Flurbiprofen

(Ansaid) 200 to 300 mgdaily given in two to four di- vided doses

50, 100 mg

Ibuprofen

(Motrin) 400 to 800 mgthree or four times daily (maximum dos- age: 3,200 mg daily) 200 mg 400 mg 600 mg 800 mg Ketoprofen Immedi- ate-release (Orudis) 150 to 300 mg daily given in three to four di- vided doses 25 mg 50 mg 75 mg Ex- tended-release (Oruvail) 150 to 300 mg daily given in three or four divided doses 100 mg 150 mg 200 mg Over-the-count er (Orudis KT) 12.5 mg every 4 to 6 hours 12.5 mg Naproxen Im- medi- ate-release (Naprosyn) 250 to 500 mg twice daily 250 mg 375 mg 500 mg De- layed-release (EC Naprosyn) 750 or 1,000 mg daily 375 mg 500 mg Naproxen so- dium Immedi- ate-release (Anaprox, Anaprox DS) 275 or 550 mg twice daily 275 mg550 mg Ex- tended-release (Naprelan) 750 or 1,000 mg daily 375 mg500 mg Over-the-count er (Aleve) 220 mg every 8 to 12 hours 220 mg Oxaprozin (Daypro) 1,200 mg daily 600 mg Nonacidic agents Nabumetone (Relafen) 1,000 to 2,000 mg given once daily or twice daily in divided doses 500 mg 750 mg

Drug Usual dosage for adults

Formulations

Cyclooxygenase-2 inhibitors

Celecoxib

(Celebrex) 100 mg twicedaily or 200 mg daily for osteoarthritis 100 to 200 mg twice daily for rheumatoid ar- thritis

100 mg 200 mg

Rofecoxib

(Vioxx) 12.5 to 25 mgdaily for osteoarthritis 50 mg daily for primary dysmenorrhea and acute pain

12.5 mg 25 mg 50 mg 12.5 or 25 mg in 5-mL susp Meloxicam

(Mobic) 7.5 mg per day. 7.5 mg Valdecoxib

(Bextra) 10-20 mg oncedaily 10 mg20 mg

D. Local analgesics. Capsaicin (eg, ArthriCare) has

been shown to be better than placebo in osteoarthritis. Capsaicin cream is available over the counter in concentrations of 0.025, 0.075 and 0.25 percent.

E. Intra-articular corticosteroid injections. Patients

with a painful flare of osteoarthritis of the knee may benefit from intra-articular injection of triamcino- lone (Aristocort) or prednisone 8-20 mg. Intra-articular steroid injections should not be administered more than three to four times per year. Knee injections significantly reduce pain for up to four weeks.

F. Intra-articular injections of hyaluronic acid-like products. Hyaluronate (Hyalgan) and hylan G-F

20 (Synvisc) injections are useful for the treatment of osteoarthritis of the knee. Hylan G-F 20 injec- tions are at least as effective as continuous NSAID therapy.

G. Surgery. Patients whose symptoms are not ade-

quately controlled with medical therapy and who have moderate to severe pain and functional impairment are candidates for surgery. Osteoarthritis of the knee may be treated with arthroscopic debridement or joint lavage. References, see page 282.