Setting: office
CC: “My knees hurt.”
VS: normal
HPI: A 64-year-old man comes to your office complaining of worsening pain and discomfort in his knees. This has been happening gradually over the past year. He claims “to hear them creaking” when he gets up from a seated position. He has pain in his hands in multiple joints. His grip strength is down and he has a hard time opening the lids of jars and twisting the knobs on water faucets. All the pain is definitely worse toward the end of the day and with increased use.
Worsening with Use = Osteoarthritis (OA)
Better with Use = Rheumatoid Arthritis (RA)
ROS:
The patient has no fever and no weight loss.
He denies injection drug use.
Discomfort makes him avoidant of exercise.
PMHX:
Hypertension
Former tobacco smoker
Medications:
NSAIDs
Nifedipine
Medications do not cause OA.
Medications do not prevent OA.
PE:
General: obese; cheerful as long as he does not move
Musculoskeletal:
Prominent tuberosities of the distal interphalangeal (DIP) joints
Crepitus palpable on movement of knees
No warmth, no redness, no tenderness
DIP Joints Affected = OA or Psoriatic Arthritis
Proximal Interphalangeal (PIP) and MCP Joints Affected = RA
Spine and SI Affected = AS
Single Large Joint Affected = Septic or Lyme
Articular cartilage is composed mostly of water.
Initial Orders:
X-ray
ESR, RF, CRP, ANA
Complete blood count (CBC)
CHEM-7
Which of these will be abnormal in OA?
a. None
b. X-ray of knees and hands
c. ESR, RF, CRP, ANA
d. CBC
e. CHEM-7
Answer a. None
You are not doing these tests because you expect anything to be abnormal in OA. Quite the opposite. You are doing these tests because if any of them is abnormal it is likely not OA! The reason for the CHEM-7 test is to be careful about the use of NSAIDs in those with renal insufficiency. The CBC is looking for a microcytic anemia that may have been caused by an occult ulcer. Although daily NSAID use leads to an ulcer in 10% to 20% of patients after a year, only half (5–10%) will be symptomatic and half of them (1–3%) will bleed from it.
What should all users of NSAIDs be taking along with the NSAIDs?
a. Proton pump inhibitor (PPI)
b. H2-blocker
c. Misoprostol
d. None
e. Sucralfate
Answer d. None
Although daily PPI use (e.g., omeprazole) will decrease the risk of ulcers, there is no routine recommendation to put every NSAID user on a PPI. H2-blockers, such as cimetidine or sucralfate, which coat the gastric lining, are even less effective. Misoprostol is never the right answer for anything in gastroenterology.
Misoprostol
• Increases prostaglandins
• Supposed to increase gastric mucous production
• Nice basic science idea
• Does not work
The patient returns to discuss his laboratory test results the following week. He has no change in symptoms.
Reports:
ANA, RF, CRP, CHEM-7, CBC: normal
X-ray: joint space narrowing, osteophytes
Be careful of nonspecific laboratory tests!
• ANA is positive in 5% of the population.
• RF increases with age.
CCS is more “liberal” or “forgiving” with the amount of testing you can order. In this case, getting some “extra tests” like the CHEM-7, ANA, or RF would be forgiven. On a single best answer question about OA, do not order any tests.
Joint Space Narrowing (Figure 8-4)
• There is loss of articular cartilage.
• Articular cartilage is water.
• Water is radiolucent.
Figure 8-4. Radiograph of a hand showing osteoarthritis of the distal interphalangeal (DIP), proximal interphalangeal (PIP), and first carpometacarpal (CMC) joints. Note the joint-space narrowing of the DIP and PIP joints compared to the metacarpophalangeal joints, as well as the bony sclerosis (eburnation) of all joints involved by the osteoarthritis process. (Reproduced with permission from Imboden JB, et al. Current Diagnosis & Treatment: Rheumatology, 3rd ed. New York: McGraw-Hill; 2013.)
Osteophytes
• They are caused by asymptomatic widening of the articular contact area.
• They “spread the load.”
• Weak bone needs more surface area.
What is the best pain medication for OA?
a. Acetaminophen
b. Ibuprofen
c. Indomethacin
d. Chondroitin sulfate
e. Glucosamine
Answer a. Acetaminophen
Acetaminophen has an equivalent analgesic capacity to NSAIDs but no adverse effects on the gastrointestinal system. Indomethacin is an NSAID that with chronic use will practically burn a hole in your stomach. Indomethacin should never be used chronically.
Glucosamine + Chondroitin = Placebo
You switch the patient from an NSAID to acetaminophen.
Orders:
Advise weight loss.
Advise exercise and weight training.
Consult physical therapy.
Weight loss will decrease force on joints.
Strengthening muscles decreases work on joints.
The patient comes to see you every few months for blood pressure (BP) management. He comes to see you on a Monday morning after his knee becomes worse after going hiking with his grandchildren.
PE:
Worsening redness and crepitans of knee
Orders:
Hyaluronic acid injection
Intraarticular triamcinolone
Orthopedic surgery evaluation
• Hyaluronic acid and steroid injection helps relieve pain but lasts for a short time.
• Hyaluronic acid increases synovial fluid volume and buoyancy.
Move the clock forward an hour after the injections of steroids and hyaluronic acid. On the Interval History, there is significant improvement in pain and discomfort. Ultimately, there is no medical therapy to reverse the process of OA. Losing weight decreases the stress on the knees and ankles. Exercise will strengthen the muscles around the joint to bear more of the load. Both of these interventions can slow the process of deterioration, but cannot reverse it. Eventually, more than 100,000 people a year in the United States alone need knee replacement. When the patient gets to the point where relief of pain and immobility requires steroid and hyaluronic acid injections, referral should be made for replacement of the affected joint.