MKSAP Quiz: preoperative evaluation for knee replacement
A 66-year-old man comes for a preoperative evaluation before total joint arthroplasty of the left knee. He has a 25-year history of rheumatoid arthritis. He has had progressive pain in his left knee with activity, which limits his ability to hike. The patient has similar pain in the right knee, but it is less severe. He reports no recent morning stiffness. He is able to climb two or three flights of stairs without chest pain or shortness of breath. He has no other medical problems and reports no additional symptoms. Medications are methotrexate and folic acid. Following a physical exam and lab tests, what is the next best step in management?
A 66-year-old man comes for a preoperative evaluation before total joint arthroplasty of the left knee. He has a 25-year history of rheumatoid arthritis. He has had progressive pain in his left knee with activity, which limits his ability to hike. The patient has similar pain in the right knee, but it is less severe. He reports no recent morning stiffness. He is able to climb two or three flights of stairs without chest pain or shortness of breath. He has no other medical problems and reports no additional symptoms. Medications are methotrexate and folic acid.
On physical examination, temperature is 37.0 °C (98.6 °F), blood pressure is 120/70 mm Hg, pulse rate is 80/min, and respiration rate is 16/min. BMI is 19. Examination of the hands reveals ulnar deviation and swan neck deformities involving the third digit of the right hand and the fourth digit of the left hand. Range of motion of the knees elicits crepitus and pain, which are worse in the left knee. There is no warmth, redness, swelling, or tenderness. Neurologic examination is unremarkable.
Recent evaluation of liver chemistry tests revealed no abnormalities.
Electrocardiogram and chest radiograph are normal.
Which of the following is the next best step in management?
A. Cervical spine radiography
B. Exercise cardiac stress testing
C. Preoperative spirometry
D. Screening coagulation studies
MKSAP Answer and Critique
The correct answer is A: Cervical spine radiography. This item is available to MKSAP 16 subscribers as item 33 in the Rheumatology section. More information is available online.
Cervical spine radiography is the appropriate preoperative diagnostic study for this patient with rheumatoid arthritis who is about to undergo total joint arthroplasty of the left knee. Cervical spine radiography with flexion and extension views is indicated for patients with aggressive or long-standing rheumatoid arthritis to evaluate for atlantoaxial subluxation and dynamic instability. Evaluation for cervical instability is particularly important in the perioperative setting, when extension of the neck for intubation may lead to spinal cord compromise and resultant paraplegia. This patient has evidence of bony changes attributable to erosive arthritis. Similar erosive changes in the cervical spine could increase risk of morbidity, particularly with neck movements that occur during intubation. These radiographic changes may be present in asymptomatic patients. If cervical instability is detected, the surgical team, including the anesthesiologist, must be alerted.
Rheumatoid arthritis is a risk factor for cardiovascular disease; however, this patient's exercise tolerance exceeds four metabolic equivalents. Therefore, exercise cardiac stress testing is not indicated in this context.
Although patients with rheumatoid arthritis can develop interstitial lung disease, preoperative spirometry should not be used routinely for predicting risk for postoperative pulmonary complications. Spirometry does not usually add information beyond what was known or suspected clinically and rarely changes management.
In the absence of a personal or family history of abnormal bleeding, liver disease, significant alcohol use, malabsorption, or anticoagulation therapy, the likelihood of a bleeding disorder is low, and no further preoperative testing is required.
Key Point
- Preoperative cervical spine radiography is indicated for all patients with aggressive or long-standing rheumatoid arthritis to evaluate for atlantoaxial subluxation and dynamic instability before intubation.