Knee and shoulder pain are common complaints for patients in the primary care office.
But identifying the source of the pain can be complicated,
and an accurate diagnosis of the underlying cause of discomfort is key to appropriate management – whether that involves simple home care options of ice and rest or a recommendation for a follow-up with a specialist.
Speaking at the annual meeting of the American College of Physicians, Greg Nakamoto, MD, department of orthopedics, Virginia Mason Medical Center, Seattle, discussed common knee and shoulder problems that patients often present with in the primary care setting, and offered tips on diagnosis and appropriate management.
The most common conditions causing knee pain are osteoarthritis and meniscal tears. “The differential for knee pain is broad,” Dr. Nakamoto said. “You have to have a way to divide it down, such as if it’s acute or chronic.”
The initial workup has several key components. The first steps: Determine the location of the pain – anterior, medial, lateral, posterior – and then whether it stems from an injury or is atraumatic.
“If you have to ask one question – ask where it hurts,” he said. “And is it from an injury or just wear and tear? That helps me when deciding if surgery is needed.”
Pain in the knee generally localizes well to the site of pathology, and knee pain of acute traumatic onset requires more scrutiny for problems best treated with early surgery. “This also helps establish whether radiographic findings are due to injury or degeneration,” Dr. Nakamoto said. “The presence of swelling guides the need for anti-inflammatories or cortisone.”
Palpating for tenderness along the joint line is important, as is palpating above and below the joint line, Dr. Nakamoto said.
“Tenderness limited to the joint line, combined with a meniscal exam maneuver that reproduces joint-line pain, is suggestive of pain from meniscal pathology,” he said.
Imaging is an important component of evaluating knee symptoms, and the question often arises as to when to order an MRI.
Dr. Nakamoto offered the following scenario: If significant osteoarthritis is evident on weight-bearing x-ray, treat the patient for the condition. However, if little or no osteoarthritis appears on x-ray, and if the onset of symptoms was traumatic and both patient history and physical examination suggest a meniscal tear, order an MRI.
An early MRI also is needed if the patient has had either atraumatic or traumatic onset of symptoms and their history and physical exams are suspicious for a mechanically locked or locking meniscus. For suspicion of a ruptured quadriceps or patellar tendon or a stress fracture, an MRI is needed urgently.
An MRI would be ordered later if the patient’s symptoms have not improved significantly after 3 months of conservative management.
Dr. Nakamoto stressed how common undiagnosed meniscus tears are in the general population. A third of men aged 50-59 years and nearly 20% of women in that age group have a tear, he said. “That number goes up to 56% and 51% in men and women aged 70-90 years, and 61% of these tears were in patients who were asymptomatic in the last month.”
In the setting of osteoarthritis, 76% of asymptomatic patients had a meniscus tear, and 91% of patients with symptomatic osteoarthritis had a meniscus tear, he added.