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 2022 American College of Physicians Internal Medicine Meeting, Greg Nakamoto, MD, Department of Orthopedics, Virginia Mason Medical Center, Seattle, Washington, 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,” 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,” 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, 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.
Nakamoto offered the following scenario: If significant osteoarthritis is evident on weightbearing 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 three months of conservative management.
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 to 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.
Treating Knee Pain
Treatment will vary depending on the underlying etiology of pain. For a possible meniscus tear, the recommendation is for a conservative intervention with ice, ibuprofen, knee immobilizer, and crutches, with a follow-up appointment in a week.
Three types of injections also can help:
Cortisone for osteoarthritis or meniscus tears, swelling, and inflammation, and prophylaxis against inflammation
Viscosupplementation (intra‐articular hyaluronic acid) for chronic, baseline osteoarthritis symptoms
Regenerative therapies (platelet-rich plasma, stem cells, etc) are used primarily for osteoarthritis (these do not regrow cartilage, but some patients report decreased pain)
The data on injections are mixed, Nakamoto said. For example, the results of a 2015 Cochrane review on cortisone injections for osteoarthritis reported that the benefits were small to moderate at 4‐6 weeks, and small to none at 13 weeks.
“There is a lot of controversy for viscosupplementation despite all of the data on it,” he said. “But the recommendations from professional organizations are mixed.”
He noted that he has been using viscosupplementation since the 1990s, and some patients do benefit from it.
The most common causes of shoulder pain are adhesive capsulitis, rotator cuff tears and tendinopathy, and impingement.
As with knee pain, the same assessment routine largely applies.
First, pinpoint the location: Is the trouble spot the lateral shoulder and upper arm, the trapezial ridge, or shoulder blade?
Next, assess pain on movement: Does the patient experience discomfort reaching overhead or behind the back, or moving at the glenohumeral joint/capsule and engaging the rotator cuff? Check for stiffness, weakness, and decreased range of motion in the rotator cuff.
Determine if the cause of the pain is traumatic or atraumatic and stems from an acute injury versus degeneration or overuse.
As with the knee, imaging is a major component of the assessment and typically involves the use of x-ray. An MRI may be required for evaluating full- and partial-thickness tears and when contemplating surgery.
MRI also is necessary for evaluating cases of acute, traumatic shoulder injury, and patients exhibiting disability suggestive of a rotator cuff tear in an otherwise healthy tendon.
Some pain can be treated with cortisone injections or regenerative therapies, which generally are given at the acromioclavicular or glenohumeral joints or in the subacromial space. A 2005 meta-analysis found that subacromial injections of corticosteroids are effective for improvement for rotator cuff tendinitis up to a 9‐month period.
Surgery may be warranted in some cases, Nakamoto said. These include adhesive capsulitis, rotator cuff tear, acute traumatic injury in an otherwise healthy tendon, and chronic (or acute-on-chronic) tears in a degenerative tendon following a trial of conservative therapy.
Office Orthopedics for the Internist: Common Knee and Shoulder Problems. American College of Physicians (ACP-IM) Internal Medicine Meeting 2022. Presented April 29, 2022.
Roxanne Nelson is a registered nurse and an award-winning medical writer who has written for many major news outlets and is a regular contributor to Medscape.