Knee and shoulder pain are common complaints for patients in the primary care practice.
But pinpointing the source of the pain can be complicated, and an accurate diagnosis of the underlying cause of the discomfort is key to proper management – whether it’s simple home care options from ice and rest or a recommendation for 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 in the primary care setting, and offered advice on diagnosis and appropriate management.
The most common conditions causing knee pain are osteoarthritis and meniscal tears. “The differential for knee pain is wide,” Nakamoto said. “You have to have a way to divide it, for example if it’s acute or chronic.”
The initial balance sheet has several key elements. The first steps: Determine the location of the pain – anterior, medial, lateral, posterior – and then whether it is from an injury or atraumatic.
“If you have to ask a question, ask where it hurts,” he said. “And is it due to injury or just wear and tear. That helps me decide if surgery is needed.”
Knee pain usually localizes well to the site of pathology, and knee pain of acute traumatic onset requires further investigation of issues best treated with early surgery. “It also helps to determine whether x-ray 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 examination maneuver that mimics joint line pain, is suggestive of pain due to meniscal pathology,” he said.
Imaging is an important part of evaluating knee symptoms, and the question often arises of when to order an MRI.
Nakamoto proposed the following scenario: if significant osteoarthritis is evident on the weight-bearing radiograph, treat the patient for this condition. However, if little or no osteoarthritis appears on the X-ray, and if the onset of symptoms was traumatic and the patient’s history and physical examination suggest a meniscal tear, order an MRI.
An early MRI is also necessary if the patient has had atraumatic or traumatic symptoms and history and physical exams suggest a mechanically locked or locked meniscus. If a rupture of the quadriceps or patellar tendon or of a stress fracturean MRI is urgently needed.
An MRI would be ordered later if the patient’s symptoms have not improved significantly after three months of conservative management.
Nakamoto pointed out how common undiagnosed meniscus tears are in the general population. A third of men between the ages of 50 and 59 and nearly 20% of women in that age range have a tear, he said. “That number jumps to 56% and 51% in men and women between the ages of 70 and 90, and 61% of these tears were in asymptomatic patients in the past month.”
In the context of osteoarthritis, 76% of asymptomatic patients had Meniscus tear and 91% of patients with symptomatic osteoarthritis had a meniscus tear, he added.
Treat knee pain
Treatment will vary depending on the underlying etiology of the pain. For a possible meniscus tear, the recommendation is for conservative intervention with ice, ibuprofenknee immobilization and crutches, with a follow-up appointment in a week.
Three types of injections can also help:
Cortisone for osteoarthritis or meniscus tears, swelling and inflammation, and prophylaxis against inflammation
Viscosupplementation (intra-articular hyaluronic acid) for basic chronic osteoarthritis symptoms
Regenerative therapies (platelet-rich plasma, stem cells, etc.) are mainly used for osteoarthritis (they don’t regrow cartilage, but some patients report a decrease in pain)
Injection data is mixed, Nakamoto said. For example, the results of a 2015 Cochrane review on cortisone injections for osteoarthritis reported small to moderate benefit at 4‐6 weeks, and small to no benefit at 13 weeks.
“There’s a lot of controversy about viscosupplementation despite all the data on it,” he said. “But recommendations from professional organizations are mixed.”
He noted that he had been using viscosupplementation since the 1990s and that some patients were benefiting from it.
The most common causes of shoulder pain are adhesive capsulitis, rotator cuff tears and tendinopathy, and impingement.
As with knee pain, much of the same assessment routine applies.
First, identify the location: is the trouble spot the lateral shoulder and upper arm, the trapezoidal ridge or the scapula?
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 rather than degeneration or overuse.
As with the knee, imaging is a major component of the evaluation and usually involves the use of X-rays. MRI may be needed to evaluate full and partial thickness tears and when considering surgery.
MRI is also needed to assess cases of acute, traumatic shoulder injury and patients with disabilities suggestive of rotator cuff tear in an otherwise healthy tendon.
Some pain can be treated with cortisone injections or regenerative therapies, which are usually administered at the acromioclavicular or glenohumeral joints or in the subacromial space. A 2005 meta-analysis found that subacromial corticosteroid injections are effective in improving the rotator cuff tendonitis up to a period of 9 months.
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 treatment. .
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 an award-winning registered nurse and medical writer who has written for many major media outlets and is a regular contributor to Medscape.