Knee Pain in Adults – Causes and Treatments

About 30 percent of adults will experience chronic knee pain, says Charles M. Lawrie, M.D., a board-certified, fellowship-trained orthopedic surgeon at Miami Orthopedics & Sports Medicine Institute.  It’s the second most common cause of chronic pain, behind lower back pain. Dr. Lawrie, who specializes in adult hip and knee joint replacement surgery, discussed the causes of and treatment for chronic knee pain in adults during a recent virtual community health webinar.

Charles M. Lawrie, M.D., a board-certified, fellowship-trained orthopedic surgeon at Miami Orthopedics & Sports Medicine Institute.

The knee is not simply a hinge joint; it is one of the largest and most complex joints in the body, Dr. Lawrie says.

“When we walk, the impact on our knees is 1.5 times our body weight. When we take the stairs or run, the impact can be three times our body weight, so maintaining a healthy weight is important to knee joint health,” he explained.

Since activities change as we age, the cause of knee pain evolves over time. Younger people often experience overuse injuries and sports injuries while older adults typically experience wear and tear that can lead to conditions such as arthritis.

The most common conditions causing knee pain in adults are:

• Bursitis
• Tendonitis
• Meniscus tear
• Inflammatory arthritis
• Osteoarthritis

Bursitis

Knee bursitis is inflammation of the bursae, which are small fluid-filled sacs that reduce friction between your bones and the tendons, muscles and skin near your joint.  Bursitis often improves over time, so treatment is usually aimed at symptom relief. Working with a physical therapist can also help people alleviate pain, improve flexibility and strengthen muscles to reduce recurring episodes of knee bursitis.

Tendonitis

Knee tendinitis is inflammation of the tendons, which are the bands of fibrous tissue that attach muscle to bone. Over time, tendons become less flexible and the muscles lose strength, both of which further stress the tendons. Being overweight can also contribute to knee tendinitis. Dr. Lawrie says the treatment plan for tendinitis pain typically includes rest, activity modification, ice and over-the-counter pain relievers or other nonsteroidal anti-inflammatory drugs (NSAIDs), if they can be tolerated.

Meniscus Tear

Tears to the meniscus, the wedge-shaped pieces of cartilage that absorb shock in the knee joint, are extremely common in older adults, says Dr. Lawrie. About 40 percent of people ages 70 to 75 have some type of meniscus tear. The injury typically occurs after years of normal wear and tear that weakens a meniscus. “The majority of tears are minimally symptomatic and heal with time, rest, ice, physical therapy and/or exercise and NSAIDs, if tolerated,” said Dr. Lawrie. In rare cases, a meniscectomy, the surgical removal of all or part of a torn meniscus, may be warranted.

Inflammatory Arthritis

Inflammatory arthritis is joint inflammation caused by an overactive immune system. Common types of inflammatory arthritis are psoriatic arthritis and rheumatoid arthritis. Remission of symptoms is more likely when treatment begins early with medications called disease-modifying antirheumatic drugs (DMARDs). A patient’s treatment plan may also include some of the same treatment options for osteoarthritis, listed below.

Osteoarthritis

Osteoarthritis, the most common form of arthritis, occurs when the protective cartilage that cushions the ends of the bones in your joints wears down over time. If cartilage wears down completely, bone will rub on bone, says Dr. Lawrie.

Conservative treatments for osteoarthritis include rest, ice, activity modification, physical therapy, low-impact exercise and NSAIDs, when appropriate. If these treatments do not relieve the pain, other treatment options include:

Injections – Corticosteroid injections into the knee joint can help relieve pain and inflammation, while hyaluronic acid injections may provide some cushioning in the knee. Both treatments can offer symptom relief for several weeks, Dr. Lawrie says.

Biologics – Platelet-rich plasma (PRP), a high concentration of plasma obtained from the patient’s own blood, is one biologic injection option. “PRP uses the patient’s own platelets and growth factors to promote musculoskeletal healing,” said Dr. Lawrie. “For some patients, it can provide anti-inflammatory and pain-relieving effects.”   

Stem-cell therapy is another type of biologic injection used by some specialists for the treatment of osteoarthritis. Stem cells, which can be harvested from the patient or a donor, may provide an anti-inflammatory effect. However, it is not a treatment Dr. Lawrie recommends for his patients because “the science is not quite there and standards are deficient,” he says. “Stem cell therapy is not effective for osteoarthritis because it is a mechanical problem, not a biologic problem. The knee is a hostile environment, and stem cell therapy will not grow cartilage or regenerate a knee joint,” he explained.

Knee replacement surgery – For many patients with chronic knee pain and deformity, total or partial knee replacement surgery, also called knee arthroplasty, is the best option. “Knee replacement might be more accurately termed a knee ‘resurfacing’ because only the surface of the bones is actually replaced,” Dr. Lawrie said. “Knee replacements can last for more than 20 years.”

Dr. Lawrie performs robotic-arm assisted knee surgery, which has many advantages, including allowing for more precision. With precision and personalization, Dr. Lawrie is able to preserve soft tissue and healthy bone for a faster recovery and ensure proper joint alignment for a good outcome. The procedure can be performed with regional anesthesia and mild sedation rather than with general anesthesia, which can also improve a patient’s recovery time.  

“Before, during and after knee replacement surgery—there are many ways we personalize a patient’s treatment plan to ensure a faster return to normal function,” Dr. Lawrie said.