In 2013, there were over 10 million patient visits to doctors’ offices due to knee injuries and knee pain. This number is expected to rise as the population ages and obesity increases. Carrying extra weight increases the pressure on your knees, it also increases the production of the hormone leptin, and studies show this may promote the early development of osteoarthritis. Smokers with osteoarthritis sustain greater cartilage loss and have more severe knee pain than nonsmokers. Certain structural problems, such as having one leg shorter than the other or flat feet, may increase the risk for developing knee pain.
Simply stated, the knee is a very complex joint. It is involved in just about every lower body activity. How does it do this? The knee has what is called “six degrees of freedom.” This means it can move in six different directions. This allows for many different movements and maneuvers; however, it also presents many ways for potential injury.
What makes up the knee?
Four bones work in unison to allow the knee to perform all of its activities: the femur, fibula, tibia and the patella. Ligaments allow these bones to attach to one another and tendons help muscles attach to the bones. Bursa help cushion the joint, and the menisci are tough fibrocartilage structures that transfer the load from the upper leg to the lower leg and stabilize the knee during flexion, extension and during circular movements. Any one of these structures can be pain sources due to injury or wear and tear.
Injuries: Anterior Cruciate Ligament (ACL) injuries are the most common sports injury. Athletes who participate in high demand sports such as football, soccer and basketball are most likely to injure their ACL. Rapid direction changes or landing from a jump incorrectly can tear the ACL; this injury is frequently accompanied by damage to other structures in the knee such as menisci or other ligaments. Collateral Ligaments (CL) can be injured by direct blunt forces that push the knee sideways. Meniscal tears are often seen in sports, these can occur with twisting and pivoting. At times, a sudden awkward twisting motion of the knee can cause injury to the meniscus. At the time of injury one should perform RICE: rest, ice, elevation and compression. Anti-inflammatory medications such as aspirin and ibuprofen will help relieve inflammation. Topical ointments such as volatren gel, pennsaid or compounding creams can be an alternative treatment option if oral NSAID's are not well tolerated. Subsequent treatment will depend on the severity of the injury.
Arthritis: Rheumatoid arthritis (RA) is an auto immune disease, where the membranes covering the knee are affected. The course of RA varies from mild disease to severe joint destructive variant that progresses rapidly, eventually leading to unremitting pain and joint deformity. Treatment for RA related pain is targeted on decreasing the body’s immune response with disease-modifying anti rheumatic drugs (DMARDs) and biological drugs such as enbrel, humira, methotrexate and Sulfasalazine. Anti-inflammatory medications and opioids may be necessary when there is significant joint destruction. Despite recent improvement in biological agents and treatment modalities in the field of rheumatology, progressive joint destruction continues to occur in a subgroup of RA patients, who eventually require joint surgery.
Osteoarthritis (OA) affects over 20 million Americans, with roughly half of those affected experiencing knee pain. This makes OA the most common cause of knee pain in America. It is a degenerative “wear and tear” type of arthritis caused by degeneration of cartilage in the knee. In its extreme form, the femur will rub on the tibia, bone on bone causing debilitating pain and difficulty ambulating. OA is commonly seen after age 50, however the increasing incidence of obesity and smoking can lead to early development of OA. The reported cases of knee OA in as early as in the 20's are steadily increasing. Treatment options may vary based on severity. Activity modifications such as participating of low impact activities such as cycling and swimming, instead of running can help reduce additional wear and tear of the knee. Weight loss is key; for every pound you are overweight there are 5 extra pounds of pressure on the knee cap, with time this leads to significant damage. Acetaminophen or anti-inflammatory medications are proven to decrease pain associated with knee pain from OA.
The patient should seek medical attention if activity modifications and over the counter medications are not providing relief. The optimal medical team should include the primary care physician, an orthopedic surgeon, pain management specialist and a physical therapist. Knee x-rays and frequently MRIs are required to make a diagnosis and to determine the best course of treatment. Intra-articular steroid injections may be necessary; these provide localized relief of inflammation. Viscosupplements such as Hyalgan, Synvisc and Euflexxa injections may also ease the pain and stiffness of osteoarthritis. These substances mimic naturally occurring synovial fluid that surrounds the knee and may provide pain relief for several months. Advanced osteoarthritis may require surgical intervention; arthroscopic surgery or total knee replacement may be indicated for severe disease. For patients who suffer from debilitating knee pain and are not surgical candidates or for those who would rather try a less invasive approach; Genicular nerve blocks and radiofrequency ablation present a new and exciting treatment option. This procedure is done in an outpatient setting under local anesthesia or moderate IV sedation if desired. It takes 10-15 minutes to complete with no down time. It is done with fluoroscopic guidance, nerve stimulation and radiofrequency heat to target the superior medial, superior lateral and inferior medial genicular nerves that are directly involved in transmitting pain signals from the knee. There is a growing amount of data that suggests genicular nerve radiofrequency has also been significantly helpful for patients who have persistent knee pain after total knee replacement. Ultimately, treatment goals should be to decrease pain and allow the patient to adopt a healthier, more active lifestyle that will help prevent further injury.
Dr. Jessica Solá-Acevedo is Board Certified by the American Board of Anesthesiology. She earned her medical degree at the University of Puerto Rico. She completed a fellowship in Pain Management at the Carolina's Pain Institute, Wake Forest Baptist Health and her residency in Anesthesiology at Wake Forest Baptist Health.
She is a member of the American Society of Anesthesiologist, the American Society of Regional Anesthesia and American Academy of Pain Management.
She can be reached at Jessica.SolaAcevedo@shcr.com