An Overview of Knee Pain
The causes of knee pain are myriad and a lot depends on the age at which time a person develops the discomfort. Normally, the knee joint enjoys an amazing range of motion from full extension to well past 120° of flexion.
Considering that the knee sees a considerable amount of stress during walking and running, even a minor injury can cause considerable knee pain.
In younger individuals, typically between the ages of 22 50, the most common reason for knee pain is due to a traumatic injury. In athletes, this may include a tear of the anterior cruciate ligament (ACL) or possibly one of the other the stabilizing ligaments such as the posterior cruciate ligament (PCL), lateral collateral ligament (LCL), or the medial collateral ligament (MCL).
If an anterior or posterior cruciate ligament is completely torn, a reconstruction may be necessary depending on the person’s desires for continued athletic activity. In certain patients, it may be prudent not to reconstruct the ligament. It is best to make that decision in conjunction with your pain doctor or an orthopedic surgeon may be necessary to consult as well.
There is also a soft tissue bursa that lays under an accumulation of tendons below the knee joint, called the pes anserine bursa. The pes anserine is a combination of three tendons coming together under the joint and inserting. These are the gracilis, semitendinosus, and sartorius.
Normally, those tendons glide over the pes anserine bursa effortlessly, but with overuse it can lead to bursitis and pain.
Knee Meniscal Tears
One of the most common reasons for knee pain in a younger individual is due to a meniscal tear. The meniscus in the knee is a shock absorber that is made of cartilage material (fibrocartilage, not articular cartilage).
When a person has a tear of the meniscus, it may not be painful at all. Or a person may experience aching of the knee, popping, clicking, locking, or in the worst cases a person’s knee may completely lock up due to a large tear (called a bucket handle tear).
Knee Cartilage Injuries
An additional reason for knee pain in the younger individual is a cartilage defect due to trauma from a sporting injury, auto accident or additional types of trauma. This may lead to premature arthritis pain as without sufficient cartilage to protect the surface of the joint, arthritic changes may occur that can lead to pain at a young age. Post-traumatic arthritis can set in within a year or two of cartilage injury, or it may take much longer.
The best study to see cartilage defects is an MRI, often with contrast placed into the joint. If nonoperative treatment fails, a knee arthroscopy can show the extent of the damage as well.
Degenerative Osteoarthritis and Meniscal Tears
As a person gets older, the most common reason for knee pain by far is degenerative
osteoarthritis, which is also known as “wear and tear” arthritis. Individuals young and old can suffer from rheumatoid arthritis pain, but for the tens of millions of Americans with degenerative arthritis, the knee pain typically comes and goes depending on activity and whether or not an exacerbation is occurring.
There are three compartments to the knee including medial, lateral and the one between the kneecap and the femur (patellofemoral). Degenerative arthritis most commonly occurs in the medial compartment, which is the inside portion of the joint.
Older individuals also suffer frequently from the pain due to a degenerative meniscal tear. These tears do not necessitate a traumatic event, just repetitive mico-trauma over time that leads to a tear. Symptoms include aching, clicking, popping or knee locking.
Unusual Reasons for Knee pain
Less common reasons for knee pain include aseptic necrosis (osteonecrosis), infection or a tumor. When an individual is having significant pain at rest, fevers, chills, or night sweats, physicians will investigate for their presence. Workup may include x-rays, MRI, CT scan, bone scan, and blood work. The following treatment does not refer to these conditions.
Nonoperative Knee Pain Treatment
Nonoperative treatment for knee pain is typically warranted as most pain conditions are elective in nature such as arthritis. Even a meniscal tear usually receives at least six weeks of conservative treatment prior to surgery and most commonly ACL tears receive the same to allow swelling to subside prior to a reconstruction.
With degenerative arthritis, if an individual has an exacerbation of the pain, a short-term course of narcotics may be indicated. Long term narcotics for arthritis knee pain are not indicated as the risks outweigh the benefits including tolerance, addiction and constipation issues.
There are creams for pain relief that may be placed over the painful area. One of these is capsaicin, which is made from chili peppers and offers significant temporary pain relief.
For those individuals with knee pain that are younger, an MRI may be necessary to see if there is a meniscal tear and/or a ligament injury. In most cases, physical rehabilitation should be implemented to attempt to treat those conditions nonoperatively. Sometimes a meniscal tear can be treated without surgery, as there is potential for it to heal without surgery. If an ACL tear is incomplete, rehab may be all that is needed.
If surgery does become necessary for a meniscal or ACL tear, usually it involves an outpatient knee arthroscopy surgery where the meniscal tear is shaved down a bit or possibly repaired.
Physical Rehabilitation and Physical Therapy
Along with medications, physical therapy (also known as physical therapy), involves stretching and strengthening of the knee joint which can help take pressure off of the painful area. This can help substantially along with ultrasound, ice/heat, electrical stimulation, and possibly a TENS unit for home use.
The theory is that by strengthening the muscles around the joint, less pressure will be seen through the joint. Therapy can significantly delay the need for knee surgery, whether for an arthroscopic procedure or a knee replacement.
TENS units are about the size of an iPod and a person can wear it on his or her belt. It runs on A TENS unit may alter the way that the brain perceives pain signals from the Navy and help substantially.
The TENS unit emits slight electrical impulses through the skin, which run through foam pads placed over the painful area. A TENS Unit may decrease pain without using medications and help considerably during periods of painful exacerbations.
Cortisone injections into the knee are indicated for degenerative and rheumatoid arthritis to help decrease inflammation and may help with reducing the discomfort for months at a time.
They can be repeated every few months. There have been some studies in animals that have shown potential deleterious effects on knee cartilage, but this has not been shown in humans.
Another type of injection that can work well in younger individuals is hyaluronic acid. These injections can help stimulate cartilage growth in the knee and studies have shown pain relief that may last for a year in over 65% of individuals.
A knee unloader can shift stresses from the arthritic painful side of the knee to the side that has sufficient cartilage and less painful. This can make walking and sporting activities more tolerable and delay the need for a knee replacement.
If the physical therapy, medications, injections and Tens unit failed to relieve an individual’s pain, then surgery may become necessary.
For a meniscal tear, a knee arthroscopy performed as an outpatient is an incredibly successful procedure. If a ligament reconstruction is performed, this is also usually very successful with getting patients back to sporting activities at high levels.
For osteoarthritis, knee replacement has been shown to be one of the top five quality-of-life procedures performed in America. Hundreds of thousands are performed in America every year, with a success rate well over 90%.
However, it is not optimal to have a knee replacement performed prior to the age of 65. The reason is that in all likelihood the person may need a revision of the procedure within 15 years or so. The results of a revision procedure are not as good as the initial surgery. So it should always be viewed as a last resort, with considerable conservative treatment being tried first.
If you are suffering from knee pain, the pain and rehab doctors at Arizona Pain Specialists are experts in nonoperative treatment. The combination of medication management, physical rehabilitation, knee injections, TENS units and knee bracing can make patients comfortable, more functional, and able to avoid surgery for a long time.