Dale Says

Osteoarthritis is a common cause of pain and disability in the knee joint. In the knee, the end of the femur (thigh bone) and tibia (shin bone) are covered in smooth articulate (surface) cartilage. Between the two bones sits a second type of cartilage, called menisci, which acts as a shock absorber. Joint fluid also adds lubrication to the knee joint. Osteoarthritis (OA) starts when articulate cartilage is thinned or missing, which results in areas of exposed bone, and then progresses into surrounding bone, tissue, and synovial fluid.

It has been estimated that 12% of Americans aged 25 years and older have osteoarthritis, which increases to 80% of people older than 75. Symptoms of osteoarthritis include joint pain with activity, night pain, morning stiffness, limited motion, joint inflammation, crepitus or noise from the knee, and deformity. There are several options in treating osteoarthritis, both surgical and nonsurgical. All options are not always appropriate for every patient. Information gained from X-rays, MRI and knee arthroscopy all are helpful in determining an appropriate treatment plan.

Nonsurgical Treatment Options

There are several non-surgical treatments for osteoarthritis; most of them start with weight loss.  Each pound of weight can put up to six pounds worth of pressure on the knee joint during activity, so heavier people tend to develop arthritis at an earlier age and to a greater severity

Muscle strength  is also vital in combating osteoarthritis. The muscles surrounding the knee joint act as shock absorbers for the pressure that daily activities and sports place on the joint. The stronger the muscles around the knee, the more stress they can absorb for the knee joint. Exercises that will increase quadriceps, hamstring and calf strength include ¼ squats, leg press and leg extension. These exercises should be pain free and done with limited flexion or bending of the knee, not greater than 45 degrees. In addition, cardiovascular exercise such as cycling, elliptical, rollerblading, and swimming will also be beneficial. Strengthening exercises should be done at least 3x/week to build muscle strength.

Knee braces are available for treatment of medial compartmental osteoarthritis (arthritis on the inside of the knee joint). These braces work by unloading the medial (inside) portion of the knee. These braces need to be custom made and therefore can be expensive.

Anti-inflammatory medications may also help decrease symptoms. Aspirin, Ibuprofen (Advil) and Naprosyn (Aleve) are all examples of over the counter anti-inflammatory medications (NSAIDs). Prescription strength NSAIDs include Indocin, Daypro, Relafen, Celebrex, Lodine, and Mobic. Acetaminophen (Tylenol) may also be taken for OA pain but it is less effective for inflammation than other medications. Supplements such as glucosamine sulfate and chondroitin sulfate are widely used but not regulated by the FDA. Glucosamine, an aminomonosaccharide, is a primary component of connective tissue (including cartilage). It is not know however, if taking glucosamine orally has any effect on the knee joint. Chondroitin sulfate is found in proteoglycans which contribute to the stability of cartilage. In supplementation form, chondroitin is derived from bovine and calf cartilage. Several clinical studies are in process to evaluate effectiveness, efficacy, and to monitor long term adverse effects of glucosamine and chondroitin.

Lubrication or Hylagan injections provide extra lubrication and shock absorption, as well as decrease friction or rubbing within the joint which may slow the progression of osteoarthritis. However, of all the patients who receive Hylagan injections, only about 50% have symptomatic relief. One injection is given into the knee each week for three weeks and may be repeated as soon as 6 months. Up to five injections may be given, but studies have shown no difference in symptom relief after 3 or 5 injections.
Injection of cortisone into the knee joint has been shown to be effective for ‘flares’ of arthritis symptoms, as they are a direct acting anti-inflammatory medication. However, research has also shown deterioration of articulate cartilage after repeated cortisone injections. Therefore, these injections are only used with caution in the knee joint.

Surgical Options

Artificial joint resurfacing involves capping the end of the femur (thigh bone) and tibia (shin bone) with plastic and or metal pieces. These pieces are glued in place to form an artificial joint surface. This procedure can be very effective in eliminating painful and severe OA, but it is limited by the fact that the articular components (plastic and metal) will eventually wear out and need to be replaced. In active people early loosening of the components can occur. For these reasons most orthopedic surgeons try to delay artificial resurfacing procedures until late in life

Unicompartmental Knee Replacement
Another option for patients with osteoarthritis in one area of the knee- usually medial or lateral is an artificial resurfacing of the cartilage surface, called a unicompartmental knee replacement. This procedure is successful in relieving symptoms from osteoarthritis if the arthritis is limited to one compartment or area of the knee

OATS Procedure
Osteochondral Autograft (or allograft) transplant (OATS procedure) can be performed for small to moderately large area of surface cartilage loss. This procedure involves first removing a cylinder shaped dowel of bone which is lacking surface cartilage and replacing it with a dowel or cylinder of bone with intact surface cartilage. Both dowels are the same size so when they are switched there is a press fit and no hardware is needed to secure it in place. The replacement dowel of bone (with surface cartilage) can either come from a non weight bearing area of bone and surface cartilage from your knee (AUTOGRAFT) or from a cadaver (ALLOGRAFT). If the lesion or area lacking surface cartilage is less than 20mm an autograft OATS may be performed, using either one or a few bone and cartilage plugs. If the lesion to be resurfaced is larger than 20mm, taking tissue from a cadaver or an allograft is needed.

Rehabilitation after an OATS procedure includes using crutches and partial weight bearing activity for 3- 6 weeks.

Osteotomy – Tibial and Femoral
Often patients with knee osteoarthritis may have more arthritis on either the inside (medial) or outside (lateral) of the knee, causing the alignment of the knee joint to shift towards becoming bow-legged or knock-knee. Unfortunately once alignment is no longer even activity and pressure on the knee joint can cause an acceleration of wearing of the vulnerable side of the knee as more and more weight is now transferred onto that area. An Osteotomy is a realignment procedure that unloads the vulnerable or arthritic side of the knee and puts the majority of the load of the knee joint onto the underutilized cartilage on the other side of the knee.

An Osteotomy is performed by wedging open either the tibia (shin bone) or femur (thigh bone) and adding bone graft putty to create new bone growth into the wedged area. After this procedure patients are on a home motion machine for one week, then progress to physical therapy.  They use a brace and crutches for the first 4-6 weeks after surgery until the bone is well healed. This procedure is very successful in relieving symptoms and preventing or delaying an artificial knee in many. 

From Treatment Options for Osteoarthritis in the Knee, Warren, King M.D.