There are multiple parts of the knee: the medial, the lateral, and the patellofemoral. All three of these parts can develop arthritis and cause pain that leads to surgery. You can address all three parts in a total knee replacement, or you can address just one or two parts in a partial knee replacement.  

Causes and symptoms of knee pain 

The most common cause of knee pain is arthritis. Overall, about 50% of the population will experience symptomatic arthritis in their knee. The most common type is osteoarthritis, which is the breakdown of the cartilage in your knee that acts as the shock absorber between your bones. Osteoarthritis is a complex disease that is related to overuse and trauma, abnormal biology or abnormal anatomy and for some, it can be genetic. Some common arthritis symptoms include joint pain, joint stiffness and swelling. You can also have cracking and grinding with movement in the knee. Eventually, if left unmanaged, you can have decreased range of motion, or your joints can get out of alignment. 

Non-surgical options for knee pain 

There are a few options to explore before surgery as a means to relieve knee pain. Modifications like avoiding activities that cause pain is the first step. If that doesn’t work, you can talk to your doctor about medication. There are both oral and topical medicines that can help with your pain. Weight loss, strengthening the muscles around your knee, and using a knee brace can also help. Finally, you may get gel injections, steroid injections, or injections of biologics with stem cells to help your pain. After all of those options have been exhausted and you can't keep going on with your current quality of life, then you can begin exploring surgical options. 

Are there age limitations on knee replacements? 

Many patients that are experiencing knee pain wonder if there are any age limitations to knee replacements. If you are medically fit and physically fit to undergo surgery, then you can be a great candidate for a partial knee replacement regardless of age. Sometimes, a partial knee replacement is a much better answer in the older age population because it is a smaller surgery with an easier recovery. It puts less stress on a patient’s body and is easier to recover from.  

Advantages of a partial knee replacement  

Partial knee replacements require a smaller cut than total knee replacements, so recovery is quicker and less painful with less blood loss. Usually, patients who have a partial knee replacement have a better range of motion before the surgery and are more likely to keep that same range of motion after surgery since a smaller part of the joint is operated on. 

Disadvantages of a partial knee replacement  

A partial knee replacement is less predictable when it comes to pain. If you’re having pain from the other parts of your knee and the surgery only addresses one part, you may still experience residual pain from those other sections. If there is a concern about joint or bone alignment, a partial knee replacement might not be the best option because it does not have the ability to change alignment. Stiff knees are also not the best candidates for partial knee replacements. If you have had ACL surgery before, a partial knee replacement is not always the best option because you will most likely experience pain in multiple compartments of the knee. A total knee replacement might be a better option because there is more cutting and more relief of tissues that can result in a greater range of motion postoperatively than what you have preoperatively. Obviously, the biggest disadvantage of a partial knee replacement is the possibility of surgery needed in the future to convert a partial knee replacement into a total knee replacement. 

Recovery 

After surgery, the recovery usually takes between four to six weeks, but you still recover and get better for up to about a year. That doesn't mean that you're incapacitated for those four to six weeks. Usually, you're up walking and doing the beginnings of rehab. Most people are off their walker or forearm crutches by the first two weeks. You can drive with your non-operative leg as soon as you are off narcotics, but it will take two to six weeks to be able to drive with your operative leg. For about three months after surgery you will be restricted from doing heavy lifting, significant bending, and twisting to allow your body to strengthen around the partial knee replacement. After a gradual advancement back to your normal activities you will have no medical restrictions on your activity, although some activities, like kneeling, high-impact running and explosive sports, may not be comfortable. In the right hands and in the right patients, partial knee replacement surgeries can last 20 to 25 years.