You may have heard the term Housemaid’s Knee before, but you may not understand that this term applies to the medical condition that can affect anyone whose occupation requires them to spend time on their knees. It is also identified by such distinctive monikers as Nun’s Knee, Carpet-layer’s Knee or Coal Miner’s Knee. Though it is most-often caused by frequent kneeling and is chronic, it can happen from a single, acute event, can also be caused by an underlying medical condition or it can be idiopathic (cause unknown). In this article, I will discuss what the condition is, how it usually occurs and what treatments are effective.
Prepatellar Bursitis is caused when a bursa (fluid filled cushioning sac) that is situated in front (Pre) of the kneecap (patella) becomes inflamed or infected (itis) = Prepatellar Bursitis. Its signature characteristic is a distinct swelling of the knee that can cause it to look like half of a softball has been stuffed under the skin of one’s knee. Sometimes it can be tender when pressure is applied directly to the swelling. The swelling may also be red or warm to the touch. A patient’s range of motion is usually not compromised when suffering from this condition; however, they may have some discomfort when straightening their leg to its fullest extension.
I make my diagnosis by doing a thorough examination of the knee, looking at x-rays and asking questions about the patient’s occupation and risk factors. I will ask about Diabetes, Gout, alcohol abuse, COPD (chronic obstructive pulmonary disease) and other issues that are known to exacerbate swelling of the bursa in the knee. I try to rule out other causes of knee swelling, such as arthritis or injury.
Occasionally, the bursa can become infected and cause the patient to run a fever. This can happen when a person also suffers abrasions to the knees while kneeling, which allows bacteria to enter the soft tissue, increasing the risk of local infection. If I suspect that the bursa may be infected, I will often draw fluid out (aspirate) with a hypodermic needle to be sent for a Gram stain and cell culture. By doing so, I can ascertain what type of bacteria is causing the infection and decide upon the best course of antibiotic treatment. Most often, the infection is caused by Staphylococcus, and less frequently Streptococcus.
For non-septic prepatellar bursitis, treatment can vary. Ice, rest, elevation of the affected knee and behavior modification is very helpful. If a person’s job requires that they kneel, the use of knee pads will be recommended to ease the pressure on the knee. Ibuprofen or other NSAIDS have been proven to be helpful in relieving inflammation. Steroid injections, in conjunction with aspiration can be used for more recalcitrant cases. Recurrent cases often have to have a formal excision of the bursa sac.
For cases where infection is present, oral antibiotics will be given as the first course of treatment. If this does not resolve the infection, IV antibiotics may be administered. If the infection does not resolve, removal of the bursa may be necessary, which can be done as a 30 minute outpatient procedure.
If you work in an occupation that requires you to spend a lot of time kneeling, take steps to prevent this condition from occurring. Buy knee pads made specifically for the type of work you do, i.e., gardening, roofing, flooring, etc. See if you can modify your job to allow you to sit or not be on your knees as much. Be cognizant of any signs of trouble, including swelling and tenderness. Take steps to address the problem quickly before it gets out of control. As Prepatellar Bursitis can be painful and time consuming to treat, my recommendation is that an ounce of prevention is worth a pound of cure.
John D. Burrow, DO is a Fellowship-Trained, Board Certified Orthopaedic Specialist with Orthopaedic and Spine Center in Newport News, VA. His areas of practice specialty include Adult Joint Replacement and Revision and General Orthopaedics.