Prepatellar bursa is a fluid-filled sac located between the patella and the overlying skin. Prolonged repetitive trauma to the knee from specific sports activities or occupations requiring kneeling on hard surface causes chronic inflammation of the bursa leading to prepatellar bursitis. It is also known as housemaid's knee due to persistent kneeling as occurs in housemaids.
Patients with Prepatellar bursitis typically present with swelling and pain in the anterior aspect of the knee . Other common symptoms include erythema of the skin over the knee, difficulty in moving the knee and kneeling on the affected side.
Typically, patients present with a history of overuse of knee, regular high impact sports, history of blunt trauma or fall on the knee or at-risk occupation. Patients with prepatellar bursitis following an acute knee trauma or injury, typically remain symptomatic for up to 10 days.
On physical examination, tenderness of the patella is present with erythema of the skin over the knee and crepitations heard on moving the knee. There is also a notable reduction in range of motion about the knee joint. One important finding on physical examination in prepatellar bursitis is a particular difficulty in flexing the knee as this movement further tenses the bursa, hence aggravating the pain. Noteworthy is the fact that in prepatellar bursitis occuring without an underlying arthritis, the knee joint is without any pathology.
Although laboratory studies are not necessary to make a diagnosis of prepatellar bursitis, they are indicated to rule out other possible differentials. Imaging studies such as an MRI and plain radiographs can be ordered, especially, if other conditions such as fractures or dislocation are suspected.
Being a common site for infection, fluid specimen from the bursa should be aspirated and sent for laboratory studies. The bursal fluid should be analysed for WBC count and differentials, glucose, lactate, crystals, protein, gram stain and culture. In prepatellar bursitis, there's usually elevated protein and lactate, with decreased glucose levels.
MRI and CT scans are usually ordered in severe cases, which are resistant to medical or conservative treatment  . In prepatellar bursitis, MRI shows a lesion with fluid-signal-intensity which is oval in shape between the patella and subcutaneous tissue. Ultrasonography may also be indicated for knee synovial fluid evaluation. Plain radiographs of the knee are necessary to exclude other pathologies such as fractures.
Conservative management is the mainstay of treatment of prepatellar bursitis. It involves rest of the knee, physical therapy, use of nonsteroidal anti inflammatory drugs (NSAIDs) for pain relief, application of ice packs and compression stockings and surgical treatment in non healing and difficult cases.
Physical therapy helps to strengthen the quadricpep and hamstring muscles and increases their flexibility.
An occupational therapist is also a part of the multidisciplinary treatment approach. Prepatellar bursitis occurring secondary to overuse is managed by occupational therapy that addresses and adjusts the activities of the patient and thus helps further worsening. Therapy emphasizes on use of knee pads, avoidance of kneeling and other activities that worsen symptoms, for example, athletes and other participants of high impact sports are instructed to avoid sports until there's satisfactory resolution of the symptoms.
The NSAIDs are used in mild to moderate pain and usually prescribed for 10 to 14 days. Ice packs can be applied several times daily for over 10 minutes each time. Cold compresses help to reduce the inflammation of the bursa. Intralesional injection of corticosteroid should only be considered after septic prepatellar bursitis has been excluded.
Generally, the etiology of the inflammation and the morphological features in the bursa determine the course of treatment adopted in prepatellar bursitis . Mainstay of the treatment is non-operative only.
Surgery is not necessary in many cases, but indicated for unresolved or recurrent prepatellar bursitis . New surgical modalities include arthroscopic or endoscopic bursectomy have shown significant success rates with lesser complications as compared to open excision  . Irrigation and aspiration of the bursa can be done along with suitable antibiotic . If the symptoms of septic bursitis doesn't improve in 36 to 48 hours, incision and drainage is recommended. It can also be used in acute suppurative bursitis  .
Prepatellar bursitis is not associated with significant mortality. It results in significant pain and limitation in the function of the knee which are the main causes of morbidity seen with this condition . Septic prepatellar bursitis is associated with high morbidity and significant complications in cases of severe secondary complications and absence of timely diagnosis. In all cases of Prepatellar bursitis, prognosis is very good with the appropriate treatment.
The prepatellar bursa is located superficial to the patella between the overlying subcutaneous tissue and the patella. High impact sports such as hockey, soccer, and wrestling, basketball, and ice hockey predispose the bursa to repetitive minor trauma, which also occurs with repetitive kneeling as notable in certain jobs such as carpet laying, mining, roofing, gardening and in housemaids, hence the monicker " housemaid's knee".
The high impact sports above mentioned predispose the participants to frequent impact and falls on the knee. Such repetitive trauma to the bursa from overuse eventually leads to a chronic inflammation of the bursa known as prepatella bursitis. Infections and other inflammatory joint diseases such as gout, tuberculosis, syphilis, and rheumatoid arthritis open link can also cause prepatella bursitis. Acute injury to the patella or knee can also lead to prepatella bursitis .
Bacterial infection of the prepatella bursa occurs in the presence of a break in the skin over the patella. The superficial location of the bursa predisposes it to easy bacterial entry. The predisposing skin breaks could be as a result of insect bites, puncture wounds, or injuries. Bacteria gain entry into the bursa through the skin break causing prepatella bursitis. Staphylococcus aureus is the most common cause of septic prepatella bursitis. Septic prepatella bursitis is, however, more common in children and in immunocompromised subjects.
Prepatellar bursitis is more common among men than women. Although, prepatellar bursitis can occur in all age groups, it is the septic type that is more common in children. Septic bursitis is also common in a setting of immunosuppression.
The prepatellar bursa is a flat round structure lined with the synovium and serves to reduce the friction at knee joint enabling maximal range of motion across the joint. It lies superficial suggesting its absence at the time of birth and separating the patella from the overlying tendon and skin. The prepatellar bursa develops in the first few months of life as an adaptive tissue in response to exposure to external forces overtime.
Prepatellar bursitis as noted earlier, comprises inflammatory changes in the bursa sequel to prolonged repetitive trauma from high impact sports or certain at-risk jobs such as carpet laying, homemaking, and mining.
Since the cause of prepatellar bursitis is repetitive or acute trauma to the bursa, the key to preventing the condition is limiting such repetitive wear and tear. The following recommendations help prevent the development of prepatellar bursitis.
Prepatellar bursitis often occurs in individuals who participate in high-impact sports such as soccer, hockey, or baseball or those with strenuous job requiring frequent kneeling such as housemaids.
These predispose the individuals to repetitive trauma to the prepatella bursa which is located superficial to the patella.
The prepatellar bursa, due to its superficial position, is also at risk of bacterial infection leading to septic prepatellar bursitis which has significant sequelae if untreated.
Prepatellar bursitis typically presents with knee pain and swelling, particularly difficulty in flexing the knee. Warmth and redness of the skin over the patella are the common features of this condition.
Treatment of prepatellar bursitis is mainly conservative with lifestyle modifications and non-steroidal anti-inflammatory drugs, cold compresses, and using compressive stockings. Surgery is indicated in recalcitrant cases and in chronic cases of septic prepatellar bursitis.
A bursa is a fluid-containing sac located in many parts of the body between bones or joints and the overlying skin serving mainly to cushion effects of external pressure on the bone. The prepatellar bursa is, however, located between the patella or the kneecap and the overlying skin where it serves mainly to cushion the patella against external forces. Overuse of the knee as in frequent kneeling notable in certain jobs such as mining, carpet laying, gardening, and in housemaids cause repetitive minor trauma to the bursa causing inflammatory changes called prepatellar bursitis.
Prepatellar bursitis is caused by repetitive trauma to the kneecap or the bursa from overuse and regular participation in high impact sports such as wrestling, soccer, hockey, and at-risk occupations such as mining, gardening, and carpet laying. Direct injuries to the knee also cause prepatellar bursitis. Bacteria can also gain entry into the bursa through skin breaks over the knee created by injuries, insect bites or cuts. This, in turn, causes an infectious form of prepatellar bursitis called septic bursitis.
Anyone can get prepatellar bursitis, although it is more commonly seen in men than women. The infectious form is more common among children and individuals with suppressed immune system.
Pain over the front of the knee, which is worsened by movement, and swelling are the hallmark of prepatellar bursitis. Other typical symptoms include difficulty in moving the knee, redness of the skin over the knee and clicking sounds on moving the knee. These features, in the setting of at least one of the predisposing factors, suggest the diagnosis of prepatellar bursitis. Infectious prepatellar bursitis may present with warmth and redness of the skin over the patella, and fever.
If your doctor suspects prepatellar bursitis, they would order certain investigations, including drawing some fluid from the bursa with a syringe. The fluid is thereafter analyzed for certain chemicals and white blood cells. Your doctor may also culture and stain the aspirated fluid to determine the particular type of bacteria implicated in cases of septic prepatellar bursitis. Imaging studies such as MRI , X-rays, and CT scans of the knee may be ordered, although these are required in severe, unresolved cases and to exclude other possible diseases.
Prepatellar bursitis is treated by concerted efforts of different specialists including, the orthopaedic surgeon, physiotherapist, and the occupational therapist. This condition is successfully treated without surgery. Immobilization of the knee, drawing or removal of the excess fluid in the bursa, compression dressings, nonsteroidal anti-inflammatory pain relievers, and antibiotics comprise this non-surgical treatment. The pain relievers are usually prescribed for use for up to two weeks . Antibiotics are prescribed for patients with the infective form of prepatellar bursitis.
Surgical removal of the bursa is indicated in severe cases and in cases which remain unresolved after non-surgical treatment. This removal of the bursa surgically is called bursectomy. Surgery may, however, be as simple as drawing excess fluid out of the bursa., however, most times, this may not resolve the symptoms. Physiotherapy is planned to strengthen the muscles holding the kneecap in place. Athletes would also be advised to restrain from high impact sports.
Home remedies for prepatellar bursitis include application of ice packs on the affected knee up to five times daily for 20 minutes each time, avoidance of activities which worsen the pain, and elevation of the affected knee especially when lying down.