Prepatellar Bursitis

Clinically Relevant Anatomy

The kneecap is a triangular shaped bone in front of the knee. It moves up and down in the groove of the femur when you bend en straighten your knee. The patellar tendon is a thick structure that connects the bottom of the patella with the tibia. The upper part of the patella is connected to the quadriceps, who provokes the knee extension and moves the patella upwards.
A bursa is a small fluid filled sac that decreases friction between two tissues. This can be between skin an a tendon or between bony structures. There are a lot of bursae around the knee. For example the semimembranosus bursa, the subsartorial bursa, the deep infrapatellar bursa, the subcutaneous infrapatellar bursa, the suprapatellar bursa and the prepatellar bursa.
The prepatellar bursitis is the most commonly injured bursa.

Epidemiology/Etiology

Prepatellar bursitis is a also called housemaid knee or carpenters knee. This is because prepatellar bursitis is often caused by sitting on the knees for a long time.
The prepatellar bursitis is caused due to a lot a friction between the skin and the patella. This results in swelling and inflammation of the bursa.
A second cause of a prepatellar bursitis is a blow on the knee. This damages blood vessels in the knee which results in inflammation and swelling of the bursa.
The last cause of a prepatellar bursitis can be a wound on the front of the knee or kneecap. The bacteria can enter the bursa due to the wound and can infect the bursa.
Chronic prepatellar bursitis is caused by repeated blows or friction on the knee.

Characteristics/Clinical Presentation

Prepatellar bursitis can be recognized by swelling of the knee, especially on the kneecap. The bursa can occur an hour after a blow and can build up over weeks when there is daily friction on the knee. The knee can also feel warm and the knee will feel painful while bending and stretching.

Differential Diagnosis

Medial Collateral and Lateral Collateral Ligament Injury, Osteoarthritis, Pes Anserinus ,Bursitis ,Posterior Cruciate Ligament Injury, Rheumatoid Arthritis, Patellar tendon rupture , Chondromalacia patella ,Patellofemoral pain

Diagnostic Procedures

To make sure that the injury is a prepatellar bursitis ,that the patella isn’t broken or that there aren’t any ruptures in the tendons in and around the knee, an x-ray, MRI and CAT-scan can be taken. A arthogram, aspiration or blood test can be used to rule out other injuries.

Medical Management

If the prepatellar bursitis is persistent, anti-inflammatory medication is often used.
If the anti-inflammatory medication has no effect, an injection of cortisone into the affected area is possible.
The bursa can also be drained by a punction. The fluid can then be analyzed for infection.
If none of the treatmants of bursitis works, surgery may be used to remove the prepatellar bursitis. Over time a new bursa will grow back.

Physical Therapy Management

The R.I.C.E method is the most common used treatment for prepatellar bursitis. Another treatment is stretching the quadriceps. It reduces the friction between the skin and the patella tendon. There is less friction when the patella tendon is more flexible.
Ultrasound on the prepatellar bursitis is a treatment that’s not often used. Click on ‘therapeutic ultrasound’ or ‘ultrasound therapy’ for more information about this technique.

Prevention

Avoid injury or an overload of your muscles. When you play sports, an appropriate warm-up and cool down is necassary.
See that the flexibility of the knee, the strength and edurance of the leg muscles stay optimal.
Prevent blows on the kneecap.
Use proper equipment, including kneepads when you spent of lot of your time one your knees.

Recent related Research(From PubMed)

Endoscopic treatment of prepatellar bursitis.

Closed bursotomy for chronic prepatellar bursitis: a self-described case.

Prepatellar septic bursitis: a case report of skin necrosis associated with open bursectomy.

Chronic posttraumatic bursitis of the medial collateral ligament: surgical treatment in 2 high-level professional athletes.

Images in clinical medicine. Infrapatellar [corrected] bursitis.

Painful suprapatellar swelling: diagnosis and discussion.

Patellar osteomyelitis presenting as prepatellar bursitis.

Massive prepatellar bursitis in cerebral palsy.

From Web of knowledge
Infectious olecranon and patellar bursitis: short-course adjuvant antibiotic therapy is not a risk factor for recurrence in adult hospitalized patients
http://apps.isiknowledge.com.ezproxy.vub.ac.be:2048/full_record.do?product=UA&search_mode=GeneralSearch&qid=1&SID=S24LCBd8ahiI4bB3hJ7&page=1&doc=2&colname=WOS

Cloxacillin-based therapy in severe septic bursitis: Retrospective study of 82 cases
http://apps.isiknowledge.com.ezproxy.vub.ac.be:2048/full_record.do?product=UA&search_mode=GeneralSearch&qid=1&SID=S24LCBd8ahiI4bB3hJ7&page=1&doc=3&colname=WOS

Ossifying Bursitis Praepatellaris of the Knee Joint
http://apps.isiknowledge.com.ezproxy.vub.ac.be:2048/full_record.do?product=UA&search_mode=GeneralSearch&qid=1&SID=S24LCBd8ahiI4bB3hJ7&page=1&doc=4&colname=WOS

Hemorrhagic prepatellar bursitis: a rare case report and review of the literature
http://apps.isiknowledge.com.ezproxy.vub.ac.be:2048/full_record.do?product=UA&search_mode=GeneralSearch&qid=1&SID=S24LCBd8ahiI4bB3hJ7&page=1&doc=8&colname=WOS

Prepatellar Septic Bursitis: A Case Report of Skin Necrosis Associated With Open Bursectomy
http://apps.isiknowledge.com.ezproxy.vub.ac.be:2048/full_record.do?product=UA&search_mode=GeneralSearch&qid=1&SID=S24LCBd8ahiI4bB3hJ7&page=1&doc=7&colname=WOS

Olecranon and prepatellar bursitis - Treating acute, chronic, and inflamed
http://apps.isiknowledge.com.ezproxy.vub.ac.be:2048/full_record.do?product=UA&search_mode=GeneralSearch&qid=1&SID=S24LCBd8ahiI4bB3hJ7&page=1&doc=30&colname=WOS

References .

Reid, d.c, Injury Assesment and Rehabilitation, New York, 1992, p 416-438, Cuchil Levington Inc(C)

Goroll, Allan H.; Mulley, Albert G.. Primary Care Medicine: Office Evaluation and Management of the Adult Patient. Lippincott Williams & Wilkins. p. 1058. ISBN 9-7807-8177-5137

Koopman, William, et al., eds. Clinical Primer of Rheumatology. Philadelphia: Lippincott Williams & Wilkins, 2003.

Babak Shadgan, Bernard J. Feldman, and Siavash Jafari, Wrestling Injuries During the 2008 Beijing Olympic Games, Am J Sports Med September 2010 38 1870-1876; published online before print June 3, 2010, doi:10.1177/0363546510369291
Kelley's Textbook of Rheumatology, W B Saunders Co, edited by Shaun Ruddy, et al., 2000.

Allen KL, Fried GW; Prepatellar Bursitis. eMedicine. Article dated 2009.
Rennie, WJ, Saifuddin, A. Pes anserine bursitis: incidence in symptomatic knees and clinical presentation. Skeletal Radiol 2005; 34:395.