- Anatomy:
- four bursae around knee are susecptible to and inflammatory response from
direct or indirect trauma;
- prepatellar bursae is most commonly affected area (housemaids knee);
- may show significant degree of swelling;
- two bursae are infrequently affected;
- infrapatellar and deep patellar bursae;
- when dx is in must also consider fat pad impingment syndrome versus
bursitis;
- fourth bursa:
- deep to pes arserinus insertion;
- rarely affected w/ bursitis (dx of exclusion)
- first r/o chondral frx, meniscal tear, or osteonecrosis;
- Infrapatellar bursitis:
- small deep subpatellar or infrapatellar bursa is located between
tuberosity of tibia & patellar tendon
and is separated from synovium of the knee by a
pad of fat;
- Prepatellar Bursitis:
- traumatic prepatellar bursitis may be caused by acute injury such as fall
directly on the patella or by
recurrent minor injuries, such as those that
produce "housemaid's" knee;
- pyogenic prepatellar bursitis is common, especially in children;
- when bursae is large, swelling may be so pronounced that dx of
pyogenic arthritis of knee joint
may be mistakenly
made;
- this mistake must be avoided because if the knee joint is opened
pyogenic arthritis will develop;
- on other hand, if correct dx is made & bursa is drained properly,
pyogenic arthritis is prevented;
- Management of Bursitis:
- aspiration and injection of an appropriate drug;
- traumatic bursitis will often respond favorably to aspiration & injection
of an appropriate steroid
preparation;
- incision and drainage when an acute suppurative bursitis fails to respond
to non surgical treatment;
- excision of chronically infected and thickened bursae
- removal of underlying bony promineces;
- Technique of Drainage:
- approach of bursa thru two longitudinal incisions, one medial and one
lateral, or thru a single
transverse incision;
- open bursa, evacuate its contents, and pack it loosely w/ petrolatum gauze
or close it loosely over a
drain as seems appropriate;
- compression dressing should be applied after aspiration;
- After Treatment:
- because cellulitis is always present, the extremity is immobilized in\
posterior splint, and appropriate
antibiotics are given;
- if gauze has been used to pack bursa, it is changed at least qod;
- even w/ good drainage, sinuses often persist on one or both sides of
joint;
- joint must not be invaded since bursa does not communicate w/ it;
- pt should be informed when first seen that complete excision of of
bursa may be necessary if
healing
fails to occur after simple drainage;
- when walls of bursa are thickened from chronic inflammation, resecting
entire bursa is usally easy,
but when lesion is acute & effusion is serous,
excising the bursa completely may be impossible,
yet enough may be excised to relieve symptoms;
- occassionally fibrosis or synovial thickening w/ painful nodules
requires excision of the bursae;