Suprapatellar bursitis occurs above the patella
- suprapatellar bursa extends superiorly from beneath the patella under the quadriceps muscle
- vulnerable to injury from both acute trauma and repeated microtrauma
- acute injuries are from direct trauma to the bursa via falls directly onto the knee
- microtrauma may occur from overuse injuries, or from jobs that result in repeated pressure on the knees, such as carpet laying
- infection may result in suprapatellar bursitis
Factors that can contribute to knee bursitis include:
- direct trauma or blow to the knee
- frequent falls on the knee
- repeated pressure on the knee (eg from activities that entail prolonged periods of kneeling) or repetitive minor trauma to the knee
- arthritis of the knee can be associated wth bursitis e.g. gout, rheumatoid arthritis, and osteoarthritis.
Clinical features include:
- suprapetallar swelling - may be clinically difficult to differentiate from prepatellar swelling
- may be limited motion of the knee
- erythema and warmth may occur in septic bursitis and secondary to gout
- knee pain may be present
- in bursitis swelling is within the bursa, not the knee joint
- is an important difference between fluid accumulation within the bursa and within the knee joint
- symptoms of knee bursitis are generally aggravated by kneeling, crouching, repetitive bending or squatting and symptoms can be relieved when sitting still
Diagnosis:
- often clinically
- an MRI or Ultrasound are the most effective for a definitive diagnosis
- blood tests e.g. FBC, CRP, uric acid - may help identify other aetiological factors
Management:
- management depends on whether septic or non-septic bursitis
- conservative management - general measures
- rest, ice, and reduced activity
- consider analgesia such as paracetamol or a nonsteroidal anti-inflammatory drug such as ibuprofen
- avoid trauma to the knees - however if this is not possible, suggest protective knee pads
Non-septic bursitis
- medical treatment
- aspiration of the bursa and injection of a corticosteroid - only indicated if non-septic bursitis
- surgical treatment
- may be indicated if chronic or recurrent
- surgical options include:
- arthroscopic bursectomy
- open bursectomy
Septic bursitis
- septic bursitis is usually successfully managed non-operatively with rest, compression, immobilisation, aspiration and antibiotics (1)
- if septic bursitis is suspected:
- treat empirically with an oral antibiotic that covers staphylococcal and streptococcal species until culture results are known
- adult doses
- flucloxacillin (500 mg four times a day) is the preferred antibiotic. Erythromycin (500 mg four times a day) may be used if the person is allergic to penicillin, or clarithromycin (500 mg twice a day) if erythromycin is poorly tolerated
- if patient is immunocompromised people then seek specialist advice
- incision and drainage of the bursa may be indicated if there has not been significant improvement in the condition after 36-48 hours
- regular review is required to guide management