Inflammation of the Fluid-Filled Cushions Around the Knee
Bursae are small, fluid-filled sacs that cushion and reduce friction between bones, tendons, and skin around the knee. When a bursa becomes irritated or inflamed, most often the prepatellar bursa in front of the kneecap or the pes anserine bursa on the inner knee, it can cause localized swelling and pain.
Causes
Knee bursitis has several common causes:
Repetitive kneeling or direct pressure on the front of the knee.
Direct trauma or a fall onto the knee.
Overuse from repetitive bending or running.
Infection of the bursa.
Underlying inflammatory conditions like gout or rheumatoid arthritis.
Symptoms
Typical symptoms include:
Swelling, often a noticeable soft lump, over the front or inner side of the knee.
Warmth and tenderness over the swollen area.
Pain with kneeling, bending, or direct pressure.
Stiffness with prolonged bending of the knee.
Seek prompt medical care if: The swelling is accompanied by fever, spreading redness, significant warmth, or worsening pain, as these can be signs of an infected bursa that needs urgent treatment. Also seek care if you can't bear weight after an injury, or for new calf pain and swelling, which can signal a blood clot.
Imaging Studies to Consider
Imaging helps confirm the diagnosis and guide treatment:
Ultrasound is the best test to identify fluid within the bursa and guide aspiration or injection.
X-ray is used to rule out an underlying bone pathology or foreign body.
MRI is reserved for cases where the diagnosis is unclear or deeper soft-tissue structures need evaluation.
Physical Therapy, Home Exercise & Other Conservative Techniques
Activity modification and a structured strengthening program are usually tried first:
Physical Therapy
Activity modification education specific to which bursa is affected.
Quadriceps strengthening to improve knee mechanics.
Flexibility exercises for the hamstrings and IT band.
Home Exercise Program
Quad sets and straight leg raises.
Hamstring and IT band stretching.
Other Studied Techniques
Ice to reduce inflammation.
Knee pads or padding for prepatellar bursitis.
Interventional Treatment Options
Most bursitis responds well to conservative, non-opioid interventional care:
Ultrasound-guided aspiration: Removing excess fluid from the bursa relieves pressure and pain. This fluid can also be tested if infection is suspected.
Cortisone injection: Injected into a non-infected bursa to reduce inflammation and swelling.
Activity modification and padding: Kneepads and avoiding prolonged kneeling help prevent recurrence.
Platelet-rich plasma (PRP): Research specific to knee bursitis is still limited, so PRP isn't a first-line treatment. It can be a reasonable option for recurrent bursitis.
Acupuncture: A technique that may help with pain in and around the knee, though evidence specific to bursitis is limited.
Neuromodulation: Spinal Cord & Peripheral Nerve Stimulation
Neuromodulation is not typically needed for straightforward bursitis, which usually resolves with the treatments above. It may be considered only in rare cases of chronic, refractory localized knee pain:
Peripheral nerve stimulation (PNS): May be considered for persistent localized knee pain that continues despite standard treatment, particularly if it overlaps with chronic knee osteoarthritis.
How Strong Is the Evidence?
A summary of the evidence supporting key treatments for knee bursitis:
How to read this: Strong means consistent results from multiple high-quality studies. Moderate means generally favorable results with some limitations. Mixed or early means results so far are inconsistent or still emerging. Limited means few or lower-quality studies; these options can still be considered in select cases following a discussion with your healthcare provider.
Ultrasound-guided aspiration: Limited evidence.
Corticosteroid injection into bursa: Moderate evidence.
Acupuncture: Limited evidence.
Platelet-rich plasma (PRP): Limited evidence; can be considered in select cases.
Evidence reviewed November 2026. These ratings summarize published research and major medical society guidelines available at that time. Research continues to evolve, and we will go over the most current evidence for your situation at your visit.
Pain Psychology Techniques
For pain that becomes persistent, pain psychology techniques can help:
Relaxation training and diaphragmatic breathing reduces muscle tension around the joint.
Graded activity pacing helps return to kneeling-related activities gradually.
Cognitive behavioral therapy (CBT) for pain is useful if bursitis becomes a recurring, chronic issue.
Non-Opioid Medication Options
Non-opioid medications are typically effective for bursitis pain:
Anti-inflammatory options
NSAIDs like ibuprofen or naproxen can reduce inflammation and swelling.
Topical NSAID gel is applied directly over the bursa with minimal whole-body absorption.
Acetaminophen for additional pain relief.
If infection is present
Antibiotics are required for septic bursitis and should be started promptly. This is a medical, not pain-management, treatment and takes priority over injections.
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Talk With Us About Your Options
Call 650-507-4113 or send us a message to schedule a consultation at our Daly City, Los Altos, or Stockton office. We will review what may be causing your pain and walk through the risks, benefits, and alternatives of each option with you.
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This information is provided for general patient education and does not replace individualized medical advice. Please discuss your specific symptoms, diagnosis, and treatment options with your pain management physician.
