- Knee bursitis involves inflamed fluid sacs around your knee, causing pain and swelling, often due to friction or pressure.
- Avoiding repetitive kneeling, excessive friction, or direct knee trauma can significantly help prevent various types of knee bursitis.
- Persistent knee pain, swelling, or redness, especially after injury or repetitive activity, warrants medical evaluation for bursitis.
- Certain activities like running, kneeling work, or conditions like osteoarthritis increase your risk of developing knee bursitis.
Table of Contents
Knee bursitis
Knee bursitis is an inflammation of one of the synovial bursae that surround the knee joint. Bursae are small sacs containing synovial fluid that act as cushions between bones, tendons, muscles, and skin, reducing friction during movement. The knee has approximately 12-14 bursae, some of which are particularly prone to inflammation due to their superficial position or the mechanical stresses they undergo.
Table of Contents
- Types of Knee Bursitis
- General Causes
- Symptoms
- Diagnosis
- Treatment
- Physiotherapy and Rehabilitation
- Recovery Times
- Prevention
- Frequently Asked Questions (FAQ)
- Frequently Asked Questions
- Sources and Scientific References
Types of Knee Bursitis
Prepatellar bursitis (housemaid’s knee)
The most common type, involving the bursa located between the skin and the anterior surface of the patella.
- Causes: repeated pressure on the knees (tilers, gardeners, floor layers, religious devotees), direct trauma, infection
- Symptoms: obvious swelling over the patella, pain when kneeling, redness in septic form
- Note: historically called “housemaid’s knee” or “carpenter’s knee”
Infrapatellar bursitis (superficial and deep)
Involves the bursae located below the patellar tendon, between the tendon and the tibial tuberosity (superficial) or between the tendon and the tibia (deep).
- Causes: repeated friction, patellar tendon overload, kneeling position
- Symptoms: swelling and pain below the patella, in the region of the patellar tendon
Pes anserine bursitis
Affects the bursa located on the medial aspect of the tibia, where the tendons of the sartorius, gracilis, and semitendinosus muscles insert.
- Causes: knee osteoarthritis, overload in runners, obesity, genu valgum
- Frequency: very common in overweight women with knee osteoarthritis
- Symptoms: pain on the inner aspect of the knee, 5-7 cm below the joint line
Popliteal bursitis (Baker’s cyst)
Technically an expansion of the gastrocnemius-semimembranosus bursa in the posterior region of the knee.
- Causes: often secondary to intra-articular pathologies (meniscal tears, osteoarthritis, rheumatoid arthritis)
- Symptoms: popliteal swelling, sensation of posterior tension
General Causes
Mechanical causes
- Repeated pressure: frequent kneeling for work or hobbies
- Friction: repetitive movements that stress the bursa (running, cycling)
- Direct trauma: falling on the knees, blow during contact sports
- Overload: sudden increase in sports activity
Infectious causes (septic bursitis)
- Entry of bacteria through wounds, abrasions, or skin punctures
- Staphylococcus aureus responsible in 60-80% of cases
- More common in prepatellar bursitis due to its superficial position
Systemic causes
- Osteoarthritis: pes anserine bursitis is frequently associated with knee osteoarthritis
- Rheumatoid arthritis: chronic inflammation that can involve the bursae
- Gout and pseudogout: crystal deposition in the bursae
- Diabetes: increased risk of septic bursitis
Risk factors
| Factor | Most frequent type of bursitis |
|---|---|
| Kneeling work | Prepatellar |
| Running, jogging | Pes anserine, infrapatellar |
| Knee osteoarthritis | Pes anserine, Baker’s |
| Overweight/obesity | Pes anserine |
| Genu valgum | Pes anserine |
| Contact sports | Prepatellar |
| Rheumatoid arthritis | Baker’s, prepatellar |
Symptoms
Aseptic bursitis
- Localized swelling: fluctuating swelling at the site of the inflamed bursa
- Pain: on pressure and during specific movements
- Functional limitation: difficulty kneeling (prepatellar), pain when running or on stairs (pes anserine)
- Mild local warmth
- Knee flexion may be limited due to tension from the swollen bursa
Septic bursitis
- Marked skin redness
- Intense warmth on palpation
- Severe pain even at rest
- Fever and general malaise
- Possible lymphangitis (red streaks along the leg)
- Wound or skin abrasion in the area
Warning signs:
- Fever > 38°C with a swollen and red knee
- Rapid spread of redness
- Intense pain with inability to move the knee
- Rapid worsening despite rest
Diagnosis
Clinical examination
- Inspection: localization and size of swelling
- Palpation: consistency (fluctuating, tense), warmth, tenderness
- Specific tests: pain on pressure over the pes anserine (pes anserine), patellar ballotment sign
- Assessment of mobility: generally preserved unless limited by swelling
- Complete knee examination: to rule out associated intra-articular pathologies
Fluid aspiration
Crucial in prepatellar bursitis to distinguish septic from aseptic forms:
- Fluid analysis: leukocyte count, crystals, bacterial culture
- Macroscopic appearance: clear (aseptic), turbid/purulent (septic)
Instrumental examinations
- Ultrasound: first instrumental examination, assesses the bursa (size, content, walls), guides eventual aspiration
- X-ray: rules out fractures, highlights calcifications, assesses associated osteoarthritis
- Magnetic resonance imaging: in doubtful cases, assesses associated intra-articular pathologies (especially in Baker’s cyst)
- Blood tests: complete blood count, CRP, ESR, uric acid if systemic cause is suspected
Recommended product
Le bande elastiche sono tra gli strumenti piu’ utilizzati in fisioterapia per il rinforzo del quadricipite.
Bande elastiche per esercizi ginocchio — View on Amazon
(paid link)
Treatment
Conservative treatment (aseptic bursitis)
Rest and protection:
- Avoid the activity or position that caused the bursitis
- Use padded knee pads for those who work on their knees
- Temporarily reduce running (pes anserine bursitis)
Cryotherapy:
- Ice for 15-20 minutes, 3-4 times a day
- Particularly effective in the first 48-72 hours
Compression:
- Light elastic bandage to contain swelling
Medications:
- Topical NSAIDs (diclofenac gel, ketoprofen) as first line
- Oral NSAIDs for short periods if necessary
- Cortisone injection into the bursa: effective, especially in pes anserine bursitis
Aspiration:
- Drainage of fluid from the bursa with a sterile needle, provides immediate relief
- Often associated with corticosteroid injection
Treatment of septic bursitis
- Antibiotic therapy: oral in mild cases, intravenous in severe cases
- Repeated aspirations of infected fluid
- Surgical bursectomy: in cases refractory to medical treatment
Physiotherapy and Rehabilitation
Prepatellar and infrapatellar bursitis
Acute phase (weeks 1-2):
- Cryotherapy post-activity
- Active knee mobilization in a pain-free range
- Isometric quadriceps contractions
- Patellar mobilization
Recovery phase (weeks 2-6):
- Quadriceps strengthening: low-load leg extension, mini-squats, leg press
- Quadriceps and hamstring stretching
- Proprioception exercises: single-leg stance
- Gradual return to activity
Pes anserine bursitis
Phase 1 — Inflammation reduction (weeks 1-3):
- Cryotherapy on the medial aspect of the knee
- Therapeutic ultrasound or laser therapy on the pes anserine
- Stretching of the medial hamstrings (semitendinosus, gracilis)
- Stretching of the hip adductors
- Avoid running and stairs until pain reduces
Phase 2 — Strengthening and biomechanical correction (weeks 3-8):
- Quadriceps strengthening (especially vastus medialis obliquus)
- Gluteal strengthening: hip abduction, glute bridge, clamshell
- Core strengthening to improve knee control during running
- Stretching of the tensor fascia lata and iliotibial band
- Correction of running biomechanics if necessary
Phase 3 — Return to sport (from 2 months):
- Gradual resumption of running (alternate running and walking)
- Progressive increase in volume (10% weekly rule)
- Maintenance of stretching and strengthening as a routine
Baker’s cyst
Treatment focuses on the underlying intra-articular cause:
Recommended product
Una ginocchiera elastica puo’ offrire supporto e propriocezione (capacità di percepire posizione e movimento del corpo) durante l’attivita’ fisica.
Ginocchiera elastica di supporto — View on Amazon
(paid link)
- Treatment of the primary pathology (osteoarthritis, meniscal tear)
- Quadriceps and hamstring strengthening
- Knee mobilization
- The cyst tends to reduce when the underlying cause is managed
Recovery Times
| Type of bursitis | Treatment | Time |
|---|---|---|
| Aseptic prepatellar | Conservative | 2-4 weeks |
| Septic prepatellar | Antibiotics + aspiration | 4-8 weeks |
| Pes anserine | Physiotherapy + injection | 3-6 weeks |
| Infrapatellar | Conservative | 2-4 weeks |
| Baker’s (small cyst) | Treatment of cause | 4-8 weeks |
| Post-bursectomy | Surgical | 6-12 weeks |
Prevention
Mechanical protection
- Padded knee pads are mandatory for those who work on their knees (tilers, gardeners, floor layers)
- Use a soft mat when kneeling
- Protection during contact sports (volleyball, wrestling)
Management of sports load
- Progressive increase in running volume and intensity
- Regular stretching of quadriceps, hamstrings, and adductors
- Balanced muscle strengthening of the entire kinetic chain
- Appropriate footwear with good cushioning
Weight management
- Overweight significantly increases the risk of pes anserine bursitis
- Weight loss reduces mechanical load on the knee bursae
Skin hygiene
- Keep wounds and abrasions on the knees clean and treat them promptly
- Avoid kneeling on dirty surfaces with broken skin
Frequently Asked Questions (FAQ)
Aseptic bursitis is a benign condition that resolves in most cases with conservative treatment. Septic bursitis, however, requires timely treatment with antibiotics. It is important to consult a doctor for a correct diagnosis, especially if fever and marked redness are present.
It is advisable to reduce or temporarily suspend running in the acute phase, when pain is significant. After initial improvement with physiotherapy and biomechanical correction, running can be gradually resumed. Pes anserine bursitis in runners is often linked to training errors or correctable muscle weaknesses.
Swelling resolves in variable times: from a few days after aspiration to several weeks with conservative treatment alone. In prepatellar bursitis, swelling can persist for weeks if the irritating cause is not eliminated. Pes anserine bursitis generally has faster healing times.
Yes, corticosteroid injections are very effective, especially in pes anserine bursitis where the success rate exceeds 80%. Injection into the prepatellar bursa yields good results but with a higher risk of recurrence if the mechanical cause persists. The decision is made by the specialist doctor.
In most cases, no. Baker’s cyst is a “symptom” of an intra-articular problem (osteoarthritis, meniscal tear). By treating the underlying cause, the cyst tends to reduce spontaneously. Surgical intervention is reserved for refractory cases with significant compressive symptoms.
Consistent use of professional padded knee pads is the most important preventive measure. Frequently changing position, taking regular breaks, and using a soft mat when possible further reduces the risk. In case of initial symptoms, apply ice at the end of the day.
Frequently Asked Questions
What are the primary causes of knee bursitis?
Knee bursitis often results from mechanical factors such as repetitive friction, prolonged pressure, or direct trauma to the knee joint. It can also be caused by infectious agents, leading to septic bursitis, or be associated with systemic conditions.
How is knee bursitis typically diagnosed?
Diagnosis of knee bursitis typically involves a clinical examination by a healthcare professional to assess symptoms and physical signs. In some cases, fluid aspiration from the bursa may be performed to rule out infection, and instrumental examinations like ultrasound or MRI might be used for further evaluation.
What role does a physical therapist play in the treatment of knee bursitis?
A physical therapist plays a crucial role in the conservative management of knee bursitis, particularly for aseptic types. They can guide individuals through exercises to improve flexibility and strength, recommend activity modifications, and provide modalities to reduce pain and inflammation.
What are the key strategies for preventing knee bursitis?
Prevention of knee bursitis involves avoiding repetitive kneeling, excessive friction, and direct trauma to the knee. Strategies include using mechanical protection, managing sports load appropriately, maintaining a healthy weight, and practicing good skin hygiene.
For a broader overview of related conditions, see our our comprehensive knee pain guide.
Sources and Scientific References
- Williams BS et al. (2009). Greater trochanteric pain syndrome: a review of anatomy, diagnosis and treatment. Anesth Analg. 108:1662-70. DOI | PubMed
- Helfenstein M Jr et al. (2010). Anserine syndrome. Rev Bras Reumatol. 50:313-27. PubMed
- Hong E et al. (2014). Evaluating anterior knee pain. Med Clin North Am. 98:697-717, xi. DOI | PubMed
- Gristina AG et al. (1974). Arthritic joints. Am Fam Physician. 10:131-8. PubMed
- Del Castillo-González F et al. (2016). Ultrasound-guided percutaneous lavage of calcific bursitis of the medial collateral ligament of the knee: a case report and review of the literature. Skeletal Radiol. 45:1419-23. DOI | PubMed