Prepatellar Bursitis

Lower Limb

Overview

Prepatellar bursitis is inflammation of the fluid-filled bursa located anterior to the patella, commonly resulting from repetitive kneeling, direct trauma, or overuse. It presents with localized anterior knee swelling, pain, and functional limitation, particularly during weight-bearing activities. The condition ranges from acute inflammatory responses to chronic degenerative changes depending on etiology and duration.

Pathophysiology

The prepatellar bursa is a synovial-lined sac that normally contains small amounts of lubricating fluid to reduce friction between the skin and patella during movement. Repetitive friction, direct compression (housemaid's knee from kneeling), or acute trauma causes increased fluid production and inflammatory cell infiltration, leading to bursal swelling, pain, and restricted range of motion. Chronic cases may develop fibrosis or calcification, and secondary infection (septic bursitis) can occur through skin abrasions.

Patient Education

Avoiding prolonged kneeling and using knee pads when necessary, combined with regular ice application and gentle activity modification, helps reduce inflammation and prevent recurrence of prepatellar bursitis.

Typical Presentation

Site

Anterior knee, directly over the patella and patellar tendon; localized to the superficial prepatellar space

Quality

Dull, aching pain with localized tenderness; described as pressure-like or throbbing when inflamed

Intensity

Mild to moderate pain (4-6/10), often worse with direct palpation or pressure; can be severe (7-8/10) in acute traumatic cases

Aggravating

Kneeling, crawling, sustained weight-bearing on flexed knees, direct pressure over anterior knee, prolonged sitting with knee flexion, running or jumping

Relieving

Rest, ice application, elevation, anti-inflammatory medication, knee extension, avoiding kneeling, compression with knee sleeve

Associated

Localized swelling and prominence anterior to patella, warmth and erythema in acute inflammatory cases, limited knee flexion range, protective muscle guarding, possible skin abrasion or callus formation in chronic cases

Orthopaedic Tests

Test descriptions are written with AI assistance from standard clinical texts. Where a test lists Sources, its description has been checked against them; those sources are independent and do not endorse OsteoKit. Accuracy figures and grades (A–D) appear only when checked against the published study; tests without one are marked “No accuracy study”.

Further reading: full test procedures are described in standard clinical examination texts, e.g. Magee & Manske, Orthopedic Physical Assessment (7th ed.), and Cook & Hegedus, Orthopedic Physical Examination Tests: An Evidence-Based Approach (2nd ed.).

No accuracy study

Prepatellar Bursa Palpation

Procedure

Patient supine, knee straight. Inspect the front of the kneecap for swelling and redness, then palpate over the front of the patella for a soft, fluid swelling, warmth and tenderness. Compare with the other knee.

Positive Finding

A soft, fluctuant swelling sitting on the front of the kneecap, separate from the joint.

Interpretation

Supports prepatellar bursitis. The swelling is outside the joint, so the patella stays palpable beneath it and there is no joint effusion. Redness, heat, a break in the skin or fever suggest septic bursitis, which needs same-day medical assessment. Note: this is a clinical/palpatory sign without established diagnostic-accuracy data; bursitis is diagnosed clinically, with ultrasound as an adjunct. Any imaging figures previously shown were not traceable to a primary diagnostic-accuracy source.

Sources

No accuracy study

Knee Flexion ROM Assessment

Procedure

Patient supine. Bend the knee actively and then passively as far as comfortable, and compare with the other side.

Positive Finding

Pain over the front of the knee at end of flexion, as the skin tightens over the bursa.

Interpretation

In bursitis, knee movement is usually near full, with discomfort only at end of flexion. Marked loss of movement or a large joint effusion points to a problem inside the joint, including infection, and needs further assessment.

Sources

No accuracy study

Kneeling Test (Bursa Compression)

Procedure

Ask about pain on kneeling, or ask the patient to kneel briefly on a padded surface if they can.

Positive Finding

Pain over the front of the kneecap when kneeling.

Interpretation

Pain on kneeling fits prepatellar bursitis, and repeated kneeling is the usual cause. It also occurs with patellofemoral and patellar tendon problems, so use it with palpation. Not a validated test.

Further reading

No accuracy study

Bursa Aspiration (Diagnostic/Therapeutic)

Procedure

Performed by a doctor under sterile conditions when infection or crystal disease is suspected: fluid is drawn from the bursa and sent for cell count, Gram stain, culture and crystal analysis.

Positive Finding

Cloudy fluid with many white cells or organisms (septic), crystals (gout or pseudogout), or clear or bloody fluid (traumatic or irritant).

Interpretation

Aspiration is the way to confirm or exclude septic bursitis and crystal disease, which changes treatment. It is not needed for every bursitis.

Sources

No accuracy study

Ultrasound Imaging

Procedure

Arranged by the treating doctor or performed by a trained sonographer: ultrasound of the front of the knee.

Positive Finding

Fluid within the prepatellar bursa, with or without a thickened wall.

Interpretation

Confirms fluid in the bursa and shows that the joint is not involved. It cannot tell a septic from a non-septic bursitis; aspiration does that. Note: this is a clinical/palpatory sign without established diagnostic-accuracy data; bursitis is diagnosed clinically, with ultrasound as an adjunct. Any imaging figures previously shown were not traceable to a primary diagnostic-accuracy source.

Sources

No accuracy study

Anterior Knee Swelling Assessment (Girth Measurement)

Procedure

Measure the circumference of both knees at the mid-patella with a tape measure, using the same landmark each time.

Positive Finding

A larger measurement on the affected side.

Interpretation

Useful to track swelling over time, not to diagnose. Girth cannot separate bursal swelling from a joint effusion; use palpation and the effusion tests for that.

Further reading

⚠ Red Flags

  • •Signs of septic bursitis: systemic fever, rapidly worsening swelling, warmth, severe pain at rest, inability to bear weight
  • •Severe trauma with possible fracture: severe pain, deformity, inability to move knee
  • •Signs of cellulitis or skin infection: spreading erythema, lymphangitis, systemic illness
  • •Significant knee effusion with signs of underlying joint pathology: pain on passive movement, instability, mechanical symptoms
  • •Unilateral swelling with unilateral calf swelling suggesting deep vein thrombosis

⚡ Yellow Flags

  • •Occupational necessity for kneeling without adequate protective equipment suggesting workplace safety concerns
  • •Psychosocial stress or catastrophizing about swelling contributing to pain amplification
  • •Over-reliance on analgesic medication without activity modification
  • •Secondary gain from symptom presentation (e.g., work avoidance)
  • •Expectation of rapid resolution without understanding need for activity modification
  • •Fear-avoidance behavior leading to deconditioning and prolonged disability

Osteopathic Techniques

Most acute cases settle with rest, ice, activity changes, NSAIDs and, if needed, aspiration.

Safety: Infection is the main complication. Tell septic from non-septic bursitis early, as septic bursitis needs antibiotics; cellulitis can look similar.

Region

Tibiofemoral and patellofemoral joints

Technique

Articulation, knee (tibiofemoral and patellofemoral)No trials found

Rationale

Gentle, rhythmic glides of the knee and kneecap within their range to ease pain and stiffness.

How it's done, cautions & evidence

How it's done

Passive, low-velocity glides of the knee within its range, with no thrust: distraction and front-to-back glides of the tibia on the femur, and glides of the kneecap in each direction, usually 2–3 oscillations a second for 1–2 minutes. A Mulligan variant holds a sustained glide of the tibia while the patient actively bends and straightens the knee.

Cautions

In knee osteoarthritis trials, no serious adverse events were reported with manual therapy.

Evidence in Prepatellar Bursitis

Searched 24 Oct 2026: no trials of knee mobilisation in prepatellar bursitis.

Region

Quadriceps (rectus femoris)

Technique

Muscle energy, hip and thigh musclesNo trials found

Rationale

Low-force, patient-powered stretch for tight hip and thigh muscles.

How it's done, cautions & evidence

How it's done

The muscle (for example the hamstrings, adductors or rectus femoris) is taken to its barrier. The patient pushes gently, at about 10–20% effort, against resistance for 5–10 seconds, relaxes for 3–5 seconds, and the new barrier is taken up.

Cautions

Not used with an acute fracture, a joint infection or a bone malignancy; take care with severe osteoporosis or after surgery that limits muscle contraction. Use the least force needed: too much can tear a muscle or pull off a tendon, especially in older patients.

Evidence in Prepatellar Bursitis

Searched 24 Oct 2026: no trials of quadriceps muscle energy technique in prepatellar bursitis.

Region

Quadriceps and the tissues around the knee

Technique

Soft tissue, knee and quadricepsNo trials found

Rationale

Hands-on work to the quadriceps and the tissues around the knee to ease tension and pain.

How it's done & evidence

How it's done

Hands-on kneading, stroking and sustained pressure to the quadriceps, the patellar and quadriceps tendons, the iliotibial band near the knee and the tissues around the joint. Transverse friction massage across a tendon is one form. In trials it was given alongside exercise.

Evidence in Prepatellar Bursitis

Searched 24 Oct 2026: no trials of thigh soft tissue technique in prepatellar bursitis.

Rehabilitation Exercises

Supine Knee Flexion-Extension Glides

Range of MotionBeginner

Standing Quadriceps Stretch

StretchingBeginner

Supine Figure-Four Hip Flexor and Quadriceps Stretch

StretchingBeginner

Supine Quadriceps Sets (Isometric)

StrengtheningBeginner

Short-Arc Quadriceps Strengthening with Towel Roll

StrengtheningBeginner

Sitting Vastus Medialis Obliquus Activation with Hip Adduction

StrengtheningBeginner

Supine Bridge with Glute Activation

StrengtheningIntermediate

Single-Leg Stance with Knee Extension Hold

StrengtheningIntermediate

Prone Lying Hip Flexor and Quadriceps Release

PosturalBeginner

Standing Weight Shift Side-to-Side

BalanceIntermediate

Seated Knee Extension with Gentle Overpressure

Range of MotionBeginner

Stationary Cycling with Reduced Resistance

CardiovascularIntermediate

Referral Criteria

  • •Signs of septic bursitis with fever, severe pain at rest, or rapidly progressive swelling requiring urgent medical assessment and possible aspiration for culture
  • •Failure to improve with conservative management after 4-6 weeks despite activity modification and treatment
  • •Recurrent or chronic bursitis requiring injection therapy or surgical intervention consideration
  • •Significant trauma with suspected patellofemoral fracture requiring imaging and orthopedic assessment
  • •Presence of skin compromise, cellulitis, or signs of secondary infection requiring antibiotics
  • •Unilateral knee swelling with calf swelling or signs of deep vein thrombosis requiring vascular assessment
  • •Mechanical symptoms or instability suggesting intra-articular knee pathology requiring MRI or orthopedic review
  • •Patient with severe pain or disability significantly impacting function and quality of life requiring specialist management