Infrapatellar Bursitis

Lower Limb

Overview

Infrapatellar bursitis is inflammation of the bursa located between the patellar tendon and the tibia, commonly caused by repetitive kneeling, direct trauma, or overuse activities. This condition presents with localized swelling, tenderness, and pain below the kneecap, particularly during weight-bearing and kneeling activities. While typically self-limiting with conservative management, it can become chronic if underlying biomechanical factors are not addressed.

Pathophysiology

The infrapatellar bursa acts as a lubricating sac reducing friction between the patellar tendon and the anterior tibial surface. Repetitive trauma, prolonged kneeling, or direct blunt force initiates an inflammatory response with synovial fluid accumulation, causing localized swelling and pain. Continued mechanical irritation from poor patellar tracking, quadriceps weakness, or excessive tibial internal rotation perpetuates inflammation. Secondary changes may include bursal thickening, fibrosis, and calcification if chronic.

Patient Education

Infrapatellar bursitis typically responds well to activity modification, ice application, and gradual strengthening of the quadriceps and hip muscles to improve knee stability and patellar tracking.

Typical Presentation

Site

Anterior knee below the patella, localized to the infrapatellar region; may extend into the proximal tibia

Quality

Dull ache or sharp pain with swelling and tenderness; sensation of heaviness or fullness below kneecap

Intensity

Mild to moderate (typically 3-7/10) that worsens with activity and improves with rest; may be constant during acute phase

Aggravating

Kneeling, squatting, walking downstairs, running, direct pressure to anterior knee, prolonged sitting with knee bent

Relieving

Rest, ice application, elevation, anti-inflammatory medication, avoiding kneeling and impact activities

Associated

Visible swelling below patella, warmth and erythema over bursa, restricted knee flexion, weakness in quadriceps, altered gait pattern favoring affected leg

Orthopaedic Tests

Infrapatellar Bursa Palpation

Procedure

Patient seated with knee extended. Palpate the soft tissue immediately inferior to the patellar tendon insertion on the tibia, between the patellar tendon and the tibial tuberosity.

Positive Finding

Localized tenderness, swelling, or fullness in the infrapatellar bursa region

Sensitivity / Specificity

Unknown / Unknown

Interpretation

Direct palpation elicits pain consistent with bursal inflammation; highly specific for infrapatellar bursitis when combined with clinical context and imaging findings

Kneeling or Prone Knee Flexion Provocation

Procedure

Patient kneels on a firm surface (or lies prone and flexes knee) while clinician observes for pain or discomfort over the infrapatellar bursa region

Positive Finding

Anterior knee pain localized to the infrapatellar region, especially with sustained pressure

Sensitivity / Specificity

Unknown / Unknown

Interpretation

Direct compression of the bursa reproduces symptoms; indicates mechanical irritation of the inflamed bursa

Resisted Knee Extension with Palpation

Procedure

Patient seated with knee extended. Clinician resists knee extension isometrically while simultaneously palpating the infrapatellar bursa region

Positive Finding

Pain over the infrapatellar bursa during resistance, particularly at end-range extension

Sensitivity / Specificity

Unknown / Unknown

Interpretation

Suggests bursal irritation secondary to patellar tendon loading; helps differentiate from isolated tendinopathy

Swelling Assessment and Fluctuance Test

Procedure

Inspect the infrapatellar region for visible swelling. Perform ballottement or fluctuance testing by applying gentle pressure to assess for fluid collection within the bursa

Positive Finding

Visible swelling inferior to patellar tendon; palpable fluctuance or 'boggy' sensation over the bursa

Sensitivity / Specificity

Unknown / Unknown

Interpretation

Indicates significant bursal effusion; confirms inflammatory or infectious process; may warrant aspiration if infection suspected

Lunge or Forward Knee Bend Test

Procedure

Patient performs a shallow lunge or knee bend while bearing weight, progressing knee flexion gradually. Clinician observes for localized anterior knee pain

Positive Finding

Reproducible pain over the infrapatellar bursa with weight-bearing knee flexion

Sensitivity / Specificity

Unknown / Unknown

Interpretation

Functional provocation test; suggests symptomatic bursa during loading activities; helps identify aggravating activities

Ultrasound Assessment (When Available)

Procedure

High-frequency ultrasound probe positioned over the infrapatellar bursa region with knee in slight flexion. Measure fluid collection and assess for bursal thickening

Positive Finding

Anechoic or hypoechoic fluid collection within the infrapatellar bursa, bursal wall thickening >2 mm, or increased vascularity on Doppler

Sensitivity / Specificity

70–90% / 85–95%

Interpretation

Imaging confirmation of bursal effusion and inflammation; ultrasound is first-line imaging modality for bursitis diagnosis and guides intervention

⚠ Red Flags

  • •Signs of infection: rapid onset of severe swelling, warmth, erythema, fever, systemic malaise suggesting septic bursitis
  • •Severe traumatic injury with significant swelling or deformity requiring imaging
  • •Persistent swelling with constitutional symptoms suggesting inflammatory arthropathy
  • •Signs of deep vein thrombosis: unilateral calf swelling, warmth, Homan's sign positive
  • •Severe unrelenting pain not responding to conservative management after 6-8 weeks

⚡ Yellow Flags

  • •Occupational demands requiring prolonged kneeling without adequate support
  • •Maladaptive pain beliefs or catastrophizing about knee function
  • •High kinesiophobia limiting participation in rehabilitation
  • •Work or sport-related pressure to return prematurely to activity
  • •Low mood or anxiety related to activity limitation
  • •Poor adherence to activity modification despite clear guidance

Osteopathic Techniques

Region

Quadriceps and patellar tendon

Technique

Soft Tissue

Rationale

Direct soft tissue mobilization reduces muscular tension in the quadriceps and surrounding structures, improving patellar tracking and reducing mechanical stress on the infrapatellar bursa

Region

Knee joint

Technique

Articulation

Rationale

Gentle oscillatory movements improve synovial fluid distribution, reduce pain, and maintain proprioceptive feedback while respecting the inflammatory state of the bursa

Region

Hip flexors and tensor fasciae latae

Technique

MET

Rationale

Muscle energy techniques address tightness in hip flexors and TFL that contributes to altered hip mechanics and compensatory knee stress

Region

Posterior chain including hamstrings and gastrocnemius

Technique

Soft Tissue

Rationale

Releasing posterior compartment tightness improves knee extension mechanics and reduces compressive forces across the patellar tendon and bursa

Region

Hip abductors and external rotators

Technique

MET

Rationale

Strengthening and mobilizing these muscles restores hip stability and pelvic control, reducing compensatory internal tibial rotation and abnormal patellar tracking

Region

Tibiofemoral and patellofemoral joints

Technique

Functional

Rationale

Functional techniques normalize joint mechanics and patellar tracking patterns, reducing ongoing mechanical irritation of the bursa during weight-bearing activities

Add-On Approaches

Chinese Medicine

Acupuncture or moxibustion at local points (Ex-LE8, ST34, ST35) combined with distal points (ST36, LV3) to resolve local inflammation and improve Qi circulation; herbal formulations addressing damp-heat and blood stasis

Chiropractic

Patellar mobilizations and adjustments to normalize patellar tracking; lower limb joint manipulation to address associated restrictions in ankle, knee, and hip biomechanics

Physiotherapy

Progressive quadriceps strengthening (particularly VMO), hip abductor and external rotator strengthening; proprioceptive retraining; taping or bracing for patellar stability during return to activity

Remedial Massage

Deep tissue massage to quadriceps, VMO, and surrounding musculature; soft tissue release to hip flexors, hamstrings, and calf to improve lower limb mechanics and reduce compensatory knee stress

Rehabilitation Exercises

Seated Knee Extension Flexibility

Range of MotionBeginner

Supine Quadriceps Stretch with Ankle to Buttock

StretchingBeginner

Low Lunge Hip Flexor Stretch

StretchingBeginner

Supine Figure-Four Piriformis Stretch

StretchingBeginner

Supine Quadriceps Sets with Towel Roll

StrengtheningBeginner

Straight Leg Raise (4-way: flexion, extension, abduction, adduction)

StrengtheningIntermediate

Short Arc Quads over Foam Roll

StrengtheningBeginner

Side-Lying Hip Abduction with External Rotation

StrengtheningIntermediate

Clamshells (Hip External Rotation)

StrengtheningBeginner

Mini-Squats with Proper Patellar Tracking

StrengtheningIntermediate

Single-Leg Standing with Hip Control

BalanceIntermediate

Prone Hip Extension (Glute Activation)

PosturalBeginner

Referral Criteria

  • •Signs of septic bursitis with fever, rapid swelling progression, or systemic symptoms requiring urgent medical evaluation and possible aspiration
  • •Failure to improve with conservative management after 6-8 weeks; consider imaging (ultrasound or MRI) to exclude other pathology
  • •Recurrent bursitis despite appropriate activity modification and rehabilitation suggesting need for surgical consultation
  • •Suspicion of underlying inflammatory arthropathy (RA, psoriatic arthritis) with polyarticular involvement
  • •Significant functional limitation affecting work or quality of life warranting physiotherapy or sports medicine specialist input
  • •Traumatic knee injury with associated structural damage (ligament tear, fracture) requiring orthopedic assessment