Patella (Kneecap) FractureKneecap Fracture (Patellar Fracture)
Patella (Kneecap) Fracture — Overview
Patellar fractures compromise the continuity of the knee extensor mechanism (which magnifies quadriceps lever arm torque). Displaced transverse fractures (>2–3 mm step-off or >3 mm diastasis) or loss of active knee extension require surgical fixation (modified tension-band wiring or cannulated screws), whereas undisplaced fractures with an intact retinaculum are managed conservatively in a hinged extension brace.
A patellar fracture (kneecap fracture) is a break in the shield-like bone at the front of your knee that connects your thigh muscle to your shinbone, requiring step-by-step angle protection while bending.
Primary Causes & Biomechanics
Key Points You Should Know
- •Direct anterior impact to a flexed knee (dashboard injury or fall onto the kneecap) or violent eccentric quadriceps contraction
- •Tensile pull of the quadriceps femoris tending to separate fracture fragments during unguarded knee flexion
- •Post-immobilization patellofemoral adhesions, quadriceps atrophy, and extensor lag
- •Brace Locked Straight When Walking: In the early weeks, keeping your knee brace locked straight while standing prevents your thigh muscle from pulling the healing kneecap apart.
- •Step-by-Step Bending Angles: Only bend your knee to the exact degree limit (such as 30°, 60°, or 90°) permitted for that week.
- •Preventing Kneecap Sticking: Once healed, gentle kneecap glides and thigh tightening restore smooth knee motion.
Assessment Methods
1. Goniometric ROM & Postural / Kinematic Analysis
Controlled knee flexion arc progression (Week 1–2: 0–30°, Week 3–4: 0–60°, Week 5–6: 0–90°) and full 0° passive/active extension.
2. Special Clinical Provocation & Neurological/Functional Tests
Active straight-leg raise integrity (extensor lag assessment), patellar superior/inferior/medial/lateral mobility (once healed), and effusion grading.
3. Standardized Clinical Outcome Scales & Imaging Criteria
Lysholm Knee Score, Kujala Patellofemoral Score, KOOS, and lateral/skyline patellar radiographs.
1. Range of Motion & Posture Check
Your physiotherapist gently evaluates how comfortably and smoothly your patella (kneecap), quadriceps tendon, patellar retinaculum, and patellar tendon extensor mechanism moves and checks your overall posture.
2. Muscle Strength & Functional Movement Check
Your muscle balance, walking or reaching comfort, and specific gentle movement tests are evaluated without triggering sharp pain.
3. Typical Symptoms & Daily Impact Review
Anterior knee swelling, hemarthrosis, palpable defect over the patella (if displaced), and weakness or extensor lag when attempting to straighten the knee.
Treatment Options & Phase-Based Protocol
✨ Enriched GIF Exercise & Precaution GuidePhase 1: Acute Symptom Modulation, Tissue Protection & Early Activation
- •Phase 1 Clinical Focus & Tissue Protection: Extension Protection & Early Activation Phase (Weeks 0–4): Hinged knee brace locked at 0° extension during weight-bearing as tolerated (WBAT), submaximal isometric quadriceps setting (in 0° extension), ankle pumps, and side-lying hip abduction.
- •Pain, Edema & Neuromuscular Modulation: Targeted physical modalities, relative load management, and early protected mobility of the patella (kneecap), quadriceps tendon, patellar retinaculum, and patellar tendon extensor mechanism without provoking mechanical or inflammatory irritation.
- •Proximal & Distal Kinetic Chain Maintenance: Maintain active mobility and circulation in adjacent joints while protecting the primary healing structures in Patellar Fracture.
Phase 2: Progressive Mobility, Motor Control & Targeted Strengthening
- •Phase 2 Progressive Mobilization & Motor Control: Graduated Flexion Progression Phase (Weeks 4–8): Progressive unlocking of hinged brace (30° -> 60° -> 90° -> full ROM per surgeon protocol), controlled supine heel slides, patellar mobilizations (after bony union), and straight leg raises (SLR) once cleared.
- •Biomechanical Alignment & Co-Contraction: Restore balanced agonist-antagonist force couples, joint centration, and multi-planar neuromuscular control across the patella (kneecap), quadriceps tendon, patellar retinaculum, and patellar tendon extensor mechanism.
- •Myofascial Extensibility & Endurance: Address secondary compensatory tightness and build local muscular endurance within safe, symptom-free biomechanical parameters.
Phase 3: Functional Integration, Proprioception & Long-Term Prevention
- •Phase 3 Functional Integration & Long-Term Prevention: Extensor Strengthening & Functional Phase (Week 8–12+): Seated terminal knee extension, protected 0°–40° wall mini-squats, chair sit-to-stand, and proprioceptive balance training.
- •Proprioceptive Balance & Dynamic Loading: Progress to task-specific closed-chain, balance, and functional movement patterns tailored to daily life, occupational, or athletic demands.
- •Self-Management & Relapse Prophylaxis: Establish lifelong ergonomic habits, home exercise maintenance, and early warning-sign awareness to prevent recurrence.
Step 1: Calming Pain, Protecting the Area & Gentle Starter Motion
- •Brace Locked Straight When Walking: In the early weeks, keeping your knee brace locked straight while standing prevents your thigh muscle from pulling the healing kneecap apart.
- •Calm Protection & Gentle Start: During the initial stage of Kneecap Fracture, avoid painful overloading and perform the gentle, pain-free starter movements shown below to support circulation and comfort.
- •Respecting Your Body's Signals: Every movement should stay within a comfortable, non-painful zone—never force through sharp or radiating pain.
Step 2: Restoring Flexibility & Building Supporting Muscle Strength
- •Step-by-Step Bending Angles: Only bend your knee to the exact degree limit (such as 30°, 60°, or 90°) permitted for that week.
- •Step-by-Step Flexibility & Support: As acute sensitivity settles, gradually build mobility and strengthen the supporting muscles around the joint at a steady, controlled pace.
- •Posture & Breathing Coordination: Keep your posture upright and breathe smoothly (never hold your breath!) during every repetition.
Step 3: Safe Daily Habits, Stamina & Preventing Recurrence
- •Preventing Kneecap Sticking: Once healed, gentle kneecap glides and thigh tightening restore smooth knee motion.
- •Confident Return to Daily Life: Integrate your stronger muscles and improved balance into walking, stairs, work, and recreational activities.
- •Preventing Future Flare-Ups: Continue your core protective habits and key maintenance exercises even after symptoms resolve.
Animated (GIF) Therapeutic Exercise Guide
Animated clinical exercise protocol with biomechanical angles, target muscle groups, and dosage parameters (Click image to enlarge)
Step-by-step animated exercise demonstrations you can safely perform at home (Click image to enlarge)
🔍 Enlarge1. Isometric Quadriceps Setting (Popliteal Towel Press)
1. Under-Knee Towel Press (Quadriceps Tightening)
Isometric compression of a rolled towel beneath the popliteal fossa into the surface with simultaneous ankle dorsiflexion. Activates the Vastus Medialis Obliquus (VMO) and overcomes arthrogenic muscle inhibition with 0° joint shear stress. Specifically indicated in Patellar Fracture rehabilitation to optimize patella (kneecap), quadriceps tendon, patellar retinaculum, and patellar tendon extensor mechanism biomechanics and neuromuscular control.
Place a small rolled towel under your knee while lying on your back or sitting with your leg straight. Pull your toes toward you while firmly pressing the back of your knee down into the towel, hold for 5 seconds, and relax while exhaling. Perform smoothly within a comfortable, pain-free range to support your Kneecap Fracture recovery.
🔍 Enlarge2. Supine Active-Assisted Heel Slide & Synovial Diffusion Mobilization
2. Supine Heel Slide (Gentle Knee & Hip Bending)
Controlled flexion and extension of the lower extremity by sliding the heel along the support surface without axial weight-bearing. Stimulates synovial fluid diffusion across avascular cartilage and prevents capsular adhesions. Specifically indicated in Patellar Fracture rehabilitation to optimize patella (kneecap), quadriceps tendon, patellar retinaculum, and patellar tendon extensor mechanism biomechanics and neuromuscular control.
While lying on your back, slowly slide your heel along the bed sheet toward your hip within a comfortable, pain-free angle, hold for 3 seconds, and gently slide it back out straight. Perform smoothly within a comfortable, pain-free range to support your Kneecap Fracture recovery.
🔍 Enlarge3. Side-Lying Hip Abduction (Gluteus Medius & Frontal Plane Control)
3. Side-Lying Leg Lift (Outer Hip Strengthening)
Isolated strengthening of the gluteus medius in slight hip extension and neutral rotation. Prevents contralateral pelvic drop (Trendelenburg) and reduces dynamic knee valgus and medial compartment adduction moments. Specifically indicated in Patellar Fracture rehabilitation to optimize patella (kneecap), quadriceps tendon, patellar retinaculum, and patellar tendon extensor mechanism biomechanics and neuromuscular control.
Lie on your side with your bottom leg slightly bent for balance. Keep your top leg straight and slightly back, lift it up toward the ceiling without rolling your pelvis backward, hold for 3 seconds, and lower slowly. Perform smoothly within a comfortable, pain-free range to support your Kneecap Fracture recovery.
🔍 Enlarge4. Seated Terminal Knee Extension (Open/Closed Chain VMO Focus)
4. Seated Knee Straightening & Hold
Concentric extension of the knee to the final 30°–0° terminal arc with isometric hold and ankle dorsiflexion. Restores terminal knee extension torque and stabilizes dynamic patellofemoral tracking. Specifically indicated in Patellar Fracture rehabilitation to optimize patella (kneecap), quadriceps tendon, patellar retinaculum, and patellar tendon extensor mechanism biomechanics and neuromuscular control.
Sit upright in a chair and slowly straighten your knee completely while pulling your toes toward you. Feel the front thigh muscle tighten, hold for 5 seconds, and slowly lower your foot. Perform smoothly within a comfortable, pain-free range to support your Kneecap Fracture recovery.
🔍 Enlarge5. Straight Leg Raise (SLR — Multi-Plane Isometric Knee Lock)
5. Supine Straight Leg Raise
Maintaining the knee locked in full extension (0°) with ankle dorsiflexion while elevating the lower extremity to 45° hip flexion. Strengthens the quadriceps and iliopsoas complex without compressing or shearing the articular surfaces. Specifically indicated in Patellar Fracture rehabilitation to optimize patella (kneecap), quadriceps tendon, patellar retinaculum, and patellar tendon extensor mechanism biomechanics and neuromuscular control.
Bend your healthy knee with the foot flat on the bed. Tighten the thigh muscle of your affected leg to lock the knee straight, lift the leg to the height of the opposite knee, hold for 3 seconds, and lower slowly. Perform smoothly within a comfortable, pain-free range to support your Kneecap Fracture recovery.
🔍 Enlarge6. Protected Closed-Kinetic-Chain Wall Mini-Squat (0°–40° Safe Arc)
6. Wall-Supported Safe Mini-Squat
Closed-kinetic-chain bilateral knee flexion in the safe 0°–40° arc with the back supported against a wall. Promotes quadriceps-hamstring-gluteal co-contraction and joint proprioception without excessive patellofemoral compression. Specifically indicated in Patellar Fracture rehabilitation to optimize patella (kneecap), quadriceps tendon, patellar retinaculum, and patellar tendon extensor mechanism biomechanics and neuromuscular control.
Lean your back flat against a wall with your feet shoulder-width apart. Slowly bend your knees slightly (30–40 degrees, keeping knees behind toes), hold for 5 seconds, and push back up. Perform smoothly within a comfortable, pain-free range to support your Kneecap Fracture recovery.
Movements to Avoid & Strict Precautions
1. Bending the Knee Past the Weekly Prescribed Hinged-Brace Angle Limit
1. Forcing your knee to bend past the degree limit set by your doctor for that week
2. Walking Without Locking the Knee Brace in Full Extension (Weeks 1–4)
2. Walking with an unlocked knee brace during the early healing weeks
3. Deep Squatting, Kneeling Directly on the Kneecap, or Jumping
3. Kneeling directly on your healing kneecap, deep squatting, or jumping
4. Performing Heavy Open-Chain Leg Extensions Early in Rehab
4. Doing heavy seated leg-extension machine lifts during early healing
Patella (Kneecap) Fracture — Video Guide
Click directly on any video to open and watch in a window, or review details via 📋 Summary & Options.
Condition Overview Video (1 Video)
Summary of pathophysiology, biomechanics, and clinical presentation
What the condition is, why it develops, and its basic mechanism
What Is a Patellar (Kneecap) Fracture? Symptoms and Clinical Presentation
Patellar fractures compromise the continuity of the knee extensor mechanism (which magnifies quadriceps lever arm torque). Displaced transverse fractures (>2–3 mm step-off or >3 mm diastasis) or loss of active knee extension require surgical fixation (modified tension-band wiring or cannulated screws), whereas undisplaced fractures with an intact retinaculum are managed conservatively in a hinged extension brace.
A patellar fracture (kneecap fracture) is a break in the shield-like bone at the front of your knee that connects your thigh muscle to your shinbone, requiring step-by-step angle protection while bending.
Treatment and Exercise Videos
Phase-based physiotherapy protocols, mobilization, and therapeutic exercises
Step-by-step recovery and safe home exercise applications
Patellar (Kneecap) Fracture Rehabilitation and Exercise Principles
Phase 1: Acute Symptom Modulation, Tissue Protection & Early Activation: Phase 1 Clinical Focus & Tissue Protection: Extension Protection & Early Activation Phase (Weeks 0–4): Hinged knee brace locked at 0° extension during weight-bearing as tolerated (WBAT), submaximal isometric quadriceps setting (in 0° extension), ankle pumps, and side-lying hip abduction.
Step 1: Calming Pain, Protecting the Area & Gentle Starter Motion: Brace Locked Straight When Walking: In the early weeks, keeping your knee brace locked straight while standing prevents your thigh muscle from pulling the healing kneecap apart.
Quadriceps Strengthening Exercises After Knee and Leg Fractures
Phase 2: Progressive Mobility, Motor Control & Targeted Strengthening: Phase 2 Progressive Mobilization & Motor Control: Graduated Flexion Progression Phase (Weeks 4–8): Progressive unlocking of hinged brace (30° -> 60° -> 90° -> full ROM per surgeon protocol), controlled supine heel slides, patellar mobilizations (after bony union), and straight leg raises (SLR) once cleared.
Step 2: Restoring Flexibility & Building Supporting Muscle Strength: Step-by-Step Bending Angles: Only bend your knee to the exact degree limit (such as 30°, 60°, or 90°) permitted for that week.
Clinical Assessment, Goniometry & Special Test Videos
Displayed only in Healthcare Professional mode (hidden in Patient mode)
Knee Joint Goniometric Measurement (Controlled Flexion and Full Extension)
Goniometric ROM & Postural / Kinematic Analysis: Controlled knee flexion arc progression (Week 1–2: 0–30°, Week 3–4: 0–60°, Week 5–6: 0–90°) and full 0° passive/active extension.
Knee Joint and Patellofemoral Extensor Mechanism Clinical Examination
Special Clinical Provocation & Neurological/Functional Tests: Active straight-leg raise integrity (extensor lag assessment), patellar superior/inferior/medial/lateral mobility (once healed), and effusion grading.