Patellar Apophysitis

Last updated: February 8, 2026Reviewed date: February 8, 2026Reading time: 5 min read
Patient Tools

Read, save, and share this guide

Use these quick tools to make this medical article easier to read, print, save, or share with a family member.

Patient Mode

Understand this article easily

Switch between simple English and easy Bangla patient notes. This is for education and does not replace a doctor consultation.

Patellar Apophysitis is irritation and inflammation of the growth plate (apophysis) at the bottom of the patella (kneecap), where the patella tendon inserts. In a child, the bones grow from areas called growth plates. Apophysitis and osteochondrosis are common causes of pain in growing bones but have...

For severe symptoms, danger signs, pregnancy, child illness, or sudden worsening, seek urgent medical care.

বাংলা রোগী নোট এখনো যোগ করা হয়নি। পোস্ট এডিটরে “RX Bangla Patient Mode” বক্স থেকে সহজ বাংলা সারাংশ যোগ করুন।

এই তথ্য শিক্ষা ও সচেতনতার জন্য। এটি ডাক্তারি পরীক্ষা, রোগ নির্ণয় বা প্রেসক্রিপশনের বিকল্প নয়।

Article Summary

Patellar Apophysitis is irritation and inflammation of the growth plate (apophysis) at the bottom of the patella (kneecap), where the patella tendon inserts. In a child, the bones grow from areas called growth plates. Apophysitis and osteochondrosis are common causes of pain in growing bones but have differing etiologies and required management. Apophysitis results from a traction injury to the cartilage and bony attachment of tendons in...

Key Takeaways

  • This article explains Other Names in simple medical language.
  • This article explains Pathophysiology in simple medical language.
  • This article explains Causes in simple medical language.
  • This article explains Risk Factors in simple medical language.
Educational health guideWritten for patient understanding and clinical awareness.
Reviewed content workflowUse writer and reviewer profiles for stronger trust.
Emergency safety firstUrgent warning signs are highlighted below.

Seek urgent medical care if you notice

These warning signs are general safety guidance. Local emergency numbers and clinical judgment should always come first.

  • Severe symptoms, breathing difficulty, fainting, confusion, or rapidly worsening illness.
  • New weakness, severe pain, high fever, or symptoms after a serious injury.
  • Any symptom that feels urgent, unusual, or unsafe for the patient.
1

Emergency now

Use emergency care for severe, sudden, rapidly worsening, or life-threatening symptoms.

2

See a doctor

Book a professional medical evaluation if symptoms persist, worsen, recur often, affect daily activities, or occur in a high-risk patient.

3

Learn safely

Use this article to understand possible causes, tests, treatment options, prevention, and questions to ask your clinician.

Before reading

RX Patient Tools

Use these quick guides before reading the article, or return to them when you need help preparing questions for a doctor.

Start here Choose the right pathway for symptoms, reports, medicines, or urgent warning signs. Disease article roadmap Read this topic step by step: meaning, symptoms, warning signs, diagnosis, treatment, prevention, and follow-up. Treatment planner Prepare questions about treatment choices, benefits, risks, side effects, and follow-up. Family & caregiver guide Organize symptoms, reports, medicines, questions, and follow-up safely. Nutrition & diet guide Prepare food, hydration, supplement, and medicine-timing questions safely. Prevention guide Organize risk factors, protective habits, screening, and warning signs. Recovery guide Prepare a safe plan for activity, rehabilitation, warning signs, and follow-up.
Definition

Patellar Apophysitis is irritation and infection, or irritation, often causing pain, swelling, heat, or redness. সহজ বাংলা: শরীরের প্রদাহ; ব্যথা, ফোলা বা লালভাব হতে পারে।" data-rx-term="inflammation" data-rx-definition="Inflammation is the body’s response to injury, infection, or irritation, often causing pain, swelling, heat, or redness. সহজ বাংলা: শরীরের প্রদাহ; ব্যথা, ফোলা বা লালভাব হতে পারে।">inflammation of the growth plate (apophysis) at the bottom of the patella (kneecap), where the patella tendon inserts. In a child, the bones grow from areas called growth plates. Apophysitis and osteochondrosis are common causes of pain in growing bones but have differing etiologies and required management. Apophysitis results from a traction injury to the cartilage and bony attachment of tendons in children and adolescents. Most often it is an overuse injury in children who are growing and have tight or inflexible muscle-tendon units. Apophysitis occurs in upper and lower extremities, it occurs more often in the lower extremities, with common locations including the patellar tendon attachment at the patella or tibia (i.e., Larsen-Johansson and Osgood-Schlatter diseases), the calcaneus (i.e., Sever disease), and multiple locations around the body.

Other Names

  • Traction apophysitis of the knee
  • Sinding-Larsen-Johansson Disease
  • Sinding Larsen Johansson Disease (SLJ)
  • Superior Patellar Pole Apophysitis
  • Inferior Patellar Pole Apophysitis

Pathophysiology

Anatomic illustration of Sinding Larsen Johansson Syndrome.jpg
  • General
    • Overuse injury at the inferior pole of the patella at the proximal patella tendon attachment
    • Repetitive traction on the patellar ligament due to quadriceps contraction causes infection, or irritation, often causing pain, swelling, heat, or redness. সহজ বাংলা: শরীরের প্রদাহ; ব্যথা, ফোলা বা লালভাব হতে পারে।" data-rx-term="inflammation" data-rx-definition="Inflammation is the body’s response to injury, infection, or irritation, often causing pain, swelling, heat, or redness. সহজ বাংলা: শরীরের প্রদাহ; ব্যথা, ফোলা বা লালভাব হতে পারে।">inflammation of patellar tendon attachment
    • Leads to cartilage damage, swelling, and pain
    • Later tendon thickening and fragmentation of the lower pole of the patella
    • Present in skeletally immature adolescents (age 10-14)
  • Considered stress fractures of the apophyseal physis
    • Analogous to a nondisplaced Salter-Harris 1 fracture

Causes

    • Regular physical activity
    • Excessive physical activity is most common (i.e. overuse)
    • Direct trauma to the inferior pole of the patella

Associated Pathology

  • Osgood Schlatter Disease
  • Infrapatellar Bursitis

Pathoanatomy

  • Patella
    • The largest sesamoid bone of the skeleton
    • The patellar tendon arises from the inferior patella and inserts distally into the tibial tuberosity
    • Extensor mechanism: Quadriceps attaches to Patella, Patella Tendon inserts on Tibial Tubercle
    • Ossification begins at 3-5 years
  • Apophysis at the inferior pole of the patella
    • Opens at age 10, closes at age 14

Risk Factors

  • General
    • Middle school athletes
    • Practice > competition
    • Involvement in competitive sport at the age (around 5 or 6 years old) in which the patella begins its ossification
    • Sport specialization
  • Sports (high demands on the extensor apparatus)
    • Football
    • Running
    • Volleyball
    • Gymnastics
    • Long Jump
    • Karate
  • Biomechanical/ Structural
    • Short hamstring tendon
    • Increased posterior tibial slope

diagnosis: Differential diagnosis is a list of possible conditions that may explain symptoms. সহজ বাংলা: একই লক্ষণের সম্ভাব্য রোগের তালিকা।" data-rx-term="differential diagnosis" data-rx-definition="Differential diagnosis is a list of possible conditions that may explain symptoms. সহজ বাংলা: একই লক্ষণের সম্ভাব্য রোগের তালিকা।">Differential Diagnosis

  • Fractures
    • Distal Femur Fracture
    • Patellar Fracture
    • Tibial Plateau Fracture
  • Dislocations & Subluxations
    • Patellar Dislocation (and subluxation)
    • Knee Dislocation
    • Proximal Tibiofibular Joint Dislocation
  • Muscle and Tendon Injuries
    • Quadriceps Contusion
    • Iliotibial Band Syndrome
    • Quadriceps Tendonitis
    • Patellar Tendonitis
    • Popliteus Tendinopathy
    • Extensor Mechanism Injury
      • Patellar Tendon Rupture
      • Quadriceps Tendon Rupture
      • Patellar Fracture
  • Ligament Pathology
    • ACL Injury
    • PCL Injury
    • MCL Injury
    • LCL Injury
    • Meniscal Pathology
    • Posterolateral Corner Injury
    • Multiligament Injury
  • Arthropathies
    • Knee stiffness. সহজ বাংলা: বয়স/ক্ষয়ের কারণে জয়েন্টের ব্যথা।" data-rx-term="osteoarthritis" data-rx-definition="Osteoarthritis is wear-and-tear joint disease causing pain and stiffness. সহজ বাংলা: বয়স/ক্ষয়ের কারণে জয়েন্টের ব্যথা।">Osteoarthritis
    • Septic Arthritis
    • Gout
  • Bursopathies
    • Prepatellar Bursitis
    • Pes Anserine Bursitis
    • MCL Bursitis
    • Infrapatellar Bursitis
  • Patellofemoral Pain Syndrome (PFPS)/ Anterior Knee Pain)
    • Chondromalacia Patellae
    • Patellofemoral Osteoarthritis
    • Osteochondral Defect Knee
    • Plica Syndrome
    • Infrapatellar Fat Pad Impingement
    • Patellar Instability
  • Neuropathies
    • Saphenous Nerve Entrapment
  • Other
    • Bakers Cyst
    • Patellar Contusion
  • Pediatric Considerations
    • Patellar Apophysitis (Sinding-Larsen-Johansson Disease)
    • Patellar Pole Avulsion Fracture
    • Tibial Tubercle Avulsion Fracture
    • Tibial Tuberosity Apophysitis (Osgood Schalatters Disease)

Diagnosis

  • History
    • History of insidious onset of pain on the anterior aspect of the knee
    • Duration is weeks to months
    • Worse when the patella is loaded (running, jumping, sudden stops)[6]
  • Physical Exam: Physical Exam Knee
    • Tenderness over the inferior patella may extend into the tendon
    • Swelling over the inferior patella, Knee Effusion should be absent
    • Range of motion normal or slightly limited in flexion due to pain
    • Strength and extension should be intact but painful
  • Special Tests
    • Jump Test: Pain is easily reproduced with repetitive jumping in the examination room
Lateral left knee radiograph with an arrow demonstrating loose bony fragments at the inferior patellar pole[7]

Radiographs

  • Standard Radiographs Knee
  • Findings
    • It May be normal or show spur at the inferior pole of the patella
    • Soft tissue swelling may be noted on the lateral view
    • Can see calcifications at the origin of the patellar tendon
Focal thickening increased echogenicity of the right infrapatellar tendon (compared to left). Arrow indicates significant widening, cortical irregularity associated with the apophysis of the patellar apex.

Ultrasound

  • General
    • The imaging modality of choice as it can identify all pathology associated with the disease
    • May follow serially over time to examine for progression/resolution of disease
  • Findings[9]
    • Cartilage swelling or thickening
    • Tendon thickening
    • Fragmentation of the lower pole
    • Infrapatallar bursitis
    • Hyperemic tendon fibers with power doppler

MRI

    • If diagnosis unclear
    • Help distinguish from patellar sleeve avulsion

Classification

Unknown Classification System

  • Stage 1: Pain occurs after activity
  • Stage 2: Pain present while performing the activity and persists after activity
  • Stage 3: Pain affecting/limiting function during activity

Iwamoto Classification System

  • Based on radiographic findings[10]
  • Stage 1: Normal findings.
  • Stage 2: Irregular calcifications at the inferior patellar pole.
  • Stage 3: Coalescence of calcifications.
  • Stage 4A: Incorporation of calcifications into the patella.
  • Stage 4B: Coalesced calcified mass separate from the patella

Treatment

Nonoperative

  • The mainstay of treatment, usually self-limited
  • Activity modification
    • Abstain for 1-2 months minimum
    • Consider replacing with swimming, other sports that don’t use quadriceps muscle as much
  • NSAIDS
  • Physical therapy
    • Improve hamstring, quadriceps, and heel cord flexibility
  • Patellar Tendon Counterforce Strap
    • May provide relief, can be worn as needed
  • Consider biomechanical evaluation if not improving
    • Look for knee twisting, valgus moment
    • Neuromuscular deficits
  • Contraindicated
    • Corticosteroid Injection

Operative

  • Indications
    • Refractory to nonoperative treatment
  • Technique
    • Debridement of damaged tissue/stimulation of healing response
Doctor visit helper

Prepare before seeing a doctor

A simple rural-patient checklist to help you explain symptoms clearly, ask better questions, and avoid unsafe self-treatment.

Safety note: This is not a prescription or diagnosis. For severe symptoms, pregnancy danger signs, children with serious illness, chest pain, breathing difficulty, stroke-like weakness, or major injury, seek urgent care.

Which doctor may help?

Start with a registered doctor or the nearest qualified health center.

What to tell the doctor

  • Write when the problem started and how it changed.
  • Bring old prescriptions, investigation reports, and current medicines.
  • Write allergies, pregnancy status, diabetes, kidney/liver disease, and major past illnesses.
  • Bring one family member if the patient is weak, elderly, confused, or a child.

Questions to ask

  • What is the most likely cause of my symptoms?
  • Which danger signs mean I should go to hospital quickly?
  • Which tests are necessary now, and which can wait?
  • How should I take medicines safely and what side effects should I watch for?
  • When should I come for follow-up?

Tests to discuss

  • Vital signs: temperature, pulse, blood pressure, oxygen saturation
  • Basic physical examination by a clinician
  • CBC, urine test, blood sugar, or imaging only when clinically needed

Avoid these mistakes

  • Do not use antibiotics, steroid tablets/injections, or strong painkillers without proper medical advice.
  • Do not hide pregnancy, kidney disease, ulcer, allergy, or blood thinner use.
  • Do not delay emergency care when danger signs are present.

Medicine safety and first-aid guide

This section is for patient education only. It does not replace a doctor, pharmacist, or emergency care.

Safe first steps

  • Rest, drink safe water, and observe symptoms carefully.
  • Keep a written note of symptoms, duration, temperature, medicines already taken, and allergy history.
  • Seek medical care quickly if symptoms are severe, worsening, or unusual for the patient.

OTC medicine safety

  • For mild pain or fever, ask a registered pharmacist or doctor before using common over-the-counter pain/fever medicines.
  • Do not combine multiple pain medicines without advice, especially if you have kidney disease, liver disease, stomach ulcer, asthma, pregnancy, or take blood thinners.
  • Do not give adult medicines to children unless a qualified clinician advises it.

Avoid these mistakes

  • Do not start antibiotics without a proper medical decision.
  • Do not use steroid tablets or injections casually for quick relief.
  • Do not delay emergency care because of home remedies.

Get urgent help if

  • Severe symptoms, confusion, fainting, breathing difficulty, chest pain, severe dehydration, or sudden weakness need urgent medical care.
Medicine names, dose, and timing must be decided by a qualified clinician or pharmacist after checking age, pregnancy, allergy, other diseases, and current medicines.

For rural patients and family caregivers

Patient health record and symptom diary

Write your symptoms, medicines already taken, test results, and questions before visiting a doctor. This note stays on your device unless you print or copy it.

Doctor to discuss: Doctor / qualified healthcare provider
Tests to discuss with doctor
  • Basic vital signs: temperature, pulse, blood pressure, oxygen level if needed
  • Relevant blood, urine, imaging, or specialist tests only after clinical assessment
Questions to ask
  • What is the most likely cause of my symptoms?
  • Which warning signs mean I should go to emergency care?
  • Which tests are really needed now?
  • Which medicines are safe for my age, pregnancy status, allergy, kidney/liver/stomach condition, and current medicines?

Emergency warning signs such as chest pain, severe breathing difficulty, sudden weakness, confusion, severe dehydration, major injury, or loss of bladder/bowel control need urgent medical care. Do not wait for online information.

Safe pathway to proper treatment

Care roadmap for: Patellar Apophysitis

Use this simple roadmap to understand the next safe steps. It is educational and does not replace examination by a doctor.

Go to emergency care if you notice:
  • Severe or rapidly worsening symptoms
  • Breathing difficulty, chest pain, fainting, confusion, severe weakness, major injury, or severe dehydration
Doctor / service to discuss: Qualified healthcare provider; specialist depends on symptoms and examination.
  1. Step 1

    Check danger signs first

    If danger signs are present, seek emergency care and do not wait for online information.

  2. Step 2

    Record the symptom story

    Write when symptoms started, severity, medicines already taken, allergies, pregnancy status, and test results.

  3. Step 3

    Visit a qualified clinician

    A doctor, nurse, or qualified healthcare provider can examine you and decide which tests or treatment are needed.

  4. Step 4

    Do only useful tests

    Do tests after clinical assessment. Avoid unnecessary tests, random antibiotics, or repeated medicines without diagnosis.

  5. Step 5

    Follow up and return early if worse

    If symptoms worsen, new warning signs appear, or treatment is not helping, return for review quickly.

Rural patient practical tips
  • Take a written symptom diary and all previous prescriptions/test reports.
  • Do not hide medicines already taken, even herbal or over-the-counter medicines.
  • Ask which warning signs mean urgent referral to hospital.

This roadmap is for education. A real diagnosis and treatment plan requires history, examination, and clinical judgment.

RX Patient Help

Ask a health question safely

Write your symptom story. A health professional or site editor can review it before any answer is prepared. This box is not for emergency care.

Emergency first: Severe chest pain, breathing trouble, unconsciousness, stroke signs, severe injury, heavy bleeding, or rapidly worsening symptoms need urgent local medical care now.

Frequently Asked Questions

Is this article a replacement for a doctor?

No. It is educational content only. Patients should consult a qualified clinician for diagnosis and treatment.

When should I seek urgent care?

Seek urgent care for severe symptoms, rapidly worsening condition, breathing difficulty, severe pain, neurological changes, or any emergency warning sign.

More from this topic
  1. Distal Arthrogryposis Type 9

    DefinitionDistal arthrogryposis type 9 is an old name for congenital? contractural arachnodactyly, often shortened to CCA. Many experts now prefer the name congenital? contractural arachnodactyly because...

    March 30, 2026 • Rx Autoimmune, Genetic and Rare Diseases (A - Z)
  2. Varus Flexion Deformity

    DefinitionVarus flexion deformity means that a joint is bent in two ways at the same time.“Varus” means the lower part of the leg (or bone) points...

    February 11, 2026 • Degenerative Bones, Joints, and Spine Care (A - Z)
  3. Microphthalmia-Coloboma-Rhizomelic Skeletal Dysplasia

    DefinitionMicrophthalmia-coloboma-rhizomelic skeletal dysplasia is a very rare genetic syndrome that affects eye development, bone growth, and sometimes the brain and other organs. “Microphthalmia” means one or...

    February 11, 2026 • Rx Autoimmune, Genetic and Rare Diseases (A - Z)
  4. Chromosome 17q23.1-q23.2 Deletion Syndrome

    DefinitionChromosome 17q23.1-q23.2 deletion syndrome is a very rare genetic condition. In this syndrome, a tiny piece of DNA is missing from the long arm (q arm)...

    January 17, 2026 • Rx Autoimmune, Genetic and Rare Diseases (A - Z)
  5. Chondrodysplasia Punctata, Tibial-Metacarpal Type

    DefinitionChondrodysplasia punctata, tibial-metacarpal type, is a very rare birth bone condition. It mainly affects the small bones of the hands and the shin bone (tibia). The...

    January 13, 2026 • Degenerative Bones, Joints, and Spine Care (A - Z)
  6. Calcium Pyrophosphate Dihydrate Crystal Deposition Disease (CPPD)

    DefinitionCalcium pyrophosphate dihydrate crystal deposition disease (CPPD), also called pseudogout, happens when tiny calcium pyrophosphate crystals build up in the joint cartilage? and soft tissues. These...

    January 13, 2026 • Rx Blood, Metabolism, and Infectious Diseases (A - Z)
  7. Chondrocalcinosis

    DefinitionChondrocalcinosis means there are calcium crystals sitting inside the cartilage? of a joint. Cartilage is the smooth, rubbery tissue that covers the ends of bones and...

    January 13, 2026 • Rx Blood, Metabolism, and Infectious Diseases (A - Z)
  8. Charcot–Marie–Tooth Neuropathy Dominant Intermediate A (CMTDIA)

    DefinitionCharcot–Marie–Tooth neuropathy? dominant intermediate A (short name: CMTDIA) is a very rare, inherited nerve disease that damages the long nerves in the arms and legs. It...

    January 5, 2026 • Rx Autoimmune, Genetic and Rare Diseases (A - Z)
  9. ATP1A1-Related Autosomal Dominant Charcot-Marie-Tooth Disease Type 2 (CMT2DD)

    DefinitionATP1A1-related autosomal dominant Charcot-Marie-Tooth disease type 2 (often called CMT2DD) is a very rare inherited nerve disease. It mainly damages the “wires” (axons) of the peripheral...

    January 5, 2026 • Rx Autoimmune, Genetic and Rare Diseases (A - Z)
  10. Autosomal Dominant Intermediate Charcot-Marie-Tooth Disease Type C

    DefinitionAutosomal dominant intermediate Charcot-Marie-Tooth disease type C (often shortened to AD-CMTD type C or CMTDIC) is a rare inherited nerve disease. It mainly affects the long...

    December 23, 2025 • Rx Autoimmune, Genetic and Rare Diseases (A - Z)