Patellofemoral pain
Pain arising from the patellofemoral joint (the kneecap and its groove at the front of the knee), causing anterior knee pain aggravated by stairs, squatting, and prolonged sitting. The most common cause of anterior knee pain in young adults.
📊 Patellofemoral pain is the most common cause of knee pain in adolescents and young adults, affecting up to 25% of young active individuals. It is twice as common in females.
What is patellofemoral pain?
Patellofemoral pain (PFP) arises from altered loading of the patellofemoral joint. The patella is a sesamoid bone that sits in the trochlear groove of the femur. It acts as a pulley for the quadriceps mechanism. PFP occurs when the patella tracks abnormally or when load through the patellofemoral joint exceeds tissue tolerance, generating pain. The pain is typically diffuse, felt behind or around the kneecap, and worsens with activities that increase patellofemoral joint load.
The cause is multifactorial - hip weakness (particularly hip abductors and external rotators), quadriceps weakness, poor patellar tracking, training errors (sudden increase in load), and biomechanical factors all contribute. The Consensus Statement on Patellofemoral Pain recommends a 3-month trial of targeted physiotherapy as the first-line treatment. Surgery (lateral release, tibial tubercle transfer) has a very limited role and should only be considered in cases with clearly defined anatomical pathology.
Patellar tendinopathy (jumpers knee) is a separate diagnosis - pain at the inferior patellar pole caused by tendon degeneration from repetitive loading. It is managed with progressive tendon loading exercises (eccentric and heavy slow resistance training). Osgood-Schlatter disease - pain and swelling at the tibial tubercle in adolescents during growth - is a separate condition managed conservatively with relative rest.
Common causes
- Training load errors (sudden increase in running or sport volume)
- Weak hip abductors and external rotators causing dynamic valgus
- Quadriceps weakness
- Altered patellar tracking
- Poor foot pronation control
- Prolonged sitting with the knee bent
Who is at risk? Female sex, adolescence, participation in running and jumping sports, and sudden increases in training load are the main risk factors.
Symptoms
Symptoms vary depending on the severity and duration of the condition. Common symptoms include:
- Diffuse pain behind or around the kneecap
- Pain worse on stairs (particularly descending), squatting, and prolonged sitting (the cinema sign - pain on rising after sitting)
- Swelling around the knee (in some patients)
- Crepitus (grinding) under the kneecap
- Pain that improves with activity initially, then worsens with sustained high loads
When to seek help: See your GP or physiotherapist if anterior knee pain has not improved after 4-6 weeks of self-management with activity modification and stretching. Physiotherapy addressing the underlying causes is the most effective treatment.
How is it diagnosed?
Your surgeon will take a detailed history and examine the joint. The following investigations may be arranged to confirm the diagnosis:
- Clinical examination - J-sign (patellar maltracking), patellar tilt test, lateral facet tenderness, Clarke test
- X-ray - AP, lateral, and skyline views to assess patellar tilt, trochlear morphology, and patellar height
- MRI - to exclude other diagnoses (meniscal pathology, chondral damage) if clinical diagnosis is uncertain
- CT - for pre-operative planning if tibial tubercle transfer is considered
Patellofemoral pain is a clinical diagnosis. Imaging is used to exclude other causes of anterior knee pain rather than to make the diagnosis. Normal imaging does not exclude PFP.
Treatment pathway
Treatment is tailored to the severity of the condition, your age, activity level, and overall health. Most conditions are treated in a stepwise fashion, starting with the least invasive options.
Physiotherapy targeting the kinetic chain
The most effective treatment. Combines quadriceps strengthening (particularly VMO), hip abductor and external rotator strengthening, and movement pattern retraining. Taping and foot orthoses may provide short-term symptomatic relief. A 3-month structured programme is recommended before considering other interventions.
Load management and activity modification
Identifying and modifying provocative training loads. Temporary reduction in running volume and avoidance of provocative activities (squatting, stairs) while strengthening progresses.
Tibial tubercle transfer (for patella alta or lateral maltracking)
Surgical repositioning of the tibial tubercle (the attachment of the patellar tendon on the tibia) to correct anatomical maltracking. Only indicated in a small minority of patients with clearly defined bony pathology causing lateral patellar instability or patella alta, after failure of conservative management.
Recovery
PFP has a variable prognosis. Approximately 50% of patients have persistent symptoms at 5-8 years. Early comprehensive physiotherapy gives the best long-term outcomes. Running volume should be gradually reintroduced following symptom response.
- Physiotherapy: 3-6 months
- Significant improvement expected: 6-12 months
- Return to full sport: 3-12 months depending on severity
What results can I expect?
Approximately 70-80% of patients improve significantly with a structured physiotherapy programme over 6-12 months. A subset of patients develop chronic patellofemoral pain despite treatment. Surgery has a limited and poorly evidenced role.
Patellofemoral pain - anterior knee pain explained
In numbers
Typical activity timelines for this condition. These are approximate and vary considerably between patients. Always follow the specific guidance given by your surgeon and physiotherapist.
| Activity | Typical timeline | Notes |
|---|---|---|
| Start a physiotherapy programme | Now | A supervised hip and quadriceps strengthening programme is the proven first-line treatment.[1] |
| Modify training | During treatment | Reduce activities that aggravate pain (deep squats, downhill running, kneeling) while strength is rebuilt.[1] |
| Try a taping or brace | Short-term | Patellar taping or a soft brace may help during the rehab phase. Not a long-term solution on its own.[1] |
| Lose weight if needed | Ongoing | Reduces patellofemoral joint loading, particularly important in patients with overweight.[1] |
| Return to running | When pain-free | Gradual return guided by symptoms. Build up running volume and intensity progressively.[1] |
| Consider surgery | Only after 6+ months | Surgery is rarely indicated and only after sustained physiotherapy has failed in patients with documented anatomical pathology.[2] |
Common concerns from patients with this condition or recovering from treatment, and whether they are expected or worth mentioning to your team.
Your questions, answered
Plain-English answers to the things people most often ask, grounded in UK clinical guidance. Tap a question to open it.
About thisWhat is patellofemoral pain?
Patellofemoral pain is pain coming from the front of the knee, where the kneecap glides in its groove on the thigh bone. It is very common, particularly in active people and adolescents, and usually reflects how the kneecap is loaded and tracking rather than damage to the joint.
SymptomsWhy does it hurt on stairs and after sitting?
The kneecap is loaded most when the knee is bent under weight, which is why stairs, squatting, kneeling and prolonged sitting with the knee bent, sometimes called the cinema sign, tend to provoke it. You may also notice a grinding or clicking feeling.
TreatmentWill I need surgery?
Almost never. Patellofemoral pain is managed very effectively with physiotherapy, which is the cornerstone of treatment. Surgery is rarely needed and is reserved for the small number of cases with a specific structural cause that has not responded to thorough rehabilitation.
RecoveryHow long does it take to settle?
With a consistent exercise programme, most people improve over a few weeks to a few months. Strengthening the thigh and hip muscles, modifying aggravating activities and gradually building load are what make the difference, so sticking with the exercises matters.
Daily lifeWhat can I do to help myself?
Keep moving within comfortable limits rather than resting completely, build up activity gradually, and use supportive footwear. Some people find a short period of taping or a sleeve helpful while they strengthen. Avoiding sudden spikes in training load helps prevent flares.
When to worryWhen should this be checked further?
Get it assessed if the knee swells significantly, locks, gives way, or the pain follows a specific injury, as these features suggest something other than simple patellofemoral pain.
- 1.Chartered Society of Physiotherapy: Patient information
- 2.British Association for Surgery of the Knee: Patient information
References are to UK clinical guidance and patient information from recognised organisations. This page is for general information and does not replace personalised advice from your own clinical team.
Preparing for surgery?
Read our step-by-step guide - what to expect before, during, and after your procedure.
How is it diagnosed?
- ✓Clinical examination - J-sign (patellar maltracking), patellar tilt test, lateral facet tenderness, Clarke test
- ✓X-ray - AP, lateral, and skyline views to assess patellar tilt, trochlear morphology, and patellar height
- ✓MRI - to exclude other diagnoses (meniscal pathology, chondral damage) if clinical diagnosis is uncertain
- ✓CT - for pre-operative planning if tibial tubercle transfer is considered
Recovery milestones
- ●Physiotherapy: 3-6 months
- ●Significant improvement expected: 6-12 months
- ●Return to full sport: 3-12 months depending on severity