Patellofemoral Pain Syndrome: Dr. Parag Sancheti on the Hidden Cause of Front-of-Knee Pain

Front-of-knee pain is common, but often misunderstood. A normal MRI, a diagnosis of patellofemoral pain syndrome, and advice to rest may offer temporary relief, but rarely answer the real question: why does the pain keep coming back?

Dr. Parag Sancheti, Chairman and Managing Director of Sancheti Hospital and an internationally recognised knee pain specialist with over 34 years of experience, takes a different approach: identifying the biomechanical drivers that routine MRIs do not show and that most standard management plans do not address. This article explains what PFPS actually is, why the pain originates, and what effective treatment looks like.

What Is Patellofemoral Pain Syndrome?

Patellofemoral pain syndrome (PFPS) is an umbrella term for pain originating at or around the kneecap (patella) and the joint between the kneecap and the thigh bone (femur). It is characterised by anterior knee pain that worsens with activities requiring a bent, loaded knee: squatting, climbing stairs, prolonged sitting, running, and kneeling. It is the most common cause of anterior knee pain in active adults and adolescents.

The word ‘syndrome’ is necessary. PFPS is not a single structural injury like a ligament tear or a meniscus rupture. It is a clinical diagnosis applied when the characteristic anterior knee pain cannot be attributed to a specific identifiable structural abnormality on imaging. This is precisely why patients feel dismissed: MRI shows nothing torn, nothing broken, yet the pain is real and genuinely limiting. Understanding PFPS means understanding that the cause is functional and biomechanical rather than structural, and that this is exactly why standard rest-and-wait management consistently fails.

Runner’s Knee vs Patellofemoral Pain Syndrome

The terms are frequently used interchangeably, but they do not mean the same thing, and the distinction matters for treatment. ‘Runner’s knee’ is a colloquial term for two entirely different conditions that both cause knee pain in runners.

The first is patellofemoral pain syndrome: pain at the front of the knee, around or behind the kneecap, aggravated by squatting, stairs, and prolonged sitting. The second is iliotibial band syndrome (ITBS): pain on the outer side of the knee, at the point where the IT band crosses the lateral femoral condyle, aggravated by repetitive knee flexion and extension during running: same umbrella label, completely different anatomy, completely different mechanism, completely different treatment.

A patient who Googles ‘runner’s knee’ and reads advice for ITBS when they actually have PFPS will do the wrong exercises and wonder why nothing improves. The first step in effective management is pinning down which condition is actually present.

Hidden Front of Knee Pain Causes: How Hip Problems Are Involved

The most clinically important insight about PFPS is one that most patients never receive: the pain is in the knee, but the cause is frequently above it. The kneecap tracks in a groove on the thigh bone during knee movement. When it tracks correctly, the joint surfaces glide smoothly under load. When it does not, the compressive forces concentrate on specific areas of the cartilage and the surrounding soft tissue, producing pain.

What determines whether the kneecap tracks correctly is not primarily the knee itself. It is the alignment of the entire lower limb from the hip down. Weak hip abductors and external rotators allow the femur to rotate inward during loading activities like running and squatting, drawing the kneecap laterally off its intended tracking path. This is the hidden cause: the pain generator is at the knee, but the fault is at the hip. Most standard physiotherapy programmes that focus exclusively on quadriceps strengthening treat the site of pain and miss its source.

Who Is Prone To Patellofemoral Pain Syndrome

PFPS has a specific risk profile worth understanding because it identifies both who needs to be alert to the condition and which interventions are most relevant.

• Runners: the most affected sporting population, particularly those who increase their training volume too quickly or run with poor lower limb mechanics.
• Adolescents and young adults: the condition is more common in the second and third decade of life, when athletic participation is high, and the musculoskeletal system is still adapting to increasing training loads.
• Women: consistently higher rates than men, related to differences in hip and knee alignment (wider pelvis producing greater Q-angle) and relative differences in hip abductor strength.
• Desk-based workers: prolonged sitting with the knee flexed loads the patellofemoral joint and is a known aggravating factor, producing front-of-knee ache that worsens over the course of an office day.
• Those with flat feet or overpronation: excessive inward roll of the foot during gait is transmitted up the kinetic chain, contributing to the femoral internal rotation that disrupts patellar tracking.

How Our Doctors At Sancheti Diagnoses PFPS

PFPS is a clinical diagnosis. A patient’s history of anterior knee pain aggravated by certain activities combined with reproduction of that pain on clinical examination is sufficient for diagnosis in the majority of cases. Imaging does not diagnose PFPS and is used primarily to exclude other structural pathology.

The clinical assessment includes several specific steps. Watching the patient perform a single-leg squat is informative: an inward collapse of the knee during loading directly implicates hip abductor weakness and femoral internal rotation as drivers. Clarke’s test, which reproduces pain by resisting patellar movement during a quadriceps contraction, supports the diagnosis. Hip strength testing, particularly for abduction and external rotation, identifies the proximal weakness that is driving the distal pain.

X-ray is recommended when a structural cause needs to be ruled out or when the presentation is atypical. Most straightforward PFPS cases do not require MRI before starting treatment.

Treatment: What Experts Actually Recommend

Current evidence clearly prioritises hip and core strengthening over isolated quadriceps training for PFPS management. This is the most important shift in understanding of PFPS treatment in the past decade. A rehabilitation programme focused only on the quadriceps addresses the muscle group at the site of pain while leaving the biomechanical fault at the hip completely uncorrected.

• Load management: reducing the activities driving the pain in the acute phase while maintaining cardiovascular fitness through lower-load alternatives.
• Patellar taping (McConnell technique): applying tape to reposition the kneecap medially provides immediate, short-term pain relief for many patients, creating a window in which rehabilitation is less painful.
• Foot orthoses: in patients with significant overpronation, a prefabricated or custom orthosis that controls excessive foot pronation reduces the rotational force transmitted up to the knee.
• Activity and training modification: addressing the training load error or technique fault that produced the condition.

Recovery Timeline For Patellofemoral Pain Syndrome

Recovery from PFPS is driven by progressive loading, not rest. The timeline below reflects a structured approach to returning to full running and sport.

When Conservative Treatment Is Not Enough

The large majority of patients with PFPS achieve significant improvement with a properly structured conservative programme over 6 to 12 weeks. In cases where six months of appropriate physiotherapy-led rehabilitation has not produced adequate relief, the clinical picture needs to be reassessed rather than simply repeating the same management.

The first question is whether the diagnosis is correct: persistent PFPS despite appropriate treatment raises the possibility that a structural cause was missed, including cartilage damage under the kneecap, a symptomatic plica, or early patellofemoral arthritis.

Surgery for PFPS is rare and specifically targeted. Arthroscopic lateral release, which cuts the tight lateral retinaculum to pull the kneecap back on track, is performed in cases with documented lateral patellar tilt on imaging and a genuine failure of conservative management. It is not a routine procedure and is considered only after a thorough reassessment confirms that a specific anatomical abnormality is driving the ongoing pain. At our Sancheti Hospital’s Sports Medicine Centre in Pune, we evaluate these complex cases, with arthroscopy reserved for the small minority in which anatomy, not mechanics, is the primary driver.

Key Takeaways

• Patellofemoral pain syndrome is the most common cause of front-of-knee pain. A normal MRI does not mean the pain is not real; it means the cause is biomechanical and functional rather than structural.
• ‘Runner’s knee’ and PFPS are overlapping but distinct terms. Lateral knee pain in runners is iliotibial band syndrome. Front-of-knee and kneecap pain is PFPS. The difference determines the entire treatment approach.
• The hidden cause of PFPS is usually at the hip, not the knee. Weak hip abductors and external rotators allow the femur to rotate inward under load, pulling the kneecap off its normal tracking path. This is why knee-only treatment so often fails.
• Hip and core strengthening is the most evidence-supported intervention for PFPS, and consistently outperforms isolated quadriceps training. Programmes that focus on the quadriceps alone address the pain site while leaving the biomechanical fault uncorrected.
• Surgery is required in a small minority of cases where a specific anatomical abnormality such as a tight lateral retinaculum is driving pain that genuine conservative management has not resolved.
• For a structured assessment of the causes of front-of-knee pain and a rehabilitation programme that addresses the biomechanical root cause rather than the symptom alone, consult Sancheti Hospital, Pune, for an appointment with my knee and sports medicine team.

Frequently Asked Questions (FAQs)

Q1. My MRI was normal, but I have been told I have patellofemoral pain syndrome. Should I be concerned that something was missed?

A normal MRI in the context of PFPS is expected, not a sign that something was missed. PFPS is defined as anterior knee pain without an identifiable structural abnormality on imaging; if a structural lesion such as a cartilage defect or meniscal tear were found, the diagnosis would change. What MRI does not show is the biomechanical dysfunction driving the pain: weak hip muscles, dynamic knee valgus during loading, or patellar maltracking under functional load. These are movement-based problems visible on clinical examination but not on static imaging. A normal MRI, typical PFPS symptoms, and a positive clinical examination make for a straightforward diagnosis. The concern is not that something was missed on imaging; it is whether the treatment plan addresses the biomechanical cause rather than simply the pain.

Q2. I have been resting for six weeks, and the pain keeps returning when I run. What am I doing wrong?

Rest removes the provocative load but does nothing to address the biomechanical fault that caused the pain in the first place. When you return to running with the same hip weakness, the same patellar tracking problem, and the same movement pattern, the pain returns because the underlying cause is unchanged. Rest is not treatment for PFPS; it is a reprieve. The effective intervention is a structured rehabilitation programme that specifically strengthens the hip abductors and external rotators, improves single-leg loading mechanics, and gradually re-exposes the knee to running load in a controlled, progressive manner. Most patients who rest, feel better, return to running, and re-injure themselves repeat this cycle two or three times before reaching specialist care. Starting the rehabilitation programme rather than repeating the rest cycle is the correct next step.

Q3. Can I continue running while treating patellofemoral pain syndrome?

In most cases, yes, with modification. Complete rest is unnecessary and often counterproductive. The goal is to keep running at a level that does not provoke significant pain (more than three out of ten on a pain scale is a commonly used practical threshold) while the rehabilitation programme builds the hip and core strength that will allow the full load to be reintroduced progressively. For most recreational runners, this means reducing volume by 50%, temporarily avoiding hills and hard surfaces, and adding the hip and core programme alongside a shorter, flatter, slower running load. The volume is then increased by no more than 10% per week as symptoms allow. Stopping running entirely and restarting at the same volume that caused the original problem is one of the most common and avoidable errors in PFPS management.

Q4. My front-of-knee pain is worse after sitting for a long time in the office. Is this PFPS or something else?

The ‘theatre sign’ or ‘movie sign’, which is pain or stiffness at the front of the knee after prolonged sitting with the knee bent, is a characteristic feature of PFPS. It occurs because sustained knee flexion loads the patellofemoral joint in a position that concentrates pressure on the cartilage surfaces. Standing and walking briefly relieve it as the joint pressure redistributes. If your front-of-knee pain worsens with prolonged sitting, squatting, and stairs, and is located around or behind the kneecap rather than on the inner or outer side of the joint, PFPS is the most likely diagnosis. Pain on the inner or outer joint line (the sides of the knee, not the front) after sitting more typically indicates meniscal irritation rather than patellofemoral pain.

Q5. How long does patellofemoral pain syndrome take to resolve, and will it come back?

Most patients with PFPS achieve significant symptom improvement within 6 to 12 weeks of a properly structured rehabilitation programme targeting hip and core strength alongside graded return to activity. Full resolution, meaning pain-free running and squatting without restriction, typically takes 3 to 6 months in patients presenting with established symptoms lasting more than a few weeks. Recurrence is the main long-term challenge: PFPS has a high recurrence rate in patients who complete a rehabilitation course and then stop the hip and core maintenance exercises. The patients who do best in the long term are those who integrate the hip abductor and core programme into their regular training as a permanent habit rather than viewing it as a temporary fix. For runners specifically, a gait retraining component, whether addressing cadence, foot strike, or dynamic knee valgus, significantly reduces the risk of recurrence.