Patellofemoral Syndrome

Updated: Jan 09, 2023
Author: Noel F So, MD, FAAPMR; Chief Editor: Ryan O Stephenson, DO 


Practice Essentials

Patellofemoral syndrome (PFS) is characterized by a group of symptoms that contribute to anterior knee pain and that often respond to conservative management. The pain is associated with positions of the knee that result in increased or misdirected mechanical forces between the patella and femur.[1, 2, 3] Lack of consensus regarding the cause of PFS remains, likely because several factors associated with the syndrome present differently in each patient. Arthroscopy helps to confirm the diagnosis of PFS by allowing direct visualization of the cartilage surface. The basic exercise principles for the management of the syndrome are improving the range of motion of the iliotibial band, hip flexors, and quadriceps; strengthening the core, quadriceps, hip abductors, hip extensors, and hamstrings; and restricting the offending physical activity.

Symptoms of patellofemoral syndrome

Knee pain is the most common presentation of PFS. The pain characteristically is located behind the kneecap (ie, retropatellar) and most often manifests during activities that require knee flexion and forceful contraction of the quadriceps (eg, during squats, ascending/descending stairs).

Diagnosis and management of patellofemoral syndrome

PFS is a clinical diagnosis based on history and physical examination. Plain film radiographs can assess the patella (kneecap) position. The anterior-posterior (AP) view shows the patella over the sulcus; the lateral view is imaged at 45º of knee flexion and in full extension to determine the height of the patella (ie, whether it is baja [low] or alta [high]). The sunrise view visualizes the patellofemoral articulation in the femoral condylar groove and can determine the tilt or angle of the patella, as well as demonstrate the depth of the intercondylar groove.

Advanced imaging studies such as computed tomography (CT) scanning or magnetic resonance imaging (MRI) are rarely needed but can be part of the diagnostic workup for refractory cases to ensure that there is no concurrent intra-articular disease or other contributing pathology. In addition, arthroscopic evaluation can provide assessment of joint structures that may cause symptoms that mimic PFS when they are impaired and allows for the direct visualization of the cartilage surface.

PFS responds well to a rehabilitation program. The initial treatment stage is designed to decrease pain, using modalities such as ice, analgesic medication, nonsteroidal anti-inflammatory drugs (NSAIDs), and activity modification. Patellar taping techniques are used in patients with PFS to reduce friction on the patella. A neoprene knee sleeve with the patella cut out is also helpful, as it provides proprioceptive feedback.

The rehabilitation treatment stage uses therapeutic exercise to restore flexibility, strength, and proprioception to the lower limb kinetic chain. Orthotics or appropriate footwear are sometimes recommended.

If PFS presents concurrently with knee pain secondary to degenerative changes and conservative measures fail, aspiration of effusion, along with injection of the knee joint with steroid or hyaluronic acid, may be tried. Surgical intervention for patellofemoral syndrome usually is in the form of arthroscopic evaluation followed by release of the lateral attachments of the patella. Most authors agree that surgical treatment rarely is indicated.


While theories regarding the pathophysiology of patellofemoral syndrome vary, identification of the resultant forces involved in dynamic and static knee positions has been fundamental to the research on this syndrome. Factors believed to contribute to production of retropatellar pain include impairments affecting the patellofemoral joint interface. Such impairments may result from an imbalance of ligamentous and muscle forces, malalignment between the joint surfaces, excessive knee valgus (ie, increased Q-angle) resulting in increased lateral forces, and quadriceps contractures causing production of excessive leverage forces on the patellofemoral joint surface. Excessive use of the joint, either in frequency of loading or excessive loading, also contributes to the symptoms.



Patellofemoral syndrome is estimated to be the most common cause of anterior knee pain in athletic and nonathletic populations.

United States

Patellofemoral syndrome is common in the United States, especially among physically active persons.


Patellofemoral syndrome has an estimated prevalence rate of 20% in student populations.


Morbidity associated with patellofemoral syndrome is directly proportional to the activity level of the patient. Curtailing physical activities that place unnecessarily stressful demands upon the patellofemoral articulation may be necessary (preferably while substituting other activities into the exercise program).


No racial predilection has been identified for patellofemoral syndrome.


Patellofemoral syndrome more frequently affects females than males.


Patellofemoral syndrome occurs most frequently in adolescents and young adults.




Knee pain is the most common presentation of patellofemoral syndrome (PFS). The pain characteristically is located behind the kneecap (ie, retropatellar) and most often manifests during activities that require knee flexion and forceful contraction of the quadriceps (eg, during squats, ascending/descending stairs).

Pain may worsen in intensity, duration, and rapidity of onset if the aggravating activity is performed repeatedly.

Pain may be exacerbated by sitting with the knee flexed for a protracted period of time, such as while watching a movie, hence leading to the terms "theatre sign" and "movie-goer's knee." Patients with this condition often may prefer to sit at an aisle seat, where they may more frequently keep the knee extended.

Symptoms often occur during the activity, shortly thereafter, or sometimes even the following day.

PFS is also known as "runner's knee" or "biker's knee," as PFS is highly associated with running and biking.

Patellofemoral weight bearing increases with knee flexion as follows:

  • Walking - 0.5 times body weight
  • Ascending or descending stairs - 3.3 times body weight
  • Squatting - 6 times body weight


Physical examination of a patient with patellofemoral syndrome should include examination of the musculoskeletal system, including the following[4] :

  • The upper and lower body should be examined to exclude generalized diseases that make up the differential diagnoses (eg, osteoarthritis).

  • The usual physical findings are localized around the knee.

  • Tenderness often is present along the facets of the patella. The facets are most accessible to palpation by manipulation of the patella while the knee is fully extended and the quadriceps muscle is relaxed. Manual positioning of the patella medially, laterally, superiorly, and inferiorly allows for palpation of the respective facets.

  • An apprehension sign may be elicited by manually fixing the position of the patella against the femur and having the patient contract the ipsilateral quadriceps.

  • Crepitus may be present, but if present in isolation, crepitus does not allow for definitive diagnosis.

  • Determine the Q-angle by measuring the angle between the tibia and femur. Use the attachment of the patella to the patellar tendon as the intersection point.

  • Examination of gait may demonstrate excessive foot pronation, excessive knee valgus, or an antalgic gait pattern.

  • Repetitive squatting may reproduce knee pain.

  • Use the physical examination and historical details to help exclude other diagnoses.

  • Examination of the contralateral limb is equally important, as the syndrome often is bilateral. However, one side usually manifests more symptoms.

  • Palpation of the tibial tuberosity may detect tenderness suggesting that other impairments also are present.

  • Determining the bulk of the vastus medialis is possible, because it is situated superficially and has little overlying tissue. Bulk may be observed by direct visualization during contraction. The vastus medialis is believed to be the most active muscle in the last 15° of resisted knee extension, making this the best arc of movement for assessing its strength.

  • Genu recurvatum and hamstring weakness may contribute to the occurrence of patellofemoral syndrome, and therefore, identifying such impairments may aid in the choice of management.


A literature review by Arazpour et al found that compared with healthy subjects, persons with patellofemoral syndrome tend to have the following[5] :

  • Reduced gait velocity
  • Reduced cadence
  • Decreased knee extensor moment in association with the loading response and terminal stance
  • Delayed peak rear foot eversion in association with gait
  • Increased hip adduction

The reports used in the review differed as whether hip rotation in patellofemoral syndrome increased, decreased, or remained the same.


The potential causes of patellofemoral syndrome remain controversial and are therefore more appropriately referred to as associated factors.[2] Overuse, overloading, and misuse of the patellofemoral joint seem to be the cornerstone factors on which most authors agree.

In a 2011 study of high school running athletes, the results suggest that stronger preinjury hip abductors and weaker preinjury hip external rotators are linked to PFS development. Also, patients exhibiting PFS seem to lose hip abduction and external rotation strength in comparison with their preinjury strength. A higher hip external-to-internal rotation strength ratio was found to possibly protect against PFS development.[6]



Diagnostic Considerations

These include the following:

  • Referred pain from hip

  • Osgood-Schlatter syndrome

  • Sinding-Larsen–Johansson syndrome

  • Neuroma

  • Quadriceps rupture

  • Patellar tendonitis

  • Patella fracture or dislocation

  • Peripatellar bursitis

  • Plica syndromes of the anterior knee

  • Meniscal or ligamentous lesions

  • Radicular pain

  • Infection of the knee joint

  • Tumor (eg, knee joint, femur)

Differential Diagnoses



Laboratory Studies

See the list below:

  • Laboratory studies generally are not indicated for the diagnosis of patellofemoral syndrome.

Imaging Studies

See the list below:

  • Imaging studies usually are not necessary in order for a physician to diagnose or recommend treatment for patellofemoral syndrome (PFS). Imaging studies should be considered for unusual presentations and for persons in whom the syndrome is refractory to conservative management.

    • Sunrise views should be included with anterior-posterior (AP) and lateral radiographic imaging of the knee. Limited positions of flexion are available for such viewing. These radiographs provide more of an indirect observation of what is happening within the articulation.

    • Lateral patellar tilt and a high-riding patella (patella alta) may be observed.

    • Osteophytes or joint space narrowing may be identified, suggesting arthritic changes in the articular cartilage.[7]

  • Nuclear scans are less likely to be of value in defining PFS and are more useful in helping to identify other, less common conditions that may mimic PFS, as outlined in the differential diagnoses. When changes have occurred in the retropatellar cartilage, mild increases in uptake of radionucleotide may be observed. Increased uptake of radionucleotide is not limited to the patella; it may be seen in the proximal tibia, distal femur, or patella.[8]

  • Computed tomography (CT) scanning and magnetic resonance imaging (MRI)

    • CT scanning and MRI allow for imaging at various angles of flexion.

    • CT scanning with the knee in full extension has been demonstrated to more accurately detect patellar subluxation.

    • Cross-sectional viewing allows more direct visualization of the articulation between the patella and femur.

    • Schutzer et al identified 3 patterns of malalignment using CT scanning[9] :

      • Type 1 includes patellar subluxation without tilt.

      • Type 2 is described as patellar subluxation with tilt.

      • Type 3 is patellar tilt without subluxation.

Other Tests

Serology, joint aspiration, and related tests are indicated only when alternative diagnoses are suspected. Such investigations are not likely to provide useful information in this syndrome, as it is not a disease entity but rather a group of symptoms occurring sometimes in association with multiple factors (intrinsic and extrinsic).[10]

A study by Ferrari et al indicated that surface electromyography (sEMG) can be used in patients with referred anterior knee pain to diagnose PFS. In the study, which involved 22 persons with PFS and 29 persons without pain, the investigators found that by using the medium frequency ̶ band parameter, it was possible to differentiate between the two groups. They concluded that EMG signals from the vastus lateralis and vastus medialis muscles with referred anterior knee pain can be used in the diagnosis of PFS.[11]


See the list below:

  • Arthroscopy

    • Arthroscopy helps to confirm the diagnosis of patellofemoral syndrome (PFS) by allowing direct visualization of the cartilage surface. Arthroscopic evaluation also provides assessment of joint structures that may cause symptoms that mimic PFS when they are impaired.

    • Arthroscopy also has the ability to facilitate surgical alteration of patellar tracking (eg, lateral release). Visualization of the patella may allow for some revision of the cartilage surface. However, most authors agree that surgical treatment is rarely indicated.

Histologic Findings

Histologic findings are dependent on the extent to which the cartilage surfaces have been compromised. Shearing stresses may result in changes in subchondral bone and dysplasia of the cartilage surface. More severe cartilage changes have been identified in persons with patellofemoral syndrome that has been refractory to conservative measures.



Rehabilitation Program

Physical Therapy

The basic exercise principles for the management of patellofemoral syndrome (PFS) are improving the range of motion of the iliotibial band, hip flexors, and quadriceps; strengthening the core, quadriceps, hip abductors, hip extensors, and hamstrings; and restricting the offending physical activity. Quadriceps strengthening traditionally is performed while the knee is flexed 0-30°. Controversy remains regarding the extent to which the individual muscle groups making up the quadriceps can selectively be strengthened. Usually, the lateral forces of the vastus lateralis need to be countered better by the vastus medialis. This goal is accomplished best by strengthening all of the quadriceps.

Stretching of the quadriceps should be of long duration (20-30 seconds) and performed with low force. This technique allows for overcoming neural and connective tissue barriers to lengthening. Exercises to stretch the iliotibial band, hip, hamstring, and calf also are important for patients with PFS. Manual stretching of the lateral retinaculum may be used as a conservative approach, partially mimicking the effect of lateral retinacular release. Physical therapists should educate patients about home exercise programs that include stretching and strengthening exercises.

Syme et al found that selective and general physical therapy are valuable for the rehabilitation of patients with PFS.[12] In a prospective, single-blind, randomized, controlled trial, 8 weeks of physical therapy—which in one group of patients selectively emphasized retraining of the vastus medialis, and in another group, emphasized general strengthening of the quadriceps—proved superior to the provision of no treatment, for pain reduction and improvement in subjective function and quality of life. The investigators suggested that selective physical therapy may be appropriate early in rehabilitation.

Further evidence for the effectiveness of quadriceps strengthening in PFS therapy was found in a systematic literature review by Kooiker et al. The investigators reported that an analysis of seven studies strongly supported the superiority of physical therapist–guided quadriceps-strengthening exercises over placebo or advice/information alone in treating pain and increasing function in PFS.[13]

In a prospective, independent, group comparison by Chiu et al, 15 participants with and without PFS were given an MRI evaluation for knee strength, patellofemoral joint contact area, and patellar tilt angle. All the participants performed lower-limb weight training 3 times a week for 8 weeks. The outcomes were evaluated both before and after training. The study concluded that the weight-training exercises increased knee muscle strength and the patellofemoral joint contact area. This may reduce mechanical stress in the joint, which would lessen pain and improve function for those with PFS.[14]

A study by Kölle et al of the effects of a 12-week home exercise program on patients with PFS found benefits with regard to pain and function, as demonstrated by a 27-point improvement on the visual analog scale score and a 10-point improvement on the Kujala Anterior Knee Pain Scale score. The investigators also reported that when, on EMG, the vastus medialis showed delayed onset or reduced activity compared with the vastus lateralis, this imbalanced was reduced following the exercise program.[15]

A literature review by Alba-Martín et al indicated that the most effective therapeutic exercise programs for patellofemoral syndrome with regard to pain relief and functional improvement include “proprioceptive neuromuscular facilitation stretching and strengthening exercises for the hip external rotator and abductor muscles and knee extensor muscles.”[16]

A systematic literature review by Peters and Tyson indicated that proximal exercises are more effective than knee exercises in the treatment of PFS. In an analysis of eight studies, the investigators found that proximal exercise programs consistently reduced pain and improved function, with patients demonstrating short- and long-term improvement, while the results from knee exercise programs were more variable.[17]

In contrast to the above studies, a literature review by van der Heijden et al stated that while consistent evidence for the benefits of exercise therapy in reducing pain and improving function in PFS exists, the data is of very low quality. The investigators also stated that the evidence is too weak to indicate which type of exercise therapy is most effective.[18]

Ice packs frequently are used to decrease pain and inflammation associated with PFS, especially after completing the exercises. Other modalities that may be useful and commonly are incorporated into physical therapy include electrical stimulation and biofeedback.

Patellar taping techniques are used in patients with PFS to reduce the friction on the patella. Many physical therapists are trained in the McConnell method of taping of the knee. Some patients report reduction of pain when wearing the tape. Some individuals report that the taping allows them to complete more functional quadriceps-strengthening activities without anterior knee pain. If successful, the physician or physical therapist can teach the patient self-taping techniques to use at home. (A study by Araújo et al reported, however, that in patients with PFS engaged in proprioceptive exercises, McConnell patellar taping does not change knee and hip muscle activation differences in comparison with placebo taping.[19] )

A study by Yoon and Son indicated that during stair ambulation, both the McConnell and Kinesio taping methods reduce pain and improve gait parameters. However, McConnell taping was associated with a greater decrease in pain and, as a result, more improvement in gait variables. The investigators used the Kujala anterior knee pain scale, in which lower scores signify greater pain. Prior to intervention, scores in the McConnell and Kinesio groups were 65.16 and 65.87, respectively, while post intervention they were 74.64 and 70.24, respectively.[20]

Proper footwear also is important for individuals with PFS. Overpronation of the foot contributes to dynamic knee valgus moments. The physical therapist can evaluate the patient's biomechanics and recommend proper shoes and orthoses, which in turn can lessen knee pain.

Foot orthoses are often of benefit in returning the subtalar joint to a nearly neutral position; this reduces foot pronation, thereby decreasing rotational forces in the tibia that affect tracking of the patella during locomotion.[21] Improvement in quality of life measures has been demonstrated following provision of custom orthoses to individuals with PFS and excessive foot pronation.

One study compared the effectiveness of off-the-shelf foot orthoses in the treatment of PFS pain with that of either flat inserts or physical therapy; the report also investigated whether the combined use of orthoses and physical therapy is more effective than the employment of physical therapy alone.[21] The prospective, single-blind, randomized trial utilized 179 patients (including 100 women) between ages 18 and 40 years.

By 6 weeks, patients using orthoses had experienced greater improvement than had persons using flat inserts, but the orthotic group had experienced no significant difference in improvement over patients treated with physical therapy or with a combination of orthoses and physical therapy. By 52 weeks, a significant improvement in patellofemoral pain had occurred in all of the patient groups.

Another study focused on identifying individuals with PFS who would most likely benefit from foot orthoses. The determination was that patients who had 3 of the following clinical predictors were most likely to benefit: footwear motion control properties score of less than 5 (indicating less supportive footwear), lower levels of pain (< 22 mm), ankle dorsiflexion range of motion (< 41°), and reduced single-leg squat pain when wearing the orthoses.[22]

Soft knee braces may also be of benefit to patients with PFS by enhancing proprioception. Bracing involves control of the tracking position of the patella and restriction of full knee flexion. Braces vary in the manner in which the patella is restricted (eg, patellar window, patellar bar, patellar horseshoe), but they accomplish the same theoretical result. Braces that are tightly applied directly over the patella should be avoided, because they actually increase patellofemoral pressures and may exacerbate the condition.

A study by Uboldi et al reported that in patients with patellofemoral syndrome (PFS), employment of an elastomeric knee brace may permit faster return to sport. The brace used elastomeric bands to create an anterior weblike structure, with the extensible components elongating to reduce impact forces on the patellofemoral joint and proprioceptive contact maintained over the whole range of motion. The investigators found that at 6-month follow-up, 24 out of 30 patients (80%) in whom brace use was combined with a rehabilitation program had returned to sport, compared with 14 out of 30 patients (47%) who underwent rehabilitation without use of the brace.[23]

Occupational Therapy

Recommend a change in activity level or the ergonomics of the offending activity until the symptoms of patellofemoral syndrome are under control. Activities that require repetitive squatting are a good example. The task or sport may need to be modified to reduce the frequency of squatting, or the patient may need to choose an alternate occupation or recreational activity. Occupational therapists can be of assistance when reviewing the ergonomics of the environment in which symptoms occur with individual patients.

Recreational Therapy

Introducing alternative recreational pursuits and means of fitness may be of benefit in alleviating symptoms of patellofemoral syndrome when conservative measures are not effective. Modifications in recreational pursuits may need to be only temporary measures if other conservative measures are effective.

Medical Issues/Complications

Most symptoms of patellofemoral syndrome resolve with simple measures. As with many exercise routines, patients often fail to adhere to the exercise prescription, producing treatment results that appear to be refractory but which are actually caused by the fact that the therapeutic approach has not been given a fair trial. Follow-up studies suggest that more than 95% of persons who are compliant with treatment have results that are acceptable or better.

Surgical Intervention

Surgical intervention for patellofemoral syndrome usually is in the form of arthroscopic evaluation followed by release of the lateral attachments of the patella. Most authors agree that surgical treatment rarely is indicated. Arthroscopy has been cited as assisting the physician with clinical diagnoses; however, the visualization procedure, in and of itself, does not significantly help the symptoms of patellofemoral pain.[24]

  • Surgical procedures performed for patellofemoral arthritis include lateral facetectomy and patellar resurfacing.

  • Follow-up evaluations long after anterior advancement of the tibial tuberosity suggest limited results with this procedure.

  • Research on cartilage transplantation is being performed. Additional surgical options may be added in the future.

  • Arthroscopic drilling of osteochondral defects allows healing of the defect with fibrocartilage. This procedure routinely is performed. This form of cartilage is not of the normal type but provides for an improved surface compared to an osteochondral defect.


Management of patellofemoral syndrome overlaps many specialties, including primary care, physical medicine and rehabilitation, and orthopedics.

Other Treatment

Knee pain secondary to defined degenerative changes may be relieved by injecting the joint with steroid or synthetic hyaluronic acid. Such management of patellofemoral syndrome is rare. Injection may be used when many symptoms result from disruption of the joint surface and when all other reasonable measures have failed.

Medical Care

NSAIDs may assist with pain relief.


PFS is a common overuse injury. Varying workouts, incorporating strengthening and stretching into routines, employing proper hydration and nutrition, and increasing focused activity by 10% weekly are general guidelines to reduce the risk of developing overuse injuries.



Guidelines Summary

Consensus-based recommendations on exercise therapy and physical interventions in patellofemoral pain from the 2015 and 2017 International Patellofemoral Pain Research Retreats include the following[25] :

  • Exercise therapy reduces pain in the short-, medium-, and long-term and improves function and symptoms in the medium- and long-term
  • Compared with knee targeted exercise therapy, combined hip and knee targeted exercise treatment reduces pain and improves function, in the short-, medium-, and long-term
  • Combined interventions reduce pain in the short- and medium-term
  • Prefabricated foot orthoses reduce pain in the short-term

The consensus statements did not recommend that patellofemoral, knee, or lumbar mobilizations be employed in isolation or that electrophysical agents (such as ultrasound, phonophoresis, or laser therapy) be used. Moreover, the statements reported uncertainty with regard to the efficacy of patellar taping/bracing, acupuncture/dry needling, manual soft tissue techniques, blood flow restriction training, and gait retraining, in the treatment of patellofemoral pain.[25]



Medication Summary

Two approaches to medicating symptoms of patellofemoral syndrome are recognized. These approaches are administration of analgesic medication and administration of nonsteroidal anti-inflammatory drugs (NSAIDs). Analgesics commonly are restricted to acetaminophen or aspirin. The choices of NSAIDs available for management of joint pain are expanding continuously. Consider tolerance of medication (which may result in epigastric distress), prior history of gastric ulceration, renal disease, possible interaction with other medications, and cost. The NSAIDs all have similar efficacy, but changes in formulation have been made to reduce the frequency of adverse effects. Selective cyclooxygenase 2 (COX-2) inhibitors have fewer gastrointestinal adverse effects.

Nonsteroidal anti-inflammatory drugs

Class Summary

No NSAID has been found to be more effective in treating symptoms of patellofemoral syndrome than any other, although tolerances of NSAIDs vary between individuals. Listed below are the commonly used NSAIDs. These NSAIDs are used predominantly in the adult population. Except for the COX-2 NSAIDs, most have similar adverse effect profiles, and most have the same effect on prostaglandins.

Diclofenac (Cataflam, Voltaren)

Inhibits prostaglandin synthesis by decreasing activity of enzyme cyclo-oxygenase, which in turn decreases formation of prostaglandin precursors.

Etodolac (Lodine, Lodine XL)

Inhibits prostaglandin synthesis by decreasing activity of the enzyme cyclo-oxygenase.

The decreased activity of cyclo-oxygenase results in decreased formation of prostaglandin precursors, which in turn results in reduced inflammation.

Flurbiprofen (Ansaid)

May inhibit cyclo-oxygenase enzyme, which in turn inhibits prostaglandin biosynthesis.

These effects may result in analgesic, antipyretic, and anti-inflammatory activities.

Ibuprofen (Motrin, Ibuprin)

DOC for patients with mild to moderate pain. Inhibits inflammatory reactions and pain by decreasing prostaglandin synthesis.

Indomethacin (Indocin, Indochron ER)

Rapidly absorbed. Inhibits prostaglandin synthesis. Metabolism occurs in liver by demethylation, deacetylation, and glucuronide conjugation.

Ketoprofen (Actron, Orudis, Oruvail)

For relief of mild to moderate pain and inflammation. Small dosages initially are indicated in small and elderly patients and in those with renal or liver disease.

Doses over 75 mg do not increase therapeutic effects. Administer high doses with caution and closely observe patient for response.

Nabumetone (Relafen)

Nonacidic NSAID rapidly metabolized after absorption to a major active metabolite that inhibits cyclo-oxygenase enzyme, which in turn inhibits pain and inflammation.

Naproxen (Aleve, Naprelan, Anaprox, Naprosyn)

For relief of mild to moderate pain. Inhibits inflammatory reactions and pain by decreasing activity of cyclo-oxygenase, which results in a decrease of prostaglandin synthesis.

Oxaprozin (Daypro)

For relief of mild to moderate pain. Inhibits inflammatory reactions and pain by decreasing activity of cyclo-oxygenase, which is responsible for prostaglandin synthesis.

Piroxicam (Feldene)

Decreases activity of cyclo-oxygenase, which in turn inhibits prostaglandin synthesis. These effects decrease formation of inflammatory mediators.

Sulindac (Clinoril)

Decreases activity of cyclo-oxygenase, which in turn inhibits prostaglandin synthesis. Results in a decreased formation of inflammatory mediators.

Cyclo-oxygenase-2 (COX-2) inhibitors

Class Summary

Although increased cost can be a negative factor, the incidence of costly and potentially fatal GI bleeds is clearly less with COX-2 inhibitors than with traditional NSAIDs. Ongoing analysis of cost avoidance of GI bleeds will further define the populations that will find COX-2 inhibitors the most beneficial.

Celecoxib (Celebrex)

Inhibits primarily COX-2. COX-2 is considered an inducible isoenzyme, induced during pain and inflammatory stimuli. Inhibition of COX-1 may contribute to NSAID GI toxicity. At therapeutic concentrations, COX-1 isoenzyme is not inhibited, thus GI toxicity may be decreased. Seek lowest dose of celecoxib for each patient.



Further Outpatient Care

Allow time for conservative measures (eg, exercise) to have a therapeutic effect in patients with patellofemoral syndrome. A period of 4-6 weeks usually is adequate for some resolution of symptoms. Longer delays before follow-up often result in reduced compliance with treatment recommendations. Reinforcement of treatment goals and strategies is important.

Further Inpatient Care

The standard procedure for treatment of individuals with patellofemoral syndrome is performed on an outpatient basis. Inpatient care generally is not indicated.

Inpatient & Outpatient Medications

Outpatient medications for individuals with patellofemoral syndrome include common analgesics or NSAIDs (see Medication). Most individuals manage without medication once initial symptoms have been controlled.


Prevention of patellofemoral syndrome (PFS) is accomplished by following exercise recommendations and making changes in activity, as described in previous sections. In female athletes, decreased hamstring-to-quadriceps strength ratios have been associated with an increased prevalence of overuse injuries, suggesting that maintaining adequate hamstring strength may act as a preventative strategy. Braces have been tried on asymptomatic subjects undergoing rigorous basic military training, with a subsequent decrease in the incidence of PFS compared with the subject population that did not use the braces.


Complications in patients with patellofemoral syndrome may result secondary to the effects of NSAID use. Occasional dermatologic reactions occur due to the brace material. Prescribed exercises rarely result in aggravation of symptoms. If a specific activity is determined to be associated with aggravation of symptoms, then accordingly modify the frequency, duration, and intensity of the activity

Chronic patellofemoral overload and maltracking may predispose to chondromalacia patella

Surgical overcorrection may contribute to maltracking in the opposite direction. For example, overcompensated lateral retinacular release may cause the patella to maltrack medially.


The prognosis for full functional recovery in cases of patellofemoral syndrome is very good. In general, this syndrome is successfully treated with conservative measures. Because the prognosis is so good, refractory cases should be closely reviewed with regard to compliance and understanding of treatment recommendations.

A randomized, controlled trial suggested that gender and the duration of symptom complaints are predictive of which patients with PFS will respond to exercise therapy. The study, which included 131 patients who were randomized to receive exercise therapy or usual care, found that among patients in the exercise group, females and patients who had complained of symptoms for more than 6 months were more likely to report having achieved functional improvement beyond that of the usual-care patients at 3-month follow-up.[26]

Patient Education

Educate the patient so that he/she understands which activities aggravate patellofemoral syndrome. In addition, emphasize the need for extended adherence to the exercise regimen. The patient's physical therapist should educate the patient about a home exercise program, making sure the patient has a good understanding of the exercises.


Questions & Answers


What is patellofemoral syndrome (PFS)?

How is patellofemoral syndrome (PFS) diagnosed?

How is patellofemoral syndrome (PFS) treated?

What is the pathophysiology of patellofemoral syndrome (PFS)?

What is the prevalence of patellofemoral syndrome (PFS)?

What is the morbidity associated with patellofemoral syndrome (PFS)?

What are the racial predilections of patellofemoral syndrome (PFS)?

What are the sexual predilections of patellofemoral syndrome (PFS)?

Which age groups have the highest prevalence of patellofemoral syndrome (PFS)?


Which clinical history findings are characteristic of patellofemoral syndrome (PFS)?

Which physical findings are characteristic of patellofemoral syndrome (PFS)?

What causes patellofemoral syndrome (PFS)?


Which conditions should be included in the differential diagnoses of patellofemoral syndrome (PFS)?

What are the differential diagnoses for Patellofemoral Syndrome?


What is the role of lab tests in the workup of patellofemoral syndrome (PFS)?

What is the role of imaging studies in the workup of patellofemoral syndrome (PFS)?

What is the role of joint aspiration in the workup of patellofemoral syndrome (PFS)?

What is the role of sEMG in the workup of patellofemoral syndrome (PFS)?

What is the role of arthroscopy in the workup of patellofemoral syndrome (PFS)?

Which histologic findings are characteristic of patellofemoral syndrome (PFS)?


What is the role of physical therapy in the treatment of patellofemoral syndrome (PFS)?

What is the role of occupational therapy in the treatment of patellofemoral syndrome (PFS)?

What is the role of recreational therapy in the treatment of patellofemoral syndrome (PFS)?

What is the efficacy of physical therapy for the treatment of patellofemoral syndrome (PFS)?

What is the role of surgery in the treatment of patellofemoral syndrome (PFS)?

Which specialist consultations are beneficial to patients with patellofemoral syndrome (PFS)?

What is the role of therapeutic injections in the treatment of patellofemoral syndrome (PFS)?

Which medications are used in the treatment of patellofemoral syndrome (PFS)?

How is patellofemoral syndrome (PFS) prevented?


What are the international guidelines on the treatment of patellofemoral syndrome (PFS)?


What is the role of medications in the treatment of patellofemoral syndrome (PFS)?

Which medications in the drug class Cyclo-oxygenase-2 (COX-2) inhibitors are used in the treatment of Patellofemoral Syndrome?

Which medications in the drug class Nonsteroidal anti-inflammatory drugs are used in the treatment of Patellofemoral Syndrome?


When should conservative treatment measures for patellofemoral syndrome (PFS) be assessed?

When is inpatient care indicated for the treatment of patellofemoral syndrome (PFS)?

Which medications are used to manage pain in patellofemoral syndrome (PFS)?

What is the role of bracing in the prevention of patellofemoral syndrome (PFS)?

What are the possible complications of patellofemoral syndrome (PFS)?

What is the prognosis of patellofemoral syndrome (PFS)?

What is included in patient education about patellofemoral syndrome (PFS)?