Patellofemoral pain syndrome

The onset of the condition is usually gradual, Pain during prolonged sitting is sometimes termed the "movie sign" or "theatre sign" because individuals might experience pain while sitting to watch a film or similar activity. The pain is typically aching and occasionally sharp. Pain may be worsened by activities. The knee joint may exhibit noises such as clicking. Giving-way of the knee may be reported. ==Causes==

In most people with patellofemoral pain syndrome an examination of their history will highlight a precipitating event that caused the injury. Changes in activity patterns such as excessive increases in running mileage, repetitions such as running up steps and the addition of strength exercises that affect the patellofemoral joint are commonly associated with symptom onset. Excessively worn or poorly fitted footwear may be a contributing factor. To prevent recurrence the causal behaviour should be identified and managed correctly. • Tight anatomical structures, e.g. retinaculum or iliotibial band ==Diagnosis==

Examination People can be observed standing and walking to determine patellar alignment. The Q-angle, lateral hypermobility, and J-sign are commonly used to determine patellar maltracking. The patellofemoral glide, tilt, and grind tests (Clarke's sign), when performed, can provide strong evidence for PFPS. Lastly, lateral instability can be assessed via the patellar apprehension test, which is deemed positive when there is pain or discomfort associated with lateral translation of the patella. Individuals with PFP may be exhibit higher pain level and lower function. Magnetic resonance imaging rarely can give useful information for managing patellofemoral pain syndrome and treatment should focus on an appropriate rehabilitation program including correcting strength and flexibility concerns. In the uncommon cases where a patient has mechanical symptoms like a locked knee, knee effusion, or failure to improve following physical therapy, then an MRI may give more insight into diagnosis and treatment. Currently, there is not a gold standard assessment to diagnose PFPS. ==Treatment==

A variety of treatments for patellofemoral pain syndrome are available. Most people respond well to conservative therapy. There is consistent but low quality evidence that exercise therapy for PFPS reduces pain, improves function and aids long-term recovery. Exercise therapy is the recommended first line treatment of PFPS. Exercises are described according to 3 parameters: Hip abductor, extensor, and external rotator strengthening may help. Emphasis during exercise may be placed on coordinated contraction of the medial and lateral parts of the quadriceps as well as of the hip adductor, hip abductor and gluteal muscles. Along with the strengthening of quad muscles these targeted exercise programs would reduce knee valgus and strengthen pelvic stability, all of which would result in less stress to the patellofemoral joint. Knee and lumbar joint mobilization are not recommended as primary interventions for PFPS. It can be used as combination intervention, but as we continue to promote use of active and physical interventions for PFPS, passive interventions such as joint mobilizations are not recommended. When it comes to recovering from PFPS, it is important to build confidence in movement and encourage tissue adaptation without overloading the joint. There are psychological factors such as fear-avoidance and pain catastrophizing may play a role in PFPS. Medication Non-steroidal anti-inflammatory drugs are widely used to treat PFPS; however, there is only very limited evidence that they are effective. Although taping alone is not shown to reduce pain, studies show that taping in conjunction with therapeutic exercise can have a significant effect on pain reduction. Knee braces are ineffective in treating PFPS. There is no specific one treatment for all PFPS patients as most trials were underpowered. Over 80% of the reviewed trials did not show clinical benefits. The benefits may be sub-group specific and often short-term. Insoles Low arches can cause overpronation or the feet to roll inward too much increasing load on the patellofemoral joint. Poor lower extremity biomechanics may cause stress on the knees and can be related to the development of patellofemoral pain syndrome, although the exact mechanism linking joint loading to the development of the condition is not clear. Foot orthoses can help to improve lower extremity biomechanics and may be used as a component of overall treatment. Foot orthoses may be useful for reducing knee pain in the short term, and may be combined with exercise programs or physical therapy. However, there is no evidence supporting use of combined exercise with foot orthoses as intervention beyond 12 months for adults. Evidence for long term use of foot orthoses for adolescents is uncertain. No evidence supports use of custom made foot orthoses. Using radiofrequency energy delivered via small electrodes positioned at target genicular nerves, the treatment achieves partial sensory denervation of the joint capsule. Alternative medicine The use of electrophysical agents and therapeutic modalities are not recommended as passive treatments should not be the focus of the plan of care. There is no evidence to support the use of acupuncture or low-level laser therapy. Most studies claiming benefits of alternative therapies for PFPS were conducted with flawed experimental design, and therefore did not produce reliable results. == Prognosis ==

Patellofemoral pain syndrome can become a chronic injury, with an estimated 50% of people reporting persistent patellar-femoral pain after a year. Risk factors for a prolonged recovery (or persistent condition) include age (older athletes), females, increased body weight, a reduction in muscle strength, time to seek care, and in those who experience symptoms for more than two months. ==Epidemiology==

Patellofemoral pain syndrome is the most common cause of anterior knee pain in the outpatient. Specific populations at high risk of primary PFPS include runners, bicyclists, basketball players, young athletes and females. BMI did not significantly increase risk of developing PFPS in adolescents. However, adults with PFPS have higher BMI than those without. It is suggested that higher BMI is associated with limited physical activity in people with PFPS as physical activity levels decrease as a result of pain associated with the condition. However, no longitudinal studies are able to show that BMI can be a predictor of development or progression of the condition. == References ==