Editors

AriItälä

Patellofemoral Pain (Pfp)

Anterior knee pain is one of the most common pain states in the knee area and is seen particularly in young adults.
The pain is located behind or around the patella and associated with strain.
About 20% of the patients are less than 20 years old; 75% are under the age of 50.
The condition was previously commonly called patellar chondromalacia.

The aetiology of anterior knee pain is multifactorial and still disputed. Subjective symptoms are not necessarily accompanied by objective clinical findings.
Inappropriate strain of the patellofemoral (PF) joint is considered to be a significant aetiological factor.
Such strain may be functional or anatomical.

The diagnosis is clinical and based on typical symptoms. There is pain on exertion mainly around the patella, often mostly at its medial margin. Squatting, walking down stairs, kneeling or prolonged sitting with bent knees (cinema phenomenon) predispose to symptoms.
Patients often report crepitation, pseudolocking and snapping.
MRI can be used to exclude any other causes of pain, as necessary.
Hydrops is rarely present.

The aim of treatment is first to alleviate the irritation of the PF joint.
The next aim is to gradually strengthen the muscles affecting the function of the PF joint.
Best results are achieved by sufficiently early individual rehabilitative treatment addressing functional problems.
Significant straining of the PF joint should be reduced in daily routines and work tasks.

Partial rest for 1 to 2 weeks
Avoiding movements that strain the PF joint; cold therapy and anti-inflammatory analgesics if needed

Straight leg lifting with 20 repeats. The series is repeated 3 times a day for 2 weeks, thereafter 5 times a day. When this can be performed well, weights of 3-5 kg are attached to the ankle. The exercises are performed in a supine or sitting position. Exercises must never be started with a flexed knee. By palpating the quadriceps muscle the therapist should confirm that the patient is performing an isometric contraction, affecting the vastus medialis in particular.
The patient should be advised about the good prognosis of the condition and that it does not lead to osteoarthritis of the knee even in the long term. Furthermore, the patient should be advised that healing might take several months.
A specialist should be consulted not earlier than 3 months from the onset of symptoms for any patient with significant symptoms not alleviated by physiotherapeutic exercises.
A patellar supports or taping may be of benefit. Taping aims to realig the movement of the patella to a more medial route.

Surgical treatment is of no benefit in the treatment of anterior knee pain 3. Surgical treatment should be considered only in case of rare structural anomalies of the lower limb.

Collins NJ, Barton CJ, van Middelkoop M et al. 2018 Consensus statement on exercise therapy and physical interventions (orthoses, taping and manual therapy) to treat patellofemoral pain: recommendations from the 5th International Patellofemoral Pain Research Retreat, Gold Coast, Australia, 2017. Br J Sports Med 2018;52(18):1170-1178. [PubMed]
Dye SF. The pathophysiology of patellofemoral pain: a tissue homeostasis perspective. Clin Orthop Relat Res 2005;(436):100-10. [PubMed]
Kettunen JA, Harilainen A, Sandelin J et al. Knee arthroscopy and exercise versus exercise only for chronic patellofemoral pain syndrome: a randomized controlled trial. BMC Med 2007;5():38. [PubMed]
Rogers DL, Cosgarea AJ. Evaluating Patellofemoral Patients: Physical Examination, Radiographic Imaging, and Measurements. Clin Sports Med 2022;41(1):1-13. [PubMed]