PFFS (Patellofemoral Pain Syndrome) is one of the most common symptoms in the anterior knee area and is also known as runner’s knee. Behind PFSS there is no uniform clinical picture, but a very complex symptom, which is discussed very differently in terms of definition, diagnosis, and etiology (causes).
The definition of an Australian research group is: pain originating in the anterior knee and the patello-femoral region (area of the articulated connection between the kneecap and the femur) of mostly unclear cause.
The patellofemoral joint suffers from degenerative changes as early and frequently as hardly any other joint, and to this day there is no method for the reliable repair of cartilage damage. Frequently, young, athletically active, more often female people are affected by PFFS (Patellofemoral Pain Syndrome).
Please check our article about Meniscus damage: Causes, Symptoms, and Treatment
Symptoms of Patellofemoral Pain Syndrome
- Pain in the area of the kneecap (behind, next to, under)
- Start-up pain after prolonged resting position of the knee joint
- Pain intensifies after sporting activities, when climbing stairs, squatting
- Restricted movement, feeling of tension due to swelling in the kneecap area
Pain can occur unilaterally, bilaterally or alternately
Read more about Anterior cruciate ligament rupture: Symptoms and Treatment
Causes of kneecap pain
- Bony deviations of the patella and knee joint (bow legs / knock-knees)
- Bony deviations of the hip or ankle joint
- Too tight patella guidance due to shortening of the ligament
- Thigh muscle weakness
- Muscle shortening of the thigh, hip and calf muscles
- Classical overloading of the knee joint
- Pain due to bony deviations of the knee
Due to an underdevelopment of the patella (patellar dysplasia), a forward displacement of the thigh or a so-called patella alta (patella too high), an incongruous joint surface between patella and thigh (patella sliding bearing) occurs with the consequence of a deteriorated guidance of the patella. A patella alta is a thigh muscle tendon (patella tendon) that is too long in comparison to the longitudinal diameter of the patella. As a result of this disproportion, the patella moves too far outwards (laterally) as the knee stretches, the contact surface of the joint decreases and the pressure load of the patella on the thigh increases. The consequences are irritation of the surrounding soft tissues, damage to the patellar cartilage and pain under pressure.
An x-B adjustment of the knee joint (genu valgus) or an O-B adjustment (genu varus) also changes the tension conditions of the thigh extensor (M. Quadriceps) and the position of the patella in its sliding bearing on the thigh. This promotes arthrosis (cartilage degeneration) of the patella and knee joint cartilage.
The patellar cartilage requires adequate pressure and relief in order to remain healthy. In addition to the structural changes described above, the risk factors for cartilage damage include a lack of physical disposition, insufficient movement and load, and a disproportion between load and capacity.
You can also check other articles about Knee pain and conditions, causes and treatment
- Rathleff MS, Skuldbol SK, Rasch MN, Roos EM, Rasmussen S, Olesen JL. Care-seeking behaviour of adolescents with knee pain: a population-based study among 504 adolescents. BMC Musculoskelet Disord. 2013. 14:225. (Level of evidence [LOE]: 2) [PMC free article] [PubMed]
- Wood L, Muller S, Peat G. The epidemiology of patellofemoral disorders in adulthood: a review of routine general practice morbidity recording. Prim Health Care Res Dev. 2011;12(2):157–164. (LOE: 3) [PubMed] [Google Scholar]
- Nimon G, Murray D, Sandow M, Goodfellow J. Natural history of anterior knee pain: a 14- to 20-year follow-up of nonoperative management. J Pediatr Orthop. 1998;18(1):118–122. (LOE: 2) [PubMed] [Google Scholar]
- Molgaard C, Rathleff MS, Simonsen O. Patellofemoral pain syndrome and its association with hip, ankle, and foot function in 16- to 18-year-old high school students: a single-blind case-control study. J Am Podiatr Med Assoc. 2011;101(3):215–222. (LOE: 2) [PubMed] [Google Scholar]
- Boling MC, Padua DA, Marshall SW, Guskiewicz K, Pyne S, Beutler A. A prospective investigation of biomechanical risk factors for patellofemoral pain syndrome: the Joint Undertaking to Monitor and Prevent ACL Injury (JUMP-ACL) cohort. Am J Sports Med. 2009;37(11):2108–2116. (LOE: 2) [PMC free article] [PubMed] [Google Scholar]
- Taunton JE, Ryan MB, Clement DB, McKenzie DC, Lloyd-Smith DR, Zumbo BD. A retrospective case-control analysis of 2002 running injuries. Br J Sports Med. 2002;36(2):95–101. (LOE: 2) [PMC free article] [PubMed] [Google Scholar]