1. Patellofemoral Pain Syndrome
Cara Strodel, Adam Copp,
Rebecca Thompson & Eddie Smith

2. The Basics
Definition: Anterior knee pain typically around or behind the patella that is aggravated in weight bearing and during knee flexion
Etiology
Overuse leads to persistent overloading
Malalignment due to both static and dynamic biomechanical abnormalities
Static: Leg length discrepancy, abnormal feet, hamstring and hip tightness
Dynamic: Muscle weakness (hip abductors, VMO), insufficient or excessive pronation
Trauma from contact sports, MVA, falling
Common in single sport athletes, young adolescents, military
Just gathering info. From the readings (Becca) (2016 Patellofemoral pain consensus statement from the 4th International Patellofemoral Pain Research Retreat, Manchester. Part 1: Terminology, definitions, clinical examination, natural history, patellofemoral osteoarthritis and patient-reported outcome measures)
The core criterion required to define PFP is pain around or behind the patella, which is aggravated by at least one activity that loads the patellofemoral joint during weight bearing on a flexed knee (eg, squatting, stair ambulation, jogging/ running, hopping/jumping).
Additional criteria (not essential)
Crepitus or grinding sensation emanating from the patellofemoral joint during knee flexion movements
Tenderness on patellar facet palpation
Small effusion
Pain on sitting, rising on sitting, or straightening the knee following sitting
Differential Diagnosis
Use a thorough history. No official tests and measures for PFP. However, here are some somewhat helpful diagnostic tools:
anterior knee pain during squatting in 80% of people with PFP
Tenderness on palpation of patellar edges
Patellar grinding and aprehension tests, Clark’s test (have low sensitivity and limited accuracy)
Knee ROM and effusion
Who Gets it?
Common in young adolescents (prevalence 7-28%; incidence 9.2%)
Single sport athletes as compared to multisport athletes
Military (more common in women than men)
Treatment Recommendations (2016 Patellofemoral pain consensus statement from the 4th International Patellofemoral Pain Research Retreat, Manchester. Part 2: recommended physical interventions (exercise, taping, bracing, foot orthoses and combined interventions)
Exercise therapy
Exercise is recommended to reduce pain in the short, medium and long term, and improve function in the medium and long term.
Combining hip and knee exercises is recommended to reduce pain and improve function in the short, medium and long term, and this combination should be used in preference to knee exercises alone.
Combined interventions
Combined interventions are recommended to reduce pain in adults with patellofemoral pain in the short and medium term.
Foot orthoses
Foot orthoses are recommended to reduce pain in the short term.
Other adjunctive interventions
Patellofemoral, knee and lumbar mobilisations may not improve outcomes.
Electrophysical agents may not improve outcomes.
From Up to Date
TERMINOLOGY — Patellofemoral pain syndrome (PFPS) can be defined as anterior knee pain involving the patella and retinaculum that excludes other intraarticular and peripatellar pathology. PFPS describes a symptom complex and is a diagnosis of exclusion.
Common synonymous terms include retropatellar pain syndrome, runner's knee, lateral facet compression syndrome, and idiopathic anterior knee pain. The term chondromalacia patella is used to describe pathologic changes in the articular cartilage of the patella, such as softening, erosion, and fragmentation. While frequently confused with PFPS, chondromalacia patella is a pathologic diagnosis and constitutes a distinct cause of knee pain [3].
EPIDEMIOLOGY — Patellofemoral pain syndrome (PFPS) is among the most common diagnoses in sports medicine. Although PFPS is often seen in active individuals and may account for 25 to 40 percent of all knee problems seen in a sports injury clinic, the true incidence is not known [4]. PFPS affects many running athletes and constitutes nearly 25 percent of all identified knee injuries [5-7]. (See "Overview of running injuries of the lower extremity".)
PFPS more commonly affects women [8]. In a seven year review of patients diagnosed with PFPS at a sports medicine clinic, the ratio of women to men was nearly 2:1 (33.2 versus percent) [9]. Another retrospective review found similar results [6].
PFPS occurs disproportionately in active adolescents and adults in the second and third decades of life [9]. One observational study found a prevalence of over 20 percent among adolescents [10].

3. The Basics Continued Signs and Symptoms
Anterior knee pain during squatting in 80% of people with PFP
Tenderness on palpation of patellar edges
Crepitus or grinding sensation from patellofemoral joint during knee flexion
Pain on sitting, rising on sitting, or straightening the knee following sitting
Positive apprehension tests, Clark’s Test (though low sensitivity and limited accuracy)
Complications
Chronic pain may lead to early retirement from sport in athletes
Chronic PFPS can lead to patellofemoral osteoarthritis
Due to abnormal tracking of the patella or patellar instability

4. Knee Anatomy

5. Case Study
Dance integrates an intricate arrangement of movements that place high physical stresses on the body. The incorporation of strength training has led to a decrease in dance-related injuries, but strength training is often not prioritized in a dancer’s regime. 90% of injuries of reported injuries include the dancer’s legs, knees, ankles and hips. Previous studies have proposed that hip and core weakness can lead to anterior knee pain. This case study emphasizes the importance of strength and neuromuscular training in female dancers with anterior knee pain.

6. Case Study History Meet Josie
Josie is a 17 year old female high school student who participates in dance up to 18 hours per week. Pt initially stated that pain was present in the anterior/medial portion of the left knee in December 2007—there was no precise mechanism of injury. Josie pushed through her injury and continued to dance, but was unable to participate in her other sports (i.e. cross country) due to significant knee pain.
As a physical therapist, it’s your job to diagnose and treat their knee pain. We want you to think of PFP (PFPS, non-specific anterior knee pain) as a referral diagnosis rather than a concrete diagnosis (akin to LBP). What SPECIFIC structures, tissues, imbalances are likely the cause of each patient’s specific pain?

7. Why Josie?
“Chronic knee pain associated with overuse is the major diagnostic category to consider if pain has persisted for approximately six weeks or longer and there has been no sudden inciting trauma associated with the development of pain. This is the category of knee pain seen most often in primary care practices. Chronic knee pain associated with overuse is typically progressive, becoming more painful with increasingly less intense activity over time. Typically, the knee examination reveals no structural instability. Many such patients suffer from patellofemoral pain (although this is a diagnosis of exclusion) or another condition related to the patella or surrounding soft tissues (eg, pes anserine, iliotibial band).”
UpToDate: “Approach to the athlete or active adult w knee pain.” Nov 2015.

8. Impairments Functional Status
Pt reports difficulty running/walking for more than 10 minutes due to pain
Ascending/descending stairs at school elicits pain--must use elevator
Pt presents with unilateral squat with genu valgus with mild patellar discomfort
Tests and Measures
Increased external rotation bilaterally in the lower quarter
Femoral anteverson--leads to compensation in weight bearing
Q-angle 8 degrees bilaterally with a hypo-mobile patella on the left
AROM hip, knee ankle WNL except for R IR at 29 degrees and L IR at 39 degrees
Pt reported 8/10 pain while dancing and 0/10 at rest. Pain is 5/10 while walking for more than 10 minutes
Pt demonstrates 5/5 strength on right and ⅘ on left for all lower extremity muscle group

9. OSCE Knee Exam Protocol
Observation: Ask the patient to walk for you. See any gait abnormalities?
Inspection: Look for symmetry, muscle wasting, scars, rashes, fixed flexion deformities.
Palpation: Feel for temperature w/ back of hand, palpate border of patella for tenderness, behind the knee for swelling, along all joint lines for tenderness and at the insertion point of the patellar tendon. Tap the patella to see if there is any effusion deep to the patella.
AROM/PROM of the joint: Feel for crepitus during PROM. Any limitations, normal end feel?
Check the ligamentous stability w/ special tests: Anterior drawer/Lachman’s for ACL, Posterior drawer for PCL, Varus and Valgus stress tests for LCL and MCL.
Check the meniscus with McMurrays.
Finally, let’s do some comprehensive MMTs (the difference between PCPs and PTs!)
Knee: flexion and extension (generally done by PCPs)
Hip: flexion, extension, abduction, adduction
Ankle: dorsiflexion, plantarflexion, inversion, eversion

10. General Treatment Plan
Main issue: Muscular imbalance
Take home point: Consensus statement recommends strengthening at hip and knee as best tx for PFP, likely bc most people presenting with PFP have muscular imbalances contributing to pain. Important to do a thorough exam to figure out specific pt issues, as PFP is a diagnosis of exclusion.
Stretching:
Hamstring
Quadriceps
Strengthening Exercises
Side-lying Leg Lift
Wall Squat with Ball
Step Up
Knee Extension with Resistance
Knee Stabilization
Quadricep Isometrics
A diagnosis of exclusion (per exclusionem) is a diagnosis of a medical condition reached by a process of elimination, which may be necessary if presence cannot be established with complete confidence from history, examination or testing. Such elimination of other reasonable possibilities is a major component in performing a differential diagnosis.
The largest category of diagnosis by exclusion is seen among psychiatric disorders where the presence of physical or organic disease must be excluded as a prerequisite for making a functional diagnosis. Diagnosis by exclusion tends to occur where scientific knowledge is scarce, specifically where the means to verify a diagnosis by an objective method is absent. As a specific diagnosis cannot be confirmed, a fall back position is to exclude that group of known causes that may cause a similar clinical presentation.

11. Putting It All Together
PFPS is difficult to define, because patients experience a variety of symptoms from the patellofemoral joint with different levels of pain and physical impairments.
Three major contributing factors of PFPS are...
Malalignment of the lower extremity and/or the patella
Muscular imbalance of the lower extremity
Overactivity
Most common symptom is anterior knee pain during squatting = 80% of people
Best treatments = strengthening exercises of the hip and stretching exercises, no surgery.

12. References
Crossley, K. M., van Middelkoop, M., Callaghan, M. J., Collins, N. J., Rathleff, M. S., & Barton, C. J. (2016) Patellofemoral pain consensus statement from the 4th International Patellofemoral Pain Research Retreat, Manchester. Part 2: recommended physical interventions (exercise, taping, bracing, foot orthoses and combined interventions). British journal of sports medicine, bjsports-2016.
Crossley, K. M., Stefanik, J. J., Selfe, J., Collins, N. J., Davis, I. S., Powers, C. M., Callaghan, M. J. (2016) Patellofemoral pain consensus statement from the 4th International Patellofemoral Pain Research Retreat, Manchester. Part 1: Terminology, definitions, clinical examination, natural history, patellofemoral osteoarthritis and patient-reported outcome measures. British Journal of Sports Medicine Br J Sports Med, 50(14), doi: /bjsports
O’Connor FG., Mulvaney, SW., Patellofemoral pain syndrome. In: UptoDate. (Accessed July 3, 2016).
Thomee, R, Augustsson J, Karlsson J. Patellofemoral Pain Syndrome. Sports Medicine. 1999;28(4): doi: /
Welsh C, Hanney WJ, Podschun L, Kolber MJ. Rehabilitation of a Female Dancer with Patellofemoral Pain Syndrome: Applying Concepts of Regional Interdependence in Practice. North American Journal of Sports Physical Therapy : NAJSPT. 2010;5(2):85-97.