Please Note: This is not a diagnosis, it is being provided to help you and a health care professional understand possible causes of your
condition. You must see a local professional for an evaluation and
orthopedic testing.
Runners Knee is also known as "Patellofemoral Pain Syndrome (PFPS)" which essential describes the symptoms not the cause of the problem.
So you basically were given a term to describe what you already knew (not exactly useful). I’m surprised further testing was not done.
Chondromalacia Patella
From the limited information I have it sounds like Chondromalacia Patella.
Which is the combination of patellar tracking issues and deterioration of articular cartilage on the posterior surface of the patella.
I would have to perform special orthopedic tests to narrow down the cause.
Essentially the information below is what your PT should be looking for to rule in / out this diagnosis (normally the information below isn’t given to
patients but it sounds like you’ve been getting nowhere with this --
hopefully this gives your PT a direction to figure out what is going
on).
Clinical Picture
- Generally there is a gradual onset of diffuse aching pain over the
anterior or anteromedial aspect of the knee.
There may or may not be inflammatory signs.
There is often crepitus (cracking) as the knee moves thru its ROM
There is an exacerbation of pain with activities such as squatting,
kneeling, and ascending stairs.
There is what is referred to as a positive movie sign – that means
that refers to seating in a movie – fair amount of flexion – will get
achy in the ant/medial knee to the extent where you have to change
position or shake out the knee – patient may also have a feeling of the
knee catching or giving way.
- Typically see mechanical causes of this pathology – will affect not
only tracking but also the contact surface areas of the PF jt
Etiology – Mechanical Causes
- Genu Valgum (means knee) – where we are going to see an increase in the valgus vector at the knee- which is going to affect tracking.
- Femoral Anteversion
- Excessive Internal Femoral Rotation- alters the Q angle which
increases the lateral stresses.
- Patella Alta – if the length of the patellar tendon exceeds the top
to bottom displacement of the patella by 15% or 1 cm
- Laxity of medial capsular retinaculum
- Tightness of the lateral retinaculum
- Acute or chronic patellar subluxations
- Pronation of the foot
- External Tibial Torsion
- Weakness of the VMO
This pathology – referred from the floor up – or from the hip down
Usually there is something going on above or below the joint – results
in this pathology – must find what is causing this to be successful
Treatment
If you understand the cause you will be able to effectively plan the
intervention
There are things you can’t fix- structural deformities – if it
involves structures that displace the patella laterally
The follow will also alter patellar tracking. Excessive pronation of the foot, weakness of VMO, tightness of lateral retinaculum or ITB (ober , patellar tilt test) , weakness of frontal plane hip muscles
Misc Notes
- Terminal Extension Exercises - Don’t strengthen the VMO
- Open Kinetic Chain (OKC) – the literature says the OKC ex from a position of 90-45 degrees of flexion is the safe arc in terms of joint reaction forces to do open chain work
- Close Kinetic Chain (CKC) - that arc of safe movement – is from 0-60 degrees of knee flexion
What Professional(s) to See
An outpatient physical therapist should be able to narrow this down. As far as Musculoskeletal related issues the leading experts in this field are orthopedic surgeons (with physical therapists being #2).
Professional Bias
However be aware just like a PT will advocate therapeutic exercise - a surgeon will tend to lean toward surgery.
Also see DoctorWhom's post below as he has provided some great insight that should help guide you what to do next.
Sources
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5095938/
http://www.jospt.org/doi/pdf/10.2519/jospt.2010.0302?code=jospt-site