Week 4 Lecture 4B - Patellofemoral Joint

Question 1

Question 2

The patella helps your leg move and it wouldn’t move as well without it because it acts as a pulley and increases the moment arm. Hard to extend knee without patella. They lose power in the quads without it.
Patella takes on a lot of load.

Question 3

Patellofemoral Pain Syndrome (PFPS)

Pain in the (anterior/posterior) knee
20-40% of all knee problems

Prevalence rate:
15-30% adolescent & young adults
Female > male

AKA:
chondromalacia patella, anterior knee pain

Will see this a lot at out patient clinic.

Answer 3

anterior

Question 4

Could be tear of the meniscus
The patellar tendon 
Could be OA 
Could be lumbar spine 
Pes anserine – anteromedial part of the knee  - Seargant – Sartorius, gracilis, semitendinosus
Rule it out – by palpation 

Meniscus rule it out by history , will behave differently – will catch and click and along the joint line
IT band – location differently – nobles compression test
Pain from lumbar spine – LQ screen – make them move their lumbar spine

Question 5

Pain
Instability – patella is moving too much

Pain – could be anywhere on the knee

Provokes their pain – anything that compresses the PF joint, anything that loads the PF joint , squatting, leg extension, sitting with the knee flexed

Have them do the thing that hurts, do therapy, later on ask them to do that thing and ask them what their pain level is to track progress – asterisk sign

Question 5

PFPS Diagnosis

1. presence of patella (LOM/pain)
2. Reproduction of patella pain with squat or loading activity (step up, step down)
3. Exclusion of all other conditions that could cause (posterior/anterior( knee pain

Answer 5

pain; anterior

Question 6

Scott dye – operate on his knee without anesthesia
Fat pad is (not innvervated/ innervated/super sensitive)
The anterior capsule is (not innervated / innervated/ super sensitive)

Cartilage wasn’t painful – it (is/isn’t) innervated

Answer 6

innervated/super sensitive; innervated/super sensitive; isn’t

Question 7

Tight lateral – cut the retinaculum and loosen it up in those with PFPS

They have excessive nerve growth – more sensitive to pain – people with PFPS

Question 8

Subchondral bone is innervated – cartilage wear (thin and degraded) – puts extra stress on the bone underneath it and that is why people have pain

Question 9

Right in the middle of the joint – wears evenly . If only touching on the below pic – will cause a lot of stress

If doesn’t track well in flexion/extension it can ride the lateral rim which causes increased pressure

Question 9

Sitting flexed at 45 , xray beam comes from 60

Pics – glided to the side in those with PFPS

Question 10

Take measurements to see how far it is from normal

Should be 60 degrees medial.

Center to the apex of the patella is the measurement taken here.

Positive number - lateral

Question 11

Take two images, one on top of the other – TT and TG

If tibial tubercle is on the lateral side, as the patella moves from flexion to extension , it would get pulled off to the side in a lateral direction. Would create increased stress on the lateral side of the patella

Question 12

How deep is the trochlea – sulcus angle

Question 13

As you move from flexion to extension, if the femur IR that (increases/decreases) the contact area.

Strengthening the vmo doesn’t work

Train on track – patella on femur
Now we think about it in reverse

Answer 13

decreases

Question 14

Chris powers story

People that went into valgus – patella sitting on the (middle/lateral) part of the trochlea, contact area will be (more/less).

Answer 14

lateral; less

Question 15

All pf pain is not the same, have to figure out what is going to treat it

Answer 15

Got it

Question 16

Palpate and find the pain.

Is it the tendon? Have to differentiate it

MPFL – look at the pic – sometimes folks with instability have pain there.

Question 17

Question 18

Normal Patella Mobility

AAOS Evaluation
Superior glide: At 0°
(mid-patella/inferior pole) = joint line

Inferior glide: At 0°
(mid-patella/inferior pole) = joint line

1/4 to 1/2 of its width medially and laterally - (1-2/3-4) quadrants

It moves (less/more) superiorly than inferiorly .

Answer 18

inferior pole; mid-patella; 1-2; more;

Question 19

Lateral glide – shift in the frontal plane. Whole thing is shifted laterally

Lateral tilt – shift in the transverse plane

Things shift laterally

Question 20

A/P tilt – runs inferiorly

Rotation – he called it unicorn, hasn’t ever seen one

Question 21

shorter on the lateral side – do a (medial/lateral) glide

Answer 21

lateral

Question 22

Underneath the inferior pole is the infrapatellar fat pad which is really sensitive and highly innervated

Question 23

Medial-Lateral Tilt Normal Tilt 5 degrees (medial/lateral) (knee at 30 degrees) Should slant to lateral side 5 degrees – more than that – tight (medial/lateral) structures like the IT band

Answer 23

lateral; lateral;

Question 24

Can you get it above horizontal ? if you cant, it’s not normal – tight (medial/lateral) structures

Answer 24

lateral;

Question 25

Should be about a 1to1 ratio. Sitting position of the patella – if patella sticks out from up top when sitting – alta Patella alta describes a patella positioned too high or more proximal than normal. Conversely, patella baja describes a low-lying patella or patella positioned more distal than normal.

Question 26

Patella position: superior and inferior ``` Insall-Salvatti index T/P The Insall-Salvati ratio or index is the ratio of the patella tendon length to the length of the patella 30 degrees flexion _ - _ = normal More than _ = alta Less than _ = baja ``` Patella Alta or Baja: -(Increases/Decreases) contact area (increased pressure) -Unstable? Long tendon – the number will be above one Short tendon – less than one That affects the congruity of the joint Will be unstable – long periods of the ROM not in the trochlea could lead to dislocation

Answer 26

.8-1.2; 1.2; .8; Decreases;

Question 27

Question 28

Pushing the patella into the trochlea to see if it hurts or reduces their pain.

Question 29

If can’t maintain the contraction, positive test This and the patellar compression test are shitty (according to prof)

Question 30

Resisted KE at 15 deg, 45 deg, 90 deg + = Pain or reproduction of symptoms Resisted knee extension at three diff positions When you do that you push the patella into the trochlea to reproduce pain. If they have pain at end range – you prob won’t start there with therapy

Question 31

An unstable knee can cause PF pain.

Question 32

Diff presentations of PF pain Classifications Global Compression (Increased/Decreased) patellar mobility (Loose/Tight) soft tissue Post surgical /immobilization Lateral patellar compression syndrome: (ELPS: excessive lateral pressure syndrome) Tight (medial/lateral) structures Pain can be medial (MPFL) or lateral or both Instability Subluxation / dislocation - (medial/lateral) MPFL injury/ Medial stabilizers (Deep/Shallow) trochlea - large sulcus angle Q angle TT-TG distance Compression – hypomobile in all direction Post op patients lose patella mobility If someone has been in a brace could cause loss of mobility at the patella Tight lateral structures - Tight IT band/tight lateral retinacula. Instability – patella dislocates laterally normally. Can tear the MPFL which is a major medial stabilizer Q angle / tt-tg – if they are large could cause dislocation

Answer 32

Decreased; Tight; lateral; lateral; Shallow;

Question 33

Classification Biomechanical dysfunction ``` Kinetic chain dysfunction Distal: Excessive (pronation/supination) Muscle length (G/S) Foot arch structure ``` ``` Proximal: Structure hip strength- Recruitment Endurance Proprioception ``` ``` Local: Patella structure Alta Baja (potential cause? – ACLR) Quad strength ``` Excessive pronation – IR of the tibia and femur. IR of the femur (increases/decreases) contact area. Muscle length of gastroc and soleus Foot arch – flexible flat foot Baja – could be caused by ACLReconstruction

Answer 33

supination; decreases

Question 34

Distal Factors Subjects with PFPS: Increased navicular drop Increased Rearfoot (inversion/eversion) Ankle joint ROM (TCJ) Gastroc/soleus length Component of pronation - rearfoot eversion

Answer 34

eversion;

Question 35

Proximal Factors Structure: The Hip Femoral Anteversion: increased hip (EROT/IROT) IROT of femur causes (decreased/increased) load on (medial/lateral) patella

Answer 35

IROT; increased; lateral;

Question 36

Proximal Factors Strength PFPS vs Normals Decreased hip (adduction/abduction) strength Decreased hip (flexion/extension) strength Decreased hip (internal/external) rotation strength People with PFPS tend to have those impairments

Answer 36

abduction; extension; external;

Question 37

Proximal Factors - Frontal Plane Projection Angle PFPS caused by poorly controlled femoral (external/internal) rotation in weight bearing FPPA (dynamic valgus) greater in subjects with Decreased strength of hip (ADD/ABD) and (IROT/EROT) FPPA (dynamic valgus) (Lesser/Greater) in PFPS

Answer 37

internal; ABD; EROT; greater

Question 38

Local Factors Patellofemoral contact area Points of contact change with knee motion ``` No contact in full (flexion/extension) 15-20° = (middle/inferior) pole 45° = (middle/inferior) pole 90 = (superior/all portions) Full flexion = (superior and inferior/medial and lateral) aspects ``` Contact area increases with (flexion/extension) - Most at _ degrees Patella Alta or Patella Baja can alter these As patella moves from extension to flexion Extension – sits above trochlea

Answer 38

extension; inferior; middle all portions; medial and lateral; flexion; 90

Question 39

As you move deeper into flexion in the closed chain you have (less/more) PF reaction forces and PF compression

Answer 39

more

Question 40

As you move from flexion to extension in the open chain, the PFJR forces (increase/decrease) More PROM than AROM – Lag

Answer 40

increase