Knee patho (PF and ottawa)- Dr. Davies Flashcards
Ottawa Knee Rules (what is the point)
why do you need a radiograph
a negative result on an Ottawa Knee Rule test accurately excluded knee fx after an acute knee injury
acute knee injury- only about 7% have fracture
Ottawa Knee Rules (details on the studies)
N=4249
Sen= 98.5%, Spec= 48.5%
*quite a bit of research on this starting back in 1995, done on thousands of patients
*the final one was a systematic review on the guidelines, when to use and when not to use a radiograph
Ottawa Knee Rule (type of knee injuries)
most knee injuries results from a direct blow, fall, or twisting injury
Blows and falls are referred to as a macrotrauma or “blunt injury” and account for 25% of knee injuries (80% of all fractures)
finding a fracture in a blunt injury versus a twisting injury
finding a fracture is 4 times more likely after a blunt injury than after a twisting injury
Ottawa Knee Rule (5 yes or no)
1) age 55 years or older
2) isolated tenderness of patella (no bone tenderness of knee other than patella)
3) tenderness at head of fibula
4) inability to flex knee past 90*
5) inability to bear weight both immediately and in an ER for 4 steps (unable to transfer weight twice onto each lower limb regardless of limping)
why do you need a radiograph in adults over the age of 55?
osteoporosis, etc occurs more in older adults
tenderness on the patella (Ottawa Knee Rules)
usually secondary to landing on the patella if they fall or if something hit them directly; direct marcotrauma
tenderness over the head of the fibula (Ottawa Knee Rules)
occurs when there is a direct macrotraumic injury to the head of the fibula
which Ottawa Knee Rule does Dr. Davies not agree with
not being able to bend the knee past 90*
there are a lot other injuries (ACL, PCL, meniscus, etc) that can cause the knees to not want to bend past 90 (from a twisting injury)
Ottawa Knee Rules (practical application)
patient’s preference and point of view might influence the use of the Ottawa Knee Rules in clinical practice
what are the first two parts of the body parts to “go”
the low back is first to “go” then the knees
Patellar Femeral Pain Syndrome (other names)
(PFPS) (AKPS) anterior knee pain syndrome the black box of orthopedics the mysterious syndrome *so many different possibilities, yet the most common in the knee*
How to grade the patella
grade on a quadrant system
the patella is sitting in the center of the femoral sulcus; will push the patella out of the sulcus and grade the subluxation; grade 2 is normal
(grade 1 is hypo, grade 3 is hyper)
*testing the superficial fibers of the retinaculum
measuring a tilt of the patella
measuring the deep fibers of the retinaculum
a line through the medial and lateral epicondyles; will tilt the patella; the tilt is defined as the direction towards the femur (so the medial tilt will test the lateral deep fibers)
15* is normal
how to treat PFPS
the key to treating patients with PFPS is to treat the CAUSE and not just the SYMPTOMS
Sun Rise View
the x ray beam is at different angles to see the patella in the femoral trochlea (there are different types of views that are dictated by the doctor, Skyline view, etc)
which is higher: lateral or medial femoral condyle in relation to the patella
the lateral side should always be higher, it should acts as a boney buttress
Lateral Trochlear Dysplasia
when the lateral trochlea is the same high as the media
measurements on the sunrise view
TT: tibial tuberosity
TG: trochlear groove
Q angle
where you measure from the ASIS to the mid patella to the tibial tuberosity
it measures the pull of quadriceps at the knee
~valgus vector- 5-10 for males, 10-15 for females
Patella Alta
(grasshopper eyes)
found by the Insall-Salvati Ratio on a lateral radiograph; patient is standing and measure the tibial tuberosity to the inferior pole of the patella and inferior to the superior pole of patella; should be 1:1 ratio (.2 is the standard deviation)
unstable patella
Squinting Patellas
can be with Patella Alta or Baja;
patellas are inward
Patella Infera (Baja)
smaller Install-Salavati Ratio
more OA changes