Knee Flashcards
Meniscus Zones
Red-Red: Outer 1/3 (will heal well)
Red-White: Middle 1/3 (some vascularity, sometimes will heal but often won’t)
White-White: Inner 1/3 (potential to heal is very low)
Meniscus Pathophysiology
- Usually twisting
- Pain with movement, better with rest
- May have locking (bucket handle)
- Joint line tenderness (hallmark)
- Acute Effusion (usually within 2 hours)
Meniscus Issues Based on Age
Acute is usually sudden onset and in people less than 40. Chronic usually no specific mechanism and in people >50.
How common are meniscus lesions?
Almost as common as RTC tears. How old you are is about the percentage likelihood of having a RTC tear (20% in 20’s, 30% in 30’s).
Types of meniscal tears?
- Longitudinal
- Bucket handle
- Radial (cut along width)
- Root tear (at the root)
- Oblique/Flap (looks like a little penis coming off the middle)
- Horizontal (horizontal tear)
When will meniscal tears heal?
If less than 35 years old and on the periphery there is likelihood that it will heal.
Factors for good vs bad prognosis with meniscus tears?
Good:
- Age <35
- Longitudinal tear
- Peripheral tear
- Short tear
- Acute injury with bloody effusion
- Stable knee
Poor:
- Older patient
- Central damage
- Complete tear
- Bucket handle tear
- Chronic injury
- Unstable knee
Most sensitive test for meniscus tear
Joint line tenderness
McMurray’s and Thessaly’s Tests
They have decent specificity but poor sensitivity.
Exercises to be careful with following meniscal repair?
If medial meniscus repair the semimembranosus attaches to this so be careful with isolated hamstring strengthening.
Articular cartilage damage grades?
1: Nearly normal (superficial lesions. Soft indentation and/or superficial fissures/cracks)
2: Abnormal (extends down <50% of cartilage depth)
3: Severely abnormal (extends down >50% into calcified layer and down do but not through subchondral bone)
4: Into subchondral bone
How is articular cartilage managed surgically?
Palliative -> Reparative -> Resorative
- Debridement and levage
- Removes particle of cartilage and cleans
- Cochrane Review: Probably doesn’t do much for pain/function - Micro fracture
- Poke holes through tide mark (bottom layer of cartilage that is somewhat calcified)
- Hyaline cartilage is replaced with fribrocartilage though (fibrocartilage is less resilient)
- WB has to be controlled
- Advocated as 1st line of intervention
- Decent short term data but less optimal medium/long-term
- LIkely not appropriate for athlete - Autologous chondrocyte implantation
- 2 step process
- 1st surgery you go in and harvest chondocytes and grow them in a Petrie dish
- Then you go back in and implant then and put a periosteal flap over it
- Mixed reviews on outcomes - Osteochondral Autograft Transplantation System (OATS)
- Harvest a bone plug from NWB surface (femoral notch) and then implant into defect
- Not great outcomes
Rehab after cartilage procedure
Usually very slow rehab. Have to go slow. Need large amounts of passive motion (CPM up to 8-10 hours each day) to smooth out the surface
How to see if knee valgus is related to pain?
Have them exaggerate their valgus, it should make their pain worse. Then have them correct the valgus, they should feel better.
Ways to reduce knee valgus?
Check the sagittal plane. Anterior pelvic tilt will IR the hips. When running try to have them “run taller” this will require less knee flexion and decrease the valgus.
