Knee meniscal issues Flashcards
T or F
Meniscectomy does not impact risk of knee OA development
False. It does
What are 6 primary functions of the meniscus?
- load transmission; spreads loading over a larger area
- shock absorption
- joint stability
- joint nutrition
- joint lubrication
- proprioception
What portion of the menisci have a blood supply?
How does the rest of the meniscus get nutrition?
- the outer 10-30% has a blood supply in an adult
- diffusion of synovial fluids
Menisci are made up of ___% water
65-70%
Menisci are thick _____ and thin ______
thicker peripherally, thinner centrally
Describe the following for the lateral meniscus:
- shape
- relative size
- relative mobility
- muscle attachments?
- ligament attachments?
o Shape: 4/5s of a circle
o Smaller and more mobile than the medial (~10 mm of movement)
o Muscle attachment: directly popliteus muscle aids in stability
- attached to LCL
Describe the following for the medial meniscus:
- shape
- relative size
- relative mobility
- muscle attachments?
- ligament attachments?
o Shape: “C-shaped”
o Larger and less mobile (~2 mm of movement)
o Muscle attachment: indirectly w/ the semimembranosus
o More attachments to the joint capsule, limiting translation and mobility compared to the lateral side
- attached to MCL
Does the lateral or medial femoral condyle rotate more?
- lateral needs to rotate a bit more
What nerve innervates the menisci?
- common peroneal n (reccurent peroneal branch)
The anterior/posterior horns are stressed in what positions?
- extremes of flexion and extension
T or F;
PTs can consistently differentiate between acute vs chronic meniscal tears
- F
____% of pts with symptomatic OA also had meniscal tears
- 91%
Is the medial or the lateral meniscus more often injured?
- medial
The lateral meniscus has a higher incidence of injury in what population?
- younger/athletic
Is gender associated with meniscal injury?
- yes; more often in females
What are the characteristics of most meniscal injuries? (4)
- closed-chain
- high shear forces
- more often non-contact
- generally with a foot planted and twisting
The medial meniscus often is injured at the same time as what other two structures?
- MCL
- ACL
Is an acute dx of meniscal tear right after injury typically valid?
- if just clinical exam, no. Too much pain, swelling, irritability to differentiate structures at that point.
What should be done with palpation of the joint line when examining for a suspected meniscal tear?
- palpate w/ medial/lateral rotation, tibfem loading and ER/IR
Should you be able to differentiate between the joint line and meniscus itself with palpation?
- yes
What are 3 standard provocation tests for meniscal tear?
- McMurray’s
- Thessaly
- Apley’s compression
What 2 ROMs should Thessaly be done at?
- 5* and 20* flx
Is examining dynamic control more or less of a concern in younger patients w/ meniscal defects?
- less of a concern. With chronic degenerative tears, some stability is lost, thus dynamic stability will be more important to quantify on exam
Do you expect quad lag with older patients with chronic knee pain?
- yes. quad weakness is common with chronic knee pain, often overtly demonstrated w/ quad lag
