The Knee Flashcards
Review: Which zones of the meniscus have the highest/lowest blood supply?
Red zone: Most superficial = highest blood supply
Pink zone: Deep to red zone = intermediate blood supply?
White zone: Deepest layer of meniscus = Poor blood supply
What is considered to be normal ROM for knee flexion? What would be factors that could limit it?
140° of knee flexion is normal.
Limiting factors: Shortened position of hamstrings, physical size of hamstrings & extensibility of quads
What is the purpose of the Patella?
- Provides mechanical advantage for knee extension
- Distributes stress on femur
- Protects Pat. tendon from friction
What is the Kinetic Chain?
The connection of all joints in the body all acting in unison. This is directly affected by motions occurring at every joint beneath the spine.
The purpose of the kinetic chain is to absorb and distribute forces as they occur. If the body is unable to manage these forces, the system will breakdown, starting at the weakest link.
The knee is usually the weakest link. It’s very susceptible to injury from force absorption.
What is the Q-angle? What is the normal amount to have?
Lines which bisect the Patella relative to the ASIS and Tibial Tubercle.
Average Q-angle is 10° for males and 15° for females
Anything greater than 22° or less than 12° often leads to pathological conditions associated with improper patella tracking.
What is the A-angle?
Patella orientation relative to the Tibial Tubercle. This is a quantitative measurement of patellar realignment after rehab.
Any angle greater than 35 degrees is often correlated w/ patellofemoral pathomechanics.
What is Osteochondritis Dissecans?
A partial or complete separation of articular cartilage and subchondral bone.
What is Chondromalacia? (of the patella?)
The softening or deterioration of articular cartilage, in this specific case, caused by maltracking of the patella.
What is Patellofemoral Stress Syndrome (PFSS) ?
Result of lateral deviation of patella while tracking in femoral groove.
Could be caused by pronation, poor medial musculature, or an increased Q-angle.
What is Osgood-Schlatter disease? What differentiates it from Larsen-Johansson disease?
Osgood-Schlatter’s is an apophysitis occurring at the tibial tubercle. Usually a result of growing in young children and resolves with time.
Larsen-Johansson’s is excessive pulling on the inferior pole of the patella.
Both elicit swelling and pain with running/jumping/running and have point tenderness. Main identifier will be location of symptoms.
What is Jumper’s Knee?
Patellar tendonitis. Excessive strain on Patellar or Quad tendon.
Pain will occur at the inferior pole of patella and is categorized by 3 phases:
1. Pain after activity
2. Pain during and after activity
3. Pain during and after activity (prolonged) and could become constant
What is a common injury to the Peroneal Nerve?
Peroneal Nerve Contusion. Results from blunt force directly to nerve, compressing it.
S/S follow normal nerve disruptions: numbness, parasthesia, and localized pain.
Review: What are the most common MOI’s for an ACL injury?
- Direct blunt force
- Knee extension (indirect)
- Valgus collapse (indirect)
ex: rapid deceleration with leg extended or awkward landing from jumping with knee fully extended
