Applied Anatomy of the Knee Joint Flashcards
What are the articulating surfaces of the bones in the knee joint
- Patella
- Condyles of femur
- Condyles of tibia
What are the landmarks found on the anterior and posterior surface of the patella
- Anterior - Base, Apex, Medial border, lateral border.
- Posterior - Facet for lateral condyle of femur (larger), facet for medial condyle of femur.
What is the space between the medial and lateral condyles of the femur called and what attaches here
- Intercondylar area
- Attachment for cruciate ligaments
What are the landmarks on the superior surface of the tibia
- Intercondylar eminence
- Medial articular area
- Lateral articular area
- Anterior intercondylar area
- Posterior intercondylar area
What is attached in the intercondylar area of the tibia
- Menisci
What are the movements possible at the knee joint
- Flexion and Extension
- Associated rotation
- Locking and Unlocking
During extensions what way does the femur rotate to lock the knee
- Medial rotation
Before flexion after extension what way does the femur rotate to unlock the knee and what muscle causes this movement
- Laterally
- Popliteus
What structures are intracapsular but extra synovial
- ACL
-PCL - Tendon of popliteus
Why are ACL tears more frequent than PCL tears
- PCL is twice as strong and main stabiliser of knee joint. Prevents hyperflexion
What type of injuries are more likely to cause PCL tears
- Dashboard injuries
What are treatments for ACL and PCL tears
- Physiotherapy
- Ligament reconstruction surgery if whole tear
1What is Lachman’s test
- Flex patient’s knee to 20-30 degrees
- Grasp the distal end of the femur and proximal end of the fibula and alternately pull forward and push backward.
- Movement of 5mm or more suggests ACL tear
How do you test for injury to PCL
- Similar actions to Lachman’s test however push tibia backwards rather than pulling it forward. If there us access movement there is injury to PCL
What are the differences between medial and lateral menisci
- Medial meniscus has a thicker posterior horn whereas lateral meniscus has equal horns
- Medial meniscus merges with medial collateral ligament whereas the lateral ligament does not.
- Medial meniscus has semimembranosus ligament behind it whereas lateral meniscus has popliteus ligament behind it
Which meniscus is more prone to injury
- Medial meniscus
- Stronger medial coronary ligament is strong - less mobility
- Attachment to medial collateral ligament and capsule
- Lateral meniscus is more mobile
Where does the nutrition of the menisci come from
- Outer part has a blood supply
- Inner part relies on synovial fluid
If menisci are not pain sensitive what causes pain during meniscal tears
- Articular surfaces becoming eroded due to friction cause pain
What causes meniscal tears
- They soften with age
- Severe trauma
- Forceful twisting injury
- Osteoarthritis
What imaging technique would you use to diagnose a meniscal tear
- MRI
What is treatment for meniscal tears
- Surgical
- Arthroscopy (interventional radiology)
- Meniscopexy (observe legion and fix)
- ## Meniscectomy (removal if beyond repair)
What muscles cause extension of the knee
- Vastus medialis
- Vastus lateralis
- Vastus intermedialis
- Rectus femoris
What muscles cause flexion of the knee
- Biceps femoris
- Semimebranosus
- Semitendinosus
- Popliteus
- Plantaris
- Gastrocnemius
What does Hilton’s Law state
- The nerve supplying the muscle that lies across a joint also supplies the joint beneath and the skin overlying those muscles.
Why is it important to know motor-sparing techniques when performing procedures like total knee arthroplasty
- Do not want to effect motor supply to knee when attempting to block nerves during TKA.
Name 2 deformities of the knee
- Vagum - inturned knees
- Varum - outurned knees
What is a age related pathology of the knee
- Osteoarthritis of the knee
- Decreased compartmental space with subluxation
