Meniscal injuries. Injuries of the knee ligaments. Knee instability. Flashcards
what is meniscus ?
it is a fibrocartilage structure containing collagen one which is above the cartilage of the lateral and medial condyle of tibia
what is the function of the meniscus ?
shock absorbing
act to disperse the weight of the body and reduce friction during movement
and joint stability
which meniscus has more probability in tear ?
medial meniscus - in the posterioir horn for degenerative tear in older patients occur with arthritis
latera meniscus tear is more common with what ?
acute anterior cruciate lig tear
what causes meniscal tear ?
twisting or jumping
what are the mechanical symptoms of meniscal injury /
locking of the knee joint with a lack of full extension - especially of bucket handle tear
clicking sounds of the knee joint
swelling of knee joint
how do we diagnose the meniscal injury ?
Mc murray test
a painful pop or click when knee is brought from flexion to extension with either internal (lateral meniscus tear) or external rotation (medial meniscus tear )
arthroscopy
MRI is usually done to confirm
tear in the peripheral 1/3 of the meniscus heals why ?
peripheral 1/3 is highly vascularised - from the vehicular arteries
middle third - may or may not heal
and inner 1/3 is avascular - tear will not heal
what is the treatment of meniscal injury ?
indicated as first line of rest , NSAIDS physical therapy removing weight of the meniscus
partial meniscectomy
with degenerative
radial tear patterns
usually do minimal removal because the arthritis is risk is proportional to the amount removed
repair of meniscal tear
suturing the torn edges back into place and allowing the meniscus to heal on its own
usually done for peripheral tear because it will heal
meniscal transplant
usually done in young patient who had total menisectomy esp the lateral meniscus
not done in rheumatoid , chondromalacia , anterior cruciate ligament instability
what are the ligaments of the knee ?
anterior cruciate lig
posterioir cruciate lig
medial collateral lig
lateral collateral lig
what are the primary ligaments which leads t instability in the knee
anterior cruciate lig
what causes anterior cruciate lig ?
during sports that involve sudden stops or changes in direction, jumping and landin
what are the signs and symptoms of ALL ligament injuries?
A loud “pop” or a “popping” sensation in the knee
Severe pain
Rapid swelling
Loss of range of motion
what is the treatment of anterior cruciate lig tearing ?
A torn ACL will not heal without surgery . However, if the knee remains stable enough to allow for walking and the individual does not plan to participate in high level of activity, doctors will recommend hinged knee bracing and physical therapy rather than surgery
ACL reconstruction surgery involves replacing the torn ACL with a “graft,” Grafts can be taken from the patellar tendon, hamstring tendon can be allograft or autograft
graft serves as scaffolding upon which new ligament tissue will grow
what is the complications of anterior cruciate lig injury tear
early onset knee arthritis
what is the function of the anterior cruciate lig injury ?
ACL is to resist the motions of anterior tibial translation and internal tibial rotation
how can we diagnose ACL injury
lachman test
bring the knee to 30 degree flexion in supine portion
bring the tibia into slight external rotation
stabilise the femur with one hand
and grasp the upper tibia and draw it forward
considered positive if there is excessive anterior translation
pivot shift test
patient in supine postion
take the heel of the patient and put the leg into internal rotation of the tibia
apply valgus stress taking the knee from full extension up into extension
mimics a giving away feeling for positive t test
what is the role of the posterioir cruciate ligamnent
prevent the tibia from displacing posterior to the femur.
what causes posterior cruciate lig injury ?
direct blows to the flexed knee, such as the knee hitting the dashboard in a car accident or falling hard on the knee,
how do we diagnose posterior cruciate lig injury ?
posterioir drawer test
flex the knee to 9 degrees in supine position
sit on the feet to fixate the knee
push the tibia posteriorly in a serious of explosive energy attempts
CHECK FOR POSTERIOIR TRANSLATION
arthroscopy and MRI
what is the treatment for posterior cruciate ligament injury
It is possible for the PCL to heal on its own.
Nonoperative treatment is recommended for most grade I and grade II PCL tears.
grade 1 - partial tear
grade 2 - complete tear
quadriceps rehabilitation with a focus on knee extensor strengthening
Surgery is usually required in complete tears of the ligament or grade 3 - sprain of the ACL and/or collateral ligaments
ligament reconstruction is used to replace the torn PCL with a new ligament, which is usually a graft taken from the hamstring or Achilles tendon
what causes MCL injury ?
valgus stress is the most common mechanism of injury
or direct blo to the knee
what is the role of MCL
resists valgus stress
MCL injury is usually associated with ?
ACL TEAR
what is the grade of MCL ?
grade 1 - sprain stretch
grade 2 - partial tear of MCL
grade 3 - complete tear of the ligament , no end point with valgus stress at 30 degree flexion
no end point to valgus stress with 0 degrees flexion of the knee indicated anterior cruciate lig
how is MCL treated ?
grade 1 - NSAIDs rest and therapy
grade 2/3 -if stable to valgus stress in full extension(no cruciate lig injury)
hinged knee bracing
grade 3 with anterior create lig injury - there needs to be lig repair - hamstring tendon or Achilles tendon allograft
