Knee ligament injuries Flashcards
describe the function of the medial collateral ligament(MCL) and the lateral collateral ligament(LCL)
MCL = resists valgus stress LCL = resists varus stress
describe the function of the anterior cruciate ligament(ACL)
resists anterior subluxation of the tibia and internal rotation of the tibia in extension
describe the function of the posterior cruciate ligament(PCL)
resists posterior subluxation of the tibia, ie anterior subluxation of the femur and knee hyperextension
briefly describe how knee ligament injuries are graded
grade 1 = sprain
grade 2 = partial tear
grade 3 = complete tear
describe the healing potential of the MCL
healing expected in majority of partial and complete tears, with little or no instability
what may a MCL rupture lead to
valgus instability
what may an ACL rupture lead to
rotatory instability
what may a PCL rupture lead to
recurrent hyperextension or instability descending stairs
what is involved in the treatment of acute and chronic MCL tears
acute = hinged knee brace chronic = MCL tightening or reconstruction with tendon graft
how are ACL injuries most often caused
by sports (common)
what is the classic history of an ACL injury
“pop”, haemarthrosis and giving way on turning
what are the different outcomes of an ACL injury
patient can compensate and are able to function well
patient can avoid instability by avoiding certain activities
patient do not compensate and have frequent instability
what surgical treatment is used in ACL injury
ACL reconstruction, repair doesn’t work
when is surgical treatment used in ACL injury
rotatory instability not responding to physio, professional athletes to speed up process, protect meniscal repair
what effect does ACL reconstruction have on pain and arthritis
does not relieve pain and does not prevent arthritis
how long is the rehab process after ACL surgery
3 to 12 months, 9 months before return to sport if meeting physio targets
what type of injury does LCL injury often occur with
PCL or ACL injury
describe healing of LCL injury
does not heal
what treatment is used in LCL rupture
early repair or late reconstruction with tendon graft
what can the hyperextension and varus seen with LCL injury cause
common peroneal nerve injury from excessive stretch
what clinical features are usually seen with a LCL injury
marked instability on rotational movement
in isolated PCL injury when is surgical reconstruction considered
in those with severe laxity, recurrent instability, frequent hyperextension or instability descending stairs
what treatment is usually used in multi-ligament injuries and why
surgical reconstruction due to high instability
what does complete knee dislocation results in in terms of the knee ligaments
results in rupture of all 4 ligaments
what complications can be seen with complete knee dislocation
popliteal artery injury, neurovascular injury, compartment syndrome
