Knee ligament injuries Flashcards
What does the ACL do?
stabilise the knee joint by being the primary restraint to limit anterior translation of the tibia and contribute to rotational stability
When does an ACL tear usually occur?
When there is history of twisting the knee while weight bearing, from landing from a jump
How will an ACL tear usually present?
Rapid joint swelling and significant pain, instability
What specific tests are done for an ACL tear?
Lachmans test and anterior draw test
What is Lachmans test?
putting the knee at 30 degrees of flexion and stabilise the femur, pull the tibia forward to assess the amount of anterior movement of the tibia compared to the femur
What is the anterior drawer test?
flexing the knee to 90 degrees and placing the thumbs in the joint line and index finder on the hamstring tendons posteriorly, force is then applied anteriorly to demonstrate tibial excursions
What are the differential diagnosis for ACL tear?
Fracture, meniscal tear, collateral tear, quadriceps or patellar ligament tear
What investigations would need to be done for an ACL tear?
radiograph of the knee to exclude bony injuries and see if lipohaemarthrosis is present, MRI scan for diagnosis
What is the initial management for an ACL tear?
Rest, Ice, Compression, Elevation
What is the conservative management for an ACL tear?
rehabilitation, strength training of the quadriceps to stabilise the knee, canvas knee splint
What is the surgical treatment for an ACL tear?
tendon or an artificial graft with prehabilitiation before hand
What are the complications of ACL tear?
post traumatic osteoarthritis
What is a PCL tear and how would i present?
high energy trauma to proximal tibia, immediate posterior knee pain, instability and positive posterior draw test
What is the medial collateral ligaments function?
to act as a values stabiliser of the knee
When does the MCL usually tear?
external rotational forms are applied to the lateral knee such as a impact to the outside of the knee
What is a grade I MCL tear?
mild injury, minimally torn fibres and no loss of MCL integrity
What is a grade II MCL tear?
moderate injury with an incomplete tear and increased laxity of the MCL
What is a grade III MCL tear?
severe injury, with complete tear and gross laxity of the MCL
What are the clinical features of a MCL tear?
trauma to lateral aspect of the knee, immediate medial joint line pain, swelling, increased laxity when testing the MCL via the values stress test, tender along joint line, may be able to weight bear
How can grade II and III MCL tear be distinguished on medial stress testing?
Grade II is lax in 30 degrees of knee flexion but solid in full extension, grade III is lax in both
what are the differential diagnosis for MCL tear?
fractures, meniscal injury and collateral ligament tears
What is the gold standard for MCL tear scanning?
MRI
What is the management for a grade I MCL tear?
RICE, analgesia, strength training, full exercise in 6 weeks
What is the management of grade II MCL tear?
Analgesia with a knee brace and weight bearing/strength training, full exercise in 10 weeks
What is the management for grade III MCL tear?
analgesia with knee brace and crutches, 12 weeks full exercise
What are the complications of an MCL tear?
instability of the joint, damage to the saphenous nerve
What is a meniscal tear?
the c shaped fibrocartilage found in the knee joint tears
What is the function of the meniscus in the knee?
shock absorbers and increase articulating surface area
What is the medial meniscus attached to?
MCL, the lateral is not attached to the LCL
What is the most common cause of meniscal tear?
trauma related injury (twisted knee while flexed and weight bearing) and degenerative disease
What are the types of meniscal tears?
Vertical, longitudinal, transverse, degenerative
What are the clinical features of meniscal tears?
tearing sensation, intense sudden onset pain, swelling, locked in flexion and unable to extend if the meniscal tear causes a free body
What happens on examination of the meniscal tears?
tinderness in the joint line, joint effusion, limited knee flexion, McMurrarys test and Apleys grind test
What are the differential diagnosis of meniscal teats?
fracture, cruciate ligament tear, collateral ligament tear, osteochondritis dissecans
What imaging would you do for meniscal tears?
Plain radiograph to exclude fracture and then MRI
What is the management for meniscal tears?
rest and elevation, compression and ice, atroscopic surgery if the teat is in the outer third of the meniscus can be sutured together or if the inner third can be trimmed
What are the complications of meniscal tears?
osteoarthritis, knee arthroscopy can cause DVT, damage to local structures, saphenous nerve and vein, peroneal nerve and popliteal vessels
