Cruciate Ligament Disease Flashcards
cranial cruciate ligament
runs from the caudolateral femur to the cranial medial tibia
made of 2 bands:
1. cranio-medial
2. caudolateral
CrCL cranio-medial (CM) band
always tight (during extension and flexion)
CrCL caudolateral (CL) band
only tight during stifle extension (loose during flexion)
what are the 3 functions of the cranial cruciate
- prevent cranial translocation of the tibia
- prevents internal rotation of the tibia
- prevents hyperextension of the stifle
CrCL disease
chronic degenerative disease with unknown cause; leads to cranial translocation and internal rotation of the tibia
often rupture opposite CrCL within 18 months
partial CrCL tear
if CM band torn: joint is unstable only in flexion
if CL band torn: joint is still stable in both flexion and extension
both cause pain on hyperextension
complete CrCL tear
tearing of both the CM and CL bands
joint is unstable in flexion and extension
signalment for CrCL disease
dogs
4-8 years old
breeds: rotties, labs, newfoundlands
increased risk with obesity
diagnosis of CrCL tear
orthopedic exam
- drawer test
- tibia compression test
- radiographs
drawer test
applying passive motion to detect cranial tibial translation
check in both flexion and extension
tibia compression test
indirect drawer
mimics standing position to detect tibial translation
- keep the knee in position with one hand
- using other hand, push the tarsus upward (flex)
- if positive - the tibia will move cranially as quads contract
CrCL tear on radiographs
- joint effusion
- OA signs near tibia
- periarticular thickening (medial buttress)
- cranial displacement of infrapatellar fat pad
non-surgical CrCL treatment
allow scar tissue to form with rest, pain management, and weight loss
CrCL has little/no healing potential - if there are any signs of improvement it is only due to scar tissue formation in attempt to stabilize joint
surgical CrCL treatment
- prosthetic ligaments
- osteotomies
prosthetic ligaments
augments the function of the ligament
- stabilizes joint and prevents tibial thrust and cranial drawer
includes lateral suture and tight rope
lateral suture
suture placed around the fabella and through a hole in the tibia
better for old, small dogs
achieves normal gait at walking only
tight rope
stronger suture material but higher risk of infection
has similar outcome as TPLO even in large dogs
osteotomies
alters the biomechanics of the knee by making the tibial plateau angle (TPA) perpendicular to the patellar tendon in order to eliminate cranial tibial thrust when the quads pull upwards
knee becomes stable only when weight-bearing
- eliminates cranial tibial thrust during weight bearing
- still have positive cranial drawer motion after sx
includes TPLO and TTA
tibial plateau leveling osteotomy (TPLO)
flattening the tibial plateau
most effective in long term and fastest recovery time
tibial tuberosity advancement (TTA)
moves the insertion of the quads (tibial tuberosity) cranially to create a perpendicular force to the existing tibial plateau
post-op CrCL care
standard wound care
8-12 weeks controlled exercise
- need to allow time for bone healing and scar tissue formation
- physical rehabilitation
meniscus
C-shaped cartilage that provides stability and allows for force distribution from the femur to the tibia
how do CrCL tears predispose an animal to meniscus tear
CrCL tear increases pressure on one side of the meniscus over the other
medial meniscus
attaches to the tibia
gets crushed during cranial tibial translocation - most likely site of meniscus tear following CrCL tear
lateral meniscus
attaches to the femur
gets pulled during cranial tibial translocation
what kind of tear usually occurs on the meniscus
bucket handle tear
- torn part flips back and forth when the knee is in ROM causing clicking sound and pain
treatment for CrCL and meniscus tear
- medial meniscal release
- meniscectomy
medial meniscal release
transection of the caudal meniscotibial ligament to prevent future injury
eliminates force distribution function of the meniscus
meniscectomy
partial or segmental removal of the torn part of the meniscus
