Summary
Objective: To evaluate the usefulness of laser Doppler flowmetry (LDF) to measure surface blood
flow in canine cruciate ligaments, compare measurements in different sites of intact
and partially ruptured canine cranial cruciate ligaments (CrCL) and intact caudal
cruciate ligaments (CaCL), and investigate any association between surface blood flow
in partially ruptured CrCL and synovitis or duration of clinical signs.
Study design: Case-controlled clinical study.
Animals: Sixteen dogs with partially ruptured CrCL and five dogs with intact CrCL.
Methods: Blood cell flux (BCF) readings during three measurement cycles using LDF at two sites
in each ligament (mid-substance and the distal portion of the CrCL, and mid-substance
and the proximal portion of the CaCL) were recorded. Synovial changes were graded
grossly and histologically using the Osteoarthritis Research Society International
histopathology scoring system.
Results: The within-run coefficients of variation (CV) for a single BCF measurement cycle
were 12.2% and 12.7% in the ruptured and intact CrCL groups, respectively. The between-run
CV for three measurement cycles was 20.8% and 14.8%, respectively. The intraclass
correlation coefficient (ICC, absolute agreement) was 0.66 for a single measurement
cycle and 0.86 for the average of three cycles.
No difference in average BCF readings was found between any two sites in either group,
but BCF readings in both CrCL sites were significantly higher in the ruptured CrCL
group than the intact CrCL group. No associations between BCF and synovial grades
or duration of lameness were identified.
Conclusions: Laser Doppler flowmetry can be used to assess surface blood flow in intact and partially
ruptured canine cruciate ligaments with acceptable precision. Using this method, surface
blood flow appears greater in partially ruptured canine CrCL than intact CrCL. Further
studies are required to determine if this is a sequela of trauma or synovitis.
Keywords
Cruciate ligament - blood cell flux - dog - laser Doppler flowmetry - stifle joint