Comparison of trochlear block recession and trochlear wedge recession for canine patellar luxation using a cadaver model.
OBJECTIVE
To compare trochlear block recession (TBR) to trochlear wedge recession (TWR) with regards to patellar depth (percentage of patellar volume under the trochlear ridges), patellar articular contact, percentage of recessed trochlear surface area, and resistance to patellar luxation.


METHODS
In vitro computed tomography (CT) and biomechanical evaluation using a cadaver model.


METHODS
Twelve normal, large-breed canine cadavers.


METHODS
Bilateral pelvic limb specimens with intact stifle joints were mounted on a positioning device. The femoral trochlear ridges were reduced to provide a standard shallow trochlea. TBR or TWR was performed to a standard depth randomly on paired specimens. CT and biomechanical evaluations were performed pre- and postoperatively in both an extended (148 degrees ) and flexed (113 degrees ) stifle position. CT images were digitized and measurements made using an image-analysis software program. Biomechanical testing consisted of applying 40 degrees of internal tibial rotation and documenting patellar luxation.


RESULTS
The change in trochlear depth (depth of recession) was not significantly different between groups. In the extended stifle position (patella in the proximal trochlea), patellar depth and patellar articular contact with the recessed trochlea were significantly greater after TBR compared with TWR. The percentage of recessed trochlear surface area was significantly greater after TBR compared with TWR. In the extended position, a smaller percentage of the patellae luxated within 40 degrees of internal tibial rotation after TBR compared with TWR.


CONCLUSIONS
TBR increases proximal patellar depth, increases patellar articular contact with the recessed proximal trochlea, recesses a larger percentage of trochlear surface area, and results in a greater resistance to patellar luxation in an extended position as compared with TWR.


CONCLUSIONS
TBR may help limit the development of stifle DJD in dogs treated for canine patellar luxation.
Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA.
A L
AL
Johnson
C W
CW
Probst
C E
CE
Decamp
D S
DS
Rosenstein
J G
JG
Hauptman
B T
BT
Weaver
T L
TL
Kern
D000818:Animals; D001696:Biomechanical Phenomena; D002102:Cadaver; D004283:Dog Diseases / Q000503:physiopathology / Q000601:surgery*; D004285:Dogs; D007592:Joint Diseases / Q000503:physiopathology / Q000601:surgery / Q000662:veterinary*; D004204:Joint Dislocations / Q000601:surgery / Q000662:veterinary*; D010329:Patella / Q000503:physiopathology*; D011859:Radiography; D013264:Stifle / Q000000981:diagnostic imaging / Q000601:surgery*