Assessment of tibial morphologic alterations following correction of excessive tibial plateau angle in dogs
No Thumbnail Available
Authors
Meeting name
Sponsors
Date
Journal Title
Format
Thesis
Subject
Abstract
Given the frequent addition of new techniques used to address cases of cranial cruciate ligament disease with excessive tibial plateau angle (eTPA), we sought to document the effect of popular surgical methods used to treat eTPA on tibial morphology. In the first study, virtual corrections were performed in orthopedic planning software using the following procedures: center of rotation of angulation (CORA)- based leveling osteotomy (CBLO) and coplanar cranial closing wedge ostectomy (CCWO), TPLO and CCWO, modified CCWO (mCCWO), and proximal tibial neutral wedge osteotomy (PTNWO). Sixteen dogs (27 tibias) met inclusion criteria. Pre- and post-correction TPA, tibial length and mechanical cranial distal tibial angle (mCrDTA) were measured and compared. Techniques were compared with a one-way ANOVA with Tukey's multiple comparisons test. Mean pre-correction TPA was 42.67 [plus or minus] 6.1 degrees. Post-correction mean TPAs were 10.47 [plus or minus] 2.1 degrees, 6.77 [plus or minus] 1.6 degrees, 4.76 [plus or minus] 1.5 degrees, and 7.09 [plus or minus] 1.3 degrees for CBLO + CCWO (Group A), TPLO + CCWO (Group B), mCCWO (Group C), and PTNWO (Group D), respectively. TPA correction accuracy in Groups A and D varied least from target TPAs. Tibial shortening was documented in TPLO + CCWO in contrast to other groups. The greatest mechanical axis shift was identified in CBLO + CCWO. Overall, each of the techniques achieved TPA < 14 degrees despite having different effects on tibial morphology including alteration of tibial length, mechanical axis shift and variation in correctional accuracy. In the second study, we evaluated changes in tibial morphology following PTNWO in dogs with cranial cruciate disease affected by eTPA. Pre- and postoperative radiographs from 11 dogs (14 tibias) were retrospectively evaluated. Pre- and post-correction TPA, tibial length and mechanical cranial distal tibial angle (mCrDTA) were measured. The measurements were compared to previously obtained virtual correction data for PTNWO and analyzed using an unpaired t-test. Mean pre-operative TPA was 41.79 degrees [plus or minus] 5.52 degrees and mean post-operative TPA following PTNWO was 8.32 degrees [plus or minus] 2.96 degrees. Clinical cases under-corrected target TPA compared to virtual correction (mean TPA correction accuracy of 0.91 and 1.00 respectively; p = 0.0011). There was no difference in percent change from baseline for tibial length or mechanical axis shift between the two groups. In conclusion, the PTNWO can be considered in dogs with cranial cruciate ligament disease secondary to eTPA and resulted in minimal tibial length alteration and mechanical axis shift. Additional objective data evaluating outcomes of the various procedures is required before clinical conclusions can be drawn demonstrating one procedure to have increased efficacy over others. Gait analysis could be considered preand post-operatively to demonstrate objective assessment following surgical correction in addition to clinical findings. A procedure that results in minimal tibial morphologic alteration would theoretically provide biomechanical advantages.
Table of Contents
DOI
PubMed ID
Degree
M.S.