Geometric modelling of CORA-based levelling osteotomy in the dog

Objective and owner-reported outcomes after modified cranial closing wedge ostectomy: a case series

Immediate and longer-term outcomes of a cranial closing wedge ostectomy variant for management of canine cranial cruciate ligament disease were assessed in this single-center retrospective consecutive study. Records and radiographs were retrieved and assessed by three independent observers to evaluate tibial plateau angle, anatomical-mechanical axis angle, tibial tuberosity distalization, and mechanical axis length before and after surgery. Kinetic gait analysis and owner questionnaires were used to assess clinical outcomes. Seventeen stifles from fifteen dogs were evaluated radiographically. Mean error from target tibial plateau angle was 0.4 degrees. Anatomical-mechanical axis angles reduced from mean 2.9 degrees preoperatively to mean - 0.9 degrees postoperatively. Tibial tuberosity distalization was mean 5.0% of mechanical axis length, and mean reduction in mechanical axis length was 0.1%. Increased tibial plateau angles were noted in 8/17 stifles, with a mean of 9.6 degrees at short-term follow-up. Major complications were observed in 9/17 stifles. Long term follow-up (mean 832 days) was obtained with gait analysis in 8/15 dogs and with questionnaire in 11/15. Most dogs (9/11) were weakly to moderately affected by osteoarthritis symptoms. All values for peak vertical force and vertical impulse normalized to body weight exceeded local lower reference limits for normal dogs, indicating acceptable limb use. Satisfactory immediate and long-term clinical outcomes appear to be possible with this technique, but the high incidence of shorter-term complications may caution against the technique or the fixation and management described here.

Cranial closing wedge ostectomies for management of canine cranial cruciate ligament insufficiency: Comparison and geometric modelling of errors

Variants of the cranial closing wedge ostectomy (CCWO) may be used to manage cranial cruciate ligament deficient stifles by reduction of the tibial plateau angle (TPA). Concerns have been raised about predictability of achieving target TPA, limb shortening, axis shift, and distalization of the tibial tuberosity. Landmarks derived from tibial radiographs (n = 50) by 5 observers, along with outlines of the cranial and caudal proximal tibial cortices, were used to simulate six CCWO variants. Tested variants were Slocum-type (n = 2), modified (n = 2), isosceles, and anatomical-mechanical axis (AMA)-based CCWO. Observer specific landmarks were used to model pre- and postoperative errors in TPA measurement. Mean landmarks were used to compare key outcome variables between the variants, as well as modelling errors in positioning the wedge apex. Variants differed markedly in TPA, axis shift, mechanical axis length changes, and tibial tuberosity distalization, with more proximally positioned wedges performing better than distally positioned wedges. Errors in TPA identification appeared partially self-correcting due to altered axis shifts. Craniocaudal shifts in wedge apex position had the most severe effects on outcome variables, especially in shorter tibiae with greater initial TPA values. Recent CCWO variants are likely to achieve a satisfactory postoperative TPA with limited axis shift. The AMA-based CCWO technique appears to influence MA length and tibial tuberosity position the least, and apart from the effect on TPA where no advantage could be discerned, it appeared more robust in the face of wedge apex positioning errors than the other techniques.

Reported accuracy of cranial closing wedge ostectomy variants for management of canine cranial cruciate ligament insufficiency: A systematic review and meta-analysis

Concerns have been raised about the predictability of achieving appropriate tibial plateau angles (TPA), the occurrence of axis shift and tibial length reduction following cranial closing wedge ostectomy (CCWO). The primary objective of this review was to quantify typical errors in achieving target TPA with CCWO, with secondary objectives of assessing axis shift and length reduction. Retrospective or prospective studies of CCWO used as the primary treatment, from any date and in English, were eligible for inclusion. Searches were performed in EMBASE, Ovid MEDLINE, Agricola, Scopus, Web of Science, and CAB abstracts. Risk of bias was assessed, and data were screened for outliers and influential cases. Extracted data from 11 included studies were tabulated and underwent meta-analysis using R. Mean errors in TPA after CCWO ranged from - 0.6-2.9°, indicating the possibility of both under- and over-correction depending on the selected technique. Errors were relatively consistent for technique subgroups. Mean axis shifts ranged from 3.4° to 5.2°, and length reduction ranged from 0.4% to 3.2% of initial length, based on 6/11 and 3/11 studies, respectively. Data had high heterogeneity, many studies had small populations, and reporting standards were inconsistent. Concerns about the predictability of postoperative TPA may be overstated. With the limited data available, limb shortening does not appear to be a clinically important consideration. Axis shift will occur to varying degrees and must be considered during CCWO planning, as it influences the postoperative TPA. Careful choice of CCWO technique may allow clinicians to reliably achieve predictable TPA values.

Etiopathogenesis of Canine Cruciate Ligament Disease: A Scoping Review

The spontaneous rupture of the cranial cruciate ligament in dogs remains a pathoetiologic puzzle. Despite much progress in research over the past years, the systemic and local mechanisms leading to ligament degeneration and structural failure remain largely obscure. This scoping review focuses on pathogenesis and aims at summarizing and interpreting today's knowledge on causes of canine cruciate ligament rupture, i.e., the multifactorial mechanisms leading to degenerative stifle joint disease with collagen matrix degeneration and structural failures. Thus, the initial view of traumatic ligament rupture, fostered by "wear and tear", has clearly been replaced by a new concept of systemic processes linked to progressive degenerative joint disease and ligament failure; thus, the term "cranial cruciate ligament disease" has been coined and is generally accepted. In addition, cruciate ligament rupture in people shares some similarities with the lesion in dogs; therefore, the review also includes comparative studies. The methods used were based on the PRISMA-ScR model (Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews).

Effect of center of angulation of rotation-based leveling osteotomy on ex vivo stifle joint stability following cranial cruciate ligament transection and medial meniscal release with and without a hamstring load

Objective

To evaluate the effect of center of rotation of angulation (CORA)‐based leveling osteotomy (CBLO) and hamstring load on stifle stability following cranial cruciate ligament transection (CCLx) and medial meniscal release (MMR).

Study design

Ex vivo experimental study.

Sample population

Cadaver hind limb preparations (n = 7).

Methods

After instrumentation, constant quadriceps and gastrocnemius loads with an optional hamstring load in a 3:1:0.6 ratio were applied, and stifles were extended from fully flexed using an electrical motor during fluoroscopic recording. The recording process was repeated after each of CCLx, MMR and CBLO and the extracted landmark coordinates were used for calculation of cranial tibial translation (CTT) and patellar ligament angle (PTA).

Results

Mean initial tibial plateau angle was 28.1°: post‐CBLO the mean was 9.7°. Cranial tibial translation developed from 50° and 75° with CCLx and MMR respectively (p < .04, < .02) without hamstring loading. Hamstring loading mitigated CTT due to CCLx and delayed CTT until 120° for MMR (P < .02) in this model. CBLO prevented CTT, except at 140° without hamstring loading (P = .01). Similar results were seen for PTA, but CBLO curves were parallel to and lower than intact values at all tested angles (P < .04), consistent with induced effective joint flexion.

Conclusion

CBLO to a target tibial plateau angle of 10° largely eliminated CTT induced by CCLx and MMR. Hamstring loads of 20% quadriceps load improved stifle stability in this model.

Impact

Stifle stability following CBLO appears to be multifactorial and depends on meniscal integrity, joint angle, and hamstring strength.

Comparison of tibial anatomical-mechanical axis angles and patellar positions between tibial plateau levelling osteotomy (TPLO) and modified cranial closing wedge osteotomy (AMA-based CCWO) for the treatment of cranial cruciate ligament disease in large dogs with tibial plateau slopes greater than 30° and clinically normal Labradors retrievers

Background

The objective of this study was to evaluate tibial anatomical-mechanical axis angles (AMA-angles) and proximodistal and craniocaudal patellar positions following tibial plateau levelling osteotomy (TPLO) and AMA-based modified cranial closing wedge osteotomy (CCWO) in large dogs with tibial plateau angle (TPA) > 30°, to compare these postoperative positions with those of a control group of healthy normal dogs, and to assess which procedure yields postoperative morphology of the tibiae and stifles that is most consistent with that of the unaffected group. This study also investigated whether the occurrence of patellar ligament thickening (PLT), which is commonly observed 2 months postoperatively after TPLO, is associated with misplacement of the osteotomy. A total of 120 dogs weighing more than 20 kg, 40 of which were control animals, were enrolled in this retrospective study. Stifles were radiographically evaluated preoperatively and postoperatively on the side with CCLR and on the healthy contralateral side and compared with clinically normal stifles. PLT was reassessed after 2 months.

Results

Significant decreases in median patellar height ratio were found after both procedures (TPLO 0.24 (0.05–0.8); CCWO 0.22 (0.05–0.4)). The postoperative craniocaudal patellar position and the median AMA angle differed significantly among the groups (P = 0.000) (TPLO 87.5% caudal to the AA and 3.12° (0.76–6.98°); CCWO 100% cranial to the AA and 0° (− 1.34–0.65°); control group 5% caudal to the AA and 0.99° (0–3.39°)).

At 8 weeks, PLT grade differed significantly in the two operated groups (P = 0.000) (TPLO 40% 0–2, 20% 2–4, 40% > 4; CCWO 98.8% 0).

Conclusions

TPLO and AMA-based CCWO are associated with significant decreases in patellar height; however, the PLT results 2 months postoperatively differed between the two groups; the decrease in patellar height and PLT were independent of osteotomy position in the TPLO group. Compared to TPLO, CCWO results in reduced postoperative AMA angles and craniocaudal patellar positions that more closely resemble those of unaffected dogs, suggesting that the CCWO procedure allows us to better correct the caudal bowing of the proximal tibia that is often associated with deficient stifles in large dogs with TPA > 30°.