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

Modified Cranial Closing Wedge Osteotomy (AMA-Based CCWO) to Treat Cranial Cruciate Ligament Deficient Stifle in 204 Dogs Over 50 Kg: Magnitude of the Craniocaudal Angulation of the Proximal Tibia and Rate of Surgical Site Infection

OBJECTIVES

 The aim of this retrospective study was to report the magnitude of the craniocaudal angulation of the proximal tibia (CCAPT) quantified by the angle between the anatomical axis (AA) and the mechanical axis (MA), called the AMA angle, and the tibial plateau angle (TPA) in dogs >50 kg that were treated by cranial closing wedge osteotomy based on the AMA angle (AMA-based CCWO). Furthermore, the percentage of dogs in which the AA and MA could be aligned postoperatively and the rate of surgical site infection (SSI) were reported.

STUDY DESIGN

 Medical records (between January 2016 and September 2023) were reviewed for 204 dogs that had AMA-based CCWO stabilized with a double locking plate (DLP) fixation with or without joint exploration plus a Robert Jones bandage (RJB) and were given postoperative antibiotics.

RESULTS

 The median (range) preoperative AMA angle and TPA were 3.1° (0-5.1°) and 30° (22-49.6°), respectively, and the postoperative AMA angle and TPA were 0° (-2.4 to 1.6°) and 9.2° (4-15°), respectively. The AA and MA were aligned in 82% of dogs. Grade 4 healing occurred in all osteotomies by 8 weeks postoperatively. Except for one dog, no SSIs were recorded.

CONCLUSION

 Concerning the magnitude of CCAPT in dogs >50 kg and the low SSI rate, AMA-based CCWO stabilized with a DLP fixation plus an RJB and postoperative antibiotics should be considered for treating cranial cruciate ligament-deficient stifles in this subset of dogs.

Double-Cut Tibial Plateau Leveling Osteotomy for the Management of Cranial Cruciate Ligament Insufficiency in Dogs with an Excessive Plateau Angle: Early Clinical Results in 16 Dogs

OBJECTIVE

 To describe a modification of the tibial plateau leveling osteotomy technique wherein a double cut is made in the same plane to level the tibial plateau (double-cut tibial plateau leveling osteotomy [DCTPLO]) for treating dogs with cranial cruciate ligament (CrCL) and excessive tibial plateau angle (eTPA) diseases.

STUDY DESIGN

 The DCTPLO technique was performed on 18 stifles in dogs with CrCL and an eTPA (>34°). This study evaluated the accuracy of preoperative planning, feasibility of the technique, postoperative clinical outcomes, radiographic examinations at the postoperative follow-up for the first 120 days, evolution of the tibial plateau angle (TPA), time of union of the osteotomy, apposition of the implants, and possible complications.

RESULTS

 The described technique proved to be feasible for clinical application, with reproducibility from preoperative planning. An effective reduction in the eTPA levels was observed. The mean preoperative and postoperative TPA values were 39.4° (36°-43.5°) and 6.3° (3°-13°), respectively. Radiographic healing time was 60 days in 17/18 of stifles. Minor complications (not requiring surgical review or clinical treatment) were observed in 4/18 of stifles.

CONCLUSION

 The DCTPLO technique was effective for treating CrCL disease with TPA of up to 43.5° in dogs.

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.

Biomechanical effects of cranial closing wedge osteotomy on joint stability in normal canine stifles: an ex vivo study

BACKGROUND

Cranial closing wedge osteotomy (CCWO) is a functional stabilisation technique for cranial cruciate ligament (CrCL) ruptures. This biomechanical study aimed to evaluate the influence of CCWO on the stability of the stifle joint. Eighteen Beagle stifle joints were divided into two groups: control and CCWO. The stifle joints were analyzed using a six-degree-of-freedom robotic joint biomechanical testing system. The joints were subjected to 30 N in the craniocaudal (CrCd) drawer and proximal compression tests and 1 Nm in the internal-external (IE) rotation test. Each test was performed with an extension position, 135°, and 120° of joint angle.

RESULTS

The stifle joints were tested while the CrCLs were intact and then transected. In the drawer test, the CCWO procedure, CrCL transection, and stifle joint flexion increased CrCd displacement. The CCWO procedure and CrCL transection showed an interaction effect. In the compression test, the CCWO procedure decreased and CrCL transection and stifle joint flexion increased displacement. In the IE rotation test, CCWO, CrCL transection, and stifle joint flexion increased the range of motion.

CONCLUSIONS

CCWO was expected to provide stability against compressive force but does not contribute to stability in the drawer or rotational tests. In the CCWO-treated stifle joint, instability during the drawer test worsened with CrCL transection. In other words, performing the CCWO procedure when the CrCL function is present is desirable for stabilizing the stifle joint.

A mismatch of planning and achieved tibial plateau angle in cranial closing wedge surgery: An in silico and clinical evaluation of 100 cases

OBJECTIVE

(1) To determine whether Oxley's modified cranial closing wedge osteotomy (CCWO) results in a tibial plateau angle (TPA) of 5° in silico, (2) compare in silico to clinical postoperative TPA and (3) determine the impact of ostectomy distalization in silico.

STUDY DESIGN

Cross-sectional retrospective radiographic in silico study.

SAMPLE POPULATION

A total of 100 stifle radiographs; 90 dogs (small ≤25 kg = 84; large >25 kg = 16).

METHODS

Tibial plateau angles were measured preoperatively (TPAPre ), after in silico planning (TPAPlan ), and postoperatively (TPAPost ). Virtual ostectomies were evaluated for plate fit. Postoperative ostectomy position was measured. Virtual ostectomies were performed 5/7.5/10/15 mm from the patellar tendon insertion in 10 dogs from each preoperative TPA category (≤20°/21-25°/ 26-30°/31-35°/>35°). Comparisons for TPAPre , TPAPost , and TPAPlan were made between small and large dogs, and the outcome to the target 5° between TPA categories and ostectomy positions.

RESULTS

Mean ± SD TPAPre was 28.6 ± 6.2° and higher in small than large dogs. Mean TPAPlan was 7.6 ± 2.7°. Plate fit was appropriate in all. In silico, TPAs were greater than 5° except for cases with TPAPre  > 35°. Median TPAPost was 5.5° (-4-21) and was higher in small (7°) than large (4.5°) dogs. Postoperative ostectomy position was more distal than Oxley's guidelines. When distalized >7.5 mm in silico, the magnitude of under-correction increased.

CONCLUSIONS

Oxley's modified CCWO did not result in TPA of 5° in most cases. Ostectomy distalization exacerbated under-correction.

CLINICAL IMPACT

Current guidelines should be modified to achieve 5° TPA postoperatively.

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.

Examination of Proximodistal Patellar Position in Dogs with the Stifle at Full Extension

OBJECTIVE

 The aim of this study was to determine the factors related to functional patella alta, with which the proximodistal patellar position exceeds the reference range of healthy small dogs proximally when the stifle is at full extension.

STUDY DESIGN

 Mediolateral-view radiographs of dogs weighing less than 15 kg were obtained and classified into the medial patellar luxation (MPL) and control groups. The reference range of the proximodistal patellar position was determined from the control group. In both groups, a patellar position exceeding this reference range proximally was considered functional patella alta. Multiple logistic regression analysis was performed to examine the factors related to functional patella alta. A receiver operating characteristic (ROC) curve was made for each factor.

RESULTS

 Overall, radiographs of 127 stifles of 75 dogs were obtained. Eleven stifles in the MPL group and one stifle in the control group were determined to be functional patella alta. The factors associated with functional patella alta included a greater full extension angle of the stifle joint, longer patellar ligament, and shorter femoral trochlear length. The full extension angle of the stifle joint had the biggest area under the ROC curve.

CONCLUSION

 Mediolateral radiographs of the stifle joint in full extension are clinically important in dogs with MPL because some dogs might have a proximally positioned patella that is recognizable only when the stifles are extended.

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).