Comparison of Complication Rates and Clinical Outcome Between Tibial Plateau Leveling Osteotomy and a Modified Cranial Closing Wedge Osteotomy for Treatment of Cranial Cruciate Ligament Disease 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.

Radiographic Comparison of Virtual Surgical Corrective Options for Excessive Tibial Plateau Angle in the Dog

OBJECTIVE

 The main aim of this study is to compare the impact of six proximal tibial osteotomies on the geometry and alignment of tibias with and without excessive tibial plateau angle (TPA).

STUDY DESIGN

 Mediolateral radiographs of 30 canine tibias were divided into three groups (n = 10/group): moderate TPA (≤34 degrees), severe TPA (34.1-44 degrees) and extreme TPA (>44 degrees). Six proximal tibial osteotomies were simulated on each tibia using orthopaedic planning software: cranial closing wedge ostectomy (CCWO), modified CCWO (mCCWO), isosceles CCWO (iCCWO), neutral isosceles CCWO (niCCWO), tibial plateau levelling osteotomy with CCWO (TPLO/CCWO) and coplanar centre of rotation of angulation-based levelling osteotomy (coCBLO). All tibias were reduced to a standard target TPA. Pre- and postoperative measurements were obtained for each virtual correction. Compared outcome measures included tibial long axis shift (TLAS), cranial tibial tuberosity shift (cTTS), distal tibial tuberosity shift (dTTS), tibial shortening and osteotomy overlap.

RESULTS

 Across all TPA groups, TPLO/CCWO had the lowest mean TLAS (1.4 mm) and dTTS (6.8 mm); coCBLO had the largest TLAS (6.5 mm) and cTTS (13.1 mm); CCWO had the largest dTTS (29.5 mm). CCWO had the largest degree of tibial shortening of 6.5 mm, while mCCWO, niCCWO and coCBLO resulted in minimal tibial lengthening (1.8-3.0 mm). These trends were generally conserved across different TPA groups. All findings had a p-value less than 0.05.

CONCLUSION

 mCCWO balances moderate alterations to tibial geometry while preserving osteotomy overlap. The TPLO/CCWO has the least effect on tibial morphology alteration, whereas the coCBLO results in the largest alteration.

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.

Outcome of cranial cruciate ligament replacement with an enhanced polyethylene terephthalate implant in the dog: A pilot clinical trial

OBJECTIVE

To assess the 6-month outcome and survival of enhanced polyethylene terephthalate (PET) implants as a replacement for the cranial cruciate ligament (CCL) in dogs with spontaneous CCL disease (CCLD).

STUDY DESIGN

Pilot, prospective case series.

ANIMALS

Ten client-owned large breed dogs with unilateral spontaneous CCLD.

METHODS

Dogs were evaluated before and 6 months after intra-articular placement of a PET implant with the Liverpool Osteoarthritis in Dogs questionnaire and force platform gait analysis. Arthroscopy was performed 6 months after surgery to visually assess implant integrity.

RESULTS

Scores on owner questionnaires and limb asymmetry improved in all dogs that reached the 6-month time point, by 51.7% (p = .008) and 86% (p = .002), respectively. The PET implant appeared intact and functioning in two stifles, partially intact and functioning in four stifles and completely torn in three stifles. One dog had an implant infection and was removed from the study. Evidence of deterioration and tearing occurred in the midbody of the implant.

CONCLUSION

Although function improved over the course of this study, only 2/10 implants appeared intact 6 months after placement.

CLINICAL SIGNIFICANCE

Implant survivability prohibits further clinical investigation using this implant.

Long-term outcome of tibial plateau leveling osteotomy using an antimicrobial silver-based coated plate in dogs

Objectives

To evaluate long-term outcome using the BioMedtrix™ TPLO Curve^® plate in dogs with cranial cruciate ligament disease (CrCLd) treated by tibial plateau leveling osteotomy (TPLO).

Study design

Retrospective case study.

Animals

Dogs (n = 323, 337 stifles).

Methods

Medical records were searched for dogs presented with CrCLd and treated by TPLO with the BioMedtrix™ TPLO Curve^® plate for 3.5 mm screws between March 2018 and December 2020. Tibial plateau angles (TPA) were measured on preoperative, postoperative, and follow-up radiographs. Changes in TPA between postoperative and follow-up radiographs (ModTPA) were calculated. Radiographic bone healing was scored. Complications were evaluated. Surgical site infections (SSI) were compared to a control group of dogs treated with the Synthes™ TPLO plate between January and December 2017. Owners of both groups were contacted by telephone at least 1 year postoperatively.

Results

The BioMedtrix™ group was composed of 237 dogs (248 stifles), the control group was composed of 86 dogs (89 stifles). In the BioMedtrix™ group, radiographic follow-up was performed at a median of 48 days. Average ModTPA was 1.2°. Bone healing was graded as complete, good, poor, and none in 18%, 62%, 20%, and 0%, respectively. At a median of 786 days postoperatively, minor and major postoperative complications were observed in 6 (2.4%) and 32 (12.9%) cases in this group, respectively. During the first year following the surgery, 23 (9.3%) and 12 (13.5%) cases suffered a SSI, of which 12 (4.8%) and 7 (7.9%) had their implant explanted in the BioMedtrix™ group and the control group, respectively. There was no significant difference between groups for SSI and implant explantations (p = 0.31 and p = 0.29, respectively).

Conclusion

The BioMedtrix™ TPLO Curve^® plate provided a reliable fixation system for osteotomy healing after TPLO. Bone healing and long-term complication rates were similar to previous studies using other implants. SSI rates were similar between the BioMedtrix™ group and the control group. The antimicrobial HyProtect^® coating of the plate did not reduce SSI in this study.

Clinical significance

The BioMedtrix™ TPLO Curve^® plate can be safely used for TPLO. The value of the antimicrobial HyProtect^® coating of the plate may be questioned, as SSI rate was not lower in this study compared to the control group or previous reports.

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°.

Double-cut center of rotation of angulation-based leveling osteotomy for treatment of cranial cruciate ligament deficiency and excessive tibial plateau angle secondary to growth anomaly in two dogs

CASE DESCRIPTION

A 4-year-old female Staffordshire Bull Terrier (dog 1) and a 6-year-old male Yorkshire Terrier (dog 2) were evaluated because of left pelvic limb lameness.

CLINICAL FINDINGS

Both dogs had a partial rupture of the left cranial cruciate ligament associated with a unilateral excessive tibial plateau angle (51° in dog 1 and 41° in dog 2) secondary to a growth anomaly.

TREATMENT AND OUTCOME

Both dogs underwent a double-cut center of rotation of angulation-based leveling osteotomy combining rotation of the proximal fragment with a cranial closing wedge ostectomy. The procedure allowed leveling of the tibial plateau to a final angle of 11° in one dog and 10° in the other without perioperative complications. Both dogs had excellent functional outcomes ≤ 4 months after the surgery. No postoperative complications were reported during follow-up (12 months and 9 months for dogs 1 and 2, respectively).

CLINICAL RELEVANCE

Results for these dogs suggested that double-cut center of rotation of angulation-based leveling osteotomy can be considered as a viable treatment option for cranial cruciate ligament deficiency associated with excessive tibial plateau angle.

Evaluation of the clinical value of routine radiographic examination during convalescence for tibial plateau-leveling osteotomy

OBJECTIVE

To determine how frequently routine follow-up radiographic findings would result in a change to the postoperative plan following tibial plateau-leveling osteotomy (TPLO) in dogs.

STUDY DESIGN

Retrospective study SAMPLE POPULATION: Short-term group: 100 cases; intermediate-term group: 50 cases.

METHODS

Medical records of 100 consecutive cases meeting the inclusion criteria were reviewed (the short-term group). The cases had no owner-perceived issues and underwent routinely prescribed radiographic follow up between 40 and 60 postoperative days after TPLO performed by one experienced surgeon. Complications identified on physical examination (PE) and radiographic examination (RE) were recorded, along with any changes to the postoperative plan. Medical records of 50 consecutive cases that had short-term and intermediate-term (≥180 days) REs and PEs were reviewed similarly (intermediate-term group).

RESULTS

Fifty-one cases in the short-term group had no complications on PE or RE. Forty-nine dogs were diagnosed with minor complications (patellar ligament desmitis, patella or fibula fracture, gait abnormalities): 42 on RE only; 6 on PE and RE; 1 on PE only. Exercise restriction was extended for 2 weeks in 2 cases with radiographic patellar ligament desmitis. Two cases in the intermediate-term group had minor complications at intermediate-term RE. No new PE or RE complications developed between short-term and intermediate-term evaluations.

CONCLUSION

At routine rechecks of dogs with no owner-perceived issues after TPLO, 49% had minor complications but only 2% were deemed significant enough to alter patient management. The likelihood of new radiographic complications developing after short-term evaluation is low.

CLINICAL SIGNIFICANCE

Routine radiographic recheck examinations rarely altered the postoperative plan in TPLO cases with unremarkable clinical recoveries.

Prospective Evaluation of a Citrate-Based Biomaterial Wedge for a Modified Maquet Procedure in the Treatment of Cranial Cruciate Ligament Rupture in Dogs

OBJECTIVE

 The aim of this study was to describe short- and mid-term outcomes, complications, implant bioabsorption and owner satisfaction for a modified Maquet procedure (MMP) in which a novel bioabsorbable citrate-based implant is used as the wedge component to treat cranial cruciate ligament rupture in client-owned dogs.

STUDY DESIGN

 Prospective clinical study of dogs (n = 13) undergoing MMP (n = 15). Intraoperative complications, postoperative complications, clinical follow-up using a 5-point lameness score and radiographs at 8 weeks and 6 months postoperatively were obtained. Mid-term outcome was assessed via physical examination, radiographs, canine orthopaedic index and owner satisfaction questionnaires.

RESULTS

 No catastrophic complications occurred. Major complications occurred in 3/15 stifles. All were surgical site infections and one case required implant removal. Minor complications occurred in 9/15 stifles. Non-displaced cortical hinge fractures were the most common minor complication, and these occurred intraoperatively (4/15) or postoperatively (2/15). Three dogs achieved full function, eight dogs acceptable function and the outcome was unacceptable in two dogs. Most owners were satisfied with the procedure (11/13). Complete implant bioabsorption was not confirmed on mid-term radiographs.

CONCLUSION

 The described MMP with a citrate-based implant can produce satisfactory mid-term results. However, the long-term outcome of this procedure must be evaluated and technical modifications need to be implemented prior to larger-scale use of this implant.

Modified cranial closing wedge osteotomy to treat cranial cruciate ligament deficient stifles with excessive tibial plateau angles: Complications, owner satisfaction, and midterm to long-term outcomes

OBJECTIVE

To report midterm to long-term outcomes of dogs with cranial cruciate ligament (CCL) rupture and excessive tibial plateau angles (TPA) treated with a modified cranial closing wedge osteotomy (m-CCWO).

STUDY DESIGN

Retrospective case series.

STUDY POPULATION

Dogs (n = 21) with CCL rupture and excessive TPA treated with m-CCWO (n = 28).

METHODS

Medical records, midterm and long-term follow-up radiographic examination records, Canine Orthopedic Index data, and owner surveys were reviewed to determine functional outcomes, owner satisfaction, and complications associated with the technique.

RESULTS

Tibial plateau angle decreased from 42.3° ± 4.8° preoperatively to 4.8° ± 3.3° after m-CCWO. No catastrophic complications occurred, while major and minor complications occurred in three of 28 and six of 28 stifles, respectively. Canine Orthopedic Index scores and owner surveys were available in 16 of 21 dogs at a median of 608 days postoperatively (range 279-1225). Functional midterm or long-term outcomes for these dogs treated with m-CCWO were excellent in eight dogs, acceptable in seven dogs, and unacceptable in one dog. Progression of osteoarthritis was noted on all midterm and long-term follow-up radiographs. All owners but one were satisfied.

CONCLUSION

Modified cranial closing wedge osteotomy was associated with an acceptable morbidity and resulted in satisfactory functional outcomes in most dogs of this series.

CLINICAL SIGNIFICANCE

Modified cranial closing wedge osteotomy should be considered as an alternative to treat CCL rupture in dogs with excessive TPA.

Ex vivo evaluation of a novel surgical guide on the accuracy of closing wedge osteotomies

OBJECTIVE

To determine the influence of a novel surgical guide on the accuracy and technical difficulty of closing wedge osteotomies (CWO).

STUDY DESIGN

Ex vivo experimental study.

SAMPLE POPULATION

Canine tibia models (n = 40).

METHODS

A 20° cranial CWO (CCWO) was created without (standard procedure; STCCWO) or with the aid of a novel wedge osteotomy guide (WOCCWO). Procedures were performed by diplomate (n = 4) and resident (n = 6) surgeons, with each performing 2 STCCWO followed by 2 WOCCWO. To prevent bias, surgeons were unaware of the study purpose until after completing the STCCWO. The wedges were evaluated by comparing the deviation from the 20° target angle, divergence of the 2 osteotomies (osteotomy divergence angle [ODA]), and measurements of the wedge height at the caudomedial cortex (CMC) and caudolateral cortex (CLC). Technique difficulty was explored through a surgeon questionnaire.

RESULTS

The WOCCWO resulted in smaller mean ODA (WOCCWO = 0.86°, SD ± 0.38°, P < .001), and smaller mean difference between CMC and CLC (WOCCWO = 0.29 mm, SD ± 0.19, P < .001) than for the STCCWO (4.22°, SD ± 2.16° and 1.39 mm, SD ± 0.65 respectively). Deviation from the target 20° wedge angle was greater after STCCWO (1.46°, SD ± 1.27°) than after WOCCWO (0.53°, SD ± 0.33°, P = .004). No difference was reported regarding the difficulty of the procedures, but resident surgeons stated that they were more likely to use the guide in a clinical setting compared with diplomates.

CONCLUSION

The wedge osteotomy guide improved the accuracy of CCWO compared with standard technique.

CLINICAL SIGNIFICANCE

The clinical significance of the differences detected in this study is unclear and warrants in vivo investigation.

Tibial tuberosity advancement technique in small breed dogs: study of 30 consecutive dogs (35 stifles)

OBJECTIVES

To assess the outcome and peri-operative complications of the tibial tuberosity advancement technique in small dogs with cranial cruciate ligament rupture.

MATERIALS AND METHODS

Cranial cruciate ligament rupture was diagnosed by positive drawer sign or tibial thrust test and confirmed at surgery in 30 dogs (35 stifles) weighing less than 15 kg. Clinical and radiographic follow-up was obtained at 4 and 12 weeks or later. Thigh diameter and affected and non-affected stifle joint flexion and extension angles were also measured.

RESULTS

At 4-week follow-up 26 of 35 (74%), eight of 35 (23%) and one of 35 (3%) showed no, mild and moderate lameness, respectively. Similarly, at 12 weeks or later the respective outcomes were 32 of 35 (91%), two of 35 (6%) and one of 35 (3%). The mean thigh diameter of affected limbs at 12 or more weeks was 96% of the mean of normal limbs and stifle range of motion reached 98% of normal extension and 97% of normal flexion. There were complications in two of 35 stifles: one screw partially inserted into the joint and postoperative wound dehiscence, both of which required surgical correction.

CLINICAL SIGNIFICANCE

The tibial tuberosity advancement technique leads to acceptable outcomes in small dogs with cranial cruciate ligament rupture.

Fibular osteotomy to facilitate proximal tibial rotation during tibial plateau leveling osteotomy

OBJECTIVE

To identify factors that restrict proximal tibial rotation during tibial plateau leveling osteotomy (TPLO) and report on the outcome of concurrent fibular osteotomy (TPLO-FO).

STUDY DESIGN

Retrospective case-control study.

ANIMALS

Dogs undergoing TPLO-FO (n = 23) and dogs undergoing routine TPLO (n = 49).

METHODS

Medical records and radiographs of dogs that had undergone TPLO-FO were reviewed. Data that were collected included signalment, preoperative tibial plateau angle (TPA), mechanical medial proximal tibial angle (mMPTA), postoperative and recheck TPA and mMPTA, ratio of fibular width to tibial width (FW:TW), presence of tibiofibular synostosis, tibial osteotomy location, and use of additional implants.

RESULTS

The odds of exhibiting rotational constraints requiring FO during TPLO were 62-fold greater in dogs with tibiofibular synostosis than in dogs without synostosis. Dogs with FW:TW greater than 0.24 were 7.8-fold more likely to exhibit rotational constraints. After TPLO-FO, the postoperative increase in TPA was greater after single-plate fixation (mean, 5.4 ° ± 4.5 °) compared with fixation with 2 plates (mean, 1.4 ° ± 0.6 °).

CONCLUSION

Proximal tibiofibular synostosis and a relatively wide fibula restricted tibial plateau rotation. In these dogs, concurrent fibular osteotomy allowed adequate rotation. Adjunct plate fixation limited loss of rotation after TPLO-FO.

CLINICAL SIGNIFICANCE

Successful TPLO relies on adequate rotation of the proximal tibial segment. Fibular osteotomy and adjunct plate fixation are recommended to achieve and maintain adequate rotation of the osteotomized tibia in dogs with rotational constraints.

Welfare-Adjusted Life Years (WALY): A novel metric of animal welfare that combines the impacts of impaired welfare and abbreviated lifespan

Currently, separate measures are used to estimate the impact of animal diseases on mortality and animal welfare. This article introduces a novel metric, the Welfare-Adjusted Life Year (WALY), to estimate disease impact by combining welfare compromise and premature death components. Adapting the Disability-Adjusted Life Year approach used in human health audits, we propose WALY as the sum of a) the years lived with impaired welfare due to a particular cause and b) the years of life lost due to the premature death from the same cause. The years lived with impaired welfare are the product of the average duration of each welfare impediment, reflecting the actual condition that compromises animal welfare, the probability of an incident case developing and impaired welfare weights, representing the degree of impaired welfare. The years of life lost are calculated using the standard expected lifespan at the time of premature death. To demonstrate the concept, we estimated WALYs for 10 common canine diseases, namely mitral valve disease, dilated cardiomyopathy, chronic kidney disease, diabetes mellitus, atopic dermatitis, splenic haemangiosarcoma, appendicular osteosarcoma, cranial cruciate ligament disease, thoracolumbar intervertebral disc disease and cervical spondylomyelopathy. A survey of veterinarians (n = 61) was conducted to elicit impaired welfare weights for 35 welfare impediments. Paired comparison was the primary method to elicit weights, whereas visual analogue scale and time trade-off approaches rescaled these weights onto the desired scale, from 0 (the optimal welfare imaginable) to 1 (the worst welfare imaginable). WALYs for the 10 diseases were then estimated using the impaired welfare weights and published epidemiological data on disease impacts. Welfare impediment “amputation: one limb” and “respiratory distress” had the lowest and highest impaired welfare weights at 0.134 and 0.796, rescaled with a visual analogue scale, and 0.117 and 0.857, rescaled with time trade-off. Among the 10 diseases, thoracolumbar intervertebral disc disease and atopic dermatitis had the smallest and greatest adverse impact on dogs with WALYs at 2.83 (95% UI: 1.54–3.94) and 9.73 (95% uncertainty interval [UI]: 7.17–11.8), respectively. This study developed the WALY metric and demonstrated that it summarises welfare compromise as perceived by humans and total impact of diseases in individual animals. The WALY can potentially be used for prioritisation of disease eradication and control programs, quantification of population welfare and longitudinal surveillance of animal welfare in companion animals and may possibly be extended to production animals.

Influence of class IV laser therapy on the outcomes of tibial plateau leveling osteotomy in dogs

OBJECTIVE

To determine the effects of low-level laser therapy (LLLT) on clinical outcomes in dogs with cranial cruciate ligament disease treated with tibial plateau leveling osteotomy (TPLO).

STUDY DESIGN

Randomized, placebo-controlled clinical trial. Owners and surgeons (care providers and assessors) were masked.

ANIMALS

Ninety-five dogs were admitted for TPLO and assigned to 1 of 2 groups, laser group (LG; n = 51) or placebo group (PG; n = 44).

METHODS

Three treatments (laser or placebo) were administered within a 4-day perioperative period. A fourth treatment was recommended and was accepted in 28.4% of cases (LG, n = 14; PG, n = 13). Dogs in the LG group received laser at wavelengths 660 nm red (100 mW) and at 800, 905 and 970 nm infrared (maximum 15 W continuous wave, 20 W peak pulsed wave), administered simultaneously. Dogs in the PG group received placebo laser (660 nm, 4 mW). Other treatments were identical. Outcomes were measured by difference in clinical metrology instruments (Liverpool Osteoarthritis in Dogs and adjusted Canine Orthopedic Index [COI]), osteotomy healing on a radiographic scale, time to cessation of nonsteroidal anti-inflammatory drug administration, and wound healing by owner questionnaire.

RESULTS

The only difference detected between groups consisted of a greater improvement in the gait section of the adjusted COI (ACOI) in the LG group (median [interquartile range; IQR] = 6 [4-7.5]) compared with the PG group (median [IQR] = 4 [2-6]; P < .05).

CONCLUSION

The laser protocol used in this study was associated with a greater improvement in ACOI gait in dogs treated with TPLO but did not improve any other clinical metrology instrument scores or bone healing.

CLINICAL SIGNIFICANCE

This study provides some evidence that LLLT may improve the gait of dogs recovering from a TPLO, as assessed by owners.

A modified tibial compression test for the detection of meniscal injury in dogs

OBJECTIVE

To assess diagnostic efficacy of a modified tibial compression test in predicting medial meniscal injury in dogs with cranial cruciate ligament failure.

METHODS

Dogs admitted for surgical stabilisation of stifles with cranial cruciate ligament failure were examined by five preoperative physical tests to assess medial meniscal injury. Results of each physical test were compared with findings at arthrotomy and used to calculate sensitivities, specificities, positive and negative predictive values.

RESULTS

None of the physical tests were accurate in reflecting meniscal integrity for dogs with cranial cruciate failure. Out of the five tests, the modified tibial compression test exhibited the highest concordance and sensitivity for the detection of medial meniscal tears. A palpable click during the modified tibial compression test had a sensitivity and specificity up to 63 and 77%, respectively, for the detection of medial meniscal lesions. Concordance values were up to 40% for the modified tibial compression test, followed by the range of motion test (up to 25%), while all other physical tests had concordance values below 10%.

CLINICAL SIGNIFICANCE

Physical tests are highly available, affordable and can be easily performed, but their efficacy in diagnosing medical meniscal injury is low. Meniscal clicks associated with meniscal tears were more frequently elicited during the modified tibial compression test when compared with other traditional tests.

Comparison of tibial anatomical-mechanical axis angle between predisposed dogs and dogs at low risk for cranial cruciate ligament rupture

The purpose of this prospective, radiographic, descriptive study was to compare measurements of tibial anatomical-mechanical axis angle (AMA-angle), tibial plateau angle (TPA), relative tibial tuberosity width (rTTW) and Z-angle from mediolateral radiographs of the tibia between two canine breeds (72 dogs) not predisposed to cranial cruciate ligament rupture (CCLR) and those from a consecutive series of 185 large dogs and 17 West Highland white terriers (WHWT) diagnosed with unilateral, surgically confirmed CCLR. Correlations among these measurements were determined, and levels of inter- and intra-observer variability among and within three observers for each measurement were established using Kendall's coefficient of concordance. Breed had a significant effect on AMA-angle. The median AMA-angle of the subject population of large dogs affected by CCLR was 2.80° (range 1.09°-5.21°); for the WHWT, it was 6.34° (range 5.68°-8.88°); and for the clinically normal dogs, it was 0.74° (range 0.00°-5.40°). In the CCLR group, AMA-angle and TPA were strongly correlated (r=0.745; p<0.0001). A receiver operating characteristic (ROC) curve analysis showed that an AMA-angle higher than 1.87° had a sensitivity of 0.941 (95% confidence interval [CI]: 0.898-0.966) and a specificity of 0.965 (95% CI: 0.919-0.987) for predicting CCLR and was more accurate than TPA, rTTW and Z-angle at predicting CCLR (p<0.0001). Good inter- and intra-observer agreement was found for all measurements. The highly significant difference in AMA-angle found between clinically normal dogs and dogs with CCL injury suggests that AMA-angle magnitude may be a clinically relevant predisposing factor for the development of canine CCLR.

Systematic review of the prevalence, risk factors, diagnosis and management of meniscal injury in dogs: Part 1. [corrected]

OBJECTIVE

To systematically evaluate the evidence reporting the frequency and risk factors of meniscal injury in dogs with cranial cruciate ligament failure.

STUDY DESIGN

Systematic literature review.

MATERIALS AND METHODS

Research questions were defined. An electronic database search of PubMed and CAB Abstracts was performed during November 2013. Data were extracted for study participants, design, intervention, outcome measures and results. Studies were evaluated using a validated instrument for assessing methodological quality and assigned a quality index score. A level of evidence was then assigned to each study.

RESULTS

Sixty-two studies were identified. The median quality index score was 14 out of a possible 26. Twenty-four studies were prospective case series, 37 retrospective case series and 1 animal research study. There were no class I or class II studies, 24 class III studies and 38 class IV studies.

CLINICAL SIGNIFICANCE

Despite a large number of publications the quality of evidence was generally low. No one study or combination of studies provided high quality evidence to establish the true frequency or risk factors for meniscal injury in dogs with cranial cruciate ligament failure.

Systematic review of surgical treatments for cranial cruciate ligament disease in dogs

Surgery for cranial cruciate ligament disease is often recommended; however, it is unclear if one procedure is superior. The aim of this systematic review was to answer the a priori question, "Is there a surgical procedure that will allow a consistent return to normal clinical function in dogs with cranial cruciate ligament disease and is that procedure superior to others?" A systematic literature search was performed through September 2013. Peer reviewed publication in the English language and 6 mo of postoperative follow-up were required. In total, 444 manuscripts were identified and reviewed, and 34 met the inclusion criteria. Two studies provided level 1, 6 provided level 2, 6 provided level 3, and 20 provided level 4 evidence relative to the study question. The most common surgical procedures included tibial plateau leveling osteotomy (TPLO, n = 14), lateral extracapsular suture (n = 13), tibial tuberosity advancement (n = 6). The strength of the evaluated evidence most strongly supports the ability of the TPLO in the ability to return dogs to normal function. It also provided strong support that functional recovery in the intermediate postoperative time period was superior following TPLO compared with lateral extracapsular suture. There was insufficient data to adequately evaluate other surgical procedures.

Short-term outcome and complications of TPLO using anatomically contoured locking compression plates in small/medium-breed dogs with "excessive" tibial plateau angle

OBJECTIVES

To report short-term radiographic and clinical outcome and complications following tibial plateau levelling osteotomy for the treatment of cranial cruciate ligament insufficiency in dogs less than 18·1 kg with tibial plateau angle greater than 35° using anatomically contoured six-hole locking compression plates.

METHODS

Retrospective data were collected on: preoperative, postoperative and follow-up tibial plateau angles, plateau segment rotation, tibial tuberosity width and length of the cranial aspect of tibial tuberosity segment from the patellar tendon insertion and rotation of the tibial plateau below the level of the insertion of the patellar ligament.

RESULTS

In 26 small dogs (29 stifles in total), mean preoperative, postoperative and follow-up tibial plateau angles were 38·2°, 4·8°, and 4·4°, respectively. Documented postoperative complications were limited to patellar tendinopathy in a single case (3·4%) and tibial tuberosity or fibula fracture were not observed.

CLINICAL SIGNIFICANCE

Short-term radiographic and clinical outcome of tibial plateau levelling osteotomy stabilised with anatomically contoured six-hole locking compression plates for the treatment of small dogs with large tibial plateau angle suggests a very low risk of complications. Rotation beyond the "safe point" is necessary to perform full rotation in some cases, but does not appear to incur an increased risk of tibial tuberosity fracture.

Avulsion fragmentation of the tibial tuberosity apophysis and associated patellar tendon enthesopathy in a skeletally immature dog

A 9.5-month-old, female entire, 31.3 kg crossbred dog was presented with a 12 week history of moderate weight-bearing right pelvic limb lameness. Radiographic, computed tomographic, and ultrasonographic imaging revealed progressive avulsion fragmentation of the right tibial tuberosity apophysis and a patellar tendon insertional enthesopathy without physeal involvement. Conservative management was successful in achieving a good clinical outcome. A progressive avulsion of the contralateral proximal tibial physes that occurred concurrently resulted in development of an excessive tibial plateau slope angle. The additional development of a moderate left distal femoral varus deformity was surgically corrected. This is the first report of a progressive, traction injury to the tibial tuberosity apophysis in a dog that appears clinically and radiographically very similar to Osgood-Schlatter disease in humans.