Target Trial Emulation: Does surgical versus non-surgical management of cranial cruciate ligament rupture in dogs cause different outcomes?

Target trial emulation applies design principles from randomised controlled trials to the analysis of observational data for causal inference and is increasingly used within human epidemiology. Using anonymised veterinary clinical data from the VetCompass Programme, this study applied the target trial emulation framework to determine whether surgical (compared to non-surgical) management for cranial cruciate ligament (CCL) rupture in dogs causes improved short- and long-term lameness and analgesia outcomes. The emulated target trial included dogs diagnosed with CCL rupture between January 1, 2019 and December 31, 2019 within the VetCompass database. Inclusion in the emulated trial required dogs aged ≥ 1.5 and < 12 years, first diagnosed with unilateral CCL rupture during 2019 and with no prior history of contralateral ligament rupture or stifle surgery. Dogs were retrospectively observed to have surgical or non-surgical management. Informed from a directed acyclic graph derived from expert opinion, data on the following variables were collected: age, breed, bodyweight, neuter status, insurance status, non-orthopaedic comorbidities, orthopaedic comorbidities and veterinary group. Inverse probability of treatment weighting (IPTW) was used to adjust for confounding, with weights calculated based on a binary logistic regression exposure model. Censored dogs were accounted for in the IPTW analysis using inverse probability of censoring weighting (IPCW). The IPCWs were combined with IPTWs and used to weight each dog's contribution to binary logistic regression outcome models. Standardized mean differences (SMD) examined the balance of covariate distribution between treatment groups. The emulated trial included 615 surgical CCL rupture cases and 200 non-surgical cases. The risk difference for short-term lameness in surgically managed cases (compared with non-surgically managed cases) was -25.7% (95% confidence interval (CI) -36.7% to -15.9%) and the risk difference for long-term lameness -31.7% (95% CI -37.9% to -18.1%). The study demonstrated the application of the target trial framework to veterinary observational data. The findings show that surgical management causes a reduction in short- and long-term lameness compared with non-surgical management in dogs.

Determining predictive metabolomic biomarkers of meniscal injury in dogs with cranial cruciate ligament rupture

OBJECTIVES

This study used hydrogen nuclear magnetic resonance spectroscopy for the first time to examine differences in the metabolomic profile of stifle joint synovial fluid from dogs with cranial cruciate ligament rupture with and without meniscal injuries, in order to identify biomarkers of meniscal injury. Identifying a biomarker of meniscal injury could then ultimately be used to design a minimally invasive diagnostic test for meniscal injuries in dogs.

MATERIALS AND METHODS

Stifle joint synovial fluid was collected from dogs undergoing stifle joint surgery or arthrocentesis for lameness investigations. We used multi-variate statistical analysis using principal component analysis and univariate statistical analysis using one-way analysis of variance and analysis of co-variance to identify differences in the metabolomic profile between dogs with cranial cruciate ligament rupture and meniscal injury, cranial cruciate ligament rupture without meniscal injury, and neither cranial cruciate ligament rupture nor meniscal injury, taking into consideration clinical variables.

RESULTS

A total of 154 samples of canine synovial fluid were included in the study. Sixty-four metabolites were annotated to the hydrogen nuclear magnetic resonance spectroscopy spectra. Six spectral regions were found to be significantly altered (false discovery rate adjusted P-value <0.05) between groups with cranial cruciate ligament rupture with and without meniscal injury, including three attributed to nuclear magnetic resonance mobile lipids [mobile lipid -CH3 (P=0.016), mobile lipid -n(CH3 )3 (P=0.017), mobile unsaturated lipid (P=0.031)].

CLINICAL SIGNIFICANCE

We identified an increase in nuclear magnetic resonance mobile lipids in the synovial fluid of dogs with meniscal injury which are of interest as potential biomarkers of meniscal injury.

Prospective measurement of outcomes and complications of tibial tuberosity advancement using novel mini plates in small breed dogs

Cranial cruciate ligament (CrCL) disease is a common orthopedic disease in canine patients. Tibial osteotomy procedures for the treatment of cranial cruciate ligament disease in small breed dogs (<15 kg) have previously been limited. A total of 22 client-owned dogs, 26 stifles, with cranial cruciate ligament disease were treated with novel mini-tibial tuberosity advancement plates. The most common intraoperative complications included the need for plate-cage overlap in 7 stifles (26.92%) and screw head fracture in 1 (3.85%). Post-operative complications included tibial tuberosity fracture (3.85%), post-operative medial patella luxation (7.69%), and persistent lameness (7.69%). Of the 26 stifles evaluated in the medium term (>6-12 months) post-operatively, 92.3% had no lameness, with the remaining 7.7% having Grade 1 lameness. A good to excellent clinical outcome was noted in all 26 stifles that underwent TTA with novel mini plates.

Physical activity measured with an accelerometer in dogs following extracapsular stabilisation to treat cranial cruciate ligament rupture

OBJECTIVES

To quantify the physical activity levels in dogs with cranial cruciate ligament rupture before and after lateral fabellar suture stabilisation surgery.

MATERIALS AND METHODS

Seventeen dogs (mean weight, 12.3±5.1 kg) with unilateral cranial cruciate ligament rupture were fitted with an accelerometer for seven consecutive days at four different time points: before surgery (T0), one (T1), three (T3) and six (T6) months after surgery. The total activity and times spent in sedentary activity, light to moderate activity and vigorous activity were recorded by the accelerometer, and preoperative and postoperative data were compared. At all time points, dogs underwent clinical evaluations (lameness score, stifle pain score and thigh circumference) and their owners were asked to respond to questionnaires to subjectively score the physical activity and quality of life of the dogs.

RESULTS

At the four time points, the dogs spent between 21.2 and 21.4 hours on sedentary behaviour, 2.3 and 2.5 hours performing light to moderate activity, and 13 to 15 minutes performing vigorous activity. There was no increase in physical activity variables or decrease in sedentary behaviour over time. Lameness scores, pain score and dogs' quality of life improved significantly during the postoperative period. At T6, 17 (100%) of 17 dogs presented no lameness, 16 (94%) of 17 dogs presented no stifle pain, 16 (94%) of 17 owners rated the quality of life as very good and excellent, and 16 (100%) of 16 owners reported a total return to normal activity levels.

CLINICAL SIGNIFICANCE

The clinical recovery after extracapsular stabilisation of the stifle joint was not associated with a spontaneous increase in physical activity or a decrease in sedentary behaviour.

Tibial Plateau Leveling Osteotomy in small and large breed dogs: a comparative retrospective study of complications and outcomes

OBJECTIVE

To compare complication rates and outcomes of small and large breed dogs that had locking plate Tibial Plateau Leveling Osteotomy (TPLO) performed due to cranial cruciate ligament disease during the same time period at a single institution and identify potential influencing factors.

MATERIAL AND METHODS

136 cases with TPLO performed at a single institution between January 2013 and December 2015 were retrospectively reviewed. Dogs were grouped by plate sizes (2.0, 2.4, 2.7, 3.5 and 3.5 broad) and by small breeds (2.0-2.7 plate sizes) and large breeds (3.5 plates). Potential influencing factors on lameness and complications were recorded from the database and measured on radiographs and statistically compared.

RESULTS

Small dogs experienced fewer complications than large dogs (10% vs. 22%) and not a single major complication. Small dogs were significantly less lame at recheck and at long-term follow-up. Progression of bone healing had an influence on the lameness grade of dogs at recheck after TPLO. Distance of the most proximal screw from the joint was identified as a risk factor for implant failure. The width of the patella ligament correlated with body weight and uniformly increased 2.4 times after TPLO.

CONCLUSIONS

TPLO in small breed dogs has a lower overall complication rate than in large breed dogs. The TPLO plate should always be placed as close to the joint as possible to reduce the risk of implant failure.

CLINICAL RELEVANCE

TPLO can be recommended as treatment for cranial cruciate ligament rupture (CCLR) in dogs of all sizes.

Risk factors for unilateral cranial cruciate ligament rupture diagnosis and for clinical management in dogs under primary veterinary care in the UK

This study aimed to evaluate demographic risk factors associated with unilateral cranial cruciate ligament (CCL) rupture diagnosis and to explore demographic and clinical risk factors associated with management of unilateral CCL rupture in dogs under primary veterinary care in the UK. A retrospective cohort study design was used. Clinical records were automatically searched and manually verified for incident cases of unilateral CCL rupture during 2019 and additional clinical management information extracted. Multivariable logistic regression modelling was used to evaluate associations between risk factors and: (1) CCL rupture diagnosis; and (2) clinical management (surgical or non-surgical). The analysis included 1000 unilateral CCL rupture cases and a random selection of 500,000 non-cases. After accounting for confounding factors, dogs aged 6 to < 9 years, male neutered and female neutered dogs, insured dogs, and Rottweiler, Bichon Frise, and West Highland White terrier breeds, in particular, had increased odds of unilateral CCL rupture diagnosis. Insured dogs and dogs ≥ 20 kg had increased odds of surgical management, while dogs ≥ 9 years and dogs with one non-orthopaedic comorbidity at diagnosis with CCL rupture had reduced odds. These findings inform identification of at-risk dogs, with Rottweilers and Bichon Frise particularly predisposed. Additionally, they contribute to a greater understanding of the clinical rationales used in primary-care veterinary practices to decide between surgical or non-surgical management of unilateral CCL rupture.

Comparison of incidence of medial meniscal injury in small dogs (≤15 kg) and medium-to-large dogs (>15 kg) with naturally occurring cranial cruciate ligament disease undergoing tibial plateau levelling osteotomy: 580 stifles (2015 to 2019)

OBJECTIVES

To investigate whether a difference exists in incidence of medial meniscal tears between small (≤15 kg) and medium-to-large (>15 kg) dogs with naturally occurring cranial cruciate ligament disease.

MATERIALS AND METHODS

Records were retrospectively reviewed to identify the incidence of medial meniscal tears in dogs undergoing tibial plateau levelling osteotomy. Degree of cruciate insufficiency, method of identification (arthroscopy or arthrotomy), tibial plateau angle, weight and signalment were recorded. A two-proportion z-test with clustering adjustment was used to compare the meniscal tear rate between the two groups. Logistic regression analysis was used to investigate the effects of variables on medial meniscal tears.

RESULTS

Seventy-six stifles in 67 small dogs and 504 stifles in 384 medium-to-large dogs were included. The rate of meniscal injury at index surgery was 38.2% in small dogs and 36.7% in medium-to-large dogs. The subsequent meniscal tear rate was 1.3% in small dogs and 8% in medium-to-large dogs. The difference in meniscal tear rate was not statistically significant at either index surgery or subsequently. Degree of cruciate ligament insufficiency and use of arthroscopy were significantly associated with medial meniscal tears at index surgery. No variables were significantly associated with subsequent medial meniscal tears.

CLINICAL SIGNIFICANCE

No significant difference exists in medial meniscal tear rate between small and medium-to-large dogs either at index surgery or subsequently. The index of suspicion of concurrent medial meniscal tears should be higher in dogs with complete tear of the cranial cruciate ligament but a partial tear does not preclude meniscal pathology.

Three-dimensional kinematic evaluation of lateral suture stabilization in an in vitro canine cranial cruciate deficient stifle model

The impact of surgical correction of cranial cruciate ligament rupture (CCLR) on 3D kinematics has not been thoroughly evaluated in dogs. The success of current techniques remains limited, as illustrated by suboptimal weightbearing and progression of osteoarthritis. The inability to restore the stifle's 3D kinematics might be a key element in understanding these suboptimal outcomes. The objective of this study was to evaluate the impact of lateral suture stabilization (LSS) on the 3D kinematics of the canine stifle joint. We hypothesized that LSS would not restore 3D kinematics in our model. Ten cadaveric pelvic limbs collected from large dogs (25-40 kg) were tested using a previously validated apparatus that simulates gait. Three experimental conditions were compared: (a) intact stifle; (b) unstable stifle following cranial cruciate ligament transection (CCLt) and (c) CCLt stabilized by LSS. Three-dimensional kinematics were collected through 5 loading cycles simulating the stance phase of gait and curves were analyzed using a Wilcoxon signed-rank test. LSS restored baseline kinematics for the entire stance phase for cranial and lateromedial translation, flexion, and abduction. It restored distraction over 90% of the stance phase. Internal rotation was limited, but not restored. This in vitro study had limitations, as it used a simplified model of stifle motion and weight-bearing. The results of this study report that LSS can restore physiologic 3D kinematics largely comparable to those of healthy stifles. Suboptimal outcome in patients following CCLR stabilization by LSS may therefore result from causes other than immediate postoperative abnormal 3D kinematics.

Cranial cruciate ligament rupture in small dogs (<15 kg): a narrative literature review

Small breed dogs (<15 kg) affected by cranial cruciate ligament rupture secondary to cranial cruciate ligament disease are usually middle-aged (mean age at presentation: 5.4 to 9.8 years); terrier breeds, miniature and toy poodles are over-represented. Small breed dogs have a different morphology of the proximal tibia compared to medium and large breed dogs with a steep tibial plateau angle (mean tibial plateau angle 28.8° to 36.3°), absent base of the flare of the tibial tuberosity and a caudally bowed fibula. There is a lack of evidence regarding the optimal management of cranial cruciate ligament rupture in small dogs. The treatment options consist of conservative management, extracapsular stabilisation, cranial closing wedge ostectomy, tibial plateau levelling osteotomy and tibial tuberosity advancement. The limited evidence available shows that conservative management is likely to result in prolonged recovery time (average time to recovery approximately 4 months). There is paucity of reports focussing on extracapsular stabilisation in small breed dogs, and questions have been raised regarding the early failure of the extracapsular suture subject to higher loads due to the steep tibial plateau angle of small breed dogs. Cranial closing wedge ostectomy and tibial plateau levelling osteotomy have been reported to have low major complication rates and good subjective outcomes. It is controversial whether tibial tuberosity advancement is a suitable technique in dogs with steep tibial plateau angle, which includes most small breed dogs.

In vivo three-dimensional isometry analysis of suture attachment sites for extracapsular suture stabilization of the canine stifle

BACKGROUND

The study aimed to perform isometry analysis of a selection of suture attachment points for extracapsular stabilization with three-dimensional (3D) measurements and normal gait kinematics of the stifle joint.

METHODS

Thirteen client-owned dogs were recruited. Fluoroscopic images of the stifle during treadmill walking and computed tomography of the same joint were acquired. Stifle kinematics were reconstructed using 3D model-based fluoroscopic analysis. Variability of the distance between the femoral and tibial attachment sites across gait cycles was evaluated. The maximum length variation (MLV) and maximum length percent variation (MLPV) were quantified and used to determine the level of isometry of the attachment site combinations.

RESULTS

A selection of combinations with lower mean MLV (<2.5 mm) or MLPV (<8%) was identified from 315 combinations, and all the combinations involved femoral attachment sites near the distal pole of the lateral fabella. The combinations also involving tibial attachment sites near the proximal tibial crest showed improved isometry, with an MLPV < 6%.

CONCLUSION

Combinations using attachment sites around the distal pole of the lateral fabella and proximal tibial crest or caudal to the long digit extensor groove appeared to have improved isometry.

Femorotibial joint kinematics in nine dogs treated with lateral suture stabilization for complete cranial cruciate ligament rupture

OBJECTIVE

To quantify 3-D femorotibial joint kinematics during ambulation in dogs with cranial cruciate ligament (CCL) rupture treated with lateral fabellotibial suture stabilization (LFTS).

ANIMALS

9 adult dogs (body weight, 15 to 35 kg [33 to 77 lb]) with unilateral complete CCL rupture.

PROCEDURES

Digital 3-D bone models of the femur and fabellae and tibia and fibula were created from CT scans. Lateral fluoroscopic images of stifle joints were collected during treadmill walking before surgery and 6 months after LFTS. The LFTS was performed with nylon leader material secured with knots. Gait cycles were analyzed with a 3-D to 2-D image registration process. Femorotibial joint kinematics (craniocaudal translation, internal-external rotation, and flexion and extension angles) were compared among CCL-deficient stifle joints before LFTS, CCL-deficient stifle joints 6 months after LFTS, and unaffected contralateral (control) stifle joints. Owners and veterinarians subjectively assessed lameness by use of a visual analog scale and gait examination, respectively, at each time point.

RESULTS

At midstance phase, medial cranial tibial translation decreased from 9.3 mm before LFTS to 7.6 mm after LFTS but remained increased when compared with control stifle joint values. Following LFTS, axial rotation and stifle joint flexion and extension angles were not significantly different from control stifle joints. On the owner survey, the median walking lameness score improved from 9.3 of 10 before surgery to 0.3 after surgery. On gait examination, median walking lameness score improved from 2 of 4 before surgery to 0 after surgery.

CONCLUSIONS AND CLINICAL RELEVANCE

Stifle joint instability was only slightly mitigated at 6 months following LFTS performed with knotted nylon leader material in medium to large dogs with CCL rupture, despite improvement in lameness.

Risk factors for short-term postoperative complications in the 8 weeks after tibial plateau leveling osteotomy in dogs weighing less than 15 kilograms: A retrospective study

The purpose of this retrospective study was to evaluate the risk factors for short-term postoperative complications in the 8 weeks after unilateral tibial plateau leveling osteotomy (TPLO) for cranial cruciate ligament rupture in small dogs weighing less than 15 kg. Medical records were retrospectively reviewed for 90 dogs weighing <15 kg that underwent medial parapatellar arthrotomy with inspection of the meniscus and TPLO performed by the same surgeon between January 2012 and December 2017. The overall complication rate was 4.44% (4/90 dogs). There were four cases of partial incisional dehiscence, none of which required surgical revision. Complications were significantly more likely in dogs that had undergone placement of a 2.4-mm TPLO plate. Overall, the complication rate was less than that in previous studies of dogs weighing > 15kg. In this study, patients in which 2.4-mm TPLO plates were used were more likely to develop postoperative complications. Dogs weighing <15 kg that underwent TPLO had good short-term outcomes with minimal complications. In our study, the overall complication rate after TPLO in dogs weighing <15 kg is less than that historically reported in heavier dogs. Our data suggests that TPLO is a safe treatment option in small dogs with cranial cruciate ligament rupture.

Comparison of Outcome and Complications in Dogs Weighing Less Than 12 kg Undergoing Miniature Tibial Tuberosity Transposition and Advancement versus Extracapsular Stabilization with Tibial Tuberosity Transposition for Cranial Cruciate Ligament Disease with Concomitant Medial Patellar Luxation

OBJECTIVE

 The aim of this study was to describe a technique for performing miniature tibial tuberosity transposition and advancement (mTTTA). The secondary objective of this study was to compare the short-term outcome and complications in small breed dogs weighing less than 12 kg undergoing surgical correction of cranial cruciate ligament disease with concurrent medial patellar luxation via either extracapsular stabilization with tibial tuberosity transposition (ECS + TTT) or mTTTA.

STUDY DESIGN

 This is a retrospective case comparison study.

RESULTS

 There was no significant difference in overall outcome between the ECS + TTT group and the mTTTA group when comparing 8-week postoperative radiographic healing scores as well as 2- and 8-week postoperative lameness scores.

CONCLUSION

 This study concluded that the mTTTA procedure was feasible and the overall outcome and complications for the dogs that underwent ECS + TTT and those that underwent mTTTA were comparable.

Disease-related and overall survival in dogs with cranial cruciate ligament disease, a historical cohort study

OBJECTIVE

To analyse the effect of treatment method and other risk factors on survival in dogs with cranial cruciate ligament disease (CCLD).

METHODS

A historical cohort study of 333 dogs presenting with CCLD at two University Hospitals (2011-2016) was performed. Signalment, history, treatment and follow-up details were retrieved from medical records, dog owners and referring veterinarians. Treatment groups were defined; conservative or surgical with either lateral fabellotibial suture (LFS) or osteotomy procedures. Multivariable Cox proportional hazards models were applied to evaluate risk factors for disease-related and overall survival.

RESULTS

Sixty-five dogs were conservatively managed, 125 treated with LFS and 143 with osteotomy techniques. At follow-up (autumn 2018), 164 dogs (49.3 %) were alive and 169 (50.7 %) were dead. Both final Cox proportional hazards models included variables for treatment, age, weight and hospital. In addition, the final disease-related model included a variable for orthopaedic comorbidity, while non-orthopaedic comorbidities and a time-varying effect for age on a linear scale were included in the overall survival model. Treatment method was found to have an effect on both disease-related and overall survival and surgical treatment was associated with a lower hazard than conservative treatment.

CONCLUSION

Survival in dogs with CCLD is influenced by treatment strategy, comorbidities, age and weight.

Investigation into clients' perception of postoperative physiotherapy for dogs undergoing cranial cruciate ligament disease surgery

AIM

To evaluate clients' understanding, perception and experience of postoperative physiotherapy after undergoing an osteotomy technique for cranial cruciate ligament disease (CCLD).

METHOD

A retrospective questionnaire was sent to 202 owners of dogs that underwent CCLD surgery at the Queen Mother Hospital for Animals between 1 January 2015 and 31 December 2017, with 63 responses obtained.

RESULTS

Significant differences were found in choice of physiotherapy between clients recommended or not by their vets (p<0.01), and between those offered additional information and those who were not (p<0.01). Of those who chose physiotherapy, 85% had a satisfactory experience. No difference was found in choice of physiotherapy between clients aware of its availability and those who were not (p=0.069). No association was found between cost of the service and clients' perception of cost-worthiness (p=0.169) or between cost-worthiness and recovery outcome (p=0.420). A correlation was found between clients' perception of cost-worthiness and satisfaction level (p=0.03). Clients' knowledge was related to the choice of physiotherapy (p=0.01), but not to other investigated factors. A significant relationship was found between clients' age and choice of physiotherapy (p=0.01), with younger clients choosing physiotherapy more often.

CONCLUSION

Veterinarians recommending physiotherapy and providing accurate information affect clients' decision to choose, and perception of, physiotherapy, in addition to clients' own knowledge.

Evaluation of recovery of limb function by use of force plate gait analysis after tibial plateau leveling osteotomy for management of dogs with unilateral cranial cruciate ligament rupture

OBJECTIVE

To evaluate recovery of limb function by use of gait force analysis after tibial plateau leveling osteotomy (TPLO) in dogs with unilateral cranial cruciate ligament (CrCL) rupture.

ANIMALS

19 dogs with unilateral CrCL rupture treated with TPLO.

PROCEDURES

Force plate gait analysis was performed before and 1, 2, 4, and 7 months after TPLO. Ground reaction forces (GRFs; which comprised peak vertical force [PVF], vertical impulse [VI], peak braking force, braking impulse, peak propulsion force [PPF], and propulsion impulse), time to switching from braking to propulsion, and vector magnitude at PVF in the forelimbs and hind limbs were evaluated.

RESULTS

GRFs in the affected hind limb were significantly lower than in the contralateral hind limb before TPLO. These variables, except for PPF, were not significantly different 7 months after TPLO. Time to the switching point in the affected hind limb was significantly less from before to 2 months after TPLO. Vector magnitude at PVF had a similar pattern as PVF and VI during the recovery process. The PVF in the ipsilateral forelimb was significantly higher than in the contralateral forelimb before TPLO.

CONCLUSIONS AND CLINICAL RELEVANCE

A similar pattern was detected between PVF or VI and craniocaudal force during recovery of dogs that underwent TPLO. Rupture of he CrCl resulted in a decrease in GRFs in the affected hind limb as well as in the switching point and PVF of limbs. However, weight distribution for the craniocaudal force was normalized before PVF or VI. Vector magnitude at PVF might be effectively evaluated by combining vertical force and craniocaudal force.

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.

Treatment of canine cranial cruciate ligament disease

Objective: To describe veterinarians’ treatment recommendations and decision-making factors for dogs with cranial cruciate ligament disease (CCLD).

Methods: An online survey of American College of Veterinary Surgeons (ACVS)-Diplomates (surgeon group) and primary care veterinarians (practitioner group) was performed. The survey included questions on treatment recommendations for common case scenarios (small or large breed dog with complete or partial CCLD), treatment decision factors, non-surgical treatment options, and actual treatment, if any, provided for a client-owned dog as well as one owned by their family or close friend.

Results: The response rate was 42% for the surgeon group (n = 305/723) and four percent for the practitioner group (n = 1145/ 27,771). Extracapsular stabilization (ES) was the most common treatment recommendation for CCLD in small (9.1 kg) breed dogs amongst surgeons and practitioners. Tibial plateau levelling osteotomy (TPLO) was the most common treatment recommendation for CCLD in large (27.2 kg) breed dogs amongst both groups. The two most important treatment decision factors were dog size (78% of practitioners, 69% of surgeons) and activity level (63% of practitioners, 52% of surgeons). The most common treatment provided for a dog of their own or close relation in the surgeon group was TPLO (64%) followed by ES (15%), whereas in the practitioner group it was ES (38%) followed by TPLO (30%).

Clinical significance: Extracapsular stabilization and TPLO are the most commonly employed surgical procedures in the surveyed population; dog size and activity level (but not age) are the major factors influencing treatment decisions.

Surgical stabilization of concomitant canine medial patellar luxation and cranial cruciate ligament disease

Objectives: To compare complication rates and outcomes between cases of concomitant cranial cruciate ligament (CrCL) disease and medial patellar luxation (MPL) treated using extracapsular stabilization and tibial tuberosity transposition (ECS+TTT) and tibial tuberosity transposition and advancement (TTTA).

Methods: In a multicentre retrospective study, records from four referral hospitals were reviewed for dogs with concomitant CrCL pathology and MPL treated using ECS+TTT or TTTA. Data retrieved included signalment, partial/complete CrCL tear, MPL grade, treatment performed, occurrence of postoperative complications, and postoperative outcome grade. Associations between surgical procedure and risk of complication and surgical procedure and outcome were investigated using univariable logistic regression and proportional odds logistic regression respectively. Multiple logistic regression was used to explore confounding factors.

Results: A total of 72 stifles were evaluated in 66 dogs; 32 stifles were stabilized using ECS+TTT and 40 using TTTA. Overall complications were 2.7 times more frequent in the ECS+TTT group and major complications occurred only in this group. The TTTA group was less likely to suffer complications (17.5%) compared to the ECS+TTT group (46.9%) (p = 0.009) and TTTA cases had lower odds of a poorer clinical outcome (p = 0.047).

Clinical significance: Stifles stabilized using ECS+TTT are more likely to suffer from postoperative complications and a poorer clinical outcome when compared to TTTA.

Supplementary Material to this article is available online at https://doi.org/10.3415/VCOT-16-10-0148

Conformation of the proximal tibia and cranial cruciate ligament disease in small breed dogs

OBJECTIVES

To investigate the conformation of the proximal tibia in small breed dogs with and without cranial cruciate ligament disease (CCLD) and to identify morphologic abnormalities that may predispose to development of CCLD.

METHODS

Mediolateral radiographs of the entire tibia of dogs <15 kg with surgically confirmed CCLD were retrospectively evaluated. Proximal tibial width (PTW), tibial plateau length (TPL), tibial plateau angle as described by Slocum and Slocum (sTPA), proximal tibial tuberosity angle (PTTA), tibial plateau angle as described by Inauen and colleagues (nTPA), and diaphyseal tibial width (DTW) were measured. The same variables were obtained from mediolateral radiographs of the entire tibia of dogs <15 kg without CCLD. In addition, a quotient nTPA/PTW, relative tibial tuberosity width (rTTW), and relative body weight (rBW) were calculated for each dog. Independent two-sample t-test (p = 0.05) was used to compare mean ± SD of all measured variables between the two groups.

RESULTS

Gender, age, and weight mean ± SD were not significantly different between the two groups of dogs (p <0.05). Dogs with CCLD had significantly greater sTPA (p = 0.015) and rBW (p = 0.016).

CLINICAL SIGNIFICANCE

In dogs of small breeds, a combination of an excessively steep tibial plateau and an increased relative body weight may predispose to early CCLD development. The slope of the tibial plateau was found to be caused by an abnormal caudal angulation of the proximal tibia, a phenomenon previously associated with CCLD development in small breed dogs in individual cases.

Tibial tuberosity advancement in small-breed dogs using TTA Rapid implants: complications and outcome

OBJECTIVE

To assess the perioperative complications and the outcome when treating small-breed dogs with cranial cruciate ligament insufficiency with tibial tuberosity advancement using the TTA Rapid implant.

MATERIALS AND METHODS

40 dogs (48 stifles) with cranial cruciate ligament insufficiency and body weight of 15 kg or less. Diagnosis was confirmed by arthroscopy or arthrotomy, followed by tibial tuberosity advancement surgery. Six weeks after surgery, the dogs were re-evaluated with clinical examination and radiography. Mid- to long-term outcome was assessed using client questionnaire.

RESULTS

Intraoperative complications consisted of four osteotomy-related fissures through the cranial cortex; two complete fissures were stabilised with a screw, the others healed without intervention. After surgery there were two tibial fractures and two incisional complications. Six weeks postoperatively, limb function was good to excellent in 43 dogs (94%). Two late meniscal injuries occurred. The overall major complication rate was 7/48 14·6%). Mid- to long-term follow-up information was available for 43 stifles: 34 stifles (79%) were free of lameness at a median of 72 weeks postoperatively. The outcome was rated excellent by 88% of the clients and good by 7%.

CLINICAL SIGNIFICANCE

The use of TTA Rapid implants is an alternative for treatment of cranial cruciate ligament insufficiency in small-breed dogs, with complication rates comparable to those recorded in larger breeds and to other techniques, and with a high degree of owner satisfaction.

Long-term outcome after surgical treatment of cranial cruciate ligament rupture in small breed dogs. Comparison of tibial plateau leveling osteotomy and extra-articular stifle stabilization

OBJECTIVE

Cranial cruciate ligament rupture is the most frequently occurring disease of the canine stifle. After introduction of corrective osteotomies of the proximal tibia as surgical treatment option in medium, large and giant breeds, the tibial plateau leveling osteotomy (TPLO) evolved into one of the favorite procedures. In the past small breed dogs have usually been treated by extra-articular stabilization techniques. TPLO has recently become an accepted treatment method in these breeds as well as, and is nowadays used with increasing frequency. The purpose of this study was to evaluate long-term outcomes of TPLO compared to an extra-articular stabilization technique in small breed dogs.

MATERIAL AND METHODS

A total of 40 stifles of 30 small breed dogs weighing ≤ 15 kg were treated for cranial cruciate ligament rupture with either TPLO (n = 23) or a lateral capsular-fascial imbrication technique (CFI; n = 17). Dogs were clinically examined before and at least 6 months after surgery by treadmill analysis and radiography. Moreover a questionnaire was provided to the owners to assess postoperative function and overall satisfaction.

RESULTS

Twenty-one of 23 operated limbs (91.3%) treated with TPLO and five of 17 (29.4%) treated with the CFI showed absolute values comparable to healthy dogs when evaluated by peak vertical force, vertical impulse and its symmetry index during objective gait analysis. Both groups showed mild, but continuous progression of osteoarthritis. TPLO led to a significantly faster recovery and a higher degree of owner satisfaction.

CONCLUSION

Based on clinical examination and objective gait analysis TPLO yielded excellent long-term results and a high degree of owner satisfaction in small breed dogs ≤ 15 kg treated for cranial cruciate ligament rupture.

CLINICAL RELEVANCE

TPLO seems to be superior to CFI treatment of small breed dogs in this study, although CFI should be considered as treatment option under certain circumstances.

Comparison of the tibia plateau angle between small and large dogs with cranial cruciate ligament disease

OBJECTIVES

To compare the conformation of the proximal tibia evaluated on a medio-lateral radiograph between small and large dogs with cranial cruciate ligament disease (CCLD).

METHODS

Retrospective clinical study with dogs having radiographic evaluation and CCLD confirmed at surgery. The first group (n = 52) was comprised of dogs weighing less than 15 kg and the second group (n = 52) of dogs weighing more than 15 kg. The tibial plateau angle (TPA), the relative tibial tuberosity width (rTTW), and the Z angle were measured on preoperative radiographs with imaging measurement software. Linear mixed models were used to assess the effect of weight, age, sex, and neutered status on radiographic measurements and to estimate interobserver variabilities.

RESULTS

The small dog group had a greater TPA (30.1° ± 5.3; p <0.001 with a mean difference of 4.9° [95% CI: 3.8-6.0]) and Z angle (69.9° ± 5.6; p<0.001 with a mean difference of 6.1° ([95% CI: 4.9-7.4]) than the large dog group. Sex and neutered status further influenced the TPA and Z angle values. No significant effect was observed on the rTTW values. A strong correlation was found between the TPA and the Z angle (r = 0.61, p <0.001). Variances were not significantly different between observers. Overall the interobserver variability was low suggesting that agreement was good.

CLINICAL SIGNIFICANCE

Small dogs with CCLD have a steeper tibial plateau than large dogs with CCLD. Sex and neutered status also had an effect on some measured variables. This anatomical difference could influence the surgical technique, which may affect the outcome. The good interobserver agreement suggests the observer is unlikely to influence surgical planning.

Tibial anatomy in normal small breed dogs including anisometry of various extracapsular stabilizing suture attachment sites

OBJECTIVES

To investigate proximal tibial anatomy and its influence on anisometry of extracapsular stabilizing sutures in small dog breeds.

MATERIALS AND METHODS

Mediolateral radiographs of the femora, stifles, and tibiae of 12 small breed dogs were acquired with the stifles positioned at various angles. Measurements taken included tibial plateau angle (TPA), diaphyseal: proximal tibial angle (DPA), patellar tendon angle (PTA), Z-angle, relative tibial tuberosity width (rTTW), and the distance between six combinations of two femoral and three tibial extra-capsular stabilizing suture (ECS) attachment sites. Theoretical strain through stifle range-of-motion was recorded.

RESULTS

The TPA (32° ± 5.8°), DPA (10.2° ± 7.3°), PTA (103.7° ± 6.2°), and Z-angle (70.4° ± 9.0°) were positively correlated with one another (R >0.7), but none were correlated with rTTW (0.93 ± 0.10). The F2-T1 combination of ECS attachment sites had lowest strain for nine stifles. The shortest attachment site separation was at a stifle flexion of 50° for nine stifles. Proximal tibial anatomy measurements could not predict optimal attachment site combination, optimal stifle angle for suture placement, or ECS strain.

CLINICAL SIGNIFICANCE

There is individual variation in the optimal attachment site combination and stifle angle for suture placement, which may influence consistency of outcomes with ECS.