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.

Influence of antiseptic lavage during tibial plateau leveling osteotomies on surgical site infection in 1422 dogs.

OBJECTIVE: To determine the influence of preclosure antiseptic versus saline lavage on surgical site infections (SSI) in dogs following tibial plateau leveling osteotomy (TPLO). STUDY DESIGN: A multicenter retrospective study. SAMPLE POPULATION: Dogs treated with TPLO (n = 1422) between December 2019 and October 2021. METHODS: The medical records of dogs treated with TPLO were reviewed for preclosure antiseptic lavage or saline irrigation. Additional collected data included signalment, unilateral or bilateral TPLO, postoperative administration of antimicrobial medications, antibiotic agent, surgeon, and development of SSI within 90 postoperative days. Eleven factors were analyzed for association with SSI using univariate and multivariate analysis. RESULTS: Data were collected from the records of 519 dogs treated with antiseptic lavage and 903 dogs treated with saline lavage during TPLO. Surgical site infections were diagnosed more frequently in dogs that received preclosure antiseptic lavage (77/519, 14.84%) than those with saline irrigation (80/903, 8.86%) (p = .001). Single session bilateral TPLO increased the odds of SSI by 2.5x (p = .004). The odds of SSI increased by 11% (p = .001) for every 5 kg increase in bodyweight. Postoperative administration of antimicrobials decreased the risk of SSI (p = .008). CONCLUSION: The preclosure antiseptic lavage tested here did not decrease the incidence of SSI after TPLO. CLINICAL SIGNIFICANCE: The results of this study do not provide evidence to support preclosure antiseptic lavage during TPLOs.

Diagnosis of medial meniscal lesions in the canine stifle using multidetector computed tomographic positive-contrast arthrography.

OBJECTIVE: To assess diagnostic value and clinical utility of multidetector computed tomographic positive contrast arthrography (CTA) for meniscal lesions in dogs. STUDY DESIGN: Prospective case series. STUDY POPULATION: Client-owned dogs (n = 55) with cranial cruciate ligament injuries. METHODS: Sedated dogs underwent CTA using a 16-slice scanner, and subsequently received mini-medial arthrotomy for meniscal assessment. Scans were anonymized, randomized, and reviewed twice for meniscal lesions by three independent observers with varying experience. Results were compared with surgical findings. Reproducibility and repeatability were assessed with kappa statistics, intraobserver changes in diagnosis by McNemar's test, and interobserver differences using Cochran's Q test. Test performance was calculated using sensitivity, specificity, proportion correctly identified, and positive and negative predictive values and likelihood ratios. RESULTS: Analysis was based on 52 scans from 44 dogs. Sensitivity for identifying meniscal lesions was 0.62-1.00 and specificity was 0.70-0.96. Intraobserver agreement was 0.50-0.78, and interobserver agreement was 0.47-0.83. There was a significant change between readings one and two for the least experienced observers (p < .05). The sum of sensitivity and specificity exceeded 1.5 for both readings and all observers. CONCLUSION: Diagnostic performance was suitable for identifying meniscal lesions. An effect of experience and learning was seen in this study.

Short-term outcomes of 43 dogs treated with arthroscopic suturing for meniscal tears associated with cranial cruciate ligament disease.

OBJECTIVE: To describe short-term outcomes and complications in dogs receiving meniscal suturing and concurrent tibial plateau leveling osteotomy (TPLO) with or without augmentation with an extracapsular suture. STUDY DESIGN: Retrospective case series. ANIMALS: Forty-three client-owned dogs submitted for cruciate ligament disease. METHODS: Dogs were included if meniscal suturing was performed during or after a TPLO procedure. Criteria included an unstable medial meniscus without evidence of a tear, a caudal vertical longitudinal tear with or without displacement, or if a bucket-handle tear was debrided and the remaining rim was unstable. Stifle stabilization was performed by either a standard TPLO or an augmented TPLO (TPLO + internal brace [IB]). Outcome measures included physical examination findings, radiographs, subjective gait examination, Liverpool Osteoarthritis in Dogs (LOAD) scores, and second-look arthroscopy. RESULTS: Forty-four meniscal repairs were performed in 43 dogs. Five types of meniscal tears were treated employing eight suture materials. Complications were documented in 15 cases (34%). The stabilization technique had a significant impact on the outcome (p = .049): TPLO + IB had a 93.3% success rate and the success rate was 71.4% in the TPLO-only group. CONCLUSION: Five types of meniscal pathology were addressed successfully in the study, indicating that currently accepted criteria for meniscal suturing in dogs may be overly conservative. The majority of complications were not related to the meniscal suturing itself and did not compromise the outcome. The stifle stabilization technique had an impact on outcome. CLINICAL SIGNIFICANCE: The authors found arthroscopic meniscal suturing to be practical and successful in this patient population. Postoperative stifle stability had an impact on successful treatment.

Intra-articular Fibrolipoma of the Stifle in a Dog.

A 12 yr old male castrated miniature Australian shepherd dog presented for surgical consultation of historical bilateral medial patellar luxations with a 3 mo history of an acute onset of a left pelvic limb lameness. Physical examination confirmed medial patellar luxations and a mass effect of the left stifle medially. Radiographs showed medial distension of the joint capsule by a soft tissue opacity. Fine-needle aspirate of the left stifle revealed a mesenchymal cell population. Left medial parapatellar stifle arthrotomy found a fatty mass, which was excised at its base. A benign fibrolipoma was diagnosed on histopathology, and the excision was expected to be curative. The owners reported immediate improvement of perceived comfort postoperatively. At 2 and 24 wk, the dog returned to a normal level of function. Lipomas of the stifle, although rare, should be considered as a differential for intra-articular masses causing lameness.

Delayed Life-Threatening Hemorrhage Caused by Cranial Tibial Artery Pseudoaneurysm in Two Dogs.

Two adult dogs were presented at 25 and 30 days following tibial external skeletal fixator placement (case 1) and tibial plateau leveling osteotomy (case 2), respectively. Clinical signs at presentation for each of them included acute onset lethargy, non-weight-bearing lameness, and hemorrhage at the surgical site with large hematoma formation. On admission, emergency whole blood transfusion was required in case 2 with a preoperative packed cell volume of 13%. Both dogs were diagnosed with pseudoaneurysm of the cranial tibial artery based on color Doppler ultrasonography. Additionally, computed tomography angiography was performed in one dog. Surgical treatment of the dogs included ligation of the cranial tibial artery supplying the pseudoaneurysm and curettage of hematoma. The surgery was completed without complications in case 1, but case 2 experienced inadvertent rupture of pseudoaneurysm with significant blood loss, which required another whole blood transfusion during the procedure. Both dogs had excellent functional recovery with no recurrence of clinical signs. We hypothesized that pseudoaneurysms were primarily caused by trauma secondary to placement of surgical implants or osteotomy. For orthopedic surgeons, it is important to recognize clinical signs of a potential tibial arterial pseudoaneurysm, as early surgical intervention may prevent loss of limb or life.

The effects of tibial tuberosity avulsion and repair on tibial plateau angle in dogs.

AIMS: To assess whether tibial tuberosity avulsion injury and subsequent surgical repair in skeletally immature dogs are associated with changes in tibial plateau angle (TPA) at skeletal maturity. METHODS: Skeletally mature (> 18 months of age) dogs that had previously undergone unilateral surgery when 4-8 months of age to repair tibial tuberosity avulsion were enrolled. Bilateral, mediolateral stifle radiographs were taken. TPA was measured digitally from the radiographs independently by two readers and compared between sides within dogs. As the number of dogs that would be enrolled for the main part of the study was unknown, to understand how the variation between left and right stifles within dogs would affect the power of the main study, 29 client-owned, skeletally mature dogs without stifle pathology were recruited prior to the main study for bilateral, mediolateral projection stifle radiographs. Variation in the differences in TPA between left and right stifles was used to estimate the likely power of the major part of the study for different numbers of enrolled dogs. RESULTS: From 29 dogs enrolled in the power assessment, the SD of the differences between left and right stifles was 2.1°. With 10 dogs (20 stifles) enrolled within the main part of the study, and if the SD of the differences between operated and non-operated stifles within a dog was the same as the SD of the differences between non-operated stifles within a dog (2.1°), the study would have power ≥ 0.8 if the mean difference in TPA between operated and non-operated stifles was ≥ 2.1°.Ten dogs were enrolled in phase II of the study. In 8/10 of these dogs, the TPA in the operated stifle was less than in the non-operated stifle. The mean TPA on the operated stifle was 6.4° less than on the non-operated stifle (95% CI = 2.4-10.3° less; p = 0.002). For surgery between 4 and 8 months of age, TPA at maturity increased by 2.7° (95% CI = 1.1-4.3°; p = 0.001) for each additional month of age at surgery. CONCLUSIONS AND CLINICAL RELEVANCE: Based on this study, surgical repair of tibial tuberosity avulsion in skeletally immature dogs is associated with a smaller TPA at skeletal maturity. However, causality cannot be established from this cross-sectional study, and this association may be because stifles with a smaller TPA are predisposed to tibial tuberosity avulsion.

A modified triple tibial osteotomy for management of canine cranial cruciate ligament disease: retrospective assessment of 309 procedures (2017-2020).

CASE HISTORY: Medical records from a single referral hospital (Animal Referral Hospital, Sinnamon Park, Australia) of dogs treated with modified triple tibial osteotomy (TTO) for management of cranial cruciate ligament (CrCL) disease from June 2017 to June 2020 were reviewed. Modifications to the originally described TTO procedure included a modified wedge angle calculation and performing the tibial osteotomies without the use of pre-drilled guide holes. CLINICAL FINDINGS: A total of 253 dogs met the inclusion criteria. Two dogs were excluded, leaving 251 dogs that had undergone 309 procedures for assessment, and data from these, including complications, were reviewed. Complete, partial competent, and partial incompetent rupture of the cranial cruciate ligament was identified in 202/309 (65.4%), 79/309 (25.6%), and 28/309 (9.1%) stifles, respectively. Medial meniscal injury was identified in 207/309 (67.0%) stifles at the time of initial surgery. TREATMENT AND OUTCOME: Fifty-eight dogs had bilateral procedures, including both single-session and staged surgeries, and 48 of these were available for analyses. The modifications to the TTO procedure described herein resulted in a median wedge angle of 21° and a median post-operative tibial plateau angle of 5.8°. Tibial compression testing following surgery indicated elimination of cranial tibial thrust in all stifles in this series. The most common intra-operative complication was tibial tuberosity fracture (15/309; 4.9%). Minor post-operative complications occurred in 37/309 (12.0%) procedures, with infection being the most common (27/309; 8.7%). Major post-operative complications occurred in 9/309 (2.9%) procedures. The intra- and post-operative complication rates for dogs undergoing bilateral single-session TTO were both 8.3% (2/24). The intra- and post-operative complication rates for dogs undergoing bilateral staged TTO were both 4.2% (1/24). The low number of complications for both the bilateral single-session and bilateral staged TTO groups precluded statistical analysis. All complications resolved uneventfully as determined by the attending surgeon. CLINICAL RELEVANCE: The modified TTO technique described here was safe and effective for the management of canine CrCL disease in the dogs included in the case series. Findings of this study suggest that, with careful case selection, the modified TTO may be performed as a bilateral single-session procedure in dogs with concurrent bilateral cranial cruciate ligament disease. Future studies analysing the effects of these modifications on stifle biomechanics would be beneficial. ABBREVIATIONS: CrCL: Cranial cruciate ligament; SSI: Surgical site infection; TPA: Tibial plateau angle; TPLO: Tibial plateau levelling osteotomy; TTA: Tibial tuberosity advancement; TTO: Triple tibial osteotomy.

Novel crescentic, medial-closing, medially translating, centre-of-rotation-of-angulation-based, levelling osteotomy for lateral compartment stifle disease with partial cranial cruciate ligament tear in two dogs.

CASE HISTORY: Two mature, large breed dogs presented with chronic lameness and discomfort localised to the stifle. CLINICAL FINDINGS: No hindlimb deformities were present on physical examination or radiographic evaluation. No stifle instability was present. Arthroscopy revealed severe (grade 5/5 modified Outerbridge score) cartilage erosion in the lateral compartment (femorotibial), marked degeneration of the lateral meniscus and early cranial cruciate ligament disease in both patients. TREATMENT AND OUTCOME: Medial-closing, medially translating, centre-of-rotation-of-angulation-based, levelling osteotomy (mcmtCBLO) was performed in both patients. The procedure aims to shift the pelvic limb's mechanical axis medially to reduce pressure in the lateral compartment while also reducing craniocaudal shear forces by lowering the tibial plateau angle.Eight weeks after surgery one patient's lameness had resolved while the other had improved significantly. Second-look arthroscopy performed at this time revealed fibrocartilage formation in the lateral compartment without progression of cruciate disease in both cases. At long-term follow-up (approximately 3 and 5 years), favourable outcomes (no or minimal lameness, mild or moderate osteoarthritis) were identified on the long-term owner survey, lameness examination and radiographs. CLINICAL RELEVANCE: mcmtCBLO reduced or eliminated short- and long-term lameness in these two cases afflicted by concurrent lateral compartment and early cranial cruciate ligament disease.

Surgical Repair of Psittacine Femorotibial Luxation: A Case Series.

Luxation of the psittacine femorotibial joint most commonly occurs following trauma or as a development abnormality. Historically, this injury is considered to have a poor prognosis in birds; however, surgical management may result in acceptable and functional outcomes. This case series describes the surgical techniques, complications, and outcomes of 7 cases of femorotibial luxation in psittacine birds. Of the 7 cases, 6 were chronic injuries. Surgical repair methods included conjoined intramedullary pinning, transarticular pinning with an external skeletal fixator (ESF), a combination of extracapsular stabilization and ESF, ESF alone, and a combination of conjoined intramedullary pins with an ESF. An acceptable outcome was achieved in 75% (6/8) of luxated femorotibial joints managed with surgical methods. All cases were female birds of various species, suggesting a possible sex predisposition for stifle luxation.

Comparative kinetic and kinematic evaluation of TPLO and TPLO combined with extra-articular lateral augmentation: A biomechanical study.

OBJECTIVES: To investigate stifle kinematics and kinetics following TPLO and TPLO combined with an extra-articular lateral augmentation (TPLO-IB) during the tibial compression test (TCT) and the tibial pivot compression test (TPT), applied with an external (eTPT) and an internal moment (iTPT). STUDY DESIGN: Experimental ex vivo study. SAMPLE POPULATION: Ten cadaveric hindlimbs of dogs weighing 23-40 kg. METHODS: 3D-kinematic and kinetic data were collected while performing TCT, eTPT, and iTPT and compared under the conditions (1) normal, (2) CCL deficient, (3) TPLO, and (4) TPLO-IB. Two-way repeated-measures ANOVA was used to examine the effect of test and treatment on kinetic and kinematic data. RESULTS: Mean ± SD preoperative TPA was 24.7° ± 1.7°, postoperative TPA was 5.9° ± 0.7°. During TCT, there was no difference in cranial tibial translation between the intact stifle and after TPLO (p = .17). In contrast, cranial tibial translation was six times larger in TPLO compared to intact when performing eTPT and iTPT (p < .001). Cranial tibial translation with TCT, eTPT and iTPT was not different between intact stifle and TPLO-IB. Intraclass correlation coefficient for eTPT and iTPT after TPLO and TPLO-IB was excellent being 0.93 (0.70-0.99) and 0.91 (0.73-0.99), respectively. CONCLUSION: Whereas TCT is negative after TPLO, instability persists when a rotational moment is combined using eTPT and iTPT. TPLO-IB neutralizes craniocaudal and rotational instability when performing TCT, eTPT, and iTPT.

Outcomes and complications of a modified tibial tuberosity transposition technique in the treatment of medial patellar luxation in dogs.

OBJECTIVE: To report a modification of the tibial tuberosity transposition (m-TTT) technique used to treat medial patellar luxation (MPL) in dogs, and report its complications. STUDY DESIGN: Retrospective case series. SAMPLE POPULATION: Dogs (n = 235) undergoing MPL correction, using m-TTT (n = 300 stifles). METHODS: Medical records and client surveys were reviewed to determine complications associated with this technique and they were compared with previously reported complications using similar techniques. RESULTS: Short-term minor complications included low-grade reluxation (11 stifles, 3.6%), incisional seroma (nine stifles, 3%), pin-associated swelling (seven stifles, 2.3%), patellar desmitis (six stifles, 2%), superficial incisional infection (four stifles, 1.3%), pin migration (three stifles, 1%), tibial tuberosity (TT) fracture (two stifles, 0.6%), tibial tuberosity displacement and patella alta (one stifle, 0.3%), pin-associated discomfort (one stifle, 0.3%), trochlear block fracture (one stifle, 0.3%). Short-term major complications included pin migration (three stifles, 1%), incisional infection (two stifles, 0.6%), tibial tuberosity fracture (two stifles, 0.6%), and high grade reluxation (two stifles, 0.6%). Long-term follow-up examination data were available for 109/300 (36.3%) stifles. One minor complication and four major complications were documented. All long-term complications were due to pin migration. The overall major complication rate was 4.3% (13/300 stifles), with a minor complication rate of 15% (46/300 stifles). The owner survey indicated a 100% satisfaction rate. CONCLUSION: The m-TTT technique yielded acceptable complication rates, with high owner satisfaction. CLINICAL SIGNIFICANCE: The m-TTT should be considered as an alternative technique for treating dogs with MPL requiring a tibial tuberosity transposition.

Comparison of two postoperative complication grading systems after treatment of stifle and shoulder instability in 68 dogs.

OBJECTIVE: (1) To adapt and apply the Clavien-Dindo (aCD) postoperative complication grading system to dogs experiencing complications following a single orthopedic procedure. (2) To compare the reliability of the Clavien-Dindo system to the Cook complication grading system. STUDY DESIGN: Retrospective study. SAMPLE POPULATION: Sixty-eight client-owned dogs. METHODS: Scenarios derived from complications following TightRope stabilization of the stifle and shoulder were graded by four ACVS-boarded surgeons using two systems; the Cook 3-point scale and the aCD 5-point scale. Because the aCD system distinguishes complications from outcomes ("sequelae" or "failure to cure"), two data sets were created: one with (n = 76) and without (n = 67) inclusion of "sequelae" and "failure to cure" cases. Interobserver reliability was evaluated using intraclass correlation coefficient (ICC) calculations. RESULTS: Seventy-six scenarios from 68 records were evaluated. The ICC of the aCD system was 0.620 consistent with moderate reliability. The reliability of the Cook system was good, with an ICC of 0.848. Exclusion of cases with "sequelae" or "failure to cure" resulted in excellent reliability of the aCD system (ICC = 0.975) and good reliability of the Cook systems (ICC = 0.857). CONCLUSION: The aCD grading system was less reliable than the Cook system when evaluating all cases but more reliable when evaluating cases of complications excluding "sequelae" and "failures to cure". CLINICAL SIGNIFICANCE: The Cook grading system is reliably good in grading postoperative complications in dogs. The aCD system can also be used to assess postoperative complications with excellent reliability but is less reliable when distinguishing complications from other postoperative outcomes.

Computed tomographic imaging and surgical management of distal insertional avulsion fragments of the caudal cruciate ligament in four horses.

OBJECTIVE: To describe cases with caudal cruciate ligament (CdCL) avulsion fragments diagnosed based on computed tomography (CT) examination and report on arthroscopic fragment removal. ANIMALS: Four Warmblood horses with hindlimb lameness and osseous fragments located in the caudal medial femorotibial joint (mFTJ). STUDY DESIGN: Short case series. METHODS: CT and arthroscopic evaluation of the caudal mFTJ were performed. The caudal mFTJ and the insertion of the CdCL on the tibia were assessed and removal of the avulsion fragments was attempted in three horses using a cranial intercondylar approach. RESULTS: The fragment was not accessible via caudomedial approaches in one horse. A cranial intercondylar approach was used in three horses, allowing removal of the intra-articular fragment in two horses, and removal of two-thirds of the proximal fragment in the last horse. Acute, profuse, arterial bleeding occurred in this horse during surgery with transient postoperative soft tissue swelling. Comorbidities included medial femoral condyle cartilage defects (3), cranial cruciate ligament lesions (2), and medial collateral ligament lesions (2). Horses were followed up for 16 months (median, range 11-28 months), at which point all were back in ridden exercise; owners' satisfaction was good. CONCLUSION: CT examination confirmed the diagnosis and allowed evaluation of the stifle joint for comorbidities. A cranial intercondylar arthroscopic approach facilitated the removal of CdCL insertional avulsion fragments, although not always complete. CLINICAL SIGNIFICANCE: A cranial intercondylar approach can allow access to CdCL avulsion fragments, but complications and incomplete removal remain possible.

The value of routine radiographic follow up in the postoperative management of canine medial patellar luxation.

OBJECTIVE: To determine the influence of radiographic examination on the recommendations made at the time of planned re-evaluation of dogs after medial patellar luxation (MPL) surgery. STUDY DESIGN: Retrospective multi-institutional case series. ANIMALS: Client-owned dogs (N = 825) that underwent MPL surgery. METHODS: Records of 10 referral institutions were searched for dogs that had been treated surgically for unilateral MPL and underwent a planned follow-up visit, including radiographs. The frequency of, and reasons for, changes in further recovery recommendations were investigated. RESULTS: Follow up was performed at a median of 6 (range, 4-20) weeks postoperatively. Isolated radiographic abnormalities were identified in 3.3% (27/825) of dogs following MPL surgery and led to a change in recommendations in 3% (13/432) of dogs that were presented without owner or clinician concerns. Lameness, administration of analgesia at follow up, and history of unplanned visits prior to routine re-examination were associated with a change in postoperative plan (P < .001). In the absence of owner and clinician concerns, the odds of having a change in convalescence plans were not different, whether or not isolated radiographic abnormalities were present (P = .641). CONCLUSION: Routine radiographs at follow up did not influence postoperative management of most dogs after MPL surgery in the absence of abnormalities on clinical history or orthopedic examination. CLINICAL SIGNIFICANCE: Dogs that were presented for routine follow up after unilateral MPL surgery without owner concerns, lameness, analgesic treatment or a history of unplanned visits, and for which examination by a surgical specialist was unremarkable, were unlikely to benefit from radiographs.

Effect of gonadectomy on pain assessment in dogs undergoing orthopaedic stifle surgery.

OBJECTIVE: To compare pain perception between gonadectomized and intact dogs. STUDY DESIGN: Blinded, prospective, cohort study. ANIMALS: A group of 74 client-owned dogs. METHODS: Dogs were divided into four groups: group 1-female/neutered (F/N), group 2-female/intact (F/I), group 3-male/neutered (M/N) and group 4-male/intact (M/I). Premedication consisted of intramuscularly administered acepromazine (0.05 mg kg-1) and morphine (0.2 mg kg-1), and subcutaneously administered carprofen (4 mg kg-1). Anaesthesia was induced with propofol (1 mg kg-1 intravenously and supplementary doses to effect) and maintained with isoflurane in 100% oxygen. Intraoperative analgesia was achieved with fentanyl infusion (0.1 µg kg-1 minute-1). Pain assessments [using the University of Melbourne Pain Scale (UMPS) and an algometer at the incision site (IS), parallel to the incision site (NIS), and on the contralateral healthy limb] were performed preoperatively, and at 1, 2, 4, 6, 9 and 20 hours after extubation. The time-standardised area under the curve (AUCst) for measurements was calculated and compared by performing a one-way multivariate analysis of variance (manova). Statistical significance was set at p < 0.05. RESULTS: Postoperatively, F/N exhibited higher pain than F/I, with estimated marginal means (95% confidence intervals) AUCstISGroup1 909 (672-1146) versus AUCstISGroup2 1385 (1094-1675) (p = 0.014), AUCstNISGroup1 1122 (823-1420) versus AUCstNISGroup2 1668 (1302-2033) (p = 0.024) and AUCstUMPSGroup1 5.30 (4.58-6.02) versus AUCstUMPSGroup2 4.1 (3.2-5.0) (p = 0.041). Similarly, M/N showed higher pain than M/I with AUCstISGroup3 686 (384-987) versus AUCstISGroup4 1107 (871-1345) (p = 0.031) and AUCstNISGroup3 856 (476-1235) versus AUCstNISGroup4 1407 (1109-1706) (p = 0.026), and AUCstUMPSGroup3 6.0 (5.1-6.9) versus AUCstUMPSGroup4 4.4 (3.7-5.2) (p = 0.008). CONCLUSIONS AND CLINICAL RELEVANCE: Gonadectomy affects pain sensitivity in dogs undergoing stifle surgery. Neutering status should be taken into consideration when planning individualized anaesthetic/analgesic protocols.

Tibial Plateau and Stifle Joint Invasion with a Subcutaneous Mast Cell Tumor.

A 4 yr old female neutered Labrador retriever was referred with a history of left hind-limb lameness and an acute, nonpainful, subcutaneous mass on the medial aspect of the left stifle. Stifle radiographs and fine needle aspirates of the soft tissue mass performed by the referring veterinarian confirmed the presence of predominantly highly granulated mast cells, consistent with a mast cell tumor. Computed tomography demonstrated a soft tissue mass centered on the left medial stifle, with associated joint effusion and polyostotic lytic lesions on the tibial plateau and distal patella. Ultrasound-guided aspirates of the liver, spleen, and popliteal lymph nodes were obtained to rule out further metastatic spread. Cytology of the joint fluid demonstrated a low number of well-differentiated mast cells. Surgical and oncological interventions were discussed, and full hind-limb amputation was elected. Histopathological analysis of the submitted tissues after amputation diagnosed a subcutaneous mast cell tumor with neoplastic cell infiltrate extending into sections of joint capsule and synovial membrane. Infiltration to the tibia and distal patella were suspected following the presence of mast cell clusters in both osteolytic lesions. No evidence of metastasis was identified in the popliteal lymph node. Postoperative monitoring of iliac lymph node size using ultrasound did not identify evidence of metastasis 12 mo postoperatively.

Outcome and owner assessment after single-session bilateral tibial plateau leveling osteotomy in 127 dogs.

Objective: To retrospectively evaluate complication rates following bilateral tibial plateau leveling osteotomy (TPLO) as well as owner assessment of outcomes and post-operative management. Methods: Medical records of dogs presenting with bilateral cranial cruciate ligament (CCL) disease that underwent single-session bilateral TPLO from 2015 to 2019 in 1 referral practice were retrospectively reviewed. A non-validated questionnaire was sent to the owners to assess their ability to cope during the rehabilitation period, as well as procedure outcome. Results: In total, 127 dogs were included for analysis. The overall complication rate was 16.5% (minor complication rate 9.4% and major complication rate 10.2%). Of the 50 owners that answered the questionnaire, 31 (62%) did not need to use sling support at home at any time and 10 (20%) used sling support for < 1 wk. Furthermore, only 1 owner indicated that they would not choose to do a bilateral TPLO surgery again. Clinical significance: Bilateral single-session TPLO surgery performed by an experienced surgeon had a similar outcome and complication rate to that of unilateral TPLO surgery. Most owners reported that postoperative care of their dog was not difficult.

Résultats et évaluation par le propriétaire après une ostéotomie bilatérale de nivellement du plateau tibial e n une seule séance chez 127 chiens. Objectif: Évaluer rétrospectivement les taux de complications après une ostéotomie bilatérale de nivellement du plateau tibial (TPLO) ainsi que l'évaluation par le propriétaire des résultats et de la prise en charge postopératoire. Méthodes: Les dossiers médicaux des chiens présentant une pathologie bilatérale du ligament croisé crânien (CCL) ayant subi une TPLO bilatérale en une seule séance de 2015 à 2019 dans une pratique de référence ont été examinés rétrospectivement. Un questionnaire non validé a été envoyé aux propriétaires pour évaluer leur capacité à faire face pendant la période de réhabilitation, ainsi que le résultat de la procédure. Résultats: Au total, 127 chiens ont été inclus pour l'analyse. Le taux global de complications était de 16,5 % (taux de complications mineures 9,4 % et taux de complications majeures 10,2 %). Sur les 50 propriétaires qui ont répondu au questionnaire, 31 (62 %) n'ont pas eu besoin d'utiliser une écharpe à domicile à tout moment et 10 (20 %) ont utilisé une écharpe pendant < 1 semaine. De plus, un seul propriétaire a indiqué qu'il ne choisirait pas de refaire une chirurgie bilatérale TPLO. Signification clinique: La chirurgie TPLO bilatérale en une seule séance réalisée par un chirurgien expérimenté a eu un résultat et un taux de complications similaires à ceux de la chirurgie TPLO unilatérale. La plupart des propriétaires ont déclaré que les soins postopératoires de leur chien n'étaient pas difficiles.(Traduit par Dr Serge Messier).

The effect of a smoke-evacuation unit on ultrafine particle concentrations in the operating room during approach to the proximal tibia for tibial plateau-leveling osteotomy surgery in dogs.

OBJECTIVE: To evaluate the effectiveness of a smoke-evacuation unit on reducing ultrafine particle concentration in the operating room (OR) during the approach to the proximal tibia for tibial plateau-leveling osteotomy (TPLO). STUDY DESIGN: Prospective, randomized, controlled clinical trial. SAMPLE POPULATION: Twenty-nine client-owned dogs undergoing unilateral TPLO at a single institution were assigned to either smoke-evacuator groups (SE; n = 15) or non-smoke-evacuator groups (NSE; n = 14). METHODS: Dogs were randomly assigned to the SE group or the NSE group. An airborne particle measuring device measured and recorded baseline and intraoperative particles per cm3 (ppc) during the approach to the proximal tibia during which electrosurgery was used to provide hemostasis, dissect subcutis, transect and elevate fascia. The mean ppc, maximum ppc, and baseline ppc were compared between groups. Mean ppc was also compared to the baseline ppc within each group. RESULTS: During surgery, mean ppc (1352) and maximum ppc (62 450) for the NSE group were higher in than mean ppc (763) and maximum ppc (10 100) for the SE group (P < .0001, P < .0001, respectively). Mean ppc was higher in both SE (mean ppc = 763; P < .0001) and NSE (mean ppc = 1352; P = .0001) than their respective baseline ppc (213 and 240). CONCLUSION: The use of a smoke evacuator decreased particle concentrations 56.4% during the approach to the proximal tibia. Performing the approach to the proximal tibia resulted in higher particle concentrations than the baseline, regardless of smoke-evacuator use. CLINICAL SIGNIFICANCE: Surgeons should be aware of smoke produced by electrosurgery, potential health consequences, and methods of smoke mitigation (smoke evacuation).