Clinical relevance of positive intraoperative bacterial culture in tibial plateau leveling osteotomy in dogs: a retrospective study

BACKGROUND

Tibial plateau leveling osteotomy (TPLO) belongs to the most frequently used surgical method for the treatment of cranial cruciate ligament rupture in dogs. Surgical site infection (SSI) is one of the possible postoperative complications. The aim of this study was to evaluate the diagnostic value of intraoperative bacterial culture as a tool for the detection of intraoperative bacterial contamination progressing to infection development in canine TPLO. Electronic patient records from dogs who underwent TPLO between January 2018 to December 2020 were retrospectively reviewed. Intraoperative bacterial culture results, used antimicrobial drugs and presence of SSI were recorded.

RESULTS

Ninety-eight dogs were included in the study. SSI rate was 10.2%. All dogs who developed SSI (n = 10) had negative intraoperative bacterial cultures. None of the dogs with positive intraoperative bacterial culture (n = 6) developed SSI. The most cultured bacteria causing SSI was Staphylococcus pseudintermedius (n = 4).

CONCLUSIONS

Intraoperative bacterial culture in dogs undergoing TPLO is not suitable as a predictor of surgical site infection.

In Vitro Assessment of Compression Patterns Using Different Methods to Achieve Interfragmentary Compression during Tibial Plateau Levelling Osteotomy

OBJECTIVES

 The aim of this study was to evaluate and characterize different methods to achieve interfragmentary compression during tibial plateau levelling osteotomy (TPLO).

STUDY DESIGN

 TPLO was performed in 20 canine tibia models (Sawbones, Vashon, Washington, United States) using 3D-printed guides for standardization. Interfragmentary compression was assessed using pressure-sensitive films (Prescale, Fujifilm, Atherstone, United Kingdom). Seven compression methods were tested: (1) Kern bone holding forceps clamping the craniodistal aspect of the TPLO plate to the caudal aspect of the tibia (K); (2) using the distal TPLO plate dynamic compression hole (P); (3) pointed bone reduction forceps engaging the caudal aspect of the proximal bone fragment and the cranial aspect of the tibial crest (F); (4) K + P; (5) K + F; (6) F + P; and (7) K + F + P. Five measurements were obtained for each method, and each bone model was used for two measurements (single method, ± plate). The interfragmentary surface was digitalized and divided into quadrants for standardization and pixel density calculation: Q1, craniomedial; Q2, craniolateral; Q3, caudomedial; and Q4, caudolateral. One-way analysis of variance (ANOVA) and post hoc tests were used for statistical analysis.

RESULTS

 Mean pressures per quadrant differed significantly between methods (p < 0.001). Methods K, F, and P produced more craniomedial, craniolateral, and caudal compression, respectively. Method K resulted in loss of caudal compression (p < 0.001). Method F + P provided the most even distribution of high interfragmentary compression forces. The addition of method K to this construct (K + F + P) marginally increased cranial compression (p = 0.189 for Q1; p < 0.001 for Q2), but reduced compression caudally (p < 0.001).

CONCLUSION

 Method F + P provided more even interfragmentary compression. If method K were used, then combined use with method F + P would be recommended.

Effect of Rehabilitation in a Dog with Delayed Recovery following TPLO: A Case Report

A 7-year-old neutered Maltese dog weighing 5.1 kg was presented, with a tibial plateau-leveling osteotomy (TPLO) on the right hindlimb 42 days prior. The patient's right hind limb showed lameness, intermittent limping, and atrophy, and the patient had not experienced rehabilitation since TPLO surgery. The patient showed a pain reaction at the end of the stifle extension, and an increased body temperature was identified on the medial side of the right hindlimb when compared with the left hindlimb using a digital thermal imaging device. In addition, a type of lameness, only partial weight bearing in the right hindlimb, was also identified during the gait analysis. The pain was relieved by applying a cold pack and transcutaneous electrical nerve stimulation, and the patient's weak muscles were strengthened through treadmill exercises. In this study, physical therapy and rehabilitation exercises controlled pain and induced rapid recovery, indicating that rehabilitative intervention is required after TPLO surgery.

Effects of Autologous Microfragmented Adipose Tissue on Healing of Tibial Plateau Levelling Osteotomies in Dogs: A Prospective Clinical Trial

The aim of this study was to evaluate the effects of autologous microfragmented adipose tissue (MFAT) applied after mechanical fragmentation and assess these effects radiographically in bone healing in dogs subjected to tibial plateau levelling osteotomy (TPLO). Twenty dogs with unilateral cranial cruciate ligament disease were enrolled and randomly assigned to the treatment group (MFAT) or the control group (NT). The MFAT group underwent TPLO and autologous MFAT intra-articular administration, while the NT group underwent TPLO alone. Adipose tissue was collected from the thigh region, and MFAT was obtained by mechanical fragmentation at the end of the surgery. The patients were subjected to X-ray examination preoperatively, immediately postoperatively (T0), and at 4 (T1) and 8 (T2) weeks postoperatively. Two radiographic scores that had previously been described for the evaluation of bone healing after TPLO were used. A 12-point scoring system (from 0 = no healing to 12 = complete remodelling) was used at T0, T1, and T2, while a 5-point scoring system (from 0 = no healing to 4 = 76-100% of healing) was used at T1 and T2. The median healing scores were significantly higher at T1 and T2 for the MFAT group compared with the NT group for the 12-point (p < 0.05) and 5-point (p < 0.05) scoring systems. The intra-articular injection of autologous microfragmented adipose tissue can accelerate bone healing after TPLO without complications.

Plasma procalcitonin kinetics in healthy dogs and dogs undergoing tibial plateau leveling osteotomy

BACKGROUND

Procalcitonin (PCT) is a well-established biomarker for bacterial infection in human patients.

OBJECTIVES

We aimed to analyze the kinetics of plasma PCT (pPCT) in healthy dogs and dogs with canine cranial cruciate ligament (CCL) rupture undergoing tibial plateau leveling osteotomy (TPLO).

METHODS

This prospective, longitudinal study included 15 healthy dogs and 25 dogs undergoing TPLO. Hematology, pPCT, and C-reactive protein (CRP) were assessed on 3 consecutive days in healthy dogs and 1 day preoperatively and days 1, 2, 10, and 56 postoperatively. Inter- and intraindividual variability of pPCT were assessed in healthy dogs. Median pPCT concentrations of dogs with CCL rupture preoperatively were compared with healthy controls, and median pPCT concentrations, as well as percentage change post anesthesia, arthroscopy, and TPLO, were compared with baseline. For the correlation analysis, the Spearman rank correlation test was used.

RESULTS

Inter- and intraindividual variabilities of pPCT in healthy dogs were 36% and 15%, respectively. Median baseline pPCT concentrations were not significantly different between healthy dogs (118.9 pg/mL; IQR: 75.3-157.3 pg/mL) and dogs undergoing TPLO (95.9 pg/mL; IQR: 63.8-117.0 pg/mL). Plasma PCT concentrations were significantly lower immediately post- than preoperatively (P < 0.001). CRP, WBC, and neutrophil concentrations increased significantly on post-OP day 2 and had normalized by day 10.

CONCLUSIONS

These results indicate that CCL rupture, as well as anesthesia, arthroscopy, and TPLO combined, are not associated with increased pPCT concentrations in dogs with uncomplicated recovery. Considering the high intraindividual variability, individual serial measurements rather than a population-based reference interval should be considered.

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.

The Effect of Location of a Unicortical Defect on the Mechanical Properties of Rabbit Tibiae: A Model of the Distal Jig Pin Hole in Tibial Plateau Levelling Osteotomy

OBJECTIVE

 The aim of this study was to determine the effect of a unicortical defect at either the mid-diaphysis (MD) or distal metaphysis (DM) on the torsional properties of tibiae in an in vitro rabbit model, and to further examine optimal distal jig pin position for the canine tibial plateau levelling osteotomy (TPLO) procedure.

STUDY DESIGN

 Thirty-eight tibiae from 19 skeletally mature female New Zealand White rabbits were assigned to one of three groups; Group 1: intact, Group 2: MD defect and Group 3: DM defect. Defects were created using a 1.6 mm Ellis pin. Pure torsion was applied to each sample and peak torque and angular displacement recorded.

RESULTS

 All tibiae fractured in a spiral configuration. Fracture lines involved the defect in 33% of the MD samples and 0% of the DM samples. No differences were detected for peak torque and stiffness between groups. However, energy (mean ± standard deviation) was significantly reduced (p = 0.028) in the MD group (0.18 ± 0.07) relative to the intact tibia group (0.31 ± 0.14). Angle was also significantly reduced (p = 0.040) in the MD group (0.17 ± 0.05) compared with the intact group (0.23 ± 0.07). Placement of a DM defect had no significant effect on mechanical properties of the rabbit tibiae.

CONCLUSION

 Defects placed in the MD significantly reduced energy and angle in comparison to intact samples. No significant difference in peak torque or stiffness was observed between groups. If canine tibiae were similarly affected, our findings suggest jig pin placement in the DM to have a lesser effect on the torsional properties of the tibiae.

Three-dimensional volume rendering planning, surgical treatment, and clinical outcomes for femoral and tibial detorsional osteotomies in dogs

OBJECTIVES

To describe a computed tomographic (CT) methodology for planning the correction of femoral and tibial torsion and report the clinical outcomes after femoral (FDO) and tibial (TDO) detorsional osteotomy in dogs affected by torsion malalignment and patellar luxation (PL).

STUDY DESIGN

Multicenter retrospective study.

ANIMALS

Eighteen client-owned dogs.

METHODS

Dogs underwent CT to measure femoral (FTA) and tibial torsion angle (TTA). Abnormal femoral external torsion was defined when FTA <20°, abnormal femoral internal torsion if FTA >35°; abnormal tibial external torsion was defined when TTA < -10°, and abnormal tibial internal torsion when TTA >2°. The cortical arch length (CAL) was measured with CT and used intraoperatively to determine the magnitude of correction. The medical records and radiographs were reviewed and used to report clinical and radiographic outcomes. Radiographs were reviewed to evaluate postoperative limb alignment, patellar position, and bone healing.

RESULTS

Twenty-two detorsional osteotomies were performed. Mean preoperative FTA was 14° for medial-PL and 45.2° for lateral-PL. Mean preoperative TTA was 11° for medial-PL. Physiological patellar tracking was restored in 22/22 of cases. CAL measurement allowed for correction of abnormal torsion in 19/22 of cases. Seventeen out 18 dogs had full or acceptable functional outcome. The median radiographic follow-up was 3 months. Major complications occurred in 2/22 cases, which suffered an iatrogenic abnormal femoral internal torsion and a persistent hindlimb lameness.

CONCLUSIONS

CAL can be measured with CT and used intraoperatively to guide the correction of abnormal torsion in dogs.

CLINICAL RELEVANCE

Abnormal femoral and tibial torsion are predisposing factors for PL. A higher complication rate is expected when FDO and TDO are performed in the same hindlimb.

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.

Rotation of the Tibial Plateau Segment to Control Arterial Haemorrhage during Tibial Plateau Levelling Osteotomy: A Cadaveric Experimental Study and Nine Clinical Cases

OBJECTIVE

 The aim of this study was to describe a simple and effective method to control severe haemorrhage from intraoperative trauma to the cranial tibial artery (CTA) during tibial plateau levelling osteotomy (TPLO) and to report long-term outcomes.

STUDY DESIGN

 Cadaveric descriptive study and retrospective case series. A TPLO was performed in eight cadaveric limbs, followed by intentional laceration of the CTA under fluoroscopic guidance. Dissection of the limb was performed and the relationship between the CTA and the surrounding structures was evaluated. A computed tomography angiogram was performed following TPLO in one cadaveric limb. Medical records from cases that had intraoperative arterial bleeding between 2015 and 2019 were reviewed. Cases were included if bleeding was controlled by following the usual steps for TPLO. Radiographic follow-up 6 to 10 weeks postoperatively and long-term follow-up owner's questionnaire were available.

RESULTS

 During TPLO, the CTA is tightly compressed between the caudal aspect of the proximal tibia and the popliteal musculature. Rotation and compression of the proximal tibia followed by closure of the pes anserinus successfully controlled arterial bleeding during TPLO in nine clinical cases without the need for direct ligation.

CONCLUSION

 Continuing the usual steps of a TPLO can successfully control intraoperative bleeding from the CTA with no long-term complications. This technique should be considered in cases of arterial bleeding during TPLO before direct ligation.

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.

Evaluation of depth gauge accuracy in a canine tibial plateau leveling osteotomy model

OBJECTIVE

To evaluate the accuracy of six depth gauges used in three tibial plateau leveling osteotomy (TPLO) plate holes.

STUDY DESIGN

Ex vivo experimental study.

ANIMALS AND SAMPLE POPULATION

Cadaveric canine limbs (n = 10), one 25-mm-thick wood board, and one 33.8-mm-diameter polyvinyl chloride (PVC) pipe.

METHODS

A TPLO was performed on 10 canine cadaveric pelvic limbs. Three 3.5-mm plate holes were filled with screws. The remaining three plate holes: a compression hole, a combination compression-locking hole, and a stacked combination compression-locking hole were measured by three observers using six commercial depth gauges and using a micrometer as gold standard. The process was repeated on one wood board and one PVC pipe.

RESULTS

Bone measurements collected using two depth gauges with base diameter < 5 mm were smaller than measurements collected using the four depth gauges with base diameter > 5.5 mm (p ranging from < .001 to .038). Mean depth gauge measurements were smaller than micrometer measurements by 2.20 mm for the compression hole, 0.82 mm for the combination hole, and 3.57 mm for the stacked combination hole. Measurement differences among depth gauges were also present for wood board and PVC pipe measurements. Bone measurement variability between depth gauges was less for the combination and compression holes than for the stacked combination hole.

CONCLUSION

Depth gauges lacked accuracy. Measurements differed among gauges and measurement variability varied based on plate hole geometry.

CLINICAL RELEVANCE

Depth gauge measurement accuracy varies based on measuring devices and on 3.5-mm plate hole geometry.

Evaluation of the risk of patella fracture as the result of decreasing tibial plateau angle following tibial plateau leveling osteotomy

OBJECTIVE

To evaluate the effect of postoperative tibial plateau angle (TPA) following tibial plateau leveling osteotomy (TPLO) on the risk of patella fracture during the convalescent period.

STUDY DESIGN

Retrospective study.

SAMPLE POPULATION

Fracture group: 20 stifles; reference group: 65 stifles.

METHODS

Medical records were reviewed for stifles with patellar fractures after a TPLO procedure (fracture group) and stifles with >180 days radiographic examination with no complications following TPLO (reference group). Stifle radiographs were masked to group and final TPA (fTPA) was measured, at the time of fracture diagnosis (fracture group) and at last follow-up (reference group), using PACS software. TPAs in the fracture and reference groups were compared using the Wilcoxon rank-sum test. Statistical significance was set at .05.

RESULTS

Patellar fractures were diagnosed at a median of 69 days (range 31-189) after surgery. The median duration of follow-up time for the reference group was 471 days (range 180-1868). Median fTPA for the fracture group was 1.4° (range [-10.3]-7.1). Median fTPA for the reference group was 4.1° (range [-3.9]-14.1). The odds of patellar fractures increased by 21.7% (95% CI: 8.6%-35.6%) for every 1° decrease in fTPA.

CONCLUSION

The risk of patella fractures increased as TPAs after TPLOs decreased.

CLINICAL SIGNIFICANCE

Care should be taken to avoid excessive rotation during TPLO to decrease the likelihood of postoperative patellar fractures.

Risk factors for severe postoperative complications in dogs with cranial cruciate ligament disease - A survival analysis

OBJECTIVE

To analyze the effect of surgical technique and other risk factors on severe postoperative complications in dogs with cranial cruciate ligament disease (CCLD).

MATERIALS AND METHODS

A cohort study of 255 dogs (287 stifles) surgically treated for CCLD at two veterinary university hospitals (2011-2016) was performed. The electronic medical records were reviewed and dog owners and referring veterinarians contacted for additional information. The complications were classified as minor, major and catastrophic, where major and catastrophic were considered severe. A multivariable Cox proportional hazards model was applied to assess risk factors for severe postoperative complications.

RESULTS

Three surgical techniques were used; lateral fabellotibial suture (LFS, 141 stifles), tibial plateau leveling osteotomy (TPLO, 77 stifles) and tibial tuberosity advancement (TTA, 69 stifles). The most common severe postoperative complications were surgical site infections or complications related to the surgical implant. Severe postoperative complications occurred in 31 % of the stifles treated with TPLO, 22 % of the stifles treated with LFS and 25 % of the stifles treated with TTA. The multivariable Cox proportional hazards model identified surgical technique (p = 0.0258) as a risk factor for severe postoperative complications; TPLO had a significantly lower hazard than LFS (hazard ratio (HR) = 0.37, p = 0.007) when controlling for body weight and age, which also were identified as risk factors (HR = 1.05, p < 0.001 and HR = 0.91, p = 0.047, respectively).

CONCLUSION AND CLINICAL RELEVANCE

Although TPLO procedures had the highest occurrence of severe postoperative complications, the hazard was lower than for LFS after adjusting for body weight and age. This implies that it is important to consider potential effect-modifiers when comparing postoperative complications after CCLD surgery.

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.

Influence of radiographic examination findings on recommendations made during routine clinical re-evaluation of dogs with uncomplicated tibial plateau leveling osteotomy

OBJECTIVE

To determine the influence of follow-up radiographic examination on recommendations made during routine clinical re-evaluation of dogs that had undergone uncomplicated tibial plateau leveling osteotomy (TPLO).

STUDY DESIGN

Retrospective multi-institutional case series.

ANIMALS

Client-owned dogs (N = 1010) that underwent uncomplicated TPLO.

METHODS

Records from 11 institutions were searched for dogs that had been treated with unilateral TPLO and had no history of postoperative complications before their routine follow-up examination. The frequency of change in further clinical recommendations resulting from client- or clinician-voiced concerns or radiographic abnormalities was investigated.

RESULTS

Follow-up evaluation was performed at a median of 6 (range, 4-15) weeks after TPLO. Radiographic examination findings contributed to a change in recommendations in 4.15% (38/915) of dogs presented without client concerns and without abnormalities at orthopedic examination. Abnormal radiographic findings alone influenced the management of 3.76% (38/1010) of dogs. An association was detected between clinical features and radiological findings leading to a change in recommendations (P < .0001). Administration of analgesia at the time of follow-up was associated with radiographic abnormalities (P = .017) and change in postoperative plans (P = .0007).

CONCLUSION

Radiographic examination findings at follow-up did not influence the management of most dogs with uncomplicated TPLO.

CLINICAL SIGNIFICANCE

Radiographic examination findings are unlikely to influence the treatment of dogs that seem to be recovering uneventfully from an uncomplicated TPLO without concerns from clients, analgesia, or abnormal findings on thorough orthopedic examination by a surgical specialist, at the time of the planned clinical re-evaluation.

Influence of administration of antimicrobial medications after tibial plateau leveling osteotomy on surgical site infections: A retrospective study of 308 dogs

OBJECTIVE

To determine the influence of prophylactic administration of oral antimicrobial medications after tibial plateau leveling osteotomy (TPLO) on surgical site infections (SSI) and antimicrobial-resistant infections.

STUDY DESIGN

Retrospective study.

SAMPLE POPULATION

Dogs treated with unilateral TPLO (n = 308) between January 2013 and December 2015.

METHODS

Medical records were reviewed for signalment, surgically treated limb, duration of surgery and anesthesia, postoperative administration of antimicrobial medications, antibiotic agent, surgeon, and development of SSI. Statistical analyses included descriptive statistics, simple linear regression, analysis of variance, Fisher's protected least significant difference, and χ² testing.

RESULTS

Data were collected from records of 31 dogs that did not receive antimicrobial medications and 277 dogs that did receive oral antimicrobial medications for 14 days after TPLO. Superficial incisional SSI was detected in two of 31 dogs that did not receive antimicrobial medications and in 48 of 277 dogs that did receive antimicrobial medications (P = .1194). Deep incisional SSI occurred in two of 31 dogs that did not receive antimicrobial medications and in 27 of 277 dogs that did receive antimicrobial medications (P = .5513). Antibiotic-resistant deep incisional SSI occurred in two of 31 dogs that did not receive antimicrobial medications and in 18 of 277 dogs that did receive antimicrobial medications (P = .9920). Body weight correlated with deep incisional SSI and resistant infections. Prolonged duration of surgery and anesthesia were associated with superficial incisional SSI, deep incisional SSI, and antibiotic resistance. Surgeons influenced deep incisional SSI.

CONCLUSION

Previously reported predisposing factors for infection were confirmed, but postoperative administration of antimicrobial medications was not protective against SSI nor did it predispose to antibiotic resistance in our clinical setting.

CLINICAL SIGNIFICANCE

This study does not provide evidence to support administration of prophylactic oral antimicrobial medications after unilateral TPLO.

Extracorporeal shock wave therapy improves short-term limb use after canine tibial plateau leveling osteotomy

OBJECTIVE

To determine the influence of postoperative extracorporeal shock wave therapy (ESWT) on hind limb use after tibial plateau leveling osteotomy (TPLO).

STUDY DESIGN

Randomized, prospective clinical trial.

ANIMALS

Sixteen client-owned dogs, 2 to 10 years old weighing 18 to 75 kg.

METHODS

Dogs were randomly assigned to treatment cohorts, TPLO with ESWT (ESWT, n = 9) or TPLO without ESWT (control, n = 7). Treatment consisted of 1000 pulses at 0.15 mJ/mm² immediately and 2 weeks after surgery. Subjective pain, stifle goniometry, stifle circumference, peak vertical force (PVF) and vertical impulse (VI) were measured before surgery, prior to ESWT, and 2 and 8 weeks after surgery. Measures were compared between treatments at each time point and among time points for each treatment (P < .05).

RESULTS

The PVF (5.5 ± 1.0 N/kg, mean ± SD) and VI (0.67 ± 0.14 N-s/kg) of surgically treated limbs in the ESWT cohort were higher 8 weeks after surgery compared with preoperative (3.8 ± 1.1 N/kg, P < .0001 and 0.47 ± 0.21 N-s/kg, P = .0012, respectively) values. In the control cohort, PVF (2.9 ± 1.3 N/kg, P = .0001) and VI (0.33 ± 0.20 N-s/kg, P = .0003) 2 weeks after surgery and VI (0.42 ± 0.2 N-s/kg, P = .0012) 8 weeks after surgery were lower (4.59 ± 2.33 N/kg and 0.592 ± 0.35 N-s/kg, respectively) than before surgery. Other parameters did not differ between groups.

CONCLUSION

Weight bearing increased faster after TPLO in dogs treated with postoperative ESWT.

CLINICAL SIGNIFICANCE

This study provides evidence to consider adjunct ESWT after TPLO.

Risk of infection after double locking plate and screw fixation of tibial plateau leveling osteotomies in dogs weighing greater than 50 kilograms

OBJECTIVE

To compare surgical site infection (SSI) rates after double locking plate and screw fixation (DLP), standard locking plate and screw fixation (LP), and conventional nonlocking plate and screw fixation (NLP) in dogs weighing >50 kg undergoing tibial plateau leveling osteotomy (TPLO).

STUDY DESIGN

Retrospective study (January 2003-October 2017).

ANIMALS

Two hundred seventy-five dogs weighing >50 kg with cranial cruciate ligament disease treated with TPLO.

METHODS

Medical records of dogs weighing >50 kg that underwent TPLO by DLP, LP, and NLP with a minimum follow-up period of 12 months were included. Data collected included signalment, details of any concurrent surgical procedure, type of implant used, use of postoperative antibiotic therapy, occurrence of perioperative complications, and presence of postoperative infection. The probability, risk difference, and relative risk of SSI were estimated for each fixation with a marginal model.

RESULTS

Nonlocking plate and screw fixation was used in 114 (41.5%) dogs, LP was used in 128 (46.5%) dogs, and DLP was used in 33 (12%) dogs. Surgical site infection was diagnosed in 48 of 275 (17.5%) dogs. Postoperative antibiotic therapy was used in 74 (64.9%) dogs, 62 (48.4%) dogs, and 32 (97.0%) dogs in the NLP, LP, and DLP groups, respectively. Dogs with NLP, LP, and DLP had postoperative infection rates of 24.5%, 13.3%, and 9.1%, respectively. There were no risk differences for the three groups (Holm-adjusted P > .05).

CONCLUSION

No difference in infection rates was detected between DLP, LP, or NLP for TPLO in these dogs weighing >50 kg.

CLINICAL SIGNIFICANCE

Fixation of TPLO with DLP in dogs weighing >50 kg does not seem to increase the risk of SSI compared with LP and NLP.

Influence of fixation systems on complications after tibial plateau leveling osteotomy in dogs greater than 45.4 kilograms (100 lb)

OBJECTIVE

To determine the influence of 3 fixation systems on complications rate after tibial plateau leveling osteotomy (TPLO) in dogs >45.4 kg.

STUDY DESIGN

Retrospective case series.

SAMPLE POPULATION

Dogs (N = 287, 342 stifles) >45.4 kg with cranial cruciate ligament tear treated with TPLO.

METHODS

The medical records of dogs treated with TPLO were reviewed for fixation and postoperative complications, with a follow-up of at least 6 weeks. A random effects logistic regression model was used to evaluate the association between the type of TPLO fixation system and complications.

RESULTS

The fixation systems included a 3.5-mm broad TPLO plate alone (8P; 78.4%), a 3.5-mm broad TPLO plate with SOP (String of Pearls) plate (8AP; 14.9%), and a 3.5-mm standard TPLO plate (6P; 6.7%). Among the included stifles, 214 (62.6%) fixation systems were classified as locking, and 128 (37.4%) were classified as nonlocking. The fixation system was predictive of complications. The 8P had the lowest odds ratio for complication among the 3 fixation systems. Odds of developing complications were higher with the 8AP fixation system than with the 8P fixation system. Locking fixation eliminated the association between weight and complication rate.

CONCLUSION

Fixation of a TPLO with the 8AP increased the risk of complications compared with the 8P in this population of large dogs.

CLINICAL SIGNIFICANCE

Locking fixation of TPLO with a 3.5-mm broad TPLO plate alone should be considered in large dogs because it may reduce complications.

The use of absorbable staples for skin closure after tibial plateau leveling osteotomy

OBJECTIVE

To compare the use of stainless steel staples with absorbable staples for closure of skin incisions in dogs undergoing tibial plateau leveling osteotomy (TPLO).

STUDY DESIGN

Prospective study.

SAMPLE POPULATION

Client-owned dogs (n = 80).

METHODS

With client consent, dogs were randomly assigned a staple type (stainless steel or absorbable) immediately prior to closure of a TPLO skin incision. Incisions were compared for length, staple type and number, and an inflammation-infection score 2 weeks after surgery.

RESULTS

Overall, 18.8% of incisions were diagnosed with inflammation or infection. No difference was found between inflammation-infection scores, incision length, number of staples used, or general anesthetic time between the 2 staple groups. However, wound closure was faster with stainless steel staples (22.50 seconds; range, 11-180) by approximately 30 seconds compared with absorbable staples (56.50 seconds; range, 18-190; P < .001). Time taken to close the incision correlated negatively with the number of occasions that absorbable staples were used (P = .01).

CONCLUSION

Absorbable skin staples were successfully used to close skin incisions after TPLO and were not associated with an increased level of inflammation or infection in our clinical setting.

CLINICAL SIGNIFICANCE

Absorbable staples may be considered to close surgical wounds when subsequent suture removal would be impractical, without specific concerns over inflammation or infection of the wound.

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.

Factors associated with early tibial tuberosity fracture after tibial plateau leveling osteotomy

OBJECTIVE

To determine factors contributing to tibial tuberosity fracture (TTF) after tibial plateau leveling osteotomy (TPLO).

STUDY DESIGN

Retrospective case-control study.

ANIMALS

Dogs (n = 2490) with cranial cruciate ligament rupture that underwent 3000 TPLO surgeries.

METHODS

Radiographs of 3000 stifles from dogs that underwent TPLO were reviewed for evidence of TTF. Two ratios were generated: (1) the height of the tuberosity over the width of the tibia at the most distal extent of the osteotomy (TW) and (2) the width of the narrowest point of the tuberosity over TW.

RESULTS

Twenty-three (0.77%) cases of fracture were identified. Factors that correlated with increased odds of fracture were placement of antirotational pins distal to the insertion of the patellar ligament (PL), tuberosities with the narrowest point below the insertion of PL, placement of multiple pins distal to the PL, and bilateral simultaneous TPLO. Tuberosities that fractured were significantly taller and narrower than those that did not fracture. Rotation past the "safe point" and presence of a gap at the osteotomy were not correlated with fracture.

CONCLUSION

Placement of multiple pins, pin placement distal to the insertion of the PL, location of the narrowest point of the tibial tuberosity distal to the insertion of the PL, and simultaneous bilateral TPLO were all associated with TTF in this study CLINICAL SIGNIFICANCE: Preoperative planning and postoperative assessment of TPLO should take into consideration the predisposing factors identified in this study to prevent TTF.

Comparison of TPLO tibial tuberosity fractures with and without an in situ rotational pin

OBJECTIVE

Cranial cruciate ligament (CCL) rupture is a common cause of pelvic limb lameness in dogs. The tibial plateau leveling osteotomy (TPLO) is a well-described surgical procedure that treats CCL ruptures. The objective of this study was to compare the risk of tibial tuberosity fractures from TPLO procedures using a TPLO reduction pin in situ versus patients with a TPLO reduction pin removed at the time of surgery. Our hypothesis is that patients with a TPLO reduction pin left in situ will have a decreased incidence of tibial tuberosity fractures.

RESULTS

A total of 400 dogs that fitted the criteria of 200 consecutive TPLO surgeries performed with each group were included in the study. The Student's t-test revealed a statistically significant difference in fractures observed in group 1 (in situ pin) and group 2 (no pin). In univariate logistic regression analysis, only the covariate for the presence of the reduction pin was associated with a statistically significant reduction in the likelihood of tibial tuberosity fracture. In the multivariate model, the presence of the reduction pin was associated with an approximate 92% reduction in the likelihood of tibial tuberosity fracture.

Usefulness of C-reactive protein and serum amyloid A in early detection of postoperative infectious complications to tibial plateau leveling osteotomy in dogs

Background

Cranial cruciate ligament rupture is a prevalent injury in dogs, and tibial plateau leveling osteotomy (TPLO) is one of the preferred surgical techniques. Surgical site infection is a possible complication following TPLO and measurement of serum acute phase proteins is suggested to be a way to early recognize and distinguish postoperative infectious complications from normal postoperative inflammatory conditions. In this study we investigate the changes in concentrations of the systemic inflammatory markers C-reactive protein (CRP) and serum amyloid A (SAA) following tibial plateau leveling osteotomy (TPLO) in dogs and evaluate if deviations from the changes expectedly induced by the surgical procedure are useful in early detection of post-surgical infections. Dogs with cranial cruciate ligament injuries treated by TPLO at the Region Animal Hospital of Helsingborg during 2012 were included. Dogs with concurrent diseases, other orthopedic problems, or noninfectious post-surgical complications were excluded. Serial measurements of CRP and SAA concentrations were made. Changes in concentrations were visualized graphically and the discriminative capacity to detect infectious post-surgical complications was tested at different time points.

Results

A characteristic pattern of changes in concentrations of CRP and SAA were observed following TPLO with a significant increase 24 h post-surgery in all dogs and baseline-concentrations re-established at day 12. In dogs that developed post-surgical infections, a deviation in form of significantly higher concentrations of CRP and SAA were observed at day 6, compared to un-complicated cases. High-discriminative clinical decision limits of CRP (43.9 mg/L) and SAA (63.8 mg/L) could be established for differentiation of dogs with and without clinical signs of infectious complications at day 6 post-operatively, applicable to reliably rule out presence of infectious complications due to very high sensitivity (no false negatives).

Conclusions

The CRP and SAA levels in dogs with clinical signs of post-surgical infectious complication deviated from the typical levels expected at day 6 after surgery, and clinical decision limits to reliably rule out presence of infectious complications was suggested.

Handling of the tibial muscle envelope in tibial plateau levelling osteotomy - to elevate or not?

Objective: To compare the outcome of the tibial plateau levelling osteotomy (TPLO) procedure, using a 6-hole 3.5 mm locking TPLO plate and performed with the muscle elevation technique (ET) and placement of sponges, to the TPLO without performing these steps (non-elevation-technique [NET]).

Material and methods: Medical records and radiographs of dogs with ET (n = 21) or NET (n = 19) were retrospectively reviewed. Signalment, TPLO procedure side, meniscal treatment, surgery time, haemorrhage, preand postoperative tibial plateau angle, assistant, amount of rehabilitation, bone healing (cortical, osteotomy, combined healing scores), complications, limb function, recovery time and follow-up were recorded and analysed using multivariate analysis. A value of p <0.05 was considered significant.

Results: Surgery time was significantly shorter with the NET (68.5 min ± 3.4) than with the ET (87.8 min ± 3.4) (p <0.01). No significant differences were detected for all other evaluated factors. Soft tissue trauma was minimal and none of the dogs suffered severe haemorrhage. The bone healing scores with the NET and the ET were not significantly different (p = 0.1, p = 0.2, p = 0.1). Complications were rare, minor and not significantly different between groups (p = 0.73).

Clinical relevance: The results of this in vivo study indicate that NET is a feasible technique that can be considered for the clinical setting.

High energy focused shock wave therapy accelerates bone healing

Objectives: To evaluate the influence of shock wave therapy (SWT) on radiographic evidence of bone healing after tibial plateau leveling osteotomy (TPLO).

Methods: Healthy dogs between two to nine years of age that underwent TPLO were randomly assigned to receive either electro- hydraulic SWT (1,000 shocks) or sham treatment (SHAM). Treatment or SHAM was administered to the osteotomy site immediately postoperatively and two weeks postoperatively. Three blinded radiologists evaluated orthogonal radiographs performed eight weeks postoperatively with both a 5-point and a 10-point bone healing scale. Linear regression analysis was used to compare median healing scores between groups.

Results: Forty-two dogs (50 stifles) were included in the statistical analysis. No major complications were observed and all osteo -tomies healed uneventfully. The median healing scores were significantly higher at eight weeks postoperatively for the SWT group compared to the SHAM group for the 10-point (p <0.0002) and 5-point scoring systems (p <0.0001).

Clinical significance: Shock wave therapy applied immediately and two weeks post -operatively led to more advanced bone healing at the eight week time point in this study population. The results of this study support the use of electro-hydraulic SWT as a means of accelerating acute bone healing of canine osteotomies. Additional studies are needed to evaluate its use for acceleration of bone healing following fracture, or with delayed union.

Bacterial recovery using sonication versus swabbing of titanium and stainless steel implants inoculated with Staphylococcus pseudintermedius or Pseudomonas aeruginosa

Objective: To evaluate the use of sonication to improve recovery of bacteria from metal discs infected with bacteria commonly associated with implant infections in veterinary medicine.

Methods: In vitro study in which sterile titanium (Ti6Al4V) and stainless steel (AIS1316-L) discs were incubated with either Staphylococcus pseudintermedius or Pseudomonas aeruginosa for 24 hours. The following three groups were compared: 1) the sonication group involved immersing the discs in sterile saline and sonicating for five minutes; 2) the sham group was considered a negative control in which the discs were immersed in saline for five minutes without sonication; and 3) the swab group involved systematically swabbing the implant with a sterile culturette. All samples were plated on blood agar and incubated for 24 hours. Colonies were then counted and compared.

Results: For both species of bacteria, there was a significant increase in bacterial colonies isolated using sonication compared to the other two study groups (p = 0.0001). No differences in bacterial growth were found between the two types of metal implants. There was a significant increase in bacterial colony counts for S. pseudintermedius when comparing the swab group versus the sham group, but this was not significant for P. aeruginosa.

Clinical significance: Sonication significantly improves recovery of bacteria commonly associated with veterinary implant-associated surgical site infections compared to swabbing of implants in vitro. A prospective clinical evaluation is indicated to determine the in vivo efficacy of sonication in veterinary patients.

Comparison of two cold compression therapy protocols after tibial plateau leveling osteotomy in dogs

OBJECTIVE

To evaluate two different protocols of cold compression therapy (CCT) for pain management and functional recovery in dogs undergoing tibial plateau leveling osteotomy (TPLO).

MATERIAL AND METHODS

A total of 27 adult dogs (n = 30 stifles; staged bilateral procedures: n = 3) undergoing routine TPLO were randomly allocated to three groups (n = 10/group). Dogs of group I received CCT once before and immediately after surgery. In dogs of group II CCT was performed postoperatively four times at 6-hour intervals. Dogs of the control group did not receive CCT. Circumference of the stifle joint and the following pain-related parameters were measured by a single blinded observer before surgery and 1, 10 and 42 days after surgery: stifle joint range of motion (ROM), subjective degree of lameness, and score of a modified Glasgow Pain Scale (GPS).

RESULTS

Both CCT groups showed significantly greater ROM and lower GPS scores 24 hours after surgery compared to the control group. Ten days after surgery there was a significantly lower degree of lameness in both CCT groups compared to the control group. Fourty-two days after surgery a significantly greater ROM was observed in both CCT groups compared to the control group. Group II also showed a significant improvement in the degree of lameness and GPS. There were no significant differences in any of the parameters between the two CCT groups at any time point.

CONCLUSION

CCT applied preoperatively and immediately postoperatively showed similar short- and long-term beneficial results compared to a previously established protocol of applying CCT four times postoperatively. This protocol may be more suitable for practical use.

CLINICAL SIGNIFICANCE

The reported data can be used to establish the new protocol of CCT in a clinical surrounding and to support postoperative rehabilitation of the canine patient.

Comparison of complications following tibial tuberosity advancement and tibial plateau levelling osteotomy in very large and giant dogs 50 kg or more in body weight

OBJECTIVES

To analyse and compare major complications in dogs ≥50 kg undergoing tibial tuberosity advancement (TTA) or tibial plateau levelling osteotomy (TPLO) for treatment of cranial cruciate ligament disease.

METHODS

Medical records and radiographs of client-owned dogs (≥50 kg) treated for cranial cruciate ligament disease with either TTA or TPLO between January 2011 and November 2015 were reviewed. Ninety-one TTA cases and 54 TPLO cases met the study inclusion criteria. All complications within one year of surgery were recorded. Major complications were those requiring surgical revision or intervening medical therapy to resolve. Logistic regression analysis evaluated for associations with major complication occurrence. Major complications were statistically compared between TTA and TPLO treatment groups.

RESULTS

Incidence of major complications following TTA and TPLO surgery were 19.8% and 27.8%, respectively. Surgical site infection (SSI) was the single most common major complication following both TTA (15.4%) and TPLO (25.9%) surgery. There were no significant differences between TTA and TPLO treatment regarding the rate of SSI, surgical revision, or overall occurrence of major complications. Postoperative antibiotic therapy significantly reduced the risk of a major complication in all dogs ≥50 kg (p = 0.015; OR: 0.201: 95%CI: 0.055-0.737).

CLINICAL SIGNIFICANCE

Major complications occurred frequently following TTA and TPLO treatment of cranial cruciate ligament disease in dogs ≥50 kg. The increased chance for SSI should be considered and postoperative antibiotic therapy is recommended.

The effect of platelet-rich plasma on osseous healing in dogs undergoing high tibial osteotomy

OBJECTIVES

The purpose of this study was to investigate whether platelet-rich plasma (PRP) enhances osseous healing in conjunction with a high tibial osteotomy in dogs.

STUDY DESIGN

Randomized controlled trial.

METHODS

Sixty-four client-owned pet dogs with naturally occurring rupture of the anterior cruciate ligament and that were to be treated with a high tibial osteotomy (tibial plateau leveling osteotomy) were randomized into the treatment or control group. Dogs in the treatment group received autologous platelet-rich plasma activated with calcium chloride and bovine thrombin to produce a well-formed PRP gel that was placed into the osteotomy at the time of surgery. Dogs in the control group received saline lavage of the osteotomy. All dogs had the osteotomy stabilized with identical titanium alloy implants and all aspects of the surgical procedure and post-operative care were identical among dogs of the two groups. Bone healing was assessed at exactly 28, 49, and 70 days after surgery with radiography and ultrasonography and with MRI at day 28. The effect of PRP on bone healing was assessed using a repeated measures analysis of covariance with radiographic and ultrasonographic data and using a t-test with the MRI data.

RESULTS

Sixty dogs completed the study. There were no significant differences in age, weight, or gender distribution between the treatment and control groups. Twenty-seven dogs were treated with PRP and 33 were in the control group. The average platelet concentration of the PRP was 1.37x106 platelets/μL (±489x103) with a leukocyte concentration of 5.45x103/μL (±3.5x103). All dogs demonstrated progressive healing over time and achieved clinically successful outcomes. Time since surgery and patient age were significant predictors of radiographic healing and time since surgery was a significant predictor of ultrasonographic assessment of healing. There was no significant effect of PRP treatment as assessed radiographically, ultrasonographically, or with MRI.

CONCLUSION

The PRP used in this study did not hasten osseous union in dogs treated with a high tibial osteotomy.

Joint stability after canine cranial cruciate ligament graft reconstruction varies among femoral fixation sites

OBJECTIVE

To quantify stability in cranial cruciate ligament (CrCL) deficient canine stifles with hamstring grafts affixed at 3 femoral locations.

STUDY DESIGN

Canine stifle motion study using a multi-cohort, repeated measures design.

SAMPLE POPULATION

27 canine cadaver stifles.

METHODS

Hamstring grafts (HG) were affixed at the gracilis-semitendinosus insertion and on the lateral femur (1) proximal trochlear ridge (TR), (2) craniodistal to fabella (F), or (3) condyle center (CC). Total, cranial, and caudal tibial translation and total, medial, and lateral angular displacement, with and without translational load, were quantified with the CrCL intact, transected, and reconstructed. Angular displacement was quantified from points on the distal femur and proximal tibia. Graft strain was calculated from tissue displacement measured at joint angles of 30°, 60°, 90°, and 120°.

RESULTS

Tibial translation was lowest in F constructs, which also achieved the least difference in tibial translation from intact stifles. Tibial translation was lower in intact stifles than in CrCL transected or reconstructed stifles. Less angular displacement of the proximal tibia was detected in the medial than in the lateral direction, and tibial displacement was lower in the cranial than the caudal direction. Angular displacement was lowest in the F treatment group. F constructs had the lowest graft strain at joint angles greater than 30°.

CONCLUSIONS

Femoral fixation of a canine hamstring graft craniodistal to the lateral fabella conferred the best joint stability and lowest graft strain in vitro. No fixation method restored joint stability of the intact CrCL.

Pilot study measuring the effects of bandaging and cold compression therapy following tibial plateau levelling osteotomy

OBJECTIVES

To compare cold compression therapy, modified Robert-Jones bandage or the combination of cold compression therapy plus modified Robert-Jones bandage on operated limbs following tibial plateau levelling osteotomy in dogs.

METHODS

Twenty-one client-owned dogs with cranial cruciate ligament disease were prospectively enrolled. Dogs were randomly assigned to one of three postoperative treatment groups: cold compression therapy, modified Robert-Jones bandage or a combination of both. Patients were evaluated preoperatively and at 12, 24 and 36 hours following tibial plateau levelling osteotomy. Measurements included weight-bearing on the operated limb, stifle flexion and extension angles and circumference of the operated limb at four levels.

RESULTS

There was no significant difference in weight-bearing, range of motion or limb swelling between groups. There was a trend for dogs in the cold compression therapy and cold compression therapy with a bandage groups to have a greater increase in weight-bearing after surgery compared with the bandage-only group.

CLINICAL RELEVANCE

Cold compression therapy is a safe modality following tibial plateau levelling osteotomy surgery. The trend towards improved use of the operated limb in the groups receiving cold compression therapy compared with those treated with only a bandage may be an indication that these patients are more comfortable in the postoperative period. The small sample size limits interpretation of the data but this pilot study provides data to guide future investigation.

Tibial Plateau Leveling Osteotomy Plate Contouring and Proximal Load Screw Angulation Affect Osteotomy Compression

OBJECTIVE

To evaluate the effect of contouring a tibial plateau leveling osteotomy (TPLO) plate, the associated angulation of the dynamic compression plate (DCP) hole relative to the long axis of the tibia, and angulation of the screw relative to the DCP hole on the osteotomy compression generated by load screws in a TPLO model.

STUDY DESIGN

In vitro biomechanical study.

STUDY POPULATION

Polyoxymethylene (POM) rod and synthetic cortical bone substitute model (n = 9).

METHODS

The distal portion of a Slocum TPLO plate was attached to a horizontally positioned POM rod that was connected to a load cell. A segment of synthetic cortical bone substitute was attached to the end mount of the testing frame and adjusted to conform to the angle of the proximal portion of the TPLO plate. A 3.5 mm cortical bone screw was inserted in the proximal DCP hole and tightened to 1.5 Nm. The peak longitudinal load (N) was recorded. Screw insertion and data collection were repeated for proximal plate angles of 0-40° at 5° increments.

RESULTS

A significant increase in the compression generated was observed as the plate angle was increased from 0° to 10°. The compression ceased to significantly increase until the plate was bent more than 20°, after which a significant decrease in compression was noted. A marked reduction in the compression generated occurred at plate angles greater than 30°.

CONCLUSION

Angulation of the DCP hole and screw insertion angle can have deleterious effects on the magnitude of osteotomy compression.

A pitfall on postoperative radiographs in dogs after tibial plateau leveling osteotomy

OBJECTIVE

To identify the cause of an occasional radiolucent line in the tibia on postoperative radiographs after tibial plateau leveling osteotomy (TPLO) in dogs.

STUDY DESIGN

Retrospective case series and ex vivo experiment.

SAMPLE POPULATION

Dogs (n = 80; 87 stifles) with cranial cruciate ligament (CCL) rupture that had TPLO; and 4 canine tibia specimens.

METHODS

Medical records (2007-2010) and radiographs of dogs that had TPLO were reviewed and examined for presence of a radiolucent line on postoperative radiographs. The TPLO procedure was reproduced ex vivo to determine the origin of this line by use of metallic wires to identify bone contours.

RESULTS

A curvilinear radiolucent line was visible in 14 (16%) tibias and was 5.4 times more likely to be visible with lateral misalignment of the tibial diaphysis relative to the plateau and 2.6 times more likely visible on caudocranial radiographs with the stifle in outward rotation. Fracture complication rate was higher in dogs with this radiolucent line (P = .02) and with lateral misalignment of the tibial diaphysis relative to the plateau (risk ratio, 3.8). The line could be reproduced ex vivo and caused by superimposition of the craniomedial border of osteotomy with the tibial plateau.

CONCLUSIONS

The radiolucent line was a spurious fracture line created by the medial margin of the tibial osteotomy and confounding factors such as tibial misalignment may explain the apparently associated higher complication rate.