Deep learning discrimination of rheumatoid arthritis from osteoarthritis on hand radiography.

PURPOSE: To develop a deep learning model to distinguish rheumatoid arthritis (RA) from osteoarthritis (OA) using hand radiographs and to evaluate the effects of changing pretraining and training parameters on model performance. MATERIALS AND METHODS: A convolutional neural network was retrospectively trained on 9714 hand radiograph exams from 8387 patients obtained from 2017 to 2021 at seven hospitals within an integrated healthcare network. Performance was assessed using an independent test set of 250 exams from 146 patients. Binary discriminatory capacity (no arthritis versus arthritis; RA versus not RA) and three-way classification (no arthritis versus OA versus RA) were evaluated. The effects of additional pretraining using musculoskeletal radiographs, using all views as opposed to only the posteroanterior view, and varying image resolution on model performance were also investigated. Area under the receiver operating characteristic curve (AUC) and Cohen's kappa coefficient were used to evaluate diagnostic performance. RESULTS: For no arthritis versus arthritis, the model achieved an AUC of 0.975 (95% CI: 0.957, 0.989). For RA versus not RA, the model achieved an AUC of 0.955 (95% CI: 0.919, 0.983). For three-way classification, the model achieved a kappa of 0.806 (95% CI: 0.742, 0.866) and accuracy of 87.2% (95% CI: 83.2%, 91.2%) on the test set. Increasing image resolution increased performance up to 1024 × 1024 pixels. Additional pretraining on musculoskeletal radiographs and using all views did not significantly affect performance. CONCLUSION: A deep learning model can be used to distinguish no arthritis, OA, and RA on hand radiographs with high performance.

Three-dimensionally printed osteotomy and reaming guides for correction of a multiplanar femoral deformity stabilized with an interlocking nail in a dog.

OBJECTIVE: To describe the use of virtual surgical planning (VSP) and three-dimensionally (3D) printed surgical guides for corrective osteotomies stabilized with an interlocking nail in a dog with a multiplanar femoral deformity. STUDY DESIGN: Case report. ANIMALS: An 8-year-old male neutered mixed breed dog weighing 44 kg. METHODS: A dog was presented for a right grade 3 lateral patellar luxation secondary to a multiplanar femoral deformity due to a suspected femoral malunion. A computed tomography (CT) scan was obtained to create virtual femoral models. Corrective osteotomies were simulated with VSP. Custom osteotomy guides and reaming guides were designed to facilitate the correction and the placement of an interlocking nail. The preoperative femoral model, virtually aligned femoral model, custom osteotomy guides, and reaming guides were 3D printed, sterilized, and utilized intraoperatively. A CT scan was performed postoperatively to assess femoral length and alignment. RESULTS: Custom osteotomy and reaming guides were used as intended by the VSP. Postoperative femoral length as well as frontal, sagittal, and axial plane alignment were within 0.7 mm, 2.2°, 0.5°, and 1.6°, respectively, of the virtually planned femoral model. Two months postoperatively, the dog was sound on visual gait examination, and the patella tracked in the trochlear groove throughout stifle range of motion and was unable to be manually luxated. Radiographs obtained 2 months postoperatively revealed static femoral alignment and implants. Both osteotomies were discernable with callus bridging. CONCLUSION: Virtual surgical planning and custom osteotomy and reaming guides facilitated complex femoral corrective osteotomies and interlocking nail placement.

Complications and outcomes of total hip arthroplasty in dogs with luxoid hip dysplasia: 18 cases (2010-2022).

OBJECTIVE: To describe the complications and outcomes in dogs with luxoid hip dysplasia (LH) undergoing total hip arthroplasty (THA) and compare complication rates with THA in non-LH dogs. STUDY DESIGN: Retrospective study. SAMPLE POPULATION: Client-owned dogs (n = 217) undergoing primary THA (n = 238). METHODS: Medical records (2010-2022) of dogs undergoing THA were reviewed, and LH was defined as complete dorsal displacement of the femoral head from the acetabulum on lateral projection radiographs. Major or catastrophic complications, revisions, and outcomes were recorded for all dogs and they were compared between LH and non-LH groups. RESULTS: Eighteen cases met the subcriterion for the LH group and 220 cases met the subcriterion for inclusion in the non-LH group. There were 14 complications in 13/18 dogs with LH; seven were intraoperative (femoral fissure/fracture) and seven were postoperative (dorsal luxation, n = 5; femoral fracture, n = 1; acetabular cup septic loosening, n = 1). Revisions were performed for all LH dogs that encountered complications; satisfactory outcomes were achieved in 12/13 dogs. Overall, LH dogs had a higher risk of developing complications (p < .001), including intraoperative fracture (p < .001) and postoperative dorsal luxation (p = .019) when compared with non-LH dogs. CONCLUSION: Luxoid hip dysplasia was associated with a higher risk of major complications following THA in dogs, specifically intraoperative fissure/fracture and postoperative dorsal luxation. Despite the increased risk, revisions typically yielded satisfactory outcomes. CLINICAL SIGNIFICANCE: Luxoid hip dysplasia is an important risk factor for the development of major complications in dogs undergoing THA.

Efficacy of virtual surgical planning and a three-dimensional-printed, patient-specific reduction system to facilitate alignment of diaphyseal tibial fractures stabilized by minimally invasive plate osteosynthesis in dogs: A prospective clinical study.

OBJECTIVE: To evaluate the efficacy of a three-dimensional (3D)-printed, patient-specific reduction system for aligning diaphyseal tibial fractures stabilized using minimally invasive plate osteosynthesis (MIPO). STUDY DESIGN: Prospective clinical trial. SAMPLE POPULATION: Fifteen client owned dogs. METHODS: Virtual 3D models of both pelvic limbs were created. Pin guides were designed to conform to the proximal and distal tibia. A reduction bridge was designed to align the pin guides based on the guides' spatial location. Guides were 3D printed, sterilized, and applied, in conjunction with transient application of a circular fixator, to facilitate indirect fracture realignment before plate application. Alignment of the stabilized tibiae was assessed using postoperative computed tomography scans. RESULTS: Mean duration required for virtual planning was 2.5 h and a mean of 50.7 h elapsed between presentation and surgery. Guide placement was accurate with minor median discrepancies in translation and frontal, sagittal, and axial plane positioning of 2.9 mm, 3.6°, 2.7°, and 6.8°, respectively. Application of the reduction system restored mean tibial length and frontal, sagittal, and axial alignment within 1.7 mm, 1.9°, 1.7°, and 4.5°, respectively, of the contralateral tibia. CONCLUSION: Design and fabrication of a 3D-printed, patient-specific fracture reduction system is feasible in a relevant clinical timeline. Intraoperative pin-guide placement was reasonably accurate with minor discrepancies compared to the virtual plan. Custom 3D-printed reduction system application facilitated near-anatomic or acceptable fracture reduction in all dogs. CLINICAL SIGNIFICANCE: Virtual planning and fabrication of a 3D-printing patient-specific fracture reduction system is practical and facilitated acceptable, if not near-anatomic, fracture alignment during MIPO.

Serum acute-phase protein concentrations following uncomplicated total hip arthroplasty in dogs.

OBJECTIVES: To establish preoperative and postoperative serum C reactive protein (CRP) and serum amyloid A (SAA) levels in dogs undergoing uncomplicated total hip arthroplasty (THA). STUDY DESIGN: Prospective clinical trial. ANIMALS: Eighteen client-owned dogs. METHODS: Dogs undergoing THA were recruited. Serum CRP and SAA levels were measured in all dogs the day prior to surgery, and 3 and 6 months following surgery. All dogs received a physical examination and underwent radiography at each visit, and dogs with complications were excluded from the study. For continuous numeric data, histograms were generated and evaluated for normality. A 1-way repeated measures ANOVA was performed to find differences between time points. RESULTS: No complications were encountered in any of the recruited dogs. Median age was 30 months (12-66), and the median bodyweight was 27.3 kg (22.3-40.2). Mean CRP concentrations in the preoperative, 3-month, and 6-month periods were 3.8 mg/L ± 4.4, 0.8 mg/L ± 1.9, and 1.4 mg/L ± 1.4, respectively. The mean SAA concentrations in the preoperative, 3-month, and 6-month periods were 13.9 mg/L ± 8.8, 14.1 mg/L ± 12.6, and 18.4 mg/L ± 15.1, respectively. There were no differences for each parameter between time points. CONCLUSION: C-reactive protein and SAA levels were consistent with levels previously established for noninflammatory and normal conditions in dogs. CLINICAL SIGNIFICANCE: Postoperative CRP and SAA concentrations were low by 3 months following uncomplicated THA.

Proximal femoral deformity correction and total hip arthroplasty in a dog using 3D printed custom guides.

OBJECTIVE: To report the successful correction of a proximal femoral deformity (PFD) and total hip arthroplasty (THA) in a dog with the use of three-dimensionally (3D) printed custom surgical guides (CSGs). STUDY DESIGN: Case report. ANIMALS: One-year-old, male neutered, Goldendoodle. METHODS: Uniapical proximal varus and recurvatum femoral deformity (PFD) precluded femoral stem placement for THA, which was indicated for severe hip dysplasia. Using CT-derived bone and implant models, custom ostectomy and reduction guides for deformity correction were designed. A 13-hole 3.5 mm locking compression plate was contoured and applied to 3D printed models of the corrected femur and screw trajectory holes were incorporated into the CSGs. RESULTS: A caudolateral closing wedge ostectomy of the proximal femur was achieved with the aid of the CSGs and precontoured plate to within 2° of varus and 1° of recurvatum of the virtual surgical plan. Placement of a press-fit femoral stem was achieved with 7° of varus and 9° of caudal angulation. The plate was secured using six locking screws, two cortical screws, and two 18-gauge double-loop cerclage wires. No lameness and normal range of motion of the hip were observed on clinical examination 3 months after surgery. Radiographs at 3 and 6 months revealed static implant positioning, and complete bony union at the ostectomy site. CONCLUSION: Virtual surgical planning and CSGs led to successful concurrent THA and femoral deformity correction.

Accuracy of needle arthroscopy for the diagnosis of medial meniscal tears in dogs with cranial cruciate ligament rupture.

OBJECTIVE: To determine the accuracy of needle arthroscopy (NA) for the diagnosis of medial meniscal tears in dogs with cranial cruciate ligament rupture (CCLR). STUDY DESIGN: Prospective clinical trial. ANIMALS: Twenty-six client-owned dogs. METHODS: Dogs with CCLR and scheduled to undergo tibial plateau leveling osteotomy were recruited for the study. Needle arthroscopy was performed by an experienced surgeon; the same dog subsequently underwent standard arthroscopy (SA) by another experienced surgeon who was blinded to the NA findings. The SA arthroscopy findings were used as the gold standard. Arthroscopy time, visibility of the menisci, ability to probe the menisci, and the presence of meniscal tears were recorded for both arthroscopies. The degree of lameness before and after NA was subjectively quantified. RESULTS: The sensitivity and specificity to diagnose medial meniscal tears with NA was 95% and 100%, respectively. Visibility of the menisci was lower (P < .01), probing of the lateral meniscus was harder (P = .0017), and procedure time was shorter (P = .073) with NA when compared to SA. The lameness scores did not differ before and after NA (P = .25). CONCLUSION: Needle arthroscopy could be performed rapidly with low morbidity, and had high accuracy for detecting medial meniscal tears in dogs with CCLR. CLINICAL SIGNIFICANCE: Needle arthroscopy is a promising minimally invasive technique for diagnosing medial meniscal tears in dogs with CCLR.

Minimally invasive repair of acetabular fractures in dogs: Ex vivo feasibility study and case report.

OBJECTIVE: To describe and evaluate minimally invasive repair of acetabular fractures in dogs using plates contoured to 3D-printed hemipelvic models. STUDY DESIGN: Ex vivo feasibility study and case report. SAMPLE POPULATION: Adult canine cadavers (n = 5); 8 year old male neutered Chihuahua. METHODS: Bone plates were contoured to 3D printed hemipelvic models derived from computed tomographic scans of each dog. In cadavers, acetabular, ischial, and pubic osteotomies were performed. A small craniolateral approach to the ilial body and a caudal approach to the ischium were made and connected through epiperiosteal tunnels. Under fluoroscopic guidance, fractures were reduced, and precontoured bone plates were applied with locking screws. Postoperative computed tomographic images were used to assess fracture gaps, step defects, and pelvic angulation. Cadavers were dissected for subjective assessment of sciatic nerve injury. Radiographic and clinical follow up was acquired for the clinical case. RESULTS: Small fracture gaps (<2 mm) and step defects (<1 mm), low pelvic angulation (<5°), and minimal (none n = 4 and mild n = 1) sciatic nerve injuries were observed in cadaver testing. There was slight (~1 mm) medial displacement of the pubic segment and good functional outcome for the clinical case, with radiographic healing documented at 3 months postoperatively. CONCLUSION: Minimally invasive acetabular fracture repair in dogs with the aid of 3D printing was feasible and accurate. CLINICAL SIGNIFICANCE: Minimally invasive repair techniques assisted by 3D printing may be applicable for acetabular fractures in dogs. The technique should be evaluated further before routine use can be recommended.

Closed reduction and fluoroscopic-guided percutaneous pinning of femoral capital physeal or neck fractures: Thirteen fractures in 11 dogs.

OBJECTIVES: To report the short-term clinical outcome and complications in dogs that underwent surgical repair of femoral capital physeal or neck fractures via fluoroscopic-guided percutaneous pinning (FGPP). STUDY DESIGN: Retrospective case series. ANIMALS: Client owned dogs (n = 11) with femoral capital physeal or neck fractures (n = 13). METHODS: Records (July 2018-July 2021) of dogs that underwent surgery for femoral capital physeal or neck fracture repair with FGPP from two hospitals were reviewed. Data collected included signalment, age, weight, preoperative lameness severity, fracture factors (etiology, Salter-Harris classification, time from injury to surgery, radiographic displacement), surgical factors (surgery time, number/size of implants, reduction quality) and outcome (follow-up examination findings, radiographic findings, complications). RESULTS: Most fractures (11/13) occurred secondary to trauma. The median time from injury to surgery was 5.5 days. There was mild radiographic displacement preoperatively in 10/13 fractures. Satisfactory fracture healing and limb function was achieved in 10/13 femurs. Complications occurred in 5/11 cases and included intra-articular implants, implant failure/nonunion, implant migration (2), and malunion. Of these five complications, two resolved with implant removal, and a salvage procedure was recommended in the remaining cases. Of the three cases requiring salvage procedures, two originally presented with radiographic evidence of fracture chronicity. CONCLUSIONS: FGPP can be used to successfully treat femoral head and neck fractures with appropriate case selection and precise surgical technique.

Minimally invasive plate osteosynthesis of femoral fractures with 3D-printed bone models and custom surgical guides: A cadaveric study in dogs.

OBJECTIVE: Assess the accuracy and efficiency of reduction provided by application of plates precontoured to 3-dimensional (3D)-printed femoral bone models using a custom fracture reduction system (FRS) or intramedullary pin (IMP) to facilitate femoral minimally invasive plate osteosynthesis (MIPO) in dogs. STUDY DESIGN: Experimental cadaveric study. SAMPLE POPULATION: Seven dog cadavers. METHODS: Virtual 3D femoral models were created using computed tomographic images. Simulated, virtual mid-diaphyseal femoral fractures were created and reduced. Reduced femoral models were 3D-printed and a plate was contoured. Custom drill guides for plate screw placement were designed and 3D-printed for the FRS. Mid-diaphyseal simulated comminuted fractures were created in cadavers, and fractures were aligned using FRS or IMP and stabilized with the precontoured plates. Number of fluoroscopic images acquired per procedure and surgical duration were recorded. Computed tomographic scans were repeated to assess femoral length and alignment. RESULTS: Compared to the preoperative virtual plan, median change in femoral length and frontal, sagittal, and axial alignment was less than 3 mm, 2°, 3°, and 3° postoperatively, respectively, in both reduction groups. There was no difference in length or alignment between reduction groups (P > .05). During FRS, fewer fluoroscopic images were taken (P = .001), however, surgical duration was longer than IMP procedures (P = .011). CONCLUSION: Femoral alignment was accurate when using plates precontoured to 3D printed models, regardless of reduction method. CLINICAL SIGNIFICANCE: Accurate plate contouring using anatomically accurate models may improve fracture reduction accuracy during MIPO applications. Custom surgical guides may reduce fluoroscopy use associated with MIPO.

Use of a bone-to-tendon plate to stabilize a comminuted calcaneus fracture in a dog.

OBJECTIVE: To report the use of an ancillary plate spanning from the calcaneus to the common calcaneal tendon to stabilize a comminuted fracture in a dog. STUDY DESIGN: Case report ANIMALS: Two year old male neutered mix-breed dog. METHODS: The dog presented for a grade IIIa open highly comminuted fracture of the shaft and tuber of the left calcaneus from a suspected gunshot wound. Plantar and lateral locking plates were applied to the calcaneus, with the lateral plate extending proximally and sutured directly to the common calcaneal tendon. Autogenous cancellous and allogenic corticocancellous bone grafts were placed into the fracture site, and a human placental matrix was injected after closure. A lateral tarsal splint was applied for 17 weeks postoperatively. The lateral bone-to-tendon plate was replaced with a smaller lateral plate spanning only the calcaneus 9 weeks after the initial surgery. RESULTS: Radiographic union was documented at 17 weeks. At 25 weeks, both plates were removed due to suspected implant associated infection. At the final follow-up assessment, 36 weeks after initial surgery, the dog had returned to normal function with no observable lameness. CONCLUSION: Incorporation of the common calcaneal tendon as a proximal segment for plate fixation led to successful union of a highly comminuted calcaneal fracture.

Evaluation of a crescent saw guide for tibial plateau-leveling osteotomy: An ex vivo study.

OBJECTIVE: To evaluate the effectiveness of a novel crescent-shaped tibial plateau-leveling osteotomy (TPLO) saw guide (crescent guide) to assist with saw control in novice participants. STUDY DESIGN: Ex vivo study. SAMPLE POPULATION: Synthetic bones (n = 54) and medium sized dog pelvic limbs (n = 36). METHODS: The 6 participants (interns and residents) without any prior experience performing a TPLO each performed 9 osteotomies on synthetic tibia models, and 6 osteotomies in cadaveric limbs of medium-sized dogs. Osteotomies made with the crescent guide were compared with those made with a standard jig and a radial saw guide with a jig. Osteotomy angulation, distance of eccentricity (DOE), and medial tibial cortical damage (synthetic bone models only) were measured from calibrated photographs. Participants rated their experiences with each technique. RESULTS: There was no difference in the DOE, coronal or axial osteotomy angulation between the 3 alignment devices for synthetic bone models or cadavers. Average medial cortical damage with the crescent guide (3.8 ± 7.3 mm2 ) was lower than with the radial guide (35.7 ± 27 mm2 ) and standard jig (51.2 ± 63.2 mm2 ) guides (P = <.01). Five of 6 participants preferred the crescent guide over the standard jig and radial guide. CONCLUSION: There was no difference in accuracy of osteotomy positioning but using the crescent guide resulted in lower cortical damage and more favorable participant perceptions. CLINICAL RELEVANCE: The crescent guide may improve control of the radial saw during TPLO in novice surgeons but does not appear to aid accurate osteotomy positioning.

Subsequent meniscal tears following tibial tuberosity advancement and tibial plateau leveling osteotomy in dogs with cranial cruciate ligament deficiency: An in vivo experimental study.

OBJECTIVE: To evaluate the short- and mid-term effects of tibial tuberosity advancement (TTA) and tibial plateau leveling osteotomy (TPLO) on subsequent meniscal tears. STUDY DESIGN: Experimental in vivo study. ANIMALS: Purpose-bred beagle dogs (n = 15). METHODS: For each dog, the cranial cruciate ligaments were transected; one limb underwent TTA and the other limb underwent TPLO. Orthopedic and radiographic examinations were performed preoperatively and at 12 and 32 weeks postoperatively. Gross evaluation of the stifle joint was performed after euthanasia at 12 (n = 10) and 32 (n = 5) weeks. RESULTS: Lameness scores were not different between TTA and TPLO limbs at any time point. Radiographic osteoarthritis scores of TTA stifles (1.33 ± 0.49) were higher than TPLO stifles (0.67 ± 0.49) (p = .002) at 12 weeks postoperatively, but there was no difference between groups at 32 weeks postoperatively. Subsequent medial meniscal tears occurred in 6/10 TTA stifles, and 0/10 TPLO stifles at 12 weeks postoperatively and in 5/5 TTA stifles, and 1/5 TPLO stifles at 32 weeks postoperatively. Subsequent lateral meniscal tears occurred in 4/5 TTA stifles at 32 weeks postoperatively. Medial meniscal total gross pathology score was higher in TTA than TPLO stifles. TTA stifles had more articular cartilage damage when compared with TPLO stifles at 32 weeks postoperatively. CONCLUSION: In this within-dog experimental comparison, subsequent medial meniscal tears and cartilage injury was more prevalent following TTA when compared to TPLO. CLINICAL SIGNIFICANCE: In an experimental model, TPLO protects the medial meniscus and articular cartilage better than TTA in stifles with complete cranial cruciate ligament deficiency.

Calcium sulfate antibiotic-impregnated bead implantation for deep surgical site infection associated with orthopedic surgery in small animals.

OBJECTIVE: To report the outcomes and complications associated with antibiotic-impregnated calcium sulfate beads for prevention and treatment of orthopedic-related surgical site infection (SSI) in companion animals. STUDY DESIGN: Retrospective case series. ANIMALS: Client-owned cats (n = 2) and dogs (n = 14). METHODS: Medical records of 16 cases in which implantation of antibiotic-impregnated calcium sulfate beads was performed for the prevention or treatment of SSI were reviewed. Information collected included signalment, prior surgery, reason for bead placement, antibiotics used, bacterial culture results, and clinical outcomes. RESULTS: Surgical site infection resolved in six of 10 animals treated therapeutically and did not occur in six of six animals treated prophylactically. Susceptibility of the causative bacteria to the antibiotic implanted was confirmed in five of six cases with resolved SSI treated therapeutically but in only one of four cases with unresolved SSI treated therapeutically. Complications directly related to bead placement were evident in only one case in which beads extruded from external skeletal fixator pin tracts 7 days after implantation. At final follow-up, 11 of 12 animals without SSI had satisfactory limb use and no clinical, cytologic, or radiographic evidence of infection. CONCLUSION: Implantation was well tolerated. Resolution of SSI was inconsistent; however, when bacteria were susceptible to the antibiotic implanted, SSI resolved in all but one case. CLINICAL SIGNIFICANCE: Antibiotic-impregnated calcium sulfate beads could be considered for prevention or treatment of orthopedic SSI in small animals. A prospective clinical study is required to obtain additional information, including the value of preoperative bacterial culture.

Association of aspirin and other non-steroidal anti-inflammatory drugs with bleeding complications in image-guided musculoskeletal biopsies.

OBJECTIVE: To evaluate the safety of continuing aspirin and other non-steroidal anti-inflammatory drugs (NSAID) in patients undergoing image-guided musculoskeletal biopsies. MATERIAL AND METHODS: Prior to October 2017, patients undergoing image-guided musculoskeletal biopsy had aspirin and NSAIDs withheld for the preceding 5-7 days. The policy changed in October 2017 based on new guidelines from the Society of Interventional Radiology such that aspirin and other NSAIDs were not withheld. A retrospective review of patient records was performed for all biopsies prior to and after the policy change to assess for differences in biopsy-related bleeding complications. Additional clinical and biopsy factors including age, gender, liver disease, coagulopathy, biopsy tissue type, and histological diagnosis were assessed. RESULTS: In the pre-policy change group, there were 1853 total biopsies with 43 biopsy-related bleeding complications (2.3%). Within this group, 362 patients were on aspirin with 7 bleeding complications (1.9%) and 260 patients were on NSAIDs with 5 bleeding complications (1.9%). There were 409 total biopsies in the post-policy change group and 7 bleeding complications (1.7%). Within this group, 71 patients were on aspirin with 1 bleeding complication (1.4%). No bleeding complications were recorded in patients on NSAIDs (0%). There was no significant difference in bleeding complication between the pre- and post-policy change groups overall (p = 0.58) and in patients on aspirin (p = 1.00) or other NSAIDs (p = 1.00). CONCLUSION: Bleeding complications for musculoskeletal biopsies are rare. Leaving patients on aspirin or other NSAIDs during a musculoskeletal biopsy does not increase the incidence of bleeding complications.

Human placenta-derived matrix with cancellous autograft and demineralized bone matrix for large segmental long-bone defects in two dogs with septic nonunion.

OBJECTIVE: To report the successful treatment of septic nonunion in two dogs with large segmental defects secondary to long-bone fractures by using a novel human placenta-derived matrix (hPM) as adjunct to fixation. ANIMALS: One 3-kg 9-year-old neutered male Yorkshire terrier with a distal antebrachial fracture and one 6-kg 4-year-old spayed female miniature pinscher with a distal humeral fracture. STUDY DESIGN: Short case series. METHODS: Both dogs presented for septic nonunion after internal fixation of Gustilo type II open diaphyseal fractures from dog bite injuries. During revision, debridement of nonviable bone resulted in segmental defects of 32% and 20% of the bone length for the antebrachial and humeral fractures, respectively. The antebrachial fracture was stabilized with a circular external fixator, and the humeral fracture was stabilized with biaxial bone plating. The fracture sites were not collapsed, and full length was maintained with the fixation. Autogenous cancellous bone graft and canine demineralized bone allograft were packed into the defects, and hPM was injected into the graft sites after closure. RESULTS: Radiographic union was documented at 8 weeks and 6 weeks for the antebrachial and humeral fractures, respectively. Both dogs became fully weight bearing on the affected limbs and returned to full activity. CONCLUSION: Augmenting fixation with grafts and hPM led to a relatively rapid union in both dogs reported here.

The effect of tibial plateau leveling osteotomy on patellofemoral kinematics in dogs: An in vivo study.

OBJECTIVE: To quantitatively evaluate patellofemoral (PF) kinematics during walking in dogs with cranial cruciate ligament (CrCL) deficiency treated by tibial plateau leveling osteotomy (TPLO). STUDY DESIGN: Longitudinal observational study. ANIMALS: Dogs with unilateral CrCL deficiency treated by TPLO (n = 10). METHODS: Horizontal beam fluoroscopic images of the stifles during treadmill walking were acquired 6 months after TPLO. Computed tomography was performed, and digitized bone models of both femurs and patellae were created. These digital models were superimposed over the fluoroscopic images with shape-matching software, and sagittal plane PF kinematics for TPLO-treated and normal contralateral stifles were calculated. Patellofemoral kinematics were described according to phase of gait cycle as well as relative to femorotibial flexion angle. RESULTS: In TPLO-treated stifles, there was an approximately 1-mm increase in cranial displacement of the patella (P < .05) compared with the normal stifle at equivalent femorotibial flexion angles between 120° and 140° and predominately during the stance phase. Proximal-distal translation and patellar flexion angle were mostly unaffected by TPLO when they were assessed according to either equivalent phase of gait cycle or femorotibial flexion angles. CONCLUSION: In vivo PF kinematics in TPLO-treated stifles were subtly different from normal, characterized by slight cranial shifting of the patella relative to the trochlear groove. CLINICAL SIGNIFICANCE: The clinical significance of these results remains unknown. These results may provide further understanding into extensor mechanism abnormalities associated with TPLO.

Femorotibial kinematics in dogs treated with tibial plateau leveling osteotomy for cranial cruciate ligament insufficiency: An in vivo fluoroscopic analysis during walking.

OBJECTIVE: To determine the ability of tibial plateau leveling osteotomy (TPLO) to address abnormal femorotibial kinematics caused by cranial cruciate ligament (CCL) rupture during walking in dogs. STUDY DESIGN: Prospective, clinical. ANIMALS: Sixteen dogs (20-40 kg) with unilateral complete CCL rupture. METHODS: Lateral view fluoroscopy was performed during treadmill walking preoperatively and 6 months after TPLO. Digital three-dimensional (3D) models of the femora and tibiae were created from computed tomographic (CT) images. Gait cycles were analyzed by using a 3D-to-2D image registration process. Craniocaudal translation, internal/external rotation, and flexion/extension of the femorotibial joint were compared between preoperative and 6-month postoperative time points for the affected stifle and 6-month postoperative unaffected contralateral (control) stifles. RESULTS: In the overall population, CCL rupture resulted in 10 ± 2.2 mm (mean ± SD) cranial tibial translation at midstance phase, which was converted to 2.1 ± 4.3 mm caudal tibial translation after TPLO. However, five of 16 TPLO-treated stifles had 4.1 ± 0.3 mm of cranial tibial subluxation during mid-to-late stance phase, whereas 10 of 16 TPLO-treated stifles had 4.3 ± 0.4 mm of caudal tibial subluxation throughout the gait cycle. Overall, postoperative axial rotational and flexion/extension patterns were not different from control, but stifles with caudal tibial subluxation had more external tibial rotation during mid-to-late stance phase compared with stifles with cranial tibial subluxation. CONCLUSION: TPLO mitigated abnormal femorotibial kinematics but did not restore kinematics to control values in 15 of 16 dogs during walking. CLINICAL SIGNIFICANCE: Tibial plateau leveling osteotomy reduces cranial tibial subluxation during walking, but persistent instability is common.

Use of a cerclage cable-plate system to stabilize a periprosthetic femoral fracture after total hip replacement in a dog.

OBJECTIVE: To report the successful use of cerclage cables around the periprosthetic region of a femoral fracture after total hip replacement (THR) in a dog with bone stock too limited for other methods of fixation. STUDY DESIGN: Case report. ANIMAL: 6-year-old male neutered, golden retriever. METHODS: Locking plate fixation of a type-B1 diaphyseal periprosthetic femoral fracture (PFF) failed 14 days after cementless THR and 6 days after initial femoral fracture repair. Total hip replacement implants seemed unchanged on radiographs, but lateral retraction of the screw-plate construct from the proximal segment was evident. Bone stock was assessed as insufficient for adequate screw purchase, prompting revision of the fixation with cerclage cable fixation of the proximal segment; the cables were anchored to the original locking plate construct with threaded positioning pins that screwed into the locking holes. RESULTS: Acceptable union was documented on radiographs by 3 months after revision. No lameness and good range of motion of the hip were observed on clinical examination 13 months after surgery. Radiographs at 13 months documented static implant positioning and remodeling at the fracture site. CONCLUSION: Use of a cable-plate construct to stabilize a type-B1 PFF led to successful long-term outcome in this dog. CLINICAL SIGNIFICANCE: Use of a cable-plate construct may be considered to treat type-B1 PFF with limited bone stock.

Survey of clinician and student impressions of a synthetic canine model for gastrointestinal surgery training.

OBJECTIVE: To evaluate the perceived efficacy of a high-fidelity synthetic canine model for simulating common gastrointestinal surgical procedures. STUDY DESIGN: Survey of students and experienced clinicians. SAMPLE POPULATION: Twelve clinicians with >2 years of postgraduate experience in the field of small animal surgery and 102 senior year veterinary students. METHODS: The model was subjectively evaluated by 12 clinicians with >2 years of postgraduate experience in the field of small animal surgery. Senior year veterinary students (n = 102) were asked to complete questionnaires before and after a laboratory on common gastrointestinal surgical procedures that included rating of perceived proficiency, anatomical knowledge, and the use of synthetic models compared with live animals. RESULTS: Clinicians assessed most aspects of the model as moderately realistic and unanimously agreed that it would be helpful for students to train on this model prior to live surgery. Student survey response rates were 91% and 99% before and after the laboratory, respectively. The proportion of students that felt moderately-to-highly proficient with the procedures increased from 8% prior to the laboratories to 59% after the laboratories (P < .001). The proportion of students that felt that they had superior-to-excellent knowledge of abdominal surgical anatomy increased from 16% prior to the laboratories to 44% after the laboratories (P < .001). The proportion of students that were satisfied with synthetic models instead of live animals increased from 52% prior to the laboratories to 74% after the laboratories (P = .014). CONCLUSION: Experienced clinicians considered the model to have moderate realism. A positive shift in the students' self-perceived proficiency with gastrointestinal surgery was evident after the use of the model. CLINICAL IMPACT: This synthetic model should be considered for training of veterinary gastrointestinal surgery. However, comparison studies are recommended to ascertain the relative educational value of this model.