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.

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.

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.

A review of minimally invasive fracture stabilization in dogs and cats.

OBJECTIVE: To summarize and discuss peer-reviewed studies on minimally invasive osteosynthesis (MIO) of long bone, physeal, and articular fractures in dogs and cats. STUDY DESIGN: Invited review. METHODS: A critique of literature was performed to assess MIO feasibility, outcomes, and complications through PubMed, Scopus, and CAB abstracts research databases (2000-2020). RESULTS: More than 40 MIO articles have been published in the last 15 years, but most studies had small numbers, lacked control groups, and used limited outcome measures. Studies generally showed that MIO was feasible in dogs and cats with low complication rates. The current evidence does not demonstrate superior bone healing or functional outcomes with MIO when compared to standard methods. Although treatment principles, case selection, and techniques varied depending on the anatomical location, there were no salient differences in complication rates among long bones, physeal, and articular fractures treated by MIO. CONCLUSION: The current available evidence and the personal experience of the authors support MIO as a promising fracture management modality. MIO can yield excellent outcomes when applied in carefully selected cases, performed by surgeons experienced in the technique. We cannot, however, conclude that MIO is superior to open fracture stabilization based on the available evidence in veterinary literature. Randomized controlled studies are warranted to prospectively compare MIO with other osteosynthesis techniques and thereby validate its role in fracture management for dogs and cats.

Systematic review of the treatment options for pericardial effusions in dogs.

OBJECTIVE: To evaluate the evidence for the conservative and surgical management of pericardial effusions for neoplastic and idiopathic etiologies in dogs. STUDY DESIGN: Systematic review. SAMPLE POPULATION: Peer-reviewed English-language articles describing the treatment and outcome of naturally occurring pericardial effusion in domestic dogs. METHODS: A literature search was performed with PubMed, Cab Abstracts, Scopus, and Agricola in August 2019 for articles describing pericardial effusion treatment in dogs. Inclusion criteria were applied, and articles were evaluated for reported outcome and level of evidence by using The Oxford 2011 Levels of Evidence, a previously described hierarchical system, and GRADE (Grading of Recommendations, Assessment, Development and Evaluation). RESULTS: One hundred eight of the 641 unique articles that were identified and evaluated met inclusion criteria. Most articles included were case studies (68.2%) or retrospective case series (25.2%), with all articles providing a low level of evidence. The articles had inconsistent inclusion criteria, outcome measures, and follow-up, making comparison of outcomes difficult. CONCLUSION: Because of the low quality of evidence of the studies included in this systematic review and the variability of the outcomes, there is not sufficient evidence to recommend one treatment option rather than another. CLINICAL SIGNIFICANCE: There is a requirement for higher quality evidence such as randomized controlled trials and prospective comparative cohort studies. Standardization of outcome measures reported for each treatment option and disease process studied will allow for better comparison of outcomes between studies.

Efficacy of two reduction methods in conjunction with 3-D-printed patient-specific pin guides for aligning simulated comminuted tibial fractures in cadaveric dogs.

OBJECTIVE: To assess the feasibility and accuracy of using 2 methods for reduction and alignment of simulated comminuted diaphyseal tibial fractures in conjunction with 3-D-printed patient-specific pin guides. SAMPLE: Paired pelvic limbs from 8 skeletally mature dogs weighing 20 to 35 kg. METHODS: CT images of both tibiae were obtained, and 3-D reconstructions of the tibiae were used to create proximal and distal patient-specific pin guides. These guides were printed and used to facilitate fracture reduction and alignment in conjunction with either a 3-D-printed reduction guide or a linear type 1A external fixator. Postreduction CT images were used to assess the accuracy of pin guide placement and the accuracy of fracture reduction and alignment. RESULTS: The 3-D-printed guides were applied with acceptable ease. Guides for both groups were placed with minor but detectable deviations from the planned location (P = .01), but deviations were not significantly different between groups. Fracture reduction resulted in similar minor but detectable morphological differences from the intact tibiae (P = .01). In both groups, fracture reduction and alignment were within clinically acceptable parameters for fracture stabilization by means of minimally invasive plate osteosynthesis. CLINICAL RELEVANCE: Virtual surgical planning and fabrication of patient-specific 3-D-printed pin guides have the potential to facilitate fracture reduction and alignment during use of minimally invasive plate osteosynthesis for fracture stabilization.

Effect of Induced Incomplete Ossification of the Humeral Condyle on Ex Vivo Humeral Condylar Biomechanics.

OBJECTIVE: The aim of this study was to investigate the effects of an induced incomplete ossification of the humeral condyle (IOHC) lesion on ex vivo canine humeral condylar biomechanics. STUDY DESIGN: Nine paired cadaveric elbows were collected from mature dogs weighing between 20 and 25 kg. Left and right limbs were randomized to IOHC or normal groups. Limbs were prepared for mechanical testing; ligaments were preserved and an IOHC lesion was created. Elbows were potted, positioned into a biomaterials testing system at an angle of 135 degrees and axially loaded to failure at a rate of 30 mm/minute. RESULTS: Induced IOHC lesions reduced peak load (p = 0.02) when compared with an intact humerus. There was no difference between stiffness (p = 0.36) of intact humeri or humeri with an induced IOHC lesion. An induced IOHC lesion increased (p = 0.012) the probability of intracondylar fracture under load. CONCLUSION: Cadaveric humeri are weakened by the creation of an intracondylar osteotomy and fractures secondary to induced IOHC are similar to spontaneous humeral condylar fractures. These findings support the hypothesis that naturally occurring IOHC weakens the humeral condyle and may predispose to humeral condylar fracture.