Objective This study aimed to determine the femoral conformation of non-lame French Bulldogs using computed tomography and to evaluate the reliability of these measurements and the effect of observer experience. Study Design Computed tomographic images of normal French Bulldogs were retrospectively reviewed using open-access three-dimensional Digital Imaging and Communications in Medicine reconstruction software to measure femoral varus angle (FVA), anatomical lateral distal femoral angle (aLDFA), anatomical lateral proximal femoral angle, the mechanical caudal distal femoral angle (mCdDFA), the angle of inclination of the femoral neck (AFI) and the femoral torsion angle (FTA). Measurements were made on three occasions by three observers of varying experience using published methodology. Intraclass Correlation Coefficient (ICC) was used to assess the reliability. Results Thirty-five femurs were included. Mean FVA was 6.7 +/- 30, aLDFA was 96.7 +/- 3.0 degrees, anatomical lateral proximal femoral angle was 106.2 +/- 5.6 degrees, mechanical caudal distal femoral angle was 114.5 +/- 1.5 degrees, AFI was 133.2 +/- 4.1 degrees and FTA was 20.4 +/- 3.5 degrees. Intraobserver agreement was moderate to excellent for all measurements (ICC > 0.5). Interobserver agreement was poor for the AFI and FTA (ICC < 0.5), moderate for the FVA, aLDFA and mechanical caudal distal femoral angle (ICC 0.5-0.75), and good for anatomical lateral proximal femoral angle (ICC 0.75-0.9). Conclusion Our results provide a breed-specific reference range for the French Bulldogs' femurs using a previously published methodology. Measurements showed moderate-to-good intraobserver agreement using open-access software. The described method is appropriate for assessment of aLDFA/FVA; however, interobserver reliability varied, particularly for AFI and FTA, which were the least reproducible.
Abstract The aims of this study were to compare tibial anatomy between a cohort of dogs that had implants removed following repair of tibial tuberosity avulsion fracture and a historical cohort that had implants left in situ, and to objectively quantify patient function to determine if deformity resulted in impaired function. Dogs that had open reduction and fixation of tibial tuberosity avulsion fracture with subsequent implant removal (Cohort A) had radiographs of both hindlimbs and objective gait analysis. Tibial plateau angle, patellar position, axial and transverse tibial tuberosity position, and total pressure index were compared between operated and normal limbs. Measurements of tibial anatomy of the operated limbs were then compared with a historical cohort of dogs that did not have implants removed (Cohort B). Five dogs in Cohort A had implants removed 23 to 28 days after tibial tuberosity avulsion fracture repair with no refractures. Operated limbs had a lower tibial plateau angle, greater axial tibial tuberosity position and smaller transverse tibial tuberosity position when compared with normal limbs, but there was no significant difference in total pressure index between operated and normal limbs. There were no clearly meaningful differences in tibial anatomy between Cohort A and B. However, Cohort A had no dogs with a tibial plateau angle less than 0 degrees, while 2/6 dogs in Cohort B had a negative tibial plateau angle. Implant removal 23 to 28 days after tibial tuberosity avulsion fracture repair did not preserve normal tibial anatomy; however, objective function was maintained.
Objective The objective of this study is to compare the ex vivo biomechanical properties of four fixation techniques for stabilizing tibial tuberosity transposition (TTT) in dogs. Study Design Sixteen cadaveric tibiae from eight large-breed dogs were assigned to one of four groups. Groups were defined by the method used to stabilize the transposed tibial tuberosity: two parallel pins (PP), headless compression screw (HCS), two pins with a figure-of-eight wire (TPF8W), and rapid luxation plate system (RLPS). Following completion of the tibial crest osteotomy, the crest was transposed 4 mm laterally and stabilized according to the assigned treatment group. All constructs were loaded to failure via a force applied to the patellar ligament. Stiffness, load and displacement at yield, maximum load, and failure, and work to failure as well as the nature of the failure were recorded. Results There were no significant differences between the TPF8W and RLPS constructs in median stiffness (84.2 vs. 72.8 MPa), load to yield (778.3 vs. 644.6 N), or load to failure (786.0 vs. 691.2 N), respectively. Constructs stabilized with PP and HCS were significantly less stiff (with median of 61.7 and 47.6 MPa, respectively) and failed at lower loads (with median of 558.4 and 422.3 N, respectively). Failure modes differed among groups: pin bending occurred in all PP constructs (4/4), screw stripping in all HCS constructs (4/4), and patellar ligament rupture in all TPF8W constructs (4/4); RPLS constructs failed by either patellar ligament rupture (2/4) or tibial fracture (2/4). Conclusion TPF8W and the RLPS provided similar mechanical resistance to forces acting on the TTT and were superior to methods that did not engage the distal tibial crest.
Total hip replacement (THR) in cats remains uncommon due to species-specific anatomical features, including limited acetabular retroversion, mismatch between femoral canal and acetabular size, and technical difficulty during femoral preparation related to sclerosis secondary to slipped capital femoral epiphysis (SCFE), the main indication in this species. These factors complicate implant selection, canal preparation, and cup orientation. This retrospective study reports clinical and radiographic outcomes of 17 cementless Mini THR procedures performed in 11 cats (nine Maine Coons and two Domestic Shorthairs) between 2022 and 2025. Indications included SCFE ( n = 11), hip dysplasia ( n = 5), and femoral neck fracture malunion ( n = 1). Intraoperative fluoroscopy was used to optimize cup positioning. Two intraoperative complications occurred, consisting of minimal cortical fissures stabilized with prophylactic cerclage wires. Postoperative complications included two femoral fractures (11.8%), one resulting in limb amputation. One traumatic hip luxation occurred 10 months after surgery and was considered unrelated to the procedure. At 8 weeks, all remaining implants were pain-free, stable, and showed complete or advanced osteointegration. With careful planning, intraoperative imaging, and appropriate postoperative management, THR can provide excellent short-term outcomes in cats, although limited implant modularity may restrict optimal fit in some patients.
Objective The objectives of this study are to quantify the area of exposed caudal osseointegration surface after implantation of Biomedtrix Biological Fixation (BFX) stems and study the effect of stem size and implantation depth on this measurement as well as to quantify caudal femoral bone defect changes during femoral canal preparation and stem exposure. Study Design This is an in vitro , original research. Using 10 canine femoral model specimens, an undersized, an appropriately sized, and an oversized uncemented BFX stems were implanted in each bone, using three-dimensional-printed guides, to three levels of progressive distalization. Measurements of porous surface exposure and caudal bone defect were obtained from photographs, for all stem sizes and implantation depth. Results In correctly sized, aligned, and distalized stems, 34.8% of the caudal porous surface remains exposed. Stem distalization significantly decreases caudal surface exposure for all stem sizes and increases the extent of the caudal femoral bone defect for all stem sizes. Conclusion Complete, circumferential coverage of the proximal BFX stem is not possible. Stems should be properly distalized to reduce the exposed caudal integration surface while maintaining proper hip biomechanics. The caudal bone defect produced by femoral canal preparation progressively widens and migrates distally as stem size and depth increase. Familiarity with these features, not visible on a craniolateral approach, may be useful for surgeons performing canine uncemented hip replacement with the caudal approach.
