Proximal and distal alignment of normal canine femurs: A morphometric analysis

Statistical shape modeling of the geometric morphology of the canine femur, tibia, and patella

Bone morphometry varies among dogs of different sizes and breeds. Studying these differences may help understand the predisposition of certain breeds for specific orthopedic pathologies. This study aimed to develop a statistical shape model (SSM) of the femur, patella, and tibia of dogs without any clinical orthopeadic abnormalities to analyze and compare morphological variations based on body weight and breed. A total of 97 CT scans were collected from different facilities and divided based on breed and body weight. The 3D models of the bones were obtained and aligned to a coordinate system. The SSM was created using principal component analysis (PCA) to analyze shape variations. The study found that the first few modes of variation accounted for a significant percentage of the total variation, with size/scale being the most prominent factor. The results provide valuable insights into normal anatomical variations and can be used for future research in understanding pathological bone morphologies and developing 3D imaging algorithms in veterinary medicine.

Early Surgical Management of Medial Patellar Luxation in Juvenile Dogs

The aim of this study was to analyse a series of five cases of early surgical treatment in juvenile canine patients with high-grade medial patellar luxation. Canine patients, with immature skeleton, affected by grade III or IV medial patellar luxation and treated by multimodal surgical techniques were selected. Five dogs of different breeds, mean age 7.2 ± 3.0 months, met the inclusion criteria. Simultaneous distal femoral varus and external tibial torsion were identified in three of the five cases, whereas in the others, femoral varus with associated tibial valgus and isolated external tibial torsion were observed. Four of the five patients were treated surgically with closing wedge osteotomy of the distal femur, and three of them underwent tibial tuberosity transposition simultaneously. Only two animals required trochleoplasty. Mean time to beginning of weight bearing was 9.8 ± 5.5 days, whereas time to bone healing was 55 ± 24 days. Bone realignment of the extensor apparatus and return to limb support were achieved in all cases. Postoperative reintervention was needed in one patient; however, it was not linked to the initial surgery. Patients were followed up to 1 year postoperatively, with maintenance of extensor alignment and no late complications. The early surgical approach has been shown to be effective in the definitive treatment of juvenile dogs affected by high-grade medial patellar luxation.

Morphometric description of the koala humerus using microcomputed tomography

The current prognosis for successful return to function in koalas with appendicular fractures is poor despite being the most common fracture type to result in successful rehabilitation. The forelimb, particularly the humerus, plays a critical role in stabilisation and support while climbing trees. Successful rehabilitation therefore requires adequate internal stabilisation to promote bone healing and faster return to function. Current knowledge of koala limb bone morphometry is lacking and would provide useful clinical insight for future orthopaedic research, particularly with regards to recommendations regarding implant size and type. In this study microcomputed tomography (micro-CT) was used to describe bone length, internal and external diameters, and cortical thickness at five transverse levels along the humerus of skeletally mature koala cadavers. Qualitative descriptions were also made regarding bone features deemed clinically relevant to potential fracture repair techniques. Mean humeral length was 114.3 mm (95% CI 107.29-121.31 mm). Mediolateral diameters were greater than craniocaudal diameters at each measurement level, and the diaphysis has a distally tapering medullary cavity. Diaphyseal cortices were relatively homogenous with slight distal thickening, and medial cortices were thickest along the entire bone. The bone protuberances of the deltoid and supinator ridges projected most of the way down the lateral surface of the bone while the medial surface remained relatively uniform. Distal to the deltoid ridge the humerus curved caudally, terminating at a craniocaudally flattened distal epiphysis. Morphometric descriptions provided in this study will serve as a useful reference for future research, guiding orthopaedic surgery and improving prognosis of koala humeral fractures.

Evaluation of the Femoral and Tibial Alignments in Dogs: A Systematic Review

Simple Summary

The measurement of limb alignments is an important topic in veterinary orthopedics. These measurements enable veterinarians to assess normal limb functions, diagnose congenital or acquired disorders, and plan proper treatment protocols. Different measurement methods have been reported for fore- and hindlimb measurements in the literature, and reference ranges have been published for different breeds. These standard values can be compared with the measured values in small animal clinics, especially in the case of bilateral deformities, in which a sound extremity does not exist to provide a reference value. In this review, we aimed to compile the relevant values from the literature, sorting them according to the dog breed and the health status of the dog.

Abstract

The assessment of limb conformations in veterinary orthopedics is a significant tool used to determine the quantitative degree of limb malalignments. As in human medicine, various studies have been undertaken in veterinary medicine to determine the values in different dog breeds and to determine the values in healthy and diseased dogs. The objectives of this systematic review were to evaluate the reported values in these articles separately, to compile the standard values, and to compare the values between dogs with and without various orthopedic diseases. All of the articles included in this systematic review were collected by screening the Scopus, PubMed/Medline, and Web of Science databases. The articles were evaluated according to the measured alignments, imaging methods, dog breeds, and the health status of the dogs. Each alignment was investigated separately, and the results are summarized. Twenty-nine studies were included in this systematic review. According to the studies, in the frontal plane, distal femoral alignments, as well as proximal and distal tibial alignments, corresponded to the severity of the medial patellar luxation. The difference between affected and non-affected dogs with cranial cruciate ligament disease was limited to the proximal tibial alignments in the sagittal plane.

Measurement of the Femoral Anteversion Angle in Medium and Large Dog Breeds Using Computed Tomography

To promote the development of an optimally functional total hip prosthesis for medium and large dog breeds, accurate measurements of the normal anatomy of the proximal femur and acetabular retroversion are essential. The aim of the current study was to obtain precise normal values of the femoral anteversion angle using computed tomography on cadavers of mature dogs with normal hip joints of both medium and large breeds. Based on the length of their femora 58 dogs were allocated either to group I: ≤195 mm or group II: >195 mm. In the study the femoral anteversion angle (FAA) was measured on each femur using multi-slice spiral computed tomography (CT). The data were processed as multi-planar and three-dimensional reconstructions using Advantage Workstation software. The CT measurements showed that the mean ± standard deviation (SD) FAA of group I was 31.34 ± 5.47° and in group II it was 31.02 ± 4.95°. There were no significant mean difference associations between the length of the femur and the femoral neck angle in either group (P > 0.05). The data suggest that a prosthesis FAA of 31 degrees would be suitable for a wide range of dog sizes.

Radiographic determination of normal canine femoral alignment in the sagittal plane: A cadaveric pilot study

OBJECTIVE

To establish a reliable methodology for radiographic determination of alignment of the normal canine femur in the sagittal plane.

STUDY DESIGN

Cadaveric pilot study.

SAMPLE POPULATION

Twenty-nine cadaveric canine femurs.

METHODS

Femoral specimens were collected from the University of Missouri veterinary anatomy laboratory, and standardized sagittal plane radiographs were obtained. The anatomic and mechanical axes, joint orientation, lines and joint orientation angles were determined in the sagittal plane by using the center of rotation of angulation methodology. Landmarks were clearly described to allow repeatability and reliability of measurements. Three observers with various degrees of experience measured two centers of rotation of normal angulation, the anatomic caudoproximal femoral angle, and the mechanical caudodistal femoral angle for all femurs on three separate days. Interobserver and intraobserver reliability were measured by using two-way mixed intraclass correlation coefficients (ICC) with associated 95% CI.

RESULTS

Twenty-nine medium to large breed canine femora were measured. A high degree of correlation was present both among and between observers for all measurements performed, as defined by an ICC >0.8 for each.

CONCLUSION

The described methodology was reliable and repeatable for measurement of angulation of grossly normal canine femora in the sagittal plane when performed by observers with varying degrees of clinical experience, as evidenced by a high degree of correlation for all values measured.

CLINICAL SIGNIFICANCE

This methodology may be used for standardized evaluation of alignment of canine femora in the sagittal plane.

Corrective wedge ostectomy for an atypical femoral procurvatum deformity stabilised with a supracondylar bone plate

Physeal fractures of the distal femur are among the most commonly encountered fractures in skeletally immature dogs. These fractures respond poorly to conservative management and thus early surgical reduction and stabilisation are recommended. A 7-month-old intact male Border collie presented with a history of chronic lameness. Clinical examination revealed a predominantly non-weight-bearing lameness of the right hindlimb and concurrent muscle atrophy. A pronounced, but atypical, procurvatum deformity of the right distal femur was diagnosed on survey radiographs. Malunion of a Salter-Harris Type III physeal fracture was suspected as there was an associated history of trauma. A cranially based closing wedge ostectomy was performed to address the femoral deformity and subsequently stabilised using a supracondylar bone plate. The dog recovered well and was moderately weight-bearing lame on the right hindlimb 6 weeks post-operatively. Ten months following the operation the range of motion had improved in the right stifle and no signs of lameness were evident at a walk. We advocate surgical correction of sagittal plane deformities of the distal femur using the CORA method. Overall, a good functional outcome was achieved, which is consistent with previously reported cases with similar deformities.