Restoration of Some Anatomical Dimensions By Spiron Short Stem Hip Replacement Applied To Vietnamese People

Background: The process of using proximal bone in hip arthroplasty will allow the remaining bone to be preserved in future surgeries. To take advantage of these advantages, many types of short stem prosthetics have been developed in recent years. The obtained survey parameters combined with the obtained anatomical parameters shown that the Spiron joint is suitable when applied to adult Vietnamese.Research subjects and methods: The anatomical dimensions of the hip joint related to Spiron joint replacement were analyzed by the authors.Results: The anatomical results with Spiron showed that the acetabular average diameter and tilt angle were 49.77 mm and 41.55°. The femoral neck-to-body angle, the femoral upper-neck diameter, the distance from the crest to the hard shell along the femoral neck axis was on average 131.52°, 34, 32mm, and 51.39mm, respectively. The offset distance from the center of the crest to the axis of the femur is 38.33mm. These parameters show the working ability as well as stability when replaced by the Spiron joint.Conclusion: When applied to adult Vietnamese, the femoral neck diameter is consistent with the Spiron diameter. Preoperative planning is needed to check the femoral neck angle and femoral neck length prior to surgery to see if the Spiron joint replacement is eligible. The findings of this study support the assumption that it is feasible to use Spiron prostheses in joint replacement in Vietnamese adults.

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.

Outcome of intramedullary nailing treatment for intertrochanteric femoral fractures

Introduction The OTA/AO type 31 A3 intertrochanteric fracture has a transverse or reverse oblique fracture at the lesser trochanteric level, which accentuates the varus compressive stress in the region of the fracture and the implant. Intramedullary fixation using different types of nails is commonly preferred. The purpose of this study is to evaluate intertrochanteric femoral fractures with intramedullary nail treatment in regard to surgical procedure, complications, and clinical outcomes. Methods From one level 1 trauma center, 216 consecutive adult intertrochanteric femoral fractures (OTA/AO type 31 A3) were retrospectively identified with intramedullary nail fixation from 2004 through 2013. Of these, 193 patients (58.5% female) met the inclusion criteria. The average age was 70 years (range 19–96 years). Results Cephalomedullary nails were utilized in 176 and reconstruction nails in 17 patients. After the index procedure, 86% healed uneventfully. Nonunion development was observed in 6% and 5% had an unscheduled reoperation due to implant or fixation failure. Active smoking was reported in 16.6%. Current smokers had an increased nonunion risk compared to those who do not currently smoke (15.6% vs. 4.3%; p = 0.016). The femoral neck angle averaged 128.0° ± 5°. Fixation failure occurred in 11.1% of patients with a neck-shaft-angle < 125° compared to 2.6% (4/155) of patients with a neck-shaft angle ≥125° (p = 0.021). Patients treated with a reconstruction nail required a second surgical intervention in 23.5%, which was no different compared to 25.0% in the cephalomedullary group (p = 0.893). In the cephalomedullary group, 4.5% developed a nonunion compared to 23.5% in the reconstruction group (p = 0.002). Painful hardware led to hardware removal in 8.8%. All of them were treated with a cephalomedullary device (p = 0.180). During the last office visit, two-thirds of the patients reported no or only mild pain but most patients had reduced hip range of motion. Conclusion Intramedullary nailing is a reliable surgical technique when performed with adequate reduction. Varus reduction with a neck-shaft angle < 125° resulted in an increase in fixation failures. Patient and implant factors affected nonunion formation. Smoking increased nonunion formation. Utilization of a cephalomedullary device reduced the nonunion rate, but had higher rates of painful prominent hardware compared to reconstruction nailing.

Measurement of the femoral neck angle in medium and large dog breeds using computed tomography

The aim of this study was to get precise normal values of the femoral neck angle (FNA) in support of developing an optimally functioning total hip prosthesis for medium and large dog breeds. Accordingly, two- and three-dimensional computed tomographic images of the anatomical structures of the proximal femora of 58, hip-dysplasia-free, mature dogs of medium and large breeds were studied. Based on the length of their femora the dogs were allocated to Group I (from 145 to 195 mm) and Group II (from 196 to 240 mm). The FNA was measured on each femur using multi-slice spiral computed tomography (CT). The two- and three-dimensional image data were processed as multi-planar and threedimensional reconstructions using Advantage Workstation software. The CT measurements revealed that Group I had an average femoral neck angle of 147.59° (min. 144.05°, max. 153.35°), while in Group II the average FNA was 147.46° (min. 141°, max. 154.35°). There was no significant correlation between the length of the femur and the FNA in either group. The optimal FNA for a total hip prosthesis is 147.5° for medium and large dog breeds.

Numerical Analysis of Femoral Neck Angle Influence on Stress Distribution of Cemented Austin Moore Hip Prosthesis

This paper presents a finite element analysis regarding the stress distribution in a cemented Austin Moore type hip prosthesis. The 3-D model was obtained using a Roland PICZA 3-D laser scanner. The applied loads simulate the normal gait cycle. The prosthesis is made from stainless steel with a femoral head of 45mm diameter. The numerical analysis was performed using the ABAQUS code. The results showed that the stress level in the cement is sensitive to the femoral neck angle. Starting with a standard, 125° angle, and increasing the angle with up to 5°, the resulting stress can be reduced with more than 10%. The proposed angle increase produces a more uniform stress distribution in the cemented section, increasing the durability of the arthoplasty.

Comparison of femoral inclination angle measurements in dysplastic and nondysplastic dogs of different breeds

In this study, inclination angle of the femoral head and neck was measured on 484 limbs of 242 dogs belonging to 7 breeds, examined for hip dysplasia. These inclination angles were compared according to age, sex and joint laxity, evaluated with Subluxation Index (SI) and Norberg angle (NA) results. The findings indicate that (a) there was a minimal (nonsignificant) difference in femoral inclination angle between the dysplastic and nondysplastic dogs belonging to 7 breeds; (b) although there was no significant difference in femoral inclination angle between the nondysplastic dogs belonging to 4 breeds (Pointer, Irish Setter, Golden Retriever and German Shepherd), a significant difference was observed between Doberman and Labrador, and between Anatolian Karabash and the other six breeds (p < 0.001). Age and sex did not affect the femoral neck angle.