scholarly journals Porous Lattice Structure of Femoral Stem for Total Hip Arthroplasty

2020 ◽  
Author(s):  
◽  
A. I. Botello- Arredondo
Keyword(s):  
Body Weight ◽  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Bone Growth ◽  
Lattice Structure ◽  
Young Patients ◽  
Femoral Stem ◽  
The Body ◽  
Total Hip ◽  
Lattice Design

Total Hip Arthroplasty (THA) is one of the surgical procedures carried out satisfactorily in procedures for osteoarthritis and trauma lesions. ATC surgery reduces pain and improves the quality of life of young patients. Therefore, it is of great importance to improve the properties of hip implants, since current implants do not match their lifespan with the life expectancy of a young patient. This is because the solid prostheses that currently exist have a higher Young's modulus, and therefore are too rigid compared to the bone tissue. On the other hand, the cyclic and continuous loads to which the hip joint is subjected in daily activities, can cause loosening and consequent implant loss The present work proposes an implant manufactured with a porous lattice structure, which aims to reduce stiffness, allow bone growth and a more effective mechanical load transfer. Three computational models subjected to static charges were evaluated and compared: 1) healthy femur, 2) implanted femur with a commercial prosthesis, and 3) implanted femur with a prosthesis with lattice structure. For the computational analysis it was decided to perform a static analysis of a person standing on the left foot; a load equivalent to the body weight was applied on the head of the femur, balancing the reaction forces in the system of forces (contact force, body weight, and abductor muscle).. The results were shown in terms of displacement, compression and deformation. The model implanted with a prosthesis with a lattice design presented a slight decrease in displacement, and a decrease in compression and deformation values, which indicated that the proposed design has a better distribution and transport of the loads through its structure.

Epidemiological Study of Femoral Head Osteonecrosis

2017 ◽  
Vol 68 (5) ◽  
pp. 974-976
Author(s):  
Alexandru Patrascu ◽  
Liliana Savin ◽  
Dan Mihailescu ◽  
Victor Grigorescu ◽  
carmen Grierosu ◽  
...  
Keyword(s):  
Risk Factors ◽  
Femoral Head ◽  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Young Patients ◽  
Head Group ◽  
Bipolar Hemiarthroplasty ◽  
Aseptic Necrosis ◽  
Total Hip ◽  
Femoral Head Osteonecrosis

In recent years, there has been an increase in the number of studies on the etiology of femoral head necrosis. We retrospectively reviewed all patients diagnosed with aseptic necrosis of the femoral in the period of 2010-2015. We recorded a total of 230 cases diagnosed with aseptic necrosis of the femoral head, group was composed of 65.7% men and 34.3% women, risk factors identified was 19.13% (post-traumatic), 13.91% (glucocorticoids), 26.52% (alcohol), 3.47% (another cause) and in 36 95% of the cases no risk factors were found. The results of the study based on the type of surgery performed on the basis of stages of disease progression, 8 patients (3.48%) benefited from osteotomy, 28 patients (12.17%) benefited of bipolar hemiarthroplasty prosthesis and 188 patients (81.74%) benefited of total hip arthroplasty. Osteonecrosis of the femoral head is characteristic to young patients between the age of 30-50 years old. Predisposing factors, alcohol and corticosteroid therapy remains an important cause of the disease. Total hip arthroplasty remains the best option for the patients with osteonecrosis of the femoral head.

scholarly journals Value of 3D Preoperative Planning for Primary Total Hip Arthroplasty Based on Biplanar Weightbearing Radiographs

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Y. Knafo ◽  
F. Houfani ◽  
B. Zaharia ◽  
F. Egrise ◽  
I. Clerc-Urmès ◽  
...  
Keyword(s):  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Preoperative Planning ◽  
Femoral Stem ◽  
Leg Length ◽  
Femoral Offset ◽  
Postoperative Result ◽  
Total Hip ◽  
Planning Software ◽  
Navigated Surgery

Two-dimensional (2D) planning on standard radiographs for total hip arthroplasty may not be sufficiently accurate to predict implant sizing or restore leg length and femoral offset, whereas 3D planning avoids magnification and projection errors. Furthermore, weightbearing measures are not available with computed tomography (CT) and leg length and offset are rarely checked postoperatively using any imaging modality. Navigation can usually achieve a surgical plan precisely, but the choice of that plan remains key, which is best guided by preoperative planning. The study objectives were therefore to (1) evaluate the accuracy of stem/cup size prediction using dedicated 3D planning software based on biplanar radiographic imaging under weightbearing and (2) compare the preplanned leg length and femoral offset with the postoperative result. This single-centre, single-surgeon prospective study consisted of a cohort of 33 patients operated on over 24 months. The routine clinical workflow consisted of preoperative biplanar weightbearing imaging, 3D surgical planning, navigated surgery to execute the plan, and postoperative biplanar imaging to verify the radiological outcomes in 3D weightbearing. 3D planning was performed with the dedicated hipEOS® planning software to determine stem and cup size and position, plus 3D anatomical and functional parameters, in particular variations in leg length and femoral offset. Component size planning accuracy was 94% (31/33) within one size for the femoral stem and 100% (33/33) within one size for the acetabular cup. There were no significant differences between planned versus implanted femoral stem size or planned versus measured changes in leg length or offset. Cup size did differ significantly, tending towards implanting one size larger when there was a difference. Biplanar radiographs plus hipEOS planning software showed good reliability for predicting implant size, leg length, and femoral offset and postoperatively provided a check on the navigated surgery. Compared to previous studies, the predictive results were better than 2D planning on conventional radiography and equal to 3D planning on CT images, with lower radiation dose, and in the weightbearing position.

Activity Levels and Functional Outcomes of Young Patients Undergoing Total Hip Arthroplasty

Orthopedics ◽  
2014 ◽  
Vol 37 (11) ◽  
pp. e983-e992 ◽  
Author(s):  
Tennison L. Malcolm ◽  
Caleb R. Szubski ◽  
Amy S. Nowacki ◽  
Alison K. Klika ◽  
Joseph P. Iannotti ◽  
...  
Keyword(s):  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Functional Outcomes ◽  
Young Patients ◽  
Activity Levels ◽  
Total Hip

scholarly journals The impact of reducing the femoral stem length in total hip arthroplasty during gait

2021 ◽  
Author(s):  
Anatole Vilhelm Wiik ◽  
Adeel Aqil ◽  
Bilal Al-Obaidi ◽  
Mads Brevadt ◽  
Justin Peter Cobb
Keyword(s):  
Total Hip Arthroplasty ◽  
Gait Analysis ◽  
Hip Arthroplasty ◽  
Femoral Stem ◽  
Short Stem ◽  
Stem Length ◽  
Practical Consideration ◽  
Total Hip ◽  
Long Stem ◽  
The Impact

Abstract Aim The length of the femoral stem in total hip arthroplasty (THA) is a practical consideration to prevent gait impairment. The aim of this study was to determine if reducing the femoral stem length in THA would lead to impaired gait biomechanics. Methods Patients uniformly with the same brand implant of differing lengths (100 mm vs 140–166 mm) were taken retrospectively from a prospective trial introducing a new short stem. Twelve patients without any other disorder to alter gait besides contralateral differing length stem THA were tested at differing gradients and speed on a validated instrumented treadmill measuring ground reaction forces. An anthropometrically similar group of healthy controls were analysed to compare. Results With the same posterior surgical approach, the offset and length of both hips were reconstructed within 5 mm of each other with an identical mean head size of 36 mm. The short stem was the last procedure for all the hips with gait analysis occurring at a mean of 31 and 79 months postoperatively for the short and long stem THA, respectively. Gait analysis between limbs of both stem lengths demonstrated no statistical difference during any walking condition. In the 90 gait assessments with three loading variables, the short stem was the favoured side 51% of the time compared 49% for the long stem. Conclusion By testing a range of practical walking activities, no lower limb loading differences can be observed by reducing the femoral stem length. A shorter stem demonstrates equivalence in preference during gait when compared to a reputable conventional stem in total hip arthroplasty.

Redesign of the Femoral Stem for a Total Hip Arthroplasty for Additive Manufacturing

2018 ◽  
Author(s):  
Bradley Hanks ◽  
Shantanab Dinda ◽  
Sanjay Joshi
Keyword(s):  
Additive Manufacturing ◽  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Lattice Structure ◽  
Stress Shielding ◽  
Patient Specific ◽  
Hip Implants ◽  
Hip Implant ◽  
Total Hip ◽  
Multiple Materials

Total hip arthroplasty (THA) is an increasingly common procedure that replaces all or part of the hip joint. The average age of patients is decreasing, which in turn increases the need for more durable implants. Revisions in hip implants are frequently caused by three primary issues: femoral loading, poor fixation, and stress shielding. First, as the age of hip implant patients decreases, the hip implants are seeing increased loading, beyond what they were traditionally designed for. Second, traditional implants may have roughened surfaces but are not fully porous which would allow bone to grow in and through the implant. Third, traditional implants are too stiff, causing more load to be carried by the implant and shielding the bone from stress. Ultimately this stress shielding leads to bone resorption and implant loosening. Additive manufacturing (AM) presents a unique opportunity for enhanced performance by allowing for personalized medicine and increased functionality through geometrically complex parts. Much research has been devoted to how AM can be used to improve surgical implants through lattice structures. To date, the authors have found no studies that have performed a complete 3D lattice structure optimization in patient specific anatomy. This paper discusses the general design of an AM hip implant that is personalized for patient specific anatomy and proposes a workflow for optimizing a lattice structure within the implant. Using this design workflow, several lattice structured AM hip implants of various unit cell types are optimized. A solid hip implant is compared against the optimized hip implants. It appears the AM hip implant with a tetra lattice outperforms the other implant by reducing stiffness and allowing for greater bone ingrowth. Ultimately it was found that AM software still has many limitations associated with attempting complex optimizations with multiple materials in patient specific anatomy. Though software limitations prevented a full 3D optimization in patient specific anatomy, the challenges associated such an approach and limitations of the current software are discussed.

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