Stress Evaluation of a Short, Medium and Long Stem Proximal Fill Femoral Implants

Author(s):  
Sally Arno ◽  
Neal Kinariwala ◽  
Richelle Takemoto ◽  
Daniel Hennessy ◽  
Nguyen Q. Nguyen ◽  
...  

The femoral stem of a traditional total hip arthroplasty is believed to be essential for fixation and stability. Stems achieve early stability in a non-physiological fashion by a combination of friction and circumferential displacement of bone, similar to that of a nail being impacted into a piece of wood. In contrast, the “Revelation” femoral prosthesis, produced by DJO Surgical Corporation, relies upon a proximal lateral expansion (“Lateral Flare” design concept) to achieve stability.

Author(s):  
Anatole Vilhelm Wiik ◽  
Adeel Aqil ◽  
Bilal Al-Obaidi ◽  
Mads Brevadt ◽  
Justin Peter Cobb

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.


2014 ◽  
Vol 2014 ◽  
pp. 1-4
Author(s):  
Yasuaki Tamaki ◽  
Tomohiro Goto ◽  
Daisuke Hamada ◽  
Toshihiko Nishisho ◽  
Kiminori Yukata ◽  
...  

The surface finish of a femoral stem plays an important role in the longevity of cemented total hip arthroplasty. In efforts to decrease the rate of aseptic loosening, some prostheses have been designed to have a roughened surface that enhances bonding between the prosthesis and cement, but clinical outcomes remain controversial. We present a rare case of massive osteolysis with extreme femoral expansion that developed after cemented revision total hip arthroplasty. The destructive changes in the femur were attributable to abnormal motion of the stem and were aggravated by the roughened precoated surface of the long femoral component. Revision surgery using a total femur prosthesis was performed because there was insufficient remaining bone to fix the new prosthesis. The surgical technique involved wrapping polypropylene meshes around the prosthesis to create an insertion for the soft tissue, which proved useful for preventing muscular weakness and subsequent dislocation of the hip.


2017 ◽  
Vol 7 (2) ◽  
Author(s):  
Keith A Fehring ◽  
J. Ryan Martin ◽  
Peter K Sculco ◽  
Saaed Kalantari ◽  
Robert T Trousdale

Modular neck femoral components were introduced to optimize femoral neck anteversion, leg length, offset, and stability in total hip arthroplasty. However, concerns have been raised in recent years regarding early failure of these implants due to corrosion, pseudotumor, as well as fracture of the modular neck. Removing modular neck femoral implants is challenging as removal of the modular femoral neck leaves a proximally coated femoral stem level with the proximal bone of the femoral neck. We describe a posterior femoral single limb osteotomy  (posterior cut of an extended trochanteric osteotomy) for the removal of a modular neck femoral component.


2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Y. Knafo ◽  
F. Houfani ◽  
B. Zaharia ◽  
F. Egrise ◽  
I. Clerc-Urmès ◽  
...  

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.


2016 ◽  
Vol 24 (3) ◽  
pp. 323-327 ◽  
Author(s):  
Rajesh Malhotra ◽  
Vijay Kumar

Purpose To review the outcome of total hip arthroplasty (THA) using a short femoral stem in 33 hips. Methods Records of 33 hips in 20 men and 10 women aged 25 to 40 (mean, 30) years who underwent cementless THA using a short femoral stem by a single senior surgeon were reviewed. The diagnosis included avascular necrosis (n=9), ankylosing spondylitis (n=12), rheumatoid arthritis (n=7), post-traumatic arthritis (n=4), and Hurler syndrome (n=1). Clinical outcome was assessed using the Harris Hip Score. Radiological outcome was assessed according to a modified Gruen zoning system. Stem positioning (neutral, varus, valgus) and bone contact were evaluated, as were fixation and early host response as well as subsidence and changes in the calcar region (zone 5). Trabecular response (trabecular attachment), spot welds, cortical hypertrophy, and pedestal formation were determined. Heterotopic ossification was graded by the Brooker classification. Results The mean follow-up period was 6.5 years. The mean Harris Hip Score improved from 40 to 90. All hips achieved immediate postoperative stability. No patient had thigh pain. Four hips had varus placement (5°–7°) of the stem; all were asymptomatic and remained stable without any migration. Evidence of proximal load transfer (endosteal spot welds) between the endosteum and the stem in zones 2 and/or 4 was noted in 12 hips on both sides and in 8 hips on the lateral side only. At one year, all stems showed evidence of osseointegration. None had subsidence or progressive varus migration. There was no radiolucent line or osteolysis around the stem, pedestal formation or buttressing at the prosthesis tip, or cortical hypertrophy. One patient had grade I heterotopic ossification that was not clinically significant. One patient had a 1.5 cm leg lengthening. One patient had a discharging sinus, a loosened acetabular component, and intrapelvic migration at 2 years and underwent implant removal and debridement. One patient developed a crack in the proximal femur even with the smallest stem. The stem was fixed with cerclage wiring and remained stable with no migration. Conclusion A short femoral stem design that transfers load proximally through a prominent lateral flare achieved good short-term outcome in younger patients. Nonetheless, the ease of removal and preservation of bone at the time of revision should guide the choice of the design of the short stem.


2016 ◽  
Vol 26 (3) ◽  
pp. 209-214 ◽  
Author(s):  
Dimitrios T. Tsiampas ◽  
Emilios E. Pakos ◽  
Georgios C. Georgiadis ◽  
Theodoros A. Xenakis

2017 ◽  
Vol 16 (1) ◽  
Author(s):  
Lim Chia Hua ◽  
V.A. Jacob ◽  
N. Premchandran

The present concepts in Total Hip Arthroplasty advocate mechanical cement interlock with trabecular bone utilising the third-generation cementing technique. However, the force generated can easily reach peak pressure of 122 kPa to 1500 kPa, leading to extrusion of cement through nutrient foramina into femoral cortex into nutrient vessels, henceforth the retrograde arteriovenogram. A 76 years old lady who premorbid ADLindependent had a fall and sustained a closed right neck of femur fracture. She underwent cemented right total hip arthroplasty. Acetabulum cup of 47mm and femoral stem size 1 was utilized. Femoral canal was prepared and medullary cavity plug inserted before retrograde cement was introduced using the cementing gun. Intraoperative no complications were noted. This case has been followed up to a year with no adverse effect. The post-operative radiograph demonstrated a linear radio-opacity communicating with the posterior aspect of the femoral shaft which continues proximally and medially for approximately 10cm. Its uniformity in shape and position corresponds to the vascular supply of proximal femur. In Farouk et al cadaveric study, nutrient vessel arises in 166 ± 10 mm from the greater trochanter and is a branch of the second perforating artery from the deep femoral artery. Knight et al infer that retrograde cement extrusion occurs in female patients with small stature and small endosteal canal. Cement extrusion unlikely will influence the long haul survival of prosthesis as shown in the radiograph that cement is well pressurized to interlock with the endosteal bone. Moreover, because of extensive anastomoses of perforating branches of the deep femoral artery, segmental obliteration of nutrient artery alone is unlikely to lead to vascularity issues. Cement extrusion into the nutrient foramen is a vital differential in presence of posterior medial cement in the diaphysis of the femur following total hip replacement. This is to differentiate from extra osseous extrusions due to the iatrogenic breach of the femoral cortex suggesting periprosthetic fracture which affects the long term survival of prosthesis.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Jingyang Sun ◽  
Bohan Zhang ◽  
Lei Geng ◽  
Qingyuan Zheng ◽  
Juncheng Li ◽  
...  

Abstract Background Placement of femoral stem in excessive anteversion or retroversion can cause reduced range of motion, prosthetic impingement, and dislocation. The aim of this study was to assess the operative femoral anteversion in patients treated with total hip arthroplasty (THA) and analyze the need of adjusting stem anteversion. Methods We retrospectively included 101 patients (126 hips) who underwent cementless THA with a manual goniometer to determine the femoral anteversion between October 2017 and December 2018. The operative femoral anteversion we measured was recorded during THA. We further divided those hips into three subgroups based on the range of operative femoral anteversion: group 1 (<10°), group 2 (10–30°), and group 3 (>30°) and compared the differences of their demographic data. Univariate and multivariate logistic regression were used to identify the influencing factors for the need of neck-adjustable femoral stem. The clinical and radiographic outcomes were also assessed. Perioperative complications were recorded. Results After THA, the Harris hip scores improved from 52.87 ± 15.30 preoperatively to 90.04 ± 3.31 at the last follow-up (p < 0.001). No implant loosening, stem subsidence, and radiolucent lines were observed on radiographs. No severe complications occurred and no components needed revision at the latest follow-up. The mean operative femoral anteversion was 14.21° ± 11.80° (range, −9 to 60°). Patients with femoral anteversion more than 30° were about 10 years younger than others. Femoral anteversion >30° was more common in patients with developmental dysplasia of the hip (DDH). There were totally 14 hips treated with the neck-adjustable femoral stem. From the univariate analysis, we can observe that female sex, diagnosis of DDH (compared with osteonecrosis), and higher operative femoral anteversion and its value >30° (compared with <10°) are associated with higher rates of using the neck-adjustable femoral stem. However, all these factors were no longer considered as independent influencing factors when mixed with other factors. Conclusions This study highlighted the significance of operative femoral anteversion. Identification of abnormal femoral anteversion could assist in adjusting stem anteversion and reduce the risk of dislocation after THA.


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