scholarly journals Effect of stem position and length on bone-stem constructs after cementless hip arthroplasty

2021 ◽  
Vol 10 (4) ◽  
pp. 250-258
Author(s):  
Dae-Kyung Kwak ◽  
Sun-Hee Bang ◽  
Sung-Jae Lee ◽  
Ji-Hun Park ◽  
Je-Hyun Yoo
Keyword(s):  
Cortical Bone ◽  
Hip Arthroplasty ◽  
Femoral Stem ◽  
Region Of Interest ◽  
Early Postoperative Period ◽  
Stair Climbing ◽  
Stem Length ◽  
Mean Stress ◽  
Press Fit ◽  
Cementless Hip Arthroplasty

Aims There are concerns regarding initial stability and early periprosthetic fractures in cementless hip arthroplasty using short stems. This study aimed to investigate stress on the cortical bone around the stem and micromotions between the stem and cortical bone according to femoral stem length and positioning. Methods In total, 12 femoral finite element models (FEMs) were constructed and tested in walking and stair-climbing. Femoral stems of three different lengths and two different positions were simulated, assuming press-fit fixation within each FEM. Stress on the cortical bone and micromotions between the stem and bone were measured in each condition. Results Stress concentration was observed on the medial and lateral interfaces between the cortical bone and stem. With neutral stem insertion, mean stress over a region of interest was greater at the medial than lateral interface regardless of stem length, which increased as the stem shortened. Mean stress increased in the varus-inserted stems compared to the stems inserted neutrally, especially at the lateral interface in contact with the stem tip. The maximum stress was observed at the lateral interface in a varus-inserted short stem. All mean stresses were greater in stair-climbing condition than walking. Each micromotion was also greater in shorter stems and varus-inserted stems, and in stair-climbing condition. Conclusion The stem should be inserted neutrally and stair-climbing movement should be avoided in the early postoperative period, in order to preserve early stability and reduce the possibility of thigh pain, especially when using a shorter stem. Cite this article: Bone Joint Res 2021;10(4):250–258.

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.

scholarly journals Clinical and Radiographic Evaluation of a Commercially Pure Cancellous-Structured Titanium Press Fit Total Hip Prosthetic Stem: Ten-Year Followup of the “Natural Hip” Femoral Stem

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Thomas B. Pace ◽  
James C. Karegeannes ◽  
M. Jason Palmer ◽  
Stephanie L. Tanner ◽  
Rebecca G. Snider
Keyword(s):  
Hip Arthroplasty ◽  
Groin Pain ◽  
Stress Shielding ◽  
Femoral Stem ◽  
Thigh Pain ◽  
Radiographic Evaluation ◽  
Total Hip ◽  
Press Fit ◽  
Age Range ◽  
Hip Arthroplasties

This study evaluates the outcomes of 92 hip arthroplasties using a press fit, tapered, split tip, proximally porous ingrowth (CSTi) femoral stem (Zimmer Natural Hip) in consecutive hip arthroplasty patients followed for an average of ten years postoperatively (range 5–16 years). Patients were functionally and radiographically evaluated using Harris Hip Scores and plain radiographs assessing postarthroplasty groin or thigh pain and radiographic signs of stem subsidence, proximal femoral fixation, stress shielding, and related calcar resorption. At followup of 5–10 years, the incidence of groin pain and thigh pain was 9.1% and 3.6%, respectively. This incidence improved over time. Beyond 10 years of followup, groin pain was 2.7% and thigh pain zero. In 89% of cases, there was solid contact between the calcar and the undersurface of the stem collar. Five cases were revised for instability (5.4%). The Harris Hip Scores and the incidence of thigh or groin pain were very favorable compared to other reported press fit total hip arthroplasty stems and not significantly different across a broad age range. There were no cases of stem loosening of failure of bony ingrowth into the stem.

Surface characterization and fatigue performance of a chemical-etched Ti-6Al-4V femoral stem for cementless hip arthroplasty

2017 ◽  
Vol 309 ◽  
pp. 1126-1134 ◽  
Author(s):  
Bruno José Silva de Oliveira ◽  
Leonardo Contri Campanelli ◽  
Diego Pedreira Oliveira ◽  
Ana Paula de Bribean Guerra ◽  
Claudemiro Bolfarini
Keyword(s):  
Hip Arthroplasty ◽  
Surface Characterization ◽  
Femoral Stem ◽  
Fatigue Performance ◽  
Cementless Hip Arthroplasty

Biomechanical Evaluation of the Accuracy in Radiographic Assessment of Femoral Component Migration Measurement after Total Hip Arthroplasty

2020 ◽  
Vol 13 (1) ◽  
pp. 65-70
Author(s):  
Mikayla Forness ◽  
Zachary Podoll ◽  
Benjamin Noonan ◽  
Alexander Chong
Keyword(s):  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Femoral Stem ◽  
Stem Length ◽  
Head Diameter ◽  
Plain Radiographs ◽  
Total Hip ◽  
Image Magnification ◽  
Magnification Factors ◽  
Radiographic Measurements

Introduction: Implant subsidence is one criteria utilized to monitor for prosthesis loosening after total hip arthroplasty (THA) with initial implant subsidence assessment often done utilizing plain radiographs. The specific aim of this study was to identify the most reliable references when using plain radiographs to establish an image magnification with the goals being easy to use, inexpensive, reliable, and accurate. Methods: Two femoral stem implants (stem lengths: 127mm, 207mm) were utilized to simulate hemiarthroplasty of the hip with composite femurs. Different combinations of femoral stem distances from the radiographic film (ODD), source-detector differences (SDD), hip rotation, and hip flexion were elected. Standardized anterior-posterior pelvis for each parameter combination setup were taken. Radiographic measurements (head diameter, stem length, stem seating length) were undertaken five times by three examiners. Radiographic image magnification factors were generated from two references (head diameter and stem length). Radiograph measurement reproducibility and stem seating length errors using these magnification factors were evaluated. Results: High level of repeated measurements reliability was found for head diameter (99 ± 0%) and stem length (90 ± 7%) measurements, whereas seating length measurements were less reliable (76 ± 6%). Stem length error using the femoral head magnification factor yielded 11% accuracy. Stem seating length error using both magnification factors were not reliable (< 7% accuracy). All parameters, except SDD, showed significant effect on calibrated measurement error. Conclusions: Current methods of assessing implant subsidence after THA using plain radiographs are inaccurate or reliable. Clinicians should recognize these limitations and be cautious when diagnosing implant stability using plain radiographs alone.

Effect of femoral stem length on stress raisers associated with revision hip arthroplasty

1985 ◽  
Vol 3 (4) ◽  
pp. 447-455 ◽  
Author(s):  
Manohar M. Panjabi ◽  
Thomas Trumble ◽  
J. Erik Hult ◽  
Wayne O. Southwick
Keyword(s):  
Hip Arthroplasty ◽  
Femoral Stem ◽  
Revision Hip Arthroplasty ◽  
Stem Length ◽  
Stress Raisers

An Analytical Approach to Study the Intraoperative Fractures of Femoral Shaft During Total Hip Arthroplasty

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Leila Malekmotiei ◽  
Farzam Farahmand ◽  
Hossein M. Shodja ◽  
Aref Samadi-Dooki
Keyword(s):  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Bone Fracture ◽  
Analytical Approach ◽  
Femoral Stem ◽  
Femoral Shaft ◽  
Interference Fit ◽  
Total Hip ◽  
Press Fit ◽  
Equivalent Inclusion Method

An analytical approach which is popular in micromechanical studies has been extended to the solution for the interference fit problem of the femoral stem in cementless total hip arthroplasty (THA). The multiple inhomogeneity problem of THA in transverse plane, including an elliptical stem, a cortical wall, and a cancellous layer interface, was formulated using the equivalent inclusion method (EIM) to obtain the induced interference elastic fields. Results indicated a maximum interference fit of about 210 μm before bone fracture, predicted based on the Drucker–Prager criterion for a partially reamed section. The cancellous layer had a significant effect on reducing the hoop stresses in the cortical wall; the maximum press fit increased to as high as 480 μm for a 2 mm thick cancellous. The increase of the thickness and the mechanical quality, i.e., stiffness and strength, of the cortical wall also increased the maximum interference fit before fracture significantly. No considerable effect was found for the implant material on the maximum allowable interference fit. It was concluded that while larger interference fits could be adapted for younger patients, care must be taken when dealing with the elderly and those suffering from osteoporosis. A conservative reaming procedure is beneficial for such patients; however, in order to ensure sufficient primary stability without risking bone fracture, a preoperative analysis might be necessary.

Periprosthetic Femoral Bone Loss in Total Hip Arthroplasty: Systematic Analysis of the Effect of Stem Design

2016 ◽  
Vol 27 (1) ◽  
pp. 26-34 ◽  
Author(s):  
Ashleen R. Knutsen ◽  
Nicole Lau ◽  
Donald B. Longjohn ◽  
Edward Ebramzadeh ◽  
Sophia N. Sangiorgio
Keyword(s):  
Total Hip Arthroplasty ◽  
Bone Loss ◽  
Hip Arthroplasty ◽  
Femoral Stem ◽  
Fixation Method ◽  
Mineral Density ◽  
Periprosthetic Bone ◽  
Stem Design ◽  
Total Hip ◽  
Press Fit

Introduction Periprosthetic bone loss may lead to major complications in total hip arthroplasty (THA), including loosening, migration, and even fracture. This study analysed the influence of femoral implant designs on periprosthetic bone mineral density (BMD) after THA. Methods The results of all previous published studies reporting periprosthetic femoral BMD following THA were compiled. Using these results, we compared percent changes in bone loss as a function of: femoral stem fixation, material, and geometry. Results The greatest bone loss was in the calcar region (Gruen Zone 7). Overall, cemented stems had more bone loss distally than noncemented stems, while noncemented stems had more proximal bone loss than cemented stems. Within noncemented stems, cobalt-chromium (CoCr) stems had nearly double the proximal bone loss compared to titanium (Ti) alloy stems. Finally, within noncemented titanium alloy group, straight stems had less bone loss than anatomical, tapered, and press-fit designs. Discussion The findings from the present study quantified percent changes in periprosthetic BMD as a function of fixation method, alloy, and stem design. While no one stem type was identified as ideal, we now have a clearer understanding of the influence of stem design on load transfer to the surrounding bone.

Short-term outcomes with the REDAPT monolithic, tapered, fluted, grit-blasted, forged titanium revision femoral stem

2020 ◽  
Vol 102-B (2) ◽  
pp. 191-197 ◽  
Author(s):  
Jonathan A. Gabor ◽  
Jorge A. Padilla ◽  
James E. Feng ◽  
Erik Schnaser ◽  
William B. Lutes ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Intraoperative Complications ◽  
Femoral Stem ◽  
Stem Length ◽  
Total Hip ◽  
Early Results ◽  
One Year

Aims Although good clinical outcomes have been reported for monolithic tapered, fluted, titanium stems (TFTS), early results showed high rates of subsidence. Advances in stem design may mitigate these concerns. This study reports on the use of a current monolithic TFTS for a variety of indications. Methods A multi-institutional retrospective study of all consecutive total hip arthroplasty (THA) and revision total hip arthroplasty (rTHA) patients who received the monolithic TFTS was conducted. Surgery was performed by eight fellowship-trained arthroplasty surgeons at four institutions. A total of 157 hips in 153 patients at a mean follow-up of 11.6 months (SD7.8) were included. Mean patient age at the time of surgery was 67.4 years (SD 13.3) and mean body mass index (BMI) was 28.9 kg/m2 (SD 6.5). Outcomes included intraoperative complications, one-year all-cause re-revisions, and subsidence at postoperative time intervals (two weeks, six weeks, six months, nine months, and one year). Results There were eight intraoperative complications (4.9%), six of which were intraoperative fractures; none occurred during stem insertion. Six hips (3.7%) underwent re-revision within one year; only one procedure involved removal of the prosthesis due to infection. Mean total subsidence at latest follow-up was 1.64 mm (SD 2.47). Overall, 17 of 144 stems (11.8%) on which measurements could be performed had >5 mm of subsidence, and 3/144 (2.1%) had >10 mm of subsidence within one year. A univariate regression analysis found that additional subsidence after three months was minimal. A multivariate regression analysis found that subsidence was not significantly associated with periprosthetic fracture as an indication for surgery, the presence of an extended trochanteric osteotomy (ETO), Paprosky classification of femoral bone loss, stem length, or type of procedure performed (i.e. full revision vs conversion/primary). Conclusion Advances in implant design, improved trials, a range of stem lengths and diameters, and high offset options mitigate concerns of early subsidence and dislocation with monolithic TFTS, making them a valuable option for femoral revision. Cite this article: Bone Joint J 2020;102-B(2):191–197.

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