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.

scholarly journals Preventing Loss of Femoral Periprosthetic Bone Mineral Density in Cementless Total Hip Arthroplasty Using a Tapered Wedge Stem in Patients With Osteoporosis Treated With Denosumab: a Retrospective, Cohort Study

2021 ◽  
Author(s):  
Keiji Kamo ◽  
Hiroaki Kijima ◽  
Koichiro Okuyama ◽  
Tetsuya Kawano ◽  
Nobutoshi Seki ◽  
...  
Keyword(s):  
Bone Mineral Density ◽  
Total Hip Arthroplasty ◽  
Bone Mineral ◽  
Hip Arthroplasty ◽  
Stress Shielding ◽  
Control Group ◽  
Mineral Density ◽  
Total Hip ◽  
Cementless Total Hip Arthroplasty ◽  
Periprosthetic Bone Mineral Density

Abstract Background: Bone mineral density (BMD) of the proximal femur around the stem decreases due to stress shielding after cementless total hip arthroplasty (THA). When severe stress shielding occurs, the risk of periprosthetic femoral fractures increases, and this bone loss can also increase the difficulty of future revision THA. Denosumab is known to improve the quality and strength of cortical bone in the proximal femurs of patients with osteoporosis. The purpose of this study was to investigate whether denosumab prevents loss of proximal femoral periprosthetic BMD in cementless THA using a tapered wedge stem in patients with osteoporosis.Methods: Sixty-three consecutive patients who had undergone unilateral primary THA using a tapered wedge stem were included in this retrospective study. Twenty-four patients who received denosumab for osteoporosis were the denosumab group, and the 39 without denosumab were the control group. At 2 weeks, 6 months, and 12 months after THA, bone turnover markers and femoral periprosthetic BMD were measured.Results: BMD in zone 1 was significantly increased from baseline at both 6 and 12 months after THA in the denosumab group and significantly decreased in the control group. BMD in zone 7 was significantly decreased compared to baseline at both 6 and 12 months after THA in the control group, but not in the denosumab group. The use of denosumab for THA patients with osteoporosis was independently related to preventing loss of periprosthetic BMD of the femur at 12 months after surgery in zones 1 and 7 on multivariate analysis.Conclusions: Denosumab significantly increased proximal femoral periprosthetic BMD in zone 1 and prevented loss of BMD in zone 7 in patients with osteoporosis after cementless THA using a tapered wedge stem at both 6 and 12 months after surgery.

Risk Factors for Periprosthetic Femoral Fracture in Non-cemented Total Hip Arthroplasty Through the Direct Anterior Approach

2021 ◽  
pp. 155633162110508
Author(s):  
Zachary Berliner ◽  
Cameron Yau ◽  
Kenneth Jahng ◽  
Marcel A. Bas ◽  
H. John Cooper ◽  
...  
Keyword(s):  
Risk Factors ◽  
Total Hip Arthroplasty ◽  
Parkinson Disease ◽  
Hip Arthroplasty ◽  
Femoral Fracture ◽  
Categorical Variables ◽  
Patient Specific ◽  
Periprosthetic Femoral Fracture ◽  
Total Hip ◽  
Increased Risk

Background: Although total hip arthroplasty (THA) performed through the direct anterior (DA) approach is frequently marketed as superior to other approaches, there are concerns about increased risks of intraoperative and early postoperative femoral fracture. Purpose: We sought to assess patient-specific and radiographic risk factors for intraoperative and early postoperative (90-day) periprosthetic femoral fracture (PPFx) following DA approach THA. Methods: We retrospectively reviewed 1107 consecutive, primary, non-cemented DA THAs, performed between April 2009 and January 2015, for intraoperative and early postoperative PPFx. Patients lost to follow-up before 90 days (63), cemented or hybrid THA (52), or early femoral failure for another indication (3) were excluded, yielding 989 hips for analysis. Demographic variables and patient comorbidities were analyzed as risk factors for PPFx. Continuous variables were initially compared with 1-way analysis of variance (ANOVA) and categorical variables with chi-square test. A demographic matched-paired radiographic analysis was performed for femoral stem canal fill and compared using univariate logistic regression. Results: The incidence of perioperative PPFx was 2.02%, including 10 intraoperative and 10 early postoperative fractures. Sustaining a postoperative PPFx was associated with being 70 years old or older with a body mass index (BMI) of less than 25, or with having either osteoporosis or Parkinson disease. Radiographs demonstrated that intraoperative PPFx was associated with stems that filled greater proximally rather than distally. Conclusion: Our cohort study found older age, age over 70 with BMI of less than 25, osteoporosis, and Parkinson disease were associated with increased risk for early postoperative PPFx following DA approach THA. Intraoperative fractures may occur with disproportionate proximal femoral canal fill. Further study can evaluate whether cemented femoral components may mitigate risk in these patient populations.

scholarly journals A Multidisciplinary Patient-Specific Opioid Prescribing and Tapering Protocol Is Associated with a Decrease in Total Opioid Dose Prescribed for Six Weeks After Total Hip Arthroplasty

Pain Medicine ◽  
2019 ◽  
Vol 21 (7) ◽  
pp. 1474-1481 ◽  
Author(s):  
Mallika Tamboli ◽  
Edward R Mariano ◽  
Kerianne E Gustafson ◽  
Beverly L Briones ◽  
Oluwatobi O Hunter ◽  
...  
Keyword(s):  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Opioid Consumption ◽  
Mean Difference ◽  
Patient Specific ◽  
Prescription Data ◽  
Opioid Dose ◽  
Total Hip ◽  
Institutional Review ◽  
Discharge Protocol

Abstract Objective This retrospective cohort study tested the hypothesis that implementing a multidisciplinary patient-specific discharge protocol for prescribing and tapering opioids after total hip arthroplasty (THA) will decrease the morphine milligram equivalent (MME) dose of opioids prescribed. Methods With institutional review board approval, we analyzed a Perioperative Surgical Home database and prescription data for all primary THA patients three months before (PRE) and three months after (POST) implementation of this new discharge opioid protocol based on patients’ prior 24-hour inpatient opioid consumption. The primary outcome was total opioid dosage in MME prescribed and opioid refills for six weeks after surgery. Secondary outcomes included the number of tablets and MME prescribed at discharge, in-hospital opioid consumption, length of stay, and postoperative complications. Results Forty-nine cases (25 PRE and 24 POST) were included. Total median (10th–90th percentiles) MME for six weeks postoperatively was 900 (57–2082) MME PRE vs 295 (69–741) MME POST (mean difference = 721, 95% confidence interval [CI] = 127–1316, P = 0.007, Mann-Whitney U test). Refill rates did not differ. The median (10th–90th percentiles) initial discharge prescription in MME was 675 (57–1035) PRE vs 180 (18–534) POST (mean difference = 387, 95% CI = 156–618, P = 0.003, Mann-Whitney U test) MME. There were no differences in other outcomes. Conclusions Implementation of a patient-specific prescribing and tapering protocol decreases the mean six-week dosage of opioid prescribed by 63% after THA without increasing the refill rate.

Non-steroidal anti-inflammatory drugs for heterotopic ossification prophylaxis after total hip arthroplasty

2018 ◽  
Vol 100-B (7) ◽  
pp. 915-922 ◽  
Author(s):  
M. Joice ◽  
G. I. Vasileiadis ◽  
D. F. Amanatullah
Keyword(s):  
Total Hip Arthroplasty ◽  
Heterotopic Ossification ◽  
Hip Arthroplasty ◽  
Patient Specific ◽  
Inclusion Criteria ◽  
Total Hip ◽  
Inflammatory Drugs ◽  
Specific Factors ◽  
Anti Inflammatory ◽  
Meta Analyses

Aims The aim of this study was to assess the efficacy of non-selective and selective non-steroidal anti-inflammatory drugs (NSAIDs) in preventing heterotopic ossification (HO) after total hip arthroplasty (THA). Methods A thorough and systematic literature search was conducted and 29 studies were found that met inclusion criteria. Data were extracted and statistical analysis was carried out generating forest plots. Results Non-selective NSAIDs showed a significant decrease in the odds for forming HO after THA (odds ratio (OR) -1.35, confidence interval (CI) -1.83 to -0.86) when compared with placebo. Selective NSAIDs also showed a significant decrease in the odds for forming HO after THA when compared with placebo (OR -1.58, CI -2.41 to -0.75). When comparing non-selective NSAIDs with selective NSAIDs, there was no significant change in the odds for forming HO after THA (OR 0.22, CI -0.36 to 0.79). Conclusion Our meta-analyses of all available data suggest that both non-selective and selective NSAIDs are effective HO prophylaxis and can be used routinely after THA for pain control as well as prevention of HO. Indomethacin may serve as the benchmark among non-selective NSAIDs and celecoxib among selective NSAIDs. There was no difference in the incidence of HO between non-selective and selective NSAIDs, allowing physicians to choose either based on the clinical scenario and patient-specific factors. Cite this article: Bone Joint J 2018;100-B:915–22.

scholarly journals Fully porous 3D printed titanium femoral stem to reduce stress-shielding following total hip arthroplasty

2016 ◽  
Vol 35 (8) ◽  
pp. 1774-1783 ◽  
Author(s):  
Sajad Arabnejad ◽  
Burnett Johnston ◽  
Michael Tanzer ◽  
Damiano Pasini
Keyword(s):  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Stress Shielding ◽  
Femoral Stem ◽  
Total Hip ◽  
3D Printed
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