Low dislocation rates with the use of patient specific “Safe zones” in total hip arthroplasty

2021 ◽  
Author(s):  
Abhinav K. Sharma ◽  
Zlatan Cizmic ◽  
Douglas A. Dennis ◽  
Stefan W. Kreuzer ◽  
Michael A. Miranda ◽  
...  
Keyword(s):  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Patient Specific ◽  
Total Hip ◽  
Safe Zones

scholarly journals The Patient-Specific Combined Target Zone for Morpho-Functional Planning of Total Hip Arthroplasty

2021 ◽  
Vol 11 (8) ◽  
pp. 817
Author(s):  
Juliana Habor ◽  
Maximilian Fischer ◽  
Kunihiko Tokunaga ◽  
Masashi Okamoto ◽  
Klaus Radermacher
Keyword(s):  
Total Hip Arthroplasty ◽  
Range Of Motion ◽  
Hip Arthroplasty ◽  
Implant Design ◽  
Patient Specific ◽  
Target Zones ◽  
Target Zone ◽  
Specific Patient ◽  
Total Hip ◽  
Safe Zones

Background Relevant criteria for total hip arthroplasty (THA) planning have been introduced in the literature which include the hip range of motion, bony coverage, anterior cup overhang, leg length discrepancy, edge loading risk, and wear. The optimal implant design and alignment depends on the patient’s anatomy and patient-specific functional parameters such as the pelvic tilt. The approaches proposed in literature often consider one or more criteria for THA planning. but to the best of our knowledge none of them follow an integrated approach including all criteria for the definition of a patient-specific combined target zone (PSCTZ). Questions/purposes (1) How can we calculate suitable THA implant and implantation parameters for a specific patient considering all relevant criteria? (2) Are the resulting target zones in the range of conventional safe zones? (3) Do patients who fulfil these combined criteria have a better outcome score? Methods A method is presented that calculates individual target zones based on the morphology, range of motion and load acting on the hip joint and merges them into the PSCTZ. In a retrospective analysis of 198 THA patients, it was calculated whether the patients were inside or outside the Lewinnek safe zone, Dorr combined anteversion range and PSCTZ. The postoperative Harris Hip Scores (HHS) between insiders and outsiders were compared. Results 11 patients were inside the PSCTZ. Patients inside and outside the PSCTZ showed no significant difference in the HHS. However, a significant higher HHS was observed for the insiders of two of the three sub-target zones incorporated in the PSCTZ. By combining the sub-target zones in the PSCTZ, all PSCTZ insiders except one had an HHS higher than 90. Conclusions The results might suggest that, for a prosthesis implanted in the PSCTZ a low outcome score of the patient is less likely than using the conventional safe zones by Lewinnek and Dorr. For future studies, a larger cohort of patients inside the PSCTZ is needed which can only be achieved if the cases are planned prospectively with the method introduced in this paper. Clinical Relevance The method presented in this paper could help the surgeon combining multiple different criteria during THA planning and find the suitable implant design and alignment for a specific patient.

scholarly journals Multi-Dimensional Range-of-Motion-Based Safe Zone for Patient-Specific Total Hip Arthroplasty

10.29007/vk8v ◽  
2018 ◽  
Author(s):  
Juliana Hsu ◽  
Matias de La Fuente ◽  
Klaus Radermacher
Keyword(s):  
Total Hip Arthroplasty ◽  
Range Of Motion ◽  
Hip Arthroplasty ◽  
Spherical Surface ◽  
Safe Zone ◽  
Patient Specific ◽  
Femoral Antetorsion ◽  
Total Hip ◽  
Mathematical Formulas ◽  
Safe Zones

Proper component alignment is crucial for a successful total hip arthroplasty (THA). Some studies found safe cup orientations and corresponding stem antetorsions based on a defined desired range of motion (ROM) suitable for activities of daily living. These studies either used complex and time consuming 3D simulations or more simple mathematical formulas which cannot be extended to combined motions.With the method introduced in this work, any arbitrary motion can be applied. The ROM specified as the ROM of the femur relative to the pelvis is transformed into the ROM of the prosthesis neck relative to the cup for each cup orientation. For this transformation, the orientation and design of the stem are considered. The comparison of the neck and cup orientations is done using a 2D mapping of a 3D spherical surface which reduces the complexity of the calculation.We found that the femoral antetorsion as well as the neutral stem flexion and adduction have an influence on the resulting safe zone. The result is not just a combined anteversion but a combined orientation. For validating the plausibility of the algorithm, the resulting safe zones are compared to literature. Same results can be achieved using the same input data. Using this technique, a patient-specific safe zone based on the ROM can be derived and adjusted to the stem orientation.

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.

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 The Direct Anterior Approach Total Hip Arthroplasty Reliably Achieves “Safe Zones” for Combined Anteversion

2020 ◽  
Vol 6 (4) ◽  
pp. 651-654
Author(s):  
J. Benjamin Jackson ◽  
J. Ryan Martin ◽  
Aric Christal ◽  
John L. Masonis ◽  
Bryan D. Springer ◽  
...  
Keyword(s):  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Anterior Approach ◽  
Direct Anterior Approach ◽  
Total Hip ◽  
Combined Anteversion ◽  
Safe Zones

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.

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