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.

scholarly journals Patient-specific ROM and load-based Target Zone for Total Hip Arthroplasty and its Application in a retrospective Analysis

10.29007/fz6d ◽  
2019 ◽  
Author(s):  
Juliana Habor ◽  
Maximilian C. M. Fischer ◽  
Kunihiko Tokunaga ◽  
Masashi Okamoto ◽  
Klaus Radermacher
Keyword(s):  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Optimal Placement ◽  
Design Parameters ◽  
Patient Specific ◽  
Target Zones ◽  
Target Zone ◽  
Total Hip ◽  
Ongoing Work ◽  
Ct Data

The outcome of total hip arthroplasty (THA) depends on multiple alignment and design parameters. Unsuitable parameter settings could lead to impingement, dislocation, increased wear, and loosening. This work introduces a method for calculating a patient-specific target zone based on range of motion (ROM) related and load related criteria. Possible bone or prosthesis impingement are analyzed. The resulting hip force is calculated and compared to the pre-operative situation. The edge loading risk is analyzed. Pelvic tilt is considered for the calculation of the ROM and the load. THA parameters fulfilling all criteria are included in the target zone.The above described method has been applied to 30 cases retrospectively. All cases had been planned and navigated on the basis of CT data. From each patient, pre- and post-operative CT and EOS data and Harris Scores were acquired. The pre-operative data served as the input data for the target zone calculator. We hypothesized that cases with post-operative THA parameters inside the target zones have higher scores than other cases.The patients whose implants are within the target zones had higher scores than the remaining patients. Especially patients inside both target zones (combined target zone) had higher scores. The results also show that for 19 out of 30 patients, conventional CT-based planning and navigation does not provide optimal placement regarding the combined target zone. A further validation of the method with a larger sample size is part of our ongoing work.

scholarly journals Patient-Specific Safe Zone Based on Daily Positions and Range of Motion

10.29007/nw28 ◽  
2020 ◽  
Author(s):  
Wistan Marchadour ◽  
Guillaume Dardenne ◽  
Aziliz Guezou-Philippe ◽  
Christian Lefèvre ◽  
Eric Stindel
Keyword(s):  
Total Hip Arthroplasty ◽  
Range Of Motion ◽  
Hip Arthroplasty ◽  
Pelvic Tilt ◽  
Safe Zone ◽  
Patient Specific ◽  
Total Hip ◽  
Prosthetic Impingement ◽  
Param Eters

Cup orientation is a challenging step in total hip arthroplasty (THA), to ensure comfort of the patient and durability of the prosthesis. The safe zone defined by Lewinnek is commonly used for cup orientation, but it is nowadays being questioned because it is not patient-specific.We propose to define a new safe zone for cup orientation, that considers patient-specific parameters such as the pelvic tilt and the range of motion (ROM) of the leg.We developed a software that easily computes a unique safe zone from these param- eters in different daily positions, ensuring a cup orientation without risks of prosthetic impingement.

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

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.

Effects of the Femoral Offset and the Head Size on the Safe Range of Motion in Total Hip Arthroplasty

2009 ◽  
Vol 24 (4) ◽  
pp. 646-651 ◽  
Author(s):  
Akinobu Matsushita ◽  
Yasuharu Nakashima ◽  
Seiya Jingushi ◽  
Takuaki Yamamoto ◽  
Akio Kuraoka ◽  
...  
Keyword(s):  
Total Hip Arthroplasty ◽  
Range Of Motion ◽  
Hip Arthroplasty ◽  
Head Size ◽  
Femoral Offset ◽  
Total Hip

The effect of range of motion simulated with a patient-specific three-dimensional simulation analysis on dislocation after total hip arthroplasty

2021 ◽  
pp. 112070002110448
Author(s):  
Ryo Mitsutake ◽  
Hiromasa Tanino ◽  
Hiroshi Ito
Keyword(s):  
Total Hip Arthroplasty ◽  
Range Of Motion ◽  
Hip Arthroplasty ◽  
Preoperative Planning ◽  
Simulation Analysis ◽  
Fine Tuning ◽  
Posterior Dislocation ◽  
Flexion Angle ◽  
Total Hip ◽  
Dimensional Simulation

Background: Dislocation continues to be a common complication following total hip arthroplasty (THA). Although previous studies of computed simulation analysis investigated the range of motion (ROM), it is unclear whether the ROM before impingement simulated using computed tomography-based 3-dimensional simulation analysis (simulated ROM) is related to dislocation after THA. It is also unclear what angles are required in computed simulation analyses for stable hips after THA. In this study, we compared the simulated ROM in patients with and without dislocation. Methods: 16 patients with posterior dislocation were compared with 48 matched patients without dislocation. Risk factors including preoperative bone morphology of the hip, implant position, change of femoral offset, change of leg length, anterior aspect of the greater trochanter (GTa) length, and anterior inferior iliac spine length were also compared. Results: The mean flexion angle, internal-rotation at 90° flexion (IR) angle, cup anteversion based on the anterior pelvic plane (APP), tilt-adjusted cup anteversion and GTa length were significantly different between patients with dislocation and patients without dislocation ( p = 0.033, 0.002, 0.010, 0.047, 0.046). A receiver-operating characteristic curve analysis suggested cutoff points for flexion angle, IR angle, cup anteversion based on the APP, tilt-adjusted cup anteversion and GTa length, of 114.5°, 45.5°, 19.5°, 12.0° and 15.3 mm. Conclusions: This study suggests that preoperative planning to achieve a larger simulated ROM, flexion angle and IR angle, may reduce the risk of posterior dislocation. This study also suggests that fine-tuning of cup anteversion and/or trimming of the overhanging GTa during preoperative planning may reduce the risk of posterior dislocation.

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.

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