Patient-Specific Guides for Total Hip Arthroplasty: A Paired Acetabular and Femoral Implantation Approach

2015 ◽  
Vol 9 (1) ◽  
Author(s):  
Jacob Stegman ◽  
Chris Casstevens ◽  
Todd Kelley ◽  
Vasile Nistor

While total hip arthroplasty (THA) is a common orthopedic procedure for treatment of hip arthritis, current techniques demonstrate poor implant alignment accuracy and precision, which is critical to the replacement's long-term survivorship. Patient-specific instruments to guide bone preparation and implantation could improve accuracy, thereby improving replacement survivorship. A single cadaver was CT (computer tomography) scanned to extract the 3D bone geometry, from which the operating surgeon planned a THA. Patient-specific guides were designed, 3D printed, and used in the cadaveric THA procedure. Postprocedural CT data were used to compare measured implant positioning versus the preprocedural template. Implanted component accuracy ranged from 1 deg–12 deg.

2017 ◽  
Vol 62 (3) ◽  
Author(s):  
Samuel Mueller ◽  
Intsar Ahmad ◽  
Manuel Kraemer ◽  
Michael Utz ◽  
Johannes Gaa ◽  
...  

AbstractPatient-specific instruments (PSIs) are clinically used to support the surgeon during a planned intervention. The planning is typically done based on volumetric image data from medical imaging systems, e.g. computed tomography (CT). The PSI uses the known surface structure of a bone for orientation during the intervention. Some surfaces of human bone are covered with a layer of cartilage which is hardly visible in clinically applied CT-imaging. This experimental study investigates ten different PSI designs and their effect to the overall accuracy when neglecting the cartilage in the design process. Therefore, a model of an acetabulum is used to simulate the use case of PSI in total hip arthroplasty. The concept of the different designs is to create structural elasticities in the PSI to avoid shifting of the whole instrument and rather have a small part of it deformed by cartilage. A needle array structure, for instance, should also be able to oust or penetrate remaining soft tissue in the acetabulum.


2020 ◽  
Vol 54 (2) ◽  
pp. 174-180 ◽  
Author(s):  
Abhishek Mishra ◽  
Tarun Verma ◽  
Rajkumar ◽  
Gaurang Agarwal ◽  
Amit Sharma ◽  
...  

10.29007/fz6d ◽  
2019 ◽  
Author(s):  
Juliana Habor ◽  
Maximilian C. M. Fischer ◽  
Kunihiko Tokunaga ◽  
Masashi Okamoto ◽  
Klaus Radermacher

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.


Author(s):  
Bradley Hanks ◽  
Shantanab Dinda ◽  
Sanjay Joshi

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.


2021 ◽  
Author(s):  
Kuo-Ti Peng ◽  
Tsung-Yu Huang ◽  
Jiun-Liang Chen ◽  
Chiang-Wen Lee ◽  
Hsin-Nung Shih

Abstract Background: Total hip arthroplasty (THA) is a widely used and successfully performed orthopedic procedure for treating severe hip osteoarthritis, rheumatoid arthritis, and avascular necrosis. However, periprosthetic joint infection (PJI) after THA is a devastating complication for patients and orthopedic surgeons. Although surgical technology has been advanced and antibiotic-loaded cemented spacers or beads have developed, the treatment failure rate of one- or two-stage exchange arthroplasty for PJI is reported to be high, with >10% rate of incidence. Therefore, determining the possible pathogenesis and increasing the treatment success rate is a clinically important and urgent issue. Methods: A total of 256 patients with PJI who had undergone THA from 2005 to 2015 were included in this retrospective review. Seven patients required combined ilioinguinal and anterlateoal approach for debridement of iliac fossa abscess and infected hip lesion, included five patients with intraoperative pus leakage from the acetabular inner wall and the other two patients who underwent pre-operative pelvic computed tomography (CT) because of repeat PJI treatment failure. All available data from the medical records from all patients were retrospectively analyzed.Results: Of the 256 patients, seven (3.1%) patients was combined iliac fossa abscess in our cohort. For the microbiologic analysis, a total of thirteen pathogens were isolated from seven recurrent PJI patients with iliac fossa abscess, and Staphylococus aureus was the most commomly pathogen (4 out of 7 cases). The serum white blood cell (WBC) count was decreased significantly two weeks after debridement with combined the ilioinguinal and anterolateral approach compared to the day before surgery (11840/μL vs. 7370/μL; p<0.01), and level of C-reactive protein (CRP) was decreased at postoperative one week (107 mg/dL vs. 47.31 mg/dL; p=0.03). Furthermore, no recurrent infection was found in six revision THA patient in a follow up of 7.1 year. Conclusion: This result suggests that pre-operative pelvic CT and cautious identification of uncertain pus leakage from the inner wall of the acetabulum is essential for the diagnosis of recurrent PJI. Radical debridement with combined ilioinguinal and anterlateoal approach may aviod treatment failure in recurrent PJI with iliac fossa abscess.


2021 ◽  
pp. 155633162110508
Author(s):  
Zachary Berliner ◽  
Cameron Yau ◽  
Kenneth Jahng ◽  
Marcel A. Bas ◽  
H. John Cooper ◽  
...  

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.


Sign in / Sign up

Export Citation Format

Share Document