scholarly journals Fatigue Strength of Highly Crosslinked Polyethylene in Total Ankle Arthroplasty

2019 ◽  
Vol 4 (4) ◽  
pp. 2473011419S0037
Author(s):  
Oliver N. Schipper ◽  
Mehul A. Dharia ◽  
Justin S. Hertzler ◽  
Jeffrey E. Bischoff

Category: Ankle Introduction/Purpose: Highly crosslinked polyethylene (HXLPE) was developed for its superior wear properties in comparison to conventional polyethylene (CPE). The higher dose irradiation required for HXLPE may also cause embrittlement, which reduces fatigue resistance and leads to surface cracking or fracture of the polyethylene bearing. Concern over fatigue resistance has prevented widespread adoption of HXLPE for use in in total ankle arthroplasty (TAA). The aim of this study was to determine whether HXLPE has sufficient fatigue strength for total ankle arthroplasty under simulated physiologically relevant motion profiles and loading in the ankle. Methods: A bicondylar, semi-constrained HXLPE TAA design was subjected to 10 million cycles (Mc) of fatigue testing under loading conditions representative of a walking gait. Kinetics and kinematics of gait were incorporated into a computational model (Dassault Systemes / SIMULIA, Johnston, RI), for prediction of peak stresses on the HXLPE insert. Based on predicted peak stresses, worst case component size and loading configuration were identified. Ten samples were tested on a closed loop servohydraulic test frame (MTS Systems Corp., Minneapolis, MN) for 10Mc. Testing was conducted to a peak load of 5600 N (1259lbs), representing approximately 5 times body weight for a 240 lb individual. Following testing, all samples were evaluated for evidence of polyethylene fracture or surface cracking. Results: Peak stresses in the HXLPE insert occurred during heel off, closely corresponding to both peak axial force and dorsiflexion during gait. The smallest sized component had the highest polyethylene insert stresses, whereas larger sized components had more material to bear the same load, resulting in up to a 30% decrease in stress. All 10 specimens completed 10Mc of testing at 5 times body weight without fracture or surface cracking of the polyethylene insert. Conclusion: HXLPE has sufficient fatigue strength to withstand 10Mc of loading at 5 times body weight at the point of peak stresses during gait in total ankle arthroplasty, and therefore, may be mechanically strong enough to withstand the demands of the ankle. Further clinical evidence is necessary to determine if these results translate to adequate fatigue strength with clinical use of HXLPE.

2019 ◽  
Vol 40 (8) ◽  
pp. 880-887 ◽  
Author(s):  
Jeffrey E. Bischoff ◽  
Mehul A. Dharia ◽  
Justin S. Hertzler ◽  
Oliver N. Schipper

Background: Highly crosslinked polyethylene (HXLPE) was developed for its superior wear properties in comparison to conventional polyethylene (CPE). Concern over fatigue resistance has prevented widespread adoption of HXLPE for use in total ankle arthroplasty (TAA). The aim of this study was to determine whether HXLPE has sufficient fatigue strength for total ankle arthroplasty under simulated physiologically relevant motion profiles and loading in the ankle. Methods: Physiologic load and motion profiles representative of walking gait were incorporated into a computational model of a semiconstrained, fixed-bearing TAA to determine the loading state with highest stresses in the HXLPE bearing. Subsequent fatigue testing to 10 million cycles (Mc) at 5600 N was performed to assess bearing strength. Results: Peak stresses in the bearing were predicted at peak axial load and peak dorsiflexion during gait, occurring near heel off. All samples withstood 10 Mc of fatigue loading at that orientation without polyethylene bearing fracture. Conclusion: HXLPE had sufficient fatigue strength to withstand 10 Mc of loading at more than 5 times body weight at the point of peak stresses during simulated gait in total ankle arthroplasty. Clinical Relevance: HXLPE may be mechanically strong enough to withstand the in vivo demands of the ankle. Improvements in wear afforded by HXLPE can be obtained without compromising sufficient polyethylene strength properties in total ankle arthroplasty.


Author(s):  
Yanwei Zhang ◽  
Zhenxian Chen ◽  
Hongmou Zhao ◽  
Xiaojun Liang ◽  
Cheng Sun ◽  
...  

In vivo load and motion in the ankle joint play a key role in the understanding of the failure mechanism and function outcomes of total ankle arthroplasty. However, a thorough understanding of the biomechanics of the ankle joint in daily activities is lacking. The objective of this study was to develop a novel lower extremity musculoskeletal multibody dynamics model with total ankle arthroplasty considering the 6 degrees of freedom of the ankle joint motions and the deformable contact mechanics of the implant, based on force-dependent kinematics method. A patient who underwent total ankle arthroplasty surgery was considered. The walking gait data of the patient was measured in a gait laboratory and used as the input for the patient-specific musculoskeletal modeling. The predictions from the musculoskeletal model of total ankle arthroplasty included dorsiflexion–plantar flexion, inversion–eversion, internal–external rotation, anterior–posterior translation, inferior–superior translation, and medial–lateral translation of the tibiotalar joint, the ankle contact forces, the muscle activations, and the ligament forces. The magnitudes and tendencies of the predicted results were all within reasonable ranges, as compared with the data available in the literature. The predicted peak total ankle contact force was 6.55 body weight. In addition, the peak contact forces of the lateral and medial compartments were 4.22 body weight and 2.59 body weight, respectively. This study provides a potential new platform for the design of a better ankle prosthesis, the improvement of the operation techniques of the clinicians, and the accelerated postoperative recovery of the patients.


2019 ◽  
Vol 40 (1_suppl) ◽  
pp. 3S-4S
Author(s):  
Ilker Uçkay ◽  
Christopher B. Hirose ◽  
Mathieu Assal

Recommendation: Every intra-articular injection of the ankle is an invasive procedure associated with potential healthcare-associated infections, including periprosthetic joint infection (PJI) following total ankle arthroplasty (TAA). Based on the limited current literature, the ideal timing for elective TAA after corticosteroid injection for the symptomatic native ankle joint is unknown. The consensus workgroup recommends that at least 3 months pass after corticosteroid injection and prior to performing TAA. Level of Evidence: Limited. Delegate Vote: Agree: 92%, Disagree: 8%, Abstain: 0% (Super Majority, Strong Consensus)


2019 ◽  
Vol 101 (3) ◽  
pp. 199-208 ◽  
Author(s):  
Daniel J. Cunningham ◽  
James K. DeOrio ◽  
James A. Nunley ◽  
Mark E. Easley ◽  
Samuel B. Adams

2021 ◽  
pp. 107110072199578
Author(s):  
Frank E. DiLiberto ◽  
Steven L. Haddad ◽  
Steven A. Miller ◽  
Anand M. Vora

Background: Information regarding the effect of total ankle arthroplasty (TAA) on midfoot function is extremely limited. The purpose of this study was to characterize midfoot region motion and power during walking in people before and after TAA. Methods: This was a prospective cohort study of 19 patients with end-stage ankle arthritis who received a TAA and 19 healthy control group participants. A motion capture and force plate system was used to record sagittal and transverse plane first metatarsal and lateral forefoot with respect to hindfoot motion, as well as sagittal plane midfoot region positive and negative peak power during walking. Parametric or nonparametric tests to examine differences and equivalence across time were conducted. Comparisons to examine differences between postoperative TAA group and control group foot function were also performed. Results: Involved-limb midfoot function was not different between the preoperative and 6-month postoperative time point in the TAA group (all P ≥ .17). Equivalence testing revealed similarity in all midfoot function variables across time (all P < .05). Decreased first metatarsal and lateral forefoot motion, as well as positive peak power generation, were noted in the TAA group postoperative involved limb in comparison to the control group (all P ≤ .01). Conclusion: The similarity of midfoot function across time, along with differences in midfoot function in comparison to controls, suggests that TAA does not change midfoot deficits by 6 months postoperation. Level of Evidence: Level II, prospective cohort study.


2021 ◽  
pp. 107110072110175
Author(s):  
Jordan R. Pollock ◽  
Matt K. Doan ◽  
M. Lane Moore ◽  
Jeffrey D. Hassebrock ◽  
Justin L. Makovicka ◽  
...  

Background: While anemia has been associated with poor surgical outcomes in total knee arthroplasty and total hip arthroplasty, the effects of anemia on total ankle arthroplasty remain unknown. This study examines how preoperative anemia affects postoperative outcomes in total ankle arthroplasty. Methods: A retrospective analysis was performed using the American College of Surgeons National Surgery Quality Improvement Project database from 2011 to 2018 for total ankle arthroplasty procedures. Hematocrit (HCT) levels were used to determine preoperative anemia. Results: Of the 1028 patients included in this study, 114 patients were found to be anemic. Univariate analysis demonstrated anemia was significantly associated with an increased average hospital length of stay (2.2 vs 1.8 days, P < .008), increased rate of 30-day readmission (3.5% vs 1.1%, P = .036), increased 30-day reoperation (2.6% vs 0.4%, P = .007), extended length of stay (64% vs 49.9%, P = .004), wound complication (1.75% vs 0.11%, P = .002), and surgical site infection (2.6% vs 0.6%, P = .017). Multivariate logistic regression analysis found anemia to be significantly associated with extended hospital length of stay (odds ratio [OR], 1.62; 95% CI, 1.07-2.45; P = .023) and increased reoperation rates (OR, 5.47; 95% CI, 1.15-26.00; P = .033). Anemia was not found to be a predictor of increased readmission rates (OR, 3.13; 95% CI, 0.93-10.56; P = .066) or postoperative complications (OR, 1.27; 95% CI, 0.35-4.56; P = .71). Conclusion: This study found increasing severity of anemia to be associated with extended hospital length of stay and increased reoperation rates. Providers and patients should be aware of the increased risks of total ankle arthroplasty with preoperative anemia. Level of Evidence: Level III, retrospective comparative study.


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