Radiological evaluation before and after treatment with an osseointegrated bone-anchor following major limb amputation-a guide for radiologists

Osseointegrated implants have been developed to allow direct skeletal fixation of a prosthesis as an alternative to traditional socket-fitted prostheses for patients who have suffered from a major limb amputation. The implants contribute to improvements in functional outcome and quality of life and radiological evaluation plays a crucial role in pre- and post-operative assessment. This article acts as a guide for radiologists who may be tasked with providing the radiological information required by surgeons and prosthetists. We also look at the radiological appearances of complications that may arise in patients treated with an osseointegrated implant. Plain X-rays are used to screen patients who wish to undergo treatment. Limb-length X-rays are then used to measure the length of any residual bone, and comparisons can be made with the normal side (if present). From this, decisions about the likely size of the implant and the need for further amputation can be made. CT scans enable accurate assessment of the medullary cavity and cortical thickness. Post-operatively, plain X-rays form the mainstay of the routine monitoring of the bone-implant interface. Potential complications include infection, aseptic loosening, mechanical fracture of the implant and periprosthetic fracture. Infection and aseptic loosening can be seen as a lucency at the bone-implant interface which (if left untreated) can lead to loss of the implant. Implant and periprosthetic fractures are radiographically obvious. Radiologists involved in the care of patients undergoing treatment with an osseointegrated implant should become familiar with the imaging requirements so they can contribute to optimal patient outcomes.

Deformation in transcatheter heart valves: Clinical implications and considerations

Transcatheter aortic valve replacement (TAVR) has emerged as a preferred treatment modality for aortic stenosis, marking a significant advancement in cardiac interventions. Transcatheter heart valves (THVs) have also received approval for treating failed bioprosthetic valves and rings across aortic, mitral, tricuspid, and pulmonic positions. Unlike surgically implanted valves, which are sewn into the annulus, THVs are anchored through relative oversizing. Although THVs are designed to function optimally in a fully expanded state, they exhibit a certain degree of tolerance to underexpansion. However, significant deformation beyond this tolerance can adversely affect the valve's hemodynamics and durability, ultimately impacting patient outcomes. Such post-implantation deviations from the valve's intended three-dimensional design are influenced by a variety of physiological and anatomical factors unique to each patient and procedure, leading to underexpansion, eccentric expansion, and vertical deformation. These deformation patterns increase leaflet stress and strain, potentially causing fatigue and damage. This review article delves into the extent of THV deformation, its impact on leaflet function, hypoattenuating leaflet thickening, and structural valve degeneration. It provides an in-depth analysis of deformation specifics in different procedural contexts, including TAVR in native aortic stenosis, aortic and mitral valve-in-valve procedures, and redo-TAVR. Additionally, the review discusses strategies to mitigate THV deformation during the procedure, offering insights into potential solutions to these challenges.

A multicenter, randomized controlled trial comparing a second-generation uncemented trabecular metal-backed vs. cemented polyethylene glenoid component in total shoulder arthroplasty: 5-year results

BACKGROUND

Previously, we reported early (2-year) findings from a randomized controlled trial comparing a second-generation uncemented trabecular metal-backed (TM) glenoid vs. cemented polyethylene glenoid (POLY) in patients undergoing a total shoulder arthroplasty. The purpose of the current study is to report disease-specific quality of life, clinical, patient-reported, and radiographic outcomes at midterm (5-year) from this trial.

METHODS

Five surgeons from 3 centers participated. Patients 18-79 years with a primary diagnosis of glenohumeral osteoarthritis were screened for eligibility. Randomization to an uncemented TM or cemented POLY glenoid was performed intra-operatively after adequate bone stock was confirmed. Study intervals were baseline, 2- and 5-year postoperative. The primary outcome was the Western Ontario Osteoarthritis Shoulder (WOOS) quality of life score. Secondary outcomes included the American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form, EuroQol-5 Dimensions, and 12-Item Short Form Health Survey scores and clinical and radiographic examinations. Radiographic images were reviewed for metal debris according to Endrizzi. Mixed effects repeated measures analysis of variance for within- and between-group comparisons were performed.

RESULTS

Of the 104 patients who consented, 93 were randomized (46 TM; 47 POLY). There were no differences between groups at baseline (TM: mean age 66.5 years [standard deviation (SD) 6.4], 24 male and 22 female; and POLY: mean age 68.4 years [SD 5.5], 23 male / 24 female). Mean (SD) WOOS scores at baseline and 2 and 5 years were as follows: TM, 32 (21), 92 (13), and 93 (11); POLY, 27 (15), 93 (11), and 93 (10), respectively. No statistical or clinically relevant differences were noted with patient-reported outcomes between groups. Metal debris was observed in 11 (23.9%) patients, but outcomes were not negatively impacted, and debris severity was minor (grades 1 and 2). Complication rates were similar between groups (TM: 7 of 46 [15.2%], and POLY: 8 of 47 [17.0%]; P = .813). No aseptic glenoid failures were reported, but 1 patient in the TM group required revision because of infection.

CONCLUSIONS

Our short-term (2-year) findings were maintained with longer follow-up. At 5 years postoperation, there were no statistically or clinically significant differences between an uncemented second-generation TM glenoid and a cemented polyethylene glenoid with respect to disease-specific quality of life or patient-reported outcomes. No glenoid implant failures were reported, and complication rates were similar between groups. Only one complication was glenoid related (1 infection in the TM group). Metal debris was observed in 23.9% of patients with a TM glenoid but did not negatively influence implant survival, patient-reported outcomes, or shoulder function.

Wear of Third-Generation Cross-Linked Polyethylene in Primary Total Hip Arthroplasty: A 10-Year Analysis

BACKGROUND

Sequential modifications to the manufacturing process of highly cross-linked polyethylene (HXLPE) have improved the wear resistance and implant survival of these liners in total hip arthroplasty (THA). However, no study has examined the long-term (mean 10 year) wear rates and clinical outcomes of third-generation HXLPE in THA. The aim of our study was to report the longest-to-date analysis of wear rates and clinical outcomes of a third-generation HXLPE liner.

METHODS

A series of 133 THAs using a specific HXLPE acetabular liner were retrospectively evaluated. Linear and volumetric wear rates were determined using a validated radiographic technique and clinical outcomes were analyzed. Multivariate analyses were performed to determine risk factors for accelerated wear.

RESULTS

At a mean follow-up of 10.4 years (range, 8 to 13.4), the mean linear wear rate was 0.0172 mm/year and the mean volumetric wear rate was 16.99 mm3/year. There were no instances of osteolysis or mechanical failures at any time point and there was a 100% acetabular component survival rate. Younger age and use of offset liners were independent risk factors for increased wear (P < .01 for both).

CONCLUSIONS

Our series of a third-generation HXLPE demonstrated very low wear rates and excellent implant survival at a mean of 10.4 years following primary THA. Future comparative studies at the 15- and 20-year follow-up timepoints are necessary to determine if such findings translate to true improvements in the tribological properties and longevity of these liners when compared to previous generations of HXLPE liners.

Outcomes of thoracic endovascular aortic repair with physician-manufactured partial micropore stent grafts for aortic arch pathologies

OBJECTIVE

Thoracic endovascular aortic repair (TEVAR) has been used extensively in the management of thoracic aortic diseases. Numerous efforts have been made to enhance clinical outcomes through the use of stent grafts. This study aimed to investigate the effectiveness and safety of physician-manufactured partial micropore stent grafts (PSMGs) in TEVAR.

METHODS

Between December 2017 and June 2022, data were collected from 56 patients who underwent TEVAR using physician-manufactured PSMGs. The evaluation encompassed technical success, perioperative and follow-up morbidity and mortality, stroke incidence, and branch artery patency.

RESULTS

In this investigation, 56 patients received treatment with physician-manufactured PSMGs. Of these patients, 46 were male, with a mean age of 62.1 ± 11.2 years. Aortic pathologies comprised aortic dissection (n = 31 [55.4%]), aortic aneurysms (n = 10 [17.9%]), penetrating aortic ulcer (n = 8 [14.3%]), and intramural hematoma (n = 7 [12.5%]). During a median follow-up of 18 months (interquartile range, 13-25 months), the stroke rate, supra-aortic branch patency rate, and endoleak rate were 0%, 100%, and 7.1%, respectively. There were no occurrences of all-cause mortality, stroke, or the necessity for open conversion.

CONCLUSIONS

TEVAR with physician-manufactured PSMGs is a viable alternative for addressing aortic arch pathologies in proficient medical centers. The approach demonstrates favorable branch patency, a low complication rate, and minimal postoperative mortality.

Knee kinematics are not different between asymmetrical and symmetrical tibial baseplates in total knee arthroplasty: A fluoroscopic analysis of step-up and lunge motions

PURPOSE

This clinical fluoroscopy study investigated knee kinematics of two different cemented fixed-bearing, posterior-stabilised (PS) total knee arthroplasty (TKA) designs: an asymmetric tibial component including an asymmetric insert designed to optimise personalised balance and fit and its precursor symmetrical design with symmetric insert.

METHODS

A consecutive series of patients (16 TKAs from each treatment group) participating in a randomised controlled trial comparing TKA migration was included. The exclusion criterion was the use of walking aids. Flat-panel fluoroscopic recordings of step-up and lunge motions were acquired 1-year postoperatively. Medial and lateral contact points (CPs) were determined to calculate CP displacement, femoral axial rotation and pivot position. Using linear mixed-effects modelling techniques, kinematics between TKA designs were compared.

RESULTS

During knee extension between 20° flexion and full extension, the CPs moved anteriorly combined with a small internal femoral rotation (a screw-home mechanism). Whereas CP movement was reversed: femoral rollback, external femoral rotation while flexing the knee between full extension and 20° knee flexion, At larger flexion angles, femoral axial rotation (FAR) occurred around a lateral pivot point both during step-up and lunge. The symmetric design had a 2.3° larger range of FAR compared to the asymmetric design during lunge (p = 0.02). All other kinematics were comparable.

CONCLUSION

Despite the differences in design, this study showed that the asymmetric and symmetric PS TKA designs had mostly comparable knee kinematics during step-up and lunge motions. It is therefore expected that the functionality of the successor TKA design is similar to that of its precursor design.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

All-Polyethylene Versus Metal-Backed Tibial Components in Total Knee Arthroplasty: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

In the literature, there is no evidence suggesting the superiority in clinical performance between all-polyethylene (AP) and metal-backed (MB) tibial implants in total knee arthroplasty. The aim of this study was to systematically review the literature to collect only high-quality studies investigating the differences in terms of clinical and radiostereometric analysis (RSA) outcomes of AP compared to MB implants.

METHODS

Only randomized controlled trials (RCTs) reporting either clinical or RSA outcomes have been included. Data sources were Embase, Medline, and the Cochrane Central Register of Controlled Trials.

RESULTS

We included eleven RCTs evaluating the outcomes of 1,377 patients. Of the RCTs, 9 of them showed a low risk and 2 showed moderate risk of bias. There was no statistically significant difference in terms of clinical outcomes and survival rate between the AP and MB group; however, a statistically significant lower mean lift-off in the AP group (0.19 mm) compared to the MB group (0.3 mm) was observed on RSA.

CONCLUSIONS

The performance of AP total knee arthroplasty in terms of clinical outcomes and 5-year survival was not statistically different when compared to the MB group. However, the RSA showed a statistically significant lower mean lift-off in the AP group.

Are Flexible Metaphyseal Femoral Cones Stable and Effective? A Biomechanical Study on Hinged Total Knee Arthroplasty

BACKGROUND

Cones currently available in the market are rigid, and unless they are custom-specific designed, are unable to correctly adapt to the shape of the patient's bone. Therefore, flexible metaphyseal cones have been recently introduced to reduce potential bone trauma during implantation. Even if a preliminary clinical study on their use has shown promising results, no biomechanical study evaluates and quantifies their mechanical efficacy and safety.

METHODS

Two commercial versions of flexible cones were analyzed in this study using finite element analysis, based on a previously validated model. Each cone geometry was modeled both as flexible and as rigid, and implanted following surgical guidelines. Three activities were simulated in this study and compared among configurations: surgical impaction, walking, and chair rise.

RESULTS

During impaction, results showed considerably reduced stress in the flexible cones in comparison with rigid ones; the stress resulted was also better distributed and more homogeneous all over the cortical bone, with lower bone peaks. Considering the 2 different activities, the analysis did not show any remarkable differences between flexible and rigid cones both in terms of bone stress and implant micromotion.

CONCLUSIONS

The findings demonstrate that metaphyseal flexible cones allow macrodeformation during impaction due to their flexibility, and therefore, are safer in comparison with rigid cones. However, for the daily tasks investigated, results showed no major differences between rigid and flexible cones in terms of bone stress, implant stability, and micromotion. Therefore, their mechanical performances can be considered similar to the rigid cone.

Incidence and Predictors of Subsidence Using Modular, Tapered, Fluted Titanium Femoral Stems in Aseptic Revision Total Hip Arthroplasty

BACKGROUND

Tapered, fluted titanium (TFT) femoral stems have become the gold standard in revision total hip arthroplasty (rTHA). However, there is a paucity of data on TFT stem subsidence rates following aseptic rTHA. Subsidence can lead to instability, mechanical failure, leg-length discrepancy, and may require revision surgery. This study evaluated the incidences and predictors of TFT subsidence in aseptic rTHA.

METHODS

A total of 102 TFT femoral stems of 4 designs were retrospectively reviewed. Stem subsidence was measured on digital radiographs taken immediately after surgery and at standard clinical follow-up. Patient characteristics, risk factors for subsidence, revision etiologies, and implant characteristics were recorded. Patient-reported outcome measures were also evaluated for a subset of cases.

RESULTS

Overall, 12% of stems subsided >1 cm, and subsidence was minimal (<3 mm) in ≥64% of cases. From immediate postoperative to 1-month radiographic follow-up, 79% of stems subsided a mean of 2.9 mm (range, 0.1 to 12 mm). Beyond 1 month, subsidence was minimal for ≥77% of cases. In multivariate analyses, women and less femoral implant canal fill were associated with greater subsidence (P ≤ .034). The TFT stem design was not associated with early subsidence (P = .816). There were no modular junction fractures. There were 2 fractures and 2 subsidence-related revisions for aseptic loosening that occurred postoperatively.

CONCLUSIONS

The amount of subsidence in TFT stems was low and was detectable in the early (less than 1 year) postoperative period. Maximizing TFT stem fill within the femoral canal appears to reduce the risk of subsidence without increasing femoral fracture rates and should be the goal with implantation of these devices.

LEVEL OF EVIDENCE

IV-Case Series, No Control Group.

Impact of Two Urethral Stent Types on Complications after One-Stage Hypospadias Repair Using the Duckett Procedure

BACKGROUND

The authors evaluated whether the new nickel-titanium alloy stent (NTAS) is superior to the traditional silicone stent used in hypospadias repair surgery in preventing complications such as urinary fistula.

METHODS

This retrospective cohort study included 576 patients with hypospadias who underwent NTAS or traditional silicone stent placement after hypospadias surgery between March of 2002 and August of 2019. The primary outcome was the rate of urinary fistula occurrence at 4 weeks (stent removal time), and the secondary outcomes were the rate of other complications, such as urethral stricture, urethral diverticulum, infection, and so on. The occurrence of complications in both groups was compared, and the important contributing factors of urinary fistula and urethral stricture were determined.

RESULTS

Among 576 patients, 398 were assigned to the NTAS group, and 178 were assigned to the silicone group. Thirty-five patients in the NTAS group and 30 in the silicone group developed urinary fistula, with a rate of 8.8% and 16.9%, respectively ( P = 0.005). Subgroup analysis showed that the differences were mainly in preschool patients (6 years or younger) ( P = 0.004) and those with the penile type of hypospadias ( P = 0.008). In addition, urethral stricture complicated five patients in the NTAS group and two in the silicone group, with a rate of 1.3% and 1.1%, respectively ( P = 1.000). Logistic regression showed that hypospadias type ( P = 0.001) and stent type ( P = 0.001) are the important risk factors for urethral fistula.

CONCLUSION

The NTAS reduced the occurrence of urinary fistula complications after hypospadias repair in preschool patients, and can be presented as a better choice for hypospadias surgery.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Ten-year follow-up of posterior chamber phakic intraocular lens with central port design in patients with low and normal vault

PURPOSE

To assess the clinical outcomes and postoperative complications of the implantable collamer lens (ICL) with a central port throughout 10 years of follow-up in patients with low and normal vault.

SETTING

Fernández-Vega Ophthalmological Institute, Oviedo, Spain.

DESIGN

Retrospective and comparative case series.

METHODS

This study included eyes that underwent a V4c ICL implantation with 10 years of follow-up. The eyes were divided into 2 groups according to the vault at 1 year postoperatively: vault <250 μm and between 250 μm and 800 μm. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), intraocular pressure (IOP), endothelial cell density (ECD), vault, complications, and secondary surgeries were analyzed.

RESULTS

37 and 90 eyes were enrolled in the low and normal-vault groups, respectively. No differences in UDVA, CDVA, and refraction were found between the groups over 10 years of follow-up. No cases developed ICL-induced anterior subcapsular opacity over the follow-up period. 2 (5.4%) and 8 (8.9%) eyes in the low and normal-vault groups, respectively, required ICL exchange. 1 (2.8%) and 2 (2.2%) eyes in the low and normal-vault groups, respectively, required excimer laser to correct residual refractive error. The IOP remained stable throughout the 10-year follow-up. The loss in ECD from that preoperatively to 10 years postoperatively was 3.8% and 4.5% in the low and normal-vault groups, respectively ( P = .4). No pigment dispersion glaucoma or other vision-threatening complications were reported.

CONCLUSIONS

This study shows good long-term outcomes of the V4c ICL, supporting that the central hole provides safety to the procedure and prevents the potential risk associated with low vault.

Automatic Stub Avoidance for a Powered Prosthetic Leg Over Stairs and Obstacles

Passive prosthetic legs require undesirable compensations from amputee users to avoid stubbing obstacles and stairsteps. Powered prostheses can reduce those compensations by restoring normative joint biomechanics, but the absence of user proprioception and volitional control combined with the absence of environmental awareness by the prosthesis increases the risk of collisions. This article presents a novel stub avoidance controller that automatically adjusts prosthetic knee/ankle kinematics based on suprasensory measurements of environmental distance from a small, lightweight, low-power, low-cost ultrasonic sensor mounted above the prosthetic ankle. In a case study with two transfemoral amputee participants, this control method reduced the stub rate during stair ascent by 89.95% and demonstrated an 87.50% avoidance rate for crossing different obstacles on level ground. No thigh kinematic compensation was required to achieve these results. These findings demonstrate a practical perception solution for powered prostheses to avoid collisions with stairs and obstacles while restoring normative biomechanics during daily activities.

Ten-year clinical and echocardiographic follow-up of third-generation biological prostheses in the aortic position

OBJECTIVES

PERIMOUNT Magna Ease (Carpentier-Edwards; PME) prostheses have been widely implanted during the past decade for aortic valve replacement (AVR). Although promising results at midterm follow-up were reported, long-term outcome has yet to be confirmed. On this study we aimed to evaluate long-term results in terms of structural valve degeneration (SVD), major clinical outcomes, long-term hemodynamic valve performance, and left ventricular remodeling.

METHODS

From 2010 to 2012, 689 consecutive patients underwent AVR with PME. Complete clinical 10-year follow-up was obtained. The degree of SVD was categorized on the basis of the latest guidelines. Echocardiographic data were analyzed at 1, 5, and 10 years. Competing risk analysis was performed for major events. Cumulative incidence of SVD, reoperation, and endocarditis were also assessed according to prosthetic sizes (19-21-23 mm vs 25-27-29 mm) and age (<65 vs 65-75 vs >75 years old).

RESULTS

The overall cumulative incidence reported for SVD ≥2 and reoperation were 3.6% and 1.9% at 10 years, respectively. An early left ventricular reverse remodeling was noted after implantation and confirmed at follow-up. Patients younger than 65 years showed higher cumulative incidence of SVD ≥2 at 10 years compared with patients aged 65 to 75 and older than 75 years (9.7% vs 2.6% vs 2.7%; P = .013), as well as of redo AVR (7.8% vs 3.3% vs 0.4%; P = .002). There was no difference in terms of SVD and redo AVR for different prosthetic size categories (P > .05). The risk of endocarditis was similar among age and size groups.

CONCLUSIONS

PME provides very good durability at long-term and could be considered one of the high performing third-generation bioprostheses for AVR.

Sutureless aortic valves in isolated and combined procedures: Thirteen years of experience in 784 patients

OBJECTIVE

The aim of this study was to evaluate the outcome and experience of the Perceval sutureless valve at our institution (UZ Leuven).

METHODS

Between 2007 and 2019, 784 patients underwent sutureless aortic valve replacement using the Perceval valve (isolated or combined with other procedures). We performed a retrospective analysis of the postoperative and follow-up data.

RESULTS

Mean age was 78 years with a median European System for Cardiac Operative Risk Evaluation II score of 4.2% (interquartile range, 2.6%-7.2%). Isolated aortic valve replacement accounted for 45% of cases; 30% of cases were aortic valve replacement in combination with coronary artery bypass grafting and the remaining 25% were other combined procedures. The median crossclamp times were 38 minutes in single aortic valve replacement, 70 minutes in cases with coronary artery bypass grafting, and 89 minutes in multiple valve cases. Device success was 99.1% and in-hospital mortality was 3.3%. Postoperative stroke or transient ischemic attack occurred in 1.9% of patients and 1% of patients had a new need for dialysis after surgery and median survival time was 7.0 years with a cumulative follow-up of 2797.8 patient-years. The 1-, 5-, and 10-year freedom from reintervention were 99%, 97%, and 94%, respectively.

CONCLUSIONS

These data represent the longest follow-up available, to our knowledge, for the Perceval sutureless valve. We observed favorable early outcomes, and low rates of early mortality, stroke, and other major complications. Valve durability is promising with low rates of valve degeneration and a limited need for reintervention.

A phenomenological model of pulsatile blood pressure-affected degradation of polylactic acid (PLA) vascular stent

The stent implantation may alter the post-operative patient's blood pressure, and bioresorbable vascular stents (BVS) as a candidate to treat vascular diseases, its degradation is affected by mechanical stress, thus, the altered pressure representing varying stress level will result in different degradation behaviors of the BVS. This paper first proposed a novel stress-regulated PLA degradation model that included swelling factor, and then the degradation evolutions of a PLA BVS within 180 days under normal and high blood pressures were simulated by finite element method, and more four degradation indexes were defined to study the effects of the two blood pressures on the degradation of the PLA BVS. The results showed that the high pressure weakly accelerated the degradation of the PLA BVS with respect to the normal pressure by examining the four indexes, e.g., the residual stent volumev r ( t ) decreased to 0.72 and 0.69, respectively for the normal and high pressures at day 180. The current finding provided a theoretical understanding of the PLA BVS degradation, and hinted that the PLA BVS may not need to be elaborately selected in clinical practices for treating hypertensive patients.

Implantable cardioverter-defibrillator lead failure and revision following transcutaneous bicaval valve (TricValve®) implantation

INTRODUCTION

Tricuspid regurgitation is associated with significant morbidity and mortality, and occurs at a higher rate in patients with cardiovascular implantable electronic devices. Percutaneous strategies for managing tricuspid regurgitation are evolving, including the development of bicaval valve implantation which has been successfully used in patients with pacing leads.

METHODS AND RESULTS

We present the first documented case of lead failure following TricValve® implantation, a dedicated self-expanding system for bicaval valve implantation, and the first successful lead revision procedure in this setting.

CONCLUSION

The case illustrates important considerations in undertaking percutaneous intervention in patients with cardiovascular implantable electronic devices, and their ongoing management.

Transfemoral transcatheter aortic valve replacement with VitaFlowTM valve for pure native aortic regurgitation in patients with high surgical risk: Rationale and design of a prospective, multicenter, and randomized SEASON-AR trial

BACKGROUND

Previous studies primarily demonstrated that transfemoral transcatheter aortic valve replacement (TAVR) with self-expanding valve appeared to be a safe and feasible treatment for patients with pure native aortic regurgitation (AR). However, the routine application of transfemoral TAVR for pure AR patients lacks support from randomized trials.

TRIAL DESIGN

SEASON-AR trial is a prospective, multicenter, randomized, controlled, parallel-group, open-label trial, involving at least 20 sites in China, aiming to enroll 210 patients with pure native severe AR and high surgical risk. All enrolled patients are randomly assigned in a 1:1 fashion to undergo transfemoral TAVR with VitaFlowTM valve and receive guideline-directed medical therapy (GDMT) or to receive GDMT alone. The primary endpoint is the rate of major adverse cardiac events (MACE) at 12 months after the procedure, defined by the composite of all-cause mortality, disabling stroke, and rehospitalization for heart failure. The major secondary endpoints encompass various measures, including procedure-related complications, device success, 6-minute walk distance, and the occurrence of each individual component of the primary endpoint. After hospital discharge, follow-up was conducted through clinical visits or telephone contact at 1, 6, and 12 months. The follow-up will continue annually until 5 years after the index procedure to assess the long-term outcomes.

CONCLUSION

SEASON-AR trial is the first study designed to investigate the clinical efficacy and safety of transfemoral TAVR with a self-expanding valve in patients with pure native severe AR with inoperable or high-risk, as compared to medical treatment only.

Medium-term clinical and radiographic outcomes of a cementless prosthesis with a 140° neck-shaft angle in reverse total shoulder arthroplasty

BACKGROUND

The design of humeral implants has evolved from the initial Grammont design, notably regarding the neck-shaft angle (NSA) and through the use of cementless prostheses. Stress shielding was frequently reported with cementless implants, the 2 main risk factors being humeral stem misalignment and high filling ratios. Our hypothesis was that standard length cementless stems with an NSA of 140° would facilitate good alignment with moderate filling ratios, thereby limiting stress shielding and ensuring good clinical outcomes.

METHODS

A single-center retrospective study was conducted of patients who underwent reverse total shoulder arthroplasty between January 2015 and August 2017, with at least 2 years' follow-up. Clinical evaluations included range of motion measurements and Constant and subjective shoulder values scores. Frontal alignment was assessed in terms of the angle (α) between axes of the stem and of the humerus. Filling ratios were measured in the metaphysis of the humerus, in the diaphysis, and at the distal end of the stem and considered excessive above 0.7. Stress shielding was evidenced radiographically by the observation of medial cortical narrowing, medial metaphysis thinning, lateral metaphysis thinning or under-the-baseplate osteolysis.

RESULTS

Eighty-two shoulders were included and 70 had radiographic follow-up data available. The mean patient age was 78 years and 63/81 patients (78%) were female. The mean follow-up time was 39 ± 7 months. The mean α angle was 1.4° ± 0.9° and was less than 5° in all cases. The mean metaphyseal, diaphyseal, and distal filling ratios were 0.61 ± 0.06, 0.70 ± 0.08, and 0.64 ± 0.09, respectively. The mean Constant score improved from 28 ± 11 preoperatively to 64 ± 14 at last follow-up. The mean subjective shoulder values score at last follow-up was 81 ± 12. Seventy-nine percent of patients (55/70) had at least 1 form of stress-shielding related, which were not associated with clinical outcomes, apart from lateral metaphysis thinning, which was associated with lower active anterior elevation (mean, 106° ± 30° vs. 126° ± 28°; P = .01) and lower Constant scores (mean, 56 ± 17 vs. 65 ± 14; P = .06).

CONCLUSION

The use of cementless reverse shoulder prostheses with a NSA of 140° was associated with good clinical outcomes at 2 years' follow-up. The prosthesis stem was correctly aligned with the humeral axis and the filling ratios were <0.7 in all cases. Stress-shielding was common but, apart from lateral metaphysis thinning, this had no impact on clinical outcomes.

Intraindividual Comparison of an Enhanced Monofocal and an Aspheric Monofocal Intraocular Lens of the Same Platform

PURPOSE

To compare intraindividual differences in visual performance of a monofocal and enhanced monofocal intraocular lens (IOL) of the same platform.

DESIGN

Prospective, interventional, fellow-eye comparison clinical study.

METHODS

In total, 55 patients (110 eyes) with bilateral age-related cataract were enrolled. All patients received a monofocal ZCB00 IOL in the dominant and an enhanced monofocal Eyhance ICB00 IOL in the nondominant eye. After 2 to 4 months, monocular best-corrected distant visual acuity (BCDVA), distance-corrected intermediate visual acuity (DCIVA), distance-corrected near visual acuity (DCNVA), contrast visual acuity, monocular defocus curves, internal higher-order aberrations (HOAs) and spherical aberrations (SA), decentration, and tilt were compared.

RESULTS

The monocular mean BCDVA, DCIVA at 80 cm and 66 cm, and DCNVA were -0.03 ± 0.07, 0.24 ± 0.12, 0.32 ± 0.13, and 0.50 ± 0.13 logarithm of the minimum angle of resolution for the enhanced ICB00 and -0.06 ± 0.06 (P = .014), 0.30 ± 0.11 (P = .005), 0.38 ± 0.12 (P = .004), and 0.55 ± 0.14 (P = .034) logarithm of the minimum angle of resolution for the ZCB00, respectively. Internal HOAs (P = .001) and negative SA (P < .001) were increased with the ICB00 at 3 mm and comparable at 5 mm (P > .05). Contrast acuity, tilt, and decentration were similar (P > .05).

CONCLUSIONS

Significantly increased monocular DCIVA at 80 cm and 66 cm and DCNVA at 40 cm were observed with the enhanced ICB00 IOL, and the ZCB00 IOL demonstrated better BCDVA. This would result in a mean gain of 2 to 3 Early Treatment of Diabetic Retinopathy Study letters at near and intermediate distance. Monocular defocus curves displayed highest differences of 5 Early Treatment of Diabetic Retinopathy Study letters at -1.25 diopters (D) and -1.50 D levels of defocus and a depth of focus of 1.23 D for the ICB00 IOL and 0.94 D for the ZCB00 IOL. Decentration, tilt, and HOAs were generally low.

Developing and Validating a Model of Humeral Stem Primary Stability, Intended for In Silico Clinical Trials

In silico clinical trials (ISCT) can contribute to demonstrating a device's performance via credible computational models applied on virtual cohorts. Our purpose was to establish the credibility of a model for assessing the risk of humeral stem loosening in total shoulder arthroplasty, based on a twofold validation scheme involving both benchtop and clinical validation activities, for ISCT applications. A finite element model computing bone-implant micromotion (benchtop model) was quantitatively compared to a bone foam micromotion test (benchtop comparator) to ensure that the physics of the system was captured correctly. The model was expanded to a population-based approach (clinical model) and qualitatively evaluated based on its ability to replicate findings from a published clinical study (clinical comparator), namely that grit-blasted stems are at a significantly higher risk of loosening than porous-coated stems, to ensure that clinical performance of the stem can be predicted appropriately. Model form sensitivities pertaining to surgical variation and implant design were evaluated. The model replicated benchtop micromotion measurements (52.1 ± 4.3 µm), without a significant impact of the press-fit ("Press-fit": 54.0 ± 8.5 µm, "No press-fit": 56.0 ± 12.0 µm). Applied to a virtual population, the grit-blasted stems (227 ± 78µm) experienced significantly larger micromotions than porous-coated stems (162 ± 69µm), in accordance with the findings of the clinical comparator. This work provides a concrete example for evaluating the credibility of an ISCT study. By validating the modeling approach against both benchtop and clinical data, model credibility is established for an ISCT application aiming to enrich clinical data in a regulatory submission.

High femoral offset as a risk factor for aseptic femoral component loosening in cementless primary total hip arthroplasty

PURPOSE

Lateralized stems in primary cementless total hip arthroplasty (THA) showed to be associated with aseptic femoral loosening. However, femoral head length also affects femoral offset but was not considered so far. This study analyzed the impact of high femoral offset (hFO) combinations, formed by lateralized stems or large femoral head lengths, on aseptic femoral component loosening.

METHODS

Retrospective cohort study was performed including all patients that underwent primary cementless THA at our institution between July 2004 and December 2016. Patients were screened for aseptic femoral component loosening and grouped in aseptic loosening (AL) and non-aseptic loosening (nAL) group. Medical records were screened; implant details were noted and classified in hFO and standard femoral offset (sFO) combinations. Supposed risk factors for aseptic loosening were analyzed.

RESULTS

Two thousand four hundred fifty-nine THA could be included, containing 14 THA (0.6%) with aseptic femoral component loosening. The AL group contained 11 hFO combinations (78.6%), whereas in the nAL group, 1315 hFO combinations (53.8%) were used. Subgroup analysis showed significant difference between two groups for hFO combinations (p = 0.014), age (p = 0.002), NSAR (p = 0.001), and bilateral THA on same day (p = 0.001). The multiple logistic regression analysis showed that hFO combination was the only variable for increased probability of aseptic loosening (OR, 3.7; p = 0.04).

CONCLUSION

High femoral offset combinations, formed by lateralized stems or large femoral head lengths in our collective of standard straight stems implanted by an anterior approach, show a 3.7-fold increased probability for aseptic femoral component loosening. Adjustment of the postoperative protocol may be considered in these cases to ensure proper stem ingrowth.

Experimental periprosthetic fractures with collarless polished tapered cemented stems

PURPOSE

After cemented total hip arthroplasty, the risk of periprosthetic fracture (PPF) of taper-slip stems is higher than that of composite-beam stems. We aimed to assess the conditions resulting in PPFs of taper-slip stems using a falling weight.

METHODS

Taper-slip stems were fixed to five types of simulated bone models using bone cement, and the fractures were evaluated by dropping stainless-steel weights from a predetermined height onto the heads. The periprosthetic fracture height in 50% of the bone models (PPFH50) was calculated using the staircase method.

RESULTS

For the fixation with 0° of flexion, the values for PPFH50 were 61 ± 11, 60 ± 13, above 110, 108 ± 49, and 78 ± 12 cm for the cobalt-chromium-molybdenum alloy, stainless steel alloy (SUS), titanium alloy (Ti), smooth surface, and thick cement mantle models, respectively; for the fixation with 10° of flexion (considering flexure), the PPFH50 values were 77 ± 5, 85 ± 9, 90 ± 2, 89 ± 5, and 81 ± 11 cm, respectively. The fracture rates of the polished-surface stems were 78.6 and 35.7% at the proximal and distal sites, respectively (p < 0.05); the fracture rates of the smooth-surface stems were 14.2 and 100%, respectively (p < 0.05).

CONCLUSION

The impact tests demonstrated that the conditions that were less likely to cause PPFs were use of Ti, a smooth surface, a thick cement mantle, and probably, use of SUS.

Overset meshing in combination with novel blended weak-strong fluid-structure interactions for simulations of a translating valve in series with a second valve

Mechanical circulatory support (MCS) devices can bridge the gap to transplant whilst awaiting a viable donor heart. The Realheart Total Artificial Heart is a novel positive-displacement MCS that generates pulsatile flow via bileaflet mechanical valves. This study developed a combined computational fluid dynamics and fluid-structure interaction (FSI) methodology for simulating positive displacement bileaflet valves. Overset meshing discretised the fluid domain, and a blended weak-strong coupling FSI algorithm was combined with variable time-stepping. Four operating conditions of relevant stroke lengths and rates were assessed. The results demonstrated this modelling strategy is stable and efficient for modelling positive-displacement artificial hearts.

Optical characterization and through-focus performance of two advanced monofocal intraocular lenses

PURPOSE

To compare the refractive power profile, subjective depth-of-field and objective optical quality of two advanced monofocal intraocular lenses (IOLs) designed to improve intermediate vision.

METHODS

This prospective study evaluated forty-six eyes of twenty-three patients, aged 54-68 years, binocularly implanted with two monofocal enhanced intraocular lenses (IOLs), the Tecnis Eyhance and the Physiol Isopure. Subjective through-focus visual acuity curves were obtained by placing trial lenses in front of the eye while wearing its best spherical-cylindrical correction for distance. Objective optical quality was defined as the area under the modulation transfer function, calculated from the wavefront maps measured with a high-resolution aberrometer. The optical design of both lenses was compared based on their refractive power profiles measured with the lenses immersed in saline solution.

RESULTS

Both lenses have progressive aspherical geometries, in which the sagittal power decreases rapidly from the center to the edge of the optical zone. Mean monocular through-focus curves show a best corrected distance visual acuity of - 0.02 logMAR with both lenses. Through-focus visual acuity was marginally higher for the Eyhance, with a difference of 1 letter at the defocus position of - 0.5D and 3 letters between - 1.0D and - 2.0D. Objective assessment of optical quality revealed only a difference of about 2 points in MTF area at distance.

CONCLUSION

Both IOLs use a similar approach to improve intermediate vision. The Eyhance showed marginally better subjective performance than the Isopure at the target vergences between - 1.00D and - 2.00D, although these results did not reach statistical significance and were not replicated by the objective findings.

Can Dual Mobility Cups Reduce Revision and Dislocation Risks? An Analysis of 107,528 Primary Total Hip Arthroplasties in the United States

BACKGROUND

Dual mobility acetabular cups (DMC) were designed to increase the effective femoral head size and improve stability with the goal of reducing revision risk at the potential cost of polyethylene thickness. We sought to evaluate revision risk following primary elective total hip arthroplasty with DMC compared to highly cross-linked polyethylene (XLPE).

METHODS

A cohort study was conducted using data from a Kaiser Permanente's total joint arthroplasty registry. Patients ≥18 years who underwent primary elective total hip arthroplasty using DMC, unipolar Metal-on-XLPE (MoXLPE), or unipolar Ceramic-on-XLPE (CoXLPE) were identified (2010 to 2021). The final sample comprised 2,219 DMC, 48,251 MoXLPE, and 57,058 CoXLPE. Multiple Cox proportional hazard regressions were used to evaluate aseptic revision and any dislocation regardless of revision within 6 years follow-up.

RESULTS

In adjusted analyses, no differences in aseptic revision risk were observed for MoXLPE (hazard ratio [HR] = 1.04, 95% confidence interval [CI] = 0.72 to 1.51) or CoXLPE (HR = 0.98, 95% CI = 0.69 to 1.40) compared to DMC. No differences in dislocation risk were observed for MoXLPE (HR = 1.42, 95% CI = 0.93 to 2.15) or CoXLPE (HR = 1.25, 95% CI = 0.84 to 1.87) compared to DMC.

CONCLUSIONS

In a US-based cohort, 6-year aseptic revision risk of DMC was similar to metal or ceramic femoral head unipolar constructs. Furthermore, no difference in dislocation risk was observed. Continued longer-term follow-up may reveal if there is a reduced risk of dislocation that comes at the cost of increased late revision.

LEVEL OF EVIDENCE

Level III.

Use of physician-modified inverted limb in conjunction with Zenith fenestrated stent graft to rescue failed previous endovascular and open repair

OBJECTIVE

To evaluate outcomes and performance of inverted limbs (ILs) when used in conjunction with Zenith fenestrated stent grafts (Zfens) to treat patients with short distance between the lowest renal artery (RA) and aortic or graft bifurcation (A/GB).

METHODS

This study was a multicenter, retrospective review of prospectively maintained database of patients with complex aortic aneurysms, failed endovascular aneurysm repair (EVAR), or open surgical repair (OSR) with short distance between LRA and A/GB treated using a combination of Zfen and an IL between 2013 and 2023. Endpoints included technical success, aneurysm sac regression, long-term device integrity, and target vessel patency. We defined technical success as implantation of the device with no endoleak, conversion to an aorto-uni-iliac or OSR.

RESULTS

During this time, 52 patients underwent endovascular rescue of failed repair. Twenty (38.5%) of them required relining of the failed repairs using IL due to lowest RA to A/GB length restrictions. Two patients had undergone rescue with a fenestrated cuff alone but developed type III endoleaks. One patient with no previous implant had a short distance between the lowest RA and aortic bifurcation to accommodate the bifurcated distal device, and two patients had failed OSR or anastomotic pseudoaneurysms. The majority (94%) were men with a mean age of 76.8 ± 6.1 years. The mean aortic neck diameter and aneurysm size were 32 ± 4 cm and 7.2 ± 1.3 cm, respectively. The median time laps between initial repair and failure was 36 months (interquartile range [IQR], 24-54 months). Sixteen patients (80%) were classified as American Society of Anesthesiologists class III, whereas four were class IV. Seventy-eight vessels were targeted and successfully incorporated. Technical success was 100%, and median estimated blood loss was 100 mL (IQR, 100-200 mL). Mean fluoroscopy time and dose were 61 ± 18 minutes and 2754 ± 1062 mGy, respectively. Average hospital length of stay was 2.75 ± 2.15 days. Postoperative complication occurred in one patient who required lower extremity fasciotomy for compartment syndrome. At a median follow-up of 50 months (IQR, 18-58 months), there were no device migration, components separation, aneurysmal related mortality, and type I or type III endoleak. Aneurysm sac regression (95%) or stabilization (5%) was observed in all patients, including in four patients (25%) with type II endoleak.

CONCLUSIONS

The use of IL in conjunction with Zfen to treat patients with short distance between the lowest RA and A/GB is safe, effective, and has excellent long-term results. The technique expands the indication of Zfen, especially in patients with failed previous EVAR.

A device-related fistula between coronary artery and left atrial appendage following left atrial appendage closure: Case presentation

INTRODUCTION

Left atrial appendage (LAA) closure (LAAC) is considered a viable alternative to anticoagulation therapy for stroke prevention in nonvalvular atrial fibrillation, we report a case with a less common shunt resulting from a device-related coronary artery-appendage fistula (CAAF) following LAAC.

METHODS AND RESULTS

A 67-year-old male with a history of LAAC was referred to our emergency room with recurrent chest pain and palpitations and was diagnosed with ischemic angina pectoris. Subsequent coronary angiography (CAG) revealed 70% in-stent restenosis and an abnormal shunt of contrast originating from the left circumflex artery (LCA) to the LAA tip which did not exist before. The restenosis was successfully dilated using a drug-coated balloon, the procedure was safely completed without pericardial effusion. The patient had been implanted with a LAmbre occluder (Lifetech Scientific Corp.) in the previous LAAC procedure. This occluder had a lobe-disk design, and the distal umbrella was not fully opened after release, particularly in the lower portion. This could make the hooks embedded on the umbrella contact the LAA wall more tightly, possibly resulting in microperforation and coincidental impingement of the LCA. The epicardial adipose and hyperplastic tissue then chronically wrapped the perforated site, prevented blood outflow into the epicardium, and ultimately formed a CAAF.

CONCLUSION

CAAF is a rare complication after LAAC but may be underestimated, especially for lobe-disk designed occluders. Therefore, CAG is perhaps necessary to detect this complication.

Total Hip Arthroplasty Following Operative Fixation of Acetabular Fracture: A Contemporary Series

BACKGROUND

Total hip arthroplasty (THA) is the operation of choice for salvage of post-traumatic arthritis following acetabular fracture. While high failure rates have been reported for these procedures, existing literature reports mainly on historical implant designs and techniques. We aimed to describe implant survivorships, complications, radiographic results, and clinical outcomes of contemporary THA following prior open reduction internal fixation (ORIF) of an acetabular fracture.

METHODS

We identified 104 patients undergoing THA following prior ORIF of an acetabular fracture from 2000 to 2015 via our institutional total joint registry. Mean age at THA was 50 years (range, 18 to 79 years), 71% were men, and mean body mass index was 27 (range, 18 to 52). All patients were implanted with uncemented acetabular components, and 89% had uncemented stems. Some hardware from prior fixation was retained in 94% of cases. Mean follow-up was 10 years (range, 2 to 21 years).

RESULTS

The 10-year survivorships free of any revision and any reoperation were 98% and 97%, respectively. There were 4 revisions: 1 each for psoas tendonitis, dislocation, acetabular aseptic loosening, and periprosthetic joint infection. There were 9 complications that did not lead to reoperation: 5 dislocations, 2 periprosthetic femur fractures, 1 sciatic nerve palsy, and 1 case of symptomatic heterotopic ossification. All unrevised components appeared radiographically well-fixed. Mean Harris Hip Score improved from mean 50 preoperatively to mean 82 at 5 years (P < .001).

CONCLUSIONS

In this series of contemporary THAs following prior acetabular fracture ORIF, revision-free survivorship was excellent with only a single case of acetabular aseptic loosening. These results are encouraging and suggest that contemporary implants and techniques have notably improved on historic results.

LEVEL OF EVIDENCE

Therapeutic, Level IV.

Comparison of bare and nonbare stent grafts during thoracic endovascular aneurysm repair of the aortic arch

OBJECTIVE

We compared the outcomes of patients treated with nonbare stents (NBS) and proximal bare stents (PBS) endografts with a proximal landing zone in the aortic arch during thoracic endovascular aortic repair (TEVAR).

METHODS

We conducted a retrospective cohort, observational, multicenter study that included 361 consecutive TEVAR procedures undertaken between November 2005 and December 2021. TEVAR patients with both BS and NBS Relay stent graft configurations with proximal landing in zones 1, 2, or 3 were enrolled. Preoperative anamnestic and morphological data, clinical outcomes, and aortic modifications 30 days after surgery and at the latest follow-up available were collected. The primary outcome was freedom from proximal endoleak (type IA) comparing the two configurations. Total and detailed endoleak rates, clinical and technical success, intraoperative additional maneuvers, major adverse events, and reinterventions were secondary outcomes.

RESULTS

The median follow-up was 4.9 (interquartile range, 2.0-8.1) years. No statistically significant difference between NBS and PBS patients concerning 30-day major adverse events, retrograde aortic dissection, disabling stroke, or late type IA endoleak (10.8% vs 7.8%; P = .597). Aneurysmal disease (P = .026), PLZ diameter of >34 mm (P = .026), aortic tortuosity index of >1.4 (P = .008), type III aortic arch (P = .068), and PLZ thrombus (P = .014) identified as risk factors by univariate Cox regression analysis. PLZ thrombus was the only type IA endoleak risk factor at multivariate Cox regression (P = .016).

CONCLUSIONS

We found no statistically significant difference in freedom from type IA endoleak, retrograde dissection, or disabling stroke observed between the NBS and the BS configuration of the Relay endograft. Proximal landing zone thrombotic apposition was a prominent risk factor for type IA endoleak after TEVAR.

The impact of femoral head size on the wear evolution at contacting surfaces of total hip prostheses: A finite element analysis

Total Hip Arthroplasty has been a revolutionary technique in restoring mobility to patients with damaged hip joints. The introduction of modular components of the hip prosthesis allowed for bespoke solutions based on the requirements of the patient. The femoral stem is designed with a conical trunnion to allow for assembly of different femoral head sizes based on surgical requirements. The femoral head diameters for a metal-on-polyethylene hip prosthesis have typically ranged between 22 mm and 36 mm and are typically manufactured using Cobalt-Chromium alloy. A smaller femoral head diameter is associated with lower wear of the polyethylene, however, there is a higher risk of dislocation. In this study, a finite element model of a standard commercial hip arthroplasty prosthesis was modelled with femoral head diameters ranging from 22 mm to 36 mm to investigate the wear evolution and material loss at both contacting surfaces (acetabular cup and femoral stem trunnion). The finite element model, coupled with a validated in-house wear algorithm modelled a human walking for 10 million steps. The results have shown that as the femoral head size increased, the amount of wear on all contacting surfaces increased. As the femoral head diameter increased from 22 mm to 36 mm, the highly cross-linked polyethylene (XLPE) volumetric wear increased by 61% from 98.6 mm3 to 159.5 mm3 while the femoral head taper surface volumetric wear increased by 21% from 4.18 mm3 to 4.95 mm3. This study has provided an insight into the amount of increased wear as the femoral head size increased which can highlight the life span of these prostheses in the human body.

Osteoporotic Patients Undergoing Total Hip Arthroplasty Have a Similar 5-Year Cumulative Incidence Rate of Periprosthetic Fracture Regardless of Cemented Versus Cementless Femoral Stem Fixation

BACKGROUND

In osteoporotic patients, surgeons may utilize cemented femoral fixation to minimize risk of fracture. The purpose of this study was to compare 5-year implant survivability in patients who have osteoporosis who underwent elective total hip arthroplasty (THA) with cementless versus cemented fixation.

METHODS

A retrospective analysis of patients who have osteoporosis undergoing THA with either cemented or cementless femoral fixation was conducted using a national administrative claims database. Of the 18,431 identified THA patients who have osteoporosis, 15,867 (86.1%) underwent cementless fixation. The primary outcome was a comparison of the 5-year cumulative incidences of aseptic revision, mechanical loosening, and periprosthetic fracture (PPF). Kaplan-Meier and Multivariable Cox Proportional Hazard Ratio analyses were used, controlling for femoral fixation method, age, sex, a comorbidity scale, use of osteoporosis medication, and important comorbidity.

RESULTS

There was no difference in aseptic revision (Hazard's Ratio (HR): 1.13; 95% Confidence Interval (CI): 0.79 to 1.62; P value: .500) and PPF (HR: 0.96; 95% CI: 0.64 to 1.44; P value: .858) within 5 years of THA between fixation cohorts. However, patients who had cemented fixation were more likely to suffer mechanical loosening with 5 years post-THA (HR: 1.79; 95% CI: 1.17 to 2.71; P-value: .007).

CONCLUSIONS

We found a similar 5-year rate of PPF when comparing patients who underwent cementless versus cemented femoral fixation for elective THA regardless of preoperative diagnosis of osteoporosis. While existing registry data support the use of cemented fixation in elderly patients, a more thorough understanding of the interplay between age, osteoporosis, and implant design is needed to delineate in whom cemented fixation is most warranted for PPF prevention.

An Anterior Spike Decreases Bone-Implant Micromotion in Cementless Tibial Baseplates for Total Knee Arthroplasty: A Biomechanical Study

BACKGROUND

Cementless tibial baseplates in total knee arthroplasty include fixation features (eg, pegs, spikes, and keels) to ensure sufficient primary bone-implant stability. While the design of these features plays a fundamental role in biologic fixation, the effectiveness of anterior spikes in reducing bone-implant micromotion remains unclear. Therefore, we asked: Can an anterior spike reduce the bone-implant micromotion of cementless tibial implants?

METHODS

We performed computational finite element analyses on 13 tibiae using the computed tomography scans of patients scheduled for primary total knee arthroplasty. The tibiae were virtually implanted with a cementless tibial baseplate with 2 designs of fixation of the baseplate: 2 pegs and 2 pegs with an anterior spike. We compared the bone-implant micromotion under the most demanding loads from stair ascent between both designs.

RESULTS

Both fixation designs had peak micromotion at the anterior-lateral edge of the baseplate. The design with 2 pegs and an anterior spike had up to 15% lower peak micromotion and up to 14% more baseplate area with micromotions below the most conservative threshold for ingrowth, 20 μm, than the design with only 2 pegs. The greatest benefit of adding an anterior spike occurred for subjects who had the smallest area of tibial bone below the 20 μm threshold (ie, most at risk for failure to achieve bone ingrowth).

CONCLUSIONS

An anteriorly placed spike for cementless tibial baseplates with 2 pegs can help decrease the bone-implant micromotion during stair ascent, especially for subjects with increased bone-implant micromotion and risk for bone ingrowth failure.

Comparison of bridging stent grafts in branched endovascular aortic repair

BACKGROUND

Endovascular treatment of thoracoabdominal aortic aneurysms has become common, with satisfactory results. Nevertheless, long-term durability remains an issue mainly because of target visceral vessel (TVV) instability. Currently, no covered stent has been approved as a bridging stent graft (BSG), demanding continuous research on this topic.

METHODS

This was a multicenter observational retrospective cohort study comparing the midterm results of the Bard Covera Plus and Gore VBX as BSGs during branched endovascular aneurysm repair. The primary outcome was the comparison of the target vessel instability between the two groups. Primary patency, freedom from branch-related type I and III endoleaks and reintervention, and technical and clinical success were considered secondary outcomes. Logistic regression analysis was used to assess the association between selected baseline factors and TVV instability. TVV instability during follow-up was then evaluated using the Kaplan-Meier cumulative function.

RESULTS

Three hundred forty-five TVVs in 106 patients were considered suitable for the analysis. Two hundred twenty vessels were stented with the Covera stent graft (64%) and 125 with VBX (36%). Two hundred ninety-nine TVVs received a single BSG, 45 two BSGs, and only 1 three BSGs. Bare metal stent relining was required in 36% of TVVs, mostly in the Covera group (89 [41%] vs 36 [29%]) (P = .030). The primary technical success rate was 96% (331/345), and the assisted primary technical success rate was 99% (342/345). The TVV instability rate within 30 days was 2% (one Covera and five VBX; P = .015). Three BSG occlusions (one Covera and two VBX) and three type Ic endoleaks (three VBX) were detected. The median follow-up was 13.9 months (range, 5.8-25.5 months). Sixteen TVV instabilities were detected during the follow-up. Twelve BSG occlusions (six Covera and six VBX), three type Ic endoleaks (one Covera and two VBX), and one type IIIc endoleak (VBX). The overall target vessel instability rate was 5% (16/342). TVV instability was associated with the use of Gore VBX in the univariable logistic regression (odds ratio, 3.0; 95% confidence interval, 1.1-8.0; P = .027). Aneurysm rupture and aneurysm diameter were also associated with TVV instability in the univariable analysis (P = .002 and P = .008, respectively). The only factor predisposing to TVV instability in the multivariable logistic regression analysis was the use of Gore VBX as a BSG (odds ratio, 2.9; 95% confidence interval, 1.0-8.0; P = .043). Kaplan-Meier analysis showed a significantly higher risk of TVV instability in the VBX group (P < .001).

CONCLUSIONS

Overall midterm outcomes in this cohort were satisfactory. Patency rates were similar between the two stents. Nevertheless, VBX seems to be associated with worse TVV instability. These results may be correlated with a higher incidence of type Ic endoleaks, which require an extensive learning curve for correct stent selection and deployment.

Effect of intraocular lens material and haptic design on anterior capsule contraction after cataract surgery: A systematic review and meta-analysis

PURPOSE

To compare anterior capsule contraction (ACC) after cataract surgery with implantation of intraocular lens (IOLs) of different materials and designs.

METHODS

We searched three electronic databases for relevant studies published up to January 1, 2023. Five randomized controlled trails (RCTs) and three cohort studies involving 1,221 eyes were included in quantitative synthesis. We extracted data, assessed their quality independently, and calculated standard mean difference (SMD) using a random-effects model. Six RCTs and one retrospective cohort were included in information summary.

RESULTS

The contraction of the anterior capsule opening area in the hydrophilic group was larger than that of the hydrophobic group from one month to one year postoperatively (P < 0.001 and P < 0.001, respectively). Specifically, the hydrophilic group showed greater contraction of the anterior capsule opening area at one month postoperatively (Standardized mean difference [SMD] = -0.73, 95% confidence interval [CI] = -0.93 to -0.52), three months (SMD = -1.04, 95% CI = -1.32 to -0.75), six months (SMD = -0.99, 95% CI = -1.24 to -0.74) and one year (SMD = -1.33, 95% CI = -2.50 to -0.16). As of one year postoperatively, the anterior capsular opening area showed a trend of decreasing over time in both groups (P = 0.046 and P = 0.050, respectively). In information summary, three studies indicated no relationship between haptic design and ACC, while the other four studies reported that the number and shape of haptic would affect ACC.

CONCLUSION

This meta-analysis suggested that the postoperative ACC after the implantation of hydrophobic IOLs was less than that induced by hydrophilic IOLs. Haptic design may also affect the degree of ACC.

Prosthetic Limb Attachment via Electromagnetic Attraction Through a Closed Skin Envelope

OBJECTIVE

Current socket-based methods of prosthetic limb attachment are responsible for many of the dominant problems reported by persons with amputation. In this work, we introduce a new paradigm for attachment via electromagnetic attraction between a bone-anchored ferromagnetic implant and an external electromagnet. Our objective was to develop a design framework for electromagnetic attachment, and to evaluate this framework in the context of transfemoral amputation.

METHODS

We first used inverse dynamics to calculate the forces required to suspend a knee-ankle-foot prosthesis during gait. We then conducted cadaveric dissections to inform implant geometry and design a surgical methodology for covering the implant. We also developed an in silico framework to investigate how electromagnet design affects system performance. Simulations were validated against benchtop testing of a custom-built electromagnet.

RESULTS

The physical electromagnet matched simulations, with a root-mean-square percentage error of 4.2% between measured and predicted forces. Using this electromagnet, we estimate that suspension of a prosthesis during gait would require 33 W of average power. After 200 and 1000 steps of simulated walking, the temperature at the skin would increase 2.3 °C and 15.4 °C relative to ambient, respectively.

CONCLUSION

Our design framework produced an implant and electromagnet that could feasibly suspend a knee-ankle-foot prosthesis during short walking bouts. Future work will focus on optimization of this system to reduce heating during longer bouts.

SIGNIFICANCE

This work demonstrates the initial feasibility of an electromagnetic prosthetic attachment paradigm that has the potential to increase comfort and improve residual limb health for persons with amputation.

Hemodynamics and Wall Mechanics of Vascular Graft Failure

Blood vessels are subjected to complex biomechanical loads, primarily from pressure-driven blood flow. Abnormal loading associated with vascular grafts, arising from altered hemodynamics or wall mechanics, can cause acute and progressive vascular failure and end-organ dysfunction. Perturbations to mechanobiological stimuli experienced by vascular cells contribute to remodeling of the vascular wall via activation of mechanosensitive signaling pathways and subsequent changes in gene expression and associated turnover of cells and extracellular matrix. In this review, we outline experimental and computational tools used to quantify metrics of biomechanical loading in vascular grafts and highlight those that show potential in predicting graft failure for diverse disease contexts. We include metrics derived from both fluid and solid mechanics that drive feedback loops between mechanobiological processes and changes in the biomechanical state that govern the natural history of vascular grafts. As illustrative examples, we consider application-specific coronary artery bypass grafts, peripheral vascular grafts, and tissue-engineered vascular grafts for congenital heart surgery as each of these involves unique circulatory environments, loading magnitudes, and graft materials.

Computational analysis of prosthesis production via topology optimization

This work investigates the use of Topology Optimization (TO) to support the design of femur prosthesis to obtain more efficient solutions from the point of view of material distribution and internal forces. Computational tests were performed by the Interior-Point OPTimizer (IPOPT) method, seeking to explore the elastic mechanical characteristics of three real scenarios of daily loads on the femur. Numerical examples are presented to verify the novelty of the proposed method. The results obtained indicate that it is possible to reduce the volume of material up to 30% of the customize human femoral prosthesis, respecting all the boundary conditions.

The application of three-dimensional custom-made prostheses in chest wall reconstruction after oncologic sternal resection

BACKGROUND AND OBJECTIVES

As one of the cutting-edge advances in the field of reconstruction, three-dimensional (3D) printing technology has been constantly being attempted to assist in the reconstruction of complicated large chest wall defects. However, there is little literature assessing the treatment outcomes of 3D printed prostheses for chest wall reconstruction. This study aimed to analyze the surgical outcomes of 3D custom-made prostheses for the reconstruction of oncologic sternal defects and to share our experience in the surgical management of these rare and complex cases.

METHODS

We summarized the clinical features of the sternal tumor in our center, described the surgical techniques of the application of 3D customized prosthesis for chest wall reconstruction, and analyzed the perioperative characteristics, complications, overall survival (OS), and recurrence-free survival of patients.

RESULTS

Thirty-two patients with the sternal tumor who underwent chest wall resection were identified, among which 13 patients used 3D custom-made titanium implants and 13 patients used titanium mesh for sternal reconstruction. 22 cases were malignant, and chondrosarcoma is the most common type. The mean age was 46.9 years, and 53% (17/32) of the patients were male. The average size of tumor was 6.4 cm, and the mean defect area was 76.4 cm2. 97% (31/32) patients received R0 resection. Complications were observed in 29% (9/32) of patients, of which wound infection (22%, 7/32) was the most common. The OS of the patients was 72% at 5 years.

CONCLUSION

We demonstrated that with careful preoperative assessment, 3D customized prostheses could be a viable alternative for complex sternal reconstruction.

Optical and aberrometric evaluation of a new enhanced monofocal intraocular lens with isofocal optic design

PURPOSE

To evaluate the optical and aberrometric outcomes of an enhanced monofocal intraocular lens (ISOPure) compared with those of a standard monofocal lens (MicroPure) having the same platform and material.

METHODS

A prospective, comparative and randomised clinical study. A total of 28 eyes of 28 patients were randomly assigned to either group. Monocular visual acuity (VA) was measured at distance and intermediate under photopic and mesopic conditions. Aberrometry was analysed for 3.0-, 4.0-, 4.5- and 5.0 mm pupils. The contrast sensitivity defocus curve was measured for 3.0- and 4.5-mm pupils, while the modulation transfer function (MTF) and Strehl ratio (SR) were assessed with a double-pass system. All measurements were performed monocularly 3 months after surgery.

RESULTS

No significant differences were found for distance VA. Under photopic conditions, intermediate VA was better with the ISOPure lens, while no significant differences were found between the lenses under mesopic conditions. Internal and total aberrations were higher for the ISOPure lens. No significant differences were found for corneal aberrations. Additionally, both the contrast sensitivity defocus curve and optical quality showed similar behaviour for each lens, with the MTF cut-off frequency exceeding 30 c/deg in both cases.

CONCLUSION

The isofocal ISOPure lens enhanced intermediate VA without affecting distance VA under photopic conditions. Moreover, there were no significant differences in visual quality between the ISOPure and MicroPure lenses, despite the former exhibiting higher internal and total aberrations than the monofocal model.

Higher satisfaction and function scores in restricted kinematic alignment versus mechanical alignment with medial pivot design total knee arthroplasty: A prospective randomised controlled trial

PURPOSE

Restricted kinematic alignment (rKA) in total knee arthroplasty (TKA) and medial pivot (MP) knee designs already showed superior outcomes in independent comparative studies. The objective of this study was to assess whether rKA with MP TKA provides better clinical and functional outcomes compared to mechanical alignment (MA) with MP TKA.

METHODS

This is a randomised, parallel two group study involving a total of 98 patients with end-stage knee osteoarthritis. Patients were randomly allocated to either rKA or MA TKA procedures conducted with a MP prothesis using patient-specific instruments between 2017 and 2020. Final follow-up was at 2 years postoperatively. Demographic data and clinical and functional scores (Oxford knee score, knee society score [KSS], Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC], forgotten joint score [FJS]) were collected and compared preoperative, 1 year postoperative and 2 years postoperative. Coronal plane alignment of the knee and functional knee phenotype classification were recorded.

RESULTS

A total of 47 patients (rKA) and 51 patients (MA) were included in final analysis. Superior joint awareness scores (FJS) were found at 1 year postoperative for rKA (62.2 vs. 52.4, p = 0.04). KSS subscores (expectation score, satisfaction score) improved with rKA with significant differences at both 1 and 2 years postoperatively. Major differences between rKA and MA were found in subgroup analysis of varus and neutral CPAK phenotypes. Both 1 year and 2 years postoperatively, FJS was significantly better in KA compared with MA in varus CPAK phenotypes (63.1 vs. 44.9, p = 0.03; 71.1 vs. 46.0, p = 0.005). Further clinical and functional scores showed improvement in the varus CPAK phenotypes with predominantly significant improvement in the expectation and satisfaction KSS subscores. No significant differences were found in the comparison of rKA and MA in neutral CPAK phenotypes.

CONCLUSION

The rKA of MP TKA design shows superior patient satisfaction and self-reported function when compared to MA MP TKA. Furthermore, rKA MP TKA shows superior joint awareness at early postoperative stage. The most important clinical relevance of this study is the clear superiority of rKA in varus phenotypes.

LEVEL OF EVIDENCE

Level II.

Prosthetic Nasal Reconstruction

Prosthetic nasal reconstruction provides a restorative option for patients with nasal defects, and these can be retained with a variety of methods including adhesives and implants. These prostheses can significantly improve appearance, self-esteem, and quality of life for patients and they restore many functions of the external nose. Traditional fabrication methods are often used by the skilled professionals who make these custom prostheses, but digital technology is improving the workflow for design and fabrication of silicone nasal prostheses. Nasal prosthetic reconstruction requires multidisciplinary coordination between surgeons, maxillofacial prosthodontists, anaplastologists, and other members of the healthcare team. Prosthetic treatment can be considered as an alternative to, or an addition to treatment with surgical reconstruction.

Dual-mobility tripod cup for revision hip arthroplasty: long-term (five to fourteen years) evaluation of a new generation cementless implant

PURPOSE

The aims of this study were to evaluate the survivorships of a new generation cementless DMC with tripod additional fixation in revision total hip arthroplasty and complications at a minimum five year follow-up.

METHODS

One hundred and fifteen revisions (THA) treated with tripod DMC performed between 2009 and 2015 were included in this retrospective study. Acetabular defects were classified as Paprosky 1 (n = 38, 33%), 2 (n = 75, 65%) or 3 (n = 2, 2%). Unipolar or bipolar revision was performed for the following indications: aseptic acetabular loosening (63%), infection (14%), aseptic bipolar loosening (11%), instability (4%), aseptic femoral loosening (3%), ALVAL (3%) and iliopsoas impingement (2%). Mean follow-up was 9.4 years ± two (range, 5 to 14).

RESULTS

At the final follow-up, a single episode of dislocation occurred within three months after the procedure (0.8%) with no revision. Three cases of aseptic loosening were diagnosed (2.6%). Four infections (3.5%) required reoperation: three required a two stage bipolar revision; one was treated by DAIR procedure. At the latest follow-up, the survivorship of the acetabular cup for aseptic loosening was 98% [95% CI (91.2-99.4)] and for any reasons was 94.4% [95% CI (90.1%-98.9%)]; the mean HHS improved from 60 points (range, 18-94 points) to 83 points (range, 37-100 points) (p < .001).

CONCLUSION

This study reports a low complication rate in favour of the use of a tripod DMC in revision THA with a satisfactory survivorship at a ten year follow-up.

Computer-based analysis of the taper connection strength of different revision head and adapter sleeve designs

OBJECTIVES

Ceramic revision heads, equipped with titanium adapter sleeves, are used in femoral head revision in total hip arthroplasty to avoid ceramic fracture due to the damaged taper.

METHODS

A finite element analysis of the taper connection strength of revision heads with varying head diameters combined with adapter sleeves of different lengths was conducted. The influence of various assembly forces, head diameter, and length of the adapter sleeves was evaluated. For two combinations, the pattern of contact pressure was evaluated when applying a simplified joint load (3 kN, 45° load angle). Experimental validation was conducted with 36 mm heads and adapter sleeves in size S, as well as 28 mm heads and adapter sleeves in size XL.

RESULTS

The pull-off force increased with higher assembly forces. Using larger head diameters and adapter sleeves led to decreased pull-off forces, a reduced contact surface, and less contact pressure. The contact pressure showed significant peaks and a diagonal pattern under 45° angle loading when assembly forces were less than 4 kN, and larger adapter sleeves were utilized.

CONCLUSION

A sufficient assembly force should be ensured intraoperatively, especially with an increasing head diameter and adapter sleeve size, as lower assembly forces might lead to reduced taper connection strength.

Comparison of short-term clinical outcomes of a diffractive trifocal intraocular lens with phacoemulsification and femtosecond laser assisted cataract surgery

PURPOSE

To evaluate short-term visual and refractive outcomes after implantation of a diffractive trifocal intraocular lens (IOL) in cataract patients with phacoemulsification (PHACO) and femtosecond laser assisted cataract surgery (FLACS).

SETTING

Department of Ophthalmology, Shanghai Aier Eye Hospital, China.

DESIGN

A retrospective, observational study.

METHODS

Patients who underwent cataract surgery combined with Acrysoft IQ PanOptix trifocal IOL implantation were enrolled and divided into three groups: PHACO group, LAstig-FLACS group (astigmatism less then 1D) and HAstig-FLACS group (astigmatism more than 1D). Logarithm of the minimum angle of resolution (logMAR) visual acuity of uncorrected distance (UDVA), intermediate (UIVA), near visual (UNVA), defocus curve, surgically induced astigmatism (SIA) were evaluated in 1 months postoperatively and wavefront aberrations were evaluated in 6 months.

RESULTS

101 eyes of 60 patients were included with 31 eyes in PHACO group, 45 eyes in LAstig-FLACS group and 25 eyes in HAstig-FLACS group. Significant difference was found of internal Strehl Ratio (SR) between PHACO and LAstig-FLACS group (P = 0.026). In PHACO group, 79.31%, 86.21%, 72.41% of eyes gain visual acuity LogMAR 0.1 or more in UDVA, UIVA and UNVA, while 83.72%, 93.02%, 93.02% of those in LAstig-FLACS group and 92.00%, 84.00%, 76.00% in HAstig-FLACS group.

CONCLUSIONS

Panoptix diffractive trifocal IOL provides satisfied visual outcome in no matter FLACS or PHACO. Besides, trifocal IOL implantation via FLACS can provide a better accumulative visual acuity outcome at all distance than PHACO in 1 month. Femtosecond laser assisted limbal relaxing incisions (FLLRIs) is an excellent way to reduce a patient's corneal astigmatism.

Biomechanical and clinical outcomes of 3D-printed versus modular hemipelvic prostheses for limb-salvage reconstruction following periacetabular tumor resection: a mid-term retrospective cohort study

BACKGROUND

Debates persist over optimal pelvic girdle reconstruction after acetabular tumor resection, with surgeons grappling between modular and 3D-printed hemipelvic endoprostheses. We hypothesize superior outcomes with 3D-printed versions, yet scarce comparative research exists. This study fills the gap, examining biomechanics and clinical results retrospectively.

METHODS

From February 2017 to June 2021, we retrospectively assessed 32 patients undergoing en bloc resection for malignant periacetabular tumors at a single institution.

PRIMARY OUTCOME

limb function.

SECONDARY OUTCOMES

implant precision, hip joint rotation center restoration, prosthesis-bone osteointegration, and complications. Biomechanical characteristics were evaluated through finite element analysis on pelvic defect models.

RESULTS

In the 3D-printed group, stress distribution mirrored a normal pelvis, contrasting the modular group with elevated overall stress, unstable transitions, and higher stress peaks. The 3D-printed group exhibited superior functional scores (MSTS: 24.3 ± 1.8 vs. 21.8 ± 2.0, p < 0.05; HHS: 79.8 ± 5.2 vs. 75.3 ± 3.5, p < 0.05). Prosthetic-bone interface osteointegration, measured by T-SMART, favored 3D-printed prostheses, but surgery time (426.2 ± 67.0 vs. 301.7 ± 48.6 min, p < 0.05) and blood loss (2121.1 ± 686.8 vs. 1600.0 ± 505.0 ml, p < 0.05) were higher.

CONCLUSIONS

The 3D-printed hemipelvic endoprosthesis offers precise pelvic ring defect matching, superior stress transmission, and function compared to modular endoprostheses. However, complexity, fabrication expertise, and challenging surgical implantation result in prolonged operation times and increased blood loss. A nuanced consideration of functional outcomes, complexity, and patient conditions is crucial for informed treatment decisions.

LEVEL OF EVIDENCE

Level III, therapeutic study (Retrospective comparative study).

Reinterventions After CoreValve/Evolut Transcatheter or Surgical Aortic Valve Replacement for Treatment of Severe Aortic Stenosis

BACKGROUND

Data on valve reintervention after transcatheter aortic valve replacement (TAVR) or surgical aortic valve replacement (SAVR) are limited.

OBJECTIVES

The authors compared the 5-year incidence of valve reintervention after self-expanding CoreValve/Evolut TAVR vs SAVR.

METHODS

Pooled data from CoreValve and Evolut R/PRO (Medtronic) randomized trials and single-arm studies encompassed 5,925 TAVR (4,478 CoreValve and 1,447 Evolut R/PRO) and 1,832 SAVR patients. Reinterventions were categorized by indication, timing, and treatment. The cumulative incidence of reintervention was compared between TAVR vs SAVR, Evolut vs CoreValve, and Evolut vs SAVR.

RESULTS

There were 99 reinterventions (80 TAVR and 19 SAVR). The cumulative incidence of reintervention through 5 years was higher with TAVR vs SAVR (2.2% vs 1.5%; P = 0.017), with differences observed early (≤1 year; adjusted subdistribution HR: 3.50; 95% CI: 1.53-8.02) but not from >1 to 5 years (adjusted subdistribution HR: 1.05; 95% CI: 0.48-2.28). The most common reason for reintervention was paravalvular regurgitation after TAVR and endocarditis after SAVR. Evolut had a significantly lower incidence of reintervention than CoreValve (0.9% vs 1.6%; P = 0.006) at 5 years with differences observed early (adjusted subdistribution HR: 0.30; 95% CI: 0.12-0.73) but not from >1 to 5 years (adjusted subdistribution HR: 0.61; 95% CI: 0.21-1.74). The 5-year incidence of reintervention was similar for Evolut vs SAVR (0.9% vs 1.5%; P = 0.41).

CONCLUSIONS

A low incidence of reintervention was observed for CoreValve/Evolut R/PRO and SAVR through 5 years. Reintervention occurred most often at ≤1 year for TAVR and >1 year for SAVR. Most early reinterventions were with the first-generation CoreValve and managed percutaneously. Reinterventions were more common following CoreValve TAVR compared with Evolut TAVR or SAVR.