Ultrasound-based bone tracking using cross-correlation enables dynamic measurements of knee kinematics during clinical assessments.

Purpose: Measuring joint kinematics in the clinic is important for diagnosing injuries, tracking healing and guiding treatments; however, current methods are limited by accuracy and/or feasibility of widespread clinical adoption. Therefore, the purpose of this study was to develop and validate an ultrasound (US)-based method for measuring knee kinematics during clinical assessments. Methods: We mimicked four clinical laxity assessments (i.e., anterior, posterior, varus, valgus) on five human cadaver knees using our robotic testing system. We simultaneously collected B-mode cine loops with an US transducer. We computed the errors in kinematics between those measured using our bone-tracking algorithm, which cross-correlated regions of interest across frames of the cine loops, and those measured using optical motion capture with bone pins. Additionally, we conducted studies to determine the effects of loading rate and transducer placement on kinematics measured using our US-based bone tracking. Results: Pooling the trials at experimental speeds and those downsampled to replicate clinical laxity assessments, the maximum root-mean-square errors of knee kinematics using our bone-tracking algorithm were 2.2 mm and 1.3° for the anterior-posterior and varus-valgus laxity assessments, respectively. Repeated laxity assessments proved to have good-to-excellent repeatability (intraclass correlation coefficients [ICCs] of 0.81-0.99), but ICCs from repositioning the transducer varied more widely, ranging from poor-to-good reproducibility (0.19-0.89). Conclusion: Our results demonstrate that US is capable of tracking knee kinematics during dynamic movement. Because US is a safe and commonly used imaging modality, when paired with our bone-tracking algorithm, US has the potential to assess dynamic knee kinematics across a wide variety of applications in the clinic. Level of Evidence: Not applicable.

Regional shear wave speeds track regional axial stress in nonuniformly loaded fibrous soft tissues.

Ligaments and tendons undergo nonuniform deformation during movement. While deformations can be imaged, it remains challenging to use such information to infer regional tissue loading. Shear wave tensiometry is a promising noninvasive technique to gauge axial stress and is premised on a tensioned beam model. However, it is unknown whether tensiometry can predict regional stress in a nonuniformly loaded structure. The objectives of this study were to (1) determine whether regional shear wave speed tracks regional axial stress in nonuniformly loaded fibrous soft tissues, and (2) determine the sensitivity of regional axial stress and shear wave speed to nonuniform load distribution and fiber alignment. We created a representative set of 12,000 dynamic finite element models of a fibrous soft tissue with probabilistic variations in fiber alignment, stiffness, and aspect ratio. In each model, we applied a randomly selected nonuniform load distribution, and then excited a shear wave and tracked its regional propagation. We found that regional shear wave speed was an excellent predictor of the regional axial stress (RMSE = 0.57 MPa) and that the nature of the regional shear wave speed-stress relationship was consistent with a tensioned beam model (R2 = 0.99). Variations in nonuniform load distribution and fiber alignment did not substantially alter the wave speed-stress relationship, particularly at higher loads. Thus, these findings suggests that shear wave tensiometry could provide a quantitative estimate of regional tissue stress in ligaments and tendons.

Long-term Renal Preservation and Complication Profile With Ileal Ureter Creation.

OBJECTIVE: To examine long-term ileal ureter replacement results at over 32 years at our institution. Long segment or proximal ureteral strictures pose a challenging reconstructive problem. Ureteroureterostomy, psoas hitch, Boari flap, buccal ureteroplasty, and autotransplantation are common reconstructive techniques. We show that ileal ureter remains a lasting option. METHODS: We performed a retrospective review of patients undergoing open ileal ureter creation from 1989-2021. Patient demographics, operative history, and complications were examined. All patients were followed for changes in renal function. Demographic data were analyzed and Cox proportional hazard models were performed. RESULTS: One hundred and fifty-eight patients were identified with median follow-up time of 40 months. Eighty-one percent had a unilateral ileal ureter creation. Fifty percent were female, median age was 53.3. Twenty-seven percent of patients had radiation-induced strictures. Preoperatively, 56.3% of patients were chronic kidney disease stage 1-2 and 43.7% were stage 3-5. Post-operatively, 54% were stage 1-2 and 46% were stage 3-5. Cox proportional hazard models demonstrated no significant correlation between worsening renal function and stricture cause, bilateral repair, complications, or sex (biologically male or female). Seventy-seven percent had no 30-day complications. Clavien complications included grade 1 (18), grade 2 (4), grade 3 (9), and grade 4 (5). Long-term complications included worsening renal function (3%), incisional hernia (8.2%), and small bowel obstruction (6.9%). Five (3.1%) patients ultimately required dialysis and 5 (3.1%) patients developed metabolic acidosis. CONCLUSION: Ileal ureteral reconstruction is often a last resort for patients with complex ureteral injuries. Clinicians can be reassured by our long-term data that ileal ureteral creation is a safe treatment with good preservation of renal function and low risk of hemodialysis and metabolic acidosis.

Parental decision regret after pediatric urologic surgeries compared to decisions of everyday life.

INTRODUCTION: Parents are at risk of decision regret (DR) for decisions affecting their children. The Decision Regret Scale (DRS) measures medical DR but lacks context outside of healthcare. OBJECTIVE: To compare parental DR 1) between common pediatric urologic surgeries and everyday decisions and 2) with preference to make a different choice. METHODS: We conducted a cross-sectional online survey of randomly selected parents >1year (y) after their children underwent: orchiopexy (males ≤10y), open ureteral reimplant (OUR, females 2-6y), open pyeloplasty (OP, ≤2y), or robotic pyeloplasty (RP, 5-17y) (2017-2021). Higher DRS scores indicate increased DR (none: 0, mild: 1-25, moderate: 30-50, strong: 55-75, very strong: 80-100). Parents completed DRS on four decisions: their child's surgery, most recent/current romantic relationship, most recent leased/purchased car, and most recent purchased meal. Parents reported if they would make the same choice (yes/no). Nonparametric statistics were used. RESULTS: We surveyed 191 parents (orchiopexy n = 52, OUR n = 50, OP n = 51, RP n = 38). The median parent age was 36y (mothers: 86%). Some DR was reported for all decisions, but with significant differences in DR severity. The lowest median DRS score was seen with surgery (orchiopexy 0 [IQR 0-10], OUR 0 [IQR 0-5], OP 0 [IQR 0-0], RP 0 [IQR 0-0]), with no difference between surgery groups (p = 0.78). This was followed by relationship (0, IQR 0-20), car (15, IQR 0-25), and meal (20, IQR 0-30, p < 0.001). Most parents did not report any DR regarding surgery (orchiopexy 69%, OUR 74%, OP 76%, RP 76%, with no difference between surgery groups p = 0.85, Summary Figure). Comparatively, 59% of parents did not have any regret about their relationship, 37% their car, and 28% their meal (p < 0.001). All surgical DR was mild or moderate. No parent (0%) would have chosen differently for their child's surgery versus 4-12% for non-surgical decisions (p < 0.001). Overall, increasing DR corresponded to increasing desire to have made a different choice (DRS≤10: 0%, DRS 45-50: 32%, DRS 55-60: 66%, DRS≥75: 100%, p < 0.001). CONCLUSION: Parental DR varied between urological surgical and non-surgical decisions. It was lowest after surgery. Some regret was reported after every decision, but the subset of parents with regret was smallest after surgical decisions. Positive DRS scores do not necessarily correspond to parents wishing they made a different choice.

Prevalence of sexual abuse and intimate partner violence in adults with spina bifida.

BACKGROUND: People with disabilities and chronic medical conditions are known to be at higher risk of sexual abuse (SA) and intimate partner violence (IPV). People with spina bifida (SB) are vulnerable, but little is known about the prevalence of abuse in this population. OBJECTIVE: To evaluate the prevalence and risk factors of SA and IPV in adults with SB. METHODS: An anonymous international cross-sectional online survey of adults with SB asked about history of SA ("sexual contact that you did not want") and IPV ("hit, slapped, kicked, punched or hurt physically by a partner"). RESULTS: Median age of the 405 participants (61% female) was 35 years. Most self-identified as heterosexual (85%) and were in a romantic relationship (66%). A total of 19% reported a history of SA (78% no SA, 3% preferred not to answer). SA was more frequently reported by women compared to men (27% vs. 5%, p < 0.001) and non-heterosexual adults compared to heterosexuals (41% vs. 15%, p < 0.001). Twelve percent reported a history of IPV (86% no IPV, 2% preferred not to answer). IPV was more frequently reported by women compared to men (14% vs. 9%, p = 0.02), non-heterosexuals compared to heterosexuals (26% vs. 10%, p = 0.002), and adults with a history of sexual activity versus those without (14% vs. 2%, p = 0.01). CONCLUSION: People with SB are subjected to SA and IPV. Women and non-heterosexuals are at higher risk of both.

Urinary and Fecal Incontinence During Sexual Activity Is Common and Bothersome Among Adults With Spina Bifida.

OBJECTIVE: To evaluate the prevalence of and risk factors for urinary fecal incontinence (UI, FI) during sexual activity (UIS, FIS) among adults with spina bifida (SB). METHODS: An international online survey of adults with SB was administered through SB clinics and SB organizations via social media. Adults with a history of masturbation or partnered sexual activity were included. The primary outcome was ever experiencing UIS/FIS. Nonparametric tests and logistic regression were used for analysis. RESULTS: A total of 341 adults met inclusion criteria (median age: 36years, 59% female, 52% shunted, 48% community ambulators). Baseline UI in the last 4weeks was reported by 50% and FI by 41%. Nineteen (5%) had a urostomy. Eight (2%) had a colostomy. Overall, 93% had a history of partnered genital contact. Among adults without a diversion, UIS was more common than FIS (70% vs 45%, P < .001). Among adults without a urostomy, UIS was more common among women (76% vs 62%, P = .01) and those with baseline UI (84% vs 50%, P < .001). UIS was not associated with age, shunt, ambulatory, or catheterization status (P >=.32). On bivariate analysis, female sex and baseline UI were independent predictors of UIS (P <=.001). Among adults without a colostomy, FIS was associated with female sex (50% vs 39%, P = .046), baseline FI (59% vs 32%, P < .001), community ambulation (52% vs 40%, P = .04), but not age, shunt, or MACE status (P >=.27). On multivariate analysis, baseline FI was independently associated with FIS (P < .001). Among adults with UIS/FIS, 29% experienced UIS "almost always" to "always," compared to 5% for FIS (P < .001). Virtually all adults found UIS/FIS bothersome (>=96% for each), even when incontinence occurred "almost never." UIS/FIS mostly occurred before and/or during orgasm than afterward (P < .001). UIS was reported by 53% of adults with a urostomy (100% bothersome). FIS was reported by 38% of adults with a colostomy (100% bothersome). CONCLUSION: Incontinence during sexual activity is a common problem for men and women with SB. Baseline incontinence is an independent, but not absolute, predictor of both. While FIS is less frequent than UIS, both are virtually always bothersome.

An Apparatus for Measuring Combined Shear-Tensile Loading in Fibrous Tissues Ex Vivo.

Soft tissues such as tendon and ligament undergo a combination of shear and tensile loading in vivo due to their boundary conditions at muscle and/or bone. Current experimental protocols are limited to pure tensile loading, biaxial loading, or simple shear, and thus may not fully characterize the mechanics of these tissues under physiological loading scenarios. Our objective was to create an experimental protocol to determine the shear modulus of fibrous tissues at different tensile loads. We assembled a four-actuator experimental system that facilitated shear deformation to be superimposed on a tissue subjected to an axial preload. We measured shear modulus in axially loaded electrospun nanofiber scaffolds with either randomly oriented or aligned fibers. We found that shear modulus in the nanofiber phantoms was shear-strain stiffening and dependent on both the axial load (p < 0.001) and fiber alignment (p < 0.001) of the scaffold. The proposed system can enhance our understanding of microstructure and functional mechanics in soft tissues, while also providing a platform to investigate the behavior of electrospun scaffolds for tissue regeneration. Our experimental protocol for determining loaded shear modulus would be further useful as a method to gauge tissue mechanics under loading conditions that are more representative of physiological loads applied to tendon and ligament.

Transitioning young adults with spina bifida: Challenges and paths to success.

INTRODUCTION AND BACKGROUND: Recent medical advances, including closure of myelomeningocele defects, shunting of hydrocephalus, and focusing on renal preservation have led to many individuals with spina bifida (SB) living into adulthood. This has led to more individuals with SB transitioning their care from pediatric-based to adult-based care models. OBJECTIVE: We seek to explore the process of transition, with a focus on difficulties in transitioning individuals with SB. Additionally, we explore new problems that arise during the period of transition related to sexual function and dysfunction. We also discuss some of the difficulties managing neurogenic bladder and the sequalae of their prior urologic surgeries. STUDY DESIGN: Each of the authors was asked to provide a summary, based on current literature, to highlight the challenges faced in their area of expertise. CONCLUSIONS: Transitioning care for individuals with SB is especially challenging due to associated neurocognitive deficits and neuropsychological functioning issues. Sexual function is an important component of transition that must be addressed in young adults with SB. Management of neurogenic bladder in adults with SB can be challenging due to the heterogeneity of the population and the sequelae of their prior urologic surgeries. The aim is to ensure that all individuals with SB receive appropriate, evidence-based care throughout their lifetime.

People with spina bifida use their MACE on long-term follow-up: A single institutional retrospective cohort study.

OBJECTIVE: While the Malone antegrade continence enema (MACE) facilitates bowel movements in patients with spina bifida (SB) and neuropathic bowel, little is known about its long-term use. We aimed to assess long-term MACE use and potential risk factors for disuse. METHODS: All patients with SB who underwent MACE procedures at our institution were retrospectively reviewed. Main outcome was MACE disuse (no longer catheterizing the MACE for antegrade enemas) based on self-report on a clinic questionnaire, or medical record for patients last seen before introducing the questionnaire 5 years ago. Survival analysis used two timeframes: time after surgery (Analysis 1) and chronological age: accounting for older children reaching adulthood earlier (Analysis 2). RESULTS: Overall, 411 patients (54% female, 78% shunted, 65% augmented) underwent a MACE procedure at median 7.9 years old (median follow-up: 8.4 years). Thirty-three (8%) patients no longer used their MACE. Most common reasons for doing so were channel/stomal stenosis (61%) and excision at colostomy or other abdominal surgery (12%). Bowel management afterwards included oral agents ± enemas (55%), Chait tube (30%), colostomy (12%). After correcting for differential follow-up, 90% of participants used their MACE at 10 years and 87% at 15 years after surgery. Based on chronological age, 97% used their MACE at 15 years old, 92% at 20 and 81% at 30 (Summary Figure). On multivariate analysis, umbilical MACEs were 2.4 times more likely to be disused than right lower quadrant MACEs (p = 0.04). Without correcting for chronological age (Analysis 1), patients undergoing MACE surgery at older ages were more likely to stop MACE use (p = 0.03). However, after accounting for chronological age (Analysis 2), patients undergoing a MACE procedure at older ages were no more likely to stop its use (p = 0.47, Figure). Gender, SB type, shunt status, mobility status, bladder augmentation or a urinary catheterizable channel were not associated with stopping MACE use (p ≥ 0.10). COMMENT: Participants were regularly followed in multi-disciplinary SB clinics. We did not assess continence, satisfaction or long-term urinary channel use, making it premature to recommend optimal stomal locations. CONCLUSIONS: Most patients with SB followed by a multi-disciplinary team continue using their MACE; 1% stopped MACE use annually, particularly after adolescence. This strongly suggests it is an effective bowel management method and transitioning to self-care plays a role in maintaining long-term MACE use. Umbilical MACEs may be at high risk of disuse, but all people with a MACE can benefit from support as they transition to adult care.

Ileal Ureter Utilization in Patients With Previous Urinary Diversions.

OBJECTIVE: To evaluate a subset of patients who develop strictures requiring Ileal Ureter (IU) in the setting of prior urinary diversion or augmentation (ileal conduits, neobladders, continent urinary diversions). To our knowledge, there are no prior studies on patients with IU substitution into established lower urinary tract reconstructions. METHODS: A retrospective review of patients (18 years) undergoing IU creation from 1989 to 2021 was performed. A total of 160 patients were identified. In total, 19 (12%) patients had IUs into diversions. We examined demographics, stricture cause, diversion type, renal function, and postoperative complications. RESULTS: Nineteen patients were identified. Sixteen were male. Mean age was 57.7(SD 17.0) years. Diversions included continent urinary reservoirs (4), neobladders (5), ileal conduits (7), and bladder augmentations with Monti channels (3). Fifteen had unilateral surgery, and 4 had bilateral "reverse 7" IU creation. Average length of stay was 7.6 days (SD 2.9). Average follow-up was 32.9 months (SD 27). Mean preoperative creatinine was 1.5 (SD 0.4); mean postoperative creatinine at most recent follow-up was 1.6 (SD 0.7). There was no significant difference between pre- and postoperative creatinine (P = .18). One patient had a ventriculoperitoneal Shunt infection resulting ventriculoperitoneal shunt externalization, 1 had Clostridium difficile infection potentially causing an entero-neobladder fistula, 2 with ileus, 1 urine leak, and 1 wound infection. None required renal replacement therapy. CONCLUSION: Patients with urinary diversions and prior bowel reconstructive surgeries with subsequent ureteral strictures are a challenging cohort of patients. In properly selected patients, ureteral reconstruction with ileum is feasible and preserves renal function with minimal long-term complications.

Sexual activity and function of adult men with spina bifida.

OBJECTIVE: Data on sexual function of men with spina bifida (SB) is limited. We aimed to assess sexual activity and erectile dysfunction (ED) in a large international sample of men with SB. METHODS: Men with SB (≥18yo) were recruited in an international online survey via clinics and social media. We collected data on demographics, ambulation (Hoffer classification), penile rigidity (Erection Hardness Score), sexual activity and ED (International Index of Erectile Function). Non-parametric tests were used. RESULTS: A total of 162 men (median age 35, 62% shunted, 38% community ambulators) reported sexual desire similar to the general population (p = 0.82), but 55% were dissatisfied with their sex life (Summary Table). Overall, 36% reported full penile rigidity with erections, more commonly with better ambulation (p = 0.01), 69% had ever experienced orgasm and 84% ejaculated. In 44 men (27%) attempting sexual intercourse in the last 4 weeks, 59% had ED (11% severe, 7% moderate, 14% mild-moderate, 27% mild). In this group, 91% of men reporting less than full penile rigidity had ED, compared to 30% with full penile rigidity (p = 0.001). Overall, partnered non-genital contact in the last 3 months was reported by 56%, solo masturbation: 62%, partnered intercourse: 48% (31% vaginal). Of 54 men who used phosphodiesterase type 5 inhibitors (PDE5I), 80% reported improved erections, 56% improved intercourse. Overall, 40% reported non-genital erogenous zones as most pleasurable, especially with poorer ambulation (p = 0.002, chest/nipples: 73%). COMMENT: Strengths of this study include anonymous, voluntary, online participation maximizing participation of a heterogenous, international population. Whenever available, we compared findings to published values for the general population. Since romantic and sexual activity is a complex intersection of interest, opportunity and ability, a more comprehensive assessment was beyond the study's scope. Future work will focus on the interplay with issues like incontinence. CONCLUSIONS: ED was frequent among men with SB, especially in men with poorer ambulation. PDE5 inhibitors may be beneficial. Partnered sexual activity was reported by half of the men, although it may not involve penetrative intercourse.

Age-based risk of end-stage kidney disease in patients with myelomeningocele.

OBJECTIVE: We aimed to quantify end-stage kidney disease (ESKD) risk after infancy in individuals with myelomeningocele (MMC) followed by urology in the modern medical era and to assess if ESKD risk was higher after surgery related to a hostile bladder. METHODS: We retrospectively reviewed patients with MMC followed by urology at our institution born ≥ 1972 (when clean intermittent catheterization was introduced) past 1 year of age (when mortality is highest, sometimes before establishing urology care). ESKD was defined as requiring permanent peritoneal/hemodialysis or renal transplantation. Early surgery related to hostile bladder included incontinent vesicostomy, bladder augmentation, detrusor Botulinum A toxin injection, ureteral reimplantation, or nephrectomy for recurrent urinary tract infections. Survival analysis and proportional hazards regression were used. Sensitivity analyses included: risk factor analysis with only vesicostomy, timing of surgery, including the entire population without minimal follow-up (n = 1054) and only patients with ≥ 5 years of follow-up (n = 925). RESULTS: Overall, 1029 patients with MMC were followed for a median of 17.0 years (49% female, 76% shunted). Seven patients (0.7%) developed ESKD at a median 24.3 years old (5 hemodialysis, 1 peritoneal dialysis, 1 transplantation). On survival analysis, the ESKD risk was 0.3% at 20 years old and 2.1% at 30 years old (Figure). This was ∼100 times higher than the general population (0.003% by 21 years old, p < 0.001). Patients who underwent early surgery for hostile bladder had higher ESKD risk (HR 8.3, p = 0.001, 6% vs. 1.5% at 30 years). On exploratory analyses, gender, birth year, shunt status and wheelchair use were not associated with ESKD risk (p ≥ 0.16). Thirty-year ESKD risk was 10% after early vesicostomy vs. 1.4% among children without one (p = 0.001). Children undergoing bladder surgery between 1.5 and 5 years old had a higher risk of ESKD. No other statistically/clinically significant differences were noted. COMMENT: Patients with MMC remain at risk of progressive renal damage throughout life. We relied on the final binary ESKD outcome to quantify this risk, rather than imprecise glomerular filtration rate formulas. Analysis was limited by few people developing ESKD, inconsistent documentation of early urodynamic findings and indications for bladder-related surgery. CONCLUSIONS: While ESKD is relatively uncommon in the MMC population receiving routine urological care, affecting 2.1% of individuals in the first 3 decades, it is significantly higher than the general population. Children with poor bladder function are likely at high risk, underlining the need for routine urological care, particularly in adulthood.

Shear wave tensiometry tracks reductions in collateral ligament tension due to incremental releases.

Surgeons routinely perform incremental releases on overly tight ligaments during total knee arthroplasty (TKA) to reduce ligament tension and achieve their desired implant alignment. However, current methods to assess whether the surgeon achieved their desired reduction in the tension of a released ligament are subjective and/or do not provide a quantitative metric of tension in an individual ligament. Accordingly, the purpose of this study was to determine whether shear wave tensiometry, a novel method to assess tension in individual ligaments based on the speed of shear wave propagation, can detect changes in ligament tension following incremental releases. In seven medial and eight lateral collateral porcine ligaments (MCL and LCL, respectively), we measured shear wave speeds and ligament tensions before and after incremental releases consisting of punctures with an 18-gauge needle. We found that shear wave speed squared decreased linearly with decreasing tension in both the MCL (average coefficient of determination (R2 avg ) = 0.76) and LCL (R2 avg = 0.94). We determined that errors in predicting tension following incremental releases were 26.2 and 14.2 N in the MCL and LCL, respectively, using ligament-specific calibrations. These results suggest shear wave tensiometry is a promising method to objectively measure the tension reduction in released structures. Clinical Significance: Direct, objective measurements of the tension changes in individual ligaments following release could enhance surgical precision during soft tissue balancing in total knee arthroplasty. Thus, shear wave tensiometry could help surgeons reduce the risk of poor outcomes associated with overly tight ligaments, including residual knee pain and stiffness.

Solo and Partnered Sexual Behavior Among an International Sample of Adults With Spina Bifida.

BACKGROUND: Spina bifida (SB) may differentially impact adults' participation in solo and partnered sexual behaviors, but little research investigates this topic. AIM: Describe solo and partnered sexual behaviors among an international sample of adult men and women with SB. MAIN OUTCOME MEASURES: Ever participated (no/yes) and recent participation (>1 year ago/within last year) in solo masturbation, cuddled with a partner, held hands with a partner, kissed a partner, touched a partner's genital, had genitals touched by a partner, gave a partner oral sex, received oral sex from a partner, vaginal sex, anal sex, and sex toy use. METHODS: Data were drawn from a larger cross-sectional, internet-based survey assessing the sexual behaviors of an international sample of men and women with SB. We used logistic regression to examine the impact of background (gender, age, independent living, and relationship status) and health (shunt status, ambulation, and genital sensation) factors on each outcome. RESULTS: The sample consisted of 345 respondents aged 18-73 years from 26 nations. Very few (<3%) had no lifetime experience with any solo or partnered behaviors; 25.0% reported participating in all behaviors at some point in their lives. The median number of past year sexual behaviors (of 16 total) was 7. Lifetime and recent participation were associated with demographic and health factors. CLINICAL IMPLICATIONS: Despite impairment, adults with spina bifida do participate in solo and partnered sexual behaviors. Medical personnel who work with this population should include discussions about sexuality as part of routine care. STRENGTHS & LIMITATIONS: Although this research measured solo and partnered sexual behavior in large international sample of adults with spina bifida, it is limited by its cross-sectional retrospective design and non-clinical convenience sample. CONCLUSION: Despite disability, many adults with SB participate in solo and partnered sexual behavior. Medical and psychosocial supports are needed to help adults in this population enjoy sexuality in a healthy and safe manner. Hensel DJ, Misseri R, Wiener JS, et al. Solo and Partnered Sexual Behavior Among an International Sample of Adults With Spina Bifida. J Sex Med 2022;19:1766-1777.

Sensitivity of the shear wave speed-stress relationship to soft tissue material properties and fiber alignment.

The use of shear wave propagation to noninvasively measure material properties and loading in tendons and ligaments is a growing area of interest in biomechanics. Prior models and experiments suggest that shear wave speed primarily depends on the apparent shear modulus (i.e., shear modulus accounting for contributions from all constituents) at low loads, and then increases with axial stress when axially loaded. However, differences in the magnitudes of shear wave speeds between ligaments and tendons, which have different substructures, suggest that the tissue's composition and fiber alignment may also affect shear wave propagation. Accordingly, the objectives of this study were to (1) characterize changes in the apparent shear modulus induced by variations in constitutive properties and fiber alignment, and (2) determine the sensitivity of the shear wave speed-stress relationship to variations in constitutive properties and fiber alignment. To enable systematic variations of both constitutive properties and fiber alignment, we developed a finite element model that represented an isotropic ground matrix with an embedded fiber distribution. Using this model, we performed dynamic simulations of shear wave propagation at axial strains from 0% to 10%. We characterized the shear wave speed-stress relationship using a simple linear regression between shear wave speed squared and axial stress, which is based on an analytical relationship derived from a tensioned beam model. We found that predicted shear wave speeds were both in-range with shear wave speeds in previous in vivo and ex vivo studies, and strongly correlated with the axial stress (R2 = 0.99). The slope of the squared shear wave speed-axial stress relationship was highly sensitive to changes in tissue density. Both the intercept of this relationship and the apparent shear modulus were sensitive to both the shear modulus of the ground matrix and the stiffness of the fibers' toe-region when the fibers were less well-aligned to the loading direction. We also determined that the tensioned beam model overpredicted the axial tissue stress with increasing load when the model had less well-aligned fibers. This indicates that the shear wave speed increases likely in response to a load-dependent increase in the apparent shear modulus. Our findings suggest that researchers may need to consider both the material and structural properties (i.e., fiber alignment) of tendon and ligament when measuring shear wave speeds in pathological tissues or tissues with less well-aligned fibers.

Development and evaluation of ligament phantoms targeted for shear wave tensiometry.

Developing a shear wave tensiometer capable of non-invasively measuring ligament tension holds promise for enhancing research and clinical assessments of ligament function. Such development would benefit from tunable test specimens fabricated from well-characterized and consistent materials. Although previous work found that yarn can replicate the mechanical behavior of collateral ligaments, it is not obvious whether yarn-based phantoms would be suitable for development of a shear wave tensiometer for measuring ligament tension. Accordingly, the primary objective of this study was to characterize the mechanical properties and shear wave speed - stress relationships of ligament phantoms fabricated from yarn and silicone, and compare these results to published data from biological ligaments. We measured the mechanical properties and shear wave speeds during axial loading in nine phantoms with systematically varied material properties. We performed a simple linear regression between shear wave speed squared and axial stress to determine the shear wave speed - stress relationship for each phantom. We found comparable elastic moduli, hysteresis, and shear wave speed squared - stress regression parameters between the phantoms and collateral ligaments. For example, the ranges of the coefficients of determination (R2) and slopes across the nine phantoms were 0.84-0.95, and 0.78-1.27 kPa/m2/s2, respectively, which overlapped with the ranges found in a prior study in porcine collateral ligaments (0.84-0.996 and 0.34-1.18 kPa/m2/s2, respectively). Additionally, the shear wave speed squared - stress regression parameters varied predictably with the density of the phantom and the shear modulus of the silicone. In summary, we found that yarn-based phantoms serve as mechanical analogs for ligaments (i.e., are ligament mimicking), and thus, should prove beneficial for investigations into ligament structure-function relationships and in the development of a shear wave tensiometer for measuring ligament tension.

Troubleshooting problems with antegrade continent enema flushes: The Indiana university algorithm.

INTRODUCTION: Antegrade continence enemas have transformed treatment and improved the quality of life in children with neuropathic bowel, refractory constipation and fecal incontinence. However, it can often be difficult to manage problems that arise with ACE flushes. OBJECTIVE: We report the use of an online tool designed for nurses to help troubleshoot calls for problems associated with antegrade continence enema (ACE) flushes as well as update our algorithm for managing refractory constipation/fecal incontinence in a large single institution experience. STUDY DESIGN: We developed an online tool based on our management protocol for managing refractory constipation/fecal incontinence (Summary Figure). Patient frequency and bother was assessed prior to the intervention and at one month after the intervention using 5- and 4-point Likert scales respectively. Patient demographics, MACE/Chait information, type of difficulty, volume of flush, and use of additives were recorded. Nurses were also interviewed prior to using the tool and 14 months after its development with regards to taking these phone calls and the helpfulness of the tool. RESULTS: Over 14 months, the nurses received 22 patients calls via the nursing triage line regarding ACE flush problems and prospectively collected data. Half reported multiple episodes of fecal incontinence. Other complaints included no response to flush (8, 36.4%), occasional episodes of liquid fecal incontinence (2, 9.1%) and time of flush exceeding 60 min (1, 4.5%). While patients did not report decreased frequency of problems as a result of nurse troubleshooting using the ACE algorithm (2.5 vs. 2, p = 0.55), patients did report a significant improvement in their bother scores (4 vs. 2, p = 0.02). All but one patient reported that the recommendation was "some" or "a lot" helpful on follow up interview. The nurses all indicated that the tool helped "some" or "a lot." DISCUSSION: The antegrade continence enema is valuable in managing neurogenic bowel, refractory constipation, and fecal incontinence, however, some patients experience problems with flushes that can often be difficult to manage. CONCLUSION: Patients reported less bother with their bowel issues after using our algorithm for managing refractory constipation/fecal incontinence and nurses reported that the tool was helpful.

Technique and Outcomes of Hand-Assist Laparoscopic Continent Cutaneous Ileocecocystoplasty.

BACKGROUND: Continent cutaneous ileocecocystoplasty (CCIC) involves reconfiguring the ileocecal segment for use as a bladder augment and continent catheterizable channel. CCIC requires release of the hepatic flexure of the colon, which necessitates a longer midline laparotomy than would be required for a standard bladder augmentation. This is associated with high rates of ventral and parastomal hernias. OBJECTIVES: To describe the technique of hand-assist laparoscopic CCIC and to compare outcomes to open CCIC. MATERIALS AND METHODS: We found pure laparoscopic colon mobilization difficult due to significant colonic distension in patients with neurogenic bladder and bowel. We modified our approach to hand-assisted laparoscopic mobilization for better retraction of the bowel. A 12-mm camera port is placed through the umbilicus, which later serves as the stoma site, and a 5-mm assist port is placed a handbreadth cephalad to the 12-mm port. A Pfannenstiel incision is made for use as the hand port. After colonic mobilization is completed the remainder of the procedure is performed in an open fashion through the Pfannenstiel incision. The primary outcome was 90-day Clavien grade 2 or greater complications. Secondary outcomes included revision rates, wound infection, urinary continence, operative time, and length of stay. Data was analyzed using Mann-Whitney U test and Fisher's exact test. RESULTS: Thirty-two laparoscopic and 21 open procedures were reviewed. Those who underwent open procedures were more likely to have undergone prior catheterizable channel or bladder augmentation (7 vs 1, P < .01). There were fewer 90-day complications in the laparoscopic group (18.8% vs 47.6%, P = .03). There was no difference in operative time, hospital length of stay, wound infections, need for subsequent channel revision, or long-term continence between groups. CONCLUSION: Hand-assist laparoscopic CCIC offers a minimally invasive alternative to open CCIC with fewer short-term complications and comparable long-term outcomes.

Sexual function and dysfunction in men with spina bifida.

Spina bifida is the most common neural tube defect, which can lead to multiple urologic problems stemming from neurogenic bladder including need for lifelong renal monitoring and urinary continence. However, as males with SB age, it is clear that many also start to care about their sexuality, which may also be affected by the disease process. After reviewing the literature, the authors summarize the available information regarding sexual function and sexual dysfunction in adult males with spina bifida, specifically focusing on sexuality education, relationship status/sexual activity, continence, penile rigidity, penile sensation, ability to orgasm, ability to ejaculate, quality of ejaculation and non-genital sexual contact. Finally, the authors conclude that more research is needed in the fields of sexual function and sexual dysfunction in adults with spina bifida. This area of study is in need of objective, standardized research with large cohorts so that we can better study and educate men with SB about the impact of SB on their sexuality.