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.

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.

Contemporary multicenter outcomes of continent cutaneous ileocecocystoplasty in the adult population over a 10-year period: A Neurogenic Bladder Research Group study.

AIMS: Evidence is sparse on the long-term outcomes of continent cutaneous ileocecocystoplasty (CCIC). We hypothesized that obesity, laparoscopic/robotic approach, and concomitant surgeries would affect morbidity after CCIC and aimed to evaluate the outcomes of CCIC in adults in a multicenter contemporary study. METHODS: We retrospectively reviewed the charts of adult patients from sites in the Neurogenic Bladder Research Group undergoing CCIC (2007-2017) who had at least 6 months of follow-up. We evaluated patient demographics, surgical details, 90-day complications, and follow-up surgeries. the Mann-Whitney U test was used to compare continuous variables and χ² and Fisher's Exact tests were used to compare categorical variables. RESULTS: We included 114 patients with a median age of 41 years. The median postoperative length of stay was 8 days. At 3 months postoperatively, major complications occurred in 18 (15.8%), and 24 patients (21.1%) were readmitted. During a median follow-up of 40 months, 48 patients (42.1%) underwent 80 additional related surgeries. Twenty-three patients (20.2%) underwent at least one channel revision, most often due to obstruction (15, 13.2%) or incontinence (4, 3.5%). Of the channel revisions, 10 (8.8%) were major and 14 (12.3%) were minor. Eleven patients (9.6%) abandoned the catheterizable channel during the follow-up period. Obesity and laparoscopic/robotic surgical approach did not affect outcomes, though concomitant surgery was associated with a higher rate of follow-up surgeries. CONCLUSIONS: In this contemporary multicenter series evaluating CCIC, we found that the short-term major complication rate was low, but many patients require follow-up surgeries, mostly related to the catheterizable channel.

Frequency of patient-reported UTIs is associated with poor quality of life after spinal cord injury: a prospective observational study.

STUDY DESIGN: Cross-sectional survey of the Neurogenic Bladder Research Group (NBRG) registry; a multicenter prospective observation study. OBJECTIVES: To assess how patient-reported urinary tract infections (PRUTIs) in spinal cord injury (SCI) affect quality of life (QOL). SETTING: Multiple United States hospitals. METHODS: 1479 participants with SCI were asked about neurogenic bladder-related QOL. Eligibility: age ≥ 18 years with acquired SCI. PRUTI frequency over the last year was classified as 0, 1-3, 4-6, or >6. Four UTI QOL domains were assessed: (1) UTIs limited daily activities, (2) UTIs caused increased muscle spasms, (3) UTIs would not go away, and (4) UTIs made me avoid going out. Multivariable regression identified variables associated with poor QOL. RESULTS: PRUTI frequency was 0 in 388 patients (26%), 1-3 in 677 (46%), 4-6 in 223 (15%), and more than 6 in 190 (13%). Increasing PRUTI rate was independently associated with worse QOL for all four questions. Compared with those with 0 PRUTIs, participants reporting >6 were more likely to limit daily activities (OR 9.0 [95% CI 8.1-21.2] p < 0.0001), experience increased muscle spasms (OR 12.4 [95% CI 7.5-20.6] p < 0.0001), perceive a UTI would not go away (OR 30.1 [95% CI 15.0-60.4] p < 0.0001), and avoid going out because of UTIs (OR 7.2 [95% CI 4.2-12.4] p < 0.0001). CONCLUSIONS: An increasing rate of PRUTIs is independently associated with worse QOL. Thorough evaluation and treatment may improve QOL in this population.

Epidural Analgesia Decreases Narcotic Requirements in Patients with Low Level Spina Bifida Undergoing Urological Laparotomy for Neurogenic Bladder and Bowel.

PURPOSE: Concerns regarding anatomical anomalies and worsening neurological symptoms have prevented widespread use of epidural catheters in patients with low level spina bifida. We hypothesize that thoracic epidural placement in the T9 to T10 interspace is safe and decreases narcotic requirements following major open lower urinary tract reconstruction in patients with low level spina bifida. MATERIALS AND METHODS: We reviewed consecutive patients with low level spina bifida who underwent lower urinary tract reconstruction and received epidurals for postoperative pain control. Controls were patients with low level spina bifida who received single injection transversus abdominis plane blocks and underwent similar procedures. Complications of epidural placement, including changes in motor and sensory status, were recorded. Opioid consumption was calculated using equivalent intravenous morphine doses. Mean and maximum pain scores on postoperative days 0 to 3 were calculated. RESULTS: Ten patients with low level spina bifida who underwent lower urinary tract reconstruction with epidural were matched to 10 controls with low level spina bifida who underwent lower urinary tract reconstruction with transverse abdominis plane block. Groups were demographically similar. All patients had full abdominal sensation and functional levels at or below L3. No epidural complications or changes in neurological status were noted. The epidural group had decreased opioid consumption on postoperative days 0 to 3 (0.75 mg/kg vs 1.29 mg/kg, p = 0.04). Pain scores were similar or improved in the epidural group. CONCLUSIONS: Thoracic epidural analgesia appears to be a safe and effective opioid sparing option to assist with postoperative pain management following lower urinary tract reconstruction in individuals with low level spina bifida.

Radiographic abnormalities, bladder interventions, and bladder surgery in the first decade of life in children with spina bifida.

BACKGROUND: Spina bifida (SB) patients are at increased risk for hydronephrosis, bladder storage and emptying problems, and renal failure that may require multiple bladder surgeries. METHODS: We retrospectively reviewed patients born with SB 2005-2009, presenting to our institution within 1 year of birth. Outcomes at 8-11 years old included final renal/bladder ultrasound (RBUS) results, clean intermittent catheterization (CIC) use, anticholinergic use, surgical interventions, and final renal function. We excluded those without follow-up past age 8 and/or no RBUS or fluoroscopic urodynamic images (FUI) within the first year of life. Imaging was independently reviewed by four pediatric urologists blinded to radiologists' interpretation and initial findings compared with final outcomes. RESULTS: Of 98 children, 62 met inclusion criteria (48% male, 76% shunted). Median age at last follow-up was 9.6 years. Upon initial imaging, 74% had hydronephrosis (≥ SFU grade 1), decreasing to 5% at 10 years (p < 0.0001). Initially, 9% had ≥ SFU grade 3 hydronephrosis, decreasing to 2% (p = 0.13). CIC and anticholinergic use increased from 61% and 37% to 87% and 86%, respectively (p = 0.001 and p < 0.0001, respectively). With follow-up, 55% had surgical intervention and 23% had an augmentation. Of children with a serum creatinine/cystatin-C at 8-11 years old, one had confirmed chronic kidney disease (stage 2). CONCLUSIONS: Despite initial high incidence of hydronephrosis, this was low grade and resolved in the first decade of life. Additionally, the 8-11-year incidence of kidney disease and upper tract changes was low due to aggressive medical management.

Patient subjective assessment of urinary tract infection frequency and severity is associated with bladder management method in spinal cord injury.

STUDY DESIGN: The Neurogenic Bladder Research Group (NBRG) registry is a multicenter prospective observational study. This manuscript is retrospective based on a cross-sectional survey. OBJECTIVES: To assess patient subjective assessment of urinary tract infection (UTI) frequency and severity are associated with the degree of use of catheters or incontinence products. SETTING: Multiple hospitals across the United States. METHODS: Eligibility included: age > 18 years and acquired SCI. Over 1.5 years, 1479 eligible participants were enrolled. We excluded those with surgical reconstruction or diversion of the bladder. In total, 1282 participants were grouped by bladder management: (1) indwelling catheter (IDC), (2) clean intermittent catheterization (CIC), (3) external devices (pads/condom), and (4) volitional voiding (Void). UTI frequency was classified as 0, 1-3, 4-6, or > 6 over the prior year. UTI severity was determined by hospitalization for UTI in the prior year. Multivariate regression compared these factors across groups. RESULTS: UTIs were least frequent in Void followed by pads/condom, CIC, and IDC (all p ≤ 0.001). UTI severity followed a similar pattern. Controlling for covariates, the adjusted odds of UTI frequency (Void = reference) were 2.28 (1.38-3.76) for pads/condom, 3.42 (2.25-5.18) for CIC, and 4.3 (2.59-6.70) for IDC (all p ≤ 0.001). CONCLUSIONS: Patient subjective assessment of UTI frequency is highest with IDC, followed by CIC, pads/condom, and lowest with spontaneous voiding. The odds of hospitalization for UTI were three times higher for IDC than spontaneous voiding. UTI risk should be considered when counseling patients about bladder management options. These associations do not imply causation but warrant further investigation in a prospective manner. SPONSORSHIP: Patient-Centered Outcomes Research Institute (PCORI) Award (CER14092138).

Kinematically aligned total knee arthroplasty limits high tibial forces, differences in tibial forces between compartments, and abnormal tibial contact kinematics during passive flexion.

PURPOSE: Following total knee arthroplasty (TKA), high tibial forces, large differences in tibial forces between the medial and lateral compartments, and anterior translation of the contact locations of the femoral component on the tibial component during passive flexion indicate abnormal knee function. Because the goal of kinematically aligned TKA is to restore native knee function without soft tissue release, the objectives were to determine how well kinematically aligned TKA limits high tibial forces, differences in tibial forces between compartments, and anterior translation of the contact locations of the femoral component on the tibial component during passive flexion. METHODS: Using cruciate retaining components, kinematically aligned TKA was performed on thirteen human cadaveric knee specimens with use of manual instruments without soft tissue release. The tibial forces and tibial contact locations were measured in both the medial and lateral compartments from 0° to 120° of passive flexion using a custom tibial force sensor. RESULTS: The average total tibial force (i.e. sum of medial + lateral) ranged from 5 to 116 N. The only significant average differences in tibial force between compartments occurred at 0° of flexion (29 N, p = 0.0008). The contact locations in both compartments translated posteriorly in all thirteen kinematically aligned TKAs by an average of 14 mm (p < 0.0001) and 18 mm (p < 0.0001) in the medial and lateral compartments, respectively, from 0° to 120° of flexion. CONCLUSIONS: After kinematically aligned TKA, average total tibial forces due to the soft tissue restraints were limited to 116 N, average differences in tibial forces between compartments were limited to 29 N, and a net posterior translation of the tibial contact locations was observed in all kinematically aligned TKAs during passive flexion from 0° to 120°, which are similar to what has been measured previously in native knees. While confirmation in vivo is warranted, these findings give surgeons who perform kinematically aligned TKA confidence that the alignment method and surgical technique limit high tibial forces, differences in tibial forces between compartments, and anterior translation of the tibial contact locations during passive flexion.

Increases in tibial force imbalance but not changes in tibiofemoral laxities are caused by varus-valgus malalignment of the femoral component in kinematically aligned TKA.

PURPOSE: The purposes of this study were to quantify the increase in tibial force imbalance (i.e. magnitude of difference between medial and lateral tibial forces) and changes in laxities caused by 2° and 4° of varus-valgus (V-V) malalignment of the femoral component in kinematically aligned total knee arthroplasty (TKA) and use the results to detemine sensitivities to errors in making the distal femoral resections. Because V-V malalignment would introduce the greatest changes in the alignment of the articular surfaces at 0° flexion, the hypotheses were that the greatest increases in tibial force imbalance would occur at 0° flexion, that primarily V-V laxity would significantly change at this flexion angle, and that the tibial force imbalance would increase and laxities would change in proportion to the degree of V-V malalignment. METHODS: Kinematically aligned TKA was performed on ten human cadaveric knee specimens using disposable manual instruments without soft tissue release. One 3D-printed reference femoral component, with unmodified geometry, was aligned to restore the native distal and posterior femoral joint lines. Four 3D-printed femoral components, with modified geometry, introduced V-V malalignments of 2° and 4° from the reference component. Medial and lateral tibial forces were measured during passive knee flexion-extension between 0° to 120° using a custom tibial force sensor. Eight laxities were measured from 0° to 120° flexion using a six degree-of-freedom load application system. RESULTS: With the tibial component kinematically aligned, the increase in the tibial force imbalance from that of the reference component at 0° of flexion was sensitive to the degree of V-V malalignment of the femoral component. Sensitivities were 54 N/deg (medial tibial force increasing > lateral tibial force) (p < 0.0024) and 44 N/deg (lateral tibial force increasing > medial tibial force) (p < 0.0077) for varus and valgus malalignments, respectively. Varus-valgus malalignment did not significantly change varus, internal-external rotation, anterior-posterior, and compression-distraction laxities from 0° to 120° flexion. At only 30° of flexion, 4° of varus malalignment increased valgus laxity 1° (p = 0.0014). CONCLUSION: At 0° flexion, V-V malalignment of the femoral component caused the tibial force imbalance to increase significantly, whereas the laxities were relatively unaffected. Because tibial force imbalance has the potential to adversely affect patient-reported outcomes and satisfaction, surgeons should strive to limit errors in resecting the distal femoral condyles to within ± 0.5 mm which in turn limits the average increase in tibial force imbalance to 68 N. Because laxities were generally unaffected, instability resulting from large increases in laxity is not a clinical concern within the ± 4° range tested. LEVEL OF EVIDENCE: Therapeutic, Level II.

Internal-external malalignment of the femoral component in kinematically aligned total knee arthroplasty increases tibial force imbalance but does not change laxities of the tibiofemoral joint.

PURPOSE: The purposes of this study were to quantify the increase in tibial force imbalance (i.e. magnitude of difference between medial and lateral tibial forces) and changes in laxities caused by  2° and 4° of internal-external (I-E) malalignment of the femoral component in kinematically aligned total knee arthroplasty. Because I-E malalignment would introduce the greatest changes to the articular surfaces near 90° of flexion, the hypotheses were that the tibial force imbalance would be significantly increased near 90° flexion and that primarily varus-valgus laxity would be affected near 90° flexion. METHODS: Kinematically aligned TKA was performed on ten human cadaveric knee specimens using disposable manual instruments without soft tissue release. One 3D-printed reference femoral component, with unmodified geometry, was aligned to restore the native distal and posterior femoral joint lines. Four 3D-printed femoral components, with modified geometry, introduced I-E malalignments of 2° and 4° from the reference component. Medial and lateral tibial forces were measured from 0° to 120° flexion using a custom tibial force sensor. Bidirectional laxities in four degrees of freedom were measured from 0° to 120° flexion using a custom load application system. RESULTS: Tibial force imbalance increased the greatest at 60° flexion where a regression analysis against the degree of I-E malalignment yielded sensitivities (i.e. slopes) of 30 N/° (medial tibial force > lateral tibial force) and 10 N/° (lateral tibial force > medial tibial force) for internal and external malalignments, respectively. Valgus laxity increased significantly with the 4° external component with the greatest increase of 1.5° occurring at 90° flexion (p < 0.0001). CONCLUSION: With the tibial component correctly aligned, I-E malalignment of the femoral component caused significant increases in tibial force imbalance. Minimizing I-E malalignment lowers the increase in the tibial force imbalance. By keeping the resection thickness of each posterior femoral condyle to within ± 0.5 mm of the thickness of the respective posterior region of the femoral component, the increase in imbalance can be effectively limited to 38 N. Generally laxities were unaffected within the ± 4º range tested indicating that instability is not a clinical concern and that manual testing of laxities is not useful to detect I-E malalignment.

A novel technique for direct visualization of reservoir placement for penoscrotal inflatable penile prostheses using a single incision.

INTRODUCTION: We aim to present a modified technique and outcomes of a novel method allowing for direct visualization of the reservoir placement during a penoscrotal inflatable penile prosthesis (IPP). METHODS: Out of165 patients who underwent IPP placement from August 2012 to March 2015, 157 underwent a modified technique and comprised the cohort of this study. A Deaver's retractor was placed lateral to the penis and over the pubic bone to allow for direct visualization of the tissues overlying the lower abdomen. After dissecting through the superficial layers, the Deaver's was slowly advanced, allowing for visualization of the fascia, which was incised. Using blunt dissection, a space for the reservoir was created between the bladder and the pubic bone. The reservoir was then placed safely into this space and the Deaver's retractor was removed. RESULTS: The causes of ED in the study cohort included postprostatectomy ED (n = 107), organic impotence (n = 40), Peyronie's disease (n = 3), ED following cystoprostatectomy (n = 2), ED due to spinal cord injury (n = 2), ED resulting from priapism (n = 2), and ED after pelvic injury (n = 1); all of which were refractory to medical management. The median age of study population was 66 years and the mean (standard deviation) operative time was 72.8 (14.7) min. Eighty percent of the procedures were performed on outpatient basis. Complication rates were low (<5%), with four infections, one proximal pump migration, one scrotal hematoma, and one urinary tract infection. CONCLUSION: The modified technique for placement of the IPP's spherical reservoir under direct visualization through a penoscrotal incision is quick, safe, and effective.

Characterization and Correction of Errors in Computing Contact Location Between Curved Articular Surfaces: Application to Total Knee Arthroplasty.

In total knee arthroplasty (TKA), one common metric used to evaluate innovations in component designs, methods of component alignment, and surgical techniques aimed at decreasing the high rate of patient-reported dissatisfaction is tibiofemoral contact kinematics. Tibiofemoral contact kinematics are determined based on the movement of the contact locations in the medial and lateral compartments of the tibia during knee flexion. A tibial force sensor is a useful instrument to determine the contact locations, because it can simultaneously determine contact forces and contact locations. Previous reports of tibial force sensors have neither characterized nor corrected errors in the computed contact location (i.e., center of pressure) between the femoral and tibial components in TKA that, based on a static analysis, are caused by the curved articular surface of the tibial component. The objectives were to experimentally characterize these errors and to develop and validate an error correction algorithm. The errors were characterized by calculating the difference between the errors in the computed contact locations when forces were applied normal to the tibial articular surface and those when forces were applied normal to the tibial baseplate. The algorithm generated error correction functions to minimize these errors and was validated by determining how much the error correction functions reduced the errors in the computed contact location caused by the curved articular surface. The curved articular surface primarily caused bias (i.e., average or systematic error) which ranged from 1.0 to 2.7 mm in regions of high curvature. The error correction functions reduced the bias in these regions to negligible levels ranging from 0.0 to 0.6 mm (p < 0.001). Bias in the computed contact locations caused by the curved articular surface of the tibial component as small as 1 mm needs to be accounted for, because it might inflate the computed internal-external rotation and anterior-posterior translation of femur on the tibia leading to false identifications of clinically undesirable contact kinematics (e.g., internal rotation and anterior translation during flexion). Our novel error correction algorithm is an effective method to account for this bias to more accurately compute contact kinematics.

An Improved Tibial Force Sensor to Compute Contact Forces and Contact Locations In Vitro After Total Knee Arthroplasty.

Contact force imbalance and contact kinematics (i.e., motion of the contact location in each compartment during flexion) of the tibiofemoral joint are both important predictors of a patient's outcome following total knee arthroplasty (TKA). Previous tibial force sensors have limitations in that they either did not determine contact forces and contact locations independently in the medial and lateral compartments or only did so within restricted areas of the tibial insert, which prevented them from thoroughly evaluating contact force imbalance and contact kinematics in vitro. Accordingly, the primary objective of this study was to present the design and verification of an improved tibial force sensor which overcomes these limitations. The improved tibial force sensor consists of a modified tibial baseplate which houses independent medial and lateral arrays of three custom tension-compression transducers each. This sensor is interchangeable with a standard tibial component because it accommodates tibial articular surface inserts with a range of sizes and thicknesses. This sensor was verified by applying known loads at known locations over the entire surface of the tibial insert to determine the errors in the computed contact force and contact location in each compartment. The root-mean-square errors (RMSEs) in contact force are ≤ 6.1 N which is 1.4% of the 450 N full-scale output. The RMSEs in contact location are ≤ 1.6 mm. This improved tibial force sensor overcomes the limitations of the previous sensors and therefore should be useful for in vitro evaluation of new alignment goals, new surgical techniques, and new component designs in TKA.

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.

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.

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.

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.