The Effect of Prosthetic Limb Sophistication and Amputation Level on Self-reported Mobility and Satisfaction With Mobility.

OBJECTIVE: To determine if lower limb prosthesis (LLP) sophistication is associated with patient-reported mobility and/or mobility satisfaction, and if these associations differ by amputation level. DESIGN: Cohort study that identified participants through a large national database and prospectively collected self-reported patient outcomes. SETTING: The Veterans Administration (VA) Corporate Data Warehouse, the National Prosthetics Patient Database, participant mailings, and phone calls. PARTICIPANTS: 347 Veterans who underwent an incident transtibial (TT) or transfemoral (TF) amputation due to diabetes and/or peripheral artery disease and received a qualifying LLP between March 1, 2018, and November 30, 2020. INTERVENTIONS: Basic, intermediate, and advanced prosthesis sophistication was measured by the accurate and reliable PROClass system. MAIN OUTCOME MEASURE: Patient-reported mobility using the advanced mobility subscale of the Locomotor Capabilities Index-5; mobility satisfaction using a 0-10-point Likert scale. RESULTS: Lower limb amputees who received intermediate or advanced prostheses were more likely to achieve advanced mobility than those who received basic prostheses, with intermediate nearing statistical significance at nearly twice the odds (adjusted odds ratio (aOR)=1.8, 95% confidence interval (CI), .98-3.3; P=.06). The association was strongest in TF amputees with over 10 times the odds (aOR=10.2, 95% CI, 1.1-96.8; P=.04). The use of an intermediate sophistication prosthesis relative to a basic prosthesis was significantly associated with mobility satisfaction (adjusted ß coefficient (aß)=.77, 95% CI, .11-1.4; P=.02). A statistically significant association was only observed in those who underwent a TT amputation (aß=.79, 95% CI, .09-1.5; P=.03). CONCLUSIONS: Prosthesis sophistication was not associated with achieving advanced mobility in TT amputees but was associated with greater mobility satisfaction. In contrast, prosthesis sophistication was associated with achieving advanced mobility in TF amputees but was not associated with an increase in mobility satisfaction.

AMPREDICT PROsthetics-Predicting Prosthesis Mobility to Aid in Prosthetic Prescription and Rehabilitation Planning.

OBJECTIVE: To develop and validate a patient-specific multivariable prediction model that uses variables readily available in the electronic medical record to predict 12-month mobility at the time of initial post-amputation prosthetic prescription. The prediction model is designed for patients who have undergone their initial transtibial (TT) or transfemoral (TF) amputation because of complications of diabetes and/or peripheral artery disease. DESIGN: Multi-methodology cohort study that identified patients retrospectively through a large Veteran's Affairs (VA) dataset then prospectively collected their patient-reported mobility. SETTING: The VA Corporate Data Warehouse, the National Prosthetics Patient Database, participant mailings, and phone calls. PARTICIPANTS: Three-hundred fifty-seven veterans who underwent an incident dysvascular TT or TF amputation and received a qualifying lower limb prosthesis between March 1, 2018, and November 30, 2020 (N=357). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: The Amputee Single Item Mobility Measure (AMPSIMM) was divided into a 4-category outcome to predict wheelchair mobility (0-2), and household (3), basic community (4), or advanced community ambulation (5-6). RESULTS: Multinomial logistic lasso regression, a machine learning methodology designed to select variables that most contribute to prediction while controlling for overfitting, led to a final model including 23 predictors of the 4-category AMPSIMM outcome that effectively discriminates household ambulation from basic community ambulation and from advanced community ambulation-levels of key clinical importance when estimating future prosthetic demands. The overall model performance was modest as it did not discriminate wheelchair from household mobility as effectively. CONCLUSIONS: The AMPREDICT PROsthetics model can assist providers in estimating individual patients' future mobility at the time of prosthetic prescription, thereby aiding in the formulation of appropriate mobility goals, as well as facilitating the prescription of a prosthetic device that is most appropriate for anticipated functional goals.

Peripheral neuropathy prevalence and effect on mobility 12 months after prosthesis prescription among individuals with dysvascular lower extremity amputation.

OBJECTIVE: To determine the prevalence of peripheral neuropathy (PN) and its effect on mobility in patients who were prescribed a lower limb prosthesis (LLP) after an incident dysvascular transtibial (TT) or transfemoral (TF) lower extremity amputation (LEA). We also sought to determine if the effect of PN on mobility was modified by amputation level or depression. DESIGN: Participants were identified retrospectively through the Veterans Affairs (VA) Corporate Data Warehouse (CDW) from March 1, 2018, to November 30, 2020, then were contacted prospectively to obtain their self-reported mobility. Multiple logistic regression was used to control for potential confounders and identify potential effect modifiers. SETTING: The VA CDW, the National Prosthetics Patient Database, participant mailings and phone calls. PARTICIPANTS: Three hundred fifty-seven individuals who underwent a TT or TF amputation due to diabetes and/or peripheral arterial disease and were fitted with a qualifying LLP. INTERVENTIONS: Not applicable. MAIN OUTCOMES MEASURES: The Locomotor Capabilities Index basic and advanced mobility subscale scores. RESULTS: Two-hundred thirty seven participants (66%) had a diagnosis of PN prior to prosthesis prescription. The detrimental effect of PN on achieving basic and advanced mobility was significant after adjusting for potential confounding factors (adjusted odds ratio [aOR], 0.53; 95% confidence interval [CI], 0.30-0.94; p = .03 and aOR, 0.43; 95% CI, 0.24-0.77; p = .005, respectively). The detrimental effect of PN was more pronounced in patients with depression, especially for advanced mobility (aOR, 0.36; 95% CI, 0.14-0.95; p = .04) versus no depression (aOR, 0.53; 95% CI, 0.27-1.0; p = .07). CONCLUSIONS: PN is common in patients who have undergone an LEA due to diabetes and/or vascular disease and patients with this diagnosis should be carefully evaluated. Targeted rehabilitation programs to mitigate its potential detrimental effects on mobility are important and should specifically include mental health assessment and treatment.

PROClass: The Development and Validation of a Novel Prosthetic Component Sophistication Classification System.

Objective: To develop a lower limb prosthesis (LLP) sophistication classification system that categorizes prosthetic component prescriptions into "basic," "intermediate," and "advanced" and assess its content validity, reliability, and accuracy. Design: Classification development and validation study. Setting: The Veterans Affairs (VA) Corporate Data Warehouse database and National Prosthetics Patient Database were used to identify patients undergoing their first amputation at the transtibial or transfemoral level due to diabetes or peripheral artery disease and to identify the associated codes for each LLP. Participants: An expert panel of 6 nationally recognized certified prosthetists, a national expert in VA prosthetics data and coding, a physical medicine and rehabilitation physician, and an epidemiologist developed an LLP classification system (PROClass) using 30 transfemoral and transtibial lower limb amputees. Main Outcome Measures: The expert panel reviewed 20 consecutive participants meeting study criteria for the development of the PROClass system and a subsequent 30 consecutive cases for assessing the inter- and intra-rater reliability and accuracy. Results: The interrater and intrarater reliability was almost perfect with Gwet's AC1 values ranging from .82 to .96 for both expert panel members and research assistants. The accuracy of the research assistant's classifications to the "criterion standard" was excellent with Gwet's AC1 values ranging between .75 and .92. Conclusions: PROClass is a pragmatic, reliable, and accurate prosthetic classification system with strong face validity that will enable the classification of prosthetic components used for large data set research aimed at evaluating important clinical questions such as the effects of sophistication on patient outcomes.

Vacuum-assisted socket suspension compared with pin suspension for lower extremity amputees: effect on fit, activity, and limb volume.

OBJECTIVE: To investigate the effect of a vacuum-assisted socket suspension system as compared with pin suspension on lower extremity amputees. DESIGN: Randomized crossover with 3-week acclimation. SETTING: Household, community, and laboratory environments. PARTICIPANTS: Unilateral, transtibial amputees (N=20 enrolled, N=5 completed). INTERVENTIONS: (1) Total surface-bearing socket with a vacuum-assisted suspension system (VASS), and (2) modified patellar tendon-bearing socket with a pin lock suspension system. MAIN OUTCOME MEASURES: Activity level, residual limb volume before and after a 30-minute treadmill walk, residual limb pistoning, and Prosthesis Evaluation Questionnaire. RESULTS: Activity levels were significantly lower while wearing the vacuum-assisted socket suspension system than the pin suspension (P=.0056; 38,000 ± 9,000 steps per 2 wk vs 73,000 ± 18,000 steps per 2 wk, respectively). Residual limb pistoning was significantly less while wearing the vacuum-assisted socket suspension system than the pin suspension (P=.0021; 1 ± 3mm vs 6 ± 4mm, respectively). Treadmill walking had no effect on residual limb volume. In general, participants ranked their residual limb health higher, were less frustrated, and claimed it was easier to ambulate while wearing a pin suspension compared with the VASS. CONCLUSIONS: The VASS resulted in a better fitting socket as measured by limb movement relative to the prosthetic socket (pistoning), although the clinical relevance of the small but statistically significant difference is difficult to discern. Treadmill walking had no effect, suggesting that a skilled prosthetist can control for daily limb volume fluctuations by using conventional, nonvacuum systems. Participants took approximately half as many steps while wearing the VASS which, when coupled with their subjective responses, suggests a preference for the pin suspension system.

Prosthesis management of residual-limb perspiration with subatmospheric vacuum pressure.

For the ambulatory person with lower-limb amputation, insufficient management of perspiration can result in inadequate prosthesis adherence, reduced mobility, and discomfort. This study compared a dynamic air exchange (DAE) prosthesis designed to expel accumulated perspiration with a total surface bearing suction socket (Suction) that cannot. Five people with unilateral transtibial amputation participated in a randomized, crossover experiment. All subjects were given a 1 wk acclimation to each study prosthesis while we measured their step activity levels. A rest-walk-rest protocol, including a 30 min treadmill walk at a self-selected speed while wearing thermally insulative garments, was then used to observe residual-limb skin temperatures and perspiration. Afterward, subject opinions about the prostheses were assessed with questionnaires. During the week-long acclimation period, no statistical difference in step activity levels were detected between prostheses (p = 0.22), but this may have been due to self-reported behavioral modifications. During the rest-walk-rest protocol, no differences in skin temperatures were observed (p = 0.37). The DAE prosthesis accumulated 1.09 +/- 0.90 g and expelled 0.67 +/- 0.38 g of perspiration, while the Suction prosthesis accumulated 0.97 +/- 0.75 g. The questionnaire results suggest that participants were receptive to both prostheses. The DAE prosthesis was able to expel more than a third of the total perspiration, suggesting it may enable longer uninterrupted periods of perspiration-inducing activity.

Two-year survival and neurodevelopmental outcomes after cardiopulmonary resuscitation in neonatal patients after complex cardiac surgery.

AIM: To examine survival and neurodevelopmental outcomes in neonates having post-operative cardiopulmonary resuscitation (CPR). METHODS: This inception cohort study included all neonates (6 weeks old or less) who received postoperative CPR (Group 1) after cardiac surgery from 1996 to 2005, matched for heart defect, year of surgery, chromosomal abnormality, and socioeconomic status to two neonates who did not receive postoperative CPR (Group 2). Two-year neurodevelopment was prospectively assessed with Bayley Scales of Infant Development II and Adaptive Behavior Assessment System II. Pre-, intra-, and post-operative variables were collected prospectively. Cardiac arrest variables were collected retrospectively. Predictors of mortality were analyzed by univariate analysis and conditional multiple logistic regression. RESULTS: There were 29 patients in Group 1, and 58 patients in Group 2. In survivors, there were no significant differences between Groups 1 and 2 in outcomes [mean (SD)] of mental developmental index [84.5 (12.2) vs. 81.0 (18.9)], psychomotor developmental index [82.8 (13.8) vs. 80.1 (21.9)], General Adaptive Composite [84.6 (15.3) vs. 84.3 (19.2)], Motor scale [8.4 (3.2) vs. 8.0 (3.8)], or delay on any of these scales. Two-year mortality [58.6% Group 1; 8.6% Group 2], was associated on conditional multiple logistic regression with CPR (OR 26.6; 95% CI, 5.4, 129.5). In Group 1, on multiple logistic regression, 2-year mortality was associated with minutes of chest compressions (OR 1.04, 95% CI, 1.01, 1.08). CONCLUSIONS: Among neonates having cardiac surgery, CPR is associated with greater mortality. There is no evidence that CPR survivors have different 2-year neurodevelopmental outcomes than those neonates not having CPR.

Overestimating neurodevelopment using the Bayley-III after early complex cardiac surgery.

BACKGROUND: The newest measure of neurodevelopmental outcomes, the Bayley Scales of Infant and Toddler Development, 3rd Edition (Bayley-III), gives higher-than-expected scores for preterm infants; results after cardiac surgery are unknown. OBJECTIVES: The goal of this study was to report Bayley-III scores after cardiac surgery and compare the results with those of the Bayley Scales of Infant Development, 2nd Edition (BSID-II) on a subset of the same children. METHODS: In this prospective, inception cohort, neurodevelopmental outcome study after complex cardiac surgery in infants from 2004 to 2007, the Bayley-III was given to 110 survivors (68% boys) at a mean age of 21 months (SD: 4 months). Analysis of variance was used to compare intergroup differences. Results for both test editions on the same 25 children were compared by using paired-samples statistics. RESULTS: Mean (SD) Bayley-III mean composite scores (CSs) for 110 children were as follows: cognitive, 95.9 (14.1); language, 90.8 (18.1); and motor, 93.7 (14.2), differentiating selected cardiac surgery groups. The average difference in mean CSs was 7.4 points higher than BSID-II scores for a previous cohort from this site and 7.2 points higher than a systematic review report. Direct comparison of BSID-II and Bayley-III revealed an average difference in mean CSs of 6.1 points, similar to normative results. Mean cognitive CSs increased by 10.0 (P <.001), language by 1.4 (P = .526), and motor by 6.9 points (P = .009). CONCLUSIONS: Researchers should be careful attributing higher Bayley-III scores to changes in acute care. At-risk children who previously qualified for early developmental intervention may no longer do so. School-age longitudinal studies are needed to determine the accuracy of early developmental estimates using the Bayley-III.

Two-year neurodevelopmental outcomes of infants undergoing neonatal cardiac surgery for interrupted aortic arch: a descriptive analysis.

OBJECTIVE: This study determined neurodevelopmental outcomes of survivors of neonatal cardiac surgery for interrupted aortic arch through an interprovincial program and explored preoperative, intraoperative, and postoperative outcome predictors. METHODS: Children who underwent neonatal cardiac surgery for interrupted aortic arch at 6 weeks old or younger between 1996 and 2006 had a multidisciplinary neurodevelopmental assessment at 18 to 24 months old (mental and psychomotor developmental indices as mean +/- SD and delay [score <70]). Survivor outcomes were compared by univariate and multivariate analyses and compared between children with and without chromosomal abnormality. RESULTS: Outcomes were available for all 26 survivors (mortality, 3.7%). Mental and psychomotor developmental indices were 75.8 +/- 17.1 and 72.3 +/- 16.9, respectively, with significantly lower scores for children with chromosomal abnormalities, which accounted for 29% of the variance in developmental indices. For the remaining 17 children without chromosomal abnormalities, mental and psychomotor developmental indices were 82.7 +/- 14.5 and 79.1 +/- 14.3, respectively, with deep hypothermic circulatory arrest time and Apgar score at 5 minutes contributing 46% of the variance in mental developmental index. CONCLUSIONS: The neurodevelopmental indices of children who have undergone neonatal cardiac surgery for interrupted aortic arch are below normative values; those of children with chromosomal abnormalities are even lower. For children without a chromosomal abnormality, longer deep hypothermic circulatory arrest times and low Apgar scores predict lower mental developmental indices at 18 to 24 months of age.