Reliability and Validity of Measurement Tools for Residual Limb Volume in People With Limb Amputations: A Systematic Review

Background Measurements of residual limb volume often guide decisions on the type and timing of prosthetic prescription. To help inform these decisions, it is important that clinicians use measurement tools that are reliable and valid. Purpose The aim of this systematic review was to investigate the reliability and validity of measurement tools for residual limb volume in people with limb amputations. Data Sources A comprehensive search on MEDLINE, EMBASE, CINAHL, Scopus, and Web of Science was performed on July 11, 2016. Study Selection Studies were included if they examined the reliability or validity of measurement tools for residual limb volume, were conducted on humans, and were published in English. Data Extraction Data were extracted from 11 reliability and 4 validity studies and included study characteristics, volumetric estimates, and reliability and validity estimates. The quality of the studies was also rated. Data Synthesis Data from 2 studies (38 participants) indicated good to excellent intrarater (intraclass correlation coefficient [ICC] ≥0.88) and interrater (ICC ≥0.88) reliability and high between-session reliability (coefficient of variation [CV] = 10%) for water displacement volumetry. One study (28 participants) reported excellent intrarater and interrater reliability (ICC ≥0.93) for the circumferential method, and data from 2 studies (19 participants) indicated high between-session reliability for the optical surface scanner (CV ≤9.8%). Three studies (26 participants) indicated good to excellent between-session reliability results for computed tomography (CV = 9.2%–10.9%). One study (7 participants) showed moderate within-session reliability (CV = 50%). Using water displacement volumetry as the gold standard, 2 studies (79 participants) indicated excellent validity for the circumferential method ( r ≥0.92; ICC ≥0.92). All studies reporting measures of reliability or validity were performed with people who had transtibial amputations. Limitations Only studies published in English and in which water displacement volumetry was used as the gold standard were included in this review. The reliability and validity of the quality rating scale used in this review have not been tested. Conclusions On the basis of a limited number of moderate- to high-quality studies with small sample sizes, circumferential and water displacement methods were found to be reliable, and the circumferential method was found to be valid in people with transtibial amputations. There are inadequate data for drawing conclusions about volume measurement methods in people with other types of limb amputations

Accuracy Verification of Magnetic Resonance Imaging (MRI) Technology for Lower-Limb Prosthetic Research: Utilising Animal Soft Tissue Specimen and Common Socket Casting Materials

Lower limb prosthetic socket shape and volume consistency can be quantified using MRI technology. Additionally, MRI images of the residual limb could be used as an input data for CAD-CAM technology and finite element studies. However, the accuracy of MRI when socket casting materials are used has to be defined. A number of six, 46 mm thick, cross-sections of an animal leg were used. Three specimens were wrapped with Plaster of Paris (POP) and the other three with commercially available silicone interface liner. Data was obtained by utilising MRI technology and then the segmented images compared to corresponding calliper measurement, photographic imaging, and water suspension techniques. The MRI measurement results were strongly correlated with actual diameter, surface area, and volume measurements. The results show that the selected scanning parameters and the semiautomatic segmentation method are adequate enough, considering the limit of clinical meaningful shape and volume fluctuation, for residual limb volume and the cross-sectional surface area measurements

Focal Spot, Spring 1996

https://digitalcommons.wustl.edu/focal_spot_archives/1072/thumbnail.jp

Focal Spot, Fall/Winter 1996

https://digitalcommons.wustl.edu/focal_spot_archives/1071/thumbnail.jp

Doctor of Philosophy

dissertationAltered mechanics are believed to initiate osteoarthritis in hips with acetabular dysplasia. Periacetabular osteotomy (PAO) is the preferred surgical treatment; however, it is unknown if the procedure normalizes joint anatomy and mechanics. Changes in three-dimensional (3D) morphology and chondrolabral mechanics were quantified after PAO. Finite element (FE) models demonstrated that PAO improved the distribution of coverage, reduced stress, increased congruity, and prevented cartilage thinning. However, changes in mechanics were not consistent. In fact, one patient exhibited increased stress after surgery, which was believed to be a result of over-correction. Therefore, methods to integrate morphologic and biomechanical analysis with clinical care could standardize outcomes of PAO. FE simulations are time-intensive and require significant computing resources. Therefore, the second aim was to implement an efficient method to estimate mechanics. An enhanced discrete element analysis (DEA) model of the hip that accurately incorporated cartilage geometry and efficiently calculated stress was developed and analyzed. Although DEA model estimates predicted elevated magnitudes of contact stress, the distribution corresponded well with FE models. As a computationally efficient platform, DEA could assist in diagnosis and surgical planning. Imaging is a precursor to analyzing morphology and biomechanics. Ideally, an imaging protocol would visualize bone and soft-tissue at high resolution without ionizing radiation. Magnetic resonance imaging (MRI) with 3D dual-echo-steady-state (DESS) is a promising sequence to image the hip noninvasively, but its accuracy has not been quantified. Therefore, the final aim was to implement and validate the use of 3D DESS MRI in the hip. Using direct measurements of cartilage thickness as the standard, 3D DESS MRI imaged cartilage to ~0.5 mm of the physical measurements with 95% confidence, which is comparable to the most accurate hip imaging protocol presented to date. In summary, this dissertation provided unique insights into the morphologic and biomechanical features following PAO. In the future, DEA could be combined with 3D DESS MRI to efficiently analyze contact stress distributions. These methods could be incorporated into preoperative planning software, where the algorithm would predict the optimal relocation of the acetabulum to maximize femoral head coverage while minimizing contact stress, and thereby improve long-term outcomes of PAO

Advanced Algorithms for 3D Medical Image Data Fusion in Specific Medical Problems

Fúze obrazu je dnes jednou z nejběžnějších avšak stále velmi diskutovanou oblastí v lékařském zobrazování a hraje důležitou roli ve všech oblastech lékařské péče jako je diagnóza, léčba a chirurgie. V této dizertační práci jsou představeny tři projekty, které jsou velmi úzce spojeny s oblastí fúze medicínských dat. První projekt pojednává o 3D CT subtrakční angiografii dolních končetin. V práci je využito kombinace kontrastních a nekontrastních dat pro získání kompletního cévního stromu. Druhý projekt se zabývá fúzí DTI a T1 váhovaných MRI dat mozku. Cílem tohoto projektu je zkombinovat stukturální a funkční informace, které umožňují zlepšit znalosti konektivity v mozkové tkáni. Třetí projekt se zabývá metastázemi v CT časových datech páteře. Tento projekt je zaměřen na studium vývoje metastáz uvnitř obratlů ve fúzované časové řadě snímků. Tato dizertační práce představuje novou metodologii pro klasifikaci těchto metastáz. Všechny projekty zmíněné v této dizertační práci byly řešeny v rámci pracovní skupiny zabývající se analýzou lékařských dat, kterou vedl pan Prof. Jiří Jan. Tato dizertační práce obsahuje registrační část prvního a klasifikační část třetího projektu. Druhý projekt je představen kompletně. Další část prvního a třetího projektu, obsahující specifické předzpracování dat, jsou obsaženy v disertační práci mého kolegy Ing. Romana Petera.Image fusion is one of today´s most common and still challenging tasks in medical imaging and it plays crucial role in all areas of medical care such as diagnosis, treatment and surgery. Three projects crucially dependent on image fusion are introduced in this thesis. The first project deals with the 3D CT subtraction angiography of lower limbs. It combines pre-contrast and contrast enhanced data to extract the blood vessel tree. The second project fuses the DTI and T1-weighted MRI brain data. The aim of this project is to combine the brain structural and functional information that purvey improved knowledge about intrinsic brain connectivity. The third project deals with the time series of CT spine data where the metastases occur. In this project the progression of metastases within the vertebrae is studied based on fusion of the successive elements of the image series. This thesis introduces new methodology of classifying metastatic tissue. All the projects mentioned in this thesis have been solved by the medical image analysis group led by Prof. Jiří Jan. This dissertation concerns primarily the registration part of the first project and the classification part of the third project. The second project is described completely. The other parts of the first and third project, including the specific preprocessing of the data, are introduced in detail in the dissertation thesis of my colleague Roman Peter, M.Sc.

Inertial sensors signal processing methods for gait analysis of patients with impaired gait patterns

Analiza hoda je postala široko rasprostranjen klinički alat koji se koristi za objektivnu evaluaciju obrasca hoda, efekata hirurških intervencija, oporavka ili efekata terapije. Sve veći broj kliničara bira pogodne tretmane za lečenje pacijenata na osnovu informacija o kinematici i kinetici hoda. Procena i kvantifikacija parametara hoda je važan zahtev u oblasti ortopedije i rehabilitacije, ali takođe i u sportu, rekreaciji i posebno u razvoju tehnologija za ljude u procesu starenja. U cilju objektivne procene obrasca hoda, razvijen je bežični senzorski sistem čije su senzorske jedinice bežične, malih dimenzija i jednostavno se montiraju na segmente nogu subjekta čiji se hoda analizira. Senzorske jedinice podržavaju 3D inercijalne senzore (senzore ubrzanja i ugaonih brzina, tj. akcelerometre i žiroskope), kao i senzore sile. Osnovni cilj istraživanja je doprinos metodologiji za obradu podataka sa inercijalnih senzora i razvoj novih metoda obrade signala sa inercijalnih senzora u procesu određivanja kinematičkih veličina koje su uobičajene u analizi hoda (uglovi u zglobovima, brzina kretanja, dužina koraka). Ova metodologija je od posebne važnosti za objektivnu procenu nivoa motornog deficita, progresa bolesti i efikasnosti terapija, kao i efikasnosti primenjene motorne kontrole (prilikom funkcionalne električne stimulacije). U toku istraživanja razvijeno je nekoliko metoda za računanje uglova segmenata nogu ili zglobova, u zavisnosti od senzorske konfiguracije i složenosti algoritma. U disertaciji su odvojeno prikazani slučajevi u kojima je neophodno posmatrati kretanje u prostoru (3D analiza) i mnogo češći slučaj kad se kinematika može redukovati na sagitalnu ravan (2D analiza). Algoritmi uključuju i kalibraciju senzora, eliminaciju viii drifta, rekonstrukciju trajektorije i izračunavanje niza drugih relevantnih podataka koji karakterišu obrazac hoda. Dobijeni rezultati su poređeni sa postojećim sistemima za analizu hoda koji su validirani za kliničke primene. (sistemi sa kamerama, goniometri, enkoderi)...Gait analysis has become a widely used clinical tool which provides objective evaluation of the gait pattern, the effects of surgical interventions, recovery or therapy progress, and more and more clinicians are choosing therapy treatments based on gait kinematics and kinetics. Measuring gait parameters is an important requirement in the orthopedic and rehabilitation fields, but also in sports and fitness, and development of technologies for elderly population. In order to provide objective evaluation of the gait pattern, we have developed sensor system with light and small wireless sensor units, which can be easily mounted on body. These sensor units comprise 3-D inertial sensors (accelerometers and gyroscopes) and force sensing resistors, and our recommended setup includes one sensor unit per each segment of both legs. The main goal of this research is contribution to the methodology for processing of signals from inertial sensors (accelerometer pairs, or accelerometer and gyroscope sensor units). By using signal processing algorithms developed for this research, inertial sensors allow objective assessment of the quality of the gait pattern. This methodology is especially important for assessment of the motor deficit, progress of the disease and therapy effectiveness, and effectiveness of performed motor control (functional electrical stimulation). We have developed several methods for estimation of leg segment angles and joint angles, which differ in sensor configuration and algorithm complexity. Methods based only on accelerometers offer reliable angle estimations, which are limited to sagittal plane analysis, while the method using accelerometers and gyroscopes allows 3- D analysis. All this algorithms include sensor calibration, drift minimization, trajectory x reconstruction and calculation of numerous other parameters relevant to gait pattern analysis. The obtained results were compared with other commercial systems which are validated for clinical applications (camera systems, goniometers, encoders)..

The effects of ankle-foot orthoses on gait deviations associated with untreated developmental dysplasia of the hip during walking: case study

Developmental dysplasia of the hip (DDH) is considered to be one of the most common orthopaedic disorders, referring to a range of conditions from mild to severe dislocation of the hip joint. Knowledge of ankle-foot orthosis (AFO) use in patients with severe developmental dysplasia of the hip bone is crucial and may help improve the gait cycle during walking. The plantar pressure sensing mat and insole plantar sensor pad are ideal low cost alternatives to the force plate for capturing plantar centre pressure excursion during gait. Acquired centre of pressure (COP) traces are favoured by many medical clinicians and allied health professionals evaluating foot loading and body balance with respect to foot biomechanics, foot injury, foot deformation and foot ulceration. Researchers have recommended the use of COP traces for the study of the deformed foot and deformed lower limb to improve orthosis assessment and orthosis performance testing. Knowledge of the COP and plantar pressure characteristics such as peak pressure, contact pressure and pressure time integral during walking can help identify possible foot pathology, help determine the most effective foot orthosis, and allow for the appropriate calculation of balance control and joint kinetics and kinematics during gait. However, there are unclear gait alterations in individuals with DDH which have clinical implications such as the investigation of AFOs and their effect on lower limb kinematics and kinetics, and their impact on the plantar pressure characteristics of the joints during walking and running. This research aimed to provide a better understanding of the gait characteristics of patients with severe DDH. The first set of objectives was to study and evaluate the kinematics and kinetics of the ankle, knee and hip joints during walking in the sagittal plane for a patient aged 27 years (the author of this research) with severe dysplasia of the left hip, using two different types of ankle-foot orthosis (custom-made, and leaf-AFO). The data were collected using ten cameras and one force plate under four conditions: barefoot, custom-made AFO, leaf AFO, and shoes only. The angles between every two segments were calculated using the Euler rotation sequence. An inverse dynamic approach was used to calculate sagittal joint moments and power. The results showed that the planter flexion angle reached its maximum during the time between the toes-off, the ground phase and the initial swing phase with a mean difference of 21.1° and 14°, respectively. Moreover, the results indicated that the fabricated orthosis decreased both the right and left extensor moments significantly during the load-bearing phase in comparison to barefoot by a mean difference of 0.29, and 0.43 Nm/kg respectively for both limbs. Results showed that the custom-orthosis had a higher moment during the late stance of the gait cycle compared to barefoot, with the data showing significant change by a mean difference of 0.1604 Nm/kg. However, the Leaf Spring AFO had little impact on the flexion moment during the late stance phase. The second set of objectives of this study was to evaluate the effect of wearing the two ankle-foot orthosis on the plantar pressure distribution of specific foot regions for the patient with DDH. These objectives were achieved by developing a correlation technique between the COP trajectory and the lower limb trajectory during the three main phases of gait (heel strike, midstance and push off). The lower limb trajectory data were collected using a new close-range photogrammetry system that employed six HD video cameras to capture the lower limb trajectory. The COP trace and pressure data were collected using 3000E F-scan in-shoe sensors sampling at 100 Hz inserted inside the patient’s shoes. Six walking trials (ten steps per trial) were recorded for each condition (barefoot, custom-made orthosis, and Leaf-AFO). The average of the three middle steps was taken out of the ten steps for each trial under each condition. The corresponding results showed that the highest values of the pressure time integral for the left foot barefoot condition were registered under the lateral heel (LH) 115.92±2.91 kPa.sec, medial heel (MH) 101.66±2.55 kPa.sec, first toe (T1) 73.79±1.85 kPa.sec, fourth and fifth toes (T45) 49.90±1.25 kPa.sec and second toe (T2) 42.94±1.08 kPa.sec. The research concluded that the kinematics and kinetics of the ankle and hip joint were improved by the custom-made orthosis more than that of the Leaf AFO-Spring Orthoses. The current work also concluded that both AFOs did not much change the kinematics of the knee joint however, there were some improvements in the moments and power generated. Finally, the researcher concluded that both orthoses enhanced body stability, minimized foot pain, and minimizing the risk of injury beneath specific foot regions. More investigations are required in the future, such as the investigation of the customized Knee-Ankle-Foot Orthosis (KAFOs) and increasing the number of samples