scholarly journals Changes in tissue composition and load response after transtibial amputation indicate biomechanical adaptation

2021 ◽  
Author(s):  
Jennifer Bramley ◽  
Peter Worsley ◽  
Dan Bader ◽  
Chris Everitt ◽  
Angela Darekar ◽  
...  
Keyword(s):  
Mechanical Loading ◽  
Soft Tissues ◽  
Load Transfer ◽  
Morphological Changes ◽  
Limb Amputation ◽  
Transtibial Amputation ◽  
Prosthetic Socket ◽  
Design Variables ◽  
Damage Imaging ◽  
Tissue Changes

Despite the potential for biomechanical conditioning with prosthetic use, the soft tissues of residual limbs following lower-limb amputation are vulnerable to damage. Imaging studies revealing morphological changes in these soft tissues have not distinguished between superficial and intramuscular adipose distribution, despite the recognition that intramuscular fat levels indicate reduced tolerance to mechanical loading. Furthermore, it is unclear how these changes may alter tissue tone and stiffness. This study was designed to compare the morphology and biomechanical response of limb tissues to mechanical loading in individuals with and without transtibial amputation, using magnetic resonance imaging in combination with tissue structural stiffness. The results revealed higher adipose infiltrating muscle in residual limbs than in intact limbs (residual: median 2.5% (range 0.2-8.9%); contralateral: 1.7% (0.1-5.1%); control: 0.9% (0.4-1.3%)), indicating muscle atrophy and adaptation post-amputation. The intramuscular adipose content correlated negatively with daily socket use, although there was no association with time post-amputation. Residual limbs were significantly stiffer than intact limbs at the patellar tendon site, which plays a key role in load transfer across the limb-prosthesis interface. The tissue changes following amputation can have relevance in the clinical understanding of prosthetic socket design variables and soft tissue damage risk in this vulnerable group.

scholarly journals Changes in Tissue Composition and Load Response After Transtibial Amputation Indicate Biomechanical Adaptation

2021 ◽  
Author(s):  
J. L. Bramley ◽  
P. R. Worsley ◽  
D. L. Bader ◽  
C. Everitt ◽  
A. Darekar ◽  
...  
Keyword(s):  
Mechanical Loading ◽  
Soft Tissues ◽  
Load Transfer ◽  
Morphological Changes ◽  
Limb Amputation ◽  
Transtibial Amputation ◽  
Prosthetic Socket ◽  
Design Variables ◽  
Damage Imaging ◽  
Tissue Changes

AbstractDespite the potential for biomechanical conditioning with prosthetic use, the soft tissues of residual limbs following lower-limb amputation are vulnerable to damage. Imaging studies revealing morphological changes in these soft tissues have not distinguished between superficial and intramuscular adipose distribution, despite the recognition that intramuscular fat levels indicate reduced tolerance to mechanical loading. Furthermore, it is unclear how these changes may alter tissue tone and stiffness, which are key features in prosthetic socket design. This study was designed to compare the morphology and biomechanical response of limb tissues to mechanical loading in individuals with and without transtibial amputation, using magnetic resonance imaging in combination with tissue structural stiffness. The results revealed higher adipose infiltrating muscle in residual limbs than in intact limbs (residual: median 2.5% (range 0.2–8.9%); contralateral: 1.7% (0.1–5.1%); control: 0.9% (0.4–1.3%)), indicating muscle atrophy and adaptation post-amputation. The intramuscular adipose content correlated negatively with daily socket use, although there was no association with time post-amputation. Residual limbs were significantly stiffer than intact limbs at the patellar tendon site, which plays a key role in load transfer across the limb-prosthesis interface. The tissue changes following amputation have relevance in the clinical understanding of prosthetic socket design variables and soft tissue damage risk in this vulnerable group.

scholarly journals Key considerations for finite element modelling of the residuum–prosthetic socket interface

2020 ◽  
pp. 030936462096778
Author(s):  
JW Steer ◽  
PR Worsley ◽  
M Browne ◽  
Alex Dickinson
Keyword(s):  
Finite Element ◽  
Soft Tissue ◽  
Finite Element Modelling ◽  
Soft Tissues ◽  
Shear Stresses ◽  
Material Models ◽  
Element Modelling ◽  
Prosthetic Socket ◽  
Highly Nonlinear ◽  
Socket Interface

Background: Finite element modelling has long been proposed to support prosthetic socket design. However, there is minimal detail in the literature to inform practice in developing and interpreting these complex, highly nonlinear models. Objectives: To identify best practice recommendations for finite element modelling of lower limb prosthetics, considering key modelling approaches and inputs. Study design: Computational modelling. Methods: This study developed a parametric finite element model using magnetic resonance imaging data from a person with transtibial amputation. Comparative analyses were performed considering socket loading methods, socket–residuum interface parameters and soft tissue material models from the literature, to quantify their effect on the residuum’s biomechanical response to a range of parameterised socket designs. Results: These variables had a marked impact on the finite element model’s predictions for limb–socket interface pressure and soft tissue shear distribution. Conclusions: All modelling decisions should be justified biomechanically and clinically. In order to represent the prosthetic loading scenario in silico, researchers should (1) consider the effects of donning and interface friction to capture the generated soft tissue shear stresses, (2) use representative stiffness hyperelastic material models for soft tissues when using strain to predict injury and (3) interrogate models comparatively, against a clinically-used control.

scholarly journals A Perioral Soft Tissue evaluation after Orthognathic Surgery Using Three-Dimensional Computed Tomography Scan

2018 ◽  
Vol 12 (1) ◽  
pp. 366-376
Author(s):  
Rahul Tiwari ◽  
P. Srinivas Chakravarthi ◽  
Vivekanand S. Kattimani ◽  
Krishna Prasad Lingamaneni
Keyword(s):  
Computed Tomography ◽  
Soft Tissue ◽  
Orthognathic Surgery ◽  
Soft Tissues ◽  
Three Dimensional ◽  
Computed Tomography Scan ◽  
Nasolabial Angle ◽  
Tissue Changes ◽  
Soft Tissue Changes ◽  
Tomography Scan

Background: Facial appearance is an important factor, affects social and psychological well-being. The ideal positioning of jaws and soft tissues is crucial during orthognathic surgery for a better outcome, but the response of facial soft tissues does not always reflect the exact movements of the underlying jaws in 1:1 ratio. So, soft tissue changes following orthognathic surgery require utmost attention during surgical correction to make successful treatment. Aims and Objectives: Evaluation of perioral soft tissue changes after orthognathic surgical procedures. The objectives of the study were to assess and compare pre and post-operative perioral soft tissue changes of lip width, nasolabial and mentolabial angle using Three Dimensional Computed Tomography scan (3DCT). Patient and Methods: The study involved ten patients for evaluation requiring orthognathic surgical procedures (maxillary or mandibular anteroposterior excess or deficiency, transverse deformities, vertical maxillary excess and facial asymmetry) presented to the department of oral and maxillofacial surgery during 2014-2016. Pre and post-operative 3DCT scan were taken after 12 months using iCT 256 slice whole body CT scanner and evaluated for changes using Dicom PMS D view. Results: Significant changes were observed in nasolabial angle after maxillary advancement (1.81°) and maxillary setback procedure (2.73°). The mentolabial angle was significantly increased with mandibular setback procedures (3.27°). Mandibular advancement procedures showed both increase (3.6°) and decrease (7.6°) in mentolabial angle. Conclusion: 3DCT showed a significant difference in perioral soft tissue changes in nasolabial and mentolabial angle but no significant change was observed in lip width. 3DCT is a reliable tool for 3D assessment. The conventional thought of changes in Nasolabial angle after surgery is changing due to the underlying factors which should be considered for prediction.

scholarly journals Morphological changes during early trans-tibial prosthetic fitting

1998 ◽  
Vol 22 (2) ◽  
pp. 115-122 ◽  
Author(s):  
M. Lilja ◽  
P. Hoffmann ◽  
T. Öberg
Keyword(s):  
Morphological Changes ◽  
Muscle Group ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Transtibial Amputation ◽  
Negative Power ◽  
Lateral Muscle ◽  
Amputation Stump ◽  
The Cross

Morphological changes in the amputation stump may have serious implications regarding the suspension and fit of the prosthetic socket. In an earlier study (Lilja and Öberg, 1997) the authors have shown that the volume of the transtibial amputation stump decreases according to a negative power function after amputation, and that the stump volume does not stabilise until four months after the operation. In the present study, Magnetic Resonance Imaging (MRI) technique was used to examine morphological changes in the amputation stump after transtibial amputation in a small number of cases. The authors expected to find a decrease in the cross-sectional area of the stump and of the separate muscles similar to the findings in earlier studies. However, two different patterns were found. The cross-sectional area of the entire stump as well as that of the medial muscle group changed according to the authors' hypothesis, i.e. an initial fast decrease, followed by a more moderate decrease of the area. In the lateral muscle group another pattern was found. After an initial rapid decrease the area increased, sometimes to a magnitude larger than the initial value. After the amputation the lateral muscle group may acquire a new function, contributing to the suspension of the socket. Despite the limited number of patients, this study presents findings which may be important in the clinical fitting of trans-tibial prostheses.

Effects of an improved biomechanical backpack strap design on load transfer to the shoulder soft tissues

2018 ◽  
Vol 76 ◽  
pp. 45-52 ◽  
Author(s):  
Amir Hadid ◽  
Gal Gozes ◽  
Avihai Atoon ◽  
Amit Gefen ◽  
Yoram Epstein
Keyword(s):  
Soft Tissues ◽  
Load Transfer

A Microscale Collagen-Fibrin Interacting Network Model With Comparison to Experimental Results

2012 ◽  
Author(s):  
Jeffrey D. Hyypio ◽  
Mohammad F. Hadi ◽  
Victor K. Lai ◽  
Victor H. Barocas
Keyword(s):  
Mechanical Loading ◽  
Network Model ◽  
Computer Model ◽  
Soft Tissues ◽  
Uniaxial Extension ◽  
Tissue Mechanics ◽  
Experimental Results ◽  
Large Strains ◽  
Heterogeneous Nature ◽  
Engineered Tissue

Many native and bioengineered soft tissues are composed of two or more types of biopolymer networks that mechanically define and support the material [1]. Modeling the response of multi-network soft tissues to mechanical loading can be difficult due to the heterogeneous nature of these materials and the large strains (>1) involved. As tissues deform, the different biopolymer networks interact with one another and determine the overall stress-strain outcome for the tissue. Capturing this interaction could help improve the accuracy of a computer model to simulate the microscale behavior of soft tissues under load. We have developed a two-network model to reflect interactions between collagen and fibrin biopolymer networks loaded in uniaxial extension. The model can help improve our understanding of native and engineered tissue mechanics.

scholarly journals Histological Change in Soft Tissue Surrounding Titanium Plates after Jaw Surgery

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3205 ◽  
Author(s):  
Gabriel Armencea ◽  
Dan Gheban ◽  
Florin Onisor ◽  
Ileana Mitre ◽  
Avram Manea ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Acute Inflammation ◽  
Soft Tissues ◽  
Morphological Changes ◽  
Histological Change ◽  
Plate Removal ◽  
Metallic Particles ◽  
Routine Removal ◽  
Jaw Surgery ◽  
Soft Tissue Covering

The aim of this study was to evaluate the microscopic structure of soft tissue covering titanium plates and screws used in jaw surgery (mandible fracture and orthognathic surgery), after a minimum period of 12 months from insertion, and to quantify the presence of any metallic particles. Periosteum covering the osteosynthesis plates was removed from 20 patients and examined by light microscopy in order to assess the cell morphological changes and the possibility of metal particles presence in the soft tissue. Local signs of tissue toxicity or inflammation were taken into consideration when evaluating the routine removal of titanium maxillofacial miniplates. No signs of screw loosening or acute inflammation were detected on the osteosynthesis site, but de-coloration of the periosteum was seen, and metallic particles were observed to have migrated into the soft tissues. Even if the titanium is well-tolerated by the human body in time, without severe local or general complications, our findings suggest that plate removal should be considered after bone healing has occurred.

scholarly journals SKIN AND SUBCUTANEOUS ADIPOSE TISSUE DAMAGE AFTER RADIATION THERAPY IN BREAST CANCER PATIENTS

2021 ◽  
Vol 26 ◽  
pp. 18-35
Author(s):  
D. Bazyka ◽  
◽  
O. Litvinenko ◽  
S. Bugaytsov ◽  
G. Shakhrai ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Radiation Therapy ◽  
Adjuvant Radiotherapy ◽  
Soft Tissues ◽  
Morphological Changes ◽  
Subcutaneous Tissue ◽  
Adjuvant Radiation ◽  
Pathological Changes ◽  
Breast Cancer Patients ◽  
Adjuvant Radiation Therapy

The analysis of long-term researches of the pathological changes arising in soft tissues at patients with a breast cancer as a result of radical surgical treatment and adjuvant radiotherapy is carried out in work. The article shows that the standard approach to postoperative radiation therapy, which is based only on the prevalence of the primary tumor process is not always justified. Very often it leads to excessive radiation load on the patient's body and the development of local acute and chronic radiation reactions of the skin, subcutaneous tissue and other soft tissues. In this regard, the question of differentiated purpose of radiotherapy acquires special value first of all at patients with small primary prevalence of tumor process. The paper presents the results of studies to study changes in the anterior chest wall in patients with breast cancer. In relation to the conduct of adjuvant radiotherapy more often need to use the concept of personalized radiation therapy. Radical operation, post-radiation early and late pathological changes in soft tissues, disturbance of microcirculation of lymph and blood, disturbance of innervation of vessels of an upper extremity, peripheral nerves in system of a cervical and plexus plexus, leads to intensive degenerative and dystrophic changes in soft tissues of the upper. and causes morphological changes in them and further progression of reflex neurovascular and neurodystrophic disorders. Based on the data of adverse effects of radiotherapy on the skin and surrounding tissues, as well as to reduce excessive radiation exposure to the patient's body, a differentiated approach to the appointment of adjuvant radiation therapy. The Scientific Council meeting of NAMS approved the NRCRM Annual Report. Key words: breast cancer, radiation therapy, adjuvant radiation therapy, complications of radiation therapy, radiation reactions, radiation injuries.

scholarly journals Design & Development of a Trans Tibial Socket Stabilized by Alternating Areas of Tissue Compression and Release - A Case Study

2021 ◽  
Vol 11 (7) ◽  
pp. 317-321
Author(s):  
Prachi Prava Pattnaik ◽  
Jonathan T
Keyword(s):  
Single Case ◽  
Weight Bearing ◽  
Gait Pattern ◽  
Extensive Study ◽  
Adaptation Period ◽  
Design Development ◽  
Transtibial Amputation ◽  
Prosthetic Socket ◽  
Tissue Compression

The socket is the most important aspect of the artificial limb, constituting the critical interface between the amputee’s stump and prosthesis. The design and fitting of the socket is also the most difficult procedure due to the uniqueness of each amputee’s stump. An uncomfortable socket fit is the most common complaint from lower limb amputees with surveys revealing that amputees believe comfort are the most important aspects of the prosthesis and over half of all wearers are in moderate to severe pain for most of the time whilst wearing the prosthesis. Kristinsson argued that a transtibial socket can be designed to transfer loads primarily to limited areas of the limb such as the patella tendon and the medial flare, which in most cases found both ineffective and uncomfortable. There were inconsistencies in producing satisfactory PTB sockets because of inadequate training of prosthetist in the PTB technique. However, the TSB silicon liner socket has problems such as causing excessive perspiration, heating and odor etc. Therefore, a new socket is designed following the principle of alternative pressure and release to overcome the disadvantages and to check the socket with regard to stability, comfort and satisfaction. Method: A single case study of a person 37-year-old, with transtibial amputation population took part in this study and was selected according to the inclusion criteria. The participant was provided patient information sheet and after taking the informed consent, the assessment and fabrication of the new socket were being proceeded, taking the cast on the first day. On the third day the newly designed socket along with prosthesis was provided with an adaptation period of 7 days. After 7 days the patient was called to check the stability with standing, comfort and satisfaction with a prosthetic socket comfort score. Results and Discussion: The present socket is well suitable for transtibial patient in weight bearing position. It fits well to the contour of the adult patient. The socket was adjusted manually during rectification phase providing respective pressure in areas required. Conclusion: The developed socket had a great effect on gait pattern of transtibial amputee. This socket provides adjustment for pressure, anterior, posterior, medial and lateral of the stump. It also creates surface for the placement of bony prominences. As it is a complex casting procedure, proper care should be taken to fabricate the casting of socket with minimal error. Further, innovative inventions will be required to refine more products and extensive study has to be carried out on the existing mode. Key words: transtibial amputation, transtibial socket, tissue compression and release.

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