PubMed HealthSearch

PubMed · 7304052

Knee-disarticulation.

Abstract

The disarticulation of the knee joint is--in contrary to the above-knee level--a fast and tender method for amputation, resulting in a vigorous, complete weightbearing stump. Without problems the bulky stump is fitted in an exactly moulded plastic or resin socket--eventually combined with a soft socket--, which can be easily put on and off also by older patients suffering from general dysvascular disorders. Nowadays special joints are used for functionally as well as cosmetically satisfying knee-disarticulation-prostheses. The surgical technique with alternative incisions, the peculiarities in dysvascular patients, the postoperative care including immediate or early fitting, the management after wound-healing with a temporary exercise-prosthesis and finally the various possibilities of the definitive prosthetic fitting are stressed in detail.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

G Neff. Knee-disarticulation.. https://pubmed.ncbi.nlm.nih.gov/7304052/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Automated hexahedral mesh generation from biomedical image data: applications in limb prosthetics.

A general method to generate hexahedral meshes for finite element analysis of residual limbs and similar biomedical geometries is presented. The method utilizes skeleton-based subdivision of cross-sectional domains to produce simple subdomains in which structured meshes are easily generated. Application to a below-knee residual limb and external prosthetic socket is described. The residual limb was modeled as consisting of bones, soft tissue, and skin. The prosthetic socket model comprised a socket wall with an inner liner. The geometries of these structures were defined using axial cross-sectional contour data from X-ray computed tomography, optical scanning, and mechanical surface digitization. A tubular surface representation, using B-splines to define the directrix and generator, is shown to be convenient for definition of the structure geometries. Conversion of cross-sectional data to the compact tubular surface representation is direct, and the analytical representation simplifies geometric querying and numerical optimization within the mesh generation algorithms. The element meshes remain geometrically accurate since boundary nodes are constrained to lie on the tubular surfaces. Several element meshes of increasing mesh density were generated for two residual limbs and prosthetic sockets. Convergence testing demonstrated that approximately 19 elements are required along a circumference of the residual limb surface for a simple linear elastic model. A model with the fibula absent compared with the same geometry with the fibula present showed differences suggesting higher distal stresses in the absence of the fibula. Automated hexahedral mesh generation algorithms for sliced data represent an advancement in prosthetic stress analysis since they allow rapid modeling of any given residual limb and optimization of mesh parameters.

Artificial Limbs

Rotationplasty.

Today rotationplasty is well established as an acceptable procedure for limb salvage in patients who have a malignant tumor in the femur or tibia. The main indication is that it is the alternative to amputation. Rotationplasty should further be used in the very young child because of growth-dependent complications that can be expected after tumor resection and any kind of reconstruction. This article covers the classification of the different types of rotationplasties, the operative procedure, prosthetic care, and the functional results.

Artificial Limbs

Development of a non-linear finite element modelling of the below-knee prosthetic socket interface.

A non-linear finite element model has been established to predict the pressure and shear stress distribution at the limb-socket interface in below-knee amputees with consideration of the skin-liner interface friction and slip. In this model, the limb tissue and socket liner were respectively meshed into 954 and 450 three-dimensional eight-node isoparametric brick elements, based on measurements of an individual's amputated limb surface; the bone was meshed into three-dimensional six-node triangular prism elements, based on radiographic measurements of the individual's residual limb. The socket shell was assumed to be a rigid boundary. An important feature of this model is the use of 450 interface elements (ABAQUS INTER4) which mimic the interface friction condition. The results indicate that a maximum pressure of 226 kPa, shear stress of 53 kPa and less than 4 mm slip exist at the skin-liner interface when the full body weight of 800 N is applied to the limb. The results also show that the coefficient of friction is a very sensitive parameter in determining the interface pressures, shear stresses and slip. With the growth of coefficient of friction, the shear stresses will increase, while the pressure and slip will decrease.

Artificial Limbs