Clinical Biomechanics

The activities of clinical biomechanics are:

  • Computational methods for joint biomechanics;
  • In-vitro studies of joint biomechanics;
  • In-vivo studies of joint kinematics.

Computational methods for joint biomechanics

Fiber-based 3D model of anterior cruciate ligamentStudies on knee biomechanics starter to help optimizing the results of conventional or assisted surgical procedures, for better understanding injury and healing processes, for validating hypotheses on new surgical techniques.

These studies included the development of knee models for simulation of rehabilitative or daily life actions, for predicting the individual injury risk or for planning surgical reconstruction of anterior cruciate ligament  (see the image aside) or the knee (see the document Knee Models).
Moreover we developed new and dedicated algorithms and methods for computing the knee degrees of freedom (see the image below) and in general for a computerized anatomical an functional analysis of human joints (see the document Functional method).

The many application-specific computational methods have been extended to a general-purpose environment for standard biomechanical analysis of diarthrodial joints (e.g. human knee, hip, shoulder or elbow), we called StudyJoint.

 

Computation of knee rotations during the passive range of motion

 

The final goal of our project is to provide physicians, medical experts or researchers involved in clinical or medical applications, with a free software that allows to compute kinematics or geometrical quantitative parameters without the need of advanced mathematical skills. The tool provides specifically a number of elaboration functions to investigate the joint kinematics, bone anatomy, and ligament and tendon properties. In particular, the shapes and the contact points of the articulating surfaces can be displayed and analysed through 2D user-defined sections and fittings (lines or conics). Ligament behaviour can be evaluated during joint movement, through the computation of elongations,  orientations, and fibre strain. Motion trajectories can be also analysed through the calculation of helical axes, instantaneous rotations, and displacements in specific user-chosen coordinate reference frames.

 

Main interface of study_joint software for anatomical and functional joint investigations

 

This tool has been successfully applied to both in-vitro and in-vivo datasets, and the evaluation of joint kinematics in specific clinical cases, such as anterior cruciate ligament reconstruction in knee.
StudyJoint package is available free of charge upon request. A version updated in summer 2008 is available for download at this page. Input data transformation or plug-ins for specific acquisition devices can be obtained from the authors within the frame of a research agreement.

In-vitro studies of joint biomechanics

Numerous studies were conducted on cadaver joints to validate mathematical models, hypothesis on joint function, to investigate about soft tissues and their role. In particolar we studied the tibio-femoral anatomy (see the document Knee anatomy), the axes of rotations of the knee (see the document Knee axes of rotation), the behaviour of cruciate ligaments (see the document Cruciate ligaments) and of the rotator cuff (see the document Shoulder).
These studies provided a better understanding of surgical actions, such as ligaments release during total knee prosthesis implant, the choice of tunnel orientation during the anterior cruciate ligament reconstruction (see the picture below) or the choice of the design of knee prostheses.

 

Computer analysis of the anterior cruciate ligament reconstruction

 

 

In-vivo studies of joint kinematics

The evaluation of the joint kinematics is fundamental during surgical reconstructions and therefore special projects were devoted to develop intra-operative tools for this task.
The first methodology for acquisition and elaboration of kinematic data was developed for the computer and robot assisted procedures (see the images below and the document FARO method).

 

Intra-operative kinematic acquisitions with FARO Arm electrogoniometer

 

Intra-operative kinematic acquisitions with FARO Arm electrogoniometer

Recently we have developed a navigation system for intra-operative monitoring of knee kinematics suitable also for minimally invasive surgery, which provide the surgeon quantitative information. The goal of the study was to evaluate accurately knee motion in-vivo and to obtain and compare the knee laxity before, during and after the reconstruction. This will help to better understand the effect of different pathology on the knee function, to evaluate the efficacy of the reconstruction and finally to improve the surgical action.
This methodology is based on the use of a commercial navigation system (Polaris), a dedicated  software developed in collaboration with IPiù (Firenze, IT) and an original procedure to acquire and elaborate data in real-time.

 

System for navigated kinematic evaluations used during anterior cruciate reconstruction

 

The present research studies aim at the improvement of the intra-operative tests, the identification of the manoeuvres able to discriminate pathological knees, the definition of new algorithms for kinematic decomposition and the analysis of different surgical techniques. This methodology has been used during more than 60 for anterior cruciate ligament reconstructions with single e double 'bundle technique.

Partnership:
Past: Lab-University of Barcellona (2003)
Past: Univ. Southampton (2001)
Past: Lab-ENEA
Past: Freeman, Pinskerova, Karrholm (1998-2002)
Past: University of Grenoble (1994-5)

Content updated 13/10/2010 - 15:48
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