Mr Marco Schneider
Marco has a Bachelor of Engineering (Honours) in Biomedical Engineering from the University of Auckland.
Research | Current
Modelling the form and function of the carpometacarpal joint
The thumb carpometacarpal (CMC) joint is saddle-like joint which allows the hand to perform a range of complex motions requiring strength and dexterity. However, the CMC joint is susceptible to osteoarthritis (OA) which is a serious and pervasive problem and is approximately twice as prevalent in women as in men.
We believe that morphology of the CMC joint plays a role in the development of CMC OA, and in this thesis we will create population based modelling methods to characterise the size and shape of the trapezium and metacarpal bones to investigate and address the questions: Firstly, are there morphological differences between the CMC joints of men and women and how are they different? Secondly, how do the different morphologies between men and women influence the stress distribution patterns in the articulating surface when performing key tasks and do these patterns correspond to regional measures of cartilage thickness, subchondral bone thickness, trabecular architecture, and morphology? And lastly, how does this correlate to OA, if at all?
Currently we have a cohort of 67 clinical CT data sets of the CMC joint we can work with to perform investigating. In order to perform population based modelling methods, we will require methods for automation to work with the large data sets we have obtained through Brown and Stanford Universities as well as our other collaborators. We have already created a statistical shape model for the analysis of trapezium and metacarpal morphologies. Over the next couple of years we intend to use the model to generate sex-specific mean geometries for finite element analysis to calculate the stress patterns in the joint to see how the stress patterns are affected by the morphology.
From our statistical shape models, we have found that the trapezium and first metacarpal bones were significantly smaller (p < 0.001) in women than in men. We found that when normalised to bone size, women displayed significantly more positive (p=0.01) weights in the first principal component of the size-normalized shape model than men. In women, this manifested as a higher aspect ratio in the first metacarpal and a more prominent ulnar ridge in the trapezium. We have also determined that these effects are directly related to the articulating surface area, and thus women in general have smaller articulating surfaces in the CMC joint than men. We believe these are indicative of higher stresses in the CMC joint, since the moment arms are lower higher forces are required to perform similar activities of daily living (such as a jar twist) which in concert with smaller surface areas may lead to higher stresses.
If successfully completed, the implications of this research are numerous. This is the first time statistical shape models have been created for the CMC joint. Apart from furthering our current understanding of CMC joint mechanics and stress distributions, we may be able to gain insight on how CMC OA develops and perhaps be able to diagnose and treat CMC OA preventatively. The tools created in the PhD will contribute to the greater MAP client and would allow researchers and clinicians to perform further analysis of the CMC joint.
Selected publications and creative works (Research Outputs)
- Schneider, M. T. Y., Zhang, J., Crisco, J. J., Weiss, A. P. C., Ladd, A. L., Nielsen, P., & Besier, T. (2015). Men and women have similarly shaped carpometacarpal joint bones. Journal of biomechanics, 48 (12), 3420-3426. 10.1016/j.jbiomech.2015.05.031
Other University of Auckland co-authors: Poul Nielsen, Thor Besier, Ju Zhang