Orthopaedic Biomechanics Laboratories
Osteoarthrosis has been the subject of study at the OBL. Our researchers are developing new ideas about the effect of impact trauma on this disease and studying methods to prevent acute damage of cartilage that may cause OA. Below is a description of major projects underway in these areas.
The Mechanisms of Osteoarthrosis
A
study to investigate the relationship between knee flexion and impact
loads resulted in a paper published in the Journal
of Orthopaedic Research, titled "Injuries Produced by Blunt
Trauma to the Human Patellofemoral Joint Vary with Flexion Angle
of the Knee" (Volume 19, pp. 827-833) (Abstract).
The major finding of this research was that the response of the
patellofemoral joint to blunt trauma varies with joint flexion angle.
This data is important in the prediction of injury to automotive
occupants of various stature. |
This figure shows how the joint contact area developed during impact loading of the patello-femoral joint changes with knee flexion angle. For a higher resolution image, click here or on the image. |
Another
recent research study involved the rate at which load is applied
to articular cartilage. In a peer-reviewed Journal
of Orthopaedic Research paper entitled "The Extent of Matrix
Damage and Chondrocyte Death in Mechanically Traumatized Articular
Cartilage Explants Depends on the Rate of Loading" (Volume
19, pp. 779-784) (Abstract),
our investigators found that high rate impacts generate more cartilage
matrix damage than low rate impacts. In contrast, low rates of loading
cause relatively more cellular death in the cartilage. This data
helps us understand the correlation of impact trauma to the development
of a chronic disease. |
Comparison of High Rate Loading (left) and Low Rate Loading (right) on cartilage explants. |
 |
A
recent study by OBL researchers "Tolerance of the Isolated
Human Knee to Blunt Force Trauma Significantly Decreases for Oblique
Versus Direct Oriented Impacts on the Patella" in The Stapp
Car Crash Journal (47: 1-19, 2003) (Abstract)
involves the analysis of blunt impact on the human knee at different
angles. Recent research has shown that people usually do not sit
in a position that would cause the knee to experience a head-on
impact. Therefore, studies have been developed to compare and contrast
oblique versus central-oriented impact loads on the human knee.
Results of this study may suggest that the human knee is more vulnerable
to chronic degeneration following an oblique versus a central-oriented
blunt impact. |
Possible Interventions for Post-Traumatic Osteoarthrosis
The
OBL has worked to develop methods of treating the damaged joint
to delay or mitigate the onset of a chronic disease. A great deal
of research focus has been on treating cells in cartilage explants
with a compound called poloxamer 188. Cartilage which has undergone
blunt trauma can be treated with poloxamer 188, which has been shown
by other researchers to repair cell membranes damaged by shear stress.
By comparing the cell viability between cartilage with poloxamer
and cartilage without, we can determine the effects the poloxamer
has on the explants, repairing damage caused by such impacts. This
research spearheaded a presentation (Abstract)
at the 49th Orthopaedic Research Society
meeting. |
Figure illustrating the effects of poloxamer 188 on cartilage explants 1 hour and 24 hours post-impact |
| Our researchers recently presented a paper at the 48th Orthopaedic Research Society meeting illustrating the effects of regular exercise on an injured joint. This presentation indicated that post-trauma exercise is a benefit to an injured, but stable joint. The adjacent figure shows significant pathology in the rabbit's patello-femoral joint that were not exposed to a regular regimen of joint exercise post-trauma. |
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Histogram showing the functional properties of the retropatellar cartilage and the thickness of the underlying subchondral bone with and without PSGAG treatment post-trauma. |
Furthermore,
the OBL has investigated treatment of the damaged joint with polysulfated
glycosaminoglycans (PSGAG). In vitro experiments have shown that
PSGAG increases the synthesis of collagen and glycosaminoglycans
in tissue explants. Therefore, it was hypothesized that PSGAG could
mitigate the degradative effects of blunt trauma to a diarthrodial
joint. Our research found that early administration of PSGAGs post-trauma
had a positive effect on the mechanical integrity of retro-patellar
articular cartilage. On the other hand, this intervention had no
effect on remodeling of the underlying subchondral bone nor did
it help repair surface lesions created by the blunt insult. This
experiment was the foundation of a paper published in the Journal
of Orthopaedic Research entitled, "Polysulphated Glycosaminoglycan
Treatments can Affect Some Early Signs of Osteoarthrosis in a Traumatized
Animal Joint" (18(5):756-761) (Abstract). |
In
another study the effect of pretreating cartilage explants with
glucosamine was investigated using different rates of impact loading.
This study, entitled "The Effect of Pretreatment with Glucosamine
on Mechanically Traumatized Cartilage Explants," (Abstract)
was presented at the 47th Meeting of the Orthopaedic
Research Society. We found that glucosamine pretreatment can
minimize the degree of cartilage matrix damage, but does not statistically
affect the amount or distribution of cell death following a severe
blunt impact. This data might suggest that this nutriceutical may
provide some degree of protection to joint cartilage during vigorous
athletic activity. |
Change in water content (and thus, matrix damage) after one day post-impact with and without GS |
Attn: Dr. Roger Haut
A-407 East Fee Hall
East Lansing, MI 48824
phone:(517) 355-0320
email: haut@msu.edu
© 8/10/05
by MSU OBL.
All Rights Reserved.