Investigating carpal kinematics, dynamic 4-dimensional Rotational X-ray vs. quasi dynamic imaging. A Pilot study

Wrist problems are responsible for a significant social-economic problem for
the employers and the community as they are responsible for the longest absence
period from work with substantial financial consequences due to workers'
compensation, medical expenses, and productivity losses. Malfunctioning of the
wrist often leads to reduced quality of life and has profound consequences for
the patients involved. Due to the complex anatomy, diagnosis of wrist injuries
is hampered by the various levels of trauma severity and the large number of
possible trauma locations. Therefore it is of great importance for the patient
and the medical doctor to recognize and properly diagnose problems in the wrist
at an early stage. The year-prevalence of wrist complaints among Dutch adults
in 1998 was estimated by the Dutch Institute
for public health and environment (RIVM) at approximately 17.5%. Injuries to
hand and wrist account for 28.6% of all attendances at the accident and
emergency department. Since ligament injury is believed to be present in 5-25%
of wrist traumas it is of great importance to diagnose a ligamentous injury at
an early stage in order to avoid progression of wrist pathology. Scapholunate
ligament (SLL) injury is the most common form of ligamentous injury of the
wrist seen in 60% of the cases . If undiagnosed, SLL injury leads to
progressive limitation of movement, chronic pain and other irreversible changes
within the joint. If Untreated, SLL injury is by far the most frequent cause of
degenerative osteoarthritis of the wrist. The wrist is the most complex joint
in the human body. It consists of 8 wrist bones, 26 ligaments and numerous
articular surfaces. The complex movements of these bones during wrist motion
are still poorly understood. Diagnosis is sometimes difficult owing to poor
understanding of carpal kinematics; inconsistencies in the physical examination
and limited value of imaging methods Treatment outcomes are variable by lack of
quantitative data. In order to functionally stabilize the wrist, numerous
strong ligaments interconnect the wrist bones together and to other surrounding
structures allowing them to function cohesively. Wrist stability can be
described as the ability of the wrist to maintain a normal balance between the
articulating bones under physiologic loads and movements without overloading or
loss of motion control. However, the functional balance between the
articulating bones may be disturbed due to ligament dysfunction. This can
beobserved as a loss of joint integrity and malfunctioning of the wrist during
movements which is manifestated as pain, typical snaps, painful clicks and the
sense of loss of control and strength during hand use.
In the current diagnostic practice, plain radiographs are acquired for the
evaluation of the wrist after a trauma. Although for skeletal pathology static
imaging modalities are in most cases sufficient to diagnose fractures and
dislocations of bony structures, for dynamic abnormalities, static images are
insufficient.
Unless there is an obvious gap between wrist bones, ligamentous injury and its
related abnormal wrist movements are missed. Current static diagnostic
modalities have shown to have limited value in detection of wrist ligament
injuries.

Currently it is only possible to diagnose isolated injuries of ligaments with
invasive methods such as arthroscopy which is now seen as the "gold standard".
Beside the fact that it is a surgical procedure, it has also the disadvantage
of being laborious, time consuming, and too expensive to use as a standard
diagnostic tool. Consequently, SLL injury frequently goes undiagnosed and
untreated, often being passed off as a simple sprain. As a result, late
recognition of SLL injuries often leads to damage of the joint that cannot be
treated without residual problems in joint function. In these cases, the
instability has progressed so much that the chances for success after surgical
reconstruction are strongly diminished.
Unfortunately this is a frequently observed situation for many patients seen in
the clinic [12]. In this light the specific clinical problem that is addressed
in the study is:

*Due to lack of a validated non-invasive diagnostic tool, scapholunate ligament
injuries in the wrist are
currently not diagnosed after a wrist trauma. This makes an early intervention
impossible causing
irreversible damage to the wrist*.

Previous cadaver studies have proven that total SLL ruptures result in
detectible alterations of wrist kinematics. Since dynamic abnormalities are
believed to be of greater value for detecting of partial and total ligamentous
injuries, various authors have pleaded for a diagnostic technique that is both
noninvasive and capable of documenting abnormal kinematics. Concomitant to
these expectations we hypothesize that ligamentous injury of the wrist will be
better detectible by dynamic diagnostic methods, implying that the wrist
kinematics will be indicative for ligament function. By providing us
quantitative data such tool enables us to diagnose ligament injuries and
evaluate the benefits of such interventions
afterwards. The aim of this study is to compare two methods for descrbing
carpal kinematics. The aim is to study wether there are any differences in
dynamic acquired carpal kinematics vs those acquired with a semi dynamic
method.

The aim is to gain basic dynamic information for an upcoming accuracy studies
whereby the diagnostic value of one of the both will be determined.
understanding motion patterns will enable us to set up new definitions for
diagnosing ligamentous wrist pathologies.

Pilot research comparing 2 diagnostic methods for describing carpal kinematics.

For healthy individuals this means a net radiation exposure of 0.5 mSv. This is
comparable to 8 weeks natural background radiation in the Netherlands.