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K. J. van Zwieten a, K. P. Schmidta, S. De Munter a, L. Kosten a, A. Hotterbeekx a, P. L. Lippens a, P. Adriaensens a, I. Lambrichtsa, P. P. Geusens a’b
FINGER PROXIMAL INTER PHALANGEAL (P.I.P.) MOTION:
JOINT SURFACES AND LIGAMENTOUS GEOMETRIES ARE INTERRELATED
a) Functional Morphology, Department of Anatomy, University of Hasselt, BioMedical Research Institute, Diepenbeek, Belgium, koosjaap.vanzwieten@uhasselt.be
b) Department of Internal Medicine, Maastricht University Medical Center, Maastricht, The Netherlands
Introduction - observations and problems
The morphogenesis of the finger joints was first elucidated by Kaplan (1950) by means of transversal sections of fetal hands. The author also showed the developing morphology of the articular surfaces of the fingers, as well as their relation to the soft tissues such as finger tendons, and ligaments of various small joints of the fingers. Very recently, the essential influence of prenatal movements during morphogenesis (i.e. during fetal life) on the definite shapes of joint surfaces, was convincingly demonstrated in the mouse knee (Roddy et al., 2011). Because in man, the knee joint and the Proximal Inter Phalangeal (P.I.P.-) joint of the finger show several similarities (Slattery, 1990), it is justified to analyze some of the human P.I.P.-joint's functional morphology by making use of methodologies elsewhere applied on form and function of the human knee. Analyzing the shapes of the articular surfaces of the finger P.I.P.-joint is also needed in view of somber perspectives of some P.I.P. joint arthroplasties after a certain time (Sweets and Stern, 2011).
With respect to the knee-joint, a widely accepted kinematic analysis that takes into account the ligaments of the knee, especially its cruciate ligaments, was first introduced by Huson and his co-workers (1989). They made use of a crossed four bar linkage system, consisting of two articulating bones viz. the solids of femur and tibia, as well as the taut two cruciate ligaments connecting them, conceived as tense cords and therefore behaving as bars, during the alternating flexion and extension of the knee. The authors showed the close inter-relationship of the behavior of such a crossed system, and the morphology i.e. the characteristic curvatures of the joint surfaces of femur and tibia.
In the present study, we apply a comparable analysis on the P.I.P.-joint of the finger consisting of two articulating bones viz. solids of the proximal phalanx's head and the middle phalanx's base, and some collateral ligaments connecting them (Figs. 1-3). As far as they are taut during flexion of the P.I.P.-joint, ligamentous bundles may be considered as tense cords, also because of their homogeneous composition.
Tracing of a photomacrograph of the osteology of the proximal interphalangeal joint of a human finger (lateral view). Note concave base of middle phalanx (MP) and convex head of proximal phalanx (PP).
Figure 1
A recent report on the histological properties of the so-called Proper Collateral Ligament (P.C.L.) of the P.I.P.-joint of the finger, described the collagen fiber bundles herein as being equally inelastic (van Zwieten et al., 2011).
After the basic work by Kuczinsky (1968), the collateral ligaments of the adult P.I.P.-joint were described more in detail by Hintringer and Leixnering (1991), mainly by means of micro-dissection techniques. Allison (2005) combined micro-dissection, with transverse histological sections of the P.I.P.-joint. Our present study adopted a similar approach, coronal HR MRI-slicing, however, was used instead. In frontal planes of the P.I.P.-joint, we observed superficial, as well as deep bundles as parts of the Proper Collateral Ligament (P.C.L.). These “S.P.C.L.” and “D.P.C.L.” respectively, are indicated in the figure (Fig. 2) by different colors. At either lateral (i.e. ulnaras well as radial-) side of the P.I.P.-joint these “S.P.C.L.” and “D.P.C.L.” are readily recognized after micro-dissection of anatomical specimens of the finger (Fig. 3). Their obvious intercrossing (Hintringer and Leixnering, 1991) was also observed. The well-known Accessory Collateral Ligament (A.C.L.) (Kuczinsky, 1968; Hintringer and Leixnering, 1991; Allison, 2005) was also observed and depicted. As in P.I.P.-flexion the Accessory Collateral Ligament becomes lax, this A.C.L. is explicitly not taken into consideration in our further kinematical analyses offered below.
Tracing of photomacrograph of P.I.P.-joint of human finger. A.C.L. = Accessory Collateral Ligament; other symbols: see text or figures above
’ spcl "
ACL
Figure 3
Kinematical analysis
Based on the model-wise crossed four bar linkage system cited above (Huson et al., 1989), an initially symmetrical representation including “S.P.C.L.” (red) and
“D.P.C.L” (green) was proposed as indicated in Figure 4. Starting here, appropriate lengths of the crossing bundles plus the lengths of their origin and insertion areas, as measured from HR-MRI slices, were substituted quantitatively in Freudenstein's equation. This permitted us to eventually calculate the trajectory of the left bar, while the right bar is kept immobile, but all other bars move (Fig. 5). The envelope curve composed of the left bar's positions, not only represents sites of contact between two articular surfaces i.e. the base of the second phalanx and the curvature of the head of the first phalanx, but it also represents the latter curvature itself (Huson et al., 1989).
Results
We approximated the anatomical situation by a four bar linkage. The system base represents the first phalanx's head, its opposite represents the base of the second phalanx, and the other two connecting bars are formed by the crossing ligament bundles. Substituting two measured data sets into Freudenstein's equation in the crossed four bar linkage while simulating 0 ° to 90 ° P.I.P.-joint flexion, produced the following. During this P.I.P. flexion, the envelope of the moving bar that represents the base of the second phalanx produces a curvature which according to Huson and co-workers (1989) can be approximated by an ellipse-like curve.
Applications
“Arthroplasty with interphalangeal joint prostheses is currently recommended to overcome intractable rheumatoid arthritis and osteoarthritis. Small finger joint pros-theses may however be improved with the help of our data on these finely tuned correlations between ligaments behavior, and the shapes of joint surfaces” (van Zwieten et al., 2011). Remarkably, a ten-year endurance evaluation on certain P.I.P.-joint prostheses revealed a variety of adverse events (Sweets and Stern, 2011). Also because of that, we suggest that the behavior of P.I.P.-joint soft-tissues, viz. the bundles of the Proper Collateral Ligament (P.C.L.), is taken into account as well.
Acknowledgements
The authors wish to thank Ms. Merel Van Walleghem, BSc, Junior Master of Biomedical Sciences, for her helpful interest and enthusiasm during the preparation of this survey, as well as the many other medical and biomedical students at the University of Hasselt, Belgium, over the years.
References
1) Kaplan EB (1950) Embryological development of the tendinous apparatus of the fingers: relation to function. Journal of Bone and Joint Surgery, 32, 820-826
2) Roddy KA, Prendergast PJ, Murphy P (2011) Mechanical influences on morphogene-
sis of the knee joint revealed through morphological, molecular and computational analysis of immobilised embryos. PLoS ONE 6, 2, e17526.
doi:10.1371/journal.pone.0017526
3) Slattery PG (1990) The dorsal plate of the proximal interphalangeal joint. Journal of Hand Surgery, British Volume, 15B, 1, 68-73
4) Sweets TM, Stern, PJ (2011) Pyrolytic carbon resurfacing arthroplasty for osteoarthritis of the proximal interphalangeal joint of the finger. Journal of Bone and Joint Surgery, 93, 1417-1425
5) Huson A, Spoor CW, Verbout AJ (1989) A model of the human knee, derived from
kinematic principles and its relevance for endoprosthesis design. Acta Morphologica Neerlando-Scandinavica, 27, 45-62
6) Hintringer W, Leixnering, M (1991) Knöcherne oder ligamentäre Verletzungen am Mittelgelenk und ihre Behandlung. Handchirurgie, Mikrochirurgie, plastische Chirurgie, 23, 59-66
7) Allison DM (2005) Anatomy of the collateral ligaments of the proximal interphalan-geal joint. Journal of Hand Surgery, American Volume, 30, 5, 1026-1031
8) van Zwieten KJ, De Munter S, Kosten L, de Kooter M, Lambrichts I, Lippens PL, Schmidt KP, Helder P, Geusens PP, van den Bergh JPW, van Rietbergen B (2011) Handling the PC mouse, and our small finger joints. In: van Dorp C. E. (Ed.) European Society for the Systemic Innovation of Education (ESSIE) Annual Assembly 2011, Leuven, 80-83. ISBN: 978-90-817453-0-7
9) Kuczinsky K (1968) The proximal interphalangeal joint. Journal of Bone and Joint Surgery, 50B, 3, 656-663.
K. J. van Zwieten a, K. P. Schmidta, P. Helder b, P. L. Lippens a, I. A. Zoubovac, A. V. Zinkovsky c
EFFECTS OF THE USE OF A SPECIAL COMPUTER MOUSE THE HANDSHOE MOUSE
a) Functional Morphology, Department of Anatomy, University of Hasselt, BioMedical Research Institute, Diepenbeek, Belgium, koosjaap.vanzwieten@uhasselt.be
b) HandShoe Mouse, Hippus NV, Rotterdam, The Netherlands
c) Department of Biomechanics and Health Sciences, Saint Petersburg State Polytechnical University, Saint Petersburg, Russia
Introduction - problems and observations
Based on fundamental biomechanical research it was noted that the level of forearm muscle activity varies depending on the type of computer mouse used.
EMG values showed that a supporting contour can realize significant reduction of activity in between muscle actions like switching and scrolling or moving the mouse over the desktop.
Next to the contour of the supporting surface, the plane angle variation from fully pronated to 900 supination, “handshake position” has a significant effect on muscle activity.
With a conventional mouse a combination of thumb, ring- and little finger is required to realize optimal control in the horizontal (X-Y) plane. By providing a supporting contour for hand palm and fingers, it was noted that gripping and pinching of thumb and fingers (m. extensor carpi radialis longus and brevis) to control the mouse in the X-Y plane was no longer necessary (1).
