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Changes in Lengths of the Collateral Ligament and the Accessory Collateral Ligament during Flexion of the Metacarpophalangeal Joint
9. Sakuma M, Nakamura R, Inoue G, Horii E. Avulsion fracture of the metacarpophalangeal joint of the finger. Journal of Hand Surgery - British Volume. 22(5):667-71, 1997 Oct. 10. Gross DL, Moneim M. Radial collateral ligament avulsion fracture of the metacarpophalangeal joint in the small finger. Orthopedics. 21(7):814-5, 1998 Jul.
PAPER 72 ∙
Saturday, October 9, 2010 9:49-9:56AM Paper Session 8: Microvascular and Trauma
Changes in Lengths of the Collateral Ligament and the Accessory Collateral Ligament during Flexion of the Metacarpophalangeal Joint Not a clinical study v Toshiyuki Kataoka, MD
SUMMARY POINTS ∙ The CL and AL are functionally divided into 3 portions: the dorsal portion of the CL, which becomes taut during flexion and acts as a lateral stabilizer; the volar portion of the AL, which becomes taut during extension and prevents volar subluxation of the proximal phalanx; and the volar portion of the CL and the dorsal portion of the AL, which essentially act as isometric stabilizers of the MP joint. ∙ The radial AL of the index finger and the ulnar AL of the little finger curved around the volar tubercle of the metacarpal head during flexion of the MP joint. REFERENCES 1. Hakstian RW, Tubiana R. Ulnar deviation of the fingers. The role of joint structure and function. J Bone Joint Surg Am, 1967. 49(2): p. 299-316. 2. Minami A, et al. Ligamentous structures of the metacarpophalangeal joint: a quantitative anatomic study. J Orthop Res, 1984. 1(4): p. 361-8. 3. Moritomo H, et al. Interosseous membrane of the forearm: length change of ligaments during forearm rotation. J Hand Surg Am, 2009. 34(4): p. 685-91. 4. Moritomo H, et al. Change in the length of the ulnocarpal ligaments during radiocarpal motion: possible impact on triangular fibrocartilage complex foveal tears. J Hand Surg Am, 2008. 33(8): p. 1278-86.
Hisao Moritomo, MD, PhD Tsuyoshi Murase, MD, PhD Junichi Miyake, MD Kazuomi Sugamoto, MD,PhD HYPOTHESIS The collateral ligament (CL) and the accessory collateral ligament (AL) play an important role in stabilizing the metacarpophalangeal (MP) joint. However, the functional role of each of these ligaments during flexion is still unknown. We hypothesized that the CL acts as a lateral stabilizer during flexion and that the AL prevents volar subluxation during extension. METHODS We disarticulated 12 embalmed fingers (3 of each finger: index, middle, ring, and little finger) at the carpometacarpal joint. The origin and insertion points of 12 ligamentous fibers, including the dorsal, middle, and volar portions of both the radial and ulnar CL and AL, were identified and recorded for each finger. Since the insertion point of the radial and ulnar ALs is the volar plate, 6 metal markers were inserted into the volar plate at the respective insertion points of the fibers. Micro three-dimensional computed tomography (3D-CT) was performed during passive flexion for every 10 degrees from 0° to 80°. We created 3D models of the metacarpus, proximal phalanx, and paths of the 12 ligament fibers (Figure 1) and calculated the changes in lengths of the CL and AL during flexion of the MP joint. RESULTS During flexion, the length of the dorsal and middle portion of the CL increased significantly (Figure 2), while that of the volar portion of the AL decreased significantly. The lengths of the volar portion of the CL and the dorsal portion of the AL changed minimally during flexion. The paths of the radial AL of the index finger curved around the radial volar tubercle of the metacarpal head at 80° flexion. Similarly, the ulnar AL of the little finger curved around the ulnar volar tubercle. Despite the difference in the paths, the length change patterns of the CL and AL were not significantly different in the various fingers. 56
Figure 1. Three-dimensional model of the 6 ligamentous paths, including the dorsal, middle, and volar portion of the radial CL (red line) and AL (purple line) at 0º (A) or 80º (B) MP flexion of the right index finger viewed from the radial side in a representative case. Note that the insertion points of the ALs are the volar plate which is transparent here.
Figure 2. Changes in lengths of the collateral ligament and accessory collateral ligament during flexion of the metacarpophalangeal joint: A, radial collateral ligament (RCL); B, ulnar collateral ligament (UCL); C, radial accessory collateral ligament (RAL); D, ulnar accessory collateral ligament (UAL). Significant changes were observed in the dorsal and middle portion of the CL and the volar portion of the AL during flexion.
v Speaker has nothing of financial value to disclose
PAPER 72 ∙
Saturday, October 9, 2010 9:49-9:56AM Paper Session 8: Microvascular and Trauma
Changes in Lengths of the Collateral Ligament and the Accessory Collateral Ligament during Flexion of the Metacarpophalangeal Joint Not a clinical study v Toshiyuki Kataoka, MD
SUMMARY POINTS ∙ The CL and AL are functionally divided into 3 portions: the dorsal portion of the CL, which becomes taut during flexion and acts as a lateral stabilizer; the volar portion of the AL, which becomes taut during extension and prevents volar subluxation of the proximal phalanx; and the volar portion of the CL and the dorsal portion of the AL, which essentially act as isometric stabilizers of the MP joint. ∙ The radial AL of the index finger and the ulnar AL of the little finger curved around the volar tubercle of the metacarpal head during flexion of the MP joint. REFERENCES 1. Hakstian RW, Tubiana R. Ulnar deviation of the fingers. The role of joint structure and function. J Bone Joint Surg Am, 1967. 49(2): p. 299-316. 2. Minami A, et al. Ligamentous structures of the metacarpophalangeal joint: a quantitative anatomic study. J Orthop Res, 1984. 1(4): p. 361-8. 3. Moritomo H, et al. Interosseous membrane of the forearm: length change of ligaments during forearm rotation. J Hand Surg Am, 2009. 34(4): p. 685-91. 4. Moritomo H, et al. Change in the length of the ulnocarpal ligaments during radiocarpal motion: possible impact on triangular fibrocartilage complex foveal tears. J Hand Surg Am, 2008. 33(8): p. 1278-86.
Hisao Moritomo, MD, PhD Tsuyoshi Murase, MD, PhD Junichi Miyake, MD Kazuomi Sugamoto, MD,PhD HYPOTHESIS The collateral ligament (CL) and the accessory collateral ligament (AL) play an important role in stabilizing the metacarpophalangeal (MP) joint. However, the functional role of each of these ligaments during flexion is still unknown. We hypothesized that the CL acts as a lateral stabilizer during flexion and that the AL prevents volar subluxation during extension. METHODS We disarticulated 12 embalmed fingers (3 of each finger: index, middle, ring, and little finger) at the carpometacarpal joint. The origin and insertion points of 12 ligamentous fibers, including the dorsal, middle, and volar portions of both the radial and ulnar CL and AL, were identified and recorded for each finger. Since the insertion point of the radial and ulnar ALs is the volar plate, 6 metal markers were inserted into the volar plate at the respective insertion points of the fibers. Micro three-dimensional computed tomography (3D-CT) was performed during passive flexion for every 10 degrees from 0° to 80°. We created 3D models of the metacarpus, proximal phalanx, and paths of the 12 ligament fibers (Figure 1) and calculated the changes in lengths of the CL and AL during flexion of the MP joint. RESULTS During flexion, the length of the dorsal and middle portion of the CL increased significantly (Figure 2), while that of the volar portion of the AL decreased significantly. The lengths of the volar portion of the CL and the dorsal portion of the AL changed minimally during flexion. The paths of the radial AL of the index finger curved around the radial volar tubercle of the metacarpal head at 80° flexion. Similarly, the ulnar AL of the little finger curved around the ulnar volar tubercle. Despite the difference in the paths, the length change patterns of the CL and AL were not significantly different in the various fingers. 56
Figure 1. Three-dimensional model of the 6 ligamentous paths, including the dorsal, middle, and volar portion of the radial CL (red line) and AL (purple line) at 0º (A) or 80º (B) MP flexion of the right index finger viewed from the radial side in a representative case. Note that the insertion points of the ALs are the volar plate which is transparent here.
Figure 2. Changes in lengths of the collateral ligament and accessory collateral ligament during flexion of the metacarpophalangeal joint: A, radial collateral ligament (RCL); B, ulnar collateral ligament (UCL); C, radial accessory collateral ligament (RAL); D, ulnar accessory collateral ligament (UAL). Significant changes were observed in the dorsal and middle portion of the CL and the volar portion of the AL during flexion.
v Speaker has nothing of financial value to disclose