The Effects of Simulated Transverse, Anterior Column, and Posterior Column Fractures of the Acetabulum on the

Stability of the Hip Joint*

by MARK S. VRAHAS, KIRSTIN K. WIDDING, and KEVIN A. THOMAS

J Bone Joint Surg AmVolume 81(7):966-74

July 1, 1999

©1999 by The Journal of Bone and Joint Surgery, Inc.

Figs. 1-A, 1-B, and 1-C: Measurement of the roof-arc angles as defined by Matta et al.10.

MARK S. VRAHAS et al. J Bone Joint Surg Am 1999;81:966-74

©1999 by The Journal of Bone and Joint Surgery, Inc.

Fig. 1-B: The anterior roof-arc angle is measured on an obturator oblique radiograph.

MARK S. VRAHAS et al. J Bone Joint Surg Am 1999;81:966-74

©1999 by The Journal of Bone and Joint Surgery, Inc.

Fig. 1 The posterior roof-arc angle is measured on an iliac oblique radiograph.

MARK S. VRAHAS et al. J Bone Joint Surg Am 1999;81:966-74

©1999 by The Journal of Bone and Joint Surgery, Inc.

Figs. 2-A and 2-B: Schematic diagrams showing the location of the simulated anterior column and posterior column fractures.

MARK S. VRAHAS et al. J Bone Joint Surg Am 1999;81:966-74

©1999 by The Journal of Bone and Joint Surgery, Inc.

Fig. 2 The simulated posterior column fractures were classified as very low (just superior to the ischial spine), low, intermediate, and high (at the level of the greater sciatic notch).

MARK S. VRAHAS et al. J Bone Joint Surg Am 1999;81:966-74

©1999 by The Journal of Bone and Joint Surgery, Inc.

Figs. 3-A, 3-B, and 3-C: Graphs showing the results of testing with the specimens intact and after the creation of transverse fractures with roof-arc angles of 60, 50, and 40 degrees.

MARK S. VRAHAS et al. J Bone Joint Surg Am 1999;81:966-74

©1999 by The Journal of Bone and Joint Surgery, Inc.

Fig. 3-B: Results after loading to 1200 newtons.

MARK S. VRAHAS et al. J Bone Joint Surg Am 1999;81:966-74

©1999 by The Journal of Bone and Joint Surgery, Inc.

Fig. 3 Results after loading to 1600 newtons.

MARK S. VRAHAS et al. J Bone Joint Surg Am 1999;81:966-74

©1999 by The Journal of Bone and Joint Surgery, Inc.

Fig. 4 Graphs showing the results of testing with the specimens intact and after the creation of successive anterior column fractures.

MARK S. VRAHAS et al. J Bone Joint Surg Am 1999;81:966-74

©1999 by The Journal of Bone and Joint Surgery, Inc.

Fig. 5 Graphs showing the results of testing with the specimens intact and after the creation of successive posterior column fractures.

MARK S. VRAHAS et al. J Bone Joint Surg Am 1999;81:966-74

©1999 by The Journal of Bone and Joint Surgery, Inc.