- Discussion:
- frx consist of frxs of both pubic rami plus posterior frx of
SI complex or
sacrum:
- there is vertically oriented frx thru anterior and posterior pelvis together w/ superior displacement of lateral "acetabulum-containing" fragment of pelvis;
- this injury is characterized by rupture of entire pelvic floor, including posterior
SI complex as well as sacrospinous and sacrotuberous ligaments;
- vertial stability:
- sacrotuberous ligament: stout ligament which exteds to the posterolateral sacrum and dorsal aspect of the posterior
iliac spine to the ischial tuberosity;
- posterior sacroiliac ligaments, provides vertical stability
to the pelvis.
- injury may be unilateral or bilateral;
- these frx are unstable owing to the significant posterior pelvic disruption;
- usually results from fall from height onto lower limbs;
- Physical Exam:
- displacement in vertical plane is diagnosed by applying one hand to pelvic iliac crest and using other to apply traction to leg which should
cause displacement in vertical plane;
- Radiographic Evaluation:
-
anterior lesion: (see:
anterior pelvic injuries)
- disruption of the symphysis
- disruption of the inferior and superior pubic rami
- disruption of all four rami
- disruption of two rami plus symphysis pubis;
-
posterior lesion: (
posterior pelvic injury:)
- posterior lesion may be a fracture of ileum
- dislocation or frx dislocation of
SI joint
- more than
5-15 mm of cephalic displacement of posterior SI complex on
outlet views gap implies instability;
- frx of 4th or 5th lumbar transverse process;
-
ref: Fracture of the transverse process of the fifth lumbar vertebra.
- detachment of bony insertion of sacrospinous ligaments from either sacrum or ischial spine are evidence of vertical instability;
-
frx of sacrum;
- the following is an example of a Malgaine frx equilavent, in a patient who fell out of a tree;
- the frx appears to have a shear component w/ vertical displacement of the fracture;
-
ref:
-
The role of standard roentgenograms in the evaluation of instability of pelvic ring disruption.
-
Fracture of the transverse process of the fifth lumbar vertebra.
- Initial Management:
- Malgaigne frxs are associated w/ heavy bleeding (see:
bleeding from pelvic frx), requiring on average 7-8 units of
pRBC;
- if pelvis is unstable w/ vertical migration or posterior displacement, then place of
supracondylar femoral pin w/ 25-30 lbs of traction is used to
pull the pelvis back down into a reduced position (w/ equal leg lengths);
- approximately one half of patients treated non operatively w/ traction may expect long term low back pain and/or leg discomfort;
- approximately one third will have a pelvic obliquity and/or limp;
- External Fixation::
- serves only as adjunct to other forms of treatment for these frx;
- has little potential to control pelvic frx w/ involvement of SI joint, including sacral frxs & some posterior iliac wing fractures;
-
indications:
- isolated pelvic frxs when pt does not require mobilization
- use traction to reduce vertical and/or posterior displacement, while
external fixation frame is used to control rotation;
- complex frxs: where internal fixation may not be suitable;
- in the study by J. Lindahl et al (J Bone Joint Surg-Br 1999), the external fixator failed to give and maintain a proper reduction in 38 of the 40 type-C injuries.
- in type-C injuries more than 10 mm of residual vertical displacement of the injury to the posterior pelvic ring was significantly related to poor outcome;
- in 14 patients in this unsatisfactory group poor functional results were also affected by associated nerve injuries;
-
special considerations:
- resistance to verticle displacement is almost doubled by using 5mm rather than 4 mm half pins for iliac wing fixation;
- stability is also enhanced by adding second pin group in each ilium between antero-inferior & superior iliac spines;
- most rigid construction:
- involves combination of
SI jont fixation & external frame placed anteriorly;
-
ref:
-
Anatomic and radiographic considerations in the placement of anterior pelvic external fixator pins.
-
Biomechanical testing of new and old fixation devices for vertical shear fractures of the pelvis.
-
External fixation of unstable Malgaigne fractures: the comparative mechanical performance of a new configuration.
-
Unstable fractures of the pelvis treated by external fixation.
-
The Role of External Fixation in Pelvic Disruptions. Kellam JF: Clin Orthop 1989;241:66-82.
- Sacral Bars:
- safest method of stabilizing a sacral fracture is to use sacral bars;
- these bars pass from one posterior superior spine to other, thereby making direct fixation of fracture w/ lag screws unnecessary;
- two sacral bars are used to prevent rotation;
- bars must be posterior to sacrum to avoid entering sacral spinal canal;
The pathological anatomy of Malgaigne fracture-dislocations of the pelvis.
Critical analysis of results of 53 Malgaigne fractures of the pelvis.
The pathological anatomy of Malgaigne fracture-dislocations of the pelvis.
Femoral Shaft Fractures Associated With Unstable Pelvic Fractures.
Open reduction and internal fixation of vertical shear pelvic fractures Schweitzer G. Journal of Trauma. 27(11):1308, 1987 Nov.
The Unstable Pelvic Fracture: Operative Treatment. JF Kellum MD, RY McMurty MD, D. Paley MD, and M. Tile MD. Orthopaedic Clinics of North America. Vol 18. No 1, Jan 1987. p 25.
