- Discussion:
- indicated for disruption of anterior pelvic ring frx: (
APC II)
when conditions for open forms of fixation are not optimal;
- serve as an alternative to standard plating techniques for pubic ramus fixation;
- in the case of pubic ramus frx in addition to symphysis dislocation, the retrograde
screw is inserted first (to fix the frx) and subsequently the diastasis is
fixed w/ a plate;
- stability is comparable to reconstruction plate fixation;
- a technique for insertion of a 4.5 mm cortical screw 80 mm long, which is inserted
retrograde into the superior ramus, medial to the hip joint;
- pubic ramus is preferably closed reduced prior to screw fixation;
- otherwise open reduction is required;
- Radiographs:
- inlet radiographs:
- identifies the anterior pelvic ring;
- slight variations in flouroscopic rotation help distinguish the superior
and inferior pubic rami;
- obturator oblique view:
- this view is essential for demonstrating the safe zone for
screw placement;
- C-arm is placed on injured side;
- is obtained from
outlet view along w/ 20-30 deg lateral rotation;
- Technique:
- stab incision is made at level of contra-lateral pubic tubercle;
- blunt clamp is used to spread down to injured tubercle;
- drill and drill sleeve are inserted parallel to superior ramus;
- starting hole is just inferior to to the injured pubic tubercle and
lateral to symphysis;
- ML Chip et al recommend use of a oscillating 2.5 mm diameter 200 mm length
triple fluted drill point (from Synthes);
- be careful not to direct the drill cephalad out of the ramus;
- use the inlet and the oblique-outlet views to direct the drill across
the fracture and subsequently superior to the hip joint;
- an appropriately sized 3.5 mm or 4.5 mm screw is then inserted;
- it is not necessary for screws to pass above the hip joint, unless the
ramus frx is lateral to the iliopectineal ramus;
-------------------------------------------------------
- ref:
- Internal Fixation of the Unstable Anterior Pelvic Ring: A Biomechanical Comparison of Standard
Plating Techniques and Retrograde Medullary Superior Pubic Ramus Screw.
PT Simonian, ML Chip Routt Jr, RM Harrington, and AF Tencer
J. Orthop Trauma. 1994. Vol 8. No 6. p 476 482.
- The Retrograde Medullary Superior Pubic Ramus Screw for Treatment of Anterior
Pelvic Ring Disruptions: A New Technique.
M.L. Chip Routt Jr, P.T. Simonian, and L. Grujic.
J.Orthop.Trauma. 1995. Vol 9. No 1. pages 35-44.
