- 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;