Minimally invasive spinopelvic "crab-shaped fixation" for unstable pelvic ring fractures: technical note and 16 case series.
BACKGROUND
Unstable sacral fractures are high-energy injuries and comprise polytrauma. Internal fixation to enable withstanding vertical loads is required to get up early from the bed after an unstable sacral fracture. We developed a new minimally invasive surgical (MIS) procedure for unstable pelvic ring fractures and reported it in Japanese in 2010. We presented our minimally invasive surgical technique of crab-shaped fixation for the treatment of unstable pelvic ring fractures and report on its short-term outcomes.


METHODS
Sixteen patients with unstable pelvic ring fractures (AO types C1, 2, and 3) were treated using crab-shaped fixation. All procedures were performed with the patient in the prone position through 5-cm skin incisions created bilaterally at the level of the posterior superior iliac spine. Four iliac screws were inserted and connected with two rods under the fascia. Percutaneous pedicle screws were inserted at L5 or L4 and connected to the iliac rod using offset connectors. Fracture reduction was then performed.


RESULTS
The average surgical time was 158 min (range, 117-230 min), with an intraoperative bleeding volume of 299 ml (range, 80-480 ml). Thirty-three pedicle screws and 64 iliac screws were implanted with no instance of malpositioning or perforation. A surgical site infection developed in 2 of the 16 cases. Both were deep methicillin-resistant Staphylococcus aureus infections, with the removal of the distal implants required in only one of these cases. Bony union was achieved in all patients, and all vertical displacements reduced by 7.0 mm, on average (range, 5.4-9.0 mm), to < 10 cm. Correction was retained in all cases.


CONCLUSIONS
Crab-shaped fixation provides a feasible MIS approach for spinopelvic fixation, which allows good reduction of the vertical displacement of unstable pelvic ring fractures and bony union.
['Okuda|Akinori|A|', 'Maegawa|Naoki|N|', 'Matsumori|Hiroaki|H|', 'Kura|Tomohiko|T|', 'Mizutani|Yasushi|Y|', 'Shigematsu|Hideki|H|', 'Iwata|Eiichiro|E|', 'Tanaka|Masato|M|', 'Masuda|Keisuke|K|', 'Yamamoto|Yusuke|Y|', 'Tada|Yusuke|Y|', 'Kogeichi|Yohei|Y|', 'Takano|Keisuke|K|', 'Asai|Hideki|H|', 'Kawai|Yasuyuki|Y|', 'Urisono|Yasuyuki|Y|', 'Kawamura|Kenji|K|', 'Fukushima|Hidetada|H|', 'Tanaka|Yasuhito|Y|']
D000328:Adult D000368:Aged D000369:Aged, 80 and over D005260:Female D005593:Fracture Fixation, Internal D050723:Fractures, Bone D006801:Humans D008297:Male D008875:Middle Aged D019060:Minimally Invasive Surgical Procedures D010384:Pelvic Bones D012447:Sacrum D055815:Young Adult
Crab-shaped fixation Pelvic ring fracture Sacral fracture Vertical displacement Minimally invasive surgery Spino-pelvic fixation