title: Anatomical risks of using supra-acetabular screws in percutaneous internal fixation of the acetabulum and pelvis.
abstract: We conducted a study to determine whether a lag screw placed percutaneously at the level of the pelvic brim for treatment of iliac fracture risks injury to the lateral femoral cutaneous nerve (LFCN). A 4-mm Kirschner wire (K-wire) was placed percutaneously into each of 8 human cadaveric hemipelvises (4 pelvises) at the level of the pelvic brim to represent the path of screw placement. Under fluoroscopic guidance, each K-wire was advanced from the anteroinferior iliac spine toward the posterior iliac crest. Cadavers were dissected at study end. Proximity of the LFCN to the percutaneously inserted K-wire was the main outcome measured. In 4 of the 8 hemipelvises, the LFCN was disrupted; in 3 hemipelvises, it was within 4 mm of the K-wire; in the last hemipelvis, it was 23 mm away. LFCNs varied anatomically from 1 to 5 branches; disruptions occurred more in LFCNs with multiple branches than in those with 1 branch. The results suggest considerable risk for injury to the LFCN during percutaneous fixation of iliac and acetabular fractures using a percutaneous screw at the level of the pelvic brim.
authors.affiliation: Division of Orthopedic Surgery, McGill University, Montreal, Canada. ejharvey@hotmail.com
authors.forename: Milan
authors.initials: M
authors.lastname: Sen
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Harvey
authors.forename: Daniel
authors.initials: D
authors.lastname: Steinitz
authors.forename: Pierre
authors.initials: P
authors.lastname: Guy
authors.forename: Rudy
authors.initials: R
authors.lastname: Reindl
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging / Q000293:injuries / Q000601:surgery*; D000368:Aged; D001863:Bone Screws; D002102:Cadaver; D004867:Equipment Design; D004868:Equipment Failure; D005260:Female; D005593:Fracture Fixation, Internal / Q000295:instrumentation* / Q000379:methods; D050723:Fractures, Bone / Q000000981:diagnostic imaging / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D010388:Pelvis / Q000000981:diagnostic imaging / Q000293:injuries* / Q000601:surgery*; D011859:Radiography; D012307:Risk Factors; D012680:Sensitivity and Specificity