Stoppa approach: clinical anatomy and application in pelvic anterior ring fracture

Abstract

Objective To study the clinical anatomy and application of Stoppa approach in fixation of pelvic anterior ring fractures.Methods The frequency of Corona Mortis in pelvis were observed in 20 cadavers (40 sides).The safe areas for screw insertion into the medial sidewall of the pelvis were measured in anteroposterior X-ray films of the pelvis.A retrospective study was performed of a series of 22 patients (14 males and 8 females) with pelvic anterior ring fracture who had been treated by Stoppa approach.They were 17 to 56 years of age (mean,32.6 years).Simple anterior ring fractures occurred in 16 patients who were fixated with plate of pelvic anterior ring.The other 6 cases were complicated with fracture dislocation of the sacroiliac articulation and treated with plate of pelvic anterior ring and sacroiliac screws.According to the Tile classification,3 fractures were type A2,6 type B2,7 type B3,4 type C2 and 2 type C3.Results The presence rate of Corona Mortis was 85.0％ (34/40) in the 20 cadavers.Of the inner margin of a true pelvis,the pubic branch district was safe for screw insertion of a 4-hole plate and the supra-acetabular region was also safe for screw insertion of a 3-4-hole plate,but the acetabular region was unsuitable for screw insertion of a 3-4-hole plate.The blood vessel,Corona Mortis,was found in 18 of the patients (18/22) and ligated in the operation.According to the Matta criteria,14 cases obtained anatomic reduction,7 good reduction and one poor reduction (the pelvic anterior ring fracture).Nineteen patients obtained follow-ups for 6 to 12 months (average,10.4 months) and all achieved bony union at 2.8 months postoperatively on average(range,2 to 4 months).At the last follow-up,the pelvic function was rated as excellent in 12,good in 5 and fair in 2 cases according to the Majeed evaluation system.Conclusions The presence of Corona Mortis is high by the cadaveric and clinical observations.Consequently,Stoppa approach is appropriate for internal fixation of an unstable pelvic ring fracture because it allows an adequate exposure for visualization and managernent of the vessel to achieve good clinical outcomes. Key words: Pelvis; Fractures, bone; Anatomy; Stoppa approach