Iso-C 3D navigation versus conventional C-arm fluoroscopy in minimally invasive treatment of acetabular fractures

Abstract

Objective To compare isocentric C-arm 3-dimensional (Iso-C 3D) navigation and conventional C-arm fluoroscopy in percutaneous screw fixation for acetabular fractures. Methods From June 2005 to December 2010,37 patients (23 males and 14 females) with acetabular fracture were treated through percutaneous screw fixattion technique.Their average age was 35.8 years (from 18 to 56 years).According to AO classification,9 cases were of A2 type,18 cases of A3 type, and 10 cases of B1 type.They were assigned into 2 groups.In Group A of 16 cases,the cannulated screws were inserted with assistance of C-arm fluoroscopy,while in Group B of 21 cases,the operations were assisted by Iso-C 3D navigation system.Average operation time,average radiation time,average screw fixation time,average bone union time,functional recovery and satisfactory reduction rate were recorded and compared between the 2 groups.Results Altogether 49 cannulated screws were inserted in 37 patients.No complication was noted in any patient postoperatively.By Matla evaluation sysem,the operations were rated as excellent in 25,good in 10and fair in 2,with a good to excellent rate of 94.6％.Thirty-four patients were followed up for 6 to 18 months (average,12.4 months).The average screw fixation time (28.1 ± 1.3 minutes vs.37.6 ± 1.8 minutes) and the average radiation time (43.9 ± 0.3 seconds vs.63.2 ± 2.9 seconds) were significantly shorter in Group B than in Group A ( P ＜ 0.05).There were no significant between-group differences in average operation time (78.4 ±2.4 minutes vs.73.1 ± 2.0 minutes),satisfactory reduction rate (93.8％ vs.95.2％ ),average bone union time (12.1 ± 0.5 weeks vs.11.6 ± 0.3 weeks) or satisfactory functional recovery rate (86.7％vs.89.5％ ) ( P ＞ 0.05).Functional recovery by Majeed evaluation system after 6 months showed 9 excellent cases,11 good cases,2 fair cases and 2 poor cases,with a good to excellent rate of 88.2％ and no between-group difference.All fractures were healed,and no delayed union or nonunion happened. Conclusions Percutaneous screw fixation under Iso-C 3D navigational system is not only minimally invasive and precise but also safer to the patient and medical staff.It is a reliable method of treating undisplaced or mildly displaced acetabular fractures. Key words: Acetabulum; Fractures; Surgery, computer-assisted; Surgical procedures, minimally