ABSTRACT
Objective:To compare Jefferson-fracture reduction plate (JeRP) and micro titanium plate in the transoral single-segment fixation of unstable atlas fractures.Methods:From January 2008 to December 2020, 45 patients with unstable atlas fracture were treated by single-segment fixation through an oral approach with a JeRP or a micro titanium plate at Department of Orthopedic Surgery, General Hospital of Southern Theatre Command. They were 24 males and 21 females, aged from 15 to 67 years. By the Gehweiler classification, 11 atlas fractures were type Ⅰ and 34 type Ⅲ; by the American Spinal Injury Association (ASIA) classification, the spinal cord injury was grade D in 7 cases and grade E in 38 cases; by the Dickman classification, the atlas transverse ligament injury was type Ⅰ in 4 cases and type Ⅱ in 11 cases. Of the patients, 26 were treated by transoral single-segment fixation with a JeRP and 19 by transoral single-segment fixation with a micro titanium plate. The 2 groups were compared in terms of baseline data, operation time, blood loss, hospital stay, visual analog scale (VAS) for neck pain and atlas lateral mass displacement (LMD) before operation and at the last follow-up, and intraoperative and postoperative complications.Results:The 2 groups were comparable because there was no significant difference between them in the preoperative general data ( P>0.05). All patients were followed up for 12 to 55 months (mean, 21.8 months). Wound dehiscence or infection was observed in none of the patients after operation. About 12 months after operation, all fractures achieved bony union, neck pain basically disappeared, and neck movement had no obvious limitation. The hospital stay was (13.9±2.2) d for the JeRP group and (14.2±2.9) d for the micro titanium plate group, showing no significant difference between the 2 groups ( P>0.05). The operation time was (203.5±173.4) min and the blood loss (167.3±138.6) mL in the JeRP group, significantly more than those in the micro titanium plate group [(121.5±50.5) min and (98.4±57.2) mL] ( P<0.05). In the JeRP group, the preoperative LMD was (6.7±1.7) mm and the preoperative VAS score (6.8±1.0) points, significantly higher than the last follow-up values [(0.7±0.6) mm and (0.7±0.6) points] ( P<0.05). In the micro titanium plate group, the preoperative LMD was (6.6±1.5) mm and the preoperative VAS score (6.7±0.9) points, significantly higher than the last follow-up values [(0.9±0.6) mm and (0.8±0.7) points] ( P<0.05). However, there was no significant difference in the preoperative or the last follow-up comparison between the 2 groups ( P>0.05). Implant loosening was observed in one patient in the JeRP group while foreign body sensation in the throat was reported in one patient after operation in the micro titanium plate group. Conclusions:Both JeRP and micro titanium plate in the transoral single-segment fixation can lead to effective treatment of unstable atlas fractures. Compared with JeRP, the micro titanium plate can effectively shorten operation time and reduce blood loss due to its smaller size and lower incision.
ABSTRACT
Objective To compare the biomechanical stability of 4 internal fixations in treatment of acetabular fracture of the lower anterior column through finite element analysis.Methods One normal adult male pelvis was subjected to 0.7mm thin-section CT scanning and 379 CT pictures were obtained.Finite element modeling software was used to establish internal fixation models for acetabular fracture of the lower anterior column,including lag screws (A),anterior column reconstruction plate (B),subcutaneous plate not crossing the pubic symphysis (C) and subcutaneous plate crossing the pubic symphysis (D).Finite element analysis was carried out to compare the biomechanical differences among the 4 internal fixation models which were subjected to the same loading conditions at both standing and sitting positions.Results At standing and sitting positions,the maximum displacement and the mean node displacement of fracture lines were the greatest in group A (0.558 mm and 0.462 ±0.092 mm at standing;0.634 mm and 0.473 ±0.108 mm at sitting),the smallest in group D (0.512 mm and 0.425 ±0.083 mm at standing;0.031 mm and 0.025 ± 0.004 mm at sitting),and in between in group B (0.513 mm and 0.432 ±0.085 mm at standing;0.630 mm and 0.466 ± 0.109 mm at sitting) and in group C (0.514 mm and 0.433 ± 0.085 mm at standing;0.627 mm and 0.464 ± 0.107 mm at sitting).At both standing and sitting positions,the maximum stress at the fracture line was the greatest in group D (10.519 MPa and 24.879 MPa),the smallest in group A (3.254 MPa and 8.954 MPa),and in between in group B (4.873 MPa and 9.431 MPa) and in group C (4.384 MPa and 10.128 MPa).Conclusions In treatment of acetabular fracture of the lower anterior column,subcutaneous plate crossing the pubic symphysis may result in the greatest biomechanical stability,lag screws the smallest biomechanical stability,and anterior column reconstruction plate and subcutaneous plate not crossing the pubic symphysis the moderate biomechanical stability.