Abstract: Objective To investigate the efficacy of internal fixation combined with external fixation in the treatment of vertically unstable pelvic fractures. Methods Fifteen patients were treated with percutaneous hollow screw fixation of the sacroiliac joint combined with external fixation brace fixation. Matta imaging score: excellent in 10 cases and moderate in 5 cases. According to Majeed’s efficacy criteria: excellent in 9 cases, good in 5 cases, and acceptable in 1 case. Conclusion Percutaneous hollow screw fixation of the sacroiliac joint combined with external fixation brace fixation of vertically unstable pelvic fractures is less invasive and can restore pelvic stability immediately and effectively.
Keywords: fracture pelvis, minimally invasive, sacroiliac screw, external fixation brace
Surgical treatment of unstable pelvic fractures with percutaneous internal fixation combined with external fixation. WU Xiao-san,SHAO Song,LIU Xing-guo(Section Ⅲ, Dept of Orthopaedics, Lu’an Affiliated Hospital of Anhui Medical University, Lu’an, Anhui 237000, China)
Abstract：objective To discuss the clinical outcomes of minimally invasive internal fixation combined with external fixation in treatment of vertically unstable pelvic fractures.Methods From May 2005 to August 2011,15 patients with a vertically unstable pelvic fracture were treated with minimally invasive percutaneous hollow screw fixation of the sacroiliac joint combined with external fixation. Results All patients were foIlowed up 3-32months after surgery.After being evaluated by the Matta scale,the outcomes of reduation were excellent in 10 cases,good in 5. Accoding to Majeed functional scoring,9 patients were excellent,5 good and 1 normal.Conclusions In the management of vertically unstable pelvic fracture, a Key words: pelvic fractures; Minimally invasive; Sacroiliac screw; external fixation. In the management of vertically unstable pelvic fracture, a stable pelvis can be reconstructed by minimally invasive internal fixation combined with the most severe type of pelvic fracture. Conservative treatment often leaves complications such as pain in the pelvic region, unequal length of both lower extremities, and non-union or malunion of the fracture [1]. 15 cases of vertical unstable pelvic fractures were fixed by percutaneous hollow screw fixation of the sacroiliac joint combined with external fixation stent in our department from May 2005 to August 2011, and good clinical results were achieved, as reported below. 1.Materials and methods 1.1 Case data The 15 patients in this group, 9 males and 6 females, aged 32-58 years. Combined injuries: 10 cases of early traumatic shock, 4 cases of cranial injury (2 cases of subarachnoid hemorrhage, 1 case of cerebral contusion, 1 case of epidural effusion); 3 cases of multiple rib fractures and hemopneumothorax with pulmonary contusion; 2 cases of closed abdominal injuries (1 case of splenic rupture and 1 case of subperitoneal hemorrhage); 2 cases of spinal compression fractures; 8 cases of fracture dislocation of extremities. Fractures according to Tile classification: 8 cases of C1 type, 2 cases of C2 type, and 5 cases of C3 type. The anterior ring injury mainly showed 6 cases of pubic symphysis separation, 2 cases of pubic symphysis strangulation, 5 cases of double fracture of the upper and lower pubic branches, and 2 cases of Tile fracture; the posterior ring injury showed 4 cases of sacroiliac joint fracture dislocation and 11 cases of sacral fracture; 5 cases of acetabular comminuted fracture occurred. The time from injury to surgery ranged from 7 to 10 d. 1.2 Preoperative preparation Rapid fluid infusion, active preparation for blood transfusion, indwelling catheterization, diagnostic laparotomy or closed chest drainage if necessary, and imaging after correction of shock. Routinely take anteroposterior, entrance, exit and lumbar front and lateral x-ray of the pelvis, CT scan and 3D reconstruction to determine the type of pelvic fracture. The affected limb was routinely subjected to supracondylar femoral traction with a weight of 1/6~1/4 of body weight, generally for 7~9 d. Surgery was performed after complete or basic repositioning of the vertical displacement was confirmed by imaging examination. pelvic pockets with appropriate draping. 1.3 Surgery method The surgery was performed under general anesthesia with tracheal intubation. The patient was placed in the prone position with the affected lower limb in traction, and the C-arm machine was accurately positioned before fixation for intraoperative fluoroscopic positioning. The posterior pelvic ring was repositioned and fixed first, and the anterior ring was repositioned and fixed later. The needle entry point of the sacroiliac screw was selected 2-3 cm below the posterior superior iliac spine, a small incision of 1-2 cm was made, blunt separation was made, the iliac bone was reached, the needle was positioned under fluoroscopy, the guide needle was inserted from the posterior to the anterior at 30°-45°, and the S1 vertebral body was entered through the iliac bone and sacroiliac joint, the needle penetration process was repeatedly fluoroscopic in the anterior-posterior pelvic position, standard lateral position, entrance position and exit position, the entrance position was fluoroscopic in the anterior tilt angle to avoid the spinal canal, the exit position was fluoroscopic upward inclination to avoid the sacral nerve foramen, and standard lateral fluoroscopy to grasp the screw length. After satisfactory positioning, a 7.3 mm diameter hollow screw was slowly screwed in the direction of the guide pin. After internal fixation, C-arm machine fluoroscopy was used to check the fracture deformity correction, and external fixation brace was used to repair the residual pelvic displacement for pubic symphysis dislocation and fracture of the upper and lower pubic branches; C3 patients with acetabular fracture were treated with internal fixation. 1.4 Postoperative treatment Prophylactic application of antibiotics for 1 week. On the first postoperative day, patients were encouraged to perform active or passive functional exercises, and after 1 week, they were placed in sitting or semi-recumbent position. 1.5 Follow-up evaluation Imaging evaluation was based on the Matta criteria [2], according to the maximum fracture displacement distance on pelvic plain films in 3 positions (anterior-posterior, entrance and exit positions), ≤4 mm was considered excellent, 5-10 mm was considered good, 10-20 mm was considered moderate and >20 mm was considered poor; the Majeed functional scoring system [3] was used for 5 aspects of pain, work, seating, sexual life and standing, respectively The score was 85-100 as excellent, 70-84 as good, 55-69 as moderate, and <55 as poor. 2. Results All 15 cases were followed up for 3 to 32 months. Imaging scores: 10 cases were excellent, 5 cases were moderate, and all fractures achieved healing. Functional scores: excellent in 9 cases, good in 5 cases, and acceptable in 1 case. Four patients still had pain after six months, but the degree was mild to moderate, and the rest could do the same work as before the injury. one case had posterior right lower extremity nerve root pain, and after conservative treatment, the pain disappeared 2 months after surgery. No screw loosening or fracture occurred. Evaluation of sexual quality of life:Most patients reported that it had little effect on their The typical cases are shown in Figure 1. Figure 1 Patient, female, 45 years old, with vertical unstable pelvic fracture Tile C2 type A preoperative orthopantomogram; B postoperative orthopantomogram showed restoration of pelvic ring integrity and correction of vertical displacement. 3. Discussion 3.1 The importance of percutaneous sacroiliac screw fixation of the posterior pelvic ring. The standard treatment procedures recommended for type C pelvic fractures include: early anticonvulsion, pelvic external fixator to immobilize the pelvis to reduce bleeding and further damage to the abdominal and pelvic organs. Early large-weight traction to correct vertical pelvic displacement. Internal fixation was performed to re-establish the stability of the anterior and posterior pelvic rings when conditions permitted. For anterior-posterior pelvic ring instability fractures, the stability of the posterior ring is critical, so in principle, the posterior ring should be fixed first. There are various methods of posterior ring fixation in common use: such as internal fixation with sacral rods, internal fixation with anterior sacroiliac joint plates, internal fixation with the spinal arch nail rod system [4, 7], and internal fixation with percutaneous or incisional sacroiliac screws. The anterior plate fixation takes an iliac crest incision through extraperitoneal access to reposition the sacroiliac joint under direct vision, but it is more invasive and the fixation effect is not significantly different from that of sacroiliac joint screws via posterior fixation [5]. In patients with anterior-posterior pelvic ring injuries, the use of sacral rod fixation exclusively has been shown to have poor rotational resistance in biomechanical tests [6]. The posterior lumbosacral support fixation technique via the lumbar arch root pelvis has gradually evolved into the iliolumbar fixation mode, and this spinal-pelvic internal fixation concept has now been affirmed and recognized by certain operators, and this dual-plane support fixation mode can balance the abnormal stress of the posterior pelvic ring and can play the dual role of repositioning and fixation to a certain extent, and its shortcoming is that the intraoperative exposure is large, and the screws located in the posterior iliac spine The tail is often overly protruding and compressing the sacrococcygeal region resulting in skin pressure sore formation [7]. The sacroiliac screw technique has good biomechanical effects, small incision, low bleeding, and relatively low risk of surgical trauma and infection. With the help of imaging techniques, the percutaneous sacroiliac screw fixation technique minimizes the risk of surgical trauma and infection. 3.2 Safety control of percutaneous sacroiliac screw fixation. The percutaneous sacroiliac screw fixation technique is an extremely risky technique, and various surgical complications are constantly reported due to the specific anatomy of the pelvic region and the high variability of the sacrum, differences in operator level, and limitations of intraoperative imaging. We believe that successful closed reduction of fractures and dislocations is a prerequisite for safe screw placement. It is generally accepted that closed traction repositioning is more likely within 5 d after injury and more difficult beyond 1 week. For patients who cannot be anatomically repositioned, especially for sacral fractures via the anterior sacral foramen, a few millimeters of misalignment will greatly increase the risk of screw penetration into the bone. In this group of patients, after routine supracondylar bone traction of the femur for 7-9 d after admission, most of the joint dislocations (fractures) were completely repositioned or basically repositioned, and only one patient had a significant separation of the sacroiliac joint, a large longitudinal displacement of the hemipelvis, and an injury to the posterior sacroiliac ligament, and the preoperative large weight traction of the lower extremity failed to completely correct the displacement, and percutaneous internal fixation was used after satisfactory repositioning with a small incision, which expanded the surgical indications for percutaneous internal fixation. The percutaneous screw technique is demanding for the operator, who should be familiar with the anatomy of the sacroiliac joint, sacrum and its surrounding structures. The lumbosacral trunk branch of L4 nerve, L5 nerve root and lumbosacral trunk were located before the lumbar vertebrae and sacroiliac joint, and the L5 nerve root and lumbosacral trunk traveled close to the surface of the sacral wing, which were easily damaged, and the S1 nerve was located in the anterolateral side of the L5 nerve, and there were sacral median vessels in front of the vertebral body, and the sacral sympathetic trunk traveled down through the medial side of the anterior sacral foramen and the surface of the anterior branch of S1 nerve. However, the abnormal morphology of the upper part of the sacrum makes safe screw placement difficult, and up to 40% of patients have anatomical deformities, requiring the operator to pay attention to preoperative radiographs, such as x-rays of the pelvis and CT plain and 3D reconstructed images. At the same time, good imaging guidance is essential in sacroiliac screw technique, and the patient and C-arm machine must be accurately positioned before surgery, and fluoroscopic examination of the pelvis in ortho-position, standard lateral pelvis position, pelvis entrance position and pelvis exit position should be performed intraoperatively. The screw should be located between the anterior and posterior margins of the sacroiliac in the pelvic entry position, where it is easiest to observe if the screw enters the sacral wing anteriorly; below the S1 vertebral body above the 1st sacral foramen, where it is easiest to observe if the screw enters the 1st sacral foramen incorrectly or above the S1; in the lateral pelvic position, where the screw should be located in the S1 vertebral body anterior to the sacral canal, where it is easiest to observe if the screw enters the sacral canal incorrectly or anterior to the S1 vertebral body; in the In the pelvic orthogonal position, the screw head should preferably be located in the center of the sacrum and not into the opposite side. Sacroiliac screw placement includes 4 types: single S1 screw, single S2 screw, double S1 screw and S12 parallel double screw. Most operators are more comfortable placing S1 screws because the S2 pedicle block is more narrow and difficult to place safely compared to S1 [8]. However, Georg et al [9] concluded that S2 screw placement did not increase the risk of nerve injury and thus the need for secondary surgery, and they considered accurate intraoperative C-arm X-ray machine positioning to be more important. The number of screws that should be placed for stable percutaneous sacroiliac screw fixation is still controversial. Biomechanical studies have shown that when the anterior ring is not fixed, the strength of posterior ring fixation with two screws is significantly better than that with one screw; after stable fixation of the anterior ring, there is no significant difference in the strength of posterior ring fixation with one and two screws [10]. Single screws carry a risk of injury to the lumbosacral nerve roots, while double screw placement carries a higher risk. Four patients in our group were placed with double S1 screws, and one patient was left with postoperative radicular pain in the affected lower extremity, which was considered to be due to screw placement injury, while the rest of the patients were placed with single S1 screws, and no medically induced nerve injury occurred. 3.3 The necessity of combined anterior-posterior approach for one-stage repositioning surgery. The external fixation brace is simple to install, provides early repositioning and fixation of the fracture, restores stable hemodynamics, and is the best choice for early salvage of pelvic injuries. However, in Tile C fractures, fixation of the anterior pelvic ring alone does not maintain posterior ring stability, nor does fixation of the posterior ring alone stabilize the anterior ring [11]. External fixator combined with percutaneous sacroiliac screw fixation is mainly used to treat vertically unstable pelvic fractures, including those with combined anterior ring injury: (1) sacroiliac joint injury, dislocation, and definite sacroiliac ligament injury causing pelvic instability; (2) longitudinal transsacral fractures with a tendency of displacement and possible secondary sacral nerve injury; (3) bilateral sacroiliac complex structure injury. All patients in this group were fixed with a combined anterior-posterior approach with one-stage repositioning, with good biological stability, secure fixation, and rapid postoperative recovery, and no broken nail or screw loosening occurred in any of the cases. Patients can be stabilized in weight-bearing position (sitting) early after surgery, and can get out of bed after 6 to 8 weeks with the help of double abduction. However, external fixation frame combined with percutaneous sacroiliac screw fixation also has certain limitations: ①patients need to be turned during surgery, combined anterior-posterior treatment; ②percutaneous nail placement requires good anatomical repositioning of the sacroiliac complex, and when it is difficult to satisfactorily reposition the sacroiliac joint with preoperative lower limb bone traction, the placed sacroiliac screw may easily enter the sacral canal by mistake or penetrate the sacral spine causing nerve and vascular injury; ③for large bone defects and comminuted fractures of the sacrum not It is suitable for application, and should be used with caution for those with abnormal sacral spine development. In conclusion, sacroiliac screw percutaneous closed penetration nailing combined with anterior ring fixation for complex pelvic fractures is a relatively good minimally invasive surgical method with less trauma, less bleeding and faster recovery. Reference. [1] Davarinos N, Ellanti P, Morris S, et al. Epidemiology of pelvic and acetabular trauma in A Dublin tertiary hospital: a 10-year experience[J]. Ir J Med Sci, 2012, 181(2):243-246. [2] Matta J M,Tornetta P 3rd.Internal Fixation of Unstable Pelvic Ring Injuries[J].Clin Orthop Relat Res.1996 Aug;(329):129-140. [3] Majeed S A.Grading the outcome of pelvic fractures[J].J Bone Joint Surg Br.1989 Mar;71(2):304-306. [4] Wu M, Li X.F. TSRH system for Tile C pelvic fractures[J]. Journal of Clinical Orthopaedics.2012,15(2):218. [5] Griffin D R, Starr A J, Reinert C M,et al. Vertically unstable pelvic fractures fixed with percutaneous iliosacral screws: does posterior injury pattern predict fixation failure [J]? J Orthop Trauma, 2006, 20(1 Suppl): S30-36. [6] Bellabarba C, Schildhauer T A, Vaccaro A R, et al. Complications associated with surgical stabilization of high-grade sacral fracture dislocations with spino-pelvic instability [J]. Spine (Phila Pa 1976), 2006, 31(11 Suppl): S80-88. [7] Hu H, Cai L, Jin W, et al. external fixation frame combined with iliolumbar fixation for vertically unstable pelvic fractures[J]. Chinese Journal of Orthopaedics,2011,31(1):61-65. [8] Trumm C G, Rubenbuer B, Piltz S, et al. Screw placement and osteoplasty under computed omographicCfluoroscopic guidance in a case of advanced metastatic destruction of the iliosacral joint[J]. Cardiovasc Intervent Radiol, 2011, 34(2):288-293. [9] Osterhoff G, Ossendorf C, Wanner G A, et al. Percutaneous iliosacral screw fixation in S1 and S2 for posterior pelvic ring injuries: technique and perioperative complications [J]. Arch Orthop Trauma Surg,2011, 131(6):809-813. [10] Sagi H C, Ordway N R, DiPasquale T. Biomechanical analysis of fixation for vertically unstable sacroiliac dislocations with iliosacral screws and symphyseal plating [J]. J Orthop Trauma, 2004, 18(3):138-143. [11] Choy W S, Kim K J, Lee S K, et al. Anterior pelvic plating and sacroiliac joint fixation in unstable pelvic ring injuries [J]. Yonsei Med J, 2012, 53(2):422-426.