M. L. Chip Routt

Percutaneous Stabilization of U-shaped Sacral Fractures Using Iliosacral Screws: Technique and Early Results

Purpose To present the technique and early results of percutaneous stabilization of U-shaped sacral fractures with attention to neurologic recovery and maintenance of fracture reduction of the sacrum. Design Retrospective clinical study. Setting Level I trauma center. Patients During a thirty-eight-month period, 442 patients with pelvic ring disruptions were treated at a Level I trauma center. Thirteen (2.9 percent) of these patients had displaced U-shaped sacral fractures treated with percutaneous stabilization. Intervention Fracture stabilization was accomplished using fluoroscopically guided iliosacral screws inserted percutaneously with the patient positioned supine. Neurodiagnostic monitoring was not used during screw insertions. This technique was limited to patients with sacral kyphotic deformities, which allowed in situ fixation. Sacral neurologic decompression was not performed. Main Outcome Measurements Fracture healing and the stability of fixation were assessed on inlet and outlet radiographs and a lateral sacral view. Detailed neurologic examinations were performed at injury and at follow-up. Results The sacral fractures were classified based on plain pelvic radiographs and computed tomography scans and included one Type 1, eight Type 2, and four Type 3 fracture patterns. Twenty-five fully threaded cancellous 7.0-millimeter cannulated screws were used. Eleven patients had bilateral screw fixations; one patient had unilateral double screw fixation; and one patient had unilateral single screw fixation. Operative time for screw insertion averaged forty-eight minutes, with 2.1 minutes of fluoroscopy per screw. Accurate screw insertions without neuroforaminal or sacral spinal canal violations were confirmed in all patients with postoperative pelvic plain radiographs and computed tomography scans. A paradoxical inlet view of the upper sacral segments on the injury anteroposterior pelvis was seen in twelve of thirteen patients (92.3 percent), and the diagnosis was confirmed with the lateral sacral view in all thirteen (100 percent) patients. Preoperatively, sacral kyphosis averaged 29 degrees, whereas postoperative sacral kyphosis averaged 28 degrees. Screw disengagement occurred without a change in position of the sacral fracture in the only patient treated with a single unilateral screw. All fractures healed clinically and radiographically. Of the nine patients with preoperative neurologic abnormalities, two (22 percent) patients had residual neurologic deficits. Both patients had associated multiple level lumbar burst fractures, which required decompression and instrumented stabilization. Conclusions These sacral fractures are rare and occur after significant spinal axial loading. A paradoxic inlet view of the upper sacrum on the anteroposterior plain pelvic radiograph heralds the diagnosis. Delayed diagnosis is avoided by a high clinical suspicion, early lateral sacral radiographs, and pelvic computed tomography scans. Surgical stabilization may assist in early mobilization of the patient from recumbency and prevents progressive deformity with associated nerve root injury. Percutaneous fixation diminishes potential blood loss and operative times, yet still allows subsequent sacral decompression of the local neural elements using open techniques when necessary. Early percutaneous iliosacral screw fixation is effective treatment for these injuries.

Closed reduction and percutaneous skeletal fixation of sacral fractures.

Closed manipulative reduction and percutaneous fixation of a displaced sacral fracture is a treatment alternative that offers several advantages. The fracture is reduced and stabilized without an extensile surgical exposure. The risks of surgical wound problems, especially infection, are lessened. Operative and anesthesia times are decreased by using percutaneous techniques of reduction and fixation. Blood loss is also minimized by the percutaneous procedure. Sacral nonunion after this technique is rare. The procedure is dependent on quality fluoroscopic pelvic imaging, a thorough understanding of the posterior pelvic anatomy and early operative intervention, especially in patients with severe posterior pelvic deformities.

The retrograde medullary superior pubic ramus screw for the treatment of anterior pelvic ring disruptions: A new technique

Summary: Retrograde medullary screws were used in 26 patients with unstable pelvic ring injuries to stabilize the superior pubic ramus fractures. The posterior pelvic ring fractures and dislocations were fixed with iliosacral screws. The retrograde screws were inserted after closed manipulative reductions of the superior pubic ramus fractures in 15 patients and after open reduction in nine patients. We were unable to insert the screw in two patients due to anatomical variations. One screw was misplaced superior to the pubic ramus and noted only on the postoperative computed tomography scan. Another patient experienced symptomatic screw disengagement that required reoperation. All fractures healed and no infections developed. Blood loss was minimal for the percutaneous procedures. The technique provides stability to the anterior pelvic ring without the need for extensile surgical exposures. The complications of both anterior pelvic external fixation and plating are avoided, yet this technique has its own potential problems. The procedure is described in detail, and the early results and complications are documented in our first 26 patients

Triangular osteosynthesis and iliosacral screw fixation for unstable sacral fractures: a cadaveric and biomechanical evaluation under cyclic loads.

Objective To conduct a biomechanical comparison of a new triangular osteosynthesis and the standard iliosacral screw osteosynthesis for unstable transforaminal sacral fractures in the immediate postoperative situation as well as in the early postoperative weight-bearing period. Design Twelve preserved human cadaveric lumbopelvic specimens were cyclicly tested in a single-limb-stance model. A transforaminal sacral fracture combined with ipsilateral superior and inferior pubic rami fractures were created and stabilized. Loads simulating muscle forces and body weight were applied. Fracture site displacement in three dimensions was evaluated using an electromagnetic motion sensor system. Intervention Specimens were randomly assigned to either an iliosacral and superior pubic ramus screw fixation or to a triangular osteosynthesis consisting of lumbopelvic stabilization (between L5 pedicle and posterior ilium) combined with iliosacral and superior pubic ramus screw fixation. Main Outcome Measures Peak loaded displacement at the fracture site was measured for assessment of initial stability. Macroscopic fracture behavior through 10,000 cycles of loading, simulating the early postoperative weight-bearing period, was classified into type 1 with minimal motion at the fracture site, type 2 with complete displacement of the inferior pubic ramus, or type 3 with catastrophic failure. Results The triangular osteosynthesis had a statistically significantly smaller displacement under initial peak loads (mean ± standard deviation [SD], 0.163 ± 0.073 cm) and therefore greater initial stability than specimens with the standard iliosacral screw fixation (mean ± SD, 0.611 ± 0.453 cm) (p = 0.0104), independent of specimen age or sex. All specimens with the triangular osteosynthesis demonstrated type 1 fracture behavior, whereas iliosacral screw fixation resulted in one type 1, two type 2, and three type 3 fracture behaviors before or at 10,000 cycles of loading. Conclusion Triangular osteosynthesis for unstable transforaminal sacral fractures provides significantly greater stability than iliosacral screw fixation under in vitro cyclic loading conditions. In vitro cyclic loading, as a limited simulation of early stages of patient mobilization in the postoperative period, allows for a time-dependent evaluation of any fracture fixation system.

Percutaneous iliosacral screws with the patient supine technique

Complex pelvic fractures can be frustrating to treat. High-energy pelvic ring disruptions often are associated with severe local soft tissue injuries that complicate management. Percutaneous posterior pelvic ring fixation became attractive with the refinement of fluoroscopy. Originally, iliosacral screw fixation of the posterior pelvis was described with the patient in the prone position. We describe the technique of placement of percutaneous iliosacral screws with the patient in the supine position.

STABILIZATION OF PELVIC RING DISRUPTIONS

Pelvic ring disruptions are challenging management problems for the orthopedic surgeon. Early hemorrhage, permanent nerve injury, and late pain caused by residual pelvic deformity are some of the many complicating factors. A variety of treatment alternatives are available to stabilize the disrupted pelvic ring. Each technique has inherent advantages and problems.

Diagnosis and Management of Thoracolumbar Spine Fractures

The lack of robust clinical studies has contributed to controversy regarding optimal treatment for patients with injuries to the thoracolumbar spine. The transitional anatomy of the thoracolumbar spine makes it vulnerable to injury resulting from high-energy motor vehicle collisions and falls; osteoporosis is an underlying factor in most of the compression fractures identified in elderly patients. The formulation of a treatment plan for patients with injuries to the thoracolumbar spine depends on the presence and extent of neurologic injury and deformity and an estimate concerning spinal stability. Both nonsurgical and surgical treatment options are available to achieve the goals of preservation of neurologic function and restoration of spinal stability.

Internal fixation of the unstable anterior pelvic ring: a biomechanical comparison of standard plating techniques and the retrograde medullary superior pubic ramus screw.

Summary: The purpose of this study was to evaluate pubic ramus fracture fixation. This biomechanical evaluation compared standard plating techniques with retrograde medullary screw fixation of a superior pubic ramus fracture in a pelvic fracture model. Six fresh-frozen, cadaveric pelvic specimens with a mean age of 79 years were harvested. These specimens were physiologically loaded according to the following modifications and instrumentations: (a) intact; (b) an APC-II unstable pelvic injury, specifically, unilateral superior and inferior rami osteotomies combined with ipsilateral anterior sacroiliac (SI) joint, sacrospinous, and sacrotuberous ligamentous disruptions, without fixation; (c) disrupted as in (b) but fixed anteriorly with a 10-hole 3.5-mm reconstruction plate contoured to the superior ramus and secured with four 3.5-mm cortical screws; (d) disrupted as in (b) but fixed anteriorly with a 10-hole 3.5-mm reconstruction plate contoured to the superior ramus and secured with six 3.5-mm cortical screws; (e) disrupted as in (b) but fixed anteriorly with a 4.5-mm retrograde medullary superior pubic ramus cortical screw 80 mm long (medial to the hip joint); and (f) disrupted as in (b) but fixed anteriorly with a 4.5-mm retrograde medullary superior pubic ramus cortical screw 130 mm long that was extraarticular and engaged the lateral iliac cortex cephalad to the ipsilateral hip joint. The posterior disruptions of the pelvic ring were not fixed. The APC-II injury created in this study resulted in significant (p < 0.05) motion at the disrupted rami and the injured SI joint, compared with the intact pelvic specimen. When compared with the disrupted specimen without fixation, displacement at the superior ramus was significantly (p < 0.05) decreased by all forms of ramus fixation evaluated. Plate fixation decreased pubic ramus and sacroiliac deflections slightly better than retrograde screw fixation did, yet not significantly better. The number of screws in the plate did not significantly affect displacement measurements at either the disrupted ramus or the disrupted SI joint. Similarly, the length of the retrograde ramus screw did not significantly alter displacements at either the injured pubic ramus or the disrupted SI joint. Sacroiliac joint deflections were not significantly (p < 0.05) decreased by any of the forms of anterior pelvic fixation. Flexion at the disrupted SI joint was slightly, but not significantly (p < 0.05), decreased with all forms of fixation when compared with the disrupted specimen. The long retrograde screw and the plate with six screws decreased flexion slightly, but not significantly, better than the short retrograde screw and the plate with four screws.

Simple anterior pelvic external fixation

BACKGROUND Unstable pelvic ring disruptions are often associated with significant morbidity and mortality, especially in patients with multiple injuries. Early pelvic fixation provides stability and should diminish ongoing hemorrhage. A simple anterior single-pin pelvic external fixator can be applied rapidly and accurately to stabilize pelvic ring injuries as a part of the initial patient resuscitation of such patients. Simple anterior pelvic external fixation (SAPEF) frames can be used as either temporary, definitive, or supplementary fixation depending on the pelvic injury pattern. METHODS Over a 32-month period, 41 patients with unstable pelvic ring disruptions were stabilized using a simple anterior pelvic external fixator. Eight patients had open pelvic ring injuries and 13 others had genitourinary system disruptions. Fluoroscopic imaging was used to insert all of the fixation pins into the iliac crest between the iliac cortical tables to a depth of at least 5 cm. Each patient had closed manipulative reduction of the pelvic ring using external methods before SAPEF application. RESULTS One patient died less than 24 hours after injury because of torrential hemorrhage. Clinical evaluations and serial radiographs, including postoperative computed tomographic scans, were available for the other 40 patients postoperatively. Seventy-five of the 80 (94%) pins were completely contained between the iliac cortical tables, according to the computed tomographic scans. The initial pelvic closed reductions were maintained until the fixators were removed in 37 of 40 patients (93%). Only one deep pin track infection developed, mandating early frame removal and intravenous antibiotic therapy. CONCLUSION Simple anterior pelvic external fixation can be applied rapidly using fluoroscopic guidance to direct accurate pin insertion and closed manipulative reduction of the pelvis. Depending on the specific pelvic ring injury pattern and clinical scenario, SAPEF can serve as a resuscitative temporary fixation device, as definitive pelvic treatment, or as a supplement for pelvic internal fixation implants.

Superior gluteal artery injury during iliosacral screw placement.

Percutaneous fixation of an unstable pelvic ring injury is becoming a popular method of pelvic stabilization. As posterior pelvic percutaneous techniques become more common, the possibility of iatrogenic complications increases. This case report describes an injury to the superior gluteal artery during percutaneous iliosacral screw insertion and the treatment of this potentially devastating injury.