Early fixation of the vertically unstable pelvis: the role of iliosacral screw fixation of the posterior lesion

Reduction of displaced pelvic ring disruptions using a pelvic reduction frame

The need for reduction in displaced pelvic ring disruptions is well established, but actual techniques to perform this difficult task are evolving. Reduction is often difficult, especially if minimally invasive techniques are used. This pelvic reduction frame (Starr Frame LLC, Richardson, TX) provides stabilization of the intact hemipelvis to the operating table and facilitates multiplanar reduction of the injured hemipelvis with the use and manipulation of external fixator pins. With the pelvis reduced and locked on the frame, the surgeon is free to place, or teach, fixation in a controlled manner. This lessens the usual assistance, training, and hardware placement difficulties associated with the surgical treatment of these injuries. The basic surgical technique and 2 cases of acute fracture treatment are presented.

Closed reduction and iliosacral percutaneous fixation of unstable pelvic ring fractures

OBJECTIVE

To report clinical results of patients treated with closed reduction and percutaneous iliosacral screw fixation for unstable pelvic ring fractures.

MATERIALS AND METHODS

Retrospective study using medical records, images and late clinical assessment of all patients treated in our centre with percutaneous iliosacral screw fixation for unstable pelvic ring fractures, with a minimum follow-up of 12 months. Seventy-three patients with a mean age of 40.3 years old (range 14-70 years) were treated between July 1998 and December 2005. Seventy-one patients were included. Fractures types included 10 AO type B and 61 AO type C injuries. Forty-two patients had associated injuries. Mean follow-up was 31 months (12-96). Functional status was assessed using Majeed's grading score for pelvic fractures at final follow-up.

RESULTS

Sixty-nine patients obtained a satisfactory initial reduction. Two patients had transitory postoperative neurological deficit. Five patients presented hardware failure. Fifteen patients developed sacroiliac osteoarthritis during follow-up. Good and excellent functional results were observed in 66 patients at final follow-up. Five patients had bad results, one due to infection of an anterior pelvic plate and the others due to painful refractory sacroiliac osteoarthritis that required a sacroiliac fusion. Sixty-one (86%) patients were able to return to pre-injury occupation.

CONCLUSIONS

Good clinical results with a low and predictable rate of complications can be expected using closed reduction and percutaneous iliosacral screw fixation for unstable pelvic ring fractures.

Pelvic ring disruptions: treatment modalities and analysis of outcomes

A systematic review of the English literature over the last 30 years was conducted in order to investigate the correlation of the clinical outcome of different types of pelvic ring injuries to the method of treatment. Three basic therapeutic approaches were analysed: non-operative treatment (group A), stabilisation of anterior pelvis (group B) and internal fixation of posterior pelvis (group C). Of 818 retrieved reports, 27 case series, with 28 groups of patients and 1,641 patients, met our inclusion criteria. The quality of the literature was evaluated using a structured questionnaire. Outcomes of the eligible studies were summarised by the medians of the reported results. Most of the component studies were of fair or poor quality. Certain radiological results (quality of reduction, malunion rates) were significantly better in group C. From the functional point of view only walking capacity was proved to be significantly better in the groups of operative treatment compared to the non-operative group.

Anterior plating and percutaneous iliosacral screwing in an unstable pelvic ring injury

BACKGROUND

This study was carried out to evaluate the effectiveness of anterior plating with subsequent percutaneous iliosacral screwing for the management of unstable pelvic ring injuries.

METHODS

Nineteen patients with unstable pelvic ring injuries were included in this retrospective study. All patients were followed up for at least 1 year, and their mean age was 43 years. According to the Association for Osteosynthesis-Orthopaedic Trauma Association (AO-OTA) classification, there were 5 B2 injuries, 11 C1 injuries, and 3 C2 injuries. After anterior fixation by means of plating, an iliosacral screw fixation was carried out percutaneously using a C-arm fluoroscope.

RESULTS

All fractures healed, except for 1 case of nonunion at the pubic ramus. Radiological results showed that there were 9 anatomic, 7 nearly anatomic, 2 moderate, and 1 poor reduction. Sixteen of the 19 patients had good or excellent results for function, and all these had satisfactory (anatomic or nearly anatomic) reductions. The two moderate and 1 poor result were from an unsatisfactory reduction in a type-C injury with residual neurological signs. A screw misplacement with a neurological compromise occurred in 1 patient, but there were no adverse sequelae after its removal. The complications encountered were 2 cases of screw loosening, 2 cases of anterior metal failure, and 1 deep infection.

CONCLUSIONS

Anterior plating with subsequent percutaneous iliosacral screwing may be a useful method of treatment for unstable pelvic ring injuries, and the reduction quality and residual neurological signs were important in its functional outcome.

Minimally invasive transiliac plate osteosynthesis for type C injuries of the pelvic ring: a clinical and radiological follow-up

OBJECTIVE

To evaluate radiological and functional outcome in patients treated with minimally invasive transiliac plate osteosynthesis for unstable pelvic injuries.

DESIGN

Retrospective analysis of a prospective treatment protocol in a consecutive patient series.

SETTING

Level 1 trauma center.

PATIENTS

Between January 1998 and December 2005, 31 patients with type C injuries of the pelvic ring were treated with minimally invasive transiliac plate osteosynthesis. According to the AO classification, 16 patients had a C1-injury, 9 had a C2 fracture, and 6 patients sustained a C3 injury of the pelvic ring. Anterior-posterior, inlet, and outlet radiographs were obtained preoperatively, immediately postoperatively, and during follow-up. Clinical outcome was determined according to the Hannover pelvic outcome score.

INTERVENTION

Posterior plate osteosynthesis for type C injuries of the pelvic ring.

MAIN OUTCOME MEASUREMENT

Preoperative and postoperative dislocation of the posterior pelvic ring, loss of reduction, implant failure, implant removal, clinical results of the pelvic injury and general limitations following the trauma.

RESULTS

Maximum average dislocation of the posterior pelvic ring was 16.1 mm preoperatively; postoperatively, it was 6.1 mm. A total of 23 patients (74.2%) could be followed up after an average of 20 months (range 7-57 months). Seven patients underwent follow-up treatment at other hospitals closer to their respective residences, whereas 1 patient passed away in the early postoperative phase due to multiorgan failure. Loss of reduction occurred in 2 cases. The clinical outcome regarding the pelvis was very good in 8 cases, good in 9 cases, fair in 4 cases, and poor in 2 cases. Social reintegration according to the Hannover pelvic outcome score was complete in 9 cases, poor in 10 cases, and incomplete in 10 cases.

CONCLUSION

Posterior plate osteosynthesis is a sufficiently stable method for the treatment of unstable pelvic ring injuries with a low risk of iatrogenic nervous tissue and vascular lesions. The disadvantages are limited reduction possibilities, the necessity of bilateral bridging of the sacroiliac joint in a unilateral injury, as well as a higher rate of symptomatic hardware.

Percutaneous fixation of the pelvic ring: an update

With the development of systems of trauma care the management of pelvic disruption has evolved and has become increasingly refined. The goal is to achieve an anatomical reduction and stable fixation of the fracture. This requires adequate visualisation for reduction of the fracture and the placement of fixation. Despite the advances in surgical approach and technique, the functional outcomes do not always produce the desired result. New methods of percutaneous treatment in conjunction with innovative computer-based imaging have evolved in an attempt to overcome the existing difficulties. This paper presents an overview of the technical aspects of percutaneous surgery of the pelvis and acetabulum.

Removal of an iliosacral screw entrapping the L5 nerve root after failed posterior pelvic ring fixation: a case report

We present a case of a pelvic ring fracture that was originally treated with anterior symphyseal plating and a misplaced percutaneous iliosacral screw. The anterior extraosseus portion of the misplaced 7.3-mm cannulated screw irritated the L5 nerve root, resulting in a radiculopathy. Subsequent surgery involved and mandated removing the bent screw after open identification and protection of the L5 nerve root to avoid further nerve damage; the sacroiliac joint was subsequently debrided and fused. This case represents a complication of acute percutaneous iliosacral screw fixation of pelvic ring injuries and the subsequent strategy for successful salvage.

Percutaneous Placement of Iliosacral Screws for Unstable Pelvic Ring Injuries: Comparison between One and Two C-arm Fluoroscopic Techniques

BACKGROUND

This study compares the efficacy and safety of percutaneous placement of iliosacral screws between one and two C-arm fluoroscope groups.

METHODS

This case series contains consecutive 18 unstable pelvic injuries, which were treated with percutaneous placement of iliosacral screws. A single orthopaedic surgeon (K.-T.P.) operated on all these patients. The patients were divided into two groups on the basis of the method of radiographic control. In group 1 (10 patients), iliosacral screws were introduced under the assistance of one C-arm fluoroscope. In group 2 (eight patients), percutaneous placements of iliosacral screws were performed under the control of two sets of fluoroscope.

RESULTS

There were neither clinical complications nor malpositioned screws in both groups. The median time from initial preparation to completion of the first screw insertion was 45.0 and 16.0 minutes for groups 1 and 2, respectively; the radiation exposure was 5.7 and 4.5 minutes, respectively. The differences between groups were statistically significant (p<0.001).

CONCLUSIONS

The use of two sets of fluoroscope provides a speedier method with less radiation exposure for percutaneous placement of iliosacral screws than the use of one set.

Vertically unstable pelvic fractures fixed with percutaneous iliosacral screws: does posterior injury pattern predict fixation failure?

OBJECTIVE

To measure the failure rate of percutaneous iliosacral screw fixation of vertically unstable pelvic fractures and particularly to test the hypothesis that fixations in which the posterior injury is a vertical fracture of the sacrum are more likely to fail than fixations with dislocations or fracture-dislocations of the sacroiliac joint.

DESIGN

Retrospective review.

SETTING

Level 1 trauma center.

METHODS

All patients with pelvic fractures admitted between January 1, 1993, and December 31, 1998, were identified from the trauma registry. Hospital records were used to identify patients treated with iliosacral screws. Radiologic studies were examined to identify patients who had unequivocally vertically unstable pelvic fractures. Immediate postoperative and follow- up anteroposterior, inlet, and outlet radiographs from a minimum of 12 months postinjury were examined. Position, length, and numbers of iliosacral screws and any evidence of screw failure (eg, bending or breakage) were recorded. Residual postoperative displacement and late displacement of the posterior pelvis were measured. The main outcome measure was failure, defined as at least 1cm of combined vertical displacement of the posterior pelvis compared with immediate postoperative position. The main analysis was for association between fracture pattern and failure. Patient demographic data, iliosacral screw position, and anterior pelvic fixation method also were studied.

RESULTS

The study group comprised 62 patients with unequivocally vertically unstable pelvic fractures in whom the posterior injury was treated with closed reduction and percutaneous iliosacral screw fixation. Of patients, 32 had dislocations or fracture-dislocations of the sacroiliac joint, and 30 had vertical fractures of the sacrum. Fixation failed in four patients, all with vertical sacral fractures and all within the first 3 weeks after surgery. These four patients required revision fixation. In two further cases with vertical sacral fractures, there was evidence that the fracture had only barely been held by the fixation, but these fractures healed, and followup radiographs did not meet the displacement criteria for failure. A vertical sacral fracture pattern was associated significantly with failure (Fisher exact test, P = 0.04); the excess risk of failure compared with sacroiliac joint injury was 13% (95% confidence interval 1% to 25%). There was no significant association between failure and anterior fixation method, iliosacral screw arrangement or length, or any demographic or injury variable.

CONCLUSIONS

Percutaneous iliosacral screw fixation is a useful technique in the management of vertically unstable pelvic fractures, but a vertical sacral fracture should make the surgeon more wary of fixation failure and loss of reduction.

High incidence of ischemic necrosis of the gluteal muscle after transcatheter angiographic embolization for severe pelvic fracture

BACKGROUND

After transcatheter angiographic embolization (TAE), massive gluteal muscle necrosis was found in patients during open reduction and internal fixation for pelvic fracture.

METHODS

In our six patients, magnetic resonance imaging (MRI) scans obtained 1 and 4 weeks after TAE demonstrated ischemic damage of the gluteal muscle.

RESULTS

Total reopening of the embolized artery was confirmed in only one case on the second angiogram obtained 1 month after TAE. In five patients, massive muscle necrosis, previously confirmed on MRI, was macroscopically found during open reduction and internal fixation or debridement surgery. In two patients, severe complications developed, such as soft tissue infection caused by necrosis, skin necrosis accompanied by subcutaneous infection, and sepsis.

CONCLUSION

MRI revealed that TAE more frequently causes profound ischemic damage or necrosis than has been thought. This will be a warning to those who use TAE. Before definitive stabilization, external fixation may be recommended as a first-choice procedure for resuscitation and, then, unilateral selective TAE.

Cyclic loading of sacroiliac screws in Tile C pelvic fractures

BACKGROUND

To investigate the stiffness and strength of completely unstable pelvic fractures fixated both anteriorly and posteriorly under cyclic loading conditions, the authors conducted a randomized, comparative, cadaveric study.

METHODS

In 12 specimens, a Tile C1 pelvic fracture was created. The authors compared the intact situation to anterior plate fixation combined with one or two sacroiliac screws. In 2,000 measurements, each pelvis was loaded with a maximum of 400 N. The translation and rotation stiffness of the fixations were measured using a three-dimensional video system. Furthermore, the load to failure and the number of cycles before failure were determined.

RESULTS

Both translation and rotation stiffness of the intact pelvis were superior to the fixated pelvis. No difference in stiffness was found between the techniques with one or two sacroiliac screws. However, a significantly higher load to failure and significantly more loading cycles before failure could be achieved using two sacroiliac screws compared with one screw.

CONCLUSION

Although the combination of anterior plate fixation combined with two sacroiliac screws is not as stable as the intact pelvis, in this study, embalmed aged pelves could be loaded repeatedly with physiologic forces. Given the fact that the average trauma patient is younger and given the fact that the quality (or grip) of the fixation was a significant covariable for longer endurance of the fixation, this suggests that direct postoperative weight bearing could be possible if these results are confirmed in further research.

Inadvertent intraforaminal iliosacral screw placement despite apparent appropriate positioning on intraoperative fluoroscopy

We present the case of an intraforaminal iliosacral screw placed percutaneously with aid of C-arm using inlet, outlet, and lateral views of the pelvis. The iliosacral screw was placed above the S1 foramen on the outlet view, into the middle of S1 via the ala on the inlet view, and below the cortical shadow of the ala on the lateral view. The patient was neurologically intact postoperatively, but began to complain of severe radicular pain in the S1 distribution down to the foot within 1 week postsurgery. There was mild weakness of plantar flexion. Postoperative computed tomography scan showed that the iliosacral screw was within the S1 foramen. Because of the tangential nature of the S1 foramen, slight posterior placement of the screw into the S1 body and not into the promontory resulted in violation of the foramen despite it being above the cortical shadow on the outlet view.

[Is implant removal after percutaneous iliosacral screw fixation of unstable posterior pelvic ring disruptions indicated?]

The aim of this study was to examine the indication for implant removal (IR) after percutaneous iliosacral screw fixation of unstable posterior pelvic ring disruptions by systematic literature analysis and clinical follow-up examination. Retrospective identification revealed 27 operatively stabilized patients [12 females, mean age: 35 years, ISS 22 points (range: 14-37)] between January 1996 and July 2001. Patient characteristics, AO classification, Hannover fracture scale pelvis, ISS, and DGU pelvis score points were analyzed. All cases showed a C-type lesion (C1:67%, C2:33%). A total of 21 patients were seen at follow-up, 12 with and 9 without IR. In ten cases with IR, clinical outcome improved after surgery according to the DGU pelvis score ( p=0.001, Wilcoxon's test). These mostly young patients also showed a better outcome compared with those cases without IR. Due to the good clinical results, implant removal seems to be beneficial for selected individual patients, especially when pain is present.

Biomechanical comparison of sacroiliac screw techniques for unstable pelvic ring fractures

OBJECTIVE

To determine the stiffness and strength of various sacroiliac screw fixations to compare different sacroiliac screw techniques.

DESIGN

Randomized comparative study on embalmed human pelvises.

MATERIALS AND METHODS

In 12 specimens, we created a symphysiolysis and sacral fractures on both sides. Each of these 24 sacral fractures was fixed with 1 of the following methods: 1 sacroiliac screw in the vertebral body of S1, 2 screws convergingly in S1, or 1 screw in S1 and 1 in S2. On the left and right side of a pelvis, different techniques were used. The pubic symphysis was not stabilized. We measured the translation and rotation stiffness of the fixations and the load to failure using a 3-dimensional video system.

RESULTS

The stiffness of the intact posterior pelvic ring was superior to any screw technique. Significant differences were found for the load to failure and rotation stiffness between the techniques with 2 screws and a single screw in S1. The techniques utilizing 2 screws showed no differences.

CONCLUSIONS

Based on the results of this study, we can conclude that a second sacroiliac screw in completely unstable pelvic fractures increases rotation stiffness and improves the load to failure.

Treatment of Unstable Pelvic Fractures: Use of a Transiliac Sacral Rod for Posterior Lesions and an External Fixator for Anterior Lesions

BACKGROUND

This study sought to define the role of transiliac sacral rods used in combination with an external fixator for the management of unstable pelvic fractures.

METHODS

This retrospective study evaluated cases in which the surgical strategy was open reduction and internal fixation of posterior lesions with two transiliac sacral rods and closed reduction and external fixation of anterior lesions with an AO external fixator. The data for 65 cases were analyzed. Comprehensive Classification (AO) identified 42 C1 cases, 21 C2, cases and 2 C3 cases. Fractures with iliac bone involvement that impeded the application of an external fixator or transiliac sacral rods were excluded. The follow-up period was 85 months (range, 24-140 months).

RESULTS

All the fractures/dislocations healed well. The complications involved 17 cases (26.2%) of persistent posterior pain, 16 cases (24.6%) of irreversible neurologic deficit, 2 cases (3.1%) of posterior wound infection, 3 cases (4.6%) of pin tract infection, and 4 cases (6.2%) of irreversible urologic deficit. The functional results showed that the surgical results were satisfactory in 42 cases (64.6%) and unsatisfactory in 23 cases (35.4%).

CONCLUSIONS

For type C pelvic fractures without significant iliac bone involvement, surgical management with posterior transiliac fixation using sacral rods and anterior external fixation yields good radiologic results. The functional results correlated primarily with avoidance of complications and not necessarily with the radiologic results.

Vertically unstable pelvic fractures fixed with percutaneous iliosacral screws: does posterior injury pattern predict fixation failure?

OBJECTIVE

To measure the failure rate of percutaneous iliosacral screw fixation of vertically unstable pelvic fractures and particularly to test the hypothesis that fixations in which the posterior injury is a vertical fracture of the sacrum are more likely to fail than fixations with dislocations or fracture-dislocations of the sacroiliac joint.

DESIGN

Retrospective review.

SETTING

Level 1 trauma center.

METHODS

All patients with pelvic fractures admitted between January 1, 1993, and December 31, 1998, were identified from the trauma registry. Hospital records were used to identify patients treated with iliosacral screws. Radiologic studies were examined to identify patients who had unequivocally vertically unstable pelvic fractures. Immediate postoperative and follow-up anteroposterior, inlet, and outlet radiographs from a minimum of 12 months postinjury were examined. Position, length, and numbers of iliosacral screws and any evidence of screw failure (eg, bending or breakage) were recorded. Residual postoperative displacement and late displacement of the posterior pelvis were measured. The main outcome measure was failure, defined as at least 1cm of combined vertical displacement of the posterior pelvis compared with immediate postoperative position. The main analysis was for association between fracture pattern and failure. Patient demographic data, iliosacral screw position, and anterior pelvic fixation method also were studied.

RESULTS

The study group comprised 62 patients with unequivocally vertically unstable pelvic fractures in whom the posterior injury was treated with closed reduction and percutaneous iliosacral screw fixation. Of patients, 32 had dislocations or fracture-dislocations of the sacroiliac joint, and 30 had vertical fractures of the sacrum. Fixation failed in four patients, all with vertical sacral fractures and all within the first 3 weeks after surgery. These four patients required revision fixation. In two further cases with vertical sacral fractures, there was evidence that the fracture had only barely been held by the fixation, but these fractures healed, and follow-up radiographs did not meet the displacement criteria for failure. A vertical sacral fracture pattern was associated significantly with failure (Fisher exact test, P = 0.04); the excess risk of failure compared with sacroiliac joint injury was 13% (95% confidence interval 1% to 25%). There was no significant association between failure and anterior fixation method, iliosacral screw arrangement or length, or any demographic or injury variable.

CONCLUSIONS

Percutaneous iliosacral screw fixation is a useful technique in the management of vertically unstable pelvic fractures, but a vertical sacral fracture should make the surgeon more wary of fixation failure and loss of reduction.

Percutaneous computed tomographic stabilization of the pathologic sacroiliac joint

Metastases to the sacroiliac joint region can be a source of significant pain in many patients who are terminally ill. Six patients with metastatic lesions in the sacroiliac region who presented with significant posterior pelvic pain were treated with computed tomography-guided insertion of iliosacral screws. All patients reported excellent pain control in the early postoperative period. Computed tomography-guided insertion of iliosacral screws in an area of relatively preserved bone stock provides good purchase of the screws. It is a safe percutaneous procedure and it helps alleviate pain in patients with sacroiliac metastases.

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) ( = 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.

Endoscopic-assisted, minimally invasive anterior pelvic ring stabilization: a new technique and case report

This report describes the technique of endoscopic-assisted reduction and stabilization of the anterior pelvic ring with endoscopic visualization of all critical bone and soft tissue structures. Compared with the conventional ilioinguinal approach of Letournel, the endoscopic technique facilitates a reliable internal fixation of anterior pelvic ring fractures with minimal soft tissue trauma. Thus, the use of the endoscope enables us to apply the concept of minimal invasive plate osteosynthesis to the pelvis. We recommend the described technique for complex anterior pelvic ring fractures, in which the anterior stabilization has to be achieved with a plate from the symphyseal region to the iliac wing.

Fluoroscopy-based multiplanar image guidance for insertion of sacroiliac screws

A prospective controlled experimental study was done to assess the value of fluoroscopy-based, computer-assisted orthopaedic surgery for the insertion of sacroiliac screws and to compare this new technology with the conventional technique, using image intensification. In a simulated surgical setup, 140 cannulated screws were placed into the S1 and S2 vertebral bodies of 35 pelvic models. The screws were inserted under fluoroscopy-based image guidance or with the conventional technique. Different drills were tested with both techniques, including a 2.8-mm guide wire and a 5-mm solid drill. The 2.8-mm guide wire proved inaccurate with the computer-assisted image guidance system because of guide wire flexibility. Using the more rigid 5-mm drill, the results of computer-assisted image guidance were comparable with the image intensifier technique. The radiation exposure during screw insertion was reduced considerably when using the image guidance system. System-specific requirements warranted adjustment of surgical technique and instruments. The major advantages of this new technology are immediate intraoperative image acquisition and provision of surgical guidance in as much as four planes simultaneously. The results of this experimental study are encouraging and have led to initiation of a clinical trial.

High-energy pelvic ring disruptions

High energy pelvic ring disruptions are associated with numerous primary organ system injuries. Early, accurate pelvic reduction and stable fixation optimize patient outcome. A variety of fixation techniques have been advocated. A multispecialty team approach is advantageous when managing these patients and their pelvic injuries.

Accuracy of computer-guided screw fixation of the sacroiliac joint

Computer-assisted image guidance allows precise preoperative planning and intraoperative localization of surgical instruments. The technique recently was validated for the insertion of pedicle screws. In the laboratory, the precision of a surface-matching algorithm was evaluated for registration and accuracy and safety of screw placement into the vertebral bodies of S1 and S2 for fixation of the sacroiliac joint. Using six plastic pelves, 24 screw holes were made through the sacroiliac joint into the vertebral body of S1, and 12 holes were made through the sacroiliac joint into S2. The accuracy of the hole position was evaluated using a postoperative computed tomography examination. The safety factor was assessed by analysis of the remaining bone stock around the holes calculating a theoretical cylindrical volume being outside bone with increasing bore hole diameters. The registration was accurate with a mean error less than 1.4 mm in the posterior parts of the pelvis. The drilling followed precisely the preoperatively planned trajectories; perforation of the cortex of the sacrum was not observed. The safety factor of the S1 vertebral body is higher than that of S2 allowing larger diameter screw insertion into S1. This technique provides a safe and precise guide for transcutaneous or open insertion of iliosacral screws in cases of iliosacral dislocation or sacral fracture.

Open reduction internal fixation of a pelvic malunion through an anterior approach

Whereas the initial treatment of pelvic fractures and their long-term outcomes have been well researched, little has been written concerning the surgical management of late pelvic malunions and nonunions causing residual pain and deformity. The available literature describes osteotomies usually done in multiple stages. The authors report the case of a progressive lateral compression pelvic disability treated in a unique one-stage procedure. This one-stage anterior approach allowed excellent correction of the deformity. In cases in which the deformity is purely one of internal or external rotation or medial or lateral displacement with no vertical migration, the authors think it is possible to adequately mobilize the pelvis to an anatomic reduction in a single-stage anterior approach. In cases in which vertical migration of the hemipelvis causes symptoms, it is probably necessary to approach the patient posteriorly to safely mobilize and adequately reduce the hemipelvis. With these factors in mind, the authors think a one-stage anterior approach can be an effective treatment for appropriately selected pelvic malunions.

A rare complication of percutaneous iliosacral screw in a vertically unstable pelvic disruption in a child

The use of iliosacral screws in managing vertically unstable fractures in adults has been popularised and the early results are quite promising. However, the role and indication of this technique in paediatric patients are not clear. There has been a concern about its safety and risk of screw misplacement.

Percutaneous fixation of pelvic ring disruptions

Percutaneous pelvic fixation is possible because intraoperative fluoroscopic imaging and other technologies have been refined. Anterior and posterior unstable pelvic ring disruptions are amenable to percutaneous fixation after closed manipulation or open reduction. Stable and safe fixation is achieved only after an accurate reduction. Anterior pelvic external fixation remains the most common form of percutaneous pelvic fixation; however, percutaneously inserted medullary pubic ramus, transiliac, and iliosacral screws stabilize pelvic disruptions directly while diminishing operative blood loss and operative time. These percutaneous techniques do not decompress the pelvic hematoma allowing early definitive fixation without the risk of additional hemorrhage. Complications associated with open posterior pelvic surgical procedures are similarly avoided by using percutaneous techniques. A thorough knowledge of pelvic osseous anatomy, injury patterns, deformities, and their fluoroscopic correlations are mandatory for percutaneous pelvic fixation to be effective.