Stabilization of pelvic ring disruptions

Variations in the branching pattern of the internal iliac artery and its implications in trauma and surgery - a South Indian cadaveric study

Background

The internal iliac artery (IIA) frequently shows variations in its branching pattern. Knowledge of its variations is helpful during gynecological and orthopedic surgical procedures.

Objectives

To observe the branching pattern of IIA in the human pelvises and discuss its clinical implications.

Methods

The study was conducted on 80 male hemipelvises (40 left halves and 40 right halves). The pelvic halves were obtained by making mid-line saw cuts through formalin embalmed adult human cadavers aged approximately 50-80 years. The IIA were dissected and cleaned. Variations of the internal iliac artery and its branches were noted. Relevant photographs were taken. Results were expressed as percentages.

Results

Variations in the branching pattern were observed in 49 (61%) hemipelvises (right: 21, left: 28). Variations were more common (48%) in the branching pattern of the anterior division of IIA than the posterior division (20%). Variations of the main trunk were observed in 29% of cases. In 3% of cases, the IIA did not divide into two divisions. Among the individual branches, the iliolumbar artery showed variations in 29% of cases and the obturator artery in 25%. A common trunk of the internal pudendal and middle rectal arteries was found in 24% of cases and variations of the inferior gluteal artery were seen in 18% of cases.

Conclusions

The study showed a high rate of occurrence of variant IIA branching patterns. Understanding the anatomical variations of the IIA and its branches is essential to minimize intraoperative blood loss and other complications during pelvic surgeries.

High-energy blunt pelvic ring injuries and pre-hospital pelvic binder applications - A retrospective assessment based on a prospective registry

INTRODUCTION

Application of a pelvic binder in the pre-hospital settings is a crucial step of high-energy blunt pelvic ring injury (PRI) management protocols. The aim of this retrospective cohort study was to evaluate the percentage of pre-hospital pelvic binder's applications in high-energy blunt type B or C PRI patients managed at a single level I trauma center, and to assess its impact on the medical resource requirements and patients' outcomes.

METHODS

The institutional Severely Injured Patients' Registry was screened for patients meeting the following inclusion criteria: (1) high-energy blunt PRI; (2) admission between 2014.01.01 and 2022.12.31; (3) age ≥16 years; and (4) available computed tomography of the pelvis. Exclusion criteria were: (1) death before admission; (2) low-energy injury; (3) penetrating, blast and electrical injuries; and (4) secondary transfers. Study variables, including pre-hospital application of a pelvic binder and demographic, clinical, management and outcome data were extracted from the registry. Additionally, AO/OTA classifications were determined.

RESULTS

A consecutive series of 262 patients was included into the final analysis. Of these, 58.8 % received a pre-hospital pelvic binder (PPB), increasing from type A (45.1 %) to type B (57.8 %) and type C (73.7 %). Pre-hospital hemodynamic instability was a major factor triggering the use of PPB in high-energy blunt type B PRI patients with PPB in 76.9 % of the cases with hemodynamic instability vs. 51.3 % of the cases without hemodynamic instability (p = 0.009). This difference was not statistically significant for high-energy blunt type C PRI patients (82.8 % vs. 64.3 %, p = 0.200). The presence of a physician on the trauma site contributed to the increased percentage of PRI managed with PPB from 43.5 % to 67.3 % in type B PRI (p = 0.011), and from 50 % to 77.1 % in type C PRI (p = 0.257). This study showed an increased need for packed red blood cells (PRBC) transfusions in subgroups treated with PPB and no statistically significant differences in term of intensive care unit (ICU) and total hospital length of stay and complications between high-energy blunt type B or C PRI patients with or without PPB. Comparison of mortality rates in patients with and without PPB showed a trend towards lower mortality rates with PPB in patients with AIS extremity participating in at least 50 % of the total ISS.

CONCLUSION

In the ideal pre-hospital scenario, every high-energy blunt type B or C PRI patient should be managed with a PPB. Continuous pre-hospital team training and information is crucial to achieve this goal. The preparation of Emergency Department and ICU who admit a patient with PPB should include a sufficient number of PRBC ready for transfusion. Mortality rates did not seem to be affected by PPB, except for a trend towards lower mortality rates in patients in whom their PRI was the major component of the global severity of their injury. This might point out the critical and positive effect of PPB in high-energy blunt PRI patients.

Experimental study of fractures of the posterior pelvic ring C1.1 using LC-II screws and internal fixation by plate

INTRODUCTION

To compare the biomechanical outcomes of C1.1 posterior pelvic ring fractures treated with different numbers of LC-II screws and plate internal fixation.

MATERIALS AND METHODS

Nine adult preserved pelvic specimens were used. After being measured by bone densitometry, the specimens were randomly divided into 3 groups of 3 pelvic specimens each. The C1.1 pelvic fractures were generated by iliac osteotomies and anterior pelvic ring osteotomies. The fractures were fixed and randomly divided into three groups: (1) one LC-II screw, (2) two LC-II screws, and (3) two reconstruction plates. The anterior pelvic rings were all fixed with pubic branch screws. A biomechanical testing machine loaded all specimens vertically, recording the displacement and ultimate load of the specimens to quantify the stiffness.

RESULTS

When loads up to 1000 N were applied, the displacement of the iliac bone was close between the one LC-II screw and the two LC-II screw group specimens; (P > 0.05); when loads such as 1000 N, 1200 N and 1400 N were applied, there was no significant difference in displacement between the plate fixation group and the two LC-II screw fixation group (P > 0.05), both of which were superior to the one LC-II screw fixation group (P < 0.05). There was no significant difference in compressive stiffness between the two LC-II screw fixation groups and the plate fixation group (P > 0.05), and both were superior to the one LC-II screw fixation group (P < 0.05) the ultimate load of both the two LC-II screws and the steel plate is greater than that of one LC-II screw (1.74 times the ultimate load of one LC-II screw for the two LC-II screws and 1.83 times the ultimate load of one LC-II screw for the steel plate).

CONCLUSION

For posterior pelvic ring fractures of type C1.1, placement of two LC-II screws provides comparable posterior pelvic ring stability compared to reconstructed plates. At loads below 1000 N, one LC-II screw fixation and two LC-II screws were comparable in restoring posterior pelvic ring stability.

Antegrade anterior column acetabulum fracture fixation with cannulated compression headless screws-A biomechanical study on standardized osteoporotic artificial bone

PURPOSE

Due to the increase in life expectancy and high-energy traumas, anterior column acetabular fractures (ACFs) are also increasing. While open reduction and internal fixation (ORIF) is still the standard surgical procedure, minimally invasive, percutaneous fixation of osteoporotic acetabulum fractures (AF) are growing in popularity. The aim of this biomechanical study was to evaluate the biomechanical competence following antegrade fixation with a standard screw versus a cannulated compression headless screw.

METHODS

Eight anatomical osteoporotic composite pelvises were given an anterior column fracture. Two groups of eight specimens each (n = 8) for fixation with either a 6.5 mm cannulated compression headless screw in group Anterior Acetabulum Canulated Compression Headless Screw (AACCH), or with a 6.5 mm partially threaded cannulated screw in group Anterior Acetabulum Standard Screw (AASS) where compared. Each specimen was biomechanically loaded cyclically at a rate of 2 Hz with monotonically increasing compressive load until failure. Motions were assessed by means of optical motion tracking.

RESULTS

Initial construct stiffness trended higher in group AACCH at 152.4 ± 23.1 N/mm compared to group AASS at 118.5 ± 34.3 N/mm, p = 0.051. Numbers of cycles and corresponding peak load at failure, were significantly higher in group AACCH at 6734 ± 1669 cycles and 873.4 ± 166.9 N versus group AASS at 4440 ± 2063 cycles and 644.0 ± 206.3 N, p = 0.041. Failure modes were breakout of the screws around the proximal entry point.

CONCLUSION

From a biomechanical perspective, group AACCH was associated with superior biomechanical competence compared to standard partially threaded cannulated screws and could therefore be considered as valid alternative for fixation of anterior acetabulum fractures.

Less Invasive Triangular Osteosynthesis in the Management of AO Type-B Unstable Sacral Fractures

Objective: This prospective cohort study investigated the clinical and radiological efficacy of triangular osteosynthesis (TO) in the management of AO type-B unstable sacral fractures.Methods: All patients with unstable AO type-B sacral fractures were included in this study. They were evaluated clinically and radiologically and underwent TO. Pre- and postoperative clinical parameters included the visual analogue score (VAS) for back pain, Oswestry Disability Index (ODI), and Gibbon classification. Radiological parameters included x-rays and multislice 3-dimensional computed tomography scans of the pelvis and the Tornetta and Matta criteria for fracture reduction.Results: This study included 30 patients (17 males and 13 females; mean age, 31.63±9.65 years). The reported causes of trauma were a fall from height in 17 patients, road traffic accident in 11 patients, and hard objects falling onto the pelvis in 2 patients. According to the AO spine sacral fracture classification system, 8 cases were type B2 and 22 were type B3. At the last postoperative follow-up, the mean VAS improved from 7.77±1.19 preoperatively to 3.97±1.59 (p<0.001), the mean ODI was 15.27±3.34, and the Gibbon classification of cauda equina injury improved from 2.87±0.97 preoperatively to 1.27±0.52 (p<0.001). According to Tornetta and Matta criteria for fracture reduction, the results were excellent (<4 mm) in 73.3% of patients, good (4–10 mm) in 20%, and fair (10–20 mm) in 6.7%. All patients experienced complete fracture healing.Conclusion: TO is a less invasive, safe, and effective option for the management of unstable AO type-B sacral fractures with good clinical and radiological outcomes.

A New Technology Using Mixed Reality Surgical Navigation with the Unlocking Closed Reduction Technique Frame to Assist Pelvic Fracture Reduction and Fixation: Technical Note

BACKGROUND

Pelvic ring disruption (PRD) is a serious trauma associated with high mortality and disability rates. Poor reduction can lead to complications such as pelvic deformity and delayed fracture healing. Here, we introduce a new technology using mixed reality surgical navigation (MRSN) with an unlocking closed reduction technique (UCRT) frame to assist pelvic fracture reduction and fixation.

METHODS

Thirty patients with PRD were enrolled in this study. All of the patients underwent preoperative CT scans, with the pelvis and tracker segmented into three-dimensional models. Under MRSN guidance, auxiliary reduction screws were inserted to grasp the pelvic bone. An ideal trajectory for closed reduction was planned, and suitable CS screws were used for stable fixation after good reduction. Operation time, fluoroscopy frequency, and both Matta and Majeed scores were analyzed.

RESULTS

The mean follow-up period was 10.8 months (7.5, 12.25 months) (range 6-24 months). The average duration of operation was 212.5 min (187.5, 272.8 min) (range 133-562 min), and the average reduction time was 23.0 min (15.0, 42.5 min) (range 10-70). The average fluoroscopy frequency was 34.0 times (31.5, 52.5 times) (range 23-68 times). One hundred and fifty screws were successfully inserted on the first attempt. All the fractures healed well with no complications. Excellent reduction quality (Matta score ≤4 mm) was achieved in 29/30 cases, and good reduction quality (Matta score between 4 and 10 mm) was achieved in 1/30 cases. All patients achieved bone healing after an average of 4.0 months (3.5, 5.9 months) (range 3-6), as well as good function recovery with an average Majeed score of 91.0 (87.8, 95.0) (range 71-100).

CONCLUSION

The MRSN technique described improved reduction accuracy and radiation exposure without considerable extension of operation time.

A standard canulated screw may not fit up to 1/3 of the patients treated percutaneously for anterior column acetabular fractures-A pilot study

A proper evaluation of the narrowings and length of the anterior acetabular column would offer better predictability and precision for implant insertion in the case of an acetabular fracture.

OBJECTIVE

To determine the diameter and length of the safety corridor of the anterior column of the acetabulum in patients with available pelvic computed tomography (CT), analyze the obtained measurements against those of a standard 6.5-mm implant, and verify possible sex differences regarding these measurements. A secondary aim was to develop a method for measurement of the anterior column of the acetabulum based on CT images.

MATERIALS AND METHODS

In 200 CT scans of hemipelvises we measured the diameter of two areas of narrowing and the length of the safety corridor of the anterior column. The images were submitted to multiplanar reformatting adjusted to a plane orthogonal to the bone corridor, drawn at the level of the superior pubic ramus.

RESULTS

Measurement #1 had a mean value of 8.12 (2.27) mm in the overall sample and median values of 9.03 (7.76-10.48) mm in men and 6.77 (5.44-7.19) mm in women. Measurement #2 had a mean value of 7.29 (2.19) mm and median values of 8.23 (7.18-9.82) mm in men and 5.9 (4.65-7.19) mm in women. Measurement #3 had a mean value of 109.53 (13.66) mm in the overall sample and median values of 117.17 (112.9-122.9) mm in men and 100.91 (90.95-111.17) mm in women (p<0.001 all three measurements). Measurement #1 was smaller than 6.5 mm in 22.5% of the patients (of whom 90% were women). Measurement #2 was smaller than 6.5 mm in 35% of the patients (of whom 80% were women).

CONCLUSIONS

This study proposed an anatomic evaluation of the anterior column of the acetabulum using conventional CT images The areas of narrowing in the anterior column had an average of 8.12 mm at the level of the pubic tubercle and 7.29 mm at the level of the acetabular fossa. The mean length of the safety corridor was 109.53 mm. In 35% of the cases, a 6.5 mm percutaneous screw would have violated the cortical bone of the safety corridor.

Robot-Assisted Autonomous Reduction of a Displaced Pelvic Fracture: A Case Report and Brief Literature Review

Displaced pelvic fracture is among the most complicated fractures in traumatic orthopedics, with high mortality and morbidity. Reduction is considered a complex procedure as well as a key part in surgical treatment. However, few robotic techniques have been employed in the reduction of pelvic fracture, despite the rapid advancement of technologies. Recently, we designed a robot surgery system specialized in the autonomous reduction of displaced pelvic fracture and applied it in the true patient for the first time. In this paper, we report its successful clinical debut in the surgery of a displaced pelvic fracture. Total surgery time was 110 min and an anatomic reduction was achieved. We then present a brief overview of the literature about reduction techniques in pelvic fracture and introduce related principles involved in our robot-assisted reduction system.

Epidemiological and Therapeutic Developments in Pelvic Ring Fractures Type C from 2004 to 2014 - a Retrospective Data Analysis of 2,042 Patients in the German Pelvic Register (DGU)

BACKGROUND

Pelvic ring fractures type C present a special challenge due to their high instability, the possible accompanying injuries and the high mortality rate of up to 18.9%. The aim of this retrospective analysis was to use the data from the DGU pelvic register to identify changes in the epidemiology and therapy for type C pelvic ring fractures between 2004 and 2014.

MATERIALS AND METHODS

2,042 patients with type C pelvic ring injury were retrospectively included. Three time periods with roughly equal patient groups were specified and differences in epidemiology and the type of therapy were evaluated. For the surgical cases, the time of the operation, the duration of the operation, blood loss, the location of the fracture and the type of osteosynthesis were evaluated and the reduction result was recorded.

RESULTS

For the period under review, there is an age shift in the incidence of a type C pelvic ring fracture towards older age. The isolated pelvic injury has increased, while the proportion of pelvic injuries in the context of polytrauma has steadily decreased. Complications and mortality decreased as a percentage. The tendency towards minimally invasive procedures could be shown in the surgical care. Navigated procedures in the area of the pelvic ring have so far not proven successful.

CONCLUSIONS

We were able to show that the majority of the patients are increasingly old, that there is no relevant trauma in the history and that there is an increase in the isolated pelvic fracture type C and a decrease in the number of polytraumatised or multiply injured patients. In conjunction with mortality from pelvic ring injuries, the successes of standardised, pelvic-specific emergency management, an adapted time of operation outside the vulnerable phase and stable osteosynthesis care, which enable early functional follow-up treatment, are also evident.

A novel Patient-Specific Three-Dimensional Printing Template Based on External Fixation for Pelvic Screw Insertion

PURPOSE

To investigate the clinical effect of novel patient-specific 3D printing templates based on external fixation for pelvic screw insertion compared with the fluoro-navigation technique.

MATERIALS AND METHODS

We retrospectively studied 18 pelvic fracture patients from July 2017 to July 2018. For analysis, patients were divided into two groups: the template group (15 screws in 8 patients) and the fluoro-navigation group (22 screws in 10 patients). The screw insertion time, radiation exposure time, and accuracy of the screw insertion as evaluated by postoperative CT scans were analyzed.

RESULTS

In the template group, the average screw insertion time (11.5 ± 2.3 min/screw) was significantly 50.6% less than that in the fluoro-navigation group (23.3 ± 3.1 min/screw; P < 0.05). The average time of X-ray exposure in the template group (11.5 ± 3.9 s/screw) was also significantly 39.8% less than in the fluoro-navigation group (19.1 ± 2.5 s/screw; P < 0.05). In the template group, the mean deviation distance and angle between the actual and planned screw position was 2.6 ± 0.2 mm and 2 ± 0.3°.

CONCLUSIONS

The patient-specific template based on external fixation can guide the insertion of the pelvic screw accurately and safely while significantly reducing operation and radiation exposure time.

Surgical Fixation of Geriatric Sacral U-Type Insufficiency Fractures: A Retrospective Analysis

OBJECTIVES

To define the incidence of sacral U-type insufficiency fracture and describe management of a consecutive series of patients with this injury.

DESIGN

Retrospective analysis.

SETTING

Single Level II trauma center.

PATIENTS/PARTICIPANTS

Sixteen adult patients with sacral U-type insufficiency fractures treated over a 36-month period.

INTERVENTION

Patients were indicated for percutaneous screw fixation of the posterior pelvis if they had posterior pelvic pain that prohibited mobilization.

MAIN OUTCOME MEASUREMENTS

Visual analog scale for pain, distance ambulated on postoperative day 1, and change in sacral kyphosis.

RESULTS

The sacral U-type insufficiency fracture incidence was 16.7% (19/114); average patient age was 75 years. Delayed surgery was performed after primary nonoperative treatment had failed in 62.5% (10/16) at an average 83 days postinjury. Acute surgery was performed in 37.5% (6/16) at an average 5 days postinjury. Distance ambulated on postoperative day 1 was 114.4 feet [95% confidence interval (CI) (50.6, 178.2)] and 88.7 feet [95% CI (2.8, 174.6)] in the delayed and acute surgery groups, respectively, P = 0.18. Change in visual analog scale for pain was -3.2 [95% CI (-5.0, -1.4)] and -3.7 [95% CI (-7.0, -0.4)] in the delayed and acute surgery groups, respectively, P = 0.15. Change in sacral kyphosis from presentation to surgery was 12.3 degrees [95% CI (6.7, 17.9)] and 0.3 degrees [95% CI (-0.2, 0.9)] in the delayed and acute surgery groups, respectively, P < 0.01. Minimum follow-up was 12 months.

CONCLUSIONS

Treatment of sacral U-type insufficiency fractures by percutaneous screw fixation permits early mobilization, provides rapid pain relief, and prevents progressive deformity.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Clinical and radiological short-term outcomes of pubic symphysis diastasis treated with modified pedicle screw-rod fixation

PURPOSE

Pubic symphysis diastasis with an incidence of approximately 20% in pelvic fractures is a severe lesion which needs to be treated properly. The objective of this retrospective study was to describe and evaluate the clinical and radiological outcomes including its advantages and limitations of this modified minimal invasive technique.

METHODS

Totally 29 patients with pubic symphysis diastasis, with or without posterior ring instability, were treated by modified pedicle screw-rod fixation (modified PSRF) between January 2010 and December 2016. The duration from injury to surgery, operation time, intraoperative blood loss as well as complications were recorded. During follow-up, the functional outcomes were assessed according to the Majeed evaluation criteria 1 year postoperatively. The evaluation of the postoperative reduction quality was carried out according to Matta criteria.

RESULTS

According to Tile classification, there were 9 cases of Type B1 underwent only anterior-modified PSRF and 20 cases of Type C1 experienced anterior-modified PSRF combined with posterior fixation. The duration from injury to operation, operation time and intraoperative blood loss were 3.27 days (range 1-6 days), 42.07 min (range 38-45 min), and 46.14 ml (range 40-55 ml). The results of reduction quality were rated as excellent in 16, good in 11 and fair in 2 based on Matta criteria. The Majeed functional scores ranged from 68 to 95 and there were excellent in 15, good in 12 and fair in 2. No patients experienced incision infection. Slight loosening of middle-two screws was verified during follow-up in one patient. Two patients underwent femoral nerve palsy. Irritation to the LFCN was detected in four patients.

CONCLUSIONS

Modified PSRF can be performed as an alternative to manage pubic symphysis diastasis due to its merits of minimal invasive, less blood loss, less soft tissue injuries as well as shorter operation time, even with the early weight-bearing.

TRIAL REGISTRATION

Researchregistry3905.

Modified pedicle screw-rod fixation versus anterior pelvic external fixation for the management of anterior pelvic ring fractures: a comparative study

Background

Anterior pelvic ring fracture, as high-energy trauma, needs to be effectively treated. The purpose of the current study was to evaluate the clinical applications of modified pedicle screw-rod fixation and anterior pelvic external fixation for the treatment of anterior pelvic ring fracture.

Methods

Either modified pedicle screw-rod fixation (modified PSRF group, N = 21) or anterior pelvic external fixation (APEF group, N = 22) was performed to 43 patients, with or without fixation of posterior ring. Clinical outcomes were evaluated via Majeed scores. Relevant clinical evaluation indicators including operation time, intraoperative blood loss, hospitalization duration, and complications were compared between these two groups.

Results

The operation time in APEF group was significantly less than that in modified PSRF group (P < 0.0001). No significant difference with respect to intraoperative blood loss and hospitalization duration between the two groups was shown (P = 0.51 and P = 0.33, respectively). Six patients developed surgical site infection in APEF group. Three patients experienced loss of fixation, and two patients experienced loosening of fixator in APEF group. Temporary lateral femoral cutaneous nerve irritation occurred in three patients in modified PSRF group while two patients in APEF group. One patient experienced femoral nerve palsy in modified PSRF group. Fractures of all patients healed well eventually. No statistical difference regarding Majeed evaluation scores was found between two groups.

Conclusions

Application of both modified PSRF and APEF could provide similar satisfactory clinical outcomes for anterior pelvic ring fracture. Modified PSRF, a minimally invasive technique with the advantages of internal fixation, could be performed as an alternative method for instable pelvic fractures.

Trial registration

Research Registry UIN: researchregistry2776.

Sacral Fractures and Associated Injuries

STUDY DESIGN

Literature review.

OBJECTIVE

The aim of this review is to describe the injuries associated with sacral fractures and to analyze their impact on patient outcome.

METHODS

A comprehensive narrative review of the literature was performed to identify the injuries associated with sacral fractures.

RESULTS

Sacral fractures are uncommon injuries that result from high-energy trauma, and that, due to their rarity, are frequently underdiagnosed and mistreated. Only 5% of sacral fractures occur in isolation. Injuries most often associated with sacral fractures include neurologic injuries (present in up to 50% of sacral fractures), pelvic ring disruptions, hip and lumbar spine fractures, active pelvic/ abdominal bleeding and the presence of an open fracture or significant soft tissue injury. Diagnosis of pelvic ring fractures and fractures extending to the lumbar spine are key factors for the appropriate management of sacral fractures. Importantly, associated systemic (cranial, thoracic, and abdominopelvic) or musculoskeletal injuries should be promptly assessed and addressed. These associated injuries often dictate the management and eventual outcome of sacral fractures and, therefore, any treatment algorithm should take them into consideration.

CONCLUSIONS

Sacral fractures are complex in nature and often associated with other often-missed injuries. This review summarizes the most relevant associated injuries in sacral fractures and discusses on their appropriate management.

Traumatic Hemipelvectomy with a Contralateral Unstable Pelvis and Acetabular Fracture: A Case Report and Review of the Literature

CASE

A traumatic hemipelvectomy (THP) is a rare life-threatening injury, with limited reports in the civilian population. We present the case of a patient who sustained a massive pelvic injury with an incomplete unilateral THP, a contralateral unstable pelvis, and a fracture of the acetabulum.

CONCLUSION

With advancements in resuscitative techniques, carefully timed and planned surgical interventions, and a coordinated multidisciplinary approach, a greater number of patients may be able to survive a massive pelvic injury.

Fractures of the pelvic ring

Traumatic disruptions of the pelvic ring are high energy life threatening injuries. Management represents a significant challenge, particularly in the acute setting in the presence of severe haemorrhage. Initial management is focused on preserving life by controlling haemorrhage and associated injuries. Advances in prehospital care, surgery, interventional radiology and the introduction of treatment algorithms to streamline decision making have improved patient survival. As more patients with unstable pelvic injuries survive, the poor results associated with nonoperative management and increasing patient expectations of outcome are making surgical management of these fractures increasingly common. The aim of operative fracture fixation is to correct deformity and restore function. The advent of percutaneous fixation techniques has reduced the morbidity previously associated with large operative exposures and internal fixation.

Computational analysis of the safe zone for the antegrade lag screw in posterior column fixation with the anterior approach in acetabular fracture: A cadaveric study

OBJECTIVE

The fluoroscopically-guided procedure of antegrade posterior lag screw in posterior column fixation through anterior approach is technique-dependent and requires an experienced surgeon. The purpose of this study was to establish the safe zone for the antegrade posterior lag screw by using computational analysis.

METHOD

The virtual three-dimensional model of 178 hemi-pelvises was created from the CT data (DICOM format) by using Mimics^® program, and were used to measure the safe zone of antegrade lag screw fixation on the inner table of the iliac wing, and the largest diameter of cylindrical implant inside safe zone. The central point (point A) of the cylinder was assessed and was compared with the intersection point (point B) between the linea terminalis and the anterior border of the sacroiliac articulation.

RESULTS

The safe zone was triangular with an average area of 670.4mm² (range, 374.8-1084.5mm²). The largest diameter of the cylinder was a mean 7.4mm (range, 5.0-10.0mm). When height was under 156.3cm, the diameter of the cylindrical implant was smaller than 7.0mm (p<0.001, regression coefficient=0.09). The linear distance between points A and B was 32.5mm (range, 19.2-49.3mm). Point A was far enough away from the well-positioned anterior column plate to prevent collision between the two.

CONCLUSION

The safe zone was shaped like a triangle, and was large enough for multiple screws. Considering the straight-line distance between points A and B, the central screw can be fixed without overlapping with the well-positioned anterior column plate at the point between holes 2 and 3.

Impact of surgical correction of a U-shaped sacral fracture on sagittal spino-pelvic alignment: Regarding one case

U-shaped sacral fractures are uncommon and are mostly the consequence of a high-energy kinetic trauma. The sacrum is a crucial element for sagittal alignment in a standing position as it determines the value of the pelvic incidence, which is a fixed and unchanging parameter for a given individual. We report the case of a 21-year-old man who underwent corrective surgery for a type II U-shaped fracture of the sacrum (according to the Roy-Camille classification), associated with a S1-S2 dislocation and sacral kyphosis that modified the patient's pelvic incidence. At one-year follow-up, radiographic examinations revealed solid bony fusion and stable results after removal of the implants. The surgery was managed for neurological decompression, stabilization of the fracture and correction of sacral kyphosis. The restoration of the theoretical pelvic incidence depended on the estimated lumbar lordosis. The aim of this study was to highlight the particularities in the management of a sacral U-shaped fracture and their relationship with the sagittal alignment.

Minimally invasive surgery under fluoro-navigation for anterior pelvic ring fractures

BACKGROUND

The incidence of pelvic fractures in trauma patients is reported to be 3-8.2%, with roughly half of these fractures being caused by high energy injuries with a potential for catastrophic hemorrhage and death. Indications for internal fixation of anterior pelvic ring are controversial. Because of fears of disturbing the pelvic hematoma and causing additional hemorrhage, open reduction and internal fixation of pelvic ring disruption is routinely delayed. In contrast to conventional surgery, percutaneous screw fixation is gaining popularity in the treatment of pelvic and acetabular fractures mainly because of minimal soft tissue damage, less operative blood loss, early surgical intervention and comfortable mobilization of the patient. Fluoro-navigation is a new surgical technique in orthopedic trauma surgery. This study is to investigate clinical results of fluoro-navigation surgery in anterior pelvic ring fractures.

MATERIALS AND METHODS

From January 2006 to October 2011, 23 patients with anterior pelvic ring fractures were treated with percutaneous cannulated screw under fluoro-navigation. There were 14 men and 9 women, with a mean age of 40.1 years (range 25-55). According to the AO and Orthopedic Trauma Association classification, there were seven A 2.1, two A 2.2, one A 2.3, six B 1.2, one B 2.1: 1, one B 2.2, one C 1.2, two C 1.3 and two C 2.3 types of fractures. Amongst these patients, 13 had posterior pelvic ring injuries, 8 had other injuries including urethral, lumbar vertebrae fractures and femoral fractures. All patients were operated when their general condition stabilized after emergency management. The mean time from injury to percutaneous screw fixation of the anterior pelvic ring fracture was 12 days (3-15 days). All the anterior ring fractures were fixed with cannulated screws by two senior surgeons. They were familiar with the navigation system and had gained much experience in the computer-assisted percutaneous placement of screws.

RESULTS

A total of 32 screws were inserted, including 19 in the pubic ramis and 13 in the anterior acetabular columns. The average surgical time was 23.3 min/screw. The average time of X-ray exposure was 19.1 ± 2.5 s/screw. The virtual images of fluoro-navigation were compared with real-time X-rays during and after the surgery. Compared to the final position of the screw, the average deviated distance was 3.11 mm and the average trajectory difference was 2.81°. Blood loss during the operation was minimal (22.3 ml/screw). One screw (3.1%) deviated out of the fracture site during the operation. No superficial or deep infection occurred. No patient sustained recognized neurologic, vascular, or urologic injury as a result of the percutaneous screw fixation. All fractures united at the last followup.

CONCLUSIONS

Fluoro-navigation technique could become a safe, accurate, and fairly quick method for the treatment of anterior pelvic ring fractures. Standardization of the operative procedure and training are mandatory for the success of this procedure.

Computer-aided pelvic reduction frame for anatomical closed reduction of unstable pelvic fractures

Traditional closed reductions of unstable pelvic fractures are mainly performed by surgeons using manual manipulation and subjective verification based on intra-operative roentgenography. It is difficult to perform an accurate closed reduction because of a lack of adequate knowledge of the displacement patterns and an inability to apply the reduction in correct direction. Using the concept of the remote center of motion mechanism and computer-aided design software, we developed a pelvic reduction frame for use in anatomical closed reductions of unstable pelvic fractures. With three-dimensional reconstruction technique and the matrix algorithm, the spatial orientation of the displaced hemipelvis can be calculated and deconstructed into several rotational and translational movements that can be completed with the frame. To verify the accuracy of this system, the rotations were repeated 10 times in arbitrary degrees and directions. After the matrix is calculated, the displaced hemipelvis can be reduced to the anatomical position using our frame. The maximum residual translational and rotational displacements were less than 5 mm and 4 degrees, which indicated the accuracy of this system. The maximum average residual translation and rotation were 1.87 mm in Z-axis (ranging: 4.63-0.1 mm) and 1.1 degrees around Y-axis (ranging: 3.81-0.13 degrees), respectively. Only the Z-axial translation showed a statistically significant difference (p < 0.05). In conclusion, the proposed pelvic reduction frame could be a useful tool for the anatomical reduction of unstable pelvic fractures.

Management of neglected sacral fracture with cauda equina syndrome: report of two cases with review of literature

STUDY DESIGN

A retrospective study was performed.

OBJECTIVES

To analyze the outcome of two neglected sacral fractures who presented late to us after 6 weeks of injury with main complaints of incontinence and numbness in sacral region. There are no guidelines for management of complex fractures of sacrum who present late, and available literature is equally perplexing.

METHODS

Patients were evaluated and radiological investigations were done. Anterior-displaced U-shaped fracture was found to be present between S2 and S3 with bony fragments encroaching the canal. Decompression with wide sacral laminectomies was done without any fixation.

RESULTS

Case 1 showed complete recovery of bladder and perineal sensations 6 months post surgery. Second patient (case 2) had partial recovery of bladder control but numbness persisted till last follow-up at 6 months.

CONCLUSION

Neglected fractures of sacrum that present later than 6 weeks post injury with cauda equina syndrome could be given a chance for decompression if imaging shows canal encroachment with bony fragments. Fixation of fracture may not be required in all unstable sacral fractures after 6 weeks.

Percutaneous Sacroiliac Screw Fixation of the Posterior Pelvic Ring

Percutaneous sacroiliac (SI) screw fixation is indicated for unstable posterior pelvic ring injuries, sacral fractures, and SI joint dislocations. This article provides a review of indications and contraindications, preoperative planning, imaging techniques and relevant anatomy, surgical technique, complications and their management, and outcomes after SI screw insertion.

Radiographic diagnosis of sagittal plane rotational displacement in pelvic fractures: a cadaveric model and clinical case study

PURPOSES

Our objective was to measure the sagittal plane rotational (flexion and extension) displacement of hemipelvis radiologically and analyze the ratio of flexion and extension displacement of unstable pelvic fractures.

METHODS

We used 8 cadaveric models to study the radiographic evidence of pelvic fractures in the sagittal plane. We performed pelvic osteotomy on 8 cadavers to simulate anterior and posterior pelvic ring injury. Radiological data were measured in the flexion and extension group under different angles (5°, 10°, 15°, 20°, and 25°). We retrospectively reviewed 164 patients who were diagnosed with a unilateral fracture of the pelvis. Pelvic ring displacement was identified and recorded radiographically in cadaveric models.

RESULTS

The flexion and extension displacement of pelvic fractures was measured in terms of the vertical distance of fracture from the top of iliac crest to the pubic tubercle (CD) or from the top of iliac crest to the lowest point of ischial tuberosity (AB). Fifty-seven pelves showed flexion displacement and 15 showed extension displacement. Closed reduction including internal fixation and external fixation was successfully used in 141 cases (86.0 %). The success rates of closed reduction in flexion and extension displacement groups were 77 and 73 %, respectively, which were lower than in unstable pelvic ring fractures.

CONCLUSIONS

The sagittal plane rotation (flexion and extension) displacement of pelvic fractures could be measured by special points and lines on the radiographs. Minimally invasive reduction should be based on clearly identified differences between the sagittal plane rotation and the vertical displacement of pelvic fractures.

Fluoroscopically assisted computer navigation enables accurate percutaneous screw placement for pelvic and acetabular fracture fixation

Percutaneous fixation of pelvic and acetabular fractures are technically demanding procedures, and high rates of screw misplacement and potential neurovascular complications have been reported. One hundred and sixty two screws from a prospectively collected database were analysed to evaluate the accuracy of a fluoroscopically assisted computer navigated technique to insert a cannulated screw to treat pelvic and acetabular fractures. Actual screw position and trajectory with the intraoperative surgical plan stored in the navigation computer. The actual screw position differed from the surgical plan by a mean of 3.9 mm, with a mean 1.4 degree difference in screw trajectory. Post operative CT analysis of patients showed 10 screws perforated cortical bone. Our results show that the use of computer navigation can aid in the accurate placement of percutaneous screws along a predefined plan. It is still possible to incorrectly place a screw and great care needs to be taken with the surgical plan and also to understand the complex anatomy of the bony pelvis.

Anatomical measurement and finite element study on screw channel parameter in percutaneous fixation of canulated screw for symphyseolysis

To provide anatomical basement for symphyseolysis treatment with percutaneous fixation of canulated screw, through anatomical measurement on pubic symphysis and the surrounding tissues, and conduct the finite element studies on screw channel parameters. 20 cases of normal pelvic specimens from embalmed adult cadavers were taken to measure the anatomical parameter of bony remark of pubic symphysis and the space between spermatic cord (round ligament of the uterus) and pubic tubercle. Anatomical measurement results showed that the narrowest diameter of the superior ramus of pubis was 9.127 ± 1.189 mm, distance between two pubic tubercles was 55.656 ± 3.780 mm, thickness of the upper pubic symphysis was 10.510 ± 0.814 mm, and distance between upper and lower pubic symphysis was 40.872 ± 1.211 mm; the distance between round ligament of the uterus and pubic tubercle was 4.408 ± 0.304 mm, and the distance between spermatic cord and pubic tubercle was 5.196 ± 0.251 mm. The angle between canulated screw guide pin and horizontal plane was 8.342 ± 2.152°, the one between guide pin and coronal plane was 5.236 ± 1.612°, and the distance from entry point to the outer edge of pubic tubercle was 10.023 ± 1.245 mm, which was measured by Mimics software. Percutaneous surgery at horizontal position was simulated on cadaver. And the screw was correctly placed in postoperative imaging examination. According to the anatomical data and finite element studies of screw channel parameter in percutaneous fixation of canulated screw for symphyseolysis, the method can improve the accuracy of screw placement and reduce complications.

Anatomical study of anterior column screw tunnels through virtual three-dimensional models of the pelvis

We created 66 male and 74 female virtual three-dimensional models of the pelvis based on computed tomography data from 140 patients. Virtual cylindrical bolts (VCBs) were placed in the anterior column (AC), which was then resliced serially along the bolt's long axis. AC screw tunnel mainly comprises two long, narrow triangular prisms [zone III (acetabular fossa) and zone V (obturator foramen)]--forming the III/V angle--linked by a larger, shorter cylinder [zone IV (acetabular notch)]. VCBs' mean length and maximum diameter were 111.13 ± 7.33 and 7.37 ± 1.90 mm, respectively. The models' anatomical zone lengths were similar between the sexes. Zone V's narrowest diameters and the III/V angles were significantly different. VCBs >6.5 mm were accommodated in 65 of 66 male models and 31 of 74 female models. VCBs >5.0 and <6.5 mm were accommodated in one male and 30 female models. Eleven female models accommodated only VCBs >3.5 and <5.0 mm. However, to 13 female pelvic models with maximum VCB accommodation of <5 mm for the anterior column, the maximum diameter of the VCBs was 8.23 ± 1.22 mm in medial passage and 10.3 ± 1.91 mm in lateral passage, respectively. Percutaneous fixation of the AC with screws is a safe technique, even though in Chinese female patients. The narrowest diameters in zone V and the III/V angles are the key factors for application of AC screws. Female patients with a smaller interosseous space at zone V and a large III/V angle can accommodate segmental passage screws.

Minimising blood loss in early trauma resuscitation

Worldwide, trauma is responsible for more than 10,000 deaths each day with hundreds of thousands seriously injured. Current trauma resuscitation strategies are based on supporting haemostasis, maintaining circulating volume and rapidly identifying sites of blood loss. Approaches include hypotensive/hypovolaemic resuscitation, avoidance of colloids and crystalloids, early blood product based resuscitation, early imaging to identify sites of blood loss and damage control surgery. In this paper, we focus on ways to minimise blood loss and preserve the circulating volume. These include minimal movement of the patient, splinting fractures, use of tourniquets, application of local haemostatic dressings/agents, keeping the patient warm and giving tranexamic acid to improve clot strength. The recent CRASH-2 trial provided unequivocal evidence that tranexamic acid reduces mortality in bleeding trauma patients. This will be discussed in detail. When employed as part of a package of care in a well-rehearsed trauma system, these interventions to preserve the remaining circulating volume have the potential to save lives and allow patients to survive until timely definitive haemostasis can occur.

Surgical technique: a percutaneous method of subcutaneous fixation for the anterior pelvic ring: the pelvic bridge

BACKGROUND

Management of pelvic ring injuries using minimally invasive techniques may be desirable if reduction and stability can be achieved. We present a new technique, the anterior pelvic bridge, which is a percutaneous method of fixing the anterior pelvis through limited incisions over the iliac crest(s) and pubic symphysis.

DESCRIPTION OF TECHNIQUE

An incision is made over each anterior iliac crest and a 6- to 8-cm incision is centered over the symphysis. Either a locking reconstruction plate or a spinal rod is placed through a subcutaneous tunnel overlying the external oblique fascia in the subcutaneous tissue, and fixation into the iliac crest and pubis is achieved to effect stability.

METHODS

A randomized controlled trial comparing anterior pelvic external fixation (APEF) versus anterior pelvic internal fixation (APIF) for unstable pelvic ring injuries was begun in October 2010. Patients with unstable pelvic ring injuries were enrolled and followed with respect to fracture reduction, surgical pain, complications, and functional outcome scores.

RESULTS

As of January 2012, 23 patients met inclusion; however, 12 patients refused participation because of the possibility of external fixation, leaving 11 patients (four male, seven female) enrolled. At 6-month followup, there was a single pin tract infection in the APEF cohort and no complications or pain in the APIF cohort.

CONCLUSIONS

This clinical experience lends support to the use of a new minimally invasive technique to stabilize the anterior pelvis, particularly given the resistance on the part of patients to consider external fixation.

LEVEL OF EVIDENCE

Level II, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Efficacy and safety of emergency non-invasive pelvic ring stabilisation

BACKGROUND

Urgent non-invasive pelvic ring stabilisation (pelvic binding, PB) in shocked patients is recommended by state and institutional guidelines regardless of the fracture pattern. The purpose of this study was to determine the adherence to the guidelines, efficacy of the technique and identification of potential adverse effects associated with PB.

PATIENTS AND METHODS

A 41-month retrospective analysis of the prospective pelvic fracture database was undertaken at a level 1 trauma centre. High-energy pelvic fractures were included in the analysis with exclusion of the A type injuries (AO/OTA classification) and patients who were dead on arrival. Collected data included patient demographics, injury severity score, fracture classification, application and timing of PB, associated injuries, physiological parameters, resuscitation fluids and outcomes. Pre and post-PB radiographs were reviewed. The potential effects of the PB on soft tissue (femoral vessel, bladder and rectal injury) complications were assessed by independent experts.

RESULTS

115 patients with high-energy B and C type pelvic ring injuries were included. Thirty-six (31%) patients presented in haemorrhagic shock on arrival. A total of 43 pelvic bindings were performed, 18 of them on shocked patients. The adherence to the guidelines was 50% (18/36) overall. Analysing fracture types of shocked patients the adherence was: B1 80%, B2 20%, B3 20%, C1 66%, C2 86%, C3 33%. The alignment of the pelvis was improved or perfect on post-PB radiographs in 68% and had not changed in 21%. In some cases of B2 and B3 type injuries the PB increased the deformity after application (11%). There were 10 deaths (8.7%) in the study group, with 4 deaths attributed to acute pelvic bleeding. Two of these had PB applied and two were identified as potential for improvement. One femoral artery injury, four bladder injuries and three rectum injuries were identified in patients who had PB applied. Association between the PB and these injuries is unlikely.

CONCLUSION

The adherence to the guidelines should be improved with further education and system development. The good effect of the technique was evident on radiographs. Although in some lateral compression fracture patterns the deformity increased, no hazards were associated with the use of PB.

Oblique distraction external pelvic fixation

Simple anterior pelvic external fixation is a safe and effective strategy for reduction of pelvic ring deformity as well as the provisional or definitive stabilization of selected patterns of pelvic ring disruption. A two-pin oblique anterior pelvic deformity correction frame is a unique frame configuration designed to reduce and stabilize lateral compression pelvic ring disruptions associated with flexion/internal rotation hemipelvic deformities. In a small case series, we demonstrate that the oblique distraction external fixation frame alone or in combination with internal fixation is a simple and safe strategy for reduction and stabilization of unstable multiplanar hemipelvic deformities associated with partial posterior ring stability.

Anterior pelvic external fixator versus subcutaneous internal fixator in the treatment of anterior ring pelvic fractures

OBJECTIVES

To compare the short-term results of anterior pelvic external fixation (APEF) versus anterior pelvic internal fixation (APIF) applied subcutaneously in the context of surgical treatment of pelvic ring injuries.

DESIGN

A single center retrospective chart review.

SETTING

A level 1 trauma center.

METHODS

A consecutive series of 48 patients who underwent surgical stabilization of their anterior pelvic ring (24 utilizing APIF and 24 utilizing APEF) by 2 surgeons at a single hospital were studied. The choice to use either APEF or APIF was left up to each surgeon, the indications for use are the same. Data collected included surgical or postoperative complications including infection, implant failure, reoperation, documented surgical site pain persisting to clinical follow-up visits, and radiographic union. Measurements on inlet and outlet pelvic radiographs were made immediately postoperation and at all follow-up clinic visits to determine whether there were differences in maintaining pelvic fracture reduction. Statistical analysis was performed to evaluate significant differences between the 2 groups with regard to each of these variables.

RESULTS

The APIF group was found to have a significantly lower incidence of wound complication (P < 0.05) and a lower occurrence of associated morbidity events as compared with the APEF group. In addition, the APIF group was found to have a significantly lower rate of surgical site pain persisting through all clinical follow-up intervals (P = 0.05). There was no difference between the 2 groups in terms of maintenance of pelvic reduction in the early postoperative phase or at final follow-up. No other significant differences were observed between the 2 groups.

CONCLUSIONS

The present study, which was based on our initial experience with the subcutaneous anterior pelvic fixator, demonstrated encouraging clinical outcomes in terms of a lower wound complication rate and associated morbidity, and surgical site symptoms, although maintaining equivalent reduction. These findings suggest that further analysis of this technique is warranted to determine if it can be definitively recommended for general use.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Traumatic spinopelvic dissociation or U-shaped sacral fracture: a review of the literature

Traumatic spinopelvic dissociation is a rare high-energy injury pattern, characterised by a transverse sacral fracture in conjunction with bilateral sacral fracture-dislocations. It has a high incidence of neurological complications. The true nature of the injury is easily missed and diagnosis is delayed because it commonly presents in patients with severe associated injuries. In the absence of diagnosis and treatment, it can lead to progressive deformity and chronic pain. Early realignment and fixation of the unstable lumbopelvic junction, with adjunctive decompression of compromised lumbosacral roots, are currently thought to provide the best possible environment for early mobilisation of the polytraumatised patient. Plain pelvic radiographs (anteroposterior, inlet, and outlet), lateral sacral radiograph, CT scan and reconstruction are essential to provide optimal imaging and understanding of the fracture pattern. There is no single treatment paradigm and various surgical strategies have been described in the literature. Lumbopelvic fixation or triangular osteosynthesis has recently been recommended by several authors to restore stability at the lumbosacral junction. This article presents a review of the incidence, clinical evaluation, treatment methods and outcomes of this injury pattern.

Isolated transverse sacral fractures

BACKGROUND CONTEXT

The limited literature available about transverse sacral fractures describes two populations of patients: one with severe associated injuries and neurologic impairment and another with insufficiency fractures after low-energy trauma. Nevertheless, we have observed that isolated sacral fractures can occur in a third group of patients without the previously described features.

PURPOSE

To describe the clinical features of a population of patients with isolated transverse sacral fractures and evaluate the results of their conservative treatment according to our experience.

STUDY DESIGN

Retrospective cohort study.

PATIENT SAMPLE

Forty-two patients with isolated transverse sacral fractures with a mean follow-up of 22 months (range, 18-24 months).

OUTCOMES MEASURES

Neurologic recovery, pain relief, time out of work, and disability.

METHODS

We included all the patients admitted at our institution for an isolated transverse sacral fracture between 1996 and 2005. The information obtained from their medical records was analyzed using an electronic spreadsheet (Microsoft Excel for Mac v.2011; Microsoft, Redmond, WA, USA).

RESULTS

Thirty-four patients (80%) sustained a low-energy trauma, whereas only two (4.8%) presented transient neurologic impairment. Every fracture was confirmed with a sacrococcygeal computed tomography (CT) scan. All the patients referred no local pain 6 months after the accident and were able to return to their preinjury activity level. None of the patients required compensation for disability.

CONCLUSION

Transverse sacral fractures should be suspected in patients referring local pain after sustaining low-energy trauma, even in the absence of risk factors for an insufficiency fracture. These injuries are difficult to detect in plain X-rays, so a sacrococcygeal CT scan is recommended. Conservative treatment is associated with excellent results in this population of patients.

A minimally invasive stabilizing system for dorsal pelvic ring injuries

BACKGROUND

Open reduction and stabilization of dorsal pelvic ring injuries is accompanied by a high rate of soft tissue complications. Minimally invasive techniques have the potential to decrease soft tissue trauma, but the risk of iatrogenic nerve and vessel damage through the reduced surgical exposure should be considered. We treated these injuries using a transiliac internal fixator (TIFI) in a minimally invasive technique characterized by implantation of a pedicle screw and rod system, bridging the sacroiliac joints and the sacral area.

QUESTIONS/PURPOSES

We asked whether (1) we could achieve anatomic restoration with the device, (2) specific complications were associated with this minimally invasive approach (particularly enhanced intraoperative blood loss, soft tissue complications, and iatrogenic neurovascular damage), and (3) function 3 years after trauma was comparable to that of established methods.

METHODS

We retrospectively reviewed 67 patients with dorsal pelvic injuries during a 7-year period. We evaluated the (1) reduction by grading the maximal displacement measured with three radiographic views, (2) the complications during the observation period, and (3) the function with a validated questionnaire (Pelvic Outcome Score) in all but five patients at least 3 years after trauma (mean, 37 months; range, 36-42 months).

RESULTS

At last followup we observed a secondary fracture displacement greater than 5 mm in one patient. The intraoperative blood loss was less than 50 mL in all patients. No neurovascular lesions occurred owing to implantation. Four patients had wound infections, one had loosening of a single pedicle screw, and one had an iatrogenic screw malpositioning. Thirty-five of the 62 patients achieved Pelvic Outcome Scores of either a maximum score or 6 of 7 points.

CONCLUSION

Our observations suggest TIFI is a reasonable alternative to other established fixation devices for injuries of the dorsal pelvic ring with minor risks of major blood loss or iatrogenic neurovascular damage.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Transcatheter embolization in the treatment of hemorrhage in pelvic trauma

Massive hemorrhage related to pelvic trauma is relatively rare, but when it occurs rapid triage to therapeutic intervention is essential for survival. Traditional surgical repairs had limited success. Anatomic and clinical studies indicate that arterial hemorrhage is often identified in patients with hemodynamic instability that do not respond to initial resuscitation. Transcatheter angiography directly identifies arterial injury, and embolization can control retroperitoneal arterial hemorrhage. Stent-graft technology extends the scope of interventional therapy to include rapid and definitive repair of nonexpendable artery injury. Successful management requires coordination between multiple services and the continuation of resuscitative procedures in the angiography suite.

External fixation in pelvic fractures

Pelvic fractures account for 4-5% of all fracturated patients, and they occur in 4-5% of polytraumatized patients. In the most of the cases, they are consequent to high-energy trauma with a high percentage of lesions of other organs (cerebral, thoracic, and abdominal lesions. The most of the patients (80%) who die are dying within the first hours after trauma for a massive hemorrhagic shock. When the pelvic fracture and the patient's hemodynamic conditions are both unstable, osteosynthesis of the fracture is mandatory. Fracture stabilization should be performed within the first hour after trauma (as soon as possible), and it should be considered as part of the resuscitation procedure. We usually make an urgent stabilization of pelvic fracture with an anterior external fixator technique. We have revised all unstable pelvic fractures treated in our department (Orthopaedic Clinic Pisa University) from 2000 up to the 2005 to determine a correct treatment protocol for these lesions. Pelvic stabilization, reducing the pelvic volume and bleeding from the stumps of fracture, determines the arrest of the hemorrhage, as evidenced by the sharp decline in the number of transfusions in postoperative period. In these cases, there is an absolute indication for an urgent pelvic stabilization. Pelvic stabilization, whether temporary or permanent, allows to control the bleeding because it (1) leads to a reduction in the volume pelvis with a containment on the retro-peritoneal hematoma (2) reduces bleeding from the fracture fragments (3) reduces motility fracture promoting the blood clotting. The stabilization of the pelvis also makes it easier to manage the patient and his mobilization for the implementation of subsequent investigations. In our experience, external fixator accounts for its characteristics the gold standard approach for the urgent stabilization of these lesions, and, for most of them, it can be used as the definitive treatment. External fixation is a quick and easy procedure for pelvic fractures stabilization for surgeons with experience with this technique.

An anatomical update on the morphologic variations of S1 and S2

Although percutaneous fixation with iliosacral screws has been shown to be a safe and reproducible method for sacroiliac dislocation and sacral fractures, it is a technically demanding technique, and one of its contraindications is sacral anatomical variations and dysmorphism. The incidence and pattern of S1 and S2 anatomical variations were evaluated in 61 patients (35 women and 26 men) using magnetic resonance imaging of the sacrum in an attempt to explore the possible existence of groups of individuals in whom percutaneous sacroiliac fixation is difficult due to local anatomy. S1 and S2 dimensions in both the transverse and coronal planes were recorded and evaluated. In each individual, S1 and S2 dimensions both in the coronal and transverse planes were proportional, with S2 dimensions being 80% of those of S1 on average. Patients were separated into 4 groups based on the S1 and S2 body size and the asymmetry of dimensions in the transverse and coronal planes. In 48 patients (78.6%), dimensions in both planes were symmetrical despite the varying size of the S1 and S2 body. In 2 patients (3.3%) there was a combination of large transverse plane and small coronal plane dimensions, with large S1 and S2 body size. In 9 patients (14.8%), coronal plane dimensions were disproportionately smaller compared to those of the transverse plane, with a varying size of S1 and S2 body making effective sacroiliac screw insertion a difficult task. Thus, a preoperative imaging study, preferably computed tomography scan, of S1 and S2 body size and coronal plane dimensions and an intraoperative fluoroscopic control of S1 and S2 dimensions on the coronal plane are suggested for safe sacroiliac screw fixation.

Traction vertical shear pelvic ring fracture: a marker for severe arterial injury? A case report

Vertical shear pelvic ring fractures have been described as being produced only by a force directed cephalad, typically from falls or motor vehicle collisions. We report a seemingly similar vertical injury with the displacement of the hemipelvis being caudad rather than cephalad. Caudad displacement of the hemipelvis might disrupt the pelvic floor and vasculature far more than a standard vertical shear injury would and might be more prone to vascular injury. The clinical examination of the pelvic wound in our patient was not impressive and the magnitude of displacement seen on the admission radiograph was not different from that seen with a typical vertical shear injury. It is the caudal direction of the displacement that we think should alert the surgeon to the possibility of massive vascular injury and potential for limb loss.

Computer Assisted Pelvic Surgery: Registration Based on a Modified External Fixator

A fundamental step in Computer Assisted Surgery (CAS) is the registration, when the preoperative virtual data and the corresponding operative anatomy of the region of interest are merged. To provide exact landmarks for anatomical registration, a tubular external fixator was modified. Two intact pelvic bones (one artificial foam pelvis and one cadaver specimen) were used for the experimental setup. Registration was carried out using a standardized protocol for anatomy-based registration in the control group; anatomical registration was achieved using a modified external fixator in the study group. This external fixator had titanium fiducials wedged into the fixator carbon tubes serving as landmarks for paired-point registration. The tubes were used for surface registration. The standard anterior pelvis fixator assembly was augmented with additional bilateral tubes oriented towards the posterior, enabling registration of the sacroiliac areas. The accuracy of registration was checked by "reversed verification", where the examiner used only the screen display to control the virtual position of the pointer tip in relation to selected landmarks. By virtual matching, the real distance was measured with a digital caliper. We defined the verification as "accurate" when the residual distance was less than 1 mm; "acceptable" when it was between 1 mm and 2 mm; and "insufficient" when it exceeded 2 mm. The paired T-test with significance levels of p < 0.05 was used for statistical analysis. The anatomical registration based on the external fixator landmarks was statistically as accurate as that obtained using anatomical landmarks on the pelvic bone. This study concludes that the external fixator, a conventional tool in the management of acute traumatic pelvic instability, can also be useful for landmark registration in CAS.

Car versus bicycle: conclusion

A 58-year-old man was riding his bicycle and was struck by a car. He was ejected and landed on his back on the pavement of the roadway. He complained of severe pain in his lower back and sacral area. Ground emergency medical services (EMS) arrived to find a pale, diaphoretic man who was alert but in distress. His medical history was negative, and he was taking no medications. The initial heart rate was 130 beats/minute, and the blood pressure was 70 mmHg by palpation. A helicopter air ambulance was requested from the rural scene location to transport the patient to a trauma center. The physical examination by the flight crew demonstrated the patient had not changed from the original EMS assessment, despite the administration of 1 L normal saline intravenously. There were no apparent injuries to his head, neck, chest, or extremities.

Percutaneous pelvic fixation using working portals in a circumferential pelvic antishock sheet

Unstable pelvic ring injuries are associated with an increased mortality rate, most commonly from severe hemorrhage. Circumferential pelvic antishock sheeting has proven effective for rapidly stabilizing the pelvic ring and has become an integral part of resuscitation protocols. Acute antishock sheet placement frequently results in patient hemodynamic stabilization and an accurate pelvic reduction. In these situations, we describe a technique of maintaining the pelvic sheet position for continued use as a reduction aid and using working portals to insert definitive percutaneous pelvic implants.

Sacral fractures: current strategies in diagnosis and management

Sacral fractures are commonly associated with pelvic ring fractures due to high-energy mechanisms of injury. An understanding of the anatomic relation of the sacrum to the lumbar spine, pelvis, and surrounding neurovascular structures is critical in evaluating functional deficits that may be associated with sacral fractures. While displaced fractures can be easily diagnosed on high quality plain radiographs, nondisplaced or transverse fracture patterns may be difficult to diagnose without a computed tomography scan. Once identified, correct classification of a sacral fracture can facilitate ideal treatment strategies. Stable nondisplaced fractures are usually treated nonoperatively, while significantly displaced fractures require reduction and internal fixation. Surgical fixation techniques include percutaneously placed iliosacral screws, posterior sacral "tension band" fixation, and for certain fracture patterns osteosynthesis that incorporates the lower lumbar spine (lumbopelvic or triangular fixation). This article reviews the approach to sacral fracture diagnosis and management.

U-shaped sacral fractures: surgical treatment and quality of life

BACKGROUND

U-shaped sacral fractures are rare and highly unstable pelvic ring fractures. They are not recognised in the standard classification systems of these fractures. The fracture pattern is associated with significant neurological injury and can lead to progressive deformity and chronic pain if not diagnosed and treated properly. In recent years a variety of surgical strategies have been shown to facilitate early mobilisation and reduce early mortality as compared to non-operative strategies. Poor evidence, however, has hampered the development of a standard treatment algorithm. As for the long-term morbidity, the influence of operative treatment may be difficult to assess due to associated injury. However, evidence exists that there is a significant effect on the long-term morbidity.

OBJECTIVE

To assess the injury characteristics, choice of treatment and quality of life of U-shaped sacral fractures.

METHODS

Eight polytraumatised patients with U-shaped sacral fractures were identified over a 7-year period and evaluated retrospectively. They were analysed for fracture classification, associated injury, and injury severity. Clinical and Radiological results were evaluated. Neurological outcome was retrospectively classified by Gibbons' criteria. Long-term quality of life outcome was evaluated using the EuroQoL-6D questionnaire.

RESULTS

The study population consists of five women and three men; with a median age of 29 years. All patients sustained severe associated injury. The Injury Severity Score ranged from 17 to 45 (median 23). The median time between trauma and definitive internal fixation was 4 days (range, 2-22 days). Definitive fixation included either percutaneous iliosacral screws (n=2), transsacral plate osteosynthesis (n=1) or triangular osteosynthesis with (n=4) or without transsacral plating (n=1). Early postoperative mobilisation and early partial weight-bearing were encouraged when possible. Follow-up ranged from 5 to 65 months (median, 36 months). Pain, mood disorders and mobility problems mainly influenced patients' present general health status.

CONCLUSION

U-shaped sacral fractures present a rare and heterogeneous injury. Operative treatment depended mainly on fracture type, associated spinal fractures, and the surgeon's preference. Long-term quality of life is dominated by pain, mood disorders and moderate mobility problems.

Differences of percutaneous retrograde screw fixation of anterior column acetabular fractures between male and female: a study of 164 virtual three-dimensional models

INTRODUCTION

Percutaneous retrograde screw fixation of the anterior column has been recommended for the treatment of minimally displaced acetabular fractures. However, proper placement of the screw in anterior column is challenging because of its unique anatomy. There are few anatomic studies on this technique, and the differences between male and female have never been reported.

METHODS

We created virtual three-dimensional reconstruction models of the pelvis from CT scan data obtained from 82 adult patients without any bony problems. Virtual cylindrical implants were placed intraosseously both in left and right anterior column. The maximum diameter, length and optimal direction of the virtual cylindrical implant were determined for the screw. The perpendicular distance from the insertion point (P) of virtual cylindrical implant to the pubic symphysis (A) and the rim of superior ramus of pubis (B) were measured respectively. In the same model, cross-sections of the anterior column were created and the diameters of them were measured.

RESULTS

164 (80 males and 84 females) hemipelvis models were obtained. The mean maximum diameter and length of virtual cylindrical implant were 8.16+/-1.21 mm (range: 5.60-10.80 mm) and 109.39+/-8.95 mm respectively. The angles of the virtual cylindrical implant to transverse, coronal and sagittal planes were 39.66+/-3.92 degrees , 20.81+/-4.58 degrees and 42.66+/-3.23 degrees respectively. The distance of PA and PB were 18.42+/-4.82 mm and 17.76+/-2.63 mm. Both the differences of the diameter and length of the virtual cylindrical implant, and the distance of PA between the male and female were of statistical significance (p<0.00001). The mean minimum cross-sectional diameter of anterior column was larger than the mean diameter of the virtual cylindrical implant.

CONCLUSIONS

The anterior column of a male will accommodate a 6.5mm lag screw very well, but it does not fit all the females. The same direction of screw can be used in both male and female, but the insertion points of the screw are different. In addition, the determination of the size of the screw used for the anterior column cannot be based solely on the measurement of cross-sectional diameter and the virtual three-dimensional reconstruction model might be useful in preoperative planning.

Internal rotation and taping of the lower extremities for closed pelvic reduction

External rotation of the disrupted hemipelvis is a common deformity after pelvic ring trauma, especially in anteroposterior compression injury patterns. This displacement is associated with significant pelvic hemorrhage. Emergent closed reduction techniques are necessary to diminish the potential pelvic volume, provide temporary stability, and allow tamponade with clot formation. Circumferential pelvic antishock sheeting is effective but may be cumbersome, especially in patients with truncal obesity. In such scenarios, circumferential pelvic area sheeting does not always achieve a complete reduction. We present a technique of internal rotation and taping of the lower extremities as an alternative or supplemental pelvic closed reduction method.

Prise en charge radiologique des lésions vasculaires secondaires aux traumatismes du bassin

Pelvic injuries are serious, with mortality higher than 40% if the patient is in shock upon arrival at the hospital. These injuries are generally secondary to traffic accidents with violent kinetics, which explains the frequency of the associated extrapelvic lesions. With the vital prognosis at stake, management of these patients is a true challenge from both the radiographic and emergency care points of view. The objectives of this review are to present the epidemiological and physiological issues involved in pelvic injuries and the place of imaging today, necessarily integrated within a multidisciplinary team associating emergency physicians, surgeons, radiologists, and biologists.

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.