Operative stabilization of fracture dislocations of the sacroiliac joint

Open reduction and internal fixation of crescent fracture-dislocation: anterior or posterior approach?

INTRODUCTION

To date, the approach that prevails in the open reduction and internal fixation of crescent fracture-dislocations (CFD) remains unknown. This study aimed to compare the outcomes of CFD treated via the anterior or posterior approach.

MATERIALS AND METHODS

Data from 64 cases of CFDs openly reduced through an anterior (group A, n = 31) or a posterior (group B, n = 33) approach were retrospectively analyzed. Functional results, reduction quality, residual displacements in the axial and coronal planes, pelvic asymmetry deformity, and correlations between Day's classification were compared. Complications and fracture union were also recorded. All patients were followed up for at least 12 months.

RESULTS

The functional scores were similar between the two groups, and all fractures achieved good or excellent reduction postoperatively. In the coronal plane, the excellent/good ratio in group B was higher than in group A. The mean residual displacement in the coronal plane was significantly higher in group A than in group B, with group A showing greater displacement in both planes for Day I fractures and in the coronal plane for Day II fractures. The residual displacement in both planes for Day III fractures was comparable between the groups. The pelvic asymmetry deformity was equal between the two groups and among the different Day's fracture types.

CONCLUSIONS

Open reduction and internal fixation of CFDs obtained satisfactory outcomes through an anterior or posterior approach. The posterior approach achieved a better sacroiliac joint reduction. The optimal indication for the posterior approach was a Day I fracture, followed by a Day II fracture. No correlation was found between the surgical approach and reduction quality in Day III fractures.

Crescent Fracture of the Pelvis: A Case Report

Crescent fractures are a rare type of pelvic injury. They result from a lateral compression force and are rotationally unstable. The following is a case of a young male who suffered a crescent fracture on the right side of the pelvis and was treated for the same. These fractures, being rare and complex, need to be managed in accordance with other injuries sustained by the patient and also need fixation for a better functional outcome.

Bilateral pelvic crescent fracture combined with left acetabular fracture: A case report

Introduction

Presentation of case

Conclusion

•

Bilateral crescent fracture is a rare entity of the pelvic ring injury and is usually secondary to high-velocity impact.

•

Only 3 cases of bilateral crescent fracture were reported in the litterateur but not with acetabulum fracture.

•

Initial management of such injury consists of hemodynamic stabilization of the patient and afterword the injury can be addressed.

•

No standard of treatment is been described yet, but staged surgical stabilization of such combined fractures is recommended which affect the outcome.

Lateral Compression Type 2 Pelvic Fractures-A Clinical Study of Fracture Displacement Measurement and Closed Reduction

Objective

To evaluate the displacement in four lateral compression type 2 (LC2) fracture subtypes (iliac wing and three kinds of crescent fractures) and to investigate the appropriate closed reduction for treatment using a pelvic reduction frame.

Methods

A total of 71 patients with LC2 pelvic fractures from February 2014 to November 2019 were included in this retrospective cohort study. Preoperative X‐ray and computed tomography data were used to assess the direction of the fracture displacement and the sacroiliac joint dislocation. The fractures in all patients were reduced with a pelvic reduction frame and fixed with percutaneous screws as well as an anterior subcutaneous pelvic ring internal fixator. Two different closed reduction strategies were adopted, one was first longitudinal traction and then transverse traction, the other was first transverse traction then longitudinal and LC2 traction. The Matta score system was used to evaluate the postoperative X‐ray and the Majeed score system was used for follow‐up evaluation.

Results

A total of 13 iliac wing fractures (86.7%) and 16 Day type 1 fractures (94.1%) were vertically stable with only internal displacement, the ring width displacements were 5 (3, 8.75) and 8 (4, 12) mm, the posterior superior iliac spine (PSIS) differences were 0 (0, 0) mm and 0 (0, 0) mm. A total of 21 Day type 2 fractures (95.5%) and 16 Day type 3 fractures (94.1%) were characterized by cephalic and dorsal fracture dislocation on the basis of internal displacement, the ring width displacements were 6 (4.25, 12) and 4 (0, 7.5) mm and the PSIS differences were 4 (2, 5) and 0 (0, 3.75) mm. Based on the Matta scores, excellent reduction was achieved in 51 patients, good reduction in 17 patients, and poor reduction in three patients. The average Majeed score was 91.6, with a minimum outpatient follow‐up of 12 months (average 31.6 months).

Conclusion

LC2 fractures involve two different kinds of fracture displacement: internal displacement only and a combination of internal, cephalic, and dorsal dislocation through the sacroiliac joint. Good clinical outcomes can be achieved for LC2 fractures using two different closed reduction strategies.

Nonoperative Treatment of Select Lateral Compression Type II Pelvic Ring Injuries (OTA/AO 61B2.2) Results in a Low Rate of Radiographic Displacement

OBJECTIVES

To quantify radiographic outcomes and to identify predictors of late displacement in the nonoperative treatment of lateral compression type II (LC-2) pelvic ring injuries.

DESIGN

Retrospective review.

SETTING

Two Level 1 trauma centers.

PATIENTS/PARTICIPANTS

Thirty eight patients 18 years of age or older with LC-2 pelvic ring injuries were included in the study.

INTERVENTION

Nonoperative treatment.

MAIN OUTCOME MEASUREMENTS

Crescent fracture displacement (CFD) was measured on initial axial computed tomography scan. Change in pelvic ring alignment was measured by the deformity index, simple ratio, and inlet and outlet ratios on successive plain radiographs.

RESULTS

Patients in this study had minimally displaced LC-2 pelvic ring injuries, with median initial CFD of 2 mm and median initial deformity index of 2%. No patients had a change of more than or equal to 10 percentage points in deformity index over the treatment period, but small amounts of displacement were seen on the other ratios. No patients initially selected for nonoperative treatment converted to operative treatment. No radiographic predictors of late displacement were identified. Bilateral pubic rami fractures and the presence of a complete sacral fracture ipsilateral to the crescent fracture were not associated with late displacement.

CONCLUSIONS

A spectrum of injury severity and stability exists in the LC-2 pattern. Nonoperative treatment of LC-2 injuries with low initial deformity and CFD results in minimal subsequent displacement.

LEVEL OF EVIDENCE

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

Comparison of percutaneous cross screw fixation versus open reduction and internal fixation for pelvic Day type II crescent fracture-dislocation: case-control study

Objective

To investigate the clinical outcomes of percutaneous cross screws internal fixation for pelvic Day type II crescent fracture-dislocation.

Methods

We reviewed 66 consecutive patients undergoing surgical treatment for Day type II crescent fracture-dislocation from June 2005 to December 2017. Percutaneous cross screws internal fixation was performed in 40 patients, and open reduction and internal fixation was performed in 26 patients. The patient characteristics, surgical complications, radiographic and clinical outcomes and were compared.

Results

There was no statistically difference on the mean time from injury to surgery between the two groups. The time of operation, the amount of blood loss, the length of incision, and the hospital stay were significantly shorter in the percutaneous cross screws internal fixation group. No significant difference on Matta scores and Majeed scores between the two groups. The open reduction and internal fixation group resulted in a higher rate of intraoperative hemorrhage, nerve injury, discomfort, and pain.

Conclusion

Percutaneous cross screws internal fixation for Day II type pelvic crescent fracture-dislocation was safe and effective. Minimally invasive fixation had the advantages of short operation and hospitalization time, less intraoperative bleeding, and surgical trauma.

Cannulated iliac screw fixation combined with reconstruction plate fixation for Day type II crescent pelvic fractures

Objective

Method

Results

Conclusion

A novel percutaneous crossed screws fixation in treatment of Day type II crescent fracture-dislocation: A finite element analysis

Objective

Day type II crescent fracture–dislocation is a subtype of pelvic lateral compression injury. At present, there is still a controversy on the operative approach and fixation technique. We have put forward closed reduction and percutaneous crossed screws fixation for treating type-II crescent fracture–dislocation. Finite element analysis is used to compare the biomechanical properties between percutaneous crossed screws and other internal fixations.

Methods

A three-dimensional finite element model of Day type-II crescent fracture–dislocation was simulated using 5 implants, including double anterior plates (Model A), one posterior plate and one iliac screw (Model B), one sacroiliac joint screw (Model C), crossed one iliac screw and one sacroiliac joint screw (Model D), and crossed two iliac screws and one sacroiliac joint screw (Model E). 600-N stress was applied to S1 vertebral end-plate. To evaluate the biomechanical properties, the stress distribution and displacement distribution of the pelvis, stress distribution of the crescent fragment and stress distribution of plate and cannulated screw were recorded and analyzed.

Results

Under the loading of 600N, the maximum pelvic displacements in the finite element model were compared as follows: model E (0.070 ​mm), model D (0.071 ​mm), model A (0.080 ​mm), model C (0.096 ​mm), and model B (0.112 ​mm). The maximum displacements of crescent fragment were compared as follows: model E (0.018 ​mm), model B (0.022 ​mm), model D (0.023 ​mm), model A (0.030 ​mm), and model C (0.043 ​mm). The maximum stress of all implants were compared as follows: model D (90.01 ​Mpa), model E (81.60 ​Mpa), model C (69.07 ​Mpa), model A (56.51 ​Mpa), model B (18.29 ​Mpa). Model E and model D could provide better mechanical support for whole pelvic.

Conclusions

With sufficient biomechanical stability and minimally invasive advantage, percutaneous crossed screw fixation is a recommended treatment for Day Type-II Crescent Fracture–dislocation. It is recommended to fix crescent fracture fragment and sacroiliac joint simultaneously during the operation. If it is difficult to fix the both position, the sacroiliac joint is preferentially fixed.

The translational potential of this article

There is a controversy on the operative approach and fixation technique of Day type-II crescent fracture–dislocation. This article proves that percutaneous crossed screw fixation is a recommended treatment for Day type-II crescent fracture–dislocation by finite element analysis.

[Treatment of Day type pelvic crescent fracture by using percutaneous cannulated screw fixation technique]

Objective

To evaluate the feasibility and effectiveness of percutaneous cannulated screw fixation for the treatment of Day type Ⅱ pelvic crescent fracture.

Methods

The clinical data of 14 patients with Day type Ⅱ pelvic crescent fractures underwent closed reduction and percutaneous cannulated screw fixation between January 2009 and July 2016 were retrospectively analysed. There were 9 males and 5 females, aged 17-65 years (mean, 38 years). The causes of injury included traffic accident in 8 cases, falling from height in 3 cases, bruise injury in 3 cases; all were closed fractures. According to Tile classification, there were 8 cases of type B, 6 cases of type C. There were 13 cases combined with fracture of the anterior pelvic ring, including 8 cases of superior and inferior ramus of pubis fracture, 1 case of superior ramus of pubis fracture with symphysis separation, and 4 cases of symphysis separation. The interval of injury and admission was 1- 72 hours (mean, 16 hours), and the interval of injury and operation was 3-8 days (mean, 5 days). After operation, the reduction of fracture was evaluated by the Matta evaluation criteria, the clinical function was assessed by Majeed function assessment.

Results

The operation time was 35-95 minutes (mean, 55 minutes), cumulative C-arm fluoroscopy time was 3-8 minutes (mean, 5 minutes), no iatrogenic vascular injury and pelvic organ damage occurred. Postoperative X-ray films at 2 days indicated that 2 cases of vertical shift and 2 cases of mild rotation were not completely corrected. Postoperative CT examination at 3 days indicated that 2 pubic joint screws broke through the obturator bone cortex. None of the pubic ramus screws entered into the acetabulum, but a screw of superior pubic branch broke through the posterior cortical of superior pubic branch, a screw of posterior ilium column broke through the medial bone cortex of the ilium, and no clinical symptom was observed. One patient suffered from wound infection in the pubic symphysis, then healed after 2 weeks of wound drainage, the other wounds healed by first intention. According to Matta criterion for fracture reduction, the results were excellent in 9 cases, good in 4 cases, and fair in 1 case with an excellent and good rate of 92.9%. All patients were followed up 8-24 months (mean, 14 months). All fractures healed at 4 months and restored to the normal walking at 6 months after operation, 3 patients suffered from slight pain in the sacroiliac joints and slight claudication when they were tired or walked for a long time and unnecessary for special treatment. One patient felt pain in the back of the iliac spine when he was lying down. During the follow-up, no screw loosening or other internal fixation failure occurred. At last follow-up, according to Majeed functional evaluation criteria, the results were excellent in 7 cases, good in 5 cases, and fair in 2 cases with an excellent and good rate of 85.7%.

Conclusion

The percutaneous cannulated screw fixation is a safe treatment for Day type Ⅱ pelvic crescent fracture, which has a reliable fixation and good effectiveness.

Pelvic fracture of the sacroiliac joint region in a child - a case study and literature review

The aim of the paper is to present the case of a 3-year-old boy with an unaligned fracture of the sacroiliac joint region to propose a minimally invasive method of fracture fixation without using metal implants and to review the literature addressing this injury, which is uncommon in children. The patient was hit by a car; he suffered a fracture of the iliac ala with a complete traumatic damage to the L4-L5 nerve roots. The fracture was fixated by osteosuture and normal bone fusion was achieved. The follow-up period was 4 years. The boy manifested persistent flaccid paresis of the right foot and symptoms of a neurogenic bladder. Late radiological follow-up indicated disturbances of pelvic bone development and shortening of the lower extremity at the side of the injury.

A Quantitative Exposure Planning Tool for Surgical Approaches to the Sacroiliac Joint

OBJECTIVES

To aid in surgical planning by quantifying and comparing the osseous exposure between the anterior and posterior approaches to the sacroiliac joint.

METHODS

Anterior and posterior approaches were performed on 12 sacroiliac joints in 6 fresh-frozen torsos. Visual and palpable access to relevant surgical landmarks was recorded. Calibrated digital photographs were taken of each approach and analyzed using Image J.

RESULTS

The average surface areas of exposed bone were 44 and 33 cm for the anterior and posterior approaches, respectively. The anterior iliolumbar ligament footprint could be visualized in all anterior approaches, whereas the posterior aspect could be visualized in all but one posterior approach. The anterior approach provided visual and palpable access to the anterior superior edge of the sacroiliac joint in all specimens, the posterior superior edge in 75% of specimens, and the inferior margin in 25% and 50% of specimens, respectively. The inferior sacroiliac joint was easily visualized and palpated in all posterior approaches, although access to the anterior and posterior superior edges was more limited. The anterior S1 neuroforamen was not visualized with either approach and was more consistently palpated when going posterior (33% vs. 92%).

CONCLUSIONS

Both anterior and posterior approaches can be used for open reduction of pure sacroiliac dislocations, each with specific areas for assessing reduction. In light of current plate dimensions, fractures more than 2.5 cm lateral to the anterior iliolumbar ligament footprint are amenable to anterior plate fixation, whereas those more medial may be better addressed through a posterior approach.

An Atraumatic Symphysiolysis with a Unilateral Injured Sacroiliac Joint in a Patient with Cushing's Disease: A Loss of Pelvic Stability Related to Ligamentous Insufficiency?

Glucocorticoids are well known for altering bone structure and elevating fracture risk. Nevertheless, there are very few reports on pelvic ring fractures, compared to other bones, especially with a predominantly ligamentous insufficiency, resulting in a rotationally unstable pelvic girdle. We report a 39-year-old premenopausal woman suffering from an atraumatic symphysiolysis and disruption of the left sacroiliac joint. She presented with external rotational pelvic instability and immobilization. Prior to the injury, she received high-dose glucocorticoids for a tentative diagnosis of rheumatoid arthritis over two months. This diagnosis was not confirmed. Other causes leading to the unstable pelvic girdle were excluded by several laboratory and radiological examinations. Elevated basal cortisol and adrenocorticotropic hormone levels were measured and subsequent corticotropin-releasing hormone stimulation, dexamethasone suppression test, and petrosal sinus sampling verified the diagnosis of adrenocorticotropic hormone-dependent Cushing's disease. The combination of adrenocorticotropic hormone-dependent Cushing's disease and the additional application of exogenous glucocorticoids is the most probable cause of a rare atraumatic rotational pelvic instability in a premenopausal patient. To the authors' knowledge, this case presents the first description of a rotationally unstable pelvic ring fracture involving a predominantly ligamentous insufficiency in the context of combined exogenous and endogenous glucocorticoid elevation.

Percutaneous Screw Fixation of Crescent Fracture-Dislocation of the Sacroiliac Joint

Crescent fracture-dislocation of the sacroiliac joint (CFDSIJ) is a type of lateral compression pelvic injury associated with instability. Open reduction and internal fixation is a traditional treatment of CFDSIJ. However, a minimally invasive method has never been reported. The purpose of this study was to assess the outcome of closed reduction and percutaneous fixation for different types of CFDSIJ and present their clinical outcome. The authors reviewed 117 patients diagnosed with CFDSIJ between July 2003 and July 2013. Closed reduction and percutaneous fixation was performed in 73 patients. Treatment selection was based on Day's fracture classification. For type I fractures, fixation perpendicular to the fracture line were performed. For type II fractures, crossed fixation was performed. For type III fractures, fixation was performed with iliosacral screws. Forty-four patients were treated by open reduction and plate fixation. Demographics, fracture pattern distribution, blood loss, incision lengths, revision surgeries, radiological results, and functional scores were compared. All 117 patients were followed for more than 6 months (mean, 14 months [range, 6-24 months]). Blood loss, extensive exposure, duration of posterior ring surgery, duration of hospital stay, and infection rates were lower in the closed group (P<.01). Patients in the closed group achieved better functional performance (P<.01). There were no significant differences in reduction quality (P=.32), revision surgery rates (P=.27), and iatrogenic neurologic injuries (P=.2) between the 2 groups. The authors' results indicate that closed reduction and percutaneous fixation is a safe and effective surgical method for CFDSIJ.

Three-dimensional navigation is more accurate than two-dimensional navigation or conventional fluoroscopy for percutaneous sacroiliac screw fixation in the dysmorphic sacrum: a randomized multicenter study

OBJECTIVES

To evaluate the accuracy of computer-assisted sacral screw fixation compared with conventional techniques in the dysmorphic versus normal sacrum.

DESIGN

Review of a previous study database.

SETTING

Database of a multinational study with 9 participating trauma centers.

PATIENTS

The reviewed group included 130 patients, 72 from the navigated group and 58 from the conventional group. Of these, 109 were in the nondysmorphic group and 21 in the dysmorphic group.

INTERVENTION

Placement of sacroiliac (SI) screws was performed using standard fluoroscopy for the conventional group and BrainLAB navigation software with either 2-dimensional or 3-dimensional (3D) navigation for the navigated group.

MAIN OUTCOME MEASUREMENTS

Accuracy of SI screw placement by 2-dimensional and 3D navigation versus conventional fluoroscopy in dysmorphic and nondysmorphic patients, as evaluated by 6 observers using postoperative computerized tomography imaging at least 1 year after initial surgery. Intraobserver agreement was also evaluated.

RESULTS

There were 11.9% (13/109) of patients with misplaced screws in the nondysmorphic group and 28.6% (6/21) of patients with misplaced screws in the dysmorphic group, none of which were in the 3D navigation group. Raw agreement between the 6 observers regarding misplaced screws was 32%. However, the percent overall agreement was 69.0% (kappa = 0.38, P < 0.05).

CONCLUSIONS

The use of 3D navigation to improve intraoperative imaging for accurate insertion of SI screws is magnified in the dysmorphic proximal sacral segment. We recommend the use of 3D navigation, where available, for insertion of SI screws in patients with normal and dysmorphic proximal sacral segments.

LEVEL OF EVIDENCE

Therapeutic level I.

Atypical Pelvic Crescent Fracture Caused by Vertical Shear Force

The crescent fracture consists of a posterior iliac wing fracture with extension into the sacroiliac joint and a dislocation of the sacroiliac joint. This fracture represents a subset of lateral compression injury. The strong posterior ligaments of sacroiliac joint remain intact and a fracture fragment (crescent shape) involving the posterior superior iliac spines remains firmly attached to the sacrum. We report a patient with atypical pelvic crescent fracture that is mainly influenced by vertical shear injury and is characterized by posterior fracture-dislocations of the sacroiliac joint. In this case report, we review the literature on classification and treatment of atypical type of crescent fracture.

Posterior iliac crescent fracture-dislocation: is it only rotationally unstable?

Posterior iliac crescent fracture-dislocation is generally considered rotationally unstable and vertically stable. The current study (1) investigated whether vertical instability may occur in posterior iliac crescent fracture-dislocation and (2) analyzed the clinical features of vertically unstable iliac crescent fracture-dislocation as well as treatment strategies. Patients with pelvic fracture who were treated in the authors' department from June 2009 to June 2012 were retrospectively reviewed. This study analyzed the clinical features, including incidence, hemodynamic state, associated injuries, injury severity score, and treatment methods for vertically unstable iliac crescent fracture-dislocation. Four patients had vertically unstable fracture-dislocation, accounting for 12.9% of all iliac crescent fracture-dislocations. All 4 patients were hemodynamically unstable on admission and had complications of associated injuries with a higher injury severity score. In 3 of the 4 patients, iliac crescent fracture-dislocations were reduced via the posterior approach at the initial stage and these patients underwent fixation with a plate. The remaining patient was initially given transcondylar traction because of severe complications and underwent open reduction and internal fixation (ORIF) via a posterior approach at a later stage. The outcomes of all 4 patients were rated as good or excellent by the Kobbe rating system at the last follow-up. Vertical instability may occur in iliac crescent fracture-dislocation. The authors propose ORIF of the fracture-dislocation via a posterior approach. When initial surgery is not possible because of severe associated organ injuries, the authors propose transcondylar traction to allow reduction of the sacroiliac joint and ORIF at a later stage.

The posterior approach to pelvic ring injuries: A technique for minimizing soft tissue complications

Surgical techniques and fixation strategies for the treatment of unstable posterior pelvic ring injuries continue to evolve. The safety of the posterior surgical approach in particular has been questioned due to historically high rates of wound related complications. More contemporary studies have shown lower infection rates, however concern still persists. These concerns for infection and wound necrosis have led, in part, to increased interest in closed reduction and percutaneous fixation for treatment of these injuries but an open posterior approach remains the optimal strategy in some injury patterns. We describe herein a modified posterior approach to the pelvis designed to minimize wound related complications and present our clinical results demonstrating wound complication rates consistent with contemporary publications.

[Posterior approaches to the pelvic ring]

The posterior pelvic ring is critical for the mechanical stability of the pelvis. There is considerable variability in the degree of traumatic injury to the posterior pelvis which results in damage to the ligaments, the bones or a combination of these two functional structures. For management of combined posterior and anterior pelvic ring injuries it is crucial to decide which side has to be treated with priority. Surgical approaches for the posterior pelvic ring include transiliacal plate osteosynthesis, local plate osteosynthesis, iliosacral screw ostheosynthesis and spinopelvic stabilization. The degree of soft tissue damage represents an important criterion that should be considered when determining the surgical approach because extensive soft tissue damage often prevents enlarged explorative surgical access. Especially in posterior pelvic ring injuries, soft tissues should be preserved as much as possible because long periods of immobilization in severely injured patients can compromise wound healing. The aim of this paper is to provide an overview of the most commonly used posterior surgical approaches for pelvic ring injuries.

Posterior iliac crescent fracture-dislocation: what morphological variations are amenable to iliosacral screw fixation?

OBJECTIVES

Posterior iliac crescent fracture with associated sacroiliac joint disruption (PICFSID) is a type of traumatic posterior pelvic injury associated with instability. Posterior iliac fracture location and obliquity along with other details determine the treatment. Open reduction and internal fixation has been previously recommended for the majority of crescent fractures. Our objectives were to determine whether all crescents can be categorised according to the previously described Day crescent classification scheme, and to see which crescent types are amenable to percutaneous fixation.

PATIENTS AND METHODS

We identified 129 crescents in 128 patients during a 7-year time period. Of these, 100 patients met the inclusion criteria of at least 3 months of clinical and radiographic follow-up. There were 57 males and 43 females, with a mean age of 42 years and a mean injury severity score of 25.5. Treatment selection was based on fracture type and overall patient factors and consisted of non-operative management, pelvic external fixation, open reduction and internal fixation, and closed reduction and percutaneous iliosacral screw fixation.

RESULTS

There were 16 Type I, 47 Type II and 37 Type III crescent fractures. Twelve injuries could not be classified according to the Day scheme. Percutaneous iliosacral screw fixation was utilised in 60% of all crescents after either closed or open reduction of the PICFSID.

CONCLUSIONS

The majority of PICFSIDs are amenable to closed reduction and percutaneous iliosacral screw fixation. The Day classification for PCIFSID should be expanded to include variant injury patterns.

A bilateral crescent and anterior ring pelvic fracture sustained by inadvertently performing the 'splits'

A case is presented of a healthy 57 year old female who slipped and fell awkwardly into what is known in athletic terms as the front splits. As a result of her fall she sustained bilateral crescent and superior and inferior rami pelvic fractures. Successful operative fixation was undertaken by a combination of open and percutaneous techniques. To our knowledge this is the first reported case of bilateral crescent fractures, and of a pelvic fracture as a result of this mechanism of injury.

The relationship between the angle of version and rate of wear of retrieved metal-on-metal resurfacings: a prospective, CT-based study

We measured the orientation of the acetabular and femoral components in 45 patients (33 men, 12 women) with a mean age of 53.4 years (30 to 74) who had undergone revision of metal-on-metal hip resurfacings. Three-dimensional CT was used to measure the inclination and version of the acetabular component, femoral version and the horizontal femoral offset, and the linear wear of the removed acetabular components was measured using a roundness machine. We found that acetabular version and combined version of the acetabular and femoral components were weakly positively correlated with the rate of wear. The acetabular inclination angle was strongly positively correlated with the rate of wear. Femoral version was weakly negatively correlated with the rate of wear. Application of a threshold of > 5 μm/year for the rate of wear in order to separate the revisions into low or high wearing groups showed that more high wearing components were implanted outside Lewinnek's safe zone, but that this was mainly due to the inclination of the acetabular component, which was the only parameter that significantly differed between the groups. We were unable to show that excess version of the acetabular component alone or combined with femoral version was associated with an increase in the rate of wear based on our assessment of version using CT.

The floating hip: complications and outcomes

BACKGROUND

To perform a descriptive study of the course, treatment decisions, complications, and outcome of patients suffering simultaneous ipsilateral fractures of the femur and pelvis.

METHODS

Medical records and radiographs of 57 patients were reviewed retrospectively.

RESULTS

The average follow-up was 28 months. Fifteen patients (26%) had an acetabular fracture, 17 (30%) had a pelvic ring fracture, and 25 (44%) had both fractures concomitant with the ipsilateral femoral fracture. Eighty percent of acetabular fractures and 55% of pelvic ring fractures were treated surgically. Femur fractures underwent operation in 94% of cases. When multiple operative settings were used, the femur fracture was always fixed at the first operation. Complications included deep venous thrombosis (DVT) (12%), heterotopic ossification (HO) (34%), femoral head avascular necrosis (AVN) (2%), osteoarthritis (OA) (16%), and traumatic sciatic nerve palsy (33%). At least partial nerve palsy resolution occurred in 53% of patients.

CONCLUSIONS

Ipsilateral injuries to the femur and the pelvis or acetabulum ("floating hip") are severe injuries usually caused by high-energy trauma. The acetabulum and pelvic ring are more commonly fractured together than either alone. The femur fracture will most commonly be addressed first, as in 65% of our cases in which both components were addressed at the same setting, and 100% of cases in which they were addressed in separate settings. Delays of surgery were common because of severity of systemic trauma. Surgeons should be aware of the high incidence of sciatic nerve palsy as well as treatment options and potential complications associated with this devastating combination of injuries.

Bilateral Sacroiliac Joint Dislocation in an Adolescent after a Skiing Accident

A bilateral sacroiliac joint (SI joint) dislocation is a rare injury pattern, in contrast to bilateral fracture dislocations of the SI joint. The incidence of pelvic dislocation of the SI joint without significant bone structural damage would most likely be observed in young children or adolescents after receiving a blunt, high energy impact. These young patients often suffer life threatening injuries to the intestines, neural or vascular systems or severe injury of the urinary tract. In these scenarios, plain projection radiographic imaging often leads to an inconclusive diagnosis making computer tomography indispensable to plan the treatment strategy. These strategies vary and the optimal approach is a subject to dispute. A surgical treatment of these injuries should ensure an immediate primary stability to allow early ambulation. The following study reports a unique trauma pattern with an isolated bilateral SI dislocation without fracture of the posterior or anterior pelvic ring nor concomitant injuries. This rare injury is a consequence of a pure vertical shear impact. This case report describes a technical pitfall of the iliolumbar transfixation and a solution to the problem. A dorso-ventro-dorsal approach, which utilizes both iliolumbar transfixation and ventral bilateral double plating osteosynthesis will be presented.

Crescent fracture-dislocation of the sacroiliac joint

Crescent fracture dislocations are a well-recognised subset of pelvic ring injuries which result from a lateral compression force. They are characterised by disruption of the sacroiliac joint and extend proximally as a fracture of the posterior iliac wing. We describe a classification with three distinct types. Type I is characterised by a large crescent fragment and the dislocation comprises no more than one-third of the sacroiliac joint, which is typically inferior. Type II fractures are associated with an intermediate-size crescent fragment and the dislocation comprises between one- and two-thirds of the joint. Type III fractures are associated with a small crescent fragment where the dislocation comprises most, but not all of the joint. The principal goals of surgical intervention are the accurate and stable reduction of the sacroiliac joint. This classification proves useful in the selection of both the surgical approach and the reduction technique. A total of 16 patients were managed according to this classification and achieved good functional results approximately two years from the time of the index injury. Confounding factors compromise the summary short-form-36 and musculoskeletal functional assessment instrument scores, which is a well-recognised phenomenon when reporting the outcome of high-energy trauma.

Two-stage surgical procedure for treating pelvic malunions

When surgically treated, pelvic-ring deformities due to post-traumatic malunions in adults usually require invasive three-stage (prone/supine/prone or supine/prone/supine) procedures. A standardised two-stage prone/supine procedure was developed by the authors. Technical points and first clinical results are presented. Malunuions related to Tile B and C types of fracture were successfully corrected.

Trans-iliac removal of bullet fragments from the sacroiliac joint

The need for removal of intra-articular bullet fragments is well documented in the literature. Arthroscopy and arthrotomy are the preferred methods to access large superficial joints; however, these methods cannot be effectively used to access the sacroiliac joint. Its relationship to vital soft tissues and its convoluted joint anatomy make it almost impossible to explore even under open methods. We propose a new percutaneous technique for the removal of intra-articular bullet fragments from the sacroiliac joint. Our method meets two important goals: 1) percutaneous minimally invasive approach to the joint, and 2) removal of the bullet fragments while avoiding the potential morbidity of an open procedure.

Emergency management of pelvic fractures

Pelvic fractures are relatively uncommon, accounting for 1-3% of all fracture. Around 60% occur in men. This article discusses the multidisciplinary management of pelvic ring disruptions resulting from high energy transfer.

A posterior approach for inspection of reduction of sacroiliac joint disruption

This anatomic study was undertaken to describe a new posterior approach enabling direct inspection of reduction of sacroiliac joint disruption (SIJD), and guidance of iliosacral screw placement. The reduction of SIJD is usually monitored by inspection of the opposing sacrum and ilium at the posterior margin of the greater sciatic notch and there is a relative lack of information concerning inspection of reduction of SIJD from the posterosuperior aspect of the sacroiliac joint surface. Ten cadavers were dissected to determine the possibility of inspecting reduction of SIJD from the posterosuperior aspect of the sacroiliac joint by means of a posterior approach which passed immediately lateral to the deep back muscles and the fifth lumbar transverse process. The results indicated that the posterosuperior aspect of the sacroiliac joint surface and sacral ala can be directly palpated or visualised. This approach facilitates improved access for inspection of reduction of SIJD and guidance of iliosacral screw placement.

Radiologic evaluation of the pelvis

Careful radiographic assessment is essential in the diagnosis of pelvic fractures. The standard radiographic assessment of the pelvis includes the anteroposterior, inlet, outlet, Judet views, and axial computed tomography images. The different radiographic projections of the pelvis and their corresponding anatomic landmarks and the anatomy of the pelvis and the different anterior and posterior pelvic lesions are discussed. Description of the proper views and their uses are included.