CT characteristics of traumatic sacral fractures in association with pelvic ring injuries: correlation using the Young-Burgess classification system

Purpose

The purpose of the study is to determine the incidence of sacral fracture patterns on CT imaging of pelvic trauma patients with correlation with mechanism of injury and pelvic ring injury pattern using the Young-Burgess classification system.

Materials and methods

This is a retrospective review of all pelvic CTs with pelvic fractures performed at our level 1 trauma center during a 4-year period from July 2010 to June 2014.

Results

Sacral fractures were very common in pelvic trauma patients, being present in 60% of patients presenting to our institution with pelvic fractures. Longitudinal fractures were almost always associated with additional pelvic ring injuries. Denis zone 1 fractures had the highest association with lateral compression pelvic ring injuries. Denis zone 2 and 3 fractures were seen with increased frequency in AP compression and vertical shear injuries. A third of transverse sacral fractures occurred in isolation, with isolated transverse sacral fractures typically occurring in the low (S3–S5) sacrum. Almost half of combined transverse and longitudinal sacral fractures occurred without an additional pelvic fracture present. Sacral avulsions almost always occurred as part of a pelvic ring fracture pattern, most commonly in AP compression injuries. Coccyx fractures frequently occurred in isolation, but were commonly seen in vertical shear injuries when associated with a pelvic ring injury pattern.

Conclusion

Avulsion fractures and longitudinal fractures of the sacrum are almost always associated with anterior pelvic ring injury. Conversely, transverse fractures of the lower sacrum and combined longitudinal and transverse sacral fractures are prone to occur in isolation.

     

C臂引导下骶骨钉固定骨盆骨折后环不稳的临床疗效

目的回顾性研究经皮骶骨钉内固定治疗骨盆骨折后环不稳的临床疗效。方法对42例C型骨盆骨折患者使用前环钢板内固定和后环骶骨钉内固定治疗的临床资料进行回顾性分析,应用Tornetta复位情况评价表评估复位情况,应用Majeed骨盆骨折评分系统评价疗效。结果 42例均获随访,随访时间为4～34个月,平均随访15个月。闭合复位骶骨钉内固定骨盆骨折后环不稳术后疗效满意。结论掌握C臂引导下骶骨置钉技巧,应用骶骨钉固定骨盆骨折后环不稳,手术效果良好,手术操作简单,适于在基层医院广泛开展。     

Vacuum phenomena in insufficiency fractures of the sacrum

Objective. Insufficiency fractures of the sacrum are found in women who have undergone radiation therapy to the lower abdomen as well as those suffering from osteoporosis of postmenopausal, steroid-induced, or primary biliary cirrhosis-related origin. Increased up-take in bone scintigraphy and osteolytic changes in these fractures can be misinterpreted as bone metastases, leading to unnecessary biopsies and other procedures in the ensuing search for non-existent primary tumor.Patients. In eight female patients averaging 69.4 years of age, insufficiency fracture of the sacrum was diagnosed by computed tomography (CT) and bone scintigraphy. Three underwent a total of five MRI examinations. Malignancy was excluded by histology in two patients and follow-up of at least 6 months in the remainder. Retrospective analysis of CT scans of 13 patients with metastases in the sacrum revealed no vacuum phenomena.Results. In seven of eight patients with insufficiency fracture of the sacrum, vacuum phenomena were shown on CT examination. The gas was localized centrally within the ventral part of the fracture in three patients; gas was located in ten adjacent sacro-iliac joints of six patients.Conclusions. The vacuum phenomenon may be an incidental finding in osteoarthritis of the sacro-iliac joint, but it has not been previously recognized in IFS. The presence of intra-articular vacuum phenomena in the sacro-iliac joints in combination with a sacral fracture and vacuum phenomena located within the sacral fracture supports a diagnosis of insufficiency fracture or may indeed be the clue by which this diagnosis is established. Insufficiency fractures of the sacrum are a well-known complication in women who have undergone radiation therapy of the pelvis or are suffering from postmenopausal, steroid-induced, or primary biliary cirrhosis-related osteoporosis [1–11]. These fractures are characterized by increased activity on radionuclide bone scans. The lateral masses of the sacrum contain large amounts of hematopoetic bone marrow and are therefore often the site of bone metastasis. Increased uptake in bone scintigraphy in lateral masses of the sacrum and osteolytic destructions on radiographs and computed tomography (CT), especially in patients with a history of a tumor elsewhere, are suggestive of skeletal metastasis, prompting biopsies and additional diagnostic procedures to find a primary tumor [2]. We present seven out of eight patients with insufficiency fractures of the sacrum, in whom we observed vacuum phenomena within the fracture or in the adjacent sacroiliac joints, indicating the benignity of the lesion. This phenomenon has not been recognized previously.     

Insufficiency fracture of the sacrum after hormonal therapy and radiotherapy for prostate cancer: A case in which 99mTc-MDP bone scintigraphy was useful for differential diagnosis

A case in which radiotherapy was requested for bone metastases from prostate carcinoma after hormonal and radiation therapy and diagnosed as insufficiency fracture of the sacrum on bone scan was reported. A 78-year-old man underwent endocrine therapy with luteinizing hormone releasing hormone agonists and radical radiotherapy toward pelvis for prostate cancer. The onset of buttock pain started from the nine-month after the beginning of radiotherapy, and was diagnosed as sacrum metastasis by MRI, and radiotherapy was requested again for pain control. However, on bone scan, butterfly-like changed accumulation was noted, therefore sacrum insufficiency fracture was suspected. Addition of CT inspection and reconfirmation of MRI were performed, and bone metastases became negative, and serial observation was performed of the painkilling effect after that. No tumor marker rise was seen after five months without sigh of new bone metastases and the final diagnosis became insufficient fracture. In order to avoid unnecessary treatment, we think that the view of bone scintigram for diagnosis of sacrum insufficient fracture should be known.     

车祸伤致脊柱骨折临床特点分析

目的分析车祸伤致脊柱骨折的临床特点,以提高车祸伤致脊柱骨折的预防及救治水平。方法总结沈阳军区总医院骨科自2006年1月至2016年1月收治的166例脊柱骨折患者的临床资料,并进行流行病学统计分析。结果本组166例患者,年龄分布主要集中在40~59岁,占50.0%(83/166)。驾驶员是主要致伤身份,占48.2%(80/166)。235个损伤节段中,颈椎、胸椎、腰椎及骶尾椎损伤所占比例依次为40.9%(96/235)、30.2%(71/235)、28.1%(66/235)、0.9%(2/235),其中,L1、C2、T12分别为17.0%(40/235)、14.0%(33/235)、12.3%(29/235)。合并症及神经损伤发生率在年龄≤19岁组最高,分别为50.0%和50.0%。行人组的合并症发生率最高为43.5%,驾驶员组的神经损伤发生率最高为55.0%。结论由车祸伤致脊柱骨折的流行病学特点可见,驾驶员是主要车祸伤来源,根据车祸时的身份不同,神经损伤和合并症发生情况有所不同,应根据其特点进行防治。     

骶骨骨折的常规X线和三维CT对比研究

目的探讨多层螺旋CT三维重组对骶骨骨折的临床应用价值。资料与方法对46例骶骨骨折患者的X线、多层螺旋CT三维成像资料进行回顾性对比分析。结果X线平片确诊27例(58.7%,27/46),漏诊19例(41.3%,19/46),CT三维成像明确诊断44例(95.7%,44/46),漏诊2例(4.3%,2/46)。对确诊的骶骨骨折进行Denis分类,X线平片正确分型20例(74.1%,20/27),CT三维成像正确分型44例(100%,44/44),X线平片与CT三维成像组之间的差异有显著的统计学意义(P值均<0.01)。46例骶骨骨折患者,34例行保守治疗,12例手术治疗,手术所见与CT扫描结果完全一致。结论螺旋CT三维成像对骶骨骨折的诊断、分类及指导治疗具有重要的意义和作用。     

CT三维重建在骨盆骨折及盆腔脏器损伤手术治疗方案设计中的价值

目的：探讨螺旋CT三维重建在骨盆骨折及盆腔脏器损伤手术治疗方案设计中的价值。方法分析2007年1月至2013年12月行手术治疗的骨盆骨折及盆腔脏器损伤的患者CT三维重建影像资料,比较术前与术后影像资料及疗效。采用SPSS 17．0统计软件和χ2检验分析轴位CT及三维CT对骨盆骨折诊断的差异。结果149例骨盆骨折患者通过CT三维重建确诊髂骨骨折19例、骶尾骨骨折43例、耻骨上下支骨折30例及髋臼骨折57例;关节脱位21例、耻骨联合分离5例。轴位CT组与三维CT组间比较在髋臼骨折及骶尾骨骨折上,差异有统计学意义（P＜0．05）。髂骨骨折、耻骨上下支骨折、关节脱位及耻骨联合分离无统计学意义。合并盆腔脏器损伤有17例,其中膀胱破裂8例、后尿道损伤5例,盆腔血肿4例。149例患者术后复位效果中解剖复位64例,满意75例,不满意14例。获得随访20 d至83个月。按Matta疗效标准评定,临床标准：优97例,良45例,可7例,优良率95％;X线标准：优95例,良45例,可9例,优良率94％。结论螺旋CT三维成像多平面重建（MPR）、容积重建（VR）及表面遮盖重建（SSD）以最直观、全面的骨盆骨折及盆腔脏器损伤图像肯定并明确螺旋CT对骨盆骨折的分型;对治疗方案、手术入路、内固定物的选择和制定详细的手术计划可提供正确指导,在骨盆骨折及盆腔脏器损伤术前、术后影像检查中有较高的价值。     

Case report: lethal fetal head injury and placental abruption in a pregnant trauma patient

Fetal trauma in blunt abdominal trauma is uncommon, but traumatic fetal head injury is almost universally fatal to the fetus. Placental abruption is the most common injury to the gravid uterus in trauma, and when the mother survives, it is the most common cause of fetal death. The imaging diagnosis of these conditions may be difficult since there are only three cases reported in the literature of intrauterine skull fractures on plain films [3, 8, 10], ultrasound is in sensitive in the diagnosis of placental abruption [24], and the most sensitive test to diagnose placental abruption is external fetal monitoring with devices that measure uterine tone and contractility and fetal heart rate [23]. The diagnosis of fetal trauma and placental abruption may be made on contrast enhanced CT performed through the abdomen and pelvis of pregnant trauma patients. For these reasons, it is useful for the radiologist interpreting the CT scan to recognize fetal head injuries and placental abruption in pregnant trauma patients.Fig. 7 Axial scans through the bony pelvis demonstrate an unstable pelvic fracture with posterior pelvic ring disruption.There is a zone 2 fracture of the left sacrum and a fracture of the left obturator ring (arrowheads)     

Percutaneous augmentation of the superior pubic ramus with polymethyl methacrylate: treatment of acute traumatic and chronic insufficiency fractures

The injection of polymethylmethacrylate (PMMA) is a minimally invasive image-guided procedure that is typically used to treat vertebral body fractures due to osteoporosis or neoplastic involvement. The injection of PMMA into various other locations including the sacrum, acetabulum, pedicles, femur and tibia has been reported previously, and these procedures have, overall, been highly effective at alleviating pain and discomfort. Although the injection of PMMA into the vertebral body is a very common procedure that has been performed for over 2 decades for the percutaneous treatment of vertebral body fractures, the percutaneous injection of PMMA has not been reported in the English literature as treatment for superior pubic ramus fractures. We report the percutaneous treatment of an acute superior pubic ramus fracture and of a chronic insufficiency fracture of the superior pubic ramus using a parasymphyseal approach to access the region of injury.     

Hemophiliac pseudotumor of the sacrum

Although the pelvis is a common site for hemophiliac pseudotumors, involvement of the axial skeleton, such as the spine and sacrum, is rare. A rare case of hemophiliac pseudotumor arising from a healed fracture of the sacrum is reported. Findings of plain radiographs, CT, and radionuclide bone scan may simulate tumors of neural origin, but the heterogeneity of MRI is suggestive of hemophiliac pseudotumor.     

Percutaneous sacroplasty: long-axis injection technique

OBJECTIVE: Sacroplasty, or the injection of percutaneous polymethyl methacrylate into a sacral insufficiency fracture, has been previously described using needle placement in the short axis of the sacrum. We describe a new technique of needle placement along the long axis of the sacrum. CONCLUSION: This approach is easier to perform and results in improved cement distribution along the length of the sacral ala.     

One-Stage Percutaneous Treatment in a Patient with Pelvic and Vertebral Compression Fractures

An active 38-year-old patient presenting a vertebral compression fracture associated with a pelvic fracture was treated in one stage with CT-guided fixation of the sacrum and kyphoplasty. This treatment decreased the pain, restored the vertebral height, and enabled the patient to be ambulatory. The main advantage of this double approach was to shorten the hospital stay and the nonworking period.     

Acute plain anterioposterior radiograph of the pelvis is not useful in detecting fractures of iliac wing and os sacrum: a prospective study of 73 patients using CT as gold standard

Conflicting opinions exist to what extent interpreters of an acute anterioposterior (AP) radiograph of the pelvis underdiagnose pelvic injury. We have prospectively evaluated the usefulness of a plain AP radiograph of the pelvis in detecting injuries, using CT as the gold standard. Seventy-three haemodynamically stable blunt trauma patients, who had an AP radiograph of the pelvis and an abdominopelvic CT as part of their initial imaging evaluation, were included. There were 14 women and 59 men, with a mean age of 30 (3-61) years. Two senior radiologists, with special interest in CT examinations evaluating trauma, reviewed the radiographs and a month later the CT scans, blinded and independently. Usefulness index of the plain AP radiograph of the pelvis in detecting specific injuries was calculated using CT as the gold standard. A radiograph is regarded as useful if the usefulness index is 0.35 or more. The usefulness index for a plain AP radiograph of the pelvis for detecting a fracture of iliac wing and os sacrum was 0.25 and 0.01, respectively. An acute AP radiograph of the pelvis is not useful in detecting a fracture of iliac wing or os sacrum.     

Role of MRI in the diagnosis of insufficiency fractures of the sacrum and acetabular roof

 Objective. To review the risk factors and the radiological appearance of insufficiency fractures of the sacrum and acetabular roof. Design and patients. Twenty patients with sacral and acetabular roof insufficiency fractures were reviewed retrospectively. There were 16 women (80%) and 4 males (age range 48–86 years, excluding an 8-year-old boy). Thirteen patients had a known tumour, and nine had received pelvic irradiation. All patients, except one who was asymptomatic, presented with low back or hip pain. In patients with a known tumor, metastases were suspected. Plain radiography (20), bone scintigrams (16), MR examinations (20), and bone densitometry (14) were performed. Nine patients also each had a CT scan. Results and conclusions. In three cases the CT scan performed 10–25 days after onset of symptoms was interpreted as normal. MR examination performed a few days after the CT scan showed in each of these three patients a fracture line with a band of edema. Scintigraphy was very sensitive, but the H-shaped pattern of sacral uptake, specific for an insufficiency fracture, was detected in only three of 16 cases. The earliest MR sign was medullary edema, seen as early as 18 days after the onset of symptoms. On spin echo (SE) T1-weighted images (T1WI), the hypointense signal of edema could mask a fracture line. On SE T2WI the fracture line could be detected within the hyperintense edema (10 of 17 patients with examinations including SE T2WI). However, in four patients a fracture of the sacrum was not seen on T2WI, these having been obtained in the axial plane. For this reason, intravenous gadolinium was injected, revealing a fracture line in 12 of 14 examinations, or fat suppression sequences were performed, revealing a fracture line in five of five cases. The total number of fractures detected was 17 [15 fractures of the sacrum (bilateral in 10 cases) and two of the acetabular roof]. At a later stage, the edema resolved and the fracture was clearly seen. The two cases of fracture of the acetabular roof were easily recognized at MRI, particularly in the sagittal plane.     

Spontaneous fracture of the sacrum due to "insufficiency". An overlooked cause of low lumbago in elderly women

A case of insufficiency fracture of the sacrum is reported. These fractures usually occur in elderly women and are secondary to various conditions, mainly postmenopausal or steroid-induced osteoporosis and radiation therapy. They are often overlooked or confused clinically and radiographically with metastatic disease. Findings on plain films are often subtle. Radionuclide bone scan shows a characteristic H or butterfly shaped pattern of increased uptake in the sacral alae. The diagnosis is confirmed by conventional tomograms or CT which show the fracture always surrounded by prominent sclerosis.     

Fatigue fracture of the sacrum: a case report

We report a patient with a stress fracture in the sacrum. This may be a cause of hip or back pain. In contrast to typically bilateral insufficiency fractures, fatigue fractures are usually unilateral and the appearances are not diagnostic on scintigraphy. As the plain film findings may be subtle and overlooked, computed tomography is more specific in delineating a sclerotic vertical fracture parallel to the sacroiliac joint. Recognition of the characteristic radiographic pattern in sacral fatigue fractures can avoid incorrect diagnosis and unnecessary tests or treatment.     

F-18 FDG PET/CT findings in postradiation pelvic insufficiency fracture

We retrospectively identified eight patients who underwent F-18 FDG PET/CT and had diagnostic findings of postradiation pelvic insufficiency fracture. The fractures had a median SUV_max of 2.5 (range, 1.6 to 6.0) and were initially interpreted as possible metastases in six patients. A new bone lesion developing in the sacrum, pubic ramus, or acetabulum after radiation for pelvic malignancy is likely to be a postradiation pelvic insufficiency fracture, even if associated with increased FDG uptake at PET.     

Coronal oblique turbo STIR imaging of the sacrum and sacroiliac joints at routine MR imaging of the lumbar spine

The objective of the study was to evaluate the clinical impact of coronal oblique imaging of the lumbrosacral junction and the sacrum at initial presentation for MR imaging of the lumbar spine in patients presenting with low back pain or sciatic pain. Two hundred and sixty consecutive patients attending for MRI of the lumbar spine underwent simultaneous coronal oblique turbo short tau inversion recovery (STIR; TR 2500, TE 40, TI 150, echo train length 7, number of scan acquisitions 2) imaging of the sacrum and the sacroiliac joints with a field of view of 30-cm and 3-mm slices (acquisition time 3 min and 20 s). Images were reviewed by two experienced radiologists to determine the cause of back pain, with and without images of the sacrum and sacroiliac joints. The added value of the additional sequence was assessed. Correlation was made with surgery, response to nerve root injection or clinical follow-up at 3 months. Subgroup analysis was performed to determine if patient stratification according to sex or symptoms would be useful. In total, in 19 of 260 patients (7.3%), abnormalities were identified at coronal STIR imaging. In 7 of 260 patients (2.7%), pathology was identified in the sacrum thought to account for back pain, altering the diagnosis made on the standard sequences. These diagnoses were sacroiliitis (n=2), sacral stress fracture (n=1), degenerative sacroiliac joints (n=1), degenerative accessory articulation between the lumbar spine and the sacrum (n=1), Tarlov cyst of nerve root (n=1) and retroverted uterus causing sciatic pain (n=1). Patient stratification according to sex or the presence or absence of sciatic symptoms was not useful in predicting the added benefit of the additional sequence. Routine coronal STIR imaging of the sacrum as part of lumbar spine MRI improves assessment of patients presenting with low back pain or sciatica in only a small number of patients.     

Percutaneous treatment of insufficiency fractures

Insufficiency fractures of the pelvis, sacrum, spine, and long bones are painful, debilitating, and are common consequences of osteoporosis. Conventional treatment for these fractures varies from conservative therapy to surgery with plate and screw fixation. The former fails to address the underlying problem of fracture and frequently does not alleviate symptoms, while the latter is invasive and not always possible in older populations with low bone density and numerous co-morbidities. Osseous augmentation with polymethylmethacrylate (PMMA) has been used for over two decades to treat fractures related to osteoporosis, but has not been commonly used to treat fractures outside of the vertebral bodies. Osseous augmentation with PMMA is an image-guided procedure and various techniques have been utilized to treat fracture in different locations. We describe various techniques for image-guided osseous augmentation and treatment of insufficiency fractures with bothPMMA and allograft bone for fractures of the pelvis including sacrum, acetabulum, pubic symphysis, pubic rami ilium; appendicular skeleton including distal radius, proximal femur, and vertebral body. We also describe the potential risks and complications associated with percutaneous treatment of insufficiency fractures and techniques to avoid the pitfalls of the various procedures. We will present the process for patient follow-up and data regarding the pre- and postprocedure pain response in patients undergoing treatment for pelvic insufficiency fractures.