Sacral insufficiency fractures. Spectrum of radiological features

Posterior pelvic ring involvement detected with CT taken within a week of admission in acute fragility fractures of the pelvis (FFP) does not predict failure of conservative treatment: a retrospective cohort study

BACKGROUND

Acute low energy pubic rami fractures in the elderly receive primarily conservative treatment. There is debate to what extent posterior ring involvement, which is detected superiorly by CT compared to X-ray, has an impact on outcome and may require modified treatment. We want to demonstrate if posterior ring involvement has an influence on different types of outcome in primarily conservatively treated acute FFP, questioning the usefulness of early CT. Additionally we analysed the early fracture pattern in cases where conservative treatment failed with need for secondary surgery.

METHODS

A retrospective cohort study of 155 consecutive patients, recruited between 2009 and 2016, aged over 65 years diagnosed with an acute LE-PFr on X-ray at the emergency department of a single, level-one trauma centre and receiving an early CT. A set of outcome parameters was compared between patients with an isolated pubic rami fracture (CTia) and patients who had a combined posterior pelvic ring fracture (CTcp).

RESULTS

There were 155 patients of whom 85.2% were female with a mean age of 83 years. 76.8% of patients living at home returned home and 15.5% moved to a nursing home. Mortality rate during hospitalisation was 6.4% and 14.8% at one year post-trauma. Secondary fracture displacement occurred in 22.6%. Secondary surgery was performed in 6 cases (3.9%). Median hospitalisation length of stay was 21 days (range 0 to 112 days). There was no significant association between the subgroups and change in residential status (p = 0.65), complications during hospitalisation (p = 0.75), mortality rate during admission (p = 0.75) and at 1 year (p = 0.88), readmission within 30 days (p = 0.46) and need for secondary surgery (p = 0.2). There was a significant increased median length of stay (p = 0.011) and rate of secondary displacement (p = 0.015) in subgroup CTcp. Secondary displacement had no impact on in-hospital complications (p = 0.7) nor mortality rate during admission (p = 0.79) or at 1 year (0.77). Early CT in patients who underwent secondary surgery showed stable B2.1 lesions in 4 of 6 cases.

CONCLUSIONS

Our data suggest that early CT in patients with conservatively treated acute LE-PFr in order to detect posterior lesions, has limited value in predicting failure of conservative treatment.

Additional clinical value of routine CT imaging in fragility fractures of the pelvis: a prospective cohort study (ARTIFACT)

PURPOSE

Additional CT imaging for fragility fractures of the pelvis (FFP) has a high detection rate for concomitant posterior ring fractures (cPRFs). However, the clinical value of routine additional CT imaging is unknown. This study aimed to determine the additional clinical value of routine CT imaging by changes in treatment policy and to establish the predictive value of pain localized around the sacroiliac joint (SIJ) for cPRFs.

METHODS

A prospective cohort study was conducted in a single teaching hospital in the Netherlands between November 2019 and November 2020. Patients were included if they were ≥ 65 years and had a (suspected) FFP on the pelvic radiograph. All patients underwent additional CT imaging. Changes in treatment policies ((possible) surgery, restrictive weight-bearing, hospital admission and outpatient follow-up) after CT imaging were registered.

RESULTS

Fifty-one patients (44 female) were included with a mean age of 80.6 years. Routine CT imaging revealed an additional cPRF in 27 patients (53%). A change in treatment occurred in 29 patients (57%), of which 7 (12%) were managed either surgical or with restrictive weight-bearing. The presence of pain around the SIJ had a sensitivity of 89% and specificity of 61% for detecting a cPRF.

CONCLUSION

Routine additional CT imaging has few direct therapeutic consequences with regards to surgical management or restrictive weight-bearing. These findings may be altered when considering a lower threshold for surgical intervention. The presence of pain around the SIJ was highly predictive for a clinically relevant cPRF.

TRIAL REGISTRATION

NL8011 on 02-09-2019.

ASSERT (Acute Sacral inSufficiEncy fractuRe augmenTation): Perceptions in the Assessment and Treatment of Pubic Rami and Sacral Fragility Fractures Amongst Healthcare Professionals in Geriatric Medicine and Surgery-A Qualitative Study

Background:

Pubic rami fragility fractures are common in older people and result in significant morbidity and increased mortality. Co-existing fractures of the sacrum are common, but routinely missed. The aim of the study was to explore the perceptions in the assessment and treatment of pubic rami and sacral fragility fractures amongst healthcare professionals.

Methods:

We interviewed 14 participants about their experience in the assessment and treatment of patients presenting with pubic rami fragility fractures. Data was analyzed using an inductive thematic approach.

Results:

The majority of patients presenting with a pubic rami fragility fracture were managed by geriatricians. However, many of the geriatricians were not aware that these fractures have a high association with co-existing sacral fragility fractures. Furthermore, they were not aware of the limitations of standard x-ray imaging, nor of the potential benefits of surgical intervention for sacral fragility fractures. Spinal surgeons recommended that early, more specialist imaging in patients with pubic rami fragility fractures failing to mobilize, would change clinical management, if found to have a coexisting sacral fragility fracture, amenable to surgical intervention.

Conclusions:

The awareness, assessment and management of sacral fragility fractures in patients presenting with pubic rami fragility fractures is poor amongst healthcare professionals in geriatric medicine. Spinal surgeons in this study advocate early further imaging and surgical intervention in patients confirmed to have a concomitant sacral fragility fracture who are failing to mobilize.

[Sacred sacrum!]

L'ostéolyse post-fracturaire du sacrum est une entité radiologique rare mimant une pathologie grave. Nous en rapportons une observation. Notre patiente a été perdue de vue après que l'indication de biopsie soit retenue, et elle n'a reconsulté qu'après 4 mois. Au moment de la réalisation des coupes de repérage précédant la biopsie, nous avons constaté un changement d'aspect de la lésion associant une image linéaire (correspondant au trait de fracture) à une condensation des berges. L'évolution était bonne, sous repos, après 6 mois de recul. Notre cas illustre l'aspect atypique de l'imagerie et les difficultés diagnostiques qui s'y associent. La particularité de notre patiente est que sa symptomatologie était masquée par un conflit disco-radiculaire avec la racine L5 droite et que l'ostéolyse sacrée était de découverte fortuite à la tomodensitométrie.

Outcome of pubic rami fractures with or without concomitant involvement of the posterior ring in elderly patients

INTRODUCTION

Pubic rami fractures are common fractures in a growing osteoporotic geriatric population. Concomitant posterior ring fractures (cPRF) are often found when properly looked for. The pain and consequent immobilization leaves this vulnerable patient group at risk for complications. Conservative therapy is usually sufficient, but with cPRF's surgery can be indicated. Although previous studies have pointed out that mortality rates are high, longer term morbidity outcomes are lacking. This study aims to further establish the longer term consequences of these fractures. Risk factors will be identified for complications, also addressing the possible differences between patients with or without a cPRF.

METHOD

Retrospective analysis of patients aged over 65 years sustaining a pubic rami fracture in the North-West Hospital Group Alkmaar combined with a survey to establish risk factors for morbidity and mortality after 6 months' post trauma. Multiple logistic regression analysis was used to identify risk factors.

RESULTS

117 patients matched inclusion criteria with a median age of 83 and of which 86% was female. 23 cPRF's were identified. Significant deterioration in ambulation and independency was found. 34% was institutionalized at discharge. 49% lost their independent mobility status and 40% of the patients did not experience a full recovery. One-year mortality rate was 23%. Patients with a cPRF had a significant higher complication rate (44 vs 18% p = 0.02), but mortality and other morbidity outcomes did not statistically differ. The strongest predictor for 1-year mortality was complications during admission and a dependent ambulatory status (OR 5.2 and 4.1 respectively).

CONCLUSION

Pubic fractures with or without involvement of the posterior pelvic ring in patients aged over 65 have a significant impact on mobility and independency. Mortality rates are similar to hip fracture patients. Careful evaluation of every patient's mobility status is necessary to identify patients at risk for complications and determine their future health care needs. Future studies are needed to achieve consensus on diagnostic and treatment protocols and identify ways to decrease the significant impact of this injury.

Sacral Insufficiency Fractures: Recognition and Treatment in Patients with Concurrent Lumbar Vertebral Compression Fractures

INTRODUCTION

In reviewing a larger group of osteoporotic vertebral compression fractures (VCFs), we found that the overall incidence of sacral insufficiency fractures (SIFs) is higher than commonly reported values. This is especially seen in patients with previous or concurrent lumbar VCFs and also in a subgroup that had lumbar stenosis or hip arthroplasty. The altered biomechanics due to associated lumbar stenosis or hip arthroplasty lead to increased mechanical stress on already weakened and deficient sacral alae, which are more vulnerable to osteoporotic weakening than other parts of the sacrum.

MATERIALS & METHODS

We studied an overall population of patients with VCF seen clinically and separated the patients into the following groups: patients not previously treated, patients treated with vertebroplasty or kyphoplasty at one or more levels, and patients diagnosed with sacral fractures and treated with vertebroplasty or kyphoplasty. We wanted to see if a pattern existed among the patients who had sacral symptoms, were diagnosed with sacral insufficiency fractures, and subsequently underwent sacroplasty.

RESULTS

In a review of 79 consecutive patients, over a 24-month period, with VCF who underwent surgical treatment, there were 10 patients who also had sacral insufficiency fractures. Four of the patients had sacral insufficiency fractures without VCF. None of the patients with sacral insufficiency fractures were on treatment for osteoporosis at the time of diagnosis. The following symptoms indicated SIF: lower sacral pain (n = 10), buttock pain (n = 7), lateral hip pain (n = 5), and groin pain radiating to the thigh (n = 4). The average time to diagnose SIF was two months after the onset of pain.

CONCLUSIONS

Sacral insufficiency fractures are a frequent cause of both acute and chronic pain; however, they are often missed by the majority of physicians. The frequency of undetected sacral fractures is high. This is due to a number of potential pitfalls, which include both subjective and objective reasons: the patient presenting with vague symptoms, the physician only performing a physical examination of the lumbar spine, and the physician ordering the inadequate standard lumbosacral radiographs, computed tomography (CT), or magnetic resonance imaging (MRI), as well as automatically relating the pain and other symptoms to preexisting MRI findings that are very commonly found in the elderly population. All of these pitfalls lead to SIFs being overlooked.

Postpartum Sacral Stress Fracture: An Atypical Case Report

Sacral stress fractures are common in elderly people. However, sacral stress fracture should be always screened in the differential diagnoses of low back pain during the postpartum period. We present a case of sacral fracture in a thirty-six-year-old woman with low back pain and severe right buttock pain two days after cesarean section delivery of a 3.9 Kg baby. The diagnosis was confirmed by MRI and CT scan, while X-ray was unable to detect the fracture. Contribution of mechanical factors during the cesarean section is not a reasonable cause of sacral fracture. Pregnancy and lactation could be risk factors for sacral stress fracture even in atraumatic delivery such as cesarean section. Our patient had no risk factors for osteoporosis except for pregnancy and lactation. Transient or focal osteoporosis is challenging to assess and it cannot be ruled out even if serum test and mineral density are within the normal range.

Risk factors associated with sacral stress fractures: a systematic review

OBJECTIVES

The objective of this study was to examine and identify risk factors associated with the development of sacral stress fractures in order to improve diagnosis in clinical practice.

METHODS

Electronic search strategies in PubMed, CINAHL, Scopus, and SPORTDiscus were combined with a hand search to identify articles for inclusion. Studies were considered if they described patient cases in which imaging confirmed diagnosis of a sacral stress fracture, and the diagnosis included whether the fracture was a sacral insufficiency or sacral fatigue stress fracture.

RESULTS

In those that developed sacral insufficiency fractures, the risk factors that were most prevalent included osteoporosis, pelvic radiation therapy, rheumatoid arthritis, long-term corticosteroid therapy, and postmenopausal, each with a prevalence of 100%. Risk factors with 100% prevalence in those diagnosed with sacral fatigue fractures included recent increase in training intensity and deficient diet.

DISCUSSION

A pattern of signs and symptoms are consistent among subjects with sacral stress fractures. Patients being unsuccessfully treated for low-back and buttock pain who fit the risk factor profiles for sacral stress fractures should be referred to a physician for further diagnostic workup.

[4-point internal fixator stabilization of a sacral insufficiency fracture]

Sacral insufficiency fractures develop due to a discrepancy between physiological load and load-bearing capacity. Besides osteoporosis as the main predisposing factor, other diseases lead to a loss of the bony elastic resistivity and therefore are able to cause these characteristic bilateral sacral stress fractures. Most patients complain of low back pain and show difficulties in mobilization.The non-operative therapy is based on analgesics and pain-adapted mobilization. Due to the noticeable functional deficit and persistent discomfort, surgery is necessary in many cases. Various operative methods are available, without significant differences regarding stability. We present the case of a 56-year-old man, in whom the progression of B-cell chronic lymphocytic leukemia (B-CLL) led to the development of osteolysis in the posterior pelvic ring and caused a sacral insufficiency fracture. Due to the progressive deterioration of mobilization and the persistent severe pain, we decided to stabilize the posterior pelvic ring. After surgery the patient could be mobilized and the pain was significantly reduced.

Sacral fractures

Sacral fractures are uncommon lesions and most often the result of high-energy trauma. Depending on the fracture location, neurological injury may be present in over 50% of cases. In this article, the authors conducted a comprehensive literature review on the epidemiology of sacral fractures, relevant anatomy of the sacral and pelvic region, common sacral injuries and fractures, classification systems of sacral fractures, and current management strategies. Due to the complex nature of these injuries, surgical management remains a challenge for the attending surgeon. Few large-scale studies have addressed postoperative complications or long-term results, but current evidence suggests that although fusion rates are high, long-term morbidity, such as residual pain and neurological deficits, persists for many patients.

Fragility fractures of the pelvis

Fragility fractures of the pelvis are common and the incidence is increasing with the aging population. The primary risk factor is osteoporosis. Diagnosis is challenging and advanced imaging with computed tomography (CT), bone scintigraphy, and magnetic resonance imaging (MRI) is helpful. These injuries result in significant morbidity, including prolonged hospitalization, immobility, and loss of autonomy in previously active patients. The mortality rate is high, similar to hip fracture patients. This problem is underappreciated and deserves attention. An opportunity exists to improve outcomes with medical and surgical management.

Cauda equina syndrome following sacral fractures: a report of three cases

We report 3 patients with cauda equina syndrome (CES) secondary to a sacral fracture. The difficulty in early diagnosis of CES and the lack of evidence and guidance on treatment are highlighted. When there is a sacral fracture, CES should be suspected. Thorough clinical examination including digital rectal examinations and bladder function quantification is advised. The threshold for performing computed tomography and/or magnetic resonance imaging of the pelvis should be low. Patients should be treated by a multi-disciplinary team with both orthopaedic and neurosurgical input. Further studies are needed to identify the timing and to which patients surgical decompression should be performed.

[Percutaneous iliosacral screw fixation for pelvis insufficiency fracture after implantation of a pedestal cup: case report]

Insufficiency fractures of the sacrum are frequently overlooked injuries especially in postmenopausal women with an osteoporotic bone structure and without a history of significant trauma. Plain radiographs are frequently inadequate in showing insufficiency fractures of the sacrum. Regarding this a fracture of a pubic ramus combined with appropriate clinical symptoms should raise the suspicion of a concomitant sacral injury. Therefore, further investigations including a CT scan are necessary.The case of an osteoporotic female patient with bilateral insufficiency fractures of the sacrum and a fracture of the right superior and inferior pubic ramus 5 weeks after primary total hip arthroplasty and implantation of a pedestal cup due to an intraoperative fracture of the right acetabulum is presented. To ensure early mobilization as well as avoidance of further concomitant morbidities a percutaneous iliosacral screw fixation was performed. This approach has been established as an operative treatment for minimally or non-displaced insufficiency fractures of the sacrum.

Imaging and treatment of sacral insufficiency fractures

SIFs are a common, though often unsuspected, cause of low back pain in the elderly. Although numerous radiographic modalities can be used to diagnose SIFs, bone scintigraphy and MR imaging are the most sensitive. Conservative management involves various combinations of bed rest, rehabilitation, and analgesics. More recently, sacroplasty has emerged as an alternative therapy for the treatment of SIFs, with prospective studies and case reports suggesting that it is a safe and effective therapy. This article reviews the imaging appearance of SIFs and discusses treatment options with a focus on sacroplasty.

Anatomical and biomechanical analyses of the unique and consistent locations of sacral insufficiency fractures

STUDY DESIGN

Correlation of locations of sacral insufficiency fractures is made to regions of stress depicted by finite element analysis derived from biomechanical models of patient activities.

OBJECTIVE

Sacral insufficiency fractures occur at consistent locations. It was postulated that sacral anatomy and sites of stress within the sacrum with routine activities in the setting of osteoporosis are foundations for determining patterns for the majority of sacral insufficiency fractures.

SUMMARY OF BACKGROUND DATA

The predominant vertical components of sacral insufficiency fractures most frequently occur bilaterally through the alar regions of the sacrum, which are the thickest and most robust appearing portions of the sacrum instead of subjacent to the central sacrum, which bears the downward force of the spine.

METHODS

First, the exact locations of 108 cases of sacral insufficiency fractures were catalogued and compared to sacral anatomy. Second, different routine activities were simulated by pelvic models from CT scans of the pelvis and finite element analysis. Analyses were done to correlate sites of stress with activities within the sacrum and pelvis compared to patterns of sacral insufficiency fractures from 108 cases.

RESULTS

The sites of stress depicted by the finite element analysis walking model strongly correlated with identical locations for most sacral and pelvic insufficiency fractures. Consistent patterns of sacral insufficiency fractures emerged from the 108 cases and a biomechanical classification system is introduced. Additionally, alteration of walking mechanics and asymmetric sacral stress may alter the pattern of sacral insufficiency fractures noted with hip pathology (P = 0.002).

CONCLUSION

Locations of sacral insufficiency fractures are nearly congruous with stress depicted by walking biomechanical models. Knowledge of stress locations with activities, cortical bone transmission of stress, usual fracture patterns, intensity of sacral stress with different activities, and modifiers of walking mechanics may aid medical management, interventional, or surgical efforts.

Cauda equina syndrome presentation of sacral insufficiency fractures

INTRODUCTION

Sacral insufficiency fractures are a well recognised cause for low back, buttock and groin pain in the elderly. However, over a 4 year period, four patients have presented with symptoms of cauda equina syndrome, who were found on investigation to have acute sacral insufficiency fracture without any other aetiological spinal abnormality.

PATIENTS AND METHOD

Four patients who presented to the spinal surgeons of our institution with symptoms of cauda equina syndrome were referred for spinal MR. Sagittal and axial T1 and T2 weighted turbo spin echo sequences of the lower thoracic and lumbar spine were performed on all patients. Subsequent studies included MR of the sacrum supplemented where appropriate by CT and technetium MDP bone scintigraphy.

RESULTS

No evidence of a compressive lesion of the lower thoracic or lumbar spine was present in any of the four patients. Dedicated MR examination of the sacrum in these patients revealed unilateral acute insufficiency fractures involving zone 1 from S1 to S3 extending from the sacro-iliac joint to the lateral margin of the sacral foramen. There was no evidence of compression of the sacral nerve roots. The possible mechanism for the symptomatic presentation is discussed.

CONCLUSION

Sacral insufficiency fractures should be excluded in elderly or osteoporotic patients presenting with cauda equina syndrome who have no evidence of compression in the thoraco-lumbar MR studies.

Degenerative Erkrankungen der Wirbelsäule

GOAL

The aim of this article is to describe rare and often unrecognized causes of spinal pain syndromes.

METHOD

Intervertebral disc degeneration frequently appears in early adulthood and can have a symptomatic or asymptomatic course. This article discusses incidence, pathophysiology, imaging, and pain symptomatology involved in the origin of back pain.

RESULTS

Anulus tears are often found in asymptomatic individuals but could be implicated in lumbar pain symptomatology in correlation with the provocative discography. Transient disorders can lead to pseudarthrosis of the iliac bone and to degeneration or to a reactive hypermobility with intervertebral disc degeneration in the level above. Modic type 1 erosive osteochondrosis is characterized by bone marrow edema near the hyaline cartilage end plate, which mostly elicits severe pain and results in serious limitations in everyday activities. The most important differential diagnosis is spondylodiscitis. Schmorl's nodes can exhibit considerable surrounding bone marrow edema that can be mistaken for metastases. A combination of MRI and CT should be employed for the diagnostic work-up of fatigue fracture of the interarticular portion, which is often overlooked due to its location. Synovial cysts of the facet joints can lead to radicular symptoms. Insufficiency fracture of the sacrum is frequently mistaken for metastasis due to intense scintigraphic enhancement and its signal behavior in MRI. CT provides instructive information.

CONCLUSION

Differential diagnosis should include less common causes such as anulus tears, transient disorders, activated Schmorl's nodes, synovial cysts of the facet joints, fatigue fractures of the interarticular portion of the spine and the sacrum and distinguish from metastases in particular.

Symptomatic osteoradionecrosis of pelvic bones in patients with gynecological malignancies-result of a long-term follow-up

The aim of this study was to assess the incidence and risk factors of pelvic fractures as a result of radiation therapy in women with gynecological cancer. We retrospectively reviewed 3530 female patients treated at our institute between 1980 and 1998 with megavoltage radiation with or without brachytherapy for cancer in the pelvic area. Eligible were patients with vulvar, vaginal, cervical, endometrial, and fallopian tube cancer. Median follow-up was 88 months (range 0-240). Emphasis was put on treatment-related and patient-related risk factors. Of the eligible 3155 patients, 15 developed symptomatic bone fracture caused by osteoradionecrosis, which makes an overall incidence of 0.44% The diagnosis was based on anamnesis, clinical course, and X-ray or computed tomography images. Median time of onset was 44 months (range 6-197). All patients had pain as the first symptom. The only independent predictive factor for developing osteoradionecrosis seemed to be preexistent osteoporosis. Other risk factors that are related to osteoporosis include higher age, postmenopausal status, or steroid treatment. We did not find any significant treatment-related predictive factor for pelvic osteoradionecrosis. Patients with osteoporosis are probably at the highest risk for developing osteoradionecrotic fractures after pelvic radiotherapy. More studies are needed to find out other endogenous predictive factors.

An unusual natural history of a L5-S1 spondylolisthesis presenting with a sacral insufficiency fracture

Sacral insufficiency fractures have been described in association with conditions leading to osteoporosis. No association with spondylolisthesis has been described to date. A 60-year-old patient with known lumbosacral isthmic spondylolisthesis presented with exacerbation of symptoms initially thought to be linked to her known spinal pathology. Plain radiography, computer tomography, MRI and bone scan confirmed the presence of a recent sacral insufficiency fracture with anterior angulation. Conservative treatment resulted in improvement of symptoms after 6 months. Care should be taken when considering older patients for more aggressive treatment if they present with exacerbation of back pain and sciatica in the presence of a pre-existing spondylolisthesis. A suspicion of insufficiency fracture should be raised if risk factors exist and further investigations ordered in particular if plain radiography is normal. Lumbosacral fusion might be inappropriate in this setting.

‘Spot the difference’: the importance of recognizing symmetrical trauma

The eye can play tricks on us and optical illusions are commonly used to illustrate the fact that the brain interprets perceived images according to what it ‘expects’ to see. When viewing trauma imaging, we tend to subconsciously use the body’s symmetry as a reference point and therefore symmetrical injuries can easily be overlooked, even when gross. In this article, we will illustrate this phenomenon with examples of imaging from trauma cases and suggest how recognition of typical patterns of injury in addition to knowledge of some common pitfalls in trauma radiology can help us avoid the misinterpretation of bilateral symmetrical abnormalities.

Post-fracture osteolysis of the pubic bone simulating a malignancy: report of a case

Post-fracture osteolysis of the pubic bone is rare. We report a case of a 70-year-old woman with osteoporosis and a history of radiation therapy 2 years earlier. At presentation, she was found to have a bilateral sacral fracture and fractures of both pubic rami on one side. The pain persisted, and follow-up radiographs showed osteolysis of the pubic rami suggestive of metastatic disease. The development of a bony callus within 8 months established the diagnosis of benign osteolysis. About 50 cases of osteolysis at fracture sites have been reported to date, of which about a dozen occurred after radiation therapy. All the patients were elderly women with post-menopausal osteoporosis. Radiation therapy probably further increases the risk in this setting. The possibility of osteolysis at fracture sites in patients with osteoporosis should be borne in mind to avoid unnecessary and burdensome investigations that are costly and cause undue anxiety to the patients. Rest is the only effective treatment.

Sacral Fractures:A Potential Pitfall of FDG Positron Emission Tomography

OBJECTIVE

Positron emission tomography (PET) with FDG is useful for tumor imaging, but false-positive results can occur. The purpose of this study is to describe three oncology patients with sacral fractures in whom FDG uptake in the sacrum increased on PET.

CONCLUSION

Sacral fractures can show increased uptake of FDG on PET. Therefore, correlative cross-sectional imaging is necessary to avoid the erroneous diagnosis of sacral metastases on PET and prevent inappropriate treatment of patients.

Sacral insufficiency fractures: a report of two cases and a review of the literature

Sacral insufficiency fractures (SIF) are a type of stress fracture that occur primarily in postmenopausal women. They were first described in 1982 by Lourie and have since been frequently overlooked as a cause of low back, buttock, or groin pain. We present two cases of SIF to demonstrate the clinical presentation, diagnosis, and treatment of patients with SIF. Both patients were elderly women with complaints of pelvic and low back pain in the absence of significant trauma. Physical examination was significant for marked sacral tenderness. Diagnostic imaging supported the diagnosis of SIF. Both patients underwent early rehabilitation, including early ambulation, and had good functional outcomes. These patients serve to illustrate how conservative treatment yields excellent clinical results in the majority of patients, with most reporting improvement within 1-2 weeks after fracture and complete resolution of symptoms after 6-12 months of treatment.

The controversy surrounding sacral insufficiency fractures: to ambulate or not to ambulate?

Sacral insufficiency fractures are an often unsuspected cause of low back pain in elderly women with osteoporosis who have sustained minimal or no trauma. Many of the references in the literature advocate bed rest initially; however, we support early mobilization, because most of these fractures are stable and require no surgical intervention. With good pain control, patients can begin progressive ambulation with assistive devices in a supervised environment and minimize the complications of immobility.

Pelvic fractures following irradiation of endometrial and vaginal cancers-a case series and review of literature

PURPOSE

To review the induction of pelvic fractures as a result of radiation therapy and to assess their management.

MATERIALS AND METHODS

The charts of patients with endometrial and vaginal cancers irradiated between 1991 and 1995 were reviewed. All patients were treated with megavoltage machines, energy ranging from cobalt to 25 MV photons.

RESULTS

We treated 336 patients, with a median follow-up duration of 28.9 months (range 0-73.3). Sixteen patients had symptomatic pelvic fractures. The 5-year actuarial incidence of symptomatic pelvic fracture was 2.1%. All patients had pain as the first symptom. The median time of onset was 11 months (range 4-46). Imaging studies of 37.5% (6/16) were initially interpreted to be recurrent malignancy. All patients were managed conservatively and nine patients showed radiological evidence of healing over a median time of 13 months (range 2-34). Six patients had specific drug treatment including provera, premarin, calcium supplements, or pamidronate. Of these, five healed. For the ten patients who did not have any specific treatment, only four showed signs of healing at the time of last follow-up. There was a trend toward earlier healing with specific drug treatment (P=0.11).

CONCLUSIONS

Fractures can easily be mistaken for metastatic lesions (37.5% in this series) which might be treated with further irradiation. Although not statistically significant, there was a trend towards early healing with drug therapy. More studies are required to generate quantitative data for dose-response relationships and to evaluate the effect of drug therapy on the healing of such fractures.

A case of parasymphyseal and associated insufficiency fractures of pubic rami in a patient with mixed connective tissue disease

Parasymphyseal insufficiency fractures are uncommon. Furthermore, none have been reported in systemic rheumatic diseases other than rheumatoid arthritis. In this article we report on parasymphyseal insufficiency fractures in a patient with mixed connective tissue disease.

Transient bone marrow oedema: a variant pattern of sacral insufficiency fractures

A 71-year-old woman presenting with severe low back pain was found to have a large oval area of increased sacral uptake on Tc-99m MDP scan, with corresponding T1-hypointense and T2-hyperintense areas on magnetic resonance (MR) images, highly suggestive of malignancy. Open biopsies showed only callus formation. The patient responded clinically to conservative measures, with twice-repeated follow-up Tc-99m MDP and MR scans documenting resolution of transient bone marrow oedema. We suggest that this form of marrow oedema represents a variant pattern of sacral insufficiency fractures.

Vacuum phenomena in the sacroiliac joints and in association with sacral insufficiency fractures. Incidence and significance

STUDY DESIGN

The computed tomography scans of two groups of patients of similar age and sex, with and without sacral insufficiency fractures, respectively, were assessed retrospectively.

OBJECTIVES

To determine the incidence of sacroiliac joint vacuum phenomena in individuals with and without sacral insufficiency fractures and to evaluate a possible association between vacuum phenomena and sacral insufficiency fractures.

SUMMARY OF BACKGROUND DATA

The occurrence of vacuum phenomena is well recognized in the vertebra, but not in the sacroiliac joint. Gas foci in sacral insufficiency fractures recently has been reported. It has been suggested that the presence of vacuum phenomena may aid in the diagnosis of these fractures.

METHODS

The computed tomography scans of 28 female patients with sacral insufficiency fractures and of 60 age- and sex-matched control individuals were evaluated.

RESULTS

In the group with sacral insufficiency fractures, vacuum phenomena were detected in 69.2% of patients and in 63.5% of sacroiliac joints, with sacroiliac joint-related osteophytes found in 19.2% of patients. Very similar incidences were demonstrated in the control group. There was no correlation between sacroiliac joint osteophytes and vacuum phenomena in either group. The vacuum phenomenon was detected within the sacral insufficiency fracture in only one patient, in whom the fracture communicated with the adjacent sacroiliac joint.

CONCLUSION

Vacuum phenomena are frequently found in the sacroiliac joints of elderly women, and their presence is of no diagnostic significance when demonstrated in patients with sacral insufficiency fractures.

Sacral and pubic insufficiency fractures after irradiation of gynaecological malignancies

The association between radiotherapy and insufficiency fractures of the pelvis has not been well documented. Fractures were detected over a 2-year period in eight postmenopausal women who had previously undergone irradiation for gynaecological malignancies. Six of these patients also had local soft tissue complications, such as rectal bleeding and haematuria, in addition to severe low back, buttock or groin pain, caused by the fractures. Plain radiographs were unhelpful in the detection of sacral insufficiency fractures, but showed the pubic fractures in five patients. Diagnoses of insufficiency fractures were made on bone scintigraphic demonstration of the typical 'H' shaped sacral pattern, or the combination of the partial 'H' pattern together with public uptake. Computed tomography was useful for confirmation of insufficiency fractures in doubtful cases. Recognition of insufficiency fractures helps to avoid the pitfalls of misdiagnosing tumour recurrence or bony metastases.