The role of MRI in the diagnosis of proximal femoral fractures in the elderly

Occult Intertrochanteric Fracture Detected by Bone Scan Imaging: A Case Report

Femoral intertrochanteric fractures can be occult and not visible on plain radiographs, even when there is a high clinical suspicion. This case study reports an occult intertrochanteric fracture that was diagnosed using a bone scan rather than an MRI or CT scan. A 91-year-old woman arrived at the emergency room with a complaint of left hip pain after slipping at home. Clinical examination revealed tenderness, mild swelling, limited range of motion, and an inability to bear weight. Radiographs and CT scans of the hip and pelvis showed no evidence of a fracture. An MRI was planned, but the patient's agitation resulted in improper images. Consequently, a bone scan identified an ill-defined focal area with slightly increased activity, consistent with an intertrochanteric femur fracture. In such challenging scenarios, bone scans can still serve as an alternative diagnostic tool, aiding in clinical decision-making.

An Umbrella Review and Updated Meta-Analysis of Imaging Modalities in Occult Scaphoid and Hip and Femoral Fractures

Background: Occult fractures may cause multiple morbidities. If occult fractures were detected earlier, complications may be preventable. This umbrella review and updated meta-analysis will aim to evaluate the use of imaging modalities in detecting occult scaphoid and hip fractures. Methods: The protocol for this study is available in the International Prospective Register of Systematic Reviews (PROSPERO) database (CRD42024525388). The literature search started and ended on 17 March 2024. We searched seven academic databases: MEDLINE, Cochrane Library, Pubmed, Science Direct, Google Scholar, WHO International Clinical Trials Registry Platform, and The Joanna Briggs Institute (JBI) database. The meta-analysis was conducted with the STATA program using the "midas" command. Results: There are four systematic reviews evaluating occult hip and femoral fractures with 6174 patients and two reviews evaluating occult scaphoid fractures with 1355 patients. The prevalence of occult scaphoid fracture and occult hip and femoral fractures is 23.87% (95% CI 18.25-29.49) and 44.8% (95% CI 39.38-51.4), respectively. Magnetic resonance imaging (MRI) had the best posterior probability of positive likelihood ratio (LR+) with 95% and 96% and negative likelihood ratio (LR-) with 0.15% and 1% for both occult scaphoid and hip fractures, respectively, assuming a 25% baseline. MRI could both confirm and exclude occult hip fractures while it can only confirm occult scaphoid fractures. Bone scans are inappropriate for either type of occult fractures The level of evidence for occult scaphoid fracture is weak while it is suggestive for occult hip fractures. Conclusion: The findings strengthen the use of MRI after an initially negative radiograph fracture for occult hip and femoral fractures, with a CT scan as a viable second option.

Dual-Energy Computed Tomography and Beyond: Musculoskeletal System

Traditional monoenergetic computed tomography (CT) scans in musculoskeletal imaging provide excellent detail of bones but are limited in the evaluation of soft tissues. Dual-energy CT (DECT) overcomes many of the traditional limitations of CT and offers anatomical details previously seen only on MR imaging. In addition, DECT has benefits in the evaluation and characterization of arthropathies, bone marrow edema, and collagen applications in the evaluation of tendons, ligaments, and vertebral discs. There is current ongoing research in the application of DECT in arthrography and bone mineral density calculation.

Application of Scanning Magnetic Resonance Imaging in the Diagnosis of Prenatal Placental Implantation and Related Care

In order to solve the problem of scanning magnetic resonance imaging in prenatal diagnosis, the application and research of placental implantation have been proposed. Placental implantation is a serious obstetric emergency, which refers to the abnormal attachment of placental villi caused by the dysplasia of decidual basal layer. A study from the United States showed that the incidence of placental implantation in pregnant women during delivery increased from 9.9/30000 to 11.6/20000 from 2006 to 2019, which increased the risk of prenatal or postpartum hemorrhage, hysterectomy, stillbirth, abdominal organ injury, and so on. Clinically, patients can show severe prenatal or postpartum hemorrhage, postpartum placental retention, uterine perforation, and secondary infection, which may seriously endanger the lives of pregnant mothers and fetuses. Placental implantation can also have no obvious symptoms before delivery, which leads to insufficient prenatal diagnosis. Gielchinsky retrospectively studied 410 patients with placental implantation and found that only 9 patients were detected by prenatal ultrasound or magnetic resonance imaging (MRI), and the detection rate was only 6.6%. It can be seen that if the accurate diagnosis of placental implantation can be made before prenatal or symptoms appear, clinical intervention treatment can be carried out in time to reduce the probability of hysterectomy and improve the examination means of patients' prerecovery. At present, studies at home and abroad suggest that it has good clinical application value and research prospect in the clinical diagnosis of placental implantation.

Cost-Effective Analysis of Dual-Energy Computed Tomography for the Diagnosis of Occult Hip Fractures Among Older Adults

OBJECTIVE

Early and accurate diagnosis of hip fractures minimizes morbidity and mortality. Although current guidelines favor magnetic resonance imaging (MRI) for the diagnosis of occult hip fractures, a new technology called dual-energy computed tomography (DECT) seems an effective alternative. This article investigates a potentially cost-effective strategy for the diagnosis of occult hip fractures in older adults in Singapore.

METHODS

A decision tree model was developed to compare costs from a payer's perspective and outcomes in terms of quality-adjusted life-years (QALYs) of different imaging strategies for diagnosing occult hip fracture, comparing MRI with DECT supplementing single-energy computed tomography (SECT) and SECT alone. Model inputs were obtained from local sources where available. Sensitivity analyses are performed to test the robustness of the results.

RESULTS

The MRI strategy was dominated by the DECT strategy, whereas DECT supplementing SECT provided 0.30 more QALYs at an incremental cost of SGD106.41 with an incremental cost-effectiveness ratio of SGD352.52 per QALY relative to SECT alone. DECT seemed a cost-effective strategy at a willingness-to-pay threshold of SGD50 000 per QALY.

CONCLUSION

DECT supplementing SECT is a cost-effective imaging strategy to diagnose occult hip fractures among older adults in Singapore and should be included in clinical pathways to expedite timely treatment and considered for reimbursement schemes.

Use of Advanced Imaging for Radiographically Occult Hip Fracture in Elderly Patients: A Systematic Review and Meta-Analysis

Background The overall rate of hip fractures not identified on radiographs but that require surgery (ie, surgical hip fractures) remains unclear in elderly patients who are suspected to have such fractures based on clinical findings. Moreover, the importance of advanced imaging in these patients has not been comprehensively assessed. Purpose To estimate the frequency of radiographically occult hip fracture in elderly patients, to define the higher-risk subpopulation, and to determine the diagnostic performance of CT and bone scanning in the detection of occult fractures by using MRI as the reference standard. Materials and Methods A literature search was performed to identify English-language observational studies published from inception to September 27, 2018. Studies were included if patients were clinically suspected to have hip fracture but there was no radiographic evidence of surgical hip fracture (including absence of any definite fracture or only presence of isolated greater trochanter [GT] fracture). The rate of surgical hip fracture was reported in each study in which MRI was used as the reference standard. The pooled rate of occult fracture, diagnostic performance of CT and bone scanning, and strength of evidence (SOE) were assessed. Results Thirty-five studies were identified (2992 patients; mean age, 76.8 years ± 6.0 [standard deviation]; 66% female). The frequency of radiographically occult surgical hip fracture was 39% (1110 of 2835 patients; 95% confidence interval [CI]: 35%, 43%) in studies of patients with no definite radiographic fracture and 92% (134 of 157 patients; 95% CI: 83%, 98%) in studies of patients with radiographic evidence of isolated GT fracture (moderate SOE). The frequency of occult fracture was higher in patients aged at least 80 years (44%, 529 of 1184), those with an equivocal radiographic report (58%, 71 of 126), and those with a history of trauma (41%, 977 of 2370) (moderate SOE). CT and bone scanning yielded comparable diagnostic performance in the detection of radiographically occult hip fracture (P = .67), with a sensitivity of 79% and 87%, respectively (low SOE). Conclusion Elderly patients with acute hip pain and negative or equivocal findings at initial radiography have a high frequency of occult hip fractures. Therefore, the performance of advanced imaging (preferably MRI) may be clinically appropriate in all such patients. © RSNA, 2020 Online supplemental material is available for this article.

Value of CT to detect radiographically occult injuries of the proximal femur in elderly patients after low-energy trauma: determination of non-inferiority margins of CT in comparison with MRI

PURPOSE

To determine the margins of non-inferiority of the sensitivity of CT and the sample size needed to test the non-inferiority of CT in comparison with MRI.

MATERIALS AND METHODS

During a 2-year period, elderly patients with suspected radiographically occult post-traumatic bone injuries were investigated by CT and MRI in two institutions. Four radiologists analyzed separately the CT and MRI examinations to detect post-traumatic femoral injuries. Their sensitivities at CT (SeCT) and MRI (SeMRI) were calculated with the reference being a best valuable comparator (consensus reading of the MRI and clinical follow-up). ROC analysis followed by an exact test (Newcombe's approach) was performed to assess the 95% confidence interval (CI) for the difference SeCT-SeMRI for each reader. A sample size calculation was performed based on our observed results by using a one-sided McNemar's test.

RESULTS

Twenty-nine out of 102 study participants had a post-traumatic femoral injury. SeCT ranged between 83 and 93% and SeMRI ranged between 97 and 100%. The 95% CIs for (SeCT-SeMRI) were [- 5.3%, + 0.8%], (p^R1 = 0.1250), [- 4.5%; + 1.2%] (p^R2 = 0.2188), [- 3.4%; + 1.1%] (p^R3 = 0.2500) to [- 3.8%; + 1.6%] (p^R4 = 0.3750) according to readers, with a lowest limit for 95% CIs superior to a non-inferiority margin of (- 6%) for all readers. A population of 440 patients should be analyzed to test the non-inferiority of CT in comparison with MRI.

CONCLUSION

CT and MRI are sensitive for the detection of radiographically occult femoral fractures in elderly patients after low-energy trauma. The choice between both these modalities is a compromise between the most available and the most sensitive technique.

KEY POINTS

• The sensitivity of four separate readers to detect radiographically occult post-traumatic femoral injuries in elderly patients after low-energy trauma ranged between 83 and 93% at CT and between 97 and 100% at MRI according to a best valuable comparator including MRI and clinical follow-up. • CT is a valuable alternative method to MRI for the detection of post-traumatic femoral injuries in elderlies after low-energy trauma if a 6% loss in sensitivity can be accepted in comparison with MRI. • The choice between CT and MRI is a compromise between the most available and the most sensitive technique.

Femoral Intertrochanteric Fractures of the Patients in the Emergency Department due to Minor Falls: Special Consideration in the Middle-old to Oldest-old Patients

BACKGROUND

The older population (≥65 years) has rapidly increased in size in recent years. Among them, the middle-to-oldest-old (≥75 years) tend to have a poor health status. Therefore, subdivision and evaluation of older patients with traumatic injury are required. We focused on the risk of femoral intertrochanteric fractures occurring in older adults due to minor falls and compared young-old and middle-to-oldest-old populations.

METHODS

The medical records of patients who visited the emergency center due to hip injuries between March 2017 and March 2019 were retrospectively analyzed. Patients were divided into older adult (≥65 years) and non-older (age 18-64 years) groups; the older adult group was subdivided into young-old (65-74 years), middle-old (75-84 years), and oldest-old (≥85 years) groups. This study investigated the occurrence rate of femoral intertrochanteric fractures and related factors.

RESULTS

The older adult group had a higher incidence of femoral intertrochanteric fractures than that in the non-older adult group (95.3% vs. 4.7%, p<0.001). However, there was no significant difference between young-old and non-older groups (58.8% vs. 41.2%, p=0.145). Middle-old to oldest-old age and osteoporosis were associated with an increased incidence of femoral intertrochanteric fractures (p<0.001, p=0.004).

CONCLUSION

A higher incidence of femoral intertrochanteric fractures from minor falls was found among middle-old to oldest-old patients compared to that in young-old patients. Therefore, physicians should perform more thorough physical examinations and radiograph reading in middle-old to oldest-old patients even if the patients do not complain of pain.

Outcomes of Magnetic Resonance Imaging Detected Occult Neck of Femur Fractures: Do They Represent a Less Severe Injury with Improved Outcomes?

Purpose

Occult hip fractures in the elderly can be missed on standard radiographs and are a known cause of morbidity. These are generally diagnosed on either magnetic resonance imaging (MRI) or computed tomography scan, depending upon local hospital policy. While there is an abundance of literature on hip fractures in general, little is known about the clinical outcome of patients with occult hip fractures. The aim of this study was to review the demographics, injury characteristics, management and clinical outcome of patients diagnosed with occult femoral neck fractures on MRI.

Materials and Methods

Using an existing hospital database, a retrospective analysis of all patients with occult hip fractures diagnosed by MRI scan from 2005 to 2014 was conducted.

Results

Sixty-four patients (23 males and 41 females) were included. The mean duration of hospitalisation was 16 days. A significantly higher percentage of patients were discharged to their pre-existing residence compared to National Institute for Health and Care Excellence (NICE) commissioning guidelines (66% vs. 45%). The 30- and 60-day mortalities were 3% and 10%, respectively. Mortality was lower in patients who underwent internal fixation (n=3/31) compared with those undergoing replacement (hemi/total hip arthroplasty) (n=5/12) (P=0.056).

Conclusion

Patients with occult hip fractures diagnosed on an MRI scan are more likely to be discharged to their pre-existing residence and have lower mortality rates compared to NICE guidelines and National Hip Fracture Database (NHFD).

Segmentation of the proximal femur in radial MR scans using a random forest classifier and deformable model registration

BACKGROUND

Radial 2D MRI scans of the hip are routinely used for the diagnosis of the cam type of femoroacetabular impingement (FAI) and of avascular necrosis (AVN) of the femoral head, both considered causes of hip joint osteoarthritis in young and active patients. A method for automated and accurate segmentation of the proximal femur from radial MRI scans could be very useful in both clinical routine and biomechanical studies. However, to our knowledge, no such method has been published before.

PURPOSE

The aims of this study are the development of a system for the segmentation of the proximal femur from radial MRI scans and the reconstruction of its 3D model that can be used for diagnosis and planning of hip-preserving surgery.

METHODS

The proposed system relies on: (a) a random forest classifier and (b) the registration of a 3D template mesh of the femur to the radial slices based on a physically based deformable model. The input to the system are the radial slices and the manually specified positions of three landmarks. Our dataset consists of the radial MRI scans of 25 patients symptomatic of FAI or AVN and accompanying manual segmentation of the femur, treated as the ground truth.

RESULTS

The achieved segmentation of the proximal femur has an average Dice similarity coefficient (DSC) of 96.37 ± 1.55%, an average symmetric mean absolute distance (SMAD) of 0.94 ± 0.39 mm and an average Hausdorff distance of 2.37 ± 1.14 mm. In the femoral head subregion, the average SMAD is 0.64 ± 0.18 mm and the average Hausdorff distance is 1.41 ± 0.56 mm.

CONCLUSIONS

We validated a semiautomated method for the segmentation of the proximal femur from radial MR scans. A 3D model of the proximal femur is also reconstructed, which can be used for the planning of hip-preserving surgery.

Magnetic resonance imaging for verifying hip fracture diagnosis why, when and how?

INTRODUCTION

Hip fractures are commonly diagnosed by plain radiography. When a patient presents with negative radiographs and high clinical suspicion of fracture, guidelines recommend proceeding with magnetic resonance imaging (MRI) to diagnose the patient. The aim of this study was to assess the use of MRI in diagnosing hip fractures following trauma to the hip and describe clinical outcome after MRI-diagnosed hip fractures. The perspective was to develop new recommendations for MRI use.

MATERIALS AND METHODS

616 patients at a university hospital fulfilled the inclusion criteria of having an MRI scan of the hip following trauma between the years of 2005 and 2014. Data was collected from the patients' medical records.

RESULTS

The annual number of MRIs increased over the ten-year period. Out of 616 MRI scans 228 (37%) showed fracture of the hip with a dominance of trochanteric fractures, 185 (30%) revealed pelvic fracture and 183 (29%) were negative. No patient with acute pelvic fracture had associated fracture of the hip. The main reason to proceed with MRI was a strong clinical suspicion of fracture in patients with negative initial radiographs. Amongst the 228 patients with fracture, 187 (82%) were treated operatively. Of patients with hip fracture, 90 (39%) patients suffered a general complication and 11 (5%) had hip complications. The complication rate of patients with fracture on MRI was compared to that of a cohort of general hip fracture patients at our hospital. No significant difference in twelve months' survival or general complications could be found, but the MRI group had a significantly lower hip complication rate.

CONCLUSION

The diagnosis set by MRI, with high share of pelvic fractures or no fracture, reflects the difficulty in differential diagnosing this group of patients. The rate of occult hip fractures was low and patients with pelvic fractures already known from X-ray did not have additional hip fractures. We found an increase in the annual number of MRIs during the 10-year-period. MRI-diagnosed hip fracture patients do not suffer more complications than the regular hip fracture patient.

The sensitivity of ct scans in diagnosing occult femoral neck fractures

Non-displaced hip fractures can be difficult to diagnose on plain film radiographs. When there is ongoing clinical suspicion of an occult fracture, further imaging is obtained. We investigated the sensitivity of computed tomography (CT) scans in detecting these fractures and the delays to surgery that three-dimensional imaging causes. We identified 78 CT scans performed for possible hip fractures over the past 3 years with the presence and absence of a fracture recorded. Based on subsequent imaging, the accuracy of CT scans was determined. CT scanning yielded sensitivity was 86% and specificity 98% for occult hip fracture (OHF). The median delay to definitive diagnosis was 37h. Our results demonstrate that CT scan does not bear sufficient sensitivity to detect all OHFs. We therefore recommend that MRI should be offered when a fracture is suspected. CT scans should be reserved for when MRI is not available, but a negative scan should be confirmed with subsequent MRI.

A computer-assisted systematic quality monitoring method for cervical hip fracture radiography

BACKGROUND

A thorough quality analysis of radiologic performance is cumbersome. Instead, the prevalence of missed cervical hip fractures might be used as a quality indicator.

PURPOSE

To validate a computer-based quality study of cervical hip fracture radiography.

MATERIAL AND METHODS

True and false negative and positive hip trauma radiography during 6 years was assessed manually. Patients with two or more radiologic hip examinations before surgery were selected by computer analysis of the databases. The first of two preoperative examinations might constitute a missed fracture. These cases were reviewed.

RESULTS

Out of 1621 cervical hip fractures, manual perusal found 51 (3.1%) false negative radiographic diagnoses. Among approximately 14,000 radiographic hip examinations, there were 27 (0.2%) false positive diagnoses. Fifty-seven percent of false negative reports were occult fractures, the other diagnostic mistakes. There were no significant differences over the years. Diagnostic sensitivity was 96.9% and specificity 99.8%. Computer-assisted analysis with a time interval of at least 120 days between the first and the second radiographic examination discovered 39 of the 51 false negative reports.

CONCLUSION

Cervical hip trauma radiography has high sensitivity and specificity. With computer-assisted analysis, 76% of false negative reports were found.

Imaging of Hip Pain: From Radiography to Cross-Sectional Imaging Techniques

Hip pain can have multiple causes, including intra-articular, juxta-articular, and referred pain, mainly from spine or sacroiliac joints. In this review, we discuss the causes of intra-articular hip pain from childhood to adulthood and the role of the appropriate imaging techniques according to clinical suspicion and age of the patient. Stress is put on the findings of radiographs, currently considered the first imaging technique, not only in older people with degenerative disease but also in young people without osteoarthritis. In this case plain radiography allows categorization of the hip as normal or dysplastic or with impingement signs, pincer, cam, or a combination of both.

An Unusual Case of Acl Cyst with Multiple Melon Seed Bodies of the Knee

INTRODUCTION

The cyst of anterior cruciate ligament (ACL) is a known clinical entity, but its association with knee synovitis and melon or rice bodies is not documented.

CASE REPORT

We report a rare case of ganglionic cyst of of the knee in association with diffuse synovitis and multiple melon or rice bodies in a 36 year old male. The case was treated arthroscopically with removal ofthe cyst of ACL and multiple melon seed bodies.

CONCLUSION

Information regarding incidence, treatment, and outcomes for patients with synovial cysts and melon seed bodies is lacking. Arthroscopic examination of joint gives the opportunity to diagnose such rare entity of the joint and also provide minimally invasive effective treatment of such pathology.

Bilateral occult hip fracture

One of the most common acute injuries seen in the emergency department is the hip fracture. This injury is usually diagnosed by plain radiographs, however these fractures are sometimes not obviously apparent. Occult hip fractures present a pitfall for emergency department physicians. We present a case of a patient who sustained bilateral occult hip fractures. We review the epidemiology of the condition, examine what diagnostic studies are available that may help the physician avoid missing the occult hip fracture and what the literature tells us about the utility of each of these modalities. The prognosis of the occult hip fracture along with options for treatment is also discussed.

Magnetic resonance imaging of the hip: poor cost utility for treatment of adult patients with hip pain

BACKGROUND

Although MRI is frequently used to diagnose conditions affecting the hip, its cost-effectiveness has not been defined.

QUESTIONS/PURPOSES

We performed this retrospective study to determine for patients 40 to 80 years old: (1) the differences in hip MRI indications between orthopaedic and nonorthopaedic practitioners; (2) the clinical indications that most commonly influence treatment decisions; (3) the likelihood that hip MRI influences treatment decisions separate from plain radiographs; and (4) the cost of obtaining hip MRI studies that influence treatment decisions (impact studies).

METHODS

We retrospectively assessed 218 consecutive hip MRI studies (213 patients) at one institution over a 5-year interval. Medical records, plain radiographs, and MRI studies were reviewed to determine how frequently individual MRI findings determined treatment recommendations (impact study). The cost estimate of an impact study was calculated from the product of institutional MRI unit cost (USD 436) and the proportion of impact studies relative to all studies obtained either for a specific indication or by an orthopaedic/nonorthopaedic clinician.

RESULTS

Nonorthopaedic clinicians more frequently ordered hip MRI without a clinical diagnosis (72% versus 30%, p < 0.01), before plain radiographs (29% versus 3%, p < 0.001), and with less frequent impact on treatment (6% versus 15%, p < 0.05). Hip MRI most frequently influenced treatment when assessing for a tumor (58%, p < 0.001) or infection (40%, p < 0.001) and least frequently when assessing for pain (1%, p < 0.002). Hip MRI impacted a treatment decision independent of plain radiographic findings in only 7% of studies (3% surgical, 4% nonsurgical). Hip MRI cost was least when assessing for a neoplasm (USD 750) and greatest when assessing undefined hip pain (USD 59,000). The cost of obtaining an impact study was also less when the ordering clinician was an orthopaedic clinician (USD 2800) than a nonorthopaedic clinician (USD 7800).

CONCLUSIONS

Although MRI can be valuable for diagnosing or staging specific conditions, it is not cost-effective as a screening tool for hip pain that is not supported by history, clinical examination, and plain radiographic findings in patients between 40 and 80 years of age.

LEVEL OF EVIDENCE

Level IV, economic and decision analysis study. See Instructions for Authors for a complete description of levels of evidence.

Reunderstanding of garden type I femoral neck fractures by 3-dimensional reconstruction

Garden type I fractures include incomplete fractures and impacted fractures. With advances in scientific technology and medical treatment, certain deficiencies of the Garden classification have become apparent. The authors hypothesized that the incidence of incomplete femoral neck fractures was low and that impacted femoral neck fractures were not undisplaced and stable fractures. A new method was developed to precisely measure the spatial displacement of the femoral head in impacted femoral neck fractures. Between 2008 and 2011, nine hundred sixty-six patients with femoral neck fractures were treated, 48 of whom had Garden type I fractures, as seen on anteroposterior radiographs. Seven fractures were classified as incomplete on radiographs; however, after 3-dimensional reconstruction, 3 were classified as incomplete and 4 as complete fractures. Furthermore, the remaining 41 Garden I fractures that were classified as impacted on radiographs showed large spatial displacement on 3-dimensional reconstruction. The average rotational displacement of the femoral head was 19.29°±10.51°, and the average displacements of the femoral head center and the lowest point of the fovea capitis were 8.76±4.45 and 14.39±8.08 mm, respectively. This study showed that the incidence of incomplete femoral neck fractures was low. Impacted femoral neck fractures showed variable degrees of displacement and were not undisplaced, stable fractures. Garden classification for impacted femoral neck fractures has certain limitations. Impacted femoral neck fractures should be differentiated from Garden type I fractures so clinicians can select appropriate treatments for these fractures.

Investigation of occult hip fractures: the use of CT and MRI

Aim. At present there is no data looking at modern multislice computerised tomography (CT) in the investigation of occult hip fracture. The aim of this study was to retrospectively compare the reports of patients sent for magnetic resonance imaging (MRI) or CT with negative radiographs and a clinical suspicion of a fractured neck of femur. Methods. All patients presenting to the hospital with a clinical suspicion of a hip fracture but initial negative radiographs over a three-year period were included. Patients were either investigated with an MRI scan or CT scan. The presence of a fracture, the requirement for surgery, and any further requirement for imaging were recorded. Results. Over three years 92 patients were included of which 61 were referred for a CT and 31 for an MRI. Thirty-four patients were found to have a fracture. Of these, MRI picked up a fracture in 36% and CT in 38% of referrals. Discussion. Up to 10% of proximal femur fractures may be missed on initial radiographs. Current guidelines state patients should be offered MRI if hip fracture is suspected despite negative hip radiographs. Our findings show that modern multislice CT may be comparable with MRI for detecting occult fracture.

Radiographically occult femoral and pelvic fractures are not mutually exclusive: a review of fractures detected by MRI following low-energy trauma

OBJECTIVES

The purpose of this study was to review the MRI examinations of a large group of low-energy trauma patients in whom pelvic MRI had detected radiographically occult fractures, in order to characterize prevailing fracture patterns and determine how often co-existing proximal femoral and pelvic fractures were observed.

METHODS

All patients having pelvic MRI over 5 years were identified. Word-search software selected 269 MRI reports containing the term ‘fracture’. Further scrutiny identified 168 with diagnosis of fracture. MRI request and imaging record review identified 102 low-energy trauma cases that had MRI for clinical suspicion of fracture despite normal radiographs. Sixty-six cases were excluded for the following reasons: no expressed clinical suspicion of occult fracture; history suggesting high-energy trauma;skeletal co-morbidity hindering acute fracture identification;interval more than 2 weeks between radiographs and MRI. The 102 study MRI examinations, which employed a limited two-sequence protocol, were reviewed. Any fracture that had not been appreciated on radiographs was recorded and characterized as femoral, pelvic, or co-existing femoral and pelvic fractures.

RESULTS

The 102 study cases had a median age of 82 years.The median interval between pelvic radiographs and MRI was 3 days. MRI showed undiagnosed femoral fracture in 48/102 cases (47.1%), sacral fracture in 41/102 (40.2%),and pubic fracture in 55/102 (53.9%). In 11/102 cases(10.8%), MRI showed undiagnosed fractures of both proximal femur and pelvic ring (seven sacral, six pubic bone, two other site fractures). In 10/11 cases with coexisting femoral and pelvic fractures, the femoral fracture was incomplete.

CONCLUSIONS

Limited pelvic MRI found a high prevalence of radiographically occult femoral and pelvic fractures in low-energy trauma patients, with clinical suspicion of fracture despite normal radiographs. Co-existing occult femoral and pelvic ring fractures were commonly observed, and in such cases, the femoral fracture was likely to be incomplete and multiple pelvic fractures were typically present.

The value of T1-weighted coronal MRI scans in diagnosing occult fracture of the hip

A delay in establishing the diagnosis of an occult fracture of the hip that remains unrecognised after plain radiography can result in more complex treatment such as an arthroplasty being required. This might be avoided by earlier diagnosis using MRI. The aim of this study was to investigate the best MR imaging sequence for diagnosing such fractures. From a consecutive cohort of 771 patients admitted between 2003 and 2011 with a clinically suspected fracture of the hip, we retrospectively reviewed the MRI scans of the 35 patients who had no evidence of a fracture on their plain radiographs. In eight of these patients MR scanning excluded a fracture but the remaining 27 patients had an abnormal scan: one with a fracture of the pubic ramus, and in the other 26 a T1-weighted coronal MRI showed a hip fracture with 100% sensitivity. T2-weighted imaging was undertaken in 25 patients, in whom the diagnosis could not be established with this scanning sequence alone, giving a sensitivity of 84.0% for T2-weighted imaging.

If there is a clinical suspicion of a hip fracture with normal radiographs, T1-weighted coronal MRI is the best sequence of images for identifying a fracture.

Objective sound wave amplitude measurement generated by a tuning fork. An analysis of its use as a diagnostic tool in suspected femoral neck fractures

INTRODUCTION

Hip injuries are becoming a more common problem as the elderly population increases and their management represents a significant proportion of health care costs. Diagnosis of a fracture based on clinical assessment and plain films is not always conclusive and further investigations for such occult fractures, such as magnetic resonance imaging (MRI), are sometimes required which are expensive and may be difficult to access. Disruption to the conduction of a sound wave travelling through a fractured bone is a concept that has been used to diagnose fractures.

PATIENTS AND METHODS

In our study we used a tuning fork with frequency of 128 Hz to objectively measure the reduction in sound amplitude in fractured and non-fractured hips. We looked at the feasibility of using this test as a diagnostic tool for neck of femur fractures.

RESULTS

A total of 20 patients was included in the study, using MRI scan as the standard for comparison of diagnostic findings. Informed consent was obtained from the patients. There was a significant difference in the amplitude reduction of the sound waves when comparing normal to fractured hips. This was 0.9 in normal hips, compared to 0.31 and 0.18 in intra-capsular and extra-capsular fractures, respectively. Our test was 80% accurate at diagnosing neck of femur fractures.

CONCLUSION

In conclusion this test may be used as a diagnostic test or screening tool in the assessment of occult hip fractures.

Analysis of initial injury radiographs of occult femoral neck fractures in elderly patients: a pilot study

Diagnosis of occult hip fractures by initial radiographs remains challenging in the emergency department. Previously, the gold standard for accurate diagnosis of occult hip fractures was magnetic resonance imaging. This study used initial radiographs obtained in the emergency department to evaluate specific signs and measurements as diagnostic references for occult femoral neck fractures in elderly patients.Initial negative radiographs were reviewed for 2 groups of patients: a group with occult femoral neck fractures (n=16) and a group without fractures (n=32). Reviews of initial radiographs and all imaging studies were performed by a senior orthopedist (C-C.C.) and a radiologist (H-T.W.). Diagnostic signs included lateral, medial, anterior, and posterior signs; measurements included elevation of the fat pad and external rotation of the femur. The prevalence of occult femoral neck fracture was 3.3%. Initial radiographs of occult femoral neck fractures were not routinely negative; 14 (87.5%) of 16 patients with fractures had at least 1 radiographic sign. Using the positive lateral or posterior sign as the diagnostic reference, the sensitivity was 0.875 and the specificity was 0.906. When elevation of the fat pad was ⩾1.5 mm, the sensitivity was 0.867 and the specificity was 0.857 for the diagnosis of occult femoral neck fracture.The lateral and posterior signs and elevation of the fat pad ⩾1.5 mm on initial radiographs are recommended as diagnostic references for occult femoral neck fracture. These references are clearly defined and may offer important information for all clinicians and radiologists in the emergency department.

Hip avulsion fractures

An avulsion fracture is a separation of a small fragment of a bone cortex at the site of a ligament or tendon attachment. It is commonly seen in adolescent athletes. The mechanism of injury is either a sudden violent muscular contraction or an excessive amount of muscle stretch across an open epiphysis. This may also occur where the bone has been weakened by osteoporosis or local lesion. The common sites of avulsion injuries are the tibial tubercle and the medial epicondyle. However, hip avulsion fractures are not uncommon. They may occur in adolescents, young adults and in elderly people. There are various protocols for management depending on the patient’s age, mechanism of injury and the underlying pathology.

Bone bruise, lipohemarthrosis, and joint effusion in CT of non-displaced hip fracture

BACKGROUND

A suspected occult hip fracture after normal radiography is not uncommon in an elderly person after a fall. Despite a lack of robust validation in the literature, computed tomography (CT) is often used as secondary imaging.

PURPOSE

To assess the frequency and clinical utility of non-cortical skeletal and soft tissue lesions as ancillary fracture signs in CT diagnosis of occult hip fractures.

MATERIAL AND METHODS

All fracture signs (cortical and trabecular fractures, bone bruise, joint effusion, and lipohemarthrosis) were recorded in 231 hip low-energy trauma cases with CT performed after normal or equivocal radiography in two trauma centers.

RESULTS

There were no fracture signs in 110 patients. Twelve of these had a joint effusion. In 121 patients with 46 cervical hip fractures and 75 trochanteric fractures one or more fracture signs were present. Cortical fractures were found in 115 patients. Bone bruise was found in 119 patients, joint effusion in 35, and lipohemarthrosis in 20 patients.

CONCLUSION

Ancillary signs such as bone bruise and lipohemarthrosis can strengthen and sometimes indicate the diagnosis in CT of occult hip fractures. Joint effusion is a non-specific sign.

Occult hip and pelvic fractures and accompanying muscle injuries around the hip

METHOD

We investigated the incidence of occult hip and pelvic fractures and associated muscle injuries around the hip.

PATIENTS

A total of 113 patients aged 60-102 years with suspected hip fracture but negative plain radiographs underwent further examination by magnetic resonance imaging (MRI) within 2 days after an X-ray examination. Coronal and axial T1 and T2 or short tau inversion recovery sequences of MRI of the hip including the sacrum were obtained.

RESULTS

One hundred and two cases (90.2%) had bone or soft-tissue abnormalities and 83 cases (73.5%) had fractures of the hip and/or pelvis. The frequency of hip fracture and pelvic fracture was almost the same. More than half of the patients among those with pelvic fractures sustained occult sacral fractures; therefore, it was important to determine if a sacral fracture was involved when occult hip fracture was suspected. Muscles located at the lateral aspect of the hip, such as gluteus maximus, gluteus medius, gluteus minimus and quadratus femoris, were frequently injured in cases with intertrochanteric and greater trochanter fracture, suggesting that direct impact may be associated with fractures of the trochanteric region. However, hip rotator and adductor muscles such as obturator internus, obturator externus and adductor brevis were commonly injured in cases with pelvic fracture, indicating indirect force mediated by these muscles may be associated with pelvic fracture.

CONCLUSION

Occult hip and pelvic fractures were almost equally seen among 113 cases with suspected hip fracture but were negative on plain radiography. Different patterns of associated muscle injuries in cases of occult hip fracture and pelvic fracture suggest that the mechanism of hip fracture and pelvic fracture is possibly different.

Review article: Magnetic resonance imaging and computed tomography in the diagnosis of occult proximal femur fractures

Electronic databases of MEDLINE, EMBASE, CINAHL, and the Cochrane Library as well as the Google Scholar search engine were used. Studies written in the English language highlighting the use of magnetic resonance imaging (MRI) and computed tomography in diagnosing occult proximal femoral fractures despite negative or equivocal plain radiographs were included. Two reviewers independently extracted data from each article. Raw frequencies for each of the details investigated were calculated. 15 prospective and 7 retrospective studies from 1989 to 2009 were included in this systematic review. A total of 996 patients (mean age, 75 years; standard deviation, 5 years) with suspected occult proximal femur fractures underwent MRI for further assessment. 350 (35%) of the patients tested positive for proximal femoral fractures, of whom 295 (84%) underwent further treatment/surgical interventions. MRI also detected other fractures and soft-tissue injuries. MRI was superior to other imaging modalities in diagnosing occult proximal femoral fractures and should be performed within 24 hours of injury. Early diagnosis and management may avoid substantial displacement and complications, and improve overall mortality and morbidity.

Clinical characteristics and long-term mortality of occult hip fracture elderly patients

BACKGROUND AND OBJECTIVE

Occult hip fractures (OHF) occur in a minute population of patients. Diagnosis is made via magnetic resonance imaging (MRI) or alternatively via bone scan. Very little is known about the clinical characteristics of OHF patients. Our aim was to characterize the clinical and long-term survival of OHF in elderly patients and to determine if a certain subgroup of patients would benefit from an MRI investigation following normal or equivocal radiography.

METHODS

Twenty-nine OHF patients diagnosed by a bone scan during 1995-2004 were compared with a control group of 94 randomly chosen hip fractured patients diagnosed by plain radiography in the same hospital and during the same period.

RESULTS

Mean age, women/men ratio, place of residence, comorbidities, cognitive and functional status were similar in the OHF and control group. Twenty-two (75.9%) and 4 (13.8%) patients in the OHF group had had subcapital and intertrochanteric fractures respectively, vs. 41 (43.6%) and 47 (50%) in the control group (p=0.003). Diagnosis delay in the OHF group was 16.8+/-26.5 days vs. 2.5+/-2.9 days (p<0.001) in the control group. There were fewer operations and complications in the OHF group compared to the control group (p<0.001 and p=0.017, respectively). During a 13-year follow-up, no differences in survival were found between the two groups nor any differences between those operated on and those who were not.

CONCLUSIONS

OHF patients have no distinctive clinical characteristics or long-term survival. The delay in diagnosing OHF is too much long and is probably related to the high prevalence of conservative treatment. MRI investigation is recommended whenever OHF are suspected and surgical treatment is considered, in order to improve diagnosis and treatment.

Posttraumatic painful hip: sonography as a screening test for occult hip fractures

OBJECTIVE

Nondisplaced hip fractures may be radiographically occult and require magnetic resonance imaging (MRI) or bone scintigraphy for diagnosis. Both examinations are expensive and are not readily available in many hospitals. Our objective was to evaluate sonography as a screening tool for occult hip fractures in posttraumatic painful hips in elderly patients.

METHODS

We prospectively evaluated 30 patients (mean age, 73 years), who were admitted for painful hips after having low-energy trauma with nondiagnostic hip radiographs. After inclusion, patients underwent sonography of both hips for signs of injury. After completion of the sonographic examination and analysis of the results, patients underwent MRI of both hips. The sonographic findings were compared with the MRI findings, which served as the reference standard for accurate detection of a hip fracture.

RESULTS

Ten hip fractures were diagnosed by MRI. Sonography showed trauma-related changes in all of those patients and in 7 additional patients, 3 of whom had pubic fractures. Sonography correctly identified 13 patients without hip fractures. The sensitivity of sonography was found to be 100%, whereas the specificity for hip fractures was 65%.

CONCLUSIONS

Sonography for posttraumatic hip pain with negative radiographic findings did not result in a single missed hip fracture. Therefore, sonography may serve as an effective screening tool, mandating MRI only for cases with positive findings, whereas patients with negative sonographic findings need no further investigation. Sonography may therefore be very useful in hospitals around the world, where MRI may not be readily affordable or available.

The use of MRI to detect occult fractures of the proximal femur: a study of 102 consecutive cases over a ten-year period

An MR scan was performed on all patients who presented to our hospital with a clinical diagnosis of a fracture of the proximal femur, but who had no abnormality on plain radiographs. This was a prospective study of 102 consecutive patients over a ten-year period. There were 98 patients who fulfilled our inclusion criteria, of whom 75 were scanned within 48 hours of admission, with an overall mean time between admission and scanning of 2.4 days (0 to 10). A total of 81 patients (83%) had abnormalities detected on MRI; 23 (23%) required operative management. The use of MRI led to the early diagnosis and treatment of occult hip pathology. We recommend that incomplete intertrochanteric fractures are managed non-operatively with protected weight-bearing. The study illustrates the high incidence of fractures which are not apparent on plain radiographs, and shows that MRI is useful when diagnosing other pathology such as malignancy, which may not be apparent on plain films.

Patient screening by a physical therapist for nonmusculoskeletal hip pain

BACKGROUND AND PURPOSE

Mechanical hip pain and disease-based hip pain can have similar signs and symptoms, thereby presenting a differential diagnostic challenge for clinicians. Hip pain is a common complaint addressed by physical therapists; therefore, it would be advantageous for them to be knowledgeable about differential diagnosis for hip pain, so that they can screen for possible serious conditions outside the realm of physical therapist practice and make the appropriate referral.

CASE DESCRIPTION

A 77-year-old man was referred for physical therapy by his primary care physician (PCP) with diagnoses of lumbar spine and left hip osteoarthritis and possible trochanteric bursitis. After the examination, the physical therapist determined that the patient should return to his PCP for further testing. Findings leading to this conclusion were pain severity out of proportion to the reported injury, the presence of night pain, a positive "sign of the buttock," and empty end feels of all hip joint motions, which represented a noncapsular pattern of joint restriction.

OUTCOMES

The patient was diagnosed later with primary lung adenocarcinoma with widespread metastases. A computerized tomography scan of the left hip revealed a metastatic lesion at the left proximal femur.

DISCUSSION

Physical therapists' ability to adequately screen for conditions requiring examination by a physician can lead to a more timely diagnosis of serious medical conditions. Investigators have found published descriptions of end feels, capsular versus noncapsular patterns of restriction, and the sign of the buttock to be beneficial screening tools for use in people with hip, pelvis, or lumbar spine pain.

Digital image enhancement improves diagnosis of nondisplaced proximal femur fractures

Today most emergency room radiographs are computerized, making digital image enhancement a natural advancement to improve fracture diagnosis. We compared the diagnosis of nondisplaced proximal femur fractures using four different image enhancement methods using standard DICOM (Digital Imaging and Communications in Medicine) after window-leveling optimization. Twenty-nine orthopaedic residents and specialists reviewed 28 pelvic images consisting of 25 occult proximal femur fractures and three images with no fracture, using four different image filters and the original DICOM image. For intertrochanteric fractures, the Retinex filter outperforms the other filters and the original image with a correct fracture type diagnosis rate of 50.6%. The Retinex filter also performs well for diagnosis of other fracture types. The Retinex filter had an interobserver agreement index of 53.5%, higher than the other filters. Sensitivity of fracture diagnosis increased to 85.2% when the Retinex filter was combined with the standard DICOM image. Correct fracture type diagnosis per minute for the Retinex filter was 1.43, outperforming the other filters. The Retinex filter may become a valuable tool in clinical settings for diagnosing fractures.

LEVEL OF EVIDENCE

Level I, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Imaging choices in occult hip fracture

BACKGROUND

Hip fracture is a common injury, with an incidence rate of > 250,000 per year in the United States. Diagnosis is particularly important due to the high dependence on the integrity of the hip in the daily life of most people.

OBJECTIVES

In this article we review the literature focused on hip fracture detection and discuss advantages and limitations of each major imaging modality.

DISCUSSION

Plain radiographs are usually sufficient for diagnosis as they are at least 90% sensitive for hip fracture. However, in the 3-4% of Emergency Department (ED) patients having hip X-ray studies who harbor an occult hip fracture, the Emergency Physician must choose among several methods, each with intrinsic limitations, for further evaluation. These methods include computed tomography, scintigraphy, and magnetic resonance imaging.

CONCLUSION

We present an evidence-based algorithm for the evaluation of a patient suspected to have an occult hip fracture in the ED. Also outlined are future directions for research to distinguish more effective techniques for identifying occult hip fractures.

Fractures of the neck of the femur

A hip fracture represents one of the commonest reasons for an elderly patient to be admitted to an acute orthopaedic ward. The average age of patients is about 80 years and the most patients are female. Surgical treatment is recommended for the majority of fractures. For intracapsular fractures internal fixation is indicated for all undisplaced fractures and displaced fractures in those aged less than about 65—70 years. Arthroplasty is more appropriate for the elderly patient with a displaced intracapsular fracture. A cemented unipolar hemiarthroplasty is generally used, but for the fitter active patients a total hip replacement may be superior. The sliding hip screw remains the implant of choice for trochanteric hip fractures with intramedullary fixation being mainly used for subtrochanteric fractures. Aggressive rehabilitation methods with minimally transfer of patients and early community support programmes can reduce the length of hospital stay.

Is magnetic resonance imaging (MRI) necessary to exclude occult hip fracture?

The possibility of occult hip fracture in older patients after a fall is a common problem in emergency and orthopaedic departments. Magnetic resonance imaging (MRI) scanning is the best investigation, but is expensive and may be difficult to obtain. The value of various clinical signs to determine which patients are at risk of occult hip fracture has not been reported. We reviewed all patients who had MRI scan for suspected hip fractures but had normal initial X-rays over a 6-year period. We identified 76 patients. Twelve patients were excluded. Two patients had MRI scan for suspected stress fracture and two patients had metastatic fractures. Eight patients had inadequate or untraceable clinical notes. Each patient's personal details, mobility, independence and detail clinical details were recorded. Following case review of 64 patients we excluded 5 patients with associated osteoarthritis of the hip joint, 1 patient with fibromyalgia and 1 patient with pre-existing multiple myeloma. Thirty-five patients had occult proximal femoral fractures. Of them four patients had isolated pubic ramus fractures and five patients had isolated greater trochanter fractures. Twenty-two patients had no fracture. The value of the individual tests was evaluated using Fisher exact and chi square analysis; with Bonferroni correction for multiple comparisons (10 tests) p<0.005 was deemed significant. Pain on axial loading of the limb and pre-fracture restricted patient mobility were both associated with the presence of a fracture (p<0.005). Both factors had identical positive predictive value=0.76, a negative predictive value=0.69 and post-test probability of disease given a negative test=0.30. Predictive values remained the same when both factors were considered together. Patients who were independently mobile before the fall and who do not have pain on axial compression of the limb are less likely to have a fracture, but these signs alone or in combination do not exclude a fracture. The clinical signs investigated cannot distinguish between patients with and without a hip fracture, and MRI scanning is necessary to establish whether some patients have an occult fracture.