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

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.

Musculoskeletal Trauma and Infection

MR is often the most definitive imaging for assessment of musculoskeletal trauma and infection. Although it is not possible to address all the intricacies of these complex topics in a single article, this review will attempt to provide a useful toolbox of skills by discussing several common clinical scenarios faced by emergency radiologists in interpretation of adult trauma and infection. These scenarios include MR assessment of hip and pelvic fracture, traumatic soft tissue injuries, septic arthritis, soft tissue infection, and osteomyelitis.

Clinical outcomes of patients with Garden I and II femoral neck fractures as verified on MRI: a retrospective case series

Background

Between 2 to 10% of non-displaced femoral neck fractures (nFNF) cannot be diagnosed on plain radiographs and require further imaging investigation to be detected or verified. These fractures are referred to as occult hip fractures. This study aimed to report treatment failures, reoperations and mortality in a consecutive series of occult femoral neck fractures (FNF) treated with internal fixation (IF).

Methods

A retrospective multicenter study was performed based on a consecutive series of patients aged ≥ 60 years with an occult magnetic resonance imaging (MRI) verified Garden I and II FNF sustained after a trauma and treated with primary IF. We included 93 patients with a minimum 2-year follow-up. Radiographic assessment encompassed pre- and postoperative tilt, implant inclination, MRI and treatment failure. Data on reoperation and mortality were collected. Treatment failure was defined as fixation failure, nonunion, avascular necrosis or posttraumatic osteoarthritis.

Results

The study comprised of 93 patients (72% women, 67/93) with a mean age of 82 (range, 60–97) years. Overall, 6 (6%) patients had major reoperations. 2 (2%) had minor reoperations. One-month mortality was 7%, 1-year mortality was 20% and 2-year mortality was 31%.

Conclusion

This multicenter cohort study identifies a subgroup of elderly patients with MRI verified Garden I and II FNFs sustained after trauma, i.e. occult fractures. These fractures seem to have a lower complication rate compared to nFNF identified on plain radiographs.

Level of evidence

Prognostic Level V. See Instructions to Authors for a complete description of levels of evidence.

The Necessity of CT Hip Scans in the Investigation of Occult Hip Fractures and Their Effect on Patient Management

The diagnostic challenge of negative plain radiography in the context of a previously ambulatory patient is increasing with the rise in geriatric trauma. These patients are often diagnosed with small undisplaced fractures of the pelvis and femur which may not alter management. This study aims to assess the frequency at which computed tomography (CT) hip scans altered patient management and whether two X-ray projections of the hip affected fracture detection rate. All CT hip scans performed over a three-year period were identified retrospectively. Only CT hips pertaining to the identification of occult fractures were included in the study. A total of 447 (63.6%) CT hips were performed to exclude an occult fracture, which was only detected in 108 (24.1%) of the scans requested. The majority were subcapital (n = 58, 53.7%) or intertrochanteric (n = 39, 36.1%). There was no significant difference between fracture detection rates when comparing one and two views of the pelvis. 82.4% (n = 89) of occult hip fractures were managed operatively. CT imaging led to a change in patient management in 20% of cases. The frequency at which CT scan detects and alters management in occult hip fractures confirms the justification for its use. Increasing the number of X-ray projection views does not decrease the reliance on CT. Pelvic ring fractures are common in nonambulatory patients following trauma, and if confirmed on initial imaging, subsequent imaging to exclude a concurrent occult hip is unnecessary. The focus of further research should be towards the development of investigation algorithms which decrease the reliance on CT and defining the optimal surgical criteria for occult hip fractures.

Computed tomography-based diagnosis of occult fragility hip fractures offer shorter waiting times with no inadvertent missed diagnosis

PURPOSE

Surgical delay due to the wait for advanced cross-sectional imaging in occult fragility hip fracture management is not well studied. Our study aims to investigate computed tomography (CT) as an alternative to the gold standard magnetic resonance imaging (MRI) in occult hip fracture workup to decrease surgical delay.

METHODS

We conducted a retrospective review of all CTs and MRIs performed between 2015 and 2017 for patients with clinically suspected fragility hip fractures and negative plain radiographs to investigate surgical delay resulting from the wait for advanced imaging and representations due to missed fractures.

RESULTS

A total of 243 scans (42 CTs and 201 MRIs) were performed for occult hip fracture workup over the study timeframe, of which 49 patients (20%) had occult hip fractures [CT: 6 (14%), MRI: 43 (21%), p = 0.296)]. There were no readmissions for fracture in the 12 months following a negative scan. The CT group had shorter waiting times (CT: 29 ± 24 h, MRI: 44 ± 32 h, p = 0.004) without significantly reducing surgical delay (CT: 82 ± 36 h, MRI: 128 ± 58 h, p = 0.196). The MRI group had a higher number of patients with a cancer history (p = 0.036), reflective of the practice for workup of possible metastases as a secondary intention.

CONCLUSION

Advanced cross-sectional imaging wait times in occult hip fracture workup contribute significantly to surgical delay. Modern CT techniques are not inferior to MRI in detecting occult fractures and may be a suitable alternative in the absence of a cancer history if MRI cannot be obtained in a timely fashion or is contraindicated. Clinicians should utilize the more readily available imaging modality to reduce surgical delay.

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.

Emergency Orthogeriatrics: Concepts and Therapeutic Considerations for the Geriatric Patient

Appropriate recognition of the physiologic, psychological, and clinical differences among geriatric patients, with respect to orthopedic injury and disease, is paramount for all emergency medicine providers to ensure they are providing high-value care for this vulnerable population.

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).

Does isolated greater trochanter implication affect hip abducent strength and functions in intertrochanteric fracture?

Background

A fracture in the isolated greater trochanter is an infrequent type of femoral intertrochanteric fracture. The gluteus medius and gluteus minimus are abducent muscle groups with attachments located on the greater trochanter. Thus, a fracture of the greater trochanter could cause avulsion injury of these attachment points and eventually affect the abducent function of the hip joint and cause chronic pain. Despite these prospects, the impact of a greater trochanter fracture on abducent strength and hip joint function have yet to be investigated.

Methods

Patients who were diagnosed with an isolated greater trochanter fracture (via computed tomography scan and X-ray) and underwent conservative treatment from June 2013 to October 2016 were included in the present study. Magnetic resonance imaging (MRI) was used to verify the morbidity of recessive fractures. Patients’ Harris Hip Scores were determined at 3 months, 6 months, and 12 months and the abducent strength and range of motion of the hip joint on the injured side were analyzed and compared to those on the healthy side.

Result

Among 32 patients, there were 7 individuals diagnosed with isolated greater trochanter fractures by MRI, and 25 individuals whose fractures were found to have extended into the intertrochanteric region, wherein the recessive intertrochanteric region fractures had no relationship with patients’ age, gender, or weight. After 12 months of conservative treatment, 7 patients still complained of pain in the hip joint. The average Harris Hip Score was 87.84 ± 4.83, and the abducent range of the hip joint on the injured side (42.02 ± 13.93°) was not significantly different from that of the healthy side (46.24 ± 7.93°). The abducent strength of the hip joint of the injured side was 121.32 ± 41.06 N which was significantly lower than that of healthy side (137.44 ± 42.21 N).

Conclusion

Results from this investigation suggest that an isolated greater trochanter fracture attenuates the abducent strength of the hip joint, which may be related to injuries of the ligaments and muscles around the greater trochanter. The surgical skills and methods of addressing isolated greater trochanter fractures merit further investigation.

Clinical characteristics and short to mid term functional outcomes of surgically treated occult hip fractures in the elderly

BACKGROUND

Occult hip fractures in the elderly are challenging to diagnose and often result in surgical delays which may worsen outcomes. However, the minimally displaced nature of these fractures may conversely lead to better outcomes. The aim of this study was to determine if surgically treated occult hip fractures have better short to mid term functional outcomes when compared to non-occult fractures. The secondary aim was to determine if there are any differences in clinical characteristics of patients who present with occult hip fractures.

METHODS

This was a retrospective cohort study of all elderly patients aged 65 years and above who presented with hip fractures in a single institution from January 2012 to December 2013. Elderly patients who presented with hip fractures were enrolled into an Ortho-geriatric carepath and were eligible for recruitment. The exclusion criteria included patients with pathological fractures and multiple injuries. Demographic and pre-injury variables were collected. The functional outcome measurement was the Modified Barthel's Index (MBI). Patients were divided into non-occult hip fractures (Group 1) and occult hip fractures (Group 2).

RESULTS

A total of 1017 patients were admitted during this period into the hip fracture carepath, of which 49 (4.8%) were diagnosed to have occult hip fractures. There was no significant difference between the demographics, Charlson co-morbidity index, abbreviated mental test scores or pre-morbid patient dependence between the groups. There was a significant delay to surgery for occult hip fractures when compared to non-occult fractures. (p = 0.03) Subgroup analysis showed that pre-morbidly, patients with occult inter-trochanteric fractures were significantly more independent than patients with non-occult inter-trochanteric fractures. (p = 0.03) There was no significant difference between the length of stay, surgical complications and 1-year mortality between the 2 groups. Occult inter-trochanteric fractures had better MBI scores at all time points when compared to non-occult inter-trochanteric fractures.

CONCLUSIONS

Despite the significant delay to surgical intervention for patients with occult hip fractures, the short to mid term functional outcomes for this group of patients are comparable to surgically treated non-occult hip fractures. There are no distinctive clinical characteristics of elderly patients who are more likely to suffer occult hip fractures.

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.

Diagnostic Imaging Strategies for Occult Hip Fractures: A Decision and Cost-Effectiveness Analysis

OBJECTIVE

Hip fractures cause significant morbidity and mortality. Determining the optimal diagnostic strategy for the subset of patients with potential occult hip fracture remains challenging. We determined the most cost-effective strategy for the diagnosis of occult hip fractures from the choices of performing only computed tomography (CT), performing only magnetic resonance imaging (MRI), performing CT and if negative performing MRI (MRI-selective strategy) or discharging the patient without advanced imaging.

METHODS

We developed a decision-analytic model to compare outcomes and costs of different diagnostic strategies for the diagnosis of an occult hip fracture from a societal perspective. Model inputs were derived from charge data, Medicare reimbursements, and the literature. Strategies with an incremental cost-effectiveness ratio (ICER) below $100,000 per quality-adjusted life-year (QALY) gained were considered cost-effective. We tested the robustness of our results using probabilistic sensitivity analysis.

RESULTS

Compared to a CT strategy, MRI provides an additional 0.05 QALY at an incremental cost of $1,227 and ICER of $25,438/QALY. For facilities without MRI capability, if the cost of transfer is below $1,228, transferring the patient to a MRI-capable facility is the most cost-effective strategy. Above this cost, employing a CT and if negative transfer to a MRI-capable facility strategy was more cost-effective. When the cost of a transfer reached more than $4,039, it became more cost-effective to only obtain a CT.

CONCLUSION

MRI is a cost-effective strategy for the diagnosis of an occult hip fracture. For facilities without MRI capability, the most cost-effective strategy depends on the cost of the interfacility transfer.

Imaging of occult hip fractures: CT or MRI?

OBJECTIVES

Patients presenting with hip pain but normal plain radiographs may ultimately be shown on further investigation to have suffered an occult hip fracture (OHF). This diagnosis can be made with CT or MRI. Traditionally MRI has been considered a superior modality. We performed a retrospective review of all patients presenting to our service with a suspected OHF over a four-year period, investigated with either CT or MRI.

DESIGN

Retrospective review.

SETTING

Urban trauma centre.

PATIENTS

Patients with suspected hip fractures and negative radiographs.

INTERVENTION

CT or MRI.

MAIN OUTCOME MEASURES

Detection rate; delay in request for further imaging; delay to theatre; re-presentations with missed fractures.

RESULTS

A total of 179 patients were investigated, with a mean age of 82±13 years. The ultimate diagnosis was of an OHF in 71 cases and pelvic or acetabular fracture in 34. The average time from presentation plain radiograph to further imaging was 2.0±2.7 days, but was significantly shorter for CT. No patient re-presented with unidentified fractures or other localised hip pathology within a 12-month period.

CONCLUSIONS

Modern imaging technology does not appear to miss clinically significant fractures. As CT is usually more accessible than MRI, the results of our study should encourage surgeons to consider CT as a first line investigation for occult hip fractures. We advocate a high index of suspicion and early imaging referral for elderly patients presenting with non-specific hip pain following a fall. Level 3 Evidence.

Use of advanced imaging techniques during visits to emergency departments--implications, costs, patient benefits/risks

25 years ago, on a Friday evening at 9 pm, the emergency department (ED) was full of patients with a wide range of clinical problems. Their investigations included plain radiographs, but no other imaging was included until the next working day. At present, many patients are receiving advanced imaging such as ultrasound, CT and MRI, often delivered out of hours--an obvious advance for patients or sometimes an unnecessary development? In this article, we will consider how to assess patient benefits and whether increased use of advanced imaging is an overall advance for patients. We will address the general implications for healthcare services which come with greater use of advanced imaging. We will then address the effect of advanced imaging on individual fictional ED patients with a variety of complaints.

Is magnetic resonance imaging necessary in isolated greater trochanter fracture? A systemic review and pooled analysis

Background

Isolated fractures of the greater trochanter (GT) of the femur are uncommon and few studies have assessed the diagnosis and appropriate therapeutic schedule for these fractures. The current data regarding assessment of isolated fractures of the GT are limited to a few reviews based on the experience of a single institution. Therefore, we asked the following questions: (1) what proportion of cases has an associated extension of the fracture into the intertrochanteric region in isolated GT fracture and (2) what are the treatment options and outcomes of GT fractures with occult intertrochanteric fractures.

Methods

We conducted a systematic review of published studies that evaluated patients who displayed isolated GT fracture on routine radiographic examination and underwent a magnetic resonance imaging (MRI) scan because of the suspicion of extension into the intertrochanteric region. A structured literature review of multiple databases (PubMed, EMBASE, CINAHL, and Cochrane systematic reviews) referenced articles from 1950 to 2015.

Results

A total of 110 patients were identified from 7 published studies. MRI documented isolated GT fractures diagnosed on initial radiographs in only 11 of 110 patients (10 %). In 99 patients (90 %), MRI examinations revealed extension of the fracture into the intertrochanteric region. Surgical fixation was necessary for 61 patients, with a pooled percentage of 55 %. No complications were observed after surgery.

Conclusions

Our study has helped to elucidate further the assessment of isolated fracture of the GT. We believe that MRI is a reasonable option for patients presenting with isolated GT fracture on plain radiographs.

Occult fractures of the proximal femur: imaging diagnosis and management of 82 cases in a regional trauma center

BACKGROUND

Occult hip fractures are often difficult to identify in busy trauma units. We aimed to present our institutions experience in the diagnosis and treatment of occult fractures around the hip and to help define a clinical and radiological management algorithm.

METHOD

We conducted a seven-year retrospective hospital medical record analysis. The electronic database was searched for ICD-10 CM codes S72.0 and S72.1 used for proximal femoral fractures upon patient discharge. We identified 34 (4.83 %) femoral neck fractures and 48 (4.42 %) trochanteric fractures labeled as occult.

RESULTS

The majority of the cases were diagnosed by primary MRI scan (57.4 %) and 12 were diagnosed by emergency CT scan (14.6 %). For the remaining cases the final diagnosis was confirmed by 72 h CT scan in 9 patients (representing 39 % of the false negative cases) or by MRI in the rest of 14 patients. MRI was best at detecting incomplete pertrochanteric fracture patterns (13.45 % of total) and incomplete fractures of the greater trochanter (3.65 % of total) respectively. It also detected the majority of Garden I femoral neck fractures (20.7 % of total). CT scanning accurately detected 100 % of Garden 2 fractures (2.44 %) and 25 % (3.65 %) of the complete pertrochanteric fractures (false negative 25 %).

CONCLUSION

Occult fractures should be suspected in all patients with traumatic onset of hip pain that is inconsistent with normal radiographic findings. MRI is the golden standard but not as readily available not as cheap and not quite as quick to perform as as a CT scan. The latter which in turn can provide falsely negative results in the first 24 h. Improved imaging protocols could expedite management and improve treatment.

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.

Rapid access imaging for occult fractured neck of femur

We completed a full audit cycle to assess waiting times for inpatients with suspected occult femoral neck fracture to get MRI scan, identify the causes of delay and implement the changes to reduce the waiting times. We have proved that inpatient MRI waiting times can significantly be reduced by a targeted approach.

INTRODUCTION

The timely management of hip fractures is now underpinned by NICE Guidance, June 2011. This includes a statement that magnetic resonance imaging (MRI) should be offered if occult femoral neck fracture is suspected and that MRI should be made available within 24 hours. We completed a full audit cycle: (1) analyse the time taken for inpatient MRI to be performed for suspected occult femoral neck fractures, (2) identify correctable reasons for delay, (3) develop and implement changes and (4) re-audit.

METHODS

Data was collected from the computerised radiology information system on consecutive patients between 01/04/2010 and 31/03/2012. This data was presented at a number of directorate audit meetings. Following the development and implementation of targeted improvements, a prospective re-audit was carried out between 01/08/2012 and 31/07/2013.

RESULTS

After the initial audit, various reasons of delay were identified. The correctable causes for delay were (1) duty radiologist not directly contacted by clinician to request urgent scan, (2) slow vetting and protocoling of electronic requests, (3) resistance to weekend scanning and (4) delay in completing MRI safety questionnaire. After implementing strategies to address these remediable causes of delay, the re-audit demonstrated a 16% improvement in patients scanned within 24 h. The mean waiting time to get an MRI was 2,025.4 min (SD 2,406.4) for the baseline audit and 1,374 min (SD 1,635.7) for the re-audit. Mean difference is 651.4 min (95% CI 85.21, 1,217.5; p = 0.0243).

CONCLUSION

MRI is a useful and sensitive tool to investigate occult femoral neck fracture. Inpatient MRI waiting times can significantly be reduced by a targeted approach which embodies improved team working.

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.

A systematic review of the diagnostic performance of orthopedic physical examination tests of the hip

BACKGROUND

Previous reviews of the diagnostic performances of physical tests of the hip in orthopedics have drawn limited conclusions because of the low to moderate quality of primary studies published in the literature. This systematic review aims to build on these reviews by assessing a broad range of hip pathologies, and employing a more selective approach to the inclusion of studies in order to accurately gauge diagnostic performance for the purposes of making recommendations for clinical practice and future research. It specifically identifies tests which demonstrate strong and moderate diagnostic performance.

METHODS

A systematic search of Medline, Embase, Embase Classic and CINAHL was conducted to identify studies of hip tests. Our selection criteria included an analysis of internal and external validity. We reported diagnostic performance in terms of sensitivity, specificity, predictive values and likelihood ratios. Likelihood ratios were used to identify tests with strong and moderate diagnostic utility.

RESULTS

Only a small proportion of tests reported in the literature have been assessed in methodologically valid primary studies. 16 studies were included in our review, producing 56 independent test-pathology combinations. Two tests demonstrated strong clinical utility, the patellar-pubic percussion test for excluding radiologically occult hip fractures (negative LR 0.05, 95% Confidence Interval [CI] 0.03-0.08) and the hip abduction sign for diagnosing sarcoglycanopathies in patients with known muscular dystrophies (positive LR 34.29, 95% CI 10.97-122.30). Fifteen tests demonstrated moderate diagnostic utility for diagnosing and/or excluding hip fractures, symptomatic osteoarthritis and loosening of components post-total hip arthroplasty.

CONCLUSIONS

We have identified a number of tests demonstrating strong and moderate diagnostic performance. These findings must be viewed with caution as there are concerns over the methodological quality of the primary studies from which we have extracted our data. Future studies should recruit larger, representative populations and allow for the construction of complete 2×2 contingency tables.

Fracturas en extremidades "Cuando se convierten en un reto diagnóstico"

El trauma en extremidades es un evento que se presenta a diario en los servicios de urgencias en la mayoría de veces es de fácil diagnóstico imagenológico solo con la radiología convencional. En algunas ocasiones la persistencia del dolor osteomuscular, sin mejoría con el manejo médico, es la situación que lleva a consultar de nuevo al paciente para explorar su causa y la radiología convencional no muestra lesión ósea por lo cual la patología se convierte en un reto diagnóstico para el personal médico lo que retraso en su diagnóstico y conlleva a posibles complicaciones. Dado a estas condiciones es importante conocer por parte del clínico la fisiopatología y los diferentes tipos de ayudas diagnósticas imagenológicas que le permitan diagnosticar a tiempo las fracturas ocultas. Nuestro objetivo es valorar la utilidad de las diferentes técnicas de imágenes diagnósticas en el estudio de las fracturas ocultas, realizando una búsqueda sistemática en la literatura de su fisiopatología, características, interpretación, uso racional y adecuado en las imágenes diagnósticas. [Pérez, L. Fracturas en extermidades. Cuando se convierten en un reto diagnóstico. MedUNAB 2013;16(1):24-33].

Radiographically occult and subtle fractures: a pictorial review

Radiographically occult and subtle fractures are a diagnostic challenge. They may be divided into (1) “high energy trauma fracture,” (2) “fatigue fracture” from cyclical and sustained mechanical stress, and (3) “insufficiency fracture” occurring in weakened bone (e.g., in osteoporosis and postradiotherapy). Independently of the cause, the initial radiographic examination can be negative either because the findings seem normal or are too subtle. Early detection of these fractures is crucial to explain the patient's symptoms and prevent further complications. Advanced imaging tools such as computed tomography, magnetic resonance imaging, and scintigraphy are highly valuable in this context. Our aim is to raise the awareness of radiologists and clinicians in these cases by presenting illustrative cases and a discussion of the relevant literature.

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.

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.

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.

Emergency orthogeriatrics: concepts and therapeutic alternatives

Multidisciplinary orthogeriatric care can enhance prompt ED diagnosis, optimal pre- and postoperative care, and functional recovery in older adults with bony injuries. Emergency care providers should be cognizant of prevalent geriatric syndromes including delirium and standing level falls to minimize fracture-related morbidity. Recognizing the implications of aging physiology, acute care physicians should be aware of effective alternatives to analgesia, procedural sedation, and definitive imaging to promote early surgical management and postoperative recovery.

Initially missed occult fractures of the proximal femur in elderly patients: implications for need of operation and their morbidity

INTRODUCTION

Occult fractures of the proximal femur are not evident on radiographs and the diagnoses are often missed or delayed. We tried to determine whether the delay of diagnosis in elderly patients lead to increased morbidity and increased need for operation.

MATERIALS AND METHODS

We identified 26 elderly patients (> or =65 years of age) who were diagnosed as having an occult fracture of the proximal femur over a 3-year period. In 17 patients (17 hips, non-delayed group), the occult fracture was suspected at the first visit and the diagnosis was made on CT and/or MR images (MRI). In the remaining nine patients (9 hips, 34.6% delayed group), the diagnosis was delayed by a mean of 8.4 days (range 4-25 days). We compared the occurrence of fracture displacement, need for operation, change in activity level, and mortality between the non-delayed and delayed groups.

RESULT

Displacement of fracture occurred in 4 of 9 delayed patients and none of 17 non-delayed patients. Ten non-delayed patients needed operative treatment, whereas eight delayed patients needed operative treatment (p = 0.190). The activity level decreased in 6 of 7 surviving patients of the delayed group, whereas it decreased in 4 of 15 surviving patients of the non-delayed group (p = 0.020).

CONCLUSION

A delayed diagnosis of occult fracture in elderly patients resulted in increased rate of secondary displacement of the fracture and increased morbidity. In patients suspected of having occult hip fractures, additional studies, such as MRI and/or CT scans should be recommended to confirm the presence of hip fracture.

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.

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.