Occult Intertrochanteric Fracture Mimicking the Fracture of Greater Trochanter

Outcomes of treatment for isolated greater trochanteric fractures with occult intertrochanteric extension: a retrospective cohort of 118 patients

INTRODUCTION

Isolated greater trochanteric fractures are uncommon among the pertrochanteric femoral fractures. Magnetic resonance imaging (MRI) is recommended to confirm occult intertrochanteric extension fractures and prevent potential displacement. While treatment guidelines lack consensus, surgical intervention is suggested for intertrochanteric extension (IE) beyond the medial third portion. Our primary aim was to assess complications and functional outcomes of conservative treatment in patients with IE.

METHODS

In this retrospective study, all patients aged 65 years and above with isolated greater trochanteric fractures diagnosed by X-ray were included. Subsequently, MRI divided the intertrochanteric area into lateral, medium, or medial portions based on extension proposed by Park. A minimum three-month follow-up was required. Treatment decisions, surgical or conservative, were based on surgeon criteria. Rehabilitation allowed weight-bearing as tolerated for both treatments. Analysis included demographic variables, complications, pre- and posttreatment functional status using the Parker mobility score, and overall mortality rate.

RESULTS

From 2010 to 2022, 118 IGTF patients were analyzed, with a mean age of 79.8 years (SD: 11.3) and 69.5% female. Conservative treatment was performed in 93 patients (78.8%), with Park I: 8 (8.6%), Park II: 52 (55.9%), and Park III: 33 (35.5%). Surgical treatment was performed in 25 patients (21.2%), with Park I: 3 (12%), Park II: 7 (28%), and Park III: 15 (60%). The complication rate was 4.8% (n = 4) for conservative treatment (all due to secondary displacement, resolved surgically) and 4% (n = 1) for surgical treatment (deep infection). Radiological extension differed significantly by Park classification (p = 0.042). Functional outcomes (Parker scores) showed no significant changes at three months posttreatment (p = 0.177). Overall survival was 94% at three months and 90% at one year.

CONCLUSION

This study suggests that conservative treatment is a viable option for patients with isolated greater trochanter fractures and IE, including cases involving the medial third. Decisions regarding treatment should take into account not only the location and extent of IE as identified by MRI, but also individual clinical factors.

Surgical versus conservative treatment of greater trochanteric fractures with occult intertrochanteric fractures: Retrospective cohort study

BACKGROUND

Greater trochanter (GT) fractures are rare and frequently associated with occult intertrochanteric (IT) fractures. No consensus has been reached regarding whether surgical or conservative treatment is preferred for such fractures. The purpose of this study was to evaluate the clinical outcomes of surgical versus conservative treatment for coexistent GT and occult IT fractures.

MATERIALS AND METHODS

Between January 2006 and December 2021, we enrolled patients who were diagnosed with GT fracture on radiography or CT and underwent MRI to reveal occult IT fracture. Eligible patients were divided into two treatment groups: surgical and conservative treatment. The characteristics and outcomes of the patients were compared between the two groups.

RESULTS

Fifty patients were included in this study. There were 29 patients (3 male, 26 female; mean age: 84.45 ± 10.68 years) in the surgical treatment group and 21 patients (3 male, 18 female; mean age: 83.33 ± 9.34 years) in the conservative group, respectively. The demographic and clinical characteristics of the two groups were comparable, including sex, age, body mass index (BMI), percentage of extension into the IT area, days from injury to diagnosis, and activities of daily living (ADL) before injury. All 50 patients healed without displaced fractures, regardless of the percentage of extension into the IT area. There were no significant differences in the modified functional ambulation category scores between the two groups at one week, one month, and three months following the start of the treatment intervention (P = 0.653, 0.923, and 0.577, respectively). The length of hospital stay was 48.4 ± 5.97 days in the surgical treatment group and 50.6 ± 7.55 days in the conservative treatment group (P = 0.422). There was no significant difference in one-year mortality between surgical and conservative treatments (P = 0.219).

CONCLUSIONS

There were no significant differences in any outcome between the surgical and nonsurgical treatment groups. The results of the study suggested that coexistent GT and occult IT fractures may be managed conservatively without developing complete fractures, regardless of extension into the IT area.

A Scientific Proposal for Surgical Decision-Making in Occult Intertrochanteric Fractures Based on Finite Element Analysis

Background In the treatment of femoral intertrochanteric fractures, there is still a lack of consensus on the optimal approach for isolated greater trochanteric fractures and insufficient intertrochanteric fractures. The limited number of patients and restricted access to accurate assessment of fracture extension using magnetic resonance imaging contribute to the unclear treatment strategy. This study aims to utilize finite element (FE) analysis to analyze stress values at the fracture line and investigate their influence on intertrochanteric fracture extension under different loading conditions. The hypothesis is that fracture extension occurs following certain conditions, supporting the need for surgery based on scientific evidence. Methodology Osseous data from a computed tomography (CT) scan was used to create a proximal femur FE model using FEA software. CT scan data were converted to Digital Imaging and Communications in Medicine format and used to generate the FE model. Trabecular bone and cortex were meshed into tetrahedral elements. The model consisted of 1,592,642 elements and 282,530 nodes. Two models were created, namely, healthy proximal femur (HF) and femoral insufficient intertrochanteric fracture (FIF). Material properties were assigned based on CT values and conversion equations. The distal end of the femur was constrained. Stress analysis using the dynamic explicit approach was performed. Von Mises stresses were calculated for the proximal femur. The number of elements exceeding yield stress was counted to predict fracture risk by focusing on fracture line spots. In this study, the distribution of von Mises stress was compared between the HF and the FIF models. Six loading combinations were considered, namely, two weight-bearing conditions (3 W loading simulating for walking and 1/3 W for touch-down standing) and three hip flexion angles (0°, 15°, and 23°). Results Under 3 W loading, no significant stress elevations were observed in the HF model at any flexion angles. However, the FIF model exhibited increased stress at the site of the posterior fracture line extension. This stress-induced element destruction was observed in both cortical and cancellous bone. For the 1/3 W loading condition, only minimal stress elevation was observed in both HF and FIF models. To assess the influence on fracture extension, the number of yielded elements was evaluated along the fracture line edges (greater trochanter and middle of the intertrochanteric ridge). Under 3 W loading, the HF model had only one yielded element, indicating minimal fracture risk. In contrast, the FIF model exhibited a notable presence of yield elements in various regions (total/greater trochanter/shaft) at different flexion angles: 0° (115/16/28), 15° (265/158/23), and 23° (446/233/34). Under the 1/3 W loading condition, neither the HF nor the FIF models showed any yielding elements, regardless of the direction of external force. Conclusions The results demonstrated elevated stress levels at the fracture line in the FIF model, particularly during walking, indicating a higher risk of fracture extension at the flex position. However, under reduced weight-bearing conditions, the stress at the fracture site remained within the yield stress range, suggesting a relatively low risk of fracture extension. These findings hold significant clinical implications for developing surgical protocols that consider patients' compliance with weight-bearing restrictions.

Fracture of the greater trochanter with occult intertrochanteric fracture in an adult treated by percutaneous screw fixation: Case report of an often missed injury

INTRODUCTION AND IMPORTANCE

Fractures of the greater trochanter with occult intertrochanteric extension are rare and difficult to diagnose. This type of fracture is not identified on standard radiographs and is considered to be an isolated fracture of the greater trochanter that is not subject to surgery. MRI is used to make the diagnosis or, failing that, CT. These fractures are most often surgically fixed to avoid further displacement, prevent complications of bed rest and allow early rehabilitation.

CASE PRESENTATION

We present the case of a patient who was diagnosed with a fracture of the greater trochanter with an occult intertrochanteric fracture based on CT, treated by percutaneous screw fixation with full recovery of hip mobility and consolidation after 3 months.

CLINICAL DISCUSSION

Isolated fractures of the greater trochanter are most often associated with an occult intertrochanteric fracture found on MRI. This diagnosis changes the prognosis and management since an isolated greater trochanter fracture is usually treated conservatively whereas an intertrochanteric extension most likely requires surgical fixation. Various approaches have been used to fix this type of fracture. In our case, we opted for percutaneous screw fixation with good results.

CONCLUSION

Isolated fractures of the greater trochanter with an occult intertrochanteric fracture are a rare entity that most often go unnoticed. MRI or, alternatively, CT should be systematically requested in the presence of an isolated fracture of the greater trochanter on standard radiographs. Surgical management can avoid complications and early management while restoring gluteal muscle function.

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.

Occult fracture propagation in patients with isolated greater trochanteric fractures: patterns and management

OBJECTIVE

To demonstrate the degrees of occult intertrochanteric extension on MRI in patients with a greater trochanteric fracture on radiography or computer tomography (CT) and whether these patients undergo conservative or surgical management with hardware.

MATERIALS AND METHODS

Retrospective review was performed of 146 patients (104 females, 42 males, ages 33-102) who had follow-up MRI after identification of a greater trochanteric fracture without intertrochanteric extension on radiography or CT. Extent of intertrochanteric extension was recorded. Subsequently, EMR review was performed to see if patients underwent surgery. Specific note was made of hardware type. Analysis was performed to determine if there is a correlation with fracture type and surgical management as well as fracture type and age and gender.

RESULTS

Nineteen patients had horizontal greater trochanter fractures without intertrochanteric extension; none underwent surgery. Seventeen patients had a vertical fracture along the lateral femoral cortex; one underwent surgery. Thirty-three patients had a fracture with intertrochanteric extension less than 50% in the mid coronal plane; 21 underwent surgery. Forty patients had intertrochanteric extension greater than 50% in the midcoronal plane not contacting the medial cortex; 28 underwent surgery. Thirty-seven patients had fractures contacting the medial cortex; 28 underwent surgery. There was significant difference with fractures extending 50% or greater of the midline of the intertrochanteric region undergoing surgical management compared with fractures less than 50% (p < 0.0001).

CONCLUSION

MRI identifies the presence and extent of occult intertrochanteric fractures in patients with greater trochanteric fractures. Description of intertrochanteric fractures on MRI helps determine the patient's treatment course and influence surgical decisions.

Incomplete Intertrochanteric Fracture: A Pattern Analysis Using Multiplanar Reformation Computed Tomography

Background

Incomplete fractures are assumed to occur in the intertrochanteric area as fractures at other sites, but reports of incomplete intertrochanteric fractures (IIFs) are rare. In 1999, Schultz et al. defined isolated greater trochanter fractures (GTFs) as IIFs when intertrochanteric extension is observed on magnetic resonance (MR) images. On multiplanar reformation computed tomography (MPR CT) images acquired for further study of apparently isolated GTFs, we noted incomplete cortical breakage in the intertrochanteric area. We then found that the fracture line was incomplete on plain radiographs in some intertrochanteric fractures. We evaluated IIFs and apparently isolated GTFs using MPR CT and analyzed the fracture patterns of IIFs that were confirmed using MPR CT.

Methods

Between February 2006 and June 2019, 36 cases of IIF were detected using MPR CT in 36 patients. They were 17 women and 19 men with a mean age of 74.7 years (range, 26–94 years). Plain radiographs and MPR CT images were evaluated by two experienced orthopedic surgeons. In addition, MR imaging was performed in 5 cases.

Results

Plain radiographs showed no evidence of fracture in 2 cases, isolated GTF in 7 cases, and IIF in 27 cases. In all cases, incomplete cortical breakage in the intertrochanteric area was confirmed on MPR CT images. Cortical breakage was located in the anterior portion of the intertrochanteric area, whereas the posterior portion remained intact in all cases. The detection rate of cortical breakage was higher on coronal or sagittal images than that on axial images. On MR images of 5 cases, intertrochanteric extensions were found in the medullary space. All extensions originated in the greater trochanter area and extended anteriorly in the axial plane and inferomedially in the coronal plane. On the T1-weighted mid-coronal image, the extension reached or passed the midline in 3 cases, and cortical breakage was detected in only 2 cases.

Conclusions

In all cases of IIF, cortical breakage was detected in the anterior portion of the proximal femur, leaving the posterior cortex intact. This finding is notably different from that of intertrochanteric extension (from posterior to anterior) detected on MR images of isolated GTFs.

The incidence and management of Isolated Greater Trochanteric Fractures - A systematic review of 166 cases

BACKGROUND

Isolated fractures of the greater trochanter are unusual injuries with a wide spectrum of presentation, investigations and management strategies.

AIMS

The objective of this study was to evaluate the incidence and treatment protocols used in the management of Isolated Greater Trochanteric Fractures (IGTF).

METHODS

A systematic literature review of the PubMed and Central Register of Controlled Trials (Cochrane) databases by using the search term 'greater trochanter fracture and hip fracture' was conducted for Randomised Controlled Trials (RCT's), including prospective and retrospective non-experimental studies.

RESULTS

The search yielded 15 studies meeting our inclusion criteria encompassing 166 patients with Isolated Greater Trochanteric Fractures (IGTF). Most of the reports were observational studies due to paucity of coverage on this topic in literature. Computed Tomography (CT) or Magnetic Resonance Imaging (MRI) were the common modalities used to diagnose these injuries. Most of the patients were managed with non-operative methods.

CONCLUSION

This systematic review analyses the consensus of treatment of IGTF based on evidence-based practice. When the IGTF is identified, the majority of studies advocate conservative management to surgery for such cases. Furthermore, large cohort studies with clearly documented outcome follow up are required to establish objective treatment guidelines for IGTF.

Management of isolated greater trochanteric fractures of the hip – Experience from a major trauma centre over a 24-month period

Introduction

Isolated greater trochanteric fractures (IGTfs) of the femur are uncommon. At least 10% of these fractures have an occult intertrochanteric extension. Mobilisation too early without care can lead to fracture propagation, requiring surgical fixation. There is no definite consensus in the literature on how to manage initially diagnosed IGTf with potential occult intertrochanteric extension. We reviewed the management of IGTf in our major trauma centre (MTC) and propose a management flow chart.

Methods

The electronic notes and images for all IGTf admitted under or referred to the orthopaedic team at a MTC, from June 2015 to July 2017, were reviewed. Data were collected on fracture pattern and diagnostic imaging modalities. Periprosthetic fractures were excluded.

Results

1550 neck of femur fracture patients were admitted over the 2-year period; 790 patients (51%) had a fracture around the intertrochanteric region and 49 (3.2%) were diagnosed with a IGTf on plain radiographs. 98% of patients had further imaging after initial plain film radiographs, and 58% of all IGTf were shown to have an intertrochanteric extension. Overall 16/49 patients (32.7%) needed an operation.

Conclusions

An IGTf not crossing the medullary canal into the calcar (i.e >50% of the diameter) does not require surgical fixation and can be managed with analgesia and supervised mobilisation. The 30-day mortalities in both operative and non-operative groups were similar at 2% and 2.2%, respectively. Overall mortality is half of the total neck of femur fracture population (4.1%) in our MTC. We propose a management flow chart for this patient cohort.

Treatment strategy for elderly patients with the isolated greater trochanteric fracture

BACKGROUND

The objective of this study was to evaluate the risk of femur intertrochanteric fracture associated with femur trochanter major fractures in patients over 65 years of age with magnetic resonance examination for better diagnosis and treatment.

METHODS

Thirty-one patients who had incomplete femur intertrochanteric fracture diagnosed were included in the study. Patients were classified according to the length of the fracture line crossing the intertrochanteric border. Fracture patterns were described on magnetic resonance imaging coronal views. Group A, pattern 1, greater trochanteric fracture extends to intertrochanteric region with both cortices; Group B, pattern 2, fracture has characteristics of pattern 1 fracture including diametaphysis fracture line; Group C, pattern 3, greater trochanteric fracture only has extending superolateral cortex fracture line of intertrochanteric region; and Group D, pattern 4, fracture has characteristics of pattern 1 fracture and including superior extension to the baso-cervical line. Surgical treatment with dynamic hip screw was applied to all patients with intertrochanteric extension after magnetic resonance examination.

RESULTS

This study included 16 women (80.3 ± 6.7 years) and 15 men (76.9 ± 10.94 years). Group A had 11 patients, group B had 8 patients, group C had 6 patients, and group D had 6 patients. Ambulation was initially prescribed for these patients 1 day after the surgery. The average surgery durations of the A, B, C, and D patterns were 44.54 ± 7.56, 49.37 ± 12.65, 49.16 ± 3.76, and 44.16 ± 5.84 min, respectively. No statistically significant differences were observed among the four patterns (P = 0.404).

CONCLUSION

Surgical treatment of the greater trochanteric fracture which is considered an indicator of occult intertrochanteric fracture is a good choice for the treatment because of the procedure safety and early mobilization after the surgery.

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.

The Frequency of Occult Intertrochanteric Fractures among Individuals with Isolated Greater Trochanteric Fractures

Purpose

Isolated greater trochanteric (GT) fractures are often identified using plain radiography of patients with post-traumatic hip pain. In many cases, the fracture extends to form an occult intertrochanteric fracture. We conducted a study to determine the frequency of occult intertrochanteric fractures in patients diagnosed with isolated GT fractures using plain radiographs.

Materials and Methods

Among 3,017 individuals who visited our emergency department with a trauma-induced pertrochanteric femur fracture between July 2004 and March 2018, 100 patients diagnosed with isolated GT fractures using plain radiographs were retrospectively analyzed. Patients were divided into two groups, those with: i) isolated GT fractures (group A) and ii) occult intertrochanteric fractures (group B). In addition, plain radiographs, magnetic resonance imaging results, and treatment methods were further analyzed in each group. If surgery treatment was needed, it was performed by one surgeon, and in all cases, a 2-hole dynamic hip screw was used.

Results

Among the 100 cases of isolated GT fractures diagnosed using plain radiograph, additional examinations revealed that 10 (10.0%) were suffering from isolated GT fractures alone, while the remaining 90 (90.0%) were further diagnosed with occult intertrochanteric fracture. Gender, age, mechanism of injury, and bone mineral density did not correlate with fracture type.

Conclusion

In our analysis, 90% of injuries initially diagnosed as isolated GT fractures were found to extend into occult intertrochanteric fractures upon further examination with additional imaging modalities. Therefore, additional evaluation should be performed to test for the potential presence of occult intertrochanteric fractures and to establish appropriate treatment plans.