Who is more accurate in the diagnosis of neck of femur fractures, radiologists or orthopaedic trainees?

Objective

Our study aims to compare the sensitivity and specificity between orthopaedic trainees and radiologists in diagnosing occult hip fractures from pelvic radiographs.

Methods

All patients undergoing computed tomography (CT) of the hip for a suspected occult hip fracture at our two centres between November 1, 2010 and October 31, 2011 were retrospectively identified. Two orthopaedic trainees (RJ and ED) independently reviewed the initial radiographs, and if both agreed a fracture was present this was recorded. The reports from the radiologist of the initial radiograph and subsequent CT were recorded, with the CT report used as the standard of reference for comparison of performance.

Results

239 CTs were performed for suspected neck of femur fractures during the study period, compared to only 20 in 2006–07, reflecting a 1,095 % increase. The interpretation of radiographs by the orthopaedic trainees showed a sensitivity of 55.4 % and specificity of 96.6 %. In comparison, the radiologists had a sensitivity of 60.7 % and specificity of 92.9 %; this difference was shown not to be statistically significant. Radiologists and orthopaedic trainees agreed when interpreting the majority of radiographs with a Kappa co-efficient of 0.77 (a statistical measure of inter-rater agreement). In 20 of the 174 cases (11.5 %) where the radiologist and orthopaedic trainees agreed no fracture was present, the subsequent CT revealed a fracture.

Conclusion

Orthopaedic trainees and radiologists have similar accuracy at interpreting pelvic radiographs for suspected hip fractures, so the trainee’s opinion can be relied upon. If uncertainty exists, then either the orthopaedic trainee or radiologist should request further imaging urgently as we believe this will expedite diagnosis and treatment of hip fractures, and ensure judicious use of CT.     

Automatic detection of osteoporotic vertebral fractures in routine thoracic and abdominal MDCT

Objectives

To develop a prototype algorithm for automatic spine segmentation in MDCT images and use it to automatically detect osteoporotic vertebral fractures.

Methods

Cross-sectional routine thoracic and abdominal MDCT images of 71 patients including 8 males and 9 females with 25 osteoporotic vertebral fractures and longitudinal MDCT images of 9 patients with 18 incidental fractures in the follow-up MDCT were retrospectively selected. The spine segmentation algorithm localised and identified the vertebrae T5-L5. Each vertebra was automatically segmented by using corresponding vertebra surface shape models that were adapted to the original images. Anterior, middle, and posterior height of each vertebra was automatically determined; the anterior-posterior ratio (APR) and middle-posterior ratio (MPR) were computed. As the gold standard, radiologists graded vertebral fractures from T5 to L5 according to the Genant classification in consensus.

Results

Using ROC analysis to differentiate vertebrae without versus with prevalent fracture, AUC values of 0.84 and 0.83 were obtained for APR and MPR, respectively (p?<?0.001). Longitudinal changes in APR and MPR were significantly different between vertebrae without versus with incidental fracture (ΔAPR: -8.5 %?±?8.6 % versus -1.6 %?±?4.2 %, p?=?0.002; ΔMPR: -11.4 %?±?7.7 % versus -1.2 %?±?1.6 %, p?<?0.001).

Conclusions

This prototype algorithm may support radiologists in reporting currently underdiagnosed osteoporotic vertebral fractures so that appropriate therapy can be initiated.

Key points

? This spine segmentation algorithm automatically localised, identified, and segmented the vertebrae in MDCT images. ? Osteoporotic vertebral fractures could be automatically detected using this prototype algorithm. ? The prototype algorithm helps radiologists to report underdiagnosed osteoporotic vertebral fractures.     

Union of the ulnar styloid fracture as a function of fracture morphology on conventional radiographs

Objective

In a retrospective radiological study, the authors aimed to detect the influence of fracture morphology on the union rate of ulnar styloid fractures associated with distal radial fractures.

Materials and methods

Eighty-two out of 101 ulnar styloid fractures were included in the final statistical analysis. Initially, they were grouped into six different morphological types based on a novel classification system. They were also classified as per the established Fernández and Frykman classification systems. Furthermore, the initial ulnar styloid displacement was measured in conventional anteroposterior radiographs. Union of the ulnar styloid fracture was evaluated after at least 6 months of follow-up.

Results

The current investigators demonstrated that the various ulnar styloid fracture patterns have no significant predictive value for ulnar styloid union. In contrast, it could be attested, that an initial fragment dislocation of greater than 2.4 mm in the conventional AP radiographs has a significantly lower chance of successful union (p?=?0.022).

Conclusion

Initial displacement of the ulnar styloid should be measured in each distal radial fracture with a concomitant ulnar styloid fracture. This could be useful to inform the decision regarding surgical fixation of the ulnar styloid fragment in patients with an unstable distal radioulnar joint (DRUJ) or persistent symptoms at the ulnar aspect of the wrist.     

Analysis of mandibular condylar and glenoid fossa fractures with computed tomography

Objectives

The purpose of this study was to investigate the prevalence of glenoid fossa and condylar fractures in patients with mandibular fractures using multidetector computed tomography (MDCT).

Methods

A prospective study was performed in 227 patients with mandibular fractures who underwent 64-MDCT. Mandibular fractures were classified into four types: median, paramedian, angle and condylar. Statistical analysis of the relationship between prevalence of condylar fractures and mandibular fracture locations was performed using χ² test with Fisher’s exact test. A P value less than 0.05 was considered statistically significant.

Results

The prevalence of condylar fracture was 64.8 % of all patients with mandibular fractures, 66.7 % of median type (P?=?0.667), 45.5 % of paramedian type (P?=?0.001) and 12.3 % of angle type (P?=?0.000), respectively. Furthermore, glenoid fossa fracture was seen in 1.4 % of patients with condylar fractures.

Conclusions

The results of the presented study suggest focusing also on incidental findings such as glenoid fossa fractures.

Key Points

? The prevalence of condylar fracture was 64.8 % in patients with mandibular fractures. ? Glenoid fossa fracture was seen in 1.4 % of patients with condylar fractures. ? The study suggests a focus on incidental findings such as glenoid fossa fractures.     

Digital X-ray radiogrammetry of hand or wrist radiographs can predict hip fracture risk—a study in 5,420 women and 2,837 men

Objectives

To assess whether digital X-ray radiogrammetry (DXR) analysis of standard clinical hand or wrist radiographs obtained at emergency hospitals can predict hip fracture risk.

Methods

A total of 45,538 radiographs depicting the left hand were gathered from three emergency hospitals in Stockholm, Sweden. Radiographs with insufficiently included metacarpal bone, fractures in measurement regions, foreign material or unacceptable positioning were manually excluded. A total of 18,824 radiographs from 15,072 patients were analysed with DXR, yielding a calculated BMD equivalent (DXR-BMD). Patients were matched with the national death and inpatient registers. Inclusion criteria were age ≥ 40 years, no prior hip fracture and observation time > 7 days. Hip fractures were identified via ICD-10 codes. Age-adjusted hazard ratio per standard deviation (HR/SD) was calculated using Cox regression.

Results

8,257 patients (65.6 % female, 34.4 % male) met the inclusion criteria. One hundred twenty-two patients suffered a hip fracture after their radiograph. The fracture group had a significantly lower DXR-BMD than the non-fracture group when adjusted for age. The HR/SD for hip fracture was 2.52 and 2.08 in women and men respectively. The area under the curve was 0.89 in women and 0.84 in men.

Conclusions

DXR analysis of wrist and hand radiographs obtained at emergency hospitals predicts hip fracture risk in women and men.

Key Points

? Digital X-ray radiogrammetry of emergency hand/wrist radiographs predicts hip fracture risk. ? Digital X-ray radiogrammetry (DXR) predicts hip fracture risk in both women and men. ? Osteoporosis can potentially be identified in patients with suspected wrist fractures. ? DXR can potentially be used for selective osteoporosis screening.     

Association of femoral head and acetabular fractures on computerized tomography: correlation with the Judet-Letournel classification

Purpose

Tha aims of this study were to identify the incidence of femoral head fractures in the setting of acetabular fractures and to determine the relationship between acetabular fracture pattern, the degree of acetabular fracture displacement, and the incidence of femoral head fractures.

Materials and methods

This is a retrospective cross-sectional study of 274 patients with 300 acetabular fractures diagnosed on pelvic CT. Acetabular fractures were categorized using the Judet-Letournel classification system.

Results

Femoral head fractures were present in 18.0% of acetabular fractures. Fracture patterns with a posterior wall component had a very high (56.3%) incidence of femoral head fracture. Anterior column and anterior column with posterior hemitransverse fractures have a very low (3.4%) incidence of femoral head fracture. Anterior hip dislocation had a 66.7% incidence of femoral head fracture, while posterior dislocation had a 71.9% incidence. Acetabular fractures displaced by more than 5 mm had a 26.9% incidence of femoral head fracture, while acetabular fracture displaced less than 5 mm had only 4.2% incidence of femoral head fracture.

Conclusion

Femoral head fractures are a very common associated finding in patients presenting with acetabular fractures. In patients with a posterior wall component of the fracture or associated hip dislocation, a femoral head fracture is more likely than not present. Conversely, in acetabular fractures with less than 5 mm displacement or anterior column fractures without posterior acetabular involvement, femoral head fractures are very unlikely in the absence of a dislocation event.

     

Radiographic prevalence of CAM-type femoroacetabular impingement after open reduction and internal fixation of femoral neck fractures

Purpose

The purpose of this study was to estimate the radiographic prevalence of CAM-type femoroacetabular impingement (FAI) in elderly patients (≥50 years) who have undergone internal fixation for femoral neck fracture.

Methods

A total of 187 frog-leg lateral radiographs of elderly patients who underwent internal fixation for a femoral neck fracture were reviewed by two independent reviewers. The alpha angle, beta angle, and femoral head–neck offset ratio were calculated. The presence of two abnormal radiographic parameters was deemed to be diagnostic of radiographic CAM-type impingement.

Results

Radiographic CAM-type FAI was identified in 157 out of 187 (84 %) patients who underwent internal fixation for fractures of the femoral neck. Moderate-to-good inter-observer reliability was achieved in the measurement of radiographic parameters. With reference to fracture subtypes and prevalence of radiographic features of CAM-type morphology, 97 (72 %) out of 134 patients were positive for CAM in Garden subtypes I and II, whereas 49 (85.9 %) out of 57 patients had radiographic CAM in Garden III and IV subtypes.

Conclusion

There was a high prevalence of CAM-type FAI in patients that underwent surgical fixation of femoral neck fractures. This is significantly higher than the reported prevalence in non-fracture patient populations. The high prevalence of CAM morphology could be related to several factors, including age, fracture morphology, quality of reduction, type of fixation, and fracture healing.

Level of evidence

IV.     

The added value of cross-sectional imaging in the detection of additional radiographically occult fractures in the setting of a Chopart fracture

Purpose

Radiography has a low sensitivity for the detection of fractures related to the talonavicular and calcaneocuboid articulations, also known as Chopart fractures. The purpose of this study is to determine the sensitivity of radiographs for detecting additional foot and ankle fractures related to Chopart fracture using CT or MRI as the reference standard.

Method

We performed an IRB-approved, retrospective review of radiology reports between 2010 and 2014. Inclusion criteria were (1) diagnosis of a Chopart fracture and (2) at least one radiograph and subsequent cross-sectional imaging (CT or MR). CT or MRI was considered the diagnostic reference standard. Results were stratified by the energy of trauma and by type of radiograph performed (weight-bearing (WB) versus non-WB).

Results

One hundred eight patients met the inclusion criteria. The calcaneocuboid articulation was the most commonly involved type of Chopart fracture, seen in 75% of cases (81/108). Chopart fractures were detected on the initial radiographs in 67.6% of cases (73/108). Additional fractures of the ankle and midfoot were diagnosed in 34.2% of cases (37/108), with 56.7% (21/37) of these cases having at least one additional fracture seen on CT or MRI that was not seen on the initial radiographs, with fractures of the midfoot most often missed. In 56.7% (17/30) patients whose radiographs detected Chopart fractures, at least one additional fracture was missed; 30% of them demonstrated intra-articular extension and 56.7% were considered displaced. High-energy trauma was related to higher incidence of additional fractures. There was no significant difference in the sensitivity of radiographs to detect additional fractures between high versus low-energy trauma (p?=?0.3) and WB versus non-WB radiographs (p?=?0.5). Most patients were treated nonoperatively (56.5%, 61/108), with surgical intervention more frequent in patients with a high energy of trauma (51.7% versus 33.3%, p?=?0.05).

Conclusion

In the setting of a Chopart fracture, CT or MRI can add significant value in the detection of additional ankle or midfoot fractures, irrespective of the energy of trauma. Since additional fractures can have important management implications, CT or MRI should be considered as part of the standard workup for all midfoot fractures.

     

Accuracy of multidetector-row CT for restaging after neoadjuvant treatment in patients with oesophageal cancer

Objectives

To assess the diagnostic accuracy of 64-multidetector CT (MDCT) for restaging of patients with oesophageal cancer undergoing neoadjuvant therapy.

Methods

Results of pathological staging were correlated with those from 64-MDCT before and after neoadjuvant treatment in 35 patients using the American Joint Committee on Cancer/TNM classification (7th edition). CT response was determined using the Response Evaluation Criteria in Solid Tumours (RECIST) method, modified for one-dimensional tumour diameter measurement.

Results

64-MDCT predicted T stage correctly in 34 % (12/35), overstaged in 49 % (17/35) and understaged in 17 % (6/35). Sensitivity/specificity values were as follows: T0, 20 %/92 %; T1–T2, 31 %/59 %; T3, 60 %/64 %; T4, 100 %/4 %. Negative predictive values for T3/T4 were 80 %/100 %. MDCT accurately predicted complete histopathological response in 20 % (accuracy 74 %) and overstaged in 80 %. Tumour regression grade was predicted correctly in only 8 % (2/25) and underestimated in 68 % (17/25). Accurate N stage was noted in 69 % (24/35).

Conclusion

Although MDCT tends to be able to exclude advanced tumour stages (T3, T4) with a higher likelihood, the diagnostic accuracy of high resolution MDCT for restaging oesophageal cancer and assessing the response to neoadjuvant therapy has not improved in comparison to older-generation CT. Therefore, the future assessment of oesophageal tumour response should focus on combined morphologic and metabolic imaging.

Key Points

? Multidetector CT (MDCT) has been beneficial for the evaluation of many tumours. ? However diagnostic accuracy for restaging oesophageal cancer has not improved with MDCT. ? MDCT tends to be able to exclude advanced tumour stages (T3/T4). ? MDCT has a low accuracy for determining lymph node metastasis. ? Oesophageal tumour response should be assessed by combined morphological and metabolic imaging.     

Comparison of air kerma between C-arm CT and 64-multidetector-row CT using a phantom

Purpose

To compare air kerma after scanning a phantom with C-arm CT and with 64-multidetector row CT (64MDCT).

Materials and methods

A phantom was scanned using parameters based on data of ten patients with hepatocellular carcinoma who had C-arm CT during hepatic arteriography and 64MDCT during arterial portography. Radiation monitors were used to measure air kerma ten times at each of five points: the center (A), top (B), left side (C), bottom (D), and right side (E).

Results

For C-arm CT vs. 64MDCT, air kerma after scanning was 10.5 ± 0.2 vs. 6.4 ± 0.0 for A, 1.5 ± 0.0 vs. 11.6 ± 0.2 for B, 37.1 ± 0.2 vs. 11.1 ± 0.1 for C, 55.6 ± 1.0 vs. 10.6 ± 0.1 for D, and 40.5 ± 0.5 vs. 11.7 ± 0.1 for E, respectively. Air kerma for A, B, C, D, and E was 1.64, 0.13, 3.34, 5.24, and 3.46 times greater for C-arm CT than for 64MDCT, respectively.

Conclusion

Using the same scanning parameters as for clinical cases, air kerma values were greater with C-arm CT than with 64MDCT; at the dorsal side of the phantom, they were 5.24 times greater with C-arm CT compared with 64MDCT.     

Computed tomography for occult fractures of the proximal femur,pelvis, and sacrum in clinical practice: single institution,dual-site experience

Purpose

The purpose of this study was to evaluate the diagnostic performance of CT for assessment of occult fractures of the proximal femur, pelvis, and sacrum.

Materials and methods

A retrospective review was performed on patients who received a CT of the hip or pelvis for suspected occult fracture after negative or equivocal radiographs performed within 24 h. The official radiology report was utilized for the determination of CT findings and calculation of sensitivity and specificity. Surgical reports, MRI reports, and clinical follow-up were used as the standard of reference. Sensitivity and specificity were calculated with 95% confidence intervals.

Results

Seventy-four patients received CT of the hip or pelvis for clinical concern for occult fracture after negative or equivocal radiographs. By the reference standard, a total of 40 fractures were present in 25/74 (33.8%) patients, including 35 conservatively treated fractures of the greater trochanter, pelvis, and sacrum, and 5 operatively treated proximal femoral fractures. A total of 14/74 (18.9%) of patients had an MRI within 1 day of CT. MRI identified an operatively treated femoral neck fracture not seen on CT and an operatively treated intertrochanteric fracture, which CT described as a greater trochanteric fracture. There were two false negative conservatively treated pelvic fractures not seen on CT but diagnosed on MRI. On a per-patient basis, CT had an overall sensitivity of 88% (22/25; 95% confidence intervals 69–97%), specificity of 98% (48/49; 95% confidence intervals 89–100%), and negative predictive value of 94%. For the five operative proximal femoral fractures, the sensitivity of CT was 60% (3/5; 95% confidence intervals 15–95%), specificity was 99% (68/69; 95% confidence intervals 92–100%), and negative predictive value was 97%.

Conclusions

In the clinical setting of suspected occult fracture, the sensitivity of clinical CT reports for detection of any type of fracture of the proximal femur, pelvis, or sacrum was 88%. For the small number of operatively treated proximal femoral fractures seen in the study, sensitivity of CT was 60% (3/5) and negative predictive value was 97%, although the relatively few patients needing fixation precludes statistical analysis.

     

The degree of articular depression as a predictor of soft-tissue injuries in tibial plateau fracture

Purpose

Magnetic resonance imaging (MRI) provides sufficient information with regard to specific soft-tissue injuries in the knee, but it is not generally used to evaluate acute tibial plateau fractures. The aim of the present study was to determine whether the amount of tibial plateau fracture depression on multi-detector computed tomography (MDCT) scans correlates with the incidence of associated soft-tissue injuries on MRI.

Methods

A total of 54 consecutive patients with a mean age of 51.2 years (SD = 18.3) were included in this retrospective study. All patients were admitted to the emergency department of a university clinic with acute tibial plateau fracture. The amount of articular depression was assessed from MDCT scans. Magnetic resonance images were evaluated for crucial and collateral ligament injury, meniscal tears, and patellar retinaculum lesions.

Results

Logistic regression revealed a significant impact of increasing tibial plateau fracture depression on the incidence of meniscus lateralis tears (P = 0.025) and anterior cruciate ligament lesions (P = 0.018). Analysis of covariance demonstrated a significant correlation between the amount of articular depression and absolute number of soft-tissue injuries (P = 0.001).

Conclusions

Articular depression is a potential predictor of specific meniscal and ligamentous injuries in acute tibial plateau fracture. Magnetic resonance imaging is generally recommended with respect to associated soft-tissue injuries, especially in cases with distinct tibial plateau fracture depression on multi-detector computed tomography scans.

Level of evidence

Case series, Level IV.     

Current clinical use of 18FDG-PET/CT in patients with thoracic and systemic sarcoidosis

Purpose

This study assessed the role of whole-body ¹⁸fluorodeoxyglucose positron-emission tomography/computed tomography (¹⁸FDG PET/CT) in the restaging and follow-up of patients with sarcoidosis previously studied by multidetector computed tomography (MDCT).

Materials and methods

This retrospective study enroled 21 patients to evaluate the sensitivity, specificity and accuracy of ¹⁸FDG-PET/CT and MDCT. The results of the two techniques were compared with the Mc Nemar test. Cohen’s K was used to compare concordance at the different lesion sites.

Results

The sensitivity, specificity and accuracy of ¹⁸FDG-PET/CT were 80, 66.67, and 76.19 %, respectively. The sensitivity, specificity and accuracy of MDCT were 93.33, 33.33, and 76.19 %, respectively. In 16 patients who underwent whole-body MDCT, the sensitivity, specificity and accuracy values were 91.67, 81.25, and 50 % (MDCT) and 100, 50, and 87.5 % (¹⁸FDG-PET/CT).

Conclusions

¹⁸FDG-PET/CT is useful in evaluating the extent of sarcoidosis and recognising lesions at different sites, including lymph nodes, lungs, liver, spleen and bone. It also improves the interpretation of the morphological lesions seen on MDCT and depicts a larger number of lesions. Therefore, ¹⁸FDG-PET/CT could be used to complement other more traditional techniques for the restaging and follow-up in patients with sarcoidosis.     

A comparative study of FDG PET/CT and enhanced multi-detector CT for detecting liver metastasis according to the size and location

Purpose

The aim of this study was to compare the diagnosability between ¹⁸F-fluorodeoxyglucose (FDG) PET/CT and enhanced multi-detector CT (MDCT) for the detection of liver metastasis (LM) according to the size and location in liver and to evaluate standard maximum standardized uptake values (SUVmax) of all liver metastatic lesions.

Materials and methods

One hundred two consecutive patients with malignancy who underwent both FDG PET/CT and MDCT for LM evaluation were retrospectively reviewed. Among them, 56 patients with LM were enrolled in this study. LM was confirmed by follow-up imaging studies after at least 6 months or by histopathology. FDG PET/CT and MDCT images were visually analyzed using three-point scale by the consensus of two radiologists and two nuclear medicine physicians. The size and location (central vs. sub-capsular) of the all liver lesions were evaluated using MDCT images. Furthermore, SUVmax of all liver lesions on FDG PET/CT images were calculated.

Results

A total of 146 liver lesions were detected by FDG PET/CT and MDCT and 142 of the lesions were diagnosed as LM. The detection rates of MDCT and FDG PET/CT for LM by visual analysis were 77 and 78 %, respectively. There was no significant difference of detection rate according to the overall location and size of the lesions. However, FDG PET/CT was more sensitive than MDCT for detecting small and sub-capsular LM. The detection rate of FDG PET/CT for LM was 68 % by the cutoff SUVmax of 2.7.

Conclusions

Although the diagnosabilities of MDCT and FDG PET/CT for detecting LM were comparable, FDG PET/CT is superior to MDCT for detecting small LM located in the sub-capsular portion of liver.     

Adolescent patellar osteochondral fracture following patellar dislocation

Purpose

Patellar dislocations in adolescents may cause osteochondral fractures of the patella. The aim of this study was to review the outcomes of adolescent patients who underwent surgical intervention for patellar osteochondral fracture following patellar dislocation.

Methods

Nine patients who underwent surgery for osteochondral fracture of the patella following dislocation were identified retrospectively. Following arthroscopic examination, if the fragment was large enough to support fixation, headless screws or bioabsorbable pins were used. Otherwise, the loose body was excised, and the donor site was managed with a microfracture. Postoperatively, patients were assessed using the International Knee Documentation Committee (IKDC) and Knee injury and Osteoarthritis Outcome Score (KOOS) outcome measures.

Results

The average age of the patients was 14.6 with average follow-up 30.2 months. Four of the nine patients underwent fixation, while five patients underwent removal of loose body with microfracture. The average defect size in the nonfixation group was 1.2 cm² compared with 3.2 cm² in the fixation group. The IKDC scores for fixation and nonfixation groups were 63.9 (SD = 18) and 76.1 (SD = 11.7), respectively. The KOOS subscale scores for symptoms, function in sports and recreation, and knee-related quality of life were higher for the nonfixation group when compared to the fixation group.

Conclusions

This is the first known series examining surgical outcomes of osteochondral fractures of the patella following patellar dislocations in the adolescent population. While patients without fixation were less symptomatic in this series, this may be attributable to more severe injuries in patients undergoing fracture fixation.

Level of evidence

Retrospective case series, Level IV.     

Surgical indications for treatment for femoroacetabular impingement with surgical hip dislocation

Purpose

There is a lack of detailed information about the indications of surgical treatment for femoroacetabular impingement (FAI), particularly using open surgical dislocation. The purpose of this review was to systematically review the reported indications for surgical dislocation of the hip for FAI.

Methods

Two databases (MEDLINE and EMBASE) were screened for clinical studies involving the treatment for FAI with surgical hip dislocation. We conducted a full-text review and the references for each included paper were hand-searched for other eligible studies. Papers published until September 2011 were included in this review. Two individuals reviewed all identified studies independently, and any disagreement was resolved through consensus.

Results

Fifteen studies met the eligibility criteria, which included a total of 822 patients. We identified a lack of consensus for clinical and radiographic indications for surgical hip dislocation to treat FAI. The most common clinical indications reported were clinical symptoms such as hip pain in 10 papers (67 %), a positive impingement sign in 9 papers (60 %), painful/reduced range of motion in 9 papers (60 %), activity-related groin pain in 4 papers (27 %), and non-responsive to non-operative treatment in 4 papers (27 %). The most commonly reported radiographic indicators for surgical hip dislocation were a variety of impingement findings from radiographs in all 15 included papers (100 %), a combination of radiographs and MRA in 5 papers (33 %) or radiographs and MRI in 3 papers (20 %).

Conclusions

These results showed that that there was an inconsistency between the clinical and radiographic indications for surgical hip dislocation as a treatment for femoroacetabular impingement. This review suggests that there is a need for the development of standardized clinical and radiological criteria that serve as guidelines for surgical treatment for FAI.

Level of evidence

Systematic review, Level IV.     

Radiographic features of multifocal endosteal thickening of the femur in patients on long-term bisphosphonate therapy

Objectives

To describe the characteristics of multifocal endosteal thickening in patients on bisphosphonate therapy.

Method

A retrospective study of 68 patients with atypical femoral fractures (as defined by ASBMR) whilst on bisphosphonate therapy was performed. Femoral radiographs were assessed for: focal endosteal thickening, number of lesions, lesion location, femoral bowing, periosteal beak and black line. Medical records were reviewed to obtain relevant clinical data.

Results

Forty-eight lesions with multifocal endosteal thickening were detected in seven patients (2 unilateral, 5 bilateral), affecting 11.8 % of femora. Location was mainly diaphyseal (95.8 %), upper (10.4 %), middle (58.3 %) and lower femur (31.3 %), involving the lateral (85.4 %), anterior (6.3 %), anterolateral (2.1 %) and posterior cortices (6.3 %). Femoral bowing was present in 85.7 %. Associated findings of a periosteal beak and/or a black line, seen in 14.6 %, were associated with increased fracture risk (100.0 % sensitivity, 93.2 % specificity).

Conclusions

Multifocal endosteal thickening is a new finding seen in patients with low bone mineral density on bisphosphonate therapy. They are rare, frequently bilateral, predominantly diaphyseal in location involving the lateral cortex and often associated with bowing. Caution is advised when seen in association with periosteal beak and/or black line because of a high rate of progression to complete fracture.

Key Points

? Multifocal endosteal thickening in the femur is a newly described radiographic finding. ? It is seen in patients with atypical femoral fractures whilst on bisphosphonate therapy. ? It typically involves the lateral cortex in the lower femur. ? A periosteal beak and/or black line may indicate an impending fracture.     

Explorative study of the sensitivity and specificity of the pronator quadratus fat pad sign as a predictor of subtle wrist fractures

Objective

To investigate the value of post-traumatic pronator quadratus (PQ) fat pad sign as a reliable predictor of subtle wrist fractures.

Materials and methods

This was a prospective study of 68 patients undergoing X-ray for traumatic wrist injuries and subsequent MRI. The reliability of a positive PQ fat pad sign on X-ray, defined as either raised, interrupted or obliterated, was evaluated in detection of subtle wrist fractures.

Results

Out of 68 patients, 28 had a positive PQ sign without any obvious bony injuries on plain radiographs; of these, the PQ fat pad was obliterated in 11, disrupted in 12, and raised in five cases. Fractures defined as cortical interruption or trabecular fractures were revealed in 13/28 (46 %) patients with a positive PQ sign but only in 7/40 (18 %) patients with a negative sign. With regards to different types of abnormal PQ fat planes, fractures were present in 7/12 patients with a disrupted plane (58 %), 6/11 patients with an obliterated plane (54 %), and none of the patients with a raised plane. The overall sensitivity and specificity of a positive PQ sign in the prediction of occult wrist fractures were 65 and 69 %, respectively.

Conclusions

Our findings indicate that a positive pronator quadratus (PQ) fat pad sign is not a reliable predictor of subtle fractures of the wrist, although we believe that it is a useful radiographic sign in justifying MRI for further clarification of possible joint abnormalities including occult fracture and cortex interruption.     

The difficult diagnosis of cartilaginous tibial eminence fractures in young children

Purpose

Anterior tibial eminence fracture is the main mode of ACL failure in patients with open physes. In young children, purely cartilaginous avulsions of the tibial ACL insertion are possible. The aim of this study was to focus on patients referred for misdiagnosed cartilaginous tibial eminence fractures.

Methods

Ten young patients with cartilaginous tibial eminence fractures were identified in the hospital database. Six of them were misdiagnosed and included in this retrospective case series. Clinical data at the time of injury, radiographs and MRI were analysed in order to evaluate the causes which could have led to inappropriate management.

Results

The patients’ median age at the time of injury was 7 years (5–8.5). The main cause of injury was a low-energy domestic accident (n = 4). Radiographs at the time of injury were normal (n = 4) or showed a very thin ossification (n = 2). The traditional MRI findings of ACL injuries were all negative. On T2 sequences, an epiphyseal fluid signal allowed for a retrospective diagnosis. Cartilaginous tibial eminence fractures were regularly prolonged posteriorly giving a ‘double-PCL sign’ in 4 of the 6 patients. On a median of 6 months (2.5–48) after the injury, patients were referred for repeat giving ways (n = 5) and/or limitation of extension or hyperextension (n = 4). Symptoms were related to non-union, ossification and secondary enlargement of the avulsed fragment.

Conclusions

Post-traumatic knee joint effusions in children aged 9 or younger, even occurring after a low energy trauma and with normal radiographs, should suggest a cartilaginous tibial eminence fracture. Systematic MRI examinations should be mandatory in these patients in whom the avulsed fragment may appear as a double-PCL sign. During follow-up, new radiographs are recommended. A better knowledge of this rare entity should allow us to avoid misdiagnosis and to perform an early refixation of the avulsed fragment.

Level of evidence

III.