Faculty Bibliography

OBJECTIVES: Progression of an incomplete atypical femoral fracture (IF) to a complete fracture in patients on long term bisphosphonate (BP) therapy can be catastrophic. We aimed to determine the frequency and imaging features of IF in asymptomatic patients on long-term BP therapy and to identify distinguishing clinical and laboratory markers in the subset of patients who develop these fractures. MATERIAL AND METHODS: From August 2009 to March 2011, 220 femoral radiographs in 110 asymptomatic patients (101 women, 9 men, age 47-94) were reviewed by 2 radiologists. All patients were on BP therapy for at least 3years and had no history of hip/thigh pain or recent trauma. MRI was performed when a fracture was suspected on radiographs. Bone mineral density, serum calcium, 25-hydroxy vitamin D, intact parathyroid hormone, serum c-telopeptide and urine n-telopeptide were obtained in all patients. RESULTS: Two of 110 patients (1.82%, confidence interval of 0.6% to 6.3%) had 3 IFs. Both patients, age 50 and 57, were Caucasian, active and on BP for 8years. MRI confirmed radiographic findings in both patients. Both women had T-scores in the osteopenic range at 2 sites and osteoporotic range at 1 site. CONCLUSION: The 1.82% frequency of IF in asymptomatic patients on long term BP therapy is higher than that suggested in the literature. Statistical differences between fracture and non-fracture groups were not presented as the patient population was too small to draw any significant conclusions.

Objectives: To elucidate the effects of prolonged bisphosphonate (BP) exposure on the development of atypical fragility fractures and to define risk factors.Methods: Approval was obtained from the IRB. A retrospective chart analysis was performed on 51 patients with complete subtrochanteric or diaphyseal femoral fracture(s) from January 2005 to April 2011 while on BP for at least 3 years; 25 patients (mean age 67.52) had all available data. All fractures included in the study were low or no energy fractures. Relevant clinical and demographic data including age, gender, ethnicity, height, weight, comorbid medical conditions, and medications were collected. Imaging and laboratory data including calcium, alkaline phosphatase, 25-hydroxy vitamin D(25-OHD), intact parathyroid hormone(PTH), serum c-telopeptide(CTX), urine n-telopeptide(NTX), bone mineral density, radiography and MRI were obtained in all patients.Results: The majority of patients were Caucasian, on alendronate, had bilateral findings, and almost half had prodromal symptoms. 45.8% had a 25-OHD level that was suboptimal (less than 30 ng/ml). Mean BP duration was 9.84 years and mean bone densities were in the osteopenic, not osteoporotic, range.Conclusion: Certain characteristics in patients with atypical BP-related fracture include relatively young age, long duration of BP use, suboptimal 25-OHD and bone densities in non-osteoporotic ranges. All of these may be significant risk factors for insufficiency fracture development.

OBJECTIVE: The purpose of this study was to assess the performance of a near-isotropic 3D turbo spin-echo sequence in comparison with a standard 2D protocol and with arthroscopy in direct 1.5-T MR arthrography of the shoulder. SUBJECTS AND METHODS: Dilute gadolinium was injected into three cadaver shoulders, and 3D turbo spin-echo and 2D sequences were evaluated with respect to the signal-to-noise and contrast-to-noise ratios of key tissues. In a prospective study, the 3D intermediate-weighted fat-suppressed sequence (reformatted in three planes) was added to shoulder MR arthrography of 43 consecutively registered patients, 13 of whom later underwent arthroscopy. Two radiologists independently graded the 3D and 2D images in separate sessions to visualize normal anatomic features and to detect pathologic changes in the labrum, cartilage, cuff, and glenohumeral ligaments, assigning confidence levels to their readings. One reader repeated the readings of images of 10 patients. Reports of subsequent arthroscopy were available for 13 patients. RESULTS: The sequences performed comparably with respect to signal-to-noise and contrast-to-noise ratios in the cadavers. The 3D images suffered from mildly increased blurring, but the readers were significantly more confident in assessing the proximal biceps tendon and curved portions of the labrum and in their findings of partial tears of the articular side of the supraspinatus tendon and posterior labral tears on the 3D images. A larger number of partial-thickness cartilage defects were found on 2D images. CONCLUSION: The 3D turbo spin-echo sequence is a promising technique that can be used in shoulder arthrography with image quality and results comparable to those of traditional 2D techniques. Use of the 3D technique may result in greater anatomic detail in evaluating small obliquely oriented structures, including the curved portions of the labrum and the intraarticular portion of the biceps tendon.

OBJECTIVE: The purpose of our study was to determine the frequency and imaging features of atypical femoral fractures in a consecutive asymptomatic patient population on long-term bisphosphonate treatment and search for distinguishing clinical and laboratory parameters in the subset of patients with fractures. SUBJECTS AND METHODS: Two hundred femoral radiographs in 100 asymptomatic patients (93 women and seven men; age range, 47-94 years; mean age, 69.3 years) were prospectively reviewed by two radiologists. All patients had received bisphosphonate treatment for at least 3 years and had no history of pain or recent trauma. MRI studies were performed when a fracture was suspected on radiographs. Bone mineral density, serum calcium, albumin, 25-hydroxy vitamin D, intact parathyroid hormone (iPTH), serum C-telopeptide, and urine N-telopeptide values were obtained. RESULTS: Two of 100 patients (2%) had three insufficiency fractures. Both patients, 50 and 57 years old, were white, active, and had been receiving bisphosphonate therapy for 8 years. The patient with bilateral atypical femoral fractures showed typical features of bisphosphonate-related incomplete atypical femoral fractures. MRI confirmed the radiographic findings in both patients. The two patients with incomplete atypical femoral fractures were significantly younger than those without atypical femoral fractures. There were no significant differences among the fracture and nonfracture groups in terms of clinical or laboratory results, except for mean iPTH, which was significantly decreased in the fracture group. CONCLUSION: The 2% frequency of incomplete atypical femoral fractures in asymptomatic patients on long-term bisphosphonate therapy is higher than suggested in the literature. Aside from age and mean iPTH, there were no significant differences in clinical or laboratory data between the two groups.

Improvement in both hardware and software has opened up new opportunities in magnetic resonance (MR) imaging of the shoulder. MR imaging at 3-T has become a reality, with the prospect of 7-T imaging on the horizon. The art of MR arthrography continues to improve, aided by the use of novel imaging positions. New techniques for three-dimensional imaging, the reduction of metal artifact, and biochemical imaging of cartilage hold great promise.

The compartment-specific lipid changes in femoral-tibial bone of healthy controls and mild osteoarthritis (OA) patients were quantified at 3.0 T. Healthy volunteers [Kellgren-Lawrence (KL) grade = 0; n = 15, 4 females, 11 males, mean age 39 +/- 16 years, age range = 24-78 years] and mild OA patients (KL = 1, 2; n = 26, 12 females, 14 males, mean age 61 +/- 14 years, age range = 27-80 years) were scanned on a 3 T scanner. Clinical proton density (PD)-weighted fast spin echo (FSE) images in the sagittal (without fat-saturation), axial and coronal (fat-saturation) planes were acquired for cartilage Whole-Organ MR Imaging Score (WORMS) grading. A voxel of 10 x 10 x 10 mm(3) was positioned in the medial and lateral compartments of the tibia [medial tibial (MT) and lateral tibial (LT)] and femur [medial femoral (MF) and lateral femoral (LF)] for MRS measurements using the single voxel-stimulated echo acquisition mode (STEAM) pulse sequence. All MRS data were processed with Java-based Magnetic Resonance User Interface (JMRUI). Wilcoxon's rank sum test and mixed model two-way analysis of variance (anova) were performed to determine significant differences between different compartments as well as examine the effect of OA grade and compartment, and their interactions. Generally, the MF compartment index of unsaturation was increased in healthy subjects compared with OA subjects (whether graded by KL or WORMS score). Differences between MF at KL0 and all other compartments at KL1 except LF approached statistical significance (p < 0.05). Differences in saturated lipids signals could be observed predominantly in the 2.03 p.p.m. frequency shift. Healthy controls in the MF compartment had the lowest saturated lipid signals, and mild OA patients with KL2 and WORMS5-6 in the MF compartment had the highest saturated lipid signals compared with other compartments at 2.03 p.p.m. (p < 0.05).

OBJECTIVE: To assess and compare subregional and whole T1rho values (median+/-interquartile range) of femorotibial cartilage and menisci in patients with doubtful (Kellgren-Lawrence (KL) grade 1) to severe (KL4) osteoarthritis (OA) at 3T. MATERIALS AND METHODS: 30 subjects with varying degrees of OA (KL1-4, 13 females, 17 males, mean age+/-SD=63.9+/-13.1 years) were evaluated on a 3T MR scanner using a spin-lock-based 3D GRE sequence for T1rho mapping. Clinical proton density (PD)-weighted fast spin echo (FSE) images in sagittal (without fat saturation), axial, and coronal (fat-saturated) planes were acquired for cartilage and meniscus Whole-organ MR imaging score (WORMS) grading. Wilcoxon rank sum test was performed to determine whether there were any statistically significant differences between subregional and whole T1rho values of femorotibial cartilage and menisci in subjects with doubtful to severe OA. RESULTS: Lateral (72+/-10ms, median+/-interquartile range) and medial (65+/-10ms) femoral anterior cartilage subregions in moderate-severe OA subjects had significantly higher T1rho values (P<0.05) than cartilage subregions and whole femorotibial cartilage in doubtful-minimal OA subjects. There were statistically significant differences in meniscus T1rho values of the medial posterior subregion of subjects with moderate-severe OA and T1rho values of all subregions and the whole meniscus in subjects with doubtful-minimal OA. When evaluated based on WORMS, statistically significant differences were identified in T1rho values between the lateral femoral anterior cartilage subregion in patients with WORMS5-6 (advanced degeneration) and whole femorotibial cartilage and all cartilage subregions in patients with WORMS0-1 (normal). CONCLUSION: T1rho values are higher in specific meniscus and femorotibial cartilage subregions. These findings suggest that regional damage of both femorotibial hyaline cartilage and menisci may be associated with osteoarthritis

OBJECTIVE: The purpose of this study was to describe the MRI features of cortical desmoids associated with acute trauma. CONCLUSION: Marrow edema, periostitis, and adjacent soft-tissue edema can be seen in cases of cortical desmoid associated with acute trauma

OBJECTIVE: The objective of our study was to evaluate the diagnostic utility of conventional radiography for diagnosing bisphosphonate-related atypical subtrochanteric femoral fractures. MATERIALS AND METHODS: Retrospective interpretation of 38 radiographs of complete subtrochanteric and diaphyseal femoral fractures in two patient groups-one group being treated with bisphosphonates (19 fractures in 17 patients) and a second group not being treated with bisphosphonates (19 fractures in 19 patients)-was performed by three radiologists. The readers assessed four imaging criteria: focal lateral cortical thickening, transverse fracture, medial femoral spike, and fracture comminution. The odds ratios and the sensitivity, specificity, and accuracy of each imaging criterion as a predictor of bisphosphonate-related fractures were calculated. Similarly, the interobserver agreement and the sensitivity, specificity, and accuracy of diagnosing bisphosphonate-related fractures (i.e., atypical femoral fractures) were determined for the three readers. RESULTS: Among the candidate predictors of bisphosphonate-related fractures, focal lateral cortical thickening and transverse fracture had the highest odds ratios (76.4 and 10.1, respectively). Medial spike and comminution had odd ratios of 3.8 and 0.63, respectively. Focal lateral cortical thickening and transverse fracture were also the most accurate factors for detecting bisphosphonate-related fractures for all readers. The sensitivity, specificity, and overall accuracy for diagnosing bisphosphonate-related fractures were 94.7%, 100%, and 97.4% for reader 1; 94.7%, 68.4%, and 81.6% for reader 2; and 89.5%, 89.5%, and 89.5% for reader 3, respectively. The interobserver agreement was substantial (kappa > 0.61). CONCLUSION: Radiographs are reliable for distinguishing between complete femoral fractures related to bisphosphonate use and those not related to bisphosphonate use. Focal lateral cortical thickening and transverse fracture are the most dependable signs, showing high odds ratios and the highest accuracy for diagnosing these fractures

OBJECTIVE: The appearance and distribution of the intra-articular plicae of the hip have been addressed in few reports in the anatomic and radiological literature. This study aims to determine the prevalence of visible synovial hip plicae using MR arthrography and to measure the association of visible synovial hip plicae with MR arthrographic diagnosis of labral tears, femoroacetabular impingement, and osteoarthritis. MATERIALS AND METHODS: Following institutional review board approval, 63 direct MR arthrographic examinations of the hip in 61 patients with a clinical history of hip pain were retrospectively reviewed by two experienced musculoskeletal radiologists in consensus. The following variables were measured using a binary system (0 = absent; 1 = present): labral plica, neck plica, ligamental plica, labral tear, femoroacetabular impingement, and osteoarthritis. The surgical reports and arthroscopic images of 10 patients were reviewed. Statistical analysis was performed using the Fisher's exact test. RESULTS: In all 63 cases at least one plica was visualized on MR-arthrographic images. Labral, neck, and ligamental plicae were found with a prevalence of 76, 97, and 78%, respectively. There was no statistically significant association between the presence of labral tears, femoroacetabular impingement, and osteoarthritis among patients with visible labral, neck, and ligamental plicae. The prevalence of labral tears, femoroacetabular impingement, and osteoarthritis in our patient population was 79, 28, and 28%, respectively. The presence of intra-articular plicae was the only MR-arthrographic finding in 5 of our 63 symptomatic cases. CONCLUSION: Visible labral, neck, and/or ligamental plicae are highly prevalent on MR-arthrographic images of the hip performed in the setting of hip pain. There was no statistically significant association between the presence of labral tears, femoroacetabular impingement, and osteoarthritis and visible labral, neck, and ligamental plicae