Atypical Femoral Fractures: Transverse Morphology at Lateral Cortex Is a Critical Feature

In 2010, the American Society for Bone and Mineral Research (ASBMR) task force defined major and minor features to assist in the case finding and reporting of atypical femoral fractures (AFFs). One major feature that was proposed was a “transverse or short oblique configuration.” Our primary aim was to compare the conventional overall fracture morphology (OFM) with its associated angle (OFMA) and our proposed lateral cortical fracture angle (LCFA) in the assessment of fracture configuration in suspected AFFs and non‐AFFs. The radiographs of 79 patients with AFFs and 39 patients with non‐AFFs were each analyzed by two blinded reviewers to obtain the OFM, OFMA, and LCFA. Using the overall fracture morphology to assess the suspected AFFs resulted in discordance between reviewers in 18 cases (22.8%), of which 5 (6.3%) were discordant between short oblique (>30° to 60°) and long oblique (>60° to 90°) configurations, therefore affecting their classifications as AFFs. By assessing only the critical component within the lateral cortex, all the suspected AFFs fell well within the classification as transverse fractures with a mean LCFA of 4.8° (range 0.3 to 18.0, SD = 4.23). The inter‐reader variability was also lower for LCFA versus OFMA (4.1° versus 6.9°, p = 0.001) when used to assess AFFs. Fracture angles were significantly different in AFFs versus non‐AFFs regardless of whether the OFMA or LCFA methodology was employed, but the greater difference associated with LCFA suggests its greater discriminating power. When LCFA was used in conjunction with 0° to 30° as the criteria for transverse morphology, all the AFFs and non‐AFFs were correctly classified. By using a standardized and precise method in measuring the fracture angle, specifically using only the component of the lateral cortex and limiting to truly transverse fractures, ie, between 0° and 30°, the LCFA is a robust and accurate method to assess the fracture morphology in suspected AFFs. © 2014 American Society for Bone and Mineral Research.     

Potent Synergy and Sustained Bactericidal Activity of a Vancomycin-Colistin Combination versus Multidrug-Resistant Strains of Acinetobacter baumannii

Multidrug-resistant Acinetobacter baumannii (MDRAB) presents an increasing challenge to health care. Although colistin has been used as a treatment of last resort, there is concern regarding its potential for toxicity and the emergence of resistance. The mechanism of action of colistin, however, raises the possibility of synergy with compounds that are normally inactive against Gram-negative organisms by virtue of the impermeability of the bacterial outer membrane. This study evaluated the effect of colistin combined with vancomycin on 5 previously characterized epidemic strains and 34 MDRAB clinical isolates by using time-kill assay, microdilution, and Etest methods. For all the isolates, significant synergy was demonstrated by at least one method, with reductions in the MIC of vancomycin from >256 μg/ml to ≤48 μg/ml for all strains after exposure to 0.5 μg/ml colistin. This raises the possibility of the clinical use of this combination for infections due to MDRAB, with the potential for doses lower than those currently used.Infections due to multidrug-resistant Acinetobacter baumannii (MDRAB) present an enormous challenge to health care. The organism has been implicated in infections at a variety of sites, including the respiratory tract, bloodstream, skin and soft tissues, and prosthetic devices (26), and has become a particular problem in intensive therapy units (ITU) (6). The emergence of strains resistant to almost all currently available antibiotics has resulted in increased reliance on the polymyxins, a class of antibiotics largely abandoned in past decades due to concerns about the neurotoxicity and nephrotoxicity of the commercially available polymyxin E formulations, colistin sulfate and sodium colistin methanesulfonate (9). As a result, there is some uncertainty regarding their clinical efficacy, optimal dosing regimens, and the potential for the development of resistance. In some MDRAB isolates, heteroresistance to colistin has been observed in vitro and has also developed during therapy (11, 13, 28), raising concerns that colistin alone may lack sufficient killing activity to be used as a monotherapy (24).A number of studies have assessed the activity of polymyxins when combined with other antimicrobials. In vitro synergy against MDRAB can be demonstrated when colistin is combined with rifampin, minocycline, ceftazidime, imipenem, or azithromycin (31, 32, 38), although often the effect is marginal, with little concordance between the different methods used to assess the potency of the observed effect (2).The precise mechanism of action of colistin is not entirely clear. Polymyxins have been shown to disrupt the integrity of the Gram-negative bacterial membrane (16) via an electrostatic interaction with negatively charged phosphate residues in the core region of the lipid A component of lipopolysaccharide (LPS). Although the bactericidal activity of colistin arises from osmotic rupture of the cytoplasmic membrane, it also increases the permeability of the outer membrane to substances that are usually excluded (36) and may enhance the activity of hydrophobic antibiotics, which otherwise have little effect on Gram-negative bacteria (15).The glycopeptide vancomycin, an inhibitor of bacterial peptidoglycan synthesis, is one such molecule that, due to its large size and hydrophobicity, lacks activity against Gram-negative bacteria. The cell-permeabilizing properties of colistin could, however, be exploited to improve the penetration of glycopeptides through the A. baumannii outer membrane toward their targets in the cell wall. In order to determine its potential for the treatment of MDRAB, we assessed the in vitro activity and kill kinetics of a vancomycin-colistin combination against a number of MDRAB isolates prevalent in the United Kingdom.     

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.     

Prognostic factors for upper tract transitional cell carcinoma: a retrospective review of 66 patients

OBJECTIVE: We assessed the prognostic factors on recurrence and disease-specific survival of patients treated for upper tract transitional cell carcinoma (TCC). METHODS: Data on 66 patients who were treated for upper tract TCC in a single centre over a 13-year period were analysed. Mean follow-up time was 49.2 months. Fifty-five out of 66 (83.3%) underwent nephroureterectomy with excision of a bladder cuff. Four (6.1%) patients had nephrectomy alone while three (4.5%) had renal-sparing surgery. Four patients did not receive surgery due to advanced age and other comorbidities. Age, sex, tumour location, stage and grade were analysed as prognostic factors for disease recurrence and disease-specific survival using log rank univariate analysis. RESULTS: Disease recurrence occurred in 45 (68.2%) patients at a median time of 11.0 months. Recurrences were found in the bladder in 27.3%, the contralateral renal pelvis in 4.5%, local retroperitoneum in 19.7%, distant sites in 13.6%, with simultaneous local and distant metastases occurring in 3.0%. Tumour stage was the only significant prognostic factor for recurrence. Presence of extraurothelial recurrence, stage and grade were significant prognostic factors for disease-specific survival. CONCLUSION: Tumour stage was the most consistent predictor of both disease recurrence and survival. These findings would guide the need for any adjuvant chemoradiotherapy.     

Vertebrae adjacent to spinal bone lesion are inconsistent reference markers: a magnetic resonance spectroscopic viewpoint

PURPOSE: To ascertain the suitability of vertebrae adjacent to spinal bone lesions as a signal intensity reference on MRI, and compare the MR spectroscopic appearance of vertebral body compression fractures due to malignant tumor infiltration, bone weakening (e.g., osteoporosis), and/or minor trauma. MATERIALS AND METHODS: Twenty-five patients with spinal compression fractures underwent routine spinal MRI with an additional 1H MRS study protocol to assess the percent fat fraction of the compressed vertebrae as well as the adjacent bony environment. Peak areas for water and total lipid were calculated from short-TE single-voxel 1H MR spectra using the LCModel analyzing tool. RESULTS: There were consistent water-only patterns in the fractured vertebra suggesting either near complete marrow replacement by malignant tissue or local edematous fluid/hemorrhage within the marrow spaces. However, the adjacent vertebrae showed a wide range of patterns from a dominant lipid signal to the inverse of a pronounced water level. These results far exceed the normal variation expected based on age and sex. CONCLUSION: The results suggest that the adjacent vertebrae may not be an accurate reference, especially in diffusion-weighted imaging (DWI), because of the large difference between the two compartments. Furthermore, in the case of gradient-echo measurements, the in-phase vs. opposed-phase effects are significant.     

Contemporary management of urethral trauma and the post-traumatic stricture

This review discusses the contemporary management of urethral trauma and post-traumatic urethral strictures occurring in both the anterior and posterior urethra. Experience in the full spectrum of urethral reconstructive procedures is important. The initial management of patients relies upon adequate drainage of the bladder and management of any other associated acute life-threatening injuries. The principles of urethral reconstruction in both the anterior and posterior urethra are discussed, with reference to the recent literature on the subject.