Low avascular necrosis rates in femoral neck fractures: efficacy of cannulated screw fixation.

PURPOSE: Cannulated screw fixation for femoral neck fractures is often limited by concerns of avascular necrosis (AVN) occurring, historically seen in 5-40% of fixed intracapsular fractures. This study aims to assess the outcomes, particularly the AVN rate, associated with current surgical techniques within our unit. METHODS: We conducted a single-center cross-sectional study, manually searching operative records between July 14, 2014, and December 1, 2018, identifying patients with intracapsular fractured neck of femur fixed with cannulated screws, with a minimum of two years follow-up. Patient records and radiographs were reviewed for clinical and radiographic diagnoses of AVN, non-union, post-operative metalwork infection, and screw penetration of the head. Additionally, fracture pattern and displacement, screw configuration, reduction techniques, and adequacy of reduction were recorded, with radiographs independently analyzed by four orthopedic surgeons. RESULTS: Fifty-six patients were included; average age of 67 years (range 30-100). Forty-two patients (75%) sustained displaced fractures and 14 patients (25%) had undisplaced fractures. Two (4%) patients developed AVN, with no cases of non-union, post-operative metalwork infection or screw penetration of the head. Eight patients (14%) sustained a high-energy injury, though none of these patients developed AVN. All fractures required closed reduction; no open reductions performed. Twenty-seven (64%) of reductions were adequate. CONCLUSION: Our observed AVN rate is notably lower than the widely reported figures, even among a significant proportion of displaced fractures that were fixed. This study underscores that with adequate fixation, cannulated screws represent an excellent option for treating intracapsular neck of femur fractures, even in cases of displaced fracture patterns with imperfect reduction.

Juvenile bovine bone is an appropriate surrogate for normal and reduced density human bone in biomechanical testing: a validation study.

Orthopaedic research necessitates accurate and reliable models of human bone to enable biomechanical discoveries and translation into clinical scenarios. Juvenile bovine bone is postulated to be a potential model of normal human bone given its dimensions and comparatively reduced ethical restrictions. Demineralisation techniques can reduce bone density and alter bone properties, and methods to model osteoporotic bone using demineralised juvenile bovine bone are investigated. Juvenile bovine long bones were quantitatively CT scanned to assess bone density. Demineralisation using hydrochloric acid (0.6, 1.2 and 2.4 M) was performed to create different bone density models which underwent biomechanical validation for normal and osteoporotic bone models. All long bones were found to have comparable features to normal human bone including bone density (1.96 ± 0.08 gcm-3), screw insertion torque and pullout strength. Demineralisation significantly reduced bone density and pullout strength for all types, with 0.6 M hydrochloric acid creating reductions of 25% and 71% respectively. Juvenile bovine bone is inexpensive, easy to source and not subject to extensive ethical procedures. This study establishes for the first time, the use of its long bones as surrogates for both normal and osteoporotic human specimens and offers preliminary validation for its use in biomechanical testing.

Can FDG-PET be used to predict growth of stage I lung cancer?

AIM: To determine the relationship between the metabolic activity measured by 2-[(18)F]-fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET) and computed tomography (CT)-derived tumour growth rates for stage 1 lung cancer. METHODS: Stage I lung cancer patients at our institution who underwent FDG PET, and who had at least two pre-treatment chest CT examinations (n=51), were retrospectively identified. Metabolic activity was defined by maximum lesion standardized uptake value (SUV) and maximum lesion-to-mean background activity (LBR). Growth rates were determined from serial CT volume measurements and the doubling time (DT) was calculated. Tumour growth rates were divided into rapid (DT<180 days), intermediate (DT=180-270 days), and slow (DT>270 days) groups. RESULTS: Rapid, moderate, and slow DT were seen in 22, 19, and 10 patients, respectively. Means (standard deviations) of SUV in the three groups (from rapid to slow growth rate) were 8.2 (4.8), 5.5 (4.5), and 2.2 (1.1), respectively and of LBR were 22.7 (10.1), 15.1 (12.6), and 6 (2.6), respectively. There was a significant relationship between SUV and DT (p<0.05), as well as between LBR and DT (p<0.05). CONCLUSIONS: For stage I lung tumours, there is a significant relationship between growth rates, as measured by serial CT examinations, and the initial pre-treatment metabolic activities, as measured by FDG uptake. This suggests that in patients in whom it is difficult to decide on the aggressiveness on treatment, FDG-PET may be used as additional prognostic tool for determining management.

Salmonid microarrays identify intestinal genes that reliably monitor P deficiency in rainbow trout aquaculture.

Nutrient-responsive genes can identify important metabolic pathways and evaluate optimal dietary levels. Using a 16K Salmo salar microarray, we identified in rainbow trout (Oncorhynchus mykiss) 21 potential phosphorus (P)-responsive genes, mainly involved in immune response, proteolysis or transport, whose expression levels changed in the intestine after 5 days of feeding a low-P (LP) diet. Diet-induced changes in the expression levels of several genes in each fish were tightly correlated with changes in serum P, and the changes persisted for an additional 15 days after dietary P deficiency. We then evaluated these and previously identified P-responsive genes under simulated farm conditions, and monitored the intestinal gene expression from 6 h to 7 days after the trout were switched from a sufficient-P (SP) diet to a LP diet (SP-->LP), and from a LP diet to a SP diet (LP-->SP). After 7 days, mean serum P decreased 0.14 mM/day for SP-->LP and increased 0.10 mm/day for LP-->SP. The mRNA abundance of the metalloendopeptidase meprin 1alpha (MEP1alpha), the Na(+)-dependent phosphate co-transporter (NaPi2b,SLC34A2), the sulfotransferase SULT2beta1 and carbonic anhydrase XIII genes all increased after SP-->LP and decreased after LP-->SP, suggesting that adaptive expression is reversible and correlated with dietary P. The duration of change in gene expression in response to SP-->LP was generally shorter than that of LP-->SP, suggesting potentially different mechanisms of adaptation to deficiency as opposed to excess. Diet-induced changes in mRNA abundance of other genes were either transient or modest. We identified, by heterologous microarray hybridization, new genes sensitive to perturbations in dietary P, and then showed that these genes can reliably monitor P deficiency under field conditions. Simultaneous changes in the expression of these P biomarkers could predict either P deficiency (to prevent economic losses to the farmers) or P excess (to prevent inadvertent pollution of nearby waters).

Dietary P regulates phosphate transporter expression, phosphatase activity, and effluent P partitioning in trout culture.

Phosphate utilization by fish is an important issue because of its critical roles in fish growth and aquatic environmental pollution. High dietary phosphorus (P) levels typically decrease the efficiency of P utilization, thereby increasing the amount of P excreted as metabolic waste in effluents emanating from rainbow trout aquaculture. In mammals, vitamin D3 is a known regulator of P utilization but in fish, its regulatory role is unclear. Moreover, the effects of dietary P and vitamin D3 on expression of enzymatic and transport systems potentially involved in phosphate utilization are little known. We therefore monitored production of effluent P, levels of plasma vitamin D3 metabolites, as well as expression of phosphatases and the sodium phosphate cotransporter (NaPi2) in trout fed semipu diets that varied in dietary P and vitamin D3 levels. Mean soluble P concentrations varied markedly with dietary P but not with vitamin D3, and constituted 40-70% of total effluent P production by trout. Particulate P concentrations accounted for 25-50% of effluent P production, but did not vary with dietary P or vitamin D3. P in settleable wastes accounted for <10% of effluent P. The stronger effect of dietary P on effluent P levels is paralleled by its striking effects on phosphatases and NaPi2. The mRNA abundance of the intestinal and renal sodium phosphate transporters increased in fish fed low dietary P; vitamin D3 had no effect. Low-P diets reduced plasma phosphate concentrations. Intracellular phytase activity increased but brushborder alkaline phosphatase activity decreased in the intestine, pyloric caeca, and gills of trout fed diets containing low dietary P. Vitamin D3 had no effect on enzyme activities. Moreover, plasma concentrations of 25-hydroxyvitamin D3 and of 1,25-dihydroxyvitamin D3 were unaffected by dietary P and vitamin D3 levels. The major regulator of P metabolism, and ultimately of levels of P in the effluent from trout culture, is dietary P.

Recurrent myxoma of the hand.

Myxoma is a rare benign tumor composed of stellate or spindle-shaped cells in a loose myxoid stroma. Few cases involving the hand have previously been described. We present a rare case of recurrent myxoma in the intermetacarpal space and detail the clinical behavior of this indolent tumor.

Surveillance for recurrent head and neck cancer using positron emission tomography.

PURPOSE: Earlier detection of head and neck cancer recurrence may improve survival. We evaluated the ability of [(18)F]fluorodeoxyglucose positron emission tomography (FDG-PET) to detect recurrence in a prospective trial using sequential PET scans. PATIENTS AND METHODS: Serial posttherapy FDG-PET was prospectively performed in 44 patients with stage III or IV head and neck cancer. PET was performed twice during the first posttreatment year (at 2 and 10 months after therapy) and thereafter as needed. After therapy, patients were grouped, based on tissue biopsies, into those who achieved a complete response (CR) and those who had residual disease (RD). Patients who achieved a CR were further grouped into those without evidence of disease and those who had recurrence by 1 year after completion of therapy. Disease status as determined by physical examination (PE), PET, and correlative imaging was compared. RESULTS: Eight patients were lost to follow-up and six had RD after therapy. Of the remaining 30 patients with a CR, 16 had recurrence in the first year after therapy. Five of these 16 patients had recurrence detected by PET only, four by PET and correlative imaging only, five by PE and PET only, and two by PE, correlative imaging, and PET. Only PET detected all recurrences in the first year. PET performed better than correlative imaging (P =.013) or PE (P =.002) in the detection of recurrence. CONCLUSION: PET can detect head and neck tumor recurrence when it may be undetectable by other clinical methods. FDG-PET permits highly accurate detection of head and neck cancer recurrence in the posttherapy period.

Anatomy of a meta-analysis: a critical review of "exercise echocardiography or exercise SPECT imaging? A meta-analysis of diagnostic test performance".

BACKGROUND: Accurate diagnosis of coronary heart disease has the potential to contribute substantially to cost-effective delivery of health services. Recent work by Fleischmann et al (JAMA 1998;280:913-20) represents an effort to summarize the accuracy of exercise echocardiography and exercise single photon emission computed tomography (SPECT). METHODS AND RESULTS: A critique of the previous work was constructed, obtaining the 44 articles used. These articles were reviewed and summarized with established techniques for meta-analysis. The studies summarized by Fleischmann et al were found to be significantly heterogeneous (echocardiography and SPECT, both P<.001). In the SPECT cohort, combination of different radioisotopes and reading techniques, and inclusion of reports using experimental techniques, were sources of heterogeneity. In the echocardiography cohort, experimental techniques and an individual series were identified. When the sample was stratified for sources of heterogeneity, it was found that there was no significant difference in diagnostic accuracy between the echocardiography and SPECT techniques used in current clinical practice. Meta-regression with summary receiver operating characteristic curve techniques, after adjustment of the model for multicolinearity and outliers, revealed that there were no significant differences between SPECT as used in current clinical practice and echocardiography. CONCLUSION: The report by Fleischmann et al contains serious flaws that limit its validity and generalizability.

Primary and recurrent early stage laryngeal cancer: preliminary results of 2-[fluorine 18]fluoro-2-deoxy-D-glucose PET imaging.

PURPOSE: To evaluate the effectiveness of 2-[fluorine 18]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) in the identification of early stage (T1-T2) primary and recurrent laryngeal cancer. MATERIALS AND METHODS: Twelve patients with T1 or T2 laryngeal cancer underwent imaging prospectively with PET. Seven patients had new disease, and five had recurrent disease. All patients underwent imaging prior to planned therapy and tissue biopsy. PET images were evaluated by using standardized uptake ratios and visual analysis. RESULTS: Histopathologic evidence of early stage cancer was documented in the 12 patients. One had a carcinoma in situ, nine had T1 tumors, and two had T2 tumors. Of the 12 patients, 10 had vocal cord tumors, one had a hypopharyngeal tumor, and one had a preepiglottic tumor. Eleven (92%) patients with early stage cancer had standardized uptake ratios indicative of malignancy (mean, 4.6; SD, 1.8; 95% CI, 1.2; range, 2.8-7.6). One had false-negative results (standardized uptake ratio = 2.3). Nine underwent CT, and results in the larynx were normal in seven and abnormal in two. CONCLUSION: FDG PET can be used to identify primary and recurrent early stage laryngeal cancer. It may be useful for follow-up after therapy.

Overexpression of MPS antigens by squamous cell carcinomas of the head and neck: immunohistochemical and serological correlation with FDG positron emission tomography.

Survival from advanced primary or recurrent Squamous Cell Carcinoma (SCC) of the head and neck (H&N) is poor. More accurate detection of primary tumors and recurrence may provide ways to improve survival. No standard serum tumor marker is routinely used for surveillance of SCC-H&N. In this paper, we evaluated the performance characteristics of the MPS-H tumor marker test for the quantitative measurement of "MPS-H" heat-generated immunoreactive proteins and assessed the clinical utility of this marker in the detection and monitoring of SCC-H&N. In approximately 92% of the subjects having no evidence of SCC-H&N, the MPS-H levels were lower than 15 ng/mL. In 76% of patients having SCC-H&N at various stages (T1-T4), the MPS-H level was > 15 ng/mL (range: 20-200 ng/mL). In addition, we found a statistically significant correlation between PET positive cases and high MPS-H serum levels in SCC-H&N patients with recurrent disease. These results suggest that MPS-H may provide an initial screening test that would allow for selective PET imaging in these patients. Furthermore, we found that there was greater expression of MPS-1 in tumors of higher histological grades. Thus, in tumors with more histological aggressiveness there is more MPS-1, indicating the potential usefulness of this marker in prognosis for SSC-H&N. Considering the immunohistochemical, serological, and FDG-PET data presented here, and the compelling need to expedite the early diagnosis of primary and recurrent epithelial malignancies of the head and neck, we are further evaluating the system of MPS antigens in a large patient population as a tool for the early serologic and histologic diagnosis of SCC-H&N.

Prospective investigation of positron emission tomography in lung nodules.

PURPOSE: Solitary pulmonary nodules (SPNs) are commonly identified by chest radiographs and computed tomography (CT). Biopsies are often performed to evaluate the nodules further. An accurate, noninvasive diagnostic test could avoid the morbidity and costs of invasive tissue sampling. We evaluated the ability of fluorine-18 deoxyglucose positron emission tomography (FDG-PET) to discriminate between benign and malignant pulmonary nodules in a prospective, multicenter trial. METHODS: Eighty-nine patients who had newly identified indeterminate SPNs on chest radiographs and CT were evaluated with FDG-PET. PET data were analyzed semiquantitatively by calculating standardized uptake values (SUVs) as an index of FDG accumulation and also by a visual scoring method. PET results were compared with pathology results. RESULTS: Sixty SPNs were malignant and 29 were benign. Using SUV data, PET had an overall sensitivity and specificity for detection of malignant nodules of 92% and 90%. Visual analysis provided a slightly higher, but not statistically significant, sensitivity of 98% and lower specificity of 69%. For SPNs < or = 1.5 cm (34 of 89), the sensitivity and specificity of SUV and visual analysis were 80% and 95% and 100% and 74%, respectively. CONCLUSION: FDG-PET can accurately characterize indeterminate SPNs. PET imaging provides a noninvasive method to evaluate indeterminate SPNs, which can reduce the need for invasive tissue biopsy.

Evaluation of chemotherapy response in patients with advanced head and neck cancer using [F-18]fluorodeoxyglucose positron emission tomography.

BACKGROUND: [F-18]Fluorodeoxyglucose (FDG)-positron emission tomography (PET) can measure the metabolic activity of tissues; FDG-PET may be able to predict response to chemotherapy by identifying changes in tumor metabolism. Measurement of response to treatment may help improve survival in the management of advanced head and neck cancer. We evaluated this particular use of FDG-PET in patients participating in a neoadjuvant organ-preservation protocol using taxol and carboplatin and compared pathologic response after chemotherapy with changes in tumor metabolism measured by FDG-PET. METHODS: Serial FDG-PET studies (n = 56) were performed in patients (n = 28) with stage III/IV head and neck cancer participating in a neoadjuvant organ-preservation protocol. The FDG-PET studies were performed before and after chemotherapy. All patients had tissue biopsies before and after chemotherapy. Patients were classified as pathologic complete response (PCR) or residual disease (RD) based on tissue biopsies. Visual analysis of PET scans was performed to identify patients with complete response by PET, and these findings were compared with pathology results. Metabolic changes were also evaluated using standardized uptake ratios (SUR) of FDG. RESULTS: The sensitivity and specificity of PET for residual cancer after therapy was 90% (19/21) and 83% (5/6), respectively. Two patients had initially negative biopsies and positive PET studies for persistent disease. Pathology review and rebiospy led to confirmation of the PET results in these cases, giving a sensitivity of 90% for initial tissue biopsy. CONCLUSIONS: In this preliminary analysis, FDG-PET was accurate in classifying response to chemotherapy in most patients. Fluorodeoxyglucose-PET may identify residual viable tumor when it is otherwise undetectable.

Metallopanstimulin is overexpressed in a patient with colonic carcinoma.

BACKGROUND: Human metallopanstimulin (MPS-1) is a 9.4-kDa multifunctional ribosomal S27 nuclear "zinc finger" protein which is expressed in a wide variety of actively proliferating cells and tumor tissues. In this paper, we present a case of overexpression of MPS-1 in colon cancer tissues of a seventeen year old male. METHODS: Biopsies at the anastomosis and adjacent normal colonic mucosa were obtained by colonoscopy twelve months after right hemicolectomy for an ascending colon well differentiated adenocarcinoma. Immunohistochemical localization of MPS-1 protein was performed by using specific anti-MPS-1 antibodies directed against the N-terminal region of this protein. RESULTS: Immunohistochemistry demostrated an overexpression of MPS-1 in colonic mucosa crypts in the samples obtained at the anastomosis. In contrast, no expression of MPS-1 was observed in the adjacent normal mucosa. Histopathology performed with hematoxilin and eosin staining revealed focal crypt distortion and proliferation, but no carcinoma. CONCLUSIONS: In this case, the overexpression of MPS-1 was a more definitive evidence of malignant transformation than histology, as demonstrated by the clinical course of the disease. The results support the hypothesis that increased levels of tissue MPS-1 may correlate with a more aggressive behavior of colon malignancy.

Expression of metallopanstimulin and oncogenesis in human prostatic carcinoma.

BACKGROUND: We have previously shown that human metallopanstimulin (MPS-1) is a 9.4-kDa multifunctional ribosomal S27/nuclear "zinc finger" protein which is expressed in a wide variety of actively proliferating cells and tumor tissues. Furthermore, we have shown that detection of MPS-N immunoreactive material in sera corresponding to the NH2 terminus of MPS-1 provides a method for determining the presence of certain types of abnormal proliferative conditions and/or active oncogenic processes in patients. In this study, we investigated MPS-N and MPS-N-like antigens present in the blood of patients with prostatic carcinoma (PC) and their relationship to the clinical status of patients with PC. METHODS: The presence of MPS-N immunoreactive material was determined using a sensitive and specific radioimmunoassay (RIA) which has been developed to measure circulating levels of MPS-N antigen(s). In addition, MPS-N levels were compared to the primary bio-marker used in PC patient management, Prostatic Specific Antigen (PSA). RESULTS: MPS-N concentrations were determined in the blood of 107 males having no evidence of PC, and in 126 patients diagnosed with PC. In patients, not having PC the MPS-N levels were lower than 10 ng/mL. In untreated patients having PC stages T1/T2, the MPS-N level range was 10-30 ng/mL; in stages T3/T4 the MPS-N level range was 30-50 ng/mL; and in stage Mlb (distant metastasis to the bones) the MPS-N levels were extremely high (> 50 ng/mL). In Mlb patients that did not respond to therapy, the MPS-N levels remained very high (> 50 ng/mL). In Mlb patients that went into remission after treatment, the MPS-N levels were dramatically reduced. In addition, a comparison of the test properties of MPS-N and PSA for prostate cancer were evaluated in a total of 231 patients. In both the low and high value range, both MPS-N and PSA appear to be equally effective in modifying the probability of the target condition-prostatic cancer. CONCLUSIONS: These findings show that (1) in untreated PC patients, the increase in serum MPS-N correlated with the stage of the disease; (2) MPS-N tumor marker predicted the degree of aggressiveness of tumor growth and response to therapy. In summary, despite the uncertainties of the relative contributions of the molecules being measured in cancer patients (authentic MPS-1, and MPS-N-like protein sequences), the MPS-N test is a pragmatic test that correlates well with active prostatic malignancy.

Quantitative technetium-99M dimercaptosuccinic acid renal scanning in children.

OBJECTIVES: To develop a method for assessing absolute renal function (as well as morphology) in children, using gamma camera imaging of intravenously injected technetium-99m (99mTc) dimercaptosuccinic acid (DMSA). METHODS: Forty-five children (ages 1 week to 10 years; mean, 2.0 years) were imaged using a planar technique in which not only the appearance but the absolute amount of intravenously administered 99mTc DMSA taken up by the kidneys was calculated for each child and compared with contemporaneous determinations of creatinine clearance. RESULTS: There was a close correlation between the absolute DMSA uptake and creatinine clearance (r = 0.752). CONCLUSIONS: Renal function in children, expressed as creatinine clearance, can be accurately estimated by measuring absolute DMSA uptake with planar gamma camera imaging using 99mTc DMSA.

Consensus development for producing diagnostic procedure guidelines: SPECT brain perfusion imaging with exametazime.

UNLABELLED: A method for developing diagnostic practice guidelines is presented in which a team of experts used a semiquantitative scoring system to reach consensus on a standard procedure for SPECT cerebral perfusion imaging. METHODS: An expert panel generated a list of elements that they thought were important for the optimal performance of cerebral perfusion imaging as the first phase of a modified Delphi panel technique. Panel members then scored each statement to indicate the importance of that statement for the performance of cerebral perfusion imaging. The scores were recorded for each statement and the average score, s.d. and variance for each statement were determined for each successive panel round. A total of three panel rounds were conducted. The change in average s.d. between scoring rounds was analyzed for significance using both parametric and nonparametric tests. RESULTS: The average s.d. decreased by 35% from 2.1 to 1.32 between the first and final panel round. This change in average s.d., which indicated enhanced consensus, was significant at p < 0.0001. Following consensus, all statements were grouped into four categories based on average score: critical elements, important elements, less important elements and elements of uncertain importance. This grouping formed the basis for a guideline summary narrative. Results were generated in 3 mo, at low cost and with clear documentation of rationale. CONCLUSION: Through simple adaptations of this methodology, expert panels that develop practice guidelines can replace informal discussion with systematic scoring methods to rate the quality of evidence, generalizability to practice conditions, appropriate indications and strength of recommendations.