Visualization of postoperative anterior cruciate ligament reconstruction bone tunnels: Reliability of standard radiographs, CT scans, and 3D virtual reality images

Background and purpose: Non-anatomic bone tunnel placement is the most common cause of a failed ACL reconstruction. Accurate and reproducible methods to visualize and document bone tunnel placement are therefore important. We evaluated the reliability of standard radiographs, CT scans, and a 3-dimensional (3D) virtual reality (VR) approach in visualizing and measuring ACL reconstruction bone tunnel placement. Methods: 50 consecutive patients who underwent single-bundle ACL reconstructions were evaluated postoperatively by standard radiographs, CT scans, and 3D VR images. Tibial and femoral tunnel positions were measured by 2 observers using the traditional methods of Amis, Aglietti, Hoser, Stubli, and the method of Benereau for the VR approach. Results: The tunnel was visualized in 50-82% of the standard radiographs and in 100% of the CT scans and 3D VR images. Using the intraclass correlation coefficient (ICC), the inter- and intraobserver agreement was between 0.39 and 0.83 for the standard femoral and tibial radiographs. CT scans showed an ICC range of 0.49-0.76 for the inter- and intraobserver agreement. The agreement in 3D VR was almost perfect, with an ICC of 0.83 for the femur and 0.95 for the tibia. Interpretation: CT scans and 3D VR images are more reliable in assessing postoperative bone tunnel placement following ACL reconstruction than standard radiographs. Copyright

CT pulmonary angiography: an over-utilized imaging modality in hospitalized patients with suspected pulmonary embolism

Aims: To determine if computed tomographic pulmonary angiography (CTPA) was overemployed in the evaluation of hospitalized patients with suspected acute pulmonary embolism (PE). Methods: Data were gathered retrospectively on hospitalized patients (n=185) who had CTPA for suspected PE between June and August 2009 at our institution. Results: CTPA was done in 185 hospitalized patients to diagnose acute PE based on clinical suspicion. Of these, 30 (16.2%) patients were tested positive for acute PE on CTPA. The Well's pretest probability for PE was low, moderate, and high in 77 (41.6%), 83 (44.9%), and 25 (13.5%) patients, respectively. Out of the 30 PE-positive patients, pretest probability was low in 2 (6.6%), moderate in 20 (66.7%), and high in 8 (26.6%) (p=0.003). Modified Well's criteria applied to all patients in our study revealed 113 (61%) with low and 72 (39%) with high clinical pretest probability. When modified Well's criteria was applied to 30 PE-positive patients, 10 (33.3%) and 20 (66.6%) were found to have low and high pretest probability, respectively (p=0.006). D-dimer assay was done in 30 (16.2%) of the inpatients with suspected PE and all of them were found to have elevated levels. A lower extremity duplex ultrasound confirmed deep venous thrombosis in 17 (9.1%) of the patients with suspected PE, at least 1 week prior to having CTPA. Conclusion: Understanding the recommended guidelines, evidence-based literature, and current concepts in evaluation of patients with suspected acute PE will reduce unnecessary CTPA examinations

Radiological informed consent in cardiovascular imaging: towards the medico-legal perfect storm?

Use of radiation for medical examinations and tests is the largest manmade source of radiation exposure. No one can doubt the immense clinical and scientific benefits of imaging to the modern practice of medicine. Every radiological and nuclear medicine examination confers a definite (albeit low) long-term risk of cancer, but patients undergoing such examinations often receive no or inaccurate information about radiological dose exposure and corresponding risk directly related to the radiological dose received. Too detailed information on radiological dose and risk may result in undue anxiety, but information "economical with the truth" may violate basic patients' rights well embedded in ethics (Oviedo convention 1997) and law (97/43 Euratom Directive 1997). Informed consent is a procedure needed to establish a respectful and ethical relation between doctors and patients. Nevertheless, in an "ideal" consent process, the principle of patient autonomy in current radiological practice might be reinforced by making it mandatory to obtain explicit and transparent informed consent form for radiological examination with high exposure (≥ 500 chest x-rays). The form may spell-out the type of examination, the exposure in effective dose (mSv), derived from reference values in guidelines or – better – from actual values from their department. The dose equivalent might be also expressed in number of chest radiographs and the risk of cancer as number of extra cases in the exposed population, derived from most recent and authorative guidelines (e.g., BEIR VII Committee, release 2006). Common sense, deontological code, patients'rights, medical imaging guidelines, Euratom law, all coherently and concordantly encourage and recommend a justified, optimized, responsible and informed use of testing with ionizing radiation. Although the idea of informed consent for radiation dose does not seem to be on the immediate radar screen at least in the US, the current practice clashes against these guidelines and laws

Rotational knee laxity: Reliability of a simple measurement device in vivo

<p>Abstract</p> <p>Background</p> <p>Double bundle ACL reconstruction has been demonstrated to decrease rotational knee laxity. However, there is no simple, commercially-available device to measure knee rotation. The investigators developed a simple, non-invasive device to measure knee rotation. In conjunction with a rigid boot to rotate the tibia and a force/moment sensor to allow precise determination of torque about the knee, a magnetic tracking system measures the axial rotation of the tibia with respect to the femur. This device has been shown to have acceptable levels of test re-test reliability to measure knee rotation in cadaveric knees.</p> <p>Methods</p> <p>The objective of this study was to determine reliability of the device in measuring knee rotation of human subjects. Specifically, the intra-tester reliability within a single testing session, test-retest reliability between two testing sessions, and inter-tester reliability were assessed for 11 male subjects with normal knees.</p> <p>Results</p> <p>The 95% confidence interval for rotation was less than 5° for intra-tester, test-retest, and inter-tester reliability, and the standard error of measurement for the differences between left and right knees was found to be less than 3°.</p> <p>Conclusion</p> <p>It was found that the knee rotation measurements obtained with this device have acceptable limits of reliability for clinical use and interpretation.</p

Restoring tibiofemoral alignment during ACL reconstruction results in better knee biomechanics

"Published online: 24 October 2017"PURPOSE: Anterior cruciate ligament (ACL) reconstruction (ACLR) aims to restore normal knee joint function, stability and biomechanics and in the long term avoid joint degeneration. The purpose of this study is to present the anatomic single bundle (SB) ACLR that emphasizes intraoperative correction of tibiofemoral subluxation that occurs after ACL injury. It was hypothesized that this technique leads to optimal outcomes and better restoration of pathological tibiofemoral joint movement that results from ACL deficiency (ACLD). METHODS: Thirteen men with unilateral ACLD were prospectively evaluated before and at a mean follow-up of 14.9 (SD = 1.8) months after anatomic SB ACLR with bone patellar tendon bone autograft. The anatomic ACLR replicated the native ACL attachment site anatomy and graft orientation. Emphasis was placed on intraoperative correction of tibiofemoral subluxation by reducing anterior tibial translation (ATT) and internal tibial rotation. Function was measured with IKDC, Lysholm and the Tegner activity scale, ATT was measured with the KT-1000 arthrometer and tibial rotation (TR) kinematics were measured with 3Dmotion analysis during a high-demand pivoting task. RESULTS: The results showed significantly higher TR of the ACL-deficient knee when compared to the intact knee prior to surgery (12.2° ± 3.7° and 10.7° ± 2.6° respectively, P = 0.014). Postoperatively, the ACLR knee showed significantly lower TR as compared to the ACL-deficient knee (9.6°±3.1°, P = 0.001) but no difference as compared to the control knee (n.s.). All functional scores were significantly improved and ATT was restored within normal values (P < 0.001). CONCLUSIONS: Intraoperative correction of tibiofemoral subluxation that results after ACL injury is an important step during anatomic SB ACLR. The intraoperative correction of tibiofemoral subluxation along with the replication of native ACL anatomy results in restoration of rotational kinematics of ACLD patients to normal levels that are comparable to the control knee. These results indicate that the reestablishment of tibiofemoral alignment during ACLR may be an important step that facilitates normal knee kinematics postoperatively. LEVEL OF EVIDENCE: Level II, prospective cohort study.The authors gratefully acknowledge the funding support from the Hellenic Association of Orthopaedic Surgery and Traumatology (HAOST-EEXOT)info:eu-repo/semantics/publishedVersio

Tomographic renal cortical scintigraphy: Correlation with intravenous urography, computed tomography, ultrasonography, angiography, and nuclear magnetic resonance imaging

This study evaluates single-photon renal tomoscintigraphy (SPECT) in the evaluation of renal masses and correlates this modality, where indicated, with computed tomography (CT), ultrasonography (US), angiography (ANGIO) and nuclear magnetic resonance imaging (NMR). Eight patients with renal cortical lesions detected on intravenous urography (IVP) were evaluated by SPECT and planar nuclear imaging using Tc-99m glucoheptonate (GH). Three of these patients were felt particularly likely to have renal tumors and were additionally evaluated with US, CT, ANGIO and NMR. The five patients with nodules on IVP that were not particularly suggestive of malignancy had functioning, benign, renal tissue accounting for their IVP lesions. Four of five were found by planar-GH nuclear imaging, five/five by SPECT-GH. In addition, SPECT-GH allowed better “confidence” in the normal renal tissue diagnosis in three/five cases. Of the three renal lesions that were highly suggestive of malignancy, two were hypernephromas and one was hypertrophied functioning cortical tissue. All three were correctly identified prospectively on SPECT-GH; however, one hypernephroma was missed on planar-GH. NMR, CT, and ANGIO detected only one of two hypernephromas prospectively (US detected both); all four modalities incorrectly diagnosed the hypertrophied tissue suggestive of malignancy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46822/1/259_2004_Article_BF00279072.pd

Criteria for the selective use of chest computed tomography in blunt trauma patients

Item does not contain fulltextPURPOSE: The purpose of this study was to derive parameters that predict which high-energy blunt trauma patients should undergo computed tomography (CT) for detection of chest injury. METHODS: This observational study prospectively included consecutive patients (>or=16 years old) who underwent multidetector CT of the chest after a high-energy mechanism of blunt trauma in one trauma centre. RESULTS: We included 1,047 patients (median age, 37; 70% male), of whom 508 had chest injuries identified by CT. Using logistic regression, we identified nine predictors of chest injury presence on CT (age >or=55 years, abnormal chest physical examination, altered sensorium, abnormal thoracic spine physical examination, abnormal chest conventional radiography (CR), abnormal thoracic spine CR, abnormal pelvic CR or abdominal ultrasound, base excess or=1 positive predictors, 484 had injury on CT (95% of all 508 patients with injury). Of all 192 patients with no positive predictor, 24 (13%) had chest injury, of whom 4 (2%) had injuries that were considered clinically relevant. CONCLUSION: Omission of CT in patients without any positive predictor could reduce imaging frequency by 18%, while most clinically relevant chest injuries remain adequately detected.1 april 201