Biomedical subjects

Bradley A Evanoff

Publications and source records attributed to Bradley A Evanoff.

3 recordsLinked to original sources

PubMed2006

A rapid method for mass screening for parkinsonism.

Epidemiology studies of parkinsonism employ a variety of techniques for unbiased sampling of populations. No current method permits mass screening of all subjects in a population for parkinsonism by movement disorders specialists. We developed and piloted a new approach to facilitate accurate and efficient screening of large populations for diagnosis of parkinsonism and provide data on sensitivity and specificity. We evaluated 2081 welders referred for medical-legal screening. Subjects were video taped using a standardized protocol, and videos were rated on the Unified Parkinson's Disease Rating Scale motor subsection 3 (UPDRS3). A "video rater" viewed video tapes and entered ratings through a web-based database. An "in-person" examiner performed a UPDRS3 examination in a randomly selected subgroup of 48 workers drawn from the 2081. We developed quantitative diagnostic criteria for parkinsonism that established minimum diagnostic thresholds based upon UPDRS3 scores and compared these criteria with diagnosis by an in-person examiner. Specificity of these criteria compared to in-person examination was 91-100% but sensitivity was 56%. A threshold UPDRS3 score greater than nine provided 100% sensitivity and 81% specificity. Liberal criteria identified 266 (13.1%) subjects with probable parkinsonism and 220 (10.8%) subjects with definite parkinsonism. Conservative criteria identified 260 (12.8%) with probable parkinsonism and 122 (6%) with definite parkinsonism. Our screening method permits rapid assessment of parkinsonian signs. An absolute UPDRS3 score greater than nine provided the best combination of sensitivity and specificity for the diagnosis of parkinsonism, while quantitative exam-based criteria for cardinal parkinsonian signs maximized specificity. Parkinsonism as diagnosed by our criteria was common in this group of welders.

Female↗

PubMed2004

Anatomic tilt x-rays of the distal radius: an ex vivo analysis of surgical fixation.

PURPOSE: To compare anatomic tilt radiographs with standard posteroanterior (PA) and lateral radiographs for their efficacy in detecting screw penetration of the distal radius articular surface. METHODS: Twenty-four cadaveric human forearm specimens had fixation with a dorsal distal radius plate and screws. Three groups were evaluated: (1) no articular surface screw penetration, (2) radial-sided articular screw penetration, and (3) ulnar-sided articular screw penetration. Standard PA and lateral views and anatomic tilt PA and lateral views were taken of each specimen. Three observers reviewed both individual (PA or lateral) and paired (PA and lateral) radiographs. These radiographs were evaluated based on whether or not articular penetration had occurred. A number between 1 and 5 was assigned to represent the degree of certainty of their assessment. The accuracy of the observers was calculated to determine if screw penetration of the articular surface had occurred and, if so, which screw had penetrated the joint. The sensitivity and specificity of each view, interobserver reliability, and the reviewers' confidence in evaluating presence or absence of screw penetration were calculated. RESULTS: The use of anatomic tilt lateral views significantly improved the overall accuracy, (0.93 vs 0.64), sensitivity (0.98 vs 0.77), and specificity (0.83 vs 0.38) of the detection of articular screw penetration when compared with standard lateral views. PA and lateral anatomic tilt views, when viewed together, significantly improved (p <.001) the accuracy of each observer's determination of the position of the penetrated screw (0.90 vs 0.67). In addition, anatomic tilt views significantly improved the confidence of the reviewers in their more accurate observations (4.7 vs 3.3, p <.05). CONCLUSIONS: Anatomic tilt PA and lateral radiographs of the distal radius are an accurate and clinically useful tool for the evaluation of both presence and location of screw penetration of the articular surface after dorsal plating.

Bone Plates↗

PubMed2002

Assessment of articular fragment displacement in acetabular fractures: a comparison of computerized tomography and plain radiographs.

OBJECTIVES: Quantitatively evaluate plain radiographs, relative to computed tomography (CT) scans, for assessment of articular fragment displacement (step and gap) in displaced acetabular fractures and in canine osteotomized acetabular specimens. DESIGN: Retrospective evaluation of a consecutive series of CT scans and plain radiographs of patients with displaced acetabular fractures and canine acetabulae osteotomized to represent acetabular fractures with displacement. SETTING: Level I trauma center. PATIENTS/PARTICIPANTS: Computed tomography scans and plain radiographic images of 62 consecutive patients with displaced acetabular fractures were reviewed; 20 patients met the inclusion criteria regarding location, fracture pattern, availability of plain radiographs and CT scans, and the position of the femoral head at the time of radiographic assessment. The hemipelvi of five adult mongrels underwent osteotomy of the acetabulum and similar radiographic evaluation. INTERVENTION: Three independent reviewers measured step and gap deformity on plain radiographs and CT scans utilizing a standardized measurement technique. MAIN OUTCOME MEASUREMENTS: Sensitivity and specificity of plain radiographs for detecting step and gap displacement (2 mm and 4 mm) relative to CT scans were determined. Intraclass correlation coefficient and intraobserver reliability was also calculated. For the canine specimens, sensitivities of each imaging method were determined relative to actual fragment displacement measurements. RESULTS: In the clinical images, when compared to CT, plain radiographs showed poor sensitivity at detecting step deformity (sensitivity = 25%). When analyzed by fracture type, plain radiographs were particularly poor at detecting step deformities in fractures involving a single column of the acetabulum (sensitivity = 0%). Excellent intraobserver and intraclass reliability existed among the three reviewers. Computed tomography scans were considerably more accurate in measuring step and gap displacement relative to actual measurements than plain radiographs in the canine specimens. CONCLUSIONS: 1) Plain radiographs showed poor sensitivity for the detection of step and gap deformities in patients with acetabular fractures and in osteotomized canine specimens, relative to CT scans; 2) differences between CT and plain radiographs in both specimen types were greatest with the most clinically relevant deformity-i.e., step; and 3) CT scans are essential and should continue to be used in conjunction with plain radiographs in the preoperative evaluation of displaced acetabular fractures and perhaps should be considered in the postoperative assessment of fracture reduction.

Acetabulum↗