PA Radiographs Research Articles

382 FRONTAL PLANE MALALIGNMENT AND CARTILAGE Tip AND T2 RELAXATION TIMES IN KNEE OSTEOARTHRITIS

Purpose: Frontal plane malalignment is a known risk factor for development and progression of knee osteoarthritis (OA). In established disease, using standard MR imaging has shown that varus malalignment is associated with morphological changes like meniscal degeneration, bone attrition and cartilage loss. Using quantitative MRI, T1o and T2 relaxation times have emerged as promising markers of early cartilage changes. The purpose of this study was to examine the association of frontal plane malalignment with cartilage composition using quantitative MR imaging. Methods: 38 subjects with knee OA were stratified into varus (n =12, age: 61.2±10.3y, BMI: 28.6±5.1kg/m2; axis: 174.5±4.6°), neutral (n = 19, age: 56.8±7.2y, BMI: 27.1±5.9kg/m2 axis: 179.9±1.2°) or valgus (n = 7, age: 57.1±12.2y, BMI: 25.9±4.5 kg/m2; axis: 183.8±2.1°) groups based on the anatomical alignment from weight-bearing flexed PA radiographs. MRI was done using a 3T GE Excite Signa MR Scanner. Sequences used were (i) high-resolution fat suppressed spoiled-gradient-echo (SPGR) (for cartilage thickness), (ii) T2-weighted fat-saturated FSE (for clinical WORMS grading) sagittal 3D (iii) T1o and (iv) T2 maps. T1o and T2 relaxation times were quantified for the medial and lateral tibial and femoral condyles. Medio-lateral (M/L) ratio of T1o, T2 and thickness were calculated for tibia, femur. Pearson’s correlation was used to correlate alignment with T1o and T2 relaxation times of individual compartments and M/L ratios in subjects from varus and neutral groups pooled together. One way ANOVA was used for differences in M/L ratios between the 3 groups. Results: Greater varus angle was associated with a higher M/L T1o ratio at the tibia and higher M/L T2 ratio at the femur and tibia (Table 1).

Pedicle screw instrumentation in adolescent idiopathic scoliosis (AIS)

Pedicle screw instrumentation in AIS has advantages of rigid fixation, improved deformity correction and a shorter fusion, but needs an exacting technique. The author has been using the K-wire method with intraoperative single PA and lateral radiographs, because it is safe, accurate and fast. Pedicle screws are inserted in every segment on the correction side (thoracic concave) and every 2-3 on the supportive side (thoracic convex). After an over-bent rod is inserted on the corrective side, the rod is rotated 90° counterclockwise. This maneuver corrects the coronal and sagittal curves. Then the vertebra is derotated by direct vertebral rotation (DVR) correcting the rotational deformity. The direction of DVR should be opposite to that of the vertebral rotation. A rigid rod has to be used to prevent the rod from straightening out during the rod derotation and DVR. The ideal classification of AIS should address all curve patterns, predicts accurate fusion extent and have good inter/intraobserver reliability. The Suk classification matches the ideal classification is simple and memorable, and has only four structural curve patterns; single thoracic, double thoracic, double major and thoracolumbar/lumbar. Each curve has two types, A and B. When using pedicle screws in thoracic AIS, curves are usually fused from upper neutral to lower neutral vertebra. Identification of the end vertebra and the neutral vertebra is important in deciding the fusion levels and the direction of DVR. In lumbar AIS, fusion is performed from upper neutral vertebra to L3 or L4 depending on its curve types. Rod derotation and DVR using pedicle screw instrumentation give true three dimensional deformity correction in the treatment of AIS. Suk classification with these methods predicts exact fusion extent and is easy to understand and remember.

Seeing the Spine in 3D

The Scoliosis Research Society (SRS) has appointed a committee to evaluate the clinical relevance and impact of 3D analysis on scoliotic deformities and to develop a 3D classification of adolescent idiopathic scoliosis (AIS). The goal of this article is to summarize and present the work done in recent years within this committee and show how 3D analysis of AIS has the potential to change our current methods to analyse and treat scoliosis. A database of 600 3D reconstructions of the spine of patients with AIS has been established using calibrated PA and lateral radiographs obtained from either digital radiographs or the EOS system. The 3D reconstructions were done using dedicated software and analyzed with the "da Vinci" view, a schematic top view representation of the 3D reconstructions, which summarizes the position of the End-Apex-End vertebrae planes (planes of maximum curvature). Preliminary work was done using 3D reconstructions in 409 patients with AIS. Fuzzy clustering techniques were used to show that the cohort could be segmented in 5 easily differentiated curve patterns similar to those of the Lenke and King classifications. Two subsequent articles have shown that 3D reconstructions can be divided in different groups based on the location of the plane of maximum curvature of their curves. One study of 66 cases has shown a consistent loss of kyphosis within the 5 thoracic apical vertebrae. Finally, a study of 172 Lenke 1 curves analyzed by ISO Data cluster analysis has confirmed the presence of 2 statistically different subtypes according to the planes passing through the End-Apex-End vertebrae of the main thoracic curve. The study presented suggests that a valid and clinically useful 3D classification of AIS is within reach. 3D analysis has the potential to improve our comprehension of AIS curve types and automatic 3D classification may help decrease the known variability of current 2D classifications. Level III, systematic review of retrospective comparative studies.

Irreversible Electroporation in a Swine Lung Model

This study was designed to evaluate the safety and tissue effects of IRE in a swine lung model. This study was approved by the institutional animal care committee. Nine anesthetized domestic swine underwent 15 percutaneous irreversible electroporation (IRE) lesion creations (6 with bipolar and 3 with 3-4 monopolar electrodes) under fluoroscopic guidance and with pancuronium neuromuscular blockade and EKG gating. IRE electrodes were placed into the central and middle third of the right mid and lower lobes in all animals. Postprocedure PA and lateral chest radiographs were obtained to evaluate for pneumothorax. Three animals were sacrificed at 2 weeks and six at 4 weeks. Animals underwent high-resolution CT scanning and PA and lateral radiographs 1 h before sacrifice. The treated lungs were removed en bloc, perfused with formalin, and sectioned. Gross pathologic and microscopic changes after standard hematoxylin and eosin staining were analyzed within the areas of IRE lesion creation. No significant adverse events were identified. CT showed focal areas of spiculated high density ranging in greatest diameter from 1.1-2.2 cm. On gross inspection of the sectioned lung, focal areas of tan discoloration and increased density were palpated in the areas of IRE. Histological analysis revealed focal areas of diffuse alveolar damage with fibrosis and inflammatory infiltration that respected the boundaries of the interlobular septae. No pathological difference could be discerned between the 2- and 4-week time points. The bronchioles and blood vessels within the areas of IRE were intact and did not show signs of tissue injury. IRE creates focal areas of diffuse alveolar damage without creating damage to the bronchioles or blood vessels. Short-term safety in a swine model appears to be satisfactory.

Comparison of Supine Bending, Push-Prone, and Traction Under General Anesthesia Radiographs in Predicting Curve Flexibility and Postoperative Correction in Adolescent Idiopathic Scoliosis

A prospective study comparing supine bending, push-prone, and traction under general anesthesia (UGA) radiographs in adolescent idiopathic scoliosis. To compare the effectiveness of 3 different flexibility methods on structural and nonstructural main thoracic (MT) and thoracolumbar/lumbar (TL/L) curves. Supine side bending radiographs are the major method for determining curve reducibility. Push-prone radiographs show structural and compensatory curves on the same radiograph, but have not shown comparative reducibility in recent studies. Traction UGA is a relatively new modality which may offer similar or improved flexibility, while also showing structural and compensatory curves on the same radiograph. Fifty-eight patients with adolescent idiopathic scoliosis were prospectively studied with standing PA and lateral, supine bending and push-prone radiographs before surgery; traction UGA radiographs intraoperatively; and standing PA and lateral radiographs after surgery. Traction UGA demonstrated equal flexibility to supine bending in structural MT and TL/L curves, with a trend towards more flexibility in severe MT curves > or = 60 degrees, while push-prone demonstrated significantly less flexibility. Each of the methods showed significantly less flexibility than postoperative correction in MT curves, while traction UGA and supine bending were not significantly different than postoperative correction in TL/L curves. Analysis of nonstructural TL/L curves showed that traction UGA and push-prone were not significantly different than postoperative correction, while supine bending overestimated postoperative correction. Traction UGA offers flexibility equivalent to supine bending for structural MT and TL/L curves, and flexibility comparable with push-prone for nonstructural TL/L curves. Traction UGA also shows both structural and compensatory curves on the same radiograph, and ultimately may provide a better estimate of spinal balance.

The PA projection of the clavicle: a dose-reducing technique

This study compares dose and image quality during PA and AP radiography of the clavicle. The methodology involved a cadaver-based dose and image quality study. Results demonstrate a statistically significant 56.1 % (p <or= 0.001) and 56.5 % (p <or= 0.001) reductions to breast tissue and 62.3 % (p <or= 0.001) and 78 % (p <or= 0.001) reductions in the thyroid dose with employment of PA and PA15 caudal projections. Reductions of 28.5 % (p <or= 0.08) and 11.8 % (p <or= 0.12) in the doses to the eye were demonstrated for the PA. Differences in entrance-surface and exit doses were deemed non-significant. A 5.9 % (p <or= 0.39) reduction in overall image quality was seen with PA positioning. Reductions in image quality were evaluated to be non-significant at 95 % (AP vs PA (p <or= 0.06), AP15 degrees Vs PA15 degrees (p <or= 0.28). The current study demonstrated consistent significant dose reductions to the thyroid and breast when PA projection is chosen over the AP projection. The authors recommend the implementation of PA positioning for clavicle radiography.

Risk Factors and Clinical Evaluation of Superficial Femoral Artery Stent Fracture: Protégé GPS Stent

Purpose: To evaluate the occurrence of superficial femoral artery stent fractures, the risk factors of stent fracture, and the relationship between fractures and clinical findings. Materials and Methods: Of the 38 patients who underwent treatment with Protg GPS stenting due to arterial occlusions on the superficial femoral artery, 17 also underwent a clinical analysis. Forty-three stents were inserted in the 17 superficial femoral arteries, ranging between 15 and 50 cm in length, with a mean treated length of 26.4 cm (15-50 cm). A fracture was evaluated by taking a PA and lateral simple radiography, as well as a follow-up evaluation accompanied with a CT angiography, DSA, and a color Doppler sonography. The examination involved the assessment of the difference between bone fractures due to length, placement, and frequency. Results: Fractures occurred in 13 of 43 stents (30.2%). A total of 10 (71.4%) occurred in the upper third, compared to 4 (28.6%) in the lower third of the superficial femoral artery. In addition, 10 stents (71.4%) had a single strut fracture, whereas 4 (28.6%) had multiple strut fractures. A stent fracture occurred more frequently when the stents and lesions were longer (p=0.021, 0.012) and the stents were inserted near the joint. However, there was no significant relationship between stent numbers and the fractures (p=0.126). When the stents were inserted along the popliteal artery, a stent fracture occurred more frequently in the lower third of the artery. The stent fractures did not significantly influence the patency rate of the stented artery (p=0.44) Conclusion: Protg GPS stents in the superficial femoral artery revealed a considerable number of fractures and the fracture frequency showed a significant relationship with the length of stents and lesions. The closer stent insertion was to the joints, the more frequently fractures occurred. There were no evident significant relationships between the presence of stent fractures and the patency of the stented arteries.

A comparative study for resolution and density of chest imaging using film/screen, CR and DR

The objective of this study was to compare the resolution and density appropriate to diagnosis in chest PA radiography. In comparing the resolution, we radiographed with conventional radiography, computed radiography(CR) and digital radiography(DR) using the linear resolution phantom(Nuclear Associates-Carle Place. N.Y.). 2 radiologists and 3 radiological technologists read the resolution value by the blind test. DR, conventional radiography and CR measured 3.95, 3.58, 3.48 resolution value respectively. In analysing the density, we chose the fifty normal chest CR and DR and conventional film. We estimated the density using by densitometer(X-rite company-Model 301) in seven regions(lung field, lung field margine, mediastinum I, mediastinum II, heart shadow I, heart shadow II, diaphragm) of chest film. We adapted to analysis the Japanese chest X-ray evaluating method and table. It was scored 0(farthest density value) to 2(nearest density value). DR scored 2 at mediastinum I, mediastinum II, heart shadow I, heart shadow II and diaphragm. On the contrary with, CR scored 2 at lung field and lung field margine. Consequently, DR superior than CR and conventional radiography film compairing density and resolution. It was due to small pixel size and post processing algorithm with digital radiography.

Digital tomosynthesis of the chest for lung nodule detection: Interim sensitivity results from an ongoing NIH‐sponsored trial

The authors report interim clinical results from an ongoing NIH-sponsored trial to evaluate digital chest tomosynthesis for improving detectability of small lung nodules. Twenty-one patients undergoing computed tomography (CT) to follow up lung nodules were consented and enrolled to receive an additional digital PA chest radiograph and digital tomosynthesis exam. Tomosynthesis was performed with a commercial CsI/a-Si flat-panel detector and a custom-built tube mover. Seventy-one images were acquired in 11 s, reconstructed with the matrix inversion tomosynthesis algorithm at 5-mm plane spacing, and then averaged (seven planes) to reduce noise and low-contrast artifacts. Total exposure for tomosynthesis imaging was equivalent to that of 11 digital PA radiographs (comparable to a typical screen-film lateral radiograph or two digital lateral radiographs). CT scans (1.25-mm section thickness) were reviewed to confirm presence and location of nodules. Three chest radiologists independently reviewed tomosynthesis images and PA chest radiographs to confirm visualization of nodules identified by CT. Nodules were scored as: definitely visible, uncertain, or not visible. 175 nodules (diameter range 3.5-25.5 mm) were seen by CT and grouped according to size: < 5, 5-10, and > 10 mm. When considering as true positives only nodules that were scored definitely visible, sensitivities for all nodules by tomosynthesis and PA radiography were 70% (+/- 5%) and 22% (+/- 4%), respectively, (p < 0.0001). Digital tomosynthesis showed significantly improved sensitivity of detection of known small lung nodules in all three size groups, when compared to PA chest radiography.

Oblique chest views as a routine part of skeletal surveys performed for possible physical abuse—Is this practice worthwhile?

Objective To evaluate the utility of oblique chest views in the diagnosis of rib fractures when used as a routine part of the skeletal survey performed for possible physical abuse. Methods Oblique chest views have been part of the routine skeletal survey protocol at Primary Children's Medical Center since October 2002. Dictated radiology reports since that time were reviewed, and all cases with rib fractures documented were chosen for study. For each chosen case two pediatric radiologists identified and recorded rib fractures using only the PA and lateral chest radiographs (standard two-view chest series) from the skeletal survey for each case. In a separate session they identified and recorded rib fractures using the PA, lateral, right oblique, and left oblique radiographs (four-view chest series) from the skeletal survey for each case. The results were compared. Results Twenty-two cases with rib fractures were identified. Interpretation of the four-view chest series was different than interpretation of the two-view chest series in 12 of the 22 cases (54%). Overall, the four-view chest series differed significantly in the number of rib fractures diagnosed compared with the two-view chest series ( p = .02, Wilcoxon matched-pairs signed-rank test) adding 19 rib fractures and excluding 6 rib fractures. Conclusions The results indicate that use of the four-view chest series adds information to that obtained from the two-view chest series and increases the accuracy of diagnosing rib fractures in cases of possible physical abuse. Addition of oblique chest views to the routine protocol for skeletal surveys performed for possible physical abuse is recommended.

Further evaluation of the Walter Reed Visual Assessment Scale: correlation with curve pattern and radiological deformity

BackgroundThe Walter Reed Visual Assessment Scale (WRVAS) was designed to measure physical deformity as perceived by patients with idiopathic scoliosis. Previous studies have shown that the instrument has excellent internal consistency and a high correlation with the radiological magnitude of scoliotic curves. Nonetheless, it is not known whether the scale can discriminate between the various curve patterns of the deformity, or whether the deformities represented in the scale's drawings relate to the corresponding radiological deformities.MethodsThis study included 101 patients (86 women and 15 men; mean age 19.4 years) with idiopathic scoliosis. In a single visit, patients underwent standing PA radiography of the spine and completed the WRVAS. X-ray measurements included: 1) magnitude (Cobb angle) of the proximal thoracic curve (PT), main thoracic curve (MT), and thoracolumbar/lumbar curve (TL/L); 2) difference in shoulder level; 3) T1 offset from the central sacral line (T1-CSL); 4) apical vertebra (apV) rotation at the MT and TL/L curves and 5) apical vertebra offset of the MT and TL/L curves from the central sacral line. A variable designated Cobbmax was defined as the largest angle of the three curves (PT, MT or TL/L). Patients were grouped onto three patterns: Thoracic (TH Group)(n = 30, mean MT 42.1°, TL/L 20.9°); double major (DM Group) (n = 39, mean MT 38.6°, TL/L 34.4°) and thoracolumbar (TL Group)(n = 32, mean MT 14.3°, TL/L 25.5°). The magnitude of the curves in the TL Group was significantly smaller than in the other groups (P < 0.05). The Spearman partial correlation coefficient was determined between the score for each WRVAS question and the curve pattern, adjusting for the Cobbmax variable. The Spearman correlation coefficient was determined between the WRVAS items and shoulder imbalance, T1-CSL offset, MT Cobb angle, MT apV rotation, MT apV offset, PT Cobb, TL/L Cobb, TL/L apV rotation and TL/L apV offset.ResultsThe median (interquartile range) of the total WRVAS score was 14 (IQR 6). No correlation was found between the curve pattern and the various scores on the scale (partial correlation coefficients ranged from -0.16 to 0.12). WRVAS drawings for items 1, 2, 4 and 7 correlated satisfactorily with the corresponding radiological measurements (correlation coefficients, 0.62, 0.3, 0.48 and 0.53, respectively). Items 3, 5 and 6 did not correlate with the radiological measurements (correlation coefficients -0.06, -0.07 and 0.05, respectively).ConclusionThe profile of the individual WRVAS scores does not differentiate among specific curve patterns (thoracic, double major and thoracolumbar/lumbar). Moreover, some of the drawings (items 3, 5 and 6) do not correlate with the radiological deformity they were designed to measure.

Single-exposure dual-energy subtraction chest radiography: Detection of pulmonary nodules and masses in clinical practice

The purpose of this retrospective study was to evaluate the impact of energy subtraction (ES) chest radiography on the detection of pulmonary nodules and masses in daily routine. Seventy-seven patients and 25 healthy subjects were examined with a single exposure digital radiography system. Five blinded readers evaluated first the non-subtracted PA and lateral chest radiographs alone and then together with the subtracted PA soft tissue images. The size, location and number of lung nodules or masses were registered with the confidence level. CT was used as standard of reference. For the 200 total lesions, a sensitivity of 33.5-52.5% was found at non-subtracted and a sensitivity of 43.5-58.5% at energy-subtracted radiography, corresponding to a significant improvement in four of five readers (p < 0.05). However, in three of five readers the rate of false positives was higher with ES. With ES, sensitivity, but not the area under the alternative free-response receiver operating characteristics (AFROC) curve, showed a good correlation with reader experience (R = 0.90, p = 0.026). In four of five readers, the diagnostic confidence improved with ES (p = 0.0036). We conclude that single-exposure digital ES chest radiography improves detection of most pulmonary nodules and masses, but identification of nodules <1 cm and false-positive findings remain a problem.

Radiographic Evaluation of Dorsal Screw Penetration after Volar Fixed-Angle Plating of the Distal Radius: A Cadaveric Study

Extensor tendon irritation and attritional tendon ruptures are potentially serious complications after open reduction and internal fixation of distal radius fractures. These complications are well recognized after dorsal plating of distal radii; and these are now being reported after errant screw placement during volar fixed-angle plating. Intraoperative detection of improper screw placement is critical, as corrective action can be taken before completion of the operative procedure. The purpose of this study was to define the extensor tendon compartments at risk secondary to dorsal screw penetration and to compare pronation and supination fluoroscopic images with standard lateral images in demonstrating dorsal screw prominence during volar locked plating. Eight fresh-frozen human cadaveric upper extremities underwent fixation with a volar, fixed-angle distal radius locked plate (Wright Medical Technology, Arlington, TN). Three fluoroscopic views (lateral, supinated, and pronated) followed by dorsal wrist dissections were compared to determine accuracy in detecting dorsal screw prominence and extensor tendon compartment violation. Subsequently, screws measuring 2, 4, 6, 8, and 10(mm longer than the measured depths were sequentially inserted into each distal locking screw, with each image deemed either "in" (completely inside the bone) or "out" (prominent screw tip dorsally-would typically be exchanged for a shorter screw intraoperatively). The radial most distal locking screw (position 1) violated either the first (25%) or second (75%) extensor tendon compartments. The average screw prominence required for radiographic detection was: 6.5(mm for lateral views and 2(mm for supinated views. Pronated views did not identify prominent screws. Screws occupying plate position 2 consistently entered Lister's tubercle, with 5/8 exiting the apex and 3/8 exiting the radial base. The average screw prominences for radiographic detection were: 2.75(mm-lateral views and 3.0(mm-supinated views. Although the screws entered the second dorsal compartment, they did not encroach upon either of the tendons. Screws occupying plate position 3 violated the third extensor tendon compartment in 7/8 specimens with 1/8 exiting the Ulan base of Lister's tubercle. The average screw prominences for radiographic detection were: 3.5(mm-lateral views and 2.5(mm-pronated views. Supinated views did not identify prominent hardware. Screws occupying plate position 4 all violated the IV dorsal extensor compartment-2/8 screws were noted to tent the posterior interosseous nerve. The average screw prominences required for radiographic detection were: 4.0(mm-lateral views and 2.5(mm-pronated views. The supinated views did not identify prominent screws. Volar fixed-angle plating has shown great promise in the advancement of distal radius fracture management. We have seen in our referral practices and in the literature an increase in the number of extensor tendon complications arising from unrecognized dorsally prominent screws, pegs, or tines. Standard PA and lateral radiographs cannot adequately visualize screw position and length secondary to the complex geometry of the dorsal cortex. We believe this study supports the routine application of intraoperative, oblique pronosupination fluoroscopic imaging for enhanced confirmation of distal locking screw position and length.

Differentiating Diaphragmatic Paralysis and Eventration

Although elevation of the diaphragm can be appreciated on conventional PA and lateral chest radiography, the modality is commonly viewed as inadequate to differentiate diaphragmatic paralysis from eventration. Our objective was to qualitatively and quantitatively measure the utility of chest radiography in determining the presence or absence of diaphragmatic paralysis in patients with an elevated diaphragm. A retrospective analysis of chest radiographs in 32 patients, whom underwent fluoroscopic sniff test for elevated diaphragm, was performed. Diaphragm function was graded by a senior radiology resident, as either "paralyzed" or "non-paralyzed," based on appearance/shape of elevated hemidiaphragm on PA and lateral radiograph. The diaphragm position and shape for all patients were determined using measurements relating to skeletal structures and radius of curvature, respectively. These results were correlated with the results of the fluoroscopic sniff tests. Of 32 patients with elevated diaphragm on chest radiograph, 17 had diaphragmatic paralysis confirmed with fluoroscopic sniff test. Our results indicate that the radius of curvature or shape of the diaphragm on lateral chest radiograph is the most important factor for detection of the presence or absence of diaphragmatic paralysis. HH/APD > 0.28 suggests against paralysis. Conventional chest radiography appears to be a useful modality for assessment of the functional status of an elevated diaphragm. Based on our results, evaluation of the shape of an elevated diaphragm may preclude the need for fluoroscopic sniff test to determine diaphragmatic paralysis.

Interactive Hand Clinics Number 2: A Persistently Painful Hand

INSTRUCTIONS The authors present a series of self assessment cases in hand surgery that demonstrate the many pathologies presenting to our tertiary referral hand unit. This case discusses the diagnosis and reconstructive strategy for a complex gunshot injury to the upper arm. Read the case report and accompanying questions and answer them in order. The solutions to the questions follow at the end. CASE REPORT A 38 year old RAF navigator presented to A&E after an alleged assault, where he fell heavily onto both hands. He complained of left wrist pain. Plain radiographs were taken but no initial diagnosis was made(Figure 1). The ulna sided left wrist pain persisted and at 12 months he was referred to a Hand surgeon for a specialist opinion. He complained of pain on the ulna aspect of his wrist and contact sensitivity with associated parasthesia in the ring and little fingers. Examination revealed full ROM at the wrist, a tender hypothenar eminence with no objective motor ulna nerve signs. Investigations included repeat plain radiographs, instability series (AP, lateral, clenched fist, radial and ulna deviation views) and nerve conduction studies. He was provided with a wrist splint which alleviated some of his neurological symptoms. Figure 1 Figure 1 Q1 What are the features seen in fig 1, plain PA radiograph? Q2 What is the possible diagnosis and what is the best investigation at this point? Further investigations included tangential views of the ulnar carpus, CT scan and MRI of the wrist. Figure 2 Figure 2a and 2b Interactive Hand Clinics Number 2: A Persistently Painful Hand 2 of 3 Q3 What abnormality is seen on the imaging in Figure 2? Q4 How would you manage this condition? A PERSISTENTLY PAINFUL HAND ANSWERS: Q1 WHAT ARE THE FEATURES SEEN IN FIG 1, PLAIN PA RADIOGRAPH? PA radiograph is normal. The instability series excluded ligamentous damage, and EMG studies ruled out median or ulna nerve pathology. Q2 WHAT IS THE POSSIBLE DIAGNOSIS AND WHAT IS THE BEST INVESTIGATION AT THIS POINT? Differential Diagnosis: Aneurysm of ulnar artery Thrombosis of ulnar artery Ulnar nerve compression in Guyon's canal Non-union or fibrous union of carpal bone fracture Tenosynovitis of FCU Ganglion causing ulnar compression Schwannoma of ulnar nerve

Sagittal Plane Analysis of Adolescent Idiopathic Scoliosis after VATS (Video-Assisted Thoracoscopic Surgery) Anterior Instrumentations

Radiographic sagittal plane analysis of VATS (video-assisted thoracoscopic surgery) anterior instrumentation for adolescent idiopathic scoliosis. This is retrospective study. To report, in details about effects of VATS anterior instrumentation on the sagittal plane. Evaluations of the surgical outcome of scoliosis have primarily studied in coronal plane correction, functional, and cosmetic aspects. Sagittal balance, as well as coronal balance, is important in functional spine. Recently, scoliosis surgery applying VATS has been increasingly performed. Its outcome has been reported several times; however, according to our search of the literature, the only one study partially mentioned. The study population was a total of 42 cases of idiopathic scoliosis patients (8 male, 34 female). Their mean age was 15.6 years (13 to 18 years). The 18 cases were Lenke IA type, 16 cases were Lenke IB type, and 8 cases were Lenke IC type. The preoperative Cobb's angle was 54.5 ± 13.9°. All patients were followed up for a minimum of 2 years and implanted, on average, at the 5.9 level (5 to 8 levels). The most proximal implant was the 4th thoracic spine, and the most distal implant was the 1st lumbar spine. Whole spine standing PA and lateral radiographs were taken before surgery, 2 months after surgery, and at the last follow up (range 24-48 months, mean 35 months). The C7 plumbline proximal junctional measurement (PJM), distal junctional measurement (DJM), thoracic kyphosis, and lumbar lordosis angles were measured and compared. In all cases, follow-ups were possible and survived till the last follow up. The Cobb's angle in coronal plane at the last follow up was 19.7 ± 9.3° and was corrected to 63.8% on average. The preoperative C7 sagittal plumbline before surgery was -13.9 ± 29.1 mm, the final follow up was -9.9 ± 23.8 mm, and the average positive displacement was 4 mm. Thoracic kyphosis was increased from preoperative 18.2 ± 7.7° to 22.4 ± 7.2° on average at the last follow up, and the increase was, on average, 4.2°. The PJM angel was increased from 6.2 ± 4.3° preoperative to 8.8 ± 3.7° at the last follow up, and the increment was, on the average, 2.6°. The DJM angle before surgery was 6.8 ± 5.1° and 6.7 ± 4° at the last follow up, and did not change noticeably. Preoperative lumbar lordosis was 42 ± 10.7° and 43.5 ± 11.1° after surgery. Similarly, it did not change greatly. The scoliosis surgery applying VATS displaced the C7 sagittal plumb line by 4 mm to the anteriorly, increased thoracic kyphosis by 4.2°, and increased PJM by 2.6°. DJM and lumbar lordosis, before and after operation, were not significantly different. Although the surgical technique of VATS thoracic instrumentation is difficult to make the normal thoracic kyphosis, an acceptable sagittal balance can be obtained in Lenke type I adolescent idiopathic scoliosis using VATS.

Interactive Hand Clinics Number 3: Ulnar side wrist pain

INSTRUCTIONS The author presents a series of self assessment cases in hand surgery that demonstrate the many pathologies presenting to our tertiary referral hand unit. This case discusses the investigation, differential diagnosis and management of a patient with ulnar side wrist pain. CASE REPORT A 42 year old right hand dominant gardener presented to our unit with a 2 year history of wrist pain following a simple fall on his out-stretched right hand. He had continued to work despite the pain but in the last 3 months the intensity had increased. He also described problems with aching in the wrist after a heavy day at work and occasional sleep disturbance. On direct questioning he described difficulty with opening stiff door handles, lifting a kettle and driving. Examination revealed no significant swelling. Forearm rotation was full but there was pain at the extremes of rotation. DRUJ ballottment was negative. Flexion and extension were comparable with the contralateral side. There was full radial deviation. Ulnar deviation was limited to neutral by ulnar sided pain. There was tenderness over the dorsal ulno-carpal articulation. A plain radiograph was taken and is shown below. Figure 1 Figure 1 Q1 WHAT ARE THE FEATURES SEEN IN FIG 1, PLAIN PA RADIOGRAPH? Q2 WHAT IS THE POSSIBLE DIAGNOSIS AND WHAT IS THE BEST INVESTIGATION AT THIS POINT? Interactive Hand Clinics Number 3: Ulnar side wrist pain 2 of 3 Figure 2 Figure 2 Q3 WHAT ABNORMALITY IS SEEN ON THE IMAGING IN FIGURE 2? Q4 HOW WOULD YOU MANAGE THIS CONDITION? Ulnar Side Wrist Pain ANSWERS Q1 WHAT ARE THE FEATURES SEEN IN FIG 1, PLAIN PA RADIOGRAPH? The wrist radiographs show a lunate cyst and there is a bifacetal lunate with a possible ulnar positive variance (although this must be confirmed on standardised views). Q2 WHAT IS THE POSSIBLE DIAGNOSIS AND WHAT IS THE BEST INVESTIGATION AT THIS POINT? Differential Diagnosis: Lunate Cyst (Intra-osseus ganglion) Ulnar carpal impaction with central TFCC tear Stylocarpal impaction Tenosynovitis of ECU Neutral wrist variance views would identify the positive ulnar variance, wrist MRI or CT would define the lunate cyst more accurately and MRI arthrogram would help to identify a central TFCC tear, but the best investigation to look at the lunate chondral surface and the TFCC would be a wrist arthroscopy. Q3 WHAT ABNORMALITY CAN BE SEEN ON THE IMAGING? Standard neutral rotation wrist views (90-90) were taken and clearly show a positive ulnar variance and the cyst in the lunate. Q4: HOW WOULD YOU MANAGE THIS CONDITION? The patient underwent wrist arthroscopy. The lunate was found to be intact although there was chondromalacia of the ulnar lunate facet and an associated TFCC central perforation. The Ulnar head showed similar chondral changes to the lunate. The TFCC tear was debrided arthroscopically to remove any unstable flaps. The ulnar was shortened by 2.5mm using the Stanley jig and fixed with a 5 hole DCP plate and 3.5mm screws with a lag screw across the oblique osteotomy. The DRUJ alignment is fairly neutral (Type 2) and it was debated whether ulnar shortening would be better undertaken by a “wafer” resection of the prominent ulnar head. Reverse obliquity DRUJ (Type 3) do poorly with ulnar shortening due to the overload of the DRUJ. The decision to undertake a formal ulnar shortening osteotomy was made when the relatively preserved chondral surface of the ulnar head was assessed arthroscopically. The lunate cyst was left and a plan made for later dorsal curettage and bone grafting should the patient remain symptomatic. The patient made an excellent recovery and returned to gardening work at 3/12 after osteotomy healing.

Towards optimization in digital chest radiography using Monte Carlo modelling

A Monte Carlo based computer model of the x-ray imaging system was used to investigate how various image quality parameters of interest in chest PA radiography and the effective dose E vary with tube voltage (90–150 kV), additional copper filtration (0–0.5 mm), anti-scatter method (grid ratios 8–16 and air gap lengths 20–40 cm) and patient thickness (20–28 cm) in a computed radiography (CR) system. Calculated quantities were normalized to a fixed value of air kerma (5.0 µGy) at the automatic exposure control chambers. Soft-tissue nodules were positioned at different locations in the anatomy and calcifications in the apical region. The signal-to-noise ratio, SNR, of the nodules and the nodule contrast relative to the contrast of bone (C/CB) as well as relative to the dynamic range in the image (Crel) were used as image quality measures. In all anatomical regions, except in the densest regions in the thickest patients, the air gap technique provides higher SNR and contrast ratios than the grid technique and at a lower effective dose E. Choice of tube voltage depends on whether quantum noise (SNR) or the contrast ratios are most relevant for the diagnostic task. SNR increases with decreasing tube voltage while C/CB increases with increasing tube voltage.

Radiation dose and cancer risk to children undergoing skull radiography.

Limited data exist in the literature concerning the patient-effective dose from paediatric skull radiography. No information has been provided regarding organ doses, patient dose during PA skull projection, risk of cancer induction and dose to comforters, i.e. individuals supporting children during exposure. To estimate patient-effective dose, organ doses, lifetime cancer mortality risk to children and radiation dose to comforters associated with skull radiography. Data were collected from 136 paediatric examinations, including AP, PA and lateral skull radiographs. Entrance-surface dose (ESD) and dose to comforters were measured using thermoluminescent dosimeters. Patients were divided into the following age groups: 0.5-2, 3-7, 8-12 and 13-18 years. The patient-effective dose and corresponding organ doses were calculated using data from the NRPB and Monte Carlo techniques. The risk for fatal cancer induction was assessed using appropriate risk coefficients. For AP, PA and lateral skull radiography, effective dose ranges were 8.8-25.4, 8.2-27.3 and 8.4-22.7 microSv respectively, depending upon the age of the child. For each skull projection, the organs receiving doses above 10 microGy are presented. The number of fatal cancers was found to be less than or equal to 2 per 1 million children undergoing a skull radiograph. The mean radiation dose absorbed by the hands of comforters was 13.4 microGy. The current study provides detailed tabular and graphical data on ESD, effective dose, organ doses and lifetime cancer mortality risk to children associated with AP, PA and lateral skull projections at all patient ages.

Arthroscopically assisted meniscal allograft transplantation with and without combined anterior cruciate ligament reconstruction.

The menisci provide a vital role in load transmission across the knee joint as well as contribute to knee stability, particularly in the ACL-deficient knee. Loss of the meniscus, in part or in total, significantly alters joint function and predisposes the articular cartilage to degenerative changes, which has been well documented both clinically and radiographically. This study examined clinical and patient-reported outcomes following meniscal allograft transplantation with and without combined ACL reconstruction in a select group of 31 patients with complaints of pain and/or instability (34 meniscal allografts); 11 underwent isolated meniscal transplantation and 20 meniscal transplantation combined with ACL reconstruction. Bony fixation was performed with bone plugs for medial transplants and using a bone bridge for lateral transplants. All patients completed several knee-specific and general measures of health-related quality of life and underwent a comprehensive physical examination. Flexion weightbearing PA radiographs at latest follow-up were compared to those obtained preoperatively. Mean follow-up was 2.9 years (range 2-5.5 years). The Activities of Daily Living and Sports Activities Scale scores were 86+/-11 and 78+/-16, respectively, and the average Lysholm score was 84+/-14. There were no significant differences in these scores based upon which meniscus (medial or lateral) was transplanted, concurrent ACL reconstruction, or the degree of chondrosis at arthroscopy. SF-36 scores indicated that patients were functioning at a level similar to the age- and sex-matched population. Twenty-two patients stated they were greatly improved, 8 were somewhat improved, 1 was without change. All but one patient reported that knee function and level of activity were normal or nearly normal. The average loss of motion compared to the noninvolved side was 3 degrees for extension and 9 degrees for flexion. All but one patient had a negative or 1+ Lachman's test. The remaining patient had a 2+ Lachman's test. Assessment with the KT-1000 arthrometer revealed a side-to-side difference of 2 mm (range -2 mm to 7 mm). Average hop and vertical jump indices were both 85% of the contralateral extremity. No statistically significant joint space narrowing was observed by radiography over time. Meniscal allograft transplantation with and without combined ACL reconstruction in carefully selected patients with complaints of compartmental joint line pain and/or instability appears able to provide relief of symptoms and restore relatively high levels of function, particularly during activities of daily living.