Posterior Fossa Approaches Using the Leksell Vantage Frame with a Virtual Planning Approach in a Series of 10 Patients-Feasibility, Accuracy, and Pitfalls.

The open-face design of the Leksell Vantage frame provides many advantages. However, its more rigid, contoured design offers less flexibility than other frames. This is especially true for posterior fossa approaches. This study explores whether these limitations can be overcome by tailored frame placement using a virtual planning approach. The posterior fossa was accessed in ten patients using the Leksell Vantage frame. Frame placement was planned with the Brainlab Elements software, including a phantom-based (virtual) pre-operative planning approach. A biopsy was performed in all patients; in four, additional laser ablation surgery was performed. The accuracy of virtual frame placement was compared to actual frame placement. The posterior approach was feasible in all patients. In one case, the trajectory had to be adjusted; in another, the trajectory was switched from a right- to a left-sided approach. Both cases showed large deviations from the initially planned frame placement. A histopathological diagnosis was achieved in all patients. The new Leksell Vantage frame can be used to safely target the posterior fossa with a high diagnostic success rate and accuracy. Frame placement needs to be well-planned and executed. This can be facilitated using specific software solutions as demonstrated.

Diffusion-Weighted Imaging Distinguishes Between Osteomyelitis, Bone Marrow Edema, and Healthy Bone on Forefoot Magnetic Resonance Imaging.

BACKGROUND: Diagnosis of osteomyelitis by imaging can be challenging. The feasibility of diffusion-weighted imaging (DWI) as ancillary sequence was evaluated in this study. PURPOSE: To evaluate DWI for differentiation between osteomyelitis, bone marrow edema, and healthy bone on forefoot magnetic resonance imaging (MRI). STUDY TYPE: Prospective. SUBJECTS: A total of 60 consecutive patients undergoing forefoot MRI divided into three study groups (20 subjects each): osteomyelitis, bone marrow edema, and healthy bone. FIELD STRENGTH/SEQUENCE: A 1.5T and 3T MRI scanners; readout-segmented multishot echo planar DWI. ASSESSMENT: Two independent radiologists measured apparent diffusion coefficient (ADC) values within abnormal or healthy bone. STATISTICAL TESTS: ADC values were compared between groups (pairwise t-test with Bonferroni-Holm correction for multiple testing). Intraclass correlation coefficient (ICC) was calculated to assess inter-reader agreement. Threshold ADC values were determined as the cutoffs that maximized the sum of sensitivity and specificity. Receiver operating characteristic (ROC) analysis was performed with statistical threshold of P < 0.05. RESULTS: Inter-reader agreement was 0.92 in the healthy bone group and 0.78 in both the edema and osteomyelitis groups. Average ADC values were significantly different between groups: 1432 ± 222 × 10-6  mm2 /sec (osteomyelitis), 1071 ± 196 × 10-6  mm2 /sec (bone marrow edema), and 277 ± 89 × 10-6  mm2 /sec (healthy bone). A threshold ADC value of 534 × 10-6  mm2 /sec distinguishes between healthy and abnormal bone with specificity and sensitivity of 100% each. For distinction between osteomyelitis and bone marrow edema, two cutoff values were determined: a 95%-specificity cutoff indicating osteomyelitis (>1320 × 10-6  mm2 /sec) and a 95%-sensitivity cutoff indicating bone marrow edema (<1155 × 10-6  mm2 /sec). Diagnostic accuracy of 95% was achieved for 73% (29/40) of the subjects. DATA CONCLUSION: DWI with ADC maps distinguishes between healthy and abnormal bone on forefoot MRI. Calculated cutoff values allow confirmation or exclusion of osteomyelitis in a high proportion of subjects. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 2.

Early Arthroscopic Repair of Acute Traumatic Massive Rotator Cuff Tears Leads to Reliable Reversal of Pseudoparesis: Clinical and Radiographic Outcome.

PURPOSE: It was the aim of this study to analyze the clinical and radiographic outcome after early arthroscopic repair regardless of the age of patients. METHODS: Patients with massive traumatic cuff tear and clinical pseudoparesis for forward elevation treated by subsequent early arthroscopic repair from 2011 until 2014 were included in this retrospective study. Exclusion criteria were Goutallier grade ≥3 fatty infiltration and prior shoulder problems or surgery. Magnetic resonance imaging (MRI), radiographs, and functional assessments were performed preoperatively and at follow-up. RESULTS: A total of 21 patients (male/female 15/6; age range: 30-83) were included. Preoperative MRI showed complete 2 tendon tears in 7 patients, 3 tendon tears in 13 patients and all tendons ruptured in one patient. All patients had full passive range of motion and the mean active elevation was 35.7° (range: 0°-60°). Nine patients also had a pseudoparesis for external rotation (mean: 10°, range: -30° to 40°). The mean delay until surgery was 33 days (range: 13-60). At follow-up (mean: 39 months, range: 24-60) all patients showed reversal of pseudoparesis, mean elevation of 165.2° (range: 110°-180°) and mean external rotation of 49.3° (range: -20° to 80°). The mean Constant score was 82 points (range: 56-95), and the mean subjective shoulder value was 93% (range: 50-100). The overall retear rate was 20% (n = 4). Fatty infiltration increased at least 1 grade in patients who had a retear and in 56% of patients (n = 9) without retear. Age was not a predictor for retear. CONCLUSIONS: This study shows that early arthroscopic repair of traumatic massive RCT with pseudoparesis may lead to successful results regardless of patients' age. A complete restoration of the function can be expected even in patients with retear. The retear rate is low and the increase of fatty infiltration minimal. LEVEL OF EVIDENCE: Level IV, case series.

Arthroscopic Hip Surgery: Frequency of Postoperative MR Arthrographic Findings in Asymptomatic and Symptomatic Patients.

Purpose To determine and compare the frequency of imaging abnormalities in asymptomatic and symptomatic patients after arthroscopic hip surgery. Materials and Methods This study was approved by the institutional review board. Informed consent was obtained from all patients. Thirty-four patients (17 asymptomatic and 17 symptomatic patients) underwent 1.5-T magnetic resonance (MR) arthrography of the hip 1 year after arthroscopic treatment of femoroacetabular impingement. Two readers independently analyzed all MR arthrographic images for the presence of abnormal imaging findings, including capsular adhesions at the femoral neck, obliteration of the paralabral sulcus, labral defects, and defects of the hip capsule in several anatomic positions (anterior to posterior). Postoperative findings were compared with linear and generalized linear mixed-effects regression models. Results Capsular adhesions at the anterior femoral neck were present in 12 of the 34 patients (35%), and there were no differences between the groups or readers (P = .99). The paralabral sulcus was obliterated in at least one anatomic location in 94% (reader 1, 32 of 34 patients) and 100% (reader 2, 34 of 34 patients) of patients (P = .99). Residual labral tears were detected in 35% of asymptomatic patients (six of 17 patients) and 41% of symptomatic patients (seven of 17 patients) by reader 1 and in 53% of asymptomatic and symptomatic patients (nine of 17 patients in each group) by reader 2, without significant differences between the groups (P = .81). Defects of the hip capsule were more common in asymptomatic patients (77% [13 of 17 patients] for reader 1 and 53% [nine of 17 patients] for reader 2) than in symptomatic patients (59% [10 of 17 patients] for reader 1 and 47% [eight of 17 patients] for reader 2), but without significant differences (P = .33). Conclusion Obliteration of the paralabral sulcus was the most frequent finding after arthroscopic hip surgery in both asymptomatic and symptomatic patients, and capsular adhesions at the anterior femoral neck were present in 35% of patients in both groups. © RSNA, 2016.

[Surgical treatment of fistula-in-ano--a journey between Skylla and Charybdis]. / Die Therapie der Analfistel - Wahl zwischen Skylla und Charybdis.

This review discusses the pathogenesis, symptomatology, diagnostic work-up, and treatment options for fistula-in-ano, which is a common condition that affects ~ 20 in 100,000 per year with a predominance for young males. Fistula-in-ano normally presents as an acute anorectal abscess that subsequently becomes established as a chronic discharging fistula. The illness is characterized by chronic perianal discharge and intermittent pain. The aim of surgical treatment is permanent cure of the fistula whilst maintaining patient continence. This principle forms the basis of surgical decision-making and means that treatment options often have to be individualized for each patient. Low, simple fistulae may be treated by fistulotomy because of the low risk of incontinence. In contrast, high fistulae that contain a greater proportion of sphincter muscle demand more complex operations. Traditional reconstructive techniques (transanal advancement flap, primary sphincter reconstruction) aim to eradicate the fistula whilst leaving the sphincter muscle intact or readapted, whilst newer techniques (biosynthetic plugs) provide a scaffold to encourage normal tissue ingrowth with fistula occlusion. The newer procedures preserve the sphincter ideally. On the other hand success rates of these techniques are somewhat disappointing.

Scan length adjustment of CT coronary angiography using the calcium scoring scan: effect on radiation dose.

OBJECTIVE: The objective of our study was to prospectively investigate the effect of adjusting the scan length of CT coronary angiography using the calcium scoring images instead of the scout view with regard to radiation dose. SUBJECTS AND METHODS: One hundred twenty-five consecutive patients (mean age +/- SD, 62 +/- 10 years) undergoing both calcium scoring and CT coronary angiography were included in our study. The scan length of calcium scoring was planned on the scout view; the scan length of CT coronary angiography was planned on the axial images of the calcium scoring by identifying the origin of the left main artery and cardiac apex and adding 1 cm cranially and caudally. Effective radiation doses were calculated for CT coronary angiography using both scout view-derived and calcium scoring-derived scan lengths. RESULTS: The scout view-derived scan length (mean +/- SD, 139 +/- 13 mm) was significantly greater than the calcium scoring-derived scan length (117 +/- 9 mm; p < 0.01). The average radiation dose was 0.8 +/- 0.3 mSv (range, 0.6-1.5 mSv) for calcium scoring and 9.0 +/- 0.6 mSv (range, 6.5-10.2 mSv) for CT coronary angiography. Using the scout view-derived scan length would have been associated with an effective radiation dose of 10.7 +/- 1.2 mSv (mean +/- SD) for CT coronary angiography, which is significantly higher than that using the calcium scoring-derived scan length (p < 0.05). The average difference between CT coronary angiography using a calcium scoring-derived scan length and that using a scout view-derived scan length was 1.7 +/- 0.9 mSv, corresponding to a radiation dose reduction of 16%. The average dose reduction when using a calcium scoring-derived instead of a scout view-derived scan length for CT coronary angiography-including the radiation dose of the calcium scoring scan-was 1.2 +/- 0.8 mSv (range, 0.1-2.7 mSv) (p < 0.05). CONCLUSION: Adjustment of the scan length of CT coronary angiography using the images from calcium scoring instead of the scout view is feasible and is associated with a 16% reduction in radiation dose of dual-source CT coronary angiography.