[Analysis of therapeutic effects of cannulated compression screws for the treatment of femoral neck fractures].

OBJECTIVE: To evaluate the therapeutic effects of cannulated compression screws for the treatment of femoral neck fractures, and to investigate the related factors influencing the avascular necrosis of femoral head after surgery. METHODS: A retrospective review was done for 96 patients with femoral neck fractures treated with cannulated compression screws from January 2003 to June 2009. Among them, there were 44 males and 52 females with 21 to 88 years old (averaged 56.3 years old). According to Garden classification, 4 patients were type I, 34 patients were type II, 37 patients were type III and 21 patients were type IV. Factors such as patients' age, gender, fracture type, duration from injury to surgery and fracture reduction quality were statistically analysed to find correlations with nonunion and avascular necrosis of femoral head. RESULTS: Eighty-four patients were followed up ranging from 9 to 60 months and the mean time was 25.4 months. Postoperative complications included deep venous thrombosis of lower extremity in 2 cases, bone nonunion in 8 cases and avascular necrosis of femoral head in 11 cases. According to Harris criterion, the total postoperative Harris score was 86.20 +/- 11.00, and 40 patients got an excellent result, 32 good, 7 fair and 5 poor. The incidence of avascular necrosis of femoral head in nondisplaced fracture group and displaced fractures group were 3.22% and 18.87% respectively;and there were significant difference between the two groups (P = 0.037). The incidence of avascular necrosis of femoral head in anatomical reduction group and non-anatomical reduction group were 5.00% and 20.45% respectively; also,significant difference was existed between the two groups (P = 0.036). However, there was no statistically significant difference of the incidence of avascular necrosis of femoral head according to different age, sex, operative time. CONCLUSION: The therapeutic effect of cannulated compression screws for non-displaced femoral neck fractures is good. The fracture type and reduction quality are found to be main factors correlated with avascular necrosis of femoral head statistically. For young patients with a displaced femoral neck fracture,in order to avoid incidence of avascular necrosis of femoral head, anatomical reduction should be ensured. For elder patients with a severe displaced femoral neck fracture, the total hip replacement should be recommended.

[Treatment of tibial avulsion fracture of the posterior cruciate ligament with open reduction and steel-wire internal fixation].

OBJECTIVE: To study the curative effects of the treatment of tibial avulsion fracture of the posterior cruciate ligament with open reduction and steel-wire internal fixation. METHODS: From January 2003 to June 2009, 28 patients of tibial avulsion fracture of the posterior cruciate ligament were treated with open reduction and steel-wire internal fixation through posteromedial inverted "L" approach. There were 19 males and 9 females with an average age of 35.3 years old ranging from 16 to 55 years. The X-ray examination showed that there were II degree displaced in 10 cases and III degree in 18 patients. The affected lower extremity was put in a controlled hinge knee brace after operation. The patients were asked to do passive extension and flexion of the knee joint with the assistance of a CPM 2 weeks after operation,and allowed to be partial weight-bearing as tolerated with the hinged brace locked in extension if concomitant injuries allowed 4 weeks postoperatively. The brace were removed 6 weeks later. RESULTS: Among them, 25 patients were followed up for 6 to 24 months with an average of 15 months. The X-ray examination showed satisfactory reduction, and bony union was obtained in all the patients. The Lachman test was negative in all patients. No complications such as malunion or joint stiffness were found. The extension of affected knee was normal and its flexion were (136 +/- 12) degrees. According to Lysholm knee score system,it was preoperatively (41.80 +/- 6.16) and (94.10 +/- 8.26) six months after surgery respectively. Twenty-two cases were excellent, 2 cases good and 1 fair. CONCLUSION: Treatment of tibial avulsion fracture of the posterior cruciate ligament with open reduction and internal fixation with wires through posteromedial inverted "L" approach is a safe, effective method, due to its stable fixation and relatively low expense. It is believed as an ideal choice for tibial avulsion fracture of the posterior cruciate ligament.

Prospective versus retrospective ECG gating for 320-detector CT of the coronary arteries: comparison of image quality and patient radiation dose.

PURPOSE: To compare image quality and patient radiation dose in a group of patients who underwent 320-detector computed tomography coronary angiography performed with prospective electrocardiogram (ECG) gating with image quality and radiation dose in a group of patients matched for clinical features who underwent 320-detector computed tomographic (CT) coronary angiography performed with retrospective ECG gating. MATERIALS AND METHODS: This study was approved by our institutional human research committee. All patients had clinical indications for coronary computed tomography angiography (CTA). Two independent reviewers separately scored coronary artery segment image quality for 480 cardiac CT studies in prospective group and retrospective group (240 in each group). Reviewer variability was calculated. Estimated effective radiation dose was compared for prospective versus retrospective ECG gating. RESULTS: The two groups matched well for clinical characteristics and CT parameters. There was good agreement for coronary artery segment image quality scores between the independent reviewers (k=0.73). Of the 6408 coronary artery segments scored, there were no coronary artery segments that could not be evaluated in each group. Image quality scores were not significantly different (P>.05). Mean patient radiation dose was 76.50% lower for prospective gating (4.2 mSv) than for retrospective gating (18.1 mSv) (P<.01). CONCLUSION: Use of 320-detector CT coronary angiography performed with prospective ECG gating has similar subjective image quality scores but 76.50% lower patient radiation dose when compared with use of retrospective ECG gating.

Deepgoing study on intrathoracic tuberculous lymphadenitis in adults using multidetector CT.

BACKGROUND: Studies on intrathoracic tuberculous lymphadenitis in adults are confined to the preliminary CT findings with ordinary CT and ordinary spiral CT. There has been no deepgoing study of multidetector CT to date. Multidetector CT could contribute to better imaging of intrathoracic tuberculous lymphadenitis in adults. The purpose of this study was to explore the multidetector CT features of intrathoracic tuberculous lymphadenitis in adults, and the correlation with clinical symptoms and pathologic changes. METHODS: Multidetector CT findings from 42 consecutive adult patients with intrathoracic tuberculous lymphadenitis were analyzed retrospectively with regard to locations, sizes, numbers, shapes, margins, and densities reviewing precontrast and enhanced images. CT results were correlated with clinical symptoms and pathologic results (n = 37). RESULTS: One hundred and eighty-five intrathoracic lymph nodes that had tuberculous lymphadenitis in 42 patients were distributed mainly in regions 4R (n = 37), 2R (n = 33), 7 (n = 31) and 10R (n = 21), more than 2 regions were implicated in 34 patients. One hundred and twenty-two (72.2%) of the tuberculous lymphadenitis without confluence were oval or round with clear margins. On precontrast scanning, 78.4% of tuberculous lymphadenitis had a homogeneous density. Seven enhancement patterns were demonstrated in 169 tuberculous lymphadenitis from 37 patients with pathologic results: homogeneous enhancement with no clinical symptom (n = 12), corresponded pathologically to tuberculous hyperplasia without caseous necrosis; heterogeneous enhancement with a small central no enhancement area, slight clinical symptoms (n = 22), tuberculous granulomas with a little caseous necroses; peripheral irregular thick wall enhancement with a central area with no enhancement, slight clinical symptoms (n = 52), tuberculous granulomas with some caseous necroses in the center; peripheral thin rim enhancement with a central area having no enhancement, moderate clinical symptoms (n = 36), a few tuberculous granulomas with a great quantity of caseous necroses in the center; peripheral irregular enhancement without central enhancement, extending outside the capsule, severe clinical symptoms (n = 4), caseous necroses ruptured from capsule; peripheral irregular rim enhancement with central separate enhancement, severe clinical symptoms (n = 40), multiple lymph nodes with liquefaction of caseous necroses were adherent and confluent, rim and separation were tuberculous granulomas; no obvious enhancement, severe clinical symptoms (n = 3). Caseous necrosis was usually associated with little tuberculous granulomas. CONCLUSIONS: The main multidetector CT features of intrathoracic tuberculous lymphadenitis in adults are involvement of multiregional lymph nodes with oval or round shape and clear margins, a basically homogeneous density on precontrast scanning, multiple enhancement patterns, and they correlate closely with clinical symptoms. Multidetector CT could reveal pathological changes of intrathoracic tuberculous lymphadenitis in adults.

[Clinical application of prospective electrocardiogram-gated 320-detector computed tomography coronary angiography].

OBJECTIVE: to compare the success rate, radiation dose, image quality and diagnosis of prospective electrocardiogram(ECG)-gated 320-detector computed tomography coronary angiography (CTCA) versus retrospective ECG-gated CTCA. METHODS: patients suspected coronary artery disease were divided into two groups which underwent 320-detector CTCA with prospective ECG-gated and retrospective ECG-gated scanning (n = 240 each, HR < 65 bpm). Curved-planar reconstruction (CPR), maximum intensity projection (MIP) and volume rendering (VR) were performed to demonstrate the coronary arteries. The image quality was defined as excellent, good and poor by motion and stair-step artifacts. Effective radiation exposure dose was estimated from the dose-length product. Effective radiation dose, image quality and diagnosis were evaluated. RESULTS: the success rate of examination was 100% in prospective ECG-gated group and retrospective ECG-gated group. The mean effective radiation dose of prospective ECG-gated CTCA [(3.3 ± 1.3) mSv] was significantly lower than that of retrospective ECG-gated CTCA [(13.0 ± 1.6) mSv, P < 0.01]. Segments of diagnostic image quality (95.42%, 3435/3600) and non-diagnostic coronary segments (4.58%, 165/3600) in prospective ECG-gated group were similar as those of retrospective ECG-gated group (95.81%, 3449/3600 and 4.19%, 151/3600, all P > 0.05). Compared with CAG, the sensitivity, specificity, false positive and false negative value in prospective ECG-gated group (93.22%, 99.21%, 91.64%, 99.05%) and retrospective ECG-gated group (94.55%, 98.80%, 95.86%, 98.54%) were not significantly different. CONCLUSION: though the effective radiation dose is significantly lower, the success rate, image quality and diagnosis of prospective ECG-gated 320-detector CTCA is comparable with that of retrospective ECG-gated 320-detector CTCA on patients with stable heart rates less than 65 bpm.