A method to establish the relationship between chronological age and stage of union from radiographic assessment of epiphyseal fusion at the knee: an Irish population study.

Characteristic changes during epiphyseal union provide a skeletal age, which when compared with age-based standards provides an estimation of chronological age. Currently there are no data on epiphyseal union for the purposes of age estimation specific to an Irish population. This cross-sectional study aims to investigate the relationship between stage of epiphyseal union at the knee joint and chronological age in a modern Irish population. A novel radiographic method that sub-divides the continuum of development into five specific stages of union is presented. Anteroposterior and lateral knee radiographs of 148 males and 86 females, aged 9-19 years, were examined. Fusion was scored as Stage 0, non-union; Stage 1, beginning union; Stage 2, active union; Stage 3, recent union; or Stage 4, complete union. Stage of epiphyseal union is correlated with chronological age in both males and females. Mean age gradually increases with each stage of union and also varies between male and female subjects. A statistically significant difference in mean age was recorded between stages when compared to the previous stage, for the three epiphyses. Irish children are comparable to those from previously published studies with epiphyseal union in females occurring earlier than males. A significant difference was noted between the mean age of union for males and females for each of Stages 1 and 2 for the femur and Stages 0, 1, 2 and 3 for the tibia and the fibula. The results also suggest that the stages of union occur at earlier ages in this Irish population. Implementation of standardized methodology is necessary to investigate if this is due to a secular or population variation in maturation or to a methodology which clearly identifies five stages of union.

Combined iliac angioplasty and infrainguinal revascularization surgery are effective in diabetic patients with multilevel arterial disease.

The success of percutaneous transluminal angioplasty (PTA) in the treatment of common and external iliac atherosclerotic lesions has been established for the general population. However, several studies have suggested that the presence of diabetes may reduce the effectiveness of iliac angioplasty, particularly in the setting of limb-threatening ischemia requiring concomitant lower extremity revascularization. This study compared the results of iliac artery PTA performed in conjunction with infrainguinal bypass for limb-threatening ischemia for diabetic (DM) and nondiabetic (non-DM) patients. Between 1991 and 2000, 159 PTA were performed in 126 patients (DM = 99/79%, non-DM = 27/21%) in conjunction with subsequent infrainguinal bypass for limb-threatening ischemia (gangrene = 42%, ulcer = 36%, rest pain = 22%). These patients were followed prospectively using a computerized vascular registry. Stents were placed in 34 (21.4%) cases for suboptimal angioplasty results. In this study the combined use of standard surgical and endoluminal modalities for the treatment of multilevel arterial occlusive disease resulted in excellent cumulative patency and limb salvage rates. The presence of diabetes did not alter these favorable results. Multimodal vascular therapy may be used effectively in diabetic patients with limb-threatening ischemia due to multiple levels of arterial occlusion.

Trends in bicycling-related head injuries in children after implementation of a community-based bike helmet campaign.

BACKGROUND/PURPOSE: The aim of this study was to determine the effect of a community-based bike helmet promotion campaign on bike helmet use and related head injuries in children (0 to 14 years of age) in a large North American city. METHODS: The authors established a multifaceted, multidisciplined, community-based campaign to promote bike helmet use by children in 1989. The goals were to increase helmet use by 100% per year, to reduce fatal bike-related head injuries by 50% overall, and to explore the feasibility of legislation mandating helmet use. Helmet use was measured by standardized field observations repeated annually in a single borough within the metropolitan area. To estimate head injury incidence, the number of admissions to hospital for the treatment of bike-related head injuries in a regional trauma registry, which included all residents in the target population was used. The authors were unable to control for changes in exposure to bicycling or in the criteria for admissions to hospital for the treatment of head injuries during the study period. RESULTS: The bike helmet use rate rose from 4% in 1990 to 67% in 1996. The number of head injury admissions fell from 46 in 1990 to 24 in 1996. Legislation requiring helmet use by all children went into effect in October 1995. CONCLUSIONS: Bike helmet use increased significantly during the first 4 years of the campaign and again after the helmet law was implemented. The total number of bike-related head injury admissions declined by more than 50%. The campaign achieved all of its goals except for a 50% reduction in fatal head injuries, which were too infrequent for analysis.

Efficacy of percutaneous fibrin sheath stripping in restoring patency of tunneled hemodialysis catheters.

OBJECTIVE: Our objective was to determine the effectiveness of percutaneous fibrin sheath stripping as a method of restoring function to failing tunneled hemodialysis catheters. SUBJECTS AND METHODS: A total of 131 percutaneous fibrin sheath stripping procedures were performed on 100 failing tunneled hemodialysis catheters in 91 patients. Only the initial stripping procedure of the first catheter inserted in each patient was included for analysis. Patients were excluded if an additional cause of catheter failure was noted at the time of percutaneous fibrin stripping. Failure of the hemodialysis catheter was defined as inability to sustain an average blood flow rate of 250 ml/min or more in a hemodialysis session. Patients were followed up until the time of catheter failure, catheter removal, or a second stripping. Poststripping primary patency and complication rates were determined. RESULTS: The technical success of the procedure was 95.6%. Median follow-up was 16 weeks (range, 0-128 weeks). The overall median duration of primary patency after the first stripping was 89 days (3 months). No statistically significant difference in primary patency rates was seen between patients who underwent fibrin sheath demonstration by contrast injection and those who did not (p = .71). Female patients were statistically more likely to have catheter failure after catheter stripping than were male patients (p = .02). The route of catheter insertion did not significantly influence poststripping patency rates. No complications were associated with the procedure. CONCLUSION: Percutaneous fibrin sheath stripping is a safe, effective method of restoring patency to failing hemodialysis catheters when the failure is due to fibrin sheath formation and other causes are excluded.

Human influenza: viral mutations and altered tropisms.

Influenza is a virus that is capable of causing a pandemic of the human race. Influenza has the ability to infect humans by mutating and altering its pathogenic characteristics. Efforts must be made worldwide to educate people about the possibilities of a potential outbreak. Awareness of optimal conditions which could lead to viral mutation and human to human transmission of a neogenetic strain of influenza appears to be a key deterrent against future cases.

Diabetic versus nondiabetic limb-threatening ischemia: outcome of percutaneous iliac intervention.

OBJECTIVE: The purpose of this study was to compare the effectiveness of iliac angioplasty and outcomes in diabetic patients and nondiabetic patients with limb-threatening ischemia. MATERIALS AND METHODS: Records of 91 consecutive patients with limb-threatening ischemia (rest pain, nonhealing ulceration, or gangrene) who, during a 6-year period, underwent iliac angioplasty of hemodynamically significant lesions were reviewed. Stents were placed in patients with suboptimal findings at angioplasty. Sixty-eight (75%) of the 91 patients were diabetic. Life table analysis and log-rank significance tests were used to compare rates of primary iliac artery patency, primary and secondary graft patency, limb salvage, and survival in diabetic patients versus nondiabetic patients. RESULTS: One hundred seven iliac lesions were treated with percutaneous angioplasty. Ten iliac stents were placed because of suboptimal results at angioplasty. The mean time of follow-up was 20 months (range, 2-62 months). Sixty-eight patients (75%) underwent peripheral reconstruction. Outcomes were comparable in both patient groups for primary iliac patencies at 4 years (diabetic patients, 85%; nondiabetic patients, 76%; p = .5), primary and secondary graft patencies at 4 years (diabetic patients, 65% and 73%, respectively; nondiabetic patients, 74% and 100%, respectively; p = .7 and .19, respectively), 4-year limb-salvage rates (diabetic patients, 93%; nondiabetic patients, 79%; p = .07). Major complications of angioplasty occurred in four patients (4.4%). CONCLUSION: Outcomes of iliac angioplasty and limb-salvage rates were comparable for diabetic patients and nondiabetic patients who underwent current methods of iliac angioplasty and infrainguinal reconstruction.

Acute upper extremity deep venous thrombosis: safety and effectiveness of superior vena caval filters.

PURPOSE: To evaluate the safety and effectiveness of percutaneous filter placement in the superior vena cava for prevention of pulmonary embolism (PE) due to acute upper extremity deep venous thrombosis (DVT) in patients with contraindications to or unsuccessful anticoagulation. MATERIALS AND METHODS: Forty-one patients with acute upper extremity DVT and contraindications to or unsuccessful anticoagulation underwent percutaneous placement of a superior vena caval filter for prevention of PE. Four types of filters were used. Follow-up chest radiographs were used to detect filter migration, dislodgment, and fracture. Placements of central venous and Swan-Ganz catheters after filter insertion were recorded. Patients were followed up clinically for evidence of superior vena cava syndrome and PE. Kaplan-Meier survival rates were determined. Follow-up was 1 day to 221 weeks. RESULTS: No complications such as filter migration, dislodgment, or fracture occurred (median follow-up, 12 weeks). No patients developed clinical evidence of PE due to upper extremity thrombosis or superior vena cava syndrome (median follow-up, 15 weeks). Catheters were placed subsequent to filter placement in 23 patients (56%) without complication. CONCLUSION: Percutaneous filter placement in the superior vena cava is a safe and effective method for preventing symptomatic PE due to acute upper extremity DVT in patients in whom therapeutic anticoagulation has failed or is contraindicated.

MRI of fractures of the distal radius: comparison with conventional radiographs.

OBJECTIVE: To compare the evaluation of fractures of the distal radius with MRI and conventional radiographs. To demonstrate the ability of MRI to detect unsuspected soft tissue derangement accompanying this common injury. DESIGN AND PATIENTS: Twenty-one consecutive inpatients admitted following fracture of the distal radius underwent preoperative evaluation with both conventional radiographs and MRI. In each case, analysis was made of both the osseous and soft tissue injury. MRI findings were compared with those identified on conventional radiographs and at subsequent surgical fixation. RESULTS: Of 21 patients with fractures of the distal radius, 20 had extension to the radiocarpal articulation, 14 had distal radio-ulnar joint extension and 5 had avulsion of the ulnar styloid. Occult carpal bone fractures accompanying fracture of the distal radius were identified in two patients: one of the capitate and the other of the second metacarpal base. Ten patients (48%) had associated soft tissue injury: six patients had scapholunate ligament rupture, two patients had disruption of the triangular fibrocartilage, one patient had extensor carpi ulnaris tenosynovitis and one patient had a tear of a dorsal radiocarpal ligament. Of five patients with ulnar styloid avulsions, none had evidence of triangular fibrocartilage tears. CONCLUSION: MRI affords better evaluation of osseous injury accompanying distal radial fractures than conventional radiographs. Intra-articular soft tissue injury accompanies distal radial fractures in almost 50% of cases. Scapholunate ligament disruption commonly accompanies intraarticular fracture through the lunate facet of the distal radius. Fracture of the ulnar styloid is infrequently associated with tear of the triangular fibrocartilage.

MRI of pediatric growth plate injury: correlation with plain film radiographs and clinical outcome.

PURPOSE: To evaluate pediatric growth plate injuries with conventional radiographs and magnetic resonance imaging (MRI). To review potential clinical impact of MRI on subsequent patient management and outcome. METHODS: Fourteen patients with known or suspected growth plate injury were studied. Each patient underwent imaging by conventional radiography and MRI within 2 weeks of injury. Findings on conventional radiographs and on MR images were compared and then correlated with subsequent management and outcome at a mean of 12 months. RESULTS: Direct visualization of cartilage afforded by MRI improved evaluation of growth plate injury in each case. MRI changed Salter Harris classification or staging in 2 of 9 patients with fractures visualized on conventional radiographs, allowed the detection of radiographically occult fractures in 5 of 14 cases, and resulted in a physical change in management in 5 of the 14 patients studied. CONCLUSION: MRI has an important role in the evaluation of acute pediatric growth plate injury, particularly when diagnostic uncertainty persists following the evaluation of conventional radiographs. MRI allows detection of occult fractures, may alter Salter Harris staging, and in the reported study it frequently resulted in a change in patient management.

Rice body formation in bicipito-radial bursitis: ultrasound, CT, and MRI findings.

The bicipito-radial bursa, which lies at the biceps tendon insertion on the radial tuberosity, is a rare site of chronic bursitis. We describe the clinical, radiological, and pathological findings in a case complicated by multiple rice body formation. In so doing, we describe MR appearances that allow discrimination of this entity from both synovial chondromatosis and pigmented villonodular synovitis.

Thrombolysis of infrapopliteal bypass grafts: efficacy and underlying angiographic pathology.

OBJECTIVE: The purpose of this study was to determine retrospectively the effectiveness of thrombolysis of occluded infrapopliteal bypass grafts and to identify factors affecting success. MATERIALS AND METHODS: The records of 52 consecutive patients (52 grafts) who underwent selective urokinase thrombolysis of grafts to the pedal or tibial arteries were reviewed. The need for subsequent surgery and the influence of diabetes on outcome were analyzed. RESULTS: There were 43 vein and nine Goretex (W-L Gore, Flagstaff, AZ) and vein composite grafts inserting into tibial and peroneal arteries (n = 28) or pedal arteries (n = 24). Mean time of follow-up was 19 months. All grafts were entered, and technical success was achieved in 73% of patients. Twenty-six patients required some form of graft revision. Overall patency at 30 days was 76%. Thirty-day limb-salvage and mortality rates were 82% and 4%, respectively. No significant difference was found in 1-yr outcomes between diabetic and nondiabetic patients or between pedal and tibial grafts. Major complications occurred in eight patients (15%). CONCLUSION: Thrombolysis of occluded grafts that insert into the pedal or tibial vessels was as effective as thrombolysis of more proximal grafts and native arterial thrombolysis, which have reported 30-day limb-salvage rates that range between 80% and 90%. Diabetes and grafting to foot vessels did not adversely affect response to thrombolysis. Surgery was often required to correct an underlying lesion revealed by thrombolysis. Despite the small size of the arteries to which the grafts were anastomosed, selective thrombolysis of occluded infrapopliteal bypass grafts proved to be an effective procedure.

Selective chemoembolization in the management of hepatic metastases in refractory colorectal carcinoma: a phase II trial.

PURPOSE: Metastatic involvement of the liver frequently determines the evolution of the clinical picture in colorectal cancer patients. We examined the efficacy and toxicity of chemoembolization in this setting, identifying prognostic factors to define patients most likely to benefit from the procedure. METHODS: Forty patients underwent chemoembolization of metastatic liver lesions from colorectal carcinoma. Selective angiography of the hepatic artery was performed to identify the feeding vessels of the metastatic lesions. The injected chemoemulsion consisted of 1,000 mg of 5-fluorouracil, 10 mg of mitomycin C, and 10 ml of ethiodized oil in a total volume of 30 ml. Gelfoam embolization then followed, until stagnation of blood flow was achieved. Patients were evaluated for response, overall survival, and toxicities. RESULTS: Overall median survival from date of first chemoembolization was ten months. Factors that predicted a longer median survival included favorable performance status (24 months), serum alkaline phosphatase and lactate dehydrogenase levels less than three times normal (24 and 12 months, respectively), and metastatic disease confined to the liver (14 months). Most patients tolerated the procedure well. The most common side effects were transient fevers, abdominal pain, and fatigue. Three patients died within one month from the procedure. CONCLUSION: This study suggests that chemoembolization of hepatic metastases in colorectal cancer should be further evaluated; it may be beneficial in patients who have failed systemic chemotherapy, have a good performance status, and have metastatic disease confined to the liver.

Safety of MR imaging in patients who have retained metallic materials after cardiac surgery.

OBJECTIVE: Epicardial pacing wires retained in patients who undergo cardiac surgery are thought to be a relative contraindication to MR imaging. However, to our knowledge no published evidence supports this belief. Because other metallic materials retained after cardiac surgery might represent a hazard to patients who undergo MR imaging, we sought to determine the safety of such imaging. SUBJECTS AND METHODS: We examined 200 patients who underwent MR imaging at 1 or 1.5 T after cardiac surgery. Eighty-one were examined with ECG monitoring. The presence of temporary epicardial pacing wires, prosthetic valves, and other metal materials was confirmed by chest radiography. RESULTS: Of the 200 patients reviewed, all had postoperative metallic material visible on chest radiographs. Temporary epicardial pacing wire, cut short at the skin, was seen in 51 patients. Of the 81 patients examined with ECG monitoring, we found that MR imaging produced no changes from baseline ECG rhythms. None of the 200 patients reported symptoms suggesting arrhythmia or other cardiac dysfunction during MR imaging. CONCLUSION: MR imaging can be performed safely in patients who have undergone cardiac surgery and have retained metallic material, including valve replacements and temporary epicardial pacing wires cut short at the skin. MR imaging of patients with pacemakers was not evaluated, and we recommend that pacemakers remain a contraindication to MR imaging.

Frequency dependent radial compliance of latex tubing.

Custom latex tubing is often used in medical device evaluation. Examples include thin-walled devices used to reduce leakage of porous vascular grafts, and thicker-walled prototypes used as mechanically equivalent synthetic arteries. Medical devices such as stents and balloons are introduced into these for mechanically comparable in vitro testing. The three-dimensional mechanical properties of these tubes are critically important, particularly in accelerated testing, since they are primarily designed to replicate the mechanical rather than biological properties of in vivo arteries. This paper explores the instrumentation and protocols necessary to evaluate the frequency dependent radial compliance of precision built latex tubing. Five cm long samples of custom dipped latex tubing 6 mm in diameter with wall thickness from 0.015" to 0.033" were kept dry or soaked in 37 degrees C phosphate buffered saline for 48 or 96 hours before being mounted on a dynamic internal compliance tester. Each tube was tested initially at 70 bpm to establish the internal radial compliance at the physiologically relevant rate. The frequency of the test was then increased incrementally and the radial compliance re-checked. In the most extreme case, tubes were tested up to 2700 bpm. In each case, the volume, pressure, and length of the tube was monitored continuously.

Pre-operative computed tomography in abdominal aortic aneurysms.

Major additional pathology, in the abdomen or directly related to the aneurysm itself, which influenced surgical management was demonstrated in 39 (34.5%) of 113 patients with suspected abdominal aortic aneurysm who had undergone pre-operative assessment with computed tomography (CT). Major additional pathology within the abdomen was shown in 11 (9.7%) and related to the aneurysm itself in 26 (23%). Therefore, CT has a significant impact on operative management of such patients and should be routine in the pre-operative evaluation of abdominal aortic aneurysms. The current roles of CT angiography and magnetic resonance angiography are discussed.