The use of intra-operative fluoroscopy for tibial tunnel placement in anterior cruciate ligament reconstruction.

OBJECTIVES: Our aim was to assess the use of intra-operative fluoroscopy in the assessment of the position of the tibial tunnel during reconstruction of the anterior cruciate ligament (ACL). METHODS: Between January and June 2009 a total of 31 arthroscopic hamstring ACL reconstructions were performed. Intra-operative fluoroscopy was introduced (when available) to verify the position of the guidewire before tunnel reaming. It was only available for use in 20 cases, due to other demands on the radiology department. The tourniquet times were compared between the two groups and all cases where radiological images lead to re-positioning of the guide wire were recorded. The secondary outcome involved assessing the tibial interference screw position measured on post-operative radiographs and comparing with the known tunnel position as shown on intra-operative fluoroscopic images. RESULTS: Of the 20 patients treated with fluoroscopy, the imaging led to repositioning of the tibial guide wire before reaming in three (15%). The mean tourniquet time with intra-operative fluoroscopy was 56 minutes (44 to 70) compared with 51 minutes (42 to 67) for the operations performed without. Six patients (30%) had post-operative screw positions that were > 5% more posterior than the known position of the tibial tunnel. CONCLUSION: Intra-operative fluoroscopy can be effectively used to improve the accuracy of tibial tunnel positions with minimal increase in tourniquet time. This study also demonstrates the potential inaccuracy associated with plain radiological assessment of tunnel position.

Complications after posterior dislocation of the hip.

Thirty-five consecutive patients with unilateral posterior dislocation of the hip were studied for complications at an average follow-up of 4.6 years (range 2-10 years). Thompson-Epstein type IV dislocation was most frequent (10/35), reflecting an increase in high-speed motor vehicles in the developing countries. It is also a severe injury that leads to a maximum number of complications, which include avascular necrosis, osteoarthosis, sciatic nerve injury and heterotrophic ossification. Avascular necrosis and osteoarthritis of the hip were observed maximally in type IV patients, even when reduction was achieved in less than twelve hours and may reflect the severity of initial injury. Heterotrophic ossification was observed in five of the ten patients with type IV dislocation and was associated with multiple attempts at reduction. Sciatic nerve injury did not recover completely in all cases, especially when reduction was delayed over twelve hours. Observing that the greatest numbers of complications were seen among patients with type IV dislocations, it may be prudent to warn such individuals about the likely prognosis at the outset, especially in today's world when the demands and expectations are high.

Floating knee injuries: long-term results of four treatment methods.

One hundred twenty-four consecutive patients with true floating knee injury presented between 1987 and 2001. They were treated with non-operative, operative (external fixation and intramedullary nailing) and combined modalities. Sixty patients were followed up, at an average of 7.2 years, for age, gender, type of trauma and fracture; time to fracture union and time to mobilisation. Complications that were encountered and return to normal activities were recorded. Better and comparable union rates of fractures, earlier return to activities and higher excellent and good long-term functional results were observed among combined and operative (intramedullary nail) groups. Using combined modalities of treatment is an affordable, practicable and effective approach, especially for a resource-poor environment. External fixation of the fractured femur resulted in a decreased range of movement at the knee due to quadriceps muscle fixation. Fractured tibia, treated by any of the method, did not interfere with patient's joint mobilisation whereas associated injuries did.

Nutritional status and wound healing in open fractures of the lower limb.

Forty-three patients averaging 28.2 (range 16--74) years with open fractures of the lower limbs were studied prospectively for 40 weeks using anthropometrical, biochemical and haematological parameters to ascertain their relationship to wound healing following injury. Nearly half (21/43) of the patients were malnourished at admission and the number increased to 22 a week after injury. Dietary advice and better food intake improved nutritional status with only 13 patients remaining malnourished at the 40th week. Wound healing was earlier when creatinine-height index was normal throughout the course of treatment and was delayed when serum albumin level was low.

Femoral shaft fractures in children--a comparison of treatment.

Between April 1986 and March 1997, 83 femoral-shaft fractures in children 4-8 years old were treated at Christian Medical College and Hospital, Ludhiana, India. Among 35 patients with a minimum of 12 months follow-up, 14 were treated with Hamilton-Russell (HR) skin traction and 14 with proximal tibial skeletal traction. The group treated with HR traction had a shorter duration of (a) hospital stay (average 16.8 days versus 29.7 days for skeletal traction, p=0.02), (b) time to fracture consolidation (average 8.8 weeks versus 10.8 weeks for skeletal traction, p=0.04), and (c) return to normal activities (average 12.2 weeks versus 17.2 weeks for skeletal traction, p=0.03). At final follow-up (minimum 1 year), there were no significant differences in functional outcomes. Conservative management is still a gold standard for treatment of closed femoral shaft fractures in children 4-8 years of age. There appears to be no advantage to skeletal traction over skin traction in this age group.

Lymphangioleiomyomatosis: CT of diurnal variation of lymphangioleiomyomas.

PURPOSE: To evaluate the imaging and clinical features of lymphangioleiomyomas and to describe the phenomenon of diurnal variation in the size of lymphangioleiomyomas in patients with lymphangioleiomyomatosis. MATERIALS AND METHODS: One hundred twenty-eight patients with lymphangioleiomyomatosis underwent chest and abdominopelvic computed tomography (CT). Thirteen patients underwent CT in the morning and afternoon of the same day to assess diurnal variation in lymphangioleiomyoma size. RESULTS: Twenty-seven of 128 patients (21%) had 54 lymphangioleiomyomas. The vast majority (96%) of these masses contained material of low attenuation at CT. Associated CT findings included enlarged abdominal lymph nodes, pleural effusions, ascites, and dilatation of the thoracic duct. The prevalence of lymphangioleiomyomas was 15% in patients who had mild pulmonary disease, 19% in patients who had moderate disease, and 26% in patients who had severe disease. Diurnal variation in size of masses was demonstrated in 12 of 13 patients. Seven of the 27 patients who had masses underwent biopsy; all seven were confirmed to have lymphangioleiomyomas. The most common symptoms associated with lymphangioleiomyomas were bloating, abdominal pain, and edema of the lower extremities. The majority of the patients reported worsening of symptoms as the day progressed. CONCLUSION: Lymphangioleiomyomas are common in patients with lymphangioleiomyomatosis. Diurnal variation in size may explain worsening of symptoms during the day.

Lymphangioleiomyomatosis: abdominopelvic CT and US findings.

PURPOSE: To describe the abdominal computed tomographic (CT) and ultrasonographic (US) findings in patients with thoracic lymphangioleiomyomatosis (LAM) and to relate the prevalence of the findings to the severity of pulmonary disease. MATERIALS AND METHODS: Eighty patients with LAM underwent chest and abdominopelvic CT and abdominopelvic US. The images were reviewed prospectively by one radiologist, and the abdominal findings were recorded and correlated with the severity of pulmonary disease at thin-section CT. RESULTS: Sixty-one (76%) of 80 patients had positive abdominal findings. The most common abdominal findings included renal angiomyolipoma (AML) in 43 patients (54%), enlarged abdominal lymph nodes in 31 (39%), and lymphangiomyoma in 13 (16%). Less common findings included ascites in eight (10%), dilatation of the thoracic duct in seven (9%), and hepatic AML in three (4%). A significant correlation (P =.02) was observed between enlarged abdominal lymph nodes and increased severity of lung disease. CONCLUSION: There are characteristic abdominal findings in patients with LAM that, in conjunction with the classic thin-section CT finding of pulmonary cysts, are useful in establishing this diagnosis.

Utilization of oriented peptide libraries to identify substrate motifs selected by ATM.

The ataxia telangiectasia mutated (ATM) gene encodes a serine/threonine protein kinase that plays a critical role in genomic surveillance and development. Here, we use a peptide library approach to define the in vitro substrate specificity of ATM kinase activity. The peptide library analysis identified an optimal sequence with a central core motif of LSQE that is preferentially phosphorylated by ATM. The contributions of the amino acids surrounding serine in the LSQE motif were assessed by utilizing specific peptide libraries or individual peptide substrates. All amino acids comprising the LSQE sequence were critical for maximum peptide substrate suitability for ATM. The DNA-dependent protein kinase (DNA-PK), a Ser/Thr kinase related to ATM and important in DNA repair, was compared with ATM in terms of peptide substrate selectivity. DNA-PK was found to be unique in its preference of neighboring amino acids to the phosphorylated serine. Peptide library analyses defined a preferred amino acid motif for ATM that permits clear distinctions between ATM and DNA-PK kinase activity. Data base searches using the library-derived ATM sequence identified previously characterized substrates of ATM, as well as novel candidate substrate targets that may function downstream in ATM-directed signaling pathways.

Head and neck schwannomas--a 10 year review.

Schwannomas of the head and neck are uncommon tumours that arise from any peripheral, cranial or autonomic nerve. Twenty-five to 45 per cent of extracranial schwannomas occur in the head and neck region and thus are usually in the domain of the otolaryngologist. They usually present insidiously and thus are often diagnosed incorrectly or after lengthy delays, however, better imaging and cytological techniques have lessened this to some degree more recently. For benign lesions conservative surgical excision is the treatment of choice bearing in mind possible vagal or sympathetic chain injury. Malignant schwannomas are best treated with wide excision where possible. The role of adjuvant therapy remains uncertain and irrespective of treatment modality prognosis is poor with an overall survival of 15 per cent. However, recent advances in ras oncogene inhibitors may hold hope for the future.

Autoimmune lymphoproliferative syndrome: a syndrome associated with inherited genetic defects that impair lymphocytic apoptosis--CT and US features.

PURPOSE: To describe the imaging findings in patients with autoimmune lymphoproliferative syndrome (ALPS) and to relate the findings to the clinical and genetic features of this recently recognized syndrome. MATERIALS AND METHODS: Retrospective or prospective reviews of the computed tomographic (CT) and ultrasonographic (US) studies and the clinical features in 19 consecutive patients with ALPS were performed. RESULTS: Most patients presented in the 1st year of life with symptoms of adenopathy and hepatosplenomegaly. At the time of presentation to the institution, 12 patients had already undergone splenectomy, and 14 patients had developed autoimmune disorders. All patients had multifocal adenopathy, which was massive in some patients; 14 of 15 patients who underwent CT of the chest had an enlarged thymus, and all six patients who retained their spleens and who underwent imaging had splenomegaly. Ten of 18 patients who underwent liver imaging had hepatomegaly. The adenopathy at US was hyper- and/or isoechoic relative to the liver and thyroid and was enhanced at CT in some patients. All patients had defective lymphocytic apoptosis, or programmed cell death, which was due to specific Fas (APT1 [TNFRSF6]) mutations in 15 patients. CONCLUSION: Patients with ALPS demonstrate nonspecific but often dramatic imaging findings of lymphoproliferative disorders, such as adenopathy, splenomegaly, thymic enlargement, and hepatomegaly. The stability of the clinical findings over months to years and the pattern of lymph node echogenicity may suggest the diagnosis of ALPS.

Polypoid lesions of airways: early experience with computer-assisted detection by using virtual bronchoscopy and surface curvature.

PURPOSE: To test the application of a technique developed by the authors for the computer-assisted diagnosis of polypoid airway lesions from surface rendered virtual bronchoscopic reconstructions. MATERIALS AND METHODS: A computer algorithm was developed to detect polypoid airway lesions by means of segmentation of the bronchial surface with curvature classification. This method was tested with a bronchial phantom, five cadaveric lung specimens, and virtual bronchoscopic studies in 16 patients. RESULTS: For the patient studies, the sensitivity and specificity of the method were 47%-88% and 58%-89%, respectively, depending on the value of an adjustable parameter (the mean curvature threshold). The sensitivity increased (by 20% to 34%) when only lesions larger than 5 mm in diameter were considered. CONCLUSION: With this method, polypoid airway lesions can be detected automatically, although false-positive diagnoses present an important limitation.

Grey matter heterotopia: an unusual association of intractable epilepsy.

Heterotopic grey matter is an abnormality of neuronal migration that has been reported in association with refractory epilepsy. In this study we reviewed the magnetic resonance (MR) imaging records of all patients undergoing MR scanning for evaluation of intractable epilepsy and identified sixteen patients who had grey matter heterotopia. The distribution of the grey matter heterotopia was periventricular in 9 patients, laminar in 3 and was in a "band" form in 4 patients. Congenital anomalies associated with grey matter heterotopia in this study included polymicrogyria in one patient and absence of the corpus callosum in 2 patients. Grey matter heterotopia is an important MR finding in patients with intractable epilepsy.

Advantages of polytetrafluoroethylene arteriovenous loops in the thigh for hemodialysis access.

BACKGROUND: The upper thigh is an alternative but infrequently used site to the forearm for placement of subcutaneous polytetrafluoroethylene (PTFE) arteriovenous conduits in patients requiring hemodialysis for end stage renal failure. This site has the great advantage of easier accessibility for self-cannulation. METHODS: The outcome was reviewed for 74 PTFE loops placed in 61 patients between 1985 and 1991. RESULTS: Mean loop survival time was 99.8 weeks (SD 78.0) when patients with early failure (<1 week), and those patients whose loops functioned adequately until transplantation or death were excluded. Infection occurred in 12 of 74 loops. CONCLUSIONS: Thigh PTFE loops provide satisfactory medium- to long-term vascular access for hemodialysis although, like all other forms of access currently available, they fall short of the ideal for prolonged dialysis.

Magnetic resonance imaging in the evaluation of cerebrospinal fluid fistulae.

Twenty-four patients with a clinical diagnosis of cerebrospinal fluid (CSF) fistulae who were assessed by MR are reported and the literature reviewed on the use of MR in the evaluation of CSF fistulae. Thirteen patients presented with rhinorrhoea, three had otorhinorrhoea and two had recurrent meningitis. Six patients had a combination of symptoms. Nine patients did not have active leakage of CSF at the time of MR scanning. The site of the CSF leak was identified in all 24 patients (100%) and was verified at operation in all patients. This study suggests that MR is a sensitive and accurate technique for detection of CSF leaks even in patients who are not actively leaking at the time of evaluation. MR imaging is a useful technique in the assessment of patients with CSF fistulae; it is non-invasive, offers excellent anatomical detail and has no radiation risk.

Decreased cerebral glucose metabolism in patients with brain tumors: an effect of corticosteroids.

The authors measured cerebral glucose metabolism (CMRglu) using [18F]fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) in patients with brain tumors to evaluate the effect of exogenous corticosteroids (in this instance, dexamethasone) on glucose metabolism. Fifty-six FDG-PET studies obtained in 45 patients with unilateral supratentorial brain tumors were analyzed. Patients with brain tumors were divided into three groups: 1) patients with cushingoid symptoms, who had been treated with combinations of radiotherapy and chemotherapy taking oral dexamethasone; 2) patients not taking dexamethasone but treated with radiotherapy; and 3) patients not taking dexamethasone who had not been treated with radiotherapy. Serial FDG-PET scans were obtained in eight of the cushingoid patients. Glucose metabolism was measured in the contralateral cerebral and ipsilateral cerebellar hemispheres in patients and compared to measurements taken from 19 normal volunteers. The authors found that in the cushingoid brain tumor patients there was a marked reduction in CMRglu compared to normal volunteers and other brain tumor patients (Kruskal-Wallis test; p 0.001). In the majority of patients who had serial FDG-PET scans, there was a decline in glucose metabolism over time and in one patient, in whom dexamethasone was reduced in dosage, there was a subsequent increase in CMRglu. The authors conclude that there is a generalized reduction in CMRglu in brain tumor patients taking dexamethasone compared to other brain tumor patients and normal volunteers, and that this effect is independent of radiotherapy, concurrent anticonvulsant medication, and transhemispheric functional disconnection (transhemispheric diaschisis).

Neuroimaging of juvenile pilocytic astrocytomas: an enigma.

PURPOSE: To present the imaging, metabolic, and clinical data obtained in five patients with juvenile pilocytic astrocytomas (JPAs) and discuss the paradoxical neuroimaging findings. MATERIALS AND METHODS: Five patients with JPAs who had undergone structural imaging and fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) were studied. Normalized glucose utilization rates (GURs) in the tumor were compared with GURs in histopathologically verified low-grade astrocytomas and high-grade tumors. RESULTS: All JPAs enhanced markedly after administration of contrast medium. Their glucose metabolism was significantly (P < .001) higher than that of low-grade astrocytomas and was similar to that of anaplastic astrocytomas. All patients with JPAs were in stable condition and showed no evidence of disease progression despite contrast enhancement and high tumoral glucose metabolism. CONCLUSION: The paradoxical FDG PET findings and enhancement at structural imaging might reflect the unusual vascularity of pilocytic tumors, and the increased GUR might be related to expression of the glucose transporter.