The reliability of the patellotrochlear index on magnetic resonance imaging for measuring patellofemoral height.

BACKGROUND: The purpose of this study was to determine the inter- and intra-observer reliability of the patellotrochlear index (PTI) on magnetic resonance images (MRI) in patients with patellofemoral pain. The correlation between the PTI measured on MRI and the modified Insall-Salvati (MIS) ratio measured on radiographs was also assessed. METHODS: The PTI was assessed on MRI images and the MIS ratio on radiographs of 66 knees of 62 patients. Assessment was performed by two orthopaedic surgeons, one orthopaedic surgery registrar, two radiologists and one radiology registrar. Correlation coefficients, standard errors of measurement and limits of agreement were calculated for the PTI. To assess the association between the PTI and the MIS ratio, the Pearson's correlation coefficient was calculated. RESULTS: The PTI showed good interobserver reliability (intraclass correlation coefficient (ICC) 0.79; 95% confidence interval (CI) 0.73-0.85) and excellent intra-observer reliability (ICC 0.90; 95% CI 0.89-0.91). The standard error of measurement was 0.05 and limits of agreement with the mean ± 0.09. A very weak and not significant correlation was found between the PTI and the MIS (r = 0.02; P = 0.77). CONCLUSIONS: The PTI showed good interobserver reliability and excellent intra-observer reliability. In order to conclude which measurement method of assessing patellar height is truly the most reliable, future studies should investigate agreement parameters (standard error of measurement, limits of agreement) besides solely correlation coefficients. We found a very weak correlation between the PTI and the MIS which suggests that at least one index has poor validity. Future validity studies on indices to assess patellar height are necessary.

The imaging and classification of severe pelvic ring fractures: Experiences from two level 1 trauma centres.

We describe the routine imaging practices of Level 1 trauma centres for patients with severe pelvic ring fractures, and the interobserver reliability of the classification systems of these fractures using plain radiographs and three-dimensional (3D) CT reconstructions. Clinical and imaging data for 187 adult patients (139 men and 48 women, mean age 43 years (15 to 101)) with a severe pelvic ring fracture managed at two Level 1 trauma centres between July 2007 and June 2010 were extracted. Three experienced orthopaedic surgeons classified the plain radiographs and 3D CT reconstruction images of 100 patients using the Tile/AO and Young-Burgess systems. Reliability was compared using kappa statistics. A total of 115 patients (62%) had plain radiographs as well as two-dimensional (2D) CT and 3D CT reconstructions, 52 patients (28%) had plain films only, 12 (6.4%) had 2D and 3D CT reconstructions images only, and eight patients (4.3%) had no available images. The plain radiograph was limited to an anteroposterior pelvic view. Patients without imaging, or only plain films, were more severely injured. A total of 72 patients (39%) were imaged with a pelvic binder in situ. Interobserver reliability for the Tile/AO (Kappa 0.10 to 0.17) and Young-Burgess (Kappa 0.09 to 0.21) was low, and insufficient for clinical and research purposes. Severe pelvic ring fractures are difficult to classify due to their complexity, the increasing use of early treatment such as with pelvic binders, and the absence of imaging altogether in important patient sub-groups, such as those who die early of their injuries.

Congenital vascular malformations in the hand and forearm.

PURPOSE: To review a single-center experience in the management of symptomatic congenital vascular malformations of the hand and forearm with special attention to embolotherapy. METHODS: A retrospective chart review was performed to identify patients with vascular malformations referred for arteriography and possible intervention between 1983 and 1998. Arteriography and venography were performed in all patients to differentiate between true high-flow arteriovenous malformations (AVM) and low-flow primary venous malformations (PVM). The clinical and radiological data, procedural results, and follow-up data were retrieved and reviewed. RESULTS: In a 15-year period, 39 patients (22 men; mean age 22.5 years, range 1-51) had symptomatic vascular lesions diagnosed in the forearm and hand: 21 AVMs, 17 PVMs, and one complex lesion with both AVM and PVM. Thirty-four (87%) lesions were treated with immediate technical success achieved in 31 (91%) cases; 5 (13%) lesions were not amenable to percutaneous treatment. There were no major complications, but 3 embolized AVMs had significant residual flow (81.6% technical success on intention to treat basis). Long-term follow-up ranging to 5 years was available in 26 of the 34 treated patients; the mean symptom-free period was 30 months for the AVM patients and 30.5 months for the PVM group, with an average of 1.5 and 1.2 embolization procedures, respectively. CONCLUSIONS: Vascular malformations of the hand and forearm are extremely rare lesions that demand a multidisciplinary approach for optimal diagnosis and management. Microembolotherapy with or without surgery has offered the highest level of safety and success to date.

Transcatheter embolization of complex pelvic vascular malformations: results and long-term follow-up.

OBJECTIVES: Vascular malformations of the pelvis are rare and present a difficult therapeutic challenge. Surgical treatment is notoriously difficult and carries a high likelihood of recurrence. Surgical proximal ligation of a feeding vessel may in fact be contraindicated, because it can make subsequent transcatheter therapy impossible. The purpose of this study was to review our results with transcatheter embolization therapy in symptomatic complex pelvic vascular malformations in 35 patients. METHODS: A retrospective review was conducted of a prospectively compiled database of all patients undergoing transcatheter therapy of a pelvic vascular malformation at our institution. RESULTS: The mean age of the patients was 34 years (range, 16 months-66 years), and 51% were male. The most common presenting symptoms included pain (59%), a visible or palpable lesion (62%), associated palpable pulsation or thrill (44%), hemorrhage (27%), congestive heart failure (18%), and symptoms due to mass effect (35%). A significant number of patients had undergone previous, unsuccessful attempted surgical treatment of the lesion (32%). The most common type of lesion noted on arteriography was arteriovenous shunting (89%). Patients required a mean of 2.4 embolization procedures (range, 1-11 procedures) over a mean period of 23.3 months (range, 1-144 months). The most common agents used were rapidly polymerizing acrylic adhesives. The most common vessels involved and treated were branches of the hypogastric artery (82%). More than one procedure were performed in 20 patients (53%). Seven were planned as staged embolizations, whereas 13 were due to residual or recurrent symptoms. Adjunctive surgical procedures were performed subsequent to embolization therapy in five patients (15%). Eighty-three percent of patients were asymptomatic or significantly improved at a mean follow-up of 84 months (range, 1-204 months). CONCLUSIONS: Pelvic vascular malformations are difficult to eradicate completely, and recurrences are common. Many patients require multiple therapeutic interventions. However, most of these difficult cases have good results in the long term. Transcatheter embolization plays a significant role in, and may be the treatment of choice for, symptomatic pelvic vascular malformations.

Contrast enhanced color duplex for diagnosis of subtotal stenosis or occlusion of the internal carotid artery.

BACKGROUND AND PURPOSE: We initiated this prospective study to investigate the usefulness of contrast enhancement in combination with color Doppler-assisted duplex imaging (CDDI) for the distinction of subtotal internal carotid artery (ICA) stenosis and ICA occlusion. METHODS: During 1 year all patients with a previously unknown subtotal ICA stenosis (>90%) or ICA occlusion on routine CDDI were included in the study. These patients underwent a CDDI with and without intravenous contrast, Levovist 300 mg/ml. RESULTS: The study group consisted of 32 patients, 15 with subtotal stenosis and high velocity at the ICA stenosis, two with subtotal stenosis and minimal residual color flow and relative low velocity at the ICA stenosis and 15 with ICA occlusion. In all patients the diagnosis by CDDI without and with contrast were the same. Image quality was improved with contrast in 13 of the 17 patients at the subtotal ICA stenosis. There was no significant difference in mean velocities at the subtotal ICA stenoses without and with contrast. CONCLUSION: The usefulness of contrast enhancement with CDDI for differentiating subtotal ICA stenosis and ICA occlusion is limited. Possibly it is useful in patients with moderate image quality of the CCA and ICA and in patients with a subtotal stenosis with minimal residual color flow and relative low velocity at the ICA stenosis.

Pharmacokinetics of apomorphine in Parkinson's disease: plasma and cerebrospinal fluid levels in relation to motor responses.

In this study, we measured the relationship between plasma and cerebrospinal fluid (CSF) apomorphine levels and their clinical effects in two patients with Parkinson's disease (PD). After subcutaneous injection of apomorphine, serial samples of plasma and lumbal CSF were taken and serial scoring of motor responses was done using the Webster Rating Scale. The ratio of the highest level of apomorphine in CSF and plasma was 0.036 for patient A and 0.025 for patient B. The time lag between the highest level of apomorphine in plasma and CSF was 20 min for patient A and 10 min for patient B. Plasma levels of apomorphine correlated weakly with clinical motor responses. However, we could establish a highly strong correlation between apomorphine CSF levels and clinical motor responses: 0.93 and 0.89 for patients A and B, respectively. We conclude that a two-compartment pharmacokinetic model explains the clinical effects of apomorphine better than does a one-compartment model. In a two-compartment model, clinical effect can clearly be correlated to apomorphine levels in the central compartment.