Comparison of magnetic resonance imaging findings with arthroscopic findings in discoid meniscus.

PURPOSE: It is widely accepted that although valuable in the diagnosis of the discoid meniscus and tears, magnetic resonance imaging (MRI) can be insufficient in determining the type of the tear. This study calculates the sensitivity and specificity of MRI in determining the presence and absence of tears and how these values differ for different types of tears. METHODS: This study is a retrospective review of 10 years of our experience with arthroscopic discoid meniscus treatment between 1999 and 2009. MRI findings were compared with the intraoperative arthroscopic findings in 52 patients with 50 lateral and two medial discoid menisci of which 24 were complete and 28 were incomplete. Tears were classified into six groups: (1) no tear, (2) simple horizontal tear, (3) radial tear, (4) combined horizontal tear, (5) complex tear and (6) longitudinal tear. Sensitivity, specificity, positive and negative predictive values of MRI were calculated for each group separately and for the presence and absence of tears in general. In addition, the effect of age, type of discoid meniscus, and presence and absence of shift on the distribution of tear types were analysed. RESULTS: MRI was found to be 100 % specific and 97.8 % sensitive for determining the presence or absence of a tear with a negative predictive value of 85.7 % and a positive predictive value of 100 %. The specificities were 80 % for simple horizontal, 50 % for radial, 66.7 % for combined horizontal, 55.6 % for complex and 14.3 % for longitudinal tears, whereas the sensitivities were 66.7 % for simple horizontal, 96.9 % for radial, 87.5 % for combined horizontal, 94.6 % for complex and 100 % for longitudinal tears. The presence and absence of shift and type of the discoid were found to affect the distribution of the tear type. CONCLUSIONS: MRI is successful in determining the presence or absence of tears in discoid menisci; however, its ability to determine the tear type is questionable. Complete discoid menisci were found to have tendency towards having a simple horizontal or longitudinal tear, whereas incomplete discoid menisci tend to have radial or combined horizontal tears. Determination of the shift prior to surgery is important since it alters the surgical technique.

Development of femoral trochlear groove in growing rabbit after patellar instability.

PURPOSE: The geometry of an articular surface is an important determinant of joint function. Although the geometry of the trochlear groove is considered to be important in the pathogenesis of patellofemoral joint disorders, the effects of the patella during the development of the femoral trochlear groove are unclear. This animal study aimed to investigate the relationship between the position of the patella and development of femoral trochlear groove in growing rabbits. METHODS: Twenty-four knees of 12 rabbits were included in this study and were divided into two groups. First group consisted of the left knees and was used as the control group to which no surgical procedures were applied. Second group involved the right knees to which medial soft tissue restraints release was applied before 1 month of age. Computed tomographic (CT) evaluation of both knees of each rabbit was made in their first month of age before medial retinacular release and also during post-op 1-year follow-up. CT measurements included both the angle and depth of the femoral trochlear groove from 3 different parts (proximal, middle and distal) of the distal femur, and then these measurements were averaged. RESULTS: Measurements revealed that while in the control group the groove angle decreased 27.4 degrees and the depth increased 0.11 mm, in the operated counterparts groove angle decreased 16.8 degrees and groove depth increased 0.03 mm, which indicated the flattening of the femoral groove in the operated group. These differences were found to be statistically significant (P < 0.05). CONCLUSION: The results indicated that distal femoral groove with inadequate patellar position becomes more flattened and causes predisposition for patellar instability. Consequently, the clinical relevance of this study was that early reconstruction of the patellofemoral joint should be performed in the childhood to prevent the patellofemoral problems that are likely to be encountered in the following years.

Imaging findings in congenital hepatic fibrosis.

Congenital hepatic fibrosis (CHF) is a rare congenital multisystemic disorder, mostly inherited in autosomal recessive fashion, primarily affecting renal and hepatobiliary systems. Main underlying process of the disease is the malformation of the ductal plate, the embryological precursor of the biliary system, and secondary biliary strictures and periportal fibrosis ultimately leading to portal hypertension. The natural course of the disease is highly variable ranging from minimally symptomatic disease to true cirrhosis of the liver. However, in most patients the most common manifestations of the diseases that are related to portal hypertension, particularly splenomegaly and bleeding varices. Many other disease processes may co-exist with the disease including Caroli's disease, choledochal cysts and autosomal recessive polycystic kidney disease (ARPKD) reflecting the mulstisystemic nature of the disease. The associating biliary ductal disease led the authors to think that all these entities are a continuum and different reflections of the same underlying pathophysiological process. Although, conventional method of diagnosis of CHF is the liver biopsy the advent of imaging technologies and modalities, today, may permit the correct diagnosis in a non-invasive manner. Characteristic imaging features are generally present and recognition of these findings may obviate liver biopsy while preserving the diagnostic accuracy. In this article, it is aimed to increase the awareness of the practising radiologists to the imaging findings of this uncommon clinical disorder and trail the blaze for future articles relating to this issue.

Current challenges in imaging of the diabetic foot.

Although a variety of diagnostic imaging modalities are available for the evaluation of diabetes-related foot complications, the distinction between neuroarthropathy and osteomyelitis is still challenging. The early and accurate diagnosis of diabetic foot complications can help reduce the incidence of infection-related morbidities, the need for and duration of hospitalization, and the incidence of major limb amputation. Conventional radiography, computed tomography, nuclear medicine scintigraphy, magnetic resonance imaging, ultrasonography, and positron emission tomography are the main procedures currently in use for the evaluation of diabetes-related foot complications. However, each of these modalities does not provide enough information alone and a multimodal approach should be used for an accurate diagnosis. The present study is a review of the current concepts in imaging of diabetes-related foot complications and an analysis of the advantages and disadvantages of each method.