Apostolos H. Karantanas

Bone marrow edema syndrome

Bone marrow edema syndrome (BMES) refers to transient clinical conditions with unknown pathogenic mechanism, such as transient osteoporosis of the hip (TOH), regional migratory osteoporosis (RMO), and reflex sympathetic dystrophy (RSD). BMES is primarily characterized by bone marrow edema (BME) pattern. The disease mainly affects the hip, the knee, and the ankle of middle-aged males. Many hypotheses have been proposed to explain the pathogenesis of the disease. Unfortunately, the etiology of BMES remains obscure. The hallmark that separates BMES from other conditions presented with BME pattern is its self-limited nature. Laboratory tests usually do not contribute to the diagnosis. Histological examination of the lesion is unnecessary. Plain radiographs may reveal regional osseous demineralization. Magnetic resonance imaging is mainly used for the early diagnosis and monitoring the progression of the disease. Early differentiation from other aggressive conditions with long-term sequelae is essential in order to avoid unnecessary treatment. Clinical entities, such as TOH, RMO, and RSD are spontaneously resolving, and surgical treatment is not needed. On the other hand, early differential diagnosis and surgical treatment in case of osteonecrosis is of crucial importance.

Diagnostic Accuracy of a New Clinical Test (the Thessaly Test) for Early Detection of Meniscal Tears

BACKGROUND Clinical tests used for the detection of meniscal tears in the knee do not present acceptable diagnostic sensitivity and specificity values. Diagnostic accuracy is improved by arthroscopic evaluation or magnetic resonance imaging studies. The objective of this study was to evaluate the diagnostic accuracy of a new dynamic clinical examination test for the detection of meniscal tears. METHODS Two hundred and thirteen symptomatic patients with knee injuries who were examined clinically, had magnetic resonance imaging studies performed, and underwent arthroscopic surgery and 197 asymptomatic volunteers who were examined clinically and had magnetic resonance imaging studies done of their normal knees were included in this study. For clinical examination, the medial and lateral joint-line tenderness test, the McMurray test, the Apley compression and distraction test, the Thessaly test at 5 degrees of knee flexion, and the Thessaly test at 20 degrees of knee flexion were used. For all clinical tests, the sensitivity, specificity, false-positive, false-negative, and diagnostic accuracy rates were calculated and compared with the arthroscopic and magnetic resonance imaging data for the test subjects and the magnetic resonance imaging data for the control population. RESULTS The Thessaly test at 20 degrees of knee flexion had a high diagnostic accuracy rate of 94% in the detection of tears of the medial meniscus and 96% in the detection of tears of the lateral meniscus, and it had a low rate of false-positive and false-negative recordings. Other traditional clinical examination tests, with the exception of joint-line tenderness, which presented a diagnostic accuracy rate of 89% in the detection of lateral meniscal tears, showed inferior rates. CONCLUSIONS The Thessaly test at 20 degrees of knee flexion can be used effectively as a first-line clinical screening test for meniscal tears, reducing the need for and the cost of modern magnetic resonance imaging methods.

An update on the assessment of osteoporosis using radiologic techniques

In this article, the currently available radiologic techniques for assessing osteoporosis are reviewed. Density measurements of the skeleton using dual X-ray absorptiometry (DXA) are clinically indicated for the assessment of osteoporosis and for the evaluation of therapies. DXA is the most widely used technique for identifying patients with osteoporosis. Quantitative computed tomography (QCT) is the only method, which provides a volumetric density. Unlike DXA, QCT allows for selective trabecular measurement and is less sensitive to degenerative diseases of the spine. The analysis of bone structure in conjunction with bone density is an exciting new field in the assessment of osteoporosis. High-resolution multi-slice CT and micro-CT are useful tools for the assessment of bone microarchitecture. A growing literature indicates that quantitative ultrasound (QUS) techniques are capable of assessing fracture risk. Although the ease of use and the absence of ionizing radiation make QUS attractive, the specific role of QUS techniques in clinical practice needs further determination. Considerable progress has been made in the development of MR techniques for assessing osteoporosis during the last few years. In addition to relaxometry techniques, high-resolution MR imaging, diffusion MR imaging and in-vivo MR spectroscopy may be used to quantify trabecular bone architecture and mineral composition.

Acute bone marrow edema of the hip: role of MR imaging

Acute bone marrow edema of the hip is a diagnostic challenge for both radiologists and clinicians. Marrow edema is often seen in patients with hip pain and restriction of motion. In patients with acute non-traumatic hip pain, whose radiographs are negative or inconclusive, MR imaging is the imaging study of choice. MR imaging is the most sensitive and specific imaging technique for detecting transient osteoporosis and osteonecrosis, as well as for detecting and staging fractures and microfractures. MR imaging is able to show marrow involvement in various inflammatory disorders and to diagnose reactive marrow edema from femoroacetabular impingment and greater trochanteric pain syndrome. In patients with septic arthritis, it may also depict associated marrow edema and suggest its reactive or infectious origin. For the neoplastic disorders, although plain radiographs should be the initial examination, MR imaging may follow for assessing extension to the surrounding soft tissues and/or associated pathologic fracture, facilitating thus the treatment planning. Computed tomography is more accurate compared with MR imaging in diagnosing intra-articular osteoid osteomas.

Low-Intensity Transosseous Ultrasound Accelerates Osteotomy Healing in a Sheep Fracture Model

BACKGROUND Low-intensity transcutaneous ultrasound can accelerate and augment the fracture-healing process. The aim of this study was to investigate the effect of transosseous application of low-intensity ultrasound on fracture-healing in an animal model. METHODS A midshaft osteotomy of the left tibia was performed in forty sheep. An external fixator was used to stabilize the osteotomy site. A thin stainless-steel pin was inserted into the bone, 1.0 cm proximal to the osteotomy site. Ultrasound was transmitted through the free end of this pin, with a PZT-4D transducer. In twenty animals, the treated limb received a 200-microsec burst of 1-MHz sine waves repeated at 1 kHz with an average intensity of 30 mW/cm(2) for twenty minutes daily. Twenty other animals underwent the same surgery but did not receive the ultrasound (controls). Animals were killed at seventy-five and 120 days postoperatively. Radiographic evaluation was performed every fifteen days. Mechanical testing and quantitative computed tomography were performed after death. RESULTS Fractures treated with ultrasound healed significantly more rapidly, as assessed radiographically, than did the controls (seventy-nine compared with 103 days, p = 0.027). On day 75, the mean cortical bone mineral density (and standard deviation) was 781 +/- 52 mg/mL in the treated limbs compared with 543 +/- 44 mg/mL in the control group (p = 0.014), and the average ultimate strength (as assessed with a lateral bending test) was 1928 +/- 167 N in the treated limbs compared with 1493 +/- 112 N in the control group (p = 0.012). No significant differences were noted on day 120. CONCLUSIONS This study demonstrated that low-intensity transosseous ultrasound can significantly accelerate the fracture-healing process, increase the cortical bone mineral density, and improve lateral bending strength of the healing fracture in a sheep osteotomy model.

IL-1RN and IL-1B gene polymorphisms and cerebral hemorrhagic events after traumatic brain injury.

Objective: To investigate the association of (variable number tandem repeat) interleukin (IL) 1RN and (-511) IL-1B gene polymorphisms with brain hemorrhagic events after traumatic brain injury (TBI). Methods: Data from brain CT, Glasgow Coma Scale (GCS) at admission, and 6-month Glasgow Outcome Scale (GOS) and modified Rankin Scale (mRS) were collected for 151 prospectively recruited patients with TBI. IL-1RN and IL-1B genotypes were determined using standard methods. Presence vs absence of any type of brain hemorrhage was the main outcome. Type of brain hemorrhage, GCS at admission, and 6-month GOS and mRS were secondary outcomes. Odd ratios (ORs) and corresponding 95% CI were calculated using logistic regression analyses. In adjusted models, the associations were controlled for age, gender, diffuse brain edema, volume of intracranial hematoma, neurosurgical intervention, and GCS at admission. p values less than 0.01 were considered significant. Results: Compared with noncarriers, IL-1RN allele 2 carriers had higher odds of having cerebral hemorrhages after TBI (adjusted OR = 4.57; 95% CI = 1.67 to 12.96; p = 0.004). The associations for (-511) IL-1B polymorphism were not significant. Conclusion: There is an association between the presence of interleukin-1RN allele 2 and posttraumatic brain hemorrhage.

MR cholangiopancreatography before and after oral blueberry juice administration.

Blueberry juice was used in 37 patients who underwent MR cholangiopancreatography (MRCP) examination. Quantitative and qualitative comparison between pre- and post-blueberry juice oral administration was made. Common bile duct and main pancreatic duct depiction improved statistically significantly (p < 0.05) after blueberry juice administration. Blueberry juice may be used routinely in MRCP studies as a natural, safe, and inexpensive negative contrast agent with high efficacy.

Scaphoid Nonunions: Management with Vascularized Bone Grafts from the Distal Radius: A Clinical and Functional Outcome Study

Background: Scaphoid nonunions remain controversial with regard to optimal management, especially for those located at the proximal third. In this study, the authors aim to assess the union rate, avascular proximal pole revascularization, and functional outcome of scaphoid nonunions managed with distal radius vascularized bone grafts. Methods: Thirty patients were treated with vascularized bone grafts between 1999 and 2003 and prospectively followed up. The average nonunion chronicity was 3.3 years. Nine patients (30 percent) had avascular necrosis of the proximal pole, five had unsuccessful previous surgical procedures, and four had radioscaphoid arthritis (Lichtman type III). Twenty proximal third nonunions were managed with dorsal radius bone graft, whereas 10 waist nonunions had palmar grafts. Union was assessed clinically and radiologically and, in 67 percent of the patients, by means of magnetic resonance imaging. Results: All cases were united by 12 weeks, and magnetic resonance imaging confirmed that all necrotic proximal poles were revascularized. On at least 24 months’ follow-up, 90 percent of patients achieved complete pain relief. Wrist flexion-extension and radial-ulnar deviation arcs did not change. The postoperative grip strength was 82 percent of the contralateral side. The Mayo Modified Wrist Score increased significantly from 58 to 85 points and, overall, 77 percent of patients had an excellent or good outcome. No risk factors for compromised wrist function were identified. The scapholunate angle, the scaphoid length, and the Nattrass index improved significantly. Conclusions: This series demonstrates the efficacy of distal radius vascularized bone grafts in union enhancement, proximal pole revascularization, pain relief, improved wrist function, and carpal alignment. Vascularized bone grafts are a reliable therapeutic alternative for scaphoid nonunions.

Sport injuries in the paediatric and adolescent patient: a growing problem

With an increasing number of paediatric and adolescent athletes presenting with injuries due to overuse, a greater demand is put on clinicians and radiologists to assess the specific type of injury. Repetitive forces applied to the immature skeleton cause a different type of injury than those seen in adults due to the differences in vulnerability of the musculoskeletal system, especially at the site of the growth cartilage. Intrinsic and extrinsic risk factors all play a role in the development of overuse injuries. MRI plays a key role in imaging overuse injuries due to its high potential for depicting cartilaginous and soft-tissue structures. Sport-specific biomechanics are described, since this knowledge is essential for adequate MRI assessment. An overview of several sport-related injuries is presented, based on anatomical location.

Blueberry juice used per os in upper abdominal MR imaging: composition and initial clinical data.

The aim of this study was to evaluate the use of a commercially available blueberry juice (BJ) both as a positive and negative oral contrast agent and to present the exact contents of paramagnetic ions. The concentration of Mn and Fe were determined in tinned myrtilles in syrup (atomic absorption). Nine healthy volunteers and 12 patients (age range 20–65 years) were examined using a 1-T MR scanner before and after per os administration of 430 ml of BJ. A qualitative analysis of signal alterations in the stomach, duodenum, and proximal small intestine was performed. In addition, a quantitative analysis was assessed in terms of signal-to-noise ratio calculation. The mean concentration (× ± SD) of the ions found in the content of the three cans were 3.3±0.4 µg/g for iron and 20.6±2.6 µg/g for manganese. Based on the qualitative evaluation, signal alteration on T1-weighted images after administration of BJ was statistically significant in the stomach and duodenum, but not in the proximal small bowel. Signal alteration on T2-weighted images was not statistically significant in any part of the gastrointestinal tract. The quantitative analysis of the T1- and T2 shortening showed that BJ is efficient with only T1-weighted sequences, and this applied to the stomach, duodenum, and proximal small bowel. Blueberry juice can be used as an oral contrast agent in upper abdominal MR for T1-weighted imaging.