Applying an immersive tutorial in virtual reality to learning a new technique

OBJECTIVE

The medical world is continuously evolving, with techniques being created or improved almost daily. Immersive virtual reality (VR) is a technology that could be harnessed to develop tools that meet the educational challenges of this changing environment. We previously described the immersive tutorial, a 3D video (filmed from the first-person point of view), displayed on a VR application. This tool offers access to supplementary educational data in addition to the video. Here we attempt to assess improvement in learning a technique using this new educational format.

MATERIAL AND METHODS

We selected a single neurosurgical technique for the study: external ventricular drainage. We wrote a technical note describing this procedure and produced the corresponding immersive tutorial. We conducted a prospective randomized comparative study with students. All participants read the technical note, and one group used the immersive tutorial as a teaching supplement. The students completed a multiple-choice questionnaire immediately after the training and again at six months.

RESULTS

One hundred seventy-six fourth-year medical students participated in the study; 173 were included in assessing the immediate learning outcomes and 72 were included at the six-month follow-up. The VR group demonstrated significantly better short-term results than the control group (P=0.01). The same trend was seen at six months.

CONCLUSION

To our knowledge, this study presents one of the largest cohorts for VR. The use of the immersive tutorial could enable a large number of healthcare professionals to be trained without the need for expensive equipment.

Coracoid bone block transfer procedure: Correlation between subscapularis volume below the bone graft and shoulder stability

INTRODUCTION

Coracoid bone graft transfer has become the gold standard in patients with recurrent anterior shoulder instability associated with bony defect. Several studies have shown that the main stabilizing component of this procedure is the sling effect by the conjoint tendon and the lower portion of subscapularis (SS). The purpose of this study was to determine whether a larger SS volume below the bone block was correlated to greater postoperative shoulder stability.

MATERIALS AND METHODS

This prospective study included a cohort of patients who underwent open coracoid bone graft transfer for post-traumatic recurrent anterior shoulder instability. Forty patients were reviewed at 2 years with a clinical and CT scan evaluation. A correlation analysis assessed the relation between the SS volume index (ratio of SS volume below the bone block to volume over the bone block) and Rowe and Walch-Duplay instability scores.

RESULTS

There exists a positive and significant correlation between SS volume index and postoperative Rowe score, r=0.37 (P=0.03). The same trend was observed for Walch-Duplay score without statistical significance. A larger inferior SS volume did not result in a limitation of external rotation, greater fatty infiltration, or malposition of the coracoid graft.

CONCLUSION

A larger SS volume below the bone block is related to greater postoperative shoulder stability. We recommend performing the split in the middle of the SS or higher instead of the junction of the superior two-thirds and inferior one-third as usually reported.

LEVEL OF EVIDENCE

III, prospective study.

Prevalence and topographic distribution of spinal inflammation on MR imaging in patients recently diagnosed with axial spondyloarthritis

OBJECTIVE

The primary goal of this study was to determine the prevalence and topographic distribution of spinal lesions in lower thoracic and lumbar spine on magnetic resonance imaging (MRI) in patients with recently diagnosed with spondyloarthritis. The secondary goal was to identify variables associated with vertebral patterns consistent with spondyloarthritis on MRI.

PATIENTS AND METHODS

A total of 112 HLA-B27 positive patients with recently diagnosed spondyloarthritis were retrospectively included. There were 70 women and 42 men, with a mean age of 41 years±12 (SD) (range: 17-70years). Mean symptom duration was 1year (range: 0-7years). MRI examinations of sacroiliac joints and thoracolumbar spine were reviewed for the presence of bone marrow edema, chronic structural abnormalities, and vertebral patterns consistent with spondyloarthritis. Age, gender and disease duration of patients with vertebral patterns on MRI consistent with spondyloarthritis were compared with those without MRI signs of spondyloarthritis.

RESULTS

Thirty-six patients (32.1%) showed spinal patterns of spondyloarthritis, including 16 patients (14.3%) with no associated inflammatory sacroiliitis. Posterior inflammatory lesions were present in 20.5% of patients. Posterior spinal inflammatory lesions were significantly associated with vertebral corner inflammatory lesions (P=0.03). There were no differences in age, sex or mean duration of symptoms between the two groups of patients.

CONCLUSION

Spinal involvement is observed in 32.1% of HLA-B27 positive patients with recently diagnosed spondyloarthritis and is not associated with sacroiliitis in 14.3%. Age, gender or symptom duration are not associated with spinal involvement on MRI.

Imaging of tumors and tumor-like lesions of the knee

Tumors and tumor-like lesions of the knee are common conditions. Because the synovial membrane covers a large part of the knee, tumors and tumor-like lesions of the knee are mostly synovial. Magnetic resonance imaging (MRI) plays a major role in the assessment and characterization of these lesions. However, the diagnostic approach of these lesions must be performed systematically. First, the lesion must be precisely located, and then the anatomical structure involved must be determined. Finally, clinical background that includes the age of the patient, frequency of the disease and, if any, associated signs as well as MRI characteristics must be analyzed. In this review, we describe the anatomy of the knee and its compartments and provide a description of the main tumors and tumor-like lesions of the knee. We present a diagnostic approach based on the location within the knee of the lesions and the anatomical structures involved.

Tumors of the rib

The authors propose a pictorial review illustrating the imaging features of chest wall tumors and their specific features that discusses the main differential diagnoses. This review is based on published information and on our own experience.

[Hip and pelvic injuries in the elderly]

Fractures of the hip and pelvis are frequent and serious injuries in elderly patients. Due to the aging population, their incidence should double by 2050. Therefore, the social and economical implications of these fractures are significant. Delay in diagnosis increases the associated morbidity and mortality. The purpose is to review the imaging features of these fractures, the imaging techniques (projections, CT) to depict them and their classification based on severity.

[Imaging of the postoperative knee: normal and pathologic findings]

Surgical management of lesions of the knee has exponentially increased over the last several years. MRI plays a major role in postoperative follow-up and evaluation of patients with residual symptoms. Familiarity with the different surgical procedures and potential complications and knowledge of normal and abnormal postoperative MRI findings are essential for evaluation of the postoperative knee. The main purpose of this article is to review the postoperative imaging features of ligaments, menisci and cartilage of the knee joint since these MRI features may lead the surgeon to consider repeat surgery.

[Imaging of knee prostheses]

The authors present a pictorial essay illustrating the different types of knee prostheses, their normal appearances, as well as the imaging features (radiographs, CT, US) of the main complications that may occur.

[Imaging of traumatic injuries of the knee]

Traumatic injuries to the knee are frequent (road or sports related accidents, falls in elderly people). The Ottawa knee rules are applied and dictate the need for additional evaluation. Some fractures are adequately assessed on plain radiographs alone whereas other fractures (tibial plateau fracture) require additional evaluation with CT. Some fractures may be occult: the significance of lipohemarthrosis (indirect sign of intra-articular fracture on the lateral radiograph with horizontal beam) must be known. Benign appearing avulsion fractures suggest the presence of underlying capsuloligamentous injuries requiring further evaluation with MRI. The imaging work-up of sprains is usually negative. MRI may show areas of bone contusion that further the understanding of the mechanism of injury, predict and confirm the presence of capsuloligamentous injuries. Angiography is performed to detect popliteal artery injuries after knee dislocation which is associated with a risk of ischemia.

[Imaging of traumatic injuries of the foot and ankle]

Traumatic injuries of the foot and ankle are frequent and constitute a true public health problem with over 6000 daily cases in France. The complex anatomy of this area and its association to other injuries in polytraumatized patients can lead to delayed diagnosis with worsened functional prognosis. Accurate diagnosis relies on good knowledge of osseous and ligamentous lesions and their associations and sometimes requires the use of additional imaging techniques including US and CT.

[Interventional sonography]

Diagnostic and therapeutic interventional procedures are rapidly expanding and, when guided by imaging, are more efficient then when performed with a blinded technique. Compared to fluoroscopy and CT, ultrasound does not utilize ionizing radiation. It can facilitate needle placement for arthrography, tenography or bursography or it can guide a variety of procedures such as aspiration, arthrocentesis, local steroid injections and needling of tendon calcifications. Technological improvements have increased the precision of ultrasound guidance and have contributed to reduce the risk of complication. Real time scanning allows simultaneous visualization of the target and of needle progression and has diminished the rate of complications, that are infrequent if the operator uses a strict sterile technique and respects the contraindications.

Imagerie ostéo-articulaire du pied diabétique

Destruction in diabetic feet is secondary to neuropathy (peripheral and autonomic nervous system) in association with microangiopathy. The loss of sensation to pain and the static trouble lead to increase the pressure in some areas and predispose to pedal skin ulceration, the precursor of osteomyelitis. Plain radiography should be the first step in the evaluation for diagnosis and follow-up. The initial patterns are nonspecific but very rapid evolution associating osteolysis, osteosclerosis and fragmentation lead to the Charcot foot. When osteomyelitis is suspected, scintigraphy with labelled white blood cells and MRI are necessary to differentiate infection from neuropathy.

Predictive factors of efficacy of periradicular corticosteroid injections for lumbar radiculopathy

BACKGROUND AND PURPOSE

Steroid periradicular infiltration is a common nonsurgical sciatic pain treatment of inconsistent efficacy. The purpose of this study was to identify factors for predicting the efficacy or failure of this procedure.

METHODS

Two hundred twenty-nine patients with lumbar radiculopathy were prospectively followed up at 2 weeks and 1 year after percutaneous periradicular steroid infiltration. The intensity of radicular pain was scored on the visual analog scale (VAS). Pain relief was classified as "excellent" when the pain was completely resolved or had diminished by 75% or more, "good" for a diminution of 50% to 74%, "fair" for a diminution of 25% to 49%, or "poor" for a diminution of less than 25% or an increase in pain.

RESULTS

The mean VAS scores were 6.5 (range, 3.1-9.5) before and 4.2 (range, 0-9.5) 2 weeks after the procedure. Pain relief was graded as excellent in 45 patients (19.7%), good in 48 patients (21%), fair in 45 patients (19.7%), and poor in 91 patients (39.7%). Cause of pain, conflict location, and pain intensity were not predictive factors of radicular pain relief, whereas the symptom duration before the procedure was highly correlated with the pain relief outcome. Patients with excellent results 2 weeks after the procedure had a mean duration of symptoms of 3.04 months (SD 3.28) versus 7.96 months (DS 9.04) in the group with poor pain relief.

CONCLUSIONS

Periradicular infiltration is a simple, safe, and effective nonsurgical procedure that should be performed quite early in the course of the illness to provide radicular pain relief, because corticosteroid infiltration is less beneficial for patients with more chronic radicular pain.

[Langherans' cell histiocytosis: a case report]

Langherans' cell histiocytosis is rare in adults. It should be considered in patients with lytic osseous lesions with sclerotic rim especially when involvement of adjacent soft tissues is present.

[Foraminal, epidural and intravertebral migration of a calcified degenerated intervertebral disk]

The authors report a case of inflammatory back pain associated with radiculopathy secondary to degenerative disk calcifications migrated within the foramen, epidural space and vertebral body. The purpose of this clinical case is to illustrate this uncommon cause of radiculopathy and avoid unnecessary invasive diagnostic procedures.

Efficacy of transforaminal versus interspinous corticosteroid injectionin discal radiculalgia ? a prospective, randomised, double-blind study

A prospective, randomised, double-blind study was carried out to compare the respective efficacies of transforaminal and interspinous epidural corticosteroid injections in discal radiculalgia. Thirty-one patients (18 females, 13 males) with discal radicular pain of less than 3 months' duration were consecutively randomised to receive either radio-guided transforaminal or blindly performed interspinous epidural corticosteroid injections. Post-treatment outcome was evaluated clinically at 6 and 30 days, and then at 6 months, but only by mailed questionnaire. At day 6, the between-group difference was significantly in favour of the transforaminal group with respect to Schober's index, finger-to-floor distance, daily activities, and work and leisure activities on the Dallas pain scale. At day 30, pain relief was significantly better in the transforaminal group. At month 6, answers to the mailed questionnaire still showed significantly better results for transforaminal injection concerning pain, daily activities, work and leisure activities and anxiety and depression, with a decline in the Roland-Morris score. In recent discal radiculalgia, the efficacy of radio-guided transforaminal epidural corticosteroid injections was higher than that obtained with blindly-performed interspinous injections.

[MRI study before and after extracorporal shock wave therapy in calcifying tendinitis of the shoulder]

PURPOSE

Extracorporal shock wave therapy has recently been proposed with good results (70%) for treatment of persistent painful calcifying tendinitis of the shoulder. The aim of this study was to evaluate the early impact of shock wave therapy on the anatomic structures of the shoulder.

MATERIALS AND METHODS

Eight patients (7 women and 1 man, with mean age of 48 years) were prospectively followed up after undergoing shock wave therapy (1500 pulses with 0.28 mJ/mm2 energy). MRI (T1: 500/12 [TR/TE] and STIR: 7200/60/180/180 [TR/TE/TI/alpha]) were obtained 2 hours before and 15 days after the procedure; in addition for 5 of them one more examination was carried out 6 hours after extracorporal shock wave therapy.

RESULTS

There was no significant signal change of the humeral bone or rotator cuff, and the calcification size, when seen (6 times), was unchanged at successive MR examinations. One patient had subcutaneous fat signal change (STIR) next to the zone of impact, which resolved 15 days after the extracorporal shock wave therapy. No bursitis or joint effusion was found.

CONCLUSION

Shock wave therapy has no early complications or significant impact on the anatomic structures of the shoulder.

Metastatic pudendal nerve compression presenting as atypical sciatica

A rare case of Alcock's syndrome caused by tumoral compression of the pudendal nerve is reported. Spine surgeons must be aware of the possibility of Alcock's syndrome in patients presenting with atypical sciatica.

[Imaging of complications following hip arthroplasty]

Acute complications include fractures and prosthesis dislocations. Most chronic complications involve mechanical or septic loosening and aggressive granulomatosis. Greater trochanteric pseudarthrosis, periprosthetic soft tissue ossifications or prosthesis conflict with the psoas muscle can also be responsible for groin pain. Most complications are detected with serial plain radiographs, but additional imaging techniques including CT scan and scintigraphy are sometimes necessary for pretreatment diagnosis. Pain generally indicates a complication but aggressive granulomatosis can be asymptomatic, thus warranting systematic annual plain radiographic control.

Normal vertebral body dimensions: a new measurement method using MRI

Much clinical research on osteoporosis is aimed at documenting a reduction in vertebral fracture rates, but there is considerable disagreement about defining normality. Most methods for measuring vertebral body dimensions use lateral radiographs. In the present paper, we investigate the reliability of magnetic resonance imaging (MRI) for normal reference determination. A validation study was performed on a cadaver by comparing vertebral body volume measured both with MRI (sagittal acquisition in T1 weighted sequence) and with immersion. MRI was then performed with the same protocol from T4 to L5 in a standard population of 80 women with no history of vertebral fractures. Then all vertebral measurements were standardized relative to each other, and means and standard deviations were calculated using a statistical fitting procedure derived from volume and medial area. The validation study confirmed the reproducibility and accuracy of MRI (intraclass correlation coefficient 0.95). There was a strong correlation between volume and medial area of vertebral bodies (Pearson correlation coefficient 0.95) and a constant relationship between the medial area of vertebral bodies for each subject (coefficient of variation 5.6%). The variations in vertebral body dimensions will allow comparison with pathologic vertebral fractures in further studies. This could be useful for monitoring osteoporosis treatments.

Carpal bone maturation assessment by image analysis from computed tomography scans

Bone maturation is the only reliable indicator of growth and its radiologic assessment with or without automated systems is a qualitative method. Image processing allows the study of bone maturation with quantitative data. Carpal bone maturation was studied in 20 children (13 boys and 7 girls, ages ranging from 4 to 15 years) without any clinical evidence of endocrine disease by image analysis from computed tomography (CT) scans. Each wrist CT scan was processed in order to extract the carpal bones and to measure quantitative data regarding volume, axes of inertia and density for each bone. The volumes and the length of the inertia axes were significantly correlated with age. Whatever the age, there were strong correlations between the volume or the length of the main inertia axis of one carpal bone and that of all others. The decrease in the carpal bone volume measured from the processing procedure compared with the theoretical volume of bone defined from the length of the three inertia axes indicated a change in bone shape during growth. Although the mean density was constant, there was an increase in the standard deviation of density with age. Skeletal maturity assessment with image analysis from CT scans seems to be a good complementary investigation to determine bone age in children.

Acute osteoporotic vertebral collapse: open study on percutaneous injection of acrylic surgical cement in 20 patients

OBJECTIVE

The aim of this study was to determine the efficacy of percutaneous vertebroplasty in treating painful spinal osteoporotic collapse.

SUBJECTS AND METHODS

Twenty-three cases of vertebral collapse were evaluated with CT and MR imaging to determine osteoporotic origin and recent evolution. Percutaneous vertebroplasties were performed using CT guidance. The 20 patients included in the study (17 women, 3 men; 62-92 years old) had acute pain of less than 1 month's duration that hindered ambulation and required treatment with narcotic drugs. They underwent this procedure for analgesic purposes. The analogic visual scale of Huskisson was used for pain when scoring assessment.

RESULTS

In 15 patients (75%), pain relief was complete within 24 hr after injection. Analgesic administration was stopped in 14 patients. Mild pain persisted in three (15%) of the remaining five patients. In one other patient (5%), crural pain was observed with cement leakage in the psoas muscle. In the fifth patient (5%), pain recurred after the patient was lifted. The pain was related to a new acute collapse of an adjacent vertebrae.

CONCLUSION

Vertebroplasty for the treatment of osteoporotic vertebral collapse is a minimally invasive procedure that provides immediate pain relief and enables the patient to become quickly mobile.

Amyloidosis-related cauda equina compression in long-term hemodialysis patients. Three case reports

STUDY DESIGN

These case reports illustrate the neurologic manifestations due to beta 2 microglobulin amyloid deposition at the lumbar spine level in long-term hemodialysis patients.

OBJECTIVE

Radiologic investigations suggested the amyloid origin of extradural soft tissue deposition, which was confirmed by histologic examination after surgical excision.

SUMMARY OF BACKGROUND DATA

Although cervical myelopathy is a recently recognized complication of long-term dialysis-related beta 2 microglobulin amyloidosis, neurologic manifestations due to amyloid deposition at the lumbar spine level have rarely been reported.

METHODS

Three case reports of cauda equina compression in long-term hemodialysis patients are presented. Follow-up radiography, computed tomography, and magnetic resonance imaging were performed and patients underwent surgical decompression of the thecal sac.

RESULTS

In two patients, the compression resulted from the development of a destructive spondylarthropathy, and from the infiltration of extradural spaces and ligaments by an abnormal soft tissue. The third patient had lumbar spinal stenosis due to multiple disc protrusion and to hypertrophy of facet joints and ligamentum flavum. Multilevel laminectomies enabled excision of an abnormal fibrous tissue responsible for the thecal sac compression. Histologic examination of the excised fibrous tissues disclosed amyloid deposits in intervertebral discs, apophysial joints, and ligaments.

CONCLUSIONS

In long-term hemodialysis patients, cauda equina compression may develop as the consequence of beta 2 microglobulin amyloid deposition in lumbar intervertebral discs, facet joints, and ligaments. Magnetic resonance imaging is well suited to show the extent of the compression and supports the argument for the amyloid origin of extradural soft tissue.

[Cauda equina syndrome disclosing adenocarcinoma of the ethmoid]

Cauda equina metastases have been exceptionally described in sinusal neoplasms. MRI with gadolinium injection show up the primitive lesion and its neurologic extension. We report a case of cauda equina syndrome in which, only MRI, had show up intradural metastases and localised the ethmoïd sinus carcinoma.

Sensitivity of magnetic resonance imaging of the wrist in very early rheumatoid arthritis

The aim of this study was to evaluate magnetic resonance images (MRI) of soft tissue abnormalities in the wrist of RA patients in the early stage of the disease. We performed magnetic resonance imaging of the wrist in 15 patients with early rheumatoid arthritis according to ACR criteria, of less than 10 months duration (mean duration 4.8 months). None of the patients had carpal bone erosions on standard radiography. MRI demonstrated abnormality of the soft tissue in 13 of the 15 cases. On coronal MRI, the sites of involvement of the synovitis were the recess of the distal ulnar (9 pts.), the distal radioulnar joint (4 pts.) and the radiocarpal joint (7 pts.). On axial MRI, tendon sheath effusion of the digital flexor was present in 3 patients. Carpal bone lacunae were present in only 4 patients. Disease activity was not associated with the extent of the synovitis on wrist MRI. Our study suggests that MRI is a sensitive method for the detection of synovitis in early RA.

The use of Gd-DOTA in magnetic resonance imaging of experimentally induced mammary tumors

Gd-DOTA contrast enhancement of MR images was evaluated on induced mammary tumors in female rats. A single intravenous injection of the carcinogenic N-nitrosourea ENU was administered to Wistar rats; this simple treatment led to a high percentage of mammary tumors without causing death. All the induced tumors were adenocarcinoma and their heterogeneousness depended on their size. The induced tumors did not have intra- or extravascular inflammatory spaces caused by heterotopic lesions, as is the case with implanted tumors. Before injection of Gd-DOTA, appearance of the patchy internal structure was clearly demonstrated on spin-echo images performed with long repetition times. Three doses of the paramagnetic contrast agent (0.1, 0.2, and 0.5 mmol/kg) were evaluated on two different T1-weighted MR sequences. Images were recorded before and repeatedly after intravenous injection of Gd-DOTA, and signal intensities and relaxation times were measured. On images acquired with the spin-echo 500/28 as well as the inversion-recovery 928/26/300 sequences, the results showed that 0.2 mmol/kg Gd-DOTA was the optimal dose for contrast enhancement and for clear visualization of the heterogeneousness of the mammary tumor.