MRI and spondyloarthropathy: diagnostic performance compared to long-term clinical follow-up with evaluation of gadolinium chelates injection.

OBJECTIVES: To evaluate MRI performance on both initial and long-term rheumatologic diagnosis of spondyloarthritis (SpA), taking into account clinical evolution and treatment response, and the impact of gadolinium injection. METHODS: In this single-center study, patients who underwent both spinal and sacroiliac (SI) joint MRI were prospectively recruited between May 2013 and January 2014 and followed for 7 years until 2020. Clinical, biological, and radiologic parameters were collected. At 7-year follow-up (2020), two independent readers reevaluated the initial MRI datasets for specific radiological features of SpA with a 5-point Likert scale to record the estimation of confidence. The centralized MRI interpretations were compared to the established rheumatologic diagnoses in 2013 and 2020. RESULTS: In total, 145 patients (52 men and 93 women) were included. During the 7-year follow-up, the number of patients with positive SpA diagnosis decreased from 93 to 58. Mean sensitivity, specificity, and accuracy of non-contrast MRI were 18, 97, and 49% and 27, 97, and 69% considering 2013 and 2020 rheumatologic diagnoses, respectively. Mean sensitivity, specificity, and accuracy values of gadolinium-enhanced MRI were 26, 97, and 54% and 38, 97, and 73% considering 2013 and 2020 diagnoses, respectively. Post-contrast MRI enabled identification of a subgroup of enthesis-only lesions, without any bone lesions, corresponding to 14% of the pathological cohort. It confirmed uncertain diagnoses in an additional 8.5% of pathological cases. CONCLUSIONS: MRI performance for SpA diagnosis is higher when long-term clinical follow-up is considered than when compared to initial diagnosis. Gadolinium injection increases MRI diagnostic performance and may demonstrate a pure enthesic form of the disease, without bone abnormality. KEY POINTS: • Compared to the rheumatologist's diagnosis over long-term clinical follow-up, MRI performance for SpA is higher than usually estimated. • Gadolinium injection increases diagnostic performance of MRI as it may identify a purely enthesis form of the disease. • Gadolinium injection should be discussed in patients for whom the diagnostic suspicion is strong and whose initial non-injected examination is normal or doubtful.

Three-dimensional ultrashort echo time (3D UTE) magnetic resonance imaging (MRI) of the normal and degenerative disco-vertebral complex at 4.7 T: a feasibility study with longitudinal evaluation.

OBJECTIVES: To assess feasibility of a three-dimensional ultrashort echo time (3D-UTE)-sequence to evaluate normal and pathological disco-vertebral complex (DVC), with assessment of its different portions in a rat model of degenerative disk disease (DDD) with histological correlation. To assess whether this sequence, in comparison with long echo time T2-weighted sequence, is able to monitor DDD with differentiation of early from chronic DVC changes in pathological mechanical conditions. METHODS: Five rats were induced with DDD model by percutaneous disk trituration of the tail with an 18-G needle under US-guidance and imaged at 4.7 T. MRI protocol included fat-saturated-T2 (RARE) and 3D-UTE-sequences performed at baseline (day 0. n = 5 animals /10 DVC) and each week (W) from W1 to W10 postoperatively. Visual analysis and signal intensity measurements of SNR and CNR of all DVC portions were performed on RARE and UTE images. Following killing (baseline, n = 1/2 DVC; W2, n = 2/4 DVC; W10, n = 2/4 DVC), histological analysis was performed and compared with MRI. RESULTS: In normal DVC, unlike conventional RARE-sequences, 3D-UTE allowed complete identification of DVC zonal anatomy including on visual analysis and CNR measurements. In pathological conditions, SNR and CNR measurements of the annulus fibrosus and nucleus pulposus on 3D-UTE distinguished early discitis at W1 from chronic discopathy (P < 0.001 for SNR and P < 0.001 for CNR). Neither the normal complete anatomy of the DVC nor its pathological patterns could be assessed on conventional sequences. CONCLUSIONS: Unlike conventional sequences, 3D-UTE enables visualization of the complete normal DVC anatomy and enables monitoring of DDD differentiating between early DVC changes from chronic ones. LEVEL OF EVIDENCE I: Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.

Symptomatic Schmorl's nodes: role of percutaneous vertebroplasty. Open study on 52 patients.

PURPOSE: To assess the feasibility and clinical outcome of combined CT and fluoroscopy-guided percutaneous vertebroplasty in the management of painful Schmorl's nodes (SN). METHODS: A prospective study was carried out from January 2014 to January 2016 in 52 consecutive patients. Thirty-two men and 30 women aged between 42 and 88 years old were consecutively included. Technical success was defined as the ability to deposit cement in the subchondral endplate anteriorly, around the SN and posteriorly to the SN, in a cupule-like shape. Data regarding procedure time, amount of cement injection, and cement leakage were also noted. Assessment of pain was performed with VAS score and Oswestry disability index. All patients underwent a clinical and radiological follow-up at 1 day, 1 month, 6 months, and 1 year after procedure. RESULTS: Technical success was 100%. Mean procedural time was 15 min, and mean injected cement volume was 2.8 mL. The VAS and Oswestry disability index decreased respectively from 7.2 ± 1.5 to 2.1 ± 1.0 and from 59.2 ± 16.2 to 17.1 ± 5.0 at 1 month. Follow-up mean VAS scores were 2.4 (± 1.4) at 6 months and 2.2 (± 1.2) at 12 months. CONCLUSION: PVP appears as a feasible procedure in patients with painful SN with satisfying pain decrease in the following year after procedure.

Innovative Spine Implants for Improved Augmentation and Stability in Neoplastic Vertebral Compression Fracture.

Background and objectives: Tumor-related vertebral compression fractures often result in severe back pain as well as progressive neurologic impairment and additional morbidities. The fixation of these fractures is essential to obtain good pain relief and to improve the patients' quality of life. Thus far, several spine implants have been developed and studied. The aims of this review were to describe the implants and the techniques proposed to treat cancer-related vertebral compression fractures and to compile their safety and efficacy results. Materials and Methods: A systematic MEDLINE/PubMed literature search was performed, time period included articles published between January 2000 and March 2019. Original articles were selected based on their clinical relevance. Results: Four studies of interest and other cited references were analyzed. These studies reported significant pain and function improvement as well as kyphotic angle and vertebral height restoration and maintain for every implant and technique investigated. Conclusions: Although good clinical performance is reported on these devices, the small numbers of studies and patients investigated draw the need for further larger evaluation before drawing a definitive treatment decision tree to guide physicians managing patients presenting with neoplastic vertebral compression fracture.

An open-label, prospective, observational study of the efficacy of bisphosphonate therapy for painful osteoid osteoma.

OBJECTIVES: To assess the efficacy of bisphosphonate therapy on bone pain in patients with osteoid osteoma (OO) (main objective), and to describe bisphosphonate-induced changes in nidus mineralisation and regional bone-marrow oedema (BMO). METHODS: A prospective, observational study was conducted from 2011 to 2014. Patients with risk factors for complications of percutaneous or surgical ablation or recurrence after ablation, were offered once monthly intravenous bisphosphonate treatment until significant pain alleviation was achieved. RESULTS: We included 23 patients. The first two patients received pamidronate and the next 21 zoledronic acid (mean, 2.95 infusions per patient). Bisphosphonate therapy was successful in 19 patients (83%), whose mean pain visual analogue scale score decreased by 76.7%; this pain-relieving effect persisted in 17 patients (74%) with a mean follow-up time of 36 months. Computed tomography (CT) demonstrated a mean nidus density increase of 177.7% (p = 0.001). By magnetic resonance imaging (MRI), mean decreases were 38.4% for BMO surface area and 30.3% for signal intensity (p = 0.001 and p = 0.000, respectively). CONCLUSIONS: In 17/23 patients with painful OO managed conservatively with bisphosphonates, long-term final success was achieved. Bisphosphonates may accelerate the spontaneous healing of OO. KEY POINTS: • 19/23 patients with OO managed with bisphosphonates experienced significant pain relief • Pain relief was sustained in 17/23 patients, mean follow-up of 36 months • CT demonstrated a significant increase in nidus mineralisation • MRI demonstrated a significant decrease in bone marrow oedema • Bisphosphonate therapy may accelerate the spontaneous healing of OO.

Percutaneous low-pressure bone stenting to control cement deposition in extensive lytic lesions.

OBJECTIVE: To evaluate low-pressure bone stenting combined with cementoplasty in extensive lytic lesions. METHODS: A single-centre study involving four consecutive patients (four women) with extensive lytic tumours was performed. The average age was 65 years. Surgical treatment was not indicated or not wished for by the patients. Institutional review board approval and informed consent were obtained. Percutaneous consolidation was performed by an interventional radiologist under fluoroscopy guidance. Follow-up was assessed using the visual analogue scale (VAS). RESULTS: Under general (n = 2) or local (n = 2) anaesthesia, five 11-gauge bone biopsy needles were advanced in four lesions. Five auto-expandable uncovered stents (10-14 mm diameter and 40-60 mm long) were inserted. In all cases, bone cement was successfully placed into the tumours. The volume of cement that was injected through the cannulas into the stents was 5-10 mL. Using VAS, pain decreased from more than 9/10 preoperatively to less than 2/10 after the procedure for all patients (p < 0.05). No complications occurred during the follow-up (8-19 months). CONCLUSION: This study suggests that cementoplasty combined with low-pressure bone stenting could allow effective bone stabilization resulting in pain relief. KEY POINTS: • Low-pressure bone stenting is possible. • This technique improves cement injection control. • The procedure allows effective bone stabilization resulting in pain relief.

Patient-specific 3D models created by 3D imaging system or bi-planar imaging coupled with Moiré-Fringe projections: a comparative study of accuracy and reliability on spinal curvatures and vertebral rotation data.

PURPOSE: The aim of this study is to compare the accuracy and reliability of spinal curvatures and vertebral rotation data based on patient-specific 3D models created by 3D imaging system or by bi-planar imaging coupled with Moiré-Fringe projections. METHODS AND MATERIALS: Sixty-two consecutive patients from a single institution were prospectively included. For each patient, frontal and sagittal calibrated low-dose bi-planar X-rays were performed and coupled simultaneously with an optical Moiré back surface-based technology. The 3D reconstructions of spine and pelvis were performed independently by one radiologist and one technician in radiology using two different semi-automatic methods using 3D radio-imaging system (method 1) or bi-planar imaging coupled with Moiré projections (method 2). Both methods were compared using Bland-Altman analysis, and reliability using intraclass correlation coefficient (ICC). RESULTS: ICC showed good to very good agreement. Between the two techniques, the maximum 95 % prediction limits was -4.9° degrees for the measurements of spinal coronal curves and less than 5° for other parameters. Inter-rater reliability was excellent for all parameters across both methods, except for axial rotation with method 2 for which ICC was fair. Method 1 was faster for reconstruction time than method 2 for both readers (13.4 vs. 20.7 min and 10.6 vs. 13.9 min; p = 0.0001). CONCLUSION: While a lower accuracy was observed for the evaluation of the axial rotation, bi-planar imaging coupled with Moiré-Fringe projections may be an accurate and reliable tool to perform 3D reconstructions of the spine and pelvis.

Percutaneous consolidation of loosened spine arthrodesis under CT and fluoroscopy guidance by radiologists: a new useful technique.

OBJECTIVE: The objective was to evaluate percutaneous computed tomography (CT) and fluoroscopy-guided injection of bone cement for consolidation of loosened posterior arthrodesis performed by radiologists. METHODS: A single-centre prospective study involving four consecutive patients (three women, one man) suffering from screw loosening (three at the vertebral level, one at the iliac wing level) after Posterior Lumbar Interbody Fusion (PLIF) treatment was done. The average age was 80 years. Surgical treatment was not indicated or not wished for by the patients. Institutional review board approval and informed consent were obtained. Percutaneous consolidation was performed by an interventional radiologist under CT and fluoroscopy guidance. The path of the trocars was made outside loosened screws bilaterally. Follow-up was assessed using the Visual Analog Scale (VAS). RESULTS: In all cases, bone cement was successfully placed around the loosened screw. The mean volume of cement that was injected was 3 ml. No cement leakage was observed. No neurological complication occurred. Using VAS, pain decreased from more than 9/10 preoperatively to less than 2/10 the day after the procedure for all patients (p < 0.05). CONCLUSION: This study suggests that loosening of spine arthrodesis could be successfully treated by percutaneous injection of bone cement under CT and fluoroscopy guidance. KEY POINTS: • PLIF is one of the surgical techniques for spinal arthrodesis. • Treatment indications are degenerative disease or instability following trauma, tumour, or infection. • Screw loosening is a frequent complication that can occur after surgery. • Percutaneous facet consolidation under dual guidance seems to be a feasible technique. • The procedure is performed under local anaesthesia using a minimally invasive approach.

Stabilisation of a loosened femoral gamma nail by percutaneous cement injection (cementoplasty): a new technique.

Surgical repair of pertrochanteric and subtrochanteric fractures in the elderly is usually achieved using an endomedullary nail. Unfortunately, even today, some of the patients who undergo this intervention develop periprosthetic bone absorption over time that can lead to loosening of the prosthesis, resulting in pain, joint instability and the need for revision surgery. Surgical revision is hindered by potential complications related to patients' existing underlying medical conditions. It is often the case that these patients are weak and present comorbidities, which can lead to an absolute contraindication to surgery. An interesting alternative could be the stabilisation by percutaneous injection of cement (cementoplasty) in the periprosthetic space under CT and fluoroscopic guidance. In patients with absolute contraindication we performed percutaneous cementoplasty as treatment for femoral prosthesis loosening. Our procedure was technically a success following the end of the intervention period (follow-up: 6 months). The patient no longer experienced significant pain and showed stability of the prosthesis, as demonstrated by CT.

Imaging of Spondylodiscitis: A Comprehensive Updated Review-Multimodality Imaging Findings, Differential Diagnosis, and Specific Microorganisms Detection.

Spondylodiscitis is defined by infectious conditions involving the vertebral column. The incidence of the disease has constantly increased over the last decades. Imaging plays a key role in each phase of the disease. Indeed, radiological tools are fundamental in (i) the initial diagnostic recognition of spondylodiscitis, (ii) the differentiation against inflammatory, degenerative, or calcific etiologies, (iii) the disease staging, as well as (iv) to provide clues to orient towards the microorganisms involved. This latter aim can be achieved with a mini-invasive procedure (e.g., CT-guided biopsy) or can be non-invasively supposed by the analysis of the CT, positron emission tomography (PET) CT, or MRI features displayed. Hence, this comprehensive review aims to summarize all the multimodality imaging features of spondylodiscitis. This, with the goal of serving as a reference for Physicians (infectious disease specialists, spine surgeons, radiologists) involved in the care of these patients. Nonetheless, this review article may offer starting points for future research articles.

Percutaneous facet screw fixation of lumbar spine with CT and fluoroscopic guidance: a feasibility study.

PURPOSE: To assess the feasibility of computed tomography (CT)- and fluoroscopy-guided percutaneous facet screw fixation following anterior lumbar interbody fusion (ALIF) or anterior pseudarthrosis in adults. MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained for this study. One hundred seven consecutive adult patients (46 men, 61 women; mean age ± standard deviation: 56.3 years ± 12.9) with ALIF (n = 79) or anterior pseudarthrosis (n = 28) were prospectively treated by means of percutaneous facet screw fixation with CT and fluoroscopic guidance. Two 4.0-mm cannulated screws were placed per level to fix facet joints by using either a translaminar facet or transfacet pedicle pathway. Only local anesthesia was used during these procedures. Procedural time was noted for each patient. Postoperative follow-up ranging from 1 year to 3 years was assessed by using Macnab and radiologic criteria. RESULTS: The mean procedure times for a lumbar single-level and a double-level fusion ranged from 15 to 25 minutes and from 40 to 50 minutes, respectively. All the transfacet pedicle (n = 182) and translaminar facet (n = 56) screws were successfully placed in one attempt. Radiographic fusion was observed within the year following posterior fixation in all patients despite one translaminar screw failure. According to the Macnab criteria, the clinical results were classified as excellent in 92 (86%) and good in 15 (14%) of 107 patients at the time of their last follow-up examination. CONCLUSION: This feasibility study showed that CT- and fluoroscopy-guided percutaneous facet screw fixation is a rapid, safe, and effective method.

Percutaneous screw fixation of acetabular roof fractures by radiologists under CT and fluoroscopy guidance.

OBJECTIVE: The aim of this study was to evaluate CT- and fluoroscopy-guided percutaneous screw fixation by radiologists in the management of acetabular roof fractures. SUBJECTS AND METHODS: Fifty-two consecutive adult patients with a nondisplaced and isolated acetabular roof fracture were prospectively treated by an interventional radiologist who made a percutaneous screw fixation under CT and fluoroscopy guidance. All these procedures were performed under local anesthesia. The postoperative follow-up ranged from 36 to 48 months. RESULTS: For each patient, two 6.5-mm Asnis III screws were inserted to fix the roof acetabular fracture. The mean procedure time was 45 minutes (range, 30-90 minutes). No complications were observed. Follow-up CT showed evidence of fracture healing. No evidence of secondary displacement, degenerative changes, or screw failure was noted. Using the rating system of D'Aubigne and Postel, all patients had excellent results. CONCLUSION: The results of our study showed that nondisplaced acetabular roof fractures could be successfully treated by a minimally invasive technique with an excellent long-term outcome.

CT- and fluoroscopy-guided percutaneous discectomy for lumbar radiculopathy related to disc herniation: a comparative prospective study comparing lateral to medial herniated discs.

OBJECTIVE: To evaluate and compare two groups of patients with sciatica due to intervertebral disc herniation with no neurologic deficit. The groups consisted of patients with intervertebral disc herniation in a medial location (group 1) and those in a lateral location (group 2). MATERIALS AND METHODS: A total of 200 patients were included in the study and were followed for a minimum of 6 months. In our series, we treated 80 postero-lateral herniated discs (40% of cases), 46 postero-medial herniated discs (23%), and 74 foraminal herniated discs (37%). Level L3-L4 was treated in 30 cases (15%), L4-L5 in 98 cases (49%), and L5-S1 in 72 cases (36%). The procedure was performed under dual guidance: fluoroscopic and CT. A helical probe was activated. It penetrates the herniated disc and causes the pulpous material to be mechanically evacuated through the probe. All 200 patients were followed for a minimum of 6 months. RESULTS: In group 1, the patients had a mean pain score of 7.9 ± 2.5 VAS units (range 6-10 units) prior to intervention. This was reduced to 3.2 ± 2.1 VAS units (range 0-10 units) at 48 h follow-up and increased to 3.9 ± 1.2 VAS units (range 0-10 VAS units) at 1 month follow-up and further reduced to 2.7 ± 1.2 units (range 0-10 VAS units) at 6 month follow-up. In group 2, the patients had a mean pain score of 8.2 ± 3.2 VAS units (range 6-10 units) prior to intervention. This was reduced to 2.8 ± 1.5 VAS units (range 0-10 units) at 48 h follow-up and decreased to 1.5 ± 0.9 VAS units (range 0-10 units) at 1 month and further reduced to 1.1 ± 0.5 VAS units (range 0-10 units) at 6 months. CONCLUSION: Our study showed that results were more satisfactory for the hernia located laterally (postero-lateral, foraminal, and extra-foraminal) as compared to the hernia located posteromedially.

Inhalation study of polymethyl methacrylate following radiologist exposure during percutaneous vertebroplasty.

OBJECTIVE: To assess the atmospheric concentrations of methyl methacrylate (MMA) vapors during percutaneous vertebroplasty for the interventional radiologist and the other operating room staff. MATERIALS AND METHODS: During percutaneous vertebroplasty, a polymethyl methacrylate (PMMA) mixture (about 20 mL) was prepared with a mixing system in a normally ventilated room. Atmospheric concentrations of MMA vapors were measured by a gas absorbent badge for individual exposure (GABIE) passive sampler attached to the surgical gowns of the interventional radiologist and the other operating room staff over a period of 460 min. Active sampling was performed over 15 min with an individual pump placed near the breathing zone of the radiologist. MMA vapor concentrations were then measured using gas chromatography and activated charcoal tubes. RESULTS: Mean MMA vapor concentrations measured by the GABIEs over the period of 460 min were 0.51 parts per million (ppm) for the radiologist and 0.22 ppm for the other operating room staff. The emission peaks measured by using charcoal tubes over 15 min were 3.7 ppm. CONCLUSION: MMA vapor concentrations during percutaneous vertebroplasty were well below the recommended maximum exposure of 100 ppm over the course of an 8-h workday.

Computed tomography- and fluoroscopy-guided percutaneous screw fixation of low-grade isthmic spondylolisthesis in adults: a new technique.

OBJECTIVES: To evaluate the feasibility of computed tomography (CT)- and fluoroscopy-guided percutaneous screw fixation for the treatment of low-grade isthmic spondylolisthesis in adults. METHODS: Ten consecutive adult patients (four men and six women; mean age: 57.1 [range, 44-78 years]) were prospectively treated by percutaneous screw fixation for low-grade (six grade 1 and four grade 2) isthmic spondylolisthesis of L5. For each patient, two 4.0-mm Asnis III cannulated screws were placed to fix the pars interarticularis defects. All procedures were performed under local anaesthesia by using CT and fluoroscopy guidance. Post-operative outcome was assessed using the visual analogue scale and Oswestry Disability Index (ODI) scores. RESULTS: The procedure time ranged from 45 to 60 min. The mean screw length was 27 mm (range, 24-32 mm). The VAS and ODI measurements ± SD decreased from 7.8 ± 0.9 preoperatively to 1.5 ± 1.1 at the last 2-year follow-up, and from 62.3 ± 17.2 to 15.1 ± 6.0, respectively (P < 0.001 in both cases). Neither slip progression nor screw failure was noted. CONCLUSIONS: This feasibility study showed that CT- and fluoroscopy-guided percutaneous screw fixation could be a rapid, safe and effective method of treating low-grade isthmic spondylolisthesis. KEY POINTS: CT- and fluoroscopy-guided percutaneous screw fixation of isthmic spondylolisthesis is feasible. It could become an effective method to treat low-grade isthmic spondylolisthesis. Percutaneous trans-isthmic screw fixation can be performed under local anaesthesia. This new technique can be performed as an outpatient procedure.

Symptomatic lumbar facet joint cysts treated by CT-guided intracystic and intra-articular steroid injections.

OBJECTIVE: To evaluate percutaneous computed tomography (CT)-guided intracystic and intra-articular steroid injections for the treatment of lumbar facet joint cyst causing radicular pain. METHODS: A single-centre prospective study involving 120 consecutive patients with symptomatic lumbar facet joint cyst-induced radicular pain was done (72 women, 48 men). The average age was 68.2 years (52-84). Patients were treated by percutaneous CT-guided intracystic and intra-articular steroid injections. The clinical course of nerve root pain was evaluated after 1 day, and 1, 3 and 6 months, with long-term follow-up after 12 months. RESULTS: Patient follow-ups in our series show supportive results: within 120 patients, 54% of patients were satisfied with a long-lasting result from the first intra-cystic and intra-articular steroid injections (n = 65), while 20.8% were satisfied with a long-lasting result from a second intervention. Combining these two results shows that 75% of patients were satisfied with a long-lasting result. CONCLUSIONS: Our results showed that percutaneous treatment of vertebral lumbar facet joint cysts by double injections is an effective and economic therapeutic technical management among 75% of our patients. Thus we recommend that it should be considered as a first choice of treatment. KEY POINTS: Lumbar facet joint cysts are a common feature of back and radicular pain. They may be treated effectively by interventional radiologists using CT guidance. Percutaneous treatment using double injections can save surgery in 75% of patients.

Global analysis of sagittal spinal alignment in major deformities: correlation between lack of lumbar lordosis and flexion of the knee.

INTRODUCTION: It has become well recognised that sagittal balance of the spine is the result of an interaction between the spine and the pelvis. Knee flexion is considered to be the last compensatory mechanism in case of sagittal imbalance, but only few studies have insisted on the relationship between spino-pelvic parameters and lower extremity parameters. Correlation between the lack of lumbar lordosis and knee flexion has not yet been established. MATERIALS AND METHODS: A retrospective study was carried out on 28 patients with major spinal deformities. The EOS system was used to measure spinal and pelvic parameters and the knee flexion angle; the lack of lumbar lordosis was calculated after prediction of lumbar lordosis with two different formulas. Correlation analysis between the different measured parameters was performed. RESULTS: Lumbar lordosis correlated with sacral slope (r = -0.71) and moderately with knee flexion angle (r = 0.42). Pelvic tilt correlated moderately with knee flexion angle (r = 0.55). Lack of lumbar lordosis correlated best with knee flexion angle (r = 0.72 and r = 0.63 using the two formulas, respectively). CONCLUSION: Knee flexion as a compensatory mechanism to sagittal imbalance was well correlated to the lack of lordosis and, depending on the importance of the former parameter, the best procedure to correct sagittal imbalance could be chosen.

Rotator cuff tears: should abduction and external rotation (ABER) positioning be performed before image acquisition? A CT arthrography study.

OBJECTIVE: To evaluate the impact of abduction and external rotation (ABER) positioning performed before image acquisition on the assessment of rotator cuff tears. METHODS: Twenty-seven consecutive patients with clinically suspected rotator cuff tears underwent an initial CT arthrogram of the shoulder in neutral position, immediately followed by temporary ABER positioning, before a second CT acquisition in neutral position. Two observers blinded to potential pre-procedure ABER positioning independently analysed the randomly distributed images. Lesions were classified into partial-thickness (PT) and full-thickness (FT) tear subtypes. Lesion detection and measurements of pre- and post-ABER studies were compared. RESULTS: We found no influence of pre-test ABER positioning on FT detection or measurements. Every PT detected on pre-ABER study was also detected on post-ABER study (28/28 for reader 1, and 32/32 for reader 2). Seven and eight additional PT were found by readers 1 and 2, respectively, on post-ABER study. Lesion size increased after ABER in terms of area (P < 0.001 for both readers) and Ellman's grade (P = 0.02 and 0.002 for reader 1 and 2, respectively). CONCLUSION: ABER positioning before CT is associated with improved delineation of partial tears, a higher number of detected tears and modification of treatment planning.

Foreign body extraction from soft tissue by using CT and fluoroscopic guidance: a new technique.

We report on a new minimally invasive technique for the retrieval of a surgical pin fragment after accidental migration into the soft tissue of the shoulder in two patients. The technique is performed under local anaesthesia and uses combined CT and fluoroscopic guidance. The materials used were simple, combining a bone biopsy needle and an endoscopy clamp. Pin displacement was confirmed under fluoroscopic guidance and the clamp was used to withdraw the pin to the cutaneous entry point under CT (step-by-step) guidance. The CT slices provide perfect visualisation of the vascular or nervous structures as well as perfect positioning of the extremity of the trocar relative to the material to be removed. This intervention avoids a second surgical intervention with a longer incision and avoided repeated general anaesthesia.

Anterolateral ankle impingement: diagnostic performance of MDCT arthrography and sonography.

OBJECTIVE: The purpose of our study was to compare the diagnostic performance of CT arthrography and sonography in the diagnosis of anterolateral ankle impingement. SUBJECTS AND METHODS: Fifty-one patients with clinically suspected anterolateral ankle impingement prospectively underwent ankle sonography and CT arthrography, immediately followed by an additional ankle sonography examination to evaluate a potential joint effusion impact on diagnostic performance. CT arthrographic findings as well as sonographic findings before and after arthrography were correlated to subsequent arthroscopic appearance in 41 patients. The diagnostic performance of CT arthrography and sonography before and after joint injection was calculated using arthroscopy as the reference standard and compared using McNemar tests. RESULTS: The sensitivity and specificity of sonography were respectively 77% and 57% before joint injection and 85% and 71% after joint injection. Positive Doppler masses were found to be anterolateral impingements at arthroscopy in all cases (10/10), and masses of hyperechoic appearance were found not to be anterolateral impingements in all cases (3/3). The sensitivity and specificity of CT arthrography in the diagnosis of anterolateral impingement were respectively 97% and 71%. The performances of CT arthrography and ankle sonography in the diagnosis of anterolateral ankle impingement were significantly different (p = 0.006). CONCLUSION: CT arthrography is quite accurate and superior to ankle sonography in the diagnosis of anterolateral impingement. The diagnostic performance of sonography is limited, but positive Doppler appearance and hyperechogenicity, when present, could help to exclude or confirm the diagnosis.