Genicular artery embolization for knee osteoarthritis: Results of the LipioJoint-1 trial

PURPOSE

The purpose of this study was to evaluate the safety and efficacy of transient genicular artery embolization (GAE) using an ethiodized oil-based emulsion for the treatment of knee osteoarthritis (KOA).

MATERIALS AND METHODS

This prospective, single-arm, open-label, multicenter, first-in-human cohort trial was registered on ClinicalTrials.gov (NCT04733092). The main inclusion criterion was diagnosis of KOA according to a visual analogue scale (VAS) pain score ≥ 40 mm (score range: 0-100 mm), despite conservative treatment for at least three months. Treatment efficacy was assessed using changes in VAS pain score, Mean Western Ontario & McMaster Universities osteoarthritis (WOMAC) function score (normalized to 100; score ranging from 0 to100) and outcome measures in rheumatoid arthritis clinical trials (OMERACT)-Osteoarthritis Research Society (OARSI) set of responder criteria.

RESULTS

Twenty-two consecutive participants (13 women; mean age, 66 ± 9 [standard deviation (SD)]) were included and underwent GAE. Emulsion consisted in a mixture of ioversol and ethiodized oil (ratio 1:3, respectively) prepared extemporaneously. The rate of serious adverse events attributed to GAE within one month was 5% (1/22), corresponding to reversible worsening of renal function. Immediate technical success rate was 100%. Mean VAS pain score dropped from 74.4 ± 16.5 (SD) mm at baseline to 37.2 ± 26.7 (SD) mm at three months (P < 0.001). Mean WOMAC function score (normalized to 100: score ranging from 0 to 100) decreased from 57.3 ± 17.1 (SD) at baseline to 33.5 ± 25.9 (SD) at three months (P < 0.001). At three months, 16 out of 22 participants (73%) were considered responders according to the OMERACT-OARSI set of responder criteria, including high improvement in either pain or WOMAC function, or improvement in both pain and WOMAC function.

CONCLUSION

GAE using an ethiodized oil-based emulsion is safe and improves pain and function in participants with KOA for at least three months.

Intra-arterial injection of particulate corticosteroids: mechanism of injury

Mechanism of neurologic complications after epidural spinal injections (ESI) of particulate steroids at the cervical spine include intrathecal injection, epidural hematoma, direct spinal cord injury, and brain stem or cord infarction due to an arterial spasm or inadvertent intra-arterial injection of particulate steroids. At the lumbar spine, there is evidence that a spinal cord infarction secondary to an inadvertent intra-arterial injection of particulate steroids through a transforaminal approach is the leading mechanism.Variations in the arterial supply of the spinal cord help to understand how a lumbar ESI may lead to a spinal cord infarction at the thoracic level. A radiculomedullary artery arising from the lumbar or sacral spine may participate to the supply of the spinal cord. All radicular and radiculomedullary arteries penetrate the spinal canal through the intervertebral foramen. Therefore, its catheterization carries a risk of inadvertent intraarterial injection. An ex vivo animal study has shown that particulate steroids injected in the blood stream produce an immediate and unexpected change of red blood cells into spiculated cells which aggregate and cause arterioles obstruction, while no particulate steroid macroaggregates or vascular spasm were observed. Rare instances of neurologic complications also occurred after ESI performed through a posterior approach. All occurred in previously operated on patients suggesting a pathologic role for the epidural scar.

Imaging Features of Calcium Pyrophosphate Deposition Disease: Consensus Definitions From an International Multidisciplinary Working Group

OBJECTIVE

To develop definitions for imaging features being considered as potential classification criteria for calcium pyrophosphate deposition (CPPD) disease, additional to clinical and laboratory criteria, and to compile example images of CPPD on different imaging modalities.

METHODS

The American College of Rheumatology and European Alliance of Associations for Rheumatology CPPD classification criteria Imaging Advisory Group (IAG) and Steering Committee drafted definitions of imaging features that are characteristic of CPPD on conventional radiography (CR), conventional computed tomography (CT), dual-energy CT (DECT), and magnetic resonance imaging (MRI). An anonymous expert survey was undertaken by a 35-member Combined Expert Committee, including all IAG members. The IAG and 5 external musculoskeletal radiologists with expertise in CPPD convened virtually to further refine item definitions and voted on example images illustrating CR, CT, and DECT item definitions, with ≥90% agreement required to deem them acceptable.

RESULTS

The Combined Expert Committee survey indicated consensus on all CR definitions. The IAG and external radiologists reached consensus on CT and DECT item definitions, which specify that calcium pyrophosphate deposits appear less dense than cortical bone. The group developed an MRI definition and acknowledged limitations of this modality for CPPD. Ten example images for CPPD were voted acceptable (4 CR, 4 CT, and 2 DECT), and 3 images of basic calcium phosphate deposition were voted acceptable to serve as contrast against imaging features of CPPD.

CONCLUSION

An international group of rheumatologists and musculoskeletal radiologists defined imaging features characteristic of CPPD on CR, CT, and DECT and assembled a set of example images as a reference for future clinical research studies.

Quantitative CT of the knee in the IMI-APPROACH osteoarthritis cohort: Association of bone mineral density with radiographic disease severity, meniscal coverage and meniscal extrusion

OBJECTIVE

Osteoarthritis (OA) is a highly prevalent chronic condition. The subchondral bone plays an important role in onset and progression of OA making it a potential treatment target for disease-modifying therapeutic approaches. However, little is known about changes of periarticular bone mineral density (BMD) in OA and its relation to meniscal coverage and meniscal extrusion at the knee. Thus, the aim of this study was to describe periarticular BMD in the Applied Public-Private Research enabling OsteoArthritis Clinical Headway (APPROACH) cohort at the knee and to analyze the association with structural disease severity, meniscal coverage and meniscal extrusion.

DESIGN

Quantitative CT (QCT), MRI and radiographic examinations were acquired in 275 patients with knee osteoarthritis (OA). QCT was used to assess BMD at the femur and tibia, at the cortical bone plate (Cort) and at the epiphysis at three locations: subchondral (Sub), mid-epiphysis (Mid) and adjacent to the physis (Juxta). BMD was evaluated for the medial and lateral compartment separately and for subregions covered and not covered by the meniscus. Radiographs were used to determine the femorotibial angle and were evaluated according to the Kellgren and Lawrence (KL) system. Meniscal extrusion was assessed from 0 to 3.

RESULTS

Mean BMD differed significantly between each anatomic location at both the femur and tibia (p < 0.001) in patients with KL0. Tibial regions assumed to be covered with meniscus in patients with KL0 showed lower BMD at Sub (p < 0.001), equivalent BMD at Mid (p = 0.07) and higher BMD at Juxta (p < 0.001) subregions compared to regions not covered with meniscus. Knees with KL2-4 showed lower Sub (p = 0.03), Mid (p = 0.01) and Juxta (p < 0.05) BMD at the medial femur compared to KL0/1. Meniscal extrusion grade 2 and 3 was associated with greater BMD at the tibial Cort (p < 0.001, p = 0.007). Varus malalignment is associated with significant greater BMD at the medial femur and at the medial tibia at all anatomic locations.

CONCLUSION

BMD within the epiphyses of the tibia and femur decreases with increasing distance from the articular surface. Knees with structural OA (KL2-4) exhibit greater cortical BMD values at the tibia and lower BMD at the femur at the subchondral level and levels beneath compared to KL0/1. BMD at the tibial cortical bone plate is greater in patients with meniscal extrusion grade 2/3.

Clinical and MRI outcomes of subacromial impingement syndrome with conservative treatment: a 21-month prospective study

BACKGROUND

Information is lacking on the natural history of early stages of degenerative rotator cuff disease. Such information can be obtained by using clinical and imaging assessment after conservative treatment in affected patients.

HYPOTHESIS

Subacromial impingement syndrome is a clinical presentation that can be associated with early stages of the disease. We aimed to describe the natural history of degenerative rotator cuff disease from the early stages by studying clinical and imaging outcomes in non-operated patients with subacromial impingement syndrome.

PATIENTS AND METHODS

Patients with subacromial impingement syndrome were prospectively included. They had conservative treatment and were assessed before treatment and during at least 12-month follow-up. Assessment included clinical evaluation on a 0- to 100-point Constant scale and subscales as well as MRI of the rotator cuff. Clinical results were compared to baseline MRI findings and according to lesional progression.

RESULTS

We included 26 patients with mean age 59.1 (SD 9.6), mean pain duration 23.1 (31.3) months; mean total Constant score 39.1 (12.1). Overall, 9 patients had no tear, 9 had a partial tear and 8 had a full-thickness tear. Mean follow-up was 21 (SD 10) months. Total Constant score and subscores improved at follow-up in the overall sample. Patients without tear and those with partial or full-thickness tear at baseline showed clinical improvement. MRI of the rotator cuff at follow-up indicated lesional worsening in 7 patients. However, clinical improvement did not differ by lesional progression or not.

CONCLUSION

We report on 21-month clinical and MRI assessments of degenerative rotator cuff disorders including early stages of the disease. Clinical improvement was not related to MRI changes over time. Further investigations are needed to verify our findings in larger study populations.

The DIGICOD cohort: A hospital-based observational prospective cohort of patients with hand osteoarthritis - methodology and baseline characteristics of the population

OBJECTIVE

Despite its prevalence, there are few worldwide hand osteoarthritis (HOA) cohorts. The main objective of DIGItal COhort Design (DIGICOD) cohort is to investigate prognostic clinical, biological, genetic and imaging factors of clinical worsening after 6years follow-up.

METHODS

DIGICOD is a hospital-based prospective cohort including patients>35years-old with symptomatic HOA fulfilling: (i) ACR criteria for HOA with≥2 symptomatic joints among proximal/distal interphalangeal joints or 1st interphalangeal joint with Kellgren-Lawrence (KL)≥2; or (ii) symptomatic thumb base OA with KL≥2. Main exclusion criteria were inflammatory arthritis and crystal arthropathies. Annual clinical evaluations were scheduled with imaging (X-rays of the hands and of other OA symptomatic joints) and biological sampling every 3years. Hand radiographs are scored using KL and anatomical Verbruggen-Veys scores. Follow-up visits are ongoing. Cohort methodology and baseline characteristics are presented.

RESULTS

Between April 2013 and June 2017, from the 436 HOA included patients, 426 have been analysed of whom 357 (84%) are women. Mean age±standard deviation was 66.7±7.3years and mean disease duration was 12.6±9.6years. Metabolic syndrome affected 151 (36.5%) patients. Mean Visual Analog Scale (VAS) hand pain (0-100mm) was 44.4±26.7mm at activity. Mean FIHOA (0-100) was 19.9±18.6. Elevated serum CRP level (≥5mg/L) involved 10% patients. Mean KL score (0-128) was 46.7±18 and the mean number of joint with KL≥2 was 15.1±6.3. Erosive HOA (defined as≥1 Erosive or Remodeling phase joint according to Verbruggen-Veys score) involved 195/426 (45.8%) patients and the median number (interquartile range) of erosive joints in erosive patients was 3.0 (1.0-5.0).

CONCLUSION

DIGICOD is a unique prospective HOA cohort with a long-term 6years standardized assessment and has included severe radiologically HOA patients with a high prevalence of erosive disease.

Mechanical thumb pain in a systemic sclerosis patient: simple first carpometacarpal osteoarthritis?

A 70-year-old female patient treated with methotrexate for diffuse cutaneous systemic sclerosis (SSc) came up with mechanical pain over the left thumb for several months. SSc was diagnosed based on a clinical picture associating puffy fingers, skin sclerosis, wrist arthralgia, pulmonary hypertension, presence of antinuclear factors and antibodies against Topoisomerase-I. Her complaint was attributed to first carpometacarpal joint osteoarthritis and treated with orthesis, which did not provide pain relief after 5 months of regular use. Hand radiograph showed first carpometacarpal arthropathy with joint space narrowing and marked sclerosis of the first proximal metacarpal (A). MRI showed an area of very low signal intensity on T1- and T2-weighted images (B) within the proximal metacarpal, distal trapezium and medial joint recess surrounded by bone marrow edema. Mild peripheral enhancement was present after gadolinium injection. CT-scan (C) showed that the low signal intensity material visible at MRI consisted of calcium. These aspects are suggestive of scleroderma arthropathy rather than common first carpometacarpal osteoarthritis. Though involvement of the first carpometacarpal joint is long time known in SSc [1], it remains exceptional when looking at cross-sectional studies [2]. Carefully analyzing imaging exams is the key point in order not to miss this rare scleroderma feature.

Does load-bearing materials influence hip capsule thickness in total hip replacement? An MRI case-matched study

BACKGROUND

Ceramic-on-ceramic (COC) total hip replacements (THR) have exhibited less instability and late dislocation. Hip capsule plays an important role in hip stability. Different surrounding soft tissue reactions have been observed according to the bearing material used but no study compared these data using MRI investigation. Therefore, we performed a retrospective case control study to compare hip capsule thicknesses according to the bearing materials in THR and in native hips.

HYPOTHESIS

Hip capsule is thicker after COC THR compared to ceramic- or metal-on-polyethylene (PE) bearings, or native hips.

MATERIALS AND METHOD

Magnetic resonance imaging (MRI) images, combined with a multi acquisition variable resonance image combination (MAVRIC) sequence, was used to measure the hip capsule thickness in 16 patients (29 hips) who had either COC (13 hips, median age at surgery: 64.8 years old, median follow-up at imaging: 2482 days), PE bearings (11 hips, median age at surgery: 48.4 years old (significantly different from COC THR), median follow-up at imaging: 1860 days (NS)), or a native hip with no implant (5 hips). Two independent radiologists measured capsular thicknesses in 4 different zones and were blinded regarding the bearing components. The imaged hips were classified into three groups: native, COC and PE.

RESULTS

The COC THR group had the thickest capsules (median 7.0mm, range 2.9-15.5mm). This result was statistically significant (p<0.0001) when compared to PE THR (median 4.9mm, range 2.2-10.5mm), and to native hips (median 4.1mm, range 2.7-6.9mm) measurements, respectively. Furthermore, painful hips had thinner capsules (4.6mm, range 2-10.5) compared to not painful hips (6.8mm, range 2.3-15.5) (p=0.0006).

DISCUSSION

This is the first in-vivo study measuring capsular thickness in THR with the objective of measuring variations according to the hip implant materials used. The results revealed a significantly thicker capsule for the COC bearing compared to either PE or native hips, and a thinner capsule in painful hips.

LEVEL OF EVIDENCE

III, retrospective non-consecutive cohort study.

Calcium Pyrophosphate Dihydrate Crystal Deposition in Gouty Tophi

OBJECTIVE

The coexistence of calcium pyrophosphate dihydrate (CPPD) and monosodium urate monohydrate crystals in gouty tophi has rarely been reported. We undertook this study to investigate CPPD crystal deposits in a series of surgically removed gouty tophi and to identify factors associated with these deposits.

METHODS

Twenty-five tophi from 22 gout patients were analyzed using polarized light microscopy, field emission scanning electron microscopy (FESEM), and μ Fourier transform infrared (μFTIR) spectroscopy.

RESULTS

Tophi consisted of multiple lobules separated by fibrous septa and surrounded by a foreign-body giant cell reaction. CPPD crystal aggregates were identified in 9 of 25 tophi from 6 patients. CPPD crystals were dispersed or highly compacted, localized at the edge or inside the tophus lobules, with some lobules completely filled with crystals. Both monoclinic and triclinic CPPD crystal phases were identified using FESEM and μFTIR. Compared to patients without CPPD, those with CPPD-containing tophi were older (mean 60.5 years versus 47.2 years; P = 0.009), and had longer-term gout duration (mean 17.0 years versus mean 9.0 years; P < 0.05) and tophi duration (mean 10.0 years versus mean 4.6 years; P < 0.01). None of the patients had radiographic chondrocalcinosis of the knee or wrist.

CONCLUSION

CPPD crystal formation seems to be a late and frequent event of tophus maturation, occurring more frequently with aging, and could contribute to the speed of tophus dissolution and the apparent persistence of tophus sometimes observed even after effective, long-lasting urate-lowering therapy.

Impact of meniscal coverage on subchondral bone mineral density of the proximal tibia in female subjects - A cross-sectional in vivo study using QCT

OBJECTIVE

To verify earlier data in cadavers that in female subjects with OA meniscal coverage is associated with lowered bone mineral density of the underlying subchondral bone in the proximal tibia by investigating the local bone mineral density (BMD) distribution within the epiphysis.

METHODS

BMD of the subchondral bone of the tibia was measured by QCT in 67 elderly females diagnosed with OA (Kellgren-Lawrence grades 2-3). The epiphysis was subdivided along the axis of the tibia into a subchondral-epiphyseal VOI covering the first 5-6 mm below the subchondral bone plate, a mid-epiphyseal VOI covering the adjacent 7-8 and a juxtaphyseal VOI of another 7-8 mm that bordered the growth plate. These VIOs were further divided into lateral and medial and then into anterior, mid and posterior sub-VOIs. Finally, all subVOIs were divided in one subVOI covered by the menisci (CM) and another not covered by the menisci (nCM). BMD ratios of these two subVOIs were compared.

RESULTS

In the subchondral epiphysis BMD was significantly lower (Medial: mean BMD_diff = 125 mg/cm³, p<0.001; Lateral: mean BMD_diff = 56 mg/cm³p < 0.001) in subVOIs covered by the meniscus compared to subVOIs not covered by the meniscus. The BMD difference was no longer significant in the mid epiphysis (Medial: mean BMD_diff = 10 mg/cm³, p>0.82; Lateral: mean BMD_diff = 7 mg/cm³, p=0.99) and was reversed in the juxtaphysis. With a few exceptions these BMD differences were independent of the lateral-medial and the anterior-mid-posterior position. BMD significantly (p<0.05) decreased with age independent on whether the location was covered or uncovered by the meniscus, however the BMD ratio of the corresponding nCM and CM subVOIs did not significantly (p>0.1) change with age.

CONCLUSION

In-vivo QCT measurements of the BMD distribution in the proximal tibia indicate a protective effect of the menisci in the subchondral bone close to the joint. This protective effect is age independent despite the overall age-related decrease of BMD.

Adventitious bursitis in the plantar fat pad of forefoot presenting as a tumoral mass

Adventitious bursitis of the plantar fat pad is a common cause of forefoot pain. It may develop at sites where subcutaneous tissue is exposed to friction and high pressure. In the forefoot, adventitious bursitis is usually adjacent to bony prominences of the metatarsal heads. Diagnosis and management of adventitious bursitis usually do not require imaging studies. However, the condition occasionally presents as a solid pseudotumoral mass requiring imaging. Magnetic resonance imaging (MRI) may demonstrate a heterogeneous mass with a solid component exhibiting intermediate to high signal intensity on T2-weighted images and thick nodular enhancement suggesting a neoplastic lesion. We report three cases of adventitious bursitis in patients who complained of a painful palpable mass on the forefoot, with a partially solid and enhancing component seen on MRI. In the first case, a biopsy was performed for the diagnosis of adventitious bursitis. The two other cases exhibited a solid component on MRI. However, a diagnosis of adventitious bursitis was suspected, and it was felt that a biopsy could be postponed. The spontaneous regression of the mass with relative discharge of the forefoot pressure confirmed the diagnosis. With these three cases, we illustrate the MR findings that could suggest adventitious bursitis despite the presence of a solid component and that may obviate the need for pathologic proof.

Lumbar spinal stenosis and disc alterations affect the upper lumbar spine in adults with achondroplasia

In achondroplasia, lumbar spinal stenosis arises from congenital dysplasia and acquired degenerative changes. We here aimed to describe the changes of the lumbar spinal canal and intervertebral disc in adults. We included 18 adults (age ≥ 18 years) with achondroplasia and lumbar spinal stenosis. Radiographs were used to analyze spinal-pelvic angles. Antero-posterior diameter of the spinal canal and the grade of disc degeneration were measured by MRI. Antero-posterior diameters of the spinal canal differed by spinal level (P < 0.05), with lower values observed at T12-L1, L1-2 and L2-3. Degrees of disc degeneration differed by intervertebral level, with higher degrees observed at L1-2, L2-3 and L3-4. A significant correlation was found between disc degeneration and thoraco-lumbar kyphosis at L2-3, between antero-posterior diameter of the spinal canal and lumbar lordosis at T12-L1 and L2-3, and between antero-posterior diameter of the spinal canal and thoraco-lumbar kyphosis at L1-2. Unlike the general population, spinal stenosis and disc degeneration involve the upper part of the lumbar spine in adults with achondroplasia, associated with thoraco-lumbar kyphosis and loss of lumbar lordosis.

Atlas of the OMERACT Heel Enthesitis MRI Scoring System (HEMRIS)

Objective

Assessment of enthesitis, a key feature in spondyloarthritis (SpA) and psoriatic arthritis (PsA), using objective and sensitive methods is pivotal in clinical trials. MRI allows detection of both soft tissue and intra-osseous changes of enthesitis. This article presents an atlas for the Outcome Measures in Rheumatology (OMERACT) Heel Enthesitis Magnetic Resonance ImagingMRI Scoring System (HEMRIS).

Methods

Following a preliminary selection of potential examples of each grade, as per HEMRIS definitions, the images along with detailed definitions and reader rules were discussed at web-based, interactive meetings between the members of the OMERACT MRI in Arthritis Working Group.

Results

Reference images of each grade of the MRI features to be assessed using HEMRIS, along with reader rules and recommended MRI sequences are depicted.

Conclusion

The presented reference images can be used to guide scoring Achilles tendon and plantar fascia (plantar aponeurosis) enthesitis according to the OMERACT HEMRIS in clinical trials and cohorts in which MRI enthesitis is used as an outcome.

Benefits of Polymerase Chain Reaction Combined With Culture for the Diagnosis of Bone and Joint Infections: A Prospective Test Performance Study

Background

The microbiological diagnosis of bone and joint infections (BJI) currently relies on cultures, and the relevance of molecular methods is still debated. The aim of this study was to determine whether polymerase chain reaction (PCR) could improve the etiological diagnosis of BJI.

Methods

A prospective study was conducted during a 4-year period at Lariboisiere University Hospital (Paris, France), including patients with suspicion of infectious spondylodiscitis, septic arthritis, prosthetic joint infections, and respective noninfected groups. Clinical and radiological data were collected at inclusion and during follow-up. All samples were analyzed by conventional cultures and 16S ribosomal deoxyribonucleic acid (rDNA) gene (16S-PCR). Specific cultures and PCR targeting Mycobacterium tuberculosis were also performed for spondylodiscitis samples. Case records were subsequently analyzed by an independent expert committee to confirm or invalidate the suspicion of infection and definitively classify the patients in a case or control group. The sensitivity of the combination of culture and PCR was compared with culture alone.

Results

After expert committee analysis, 105 cases of BJI cases and 111 control patients were analyzed. The most common pathogens of BJI were staphylococci (30%), M tuberculosis (19%), and streptococci (14%). Adding PCR enhanced the sensitivity compared with culture alone (1) for the diagnosis of M tuberculosis spondylodiscitis (64.4% vs 42.2%; P < .01) and (2) for nonstaphylococci BJI (81.6% vs 71.3%; P < .01). It is interesting to note that 16S-PCR could detect BJI due to uncommon bacteria such as Mycoplasma and fastidious bacteria.

Conclusions

Our study showed the benefit of 16S-PCR and PCR targeting M tuberculosis as add-on tests in cases of suspected BJI.

Shoulder adhesive capsulitis: diagnostic value of active and passive range of motion with volume of gleno-humeral capsule as a reference

BACKGROUND

The diagnosis of adhesive capsulitis is currently based on restricted range of motion (ROM) but its diagnostic value has only been rarely investigated.

AIM

The aim of this study is to assess the diagnostic value of active global and passive gleno-humeral ROM to diagnose shoulder adhesive capsulitis.

DESIGN

Cross-sectional descriptive study.

SETTING

One French center for Rehabilitation Medicine.

POPULATION

Patients referred for treatment of shoulder adhesive capsulitis in our center were included. Inclusion criteria were: shoulder pain; limitation of active global ROM (abduction or flexion <180°); limitation of passive gleno-humeral ROM (abduction or flexion <90° or 25% reduction at less of lateral rotation versus the opposite shoulder); no gleno-humeral arthropathy on radiography.

METHODS

The volume of the gleno-humeral capsule was assessed during a procedure of arthro-distension. The reference criterion for adhesive capsulitis was a volume <12 mL. We analyzed the correlation between the parameters of mobility and the volume of the gleno-humeral capsule; and the positive predictive value (PPV) of inclusion criteria, with the reference criterion for the diagnosis of adhesive capsulitis.

RESULTS

We included 38 patients. Passive gleno-humeral ROM in abduction only was correlated with volume of the gleno-humeral capsule: r=0.33, P=0.043. The PPV of inclusion criteria was 82% for the diagnosis of shoulder adhesive capsulitis. Rather than 90°, when we considered 80°, 60° and 40° as the threshold of passive gleno-humeral ROM in abduction, the PPV increased from 83% to 100%.

CONCLUSIONS

Passive gleno-humeral ROM in abduction is correlated with volume of the gleno-humeral capsule. The PPV is high for active global and passive gleno-humeral ROM for diagnosis of shoulder adhesive capsulitis.

CLINICAL REHABILITATION IMPACT

Limitation of active and passive shoulder ROM, especially passive abduction gleno-humeral, is a good criterion to diagnose shoulder adhesive capsulitis, in patients with shoulder pain and no gleno-humeral arthropathy on radiography.

Locally aggressive monostotic fibrous dysplasia of the cervical spine mimicking malignancy: a case report and literature review

We report the case of a 30-year-old woman with histologically proven monostotic fibrous dysplasia of C2 revealed by a pathological fracture of the odontoid process. Radiological investigations showed a ground-glass mineralization of the vertebral body, a centimetric lytic area with poorly defined margins involving the inferior part of the vertebral body and inferior endplate and a fracture through an osteolytic area in the base of the odontoid process. Owing to the vertebral instability, a surgical procedure combining C0-C5 fixation and posterior bone grafting was performed. The surgical biopsy was inconclusive and pathological confirmation was finally obtained through a percutaneous needle biopsy under fluoroscopic guidance. At 26-month follow-up, the patient still experienced mild persistent cervical posterior neck pain and stiffness possibly related to a C5-6 laxity below the intervertebral fixation. This case combines three radiological findings, which are unusual in fibrous dysplasia: monostotic presentation involving the spine, some aggressive radiographic features, and a pathological fracture.

Microcracks in subchondral bone plate is linked to less cartilage damage

OBJECTIVES

Osteoarthritis (OA) is a disease of the whole joint characterized by cartilage loss and subchondral bone remodeling. The role of microcracks in cartilage integrity and subchondral bone homeostasis is not fully understood. The main goal of this work was to evaluate microcrack density in both calcified cartilage and subchondral bone plate in relation to cartilage damage in humans and to better define the association of microcracks and osteocyte density in subchondral bone.

METHODS

We investigated 18 bone cores from cadaveric human knees that were stained with En-Bloc Basic Fuchsin. We quantified microcrack density, osteocyte density, cartilage surfaces and cartilage damage. The presence of microcracks was confirmed for each bone core by scanning electron microscopy. Finally, trabecular subchondral bone parameters were measured by micro-CT.

RESULTS

Microcracks were detected in both calcified cartilage and subchondral bone plate. The density of microcracks in both calcified cartilage (CC) and subchondral bone plate (SBP) was negatively correlated with cartilage damage (r = -0.45, p < 0.05). The presence of microcracks in SBP was associated with a lower histological OA score. Osteocytes formed a dendrite network that abruptly stopped at the border of calcified cartilage. Osteocyte density in subchondral bone plate was increased in the presence of microcracks in calcified cartilage.

CONCLUSIONS

Subchondral bone plate microcracks might be required for maintaining cartilage homeostasis. Microcracks in calcified cartilage may trigger osteocyte density in subchondral bone plate with subsequent regulation of subchondral bone remodeling to prevent cartilage damage.

Evaluation of the performances of 'typical' imaging abnormalities of axial spondyloarthritis: results of the cross-sectional ILOS-DESIR study

Objective

To evaluate the prevalence and performance as axial Spondyloarthritis (axSpA) diagnostic feature of radiographic and MRI lesions 'typical' of axSpA of the sacroiliac joint (SIJ) and spine in a mechanical chronic back pain (CBP) population and in an axSpA cohort.

Methods

Cross-sectional multicentre study. Patients: (1) recent onset axSpA (DESIR cohort) and (2) mechanical non-axSpA CBP matched for age and gender (ILOS study). Imaging: radiographs and MR scans were performed identically in both groups. All images were centrally read, blinded for diagnosis and for other imaging findings in the same patient. Statistical analysis: prevalence of lesions 'typical of axSpA' were compared in both groups. Sensitivity, specificity and positive likelihood ratios (LR+) of each lesion (and combination of lesions) were calculated.

Results

A total of 98 patients with CBP were included, and compared with 100 patients with recent onset axSpA. SIJ lesions were consistently more frequent in the axSpA group (35.0% vs 11.8% p<0.001, 35.0% vs 8.4% p<0.001% and 32.0% vs 10.0%. p<0.001 for modified New York criteria, MRI sacroiliitis and ≥3 erosions of the SIJ on MRI, respectively), and performed well (LR+ for ≥3 erosions 3.0 (95% CI 1.6 to 5.8)). Spine lesions were comparable across groups: radiographic lesions were rare, while all MRI lesions were frequent.

Conclusion

Our study confirms that 'typical' lesions can also be observed in patients with non-axSpA CBP but that SIJ lesions by all modalities remain the most valuable for diagnosis, including structural lesions of the SIJ. This suggests the potential interest of adding MRI SIJ structural lesions in the definition of MRI abnormalities for axSpA classification.

Percutaneous restoration of bone continuity with screws and PMMA cement in an extensive destruction of the pelvis

We report a case of combined percutaneous screw placement and cementoplasty guided by CT and fluoroscopy in a 66-year-old man with extensive osteolytic destruction of the right iliac bone and sacral wing due to metastasic infiltrative vesical carcinoma. The medical condition was responsible for very limited and painful walking. Two perpendicular screws were inserted into the iliac bone and sacroiliac joint, and bone cement injection was used to anchor the screws and restore the mechanical continuity of the pelvis ring. This minimally invasive procedure allowed for significant and rapid resumption of painless walking.

The OMERACT MRI in Enthesitis Initiative: Definitions of Key Pathologies, Suggested MRI Sequences, and a Novel Heel Enthesitis Scoring System

OBJECTIVE

To develop and validate an enthesitis magnetic resonance imaging (MRI) scoring system for spondyloarthritis/psoriatic arthritis, using the heel as model.

METHODS

Consensus definitions of key pathologies and 3 heel enthesitis multireader scoring exercises were done, separated by discussion, training, and calibration.

RESULTS

Definitions for bone and soft tissue pathologies were agreed. In the final exercise, median pairwise single-measures intraclass correlation coefficients (ICC; patient-level) for entheseal inflammation status/change scores were 0.83/0.82 for all readers. For radiologists and selected rheumatologists, ICC were 0.91/0.84 and quadratic-weighted κ (lesion-level) 0.57-0.91/0.45-0.81.

CONCLUSION

The proposed definitions and Heel Enthesitis Scoring System (HEMRIS) are reliable among trained readers and promising for clinical trials.

Three-dimensional Distribution of Muscle and Adipose Tissue of the Thigh at CT: Association with Acute Hip Fracture

Purpose To evaluate determinants of hip fracture by assessing soft-tissue composition of the upper thigh at CT. Materials and Methods In this retrospective analysis of prospectively collected data, CT studies in 55 female control participants (mean age, 73.1 years ± 9.3 [standard deviation]) were compared with those in 40 female patients (mean age, 80.2 years ± 11.0) with acute hip fractures. Eighty-seven descriptors of the soft-tissue composition were determined. A multivariable best subsets analysis was used to extract parameters best associated with hip fracture. Results were adjusted for age, height, and weight. Results of soft-tissue parameters were compared with bone mineral density (BMD) and cortical bone thickness. Areas under the receiver operating characteristic curve (AUCs) adjusted for multiple comparisons were determined to discriminate fracture. Results The hip fracture group was characterized by lower BMD, lower cortical thickness, lower relative adipose tissue volume of the upper thigh, and higher extramyocellular lipid (EML) surface density. The relative volume of adipose tissue combined with EML surface density (model S1) was associated with hip fracture (AUC, 0.85; 95% confidence interval [CI]: 0.78, 0.93), as well as trochanteric trabecular BMD combined with neck cortical thickness (model B2) (AUC, 0.84; 95% CI: 0.75, 0.92). The model including all four parameters provided significantly better (P < .01) discrimination (AUC, 0.92; 95% CI: 0.86, 0.97) than model S1 or B2. Conclusion In addition to bone mineral density and geometry of the proximal femur, the amount of adipose tissue of the upper thigh and the distribution of the adipocytes in the muscles are significantly associated with acute hip fracture at CT. © RSNA, 2018 Online supplemental material is available for this article.

Percutaneous Vertebral Augmentation Techniques in Osteoporotic and Traumatic Fractures

Percutaneous vertebral augmentation/consolidation techniques are varied. These are vertebroplasty, kyphoplasty, and several methods with percutaneous introduction of an implant (associated or not with cement injection). They are proposed in painful osteoporotic vertebral fractures and traumatic fractures. The objectives are to consolidate the fracture and, if possible, to restore the height of the vertebral body to reduce vertebral and regional kyphosis. Stabilization of the fracture leads to a reduction in pain and thus restores the spinal support function as quickly as possible, which is particularly important in the elderly. The effectiveness of these interventions on fracture pain was challenged once by two randomized trials comparing vertebroplasty to a sham intervention. Since then, many other randomized studies in support of vertebroplasty efficacy have been published. International recommendations reserve vertebroplasty for medical treatment failures on pain, but earlier positioning may be debatable if the objective is to limit kyphotic deformity or even reexpand the vertebral body. Recent data suggest that in osteoporotic fracture, the degree of kyphosis reduction achieved by kyphoplasty and percutaneous implant techniques, compared with vertebroplasty, is not sufficient to justify the additional cost and the use of a somewhat longer and traumatic procedure. In young patients with acute traumatic fractures and a significant kyphotic angle, kyphoplasty and percutaneous implant techniques are preferred to vertebroplasty, as in these cases a deformity reduction has a significant positive impact on the clinical outcome.

The lucent (CT) and enhancing (MR) rim, a sign of Paget's disease of the skull: case report

Osteoporosis circumscripta is sometimes observed at the skull vault and corresponds to the initial stage of Paget's disease of the bone. Differentiating osteoporosis circumscripta from other reasons for osteolytic images of the vault may be difficult. We report a case of osteoporosis circumscripta of the frontal bone. A lucent rim seen on CT scan, which was enhanced on gadolinium-enhanced MRI, delineated the abnormal bone. The patient was a 50-year-old woman who had CT scans of the skull for chronic sinusitis. Pathology examination showed typical bone changes of Paget's disease. The lucent and enhancing rim sign may help in differentiating Paget's disease from other conditions.

Quantitative analysis of skeletal muscle by computed tomography imaging-State of the art

The radiological assessment of muscle properties-size, mass, density (also termed radiodensity), composition, and adipose tissue infiltration-is fundamental in muscle diseases. More recently, it also became obvious that muscle atrophy, also termed muscle wasting, is caused by or associated with many other diseases or conditions, such as inactivity, malnutrition, chronic obstructive pulmonary disorder, cancer-associated cachexia, diabetes, renal and cardiac failure, and sarcopenia and even potentially with osteoporotic hip fracture. Several techniques have been developed to quantify muscle morphology and function. This review is dedicated to quantitative computed tomography (CT) of skeletal muscle and only includes a brief comparison with magnetic resonance imaging. Strengths and limitations of CT techniques are discussed in detail, including CT scanner calibration, acquisition and reconstruction protocols, and the various quantitative parameters that can be measured with CT, starting from simple volume measures to advanced parameters describing the adipose tissue distribution within muscle. Finally, the use of CT in sarcopenia and cachexia and the relevance of muscle parameters for the assessment of osteoporotic fracture illustrate the application of CT in two emerging areas of medical interest.

Tendon thickening in dialysis-related joint arthritis is due to amyloid deposits at the surface of the tendon

OBJECTIVES

Beta-2-microglobulin (β2M) dialysis-related amyloidosis (DRA), a disabiliting joint disease, has been initially reported in patients under long-term dialysis. The incidence and prevalence has significantly decreased with the improvement in dialysis techniques. Here, we attempted to clarify the clinical and MRI features to improve the diagnosis.

METHODS

We retrospectively reviewed the files of 19 patients under dialysis treatment referred for suspicion of β2M DRA. The diagnosis was based on MRI criteria (low signal intensity on both T1- and T2-weighted MR sequences). MRI analysis included a scoring of the several joint lesions. Scores were quantified according to a severity scale (0 to 3).

RESULTS

Patients had a mean age of 66.0 ± 10.5 years and mean dialysis duration of 23.7 ± 10.5 years. DRA affected mainly large joints (shoulder in 73.7%, hip in 47.3%) and spine (36.8%). MRI images for 8 shoulders, 8 hips, and 3 spines were analysed. Amyloid synovitis was present in all cases, with high mean scores in the three sites. In all joints, the most common lesions were tendon thickening (68.4%) and bone erosions (68.4%). The mean tendon thickening score was high, particularly at the shoulders and also at the spine. Bone erosions were most frequent in the shoulder and pelvis.

CONCLUSION

In patients under long-term dialysis, β2M DRA involves large joints but also the spine. Special awareness should be drawn by the thickening of the tendon. MRI is required to characterize the pattern of the lesions and to achieve the diagnosis.

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 Nailing and Cementoplasty for Palliative Management of Supra-Acetabular Iliac Wing Metastases: A Case Report

CASE

A 48-year-old woman was unable to walk due to an extensive osteolytic supra-acetabular iliac wing metastatic lymphoma involving the arcuate line. A minimally invasive technique that combined percutaneous nailing of the iliac bone with a customized nail and cementoplasty (intraosseous injection of polymethylmethacrylate) was performed. At the 1-year follow-up, she was able to walk without crutches, and computed tomography (CT) showed a stable iliac bone fixation.

CONCLUSION

Osteolytic metastasis is a common cause of bone weakening, especially in load-bearing areas. With osteolytic metastases involving the acetabulum, intraosseous injection of bone cement into the weakened acetabulum may reduce pain and prevent fracture. Nailing combined with cementoplasty may be proposed for extensive destruction of the iliac bone involving the arcuate line to relieve pain and allow for resumed walking.

A reproducible semi-automatic method to quantify the muscle-lipid distribution in clinical 3D CT images of the thigh

Many studies use threshold-based techniques to assess in vivo the muscle, bone and adipose tissue distribution of the legs using computed tomography (CT) imaging. More advanced techniques divide the legs into subcutaneous adipose tissue (SAT), anatomical muscle (muscle tissue and adipocytes within the muscle border) and intra- and perimuscular adipose tissue. In addition, a so-called muscle density directly derived from the CT-values is often measured. We introduce a new integrated approach to quantify the muscle-lipid system (MLS) using quantitative CT in patients with sarcopenia or osteoporosis. The analysis targets the thigh as many CT studies of the hip do not include entire legs The framework consists of an anatomic coordinate system, allowing delineation of reproducible volumes of interest, a robust semi-automatic 3D segmentation of the fascia and a comprehensive method to quantify of the muscle and lipid distribution within the fascia. CT density-dependent features are calibrated using subject-specific internal CT values of the SAT and external CT values of an in scan calibration phantom. Robustness of the framework with respect to operator interaction, image noise and calibration was evaluated. Specifically, the impact of inter- and intra-operator reanalysis precision and addition of Gaussian noise to simulate lower radiation exposure on muscle and AT volumes, muscle density and 3D texture features quantifying MLS within the fascia, were analyzed. Existing data of 25 subjects (age: 75.6 ± 8.7) with porous and low-contrast muscle structures were included in the analysis. Intra- and inter-operator reanalysis precision errors were below 1% and mostly comparable to 1% of cohort variation of the corresponding features. Doubling the noise changed most 3D texture features by up to 15% of the cohort variation but did not affect density and volume measurements. The application of the novel technique is easy with acceptable processing time. It can thus be employed for a comprehensive quantification of the muscle-lipid system enabling radiomics approaches to musculoskeletal disorders.

Intradiscal Glucocorticoid Injection for Patients With Chronic Low Back Pain Associated With Active Discopathy: A Randomized Trial

BACKGROUND

Active discopathy is associated with a specific phenotype of chronic low back pain (LBP). Local inflammation has a role in active discopathy-associated symptoms.

OBJECTIVE

To assess the efficacy of a single glucocorticoid intradiscal injection (GC IDI) in patients with chronic LBP with active discopathy.

DESIGN

Prospective, parallel-group, double-blind, randomized, controlled study. (ClinicalTrials.gov: NCT00804531).

SETTING

3 tertiary care centers in France.

PATIENTS

135 patients with chronic LBP with active discopathy on magnetic resonance imaging (MRI).

INTERVENTION

A single GC IDI (25 mg prednisolone acetate) during discography (n = 67) or discography alone (n = 68).

MEASUREMENTS

The primary outcome was the percentage of patients with LBP intensity less than 40 on an 11-point numerical rating scale (0 [no pain] to 100 [maximum pain] in 10-point increments) in the previous 48 hours at 1 month after the intervention. The main secondary outcomes were LBP intensity and persistent active discopathy on MRI at 12 months and spine-specific limitations in activities, health-related quality of life, anxiety and depression, employment status, and use of analgesics and nonsteroidal anti-inflammatory drugs at 1 and 12 months.

RESULTS

All randomly assigned patients were included in the primary efficacy analysis. At 1 month after the intervention, the percentage of responders (LBP intensity <40) was higher in the GC IDI group (36 of 65 [55.4%]) than the control group (21 of 63 [33.3%]) (absolute risk difference, 22.1 percentage points [95% CI, 5.5 to 38.7 percentage points]; P = 0.009). The groups did not differ in LBP intensity at 12 months and in most secondary outcomes at 1 and 12 months.

LIMITATION

Tertiary care setting.

CONCLUSION

In chronic LBP associated with active discopathy, a single GC IDI reduces LBP at 1 month but not at 12 months.

PRIMARY FUNDING SOURCE

French Ministry of Health.

Advanced Knee Structure Analysis (AKSA): a comparison of bone mineral density and trabecular texture measurements using computed tomography and high-resolution peripheral quantitative computed tomography of human knee cadavers

Background

A change of loading conditions in the knee causes changes in the subchondral bone and may be a cause of osteoarthritis (OA). However, quantification of trabecular architecture in vivo is difficult due to the limiting spatial resolution of the imaging equipment; one approach is the use of texture parameters. In previous studies, we have used digital models to simulate changes of subchondral bone architecture under OA progression. One major result was that, using computed tomography (CT) images, subchondral bone mineral density (BMD) in combination with anisotropy and global homogeneity could characterize this progression.

The primary goal of this study was a comparison of BMD, entropy, anisotropy, variogram slope, and local and global inhomogeneity measurements between high-resolution peripheral quantitative CT (HR-pQCT) and CT using human cadaveric knees. The secondary goal was the verification of the spatial resolution dependence of texture parameters observed in the earlier simulations, two important prerequisites for the interpretation of in vivo measurements in OA patients.

Method

The applicability of texture analysis to characterize bone architecture in clinical CT examinations was investigated and compared to results obtained from HR-pQCT. Fifty-seven human knee cadavers (OA status unknown) were examined with both imaging modalities. Three-dimensional (3D) segmentation and registration processes, together with automatic positioning of 3D analysis volumes of interest (VOIs), ensured the measurement of BMD and texture parameters at the same anatomical locations in CT and HR-pQCT datasets.

Results

According to the calculation of dice ratios (>0.978), the accuracy of VOI locations between methods was excellent. Entropy, anisotropy, and global inhomogeneity showed significant and high linear correlation between both methods (0.68 < R² < 1.00). The resolution dependence of these parameters simulated earlier was confirmed by the in vitro measurements.

Conclusion

The high correlation of HR-pQCT- and CT-based measurements of entropy, global inhomogeneity, and anisotropy suggests interchangeability between devices regarding the quantification of texture. The agreement of the experimentally determined resolution dependence of global inhomogeneity and anisotropy with earlier simulations is an important milestone towards their use to quantify subchondral bone structure. However, an in vivo study is still required to establish their clinical relevance.

Multiscale and multimodality computed tomography for cortical bone analysis

In clinical studies, high resolution peripheral quantitative computed tomography (HR-pQCT) is used to separately evaluate cortical bone and trabecular bone with an isotropic voxel of 82 µm³, and typical cortical parameters are cortical density (D.comp), thickness (Ct.Th), and porosity (Ct.Po). In vitro, micro-computed tomography (micro-CT) is used to explore the internal cortical bone micro-structure with isotropic voxels and high resolution synchrotron radiation (SR); micro-CT is considered the 'gold standard'. In 16 tibias and 8 femurs, HR-pQCT measurements were compared to conventional micro-CT measurements. To test modality effects, conventional micro-CT measurements were compared to SR micro-CT measurements at 7.5 µm³; SR micro-CT measurements were also tested at different voxel sizes for the femurs, specifically, 7.5 µm³ versus 2.8 µm³. D.comp (r  =  -0.88, p  <  10^-3) was the parameter best correlated with porosity (Po.V/TV). The correlation was not affected by the removal of pores under 130 µm. Ct.Th was also significantly highly correlated (r  =  -0.89 p  <  10^-3), while Ct.Po was correlated with its counterpart Po.V/TV (r  =  0.74, p  <  10^-3). From SR micro-CT and conventional micro-CT at 7.5 µm³ in matching areas, Po.V/TV and pore diameter were underestimated in conventional micro-CT with mean  ±  standard deviation (SD) biases of  -2.5  ±  1.9% and  -0.08  ±  0.08 mm, respectively. In contrast, pore number (Po.N) and pore separation (Po.Sp) were overestimated with mean  ±  SD biases of  +0.03  ±  0.04 mm^-1 and  +0.02  ±  0.04 mm, respectively. The results from the tibia and femur were similar when the results of SR micro-CT at 7.5 µm³ and 2.8 µm³ were compared. Po.V/TV, specific surface of pores (Po.S/Po.V), and Po.N were underestimated with mean biases of  -1.7  ±  0.9%, -4.6  ±  4.4 mm^-1, and  -0.26  ±  0.15 mm^-1, respectively. In contrast, pore spacing was overestimated at 7.5 µm³ compared to 2.8 µm³ with mean biases of 0.05  ±  0.03 mm. Cortical bone measurements from HR-pQCT images provided consistent results compared to those obtained using conventional micro-CT at the distal tibia. D.comp was highly correlated to Po.V/TV because it considers both the micro-porosity (Haversian systems) and macro-porosity (resorption lacunae) of cortical bone. The complexity of canal organization, (including shape, connectivity, and surface) are not fully considered in conventional micro-CT in relation to beam hardening and cone beam reconstruction artifacts. With the exception of Po.V/TV measurements, morphological and topological measurements depend on the characteristics of the x-ray beam, and to a lesser extent, on image resolution.

Bone imaging findings in genetic and acquired lipodystrophic syndromes: an imaging study of 24 cases

OBJECTIVE

To describe the bone imaging features of lipodystrophies in the largest cohort ever published.

MATERIALS AND METHODS

We retrospectively examined bone imaging data in 24 patients with lipodystrophic syndromes. Twenty-two had genetic lipodystrophy: 12/22 familial partial lipodystrophy (FPLD) and 10/22 congenital generalized lipodystrophy (CGL), 8 with AGPAT2-linked CGL1 and 2 with seipin-linked CGL2. Two patients had acquired generalized lipodystrophy (AGL) in a context of non-specific autoimmune disorders. Skeletal radiographs were available for all patients, with radiographic follow-up for two. Four patients with CGL1 underwent MRI, and two of them also underwent CT.

RESULTS

Patients with FPLD showed non-specific degenerative radiographic abnormalities. Conversely, CGL patients showed three types of specific radiographic alterations: diffuse osteosclerosis (in 7 patients, 6 with CGL1 and 1 with CGL2), well-defined osteolytic lesions sparing the axial skeleton (7 CGL1 and 1 CGL2), and pseudo-osteopoikilosis (4 CGL1). Pseudo-osteopoikilosis was the sole bone abnormality observed in one of the two patients with AGL. Osteolytic lesions showed homogeneous low signal intensity (SI) on T1-weighted and high SI on T2-weighted MR images. Most of them were asymptomatic, although one osteolytic lesion resulted in a spontaneous knee fracture and secondary osteoarthritis in a patient with CGL1. MRI also showed diffuse fatty bone marrow alterations in patients with CGL1, with intermediate T1 and high T2 SI, notably in radiographically normal areas.

CONCLUSIONS

The three types of peculiar imaging bone abnormalities observed in generalized lipodystrophic syndromes (diffuse osteosclerosis, lytic lesions and/or pseudo-osteopoikilosis) may help clinicians with an early diagnosis in pauci-symptomatic patients.

Cartilage morphology assessed by high resolution micro-computed tomography in non OA knees

OBJECTIVE

At the microscopic level, there is no established 3D method to measure cartilage volume and thickness. An easy, precise and accurate volume and thickness measurements of human cartilage has been developed from micro-computed tomography (micro-CT) images.

DESIGN

In the medial tibial plateau of twenty nine left cadaveric knees classified as normal, vertical cores (7 mm in diameter) were extracted in three locations: lateral (LAT), medial posterior (MP) and medial anterior (MA). The cores were imaged in mineral oil with micro-CT (voxel size 10.2 μm) and were measured cartilage volume (Cart.Vol, mm(3)) and cartilage thickness (Cart.Th, mm) using a thickness plugin. Short term reproducibility and standard deviation (ST_RMSCV%, ST_RMSSD, mm) were determined. To assess accuracy, holes with diameters of 2 mm, 3 mm, and 4 mm were artificially generated and nominal and measured hole sizes were compared.

RESULTS

Precision of Cart.Vol_ST_RMSCV% was 1.35%. The mean biases between nominal hole volume and measurements were -0.49 ± 1.5 mm(3) (2 mm), -0.41 ± 4.2 mm(3) (3 mm) and +0.34 ± 4.4 mm(3) (4 mm). ST_RMSSD was 100 times lower than the biological variation and the highest bias to measure volume was 24 times lower. Cart.Th results statistically differed among core extraction locations: 1.75 ± 0.28 mm (LAT), 1.84 ± 0.40 mm (MP) and 2.32 ± 0.41 mm (MA).

CONCLUSION

With a standard laboratory micro-CT system, it was possible to measure cartilage volume and thickness with good precision and accuracy relative to the biological variation of the specimen cohort. Cartilage measurements from micro-CT probably will improve the knowledge of the relationship between cartilage and subchondral bone and may allow to better understand the OA process.

Bone marrow involvement in Gaucher disease at MRI : what long-term evolution can we expect under enzyme replacement therapy?

PURPOSE

To study the long-term evolution of the bone marrow burden (BMB) score at MRI in patients with Gaucher disease (GD) under enzyme replacement therapy (ERT).

MATERIAL AND METHODS

Forty patients treated for GD were retrospectively studied in a referral centre. BMB scores were assessed on spine and femur MR examinations performed between January 2003 and June 2014. The long-term evolution of the BMB scores was analyzed using a linear mixed model.

RESULTS

A total of 121 MRI examinations were performed during the study period with a mean follow-up of 7.1 years ± 5.6, an average rate of 3.1 MR examinations ± 1.7 per patient and an interval of 2.3 years ± 1.1 between examinations. Patients had received ERT during 12 years on average ± 6.7. The trend of BMB scores with time decreased significantly by 15% (P = 0.008) during the total study period and 39% (P = 0.01) during the first 5 years of treatment. No changes in BMB scores were observed after five years of treatment.

CONCLUSION

In Gaucher patients, the trend of MRI BMB scores with time decreased significantly under ERT the first 5 years of treatment before a long-term stabilization.

KEY POINTS

• Bone marrow infiltration of Gaucher patients responds to enzyme replacement therapy • MRI BMB score decreases mainly during the first five years of treatment • MRI BMB score tends to stabilize after five years of treatment • MR examinations could be limited after five years of treatment.

Impact of osteoid osteomas of the hip on the size and fatty infiltration of the thigh muscles

We aimed to assess the impact of osteoid osteomas of the hip on the size and fatty infiltration of the muscle thigh in 42 patients. The thigh circumference, cross-sectional areas, and fatty atrophy of four anterior muscles were assessed on magnetic resonance axial T1-weighted images. A significant fatty atrophy was found in the studied muscles of the ipsilateral thigh except for the rectus femoris. No significant association was demonstrated with pain duration suggesting that muscle atrophy may rather be related to the locoregional inflammation than subsequent to the disuse of the limb.

Is pain duration associated with morphologic changes of osteoid osteomas at CT?

PURPOSE

To assess the morphologic changes of osteoid osteomas on computed tomographic (CT) scans in association with pain duration.

MATERIALS AND METHODS

Institutional review board approval was obtained. Informed consent was waived. From January 2008 to December 2012, 235 patients were treated with interstitial laser ablation at the Hôpital Lariboisière. Ninety-six patients with histopathologically proven osteoid osteomas, complete clinical files, and CT data were studied retrospectively. The following variables were assessed: age, sex, bone location, bone segment, location of the osteoid osteoma in relation to the native cortex, nidus area, nidus calcification area and attenuation at CT, and nidus mineralization ratio (percentage of the calcification area over the total nidus area). Analysis of variance, Kaplan-Meier method, and Cox multivariate regression model were used for statistical analyses.

RESULTS

The study sample consisted of 96 patients, 68 of whom were male (71%) and 28 of whom were female (29%) (ratio of male to female patients, 2.4:1). Mean age ± standard deviation was 22.2 years ± 10.4 (range, 4-54 years; median, 18.5 years). The patients' age and nidus mineralization ratio increased significantly with pain duration (hazard ratio, 0.975 [P = .031] and 0.193 [P = .007], respectively). No significant association was found between pain duration and other variables, including the nidus area. In long bones, diaphyseal osteoid osteomas were significantly less mineralized than those in other locations (P = .009).

CONCLUSION

The nidus mineralization ratio of osteoid osteomas increases significantly with pain duration and may be a marker of tumor age. Diaphyseal osteoid osteomas demonstrate a lower ratio of nidus mineralization. At the onset of symptoms, older patients experience pain for a longer period before treatment.

Tibial hyperostosis: a diagnostic approach

Tibial hyperostosis may be encountered in musculoskeletal imaging, incidentally or during the investigation of a leg pain. Hyperostosis involves the exuberant production of osseous tissue and results in cortical, periosteal and/or endosteal thickening of the bone. As a long bone with thick cortices, the tibia has a significant probability of being affected by ubiquitous bone diseases. As a tubular long bone, the tibia is likely to be involved in extensive infectious conditions such as osteomyelitis. As a bone of the lower limb, the tibia undergoes high stresses and may be affected by decrease in bone strength or repetitive submaximal stress. The tibia is also particularly involved in some bone sclerosing dysplasias and Paget's disease. In this work, we aim at highlighting the main conditions leading to tibial hyperostosis and try to provide key elements to narrow down the several diagnostic possibilities. Osteoid osteomas, fatigue or insufficiency fractures, infectious conditions, vascular lesions, sclerosing bone dysplasias and Paget's disease represent the main challenging diagnoses to discuss.

Chondrocalcinosis of femoro-tibial and proximal tibio-fibular joints in cadaveric specimens: a high-resolution CT imaging study of the calcification distribution

Objectives

To analyze calcium deposits by computed tomography (CT) in femoro-tibial compartments and proximal tibio-fibular joints; to assess the relationship with CT-assessed osteoarthritis (OA).

Methods

68 (34 pairs) cadaveric knees (mean age of 84) were scanned at high resolution CT. Menisci and hyaline cartilage calcifications in the femoro-tibial and proximal tibio-fibular joints were analyzed. OA was CT-assessed by the Kellgren and Lawrence score. Gross appearance of OA was evaluated on 29 left knees after dissection and India ink staining of tibial plateaus.

Results

In femoro-tibial joints, meniscal calcifications (MC) and hyaline cartilage calcifications (HCC) were detected in 23(34%) and 14(21%) knees respectively. Calcifications mainly involved the three meniscal segments and were mainly observed in all thirds of the femoro-tibial compartments. In proximal tibio-fibular joints, HCC were detected in 19(28%) knees. The association HCC-MC in femoro-tibial joints and between calcifications in femoro-tibial and proximal tibio-fibular joints was strong (p<0.0001). Femoro-tibial and proximal tibio-fibular CT-assessed OA were respectively found in 23(34%) and 19(28%) knees. HCC were significantly associated with femoro-tibial OA (p = 0.04) while MC were not (p = 0.34). OA macroscopic evaluation showed a mean surface of cartilage lesions of 35% (range 0.13–0.55). No significant difference was demonstrated regarding the CT-detection of MC, HCC or CT-assessed OA.

Conclusions

This is the first study to report a strong association of chondrocalcinosis between femoro-tibial and tibio-fibular joints in addition to a strong association between MC and HCC in femoro-tibial compartments. No significant relationship between chondrocalcinosis and OA was demonstrated.