Objective. Inflammation at the entheses is a distinguishing feature of psoriatic arthritis (PsA). Enthesitis at the heel is the most common location at the Achilles and plantar fascia insertions on the calcaneus. This study aimed to 1) describe the morphological features and measurements of plantar calcaneal spurs in subjects with PsA and controls and 2) determine radiological features that differentiate between inflammatory and non-inflammatory calcaneal spurs.Methods. Weight bearing lateral foot radiographs of 101 subjects with PsA and 38 control subjects without inflammatory arthritis were examined for plantar calcaneal and Achilles spurs. Three measurements were taken from each radiograph: plantar spur base, mid-segment, and length in millimeters. The differences in radiographic measurements, and the presence of fluffy periostitis of the plantar spurs were then compared between PsA patients and controls.Results. Of the 101 subjects with PsA, 76 (75%) had at least one plantar calcaneal spur and 32 (31.5%) had at least one Achilles tendon spur, compared to 18 (47%) and 3 (8%) respectively in control group (p=0.004). Fluffy plantar periostitis was identified in 14 PsA subjects and none of the controls (p=0.01). The dimensions of plantar spurs were significantly different between groups longer mid-segment distinguished patients with PsA from controls.Conclusion. Calcaneal spurs are more common in subjects with PsA than controls. Longer mid-segment measurement was associated with PsA. This study indicates that the presence of fluffy plantar periostitis and broad based and longer mid-segment dimensions are radiological features for inflammatory spurs.

Background The modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) is increasingly used to assess disease severity and progression in patients with AS but the methodology is still not well standardized. The Spondyloarthritis Research Consortium of Canada (SPARCC) and the SPondyloArthritis Research and Treatment Network (SPARTAN) have formed a working group to develop and validate a reference image module aimed at calibration of readers using the mSASSS. Objectives To develop and validate a reference imaging module aimed at standardization of the approach to scoring radiographic damage using the mSASSS. Methods The working group comprises 5 rheumatologists with variable experience in using the mSASSS and 3 musculoskeletal radiologists with special expertise in AS. The following sequence of developmental steps preceded the first scoring exercise: 1. Systematic review of the literature pertaining to radiographic scoring in AS to identify aspects of the mSASSS requiring methodological clarity. 2. Independent assessment blinded to time point of baseline and 2 year radiographs from 25 patients with AS using the mSASSS (pilot exercise). 3. Group meeting aimed at debriefing of discrepant scores, identification of gaps or lack of clarity in methodology, consensus development of uniform rules for scoring. 4. Development of an imaging module (the SPAR module) through consensus which clarifies definitions, rules and scoring methodology, and a set of reference radiographic images. A formal scoring exercise was then conducted by 6 readers on 39 patients with AS, which included 15 from the pilot exercise, where baseline and 2 year radiographs were scored blinded to time point. Reliability of the mSASSS was assessed by the intraclass correlation method (ICC). Results This process led to the development of the SPAR module comprised of 70 slides which describe the following: 1. Consensus definitions for squaring, erosions, sclerosis, 2. Consensus rules for scoring syndesmophytes (degenerative versus spondylitic, growth remote from vertebral corners) and ankylosis (including ossification in the disc space and remote from vertebral corners), 3. The approach to missing observations. The group has concluded that only syndesmophytes and ankylosis should be scored in the cervical spine, and that the antero-posterior lumbar spine radiograph be assessed together with the lateral radiograph in scoring the lumbar spine. The pilot exercise demonstrated excellent reliability for status scores (ICC for 6 readers (range) =0.92; Median (range) ICC for 15 reader pairs =0.92 (0.84-0.96)) but poor reliability for change scores (ICC for 6 readers =0.46; Median (range) for 15 reader pairs =0.52 (0.11-0.66)). In particular, ICC for change score for the radiologist reading pair was only 0.46. In the formal scoring exercise, the ICC for change score for the radiologist reading pair improved substantially to 0.62 although overall reliability for change score for the entire group improved marginally (ICC for 6 readers =0.49). Conclusions Reliable assessment of change in mSASSS is very challenging though can be improved for expert readers if they are calibrated according to the standardized methodology in the SPAR module. Disclosure of Interest None Declared

Quadrilateral Space Syndrome Caused by Glenoid Labral CystP. Robinson1, L. M. White1, M. Lax1, D. Salonen1 and R. S. Bell2Audio Available | Share

Background: Bone marrow oedema (BMO), synovitis, effusion and joint erosion on magnetic resonance imaging (MRI) may be used as outcome measures in psoriatic arthritis (PsA). Objective: To assess the impact of adalimumab on BMO, synovitis, effusion and erosions in PsA, as measured by MRI. Methods: Fifteen patients with active PsA (⩾3 tender and ⩾3 swollen joints) were enrolled in an open-label pilot study. Each received adalimumab subcutaneously every other week for 24 weeks. MRI was obtained at baseline and 24 weeks. Results: MRI was available for 11 patients, pre and post-therapy. BMO and effusion scores improved markedly after 24 weeks of adalimumab, while no significant change was noted in erosion score. An unanticipated finding, however, was the lack of improvement in the MRI synovitis score. Conclusions: Improvement in BMO and unchanged erosion scores may explain the “anti-erosive” effects of adalimumab in PsA. Persistence of BMO and synovitis on MRI suggests ongoing disease activity and supports the continuation of long-term anti-TNF therapy.

Study Design. Observational cohort study with computerized tomography (CT) analysis of in vivo pedicle screw placement.Objective. To evaluate the clinical accuracy of computer-assisted fluoroscopy for the placement of thoracic and lumbosacral (LS) pedicle screws.Summary of Background Data. Computer-assisted fluoroscopy is an adjunct for the placement of pedicle screws.Methods. Postoperative CT of 360 titanium pedicle screws ( 281 LS [L1 - S1]; 79 thoracic [T2 - T12]) were independently assessed. All screws were placed using the FluoroNav(TM) system (Medtronic Surgical Navigation Technologies, Louisville, CO). The relative position of the screw to the pedicle was graded as follows: A = completely in; B = < 2 mm breach; C = 2 - 4 mm breach; and D = > 4 mm breach. If an osseous breach occurred, the direction of the breach was further classified.Results. Eight-five percent of screws were completely contained within the pedicle. Fifty-five-pedicle breaches ( 25 medial; 30 lateral) occurred. Pedicle breaches were graded B in 13.1% ( 47 breaches), C in 1.9% ( 7), and D in 0.3% ( 1) of screws. Pedicle breach was significantly higher in the thoracic compared to the LS spine, 31.6% (25/79) and 10.6% (30/281), respectively ( P < 0.0001). In the thoracic spine, 72% of pedicle breaches were lateral. In 49% of breaches, the screw diameter was larger than the pedicle diameter. None of the pedicle breaches were associated with neurologic or other clinical sequelae.Conclusions. The clinical pedicle breach rate in this study is comparable to those reported using conventional techniques with or without fluoroscopic assistance. FluoroNav(TM) appears to be a safe adjunct for the placement of thoracic and LS pedicle screws.

OBJECTIVE. Our objective was to describe the appearance of the anteromedial tibiotalar joint on MR arthrography in patients with clinically and arthroscopically confirmed anteromedial impingement.CONCLUSION. Anteromedial impingement of the ankle is now being recognized in the orthopedic literature as a distinct entity. MR arthrographic findings of anteromedial impingement include capsular and synovial soft-tissue thickening anterior to the tibiotalar ligaments and any associated osseous abnormality. Although anteromedial impingement is uncommon compared with other impingement syndromes of the ankle. the radiologist should be aware of the diagnosis and possible findings on cross-sectional imaging.

OBJECTIVES:Ankylosing spondylitis (AS) is a chronic disease leading to progressive spinal ankylosis and deformity. The aims of this study were to (1) determine whether infliximab is an effective treatment for AS patients who have failed conventional treatment; (2) identify any baseline clinical variables that can be associated with responsiveness to treatment; and (3) resolve whether the clinical response correlated with changes from baseline inflammatory changes on magnetic resonance imaging (MRI).METHODS:Twenty-one patients who met the modified New York criteria for AS (M:F 18:3) were enrolled in this open labeled study. The mean age was 37.9+/-7.9 years and mean disease duration was 8.69+/-6.58 years. Patients received infliximab at a dose of 5 mg/kg by intravenous infusion over 2 hours at 0, 2, 6, weeks. Nine functional variables were measured [i.e., Bath AS Disease Activity Index (BASDAI), Bath AS Functional Index (BASFI) etc.], 6 clinimetrics (chest expansion, finger to floor, etc.), and inflammatory markers in the peripheral blood at baseline and each subsequent visit. Primary response to treatment was defined as a > 20% response in 5/9 functional variables. A subset of 9 consecutive patients was selected for MRI scans before and after infusions.RESULTS:Eighteen patients were available for assessment at week 14 having received 3 infusions (wks 0, 2, 6). There was > 60% improvement in functional variables, i.e., BASDAI, BASFI, Health Assessment Questionnaire, fatigue, and spinal and total body pain. Clinimetric scores selectively improved, e.g., chest expansion (p < 0.021) by 14 weeks. ESR, CRP and haptoglobin all showed significant improvement at 6 weeks and were maintained to the 14 week assessment point. Imaging studies showed improvement in all patients studied including those with advanced disease. Three patients developed headache during the infusions. Infliximab was effective in all, but degree of response varied. Very good responders were distinguished from good responders by shorter duration of disease and better baseline clinimetric scores.CONCLUSIONS:Infliximab was an effective treatment for AS in a short term trial. Longterm control of symptoms and potential alteration in clinical course of disease will require longterm assessment.

Our objective was to compare the reliability and responsiveness of the original Steinbrocker's (OS), our modified Steinbrocker's (MS) and Larsen's (L) radiological scoring methods for detecting radiological change in psoriatic arthritis over time. Two sets of radiographs of the hands and feet at least 2 yr apart were selected from 68 patients. Films were randomly presented and scored independently by a rheumatologist (DDG) and a radiologist (DS), in a blinded fashion using all methods. The index of reliability was the intraclass coefficient (ICC) and the responsiveness was assessed using plots and regression analyses. All three radiological scoring methods have excellent interobserver and good intra-observer reliability. L and MS are equally responsive and superior to OS in detecting change in joint damage over time. Thus, the L or MS radiological scoring methods can be used to monitor disease progression in psoriatic arthritis.

A variety of disorders can lead to disease and pathology of the rotator cuff tendons. The most important information is obtained during a careful history and physical examination. With the judicious use of various diagnostic modalities, evaluation of the rotator cuff disease is possible.

PURPOSETo demonstrate the plantar compartments of the foot on magnetic resonance (MR) images.MATERIALS AND METHODSThe plantar compartments of four cadaveric feet underwent MR imaging and were sectioned. Fifteen MR studies in 11 patients with compartmental fluid were evaluated. The epicenter of infection was determined from review of the history, radiographs, and MR images.RESULTSIn the cadaveric feet, distribution of contrast material conformed to the compartmental anatomic features. MR findings in the specimen correlated exactly with gross findings. All seven feet with infection centered at the second through fourth metatarsal heads demonstrated only central compartment fluid. In seven of eight feet with a more medial or lateral epicenter of infection, fluid was seen in the lateral or medial compartment and in the central compartment. In one foot with a lateral epicenter of infection, fluid was confined to the lateral compartment.CONCLUSIONMR imaging accurately depicts the compartmental anatomic features of the foot.

Pachydermoperiostosis is a rare inherited disorder that is manifest clinically by digital clubbing, extremity enlargement, painful and swollen joints, hypertrophic skin changes, and periosteal bone formation. This report illustrates the skeletal findings that may be seen with long-standing disease as evaluated with conventional radiography and with magnetic resonance (MR) imaging, with emphasis on the MR appearance of periosteal reaction in this disorder. There are features that suggest pachydermoperiostosis may represent a generalized enthesopathy.