Polymyalgia rheumatica (PMR) is the
most common inflammatory rheumatic disease in the elderly. There is
considerable uncertainty related to diagnosis and outcomes in patients
presenting with the polymyalgic syndrome. Therefore the European League against
Rheumatism (EULAR) and the American College
of Rheumatology
(ACR) are supporting a study that is being conducted to establish
classification criteria for PMR [
US depicts characteristic pathologic
findings of shoulder joints and the hip region that may aid in distinguishing
PMR from other diseases that may mimic it. Typical findings on US include
glenohumoral joint synovitis, subdeltoid bursitis, and biceps tendon
tenosynovitis of the shoulders [
Before considering US as a potential tool for the classification, there was agreement regarding the need to standardise the examination and assess the inter-observer agreement for distinguishing lesions typical of PMR from other lesions like extensive effusion or bursitis, rotator cuff tears, rotator cuff calcifications, and osteoarthritis.
To pursue this aim, members of centres participating in the PMR classification criteria study met to standardise the US examination in PMR patients for each centre and work towards achieving a high degree of inter-reader agreement in the US examination for the PMR classification criteria study. The study included both, patients with PMR and other related diseases with shoulder pain such as rheumatoid arthritis (RA). While we present a validation study, our study does not address the question of defining US characteristics of PMR.
Fifteen rheumatologists and one radiologist of varying US experience from the participating centres (listed in the Acknowledgement) met in Oranjewoud (The Netherlands) to evaluate the possibility of including US in the upcoming PMR classification criteria study. The meeting took place just following the 12th EULAR basic ultrasound course and before the annual EULAR congress in June 2006. The 16 physicians were assigned to 4 groups. Each group consisted of four assessors: one supervisor, one performing the US scans, one measuring distances between structures, and one documenting the results. The ultrasound examiners were—with the exception of the supervisor—alumni of the basic EULAR sonography course. None were career specialists in the field of musculoskeletal ultrasonography. Prior to the patient examination, each supervisor gave a review of the US examination including specifics of the standard scans to be performed for operator training. Standard definitions and pathologic findings were demonstrated. The group as a whole decided if they regarded the US findings as normal or abnormal. To ensure standardised documentation, each participant was given a report sheet that listed possible pathologic findings recorded as “yes” or “no,” indicating the presence or absence of each particular finding. All US assessments were performed independently by each group without contact with other groups and without knowledge of the patient's disease or joint status. Each group was given a maximum of 15 minutes (shoulder joint) and 10 minutes (hip joint), respectively, for US examination per joint region, rotating on a preset plan from one US station to the next. Each healthy control and each patient was assigned to every US station in rotation.
The focus of the US
examinations
was the shoulder and hip joints. Two joints (one shoulder and one hip) were
examined in 4 healthy controls and in 4 patients with RA
or PMR. Four rounds (normal shoulder, normal hip, pathologic shoulder, and
pathologic hip) for 4 groups were necessary to ensure that an examination was
performed by each group, control/patient and joint region. Patients and healthy
individuals were recruited from the Medisch Centrum Leeuwarden by GAWB. All
patients gave their consent to participation in the study. Subject characteristics were as in Tables
Healthy individuals’ characteristics | Part examined | ||
---|---|---|---|
Male, 36 years | No shoulder or hip pain | Right shoulder | Right hip |
Male, 48 years | No shoulder or hip pain | Right shoulder | Right hip |
Female, 46 years | No shoulder or hip pain | Left shoulder | Left hip |
Female, 29 years | No shoulder or hip pain | Left shoulder | Left hip |
Patients’ characteristics | |
---|---|
Female, 64 years | Symptomatic right shoulder, left hip, RA (since 1999) |
Female, 48 years | Symptomatic right shoulder, right hip, RA (since 1990) |
Female, 79 years | Symptomatic right shoulder, left hip, temporal arteritis with PMR since 2003 |
Female, 75 years | Symptomatic left shoulder, right hip, PMR, aortitis since 2005 |
Examinations were performed with several US machines
which are in use in practice and simulate the conditions of the PMR
classification study. A first phase showed a good reliability between
different US
machines [
Scanner settings were uniform for all measurements: frequency setting, B-mode gain, and 100%; one focus point position in the region of measurement. An introduction to the US device was given to the observers prior to US examinations.
Standard scans according to the EULAR
guidelines for musculoskeletal US were applied [
Synovitis, effusion, tenosynovitis,
and erosions were defined according to the OMERACT definitions for musculoskeletal
ultrasound [
Overall agreement and inter-observer agreement values were calculated. All analyses were calculated with Statistical Product and Service Solutions (SPSS) 15.0 (Chicago, Ill, USA).
The overall agreement between the 4 groups of sonographers with regard to all normal and pathologic findings for shoulders and hips was 87%, reflecting substantial agreement.
For the healthy controls, overall agreement for the shoulder was 88.8% (substantial agreement). For the hip joint, overall agreement was 100% (perfect agreement). For the patient group, overall agreement for the shoulder joint was 85.2% (moderate agreement). For the pathologic hip joint, overall agreement was 74.3% (substantial agreement).
The overall agreements with regard to the different pathologies for the
shoulder and hip joints are displayed in Tables
Overall agreements for normal and pathologic shoulders.
Structure | Pathology | Overall agreement normal shoulder | Overall agreement pathologic shoulder |
---|---|---|---|
Biceps tendon | Tenosynovitis | 100% | 75% |
Rupture | 87.5% | 100% | |
Subdeltoid bursa | Bursitis | 87.5% | 87.5% |
Glenohumeral joint | Synovitis/effusion at posterior joint space | 75% | 75% |
Glenohumeral joint | Synovitis/effusion at axillary recess | 75% | 100% |
Subscapularis tendon | Complete rupture | 100% | 100% |
Partial rupture | 87.5% | 100% | |
Calcification | 87.5% | 87.5% | |
Supraspinatus tendon | Complete rupture | 100% | 87.5% |
Partial rupture | 83.3% | 70.8% | |
Calcification | 87.5% | 54.2% | |
Infraspinatus tendon | Complete rupture | 100% | 100% |
Partial rupture | 87.5% | 100% | |
Calcification | 100% | 100% | |
Rotator cuff | Impingement | 87.5% | 100% |
Acromioclavicular joint | Osteoarthritis (osteophytes) | 62.5% | 41.6% |
Synovitis/effusion | 62.5% | 50% | |
Humeral head | Erosion | 83.3% | 70.8% |
Axillary artery | Vasculitis | 100% | 100% |
Arteriosclerotic plaques | 100% | 75% | |
Stenosis | 100% | 100% | |
Occlusion | 100% | 100% |
Overall agreements for normal and pathologic hips.
Structure | Pathology | Overall agreement normal Hip | Pathology | Overall agreement pathologic Hip |
---|---|---|---|---|
Hip joint | Effusion/synovitis | 100% | Effusion/synovitis | 88% |
Hip joint | Osteoarthritis (osteophytes) | 100% | Osteoarthritis (osteophytes) | 75% |
Trochanteric bursa | Bursitis longitudinal | 100% | Bursitis longitudinal | 70.8% |
Bursitis transverse | 100% | Bursitis transverse | 66.7% | |
Bursitis sagittal | 100% | Bursitis sagittal | 70.8% |
(a) Subdeltoid
bursitis (arrows) in a transverse view of the shoulder. (b) Longitudinal view of hip joint
synovitis. The joint capsule (short arraw) is not parallel to the bone surface of the femur
(long arrow). The distance between bone and joint capsule is pathologic (
US plays an important role in the
detection of many inflammatory processes. It is important to rigorously
evaluate the utility of US in PMR since there are no recognised laboratory or
imaging diagnostic tests for the condition. Recent studies have shown the importance
of US in depicting characteristic pathologies that aid in distinguishing PMR
from other mimicking diseases. The most frequent US
soft tissue alterations in
patients with PMR have been described for the shoulders (subdeltoid bursitis,
tenosynovitis of the biceps tendon, and glenohumeral synovitis) [
However, to date US has not yet been
included in any diagnostic or classification criteria for PMR. Therefore, a
study group has met to evaluate the possibility of including US in the upcoming
PMR classification criteria study. US examinations were performed according to
the EULAR criteria [
Some former studies have
investigated the prevalence for the detection of inflammatory changes of the
shoulder [
Since a high prevalence of synovitis is
seen in shoulder and hip joints of PMR patients, the current study focused on
whether overall agreement could be achieved between readers for typical joint
pathologies seen in PMR patients (including subdeltoid bursitis, biceps
tenosynovitis, and glenohumoral synovitis for the shoulder joint,
resp.). We found substantial overall agreement for detecting these pathologies
in normal as well as pathologic shoulder and hip joint pathologies. These
findings underline the fact that US is not as observer dependent as formerly
thought [
US is an important imaging tool for the visualisation of inflammation in shoulders and hips joints of PMR. In this exercise substantial agreement was found for the examination of healthy shoulders and pathologic hips. Agreement was moderate for pathologic shoulders and perfect for healthy hips. The results of this study confirm that US can be evaluated as a diagnostic technique in studies of PMR including the PMR classification criteria study.
The Polymyalgia Rheumatica EULAR/ACR Classification Criteria Group would like to acknowledge Esaote, Biomedica SA, Genoa, Italy, and General Electrics, Fairfield, Connecticut, USA for providing ultrasound equipments and technical support for this project. Funding for the organization and facilities were provided by a Grant from the American College of Rheumatology to Doctors Matteson and Dasgupta. Other participants in this exercise included: Fabrizio Cantini, Italy; Annamaria Lagnocco, Italy; Pierre Duhaut, France; Pierluigui Macchioni, Italy; Maria Antonietta D‘Agostino, Italy; Massimiliano Parodi, Itlay; Andy Abril, USA; Hans Weiss, Austria; Richard Wakefield, UK; Michael Schirmer, Austria; Edith Wipfler, Austria; Christropher Schaufelberger, Peter Balint, Hungary; Marina Backhaus, Germany; All authors contributed equally in this paper.