Can effusion-synovitis measured on ultrasound or MRI predict response to intra-articular steroid injection in hip osteoarthritis?

OBJECTIVES

Intra-articular steroid injection (IASI) is an effective therapy for hip osteoarthritis (OA), but carries risks and provides significant pain relief to only two thirds of patients. We attempted to predict response to IASI in hip OA patients using baseline clinical, ultrasound, and MRI data.

METHODS

Observational study of 97 subjects with symptomatic hip OA presenting for IASI. At baseline and 8 weeks we obtained hip MRI, grayscale and Doppler ultrasound, clinical range of motion (ROM), timed-up and go test (TUG) scores, and self-reported Western Ontario and McMaster Universities Osteoarthritis (WOMAC) pain, stiffness, and function scores. Bone-capsule distance (BCD) measurements of inflammation on hip ultrasound and MRI were measured at three locations: the proximal-most uncovered portion of the femoral head, the superficial-most (apex) portion of the femoral head, and the largest fluid pocket at the femoral neck.

RESULTS

Ultrasound and MRI BCD correlated with each other significantly and strongly at the apex and neck. Power Doppler findings did not correlate significantly with any other imaging indices. Eight weeks post-injection, WOMAC pain, function, and stiffness scores significantly improved and TUG time improved nearly to the level of significance, but there were no significant changes in ultrasound, MRI, or Doppler indices. Baseline variables were not significantly different between responder and nonresponder WOMAC pain or TUG time cohorts.

CONCLUSION

Basic measures of inflammation on ultrasound and MRI are highly related to each other, but provide little insight into patient function and pain after IASI. Other mechanisms to explain improvement in patient status after IASI are likely at work.

The OA Trial Bank: meta-analysis of individual patient data from knee and hip osteoarthritis trials show that patients with severe pain exhibit greater benefit from intra-articular glucocorticoids

OBJECTIVE

To evaluate the efficacy of intra-articular (IA) glucocorticoids for knee or hip osteoarthritis (OA) in specific subgroups of patients with severe pain and inflammatory signs using individual patient data (IPD) from existing trials.

DESIGN

Randomized trials evaluating one or more IA glucocorticoid preparation in patients with knee or hip OA, published from 1995 up to June 2012 were selected from the literature. IPD obtained from original trials included patient and disease characteristics and outcomes measured. The primary outcome was pain severity at short-term follow-up (up to 4 weeks). The subgroup factors assessed included severe pain (≥70 points, 0-100 scale) and signs of inflammation (dichotomized in present or not) at baseline. Multilevel regression analyses were applied to estimate the magnitude of the effects in the subgroups with the individuals nested within each study.

RESULTS

Seven out of 43 published randomized clinical trials (n = 620) were included. Patients with severe baseline pain had a significantly larger reduction in short-term pain, but not in mid- and long-term pain, compared to those with less severe pain at baseline (Mean Difference 13.91; 95% Confidence Interval 1.50-26.31) when receiving IA glucocorticoid injection compared to placebo. No statistical significant interaction effects were found between inflammatory signs and IA glucocorticoid injections compared to placebo and to tidal irrigation at all follow-up points.

CONCLUSIONS

This IPD meta-analysis demonstrates that patients with severe knee pain at baseline derive more benefit from IA glucocorticoid injection at short-term follow-up than those with less severe pain at baseline.

Do radiographic indices of distal radius fracture reduction predict outcomes in older adults receiving conservative treatment?

AIM

To investigate whether radiographic deformities suggesting inadequate reduction would be associated with adverse clinical outcomes.

MATERIALS AND METHODS

Consecutive patients over 50 years of age (n=74) with non-operatively managed distal radius fractures were enrolled in a prospective cohort study. They had radiographs at cast removal ( approximately 6 weeks) and completed DASH (Disabilities of the Arm, Shoulder and Hand), SF-12 (health-related quality of life), and satisfaction surveys 6-months post-fracture. A reference-standard musculoskeletal radiologist, blinded to outcomes status, measured palmar (dorsal) tilt, radial angle, radial height, ulnar height, and intra-articular step and gap. Radiographic indices were correlated to each other and to the various patient-reported outcomes in univariate and multivariate regression analyses. DASH score was the primary study outcome.

RESULTS

Of the cohort studied (n=74, mean age 68.5 years, primarily white women), 71% had at least one "unacceptable" radiographic deformity by traditional criteria. Acceptable reduction varied from 60-99% depending on which single index was reported, and 44% of patients had more than two indices reported as unacceptable. Despite these radiographic findings, 6-months post-reduction, self-reported disability was low (DASH=24+/-17), health-related quality of life was near normal, and 72% were satisfied with their care. No radiographic index of wrist deformity (alone or in combination) was significantly correlated to any of the patient-reported outcomes.

CONCLUSION

Self-reported outcomes in older adults with conservatively managed wrist fractures were not related to the "acceptability" of radiographic fracture reduction. The proportion of acceptable reductions varied by 40% depending on which index was reported. Consequently, detailed reporting of these indices in older adults with distal radius fracture may be inefficient or perhaps even unnecessary.

Reliability of an efficient MRI-based method for estimation of knee cartilage volume using surface registration

OBJECTIVE

To aid in detection of osteoarthritis (OA) progression in serial magnetic resonance (MR) scans, we assessed feasibility and accuracy of rapid 3D image registration of the tibial plateau in normal and arthritic subjects, and inter-scan reliability of semi-automated cartilage volume measurement from these images.

DESIGN

Two T1 fat-suppressed knee MR scans were obtained 2 weeks apart in healthy adults (n = 9, age 23-48 years). Four scans of each of three patients with established OA were obtained over 2 years. At baseline, the tibial surface was digitized by semi-automated edge detection and medial tibial plateau cartilage volume was calculated from high-intensity voxels within a manually drawn region of interest (ROI). In subsequent scans, the digitized tibial surface was registered to the baseline location by photogrammetric 3D coordinate transformation, and cartilage volume was automatically recalculated by reuse of the ROI. We measured registration accuracy by root mean square (RMS) distance between registered tibial surfaces.

RESULTS

In normals, RMS distance between tibial surfaces in baseline and subsequent scans was 1/3 voxel length (0.121 mm), and medial tibial plateau cartilage volumes varied by 1.4+/-3.2%. Despite change in cartilage volumes by up to 20% over 2 years in arthritic patients, surface registration accuracy was unaffected (0.122 mm). User-supervised processing time was 15 min at baseline and 7 min in subsequent scans.

CONCLUSION

Tibial surfaces on magnetic resonance imaging (MRI) can be rapidly and accurately co-registered, even in arthritic knees, allowing direct visualization of changes over time. Compared to most current methods, cartilage volume measurement in registered images is faster and has equivalent inter-scan reliability in initially normal subjects.

Deposition of intraosseous fat in a degenerating simple bone cyst

A simple bone cyst in the proximal humerus of an 18-year-old man was treated by percutaneous ablation with alcohol irrigation. Subsequent involution of the cyst was associated with fatty replacement within the intraosseous defect. A possible relationship between involuting bone cyst and apparent intraosseous lipoma is discussed.