Automated image analysis of hand radiographs reveals widened joint spaces in patients with long-term control of acromegaly: relation to disease activity and symptoms.

OBJECTIVE: Arthropathy is an invalidating complication of acromegaly. Although acromegalic arthropathy shares features with primary osteoarthritis, joint spaces are widened rather than narrowed in patients with long-term cure of acromegaly. The late effects of acromegaly on hand joints have not been characterized. Therefore, the objective of the current study was to assess joint space widths (JSWs) of hand joints in patients with long-term control of acromegaly and to identify factors associated with JSW. METHODS: A cross-sectional study was carried out in 89 patients (age 58 ± 12 years, 49% women) with long-term controlled acromegaly and 471 controls without hand symptoms (age 46 ± 12 years, 42% women). Radiological JSWs of individual hand joints were measured by automated image analysis. RESULTS: Patients had wider mean joint spaces than controls: metacarpo-phalangeal (MCP) joints were ~24%, proximal interphalangeal joints ~21%, and distal interphalangeal joints were ~20% wider (patients vs controls; P < 0.001 for all joints). Mean JSW exceeded the 95th percentile of the values obtained in controls in 64% of patients. Higher IGF1 and GH concentrations at diagnosis were associated with larger JSWs (adjusted ß for pretreatment GH in tertiles: 0.09 (95% confidence interval (CI) 0.03-1.84) and for IGF1 in tertiles: 0.14 (95% CI 0.05-0.23) at the MCP joints in acromegalic patients. In male patients, but not in female patients, increased JSWs were associated with more self-reported pain (P = 0.02). CONCLUSIONS: Using a new semi-automated image analysis of hand radiographs, acromegalic patients with long-term disease control appeared to have increased joint spaces of all hand joints. JSWs were positively related to disease activity at diagnosis, but not to duration of follow-up, suggesting irreversible cartilage hypertrophy. Irreversible cartilage hypertrophy may partly explain persisting hand complaints despite long-term disease control.

Validity of joint space width measurements in hand osteoarthritis.

OBJECTIVE: To investigate the validity of joint space width (JSW) measurements in millimeters (mm) in hand osteoarthritis (OA) patients by comparison to controls, grading of joint space narrowing (JSN), and clinical features. METHODS: Hand radiographs of 235 hand OA patients (mean age 65 years, 83% women) and 471 controls were used. JSW was measured with semi-automated image analysis software in the distal, proximal interphalangeal and metacarpal joints (DIPJs, PIPJs and MCPJs). JSN (grade 0-3) was assessed using the osteoarthritis research society international (OARSI) atlas. Associations between the two methods and clinical determinants (presence of pain, nodes and/or erosions, decreased mobility) were assessed using Generalized Estimating Equations with adjustments for age, sex, body mass index (BMI) and mean width of proximal phalanx. RESULTS: JSW was measured in 5631 joints with a mean JSW of 0.98 mm (standard deviation (SD) 0.21), being the smallest for DIPJs (0.70 (SD 0.25)) and largest for MCPJs (1.40 (SD 0.25)). The JSN=0 group had a mean JSW of 1.28 mm (SD 0.34), the JSN=3 group 0.17 mm (SD 0.23). Controls had larger JSW than hand OA patients (P-value<0.001). In hand OA, females had smaller JSW than men (ß -0.08, (95% confidence interval (95% CI) -0.15 to -0.01)) and lower JSW was associated with the presence of pain, nodes, erosions and decreased mobility (adjusted ß -0.21 (95% CI -0.27, -0.16), -0.37 (-0.40, -0.34), -0.61 (-0.68, -0.54) and -0.46 (-0.68, -0.24) respectively). These associations were similar for JSN in grades. CONCLUSION: In hand OA the quantitative JSW measurement is a valid method to measure joint space and shows a good relation with clinical features.