Musculoskeletal disease burden of hereditary hemochromatosis.

OBJECTIVE: To determine the prevalence, clinical picture, and disease burden of arthritis in patients with hereditary hemochromatosis. METHODS: In this cross-sectional observational study of 199 patients with hemochromatosis and iron overload, demographic and disease-specific variables, genotype, and organ involvement were recorded. The prevalence, intensity, and localization of joint pain were assessed, and a complete rheumatologic investigation was performed. Radiographs of the hands, knees, and ankles were scored for joint space narrowing, erosions, osteophytes, and chondrocalcinosis. In addition, the number and type of joint replacement surgeries were recorded. RESULTS: Joint pain was reported by 72.4% of the patients. Their mean ± SD age at the time of the initial joint symptoms was 45.8 ± 13.2 years. If joint pain was present, it preceded the diagnosis of hemochromatosis by a mean ± SD of 9.0 ± 10.7 years. Bony enlargement was observed in 65.8% of the patients, whereas synovitis was less common (13.6%). Joint space narrowing and osteophytes as well as chondrocalcinosis of the wrist and knee joints were frequent radiographic features of hemochromatosis. Joint replacement surgery was common, with 32 patients (16.1%) undergoing total joint replacement surgery due to severe OA. The mean ± SD age of these patients was 58.3 ± 10.4 years at time of joint replacement surgery. Female sex, metacarpophalangeal joint involvement, and the presence of chondrocalcinosis were associated with a higher risk of early joint failure (i.e., the need for joint replacement surgery). CONCLUSION: Arthritis is a frequent, early, and severe symptom of hemochromatosis. Disease is not confined to involvement of the metacarpophalangeal joints and often leads to severe damage requiring the replacement of joints.

Validation of a radiographic scoring system for haemochromatosis arthropathy.

BACKGROUND: Arthropathy is one of the earliest and most common manifestations of hereditary haemochromatosis with a significant impact on quality of life. Although its radiographic features are well known, there is no assessment tool for their evaluation. OBJECTIVE: To develop and validate a novel scoring system for the evaluation of radiographic features of haemochromatosis arthropathy. METHODS: A dichotomous scoring system assessing four radiographic features of haemochromatosis arthropathy and a 4-grade scale reflecting severity of radiographic change have been developed. Standard radiographs (hand, wrist, knee and ankle) of 170 subjects (116 male, 54 female) with genetically confirmed haemochromatosis and laboratory signs of iron overload were assessed by three readers and construct validity, feasibility and cross-sectional reliability (intrareader and inter-reader) were assessed. RESULTS: Intrareader and inter-reader reliability as assessed by percentage pairwise agreement and Cohen's weighed κ were good to excellent for most features and locations evaluated. Radiographic scores correlated well with clinical parameters (bony swollen joint count, hand function and physician's global health assessment; Pearson's correlation, r²=0.18-0.62, p<0.0001). A complete set of radiographs took 3.4 ± 1.2 (mean ± SD) min to be assessed. An atlas of characteristic radiographic features was compiled. CONCLUSION: A feasible and reliable radiological assessment tool for the evaluation of haemochromatosis arthropathy has been validated and an atlas of characteristic radiographic features provided.

Hereditary hemochromatosis as a risk factor for joint replacement surgery.

OBJECTIVE: Hemochromatosis is an inherited disease with iron overload and joint involvement resembling osteoarthritis. To determine the rate of joint replacement surgery in patients with hemochromatosis, we performed a cross-sectional cohort study. METHODS: A total of 199 individuals with hereditary hemochromatosis were included. The prevalence of joint replacement surgery in hip, knee, and ankle joints because of secondary osteoarthritis was assessed. Data were compared with 917 healthy subjects from the population-based Bruneck study. RESULTS: A total of 32 of 199 individuals with hemochromatosis received joint replacement surgery with a total number of 52 joints replaced. Compared with expected rates in healthy individuals, patients with hemochromatosis had a significantly higher risk for joint replacement surgery (odds ratio 9.0; confidence interval, 4.6-17.4). Joint replacement occurred significantly earlier in life in patients with hemochromatosis; 21.9% of the patients with hemochromatosis and 1.7% of healthy individuals required joint replacement before the age of 50 years (P=.0027). Moreover, patients with hemochromatosis were more likely to require multiple joint replacements (8.5%) than the control group (expected rate 0.3%; P=.0001). CONCLUSION: Hemochromatosis is a risk factor for joint replacement surgery because of severe secondary osteoarthritis.