Haemochromatosis: unexplained metacarpophalangeal or ankle arthropathy should prompt diagnostic tests: findings from two UK observational cohort studies

Hemochromatosis Genetic Variants and Musculoskeletal Outcomes: 11.5-Year Follow-Up in the UK Biobank Cohort Study

The iron overload disorder hemochromatosis is primarily caused by the homozygous HFE p.C282Y variant, but the scale of excess related musculoskeletal morbidity is uncertain. We estimated hemochromatosis-genotype associations with clinically diagnosed musculoskeletal outcomes and joint replacement surgeries in the UK Biobank community cohort. A total of 451,143 European ancestry participants (40 to 70 years at baseline) were followed in hospital records (mean 11.5-years). Cox proportional hazards models estimated HFE p.C282Y and p.H63D associations with incident outcomes. Male p.C282Y homozygotes (n = 1294) had increased incidence of osteoarthritis (n = 52, hazard ratio [HR]: 2.12 [95% confidence interval, CI: 1.61 to 2.80]; p = 8.8 × 10-8), hip replacement (n = 88, HR: 1.84 [95% CI: 1.49 to 2.27]; p = 1.6 × 10-8), knee replacement (n = 61, HR: 1.54 [95% CI: 1.20 to 1.98]; p = 8.4 × 10-4), and ankle and shoulder replacement, compared to males with no HFE mutations. Cumulative incidence analysis, using Kaplan-Meier lifetable probabilities demonstrated 10.4% of male homozygotes were projected to develop osteoarthritis and 15.5% to have hip replacements by age 75, versus 5.0% and 8.7% respectively without mutations. Male p.C282Y homozygotes also had increased incidence of femoral fractures (n = 15, HR: 1.72 [95% CI: 1.03 to 2.87]; p = 0.04) and osteoporosis (n = 21, HR: 1.71 [95% CI: 1.11 to 2.64]; p = 0.02), although the latter association was limited to those with liver fibrosis/cirrhosis diagnoses. Female p.C282Y homozygotes had increased incidence of osteoarthritis only (n = 57, HR: 1.46, [95% CI: 1.12 to 1.89]; p = 0.01). Male p.C282Y/p.H63D compound heterozygotes experienced a modest increased risk of hip replacements (n = 234, HR: 1.17 [95% CI: 1.02 to 1.33], p = 0.02), but this did not pass multiple testing corrections. In this large community cohort, the p.C282Y homozygote genotype was associated with substantial excess musculoskeletal morbidity in males. Wider HFE genotype testing may be justified, including in orthopedic clinics serving higher HFE variant prevalence populations. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.

Overview of Ankle Arthropathy in Hereditary Hemochromatosis

Hereditary hemochromatosis (HH) is an autosomal recessive bleeding disorder characterized by tissue overload of iron. Clinical systemic manifestations in HH include liver disease, cardiomyopathy, skin pigmentation, diabetes mellitus, erectile dysfunction, hypothyroidism, and arthropathy. Arthropathy with joint pain is frequently reported at diagnosis and mainly involves the metacarpophalangeal and ankle joints, and more rarely, the hip and knee. Symptoms in ankle joints are in most cases non-specific, and they can range from pain and swelling of the ankle to deformities and joint destruction. Furthermore, the main radiological signs do not differ from those of primary osteoarthritis (OA). Limited data are available in the literature regarding treatment; surgery seems to be the gold standard for ankle arthropathy in HH. Pharmacological treatments used to maintain iron homeostasis can also be undertaken to prevent the arthropathy, but conclusive data are not yet available. This review aimed to assess the ankle arthropathy in the context of HH, including all its aspects: epidemiology, physiopathology, clinical and imaging presentation, and all the treatments available to the current state of knowledge.

Analysis of Hand Joint Space Morphology in Women and Men with Hereditary Hemochromatosis

Hereditary hemochromatosis (HH) causes unbalanced iron deposition in many organs including the joints leading to severe cartilage loss and bone damage in the metacarpophalangeal joints (MCPJ). High-resolution peripheral quantitative computed tomography (HR-pQCT) and its joint space width (JSW) quantification algorithm quantifies in vivo 3D joint morphology. We therefore aimed to (i) determine feasibility and performance of the JSW algorithm in HH, (ii) quantify joint space morphology, and (iii) investigate the relationship between morphological and clinical parameters in HH. Here, we performed an exploratory study on 24 HH patients and sex- and age-matched controls using HR-pQCT imaging of MCPJ. Mineralized bone structure was automatically segmented from the grayscale image data and periosteal surface bone masks and joint space masks were generated. Mean, minimal, and maximal joint space width (JSW; JSW.MIN; JSW.MAX), JSW heterogeneity (JSW.SD), JSW asymmetry (JSW.AS), and joint space volume (JSV) were computed. Demographics and, for HH patients, disease-specific parameters were recorded. Segmentation of JS was very good with 79.7% of MCPJs successfully segmented at first attempt and 20.3% requiring semi-manual correction. HH men showed larger JSV at all MCPs (+ 25.4% < JSV <  + 41.8%, p < 0.05), larger JSW.MAX at MCP 3-4 (+ 14%, 0.006 < p < 0.062), and wider JSW (+ 13%, p = 0.043) at MCP 4 relative to HH women. Compared to controls, both HH men and HH women showed larger JSW.AS and smaller JSW.MIN at all MCP levels, reaching significance for HH men at MCP 2 and 3 (JSW.AS: + 323% < JSW.AS <  + 359%, 0.020 < p < 0.043; JSW.MIN: - 216% < JSW.MIN < - 225%, p < 0.043), and for women at MCP 3 (JSW.AS: + 180%, p = 0.025; JSW.MIN: - 41.8%, p = 0.022). Time since HH diagnosis was correlated positively with MCP 4 JSW.AS and JSW.SD (0.463 < ρ < 0.499, p < 0.040), and the number of phlebotomies since diagnosis was correlated with JSW.SD at all MCPs (0.432 < ρ < 0.535, p < 0.050). HR-pQCT-based JSW quantification in MCPJ of HH patients is feasible, performs well even in narrow JS, and allows to define the microstructural joint burden of HH.

Iron effects versus metabolic alterations in hereditary hemochromatosis driven bone loss

Hereditary hemochromatosis (HH) is a genetic disorder in which mutations affect systemic iron homeostasis. Most subtypes of HH result in low hepcidin levels and iron overload. Accumulation of iron in various tissues can lead to widespread organ damage and to various complications, including liver cirrhosis, arthritis, and diabetes. Osteoporosis is another frequent complication of HH, and the underlying mechanisms are poorly understood. Currently, it is unknown whether iron overload in HH directly damages bone or whether complications associated with HH, such as liver cirrhosis or hypogonadism, affect bone secondarily. This review summarizes current knowledge of bone metabolism in HH and highlights possible implications of metabolic dysfunction in HH-driven bone loss. We further discuss therapeutic considerations managing osteoporosis in HH.

Postoperative Complications in Patients With Hereditary Hemochromatosis Undergoing Total Joint Arthroplasty: A Matched Cohort Analysis

AIMS

The purpose of this study is to determine differences in the rates of 90-day postoperative complications and 2- and 5-year surgical outcomes between patients with and without hereditary hemochromatosis (HH) after total joint arthroplasty (TJA).

METHODS

Patients who underwent primary total hip arthroplasty (THA) or total knee arthroplasty (TKA) from 2010 to 2018 were identified in a national database (PearlDiver Technologies) using Current Procedural Terminology and International Classification of Diseases-9/10 codes. Patients with a history of HH were identified within the THA and TKA cohorts and matched with non-HH patients based on age, sex, Charlson Comorbidity Index, smoking status, and obesity (body mass index > 30). Ninety-day medical complications assessed included renal failure, arrhythmia, bleeding complications, blood transfusion, pneumonia, stroke, deep vein thrombosis, liver failure, heart failure, pulmonary embolism, sepsis, surgical site infection, wound dehiscence, readmission rate, and death. Two- and 5-year surgical complications assessed included all-cause revision, prosthetic joint infection, implant loosening, joint stiffness, and manipulation under anesthesia. All complications were analyzed using bivariate analysis and logistic regression, with significance set at P < 0.05.

RESULTS

Compared with non-HH patients, patients with HH had higher rates of stiffness at 2 and 5 years after THA (all, P < 0.001), as well as higher rates of aseptic loosening at 5 years after TKA (P = 0.036). However, patients with HH undergoing THA and TKA had no notable difference in 90-day postoperative complications when compared with non-HH patients.

DISCUSSION

Compared with non-HH patients, patients with HH undergoing TJA were shown to have worse 2- and 5-year surgical outcomes, without any increased risk of 90-day medical complications. These findings may be useful for surgical decision making for patients with HH undergoing TJA.

CLINICAL RELEVANCE

This study addresses a paucity in the current literature concerning the complication profile in HH patients with destructive joint arthropathy undergoing joint arthroplasty surgery.

Ankle arthritis - an important signpost in rheumatologic practice

Ankle arthritis is a useful clinical signpost to differential diagnosis in rheumatic disease. Biomechanical features and differences in cartilage physiology compared with the knee may confer protection of the ankle joint from factors predisposing to certain arthritides. The prevalence of ankle OA is low, and usually secondary to trauma. Primary OA of the ankle should be investigated for underlying causes, especially haemochromatosis. New presentations of inflammatory mono/oligo arthritis involving the ankle are more likely due to undifferentiated arthritis or spondyloarthritis than RA, and gout over CPPD. The ankle is often involved in bacterial and viral causes of septic arthritis, especially bacterial, chikungunya and HIV infection, but rarely tuberculosis. Periarticular hind foot swelling can be confused with ankle arthritis, exemplified by Lofgren’s syndrome and hypertrophic osteoarthropathy where swelling is due to subcutaneous oedema and osteitis respectively, and the ankle joint is rarely involved.

Bone and joint complications in patients with hereditary hemochromatosis: a cross-sectional study of 93 patients

Background

The aim of this study was to determine the frequency and characteristics of bone and joint complications, specifically bone fragility, joint replacement surgery, and arthropathy, in hereditary hemochromatosis (HH) and related factors.

Methods

This study was a cross-sectional observational study of 93 patients with HH. Radiographs of the hands, wrists, knees, and ankles were scored for joint space narrowing, erosions and cysts, osteophytes, and chondrocalcinosis. Prevalent (vertebral and non-vertebral) fragility fractures were recorded and bone mineral density (BMD) was systematically evaluated by dual energy X-ray absorptiometry. Bone fragility was defined as (i) a T-score ⩽ -2.5 at any site with or without a prevalent fragility fracture, or (ii) a T-score between -1.0 and -2.5 at any site and a prevalent fragility fracture.

Results

The mean age of the patients was 60.0 (11.2) years, and 58.0% of them were men. The frequency of radiographic MCP2-3 arthropathy was 37.6% (95% CI 0.28-0.48). Radiographic MCP2-3 arthropathy was independently associated with older age [OR 1.17 (1.09-1.26) per year, p < 0.0001], male sex [OR 3.89 (1.17-12.97), p = 0.027] and C282Y+/+ genotype [OR 4.78 (1.46-15.68), p = 0.010]. The frequency of joint replacement surgery was 12.9% (95% CI 0.07-0.21). The frequency of bone fragility was 20.4% (95% CI 0.13-0.30). Bone fragility was independently associated with hepatic cirrhosis [OR 8.20 (1.74-38.68), p = 0.008].

Discussion

Radiographic MCP2-3 arthropathy was found to occur in 37.6% of patients with HH. The association observed between this form of arthropathy and C282Y homozygosity, male sex, and older age suggests that demographic characteristics and genetic background are likely to be major determinants of this joint disorder and play a more important role than severity of iron overload. Bone fragility was observed in a fifth of the patients with HH, independently of genetic background and severity of iron overload, and was strongly associated with hepatic cirrhosis.

Conclusion

Future investigations should focus on pathogenesis and early identification of patients at risk of developing bone and joint complications secondary to HH.

Hereditary hemochromatosis is associated with increased use of joint replacement surgery: Results of a nationwide analysis

BACKGROUND

Hereditary hemochromatosis (HH) may lead to iron deposition-mediated arthropathy, causing progressive joint degeneration, necessitating replacement arthroplasty. Studies have noted an increased need for replacement arthroplasty in patients with HH. We aimed to compare the use of replacement arthroplasty and inpatient economic burden in patients with and without HH.

METHODS

For our retrospective cohort study, we used the 2014 Nationwide Inpatient Sample. Patients with an International Classification of Diseases, Ninth Revision code for HH were included. The primary outcome was use of replacement arthroplasty; secondary outcomes were hospital length of stay, hospital costs, and total hospitalization charges. Multivariate logistic regression yielded confounder-adjusted odds ratios (ORs) and means.

RESULTS

Of 18,250 patients with HH, 7,483 (41.0%) were women and 1,155 (6.3%) underwent replacement arthroplasty. Mean (SD) age for patients with HH and arthroplasty was 66 (18) years. The percentage of patients with HH who underwent replacement arthroplasty was higher than those without HH (3.4%; P<.01). On multivariate analysis, young-adult females and elderly patients with HH were more likely to undergo replacement arthroplasty compared to those without HH of the corresponding gender and age group. Mean length of stay, hospital costs, and total hospitalization charges were increased only in young adult females.

CONCLUSIONS

HH is associated with increased odds of replacement arthroplasty, particularly in the elderly, which can potentially suggest faster arthropathy progression in this age group and should raise awareness in clinicians taking care of patients with HH. Future research should identify factors mediating arthropathy progression in patients with HH.

MRI ankle and subtalar characteristics in haemochromatosis arthropathy: a case-control study

AIM

To examine the magnetic resonance imaging (MRI) features of the ankle and subtalar joints that might distinguish genetic haemochromatosis (GH).

MATERIALS AND METHODS

The present study was a retrospective case-control study comparing 30 MRI studies of GH patients with ankle or subtalar arthropathy with 30 matched controls with ankle pain. Anonymised images were scored using a semi-quantative tool adapted from the MRI osteoarthritis knee score. Scores were generated for bone marrow lesions size, number, and distinguishing the proportion of each lesion consisting of subchondral cyst versus oedema. Articular cartilage loss and osteophytes were documented. The primary comparator was bone marrow lesion size. Paired Student's t-test and the chi-squared test were utilised to compare outcomes.

RESULTS

Bone marrow lesion/cyst size and number, presence and extent of full-thickness cartilage loss, and osteophyte scores were significantly higher in ankle joints of GH cases (p<0.01). In the middle subtalar articulation, there were significantly higher scores for full-thickness cartilage loss and extent and osteophytes in GH cases (p<0.05). There were no significant differences in the posterior subtalar articulation.

CONCLUSION

The finding of both numerous and large cysts on ankle MRI should raise suspicion of GH. Other MRI features of potential diagnostic value include large osteophytes and the presence of extensive full-thickness cartilage loss in the ankle joint and middle subtalar articulation.