Bone Fragility in Hereditary Connective Tissue Disorders: A Systematic Review and Meta-Analysis

Objective: To investigate bone fragility in patients with hereditary connective tissue disorders (HCTD), including Ehlers-Danlos syndrome (EDS), Marfan's syndrome (MFS) and Loeys-Dietz syndrome (LDS).

Methods: From inception to June 2022, potentially eligible studies were identified in the Medline and EMBASE databases using search strategy that included terms for "HCTD", "Fracture" and "Osteoporosis". Eligible studies must consist of a group of patients with HCTD and report prevalence/incidence of fracture/osteoporosis in their participants, with or without comparison with healthy individuals. Point estimates with standard errors were obtained from each study and combined using the generic inverse variance method.

Results: Among the 4206 articles identified, 19 studies were included. The pooled prevalence of fracture in EDS, MFS, and LDS were 44% (95% confidence interval [CI], 25% to 65%, I² 88%), 17% (95% CI, 11% to 26%, I² 68%), 69% (95% CI, 47% to 85%, I² 83%), respectively. The pooled prevalence of osteoporosis in EDS was 17% (95% CI, 8% to 34%, I² 96%). EDS was associated with fracture [pooled odds ratio {OR} 4.90 (95% CI, 1.49 - 16.08, I² 86%)], but not osteoporosis [pooled OR 1.34 (95% CI, 0.28 - 6.36, I² 87%). One study reported a 5% (95% CI, 3% to 8%) prevalence of osteoporosis in MFS, which was associated with fracture [incidence rate ratio 1.35 (95% CI, 1.18 - 1.55)] and osteoporosis [subhazard ratio 3.97 (95% CI, 2.53 - 6.25)].

Conclusion: EDS was associated with fracture, which could be independent of osteoporosis status. MFS had a milder degree of increased risk of fracture and osteoporosis. Despite no data from cohort studies, there was a significantly higher rate of fracture in LDS.