Treatment of hip dysplasia in patients with mucopolysaccharidosis type I after hematopoietic stem cell transplantation: results of an international consensus procedure

Eveline J Langereis, Andrea Borgo, Ellen Crushell, Paul R Harmatz, Peter M van Hasselt, Simon A Jones, Paula M Kelly, Christina Lampe, Johanna H van der Lee, Thierry Odent, Ralph Sakkers, Maurizio Scarpa, Matthias U Schafroth, Peter A Struijs, Vassili Valayannopoulos, Klane K White, Frits A Wijburg

Mucopolysaccharidosis type I (MPS-I) is a lysosomal storage disorder characterized by progressive multi-organ disease. The standard of care for patients with the severe phenotype (Hurler syndrome, MPS I-H) is early hematopoietic stem cell transplantation (HSCT). However, skeletal disease, including hip dysplasia, is almost invariably present in MPS I-H, and appears to be particularly unresponsive to HSCT. Hip dysplasia may lead to pain and loss of ambulation, at least in a subset of patients, if left untreated. However, there is a lack of evidence to guide the development of clinical guidelines for the follow-up and treatment of hip dysplasia in patients with MPS I-H. Therefore, an international Delphi consensus procedure was initiated to construct consensus-based clinical practice guidelines in the absence of available evidence.