title: Corrections of diverse forms of lower limb deformities in patients with mucopolysaccharidosis type IVA (Morquio syndrome).
abstract: BACKGROUND
  Thoracolumbar kyphosis has been considered as the first presenting deformity and is often a key diagnostic clue noted in children with mucopolysaccharidosis (MPS) type IV (Morquio's syndrome). However, we observed that the progressive irregularities of the epiphyses of the long bones were the most prominent skeletal pathology, causing effectively the development of diverse forms of lower limbs deformities with extreme variation in age of onset.
  
  
  METHODS
  Ten patients (seven children and three adults) with an average age of 15 years have been enrolled in this study. Age of diagnosis of MPS IVA has a variable age of onset and a MISLEADING rate of severity. Hip dislocations, genu valgum, protrusio acetabuli and osteoarthritis were the most common lower limbs deformities in these patients. Clinical and radiographic phenotypes were the baseline tools of documentation. Urinary screening and genotypic characterizations have been applied accordingly.
  
  
  RESULTS
  Combined pelvic and femoral procedures for hip dislocation, epiphysiodeses and supracondylar osteotomy for genu valgum and hip arthroplasty for protrusio acetabuli have been performed. All patients manifested insufficient activity of N-acetylgalactosamine-6-sulphate sulphatase, an enzyme that degrades keratin sulphate and chondroitin-6 sulphate.
  
  
  CONCLUSIONS
  The extensive clinical heterogeneity contributed significantly in the delay in establishing the diagnosis particularly in adult patients with MPS IV. The epiphyseal irregularities of the long bones and the progressive flattening pathology of MPS IV A were the reason to falsely diagnose some patients as spondyloepiphyseal dysplasia congenital and/or tarda. Proximal femoral osteotomy, realignment osteotomy and total hip arthroplasty have been performed for coxa vara, genu valgum and protrusio acetabuli, respectively, in children and adult group of patients. The importance of early diagnosis on MPS IV A is to receive enzyme replacement therapy and plan for other therapeutic measures.
authors.affiliation: First Medical Department, Ludwig Boltzmann Institute of Osteology, The Hanusch Hospital of WGKK and AUVA Trauma Centre Meidling, Hanusch Hospital; Department of Paediatric, Orthopaedic Hospital of Speising, Vienna, Austria.
authors.forename: Ali
authors.initials: A
authors.lastname: Al Kaissi
authors.affiliation: Department of Foot and Ankle Surgery, Pediatric Orthopedic Institute n.a. H. Turner, Neuroorthopaedics and Systemic Disorders, Pushkin, Saint Petersburg, Russia.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Kenis
authors.affiliation: Department of Foot and Ankle Surgery, Pediatric Orthopedic Institute n.a. H. Turner, Neuroorthopaedics and Systemic Disorders, Pushkin, Saint Petersburg, Russia.
authors.forename: Eugeniy
authors.initials: E
authors.lastname: Melchenko
authors.affiliation: Department of Paediatric Orthopaedic Surgery, Children Hospital, Tunis, Tunisia.
authors.forename: Maher Ben
authors.initials: MB
authors.lastname: Ghachem
authors.affiliation: Department of Paediatric, Orthopaedic Hospital of Speising, Vienna, Austria.
authors.forename: Robert
authors.initials: R
authors.lastname: Csepan
authors.affiliation: Department of Paediatric, Orthopaedic Hospital of Speising, Vienna, Austria.
authors.forename: Franz
authors.initials: F
authors.lastname: Grill
authors.affiliation: Department of Paediatric, Orthopaedic Hospital of Speising, Vienna, Austria.
authors.forename: Rudolf
authors.initials: R
authors.lastname: Ganger
mesh_terms: D000293:Adolescent; D000367:Age Factors; D001847:Bone Diseases / Q000175:diagnosis / Q000209:etiology* / Q000601:surgery*; D002648:Child; D005260:Female; D006801:Humans; D035002:Lower Extremity; D008297:Male; D009085:Mucopolysaccharidosis IV / Q000150:complications* / Q000175:diagnosis / Q000601:surgery*; D055815:Young Adult