Upper Limb Pathology in Children with Mucopolysaccharidoses

Background. Despite the success in the treatment of children with mucopolysaccharidoses (MPS) as a result of the widespread of  enzyme  replacement  therapy  and  hematopoietic  stem  cells  transplantation,  orthopedic  manifestations  continue  to  be a  significant  problem,  while  the  pathology  of  the  upper  limbs  in  children  with  MPS  is  not  sufficiently  represented  in  the literature. The aim of this studywas to analyze orthopedic and neurological manifestations in the upper extremities of children with  mucopolysaccharidosis  based  on  a  sequential  case  series. Materials  and  Methods. We  carried  out  a  comprehensive analysis of clinical and radiological involvement of the upper extremities in 49 patients with MPS. Results. The most common complaints reated to the upper extremities were difficulties in the daily activities (dressing, self-care, playing), impairment of the fine motor skills, and muscle weakness. The most frequent clinical manifestations related to the upper extremities were limited active shoulder abduction, impaired hand grip, flexion contractures of the elbow joint, ulnar deviation of the hand. All patients with MPS types I, II, and VI had limited active and passive extension and flexion of the metacarpophalangeal and interphalangeal joints. In patients with MPS IV, hypermobility of the hand joints prevailed. We noticed minimal presence of typical clinical manifestations related to compression of the median nerve secific for carpal tunnel syndrome. The majority of patients showed a decrease in tendon and periosteal reflexes. The most pronounced decrease in muscle strength was observed in to extensors (elbow, fingers) and shoulder abductors, which may contribute to the predominant formation of a flexion pattern of contractures. On radiographs of the hand, the “melting sugar” symptom and shortening of the metacarpal bones were observed in most patients. Conclusion.Clinical and radiological manifestations related to the upper extremities take  place  in  all  types  of  the  mPS,  and  lead  to  functional  disorders  that  complicate  daily  life  and  self-care.  Upper  limb pathology in children with MPS requires earlier detection and more active treatment after comprehensive risk assessment.