{
  "abstract": "Nail–patella syndrome is a genetic disease with different phenotypes often affecting nails and knees. We present a woman with nail–patella syndrome with instability and dysfunction of the distal radioulnar joint. This is a trait which, to our knowledge, has not previously been described in nail–patella syndrome. In the clinical examination, the ulna head subluxed from the distal radioulnar joint when the wrist was fully supinated, creating a dorsal visible indentation and a volar protrusion of the ulnar head. The distal radioulnar joint instability of the case patient was quantified with a 3D visualisation and kinematic evaluation using dynamic radiostereometry analysis during a forearm rotation test and a press test. The investigation revealed limited pronation and hyper-supination during the forearm rotation compared with a healthy control. The dynamic radiostereometry analysis enabled a better understanding of the pathomechanics behind the instability. Patient-specific CT-derived bone models of ulna and radius revealed flat end dysplastic joint surfaces. The dynamic radiostereometry analysis proved to be a useful tool to describe, visualise and understand the pathomechanics of the case patient’s distal radioulnar joint.",
  "authors": [
    {
      "affiliations": [
        "AutoRSA Research Group, Department of Orthopaedics, Aarhus University Hospital, Aarhus, Denmark",
        "Department of Clinical Medicine, Aarhus University, Aarhus, Denmark"
      ],
      "name": "Marie Mølmer"
    },
    {
      "affiliations": [
        "AutoRSA Research Group, Department of Orthopaedics, Aarhus University Hospital, Aarhus, Denmark",
        "Department of Clinical Medicine, Aarhus University, Aarhus, Denmark",
        "Department of Orthopaedics, University Clinic for Hand, Hip, and Knee Surgery, Gødstrup Hospital, Gødstrup, Denmark"
      ],
      "name": "Janni Kjærgaard Thillemann"
    },
    {
      "affiliations": [
        "AutoRSA Research Group, Department of Orthopaedics, Aarhus University Hospital, Aarhus, Denmark",
        "Department of Clinical Medicine, Aarhus University, Aarhus, Denmark"
      ],
      "name": "Emil Toft Petersen"
    },
    {
      "affiliations": [
        "AutoRSA Research Group, Department of Orthopaedics, Aarhus University Hospital, Aarhus, Denmark",
        "Department of Clinical Medicine, Aarhus University, Aarhus, Denmark"
      ],
      "name": "Maiken Stilling"
    }
  ],
  "title": "Abnormal kinematics of the distal radioulnar joint due to flat bone dysplasia in nail–patella syndrome: a 3D evaluation with dynamic radiostereometry",
  "uid": "025e37a3-e75e-53b8-905f-d47962048865"
}