DIGITAL-KNEE Study: Adequately Diagnosing Total Knee Arthroplasty Loosening by Evaluating the AtMoves Knee System in a Routine Clinical Setting

Inclusion Criteria: * Age 18 years or older. * Subjects must have underwent either unilateral or bilateral TKA surgery. * Aseptic loosening is one of the differential diagnoses of the treating orthopaedic surgeon * The treating Orthopaedic Surgeon is uncertain of the diagnosis after anamnesis, physical examination and conventional x-ray. * The surgeon wants additional examinations or additional imaging to arrive at the diagnosis and proposal for treatment. * Subjects must be capable of giving informed consent and must be willing to undergo examination with the AtMoves Knee System. Exclusion Criteria: * A clear other cause for complaints other than aseptic loosening (e.g. septic loosening, neuropathic pain, non-consolidated peri-prosthetic fracture of the bone around the TKA) * Surgical interventions of the index knee in the year prior to the start of the complaints associated with TKA loosening. * Posttraumatic or congenital deformation of the leg for which the loading device does not fit. * Pregnancy or suspected pregnancy. * Unable or unwilling to understand or sign the informed consent for this study and to undergo examination with the AtMoves Knee System.