Inclusion Criteria:  For being considered enrolled in this study, a patient must meet each of the following criteria:  Patient's age ≥ 18 years old. Patient has given written informed consent approved by the study site's Institutional Review Board (IRB)/Ethical Committee (EC). Patient has undergone a total or partial hip arthroplasty with LOGICA MIRROR femoral stem. The decision to implant the investigational device was taken by the Principal Investigator prior to, and independently from, the decision to enrol the patient in the study. According to the device indications for use, patient has suffered of one or more of the following conditions: non-inflammatory degenerative joint disease including osteoarthritis, avascular necrosis and dysplasia, rheumatoid arthritis, treatment of femoral head and neck fractures. Patient is able to comply with the protocol.  Exclusion Criteria:  A patient will be excluded from the study participation if he/she meets any of the following criteria:  Patient is affected by one or more of the conditions that are stated as LOGICA MIRROR absolute contraindication for use, which are: local or systemic infection, septicaemia, persistent acute or chronic osteomyelitis, confirmed nerve or muscle lesion compromising hip joint function Patient's mass is higher than 71 kg and he/she needs to receive LOGICA MIRROR size #1 Patient's mass is higher than 66 kg and he/she needs to receive LOGICA MIRROR size #0 For female patients, current pregnancy and/or lactation or planning a pregnancy.