Z1 Hip System: Post-Market Clinical Follow Up Study

Inclusion Criteria: * Patient is at least 18 years old and skeletally mature * Patient is physically and mentally willing and able, in the Investigator's opinion at the time of enrollment, to be compliant with the protocol, including all scheduled study evaluations * Patient, or the patient's legally authorized representative, is willing and able to participate in the Informed Consent process and provide their consent * Independent of study participation, patient is a candidate and qualifies for primary total hip or hemi-arthroplasty based on physical exam and medical history including at least one of the following: * Advanced wear of the joint due to degenerative, post-traumatic or rheumatic diseases * Acute traumatic fracture of the femoral head or neck * Avascular necrosis (AVN) of the femoral head Exclusion Criteria: * Revision arthroplasty * Acute, chronic, local, or systemic infection(s) * Severe muscular, neural, or vascular diseases that endanger the limb(s) involved * Lack of bony structures proximal or distal to the joint, so that good anchorage of the implant is unlikely or impossible * Total or partial absence of the muscular or ligamentous apparatus * Any concomitant diseases that can jeopardize the functioning and the success of the implant * Allergy to the implanted material, especially to metal (e.g. cobalt, chromium, nickel, etc.) * Local bone tumors and/or cysts * Patient has any condition that would, in the Investigator's opinion, place the patient at undue risk or interfere with the study * Any vulnerable subject: * a prisoner * a patient known to be pregnant * mentally incompetent or unable to understand what participation in the study entails * a known substance abuser