Open Label Study to Collect Clinical Data to Document Clinical Performance and Safety in Total Knee Arthroplasty

Inclusion Criteria: * For the HLS-1, HLS-2, HLS Evolution and HLS Noetos retrospective group: 1. Adult patients older than 18 years old. 2. Patients who have undergone routine preoperative clinical evaluations prior to their Total Knee Replacement surgery and implanted with one of the following prostheses from the HLS range: HLS-1, HLS-2, HLS Evolution and HLS Noetos between their first date of use in 1987 and their last date of use as normal practice at the participating site in accordance to indications and intended use as described in the Instruction for Use (IFU) of the study devices. 3. Patients who have been informed about their participation into an observational study. For the HLS KneeTec prospective group (with retrospective surgeries): 1. Adult patients older than 18 years old. 2. Patients who have undergone routine preoperative clinical evaluations and received a TKR or are suitable candidates for a TKR with a fixed or mobile postero-stabilized HLS KneeTec prosthesis (cementless, cemented or hybrid combination) for the treatment of a primary or secondary knee osteoarthritis and inflammatory disease such as rheumatoid arthritis in accordance to indications and intended use as described in the Instruction for Use (IFU) of the study devices. 3. Patients who are willing and able to complete the scheduled FU visits. 4. Patients who have been informed about their participation into an observational registry study Exclusion Criteria: * Patients mentally incompetent or unable to understand what participation in the study entails. * Patients who present signs and symptoms of any of the known contraindications described in the Instruction for Use (IFU) of the study devices. * Patients who deny their participation into the study.