Randomized, prospective, single-blind clinical trial comparing two static wound retractors - the Charnley retractor and the Alexis O-Ring retractor - in primary total hip arthroplasty (THA). The primary objective is to compare surgical site contamination rates between the two devices. Secondary objectives include comparison of incision length, surgical time, intraoperative skin lesions, and postoperative complications including periprosthetic joint infection. Patients will be randomized 1:1 to either retractor group. Surgical site contamination will be assessed through four intraoperative cultures taken at standardized timepoints. Follow-up will be conducted at 1 month postoperatively.

Inclusion Criteria:

• Patients diagnosed with symptomatic hip osteoarthritis indicated for primary total hip arthroplasty (THA)

Exclusion Criteria:

• Previous surgical interventions or scar tissue over the hip to be operated Subcapital femoral fractures requiring THA (non-primary indication) History of infection in any previous joint arthroplasty procedure Immunological disorders increasing the risk of periprosthetic joint infection (diagnosed immunodeficiencies, chemotherapy or immunosuppressive treatment) Advanced dementia or severe cognitive impairment precluding informed consent

No individual participant data sharing plan is foreseen for this study