This trial is a prospective, single center, unblinded, randomized, controlled study to assess the safety and efficacy of negative pressure wound therapy in preventing infections after TKA surgery . The study will enroll 316 patients that will undergo TKA. patients will be randomized to the treatment group and undergo the study intervention - (NPWT) The intervention will take place at the end of the surgery. The Patients that are randomized to the control group will receive standard treatment. Both groups will be assessed at two weeks and six weeks. period.

Inclusion Criteria:

• Ages: 18 to 80
• Males- not involved in active military duty.
• Females-non child bearing potential, or females of child-bearing potential who have a negative pregnancy test (hCG urine) within 72 hours of informed consent.

Exclusion Criteria:

• Active systemic or local infection.
• History of malignancy, radiotherapy, or chemotherapy for malignancy (except BCC of the skin)
• Active autoimmune disease.
• Any past or present immunosuppressive treatment.
• Current treatment with chemotherapeutic agents
• History of metabolic bone disease (primary or secondary).
• Chronic renal insufficiency (defined by 50% increase of normal levels).