A washout surgery is a procedure where a surgeon flushes a wound, joint, or body cavity with large volumes of sterile fluid to remove infection, debris, dead tissue, or contamination. The medical terms you might see on paperwork are “irrigation and debridement,” sometimes abbreviated as I&D. It’s one of the most common urgent procedures in orthopedic and trauma surgery, and it can range from a relatively quick cleanup of a contaminated wound to a more involved operation inside an infected joint.
How the Procedure Works
The core idea is straightforward: physically flush out bacteria, dead cells, and foreign material that your body can’t clear on its own. The surgeon uses sterile saline (saltwater matched to your body’s natural fluid balance) delivered under controlled pressure. A typical setup generates about 25 to 40 PSI of pressure, enough to dislodge debris and bacteria without damaging healthy tissue. Pressures above 70 PSI can injure the surrounding tissue, so surgeons stay well below that threshold.
The volume of fluid depends on the size of the wound or surgical site. A common guideline is roughly 50 milliliters of saline per centimeter of wound length, meaning even a modest wound might require several hundred milliliters. Larger joints or abdominal cavities can require liters of fluid. The surgeon delivers the saline, lets it carry contaminants away, suctions it out, and often repeats the cycle multiple times until the area looks clean.
In most cases, the washout includes debridement: the surgeon uses a scalpel or surgical scissors to cut away dead, damaged, or infected tissue that irrigation alone won’t remove. The wound is also probed to check its depth and look for any hidden foreign material. Once the area is cleaned and debrided, the surgeon may place a drain, loosely close the wound, or leave it open to heal gradually depending on how contaminated it was.
Why a Washout Is Needed
Washout surgery is used whenever infection or contamination is too severe for antibiotics alone to handle. The most common scenarios include:
- Septic arthritis: Bacterial infection inside a joint, most often the knee. The joint fills with infected fluid that produces toxins, increases pressure, and can destroy cartilage quickly if not drained.
- Infected surgical wounds: Surgical site infections after orthopedic procedures sometimes require a return to the operating room. In foot and ankle surgery, for example, postoperative infection rates range from 0.5% to 6.5%, and the more serious cases need surgical washout rather than antibiotics alone.
- Traumatic wounds: Open fractures, deep lacerations, or any wound contaminated with dirt, gravel, or other debris. The goal is to reduce the bacterial load before the infection takes hold.
- Abdominal infections: Conditions like peritonitis (infection in the abdominal cavity) may require lavage, where the surgeon flushes the entire cavity.
- Infected joint replacements: When a prosthetic knee or hip becomes infected, a washout is often the first step in treatment.
Washout for Joint Replacements: The DAIR Approach
When infection develops around an artificial joint, the procedure is more involved than a simple flush. Surgeons use a protocol called DAIR, which stands for debridement, antibiotics, and implant retention. The goal is to save the implant while eliminating the infection.
DAIR is recommended when infection is caught early, typically within four weeks of the original surgery or within two weeks of symptoms starting. The procedure is done through an open incision rather than arthroscopically, because the surgeon needs full access to the joint. During the operation, the surgeon removes the skin margins around the incision, cuts away infected tissue lining the joint, and exchanges any removable plastic components. In a knee replacement, swapping out the plastic spacer between the metal parts is critical. Studies have shown that leaving the old spacer in place is an independent risk factor for the infection coming back.
After DAIR, patients typically receive intravenous antibiotics for six weeks, with blood tests tracking inflammation levels to confirm the infection is clearing. If DAIR fails, the next options become more aggressive: a full revision surgery to remove and replace the entire implant, done in either one or two stages.
Success Rates and Repeat Procedures
A single washout doesn’t always resolve the problem, particularly with joint infections. In a study of 78 patients who underwent arthroscopic washout for septic arthritis of the knee, about 60% were successfully treated with one procedure. The remaining 40% had persistent infection and needed additional washouts. Most of those patients required just one more procedure, though a small number (around 8%) needed two additional washouts, and one patient required three.
These numbers highlight an important reality: washout surgery is sometimes a multi-step process. If your surgeon mentions the possibility of needing a second procedure, that’s not a sign something went wrong. It reflects how stubborn bacterial infections inside joints can be, especially if the infection was advanced before treatment started. Factors like how long symptoms were present before surgery and the type of bacteria involved both influence whether a single washout will be enough.
What Recovery Looks Like
Recovery depends heavily on what was being treated. A washout of a contaminated traumatic wound might heal within a few weeks if infection is prevented. Joint washouts take longer because the joint itself needs time to recover from both the infection and the procedure.
After a joint washout, you can expect a course of antibiotics lasting several weeks. The joint will be swollen and stiff initially, and physical therapy is usually needed to restore range of motion. For knee washouts, weight-bearing restrictions may apply for the first days to weeks. Your surgical team will monitor inflammatory markers in your blood to confirm the infection is resolving, and follow-up imaging may be used to check for any remaining fluid collections or abscesses in the surrounding tissue.
Wound washouts are sometimes left partially or fully open after the procedure rather than stitched closed. This is intentional. Closing a contaminated wound traps bacteria inside, so surgeons often pack the wound and let it heal from the inside out, changing dressings regularly until the tissue fills in on its own.
Risks of the Procedure
Washout surgery is generally safe, but it carries the same baseline risks as any operation requiring anesthesia: bleeding, blood clots, and reactions to anesthesia. The risks specific to washouts are mostly related to the underlying infection rather than the procedure itself. Persistent or recurrent infection is the main concern, as the 40% retreatment rate in septic arthritis illustrates. Joint stiffness is common after washouts involving the knee, shoulder, or other joints, and some patients don’t regain their full pre-infection range of motion. In rare cases, if repeated washouts fail to control a prosthetic joint infection, more extensive surgery or even amputation may become necessary, though this is uncommon and typically a last resort after multiple treatment attempts.