Given the acute onset of symptoms and positive arthrocentesis, a diagnosis of acute late periprosthetic infection was made and the patient was taken the following day to the operating room for irrigation and debridement with polyethylene exchange. All infected-appearing tissue as well as the pseudomembrane was removed. Betadine scrub brushes were utilized to scrub the femoral, tibial, and patellar components, which were noted to be well fixed with no signs of loosening. All previous ethibond sutures were removed and the wound was irrigated with 6 L of normal saline pulse lavage. A new polyethylene insert of the same size was implanted. A hemovac drain was placed prior to fascial closure with #1 prolene sutures. This was followed by 2-0 subcutaneous PDS suture. The skin was closed with staples.

Due to the patient’s hypercoagulable state, he was placed on lovenox postoperatively and bridged back to coumadin. A peripherally inserted central catheter (PICC) was placed for 6 weeks of Cefepime in addition to oral Rifampin as recommended by an infectious disease consult obtained while in the hospital. His rehabilitation included range of motion exercises, full weight-bearing and gentle muscle strengthening similar to a primary total knee replacement.

Postoperatively, the patient did experience some pain relief but denied resolution of his pain. Approximately 2 months postoperatively (2 weeks after cessation of the IV antibiotic therapy), the patient returned with persistent right knee pain, erythema, and an effusion. Range of motion of the right knee was 0–105° with no evidence of instability. Repeat laboratory markers revealed an ESR of 25 mm/h, CRP of 21 mg/L, and a peripheral white blood cell count of 6. Aspiration was also performed at that time revealing 23,000 WBCs (differential of 92 % neutrophils) and cultures eventually growing MSSA.

The patient was taken back to the operating room after normalization of his INR for the first step of a two-stage exchange procedure for explant of the right knee arthroplasty and placement of a molded antibiotic-loaded knee spacer (Fig. 8.2) utilizing 3 g of tobramycin per cement package. The knee was closed in a similar fashion with hemovac drain in place. At the recommendation of infectious disease, the patient was given an additional 6 weeks of antibiotics consisting of daptomycin.

After explant, the patient was again bridged back to his coumadin with lovenox and began a physical therapy protocol in the attempt to maintain range of motion and to encourage weight-bearing. After completing his antibiotic course, his labs were again drawn demonstrating normalization of both ESR and CRP prior to reimplantation. The patient was replanted approximately 7 months later with a posterior stabilized revision construct consisting of hybrid diaphyseal engaging stems and porous metaphyseal sleeves on both the tibia and femur. Antibiotic cement was used in a limited fashion proximally under the tibial component and distally under the femoral component. Physical therapy following revision utilized the same protocol used following primary total knee replacement. Postoperatively, the patient recovered well and had no further complications with the knee.

Most recent follow-up 5 years after reimplantation reveals the patient has healed his incision nicely with no complaints of pain, drainage, or instability of the knee. X-rays reveal well-fixed implants in good alignment (Fig. 8.3) with range of motion of approximately 5–110° actively and passively. He has been participating in physical therapy off and on and has returned to his preoperative level of activity without restriction.