![Graphic][1] Infection at the site of a total joint arthroplasty can be classified into four basic categories: Type I (early postoperative), Type II (late chronic), Type III (acute hematogenous), and Type IV (positive intraoperative cultures with clinically unapparent infection). ![Graphic][1] The current standard of care for late chronic infection is considered to be two-stage revision arthroplasty including removal of the prosthesis and cement, thorough débridement, placement of an antibiotic-impregnated cement spacer, a course of intravenous antibiotics, and a delayed second-stage revision arthroplasty. ![Graphic][1] The choice of the spacer, either articulating or nonarticulating, is based on many factors, including the amount of bone loss, the condition of the soft tissues, the need for joint motion, the availability of prefabricated spacers or molding methods, and antibiotic selection. ![Graphic][1] Current data have demonstrated that the use of antibiotic-impregnated cement spacers has improved the outcomes of the treatment of infection associated with total joint arthroplasty. Total joint replacement is one of the most frequent and successful types of operations in orthopaedics. Infection is a rare yet devastating complication of the procedure, with a reported prevalence of 0.5% to 3% and with a higher reported prevalence after total knee arthroplasty than after total hip arthroplasty1-4. There is also a higher rate of infection after revision hip and knee arthroplasties than after primary hip and knee arthroplasties1-8. Two-stage revision surgery was first described in 1983 by Insall et al., who demonstrated the necessity of removing the implants as well as the cement and of introducing antibiotic therapy for definitive treatment9. This procedure has emerged as the standard of care for a late chronic infection at the site of a total joint replacement4,5,10-17. Garvin and Hanssen reviewed twenty-nine studies and found that two-stage … [1]: pending:yes

Soft-tissue balancing during total knee arthroplasty is an important step in optimizing the mechanical balance of the knee joint. Softtissue contractures that result from varus coronal plane deformity can pose a difficult problem, and the surgeon should have a standard procedure for managing

Twelve fresh frozen anatomic specimen knees were used in this study to measure changes in the tibiofemoral joint gaps after sacrificing the posterior cruciate ligament. Joint gap changes were measured using a motion tracking device in full extension and at 45° and 90° flexion. Tibiofemoral gaps were measured with no external compressive loads and under tension to define the flexion gap, the space available to be filled by components. After initial anterior cruciate ligament removal, meniscectomy, and a 1-cm tibial plateau cut, sacrifice of the posterior cruciate ligament caused significant differences in the flexion gap. At 90° flexion the tibia distracted from the femur 5.26 ± 1.9 mm (range, 3.2-9.1 mm) at rest and 6.4 ± 2.5 mm under tension. No differences in the joint space were calculated in full extension under either loading case. The authors conclude that a major result of posterior cruciate ligament sacrifice is the creation of a larger flexion gap. This result provides insight into relative joint line changes that can occur after posterior cruciate ligament sacrifice. It also suggests the need for greater attention to flexion stability when sacrificing the posterior cruciate ligament and rethinking the role of posterior cruciate ligament release in the management of pure, primary flexion contracture.

Total joint arthroplasty is one of the most common and most successful orthopaedic procedures. Infection after total joint arthroplasty is a devastating problem that expends patient, surgeon, and hospital resources, and it substantially decreases the chances of a successful patient outcome. Postoperative infection affects approximately 1% to 7% of all total joint arthroplasties, at a cost of approximately $50,000 per infection. Decreasing postoperative periprosthetic joint infection is of the utmost importance for the total joint arthroplasty surgeon. Preoperative, perioperative, intraoperative, and postoperative measures to minimize infection and optimize patient outcomes in total joint arthroplasty are discussed. Preoperative measures include management of patients colonized by Staphylococcus aureus, nutritional optimization, and management of medical comorbidities. Perioperative measures include skin preparation and prophylactic antibiotics. Intraoperative measures include body exhaust suits, laminar flow, ultraviolet light, operating-room traffic control, surgical suite enclosures, anesthesia-related considerations, and antibiotic-loaded bone cement. Postoperative measures include continued antibiotic prophylaxis, blood transfusions, hematoma formation and wound drainage, duration of hospital stay, and antibiotic prophylaxis for future invasive procedures.

Flexion is an important outcome variable after total knee arthroplasty. Traditionally, matched implant-bone resections of the distal and posterior aspects of the femur are used to prevent loss of knee flexion or extension. However, given limited implant sizes, resection of these portions of the femur may affect the shape of the knee. Variations in the anterior aspects of the femur along with implant size constraints may increase trochlear groove height in the anterior compartment, increase the arc that the extensor mechanism must travel, and thereby decrease passive flexion. We determined the trochlear groove height change in 55 patients after primary total knee arthroplasties. The thickness of the replaced lateral and medial anterior flanges increased by 1.1 +/- 2.6 mm and 0.5 +/- 2.2 mm, respectively, whereas the change in trochlear groove thickness was 0 +/- 1.1 mm. We examined varying amounts of patellofemoral buildup in a cadaver model to observe the effect on passive range of motion of the knee. A 2-mm and 4-mm buildup of the anterior cortex resulted in flexion loss of 1.8 degrees and 4.4 degrees, respectively. The change in the shape of the anterior aspect of the femur may have small effects on flexion but they may not be clinically important.