Fred D. Cushner

Rivaroxaban versus enoxaparin for thromboprophylaxis after total knee arthroplasty (RECORD4): a randomised trial

BACKGROUND Prophylaxis for venous thromboembolism is recommended for at least 10 days after total knee arthroplasty; oral regimens could enable shorter hospital stays. We aimed to test the efficacy and safety of oral rivaroxaban for the prevention of venous thromboembolism after total knee arthroplasty. METHODS In a randomised, double-blind, phase III study, 3148 patients undergoing knee arthroplasty received either oral rivaroxaban 10 mg once daily, beginning 6-8 h after surgery, or subcutaneous enoxaparin 30 mg every 12 h, starting 12-24 h after surgery. Patients had mandatory bilateral venography between days 11 and 15. The primary efficacy outcome was the composite of any deep-vein thrombosis, non-fatal pulmonary embolism, or death from any cause up to day 17 after surgery. Efficacy was assessed as non-inferiority of rivaroxaban compared with enoxaparin in the per-protocol population (absolute non-inferiority limit -4%); if non-inferiority was shown, we assessed whether rivaroxaban had superior efficacy in the modified intention-to-treat population. The primary safety outcome was major bleeding. This trial is registered with ClinicalTrials.gov, number NCT00362232. FINDINGS The primary efficacy outcome occurred in 67 (6.9%) of 965 patients given rivaroxaban and in 97 (10.1%) of 959 given enoxaparin (absolute risk reduction 3.19%, 95% CI 0.71-5.67; p=0.0118). Ten (0.7%) of 1526 patients given rivaroxaban and four (0.3%) of 1508 given enoxaparin had major bleeding (p=0.1096). INTERPRETATION Oral rivaroxaban 10 mg once daily for 10-14 days was significantly superior to subcutaneous enoxaparin 30 mg given every 12 h for the prevention of venous thromboembolism after total knee arthroplasty. FUNDING Bayer Schering Pharma AG, Johnson & Johnson Pharmaceutical Research & Development.

Potent Anticoagulants are Associated with a Higher All-Cause Mortality Rate After Hip and Knee Arthroplasty

AbstractAnticoagulation for thromboprophylaxis after THA and TKA has not been confirmed to diminish all-cause mortality. We determined whether the incidence of all-cause mortality and pulmonary embolism in patients undergoing total joint arthroplasty differs with currently used thromboprophylaxis protocols. We reviewed articles published from 1998 to 2007 that included 6-week or 3-month incidence of all-cause mortality and symptomatic, nonfatal pulmonary embolism. Twenty studies included reported 15,839 patients receiving low-molecular-weight heparin, ximelagatran, fondaparinux, or rivaroxaban (Group A); 7193 receiving regional anesthesia, pneumatic compression, and aspirin (Group B); and 5006 receiving warfarin (Group C). All-cause mortality was higher in Group A than in Group B (0.41% versus 0.19%) and the incidence of clinical nonfatal pulmonary embolus was higher in Group A than in Group B (0.60% versus 0.35%). The incidences of all-cause mortality and nonfatal pulmonary embolism in Group C were similar to those in Group A (0.4 and 0.52, respectively). Clinical pulmonary embolus occurs despite the use of anticoagulants. Group A anticoagulants were associated with the highest all-cause mortality of the three modalities studied. Level of Evidence: Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Blood loss in total knee arthroplasty.

Over a two-year period, 112 consecutive primary total knee arthroplasties (TKA) were performed according to a standard protocol and were evaluated to determine the effects of intraoperative tourniquet deflation, suction drainage, and immediate continuous passive motion (CPM) on blood loss and the need for blood transfusions. It has been reported that these measures lead to increased morbidity following TKA. The tourniquet was deflated before closure, hemostasis was obtained, and two suction drains were placed for 24 to 48 hours. CPM was started immediately, and continued for a mean of seven days. Serial hematocrits (Hct) were obtained. Mean age of the 64 males and 48 females was 65 years. The diagnosis was osteoarthritis in 86% and rheumatoid arthritis in 14%. Seventy-three percent of the prostheses were cemented and 27% were uncemented. The mean tourniquet time was 104 minutes and the mean length of surgery was 140 minutes. Blood loss measured at surgery averaged 222 ml. Total calculated blood loss averaged 794 ml, but was higher for patients with a cemented versus uncemented prosthesis (p less than .05), and males versus females (p less than .005). It was not related to diagnosis, tourniquet time, or length of surgery. Of the 38% of patients requiring a transfusion (mean, 2.2 units), there was not a significantly greater drop in Hct (from 36.6 to 26.5; change, 10.1) when compared to patients not receiving a transfusion (from 43.1 to 32.5; change, 10.6). Therefore, the need for transfusion was related to preoperative Hct and not the intraoperative or postoperative blood loss.(ABSTRACT TRUNCATED AT 250 WORDS)

Physician compliance with guidelines for deep-vein thrombosis prevention in total hip and knee arthroplasty

ABSTRACT Objective: Despite evidence-based guidelines for venous thromboembolism (VTE) prevention after total hip or knee arthroplasty (THA/TKA), many patients may not receive effective prophylaxis. Our objective was to analyze data from the multinational Global Orthopaedic Registry (GLORY) to evaluate the compliance of surgeons with the American College of Chest Physicians (ACCP) guidelines for VTE prevention. Research design and methods: Data from 8160 patients who had undergone a primary, unilateral, elective THA (n = 3950) or TKA (n = 4210), and had at least 3 months of follow-up were analyzed. Results: Almost all patients received a form of recommended prophylaxis. Compliance with guidelines in terms of type, duration, start time, and dose was achieved for 47% of THA and 61% of TKA patients in the USA, and 62% of THA and 69% of TKA patients outside the USA. Warfarin use, mostly in the USA, was fully compliant in 33% of THA and 48% of TKA patients. Low-molecular-weight heparin use was fully compliant in 63% of THA and 72% of TKA patients in the USA, and 67% of THA and 73% of TKA patients outside the USA. Conclusion: Although almost all THA and TKA patients both inside and outside the USA received prophylaxis, a large proportion did not receive treatment in accordance with the ACCP guidelines. Our study may have overestimated the use of recommended prophylaxis as some participating investigators may have had a specific interest in VTE prophylaxis. Furthermore, although analyses were restricted to approximately three-quarters of patients who had outpatient follow-up data, their characteristics were similar to those in the entire population.

Complications of Total Knee Arthroplasty: Standardized List and Definitions of The Knee Society

BackgroundDespite the importance of complications in evaluating patient outcomes after TKA, definitions of TKA complications are not standardized. Different investigators report different complications with different definitions when reporting outcomes of TKA.Questions/purposesWe developed a standardized list and definitions of complications and adverse events associated with TKA.MethodsIn 2009, The Knee Society appointed a TKA Complications Workgroup that surveyed the orthopaedic literature and proposed a list of TKA complications and adverse events with definitions. An expert opinion survey of members of The Knee Society was used to test the applicability and reasonableness of the proposed TKA complications. For each complication, members of The Knee Society were asked “Do you agree with the inclusion of this complication as among the minimum necessary for reporting outcomes of knee arthroplasty?” and “Do you agree with this definition?”ResultsOne hundred two clinical members (100%) of The Knee Society responded to the survey. All proposed complications and definitions were endorsed by the members, and 678 suggestions were incorporated into the final work product. The 22 TKA complications and adverse events include bleeding, wound complication, thromboembolic disease, neural deficit, vascular injury, medial collateral ligament injury, instability, malalignment, stiffness, deep joint infection, fracture, extensor mechanism disruption, patellofemoral dislocation, tibiofemoral dislocation, bearing surface wear, osteolysis, implant loosening, implant fracture/tibial insert dissociation, reoperation, revision, readmission, and death.ConclusionsWe identified 22 complications and adverse events that we believe are important for reporting outcomes of TKA. Acceptance and utilization of these standardized TKA complications may improve evaluation and reporting of TKA outcomes.

Minimal Incision Total Knee Arthroplasty

Minimal incision total knee arthroplasty requires increased attention to detail to be sure that the basic principles of total knee arthroplasty are not ignored in an attempt to perform the procedure through a smaller incision. The limited dissection should allow the patient to recover with less morbidity and in a shorter period of time. The cosmetic result is appealing to patients, along with the functional improvement. Minimally invasive total knee arthroplasty is evolving, and it is hoped future clinical results will support its continued use.

Arthroscopic Examination and Treatment of the Patellofemoral Joint

The patella is the largest sesamoid bone in the body and serves the following six basic functions1: 1. Increases the moment arm of the quadriceps mechanism, improving the force of extension 25% to 30%. 2. By cartilage-to-cartilage articulation, a low coefficient of friction is established, improving quadriceps efficiency. 3. The divergent forces of the four heads of the quadriceps are centralized and there-fore are transmitted to the patellar tendon. 4. Protects the quadriceps and patellar tendon from friction. 5. Shields the articular cartilage on the anterior tibia as well as the anterior femur. 6. Serves a cosmetic function.

A Quantitative Histologic Comparison: ACL Degeneration in the Osteoarthritic Knee

Newer prosthetic total knee arthroplasty (TKA) designs as well as unicondylar TKAs spare the anterior cruciate ligament (ACL). Although success of these procedures requires near normal ACL function, little has been written about the histologic features or the arthritic ACL. This study was designed to histologically evaluate the ACL for microscopic evidence of degeneration. Nineteen ACLs were harvested from 16 different patients who underwent TKA as a result of severe osteoarthritis. Control ligaments were obtained from bone bank donors (N = 14), patients with above-knee amputations (N = 5), and cadaveric formalin-preserved knees (N = 6). Orientation was maintained for each ACL. Degenerative parameters included loose, fibrous connective tissue and myxoid and cystic occurrences, and the presence of chondroid metaplasia or calcium phosphate crystals were evaluated and scored. Forty-seven percent of the osteoarthritic group had moderate/marked degeneration, whereas no control specimen showed such changes. Seventy-two percent of the controls were considered normal, compared with only 26% of the osteoarthritic group. Both of these findings were statistically significant (P<.001). Statistical analysis revealed no gender bias either within or between groups. In the control group, no statistical difference was found between patients older than age 65 and those younger than 65. In the osteoarthritic group, however, 70% of patients younger than 65 demonstrated moderate/marked changes compared with only 22% of those older than 65 (P<.05). There also was no difference demonstrated between the 4 focal sections of the ligaments that were examined.

Long-term results of total knee arthroplasty after the use of soft tissue expanders

The success of total knee arthroplasty can be jeopardized by poor wound healing. In the current study, the results of knee arthroplasty after soft tissue expansion were reviewed retrospectively in 27 patients (29 knees) at risk for problematic healing. The incidence of wound complications was recorded for all patients after the expansion procedure and the arthroplasty. A Knee Society score also was calculated at the latest evaluation. Minor wound complications occurred after 21% (six of 29) of the tissue expansion procedures and after 18% (five of 28) of the subsequent arthroplasties. One major wound complication occurred during tissue expansion necessitating abandonment of the planned arthroplasty. No major wound complications occurred in those patients who underwent knee arthroplasty. At an average followup of 34.4 months, the average Knee Society score was 83.7 points. The results of the current study show that the technique of soft tissue expansion before total knee arthroplasty in patients at high risk for wound healing problems can successfully prevent catastrophic wound complications after the arthroplasty procedure and can avoid the need for disfiguring soft tissue reconstructions.

Intraoperative Blood Management in Joint Replacement Surgery

Interest is growing in blood conservation and avoidance of transfusion in patients undergoing orthopedic surgery, especially in the field of joint replacement. Several methods have proven successful in reducing intraoperative blood loss, which can translate into lessened allogeneic and autologous transfusion requirements. Available techniques include acute normovolemic hemodilution, hypotensive anesthesia, intraoperative blood salvage, specialized cautery, topical hemostatic agents, and pharmacologic agents given in the perioperative period. The greatest potential benefit arises in operations with greater expected blood loss or in special situations such as in patients with religious issues, bilateral joint replacement, coagulation disorders, or significant preoperative anemia.