Volume 11-4, Winter 2002

A worldwide phase III program, consisting of four randomized, double-blind trials in patients undergoing surgery for hip fracture, in elective hip replacement surgery patients and in elective major knee surgery patients, was conducted to compare the benefit-to-risk ratio of a subcutaneous 2.5-mg oncedaily regimen of fondaparinux, a synthetic selective factor Xa inhibitor, starting postoperatively with enoxaparin in preventing venous thromboembolism. The overall incidence of venous thromboembolism up to day 11 was reduced from 13.7% in the enoxaparin group to 6.8% in the fondaparinux group with a common odds reduction of 55.2% in favor of fondaparinux (95% confidence interval: 45.8–63.1%, p D 10
17). This superior efficacy of fondaparinux was also demonstrated for proximal deep vein thrombosis with a reduction of 57.4%. The overall incidence of clinically relevant bleeding was low and did not differ between the two groups. The benefit of fondaparinux was consistent across all types of surgery and all subgroups. (Journal of the Southern Orthopaedic Association 11(4):182–188, 2002) Key words: fondaparinux, meta-analysis, orthopaedic surgery, prophylaxis, venous thromboembolism

Thrombosis prophylaxis in orthopedic surgery is an important consideration in order to avoid the morbidity and mortality of venous thromboembolism (VTE). Patients who do not receive prophylaxis, or receive inadequate prophylaxis, may be at risk for clinical or fatal pulmonary emboli, and a fatality, although rare, may be the first sign of a VTE. Although the surgeon may have corrected the patient’s orthopedic problem, a symptomatic or asymptomatic venous thrombosis may become a new threat to the patient’s quality of life. This problem places such patients at risk for recurrent VTE, as well as post-thrombotic syndrome, a progressive, lifelong disability. Methods of prophylaxis that prevent the most clots result in the fewest venous thromboembolic events, but no one method of prophylaxis is suitable for all patients. In order to select the appropriate modality, a careful risk assessment of each patient is necessary. Those at low or moderate risk levels do not require the same modalities that may be used in a patient with a previous history of thrombosis or with many risk factors. The purpose of this brief review is to examine the complications associated with venous thromboembolism and to discuss, in detail, the risk of thrombosis in orthopedic patients. In addition, thrombosis prophylaxis modalities are discussed and suggestions made based on current Chest Consensus Guidelines and FDA-approved products. (Journal of the Southern Orthopaedic Association 11(4):190–196, 2002) Key words: hip fracture, thrombosis prophylaxis, total joint replacement

Traditional anticoagulant drugs including vitamin K antagonists and heparins have several limitations. Despite their use, the burden of venous thromboembolism remains high, particularly in patients undergoing major orthopedic surgery. A new strategy for the design of new antithrombotic drugs is based on selective inhibition of a specific coagulation factor. Fondaparinux is a synthetic selective inhibitor of factor Xa, which is critically positioned at the start of the common pathway of the coagulation system. Its pharmacokinetic profile allows for once-daily administration without the need for laboratory monitoring or dose adjustment. Fondaparinux has demonstrated its efficacy compared to a widely used low-molecular-weight heparin in a number of thromboprophylaxis trials after major orthopedic surgery and is approved for use in this setting. (Journal of the Southern Orthopaedic Association 11(4):197–202, 2002) Key words: anticoagulants, factor Xa, fondaparinux, thromboprophylaxis, venous thromboembolism

Fractures of the proximal femur include fractures of the head, neck, intertrochanteric, and subtrochanteric regions. Head fractures commonly accompany dislocations. Neck fractures and intertrochanteric fractures occur with greatest frequency in elderly patients with a low bone mineral density and are produced by low-energy mechanisms. Subtrochanteric fractures occur in a predominantly strong cortical osseous region which is exposed to large compressive stresses. Implants used to address these fractures must be able to accommodate significant loads while the fractures consolidate. Complications secondary to these injuries produce significant morbidity and include infection, nonunion, malunion, decubitus ulcers, fat emboli, deep venous thrombosis, pulmonary embolus, pneumonia, myocardial infarction, stroke, and death. (Journal of the Southern Orthopaedic Association 11(4):203–212, 2002) Key words: femoral head fracture, hip fractures, intracapsular fractures of the hip, intertrochanteric fractures, proximal femoral fractures, subtrochanteric fractures

‘‘Minimally invasive’’ total hip replacement has been promoted in the popular media and advertising despite a lack of peer-reviewed data. This article presents the author’s early experience and preliminary outcomes with this new and potentially useful approach to total hip replacement. (Journal of the Southern Orthopaedic Association 11(4):213–217, 2002) Key words: hip replacement, minimal incision, outcomes

In the early 1970s, the condylar knee was developed independently in the United States and overseas. The concept of replacing the tibiofemoral condylar surfaces with cemented fixation, along with preservation of the cruciate ligaments, was developed and refined. To correct severe knee deformities, the condylar knee with posterior cruciate-sacrificing design was introduced, also in the early 1970s. By 1974, replacing the patellofemoral joint and either preserving or sacrificing the cruciate ligaments had become standard practice. Subsequently, condylar knee designs were improved to include modularity and noncemented fixation, with use of universal instrumentation. Today, over 19 companies in the United States distribute total knee implants of three different types: cruciate-preserving, cruciate-substituting, and TC-III. Six major companies are actively involved in designing mobile-bearing knees. Future developments, such as navigation-guided surgery, enhanced kinematics, and wear-resistant bearing surfaces with better fixation, promise a consistent evolution for the total knee replacement. (Journal of the Southern Orthopaedic Association 11(4):218–226, 2002) Key words: cemented fixation, condylar knee, cruciate-preserving, cruciate-substituting, mobile-bearing knee, modularity, noncemented fixation, TC-III

In 28 of 1656 total knee arthroplasties (TKAs) (1.7%) performed for osteoarthritis at this institution, the preoperative arc of motion was 60° or less (average 47.5°; range, 20–60°). The outcome of 22 of the 28 TKAs (21 patients) is reported at a mean follow-up of 52.9 months (range, 24–144 months). Eighty-two percent of the cases were managed with standard soft-tissue releases and posterior cruciate-retaining implants and 18% with a cruciate-substituting design. The joint score rose from 28.8 to 82.2 and the Knee Society Score from 24.6 to 77 points. The mean postoperative arc of motion improved by 46° –93.5°. At latest follow-up, 68.2% of knees achieved maximal flexion of 90° or more. Manipulation was performed in 22.7%. Complications were minimal. A functionally useful range of motion is possible after total knee arthroplasty in the majority of stiff osteoarthritic knees, often without the need for posterior cruciate substitution. (Journal of the Southern Orthopaedic Association 11(4):227–230, 2002) Key words: knee arthroplasty, osteoarthritis, range of motion, stiff knee