Osteonecrosis of the femoral head may lead to progressive destruction of the hip joint. Although the etiology of osteonecrosis has not been definitely delineated, risk factors include corticosteroid ...use, alcohol consumption, trauma, and coagulation abnormalities. Size and location of the lesion are prognostic factors for disease progression and are best assessed by MRI. The efficacy of medical management of osteonecrosis with pharmacologic agents and biophysical modalities requires further investigation. Surgical management is based on patient factors and lesion characteristics. Preservation of the femoral head may be attempted in younger patients without head collapse by core decompression with vascularized bone grafts, avascular grafts, bone morphogenetic proteins, stem cells, or combinations of the above or rotational osteotomies. The optimal treatment modality has not been identified. When the femoral head is collapsed, arthroplasty is the preferred option.
Hip arthroscopy has been shown to be a successful procedure to treat young patients with labral pathology caused by femoroacetabular impingement. However, as patients age and there is an associated ...increase in hip pathology, the results become less consistent. Although some patients will have decreased symptoms, approximately 25% to 30% will require total hip arthroplasty 2 to 5 years after the procedure.
Bone loss associated with fracture nonunion, revision total joint arthroplasty (TJA), and pseudoarthrosis of the spine presents a challenging clinical scenario for the orthopaedic surgeon. Current ...treatment options including autograft, allograft, bone graft substitutes, and bone transport techniques are associated with significant morbidity, high costs, and prolonged treatment regimens. Unfortunately, these treatment strategies have proven insufficient to safely and consistently heal bone defects in the stringent biological environments often encountered in clinical cases of bone loss. The application of tissue engineering (TE) to musculoskeletal pathology has uncovered exciting potential treatment strategies for challenging bone loss scenarios in orthopaedic surgery. Regional gene therapy involves the local implantation of nucleic acids or genetically modified cells to direct specific protein expression, and has shown promise as a potential TE technique for the regeneration of bone. Preclinical studies in animal models have demonstrated the ability of regional gene therapy to safely and effectively heal critical sized bone defects which otherwise do not heal. The purpose of the present review is to provide a comprehensive overview of the current status of gene therapy applications for TE in challenging bone loss scenarios, with an emphasis on gene delivery methods and models, scaffold biomaterials, preclinical results, and future directions.
A survey was conducted at the 2023 Annual Meeting of the American Association of Hip and Knee Surgeons (AAHKS) to assess practice management strategies among current AAHKS members.
Members of AAHKS ...used an app to answer both multiple-choice and “yes or no” questions related to a variety of issues related to their practices.
The number of AAHKS members in private practice (37%) continues to decline, and 4% are now in private equity–employed practices. Fee for service (30%) and relative value units (30%) are the major forms of compensation. The number of AAHKS members that perform total joint arthroplasties at ambulatory surgery centers continues to increase, and supply chain issues (91%) remain a problem. There has been a decrease in surgeon participation in bundled payment programs and gainsharing arrangements with hospitals.
This member’s survey provides valuable information regarding practice patterns. The shift to outpatient surgery has continued. Future surveys will be performed to monitor changes in practice patterns over time.
Venous thromboembolism (VTE) prophylaxis is recommended for all patients undergoing total hip arthroplasty or total knee arthroplasty. The selection of an appropriate prophylaxis regimen represents a ...balance between efficacy and safety. To help orthopaedic surgeons select an appropriate VTE prophylaxis regimen for their patients, the American Academy of Orthopaedic Surgeons and the American College of Chest Physicians have developed guidelines. These guidelines do not recommend an optimal regimen, however. Rather, an individualized prophylaxis regimen that balances efficacy and safety is recommended for each patient, based on various risk factors. Because of a paucity of data and a lack of adequately powered head-to-head trials, implementing these guidelines can be challenging for the orthopaedic surgeon. Knowledge of the prophylaxis options and the VTE risk factors is paramount for developing an effective VTE prophylaxis algorithm for the surgeon's practice.
The selection of a regimen for venous thromboembolic prophylaxis after total joint arthroplasty is a balance between efficacy and safety. Bleeding may have a negative impact on clinical outcomes. ...Recently, both the American Academy of Orthopaedic Surgeons (AAOS) and the American College of Chest Physicians (ACCP) developed new evidence-based guidelines for venous thromboembolic prophylaxis after total joint arthroplasty. On the basis of a review of the available literature, the AAOS guideline panel was unable to make a recommendation with respect to the selection of a specific prophylaxis regimen or duration of prophylaxis following routine total joint arthroplasty. The ACCP panel recommended one of the following modalities as prophylaxis (rather than no prophylaxis at all) for a minimum of fourteen days: warfarin, low-molecular-weight heparin, fondaparinux, aspirin, rivaroxaban, dabigatran, apixaban, or portable mechanical compression. Both the AAOS and the ACCP guidelines recommended against screening with postoperative duplex ultrasonography at the time of discharge after routine total joint arthroplasty. There is renewed interest in the use of mechanical compression as prophylaxis with the advent of portable compression devices, which allow continuation of this type of prophylaxis after hospital discharge. Although the early data are promising, appropriately powered randomized trials are needed to determine the efficacy of the devices compared with other prophylaxis regimens.
We investigated the efficacy of rivaroxaban, an orally active direct factor Xa inhibitor, in preventing venous thrombosis after total knee arthroplasty.
In this randomized, double-blind trial, 2531 ...patients who were to undergo total knee arthroplasty received either oral rivaroxaban, 10 mg once daily, beginning 6 to 8 hours after surgery, or subcutaneous enoxaparin, 40 mg once daily, beginning 12 hours before surgery. The primary efficacy outcome was the composite of any deep-vein thrombosis, nonfatal pulmonary embolism, or death from any cause within 13 to 17 days after surgery. Secondary efficacy outcomes included major venous thromboembolism (i.e., proximal deep-vein thrombosis, nonfatal pulmonary embolism, or death related to venous thromboembolism) and symptomatic venous thromboembolism. The primary safety outcome was major bleeding.
The primary efficacy outcome occurred in 79 of 824 patients (9.6%) who received rivaroxaban and in 166 of 878 (18.9%) who received enoxaparin (absolute risk reduction, 9.2%; 95% confidence interval CI, 5.9 to 12.4; P<0.001). Major venous thromboembolism occurred in 9 of 908 patients (1.0%) given rivaroxaban and 24 of 925 (2.6%) given enoxaparin (absolute risk reduction, 1.6%; 95% CI, 0.4 to 2.8; P=0.01). Symptomatic events occurred less frequently with rivaroxaban than with enoxaparin (P=0.005). Major bleeding occurred in 0.6% of patients in the rivaroxaban group and 0.5% of patients in the enoxaparin group. The incidence of drug-related adverse events, mainly gastrointestinal, was 12.0% in the rivaroxaban group and 13.0% in the enoxaparin group.
Rivaroxaban was superior to enoxaparin for thromboprophylaxis after total knee arthroplasty, with similar rates of bleeding. (ClinicalTrials.gov number, NCT00361894.)
Post-arthroplasty infections represent a devastating complication of total joint replacement surgery, resulting in multiple reoperations, prolonged antibiotic use, extended disability and worse ...clinical outcomes. As the number of arthroplasties in the U.S. will exceed 3.8 million surgeries per year by 2030, the number of post-arthroplasty infections is projected to increase to over 266,000 infections annually. The treatment of these infections will exhaust healthcare resources and dramatically increase medical costs.
To evaluate novel preventative therapeutic strategies against post-arthroplasty infections, a mouse model was developed in which a bioluminescent Staphylococcus aureus strain was inoculated into a knee joint containing an orthopaedic implant and advanced in vivo imaging was used to measure the bacterial burden in real-time. Mice inoculated with 5x10(3) and 5x10(4) CFUs developed increased bacterial counts with marked swelling of the affected leg, consistent with an acute joint infection. In contrast, mice inoculated with 5x10(2) CFUs developed a low-grade infection, resembling a more chronic infection. Ex vivo bacterial counts highly correlated with in vivo bioluminescence signals and EGFP-neutrophil fluorescence of LysEGFP mice was used to measure the infection-induced inflammation. Furthermore, biofilm formation on the implants was visualized at 7 and 14 postoperative days by variable-pressure scanning electron microscopy (VP-SEM). Using this model, a minocycline/rifampin-impregnated bioresorbable polymer implant coating was effective in reducing the infection, decreasing inflammation and preventing biofilm formation.
Taken together, this mouse model may represent an alternative pre-clinical screening tool to evaluate novel in vivo therapeutic strategies before studies in larger animals and in human subjects. Furthermore, the antibiotic-polymer implant coating evaluated in this study was clinically effective, suggesting the potential for this strategy as a therapeutic intervention to combat post-arthroplasty infections.
Background
Although surgeons use many procedures to preserve the femoral head in patients with hip osteonecrosis, there is no consensus regarding the best procedure.
Questions/purposes
We raised the ...following questions: (1) Is one surgical treatment preferred based on published data? (2) What are the rates of radiographic progression or conversion to THA after treatment of pre- and postcollapse hips? (3) Does lesion size in the femoral head influence progression? And (4) does the extent of involvement of the weightbearing surface of the femoral head influence outcome?
Methods
We searched MEDLINE and Scopus for articles published between 1998 and 2010. We included only articles assessing an operative intervention for hip osteonecrosis and having a level of evidence of I to IV. We included 54 of the 488 reviewed manuscripts.
Results
No procedure was superior to others. In pre- and postcollapse hips, 264 of 864 hips (31%) and 419 of 850 hips (49%), respectively, exhibited radiographic disease progression. There were lower failure rates when the lesion involved less than 15% of the femoral head or had a necrotic angle of less than 200° (14%–25%) and when the osteonecrotic lesion involved only the medial 1/3 of the weightbearing surface (4.6%).
Conclusions
The best treatment of precollapse lesions is difficult to determine due to the limitations of the available literature. However, the data suggest operative intervention prevents collapse of small lesions of the femoral head or when there is a limited amount of the weightbearing surface involved. Patients with head collapse have a high progression rate after a femoral head-saving procedure.
The selection of a prophylaxis regimen to prevent symptomatic pulmonary embolism and deep vein thrombosis is a balance between efficacy and safety. The latest American Academy of Orthopaedic Surgeons ...guideline recommended that either chemoprophylaxis or mechanical prophylaxis be used after total joint arthroplasty but did not recommend specific agents. However, the latest evidence-based American College of Chest Physicians guideline recommended a variety of chemoprophylaxis and mechanical agents for a minimum of 10 to 14 days after total joint arthroplasty. Risk stratification is the key to the selection of the appropriate prophylaxis regimen for the individual patient, but the optimal risk stratification protocol still needs to be developed.
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