Radiation-crosslinked UHMWPE has been used for joint implants since the 1990s. Postirradiation remelting enhances oxidative stability, but with some loss in strength and toughness. Vitamin E-stabilized crosslinked UHMWPE has shown improved strength and stability as compared with irradiated and remelted UHMWPE. With more active phenolic hydroxyl groups, natural polyphenols are widely used in the food and pharmaceutical industries as potent stabilizers and could be useful for oxidative stability in crosslinked UHMWPE.
Cochrane in CORR
Does Intraoperative Navigation Assistance Improve Bone Tumor Resection and Allograft Reconstruction Results?
Bone tumor resections for limb salvage have become standard treatment. Recently, computer-assisted navigation has been introduced to improve the accuracy of joint arthroplasty and possible tumor resection surgery; however, like with any new technology, its benefits and limitations need to be characterized for surgeons to make informed decisions about whether to use it.
Should Fractures in Massive Intercalary Bone Allografts of the Lower Limb Be Treated With ORIF or With a New Allograft?
Massive bone allografts have been used for limb salvage of bone tumor resections as an alternative to endoprostheses, although they have different outcomes and risks. There is no general consensus about when to use these alternatives, but when it is possible to save the native joints after the resection of a long bone tumor, intercalary allografts offer some advantages despite complications, such as fracture. The management and outcomes of this complication deserve more study.
The majority of published functional outcome data for tumor megaprostheses comes in the form of subjective functional outcome scores. Sparse objective data exist demonstrating functional results, activity levels, and efficiency of gait after endoprosthetic reconstruction in patients treated for orthopaedic tumors. Patients embarking on massive surgical operations, often in the setting of debilitating medical therapies, face mortality and a myriad of unknowns. Objective functional outcomes provide patients with reasonable expectations and a means to envision life after treatment. Objective outcomes also provide a means for surgeons to compare techniques, rehabilitation protocols, and implants.
Prosthetic replacement is the most commonly used option for reconstruction of osteoarticular bone loss resulting from bone neoplasm resection or prosthetic failure. Starting in late 2001, we began exclusively using a single system for large-segment osteoarticular reconstruction after tumor resection; to our knowledge, there are no published series from one center evaluating the use of this implant.
Frequent Complications and Severe Bone Loss Associated With the Repiphysis Expandable Distal Femoral Prosthesis
The treatment of choice for distal femur malignancies in skeletally immature patients remains controversial. An expandable endoprosthesis device (Repiphysis Limb Salvage System; Wright Medical Technology, Arlington, TN, USA) allows for limb preservation and noninvasive lengthening but has been associated with significant complications; however, the extent and implications of bone loss associated with this implant have not been reported.
Do Patients With Ewing’s Sarcoma Continue With Sports Activities After Limb Salvage Surgery of the Lower Extremity?
Limb salvage surgery has evolved to become the standard method of treating sarcomas of the extremities with acceptable oncologic results. However, little information exists relative to the activity level or ability to participate in sports after tumor reconstructions.
What Sports Activity Levels Are Achieved in Patients With Modular Tumor Endoprostheses of Osteosarcoma About the Knee?
Advances in multimodal treatment have improved survival of patients with nonmetastatic osteosarcoma. At the same time, implant design has improved the outcomes of limb salvage with modular endoprostheses. However, little is known about sports activity in long-term survivors with osteosarcoma.
Multilevel En Bloc Spondylectomy for Tumors of the Thoracic and Lumbar Spine Is Challenging But Rewarding
Over the years, en bloc spondylectomy has proven its efficacy in controlling spinal tumors and improving survival rates. However, there are few reports of large series that critically evaluate the results of multilevel en bloc spondylectomies for spinal neoplasms.
What Is the Use of Imaging Before Referral to an Orthopaedic Oncologist? A Prospective, Multicenter Investigation
Patients often receive advanced imaging before referral to an orthopaedic oncologist. The few studies that have evaluated the value of these tests have been single-center studies, and there were large discrepancies in the estimated frequencies of unnecessary use of diagnostic tests.
There are several options for proximal humerus reconstruction in young children after resection of a malignant tumor and no one technique has been definitively shown to be superior to others, leaving the decision to surgeon and patient choice. Claviculo pro humeri (CPH) is a biologic reconstruction of the proximal humerus using the patient’s ipsilateral clavicle as a rotational osseous flap. CPH represents a potential option for this complicated clinical problem in very young children, but little is known about it because the indications for its use are so uncommon.
What Are the 5-year Survivorship Outcomes of Compressive Endoprosthetic Osseointegration Fixation of the Femur?
Aseptic complications such as stress shielding leading to bone loss are major problems associated with revision of cemented and uncemented long-stem tumor endoprostheses. Endoprosthetic reconstruction using compressive osseointegration fixation is a relatively new limb salvage technology designed to enhance osseointegration, prevent stress shielding, and provide fixation for short end-segments.
Survival of Modern Knee Tumor Megaprostheses: Failures, Functional Results, and a Comparative Statistical Analysis
Modular megaprostheses are now the most common method of reconstruction after segmental resection of the long bones in the lower extremities. Previous studies reported variable outcome and failure rates after knee megaprosthetic reconstructions.
Does Competing Risk Analysis Give Useful Information About Endoprosthetic Survival in Extremity Osteosarcoma?
Conventional survival analysis for endoprosthetic complications does not consider competing events adequately. Patients who die of their disease are no longer at risk for complications; therefore, death as a competing event may alter survivorship estimates in the orthopaedic-oncological setting.
Systemic treatments to prevent or treat chondrosarcoma metastasis are lacking and targeted therapy has yet to be developed. Hypoxia develops in tumors as they grow and hypoxia-related alterations in gene expression underlie some of the traits of cancer. One critical trait is the ability to induce sustained angiogenesis, which is usually related to expression of vascular endothelial growth factor (VEGF). A potential hypoxia-related mechanism resulting in altered gene expression involves microRNA. Little is known about microRNA expression in chondrosarcoma and its potential role in regulation of VEGF expression.
Does Total Humeral Endoprosthetic Replacement Provide Reliable Reconstruction With Preservation of a Useful Extremity?
Controversy exists regarding the ideal method of reconstruction after proximal humeral resection and several reconstructive techniques have been reported. The reconstructive options are very limited when resection of the entire humerus is required. One option is endoprosthetic reconstruction, but there have been few published studies on the outcome of total humeral endoprosthetic reconstruction.
Biofilm-related periprosthetic infections are catastrophic to patients and clinicians. Data suggest the addition of vitamin E to UHMWPE may have the ability to reduce biofilm formation on the surface of UHMWPE; however, previous studies were performed using stagnant broth solutions that may not have simulated a physiologic environment. In addition, the observed differences in levels of bacterial attachment, though statistically significant, may not be clinically significant.
A Comparison of the Efficacy of Various Antioxidants on the Oxidative Stability of Irradiated Polyethylene
Ultrahigh-molecular-weight polyethylene (UHMWPE) is subjected to radiation crosslinking to form highly crosslinked polyethylene (HXLPE), which has improved wear resistance. First-generation HXLPE was subjected to thermal treatment to reduce or quench free radicals that can induce long-term oxidative degeneration. Most recently, antioxidants have been added to HXLPE to induce oxidative resistance rather than by thermal treatment. However, antioxidants can interfere with the efficiency of radiation crosslinking.
Multidirectional Wear and Impact-to-wear Tests of Phospholipid-polymer-grafted and Vitamin E-blended Crosslinked Polyethylene: A Pilot Study
Modifying the surface and substrate of a crosslinked polyethylene (CLPE) liner may be beneficial for high wear resistance as well as high oxidative stability and excellent mechanical properties, which would be useful in contributing to the long-term performance of orthopaedic bearings. A grafted poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) layer on a vitamin E-blended crosslinked PE (HD-CLPE[VE]) surface may provide hydrophilicity and lubricity without compromising the oxidative stability or mechanical properties.
Spectroscopic and Chromatographic Quantification of an Antioxidant-stabilized Ultrahigh-molecular-weight Polyethylene
The oxidative stability of various antioxidant-containing ultrahigh-molecular-weight polyethylene (UHMWPE) formulations has been widely reported. Depending on which specific antioxidant is used, the process by which it is incorporated into UHMWPE, and the amount of the antioxidant incorporated, there could be substantial differences in the material and toxicological properties of the UHMWPE formulation. Pentaerythritol tetrakis (3-[3,5-di tertiary butyl-4-hydroxyphenyl] propionate) (PBHP) has been extensively used as an efficient antioxidant in various applications. However, it has not thus far been used to stabilize UHMWPE in orthopaedic implants. It is therefore important to characterize and verify the concentration and homogeneity of distribution of PBHP in the composition, the chemical consequence of exposure of the antioxidant to gamma irradiation, and to assess the toxicological risk of use by the identification and quantification of leachables before the use of PBHP-containing UHMWPE in implantable devices.
Retrieval Analysis of Sequentially Annealed Highly Crosslinked Polyethylene Used in Total Hip Arthroplasty
First-generation annealed and second-generation sequentially annealed, highly crosslinked polyethylenes (HXLPEs) have documented reduced clinical wear rates in their first decade of clinical use compared with conventional gamma inert-sterilized polyethylene. However, for both types of annealed HXLPE formulations, little is known about their reasons for revision, their in vivo oxidative stability, and their resistance to mechanical degradation.
Do Crosslinking and Vitamin E Stabilization Influence Microbial Adhesions on UHMWPE-based Biomaterials?
Microorganism adhesion on polyethylene for total joint arthroplasty is a concern. Many studies have focused on vitamin E-stabilized ultrahigh-molecular-weight polyethylene (UHMWPE), whereas first-generation, highly crosslinked UHMWPE, which is the most commonly used in clinical practice, has been scarcely evaluated.
UHMWPE Wear Debris and Tissue Reactions Are Reduced for Contemporary Designs of Lumbar Total Disc Replacements
Lumbar total disc replacement (L-TDR) is a procedure used to relieve back pain and maintain mobility. Contemporary metal-on-polyethylene (MoP) L-TDRs were developed to address wear performance concerns about historical designs, but wear debris generation and periprosthetic tissue reactions for these newer implants have not been determined.
Is There a Difference in Total Knee Arthroplasty Risk of Revision in Highly Crosslinked versus Conventional Polyethylene?
Highly crosslinked polyethylene (HXLPE) was introduced to reduce wear and associated osteolysis in total knee arthroplasty (TKA). However, there is limited clinical evidence that HXLPE is more effective than conventional polyethylene (CPE) in TKA.
Metal-on-conventional Polyethylene Total Hip Arthroplasty Bearing Surfaces Have a Higher Risk of Revision Than Metal-on-highly Crosslinked Polyethylene: Results From a US Registry
Although studies have reported lower radiological wear in highly crosslinked polyethylene (HXLPE) versus conventional polyethylene in total hip arthroplasty (THA), there is limited clinical evidence on the risk of revision of these polyethylene THA bearing surfaces.
Minimizing the impact of oxidation on ultrahigh-molecular-weight polyethylene components is important for preserving their mechanical integrity while in vivo. Among the strategies to reduce oxidation in modern first-generation highly crosslinked polyethylenes (HXLPEs), postirradiation remelting was considered to afford the greatest stability. However, recent studies have documented measurable oxidation in remelted HXLPE retrievals. Biologic prooxidants and physiologic loading have been proposed as potential mechanisms.
Injury Risk to Extraosseous Knee Vasculature During Osteotomies: A Cadaveric Study With CT and Dissection Analysis
Realignment osteotomies about the knee may be performed as distal femoral or proximal tibial osteotomies; both may be performed either on the medial or lateral sides of the knee, in closing- or opening-wedge fashion. Although rare, injury to neurovascular structures may occur, and the proximity of the vascular structures to the osteotomy saw cuts has been incompletely characterized.
Diabetes Confers Little to No Increased Risk of Postoperative Complications After Hip Fracture Surgery in Geriatric Patients
Diabetes and hip fractures in geriatric patients are common, and many elderly patients have a history of diabetes. However, the influence of diabetes on surgical complications may vary based on which particular type of diabetes a patient has. To our knowledge, no prior study has stratified patients with diabetes to compare patients with noninsulin-dependent and insulin-dependent diabetes regarding rates of postoperative adverse events, length of hospitalization, and readmission rate after surgical stabilization of hip fractures in geriatric patients.
Hip Arthroscopy in the Setting of Hip Osteoarthritis: Systematic Review of Outcomes and Progression to Hip Arthroplasty
Hip arthroscopy is now commonly used to treat hip pain and pathology, including osteoarthritis (OA). Despite this, little is known about the effect of hip arthroscopy on outcomes of pain and function and progression to total hip arthroplasty (THA) in hip OA.
Topical Tranexamic Acid Does Not Affect Electrophysiologic or Neurovascular Sciatic Nerve Markers in an Animal Model
Tranexamic acid is a safe and effective antifibrinolytic agent used systemically and topically to reduce blood loss and transfusion rate in patients having TKA or THA. As the hip does not have a defined capsule, topical application of tranexamic acid may entirely envelop the sciatic nerve during THA. Accidental application of tranexamic acid onto the spinal cord in spinal anesthesia has been shown to produce seizures; therefore, we sought to investigate if topical application of tranexamic acid on the sciatic nerve has a deleterious effect.
Surgeons perform THA to address a variety of conditions in younger patients, including osteoarthritis (OA), osteonecrosis, inflammatory arthritis, and congenital deformities. Younger patients aged 50 years or younger have been characterized as active in the literature, but a direct relationship between age and activity level has not been well substantiated. Younger patients with OA may engage in higher activity levels; however, associated medical conditions in patients with other surgical indications may not support a generalization that age is a surrogate for activity level. We recently evaluated these issues in younger patients undergoing total knee arthroplasty (TKA) and noted that the majority would not be considered active. Given this observation, we considered whether younger patients undergoing THA are characterized by high activity levels, which is relevant to understanding the long-term risk of wear-related failures.
Does Nonsurgical Treatment Improve Longitudinal Outcomes of Lateral Epicondylitis Over No Treatment? A Meta-analysis
Lateral epicondylitis is a painful tendinopathy for which several nonsurgical treatment strategies are used. Superiority of these nonsurgical treatments over nontreatment has not been definitively established.
Medical Services and Associated Costs Vary Widely Among Surgeons Treating Patients With Hand Osteoarthritis
There are substantial variations in medical services that are difficult to explain based on differences in pathophysiology alone. The scale of variation and the number of people affected suggest substantial potential to lower healthcare costs with the reduction of practice variation. Our study assessed practice variation across three affiliated urban sites in one city in the United States and related healthcare costs following the diagnosis of hand osteoarthritis (OA) in patients.
Carpal tunnel syndrome is a common compressive neuropathy of the median nerve. The efficacy and safety of endoscopic versus open carpal tunnel release remain controversial.
Morbidity and Readmission After Open Reduction and Internal Fixation of Ankle Fractures Are Associated With Preoperative Patient Characteristics
Ankle fractures are common and can be associated with severe morbidity. Risk factors for short-term adverse events and readmission after open reduction and internal fixation (ORIF) of ankle fractures have not been fully characterized.
Patients who leave the hospital against medical advice are at risk for readmission and for a variety of complications and are likely to consume more healthcare resources. However, little is known about which factors, if any, may be associated with self-discharge (discharge against medical advice) among orthopaedic inpatients.
Osteoporotic bone brings unique challenges to orthopaedic surgery, including a higher likelihood of problematic screw stripping in cancellous bone. Currently, there are limited options to satisfactorily repair stripped screws. Additionally, nonstripped screws hold with less purchase in osteoporotic bone.
Corticosteroids are a common, short-term, local antiinflammatory and analgesic for treating patients with musculoskeletal disorders. Studies have shown the deleterious effects of corticosteroids on chondrocytes, suggesting a potentiation of degenerative joint disease. Mesenchymal stem cells (MSCs) are the direct progenitors of chondrocytes and other musculoskeletal tissue. Additionally, they serve an important antiinflammatory role, which can combat the chronic inflammatory state that mediates degenerative joint disease. Little is known about how corticosteroids interact with this regenerative and reparative cell population.