Clinical Orthopaedics and Related Research ®

A Publication of The Association of Bone and Joint Surgeons ®

Basic Research 169 articles


Do Crosslinking and Vitamin E Stabilization Influence Microbial Adhesions on UHMWPE-based Biomaterials?

Giuliana Banche PhD, Pierangiola Bracco PhD, Valeria Allizond PhD, Alessandro Bistolfi MD, Michele Boffano MD, Andrea Cimino MD, Elena Maria Brach del Prever MD, Anna Maria Cuffini PhD

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.

rhPDGF-BB Promotes Early Healing in a Rat Rotator Cuff Repair Model

David Kovacevic MD, Lawrence V. Gulotta MD, Liang Ying DVM, John R. Ehteshami MD, Xiang-Hua Deng MD, Scott A. Rodeo MD

Tendon-bone healing after rotator cuff repair occurs by fibrovascular scar tissue formation, which is weaker than a normal tendon-bone insertion site. Growth factors play a role in tissue formation and have the potential to augment soft tissue healing in the perioperative period.

Multidirectional Wear and Impact-to-wear Tests of Phospholipid-polymer-grafted and Vitamin E-blended Crosslinked Polyethylene: A Pilot Study

Masayuki Kyomoto PhD, Toru Moro MD, Yoshio Takatori MD, Sakae Tanaka MD, Kazuhiko Ishihara PhD

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.

Is There Material Loss at the Backside Taper in Modular CoCr Acetabular Liners?

Matthias T. Agne, Richard J. Underwood PhD, Sevi B. Kocagoz BS, Daniel W. MacDonald MS, Judd S. Day PhD, Javad Parvizi MD, Matthew J. Kraay MS, MD, Michael A. Mont MD, Gregg R. Klein MD, Harold E. Cates MD, Steven M. Kurtz PhD

Metal wear and corrosion products generated by hip replacements have been linked to adverse local tissue reactions. Recent investigations of the stem/head taper junction have identified this modular interface as another possible source of metal debris; however, little is known regarding other modular metallic interfaces, their ability to produce metal debris, and possibly to provide insight in the mechanisms that produce metal debris.

Can High-friction Intraannular Material Increase Screw Pullout Strength in Osteoporotic Bone?

Daniel Bronsnick MD, Ryan E. Harold BS, Ari Youderian MD, Giovanni Solitro PhD, Farid Amirouche PhD, Benjamin Goldberg MD

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.

A Comparison of the Efficacy of Various Antioxidants on the Oxidative Stability of Irradiated Polyethylene

Natalie Hope MBBS, MA(Cantab), MRCS, Anuj Bellare PhD

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.

Differential Cytotoxicity of Corticosteroids on Human Mesenchymal Stem Cells

Cody C. Wyles BS, Matthew T. Houdek MD, Saranya P. Wyles BA, Eric R. Wagner MD, Atta Behfar MD, PhD, Rafael J. Sierra MD

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.

Muscle Fibers are Injured at the Time of Acute and Chronic Rotator Cuff Repair

Max E. Davis BA, Patrick L. Stafford BS, Matthew J. Jergenson, Asheesh Bedi MD, Christopher L. Mendias PhD, ATC

Rotator cuff tears are a common source of shoulder pain and disability. Even after surgical repair, some patients continue to have reduced function and progression of fatty degeneration. Because patients with chronic cuff tears often experience muscle shortening, it is possible that repairing the tendon to its anatomic footprint induces a stretch-induced muscle injury that could contribute to failures of the repair and perhaps ongoing pain.

Natural Polyphenols Enhance Stability of Crosslinked UHMWPE for Joint Implants

Jie Shen MEng, Guorong Gao MEng, Xincai Liu PhD, Jun Fu PhD

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.

Vancomycin-bearing Synthetic Bone Graft Delivers rhBMP-2 and Promotes Healing of Critical Rat Femoral Segmental Defects

Jordan D. Skelly ME, Jeffrey Lange MD, Tera M. Filion PhD, Xinning Li MD, David C. Ayers MD, Jie Song PhD

Bone grafts simultaneously delivering therapeutic proteins and antibiotics may be valuable in orthopaedic trauma care. Previously, we developed a poly(2-hydroxyethyl methacrylate)-nanocrystalline hydroxyapatite (pHEMA-nHA) synthetic bone graft that, when preabsorbed with 400-ng rhBMP-2/7, facilitated the functional repair of critical-size rat femoral defects. Recently, we showed that pHEMA-nHA effectively retains/releases vancomycin and rhBMP-2 in vitro. The success of such a strategy requires that the incorporation of vancomycin does not compromise the structural integrity of the graft nor its ability to promote bone healing.