Clinical Orthopaedics and Related Research ®

A Publication of The Association of Bone and Joint Surgeons ®

Basic Research 169 articles


What Are the Biomechanical Effects of Half-pin and Fine-wire Configurations on Fracture Site Movement in Circular Frames?

Daniel J. Henderson FRCS (Orth), Jeremy L. Rushbrook FRCS (Orth), Todd D. Stewart PhD, Paul J. Harwood FRCS (Orth)

Fine-wire circular frame (Ilizarov) fixators are hypothesized to generate favorable biomechanical conditions for fracture healing, allowing axial micromotion while limiting interfragmentary shear. Use of half-pins increases fixation options and may improve patient comfort by reducing muscle irritation, but they are thought to induce interfragmentary shear, converting beam-to-cantilever loading. Little evidence exists regarding the magnitude and type of strain in such constructs during weightbearing.

Does Sclerostin Depletion Stimulate Fracture Healing in a Mouse Model?

Mohammad M. Alzahrani MD, MSc, Frank Rauch MD, Reggie C. Hamdy MB, MSc(Ortho), FRCS(C)

Sclerostin is a secreted glycoprotein that inhibits the intracellular Wnt signaling pathway, which, when inactivated, stimulates bone formation. This has been seen in fracture studies, which have shown larger and stronger calluses with accelerated fracture healing in sclerostin knockout and sclerostin antibody injection models. However, the effects of these two mechanisms have not been compared in the context of fracture healing.

Gamma Radiation Sterilization Reduces the High-cycle Fatigue Life of Allograft Bone

Anowarul Islam MS, Katherine Chapin BS, Emily Moore BS, Joel Ford MD, Clare Rimnac PhD, Ozan Akkus PhD

Sterilization by gamma radiation impairs the mechanical properties of bone allografts. Previous work related to radiation-induced embrittlement of bone tissue has been limited mostly to monotonic testing which does not necessarily predict the high-cycle fatigue life of allografts in vivo.

Transcriptional Profiling Identifies the Signaling Axes of IGF and Transforming Growth Factor-β as Involved in the Pathogenesis of Osteosarcoma

Rui Yang MD, Sajida Piperdi MS, Yue Zhang PhD, Wei Zhu PhD, Neophytos Neophytou PhD, Bang H. Hoang MD, Gary Mason MD, David Geller MD, Howard Dorfman MD, Paul A. Meyers MD, John H. Healey MD, Donald G. Phinney PhD, Richard Gorlick MD

Osteosarcoma is the most common primary bone tumor in adolescents associated with skeletal development. The molecular pathogenesis of osteosarcoma has not been completely determined, although many molecular alterations have been found in human osteosarcomas and cell lines.

Allogeneic and Autogenous Bone Grafts Are Affected by Historical Donor Environmental Exposure

Caleb Behrend MD, Jonathon Carmouche MD, Paul W. Millhouse MD, Lauren Ritter MPH, Joseph Moskal MD, Paul Rubery MD, Edward Puzas PhD

Bone graft materials are routinely evaluated for infectious agents; however, data regarding contamination of bone graft from environmental exposure of the donors to osteotoxic substances such as lead are not routinely available. In animal models, stored lead in bone has been shown to impair fracture healing and osteocyte function. In clinical studies, lead is linked to skeletal disease at relatively low concentrations. Presumably the levels of lead in allografts mirror the level of lead in bone in the population; however, the degree to which processing might decrease this and the frequency with which potentially osteotoxic levels appear in bone grafts have not been studied.

Can Near-infrared Spectroscopy Detect and Differentiate Implant-associated Biofilms?

John E. Tidwell MD, Ben Dawson-Andoh PhD, Emmanuel O. Adedipe PhD, Kofi Nkansah MS, Matthew J. Dietz MD

Established bacterial diagnostic techniques for orthopaedic-related infections rely on a combination of imperfect tests that often can lead to negative culture results. Spectroscopy is a tool that potentially could aid in rapid detection and differentiation of bacteria in implant-associated infections.

Prevalence and Risk Factors of Spine, Shoulder, Hand, Hip, and Knee Osteoarthritis in Community-dwelling Koreans Older Than Age 65 Years

Hyung Joon Cho MD, Vivek Morey MS(Ortho), Jong Yeal Kang MD, Ki Woong Kim MD, Tae Kyun Kim MD

Osteoarthritis (OA) is common and disabling among older patients around the world. Data exploring the prevalence and risk factors of OA are of paramount importance in establishing healthcare policies. However, few studies have evaluated these topics among Asian populations.

Can Cytoprotective Cobalt Protoporphyrin Protect Skeletal Muscle and Muscle-derived Stem Cells From Ischemic Injury?

Heather-Marie P. Wilson PhD, Robert E. Welikson PhD, Jun Luo MD, PhD, Thomas J. Kean PhD, Baohong Cao MD, PhD, James E. Dennis PhD, Margaret D. Allen MD

Extremity trauma is the most common injury seen in combat hospitals as well as in civilian trauma centers. Major skeletal muscle injuries that are complicated by ischemia often result in substantial muscle loss, residual disability, or even amputation, yet few treatment options are available. A therapy that would increase skeletal muscle tolerance to hypoxic damage could reduce acute myocyte loss and enhance preservation of muscle mass in these situations.

Osteoblasts Have a Neural Origin in Heterotopic Ossification

ZaWaunyka W. Lazard BS, Elizabeth A. Olmsted-Davis PhD, Elizabeth A. Salisbury PhD, Zbigniew Gugala MD, PhD, Corrine Sonnet PhD, Eleanor L. Davis, Eric Beal BS, Eroboghene E. Ubogu MD, Alan R. Davis PhD

Heterotopic ossification (HO) is the process of bone formation at a nonskeletal site. Recently, we showed that the earliest steps occur in sensory nerves. We now extend these studies by identifying unique osteogenic progenitors within the endoneurial compartment of sensory nerves.

Hydrogel-based Delivery of rhBMP-2 Improves Healing of Large Bone Defects Compared With Autograft

Laxminarayanan Krishnan PhD, Lauren B. Priddy MS, Camden Esancy BS, Mon-Tzu Alice Li PhD, Hazel Y. Stevens BS, Xi Jiang BS, Lisa Tran MD, David W. Rowe PhD, Robert E. Guldberg PhD

Autologous bone grafting remains the gold standard in the treatment of large bone defects but is limited by tissue availability and donor site morbidity. Recombinant human bone morphogenetic protein-2 (rhBMP-2), delivered with a collagen sponge, is clinically used to treat large bone defects and complications such as delayed healing or nonunion. For the same dose of rhBMP-2, we have shown that a hybrid nanofiber mesh-alginate (NMA-rhBMP-2) delivery system provides longer-term release and increases functional bone regeneration in critically sized rat femoral bone defects compared with a collagen sponge. However, no comparisons of healing efficiencies have been made thus far between this hybrid delivery system and the gold standard of using autograft.