Clinical Orthopaedics and Related Research ®

A Publication of The Association of Bone and Joint Surgeons ®

Basic Research 169 articles


Does Norepinephrine Influence Pain Behavior Mediated by Dorsal Root Ganglia?: A Pilot Study

Katsumasa Tanimoto MD, PhD, Tsuneo Takebayashi MD, PhD, Takeshi Kobayashi MD, PhD, Noritsugu Tohse MD, PhD, Toshihiko Yamashita MD, PhD

Postganglionic neurons in the sympathetic nervous system reportedly are involved in lumbar radicular pain and release norepinephrine (NE), a neurotransmitter. Increased numbers of sympathetic nerve fibers have been found in dorsal root ganglion (DRG) neurons in a root constriction model. Whether this is a reasonable model for pain, however, is unclear

Does Perception of Usefulness of Arthroscopic Simulators Differ with Levels of Experience?

Gabriëlle J. M. Tuijthof PhD, P. Visser MD, Inger N. Sierevelt MSc, C. Niek Dijk MD, PhD, Gino M. M. J. Kerkhoffs MD, PhD

Some commercial simulators are available for training basic arthroscopic skills. However, it is unclear if these simulators allow training for their intended purposes and whether the perception of usefulness relates to level of experience.

Healing of Long-term Frozen Orthotopic Bone Allografts is not Affected by MHC Differences Between Donor and Recipient

Olav Reikerås MD, PhD, Finn P. Reinholt MD, PhD, Severin Zinöcker MSc, Hamid Shegarfi MSc, Bent Rolstad MD, PhD

The use of bone grafting in orthopaedic surgery has increased dramatically in recent years. However, the degree to which immune responses are important for the survival of the allograft is not fully understood. In particular it remains unclear whether differences in the major histocompatibility complex (MHC) influence incorporation of bone allografts and their subsequent biologic performance.

Whole Bone Mechanics and Bone Quality

Jacqueline H. Cole PhD, Marjolein C. H. Meulen PhD

The skeleton plays a critical structural role in bearing functional loads, and failure to do so results in fracture. As we evaluate new therapeutics and consider treatments to prevent skeletal fractures, understanding the basic mechanics underlying whole bone testing and the key principles and characteristics contributing to the structural strength of a bone is critical.

Rationale for and Methods of Superiority, Noninferiority, or Equivalence Designs in Orthopaedic, Controlled Trials

Patrick Vavken MD, MSc, FRSPH

To provide value-based healthcare in orthopaedics, controlled trials are needed to assess the comparative effectiveness of treatments. Typically comparative trials are based on superiority testing using statistical tests that produce a p value. However, as orthopaedic treatments continue to improve, superiority becomes more difficult to show and, perhaps, less important as margins of improvement shrink to clinically irrelevant levels. Alternative methods to compare groups in controlled trials are noninferiority and equivalence. It is important to equip the reader of the orthopaedic literature with the knowledge to understand and critically evaluate the methods and findings of trials attempting to establish superiority, noninferiority, and equivalence.

Coculture of Engineered Cartilage With Primary Chondrocytes Induces Expedited Growth

Andrea R. Tan MS, Elizabeth Y. Dong BS, James P. Andry MD, J. Chloë Bulinski PhD, Gerard A. Ateshian PhD, Clark T. Hung PhD

Soluble factors released from chondrocytes can both enhance and induce chondrocyte-like behavior in cocultured dedifferentiated cells. The ability to similarly prime and modulate biosynthetic activity of differentiated cells encapsulated in a three-dimensional environment is unknown.

The In Vitro Elution Characteristics of Vancomycin from Tendons

Jane E. Grayson PhD, Gary D. Grant PhD, Shailendra Dukie PhD, Christopher J. Vertullo MBBS, FRACS

Infection after ACL reconstruction is uncommon but catastrophic. Prophylactic graft saturation in vancomycin reportedly reduces infection rates.

Infrared Assessment of Bone Quality: A Review

Eleftherios P. Paschalis PhD, Richard Mendelsohn PhD, Adele L. Boskey PhD

Bone strength depends on both bone quantity and quality. The former is routinely estimated in clinical settings through bone mineral density measurements but not the latter. Bone quality encompasses the structural and material properties of bone. Although its importance is appreciated, its contribution in determining bone strength has been difficult to precisely quantify partly because it is multifactorial and requires investigation of all bone hierarchical levels. Fourier transform infrared spectroscopy provides one way to explore these levels.

Emerging Ideas: Treatment of Precollapse Osteonecrosis Using Stem Cells and Growth Factors

Quanjun Cui MD, MSc, Edward A. Botchwey PhD

Osteonecrosis (ON) of the femoral head is a devastating disease affecting young patients at their most productive age, causing major socioeconomic burdens. ON is associated with various etiologic factors, and the pathogenesis of the disease is unknown. Most investigators believe the disease is the result of secondary microvascular compromise with subsequent bone and marrow cell death and defective bone repair.

Emerging Ideas: Matrix Metalloproteinase-2 in Muscle Atrophy

Xuhui Liu MD

Muscle atrophy impacts almost every patient seen for orthopaedic conditions. Unfortunately, no effective treatment is available to date. Matrix metalloproteinases (MMPs), especially MMP-2, are involved in skeletal muscle atrophy. MMP-2 null mice reportedly have substantially reduced muscle atrophy after tendon transection compared with wild-type mice, suggesting MMP-2 plays an important role in muscle atrophy. Although the exact mechanisms remain unknown, a newly-discovered intracellular form of MMP-2 suggests a possible novel mechanism of MMP-2 digesting muscle matrix during muscle atrophy. I propose a new pharmacologic treatment for muscle atrophy using selective MMP-2 inhibitors.