Clinical Orthopaedics and Related Research ®

A Publication of The Association of Bone and Joint Surgeons ®

Basic Research 171 articles

Articles

β-Ecdysone Augments Peak Bone Mass in Mice of Both Sexes

Weiwei Dai PhD, HongLiang Zhang MD, PhD, Zhendong A. Zhong PhD, Li Jiang MD, Haiyan Chen MS, Yu-An Evan Lay MS, Alexander Kot BS, Robert O. Ritchie PhD, Nancy E. Lane MD, Wei Yao MD

One of the strongest predictors for osteoporosis is peak bone mass. Interventions to augment peak bone mass have yet to be developed. β-Ecdysone (βEcd), a natural steroid-like compound produced by arthropods to initiate metamorphosis, is believed to have androgenic effects and so may be used to augment bone mass.

Early Characterization of Blast-related Heterotopic Ossification in a Rat Model

Ammar T. Qureshi PhD, Erica K. Crump BA, Gabriel J. Pavey MD, Donald N. Hope MD, Jonathan A. Forsberg MD, Thomas A. Davis PhD

Heterotopic ossification (HO) affects the majority of combat-related lower extremity wounds involving severe fracture and amputation. Defining the timing of early osteogenic-related genes may help identify candidate prophylactic agents and guide the timing of prophylactic therapy after blast and other combat-related extremity injuries.

How Does Bone Strength Compare Across Sex, Site, and Ethnicity?

Stephen H. Schlecht PhD, Erin M. R. Bigelow MS, Karl J. Jepsen PhD

The risk of fragility fractures in the United States is approximately 2.5 times greater among black and white women compared with their male counterparts. On average, men of both ethnicities have wider bones of greater cortical mass compared with the narrower bones of lower cortical mass among women. However, it remains uncertain whether the low cortical area observed in the long bones of women is consistent with their narrower bone diameter or if their cortical area is reduced beyond that which is expected for the sex differences in body size and external bone size.

Biomechanical Outcomes of Bridge-enhanced Anterior Cruciate Ligament Repair Are Influenced by Sex in a Preclinical Model

Ata M. Kiapour PhD, Braden C. Fleming PhD, Martha M. Murray MD

Despite the well-established role of sex on the anterior cruciate ligament (ACL) injury risk, its effects on ACL surgical outcomes remain controversial. This is particularly critical when developing novel surgical techniques to treat the injury because there are limited data existing on how these procedures will respond in each sex. One such approach is bridge-enhanced ACL repair, in which primary suture repair of the ACL is augmented with a bioactive scaffold saturated with autologous blood. It has shown comparable biomechanical outcomes to ACL reconstruction in preclinical models.

Sex Differences in Arm Muscle Fatigability With Cognitive Demand in Older Adults

Hugo M. Pereira MSc, Vincent C. Spears BSc, Bonnie Schlinder-Delap MA, Tejin Yoon PhD, April Harkins PhD, Kristy A. Nielson PhD, Marie Hoeger Bement PhD, Sandra K. Hunter PhD

Muscle fatigability can increase when a stressful, cognitively demanding task is imposed during a low-force fatiguing contraction with the arm muscles, especially in women. Whether this occurs among older adults (> 60 years) is currently unknown.

Platelet-rich Concentrates Differentially Release Growth Factors and Induce Cell Migration In Vitro

Michael O. Schär MD, Jose Diaz-Romero PhD, Sandro Kohl MD, Matthias A. Zumstein MD, Dobrila Nesic PhD

Platelet-rich concentrates are used as a source of growth factors to improve the healing process. The diverse preparation protocols and the gaps in knowledge of their biological properties complicate the interpretation of clinical results.

Women Build Long Bones With Less Cortical Mass Relative to Body Size and Bone Size Compared With Men

Karl J. Jepsen PhD, Erin M. R. Bigelow MS, Stephen H. Schlecht PhD

The twofold greater lifetime risk of fracturing a bone for white women compared with white men and black women has been attributed in part to differences in how the skeletal system accumulates bone mass during growth. On average, women build more slender long bones with less cortical area compared with men. Although slender bones are known to have a naturally lower cortical area compared with wider bones, it remains unclear whether the relatively lower cortical area of women is consistent with their increased slenderness or is reduced beyond that expected for the sex-specific differences in bone size and body size. Whether this sexual dimorphism is consistent with ethnic background and is recapitulated in the widely used mouse model also remains unclear.

Platelet-rich Plasma Modulates the Secretion of Inflammatory/Angiogenic Proteins by Inflamed Tenocytes

Isabel Andia PhD, Eva Rubio-Azpeitia MSc, Nicola Maffulli MD, MS, PhD, FRCS (Orth)

Platelet-rich plasma therapies for tendinopathy appear to provide moderate pain reduction. However, the biological mechanisms behind the observed clinical effects remain poorly characterized.

Low-intensity Pulsed Ultrasound Enhances Bone Repair in a Rabbit Model of Steroid-associated Osteonecrosis

Hanxiao Zhu MD, Xunzi Cai MD, Tiao Lin MD, Zhongli Shi MD, Shigui Yan MD

Steroids are a leading cause of femoral head osteonecrosis. Currently there are no medications available to prevent and/or treat steroid-associated osteonecrosis. Low-intensity pulsed ultrasound (LIPUS) was approved by the FDA for treating delayed union of bone fractures. Some studies have reported that LIPUS can enhance bone formation and local blood flow in an animal model of fracture healing. However, whether the effect of osteogenesis and neovascularization by LIPUS can enhance the repair progress in steroid-associated osteonecrosis is unknown.

Does Cyclic Stress Play a Role in Highly Crosslinked Polyethylene Oxidation?

Francisco Medel PhD, Steven Kurtz PhD, Daniel MacDonald MS, Francisco Javier Pascual MS, José Antonio Puértolas PhD

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.