Clinical Orthopaedics and Related Research ®

A Publication of The Association of Bone and Joint Surgeons ®

Basic Research 169 articles


Temporal Variation in Fixation Stiffness Affects Healing by Differential Cartilage Formation in a Rat Osteotomy Model

Bettina M. Willie PhD, Robert Blakytny PhD, Melanie Glöckelmann DVM, Anita Ignatius DVM, Lutz Claes PhD

Dynamization involves a reduction in fixation construct stiffness during bone healing, allowing increased interfragmentary movement of the fracture through physiologic weightbearing and muscle contraction. Within some optimal range, interfragmentary movement stimulates healing, but this range likely varies across stages of bone healing.

Human Early Fracture Hematoma Is Characterized by Inflammation and Hypoxia

Paula Kolar MD, Timo Gaber PhD, Carsten Perka MD, Georg N. Duda PhD, Frank Buttgereit MD

An effective immune system, especially during the inflammatory phase, putatively influences the quality and likelihood of bone healing. If and how this is reflected within the initial fracture hematoma is unclear.

Relationships of the Lateral Femoral Cutaneous Nerve to Bony Landmarks

Mehmet Üzel MD, PhD, Salih Murat Akkin MD, Ercan Tanyeli MD, Jürgen Koebke PhD

The lateral femoral cutaneous nerve (LFCN) can be at risk during, for example, the insertion of pins in the anterior superior iliac spine (ASIS) during external fixation of the pelvis, total hip arthroplasty through a direct anterior approach, open surgery for impingement in the hip through an anterior approach, and periacetabular osteotomy. During surgery, the surgeon usually assumes the location of the LFCN by using the ASIS as a landmark.

Bupivacaine and Triamcinolone May Be Toxic To Human Chondrocytes: A Pilot Study

Hasan M. Syed MD, Lora Green PhD, Brandon Bianski BS, Christopher M. Jobe MD, Montri D. Wongworawat MD

Intraarticular injections of corticosteroids combined with local anesthetics are commonly used for management of chronic pain symptoms associated with degenerative joint diseases and after arthroscopic procedures. Several studies suggest chondrotoxicity of local anesthetics whereas others report chondroprotective and cytotoxic effects of corticosteroids on cartilage. Given the frequency of use of these agents, it is important to know whether they are in fact toxic.

Engineered Cartilage Maturation Regulates Cytokine Production and Interleukin-1β Response

Silvia Francioli PhD, Carola Cavallo PhD, Brunella Grigolo PhD, Ivan Martin PhD, Andrea Barbero PhD

Because the injured joint has an actively inflammatory environment, the survival and repair potential of cartilage grafts may be influenced by inflammatory processes. Understanding the interactions of those processes with the graft may lead to concepts for pharmacologic or surgical solutions allowing improved cartilage repair.

Cell-based Meniscal Tissue Engineering: A Case for Synoviocytes

Derek B. Fox DVM, PhD, Diplomate ACVS, Jennifer J. Warnock DVM, PhD, Diplomate ACVS

Avascular meniscal injuries are largely incapable of healing; the most common treatment remains partial meniscectomy despite the risk of subsequent osteoarthritis. Meniscal responses to injury are partially mediated through synovial activity and strategies have been investigated to encourage healing through stimulating or transplanting adjacent synovial lining. However, with their potential for chondrogenesis, synovial fibroblast-like stem cells hold promise for meniscal cartilage tissue engineering.

Physical Stimulation of Chondrogenic Cells In Vitro: A Review

Sibylle Grad PhD, David Eglin PhD, Mauro Alini PhD, Martin J. Stoddart PhD

Mechanical stimuli are of crucial importance for the development and maintenance of articular cartilage. For conditioning of cartilaginous tissues, various bioreactor systems have been developed that have mainly aimed to produce cartilaginous grafts for tissue engineering applications. Emphasis has been on in vitro preconditioning, whereas the same devices could be used to attempt to predict the response of the cells in vivo or as a prescreening method before animal studies. As a result of the complexity of the load and motion patterns within an articulating joint, no bioreactor can completely recreate the in vivo situation.

Bioactive Glass 13-93 as a Subchondral Substrate for Tissue-engineered Osteochondral Constructs: A Pilot Study

Prakash Jayabalan MD, Andrea R. Tan MS, Mohammed N. Rahaman PhD, B. Sonny Bal MD, MBA, Clark T. Hung PhD, James L. Cook DVM, PhD

Replacement of diseased areas of the joint with tissue-engineered osteochondral grafts has shown potential in the treatment of osteoarthritis. Bioactive glasses are candidates for the osseous analog of these grafts.

Androgen Receptor CAG Repeat Size is Associated with Stress Fracture Risk: A Pilot Study

Ran Yanovich MSc, Roni Milgrom MSc, Eitan Friedman MD, PhD, Daniel S. Moran PhD

Stress fractures commonly affect military recruits during basic training. Several lines of evidence suggest genetic factors are involved in stress fracture predisposition. As gender steroid hormone levels and activity have been implicated in affecting bone strength, one of the candidate genes likely to be involved is the androgen receptor gene.

Reduced Wear of Cross-linked UHMWPE Using Magnesia-stabilized Zirconia Femoral Heads in a Hip Simulator

Marcel E. Roy PhD, Leo A. Whiteside MD, Mark E. Magill MD, Brian J. Katerberg BS

To reduce wear, the ideal bearing surface in joint arthroplasty should be smooth and hydrophilic. Ceramics generally offer better wettability than metals and can be polished to a smoother finish. However, clinical studies have found no reduction in liner wear when using yttria-stabilized zirconia (Y-TZP) instead of cobalt chromium alloy (CoCr) femoral heads.