Key Points Lower limb development occurs in utero in its entirety during the fetal stage of development. The primordium of the hip joint is an amorphous cartilage model in which the two sides of the joint are indistinct until the…
Key Points Autologous bone graft is osteogenic, osteoinductive, and osteoconductive, with complete histocompatibility and no risk of infectious disease transmission. It is considered the gold standard for bone graft and is the most favored graft material in musculoskeletal reconstruction. Advantages…
Key Points Tissue reactions can be to the products of metal wear, modular junction tribocorrosion, or both; the characteristics of the debris can vary between these different sources. Long-term systemic effects of large amounts of metallic debris rarely involve cardiomyopathy…
Key Points Periprosthetic osteolysis is an adverse biologic reaction due to wear particles from joint replacements. Other contributory factors include increased intraarticular pressure and contamination of particles with bacterial or cellular by-products. Excessive wear particle production stimulates a nonspecific chronic…
Key Points Fixation of acetabular components in total hip arthroplasty (THA) spans three phases: a transient, primary phase of fixation achieved in the operating room; an intermediate phase, which occurs only with cementless implants, in which new bone heals around…
Key Points Ceramics currently used in total hip arthroplasty (THA) include alumina, zirconia-toughened alumina, and oxidized zirconium. Ceramic implant success is dependent on manufacturing ceramic with high density, high purity, and small grains. Zirconia-toughened alumina has smaller grain size, higher…
Key Points Ultra-high-molecular-weight polyethylene (UHMWPE) remains the polymer bearing material of choice for hard-on-soft joint replacement bearing couples. Historical UHMWPE formulations were subject to high wear and oxidation-induced embrittlement, resulting in osteolysis and component delamination. Major improvements in wear and…
Key Points Bone cement (polymethylmethacrylate [PMMA]) does not act as a glue to fix implants to bone. Rather, it serves as a grout to fill space with fixation achieved by mechanical interlock. The ability to shape, form, and infiltrate PMMA…
Key Points Wear of the bearing surface is a major factor in the service life of total hip and surface replacements. The hip bearing constitutes a tribological system; thus, wear is a system property impacted by multiple variables, such as…
Key Points Muscle forces play an integral role in the loading environment of the hip. If the mechanical role of major muscles is neglected in biomechanical analyses, joint contact forces tend to be underestimated, the tensile and compressive strains in…