Developments in stem cells: implications for future joint replacements

Perichondrial progenitor cells promote proliferation and chondrogenesis of mature chondrocytes

Autologous chondrocytes (C cells) are effective sources of cell therapy for engineering cartilage tissue to repair chondral defects, such as degenerative arthritis. The expansion of cells with C cell characteristics has become a major challenge due to inadequate donor sites and poor proliferation of mature C cells. The perichondrial progenitor cells (P cells) from the cambium layer of the perichondrium possessed significantly higher mesenchymal stem cell markers than C cells. In the transwell co-culture system, P cells increased the passaging capacity of C cells from P6 to P9, and the cell number increased 128 times. This system increased the percentage of Alcian blue-positive C cells from 40% in P6 to 62% in P9, contributing about 198 times more Alcian blue-positive C cells than the control group. C cells co-cultured with P cells also exhibited higher proliferation than C cells cultured with P cell-conditioned medium. Similar results were obtained in nude mice that were subcutaneously implanted with C cells, P cells or a mixture of the two cell types, in which the presence of both cells enhanced neocartilage formation in vivo. In aggregate, P cells enhanced the proliferation of C cells in a dose–dependent manner and prolonged the longevity of mature C cells for clinical applications.

The Current Role of Stem Cells in Orthopaedic Surgery

Basic science and experimental research on stem cells has increased exponentially in the last decade. Our present knowledge about stem cell biology is better than ever before. This new paradigm shift in research has been reflected in the field of orthopaedic surgery. Various experimental models have suggested a potential application of stem cells for different orthopaedic conditions, and early clinical results of stem cell use have been encouraging. These cells can be easily isolated, processed and made available for clinical use. From healing of bone defects caused by trauma, tumor or infection to cartilage defects, nerve, tendon and ligament healing, stem cell use has the potential to revolutionize orthopaedic practice. The purpose of this article is to orient a general orthopaedic surgeon towards the current use and clinical applications of stem cell based therapy in orthopaedics and to provide a complete overview of the clinical advances in this field.

Advances in small joint arthroplasty of the hand

Substantial effort has been directed at the development of small joint prostheses for the hand. Despite advances in prosthetic joint design, outcomes have been relatively unchanged over the past 60 years. Pain relief and range of motion achieved after surgery have yet to mirror the success of large joint arthroplasty. Innovations in biotechnology and stem cell applications for damaged joint surfaces may someday make prostheses obsolete. The purpose of this review is to describe the current status, ongoing advances, and future of small joint arthroplasty of the hand.