Developments in stem cells: implications for future joint replacements.

Will stem cell research reverse the projected sevenfold increase in primary and revision knee replacements expected in the United States between 2005 and 2030? A focus on prevention and treatment of osteoarthritis may end the need for primary joint replacements. A more likely scenario can be described as slow and incremental changes in the prevention and treatment of osteoarthritis, accompanied by the continuing development of implant technology. Since the discovery of stem cells in the 1950s, research has increased exponentially. Expanded autologous chondrocytes, and more recently ex vivo expanded skeletal stem cells, are currently injected into osteochondral defects in the hope of regenerating cartilage and halting progression towards osteoarthritis. In addition, mesenchymal stem cells are being injected into human joints as a treatment for osteoarthritis despite a lack of quantitative research. Concurrently, stem cell research continues to contribute to chemical and topographical advancements in implant design. Advances in co-culture techniques mean it is possible that biologic articular replacements will develop prior to the cessation of the need for arthroplasty and radically change the nature of joint replacements. Whether it is through implant design or a potential cure for the pain attributable to osteoarthritis, as we hope to show in this 'forward look article', it is our opinion that stem cells will certainly impact future joint replacement.

An adaptation of Weil's osteotomy of the lesser metatarsal neck.

Weil's osteotomy is a useful technique for the treatment of central metatarsalgia and lesser metatarsophalangeal joint dislocation. In this report, we describe a technical maneuver that involves predrilling and tapping holes that can be used to guide translocation of the capital fragment of the metatarsal. This configures the final hole that will be used for single screw placement to secure the osteotomy in the position of correction. This technical tip is useful in regard to establishing the intraoperative orientation of the osteotomy and screw placement, and enables the use of a single, generic screw for stabilization of the realigned metatarsal.