M. Nedim Doral

Arthroscopy-assisted fracture fixation.

PurposeThe purpose of this article was to systematically analyze the results of published studies in the literature which evaluated the use of arthroscopically assisted techniques in intra-articular fracture fixation.MethodsPublished investigations to date were analyzed by classifying them according to joints that were involved with intra-articular fractures including: knee, ankle, hip, shoulder, elbow, and wrist joints. The results were studied to assess the feasibility, efficiency, and outcomes of arthroscopy-assisted fracture fixation.ResultsArthroscopy-assisted techniques have been used successfully for the treatment of fractures of the tibial plateau, tibial eminence, malleoli, pilon, calcaneus, femoral head, glenoid, greater tuberosity, distal clavicle, radial head, coronoid, distal radius, and scaphoid. The major advantages of arthroscopic fracture fixation over open methods are direct visualization of the intra-articular space, decreased invasiveness, and the possibility for multitask interventions through which fixation of the fracture, and repair of the soft tissues and the cartilage can be performed simultaneously. The time-consuming and technically demanding nature of the procedures with a prolonged learning curve and limited fixation alternatives are the main disadvantages of this technique.ConclusionArthroscopic fixation is increasingly utilized for certain intra-articular fracture types due to the minimally invasive nature of the procedures and high accuracy. Randomized controlled trials are needed to justify wider use of arthroscopy-assisted techniques for treatment of intra-articular fractures.

Augmentation of tendon-to-bone healing.

Tendon-to-bone healing is vital to the ultimate success of the various surgical procedures performed to repair injured tendons. Achieving tendon-to-bone healing that is functionally and biologically similar to native anatomy can be challenging because of the limited regeneration capacity of the tendon-bone interface. Orthopaedic basic-science research strategies aiming to augment tendon-to-bone healing include the use of osteoinductive growth factors, platelet-rich plasma, gene therapy, enveloping the grafts with periosteum, osteoconductive materials, cell-based therapies, biodegradable scaffolds, and biomimetic patches. Low-intensity pulsed ultrasound and extracorporeal shockwave treatment may affect tendon-to-bone healing by means of mechanical forces that stimulate biological cascades at the insertion site. Application of various loading methods and immobilization times influence the stress forces acting on the recently repaired tendon-to-bone attachment, which eventually may change the biological dynamics of the interface. Other approaches, such as the use of coated sutures and interference screws, aim to deliver biological factors while achieving mechanical stability by means of various fixators. Controlled Level-I human trials are required to confirm the promising results from in vitro or animal research studies elucidating the mechanisms underlying tendon-to-bone healing and to translate these results into clinical practice.

Symptomatic bipartite patella: treatment alternatives.

Abstract Bipartite patella is usually an asymptomatic, incidental finding. However, in adolescents, it may be a cause of anterior knee pain following trauma or a result of overuse or strenuous sports activity. Most patients improve with nonsurgical treatment. Surgery is considered when nonsurgical treatment fails. Excision of the fragment is the most popular surgical option, with good results. However, when the fragment is large and has an articular surface, excision may lead to patellofemoral incongruity. Lateral retinacular release and detachment of the vastus lateralis muscle insertion are other surgical options and are reported to produce good pain relief and union in some patients. These procedures reduce the traction force of the vastus lateralis on the loose fragment. Internal fixation of the separated fragment has limited support in the literature. Understanding the possible consequences of different treatment approaches to painful bipartite patella is necessary to preserve quadriceps muscle strength and patellofemoral joint function.

Multilayer scaffolds in orthopaedic tissue engineering

AbstractPurpose The purpose of this study was to summarize the recent developments in the field of tissue engineering as they relate to multilayer scaffold designs in musculoskeletal regeneration.MethodsClinical and basic research studies that highlight the current knowledge and potential future applications of the multilayer scaffolds in orthopaedic tissue engineering were evaluated and the best evidence collected. Studies were divided into three main categories based on tissue types and interfaces for which multilayer scaffolds were used to regenerate: bone, osteochondral junction and tendon-to-bone interfaces.ResultsIn vitro and in vivo studies indicate that the use of stratified scaffolds composed of multiple layers with distinct compositions for regeneration of distinct tissue types within the same scaffold and anatomic location is feasible. This emerging tissue engineering approach has potential applications in regeneration of bone defects, osteochondral lesions and tendon-to-bone interfaces with successful basic research findings that encourage clinical applications.ConclusionsPresent data supporting the advantages of the use of multilayer scaffolds as an emerging strategy in musculoskeletal tissue engineering are promising, however, still limited. Positive impacts of the use of next generation scaffolds in orthopaedic tissue engineering can be expected in terms of decreasing the invasiveness of current grafting techniques used for reconstruction of bone and osteochondral defects, and tendon-to-bone interfaces in near future.

An emerging cell-based strategy in orthopaedics: endothelial progenitor cells

PurposeThe purpose of this article was to analyze the results of studies in the literature, which evaluated the use of endothelial progenitor cells (EPCs) as a cell-based tissue engineering strategy.MethodsEPCs have been successfully used in regenerative medicine to augment neovascularization in patients after myocardial infarction and limb ischemia. EPCs’ important role as vasculogenic progenitors presents them as a potential source for cell-based therapies to promote bone healing.ResultsEPCs have been shown to have prominent effects in promoting bone regeneration in several animal models. Evidence indicates that EPCs promote bone regeneration by stimulating both angiogenesis and osteogenesis through a differentiation process toward endothelial cell lineage and formation of osteoblasts. Moreover, EPCs increase vascularization and osteogenesis by increased secretion of growth factors and cytokines through paracrine mechanisms.ConclusionEPCs offer the potential to emerge as a new strategy among other cell-based therapies to promote bone regeneration. Further investigations and human trials are required to address current questions with regard to biology and mechanisms of action of EPCs in bone tissue engineering.