The development and pre-clinical evaluation of nano-texturised, biomimetic, surfaces of titanium (Ti) implants treated with titanium dioxide (TiO₂) nanotube arrays is reviewed. In vitro and in vivo evaluations show that TiO₂ nanotubes on Ti surfaces positively affect the osseointegration, cell differentiation, mineralisation, and anti-microbial properties. This surface treatment can be superimposed onto existing macro and micro porous Ti implants creating a surface texture that also interacts with cells at the nano level. Histology and mechanical pull-out testing of specimens in rabbits indicate that TiO₂ nanotubes improves bone bonding nine-fold (p = 0.008). The rate of mineralisation associated with TiO₂ nanotube surfaces is about three times that of non-treated Ti surfaces. In addition to improved osseointegration properties, TiO₂ nanotubes reduce the initial adhesion and colonisation of Staphylococcus epidermidis. Collectively, the properties of Ti implant surfaces enhanced with TiO₂ nanotubes show great promise.

Cite this article: Bone Joint J 2018;100-B(1 Supple A):9–16.

Wire cerclage is one of the oldest forms of internal fixation. Cerclage has numerous applications in orthopaedics as a primary method of fracture fixation and as a supplement to other forms of fixation. Traditional wire cerclage, however, has several disadvantages. Monofilament wire is prone to breakage. Multifilament braided cables tend to undergo fatigue failure and fray, releasing metallic particulate debris into the body. Both have a limited ability to maintain compression. This paper presents performance data on a novel flexible, high strength, high fatigue life cable that addresses the inherent problems associated with traditional metal wire cerclage.

The iso-elastic cerclage cable consists of a nylon core encased in a jacket of UHMWPE braided fibers. A tensioning instrument tightens the assembly with a metal clasp. Cable assemblies were tested under in vitro static and dynamic loading conditions. Viscoelastic response and wear behavior under in vitro loading conditions were characterized.

The iso-elastic cerclage cable displayed an ultimate tensile strength of pproximately 650 MPa and withstood over one million cycles of simulated physiologic load without failure. After 8 weeks of static loading, initial cable tension decreased by approximately 40%. After one million loading cycles against a bone plate, the iso-elastic cable displayed no evidence of fraying or fiber breakage.

The ultimate strength of the iso-elastic cable is comparable to that of traditional metal cable while its fatigue strength is clearly superior. After initial relaxation, the iso-elastic cable maintained compressive forces that are typical of the initial compression held by metal cerclage wires. The wear characteristics of the iso-elastic cable are clearly superior to those of multifilament metal cerclage cables. The iso-elastic cable shows high tensile strength and fatigue life. An iso-elastic cable has been developed to compensate for micro-movement within the bone fracture construct while maintaining a continuous compressive force across the fracture.

A retrospective study was performed to evaluate the safety and effectiveness of an alumina-based total knee arthroplasty system (Low Friction Anatomical, LFA, Kyocera, Kyoto, Japan). The system, which uses modern materials and contemporary component design, has been in clinical use in Japan since 1992. The system uses an alumina femoral component that articulates against standard polyethylene tibial and patellar components.

The retrospective study evaluated the clinical performance of amodern-style ceramic femoral component and included 60 knees (49 patients) with an average follow-up of 3.8 years. Clinical outcomes were assessed by the Japanese Orthopaedic Association (JOA) Knee Rating Scale, which is comparable to the Knee Society Rating Scale used in the United States. Radiographic outcomes were assessed by the operating surgeon and another independent reviewer. The radiographs were reviewed for the presence or absence of lytic lines, implant and anatomical alignment, and other pertinent radiographic findings. Complications during the follow-up period were noted.

Total knee replacement with the LFA system improved JOA scores in 98% of the cases. Mechanical and prosthetic alignment were satisfactory for all knees. The following results were noted:

No fractures or failures associated with the alumina ceramic femoral component

An alumina-based total knee replacement system was found to be a safe and effective means of treating the arthritic knee joint. The use of ceramics in total knee arthroplasty applications provides an opportunity for a low friction bearing interface and a completely metal-free total joint system.