Strontium-loaded 3D intramedullary nail titanium implant for critical-sized femoral defect in rabbits.

The treatment of critical-sized bone defects has long been a major problem for surgeons. In this study, an intramedullary nail shaped three-dimensional (3D)-printed porous titanium implant that is capable of releasing strontium ions was developed through a simple and cost-effective surface modification technique. The feasibility of this implant as a stand-alone solution was evaluated using a rabbit's segmental diaphyseal as a defect model.

Bone ingrowth into a porous structure is achieved by preceding fibrogenesis and vascularization.

Porous structures are frequently used in surgical implants to strengthen the interlocking power produced by bone ingrowth. Therefore, we aimed to elucidate the mechanism underlying bone ingrowth into a porous structure accompanied by vascularization. A nonbioactive polyetheretherketone implant with a 3D-printed porous structure was prepared and implanted in a bone hole created in the tibias of rabbits.

Assessment of the Damage to Hip Abductor Muscles in Primary Total Hip Arthroplasty With a Minimally Invasive Anterolateral Approach With or Without Trochanteric Flip Osteotomy.

Background: Although introduction of minimally invasive techniques via anterolateral approaches considerably decreased prolonged limp after total hip arthroplasty (THA), potential damage to the abductor muscles is still a concern. This study aimed to evaluate the residual damage after primary THA with two types of anterolateral approach by assessing fatty infiltration and atrophy of the gluteus medius (GMed) and gluteus minimus (GMin) muscles.

Methods: We retrospectively analyzed 100 primary THAs using computed tomography; surgeries were performed by detaching the anterior part of the abductor muscles with a bone fragment (anterolateral approach with trochanteric flip osteotomy) or without it (anterolateral approach without trochanteric flip osteotomy).

Synergistic effect of sulfonation followed by precipitation of amorphous calcium phosphate on the bone-bonding strength of carbon fiber reinforced polyetheretherketone.

Sulfonation and applications of amorphous calcium phosphate are known to make polyetheretherketone (PEEK) bioactive. Sulfonation followed by precipitation of amorphous calcium phosphate (AN-treatment) may provide PEEK with further bone-bonding strength. Herein, we prepared a carbon-fiber-reinforced PEEK (CPEEK) with similar tensile strength to cortical bone and a CPEEK subjected to AN-treatment (CPEEK-AN).

Bioactivity and antibacterial activity of iodine-containing calcium titanate against implant-associated infection.

Developing antimicrobial biomaterials is a major challenge in the fields of orthopaedic and dental implants. In this study, we evaluated the bone-bonding ability and antibacterial activity of a novel biomaterial for preventing implant-associated infections. We have previously reported that NaOH heat treatment improved the bone-bonding ability of titanium, which was later modified to release target ions from the calcium titanate surface.

Radiodensity measurement is feasible for evaluating fatty infiltration in hip abductors.

Objective: This retrospective study aimed to compare radiodensity measurements and Goutallier grading systems for the evaluation of fatty infiltration in hip abductors.

Methods: The radiodensity of the gluteus minimus and medius muscles was measured in 80 hips of 40 patients. These muscles were graded for fatty infiltration using three five-grade classification systems: the original Goutallier classification on both computed tomography (CT) and magnetic resonance imaging (MRI), and a new objective classification based on the percentage of the functional muscle area (defined as 30-100 Hounsfield units).

Long-term outcome of primary total hip arthroplasty with cementless bioactive glass ceramic bottom-coated implants and highly cross-linked polyethylene: A minimum 10-year analysis.

Background: Cementless glass ceramics containing apatite and wollastonite (AW-GC) bottom-coated titanium hip implants were developed; early excellent clinical and radiographic results have been reported previously. This study aimed to investigate the long-term clinical and radiographic outcomes in detail, and the wear rate of HXLPE.

Methods: We retrospectively evaluated 99 patients (117 hips) between November 2001 and December 2007.

Surface Modification of Carbon Fiber-Polyetheretherketone Composite to Impart Bioactivity by Using Apatite Nuclei.

The authors aimed to impart the apatite-forming ability to 50 wt% carbon fiber-polyetheretherketone composite (50C-PEEK), which has more suitable mechanical properties as artificial bone materials than pure PEEK. First, the 50C-PEEK was treated with sulfuric acid in a short time to form pores on the surface. Second, the surface of the 50C-PEEK was treated with oxygen plasma to improve the hydrophilicity.

Radiolucent lines do not affect the longevity of highly cross-linked polyethylene cemented components in total hip arthroplasty.

Aims: We aimed to evaluate the long-term outcome of highly cross-linked polyethylene (HXLPE) cemented acetabular components and assess whether any radiolucent lines (RLLs) which arose were progressive.

Methods: We retrospectively reviewed 170 patients who underwent 187 total hip arthroplasties at two hospitals with a minimum follow-up of ten years. All interventions were performed using the same combination of HXLPE cemented acetabular components with femoral stems made of titanium alloy.

Bioactivity and antibacterial activity of strontium and silver ion releasing titanium.

To overcome problems associated with loosening of orthopedic implants and surgical site infections, we developed a novel, titanium (Ti)-based material that releases both strontium and silver ions (CaSrAg-Ti) based on alkali-and-heat treatment. The results of commercially pure Ti (cp-Ti), Ti that releases Sr ions only (CaSr-Ti), and the novel CaSrAg-Ti material were compared. Mechanical tests were performed to evaluate the in vivo bonding properties of CaSrAg-Ti and the bone-implant contact (BIC) ratio in histological specimens was determined at 4 and 8 weeks after implantation in a rat femur.

The Long-Term Results of Total Hip Arthroplasty With a Cemented β-Titanium Stem.

Background: We report on the outcomes of a double-tapered cemented stem made of β-titanium alloys (Ti-15Mo-5Zr-3Al) at least 10 years after total hip arthroplasty.

Methods: We retrospectively analyzed 148 consecutive, primary total hip arthroplasties using this stem performed in 130 patients between January 2004 and August 2008. The patients' mean age was 59.