Antibiotic-impregnated articulating cement spacer maintained for 7 years in situ for two-stage primary total knee arthroplasty: a case report.

BACKGROUND: Antibiotic-impregnated articulating cement spacers can maintain interim joint motion with the potential to enhance functional status and improve patient satisfaction. Articular surfaces with cement against cement have raised concerns regarding mechanical complications and cement debris during knee motion. However, long-term clinical conditions regarding these concerns are not well addressed. CASE PRESENTATION: We report a case in which articulating cement spacers were maintained in situ for 7 years. The patient had severe left knee pain with an ankylosing knee and severe tricompartmental arthritis due to tuberculous infection. We planned to perform one- or two-stage primary total knee arthroplasty (TKA), depending on the presence of infection. Persistent osteomyelitis was found intraoperatively. The second-stage TKA was delayed on the patient's request. As the patient was satisfied with the improved knee function and pain relief after using articulating cement spacers. No symptom or sign that suggested recurrent infection or systemic toxicity was found during the 7-year follow-up. However, it seemed that the bone loss progressed insidiously. At the 7-year follow-up, a broken articulating cement spacer and medial femoral condylar fracture were found. The second-stage TKA was performed, and a considerable amount of bone loss surrounded by dense granulation tissue was observed intraoperatively. Excisional biopsy of the tissue revealed chronic foreign body reaction with infiltration of giant cells and macrophages. CONCLUSION: Although the articular spacers were maintained for 7 years without major complications, regular observation of the development and progress of bone loss was required. Surgeons should take considerable bone loss into account during conversion TKA in patients with a prolonged retention of articulating cement spacers.

Arrays of nanoscale lenses for subwavelength optical lithography.

Poly(ethylene glycol) (PEG) polymer lens arrays are made by using dip-pen nanolithography to deposit nanoscale PEG features on hydrophobically modified quartz glass. The dimensions of the PEG lenses are controlled by tuning dwell time and polymer molecular weight. The PEG polymer lenses on the quartz substrate act as a phase-shift photomask for fabricating subwavelength scale features, ∼ 100 nm in width. Depending upon UV irradiation time during the photolithography, the photoresist nanostructures can be transitioned from well-shaped (short time) to ring-shaped (long time) features. The technique can be used to pattern large areas through the use of cantilever arrays.

Positive effect of timed blue-enriched white light on sleep and cognition in patients with mild and moderate Alzheimer's disease.

Conflicting results have been reported regarding the effectiveness of light treatment (LT) in patients with Alzheimer's disease (AD). We investigated the effectiveness of blue-enriched white LT on sleep, cognition, mood and behavior in patients with mild and moderate AD. The treatment group (n = 14) sat about 60 cm away from a small (136 × 73 × 16 mm) LED light box for 1 h each morning for 2 weeks. The control group (n = 11) wore dark, blue-attenuating sunglasses during the 1 h exposures. The morning light started 9-10 h after each individual's dim light melatonin onset (DLMO). Assessments were done at baseline (T0), immediate post-treatment (T1), and 4 weeks after the end of the 2 weeks of LT (T2). Sleep was measured by actigraphy. Blue-enriched LT had a significantly better effect on the Pittsburgh Sleep Quality Index at T2 compared to blue-attenuated LT, and a trend of better effectiveness on total sleep time at T2. There was a significant increase in Mini-Mental State Examination score at T2 after blue-enriched LT than that at T0. Our findings suggest that morning blue-enriched LT has a benefit in improving sleep and cognitive function in AD patients.

An Intrafascicular Neural Interface With Enhanced Interconnection for Recording of Peripheral Nerve Signals.

For implantable devices, Parylene C (hereafter referred to as Parylene) has shown promising properties such as flexibility, biocompatibility, biostability, and good barrier properties. Parylene-based flexible interconnection cable (FIC) was previously developed to connect a flexible penetrating microelectrode array (FPMA) with a recording system. However, Parylene-based FIC was difficult to handle and prone to damage during the implantation surgery because of its low mechanical strength. To improve the mechanical properties of the FIC, we suggest a mechanically enhanced flexible interconnection cable (enhanced FIC) obtained using a combination of Parylene and polyimide. To investigate the long-term stability of the enhanced FIC, Parylene-only FIC, and enhanced FIC were tested and their mechanical properties were compared under an accelerated aging condition. During the course of six months of soaking, the maximum strength of the enhanced FIC remained twice as high as that of the Parylene-only FIC throughout the experiment, although the mechanical strength of both FICs decreased over time. To show the capability of the enhanced FIC in the context of nerve signal recording as a part of a neural interfacing device, it was assembled together with the FPMA and custom-made wireless recording electronics. We demonstrated the feasibility of the enhanced FIC in an in vivo application by recording acute nerve signals from canine sciatic nerves.

Subsidence after single-level anterior cervical fusion with a stand-alone cage.

To investigate the risk factors for subsidence in patients treated with stand-alone anterior cervical discectomy and fusion (ACDF) using polyetheretherketone (PEEK) cages for single-level degenerative cervical disease. Seventy-seven consecutive patients who underwent single-level stand-alone ACDF with a PEEK cage between 2005 and 2012 were included. Subsidence was defined as a decrease in the interbody height of more than 3mm on radiographs at the 1-year follow-up compared with that in the immediate post-operative image. Patients were divided into the subsidence and non-subsidence groups. The following factors were investigated in relation to the occurrence of subsidence: age, pre-operative overall cervical sagittal angle, segmental angle of the operated level, interbody height, cage height, cage devices and cage location (distance between anterior margin of the body endplate and that of the cage). The clinical outcomes were assessed with visual analog scale, modified Japanese Orthopedic Association score and neck disability index. Twenty-six out of the 77 (33.8%) patients had radiological signs of cage subsidence. Solid fusion was achieved in 25 out of the 26 patients (96.2%) in the subsidence group and in 47 out of the 51 patients (92.2%) in the non-subsidence group. More than 3mm distance between anterior margin of the vertebral body and that of the cage was significantly associated with subsidence (p<0.05). However, subsidence did not correlate with fusion rate or clinical outcomes. Cage location was the only significant risk factor. Therefore, cage location should be taken into consideration during stand-alone ACDF using PEEK cages.

Traction Induced Vertical Displacement of Odontoid due to Type III Odontoid Fracture with Unrecognized Ligamentous Injury: A Case Report.

Dens fractures are a common traumatic cervical spine injury. Among them, a type III fracture is the second common fracture. Although there are several treatment options, it has been accepted that type III fracture is usually healed by non-surgical method. After adequate reduction with traction, subsequent external immobilization has been associated with successful union rates. However, in the review of literatures, there are some cases with neurological deterioration after application of skull traction. So, the authors report a case of type III dens fracture with initially unrecognized ligamentous injury in which vertical dissociation and quadriplegia occurred after only five-pound Gardner-Well tongs traction. And also, the authors raise awareness of this potentially injury.