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Purpose: To analyze the biologic and mechanical complications of splinted and nonsplinted implant restorations. Materials and Methods: A total of 423 patients (n = implants: 888) were included in the study. Biologic and mechanical complications that occurred for 15 years were analyzed using the multivariable Cox regression model, and the significant effect of the splinting of prostheses and other risk factors were evaluated. Results: Biologic complications occurred in 38.7% of implants: 26.4% of nonsplinted implants (NS) and 45.4% of splinted implants (SP). Mechanical complications occurred in 49.2% of implants: 59.3% NS and 43.9% SP. Implants splinted with both mesial and distal adjacent implants (SP-mid) had the highest risk of peri-implant diseases. As the number of implants splinted increased, the risk of mechanical complications decreased. Long crown lengths increased the risk of both biologic and mechanical complications. Conclusion: Splinted implants had a higher risk of biologic complications and lower risk of mechanical complications. The implant splinted to both adjacent implants (SP-mid) had the highest risk of biologic complications. The greater the number of implants splinted, the lower the risk of mechanical complications. Long crown lengths increased the risk of both biologic and mechanical complications. [ABSTRACT FROM AUTHOR]

This article reports a rare case of a total knee arthroplasty femoral component fracture. Fractures of early knee systems were attributed to design flaws. Modern design failures have been attributed to poor surgical technique or underlying osteolysis. Here, we report a fracture in the Vanguard prosthesis (Zimmer Biomet, Warsaw, IN) 12 years after implantation in a patient with a persistent flexion contracture. The fracture likely occurred due to fatigue failure of the anterior flange secondary to increased stress from a high riding patella. Although femoral component fractures are rare, they should be considered as a potential complication, especially in patients with special load considerations. For these patients, it is essential that the prosthesis be properly supported with clean cuts and an adequate cement mantle.

Ulnar or humeral component stem fractures after total elbow arthroplasty (TEA) are serious complications. We hypothesized that TEA stem component fractures are fatigue fractures that result from periarticular osteolysis caused by bushing wear, which leads to a region of unsupported stem adjacent to a region where the stem is well-fixed. A review of 2637 primary and revision TEA cases from 1972 to 2016 revealed that 47 operations in 46 patients were complicated by or performed to deal with component stem fractures. Bushing wear was graded according to percentage loss of polyethylene thickness and metal wear. In the 39 cases in which bushing wear was able to be quantitated, it was severe in 34, moderate in 2, and mild in 3. Radiographs at final follow-up were available in 47 cases. All 47 cases showed evidence of periarticular osteolysis, which was in zone 1 in 17, in zones 1 and 2 in 29, and diffuse in 1. The length of the well-fixed stem, expressed as a percentage of total stem length, averaged 63% (range, 29%-86%). Stem fractures most often (27 of 47 cases) occurred at the junction between the well-fixed stem and unsupported stem. The median distance between the site of stem fracture and the unsupported–well-fixed stem junction was 0 mm (interquartile range, 0-5 mm). On the basis of our findings, a component stem fracture after TEA seems to occur by fatigue failure at or near the junction between an unsupported stem and well-fixed stem. This area of unsupported stem occurs as a result of osteolysis caused by bushing wear. The solution for component fractures requires a solution for bushing wear. [ABSTRACT FROM AUTHOR]

A hard or coarse diet may impart a substantial off-axial load to dental implant-supported prostheses and may induce a component, implant midbody fracture or late loss of integration. This may be especially true when there is a large crown to implant ratio. A patient who is able to generate an excessive bite force along with chronic cyclic loading with hard or coarse foods may have implant body or component fractures. There are no established parameters for crown to implant ratio or for detrimental bite loads. Implant longevity may be dependent on many factors, including the supporting bone quality and volume, crown to implant ratio, implant width and length, the prosthetic occlusal scheme and bite force/arch location, and the patient's dietary load. [ABSTRACT FROM AUTHOR]

The article describes a practical approach for assessing electronic circuit cards for mechanical shock loading. The effect of mechanical shock loading on electronic cards is critical for both military equipment and commercial products. With this regard, design engineers need a practical assessment in order to evaluate circuit cards for shock loading. On the other hand, the major cause of component failure due to shock loading is discussed with details on the strain under the component caused by the flexure of the board during the shock event.