Patient "No-Show" Increases the Risk of 90-Day Complications Following Primary Total Knee Arthroplasty: A Retrospective Cohort Study of 6,776 Patients

BACKGROUND

Patients who "no-show" (NS) clinical appointments are at a high risk of adverse health outcomes. The objective of this study was to evaluate and characterize the relationship between NS visits prior to primary total knee arthroplasty (TKA) and 90-day complications after TKA.

METHODS

We retrospectively reviewed 6,776 consecutive patients undergoing primary TKA. Study groups were separated based on whether patients who NS versus always attended their appointment. A NS was defined as an intended appointment that was not canceled or rescheduled ≤2 hours before the appointment in which the patient did not show. Data collected included total number of follow-up appointments prior to surgery, patient demographics, comorbidities, and 90-day postoperative complications.

RESULTS

Patients who have ≥3 NS appointments had 1.5 times increased odds of a surgical site infection (odds ratio (OR) 1.54, P = .002) compared to always attended patients. Patients who were ≤65 years old (OR: 1.41, P < .001), smokers (OR: 2.01, P < .001), and had a Charlson comorbidity index ≥3 (OR: 4.48, P < .001) were more likely to miss clinical appointments.

CONCLUSION

Patients who have ≥3 NS appointments prior to TKA had an increased risk for surgical site infection. Sociodemographic factors were associated with higher odds of missing a scheduled clinical appointment. These data suggest that orthopaedic surgeons should consider NS data as an important clinical decision-making tool to assess risk for postoperative complications to minimize complications following TKA.

A novel finite element-based patient-specific mitral valve repair: virtual ring annuloplasty

Alterations of normal mitral valve (MV) function lead to mitral insufficiency, i.e., mitral regurgitation (MR). Mitral repair is the most popular and most efficient surgical intervention for MR treatment. An annuloplasty ring is implanted following complex reconstructive MV repairs to prevent potential reoccurrence of MR. We have developed a novel finite element (FE)-based simulation protocol to perform patient-specific virtual ring annuloplasty following the standard clinical guideline procedure. A virtual MV was created using 3D echocardiographic data in a patient with mitral annular dilation. Proper type and size of the ring were determined in consideration of the MV apparatus geometry. The ring was positioned over the patient MV model and annuloplasty was simulated. Dynamic simulation of MV function across the complete cardiac cycle was performed. Virtual patient-specific annuloplasty simulation well demonstrated morphologic information of the MV apparatus before and after ring implantation. Dynamic simulation of MV function following ring annuloplasty demonstrated markedly reduced stress distribution across the MV leaflets and annulus as well as restored leaflet coaptation compared to pre-annuloplasty. This novel FE-based patient-specific MV repair simulation technique provides quantitative information of functional improvement following ring annuloplasty. Virtual MV repair strategy may effectively evaluate and predict interventional treatment for MV pathology.

Design and operational parameters of a rooftop rainwater harvesting system: definition, sensitivity and verification

The appropriate design and evaluation of a rainwater harvesting (RWH) system is necessary to improve system performance and the stability of the water supply. The main design parameters (DPs) of an RWH system are rainfall, catchment area, collection efficiency, tank volume and water demand. Its operational parameters (OPs) include rainwater use efficiency (RUE), water saving efficiency (WSE) and cycle number (CN). The sensitivity analysis of a rooftop RWH system's DPs to its OPs reveals that the ratio of tank volume to catchment area (V/A) for an RWH system in Seoul, South Korea is recommended between 0.03 and 0.08 in terms of rate of change in RUE. The appropriate design value of V/A is varied with D/A. The extra tank volume up to V/A of 0.15∼0.2 is also available, if necessary to secure more water. Accordingly, we should figure out suitable value or range of DPs based on the sensitivity analysis to optimize design of an RWH system or improve operation efficiency. The operational data employed in this study, which was carried out to validate the design and evaluation method of an RWH system, were obtained from the system in use at a dormitory complex at Seoul National University (SNU) in Korea. The results of these operational data are in good agreement with those used in the initial simulation. The proposed method and the results of this research will be useful in evaluating and comparing the performance of RWH systems. It is found that RUE can be increased by expanding the variety of rainwater uses, particularly in the high rainfall season.

Operational data of the Star City rainwater harvesting system and its role as a climate change adaptation and a social influence

The Star City rainwater harvesting system (RWHS) was featured in the December, 2008, issue of Water 21. The article highlighted that the RWHS has a 3,000 m3 rainwater tank used in water saving, flood mitigation, and emergency response. Since then, many news media, public officials, and people from both South Korea and abroad have visited the RWHS. In this paper, two years of the system's operational data are presented and its role in short- and long-term climate change adaptation is investigated. The downstream sewer system has become safe for a 50-year rainfall without upgrading the existing sewer system, which was designed for a 10-year period. The 26,000 m3 of water saved has reduced the energy requirement of transferring water from a distant area. The success of the Star City RWHS has influenced 47 cities across South Korea, including Seoul, to enact regulations on rainwater management. It has shown that decentralized rainwater management can supplement the existing centralized system to ensure its safety.

Particle behaviour consideration to maximize the settling capacity of rainwater storage tanks

Design of a rainwater storage tank is mostly based on the mass balance of rainwater with respect to the tank, considering aspects such as rainfall runoff, water usage and overflow. So far, however, little information is available on the quality aspects of the stored rainwater, such as the behavior of particles, the effect of retention time of the water in the tank and possible influences of system configuration on water quality in the storage tank. In this study, we showed that the performance of rainwater storage tanks could be maximized by recognizing the importance of water quality improvement by sedimentation and the importance of the system configuration within the tank, as well as the efficient collection of runoff. The efficiency of removal of the particles was increased by there being a considerable distance between the inlet and the outlet in the rainwater storage tank. Furthermore, it is recommended that the effective water depth in a rainwater tank be designed to be more than 3 m and that the rainwater be drawn from as close to the water surface as possible by using a floating suction device. An operation method that increases the retention time by stopping rainwater supply when the turbidity of rainwater runoff is high will ensure low turbidity in the rainwater collected from the tank.

Basal cell adenocarcinoma of the salivary gland--a case report

Basal cell adenocarcinoma of the salivary gland is a very rare disease entity as the malignant counterpart of basal cell adenoma. On the basis of morphologic pattern, basal cell adenoma can be divided into four subtypes; trabecular, solid, tubular, and dermal analogue (membranous). We report a case of basal cell adenocarcinoma in the left parotid gland of a 33-year-old woman. Light microscopically, the tumor cells were composed of relatively uniform, monotonous basaloid cells. The tumor cell nests commonly had peripheral palisadings. The main growth pattern of the tumor cells was tubulotrabecular. However, other portions were similar to dermal analogue monomorphic adenoma and showed cribriform patterns reminiscent of adenoid cystic carcinoma. The tumor had frequent perineural invasions and an infiltrative margin. On immunohistochemistry, only scattered numbers of tumor cells showed irregular positive reaction for S-100 protein, suggesting a few myoepithelial cell components of the tumor compared with most tumor cells derived from epithelial cells.