Fixation Strength of Polyetheretherketone Sheath-and-Bullet Device for Soft Tissue Repair in the Foot and Ankle

Tendon transfers are often performed in the foot and ankle. Recently, interference screws have been a popular choice owing to their ease of use and fixation strength. Considering the benefits, one disadvantage of such devices is laceration of the soft tissues by the implant threads during placement that potentially weaken the structural integrity of the grafts. A shape memory polyetheretherketone bullet-in-sheath tenodesis device uses circumferential compression, eliminating potential damage from thread rotation and maintaining the soft tissue orientation of the graft. The aim of this study was to determine the pullout strength and failure mode for this device in both a synthetic bone analogue and porcine bone models. Thirteen mature bovine extensor tendons were secured into ten 4.0?×?4.0?×?4.0-cm cubes of 15-pound per cubic foot solid rigid polyurethane foam bone analogue models or 3 porcine femoral condyles using the 5?×?20-mm polyetheretherketone soft tissue anchor. The bullet-in-sheath device demonstrated a mean pullout of 280.84 N in the bone analog models and 419.47 N in the porcine bone models. (p?=?.001). The bullet-in-sheath design preserved the integrity of the tendon graft, and none of the implants dislodged from their original position.     

Biomechanical Characteristics of Biplane Multiplanar Tension-Side Fixation for Lapidus Fusion

Although plating on the plantar, tension-side of the metatarsocuneiform joint provides an inherent biomechanical advantage for Lapidus arthrodesis, it has not been widely adopted owing to the morbidity associated with plantar application. To overcome these limitations, a modification to 90-90 locked biplanar plating was developed to provide the biomechanical advantages of multiplanar fixation and tension-side fixation, allowing application through a conventional incision. We tested the hypothesis that biplanar plating with tension-side fixation (low-profile straight dorsal plate and anatomic medial-plantar plate) would demonstrate improved mechanical stability compared with a previously tested 90-90 biplanar construct (small straight plate dorsally and medially) under cyclic loading. Both constructs were tested in static load to failure (3 pairs) and cyclic loading (10 pairs) with plantar cantilever bending using surrogate anatomic bone models. With static ultimate failure, the biplanar plate construct with tension-side fixation failed at a significantly greater failure load than did the straight biplanar plate construct (247.3?±?18.4 N versus 210.9?±?10.4 N; p?=?.04). With cyclic failure testing, the biplanar plate construct with tension-side fixation endured a significantly greater number of cycles (206,738?±?49,103 versus 101,780?±?43,273; p?<?.001) and a significantly greater dynamic failure load (207.5?±?24.3 N versus 162.5?±?20.6 N; p?<?.001) compared with the straight biplanar plate construct. These results have demonstrated that under simulated static and cyclic Lapidus arthrodesis loading, biplanar plating with tension-side fixation provides superior strength compared with the straight biplanar construct. Thus, this construct shows promise for clinical application as a practical approach to tension-side fixation and an early return to weightbearing after Lapidus fusion.     

Closing the gap on Achilles tendon rupture: A cadaveric study quantifying the tendon apposition achieved with commonly used immobilisation practices

The relative benefits of surgical and conservative treatment of Achilles tendon rupture are widely debated. With modern conservative management protocols, the re-rupture risk appears to fall to one similar to surgical repair with negligible loss of function. Conservative management typically employs a period of time in an equinus cast with sequential ankle dorsiflexion in a functional orthosis. The optimal duration of immobilisation and rate of dorsiflexion is unknown. We aimed to quantify the change in Achilles tendon approximation achieved in common immobilisation techniques to assist the design of rehabilitation protocols.Twelve fresh-frozen cadaveric specimens had 2.5 cm of Achilles tendon excised. The gap between the tendon ends were measured via windowed full equinus casts and compared with functional boots with successively removed heel wedges.The greatest tendon apposition was achieved with the equinus cast. Each wedge removed decreased the reapproximation by approximately 5 mm.This paper supports the early use of maximal equinus casting in early management of acute Achilles tendon ruptures.     

Lower Extremity Geometry in Morbid Obesity—Considerations for Total Knee Arthroplasty

Background

Obesity has been associated with varying adverse outcomes related to total knee arthroplasty (TKA) and has long been associated with various mechanical complications. Computational modeling holds promise for investigating biomechanical aberrations related to TKA in obese patients. However, basic anthropometric information regarding the shape of the lower extremity in obese patients is lacking. We, therefore, developed a method to determine lower extremity shape both generally and subject specific as a function of body mass index (BMI) and sex.

Machine Learning and Primary Total Knee Arthroplasty: Patient Forecasting for a Patient-Specific Payment Model

Background

Value-based and patient-specific care represent 2 critical areas of focus that have yet to be fully reconciled by today’s bundled care model. Using a predictive naïve Bayesian model, the objectives of this study were (1) to develop a machine-learning algorithm using preoperative big data to predict length of stay (LOS) and inpatient costs after primary total knee arthroplasty (TKA) and (2) to propose a tiered patient-specific payment model that reflects patient complexity for reimbursement.

基于SRK模型的护理人为差错类型分析及管理对策

目的了解护理人为差错的特点及其与不良事件的关系,为减少护理不良事件、保证患者安全提供依据。方法从某三级甲等医院的护士不良事件上报系统收集护理不良事件,根据SRK模型进行人为差错分类。结果共收集护理不良事件806起,其中护理人为差错占74.32%,非人为差错占25.68%;在护理人为差错中,规则型错误所占比例最高(58.43%),其次为技能型疏忽和技能型遗忘(分别为22.37%和11.69%),知识型错误和规则型疏忽占比较少(分别为7.18%和0.33%);不同类型护理人为差错导致的不良事件严重程度比较,差异有统计学意义(P<0.01);知识型错误、规则型错误导致的不良事件严重程度显著高于技能型遗忘和技能型疏忽(均P<0.01)。结论护理人为差错是导致护理不良事件的主要因素,知识型及规则型人为差错引起的护理不良事件后果较严重,需要从组织层面和个人层面防范护理人为差错的发生。