Original Article: The impacts of DRG payment system on financial balance of multiple trauma: Experiences of three trauma centers in Taiwan.

INTRODUCTION: There are concerns regarding the adequacy of applying the diagnosis-related groups (DRG) payment system for multiple traumas (i.e., major diagnostic category 24, MDC-24) patients in Taiwan. Therefore, this study used a multi-center dataset to assess the influence of the DRG payment system on the cost and outcome of multiple trauma care. MATERIALS AND METHODS: We collected data of all multiple trauma patients from the Trauma Registry of three hospitals from 2014 - 2017. Next, we selected patients who met the criteria of MDC-24 and calculated the corresponding DRG payment. Subsequently, we combined the clinical care information with health insurance information to analyze the problems of applying the DRG payment system to multiple trauma care. RESULTS: Overall, of 465 cases, 367 met the criteria of MDC-24, and the mean injury severity score (ISS) was high (average 20.1). The total deficit of the polytrauma DRG cases amounted to 131,445 USD, and the average deficit in each case was 397 USD. In the multivariable analysis, higher revised trauma score and specific lower abbreviated Injury Scale (AIS) scores in certain body regions resulted in profits, while increased length of stay in intensive care units, longer operative time, and higher AIS score in the thorax were significantly correlated with deficits in medical costs. CONCLUSION: Our study revealed that the current DRG payment system results in financial losses for hospitals. Further, the payment grouping of MDC-24 should consider adding more disease severity factors to reduce the financial constraints faced by trauma centers.

The preventability of trauma-related death: A two-year cohort study in a trauma center in middle Taiwan.

INTRODUCTION: The preventable death rate (PDR) is an important parameter in the quality assurance of traumatic care. Medical errors or untimely management may occur during stressful trauma care, resulting in preventable deaths. We aimed to develop an applicable PDR model in a trauma center in middle Taiwan. MATERIALS AND METHODS: We identified adult trauma-related deaths which occurred from January 1, 2018 to December 31, 2019 at our hospital. Patients with a trauma and injury severity score (TRISS) <75% or ≥75% but with a chance of preventability, as determined by a trauma surgeon, were discussed by a panel comprising an emergency physician and surgeons specializing in different fields of medicine. Deaths were subsequently classified as definitely preventable (DP), potentially preventable (PP), or non-preventable (NP). Causes of DP or PP deaths were categorized as delayed diagnosis, delayed treatment, technical error, or inadequate infection prevention/control. The relationship between the time and cause of preventable deaths was also analyzed. RESULTS: This study included 127 trauma-related deaths, of which 39 were discussed by the panel. Eight patients (6.3%) were categorized as DP, eight (6.3%) as PP, and 111 (87.4%) as NP. Among patients with preventable deaths, inadequate infection prevention/control, delayed treatment, delayed diagnosis, and technical error were identified in six (37.5%), five (31.2%), three (18.8%), and two (12.5%) patients, respectively. Four patients in the inadequate infection prevention/control group (4/6, 66.7%) died of aspiration pneumonia during the recovery phase. CONCLUSION: A PDR evaluation model was developed and revealed that postoperative care is as important as a timely diagnosis and treatment to avoid preventable deaths following trauma.

Increasing nail-cortical contact to increase fixation stability and decrease implant strain in antegrade locked nailing of distal femoral fractures: a biomechanical study.

BACKGROUND: Proximity of the distal locking screw to the fracture site potentially can cause implant failure in locked nailing of distal femoral fractures. In this biomechanical study, we investigated the effects of nail-cortical contact and nail purchase in the distal subchondral bone on fixation stability and implant strain. METHODS: Using fiberglass artificial femurs, we fixed five different distal femoral osteotomies with specially manufactured locked nails representing different conditions of nail-cortical contact. In each condition, six femur-nail constructs were loaded on the femoral head axially with 700 N; then we measured the fixation stability and strain at the superiormost distal locking screw and nail hole. The tests were conducted both with and without nail purchase in distal subchondral bone. RESULTS: When there was no nail-cortical contact, the load transmitted to the distal femoral fragment was completely borne by the nail and the distal locking screws. Low fixation stability and high strain on the distal screw and nail hole resulted. Greater nail-cortical contact increased the fixation stability and decreased strains on the distal screw and nail hole. Purchase of the nail tip in distal subchondral bone significantly increased the fixation stability and decreased nail hole strain except in the situation of long nail-cortical contact. The screw strain was significantly reduced in all conditions, and the reduction in strain was significantly greater than that associated with the nail hole, 32% +/- 8% versus 15.7% +/- 2.5% (p = 0.002). CONCLUSIONS: In locked nailing of distal femoral fractures, the prime factor determining fixation stability and implant strain is nail-cortical contact. In situations without nail-cortical contact, a longer nail with purchase in the subchondral bone of the distal femur is recommended.

Comparison of Mid-term Survivorship and Clinical Outcomes between Bipolar Hemiarthroplasty and Total Hip Arthroplasty with Cementless Stem: A Multicenter Retrospective Study.

OBJECTIVES: To compare the clinical outcome between bipolar hemiarthroplasty (BHA) and total hip arthroplasty (THA) using a U2 HA cementless hip stem, and the results of elderly femoral neck fracture patients who underwent BHA with a cementless hip stem. METHODS: A multicenter retrospective study enrolled 96 BHA and 115 THA cases using U2 HA cementless hip stems with mean age (BHA: 67.9 years; THA: 64.1 years), body height (BHA: 160.4 cm; THA: 160.7 cm) and weight (BHA: 62.7 kg; THA: 64.5 kg) recorded. Mean follow-up durations were, respectively, 7.1 (BHA) and 7.8 (THA) years. Survivorship analyses and Oxford hip scores were compared. RESULTS: Both the BHA and the THA groups revealed high survival rates at 5-year (100%) and 10-year (100.0% and 90.1%) follow-up. The THA group achieved better joint performance and pain relief. The cementless HA stems had survived perfectly for 10 years for elderly femoral neck fracture patients following BHA. CONCLUSIONS: The U2 HA cementless hip stem provides an effective solution for both BHA and THA surgeries, and for elderly femoral neck fracture patients undergoing BHA. According to the findings of the current study, THA may be inadequate for addressing avascular necrosis, and pain control is a considerable concern for patients who have undergone BHA.

Partially threaded headless screw may benefit adequate interfragmentary compression and reduced driving torque for small bone fixation.

Headless compression screws (HCSs) are commonly used to fixate small bones and articular fractures. Understanding the biomechanical efficacy of different HCS designs can help surgeons make proper interfragmentary compression when a specific implant is chosen. HCSs with three different central shaft designs (unthreaded, fully threaded, and partially threaded) were studied: the Herbert-Whipple, Mini-Acutrak 2, and headless reduction (HLR). Polyurethane foam blocks were machined with a simulated fracture gap of 0.5 mm and set onto a custom-made jig to simultaneously measure compression force and driving torque during screw insertion. The maximal achievable compression forces and driving torques recorded were 47.4 ± 0.9 N and 145.11 ± 1.65 N mm for the HLR, 50.98 ± 1.29 N and 152.62 ± 2.83 N mm for the Mini-Acutrak 2, and 19.33 ± 1.0 N and 33.4 ± 2.2 N mm for the Herbert-Whipple. Overall, the compression force of the Mini-Acutrak 2 and HLR increased with the torque. Unlike the other screws, the Herbert-Whipple's driving torque increased while the compression force decreased after peak compression force was achieved. The partially threaded shaft design (HLR) demonstrated equivalent biomechanical advantage with the Mini-Acutrak 2 in interfragmentary compression. The HCSs with cone-shaped proximal ends (HLR and Mini-Acutrak 2) maintained their compression force during over-fastening, whereas the unthreaded central shaft of the Herbert-Whipple screw caused it to lose compression force.

Larger screw diameter may not guarantee greater pullout strength for headless screws - a biomechanical study.

Headless compression screws (HCSs) are commonly utilized devices for small bone fracture fixation. The Mini-Acutrak 2 and headless reduction (HLR) screws are the newer version types, in which both have fully threaded and variable pitch design. Specifically, the HLR is characterized by two thread runouts to facilitate implantation. With the thread runouts, the holding strength of the screw may be compromised. To the best of our knowledge, no study has examined the pullout force of the global sizes of a HCS. We sought to determine the pullout strength of the HLR and compare the strength of this screw with that of the Mini-Acutrak 2. Synthetic bone blocks with simulated transverse fractures were used to conduct the tests. Four commonly used sizes of the HLR were examined, and one Mini-Acutrak 2 was employed for comparison. Five screws of each size were tested. The pullout force of all screws that were tested in this study ranged from 45.23 to 233.22 N. The results revealed that the pullout force increased as the screw diameter increased. Interestingly, we found that one small screw outperformed the Mini-Acutrak 2, which has a larger diameter. This study provided extensive knowledge regarding the pullout strength of fully threaded HCSs of different sizes. An unexpected finding is that a small screw has higher holding power than a large one because of its increased number of threads. Therefore, we suggest that the thread number should be a critical consideration for the design of size distribution of HCSs.

Heel Pad Stiffness in Plantar Heel Pain by Shear Wave Elastography.

The goal of the study was to evaluate the reliability of supersonic shear wave elastography in measuring heel pad stiffness and the change in heel pad stiffness in patients with plantar heel pain. In the reliability test involving 12 normal participants, each heel pad was tested six times in succession, and adequate reliability was reflected in the intraclass correlation coefficients (0.95, 0.93 and 0.96 for the microchambers, macrochambers and bulk heel pad, respectively). In the clinical assessment involving 20 normal participants and 16 unilateral plantar heel pain patients, diseased heel pads (86.8 ± 22.9, 36.8 ± 7.7 and 46.6 ± 10.9 kPa for the microchambers, macrochambers and bulk heel pad, respectively) were significantly stiffer than unaffected heel pads (66.8 ± 14.1, 25.2 ± 5.7, 34.2 ± 6.6 kPa) and those of normal participants (60.9 ± 11.4, 26.3 ± 6.1, 31.8 ± 6.3 kPa), suggesting that the heel pad with plantar heel pain was associated with loss of elasticity.

Combined image enhancement, feature extraction, and classification protocol to improve detection and diagnosis of rotator-cuff tears on MR imaging.

PURPOSE: The diagnosis of most rotator cuff tears (RCTs) relies upon magnetic resonance (MR) imaging, but direct capture of MR images without enhanced image processing leads to poor image contrast and potential misdiagnosis. Therefore, we developed a 2-stage model for the detection and diagnosis of injury of the supraspinatus tendon. METHODS: The first stage used coupled weighted histogram separation (WHS) to improve image enhancement, and the second stage extracted suspicious texture, features of both spatial and spectral domains, and sequential floating forward selection (SFFS) selected features conducive to classification of RCTs. We then tested injuries of the supraspinatus tendon using the classifier. RESULTS: The extraction of features by SFFS can increase detection of supraspinatus injury by reducing the input vector by 57.78% from the enhanced input images. The receiver operating characteristic (ROC) curve indicated an azimuth (Az) value of 84.38% when SFFS selected 76 features to construct a support vector machine (SVM) classifier from the enhanced images, compared with 56.94% when all 180 features from the raw input images were used for the construction. CONCLUSIONS: The performance of the classifier constructed by SFFS-selected features is superior to that using all features. These findings can serve as references to improve diagnosis and treatment of supraspinatus injuries.

Predicting rotator cuff tears using data mining and Bayesian likelihood ratios.

OBJECTIVES: Rotator cuff tear is a common cause of shoulder diseases. Correct diagnosis of rotator cuff tears can save patients from further invasive, costly and painful tests. This study used predictive data mining and Bayesian theory to improve the accuracy of diagnosing rotator cuff tears by clinical examination alone. METHODS: In this retrospective study, 169 patients who had a preliminary diagnosis of rotator cuff tear on the basis of clinical evaluation followed by confirmatory MRI between 2007 and 2011 were identified. MRI was used as a reference standard to classify rotator cuff tears. The predictor variable was the clinical assessment results, which consisted of 16 attributes. This study employed 2 data mining methods (ANN and the decision tree) and a statistical method (logistic regression) to classify the rotator cuff diagnosis into "tear" and "no tear" groups. Likelihood ratio and Bayesian theory were applied to estimate the probability of rotator cuff tears based on the results of the prediction models. RESULTS: Our proposed data mining procedures outperformed the classic statistical method. The correction rate, sensitivity, specificity and area under the ROC curve of predicting a rotator cuff tear were statistical better in the ANN and decision tree models compared to logistic regression. Based on likelihood ratios derived from our prediction models, Fagan's nomogram could be constructed to assess the probability of a patient who has a rotator cuff tear using a pretest probability and a prediction result (tear or no tear). CONCLUSIONS: Our predictive data mining models, combined with likelihood ratios and Bayesian theory, appear to be good tools to classify rotator cuff tears as well as determine the probability of the presence of the disease to enhance diagnostic decision making for rotator cuff tears.

Survival of patients aged over 80 years after Austin-Moore hemiarthroplasty and bipolar hemiarthroplasty for femoral neck fractures.

OBJECTIVES: Hemiarthroplasty is recommended for treatment of displaced femoral neck fractures in physically compromised elderly patients. The objective of this study was to analyze survival of patients aged >80 years after the implantation of either an Austin-Moore type prosthesis or a bipolar bearing prosthesis. METHODS: An Austin-Moore or bipolar hemiarthroplasty was implanted into 120 patients aged >80 years. Demographic data were collected. Survival rate at 5 years and factors related to mortality were analyzed. RESULTS: Sixty-two patients received Austin-Moore hemiarthroplasty, and 58 received bipolar hemiarthroplasty. No significant differences in gender, comorbid conditions, ASA scores, duration of hospitalization, intraoperative blood loss, duration from injury to operation, or postoperative morbidity between the two groups were found. However, patients who received the Austin-Moore hemiarthroplasty were older and had shorter operation time than those who received bipolar hemiarthroplasty. Kaplan-Meier estimates of 5 years survival were 40.0% for patients who received Austin-Moore hemiarthroplasty, and 62.9% for patients who received bipolar hemiarthroplasty. Cox proportional hazard regression analysis of risks factors of death revealed that patients who underwent Austin-Moore hemiarthroplasty were 2.0-fold more likely to die when compared to those who received bipolar hemiarthroplasty. CONCLUSIONS: Elderly patients who receive bipolar hemiarthroplasty may have a more favorable survival outcome when compared to those who receive unipolar hemiarthroplasty.

Influence of age-related degeneration on regenerative potential of human nucleus pulposus cells.

Nucleus pulposus (NP) cells, sourced from herniation surgeries, may be used as a cell-based therapy for intervertebral disc (IVD) degeneration. But, both the regenerative potential of these degenerative adult NP cells and how to stimulate optimum matrix synthesis is not yet clear. The purpose of the current study was to understand the different phenotypic behaviors between degenerative adult NP cells and normal adolescent NP cells. Degenerative adult NP cells produced a significantly higher amount of proteoglycans and collagens than adolescent cells. Insulin-like growth factor-1 was the only anabolic cytokine with increased endogenous expression in degenerative adult NP cells. TGF-beta1 treatment of degenerative NP cells promoted matrix synthesis but stimulated too much type I collagen and suppressed type II collagen and aggrecan. Adult degenerative NP cells possess upregulated regenerative potential, but stimulation in addition to TGF-beta1 is needed to enhance matrix productivity and optimize the collagen expression profile.

Comparison of artificial neural network and logistic regression models for predicting mortality in elderly patients with hip fracture.

PURPOSE: Older patients with hip fracture have a mortality rate one year after surgery of 20-30%. The purpose of this study is to establish a predictive model to assess the outcome of surgical treatment in older patients with hip fracture. METHODS: A database of information from 286 consecutive cases of surgery for hip fracture from the Department of Orthopedics, National Taiwan University Hospital Yun-Lin Branch, was utilised for model building and testing. Both logistic regression and artificial neural network (ANN) models were developed. Cases were randomly assigned to training and testing datasets. A testing dataset was utilised to test the accuracy of both models (n=89). RESULTS: The areas under the receiver operator characteristic curves of both models were utilised to compare predictability and accuracy. The logistic regression training and testing datasets had an area of 0.938 (95% CI: 0.904, 0.972) and 0.784 (95% CI: 0.669, 0.899), respectively, below the 0.998 (95% CI: 0.995, 1.000) and 0.949 (95% CI: 0.857, 1.000) of the final ANN model. CONCLUSION: Overall, ANNs have higher predictive ability than logistic regression, perhaps because they are not affected by interactions between factors. They may assist in complex decision making in the clinical setting.

Brachial plexus palsy caused by secondary fracture displacement in a patient with closed clavicle fracture.

In adults, brachial plexus injury due to clavicle fractures is rare, and is most commonly caused by nonunion, malunited fragments, hypertrophic callus, or pseudoaneurysm of the subclavicular artery or vein. Brachial plexus palsy in acute fractures caused by direct fragment compression is exceptional. Conservative treatment of nondisplaced and displaced midclavicle fractures in adults usually produces satisfactory outcomes. This article presents a case of a 74-year-old man who sustained a closed, midshaft right clavicle fracture complicated by secondary displacement and brachial plexus injury. Initially, the fracture was nondisplaced, and he was treated conservatively. However, he returned 2 weeks later with shoulder pain and coldness, progressive numbness, and weakness of the right extremity. Physical examination revealed weakness of the flexion and extension of his elbow, wrist, and finger joints with slightly diminished right side radial pulsation. Radiographs demonstrated a displaced clavicle fracture with a vertically angulated intermediate fragment and narrowed costoclavicular space. Magnetic resonance imaging revealed bony fragments with a perifocal soft tissue mass encroaching on the brachial plexus and axillary artery. During surgery, the brachial plexus was found to be markedly stretched due to compression by the bony fragments and an organized blood clot. After meticulous neurolysis, the blood clot and intermediate bony fragments were removed and the distal fragments were reduced and fixed with a metal plate and interfragmentary screws. Secondary fracture displacement is possible after a nondisplaced clavicle fracture if the arm is not well protected, even if the original fracture appears stable and no neurological or circulatory symptoms are present.

Synergic co-activation in forearm pronation.

Co-activations of agonist and antagonist muscles are believed to be present in voluntary limb movement. Recent studies indicate that such co-activations are either synergic or dyssynergic. The aims of this paper are to (1) develop a novel method that can extract both the intensity and frequency information from the recordings of the surface electromyograms (EMGs) of involved muscles, and (2) investigate if the involved muscles will be under synergic co-activation during voluntary forearm pronation for normal subjects and dyssynergic co-activation for patients with radial nerve palsy. We examined 11 healthy subjects and 4 patients with right-arm radial nerve palsy in this study. For the group of healthy subjects, each one of them was asked to perform 30 trials of voluntary forearm pronation and then 30 trials of passive pronation as control experiments. As to the second group of patients, each one was asked to perform only 15 trials of voluntary pronation due to the limitation and durability of their arms. The recordings of the surface EMGs included the short and long heads of the biceps brachii, the brachialis, the lateral head of the triceps brachii, brachioradialis, and pronator teres. Experimental results of the healthy group indicated that the surface EMGs of all muscles had no statistically significant changes in fractal dimensions (FDs) and spectral frequencies of the control experiments during passive pronation. Yet, during the voluntary pronation experiments, the surface EMGs of all muscle groups were temporally synchronized in frequencies with persistent intensities. Hence, all involved muscle groups were in synergic co-activation. Statistical results of the group mean values of FDs during rest vs. forearm pronation also revealed significant difference with p < 0.01 for healthy subjects. As to the group of patients, their EMGs could still have bursting activities, but the synchronized significant frequencies might be lacking or the intensities as indicated from their FDs would not be persistent. To further compare the FDs among the three different protocols, a mixed-model ANOVA and multiple comparison tests were performed. Finally, in order to illustrate the advantages of this novel method, we have compared it with the detrended fluctuation analysis (DFA). It is believed that this proposed method will have the potential to be a biomarker for evaluating dynamical disease in neuromuscular disorders.