Perioperative allogenic blood transfusions are associated with increased fracture related infection rates,but not nonunion in operatively treated distal femur fractures

IntroductionDistal femur fractures are common injuries that remain difficult for orthopedic surgeons to treat. High complication rates, including nonunion rates as high as 24% and infection rates of 8%, can lead to increased morbidity for these patients. Allogenic blood transfusions have previously been identified as risk factors for infection in total joint arthroplasty and spinal fusion surgeries. No studies have explored the relationship between blood transfusions and fracture related infection (FRI) or nonunion in distal femur fractures.Methods418 patients with operatively treated distal femur fractures at two level I trauma centers were retrospectively reviewed. Patient demographics were collected including age, gender, BMI, medical comorbidities, and smoking. Injury and treatment information was also collected including open fracture, polytrauma status, implant, perioperative transfusions, FRI, and nonunion. Patients with less than three months of follow up were excluded.Results366 patients were included in final analysis. One hundred thirty-nine (38%) patients received a perioperative blood transfusion. Forty-seven (13%) nonunions and 30 (8%) FRI were identified. Allogenic blood transfusion was not associated with nonunion (13% vs 12%, P = 0.87), but was associated with FRI (15% vs 4%, P<0.001). Binary logistic regression analysis identified a dose dependent relationship between number of perioperative blood transfusions and FRI: total transfusion ≥2 U PRBC RR= 3.47(1.29, 8.10, P = 0.02), ≥3 RR= 6.99 (3.01, 12.40, P<0.001), and ≥4 RR= 8.94 (4.03, 14.42, P<0.001).DiscussionIn patients undergoing operative treatment of distal femur fractures, perioperative blood transfusions are associated with increased risk of fracture related infection, but not the development of a nonunion. This risk association increases in a dose-dependent relationship with increasing total blood transfusions received.     

Pupillary Reflexes in Complex Regional Pain Syndrome: Asymmetry to Arousal Stimuli Suggests an Ipsilateral Locus Coeruleus Deficit

Converging lines of evidence suggest that autonomic and nociceptive pathways linked with the locus coeruleus are disrupted in complex regional pain syndrome (CRPS). To investigate this, pupillary dilatation to arousal stimuli (which reflects neural activity in the locus coeruleus) and pupillary reflexes to light were assessed in a cross-sectional study of 33 patients with CRPS. Moderately painful electrical shocks were delivered to the affected or contralateral limb and unilateral 110 dB SPL acoustic startle stimuli were delivered via headphones. To determine whether the acoustic startle stimuli inhibited shock-induced pain, startle stimuli were also administered bilaterally 200 ms before or after the electric shock. The pupils constricted briskly and symmetrically to bright light (500 lux) and dilated symmetrically in dim light (5 lux). However, the pupil on the CRPS-affected side was smaller than the contralateral pupil before and after the delivery of painless and painful arousal stimuli. Auditory sensitivity was greater on the affected than unaffected side but acoustic startle stimuli failed to inhibit shock-induced pain. Together, these findings suggest that neural activity in pathways linked with the locus coeruleus is compromised on the affected side in patients with CRPS. This may contribute to autonomic disturbances, auditory discomfort and pain.PerspectiveThe locus coeruleus is involved not only in modulation of pain but also regulates sensory traffic more broadly. Hence, fatigue of neural activity in the ipsilateral locus coeruleus might not only exacerbate pain and hyperalgesia in CRPS but could also contribute more generally to hemilateral disturbances in sensory processing.     

Comparing bone resorption after anatomical shoulder arthroplasty between various surgical procedures using a single-stem model

BackgroundIn shoulder arthroplasty, bone resorption around the stem can lead to stem loosening and makes surgery difficult at the time of revision. Proximal bone resorption after reverse shoulder arthroplasty can cause instability because of a decrease of deltoid wrapping effect. As factors of the stem itself, such as stem coating, shape, length, and use of bone cement, may also affect bone resorption, a single-stem model should be used to compare bone resorptions between different pathologies and surgical procedures. However, to date, a few reports have compared these differences in detail using a single-stem model. Therefore, we investigated the prevalence and location of humeral bone resorption in a single-stem model.MethodsThe study included 100 shoulders that underwent anatomical total shoulder arthroplasty (TSA) or humeral head replacement (HHR) with a single uncemented humeral stem from 2008 to 2018. The patients were 31 men and 69 women. The mean age at surgery was 72.9 years (range, 41-86 years). The patients were divided into three groups: especially, 25, 61, and 14 shoulders received TSA for primary osteoarthritis without rotator cuff tears (TSA group), HHR using an anatomical head with rotator cuff repair for cuff tear arthropathy (CTA) (HHR group), and HHR using a CTA head without rotator cuff repair (CTA group), respectively. Patients were monitored for a mean of 56 months (range, 12-98 months). The location of bone resorption was divided into seven zones as follows: zone 1, greater tuberosity; zone 2, lateral diaphysis; zone 3, lateral diaphysis beyond the deltoid tuberosity; zone 4, tip of the stem; zone 5, medial diaphysis beyond the deltoid tuberosity; zone 6, medial diaphysis; and zone 7, calcar region. The degree of bone resorption was classified from grade 0 to 4.ResultsBone resorption of grade 3 or higher was significantly more frequent at the greater tuberosity in the HHR and CTA groups (P < .001 and P < .001, respectively) than that in the TSA group. Grade 4 bone resorption was significantly more frequent in the CTA than that in the TSA and HHR groups in zone 1 (P = .016 and P = .041, respectively).ConclusionThe state of attachment of the rotator cuff to the greater tuberosity might affect bone resorption at the greater tuberosity, such as the greater tuberosity after shoulder arthroplasty. In cases of shoulder arthroplasty for arthropathy with rotator cuff tear, performing rotator cuff repair might prevent bone resorption.Level of evidenceLevel IV; Prognosis Study     

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

IntroductionThere 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 MethodsWe 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.ResultsOverall, 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.ConclusionOur 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.     

Automatic Grading Assessments for Knee MRI Cartilage Defects via Self-ensembling Semi-supervised Learning with Dual-Consistency

Knee cartilage defects caused by osteoarthritis are major musculoskeletal disorders, leading to joint necrosis or even disability if not intervened at early stage. Deep learning has demonstrated its effectiveness in computer-aided diagnosis, but it is time-consuming to prepare a large set of well-annotated data by experienced radiologists for model training. In this paper, we propose a semi-supervised framework to effectively use unlabeled data for better evaluation of knee cartilage defect grading. Our framework is developed based on the widely-used mean-teacher classification model, by designing a novel dual-consistency strategy to boost the consistency between the teacher and student models. The main contributions are three-fold: (1) We define an attention loss function to make the network focus on the cartilage regions, which can both achieve accurate attention masks and boost classification performance simultaneously; (2) Besides enforcing the consistency of classification results, we further design a novel attention consistency mechanism to ensure the focusing of the student and teacher networks on the same defect regions; (3) We introduce an aggregation approach to ensemble the slice-level classification outcomes for deriving the final subject-level diagnosis. Experimental results show that our proposed method can significantly improve both classification and localization performances of knee cartilage defects. Our code is available on https://github.com/King-HAW/DC-MT.