Resolution of Murine Toxic Hepatic Injury Quantified With Ultrasound Entropy Metrics

Image-based classification of liver disease generally lacks specificity for distinguishing between acute, resolvable injury and chronic irreversible injury. We propose that ultrasound radiofrequency data acquired in vivo from livers subjected to toxic drug injury can be analyzed with information theoretic detectors to derive entropy metrics, which classify a statistical distribution of pathologic scatterers that dissipate over time as livers heal. Here we exposed 38 C57BL/6 mice to carbon tetrachloride to cause liver damage, and imaged livers in vivo 1, 4, 8, 12 and 18 d after exposure with a broadband 15-MHz probe. Selected entropy metrics manifested monotonic recovery to normal values over time as livers healed, and were correlated directly with progressive restoration of liver architecture by histologic assessment (r² ≥ 0.95, p < 0.004). Thus, recovery of normal liver microarchitecture after toxic exposure can be delineated sensitively with entropy metrics.     

Can the use of femoral notch view alone decrease measurement error of distal interlocking screws after retrograde femoral nailing

ObjectivesDetermine if using different fluoroscopic views of the knee (Notch or Tangential) improves accuracy of screw lengths assessment compared to the standard posteroanterior (PA).Participants and Methods: Orthopaedic surgeons at three ACGME-accredited residency programs were asked via survey to assess screw lengths on PA, femoral notch, and tangential radiographic views.ResultsResponders correctly identified screw length using PA, femoral notch, and medial tangential views at rates of 46.75%, 52.27%, and 44.37% respectively. Respondents detected overall screw length discrepancies most accurately using the femoral notch view (Odds Ratio 1.26; 95% confidence interval: 1.07–1.47; P < 0.005). There was no statistical difference between the residents and faculty cohort in ability to detect screw length discrepancy.ConclusionDifferentiating distal interlocking screw lengths on traditional imaging (AP/Notch/Tangential) is poor. The femoral notch view significantly improves accuracy in radiographic determination of screw length. The femoral notch view should be used in conjunction with the traditional PA view to maximize sensitivity and specificity for detecting prominent screws.     

Outpatient anterior cervical discectomy and fusion: A meta-analysis

Anterior cervical discectomy and fusion (ACDF) performed as an outpatient has become increasingly common for treating cervical spine pathology, largely due to its cost savings compared with inpatient ACDF. Nearly all outpatient ACDF patient reports have originated from single-center studies, with the procedure yet to be addressed via a meta-analysis of the peer-reviewed literature. The Entrez gateway of the PubMed database was used to conduct a comprehensive literature search for articles published in English up to 3/9/16. Data from studies meeting inclusion criteria (minimum of 25 patients, control group of inpatient ACDF patients, non-duplicative data source) was then categorized and assimilated for analysis. Seven studies met inclusion criteria, encompassing a 21-year timespan. Each provided Oxford Center for Evidence-Based Medicine Level 3 evidence. The studies yielded a total of 2448 outpatient ACDF patients; only 125 (5.1%) originated from studies published prior to 2011. Single-level surgery occurred in 63.8% of patients, with 0.5% extending beyond two-level fusions. The overall complication rate was 1.8% (mean follow-up of 141.2 days); only 2% of patients required readmission. In conclusion, outpatient ACDF has become increasingly popular, with more than 95% of patients represented by studies published since 2011. Nearly two-thirds of outpatient ACDFs underwent single-level fusion, with virtually none undergoing 3+ level ACDF. Outpatient ACDF is safe, with a low readmission rate and complication rates comparable to those (2–5%) associated with inpatient ACDF. These findings support an argument for increasing ACDFs performed on an outpatient basis in appropriately selected patients.     

Presence and magnitude of anterior physeal separation in slipped upper femoral epiphysis helps identifying those at high risk for avascular necrosis

AimsWe sought to determine if the magnitude of anterior physeal separation (APS) in slipped upper femoral epiphysis was a predictor for the subsequent development of avascular necrosis (AVN). Anterior Physeal Separation (APS) is defined as the distance between the anterior lip of the bony capital epiphysis and the lateral corresponding point of the adjacent bony metaphysis on the Lauenstein radiographic view. It represents hinging of the posterior aspect of the metaphysis with the anterior epiphysis lifting away from its adjacent metaphysis, indicating instability and potential vulnerability of the vessels.Patients and MethodsA retrospective review of all patients treated regionally for slipped upper femoral epiphysis over a 9 year period (2010–2018 inclusive) were identified. Data regarding demographics, radiological parameters and outcomes was recorded. APS was measured on a Launestein radiograph view, with the patient supine, the hip and knee are flexed to 40°, and the hip externally rotated 45°, with film-focus distance of 100 cm. Analysis of the APS was performed to validate a threshold above which AVN occurs.ResultsWe identified 147 hips in 142 patients, of which 5 had bilateral slips at the time of presentation. Average anterior physeal separation was 3.8 ± 1.8 mm, with higher grade slips having significantly greater APS values. Increased APS values were seen with Loder “unstable” slips. Seven hips (4.8%) developed AVN, and in these cases the APS was significantly larger than those who did not (8.5 ± 1.4 Vs 3.9 ± 1.7; p < 0.001). Receiver operator curve analysis demonstrated a critical value of 7.5 mm was associated with a 100% sensitivity and 98.6% specificity for AVN. We identified some grade II/moderate slips with high APS values had similar outcomes to grade III/severe slips, and therefore suggest that APS may serve to alert the surgeon on counselling patients on the risk of developing AVN and to consider strategies to minimise the risk of AVN.ConclusionsAPS is sensitive, specific, accurate and reliable for the association with AVN in SUFE. Its values closely reflect the high AVN rates seen in acute and unstable SUFE. This risk is greatest if the magnitude of APS exceeds the critical value of 7.5 mm.     

Freeze-dried and irradiated allograft bone combined with fresh autologous coagula promotes angiogenesis in an ectopic bone allograft implantation model

Background: Freeze-dried and irradiated allograft bone (FIAB) is more easily impacted than fresh-frozen allograft bone (FAB), but has weaker incorporation efficiency. We combined FIAB with fresh autologous coagula to enhance donor-host incorporation after impaction during hip revision. Methods: Thirty adult male Sprague–Dawley (SD) rats were sacrificed for bone allograft harvesting, and nine male rats were subjected to ectopic bone allograft implantation. For each rat, the container on the left (study) side was filled with freeze-dried allograft bone powder and fresh autologous blood coagula, whereas the right (control) side was filled with freeze-dried allograft bone powder and physiological saline. The extent of angiogenesis (VEGFα) was investigated at postoperative weeks 1, 4, and 8. The deformability of the material was evaluated by performing a confined-impaction mechanical test. Results: At postoperative weeks 4 and 8, angiogenesis within FIAB on the left side was more pronounced than that on the right side. At postoperative week 1, the left side showed significantly higher VEGFα expression than that on the right side. The delta ratios of compression of the allografts were found to be influenced by bone height and impaction frequency, but not by stiffness or elastic modulus (EM). Conclusion: Supplementation with fresh autologous coagula promoted angiogenesis within the FIABs. Moreover, FIABs were equivalent to FABs in terms of deformability.     

枢椎椎弓根螺钉置钉失误的影像学分析

目的:分析枢椎椎弓根螺钉置钉失误的原因,探讨提高置钉成功率的方法。方法:2002年1月～2006年12月我院因上颈椎外伤、脱位和肿瘤接受寰枢椎后路内固定手术的患者50例,共置入100枚枢椎椎弓根螺钉。根据术前CT薄层扫描结果将枢椎椎动脉孔分为Ⅰ、Ⅱ、Ⅲ、Ⅳ型;在术后颈椎侧位X线片上测量枢椎椎弓根螺钉钉道上倾角,在术后CT片上测量钉道内倾角,并根据CT结果将置钉失误分为两类,A类为钉道偏内指向椎管,B类为钉道偏外指向椎动脉孔。结果:100个枢椎椎动脉孔分为Ⅰ型76个,Ⅲ型10个,Ⅳ型14个。100枚枢椎椎弓根螺钉共发生A类失误8枚(8%),其中Ⅰ型5枚,Ⅲ型1枚,Ⅳ型2枚;B类失误2枚(2%),其中Ⅲ型、Ⅳ型各1枚。Ⅰ型、Ⅲ型、Ⅳ型的置钉失误率分别为6.6%、20%、21.4%。A类失误组的钉道上倾角为14.8°±8.5°,明显小于钉道正确组的18.3°±9.7°(P<0.05),B类失误组为17.5°±6.8°,与正确钉道组无显著性差异(P>0.05)。A类失误组的钉道内倾角为21.4°±7.1°,明显小于钉道正确组的33.7°±7.3°(P<0.05);B类失误组为44.9°±8.8°,明显大于正确钉道组(P<0.05)。结论:枢椎椎动脉孔的解剖变异是导致置钉失误的客观因素;而术中钉道内倾角和上倾角偏小是引起置钉失误的最常见原因。术前应根据CT扫描结果充分掌握枢椎椎动脉孔的特点,结合"宁上勿下,宁内勿外"的原则,合理把握钉道方向,以提高置钉成功率。     

Analysis of total joint arthroplasty costs in chinese patients

All charges for patients undergoing unilateral and bilateral hip or knee arthroplasties at 1 hospital in Beijing, China, were identified and assigned to 1 of 11 charge categories: hospital room, nursing, radiology, laboratory, anesthesia, surgery, prosthesis, pharmacy, blood transfusion, materials, and miscellaneous. The prosthesis and pharmacy charges at this institution accounted for approximately 80% of the total charges; compared with published data from institutions in North America and Taiwan, these 2 charges accounted for a greater percentage of total charges. In distinction, labor costs in China accounted for a lower percentage of total charges. Importantly, because the percentage of costs covered by medical insurance was relatively low, a substantial financial burden was imposed on patients that may limit access to joint arthroplasty in China.     

Preoperative pain sensitivity predicts postoperative pain severity and analgesics requirement in lumbar fusion surgery – a prospective observational study

BACKGROUND CONTENTThe goal of postoperative pain management is to facilitate the patient's return to normal activity and decrease the detrimental effects of acute postsurgical pain. In order to provide more tailored and successful pain treatment, it is necessary to identify individuals who are at a high risk of experiencing severe postoperative pain. The most precise way to assess pain sensitivity is by determining the pressure pain threshold and heat pain threshold by objective methods using a digital algometer and neurotouch respectively.PURPOSEThe primary aim of the study is to assess the preoperative pain threshold and its influence on postoperative pain severity and analgesics requirements in patients undergoing lumbar fusion surgeries.STUDY DESIGNProspective, observational study.PATIENT SAMPLESixty patients requiring a single-level lumbar fusion surgery.OUTCOME MEASURESPostoperative pain intensity and the amount of postoperative analgesics consumption.METHODSIn our patients, preoperative pain sensitivity was assessed by pressure pain threshold measurements with the help of a digital algometer, and heat pain threshold using a neurotouch instrument. In addition, pain sensitivity questionnaires (PSQ) were used in all our patients to determine pain sensitivity. Preoperative psychosocial and functional assessments were performed by Hospital anxiety-depression scores (HADS), and Oswestry disability index (ODI) respectively. Preoperative visual analog scale (VAS) score was determined at three instances of needle prick (phlebotomy, glucometer blood sugar, and intradermal antibiotic test dose) and during the range of movements of the lumbar spine region. Postoperative VAS score and postoperative breakthrough analgesic requirements were recorded in all of these patients from day 0 to day 3.RESULTSThe average age of the patients was 51.11±13.467 years and 70% were females. Females had lower mean algometry values (72.14±7.56) compared to males (77.34±6.33). Patients with higher HADS (p<.0016), higher PSQ (p<.001), higher ODI scores(p<.001), and female gender significantly correlated with a lower algometer average indicating high pain sensitivity. Patients with lower preoperative VAS scores and with higher neurotouch scores showed lower postoperative VAS scores at different time periods. Preoperative VAS scores, algometer average scores, neurotouch scores, and HADS scores were considered as independent variables (predictors) for postoperative VAS at 6 hours period. By the multivariate analysis, factors like preoperative VAS scores, algometer average scores, and HADS scores were statistically significant (p<.05). There was a significant correlation between algometer average scores (p<.001) with the breakthrough analgesics.CONCLUSIONPreoperative assessment of pain sensitivity can predict postoperative analgesic requirements and aid in recovery. Patients with a lower pain threshold should be counseled preoperatively and also receive a better titration of analgesics perioperatively.     

Impact of neoadjuvant chemotherapy on the difficulty and outcomes of laparoscopic and robotic major liver resections for colorectal liver metastases: A propensity-score and coarsened exact-matched controlled study

BackgroundMinimal invasive liver resections are a safe alternative to open surgery. Different scoring systems considering different risks factors have been developed to predict the risks associated with these procedures, especially challenging major liver resections (MLR). However, the impact of neoadjuvant chemotherapy (NAT) on the difficulty of minimally invasive MLRs remains poorly investigated.MethodsPatients who underwent laparoscopic and robotic MLRs for colorectal liver metastases (CRLM) performed across 57 centers between January 2005 to December 2021 were included in this analysis. Patients who did or did not receive NAT were matched based on 1:1 coarsened exact and 1:2 propensity-score matching. Pre- and post-matching comparisons were performed.ResultsIn total, the data of 5189 patients were reviewed. Of these, 1411 procedures were performed for CRLM, and 1061 cases met the inclusion criteria. After excluding 27 cases with missing data on NAT, 1034 patients (NAT: n = 641; non-NAT: n = 393) were included. Before matching, baseline characteristics were vastly different. Before matching, the morbidity rate was significantly higher in the NAT-group (33.2% vs. 27.2%, p-value = 0.043). No significant differences were seen in perioperative outcomes after the coarsened exact matching. After the propensity-score matching, statistically significant higher blood loss (mean, 300 (SD 128–596) vs. 250 (SD 100–400) ml, p-value = 0.047) but shorter hospital stay (mean, 6 [4], [5], [6], [7], [8][4], [5], [6], [7], [8] vs. 6 [5], [6], [7], [8], [9][5], [6], [7], [8], [9] days, p-value = 0.043) were found in the NAT-group.ConclusionThe current study demonstrated that NAT had minimal impact on the difficulty and outcomes of minimally-invasive MLR for CRLM.     

Chinese Experts Consensus and Practice Guideline on Discoid Lateral Meniscus

Discoid lateral meniscus (DLM) is the most common congenital variant of the lateral meniscus, which is prone to degeneration and lesions, and often leads to knee osteoarthritis. At present, there is no consensus on the clinical practice of DLM, and this expert consensus and practice guidelines on DLM was developed and approved by Chinese Society of Sports Medicine according to the Delphi method. Among 32 statements drafted, 14 statements were excluded for redundant information, and 18 statements achieved consensus. This expert consensus focused on the definition, epidemiology, etiology, classification, clinical manifestations, diagnosis, treatment, prognosis, and rehabilitation of DLM. Restoring the normal shape, retaining appropriate width and thickness, and ensuring the stability of the remnant meniscus is critical to sustaining the physiological function of the meniscus and preserving the knee. The partial meniscectomy with or without repair should be the first-line treatment when possible, given that the clinical and radiological long-term outcomes of total or subtotal meniscectomy are worse.