Thompson Score Research Articles

A Comparison of the Thompson Encephalopathy Score and Amplitude-Integrated Electroencephalography in Infants with Perinatal Asphyxia and Therapeutic Hypothermia

Background: In previous studies clinical signs or amplitude-integrated electroencephalography (aEEG)-based signs of encephalopathy were used to select infants with perinatal asphyxia for treatment with hypothermia. Aim: The objective of this study was to compare Thompson encephalopathy scores and aEEG, and relate both to outcome. Subjects and Methods: Thompson scores, aEEG, and outcome were compared in 122 infants with perinatal asphyxia and therapeutic hypothermia. Of these 122 infants, 41 died and 7 had an adverse neurodevelopmental outcome. A receiver operating characteristics (ROC) analysis was also performed. Results: Thompson scores were higher in infants with more abnormal aEEG background patterns (ANOVA, p < 0.001). The ROC analysis demonstrated that a Thompson score of 11 or higher or an aEEG background pattern of continuous low voltage or worse was associated with an adverse outcome (AUC 0.84 for both). Conclusions: High Thompson scores and a suppressed aEEG background pattern are associated with an adverse outcome after perinatal asphyxia and therapeutic hypothermia. Further studies are needed to identify the best technique with which to select patients for therapeutic hypothermia

The Thompson Encephalopathy Score and Short-Term Outcomes in Asphyxiated Newborns Treated With Therapeutic Hypothermia

BackgroundThe Thompson encephalopathy score is a clinical score to assess newborns suffering from perinatal asphyxia. Previous studies revealed a high sensitivity and specificity of the Thompson encephalopathy score for adverse outcomes (death or severe disability). Because the Thompson encephalopathy score was developed before the use of therapeutic hypothermia, its value was reassessed. ObjectiveThe purpose of this study was to assess the association of the Thompson encephalopathy score with adverse short-term outcomes, defined as death before discharge, development of severe epilepsy, or the presence of multiple organ failure in asphyxiated newborns undergoing therapeutic hypothermia. MethodsThe study period ranged from November 2010 to October 2014. A total of 12 tertiary neonatal intensive care units participated. Demographic and clinical data were collected from the “PharmaCool” multicenter study, an observational cohort study analyzing pharmacokinetics of medication during therapeutic hypothermia. With multiple logistic regression analyses the association of the Thompson encephalopathy scores with outcomes was studied. ResultsData of 142 newborns were analyzed (male: 86; female: 56). Median Thompson score was 9 (interquartile range: 8 to 12). Median gestational age was 40 weeks (interquartile range 38 to 41), mean birth weight was 3362 grams (standard deviation: 605). All newborns manifested perinatal asphyxia and underwent therapeutic hypothermia. Death before discharge occurred in 23.9% and severe epilepsy in 21.1% of the cases. In total, 59.2% of the patients had multiple organ failure. The Thompson encephalopathy score was not associated with multiple organ failure, but a Thompson encephalopathy score ≥12 was associated with death before discharge (odds ratio: 3.9; confidence interval: 1.3 to 11.2) and with development of severe epilepsy (odds ratio: 8.4; confidence interval: 2.5 to 27.8). ConclusionThe Thompson encephalopathy score is a useful clinical tool, even in cooled asphyxiated newborns. A score ≥12 is associated with adverse outcomes (death before discharge and development of severe epilepsy). The Thompson encephalopathy score is not associated with the development of multiple organ failure.

The Effect of Bone Morphogenetic Protein-2 on Chondrocyte-like Cells Derived from Degenerated Human and Canine Intervertebral Discs

Introduction Both humans and dogs experience low back pain, which is related to intervertebral disc (IVD) degeneration. Biologic repair of the degenerated IVD is mainly based on growth factors that exert anabolic matrix effects, and mesenchymal stromal cells (MSCs) to replenish the cell population of the degenerated IVD. Thus far, the anabolic effects of different growth factors have not been compared. The aim of this study was to study the effect of the frequently used growth factors transforming growth factor β 1 (TGF-β1) and bone morphogenetic protein-2 (BMP-2) on canine and human chondrocyte-like cells (CLCs) from degenerated IVDs alone and in combination with MSCs. Material and Methods CLCs from degenerated human, canine chondrodystrophic (CD) and non-chondrodystrophic (NCD) IVDs (Thompson score III) were cultured in micro-aggregates in base culture medium (negative control), or supplemented with TGF-β1 (10 ng/mL) or BMP-2 (100 or 250 ng/mL) for 28 days. The additive effect of MSCs was studied in CD CLCs. Canine male CD CLCs were cultured in an albumin-based hydrogel (3*106 cells/mL) with or without the addition of female bone marrow-derived MSCs (BMSCs) (CLC:BMSC 1:1) in control or 250 ng/mL BMP-2-supplemented culture medium for 28 days. Read out parameters were extracellular matrix (ECM) production (RT-qPCR, glycosaminoglycan (GAG) production, Safranin O/Fast Green staining, immunohistochemistry), cell proliferation (DNA content, RT-qPCR) and apoptosis (RT-qPCR). Results TGF-β1 treatment increased GAG deposition in human and canine CLC micro-aggregates, but also induced collagen type I deposition and a fibrotic rim. The latter was not observed in BMP-2-treated micro-aggregates. 250 ng/mL BMP-2 was more potent than 100 ng/mL BMP-2 in increasing GAG deposition and DNA content in canine and human micro-aggregates. Similarly, in the hydrogel culture system, BMP-2 induced GAG and collagen type II deposition and a higher DNA content compared with untreated controls. DNA and GAG content of BMSC+CLC hydrogels was higher than hydrogels with CLCs alone in the absence of BMP-2. In the BMP-2-treated hydrogels, DNA content of BMSC+CLC was higher than hydrogels with CLCs alone; GAG deposition or release was comparable between BMSC+CLC and CLC alone in the presence of BMP-2. Conclusion In two different 3D culture systems, BMP-2 exerted comparable regenerative effects as TGF-β1 on human and canine CLCs in terms of GAG deposition and cell proliferation, but BMP-2 did not induce fibrotic (re)differentiation as observed with TGF-β1 treatment. Moreover, in the BMP-2-treated BMSC:CLC-containing hydrogels, where only half of the amount of CLCs were seeded compared with CLC alone, the DNA content was higher and an equal amount of GAGs was deposited, indicating that the BMSCs exerted an additional, regenerative effect in addition to BMP-2 treatment. PCR for SRY:GAPDH genes on DNA will indicate the ratio male(CLCs):female(BMSCs) present at the end of the study. This will indicate whether the BMSCs exerted trophic effects or chondrogenically differentiated. Acknowledgments This work was supported by an AOSpine Research Network grant (SRN2011_11) and the Dutch Arthritis Foundation (LLP22).

To Study the Correlation of Thompson Scoring in Predicting Early Neonatal Outcome in Post Asphyxiated Term Neonates.

Throughout the world each year, an estimated 23% of the 4 million neonatal deaths and 8% of all deaths in <5 years of age are associated with signs of asphyxia at birth. To study the role of cord arterial blood gas analysis at birth and serial Thompson score in predicting the early neonatal outcome in post asphyxiated term neonates. The study was conducted in Department of Paediatrics, in Neonatal Intensive Care Unit (NICU), Hindu Rao Hospital, New Delhi from May 2014 to February. 2015. This study was a prospective cross-sectional study. During this period, a total of 145 post asphyxiated term neonates born in labour room/obstetric operation theatre were recruited. An informed consent was taken from all the parents. The protocol was approved by the institutional ethical committee. Inclusion criteria were full-term babies with low-Apgar score i.e., 1 min score of ≤ 7 National Neonatal Perinatal Database 2010 (NNPD 2010). SPSS 17.0 Software has been used for data analysis. The data were expressed in terms of Means, Standard Deviation and Proportion, followed by comparison between groups through chi-square test or Fisher's-exact test. A p-value of less than 0.05 was considered as statistically significant. The present study was carried out on 145 post asphyxiated full-term babies with low-Apgar score i.e., 1min score of ≤7mild Thompson score on day I,2,3 were 96 (66.2%), 119 (82.06%), 125 (86.20%), moderate Thompson score on day 1,3, 7 were 13 (8.9%), 6 (4.13%), 2 (1.37%) and severe Thompson score on day 1, 3, 7 were 36 (24.8%), 13 (8.96%), 7 (4.82%) respectively. Total 11 patients died out of 145 post asphyxiated full-term babies within 7 days, among 11 patients, 7 died within 3 days. There was clinical improvement among HIE patients as indicated by serial Thompson score done on day 1, 3 and 7. Among 145 patients 62(42.8%) had seizure and 83(57.2%) did not have seizure. Most common type of seizure was subtle seizure in 25 (40.3%) followed by multifocal in 21 (33.9%) and tonic in 16(25.8%). There is statistically significant correlation between morbidity and day 1 Thompson score (p-value 0.024). There is statistically significant correlation between mortality and day 1 Thompson score (p-value 0.001). Thompson score allows a very precise description of infants by assigning a numeric score rather than 'mild', 'moderate' or 'severe'. Inter-rater reliability is very good with a kappa co-efficient of 0.87.

PS-155 Comparison Of Clinical And Electrophysiological Signs Of Encephalopathy In Neonates With Perinatal Asphyxia Qualifying For Hypothermia

Background and aims Early prediction of neurodevelopmental outcome following hypoxic-ischaemic encephalopathy remains a challenge. The aim of this retrospective study was to evaluate the aEEG background patterns and Thompson score on admission in asphyxiated neonates receiving hypothermia regarding outcome and neonatal variables. Methods After excluding congenital malformations and muscle paralysis, 89 neonates (January 2008 to June 2012) were included (GA: 39.7 ± 1.8 wks; BW: 3504 ± 640 g). On admission the Thompson score and aEEG were recorded. aEEG was scored as Continuous Normal Voltage (CNV), Discontinuous Normal Voltage (DNV), Burst-Suppression (BS), Continuous Low Voltage (CLV) or Flat Trace (FT). The combination of one or more of the following event (s): death, cerebral palsy, and Griffiths DQ less than 85 at 18 months were considered an adverse outcome. ANOVA, correlation, and binary logistic regression analyses were performed. Results Thompson scores (in mean ± sd) were associated with aEEG pattern (CNV: 8.3 ± 1.7; DNV: 8.9 ± 1.9; BS: 11.6 ± 3.6; CLV: 12.0 ± 2.1; FT: 13.1 ± 3.2; p Conclusions Both Thompson scores and aEEG are associated with outcome in neonates receiving hypothermia for perinatal asphyxia and with 1 min Apgar scores. Further studies are needed to identify which method is preferable for selection of neonates for hypothermia.

Clinical and Radiographic Outcomes of Femoral Head Fractures Associated with Traumatic Hip Dislocations.

ABSTRACTBackgroundFemoral head fractures are an uncommon but severe injury. These high-energy injuries typically occur in association with traumatic hip dislocations. Initial treatment includes urgent concentric reduction; however, controversy exists regarding specific fracture management. The well-known complications of avascular necrosis (AVN), posttraumatic arthritis (PTA), and heterotrophic ossification can leave patients with a significant functional loss of their affected hip. The purpose of this study is to evaluate the clinical and radiographic outcomes of femoral head fractures.MethodsA retrospective review was performed at our institution assessing all patients who presented from 2007 to 2015 with a femoral head fracture associated with a hip dislocation and at least 6 months of clinical and radiographic follow-up. Twenty-two patients met our inclusion criteria. There were 15 males and 7 females with an average age of 36 years (range: 17–55). The average follow-up time was 18 months (range: 6–102). Fractures were classified according to the Pipkin classification. The Thompson and Epstein score was used to determine functional outcomes.ResultsThere were five, Pipkin I, 3 Pipkin II, 0 Pipkin III, and 14 Pipkin IV, femoral head fractures. Sixteen patients were successfully closed reduced in the emergency department (ED) and six patients required open reduction after failed reduction in the ED. Four patients (18%) were successfully treated with closed reduction alone and 18 patients (82%) required operative intervention. Of those undergoing operative intervention, one patient underwent excision of the femoral head fragment, seven underwent open reduction internal fixation (ORIF) of the femoral head, nine underwent ORIF of the acetabulum, and one underwent ORIF of the femoral head and the acetabulum. Nine patients (41%) had an uneventful postoperative course. Two patients (9%) developed AVN, both requiring total hip arthroplasty (THA). Five patients (23%) developed PTA, two eventually requiring a THA. Two patients (9%) had sciatic nerve palsy. One patient (5%) developed a postoperative infection and four patients (18%) developed heterotrophic ossification (HO), none requiring operative treatment. Two patients (9%) had persistent anterolateral (AL) thigh numbness. Overall functional results were excellent in six patients (27%), good in six (27%), fair in seven (32%), and poor in three patients (14%). Four patients (18%) required a THA.ConclusionFemoral head fractures are a rare injury with well-known complications. Early diagnosis and concentric reduction are the prerequisites for successful treatment. This study adds to the growing literature on femoral head fractures associated with hip dislocations in efforts to define treatment plans and to guide patient expectations.How to cite this articleDel Core MA, Gross B, Ahn J, et al. Clinical and Radiographic Outcomes of Femoral Head Fractures Associated with Traumatic Hip Dislocations. Strategies Trauma Limb Reconstr 2019;14(1):6–10.

8.9 Microstructural Changes in Neonatal Encephalopathy Revealed with the Neurite Orientation Dispersion and Density Imaging (NODDI) Model

BackgroundAlthough diffusion tensor imaging (DTI) fractional anisotropy (FA) is commonly used to quantify neural injury, it is non-specific and affected by a number of microstructural changes.ObjectiveTo examine alterations in white...

PC.106 Cerebral Injury and Early Childhood Neurodevelopmental Outcome following Neonatal Encephalopathy in a Middle-income Country

BackgroundAlthough neonatal encephalopathy (NE), accounts for 1 million neonatal deaths annually in low-and middle-income countries (LMIC), underlying brain injury and long term outcomes are not well characterised in LMIC.ObjectiveTo examine...

Evolution of the Thompson score during the first 6 h in infants with perinatal asphyxia

This study aimed to determine the evolution of the Thompson score, which provides composite grading of encephalopathy signs, during the first 6 h of birth in neonates with perinatal asphyxia. Twenty term infants with perinatal asphyxia were prospectively studied from the University Hospital of Kinshasa during a 12-month period. The Thompson score was performed after 1 h, then hourly until 6 h of birth. Fourteen infants had a Thompson score ≥7 and six had a score <7 after 1 h of birth. The Thompson score remained higher than 7 after 3 h in nine infants (64.3%) and in four infants (25.6%) after 6 h. After 3 h of birth, four infants moved from a score ≥7 to a score below 7. After 6 h, five infants had a score below 7. Seventy per cent of patients had a Thompson score higher than 7 after 1 h, 45% after 3 h and 20% after 6 h. The Thompson score changes over the time during the first 6 h of birth, and this should be taken into account when it is being used as an entry criterion for cooling.

Single dose recombinant erythropoietin versus moderate hypothermia for neonatal hypoxic ischemic encephalopathy in low resource settings

Objective: To determine the safety and efficacy of single dose systemic recombinant human erythropoietin (rEPO) in neonates with perinatal hypoxic Ischemic Encephalopathy (HIE), and its effect on serum brain-derived neurotrophic factor (BDNF) and neuron-specific enolase (NSE).Methods: Forty-five full-term neonates; 30 with perinatal HIE and 15 controls were studied. HIE neonates were randomized into three intervention groups (first 6 h of life): 10 received single subcutaneous 1500 U/kg rEPO at day-1, 10 subjected to hypothermia for 72 h and 10 received supportive care. BDNF and NSE measured during first 6 h and day 5 postnatal. Daily Thompson's score, MRI brain and neuromuscular function scale for survivors at 3 months of age were done.Results: Hypothermia group had best survival especially with stage-II Sarnat scale, followed by rEpo and supportive group. BDNF day-5 was significantly higher in each group compared to controls. MRI score and neuromuscular function score were non-significantly lower in the hypothermia group compared to rEPO.Conclusions: Therapeutic hypothermia was superior to single dose rEpo for neuro-protection in HIE especially in patients with stage-II Sarnat scale. Therapeutic effect of combined rEPO multiple dosing and modest hypothermia therapy should be studied.

Early clinical predictors of a severely abnormal amplitude‐integrated electroencephalogram at 48 hours in cooled neonates

There is a need to identify infants with hypoxic ischaemic encephalopathy who have a poor outcome despite therapeutic hypothermia. A severely abnormal amplitude-integrated electroencephalogram at 48h predicts death or disability. Our aim was to determine whether clinical assessment at age 3-5h predicts a severely abnormal amplitude-integrated electroencephalogram at 48h or death in cooled infants. Forty-one cooled infants, ≥36weeks' gestation, with moderate-to-severe hypoxic ischaemic encephalopathy, were prospectively enrolled. Infants who were moribund, had congenital conditions associated with encephalopathy or had severe cardio-respiratory instability were excluded. The predictive abilities of the Thompson encephalopathy score and individual signs at age 3-5h were assessed. All infants with a Thompson score ≥16 at 3-5h had a severely abnormal amplitude-integrated electroencephalogram at 6h and an abnormal short-term outcome. At 48h, 75% had a severely abnormal aEEG or died vs. 18% with a score <16 (p=0.004). Multivariate analysis did not find a significant independent association with any of the individual signs. The Thompson score could be useful to identify infants who will have a poor outcome despite cooling. A score ≥16 should be validated as a prespecified variable in prospective studies.

Early clinical signs in neonates with hypoxic ischemic encephalopathy predict an abnormal amplitude-integrated electroencephalogram at age 6 hours

BackgroundAn early clinical score predicting an abnormal amplitude-integrated electroencephalogram (aEEG) or moderate-severe hypoxic ischemic encephalopathy (HIE) may allow rapid triage of infants for therapeutic hypothermia. We aimed to determine if early clinical examination could predict either an abnormal aEEG at age 6 hours or moderate-severe HIE presenting within 72 hours of birth.MethodsSixty infants ≥ 36 weeks gestational age were prospectively enrolled following suspected intrapartum hypoxia and signs of encephalopathy. Infants who were moribund, had congenital conditions that could contribute to the encephalopathy or had severe cardio-respiratory instability were excluded. Predictive values of the Thompson HIE score, modified Sarnat encephalopathy grade (MSEG) and specific individual signs at age 3–5 hours were calculated.ResultsAll of the 60 infants recruited had at least one abnormal primitive reflex. Visible seizures and hypotonia at 3–5 hours were strongly associated with an abnormal 6-hour aEEG (specificity 88% and 92%, respectively), but both had a low sensitivity (47% and 33%, respectively). Overall, 52% of the infants without hypotonia at 3–5 hours had an abnormal 6-hour aEEG. Twelve of the 29 infants (41%) without decreased level of consciousness at 3–5 hours had an abnormal 6-hour aEEG (sensitivity 67%; specificity 71%). A Thompson score ≥ 7 and moderate-severe MSEG at 3–5 hours, both predicted an abnormal 6-hour aEEG (sensitivity 100 vs. 97% and specificity 67 vs. 71% respectively). Both assessments predicted moderate-severe encephalopathy within 72 hours after birth (sensitivity 90%, vs. 88%, specificity 92% vs. 100%). The 6-hour aEEG predicted moderate-severe encephalopathy within 72 hours (sensitivity 75%, specificity 100%) but with lower sensitivity (p = 0.0156) than the Thompson score (sensitivity 90%, specificity 92%). However, all infants with a normal 3- and 6-hour aEEG with moderate-severe encephalopathy within 72 hours who were not cooled had a normal 24-hour aEEG.ConclusionsThe encephalopathy assessment described by the Thompson score at age 3–5 hours is a sensitive predictor of either an abnormal 6-hour aEEG or moderate-severe encephalopathy presenting within 72 hours after birth. An early Thompson score may be useful to assist with triage and selection of infants for therapeutic hypothermia.

A Descriptive Study of Perinatal Asphyxia at the University Hospital of Kinshasa (Democratic Republic Of Congo)

Perinatal asphyxia is the third cause of neonatal death after prematurity and infection. The purpose of this study was to determine the incidence, the etiology and the HIE score at the first day in term and near-term newborns with perinatal asphyxia at the University Hospital of Kinshasa. 50 term and near-term neonates with perinatal asphyxia were studied prospectively after they were admitted in neonatal intensive care from November 2009 to January 2011. For each patient admitted the perinatal data were collected. Clinical assessment was performed by the Sarnat grading and the Thompson score within twenty-four hours. Medcalc® was used for statistics. 50 babies were scored. The median maternal age was 31 years. In 22% of the mothers preeclampsia was diagnosed. Urogenital infection, IUGR were other prenatal diagnoses. Median Apgar score was 4 after 1 minute, 5 after 5 minutes and 6 after 10 minutes. Sarnat grade 1 was seen in 16 patients, Sarnat grade 2 in 20 patients and grade 3 in 8. Thompson score in the first 24 hours was more than 7 in 60% of the patients. A good correlation was found between the Thompson score and the Sarnat grade (r: 0,77; p < 0,0001). 14 of the 50 babies died. Both Sarnat and Thompson score correlated significantly with mortality. The incidence of perinatal asphyxia at the University Hospital of Kinshasa remains high and the majority of patients had a severe HIE.

Clinical and Histopathological Study of Pheochromocytoma Arising in the Adrenal Gland

Background/Aims: The diagnosis and prognosis of malignant pheochromocytoma are important. Other than distant metastasis, the pathology is insufficient to diagnose malignant versus benign pheochromocytoma. Methods: We analyzed 33 pheochromocytoma cases using the histological grade on the Thompson and Kimura scales. We compared the Thompson and Kimura scores with the degree of immunohistochemical staining for Ki-67 and heat shock protein 90 (Hsp90). Results: The most frequent symptom was hypertension (17 cases; 51.5%) and four patients had accompanying tumors: one case each of multiple endocrine neoplasm, papillary carcinoma of the thyroid, gastric adenocarcinoma, and neurofibroma. The mean Thompson score was 3.67 in benign pheochromocytoma and 10 in malignant pheochromocytoma, and the Kimura score was 2.17 and 5, respectively. The average immunohistochemical staining for Ki-67 was 5.77 and 10.44 in benign and malignant pheochromocytoma, respectively, while Hsp90 immunohistochemical staining was positive only in the cytoplasm of malignant pheochromocytoma. Conclusions: Immunohistochemical staining for Ki-67 and Hsp90 was seen in malignant pheochromocytoma. The Thompson and Kimura scales and immunohistochemical results could help to differentiate benign and malignant pheochromocytoma. (Korean J Med 2012;82:60-66)

Conservative versus surgical management of Pipkin type I fractures associated with posterior dislocation of the hip: a randomised controlled trial

Conservative versus surgical management of Pipkin type I fractures associated with posterior dislocation of the hip: a randomised controlled trial

The Effects of Age, Sex, Ethnicity, and Spinal Level on the Rate of Intervertebral Disc Degeneration

A gross anatomic and magnetic resonance imaging study of intervertebral disc (IVD) degeneration in fresh cadaveric lumbar spines. The purpose of this study was to find the rate of IVD degeneration. Age, sex, race, and lumbar level are among some of the factors that play a role in IVD degeneration. The rate at which IVDs degenerate is unknown. Complete lumbar spine segments (T11/T12 to S1) were received within 24 hours of death. The nucleus pulposus, anulus fibrosus, cartilaginous and bony endplate, and the peripheral vertebral body were assessed with magnetic resonance imaging and IVD degeneration was graded by two observers from grade 1 (nondegenerated) to grade 5 (severely degenerated) on the basis of a scale developed by Tanaka et al. The specimens were then sectioned and gross anatomic evaluation was performed according to Thompson et al. RESULTS.: A total of 433 donors and 1712 IVDs were analyzed. There were 366 whites, 47 Africans, 16 Hispanics, 4 Asian. There were 306 male and 127 female donors. The age range was 14 to 81 years, (average: 60.5 ± 11.3). For donors greater than age 40, the L5/S1 IVD degenerated at a significantly faster rate of 0.043 per year compared to 0.031, 0.034, 0.033, 0.027 for L1/L2, L2/L3, L3/L4, L4/L5, respectively. For donors younger than 40, L5/S1 IVD degenerated at a significantly faster rate of 0.141/y compared to 0.033, 0.021, 0.031, 0.050 for L1/L2, L2/L3, L3/L4, L4/L5, respectively. Multiple regression analysis revealed that sex had no significant effect on IVD degeneration whereas African ethnicity was associated with lower Thompson score at L1/L2, L2/L3, L3/L4, L4/L5 when compared with whites. The relatively early degeneration at L5-S1 in all races and lower Thompson grade in donors of African ethnicity needs further investigation. Factors such as sagittal alignment, facet joint arthritis, and genetics potentially play a role in IVD degeneration.

Optimal estimating functions in incomplete data and length biased sampling data problems

AbstractIt is well known that the score function is the optimal estimating function among all regular unbiased estimating functions (Godambe, 1960). In the presence of incomplete data such as missing data or length biased sampling data, Horvitz and Thompson's (1952) method is an effective way of eliminating the possible bias induced by using complete data only. In this article, we show that the inverse weighted Horvitz and Thompson score estimating function is not optimal in the presence of incomplete data. By using Godambe's estimating function theory, we can identify the optimal estimating function in this situation. In the case of the accelerated failure time model with length bias sampling data, the optimal estimating function can produce an unbiased estimator for the slope parameter even when the underlying density function is misspecified. Simulation studies show that the estimate derived from the optimal estimating function can be substantially better than the estimate derived from the inverse weighted score estimating function. The Canadian Journal of Statistics 39: 510–518; 2011 © 2011 Statistical Society of Canada

Operative Versus Nonoperative Management of Pipkin Type-II Fractures Associated with Posterior Hip Dislocation

Little has been written on randomized, controlled studies of operative versus nonoperative management of Pipkin type-II fractures associated with posterior dislocation of the hip. It is difficult to validate the optimal management of these fractures. The goals of this study were to (1) evaluate the results of conservative and surgical treatment for Pipkin type-II fractures associated with posterior dislocation of the hip and supply the optimal management for these fractures and (2) identify whether the Smith-Petersen approach is a safe and reliable surgical approach for Pipkin type-II fractures.Twenty-four patients were randomly divided into 2 groups: the conservative group (n=12) was treated by closed reduction, and the surgical group (n=12) was treated by primary open reduction internal fixation (ORIF) by bioabsorbable screws via a Smith-Petersen approach. Minimum follow-up was 24 months. Functional outcome was measured using the Thompson and Epstein score and the d'Aubigné-Postel score. Heterotopic ossification was classified based on the Brooker classification. The outcome of the conservative group was worse than that of the surgical group (P=.037). Two patients in the conservative group needed joint replacement for avascular necrosis of the femoral head. Heterotopic ossification was found in 6 patients (1 patient in the conservative group and 5 in the surgical group).Primary ORIF by bioabsorbable screws via a Smith-Petersen approach is an effective treatment for Pipkin type-II fractures associated with posterior dislocation.

Micro-CT quantification of subchondral endplate changes in intervertebral disc degeneration

The intervertebral disc (IVD) is dependent on nutrient provision through a cartilage layer with underlying subchondral bone, analogous to joint cartilage. In the joint, subchondral bone remodeling has been associated with osteoarthritis (OA) progression due to compromised nutrient and gas diffusion and reduced structural support of the overlaying cartilage. However, subchondral bone changes in IVD degeneration have never been quantified before. The aim of this study is to determine the subchondral bone changes at different stages of IVD degeneration by micro-CT. Twenty-seven IVDs including the adjacent vertebral endplates were obtained at autopsy. Midsagittal slices, graded according the Thompson score, were scanned. Per scan 12 standardized cylindrical volumes of interest (VOI) were selected. Six VOIs contained the bony endplate and trabeculae (endplate VOIs) and six accompanying VOIs only contained trabecular bone (vertebral VOIs). Bone volume as percentage of the total volume (BV/TV) of the VOI, trabecular thickness (TrTh) and connectivity density (CD) were determined. An increase in BV/TV and TrTh was found in endplate VOIs of IVDs with higher Thompson score whereas these values remained stable or decreased in the vertebral VOIs. The increase in bone volume combined with the increase in TrTh in endplate VOIs strongly suggest that the subchondral endplate condenses to a more dense structure in degenerated IVDs. This may negatively influence the diffusion and nutrition of the IVD. The endplate differences between intact and mild degenerative IVDs (grade II) indicate an early association of subchondral endplate changes with IVD degeneration.

Conservative versus surgical management of Pipkin type I fractures associated with posterior dislocation of the hip: a randomised controlled trial

The aim of this study was to evaluate the long-term results of conservative and surgical fragment excision treatment in patients with Pipkin type 1 fractures of the femoral head associated with posterior dislocation of the hip by a randomised controlled trial. Sixteen patients were randomly divided into two groups: the conservative group was treated by closed reduction, and the surgical group was treated by closed reduction followed with fragment excision. Functional outcome was determined using the Thompson and Epstein score and the Merle d'Aubigne and Postel score. Outcome of the conservative group was worse than that of the surgical group (p = 0.032). The randomised controlled trial proves surgical fragment excision after closed reduction is an effective treatment for Pipkin type 1 fractures.