Tranexamic acid in pertrochanteric fractures: a retrospective analysis of perioperative outcomes after fixation with a proximal femoral nail.

BACKGROUND: Treatment of pertrochanteric femoral fractures is often associated with significant blood loss. It has already been demonstrated that the administration of tranexamic acid (TXA) for endoprosthetic procedures reduces blood losses and leads to a decreased frequency of postoperative complications. The aim of this study is to demonstrate whether the administration of TXA as part of osteosynthesis treatment for pertrochanteric fractures using a proximal femoral nail reduces perioperative blood losses and haemorrhage-related complications. METHODS: In a two-centre retrospective cohort study, 1 g TXA i.v. was administered preoperatively to 294 patients who had suffered from pertrochanteric femoral fractures. The subjects were compared clinically to a historical control group who did not receive TXA (nonTXA). Outcomes were evaluated on the basis of perioperative blood loss, transfusion requirement, and occurrence of complications. RESULTS: The TXA group showed evidence of a reduction in blood loss (TXA = 0.97 ± 0.47 l; nonTXA = 1.06 ± 0.47 l; p = 0.004) and a lower frequency of transfusion (TXA = 20%; nonTXA = 31%; p = 0.032) as compared to the nonTXA group. However, evidence of this therapeutic effect could only be demonstrated at one of the centres on subgroup comparison between the two centres. At the second centre, the data did not show a significant difference. A trend could be seen towards a reduction in postoperative renal failure. No complications occurred resulting from the administration of tranexamic acid. CONCLUSION: Preoperative administration of TXA does not lead to an increased rate of thromboembolic complications when applied for treatment of pertrochanteric femoral fractures. Evidence of a positive effect could be seen in principle in relation to the reduction in perioperative blood loss and the frequency of transfusion. The difference in effect between the two centres remains to be clarified: for this reason, it is possible to assume that further factors influencing the efficacy of TXA administration are at play which were not taken into account in this study.

[Local spinal profile following operative treatment of thoracolumbar and lumbar fractures : Impact of reduction technique and bone quality]. / Lokales Wirbelsäulenprofil nach operativer Behandlung thorakolumbaler und lumbaler Frakturen : Einfluss von Repositionstechnik und Knochenqualität.

BACKGROUND: The goal of surgery for spinal injuries is fracture reduction, fixation and stable healing in a physiological position. Several open and minimally invasive surgical techniques are available. OBJECTIVE: The extent of open reduction and the fixation potential achieved by the AOSpine (AT) and Kluger (KT) techniques were compared. The influence of fracture morphology, age, sex, and bone quality on fracture reduction and secure fixation was investigated. MATERIAL AND METHODS: In this monocentric retrospective cohort study data of patients with traumatic thoracolumbar and lumbar fractures treated by AT or KT were analyzed. The bisegmental kyphotic angle (bGDW) of each injured spinal segment was determined. Normal bGDW values were extrapolated from the literature. The change of bGDW over time was analyzed under consideration of the bone quality in Hounsfield units (HU), injury severity according to the AOSpine classification, gender and age of patients. RESULTS: A total of 151 data sets were evaluated. The AT and KT methods achieved a similar extent of reduction (AT 10 ± 6°, KT 11 ± 8°; p = 0.786). In follow-up a mean reduction loss of -5 ± 4° was seen. The technique had no influence on this (p = 0.998). The fracture morphology just managed to achieve a significant influence (p = 0.043). Low HU correlated significantly but weakly with lower extent of reduction (r = 0.241, p < 0.003) and greater reduction loss (r = 0.272, p < 0.001). In the age group 50-65 years 21% of men and 43% of women had bone quality of < 110 HU. Age and HU were significantly correlated (r = -0.701, p < 0.001). CONCLUSION: The AT and KT are equivalent in terms of reduction and secure fixation properties. The high proportion of male and female patients with HU < 110 in the age group under 65 years and the influence on reduction and secure fixation emphasize the need for preoperative bone densitometry.

OF-Pelvis classification of osteoporotic sacral and pelvic ring fractures.

OBJECTIVES: Osteoporotic fractures of the pelvis (OFP) are an increasing issue in orthopedics. Current classification systems (CS) are mostly CT-based and complex and offer only moderate to substantial inter-rater reliability (interRR) and intra-rater reliability (intraRR). MRI is thus gaining importance as a complement. This study aimed to develop a simple and reliable CT- and MRI-based CS for OFP. METHODS: A structured iterative procedure was conducted to reach a consensus among German-speaking spinal and pelvic trauma experts over 5 years. As a result, the proposed OF-Pelvis CS was developed. To assess its reliability, 28 experienced trauma and orthopedic surgeons categorized 25 anonymized cases using X-ray, CT, and MRI scans twice via online surveys. A period of 4 weeks separated the completion of the first from the second survey, and the cases were presented in an altered order. While 13 of the raters were also involved in developing the CS (developing raters (DR)), 15 user raters (UR) were not deeply involved in the development process. To assess the interRR of the OF-Pelvis categories, Fleiss' kappa (κF) was calculated for each survey. The intraRR for both surveys was calculated for each rater using Kendall's tau (τK). The presence of a modifier was calculated with κF for interRR and Cohen's kappa (κC) for intraRR. RESULTS: The OF-Pelvis consists of five subgroups and three modifiers. Instability increases from subgroups 1 (OF1) to 5 (OF5) and by a given modifier. The three modifiers can be assigned alone or in combination. In both surveys, the interRR for subgroups was substantial: κF = 0.764 (Survey 1) and κF = 0.790 (Survey 2). The interRR of the DR and UR was nearly on par (κF Survey 1/Survey 2: DR 0.776/0.813; UR 0.748/0.766). The agreement for each of the five subgroups was also strong (κF min.-max. Survey 1/Survey 2: 0.708-0.827/0.747-0.852). The existence of at least one modifier was rated with substantial agreement (κF Survey 1/Survey 2: 0.646/0.629). The intraRR for subgroups showed almost perfect agreement (τK = 0.894, DR: τK = 0.901, UR: τK = 0.889). The modifier had an intraRR of κC = 0.684 (DR: κC = 0.723, UR: κC = 0.651), which is also considered substantial. CONCLUSION: The OF-Pelvis is a reliable tool to categorize OFP with substantial interRR and almost perfect intraRR. The similar reliabilities between experienced DRs and URs demonstrate that the training status of the user is not important. However, it may be a reliable basis for an indication of the treatment score.

A tattoo granuloma with uveitis (TAGU) without sarcoidosis.

Tattooing is associated with a handful of potential complications. Short-term complications such as pain, pruritus, erythema, or swelling at the tattoo-site commonly occur from local skin trauma. Long-term complications tend to involve infections or immune-mediated reactions such as sarcoidosis. The sudden development of a papulonodular skin eruption affecting a particular pigment in a tattoo is often the initial manifestation of undiagnosed sarcoidosis in these patients. However, in a small number of individuals, the granulomatous change in the tattoo and uveitis occur in the absence of any evidence of sarcoidosis. A case is presented of a tattoo granuloma with uveitis (TAGU) without sarcoidosis.

Irreducible Ankle Fracture Due to Incarceration of the Long Flexor Tendons Together With the Neurovascular Bundle in the Tibial Fibular Interosseous Space: A Case Report and Short Literature Review.

Ankle fracture dislocations with frustrating attempts at closed reduction are a rare traumatic entity. We present a case of an irreducible ankle fracture due to incarceration of all the flexor tendons including the neurovascular bundle in the tibial fibular interosseous space; to date, only one such case has been published in the literature. A computed tomography scan in both bone and soft tissue windows was necessary to clarify the structures that were inhibiting repositioning. The decisive step for surgical treatment was removal of the trapped structures from the tibial fibular interosseous space by a dorsomedial approach. The malleolar joint was then reconstructed anatomically. After 12 weeks, the patient was fully mobile without restrictions in his daily professional activities.

FIVE-YEAR FUNCTIONAL OUTCOMES AFTER EPIRETINAL MEMBRANE SURGERY: A Prospective, Controlled Study.

PURPOSE: To evaluate 5-year functional outcomes involving the inner retina after epiretinal membrane (ERM) surgery. METHODS: The study eye (SE) and fellow eye (FE) of 20 patients undergoing ERM surgery were examined preoperatively and at 3, 12, 24, 36, 48, and 60 months postoperatively. Retinal nerve fiber layer and ganglion cell-inner plexiform layer (GC-IPL) thicknesses were analyzed using spectral domain optical coherence tomography. Humphrey visual field mean deviation, pattern SD, and qualitative changes were assessed and compared over time. RESULTS: Mean GC-IPL thickness in SEs was less than that of FEs at all time points with progressive thinning in SEs after ERM surgery. There was significant thinning of the superotemporal GC-IPL in SEs as compared to FEs at 3 months and 60 months (P < 0.05). Humphrey visual field mean deviation was greater in SEs as compared to FEs but statistically significant only at 0, 12, and 24 months (P < 0.05). Pattern SD increased from baseline in SEs but remained near baseline in FEs. CONCLUSION: Surgical eyes after ERM surgery demonstrated progressive thinning of the GC-IPL and transient worsening trends in Humphrey visual field mean deviation and pattern SD as compared to controls after ERM surgery.

Hounsfield units as predictor for cage subsidence and loss of reduction: following posterior-anterior stabilization in thoracolumbar spine fractures.

STUDY DESIGN: A retrospective, longitudinal cohort study. OBJECTIVE: The purpose of this study was to examine whether Hounsfield units (HUs), as an alternative bone mineral density measurement to dual-energy X-ray absorptiometry and quantitative computed tomography, which lead to additional radiation exposure for patients, has an effect on the maintenance of reduction in bisegmental Cobb angle (CA) and cage subsidence in patients who receive bisegmental spine stabilization after traumatic thoracolumbar spine fractures. METHODS: A total of 81 patients with a mean follow-up of 12 months were analyzed. CAs and cage subsidence were measured intraoperatively and at follow-up. HU was measured, and patients were subsequently assigned based on HU to three HU subgroups (group 1: HU < 110 [poor bone quality (BQ)]; group 2: HU 180-110 [diminished BQ]; group 3: HU > 180 [good BQ]). RESULTS: Following anterior stabilization, loss of reduction and cage subsidence differed between patients with poor and diminished BQ but not significantly, and both groups showed significantly more loss of reduction and cage subsidence than patients with good BQ. CONCLUSION: BQ, estimated with HU, had significant effects on cage subsidence and loss of reduction. We recommend measuring HU before surgery and applying additional treatment strategies, such as polymethylmethacrylate augmentation of endplates or anterior plates, for patients with HU < 180. These slides can be retrieved under Electronic Supplementary Material.

Spectrum and Clinical Course of Visual Field Abnormalities in Ethambutol Toxicity.

Visual toxicities from ethambutol are rare but represent one of the few causes of non-glaucomatous and non-compressive bitemporal hemianopsia. The authors present a six-patient case series illustrating variable clinical presentation and reversibility of visual loss in patients treated with ethambutol for Mycobacterium avium complex, including four patients who presented with visual field defects suggestive of bitemporal hemianopsia. Two additional patients were being followed for glaucoma, developed visual field defects with ethambutol treatment, and subsequently recovered with cessation of drug. In patients being treated with ethambutol, reversible bitemporal hemianopsia was the most commonly noted presentation of ethambutol toxicity.

A unique presentation of subretinal fluid in a type III torpedo maculopathy phenotype.

Purpose: To report a rare type III torpedo maculopathy lesion with a unique manifestation of subretinal fluid. Observations: A nine-year-old patient was referred to retina for an evaluation of a hypopigmented oval-shaped lesion in the temporal macula with an area of inferior subretinal fluid in the right eye. The lesion demonstrated inner and outer retinal and retinal pigment epithelial attenuation, intraretinal and subretinal fluid, a serous neurosensory retinal detachment, and inner choroidal excavation on optical coherence tomography. Fundus autofluorescence showed a lane of downward-tracking fluid. Intravenously administered fluorescein angiography revealed a window defect in the area of the torpedo lesion suggesting choroidal flush. Conclusions and Importance: The case is the third documented case of torpedo maculopathy with subretinal fluid in the literature with a unique combination of intraretinal cystic changes and dependent descending subretinal fluid, somewhat akin to a Best disease outside of the fovea with choroidal excavation. The morphology of torpedo maculopathy continues to expand as more cases are revealed.

Comparison of the zonal distribution of calcium salt density and fat marrow in bone-healthy and osteoporotic sacra: an image data analysis using quantitative computed tomography and magnetic resonance imaging.

PURPOSE: Pathogenesis of sacral fragility fractures is not fully understood. This study investigates zonal distribution of calcium salt and fat marrow in intact bone-healthy and osteoporotic pelvis. In addition, in unilateral sacral fractures, the fracture side was compared with the intact side. METHODS: CT and MRI images of 37 pelves were analyzed. Zonal calcium salt distribution by Hounsfield units (HU) was recorded for each CT dataset. Fat marrow content was measured in MRI mDixon-Quant sequence. The cohort was divided: intact pelves with (PEO, HU < 100, n = 8) and without osteoporosis (PE, HU ≥ 100, n = 14) based on the mean HU value in LWK5. A third group consisted of patients with osteoporosis and unilateral fractures (PEOFx, n = 10). CONCLUSION: The results suggest that in PEO sacral alae experience disproportionate skeletal rarefaction. This concerns the sacral ala at the S1 level (- 25 ± 55), whereby the calcium salt content is so low that it corresponds to the S3 level of healthy bone (- 20 ± 21 HU). This explains the occurrence of transalar fractures in the load-transmitting zone S1. In PEOFx, the calcium salt density was higher and the fat content was lower on the fractured side than on the intact side, indicating bony compacting due to lateral compression and fat displacement due to hematoma in the accident mechanism. This study makes an important contribution to the understanding of the development of sacral fragility fractures. Furthermore, impaction of the cancellous bone within the fracture can be demonstrated.

The Halofixator for the Treatment of Unstable Fractures of the Upper Cervical Spine - Our Own Experience and Narrative Review. / Der Halofixateur zur Therapie von instabilen Frakturen der oberen Halswirbelsäule ­ eigene Erfahrungen und narratives Review.

INTRODUCTION: In the treatment of upper cervical spine injuries, the semiconservative procedure of the halofixator is now of only secondary importance. Older studies from the 2000 s showed unsatisfactory rates of consolidation as well as high rates of complications. However, due to current data on therapy effectiveness, the literature is inconsistent. The aim of this work is to compare our own experiences and results of treatment with the current literature and to help to clarify the role of the halofixator. MATERIAL AND METHODS: In a monocentric retrospective cohort study, patients with unstable injuries of the axial cervical spine who were to be treated in the halofixator were investigated. Individual variables (sex, age, concomitant diseases, Charlson Comorbidity Index) and treatment characteristics (duration of treatment, consolidation status, complications) were recorded using the electronic medical record. Injuries were classified based on CT data at the time of the accident and at the end of treatment, using common classification systems, and assessed with respect to the rate of consolidation. Possible factors influencing bony consolidation as well as complications were statistically analysed. RESULTS: A total of 54 patients met the inclusion criteria. The median duration of treatment was 83 days. The most common injuries were isolated atlas fracture type III (7; 13%) and isolated dens fracture type III (24; 44%). Bony consolidation was demonstrated in 34 cases (63%) and tight pseudarthrosis in 13 cases (24%). Secondary surgical stabilisation was performed in 6 cases (11%). Isolated type III atlas fractures and type III dens fractures had very high consolidation rates of 86% and 92%, respectively. In the subgroups of patients older than 65 years or with a CCI ≥ 4, unstable pseudarthroses were found more frequently. Complications included pin infection (6%), pin dislocation (9%), and pressure ulceration from the halo vest (6%). Cardiopulmonary complications did not occur. No patient died. DISCUSSION: Good rates of bony consolidation were seen for atlas fractures type III as well as dens fractures type III, which correlate with data in the literature. Dens fractures type II (isolated and combined) and atlas fractures type III in combination with dens fractures showed a worse radiological outcome, which is also unsatisfactory compared to the literature. The rates for procedure-specific complications were relatively low. In particular, work from recent years has demonstrated very good rates for bony consolidation and low complication rates for the treatment of atlas and/or dens fractures with the halofixator, which are confirmed by our results. In contrast, however, a significantly higher cardiac/respiratory complication rate has been reported than occurred in our own patient population.

Peripheral retinal finding on fluorescein angiography in neuronal ceroid lipofuscinosis type 2 (CLN2).

Classically, peripheral vascular changes in the retina in patients with neuronal ceroid lipofuscinosis type 2 (CLN2) are described as vascular attenuation seen in the late stages of disease on the Weill Connell Ophthalmic Severity Score (WCOSS) staging system. We describe isolated, mild, peripheral vasculitis with peripheral arteriolar dropout identified by fluorescein angiography in patients with a WCOSS grade of stage 2. We believe this vasculitis represents an early vasodegenerative phase of disease that leads to the vascular attenuation seen in later stages of the disease.

Relation between sagittal pelvic and thoracolumbar parameters in supine position - Pelvic parameters and their predictive value for spinal Cobb angles.

Introduction: Predicting the pre-morbid sagittal profile of the spine or segmental angles could enhance the process of planning the extent of fracture reduction. There is evidence that spinopelvic parameters may be suitable for this purpose. Research question: Is it possible to determine the inflection point and the mono- and bi-segmental endplate angles (EPA) in the thoracolumbar transition (from Th9 to L2) based on age, gender, spinopelvic parameters, and the adjacent EPA in the supine position? Material and methods: Based on Polytrauma CT scans in the supine position, the following spinopelvic parameters were measured using non-fractured spines: pelvic incidence (PI), sacral slope (SS), lumbar lordosis (LL), and the apex of the LL. Results: In this study, a total of 287 patients with a mean age of 42±16 years were included. Age-related changes were observed, where LL, thoracic kyphosis (TK), and PI increase with age. Gender-related comparisons showed that females had a more pronounced LL and reduced TK. Significant correlations between IP and spinopelvic parameters, with the apex of LL providing the best prediction, were found. However, the overall model quality remained low. Predicting mEPA and bEPA showed positive correlations. The prediction for mEPA L2/3 demonstrated the highest correlation. For bisegmental angles, the most caudal bEPA (L2) exhibited the highest correlation, albeit with some notable absolute differences in the values between measured and predicted values. Discussion and conclusion: While this study highlights the complexity of the relationship between the pelvis and thoracolumbar parameters, finding a predictive tool for thoracolumbar reduction and stabilization was not possible.

Percutaneous reduction of thoracolumbar fractures using monoaxial screws: Comparison of two instruments based on initial reduction and loss of reduction.

Introduction: Percutaneous techniques for the surgical treatment of vertebral fractures are constantly progressing. There are different biomechanics involved. Research question: Two percutaneous, monoaxial fixation systems with different reduction tools were analyzed in relation to their reduction capacity. Additionally, the impact of anterior fusion, fracture severity and bone quality on reduction and loss of reduction were examined. Material and methods: 117 cases were retrospectively included in the monocentric study. The subsample (N = 53) with complete data at follow-up times was used to analyze the influence of anterior fusion. The dependencies on fracture severity and bone quality were determined using Spearman and Pearson correlation. Results: Both systems achieved equally good reduction (9° mean, 95%-CI: 8°-11°, p < 0.001). Anterior fused patients showed not significant (p = 0.057) less loss of reduction over time. Fracture severity had neither an influence on reduction or loss of reduction. Bone quality was positively correlated with greater amount of reduction and less loss of reduction. Early reduction within two days correlated with a greater amount of reduction (p = 0.006). Screw diameters and the patient's weight had no influence on loss of reduction. Complications occurred only in "V2" group. Discussion and conclusion: Both systems are equivalent in reduction ability. The additional anterior fusion did not result in significantly lower reduction losses. The subsample being small, is a limitation. Good bone quality correlates with better initial reduction and less reduction loss. A preoperative bone density measurement can lead to optimization of surgical techniques.

Conservative management of proximal hamstring avulsion: A clinical study.

Introduction: The management of proximal hamstring tear (PHT) is debated and consensus regarding recommended measures and individual treatment regimens is lacking. The present investigation evaluated the efficacy of a conservative management of partial and complete PHT. Methods: The present observational study was conducted following the STROBE statement. In June 2018 the medical databases of the BG Klinikum Bergmannstrost Halle, Germany were accessed. All the patients with PHT were retrieved. The outcomes of interest were to evaluate the clinical examination, PROMs, imaging, and isokinetic muscle strength at the baseline and last follow-up. Results: 31 patients were enrolled in the present study. Nine patients (29 % (9 of 31) described local pain at the ischial tuberosity in sitting situations and also in manual palpation. A persistent gap in the tendon string beneath the tuberosity in manual palpation was reported in 25.8 % (8 of 31). The mean VAS at the last follow-up was 2.3 ± 2.3. The mean LEFS score was 50.9 ± 18.8.Control MRI at follow-up showed scarring restitution in the proximal tendon in all patients in the partial tear group. In the complete tear group, a persisting defect state of the proximal tendon course was found in 45 % (9 of 20). The injured side achieved 81.5 ± 22.2 % of the force of the uninjured side, measured in the flexion movement at 60°/s. At an angular velocity of 240°/s, 83.2 ± 26.3 % of the force of the uninjured side was achieved. Conclusion: According to the main findings of the present study, conservative therapy of PTH tears is associated with good clinical outcomes. High-quality investigations are required to establish the proper therapeutic algorithm and advantages of conservative management compared to a surgical approach. Level of evidence: Level III.

High flex total knee arthroplasty--a prospective, randomized study with results after 10 years.

This prospective randomized study compares the long term results between total knee arthroplasty with a mobile bearing high flex and a fixed bearing posterior stabilized knee (LPS) in 39 patients. The Hospital for Special Surgery score (HSS) was calculated and radiographs in AP and lateral view were analyzed after a minimum follow-up of 10 years. No significant differences between the two groups were found. The mean HSS-score was 90.67 (+/- 5.75) for LPS group patients and 90.83 (+/- 8.57) points for the high flex group patients. Three patients in the high flex group had undergone a reoperation on their knee. One knee was revised for painful mid-flexion instability and the others for symptomatic aseptic loosening of the tibial prosthesis. Based on these and other findings, the use of a high flex knee system may be seriously re-considered. Further studies are required to evaluate possible long-term adverse effects of high flex knee systems.

Perioperative outcome of minimally invasive stabilisation of bilateral fragility fractures of the sacrum: a comparative study of bisegmental transsacral stabilisation versus spinopelvic fixation.

PURPOSE: Pelvic fragility fractures have steadily risen over the past decades. The primary treatment goal is the fastest possible mobilisation. If conservative therapy fails, surgical fixation is a promising approach. This study compares the outcome of bisegmental transsacral stabilisation (BTS) and spinopelvic fixation (SP) as minimally invasive techniques for bilateral fragility fractures of the sacrum (BFFS). METHODS: We performed a prospective, non-randomised, case-controlled study. Patients were included if they remained bedridden due to pain despite conservative treatment. Group assignment depended on sacral anatomy and fracture type. The outcome was estimated by blood loss calculation, cut-seam time, fluoroscopy time, complications, duration of stay at the intensive/intermediate care unit (ICU/IMC), and total inpatient stay. The mobility level at discharge was recorded. RESULTS: Seventy-three patients were included (SP: 49, BTS: 24). There was no difference in blood loss (BTS: 461 ± 628 mL, SP: 509 ± 354 mL). BTS showed a significantly lower cut-seam time (72 ± 23 min) than SP (94 ± 27 min). Fluoroscopy time did not differ (BTS: 111 ± 61 s vs. 103 ± 45 s). Thirteen percent of BTS and 16% of SP patients required ICU/IMC stay (BTS: 0.6 ± 1.8 days, SP: 0.5 ± 1.5 days) during inpatient stay (BTS: 9 ± 4 days, SP: 8 ± 3 days). Fourteen patients suffered from urinary tract infections (BTS: 8%; SP: 25%). In-patient mortality was low (BTS: 4.2%, SP: 4.1%). At discharge, the BTS group was almost back to the initial mobility level. In SP patients, mobility was significantly lower than before complaints (p = 0.004). CONCLUSION: Both methods allow early mobilization of BFFS patients. Blood loss can be kept low. Hence, transfusion requirement is correspondingly low. The IMC/ICU and the total inpatient stay are lower than reported in the literature. Both BTS and SP can be recommended as safe and low-complication methods for use in BFFS patients. BTS is superior to SP with respect to surgery duration and level of mobility at discharge.

Cup positioning in total hip arthoplasty: spatial alignment of the acetabular entry plane.

PURPOSE: Correct cup positioning is one of the keys for successful total hip replacement. There are mechanical and computer assistant guides for correct cup positioning in the market. To optimize the cup positioning, the use of navigation systems is recommended. The aim of this study was to compare spatial orientation of the acetabulary entry plane in relation to tables plane which is used by mechanical guides as well as anterior pelvic plane used for cup orientation by navigation systems. METHODS: CT raw data of 80 Caucasians (160 acetabuli) (done in supine position) with osteoartritic hips were collected. 3-D pelvic reconstruction was generated using Amira software (Visage Imaging Berlin, Germany). Anterior pelvic plane and acetabulary entry plane were defined by reliable anatomical landmarks. Spatial orientation were calculated by a custom made program code for the Amira software. RESULTS: There were no differences between anterior pelvic plane and table's plane as well as spatial orientation of acetabulary entry plane of both acetabuli in relation to anterior pelvic plane or table's plane. Furthermore, there was no correlation between age, sex or body mass index and spatial orientation of the acetabulary entry plane as well. CONCLUSIONS: The use of mechanical alignment guides for cup orientation during total hip arthroplasty based on table's plane in patient's supine position is a successful method to achieve proper cup orientation.

Impact of Spino-Pelvic Parameters on the Prediction of Lumbar and Thoraco-Lumbar Segment Angles in the Supine Position.

Background: The correction of malposition according to vertebral fractures is difficult because the alignment at the time before the fracture is unclear. Therefore, we investigate whether the spinal alignment can be determined by the spino-pelvic parameters. Methods: Pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), adjacent endplate angles (EPA), age, sex, body weight, body size, BMI, and age were used to predict mono- and bisegmental EPA (mEPA, bEPA) in the supine position using linear regression models. This study was approved by the Ethics Committee of the Medical Association of Saxony-Anhalt Germany on 20 August 2020, under number 46/20. Results: Using data from 287 patients, the prediction showed R2 from 0.092 up to 0.972. The adjacent cranial and caudal EPA showed by far the most frequently significance in the prediction of all parameters used. Anthropometric and spino-pelvic parameters showed sparse impact, which was frequently in the lower lumbar regions. On average, a very good prediction was found. For two mEPA (L3/4 R2 = 0.914, L4/5 R2 = 0.953) and two bEPA (L3 R2 = 0.899, L4 R2 = 0.972), the R2 was >0.8. However, the predicted EPA differed for individual patients, even in these very effective prediction models­roughly around ±10° as compared to the measured EPA. Conclusions: In general, the prediction showed good to perfect results. In the supine position, the spinopelvic and anthropometric parameters show sparse impact on the prediction of mEPA or bEPA.

Inter-Rater Reliability of Hounsfield Units as a Measure of Bone Density: Applications in the Treatment of Thoracolumbar Fractures.

OBJECTIVE: The study sought to investigate the reliability of computed tomography (CT)-derived Hounsfield unit (HU) measurements and ascertain the correlation between HU with quantitative CT (qCT)-derived bone mineral density (BMD) in cases of traumatic thoracolumbar fracture, based on native CT scans. METHODS: This study is a retrospective cross-sectional analysis of data sets from patients who received native CT scans and bone mineral density measurements (qCT) of the same vertebral body. Two different CT scanner models were used. The inter-rater reliability of 4 raters, which measured HU in native CT scans, was calculated using intraclass correlation coefficient for absolute agreement (ICC(3,1)). For the correlation between HU and qCT values, respectively the prediction of qCT based on HU, linear regression was used. Bland-Altman plots were used for visual comparison of predicted and measured qCT values. RESULTS: In total 305 data sets were analyzed. CT scanner model was found to have no significant impact on HU (P = 0.125). The inter-rater reliability for HU measurements from native CT scans was ICC(3,1)=0.932 (95% confidence interval 0.919-0.943, P < 0.001). The linear regression showed significant correlation of HU and qCT values for each rater (P < 0.001). The equation for qCT prediction with averaged coefficient and constant is qCT = 0.8 HU + 5. In the Bland-Altman plots no bias of predicted qCT values could be found, but a trend to overestimate predicted higher qCT values and underestimate lower qCT values, respectively. CONCLUSIONS: HU measurement shows very high inter-rater reliability. The HU values correlate closely with qCT BMD values. In summary, it seems that HU measurement is a suitable tool to readily and accurately assess bone quality without further scans or effort in cases of thoracolumbar spinal trauma.