Standardized analysis of syndesmosis stability in ankle trauma with an innovative syndesmosis-test-tool: a biomechanical study.

When treating ankle fractures, the question of syndesmosis complex involvement often arises. So far, there is no standardized method to reliably detect syndesmosis injuries in the surgical treatment of ankle fractures. For this reason, an intraoperative syndesmosis-test-tool (STT) was developed and compared to the recommended and established hook-test (HT). Tests were performed on cadaveric lower legs (n = 20) and the diastasis was visualized by 3D camera. Tests were performed at 50, 80, and 100 N in native conditions and four instability levels. Instability was induced from anterior to posterior and the reverse on the opposite side. The impact on diastasis regarding the direction, the force level, the instability level, and the device used was checked using a general linear model for repeated measurement. The direction of the induced instability showed no influence on the diastasis during the stability tests. The diastasis measured with the STT increased from 0.5 to 3.0 mm depending on the instability, while the range was lower with the HT (1.1 to 2.3 mm). The results showed that the differentiation between the instability levels was statistically significantly better for the developed STT. The last level of maximum instability was significantly better differentiable with the STT compared to the HT. An average visualizable diastasis of more than 2 mm could only be achieved at maximum instability. In conclusion, the newly developed STT was superior to the commonly used HT to detect instability.

Objective Assessment of Syndesmosis Stability Using the Hook Test.

The hook test is a widely used intraoperative method for assessing syndesmosis stability. However, there are no recommendations regarding the force required to perform this test. Furthermore, the reliability of the test is unclear. Ten experienced surgeons performed hook tests on a cadaver bone model. The applied forces were recorded in a blinded manner. In addition, standardized hook tests with defined forces (50, 80, and 100 N) were performed on 10 pairs of cadaver lower legs and the syndesmosis was sequentially destabilized. Diastasis of the syndesmosis was recorded using an optical 3D camera system. A median force of 81 N (Range: 50 N-145 N) was applied. A proportion of 82% of the tests showed a force < 100 N. The data showed good intraraterreliability and poor interraterreliability. In the standardized investigation of the hook test on the cadaver bone model, both the force and the instability of the syndesmosis had a significant influence on the syndesmosis diastasis. Nevertheless, even with maximum instability of the syndesmosis, diastasis > 2 mm could only be measured in 12 of the 19 evaluable specimens. The widely used hook test shows a high variability when performed in practice. Even in a standardized manner, the hook test cannot detect a relevant syndesmosis injury.

Tranexamic Acid in Hip Hemiarthroplasty Surgery: A Retrospective Analysis of Perioperative Outcome.

Introduction: Implantation of a dual-head hip prosthesis to treat medial femoral neck fractures is often associated with significant blood loss. In elective endoprosthetics procedures, it has already been demonstrated that administration of tranexamic acid (TXA) reduces blood loss and need for postoperative transfusions, as well as reducing the frequency of postoperative complications. The aim of this study is to show whether the administration of TXA also leads to a reduction in perioperative blood loss and haemorrhage-associated complications when applied as part of treatment of femoral neck fractures using a dual-head prosthesis. Methods: In a single-centre retrospective cohort study, 1 g TXA i.v. was administered preoperatively to 93 patients who had suffered from femoral neck fractures. This group was compared to a comparison group of 65 patients who did not receive TXA (nonTXA). Outcomes were evaluated on the basis of perioperative blood loss, frequency of transfusion, and frequency of specific complications occurring. Results: The transfusion rate in the TXA group was 6% lower, whereby the volume of blood transfused was 26.7% lower than in the nonTXA group. However, neither result was significant. The calculated perioperative blood loss remained the same. Similarly, the incidence of postoperative renal failure was not significantly lower in the TXA group, at 6.5%, as compared to the nonTXA group (7.7%). A higher rate of complications or deaths as a result of TXA administration was not observed. The tranexamic acid effect seems to be related to the dose. Conclusion: Preoperative administration of TXA during implantation of a dual-head prosthesis for treatment of a femoral neck fracture does not lead to an increased complication rate. The study revealed a trend towards fewer transfusions required, but a significant reduction in blood loss could not be demonstrated. There should be further investigation of other factors influencing blood loss, in particular the dosing regimen followed for perioperative administration of TXA. Level of Evidence: Level 4: retrospective case-control study.

Fibula Nail versus Locking Plate Fixation-A Biomechanical Study.

In the treatment of ankle fractures, complications such as wound healing problems following open reduction and internal fixation are a major problem. An innovative alternative to this procedure offers a more minimally invasive nail stabilization. The purpose of this biomechanical study was to clarify whether this method was biomechanically comparable to the established method. First, the stability (range of motion, diastasis) and rotational stiffness of the native upper ankle were evaluated in eight pairs of native geriatric specimens. Subsequently, an unstable ankle fracture was created and fixed with a locking plate or a nail in a pairwise manner. The ankles showed significantly less stability and rotational stiffness properties after nail and plate fixations than the corresponding native ankles (p < 0.001 for all parameters). When comparing the two methods, both showed no differences in their range of motion (p = 0.694) and diastasis (p = 0.166). The nail also presented significantly greater rotational stiffness compared to the plate (p = 0.001). However, both fixations remained behind the native stability and rotational stiffness. Due to the comparable biomechanical properties of the nail and plate fixations, an early weight-bearing following nail fixation should be assessed on a case-by-case basis considering the severity of fractures.

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.

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.

[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.

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.

Mid-term outcome of bilateral fragility fractures of the sacrum after bisegmental transsacral stabilization versus spinopelvic fixation.

AIMS: Minimally invasive fixation of pelvic fragility fractures is recommended to reduce pain and allow early mobilization. The purpose of this study was to evaluate the outcome of two different stabilization techniques in bilateral fragility fractures of the sacrum (BFFS). METHODS: A non-randomized, prospective study was carried out in a level 1 trauma centre. BFFS in 61 patients (mean age 80 years (SD 10); four male, 57 female) were treated surgically with bisegmental transsacral stablization (BTS; n = 41) versus spinopelvic fixation (SP; n = 20). Postoperative full weightbearing was allowed. The outcome was evaluated at two timepoints: discharge from inpatient treatment (TP1; Fitbit tracking, Zebris stance analysis), and ≥ six months (TP2; Fitbit tracking, Zebris analysis, based on modified Oswestry Disability Index (ODI), Majeed Score (MS), and the 12-Item Short Form Survey 12 (SF-12). Fracture healing was assessed by CT. The primary outcome parameter of functional recovery was the per-day step count; the secondary parameter was the subjective outcome assessed by questionnaires. RESULTS: Overall, no baseline differences were observed between the BTS and SP cohorts. In total, 58 (BTS = 19; SP = 39) and 37 patients (BTS = 14; SP = 23) could be recruited at TP1 and TP2, respectively. Mean steps per day at TP1 were median 308 (248 to 434) in the BTS group and 254 (196 to 446) in the SP group. At TP2, median steps per day were 3,759 (2,551 to 3,926) in the BTS group and 3,191 (2,872 to 3,679) in the SP group, each with no significant difference. A significant improvement was observed in each group (p < 0.001) between timepoints. BTS patients obtained better results than SP patients in ODI (p < 0.030), MS (p = 0.007), and SF-12 physical status (p = 0.006). In all cases, CT showed sufficient fracture healing of the posterior ring. CONCLUSION: Both groups showed significant outcome improvement and sufficient fracture healing. Both techniques can be recommended for BFFS, although BTS was superior with respect to subjective outcome. Step-count tracking represents a reliable method to evaluate the mobility level. Cite this article: Bone Joint J 2021;103-B(3):462-468.

Progressive instability of bilateral sacral fragility fractures in osteoporotic bone: a retrospective analysis of X-ray, CT, and MRI datasets from 78 cases.

PURPOSE: The pathogenetic mechanism, progression, and instability in geriatric bilateral fragility fractures of the sacrum (BFFSs) remain poorly understood. This study investigated the hypothesis of sequential BFFS progression by analysing X-ray, computed tomography (CT), and magnetic resonance imaging (MRI) datasets. METHODS: Imaging data from 78 cases were retrospectively analysed. Fractures were categorized using the CT-based Fragility Fractures of the Pelvis classification. MRI datasets were analysed to detect relevant fracture location information. The longitudinal sacral fracture was graded as stage 1 (bone oedema) on MRI, stage 2 (recent fracture), stage 3 (healing fracture), or stage 4 (non-union) on CT. Ligamentous avulsions at the L5 transverse process and iliac crest were also captured. RESULTS: Contralateral sacral lesions were only recognized by initial bone oedema on MRI in 17/78 (22%) cases. There were 22 cases without and 56 cases with an interconnecting transverse fracture component (TFC) [between S1/S2 (n = 39) or between S2/S3 (n = 17)]. With 30/78 patients showing bilateral fracture lines at different stages (1/2: n = 13, 2/3: n = 13, 1/3: n = 4) and 38 at similar stages, Wilcoxon tests showed a significant stage difference (p < 0.001). Forty cases had a coexistent L5 transverse process avulsion, consistent with a failing iliolumbar ligament. Analysis of variance revealed significant increases in ligamentous avulsions with higher fracture stages (p < 0.001). CONCLUSION: Our results support the hypothesis of stagewise BFFS progression starting with unilateral sacral disruption followed by a contralateral lesion. Loss of sacral alar support leads to a TFC. Subsequent bone disruption causes iliolumbar ligament avulsion. MRI is recommended to detect bone oedema.

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.

Secure corridor for infraacetabular screws in acetabular fracture fixation-a 3-D radiomorphometric analysis of 124 pelvic CT datasets.

BACKGROUND: Acetabular fracture surgery is directed toward anatomical reduction and stable fixation to allow for the early functional rehabilitation of an injured hip joint. Recent biomechanical investigations have shown the superiority of using an additional screw in the infraacetabular (IA) region, thereby transfixing the separated columns to strengthen the construct by closing the periacetabular fixation frame. However, the inter-individual existence and variance concerning secure IA screw corridors are poorly understood. METHODS: This computer-aided 3-D radiomorphometric study examined 124 CT Digital Imaging and Communications in Medicine (DICOM) datasets of intact human pelves (248 acetabula) to visualize the spatial IA corridors as the sum of all intraosseous screw positions. DICOM files were pre-processed using the Amira® 4.2 visualization software. Final corridor computation was accomplished using a custom-made software algorithm. The volumetric measurement data of each corridor were calculated for further statistical analyses. Correlations between the volumetric values and the biometric data were investigated. Furthermore, the influence of hip dysplasia on the IA corridor configuration was analyzed. RESULTS: The IA corridors consistently showed a double-cone shape with the isthmus located at the acetabular fovea. In 97% of male and 91% of female acetabula, a corridor for a 3.5-mm screw could be found. The number of IA corridors was significantly lower in females for screw diameters ≥ 4.5 mm. The mean 3.5-mm screw corridor volume was 16 cm3 in males and 9.2 cm3 in female pelves. Corridor volumes were significantly positively correlated with body height and weight and with the diameter of Köhler's teardrop on standard AP pelvic X-rays. No correlation was observed between hip dysplasia and the IA corridor extent. CONCLUSION: IA corridors are consistently smaller in females. However, 3.5-mm small fragment screws may still be used as the standard implant because sex-specific differences are significant only with screw diameters ≥ 4.5 mm. Congenital hip dysplasia does not affect secure IA screw insertion. The described method allows 3-D shape analyses with highly reliable results. The visualization of secure IA corridors may support the spatial awareness of surgeons. Volumetric data allow the reliable assessment of individual IA corridors using standard AP X-ray views, which aids preoperative planning.

Tissue engineering-relevant characteristics of ex vivo and monolayer-expanded chondrocytes from the notch versus trochlea of human knee joints.

PURPOSE: The aim was to analyse the biological characteristics of chondrocytes from the two biopsy sites notch vs. trochlea of human knee joints. The question was whether tissue engineering-relevant characteristics such as viability and mRNA expression profile would be comparable ex vivo and after monolayer expansion, as these are parts of routine autologous chondrocyte implantation (ACI). METHODS: Biopsies from the intercondylar notch and the lateral aspect of the trochlea from 20 patients with ICRS grades 3 and 4 cartilage defects were harvested during arthroscopy. Collagen types 1, 2, and 10 mRNA were quantified by polymerase chain reaction. RESULTS: Compared with notch chondrocytes, ex vivo trochlea chondrocytes had comparable cell numbers, vitality and aggrecan, collagen types 1, -2 and -10 mRNA expression. After monolayer expansion both notch and trochlea chondrocyte characteristics were comparably altered, regardless of their biopsy origin, and no significant differences in viability and mRNA expression were noted. CONCLUSIONS: Collectively, these findings suggest that tissue engineering-relevant characteristics of notch and trochlea chondrocytes are comparable ex vivo and after monolayer expansion. Thus, trochlea chondrocytes promise clinical potential and chondrocytes for ACI could potentially be generated from both notch and trochlea biopsy sites.

Desmoid Tumor of the Popliteal Fossa during Pregnancy.

Desmoid tumors are fibroblastic neoplasms that have an intermediate behavior with a highly aggressive infiltrative growth arising from deep muscle or aponeurosis. We present the case of a 34-year-old woman that developed a painless mass in the right popliteal fossa during pregnancy after intracytoplasmic sperm injection and hormonal therapy. The MRI scan showed a hyperintense mass of 6,7 cm × 4,7 cm × 3,8 cm surrounding the lateral head of the gastrocnemius muscle. The open biopsy was done one week after delivery, and the histology showed a desmoid tumor. We performed the resection one week later and found the common peroneal nerve completely surrounded by the tumor. The close resection due to the neurolysis was the reason why an adjuvant radiation with 56 Gy was done. The last clinical examination, 18 month later, did not show any signs of recurrence and an excellent functional outcome. This case demonstrates the possible influences of pregnancy and hormonal therapy on the evolution of desmoid tumors.

The influence of injecting an epidural contrast agent into the sacral canal on the fluoroscopic visibility of bony landmarks for sacroiliac screw fixation: a feasibility study.

OBJECT: In sacroiliac screw fixation of unstable pelvic injuries in geriatric patients, poor bone quality often obscures important bony landmarks in fluoroscopic images. The authors analyzed the feasibility of injecting a transhiatal contrast agent (CA) into the sacral canal to improve fluoroscopic visualization in the sacral epidural space. METHODS: Eight fresh cadaveric whole-body specimens from human donors whose mean age at the time of death was 78 years (range 69-87 years) were used. First, to identify bony landmarks without CA enhancement, the authors acquired fluoroscopy images of the native sacral canal, using lateral, inlet, and outlet projections. Through puncture of the sacral hiatus, 8-10 ml of CA was injected into the epidural space. Fluoroscopy images were then acquired in the standard pelvic views to identify the bony landmarks. To assess the effect of the CA enhancement, visibility of the landmarks was assessed before and after CA injection. Each identified landmark was scored as 1, and summative landmark scores of up to 10 were determined for each specimen. RESULTS: The cadaveric specimens were representative of bone structures in the geriatric population. In all specimens, epidural CA injection enhanced the fluoroscopic visualization of the sacral canal and of the S-1 foramina. The enhancement increased the total bony landmark score from 5.9 (range 4-8) without CA injection to 8.1 (range 6-10) after CA injection. Considering only intrasacral landmarks, the score was increased from 1.5 to 3. CONCLUSIONS: Injection of a transhiatal epidural CA improves fluoroscopic imaging of the sacral canal and of the neural foramina. Hence, this technique could be applied to help the surgeon identify anatomical landmarks during sacroiliac screw fixation in geriatric patients.

Is there a correlation between biophotonical, biochemical, histological, and visual changes in the cartilage of osteoarthritic knee-joints?

The aim of this study was to detect characteristic structural changes in the cartilage composition of osteoarthritis (OA), hereby improving the arthroscopic identification of cartilage pathology by the use of a non-destructive technique - NIRS (Near-Infrared Spectroscopy). 682 cartilage samples out of 25 knees with OA were classified visually, using the ICRS system, biophotonically, histologically (n = 66), using the Score of Mankin and the Score of Otte, and biochemically (n = 616), determining the content of glycosaminoglycan (GAG) and hydroxyproline (HP). Significant correlations were found between biophotonical, histological, biochemical and visual characteristics of cartilage lesions. NIRS values corresponded to the content of GAG, HP and to the Score of Mankin and Otte. The data show that changes in the composition and structure of articular cartilage influence the optical properties and can be measured objectively by NIRS. The ease of use during arthroscopy, the quick response and the non-destructive nature of NIRS make it a promising addition to the assessment of disease intervention in OA.

Neuronal prostaglandin E2 receptor subtype EP3 mediates antinociception during inflammation.

The pain mediator prostaglandin E2 (PGE2) sensitizes nociceptive pathways through EP2 and EP4 receptors, which are coupled to Gs proteins and increase cAMP. However, PGE2 also activates EP3 receptors, and the major signaling pathway of the EP3 receptor splice variants uses inhibition of cAMP synthesis via Gi proteins. This opposite effect raises the intriguing question of whether the Gi-protein-coupled EP3 receptor may counteract the EP2 and EP4 receptor-mediated pronociceptive effects of PGE2. We found extensive localization of the EP3 receptor in primary sensory neurons and the spinal cord. The selective activation of the EP3 receptor at these sites did not sensitize nociceptive neurons in healthy animals. In contrast, it produced profound analgesia and reduced responses of peripheral and spinal nociceptive neurons to noxious stimuli but only when the joint was inflamed. In isolated dorsal root ganglion neurons, EP3 receptor activation counteracted the sensitizing effect of PGE2, and stimulation of excitatory EP receptors promoted the expression of membrane-associated inhibitory EP3 receptor. We propose, therefore, that the EP3 receptor provides endogenous pain control and that selective activation of EP3 receptors may be a unique approach to reverse inflammatory pain. Importantly, we identified the EP3 receptor in the joint nerves of patients with painful osteoarthritis.

The "coagulation box" and a new hemoglobin-driven algorithm for bleeding control in patients with severe multiple traumas.

BACKGROUND: Extensive hemorrhage is the leading cause of death in the first few hours following multiple traumas. Therefore, early and aggressive treatment of clotting disorders could reduce mortality. Unfortunately, the availability of results from commonly performed blood coagulation studies are often delayed whereas hemoglobin (Hb) levels are quickly available. OBJECTIVES: In this study, we evaluated the use of initial hemoglobin (Hb) levels as a guide line for the initial treatment of clotting disorders in multiple trauma patients. PATIENTS AND METHODS: We have developed an Hb-driven algorithm to initiate the initial clotting therapy. The algorithm contains three different steps for aggressive clotting therapy depending on the first Hb value measured in the shock trauma room, (SR) and utilizes fibrinogen, prothrombin complex concentrate (PCC), factor VIIa, tranexamic acid and desmopressin. The above-mentioned drugs were stored in a special "coagulation box" in the hospital pharmacy, and this box could be immediately brought to the SR or operating room (OR) upon request. Despite the use of clotting factors, transfusions using red blood cells (RBC) and fresh frozen plasma (FFP) were performed at an RBC-to-FFP ratio of 2:1 to 1:1. RESULTS: Over a 12-month investigation period, 123 severe multiple trauma patients needing intensive care therapy were admitted to our trauma center (mean age 48 years, mean ISS (injury severity score) 30). Fourteen (11%) patients died; 25 (mean age 51.5 years, mean ISS 53) of the 123 patients were treated using the "coagulation box," and 17 patients required massive transfusions. Patients treated with the "coagulation box" required an average dose of 16.3 RBC and 12.9 FFP, whereas 17 of the 25 patients required an average dose of 3.6 platelet packs. According to the algorithm, 25 patients received fibrinogen (average dose of 8.25 g), 24 (96%) received PCC (3000 IU.), 14 (56%) received desmopressin (36.6 µg), 13 (52%) received tranexamic acid (2.88 g), and 11 (44%) received factor VIIa (3.7 mg). The clotting parameters markedly improved between SR admission and ICU admission. Of the 25 patients, 16 (64%) survived. The revised injury severity classification (RISC) predicted a survival rate of 41%, which corresponds to a standardized mortality ratio (SMR) of 0.62, which implies a higher survival rate than predicted. CONCLUSIONS: An Hb-driven algorithm, in combination with the "coagulation box" and the early use of clotting factors, could be a simple and effective tool for improving coagulopathy in multiple trauma patients.

Utility of the cortical thickness of the distal radius as a predictor of distal-radius bone density.

BACKGROUND: Bone density is an important factor in the management of fractures of the distal radius. OBJECTIVES: The aim of this study was to establish whether standard anteroposterior (AP) radiographs would provide the attending physician with a prediction of bone density. PATIENTS AND METHODS: Six pairs of human cadaveric radii were harvested. The mean donor age was 74 years. Standardized AP radiographs were taken of the radii. The outside diameter and the inside diameter of the cortical shell at the metaphyseal / diaphyseal junction were measured and their ratio was calculated. Dual-energy x-ray absorptiometry (DXA) was used to obtain the bone mineral density (BMD) of the distal parts of the radii. The correlation of the BMD values with these ratios was studied. RESULTS: The mean BMD was 0.559 (SD = 0.236) g / cm(2). The mean outside diameter/inside diameter ratio was 1.24 (SD = 0.013); the ratio significantly correlated with the total BMD (P = 0.001; R(2) = 0.710). In the BMD subregions, the correlation was also significant. CONCLUSIONS: The outside diameter/inside diameter ratio at the metaphyseal/diaphyseal junction of the distal radius on AP radiographs is suitable for use as a predictor of distal-radius bone density. Further studies should be performed, and clinical utility evaluated.

Biomechanical performance of different cable and wire cerclage configurations.

PURPOSE: Cerclage technology is regaining interest due to the increasing number of periprosthetic fractures. Different wiring techniques have been formerly proposed and have hibernated over years. Hereby, they are compared to current cerclage technology. METHODS: Seven groups (n = 6) of different cable cerclage (Ø1.7 mm, crimp closure) configurations (one single cerclage looped once around the shells, one single cerclage looped twice, two cerclages each looped once) and solid wire cerclages (Ø1.5 mm, twist closure) (same configurations as cable cerclages, and two braided wires, twisted around each other looped once) fixed two cortical half shells of human femoral shaft mounted on a testing jig. Sinusoidal cyclic loading with constantly increasing force (0.1 N/cycle) was applied starting at 50 N peak load. Cerclage pretension (P), load leading to onset of plastic deformation (D) and load at total failure (T) were identified. Statistical differences between the groups were detected by univariate ANOVA. RESULTS: Double looped cables (P442N ± 129; D1334N ± 319; T2734N ± 330) performed significantly better (p < 0.05) than single looped cables (P292N ± 56; D646N ± 108; T1622N ± 171) and were comparable to two single cables (P392N ± 154; D1191N ± 334; T2675N ± 361). Double looped wires (P335N ± 49; D752N ± 119; T1359N ± 80) were significantly better (p < 0.05) than single looped wires (P181N ± 16; D343N ± 33; T606N ± 109) and performed similarly to single looped cables. Braided wires (P119N ± 26; D225N ± 55; T919N ± 197) exhibited early loss of pretension and plastic deformation. CONCLUSION: Double looped cerclages provided a better fixation stability compared to a single looped cerclage. Double looped wires were comparable to a single looped cable. The use of braided wires could not be recommended mechanically.