Dual release of daptomycin and BMP-2 from a composite of ß-TCP ceramic and ADA gelatin.

BACKGROUND: Antibiotic-containing carrier systems are one option that offers the advantage of releasing active ingredients over a longer period of time. In vitro sustained drug release from a carrier system consisting of microporous ß-TCP ceramic and alginate has been reported in previous works. Alginate dialdehyde (ADA) gelatin gel showed both better mechanical properties when loaded into a ß-TCP ceramic and higher biodegradability than pure alginate. METHODS: Dual release of daptomycin and BMP-2 was measured on days 1, 2, 3, 6, 9, 14, 21, and 28 by HPLC and ELISA. After release, the microbial efficacy of the daptomycin was verified and the biocompatibility of the composite was tested in cell culture. RESULTS: Daptomycin and the model compound FITC protein A (n = 30) were released from the composite over 28 days. A Daptomycin release above the minimum inhibitory concentration (MIC) by day 9 and a burst release of 71.7 ± 5.9% were observed in the loaded ceramics. Low concentrations of BMP-2 were released from the loaded ceramics over 28 days.

Medial malleolar osteotomy in the treatment of osteochondral lesions of the Talus - incidence and impact on functional outcome: a retrospective analysis based on data from the German Cartilage Register (KnorpelRegister DGOU).

BACKGROUND: There has long been discussion regarding the impact of medial malleolar osteotomies (MMO) as an adjunctive treatment for osteochondral lesions of the talus (OCLT). MMO may improve the visibility and accessibility of the talus, but they also pose a risk of periprocedural morbidity. There is a lack of research about the prevalence and consequences of MMO in the surgical treatment of OCLT. METHODS: This study retrospectively evaluated data from the German Cartilage Register (KnorpelRegister DGOU) from its implementation in 2015 to December 2020. The impact of MMO on patient-reported outcome measures (PROMs) was investigated. Wherever possible, subgroups were built and matched using a propensity score which matched a group undergoing OCLT without MMO. Matching included age, sex, weight, localization of the OCLT, the international cartilage repair society (ICRS) grading, surgical procedure and preoperative symptoms using the Foot and Ankle Ability Measure (FAAM) and the Activities of Daily Living Subscale (ADL). RESULTS: The prevalence of MMO in the operative treatment of OCLT was 15.9%. Most of the osteotomies were performed in OCL of the medial talar dome (76.8%) and in more serious lesions with an ICRS grade of III (29.1%) and IV (61.4%). More than half of the osteotomies (55.6%) were performed during revision surgery. A matched pair analysis of n = 44 patients who underwent AMIC® via arthrotomy and MMO vs. arthrotomy alone showed no significant differences in patient-reported outcome measures (PROMs, i.e. FAAM-ADL, and FAOS) at 6,12 and 24 months. CONCLUSIONS: MMO are mostly used in the treatment of severe (≥ ICRS grade 3) OCL of the medial talar dome and in revision surgery. Functional and patient-reported outcome measures are not significantly affected by MMO compared to arthrotomy alone. TRIAL REGISTRATION: The German Cartilage Register (KnorpelRegister DGOU) was initially registered at the German Clinical Trials Register ( https://www.drks.de , register number DRKS00005617, Date of registration 03.01.2014) and was later expanded by the ankle module.

Impact of motivational feedback on levels of physical activity and quality of life by activity monitoring following knee arthroplasty surgery-protocol for a randomized controlled trial nested in a prospective cohort (Knee-Activity).

BACKGROUND: Evidence on how to improve daily physical activity (PA) levels following total knee arthroplasty (TKA) or medial uni-compartmental knee arthroplasty (mUKA) by motivational feedback is lacking. Moreover, it is unknown whether a focus on increased PA after discharge from the hospital improves rehabilitation, physical function, and quality of life. The aim of this randomized controlled trial (RCT) nested in a prospective cohort is (a) to investigate whether PA, physical function, and quality of life following knee replacement can be increased using an activity monitoring device including motivational feedback via a patient app in comparison with activity monitoring without feedback (care-as-usual), and (b) to investigate the potential predictive value of PA level prior to knee replacement for the length of stay, return to work, and quality of life. METHODS: The study is designed as a multicenter, parallel-group, superiority RCT with balanced randomization (1:1) and blinded outcome assessments. One hundred and fifty patients scheduled for knee replacement (TKA or mUKA) will be recruited through Odense University Hospital, Denmark, Vejle Hospital, Denmark and Herlev/Gentofte Sygehus, Denmark. Patients will be randomized to either 12 weeks of activity monitoring and motivational feedback via a patient app by gamification or 'care-as-usual,' including activity monitoring without motivational feedback. The primary outcome is the between-group change score from baseline to 12-week follow-up of cumulative daily accelerometer counts, which is a valid proxy for average objectively assessed daily PA. DISCUSSION: Improving PA through motivational feedback following knee replacement surgery might improve post-surgical function, health-related quality of life, and participation in everyday life. TRIAL REGISTRATION: ClinicalTrials.gov, ID: NCT06005623. Registered on 2023-08-22. TRIAL STATUS: Recruiting.

Biodegradable composites with antibiotics and growth factors for dual release kinetics.

Bone infections are still a major problem in surgery. To avoid severe side effects of systemically administered antibiotics, local antibiotic therapy is increasingly being considered. Using a pressure-based method developed in our group, microporous ß-TCP ceramics, which had previously been characterized, were loaded with 2% w/v alginate containing 50 mg/mL clindamycin and 10 µg/mL rhBMP-2. Release experiments were then carried out over 28 days with changes of liquid at defined times (1, 2, 3, 6, 9, 14, 21 and 28d). The released concentrations of clindamycin were determined by HPLC and those of rhBMP-2 by ELISA. Continuous release (anomalous transport) of clindamycin and uniform release (Fick's diffusion) of BMP-2 were determined. The composites were biocompatible (live/dead, WST-I and LDH) and the released concentrations were all antimicrobially active against Staph. aureus. The results were very promising and clindamycin was detected in concentrations above the MIC as well as a constant rhBMP-2 release over the entire study period. Biocompatibility was also not impaired by either the antibiotic or the BMP-2. This promising approach can therefore be seen as an alternative to the common treatment with PMMA chains containing gentamycin, as the new composite is completely biodegradable and no second operation is necessary for removal or replacement.

The transepicondylar distance is a reliable and easily measured parameter for estimating femoral cartilage surface area using MRI.

PURPOSE: Different cartilage repair techniques are widely used to regenerate cartilage, such as autologous chondrocyte implantation (ACI), osteochondral autograft transfer, microfracturing and minced cartilage. Defect size is a key parameter for selecting the best procedure to repair cartilage. However, the defect's size is not related to the patient's total cartilage surface. This is because assessing the femoral cartilage surface area is time-consuming and therefore unsuitable in the daily clinical routine. It has been proposed that the femur's total cartilage area correlates positively with the transepicondylar distance (TEA). METHODS: The knees of 40 subjects were analysed. Their average age was 30.1 ± 8.6 years. Twenty-four female and 16 male subjects were examined. Their mean body height was 176.2 ± 8.8 cm. MRI scans were performed via 3-Tesla MRI. These data were postprocessed and quantified using the browser-based, customizable SATORI platform (Fraunhofer MEVIS). This software computed the femoral cartilage surface area (FeCA), the patella cartilage surface area (PCA), the TEA and the patella length. RESULTS: Body height reveals a good correlation (r = 0.722, p < 0.001) with the distal femur's cartilage area surface. However, regression analysis shows only moderate dependence (R2: 0.514). A very good correlation (r = 0.830, p < 0.001) was observed between the TEA distance and the total cartilage surface area of the distal femur. The regression analysis yields a good value (R2: 0.684). The cranio-caudal length of the patella was chosen as a suitably measurable two-dimensional parameter for correlation analysis with the patella's total cartilage surface area. Those results yield a poor correlation (r = 0.577, p < 0.001) between the two parameters, and regression analysis reveals a low value (R2: 0.384). CONCLUSION: The TEA is a reliable parameter for estimating the femur's cartilage area using MRI. A simple determination of this parameter allows the estimation of the femur's total cartilage area as well as the surface-corrected defect size (SCDS) in daily routine. LEVEL OF EVIDENCE: Level II.

Mortality after major lower extremity amputation and association with index level: a cohort study based on 11,205 first-time amputations from nationwide Danish databases.

BACKGROUND AND PURPOSE: Mortality after major lower extremity amputations is high and may depend on amputation level. We aimed to examine the mortality risk in the first year after major lower extremity amputation divided into transtibial and transfemoral amputations. METHODS: This observational cohort study used data from the Danish Nationwide Health registers. 11,205 first-time major lower extremity amputations were included from January 1, 2010, to December 31, 2021, comprising 3,921 transtibial amputations and 7,284 transfemoral amputations. RESULTS: The 30-day mortality after transtibial amputation was overall 11%, 95% confidence interval (CI) 10-12 (440/3,921) during the study period, but declined from 10%, CI 7-13 (37/381) in 2010 to 7%, CI 4-11 (15/220) in 2021. The 1-year mortality was 29% overall, CI 28-30 (1,140 /3,921), with a decline from 31%, CI 21-36 (117/381) to 20%, CI 15-26 (45/220) during the study period. For initial transfemoral amputation, the 30-day mortality was overall 23%, CI 22-23 (1,673/7,284) and declined from 27%, CI 23-31 (138/509) to 22%, CI 19-25 (148/683) during the study period. The 1-year mortality was 48% overall, CI 46-49 (3,466/7,284) and declined from 55%, CI 50-59 (279/509) to 46%, CI 42-50 (315/638). CONCLUSION: The mortality after major lower extremity amputation declined in the 12-year study period; however, the 1-year mortality remained high after both transtibial and transfemoral amputations (20% and 46% in 2021). Hence, major lower extremity amputation patients constitute one of the most fragile orthopedic patient groups, emphasizing an increased need for attention in the pre-, peri-, and postoperative setting.

Major lower extremity amputations - risk of re-amputation, time to re-amputation, and risk factors: a nationwide cohort study from Denmark.

BACKGROUND AND PURPOSE: Re-amputation after lower extremity amputation is frequent. The primary aim of our study was to investigate cumulative re-amputation risk after transtibial amputation (TTA), knee disarticulation (KD), and transfemoral amputation (TFA) and secondarily to investigate time to re-amputation, and risk factors. METHODS: This observational cohort study was based on data from the Danish Nationwide Health registers. The population included first-time major lower extremity amputations (MLEA) performed in patients ≥ 50 years between 2010 and 2021. Both left and right sided MLEA from the same patient were included as index procedures. RESULTS: 11,743 index MLEAs on 10,052 patients were included. The overall cumulative risks for re-amputation were 29% (95% confidence interval [CI] 27-30), 30% (CI 26-35), and 11% (CI 10-12) for TTA, KD, and TFA, respectively. 58% of re-amputations were performed within 30 days after index MLEA. Risk factors for re-amputation within 30 days were dyslipidemia (hazard ratio [HR] 1.2, CI 1.0-1.3), renal insufficiency (HR 1.2, CI 1.1-1.4), and prior vascular surgery (HR 1.3, CI 1.2-1.5). CONCLUSION: The risk of re-amputation was more than twice as high after TTA (29%) and KD (30%) compared with TFA (11%). Most re-amputations were conducted within 30 days of the index MLEA. Dyslipidemia, renal insufficiency, and prior vascular surgery were associated with higher risk of re-amputation.

Biomechanical Effects of Chronic Ankle Instability on the Talar Cartilage Matrix: The Value of T1ρ Relaxation Mapping Without and With Mechanical Loading.

BACKGROUND: T1ρ mapping has been proposed for the detection of early cartilage degeneration associated with chronic ankle instability (CAI). However, there are limited data surrounding the influence of ankle loading on T1ρ relaxation. PURPOSE: To evaluate T1ρ relaxation times of talar cartilage, as an indicator of early degenerative changes, associated with CAI and to investigate the influence of acute axial in situ loading on T1ρ values in CAI patients and healthy controls. STUDY TYPE: Prospective. SUBJECTS: A total of 9 patients (age = 21.8 ± 2.5 years, male/female = 2/7) with chronic ankle instability and 18 healthy control subjects (age = 22.8 ± 3.6 years, male/female = 5/13). FIELD STRENGTH: 3 T. SEQUENCE: 3D gradient echo fast low-angle shot (FLASH) sequence augmented with a variable spin-lock preparation period. ASSESSMENT: Ankle T1ρ mapping was performed without and with axial loading of 500 N. The talar cartilage was segmented in five coronal slices covering the central talocrural joint. Median talar T1ρ values were separately calculated for the medial and lateral facets. STATISTICAL TESTS: Mann-Whitney U and Wilcoxon signed-rank tests, significance level: P < 0.05. RESULTS: For the combined cohorts, the statistical analysis yielded significantly lower T1ρ values with loading compared to the no-load measurement for both the lateral (no load: [51.0 ± 4.0] msec, load: [49.5 ± 5.4] msec) as well as the medial compartment (no load: [50.0 ± 5.4] msec, load: [47.8 ± 6.8] msec). In the unloaded scans, the CAI patients showed significantly increased talar T1ρ values ([53.0 ± 7.4] mse ) compared to the healthy control subjects ([48.8 ± 4.1] msec) in the medial compartment. DATA CONCLUSION: Increased talar T1ρ relaxation times in CAI patients compared to healthy controls suggest that T1ρ relaxation is a sensitive biomarker for CAI-induced early-stage cartilage degeneration. However, the load-induced T1ρ change did not prove to be a viable marker for the altered biomechanical properties of the hyaline talar cartilage. LEVEL OF EVIDENCE: 2 LEVEL OF EFFICACY: Stage 2.

Development and validation of a questionnaire to measure the severity of pain, functional limitations, and reduction of sports ability for german-speaking patients with osteochondral lesions of the ankle (OCLA-G).

BACKGROUND: There is no patient-reported functional scale specific for osteochondral lesion of the ankle (OCLA). Therefore, the objectives of this study were to develop a questionnaire that measures symptom severity, function, and sports capacity in patients with osteochondral lesions of the ankle and to determine the psychometric properties of the tool in German language (OCLA-G). METHODS: The OCLA-G questionnaire was developed according to the COSMIN guidelines. Scalable items were generated from a literature search, based on an evaluation of 71 own OCLA patients, and from expert opinions. Following a twofold item reduction the questionnaire underwent explorative data analysis and principal component analysis. Validity and reliability were analysed in four groups of participants (40 patients with OCLA, 40 patients with other foot and ankle injuries, 40 asymptomatic athletes serving as a population at risk, and 40 asymptomatic persons playing sports not at risk). The minimum age for participation in the study was set at 18 years. The mean age was 39.3 ± 15.1 years. RESULTS: The final OCLA-G questionnaire consists of eight and five questions to mirror activities of daily life (ADL) and sports, respectively. Excellent internal consistency (Cronbach's α = 0.950 for the ADL subscore and 0.965 for the sport subscale, respectively) was found. Spearman's rank correlation coefficients for test-retest reliability were 0.992 for the ADL subscore and 0.999 for the sport subscale (p < 0.001). The results of the exploratory and confirmatory factor analyses indicated that item difficulty was between 23.4 and 62.8. The Pearson correlation for the OCLA subscales ADL and sport was 0.853 (p < 0.001). Construct validity as tested against the SF-12 questionnaire subscales (Physical and Mental component scale) were r = -0.164 to -0.663 (p < 0.05). Statistically, there was no ADL and sport OCLA mean score difference between OCLA patients and patients with other foot and ankle injuries (p = 0.993 and 0.179, respectively), but both groups differed from the uninjured control groups (p < 0.001). There were no ceiling or floor effects. CONCLUSIONS: The OCLA-G was successfully developed as the first patient reported and injury specific outcome scale to measure the impact of OCLA induced symptoms on activities of daily living and sport. This study provides evidence for the reliability and validity of the OCLA-G assessing patients with OCLA. TRIAL REGISTRATION: The registration trial number is DRKS00009401 on DRKS. 'Retrospectively registered'. Date of registration: 10/12/2015.

Composite material consisting of microporous beta-TCP ceramic and alginate-dialdehyde-gelatin for controlled dual release of clindamycin and bone morphogenetic protein 2.

The aim of this study was to produce a composite of microporous ß-TCP filled with alginate-gelatin crosslinked hydrogel, clindamycin and bone morphogenetic protein (BMP-2) to prolong the drug-release behaviour for up to 28 days. The most promising alginate-di-aldehyde(ADA)-gelatin gel for drug release from microcapsules was used to fill microporous ß-TCP ceramics under directional flow in a special loading chamber. Dual release of clindamycin and BMP-2 was measured on days 1, 2, 3, 6, 9, 14, 21 and 28 by high performance liquid chromatography (HPLC) and enzyme-linked immunosorbent assay (ELISA). After release, the microbial efficacy of the clindamycin was checked and the biocompatibility of the composite was tested in cell culture. Clindamycin and the model substance FITC-protein A were released from microcapsules over 28 days. The clindamycin burst release was 43 ± 1%. For the loaded ceramics, a clindamycin release above the minimal inhibitory concentration (MIC) until day 9 and a burst release of 90.56 ± 2.96% were detected. BMP-2 was released from the loaded ceramics in low concentrations over 28 days. The release of active substances from ß-TCP and hydrogel have already been extensively studied. Directional flow loading is a special procedure in which the ceramic could act as a stabilizer in the bone and, as a biodegradable system, enables a single-stage surgical procedure. Whether ADA-gelatin gel is suitable for this procedure as a more biodegradable alternative to pure alginate or whether a dual release is possible in this composite has not yet been investigated.

Digital measurement of anterolateral knee laxity using strain sensors.

PURPOSE: The ambition of the research group was to develop a sensor-based system that allowed the transfer of results with strain sensors applied to the knee joint. This system was to be validated in comparison to the current static mechanical measurement system. For this purpose, the internal rotation laxity of the knee joint was measured, as it is relevant for anterolateral knee laxity and anterior cruciate ligament (ACL) injury. METHODS: This is a noninvasive measurement method using strain sensors which are applied to the skin in the course of the anterolateral ligament. The subjects were placed in supine position. First the left and then the right leg were clinically examined sequentially and documented by means of an examination form. 11 subjects aged 21 to 45 years, 5 women and 6 men were examined. Internal rotation of the lower leg was performed with a torque of 2 Nm at a knee flexion angle of 30°. RESULTS: Comparison of correlation between length change and internal knee rotation angle showed a strong positive correlation (r = 1, p < 0.01). Whereas females showed a significant higher laxity vs. males (p = 0.003). CONCLUSIONS: The present study showed that the capacitive strain sensors can be used for reproducible measurement of anterolateral knee laxity. In contrast to the previous static systems, a dynamic measurement will be possible by this method in the future.

Discharging the medial knee compartment: comparison of pressure distribution and kinematic shifting after implantation of an extra-capsular absorber system (ATLAS) and open-wedge high tibial osteotomy-a biomechanical in vitro analysis.

PURPOSE: Young and active patients suffering early degenerative changes of the medial compartment with an underlying straight-leg axis do face a therapeutical gap as unloading of the medial compartment cannot be achieved by high tibial osteotomy. Extracapsular absorbing implants were developed to close this existing therapeutical gap. Purpose of the present cadaveric biomechanical study was to compare the unloading effect of the knee joint after implantation of an extra-articular absorber system (ATLAS) in comparison to open-wedge high tibial osteotomy (OW-HTO) under physiological conditions. The hypothesis of the study was that implantation of an extra-capsular absorber results in an unloading effect comparable to the one achievable with OW-HTO. METHODS: Eight fresh-frozen cadaveric knees were tested under isokinetic flexion-extension motions and physiological loading using a biomechanical knee simulator. Tibiofemoral area contact and peak contact pressures were measured using pressure-sensitive film in the untreated medial compartment. The tibiofemoral superior-inferior, latero-medial translation and varus/valgus rotation were measured with a 3D tracking system Polaris. Pressures and kinematics changes were measured after native testing, ATLAS System implantation and OW-HTO (5° and 10° correction angles) performed with an angular stable internal fixator (TomoFix). RESULTS: The absorber device decreased the pressure in the medial compartment near full extension moments. Implantation of the ATLAS absorbing system according to the manufacturers' instruction did not result in a significant unloading effect. Deviating from the surgery manual provided by the manufacturer the implantation of a larger spring size while applying varus stress before releasing the absorber resulted in a significant pressure diminution. Contact pressure decreased significantly Δ0.20 ± 0.04 MPa p = 0.044. Performing the OW-HTO in 5° correction angle resulted in significant decreased contact pressure (Δ0.25 ± 0.10 MPa, p = 0.0036) and peak contact pressure (Δ0.39 ± 0.38 MPa, p = 0.029) compared with the native test cycle. With a 10° correction angle, OW-HTO significantly decreased area contact pressure by Δ0.32 ± 0.09 MPa, p = 0.006 and peak contact pressure by Δ0.48 ± 0.12 MPa, p = 0.0654 compared to OW-HTO 5°. Surgical treatment did not result in kinematic changes regarding the superior-inferior translation of the medial joint section. A significant difference was observed for the translation towards the lateral compartment for the ATLAS system Δ1.31 ± 0.54 MPa p = 0.022 and the osteotomy Δ3.51 ± 0.92 MPa p = 0.001. Furthermore, significant shifting varus to valgus rotation of the treated knee joint was verified for HTO 5° about Δ2.97-3.69° and for HTO 10° Δ4.11-5.23° (pHTO 5 = 0.0012; pHTO 10 = 0.0007) over the entire extension cycle. CONCLUSION: OW-HTO results in a significant unloading of the medial compartment. Implantation of an extra-capsular absorbing device did not result in a significant unloading until the implantation technique was applied against the manufacturer's recommendation. While the clinical difficulty for young and active patients with straight-leg axis and early degenerative changes of the medial compartment persists further biomechanical research to develop sufficient unloading devices is required.

Pneumatic tourniquet versus no tourniquet in transfemoral amputation - a study protocol for a randomized controlled trial.

BACKGROUND: Lower extremity amputation patients represent a frail group with extensive comorbidity. Transfemoral amputation is a high-risk procedure with 37-50% risk of mortality in the first year. Substantial blood loss during surgery increases the risk of anemic complications and death for these already weakened patients. The use of tourniquet during surgery may reduce blood loss, the need for blood transfusions, the related complications as well as the length of the surgery. However the use of tourniquet may be related to impaired wound healing and hence the use should be investigated in a randomized controlled trial. The primary aim of this study is to investigate the total blood loss and secondary to investigate differences in complications after transfemoral amputation between patients operated with or without tourniquet. METHODS: The total blood loss is calculated using Nadlers approach. Based on data from a pilot series, the sample size was calculated to 124, allocated 1:1 in two groups of 62 participants to ensure detection of at least 200 mL difference in the total blood loss. The primary outcome is the total blood loss. Secondary outcomes are blood transfusions, duration of surgery, length of hospital stay and risk of complications within 90 days (re-admissions, re-operations and mortality). Explorative outcomes are 1 year mortality and re-operation risk. Further explorative outcomes are postoperative quality of life (questionnaire EQ-5D-5L) and evaluation of number of prosthesis users including evaluation of prosthesis-specific function measured 3, 6, and 12 months postoperatively. DISCUSSION: The possibility to enhance patient safety is highly relevant and this trial will provide data for evidence based recommendations of best practice in amputation surgery. TRIAL REGISTRATION: The trial is registered on ClinicalTrials.gov with ID: NCT05550623. Initial release: 13/09 2022.

Patellofemoral cartilage defects are acceptable in patients undergoing high tibial osteotomy for medial osteoarthritis of the knee.

BACKGROUND: Patients suffering cartilage defects of the medial compartment with underlying varus deformity do benefit from high tibial osteotomy (HTO) even in the long term. Nonetheless, kinematic and geometric changes especially in the patellofemoral joint have been described. Purpose of the present study was to evaluate the influence of patellofemoral cartilage defects detected during the diagnostic arthroscopy and their influence on HTO's postoperative outcome. METHODS: Ninety patients with a mean follow-up of 10.08 ± 2.33 years after surgery were included. Patients were divided into four groups according to their cartilage status in the patellofemoral joint (A = no defects, B = isolated lesions of the patella, C = isolated lesions of the trochlea, D = kissing lesions). Functional outcome was evaluated before surgery and about ten years thereafter by relying on the IKDC, Lysholm, and KOOS scores. Radiological parameters were assessed pre- and six weeks postoperatively. RESULTS: In groups A to D, the HTO led to significant patellar distalisation in the sagittal view, with the mean indices remaining at or above the limit to a patella baja. All patients in all groups profited significantly from HTO (higher Lysholm score, lower VAS p < 0.001), patients in group D had the lowest outcome scores. Patella height negatively influenced outcome scores in group C (Blackburne-Peel-Index-VAS p = 0.033) and D (Caton-Deschamps-Index-Tegner p = 0.018), a larger valgus correction was associated with lower outcome scores in group D (Lysholm p = 0.044, KOOSpain 0.028, KOOSQOL p = 0.004). CONCLUSION: Long-term results of HTO for varus medial compartment osteoarthritis remain good to excellent even in the presence of patellofemoral defects. Overcorrection should be avoided. Distal biplanar HTO should be considered for patients presenting trochlear or kissing lesions of the patellofemoral joint. TRIAL REGISTRATION: DRKS00015733 in the German Registry of Clinical Studies.

Interobserver reliability is higher for assessments with 3D software-generated models than with conventional MRI images in the classification of trochlear dysplasia.

PURPOSE: Trochlear dysplasia is a significant risk factor for patellofemoral instability. The severity of trochlear dysplasia is commonly evaluated based on the Dejour classification in axial MRI slices. However, this often leads to heterogeneous assessments. A software to generate MRI-based 3D models of the knee was developed to ensure more standardized visualization of knee structures. The purpose of this study was to assess the intra- and interobserver agreements of 2D axial MRI slices and an MRI-based 3D software generated model in classification of trochlear dysplasia as described by Dejour. METHODS: Four investigators independently assessed 38 axial MRI scans for trochlear dysplasia. Analysis was made according to Dejour's 4 grade classification as well as differentiating between 2 grades: low-grade (types A + B) and high-grade trochlear dysplasia (types C + D). Assessments were repeated following a one-week interval. The inter- and intraobserver agreement was determined using Cohen's kappa (κ) and Fleiss kappa statistic (κ). In addition, the proportion of observed agreement (po) was calculated for assessment of intraobserver agreement. RESULTS: The assessment of the intraobserver reliability with regard to the Dejour-classification showed moderate agreement values both in the 2D (κ = 0.59 ± 0.08 SD) and in the 3D analysis (κ = 0.57 ± 0.08 SD). Considering the 2-grade classification, the 2D (κ = 0.62 ± 0.12 SD) and 3D analysis (κ = 0.61 ± 0.19 SD) each showed good intraobserver matches. The analysis of the interobserver reliability also showed moderate agreement values with differences in the subgroups (2D vs. 3D). The 2D evaluation showed correspondences of κ = 0.48 (Dejour) and κ = 0.46 (high / low). In the assessment based on the 3D models, correspondence values of κ = 0.53 (Dejour) and κ = 0.59 (high / low) were documented. CONCLUSION: Overall, moderate-to-good agreement values were found in all groups. The analysis of the intraobserver reliability showed no relevant differences between 2 and 3D representation, but better agreement values were found in the 2-degree classification. In the analysis of interobserver reliability, better agreement values were found in the 3D compared to the 2D representation. The clinical relevance of this study lies in the superiority of the 3D representation in the assessment of trochlear dysplasia, which is relevant for future analytical procedures as well as surgical planning. LEVEL OF EVIDENCE: Level II.

Protein Expression of AEBP1, MCM4, and FABP4 Differentiate Osteogenic, Adipogenic, and Mesenchymal Stromal Stem Cells.

Mesenchymal stem cells (MSCs) gain an increasing focus in the field of regenerative medicine due to their differentiation abilities into chondrocytes, adipocytes, and osteoblastic cells. However, it is apparent that the transformation processes are extremely complex and cause cellular heterogeneity. The study aimed to characterize differences between MSCs and cells after adipogenic (AD) or osteoblastic (OB) differentiation at the proteome level. Comparative proteomic profiling was performed using tandem mass spectrometry in data-independent acquisition mode. Proteins were quantified by deep neural networks in library-free mode and correlated to the Molecular Signature Database (MSigDB) hallmark gene set collections for functional annotation. We analyzed 4108 proteins across all samples, which revealed a distinct clustering between MSCs and cell differentiation states. Protein expression profiling identified activation of the Peroxisome proliferator-activated receptors (PPARs) signaling pathway after AD. In addition, two distinct protein marker panels could be defined for osteoblastic and adipocytic cell lineages. Hereby, overexpression of AEBP1 and MCM4 for OB as well as of FABP4 for AD was detected as the most promising molecular markers. Combination of deep neural network and machine-learning algorithms with data-independent mass spectrometry distinguish MSCs and cell lineages after adipogenic or osteoblastic differentiation. We identified specific proteins as the molecular basis for bone formation, which could be used for regenerative medicine in the future.

Laxity measurement of internal knee rotation after primary anterior cruciate ligament rupture versus rerupture.

PURPOSE: The aim of the current study was to objectify the rotational laxity after primary anterior cruciate ligament (ACL) rupture and rerupture after ACL reconstruction by instrumented measurement. It was hypothesized that knees with recurrent instability feature a higher internal rotation laxity as compared to knees with a primary rupture of the native ACL. STUDY DESIGN: Cross-sectional study, Level of evidence III. METHODS: In a clinical cross-sectional study successive patients with primary ACL rupture and rerupture after ACL reconstruction were evaluated clinically and by instrumented measurement of the rotational and antero-posterior laxity with a validated instrument and the KT1000®, respectively. Clinical examination comprised IKDC 2000 forms, Lysholm Score, and Tegner Activity Scale. Power calculation and statistical analysis were performed (p value < 0.05). RESULTS: 24 patients with primary ACL rupture and 23 patients with ACL rerupture were included. There was no significant side-to-side difference in anterior translation. A side-to side difference of internal rotational laxity ≥ 10° was found significantly more frequent in reruptures (53.6%) compared to primary ruptures (19.4%; p < 0.001). A highly significant relationship between the extent of the pivot-shift phenomenon and side-to-side difference of internal rotation laxity could be demonstrated (p < 0.001). IKDC 2000 subjective revealed significantly better scores in patients with primary ACL tear compared to patients with ACL rerupture (56.4 ± 7.8 vs. 50.8 ± 6.2; p = 0.01). Patients with primary ACL tears scored significantly better on the Tegner Activity Scale (p = 0.02). No significant differences were seen in the Lysholm Score (p = 0.78). CONCLUSION: Patients with ACL rerupture feature significantly higher internal rotation laxity of the knee compared to primary ACL rupture. The extend of rotational laxity can be quantified by instrumented measurements. This can be valuable data for the indication of an anterolateral ligament reconstruction in ACL revision surgery.

Inhibition of the anti-apoptotic protein MCL-1 severely suppresses human hematopoiesis

BH3-mimetics inhibiting anti-apoptotic BCL-2 proteins represent a novel and promising class of antitumor drugs. While the BCL-2 inhibitor venetoclax is already FDA-approved, BCL-XL and MCL-1 inhibitors are currently in early clinical trials. To predict side effects of therapeutic MCL-1 inhibition on the human hematopoietic system, we used RNAi and the small molecule inhibitor S63845 on cord blood-derived CD34+ cells. Both approaches resulted in almost complete depletion of human hematopoietic stem and progenitor cells. As a consequence, maturation into the different hematopoietic lineages was severely restricted and CD34+ cells expressing MCL-1 shRNA showed a very limited engraftment potential upon xenotransplantation. In contrast, mature blood cells survived normally in the absence of MCL-1. Combined inhibition of MCL-1 and BCL-XL resulted in synergistic effects with relevant loss of colony-forming HSPCs already at inhibitor concentrations of 0.1 µM each, indicating "synthetic lethality" of the two BH3-mimetics in the hematopoietic system.

Efficacy and safety of iloprost in trauma patients with haemorrhagic shock-induced endotheliopathy-Protocol for the multicentre randomized, placebo-controlled, blinded, investigator-initiated shine-trauma trial.

BACKGROUND: Traumatic injury accounts for 800 000 deaths in the European Union annually. The main causes of deaths in trauma patients are exsanguination and multiple organ failure (MOF). We have studied >1000 trauma patients and identified shock-induced endotheliopathy (SHINE), the pathophysiological mechanism responsible for MOF and high mortality. Pilot studies indicate that low-dose iloprost (1 ng/kg/min) improves endothelial functionality in critically ill patients suggesting this intervention may improve patient outcome in traumatic SHINE. MATERIAL AND METHODS: This is a multicentre, randomized, blinded clinical investigator-initiated phase 2B trial in trauma patients with haemorrhagic shock-induced endotheliopathy. Patients are randomized 1:1 to 72 hours infusion of iloprost 1 ng/kg/min or Placebo (equal volume of saline). A total of 220 trauma patients will be included. The primary endpoint is the number of intensive care unit (ICU)-free days, within 28 days of admission. Secondary endpoints include 28- and 90-day all-cause mortality, hospital length of stay, vasopressor-free days in the intensive care unit (ICU) within 28 days, ventilator-free days in the ICU within 28 days, renal replacement-free days in the ICU within 28 days, number of serious adverse reactions and serious adverse events within the first 4 days of admission. DISCUSSION: This trial will test the safety and efficacy of administration of iloprost vs placebo for 72 hours in trauma patients with haemorrhagic shock-induced endotheliopathy. Trial endpoints focus on the potential effect of iloprost to reduce the need for ICU stay secondary to mitigation of organ failure. TRIAL REGISTRATION: SHINE-TRAUMA trial-EudraCT no. 2019-000936-24-Clinicaltrials.gov: NCT03903939 Ethics Committee no. H-19014482.

Elevation of Inflammatory Cytokines and Proteins after Intra-Articular Ankle Fracture: A Cross-Sectional Study of 47 Ankle Fracture Patients.

INTRODUCTION: Intra-articular fractures are the leading etiology for posttraumatic osteoarthritis (PTOA) in the ankle. Elevation of proinflammatory cytokines following intra-articular fracture may lead to synovial catabolism and cartilage degradation. We aimed to compare cytokine levels in injured and healthy ankle joints, examine the longer-term cytokine levels in fractured ankles, and investigate the association between cytokine levels in fractured ankles and plasma. MATERIALS AND METHODS: In this cross-sectional study, synovial fluid (SF) and plasma of forty-seven patients with acute intra-articular ankle fractures and eight patients undergoing implant removal were collected prior to surgery. We determined concentrations of sixteen inflammatory cytokines, two cartilage degradation proteins, and four metabolic proteins and compared the levels in acutely injured ankles with those of the healthy contralateral side or during metal removal. Cytokine levels in injured ankles were also compared to serum cytokine levels. Nonparametric Wilcoxon rank-sum and Spearman tests were used for statistical analysis, and a p value below 0.05 was considered significant. RESULTS: Compared to the healthy ankles, the synovial fluid in ankles with acute intra-articular fracture had elevated levels of several proinflammatory cytokines and proteases (IL-1ß, IL-2, IL-6, IL-8, IL-12p70, TNF, IFNγ, MMP-1, MMP-3, and MMP-9) and anti-inflammatory cytokines (IL-1RA, IL-4, IL-10, and IL-13). The levels of cartilage degradation products (ACG, CTX-2) and metabolic mediators (TGF-ß1 and TGF-ß2) were also significantly higher. Synovial concentrations of ACG, IL-12-p70, IFNγ, IL-4, and bFGF correlated with serum levels. While most of the examined synovial cytokines were unchanged after implant removal, IL-4 and IL-6 levels were upregulated. CONCLUSIONS: We show that an acute ankle fracture is followed by an inflammatory reaction and cartilage degeneration. These data contribute to the current understanding of the protein regulation behind the development of PTOA and is a further step towards supplementing the current surgical treatment. This cross-sectional study was "retrospectively registered" on the 31th October 2017 at ClinicalTrials.gov (NCT03769909). The registration was carried out after inclusion of the first patient and prior to finalization of patient recruitment and statistical analyses: https://clinicaltrials.gov/ct2/show/NCT03769909?term=NCT03769909&draw=2&rank=1.