Cilostazol Stimulates Angiogenesis and Accelerates Fracture Healing in Aged Male and Female Mice by Increasing the Expression of PI3K and RUNX2.

Fracture healing in the aged is associated with a reduced healing capacity, which often results in delayed healing or non-union formation. Many factors may contribute to this deterioration of bone regeneration, including a reduced 'angiogenic trauma response'. The phosphodiesterase-3 (PDE-3) inhibitor cilostazol has been shown to exert pro-angiogenic and pro-osteogenic effects in preclinical studies. Therefore, we herein analyzed in a stable closed femoral fracture model whether this compound also promotes fracture healing in aged mice. Forty-two aged CD-1 mice (age: 16-18 months) were daily treated with 30 mg/kg body weight cilostazol (n = 21) or vehicle (control, n = 21) by oral gavage. At 2 and 5 weeks after fracture, the femora were analyzed by X-ray, biomechanics, micro-computed tomography (µCT), histology, immunohistochemistry, and Western blotting. These analyses revealed a significantly increased bending stiffness at 2 weeks (2.2 ± 0.4 vs. 4.3 ± 0.7 N/mm) and an enhanced bone formation at 5 weeks (4.4 ± 0.7 vs. 9.1 ± 0.7 mm3) in cilostazol-treated mice when compared to controls. This was associated with a higher number of newly formed CD31-positive microvessels (3.3 ± 0.9 vs. 5.5 ± 0.7 microvessels/HPF) as well as an elevated expression of phosphoinositide-3-kinase (PI3K) (3.6 ± 0.8 vs. 17.4 ± 5.5-pixel intensity × 104) and runt-related transcription factor (RUNX)2 (6.4 ± 1.2 vs. 18.2 ± 2.7-pixel intensity × 104) within the callus tissue. These findings indicate that cilostazol accelerates fracture healing in aged mice by stimulating angiogenesis and the expression of PI3K and RUNX2. Hence, cilostazol may represent a promising compound to promote bone regeneration in geriatric patients.

Sildenafil, a phosphodiesterase-5 inhibitor, stimulates angiogenesis and bone regeneration in an atrophic non-union model in mice.

Non-union formation represents a major complication in trauma and orthopedic surgery. The phosphodiesterase-5 (PDE-5) inhibitor sildenafil has been shown to exert pro-angiogenic and pro-osteogenic effects in vitro and in vivo. Therefore, the aim of the present study was to analyze the impact of sildenafil in an atrophic non-union model in mice. After creation of a 1.8 mm segmental defect, mice femora were stabilized by pin-clip fixation. Bone regeneration was analyzed by means of X-ray, biomechanics, photoacoustic and micro-computed tomography (µCT) imaging as well as histological, immunohistochemical and Western blot analyses at 2, 5 and 10 weeks after surgery. The animals were treated daily with either 5 mg/kg body weight sildenafil (n = 35) or saline (control; n = 35) per os. Bone formation was markedly improved in defects of sildenafil-treated mice when compared to controls. This was associated with a higher bending stiffness as well as an increased number of CD31-positive microvessels and a higher oxygen saturation within the callus tissue. Moreover, the bone defects of sildenafil-treated animals contained more tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts and CD68-positive macrophages and exhibited a higher expression of the pro-angiogenic and pro-osteogenic markers cysteine rich protein (CYR)61 and vascular endothelial growth factor (VEGF) when compared to controls. These findings demonstrate that sildenafil acts as a potent stimulator of angiogenesis and bone regeneration in atrophic non-unions.

Patients with combined pelvic and spinal injuries have worse clinical and operative outcomes than patients with isolated pelvic injuries analysis of the German Pelvic Registry.

BACKGROUND: Pelvic fractures are often associated with spine injury in polytrauma patients. This study aimed to determine whether concomitant spine injury influence the surgical outcome of pelvic fracture. METHODS: We performed a retrospective analysis of data of patients registered in the German Pelvic Registry between January 2003 and December 2017. Clinical characteristics, surgical parameters, and outcomes were compared between patients with isolated pelvic fracture (group A) and patients with pelvic fracture plus spine injury (group B). We also compared apart patients with isolated acetabular fracture (group C) versus patients with acetabular fracture plus spine injury (group D). RESULTS: Surgery for pelvic fracture was significantly more common in group B than in group A (38.3% vs. 36.6%; p = 0.0002), as also emergency pelvic stabilizations (9.5% vs. 6.7%; p < 0.0001). The mean time to emergency stabilization was longer in group B (137 ± 106 min vs. 113 ± 97 min; p < 0.0001), as well as the mean time until definitive stabilization of the pelvic fracture (7.3 ± 4 days vs. 5.4 ± 8.0 days; p = 0.147). The mean duration of treatment and the morbidity and mortality rates were all significantly higher in group B (p < 0.0001). Operation time was significantly shorter in group C than in group D (176 ± 81 min vs. 203 ± 119 min, p < 0.0001). Intraoperative blood loss was not significantly different between the two groups with acetabular injuries. Although preoperative acetabular fracture dislocation was slightly less common in group D, postoperative fracture dislocation was slightly more common. The distribution of Matta grades was significantly different between the two groups. Patients with isolated acetabular injuries were significantly less likely to have neurological deficit at discharge (94.5%; p < 0.0001). In-hospital complications were more common in patients with combined spine plus pelvic injuries (groups B and D) than in patients with isolated pelvic and acetabular injury (groups A and C). CONCLUSIONS: Delaying definitive surgical treatment of pelvic fractures due to spinal cord injury appears to have a negative impact on the outcome of pelvic fractures, especially on the quality of reduction of acetabular fractures.

Development of an ischemic fracture healing model in mice.

BACKGROUND AND PURPOSE: In fracture healing, ischemia caused by vascular injuries, chronic vascular diseases, and metabolic comorbidities is one of the major risk factors for delayed union and non-union formation. To gain novel insights into the molecular and cellular pathology of ischemic fracture healing, appropriate animal models are needed. Murine models are of particular interest, as they allow to study the molecular aspects of fracture healing due to the availability of both a large number of murine antibodies and gene-targeted animals. Thus, we present the development of an ischemic fracture healing model in mice. MATERIAL AND METHODS: After inducing a mild ischemia by double ligature of the deep femoral artery in CD-1 mice, the ipsilateral femur was fractured by a 3-point bending device and stabilized by screw osteosynthesis. In control animals, the femur was fractured and stabilized without the induction of ischemia. The femora were analyzed at 2 and 5 weeks after fracture healing by means of radiology, biomechanics, histology, and histomorphometry. RESULTS: The surgically induced ischemia delayed and impaired the process of fracture healing. This was indicated by a lower Goldberg score, decreased bending stiffness, and reduced bone callus formation in the ischemic animals when compared with the controls. INTERPRETATION: We introduce a novel ischemic femoral fracture healing model in mice, which is characterized by delayed bone healing. In future, the use of this model may allow both the elucidation of the molecular aspects of ischemic fracture healing and the study of novel treatment strategies.

Age and "general health"-beside fracture classification-affect the therapeutic decision for geriatric pelvic ring fractures: a German pelvic injury register study.

PURPOSE: Pelvic ring fractures in the elderly gain increasing importance. Nonetheless, data on factors influencing treatment decision in relation to fracture classification, age, and the resulting treatment are still rare. METHODS: Prospectively collected data of the German Pelvic Injury Registry from patients aged over 65 years with a pelvic ring fracture were evaluated retrospectively. Acetabular fractures, as well as type A1 and A3 fractures, were excluded. The variables age, injury pattern, type of treatment, the reason for conservative treatment, and Orthopaedic Trauma Association (OTA)/Tile classification were analyzed. Furthermore, the fracture distribution was examined after dividing patients into six age groups. RESULTS: A total of 1814 patients with a mean age of 80.7 ± 7.6 years, predominantly female (79.0%), were available for evaluation. The majority of patients suffered from isolated pelvic ring fractures (70.1%) and 8.2% were severely injured (ISS > 16). The most common fracture types were type A2 (35.4%), type B2 (38.0%), and type C1 (7.3%). Especially pelvic ring fractures of type A2 (96.9%) and type B2 (83.0%) were treated conservatively (overall 76.9%). Fracture instability according to the OTA/Tile classification increased the probability for an operative treatment (generalized odds ratio [OR] 6.90 [5.62; 8.52]). In contrary, increasing age independent of the fracture pattern decreased this probability (OR 0.47 [0.41-0.53]). With increasing fracture instability, general health conditions were up to 50% of the reasons for conservative treatment. CONCLUSION: The results of the present study underline the importance of the factors age and general health besides fracture classification for therapeutic decision-making in the treatment of pelvic ring fractures in the elderly.

Predictors for secondary hip osteoarthritis after acetabular fractures-a pelvic registry study.

PURPOSE: Secondary hip osteoarthritis after acetabular fractures requiring total arthroplasty (THA) poses a huge burden on the affected patients as well as health systems. The present study aimed to assess risk factors associated with THA after acetabular fractures based on the data from the German Pelvic Trauma Registry. METHODS: Retrospective analysis of 678 acetabular fracture cases without concomitant pelvic ring fracture treated and followed-up between January 2004 and May 2015 at six large trauma centres. Multivariate Cox regression analysis was performed assessing the association of patient/treatment characteristics with THA likelihood at an average follow-up of 2.7 years (range 0.4-9.5 years; SD 1.8 years). RESULTS: Overall, the rate of secondary osteoarthritis was 19.8%. The likelihood for THA increased with 6% per age year (95% CI 1.04-1.09) and with 21% per millimetre subluxation (95%CI 1.09-1.33). This likelihood was 3.54 (95% CI 1.77-7.08) and 3.68 times (95% CI 1.87-7.47) higher if the posterior wall was involved and a contusion and/or impaction of the femoral head was present. Other covariates (sex, ISS, trauma type, AO/OTA and Letournel classification, initial displacement, surgical approach, intra-articular fragments, contusion and/or impaction to the acetabulum, reduction, intervention type, duration of surgery, soft tissue damage, residual fracture step/gap, and prevention of heterotopic ossifications) were not significantly associated (p > 0.15). CONCLUSIONS: Twenty percent of patients with acetabular fractures require THA. The associated risk factors are patient age, femoral head lesion/subluxation, and involvement of the posterior wall. The identified risk factors support previous research and should be minded when treatment of acetabular fractures is planned.

Long-term pathological gait pattern changes after talus fractures - dynamic measurements with a new insole.

PURPOSE: The aim of the current study was to describe long-term gait changes after talus fractures, identify patterns associated with poor outcome and discuss possible treatment options based on dynamic gait analysis. METHODS: Twenty-seven patients were followed-up clinically and via gait analysis after talus fracture osteosynthesis. Continuous dynamic pedobarography with a gait analysis insole was performed on a standardized parcours consisting of different gait tasks and matched to the outcome. RESULTS: Mean follow-up was 78.3 months (range 21-150), mean AOFAS and Olerud-Molander scores 66 (range 20-100) and 54 (range 15-100). Significant correlations between fracture classification and osteoarthritis (Hawkins: rs = 0.67 / Marti-Weber: rs = 0.5) as well as several gait differences between injured and healthy foot with correlations to outcome were seen: decreased step load-integral/maximum-load; associations between centre-of-pressure displacement and outcome as well as between temporospatial measures and outcome. Overall, pressure-distribution was lateralized in patients with subtalar joint injury (Δ: 0.5765 N/cm2, p = 0.0475). CONCLUSIONS: Talus fractures lead to chronic gait changes and restricted function. Dynamic pedobarography can identify patterns associated with poor results. The observed gait patterns suggest that changes can be addressed by physical therapy and customized orthoses to improve overall outcome. The presented insole and measurement protocol are immediately feasible as a diagnostic and rehabilitation aid.

Should I Stay or Should I Go? A Prospective, Blinded Study Comparing the Diagnostic Capability of Dynamic and Stationary Pedobarography in Plantar Fasciitis.

The aim of this study was to determine the diagnostic capability of a dynamic gait analysis insole and compare its ability to detect clinical correlations to a common stationary analysis tool. Twenty-five patients with chronic plantar fasciitis were included in this prospective, blinded, diagnostic study. Conventional, stationary gait analysis on a force plate on an even surface and continuous dynamic pedobarography on a standardized course consisting of different gait tasks were performed and correlated to the disease severity. Mean patient age was 53.6 (range 41 to 68) years, with a mean pain level of 6.1 (range 4 to 10) on the Visual Analogue Scale and a calcaneodynia score of 48.7 (range 33 to 66). Significant correlations were seen between several dynamic gait values and clinical scoring: cadence (rs = 0.56, p = .004), stance time (rs = -0.6, p = .002), center-of-pressure velocity (rs = 0.44, p = .046), and double support time (rs = 0.42, p = .042). No significant correlations were seen between any force plate gait analysis values and clinical scoring. In this study setting, dynamic gait analysis was able to identify clinically relevant correlations to plantar fasciitis disease severity that standard force plate measurements could not.

Surgical treatment of pelvic ring fractures in the elderly now and then: a pelvic registry study.

BACKGROUND: With the demographic change, the treatment of elderly patients has become a major issue for health systems worldwide. AIMS: The aim of this study was to analyze the change in the rate of surgical treatment of pelvic ring fractures in patients with an age of ≥60 years over a 22-year period depending on fracture type, age and sex. METHODS: Data of 5665 patients with an age of ≥60 years, who were treated for pelvic ring fractures from 1991 to 2013 in one of 31 hospitals participating in the German Pelvic Trauma Registry, were included. The registry is divided into four time periods: t 1 = 1991-1993, t 2 = 1997-2000, t 3 = 2001-2008 and t 4 = 2009-2013. Data had been collected prospectively and was analyzed retrospectively, stratified for age and sex of the patients as well as type of fracture and mode of therapy (surgical vs. conservative). RESULTS: There was a significant increase (p < 0.05) in the overall rate of surgical treatment. Nonetheless, during all time periods patients with an age of >70 years were significantly less frequently surgically treated compared to 60- to 70-year-olds. Regardless of the fracture type, the rate of surgical treatment was significantly higher (p < 0.05) in male compared to female patients during t 1. While this difference persisted for type A and type B fractures, the frequency of surgical treatment of type C fractures approximated in males and females. CONCLUSIONS: The present data indicate that the rate of surgical treatment of pelvic ring fractures in elderly patients has significantly increased over the 22-year period. Nonetheless, older patients (>70 years) as well as female patients are still less frequently surgically treated.

Weight-bearing recommendations after operative fracture treatment-fact or fiction? Gait results with and feasibility of a dynamic, continuous pedobarography insole.

PURPOSE: Rehabilitation after lower-extremity fractures is based on the physicians' recommendation for non-, partial-, or full weight-bearing. Clinical studies rely on this assumption, but continuous compliance or objective loading rates are unknown. The purpose of this study was to determine the compliance to weight-bearing recommendations by introducing a novel, pedobarography system continuously registering postoperative ground forces into ankle, tibial shaft and proximal femur fracture aftercare and test its feasibility for this purpose. METHODS: In this prospective, observational study, a continuously measuring pedobarography insole was placed in the patients shoe during the immediate post-operative aftercare after ankle, tibial shaft and intertrochanteric femur fractures. Weight-bearing was ordered as per the institutional standard and controlled by physical therapy. The insole was retrieved after a maximum of six weeks (28 days [range 5-42 days]). Non-compliance was defined as a failure to maintain, or reach the ordered weight-bearing within 30%. RESULTS: Overall 30 patients were included in the study. Fourteen (47%) of the patients were compliant to the weight-bearing recommendations. Within two weeks after surgery patients deviated from the recommendation by over 50%. Sex, age and weight did not influence the performance (p > 0.05). Ankle fracture patients (partial weight-bearing) showed a significantly increased deviation from the recommendation (p = 0.01). CONCLUSIONS: Our study results show that, despite physical therapy training, weight-bearing compliance to recommended limits was low. Adherence to the partial weight-bearing task was further decreased over time. Uncontrolled weight-bearing recommendations should thus be viewed with caution and carefully considered as fiction. The presented insole is feasible to determine weight bearing continuously, could immediately help define real-time patient behaviour and establish realistic, individual weight-bearing recommendations.

Predictive value of clinical scoring and simplified gait analysis for acetabulum fractures.

BACKGROUND: Fractures of the acetabulum show a high, long-term complication rate. The aim of the present study was to determine the predictive value of clinical scoring and standardized, simplified gait analysis on the outcome after these fractures. METHODS: Forty-one patients with acetabular fractures treated between 2008 and 2013 and available, standardized video recorded aftercare were identified from a prospective database. A visual gait score was used to determine the patients walking abilities 6-m postoperatively. Clinical (Merle d'Aubigne and Postel score, visual analogue scale pain, EQ5d) and radiological scoring (Kellgren-Lawrence score, postoperative computed tomography, and Matta classification) were used to perform correlation and multivariate regression analysis. RESULTS: The average patient age was 48 y (range, 15-82 y), six female patients were included in the study. Mean follow-up was 1.6 y (range, 1-2 y). Moderate correlation between the gait score and outcome (versus EQ5d: rs = 0.477; versus Merle d'Aubigne: rs = 0.444; versus Kellgren-Lawrence: rs = -0.533), as well as high correlation between the Merle d'Aubigne score and outcome were seen (versus EQ5d: rs = 0.575; versus Merle d'Aubigne: rs = 0.776; versus Kellgren-Lawrence: rs = -0.419). Using a multivariate regression model, the 6 m gait score (B = -0.299; P < 0.05) and early osteoarthritis development (B = 1.026; P < 0.05) were determined as predictors of final osteoarthritis. A good fit of the regression model was seen (R2 = 904). CONCLUSIONS: Easy and available clinical scoring (gait score/Merle d'Aubigne) can predict short-term radiological and functional outcome after acetabular fractures with sufficient accuracy. Decisions on further treatment and interventions could be based on simplified gait analysis.

Wearable activity data can predict functional recovery after musculoskeletal injury: Feasibility of a machine learning approach.

Delayed functional recovery after injury is associated with significant personal and socioeconomic burden. Identification of patients at risk for a prolonged recovery after a musculoskeletal injury is thus of high relevance. The aim of the current study was to show the feasibility of using a machine learning assisted model to predict functional recovery based on the pre- and immediate post injury patient activity as measured with wearable systems in trauma patients. Patients with a pre-existing wearable (smartphone and/or body-worn sensor), data availability of at least 7 days prior to their injury, and any musculoskeletal injury of the upper or lower extremity were included in this study. Patient age, sex, injured extremity, time off work and step count as activity data were recorded continuously both pre- and post-injury. Descriptive statistics were performed and a logistic regression machine learning model was used to predict the patient's functional recovery status after 6 weeks based on their pre- and post-injury activity characteristics. Overall 38 patients (7 upper extremity, 24 lower extremity, 5 pelvis, 2 combined) were included in this proof-of-concept study. The average follow-up with available wearable data was 85.4 days. Based on the activity data, a predictive model was constructed to determine the likelihood of having a recovery of at least 50 % of the pre-injury activity state by post injury week 6. Based on the individual activity by week 3 a predictive accuracy of over 80 % was achieved on an independent test set (F1=0,82; AUC=0,86; ACC=8,83). The employed model is feasible to assess the principal risk for a slower recovery based on readily available personal wearable activity data. The model has the potential to identify patients requiring additional aftercare attention early during the treatment course, thus optimizing return to the pre-injury status through focused interventions. Additional patient data is needed to adapt the model to more specifically focus on different fracture entities and patient groups.

Different coupling mechanisms for a novel modular plate in acetabular fractures-a comparison using a laparoscopic model.

Introduction: Acetabular fractures are among the most challenging injuries in traumatology. The complex anatomy usually requires extensive surgical approaches baring the risk for iatrogenic damage to surrounding neurovascular structures. As a viable alternative, minimally invasive endoscopic techniques have emerged during the recent years. This paper reports on the feasibility of different coupling mechanisms for a novel suprapectineal plate especially designed for minimally invasive acetabular surgery. Methods: A total number of 34 participants contributed to the present study, who differed in their arthroscopic and surgical experience. A laparoscopic model was used to compare four different coupling mechanisms by the number of failed attempts, the time required for plate fixation, the influence of surgical experience as well as the learning success for each individual coupling mechanism. Moreover, the feasibility of each mechanism was evaluated by a questionnaire. Results: The results demonstrate that plates employing grooved and pressure-sliding coupling mechanisms exhibit fewer failed attempts and reduce trial times, especially in contrast to sole sliding mechanisms. Furthermore, our study revealed that proficiency in endoscopic procedures significantly influenced the outcome. Notably, the subjective evaluation of the participants show that the pressure base and pressure-slide base plate designs are the most supportive and feasible designs. Conclusions: In summary, the present study evaluates for the first-time different plate and coupling designs for minimal-invasive surgery, indicating a superior feasibility for plates with a grooved and pressure-sliding mechanism.

[Nonunions after intertrochanteric and subtrochanteric femoral fractures]. / Pseudarthrosen nach per- und subtrochantären Femurfrakturen.

INTRODUCTION: The overall frequency of proximal femoral fractures means that we are repeatedly confronted with failed healing and implant failure, despite a relatively low nonunion rate especially in intertrochanteric fractures (< 5%). The aim of this paper is to present our approach to treating these nonunions of the proximal femur and discuss the treatment results. MATERIAL AND METHODS: Between 2009 and 2023, patients with nonunion of the proximal femur were retrospectively identified and analyzed. Age, gender, time to revision, the Weber-Cech classification of pseudarthrosis and radiographic imaging before and after revision were analyzed. RESULTS: A total of 66 patients were analyzed. The mean age was 58 years (range 25-88 years). The overall healing rate was 88% with a mean consolidation time of 8 months (range 2-29 months). The main osteosynthesis procedures were plate osteosynthesis (n = 45, of which 44 were blade plates), and nail replacement (n = 12). Other procedures included augmentative plate osteosyntheses (n = 4), isolated cancellous bone graft (n = 2), nail dynamization (n = 2), and the use of a dynamic hip screw (n = 1). DISCUSSION: The analysis of our treatment data as well as the current literature, revealed a trend towards intramedullary revision procedures. Implants that can be used to correct the CCD angle, such as the blade plate, remain a predictable option to achieve correction, especially in nonunions with an increased degree of varus. Particularly in the subtrochanteric region, fractures can also be treated in a targeted manner by a combination of mechanical and biological methods with a reamed nail change to a larger caliber implant.

[Non-unions of the upper extremities]. / Pseudarthrosen der oberen Extremität.

The diagnosis and treatment of non-unions still represents an interdisciplinary challenge. Therefore, prevention, early detection and specific treatment are of great importance. Non-unions of the upper extremities, although less common than that of the lower extremities, requires special attention for successful treatment due to the central role of the shoulder girdle and arm in day to day activities. Successful treatment of non-unions requires a comprehensive evaluation of the patient's medical history, a thorough clinical examination and in particular radiological imaging. In order to effectively treat the pseudarthrosis it is crucial to distinguish between pseudarthroses that are suspected to be due to infections and those that are not. This article presents a treatment algorithm for managing both pseudarthrosis due to infection and pseudarthrosis without infection in the upper extremities.

Sildenafil delays bone remodeling of fractured femora in aged mice by reducing the number and activity of osteoclasts within the callus tissue.

The elderly exhibit a reduced healing capacity after fracture, which is often associated with delayed or failed bone healing. This is due to a plethora of factors, such as an impaired bone vascular system and delayed angiogenesis. The phosphodiesterase-5 (PDE-5) inhibitor sildenafil exerts pro-angiogenic and pro-osteogenic effects. Hence, we herein investigated in aged mice whether sildenafil can improve fracture healing. For this purpose, 40 aged CD-1 mice (16-18 months) were daily treated with 5 mg/kg body weight sildenafil (n = 20) or vehicle (control, n = 20) by oral gavage. The callus tissue of their femora was analyzed at 2 and 5 weeks after fracture by X-ray, biomechanics, micro-computed tomography (µCT), histology, immunohistochemistry as well as Western blotting. These analyses revealed a significantly increased bone volume and higher ratio of callus to femoral bone diameter in sildenafil-treated mice at 5 weeks after fracture when compared to controls. This was associated with a reduced number and activity of osteoclasts at 2 weeks after fracture, most likely caused by an increased expression of osteoprotegerin (OPG). Taken together, these findings indicate that sildenafil does not improve fracture healing in the elderly but delays the process of bone remodeling most likely by reducing the number and activity of osteoclasts within the callus tissue.

[Primary joint replacement for the treatment of acetabular fractures]. / Primär endoprothetische Versorgung von Acetabulumfrakturen.

Open reduction and internal fixation are the gold standard for the treatment of dislocated acetabular fractures. A primary joint replacement is only justified in isolated cases. The indications are merely non-reconstructable acetabular fractures, accompanying displaced fractures of the femoral neck and non-reconstructable fractures of the femoral head.Because of the difficulties in achieving sufficient cup stability, joint replacement for the treatment of acetabular fractures regularly requires implants designed for revision arthroplasty. The Kocher-Langenbeck approach provides the most versatile options, as it enables simultaneous stabilization of the dorsal acetabular structures, which are essential for the stability of the cup.For primary joint replacement as a treatment of acetabular fractures, survival of the prosthetic cup is markedly worse when compared to elective primary joint replacement. Particularly in younger patients but also in aged patients, every effort should be made to achieve a press fit of the cup. In most cases, this will include reduction and fixation of the fracture for stabilization of the acetabulum prior to joint replacement. A staged approach with an early secondary replacement intervention seems to provide better overall results than simultaneous fracture fixation and joint replacement.

Deep Learning in the Detection of Rare Fractures - Development of a "Deep Learning Convolutional Network" Model for Detecting Acetabular Fractures. / Deep Learning in der Erkennung seltener Frakturen ­ Entwicklung eines "Deep Convolutional Neural Network" (DCNN) am Beispiel der Azetabulumfraktur.

BACKGROUND: Fracture detection by artificial intelligence and especially Deep Convolutional Neural Networks (DCNN) is a topic of growing interest in current orthopaedic and radiological research. As learning a DCNN usually needs a large amount of training data, mostly frequent fractures as well as conventional X-ray are used. Therefore, less common fractures like acetabular fractures (AF) are underrepresented in the literature. The aim of this pilot study was to establish a DCNN for detection of AF using computer tomography (CT) scans. METHODS: Patients with an acetabular fracture were identified from the monocentric consecutive pelvic injury registry at the BG Trauma Center XXX from 01/2003 - 12/2019. All patients with unilateral AF and CT scans available in DICOM-format were included for further processing. All datasets were automatically anonymised and digitally post-processed. Extraction of the relevant region of interests was performed and the technique of data augmentation (DA) was implemented to artificially increase the number of training samples. A DCNN based on Med3D was used for autonomous fracture detection, using global average pooling (GAP) to reduce overfitting. RESULTS: From a total of 2,340 patients with a pelvic fracture, 654 patients suffered from an AF. After screening and post-processing of the datasets, a total of 159 datasets were enrolled for training of the algorithm. A random assignment into training datasets (80%) and test datasets (20%) was performed. The technique of bone area extraction, DA and GAP increased the accuracy of fracture detection from 58.8% (native DCNN) up to an accuracy of 82.8% despite the low number of datasets. CONCLUSION: The accuracy of fracture detection of our trained DCNN is comparable to published values despite the low number of training datasets. The techniques of bone extraction, DA and GAP are useful for increasing the detection rates of rare fractures by a DCNN. Based on the used DCNN in combination with the described techniques from this pilot study, the possibility of an automatic fracture classification of AF is under investigation in a multicentre study.

"Floating Hip": Epidemiology and Quality of Care. / "Floating Hip": Epidemiologie und Qualität der Versorgung.

INTRODUCTION: The "floating hip" is a rare and complex fracture involving the pelvis and the ipsilateral femur and is therefore difficult to treat. Data and studies on this topic are still scarce. The optimal strategy for surgical treatment and thus the resulting quality of treatment are still being debated; a femur-first strategy is often the preferred treatment. METHODS: Retrospectively, patients with a pelvic fracture treated at the Level I Trauma Centre of the University of Tübingen between 2003 and 2017 were identified. Patients with an additional ipsilateral femur fracture were identified in this collective. We compared the quality of treatment of pelvic fractures between floating and non-floating hip injuries. RESULTS: Proximal femur fractures were more common with pelvic ring fractures (n = 16) than with acetabular fractures (n = 1). Floating hip injuries occur more frequently in younger polytraumatised male patients. Pelvic fractures in floating hip injuries are operated more frequently (62.8% vs. 39.1%; p = 0.003) and the clinical course is significantly longer (27.8 ± 19.3 vs. 19.9 ± 23.1 days; p < 0.001). However, the quality of treatment of pelvic fracture, exemplified by morbidity (18.6% vs. 14.6%; p = 0.610) and mortality (7.0% vs. 2.6%; p = 0.108), shows no differences. CONCLUSION: Injury severity and complexity of pelvic fracture is significantly higher in floating hip injuries, but without affecting the resulting quality of treatment. A "femur first" treatment strategy is preferable. Algorithms for emergency treatment and definitive care are proposed in a flowchart.

Weight-bearing Restrictions after Distal Femur Fractures - Review of Current Literature. / Belastungsvorgaben nach distaler Femurfraktur - eine aktuelle Literaturübersicht.

The incidence of distal femur fractures increases in the geriatric patient. The primary treatment goal in these fractures is early mobilisation to prevent secondary injuries associated with immobility. In light of the increasing spectrum of therapeutic options for postoperative fracture treatment, including double plating, nail-plate combination and distal femur replacement as postoperative treatments, weight-bearing recommendations are becoming increasingly important. The aim of this study was thus to analyse the weight-bearing recommendations and associated therapy results within the literature of the past 9 years and compare the recommendations to our own approach.