Tibial plateau fracture: does fracture classification influence the choice of surgical approach? A retrospective multicenter analysis.

PURPOSE: The role of classification systems for the choice of surgical approach and the management of tibial plateau fractures remains unclear. The purpose of this study was to investigate the potential of classification systems to choose the appropriate operative approach. Current surgical management strategies were investigated in a large multicenter assessment. METHODS: In this study, we retrospectively analyzed all patients with tibial plateau fractures that have received surgical treatment in one of the five Level I trauma facilities between 2012 and 2015. Fractures were classified in each center by a senior orthopedic surgeon using the AO/OTA and the Luo classification. Demographics, trauma mechanism, as well as the surgical approach were recorded. RESULTS: 538 patients (46.1% male, 53.9% female) were included. The anterolateral approach was used most frequently with 54.8% of all single approaches; 76.2% of all combined approaches used anterolateral as part of the approach. Combined approaches were used in 22.5% of the cases; a combination of the anterolateral and medial (10%), anterolateral, and posteromedial approach (5.8%) were used most frequently. The lowest number was found for the posterolateral (1.3%) and the combined approaches dorsal/anterolateral and medial/dorsal (1.7%, 1.1%). The AO/OTA classification showed a peak for 41.B2 (21.9%) and B3 (35.5%) fractures. Regarding the Luo classification, the dorsal column was involved in 45.7%. In contrast, only 14.7% of the surgical approaches used were able to address the dorsal tibial plateau potentially. CONCLUSION: The use of dorsal approach seems to be of minor importance than expected in daily clinical practice in this multicenter study. It was not possible to specify whether the AO/OTA or the Luo classification can reliably predict the choice of surgical approach. The operative treatment strategy of tibial plateau fractures seems to rather rely on the surgeons' experience, education, and preferences.

A bioactive nano-calcium phosphate paste for in-situ transfection of BMP-7 and VEGF-A in a rabbit critical-size bone defect: results of an in vivo study.

The aim of this study was to prepare an injectable DNA-loaded nano-calcium phosphate paste that is suitable as bioactive bone substitution material. For this we used the well-known potential of calcium phosphate in bone contact and supplemented it with DNA for the in-situ transfection of BMP-7 and VEGF-A in a critical-size bone defect. 24 New Zealand white rabbits were randomly divided into two groups: One group with BMP-7- and VEGF-A-encoding DNA on calcium phosphate nanoparticles and a control group with calcium phosphate nanoparticles only. The bone defect was created at the proximal medial tibia and filled with the DNA-loaded calcium phosphate paste. As control, a bone defect was filled with the calcium phosphate paste without DNA. The proximal tibia was investigated 2, 4 and 12 weeks after the operation. A histomorphological analysis of the dynamic bone parameters was carried out with the Osteomeasure system. The animals treated with the DNA-loaded calcium phosphate showed a statistically significantly increased bone volume per total volume after 4 weeks in comparison to the control group. Additionally, a statistically significant increase of the trabecular number and the number of osteoblasts per tissue area were observed. These results were confirmed by radiological analysis. The DNA-loaded bone paste led to a significantly faster healing of the critical-size bone defect in the rabbit model after 4 weeks. After 12 weeks, all defects had equally healed in both groups. No difference in the quality of the new bone was found. The injectable DNA-loaded calcium phosphate paste led to a faster and more sustained bone healing and induced an accelerated bone formation after 4 weeks. The material was well integrated into the bone defect and new bone was formed on its surface. The calcium phosphate paste without DNA led to a regular healing of the critical-size bone defect, but the healing was slower than the DNA-loaded paste. Thus, the in-situ transfection with BMP-7 and VEGF-A significantly improved the potential of calcium phosphate as pasty bone substitution material.

Observed versus expected mortality in pediatric patients intubated in the field with Glasgow Coma Scale scores < 9.

PURPOSE: A Glasgow Coma Scale (GCS) score of 8 or less in patients suffering from severe traumatic brain injury (TBI) represents a decision-making marker in terms of intubation. This study evaluated the impact of prehospital intubation on the mortality of these TBI cases among different age groups. METHODS: This study included the data from patients predominantly suffering from severe TBI [Abbreviated Injury Scale (AIS) of the head ≥ 3, GCS score < 9, Injury Severity Score (ISS) > 9] who were registered in TraumaRegister DGU® from 2002 to 2013. An age-related analysis of five subgroups was performed (1-6, 7-15, 16-55, 56-79, and ≥ 80 years old). The observed and expected mortality were matched according to the Revised Injury Severity Classification, version II. RESULTS: A total of 21,242 patients were included. More often, the intubated patients were severely injured when compared to the non-intubated patients (median ISS 29, IQR 22-41 vs. 24, IQR 16-29, respectively), with an associated higher mortality (42.2% vs. 30.0%, respectively). When compared to the calculated expected mortality, the observed mortality was significantly higher among the intubated patients within the youngest subgroup (42.2% vs. 33.4%, respectively; p = 0.03). CONCLUSIONS: The observed mortality in the intubated children 1-6 years old suffering from severe TBI seemed to be higher than expected. Whether or not a GCS score of 8 or less is the only reliable criterion for intubation in this age group should be investigated in further trials.

Femoral antecurvation-A 3D CT Analysis of 1232 adult femurs.

INTRODUCTION: For optimal treatment of femoral fractures, it is essential to understand the anatomical antecurvation of the human femur. Recent clinical studies have highlighted the problem of distal anterior encroachment or even perforation of the nail tip. The aim of this study was to accurately describe the femoral antecurvation in a large cohort. Another objective was to identify the most important influences on femoral antecurvation, such as age, femur length, gender and ethnicity. METHODS: A three dimensional modelling and analytical technology was applied for the analysis of 1,232 femurs. Individual femoral antecurvation was precisely computed to determine whether gender, femur length, age, ethnicity or body mass index influence the radius of curvature (ROC). RESULTS: The calculated mean ROC for all femurs was 943 mm. The lowest ROC of 826 mm was found in female Asian femurs. A regression analysis demonstrated that age and femur length could predict the variability of the curvature, with femoral length as most powerful predictor. A matched pair subgroup analysis between Asians and Caucasians could not show any significant differences of ROC values. CONCLUSIONS: The mean radius of the femoral antecurvation may be smaller than previously reported revealing a significant mismatch between the actual individual anatomy and existing implants. In opposite to existing literature, this study suggests, that antecurvation differences between various ethnicities may exclusively be attributed to differences in femoral length and age. The findings of this study may be found helpful in the development of novel designs for intra- and extramedullary implants.

Prediction of Meniscal and Ligamentous Injuries in Lateral Tibial Plateau Fractures Based on Measurements of Lateral Plateau Widening on Multidetector Computed Tomography Scans.

BACKGROUND: The influence of increasing lateral plateau widening on the frequency of meniscal and ligamentous lesions in lateral tibial plateau fractures has been examined in very few studies using plain radiographs. Because the amount of this parameter cannot be measured accurately on plain radiographs, the purpose of this survey was to look for a possible correlation between the extent of lateral plateau widening, as measured on multidetector CT (MDCT) scans, and different soft-tissue injuries determined from magnetic resonance imaging (MRI). MATERIALS AND METHODS: 55 patients with a lateral tibial plateau fracture were included in this retrospective case series. Patient age averaged 52.6 years (SD = 18.0). The degree of lateral plateau widening was measured on CT images. MRIs were screened for meniscal and ligamentous injuries. RESULTS: We found a significant effect of increasing lateral plateau widening on the incidence of lateral meniscus lesions (P = 0.021), lateral collateral ligament tears (P = 0.047), and the overall quantity of meniscal and ligamentous lesions (P = 0.001). DISCUSSION: MRIs are not widely used as a diagnostic tool in lateral plateau fractures of the tibia. Reasons might be the costs and the fact that it is a time-consuming examination. The results of this study may help to estimate the probability of specific soft-tissue lesions in lateral tibial plateau fractures based on measurements of lateral plateau widening on MDCT scans, and they may guide the decision for additional MRI and/or arthroscopically assisted repair.

Ilioinguinal Approach: Indication and Technique.

This video on the ilioinguinal approach presents its indications and techniques for the operative treatment of acetabular fractures. The principle of the ilioinguinal approach is to work through 3 different windows. The lateral window gives access to the pelvic bone from the sacroiliac joint to the lateral border of the iliopsoas muscle, the middle window accesses the medial border of the iliopsoas muscle to the femoral artery, and the medial window allows for control of the anterior pelvic ring medially from the femoral vein to the symphysis pubis. In this video, we demonstrate anatomical reconstruction of the acetabulum in a patient with an associated both-column fracture using the ilioinguinal approach. Indications are all acetabular fracture types, where in addition to anterior column fracture, a fractured posterior column is reducible through the middle window, that is, there is no involvement of the posterior column or wall that would necessitate a direct posterior approach. The ilioinguinal approach is a standard anatomical approach that gives an excellent visual and palpatory exposure of the anterior column up to the symphysis pubis and of the quadrilateral plate. Indications and techniques, how to develop this approach for the anatomical reduction and fixation of appropriate acetabular fractures, are demonstrated in this video.

Rare Combination of a Cuboid-navicular Tarsal Coalition with a Closed Tibialis Anterior Tendon Rupture: A Case Report and Review of the Literature.

INTRODUCTION: Tibialis anterior tendon (TAT) rupture and cuboid-navicular coalition (CNC) are rare, to the best of our knowledge, only 238 cases of TAT rupture and 34 cases of CNC are described in the past century. CASE REPORT: A 47-year-old man came with a sudden onset of foot pain including drop foot to our department. We diagnosed a TAT rupture, which was fixed through suture. The pathologist testified degenerative changes in the tendon. In addition, a CNC was diagnosed. No extra treatment was necessary for the CNC. At the 6-year follow-up examination, the patient had no pain and went back to normal day activities (AOFAS 95/100 points). CONCLUSION: We presume that, in our case, the long-term stress at the TAT through the foot deformity, caused by the CNC, may have supported the tendon rupture. CNC normally is symptom free. Therapy of a painful CNC should start with a conservative therapy. When this fails, an operation can be considered.

Recombinant Human Bone Morphogenetic Protein-2 (rhBMP-2) for the Treatment of Nonunion of the Femur in Children and Adolescents: A Retrospective Analysis.

Background. The aim of this study was to examine clinical and radiographic healing after rhBMP-2 application in children and adolescents presenting with nonunion of the femur and to investigate the safety of rhBMP-2 use in these cases. Materials and Methods. We reviewed the medical records of five patients with a mean age of 11 years (5.4 to 16.2) with nonunion of the femur who were treated with rhBMP-2 and internal fixation using a locking plate at a single institution. Particular attention was paid to identify all adverse events that may be due to rhBMP-2 use. Results. Union occurred in four of five patients at a mean of 12.1 months (7.9 to 18.9). The locking plates were removed after a mean of 16 months (11 to 23). One patient had nonunion due to deep infection. After a mean follow-up of 62.5 months (17 to 100), union was still evident in all four patients and they were fully weight-bearing without pain. Discussion. In this retrospective study, rhBMP-2 combined with a locking plate has been used successfully to treat children and adolescents with nonunion of the femur in four of five cases. One major complication was thought to be possibly related to its use.

The Anterior Intrapelvic Approach for Acetabular Fractures Using Approach-Specific Instruments and an Anatomical-Preshaped 3-Dimensional Suprapectineal Plate.

OBJECTIVES: Anatomical acetabular plates the anterior intrapelvic approach (AIP) were recently introduced to fix acetabular fractures through the intrapelvic approach. Therefore, we asked the following: (1) Does the preshaped 3-dimensional suprapectineal plate interfere with or even impair the fracture reduction quality? (2) How often does the AIP approach need to be extended by the first (lateral) window of the ilioinguinal approach? DESIGN: Observational case series. SETTING: Two Level 1 trauma centers. PATIENTS/PARTICIPANTS: Patients with unstable acetabular fractures in 2014. INTERVENTION: Fracture fixation with anatomical-preshaped, 3-dimensional suprapectineal plates through the AIP approach ± the first window of the ilioinguinal approach. OUTCOME MEASUREMENTS: Fracture reduction results were measured in computed tomography scans and graded according to the Matta quality of reduction. Intraoperative parameters and perioperative complications were recorded. Radiological results (according to Matta) and functional outcome (modified Merle d'Aubigné score) were evaluated at 1-year follow-up. RESULTS: Thirty patients (9 women + 21 men; mean age ± SE: 64 ± 8 years) were included. The intrapelvic approach was solely used in 19 cases, and in 11 cases, an additional extension with the first window of the ilioinguinal approach (preferential for 2-column fractures) was performed. The mean operating time was 202 ± 59 minutes; the fluoroscopic time was 66 ± 48 seconds. Fracture gaps and steps in preoperative versus postoperative computed tomography scans were 12.4 ± 9.8 versus 2.0 ± 1.5 and 6.0 ± 5.5 versus 1.3 ± 1.7 mm, respectively. At 13.4 ± 2.9 months follow-up, the Matta grading was excellent in 50%, good in 25%, fair in 11%, and poor in 14% of cases. The modified Merle d'Aubigné score was excellent in 17%, good in 37%, fair in 33%, and poor in 13% of cases. CONCLUSION: The AIP approach using approach-specific instruments and an anatomical-preshaped, 3-dimensional suprapectineal plate became the standard procedure in our departments. Radiological and functional early results justify joint preserving surgery in most cases. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Bone morphogenetic protein-2 for the treatment of congenital pseudarthrosis of the tibia or persistent tibial nonunion in children and adolescents: A retrospective study with a minimum 2-year follow-up.

There is a lack of studies reporting on rhBMP-2 application in pediatric orthopaedics, although few reports demonstrated promising results of the use of rhBMP-2 in children, especially for spine fusion and for the treatment of congenital pseudarthrosis of the tibia. The objectives of this study were (1) to examine clinical and radiographic healing after rhBMP-2 application for the treatment of congenital pseudarthrosis of the tibia (CPT) or persistent tibial nonunion in children and adolescents, and (2) to investigate the safety of rhBMP-2 use in these cases. Therefore we reviewed the medical records of ten patients with a mean age of 8.6 years (2.3-21) with CPT (n = 7) or persistent tibial nonunion for at least six months (n = 3) who had been treated with rhBMP-2. Nine of ten patients had union at final follow-up, after a mean of 72.9 months (25-127). In the CPT group, primary healing of the pseudarthrosis occurred in six of seven patients at a mean of 5.2 months (3-12). Repeat rhBMP-2 application was performed in three patients; two patients had one additional application each, and one patient had three additional applications. Complications that may be attributed to the use of rhBMP-2 were seen in two of fifteen applications, including a compartmemt syndrome and a hematoma. In this retrospective case series rhBMP-2 has been used successfully to treat CPT or persistent tibial nonunion in pediatric patients. However, prospective randomized controlled trials are warranted to investigate the long-term efficacy and safety of rhBMP-2 use in these cases.

Prospective evaluation of the Eppendorf-Cologne Scale.

OBJECTIVES: Early diagnosis of traumatic brain injury and reliable prediction of outcome are essential for determining treatment strategies and allocating resources. This study re-evaluates the Eppendorf-Cologne Scale (ECS) and its predictive accuracy for outcome compared with the Glasgow Coma Scale (GCS). METHODS: A prospective cohort analysis of severely injured trauma patients registered in the Trauma Registry of the German Society for Trauma Surgery from 2012-2013 was carried out. Only directly admitted patients alive on admission with complete data on GCS, ECS and outcome in terms of survival to hospital discharge or death were included. The predictive accuracy in terms of the outcome of the ECS and the GCS was modelled using area under the receiver operating characteristic (AUROC) curve analysis. RESULTS: A total of 17 616 patients fulfilled the study inclusion criteria. The ECS outmatched the predictive accuracy of the GCS for outcome (AUROC, 0.853, 95% confidence interval, 0.831-0.854; and AUROC 0.836; 95% confidence interval, 0.825-0.848, respectively; P=0.062). An ECS score of 8 was associated with a 25-fold higher mortality compared with an ECS score of 0. Patients who had an ECS score of 8 had a 1.5-fold higher mortality compared with patients allocated a GCS score of 3. CONCLUSION: The ECS shows a higher accuracy for prediction of outcome compared with the GCS and enables further differentiation within the critical GCS 3 collective.

The Impact of Prehospital Intubation With and Without Sedation on Outcome in Trauma Patients With a GCS of 8 or Less.

BACKGROUND: Although unconsciousness (Glasgow Coma Scale [GCS] 3 to 8) necessitates intubation according national guidelines, there is a notable lack of evidence to support this approach. This study evaluates the impact on outcome of prehospital intubation with and without sedation in trauma patients with a GCS of ≤8. METHODS: A retrospective cohort analysis of severely injured trauma patients registered in the TraumaRegister DGU of the German Trauma Society (DGU) from 2002 to 2013 was conducted. Only directly admitted patients alive on admission and with a GCS of ≤8 at the scene were included. The observed outcome was matched with the expected outcome deriving from the Revised Injury Severity Classification, version II (RISC-II). Furthermore, a Standardized Mortality Ratio (SMR) was calculated for various subgroups. Early neurological outcome was classified using the Glasgow Outcome Scale. RESULTS: A total of 21,242 patients fulfilled the study inclusion criteria. A total of 18,975 patients (89.3%) received prehospital intubation. Intubation rates were continuously increasing with decreasing GCS score values. Difference between observed and expected mortality was lower in intubated patients (42.2% [95% confidence interval (CI), 41.5%-42.9%]; RISC-II prognosis 41.4%; SMR 1.020 [95% CI, 1.003-1.037]) compared with nonintubated (30.0% [95% CI, 28.1-31.9%] RISC-II prognosis 26.6% and SMR 1.128 [95% CI, 1.057-1.199]). Patients being sedated before intubation presented significant (P<0.001) lower observed mortality (37.7% [95% CI, 36.7-38.7%], RISC-II prognosis 39.0%, SMR 0.967 [95% CI, 0.951-0.983]) associated with a less poor early neurological outcome compared with those being intubated without sedation. CONCLUSIONS: Observed outcome of prehospital intubated patients with a GCS of ≤8 seems less poor than predicted compared with nonintubated patients. Sedation before intubation might potentially decrease mortality and improve early neurological outcome. Further studies are required to clarify this issue.

Impact of Glasgow Coma Scale score and pupil parameters on mortality rate and outcome in pediatric and adult severe traumatic brain injury: a retrospective, multicenter cohort study.

OBJECTIVE Prediction of death and functional outcome is essential for determining treatment strategies and allocation of resources for patients with severe traumatic brain injury (TBI). The aim of this study was to evaluate, by using pupillary status and Glasgow Coma Scale (GCS) score, if patients with severe TBI who are ≤ 15 years old have a lower mortality rate and better outcome than adults with severe TBI. METHODS A retrospective cohort analysis of patients suffering from severe TBI registered in the Trauma Registry of the German Society for Trauma Surgery between 2002 and 2013 was undertaken. Severe TBI was defined as an Abbreviated Injury Scale of the head (AIShead) score of ≥ 3 and an AIS score for any other part of the body that does not exceed the AIShead score. Only patients with complete data (GCS score, age, and pupil parameters) were included. To assess the impact of GCS score and pupil parameters, the authors also used the recently introduced Eppendorf-Cologne Scale and divided the study population into 2 groups: children (0-15 years old) and adults (16-55 years old). Each patient's outcome was measured at discharge from the trauma center by using the Glasgow Outcome Scale. RESULTS A total of 9959 patients fulfilled the study inclusion criteria; 888 (8.9%) patients were ≤ 15 years old (median 10 years). The overall mortality rate and the mortality rate for patients with a GCS of 3 and bilaterally fixed and dilated pupils (19.9% and 16.3%, respectively) were higher for the adults than for the pediatric patients (85% vs 80.9%, respectively), although cardiopulmonary resuscitation rates were significantly higher in the pediatric patients (5.6% vs 8.8%, respectively). In the multivariate logistic regression analysis, no motor response (OR 3.490, 95% CI 2.240-5.435) and fixed pupils (OR 4.197, 95% CI 3.271-5.386) and bilateral dilated pupils (OR 2.848, 95% CI 2.282-3.556) were associated with a higher mortality rate. Patients ≤ 15 years old had a statistically lower mortality rate (OR 0.536, 95% CI 0.421-0.814; p = 0.001). The rate of good functional outcomes (Glasgow Outcome Scale Score 4 or 5) was higher in pediatric patients than in the adults (72.2% vs 63.1%, respectively). CONCLUSIONS This study found that severe TBI in children aged ≤ 15 years is associated with a lower mortality rate and superior functional outcome than in adults. Also, children admitted with a missing motor response or fixed and bilaterally dilated pupils also have a lower mortality rate and higher functional outcome than adults with the same initial presentation. Therefore, patients suffering from severe TBI, especially pediatric patients, could benefit from early and aggressive treatment.

Acromioclavicular joint dislocations: coracoclavicular reconstruction with and without additional direct acromioclavicular repair.

PURPOSE: To evaluate different stabilisation techniques for acromioclavicular (AC) joint separations, including direct AC repair, and to compare the properties of the stabilised and native joints. METHODS: An established in vitro testing model for the AC joint was used to analyse joint stability after surgical reconstruction [double TightRope (DTR), DTR with AC repair (DTR + AC), single TR with AC repair (TR + AC), and PDS sling with AC repair (PDS + AC)]. Twenty-four human cadaveric shoulders were randomised by age into four testing groups. Joint stiffness was measured by applying an axial load during defined physiological ranges of motion. Similar tests were performed for the native joints, after dissecting the coracoclavicular and AC ligaments, and after surgical reconstruction. Cyclic loading was performed for 1000 cycles with 20-70 N and vertical load to failure determined after cyclic testing. RESULTS: Axial stiffness for all TR groups was significantly higher than for the native joint (DTR 38.94 N/mm, p = 0.005; DTR + AC 37.79 N/mm, p = 0.015; TR + AC 45.61 N/mm, p < 0.001 vs. native 26.05 N/mm). The axial stiffness of the PDS + AC group was similar to that of the native joint group (21.4 N/mm, n.s.). AC repair did not significantly influence rotational stiffness. Load to failure was similar and >600 N in all groups (n.s.). CONCLUSION: Reconstruction of AC dislocations with one or two TRs leads to stable results with a higher stiffness than the native joints. For the PDS + AC group, axial stiffness was similar to the native situation, although there might be a risk of elongation. Direct AC repair showed no significantly increased stability in comparison with reconstructions without direct AC repair. Thus, a direct AC repair seems to be dispensable in clinical practice, while TRs or PDS cerclages appear to provide sufficiently stable results.

Evaluation of complications associated with off-label use of recombinant human bone morphogenetic protein-2 (rhBMP-2) in pediatric orthopaedics.

The off-label use of recombinant human bone morphogenetic protein-2 to promote bone healing in adults has significantly increased in recent years, while reports of recombinant human bone morphogenetic protein-2 application in children and adolescents are very rare. The aim of this study was to evaluate the safety of single and repetitive recombinant human bone morphogenetic protein-2 use in pediatric orthoapedics. Therefore we reviewed the medical records of 39 patients who had been treated with recombinant human bone morphogenetic protein-2 at our institution. Their mean age was 10.9 years. Recombinant human bone morphogenetic protein-2 was used in 17 patients for spine fusion, in 11 patients for the treatment of congenital pseudarthrosis of the tibia or tibial nonunion, in 5 patients for the management of femoral nonunion, in 5 patients for nonunions at other locations, and in 1 case for tibial shortening. Special attention was paid to identify all adverse events that may be attributed to recombinant human bone morphogenetic protein-2 use, including local inflammatory reactions, allergic reactions, systemic toxicity, excessive wound swelling, hematoma, compartment syndrome, infection, heterotopic ossification, excessive bone growth, carcinogenicity, and the consequences of repeated applications of recombinant human bone morphogenetic protein-2. Follow-up was a mean of 39 months. Forty-six operations with application of rhBMP-2 were performed. Complications that may be due to application of recombinant human bone morphogenetic protein-2 were seen after 18 operations including swelling, increase in temperature, wound secretion, redness and hyperthermia. We consider the three cases of necessary revisions, one due to hematoma, one due to development of a compartment syndrome, and one due to deep infection, to be the only complications related to the use of recombinant human bone morphogenetic protein-2. In conclusion, we found few complications attributable to application of recombinant human bone morphogenetic protein-2 in pediatric patients.

On-table decision-making in intracapsular hip fracture surgery: mid-term results of a pilot study.

INTRODUCTION: At the present time, it is generally recommended to use hip replacement in dislocated fractures to avoid failure after internal fixation. A problem is that previous research has demonstrated that observers have problems in discriminating between dislocated and undislocated fractures. A possible solution to this problem would be to use arthroplasty in the majority of the cases. However, this also means that many fractures with the potential for uneventful healing would be replaced. MATERIALS AND METHODS: In the current investigation, the mid-term outcome was recorded for patients with intracapsular hip fractures who were treated with either internal fixation or arthroplasty. A novel treatment algorithm was employed. After careful exclusion of cases with known risk factors for failure after internal fixation, a technique called on-table decision was used to identify suitable patients for internal fixation. RESULTS: A total of 72 patients with intracapsular hip fractures were studied with a median follow-up time of 12 months (IQR 8-15.25 months). Nineteen (19) patients (26 %) were excluded in the selection process, leaving 53 (74 %) for on-table decision-making. Thirty patients (42 %) were identified as suitable for internal fixation and gave anatomically stable closed reductions. Two of these patients (7 %) exhibited non-unions and one (3 %) avascular necrosis. CONCLUSIONS: The mid-term outcome after internal fixation is promising. The careful selection process may be helpful in identifying fracture patterns for which internal fixation may be considered as a safe and less invasive alternative to hip arthroplasty.

Intramedullary Mg2Ag nails augment callus formation during fracture healing in mice.

UNLABELLED: Intramedullary stabilization is frequently used to treat long bone fractures. Implants usually remain unless complications arise. Since implant removal can become technically very challenging with the potential to cause further tissue damage, biodegradable materials are emerging as alternative options. Magnesium (Mg)-based biodegradable implants have a controllable degradation rate and good tissue compatibility, which makes them attractive for musculoskeletal research. Here we report for the first time the implantation of intramedullary nails made of an Mg alloy containing 2% silver (Mg2Ag) into intact and fractured femora of mice. Prior in vitro analyses revealed an inhibitory effect of Mg2Ag degradation products on osteoclast differentiation and function with no impair of osteoblast function. In vivo, Mg2Ag implants degraded under non-fracture and fracture conditions within 210days and 133days, respectively. During fracture repair, osteoblast function and subsequent bone formation were enhanced, while osteoclast activity and bone resorption were decreased, leading to an augmented callus formation. We observed a widening of the femoral shaft under steady state and regenerating conditions, which was at least in part due to an uncoupled bone remodeling. However, Mg2Ag implants did not cause any systemic adverse effects. These data suggest that Mg2Ag implants might be promising for intramedullary fixation of long bone fractures, a novel concept that has to be further investigated in future studies. STATEMENT OF SIGNIFICANCE: Biodegradable implants are promising alternatives to standard steel or titanium implants to avoid implant removal after fracture healing. We therefore developed an intramedullary nail using a novel biodegradable magnesium-silver-alloy (Mg2Ag) and investigated the in vitro and in vivo effects of the implants on bone remodeling under steady state and fracture healing conditions in mice. Our results demonstrate that intramedullary Mg2Ag nails degrade in vivo over time without causing adverse effects. Importantly, radiographs, µCT and bone histomorphometry revealed a significant increase in callus size due to an augmented bone formation rate and a reduced bone resorption in fractures supported by Mg2Ag nails, thereby improving bone healing. Thus, intramedullary Mg2Ag nails are promising biomaterials for fracture healing to circumvent implant removal.

Determination of Femoral Neck Angle and Torsion Angle Utilizing a Novel Three-Dimensional Modeling and Analytical Technology Based on CT Datasets.

INTRODUCTION: Exact knowledge of femoral neck inclination and torsion angles is important in recognizing, understanding and treating pathologic conditions in the hip joint. However, published results vary widely between different studies, which indicates that there are persistent difficulties in carrying out exact measurements. METHODS: A three dimensional modeling and analytical technology was used for the analysis of 1070 CT datasets of skeletally mature femurs. Individual femoral neck angles and torsion angles were precisely computed, in order to establish whether gender, age, body mass index and ethnicity influence femoral neck angles and torsion angles. RESULTS: The median femoral neck angle was 122.2° (range 100.1-146.2°, IQR 117.9-125.6°). There are significant gender (female 123.0° vs. male 121.5°; p = 0.007) and ethnic (Asian 123.2° vs. Caucasian 121.9°; p = 0.0009) differences. The median femoral torsion angle was 14.2° (-23.6-48.7°, IQR 7.4-20.4°). There are significant gender differences (female 16.4° vs. male 12.1°; p = 0.0001). Femoral retroversion was found in 7.8% of the subjects. CONCLUSION: Precise femoral neck and torsion angles were obtained in over one thousand cases. Systematic deviations in measurement due to human error were eliminated by using automated high accuracy morphometric analysis. Small but significant gender and ethnic differences were found in femoral neck and torsion angles.

High incidence of osteochondral lesions after open reduction and internal fixation of displaced ankle fractures: Medium-term follow-up of 100 cases.

BACKGROUND: The incidence of osteochondral lesions (OCLs) in association with displaced ankle fractures has only been examined in two previous studies. In both studies magnetic resonance imaging (MRI) was performed prior to open reduction and internal fixation (ORIF). Because MRI may overdiagnose or overestimate the extent of OCLs in an acute trauma setting the aim of this study was to determine the incidence of OCLs after ORIF of displaced ankle fractures using MRI at medium-term follow-up, and to analyse if the severity of fracture or the clinical outcome correlates with the incidence of OCLs. PATIENTS AND METHODS: Following institutional review board approval a total of 100 patients (mean age, 41.3 years; range, 17.9-64.3 years) with a displaced ankle fracture who had undergone ORIF according to the AO principles were included in this study. The American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score was used to quantify the clinical outcome and MR images were evaluated for OCLs of the talus and distal tibia after a mean of 34.5 months (range, 17.5-54.1 months). RESULTS: OCLs were found in 40.4% of the patients. Logistic regression revealed a significant correlation between the severity of fracture and the incidence of OCLs. Patients with a trimalleolar fracture (p=0.04) or an ankle fracture dislocation (p=0.003) had a significantly higher risk for developing an OCL compared to those with a type B fracture. Logistic regression also demonstrated a significant correlation between the clinical outcome (AOFAS score) and the incidence of OCLs (p=0.01). The risk for developing an OCL increases up to 5.6% when the AOFAS score decreases by one point. CONCLUSION: OCLs were frequently found in association with acute ankle fractures at medium-term follow-up, and the severity of fracture was associated with an increased number of OCLs. Considering the disadvantages of MRI including the high cost and limited availability, the results of this study may help to explain why anatomic surgical realignment of displaced ankle fractures may still be associated with poor clinical outcomes.

A novel electromagnetic navigation tool for acetabular surgery.

BACKGROUND: Acetabular fracture surgery is demanding and screw placement along narrow bony corridors remains challenging. It necessitates x-ray radiation for fluoroscopically assisted screw insertion. The purpose of this cadaver study was to evaluate the feasibility, accuracy and operation time of a novel electromagnetic navigation system for screw insertion along predefined acetabular corridors. METHODS: A controlled laboratory study with a total of 24 electromagnetically navigated screw insertions was performed on 8 cadaveric acetabula. 3 peri-acetabular bony corridors (QSS, Quadrilateral Surface Screw; IAS, Infra-Acetabular Screw; PCS, Posterior Column Screw) were defined and screws were placed in a defined order without fluoroscopy. Operation time was documented. Postoperative CT scans were performed to analyse accuracy of screw placement. RESULTS: Mean cadaver age was 70.4 ± 11.7. Successful screw placement was accomplished in 22 out of 24 (91.7%) cases. The overall mean time for all 3 acetabular screws was 576.6 ± 75.9s. All 3 complications occurred during the placement of the IAS due to an impassable narrow bony corridor. QSS mean length was 50 ± 5mm, IAS mean length was 85 ± 10mm and PCS mean length was 120 ± 5mm. CONCLUSION: In this cadaver study the novel electromagnetic navigation system was feasible to allow accurate screw placement without fluoroscopy in defined narrow peri-acetabular bony corridors.