Newly Developed Resorbable Magnesium Biomaterials for Orbital Floor Reconstruction in Caprine and Ovine Animal Models-A Prototype Design and Proof-of-Principle Study.

BACKGROUND: orbital floor fractures have not been reconstructed using magnesium biomaterials. METHODS: To test technical feasibility, ex vivo caprine and ovine heads (n = 5) were used. Head tissues were harvested from pubescent animals (n = 5; mean age: 3.2 years; mean mass: 26.3 kg) and stored below 11 degrees for 7-10 days. All procedures were performed in a university animal resource facility. Two experienced maxillofacial surgeons performed orbital floor procedures in both orbits of all animals in a step-by-step preplanned dissection. A transconjunctival approach was chosen to repair the orbital floor with three different implants (i.e., magnesium implants; titanium mesh; and polydioxanone or PDO sheets). The position of each implant was evaluated by Cone-beam computed tomography (CBCT). RESULTS: Axial, coronal, and sagittal plane images showed good positioning of the magnesium plates. The magnesium plates had a radiographic visibility similar to that of the PDO sheets but lower than that of the titanium mesh. CONCLUSIONS: The prototype design study showed a novel indication for magnesium biomaterials. Further testing of this new biomaterial may lead to the first resorbable biomaterial with good mechanical properties for extensive orbital wall defects.

[Supracondylar humeral fractures in childhood]. / Suprakondyläre Humerusfraktur im Kindesalter.

The classification of supracondylar humeral fractures in German-speaking areas is carried out according to von Laer, which has been appropriated from the AO system and has the advantage that it can be used to derive the treatment. When indicated immediate surgery is given preference over a delayed treatment. The result is controlled by functional tests directly during the operation. Instability of the fracture and correct placement of the Kirschner (K) wires are challenging. Alternatives are an external fixator and elastically stable intramedullary nailing (ESIN). Concomitant injuries initially affect the median nerve and the brachial artery and secondarily the radial nerve. Lesions of the ulnar nerve are mostly a postoperative complication. The bony consolidation is achieved after 3-4 weeks and afterwards implant removal can be safely carried out. Embedded K­wires and ESIN are removed after 3-6 months, depending on the surgical capacity and complaints of the patient.

Resorbable implants in pediatric fracture treatment.

Pediatric osteosynthesis has developed over the last 20 years, thereby reducing medical and economic burden, including long and expensive hospitalization. Currently, conventional and rigid alloying systems such as titanium are used for stabilization of bone fractures in children. In many cases, implants must be removed, as otherwise growth would be impeded. Biodegradable implant materials exhibit beneficial properties and would make a second removal surgery unnecessary. In the following article, we will give an overview of implant materials that are currently used in pediatric traumatology with a focus on Mg-based implants. Furthermore, we will discuss current scientific knowledge on resorbable implants, including results from pre-clinics and clinics.

Effects of Corroded and Non-Corroded Biodegradable Mg and Mg Alloys on Viability, Morphology and Differentiation of MC3T3-E1 Cells Elicited by Direct Cell/Material Interaction.

This study investigated the effect of biodegradable Mg and Mg alloys on selected properties of MC3T3-E1 cells elicited by direct cell/material interaction. The chemical composition and morphology of the surface of Mg and Mg based alloys (Mg2Ag and Mg10Gd) were analysed by scanning electron microscopy (SEM) and EDX, following corrosion in cell culture medium for 1, 2, 3 and 8 days. The most pronounced difference in surface morphology, namely crystal formation, was observed when Pure Mg and Mg2Ag were immersed in cell medium for 8 days, and was associated with an increase in atomic % of oxygen and a decrease of surface calcium and phosphorous. Crystal formation on the surface of Mg10Gd was, in contrast, negligible at all time points. Time-dependent changes in oxygen, calcium and phosphorous surface content were furthermore not observed for Mg10Gd. MC3T3-E1 cell viability was reduced by culture on the surfaces of corroded Mg, Mg2Ag and Mg10Gd in a corrosion time-independent manner. Cells did not survive when cultured on 3 day pre-corroded Pure Mg and Mg2Ag, indicating crystal formation to be particular detrimental in this regard. Cell viability was not affected when cells were cultured on non-corroded Mg and Mg alloys for up to 12 days. These results suggest that corrosion associated changes in surface morphology and chemical composition significantly hamper cell viability and, thus, that non-corroded surfaces are more conducive to cell survival. An analysis of the differentiation potential of MC3T3-E1 cells cultured on non-corroded samples based on measurement of Collagen I and Runx2 expression, revealed a down-regulation of these markers within the first 6 days following cell seeding on all samples, despite persistent survival and proliferation. Cells cultured on Mg10Gd, however, exhibited a pronounced upregulation of collagen I and Runx2 between days 8 and 12, indicating an enhancement of osteointegration by this alloy that could be valuable for in vivo orthopedic applications.

Clinical impact of interleukin 6 as a predictive biomarker in the early diagnosis of postoperative systemic inflammatory response syndrome after major thoracic surgery: A prospective clinical trial.

BACKGROUND: Postoperative systemic inflammatory response syndrome and sepsis are associated with high morbidity and mortality rates. Early detection of postoperative systemic inflammatory response syndrome improves the outcome. The aim of this study was to evaluate the feasibility of interleukin 6 as a predictive biomarker in the early diagnosis of postoperative systemic inflammatory response syndrome after a major thoracic operation. METHODS: A total of 94 patients were enrolled in this prospective, clinical, single-center study. The enrolled subjects underwent either lung resection or esophageal operation. Interleukin 6, procalcitonin, C-reactive protein, and leucocytes were measured sequentially before, during, and after the operation. These levels were compared between patients who developed postoperative systemic inflammatory response syndrome and those who did not. RESULTS: The enrollees who completed the study included of 55 males (79.7%) and 14 females (20.3%) with a mean age of 60.9 years. Twenty patients (29.0%) developed systemic inflammatory response syndrome at a median time of 33.0 hours postoperatively. In cases of postoperative systemic inflammatory response syndrome, interleukin 6 was the most predictive biomarker, showing a striking increase on the day of operation and preceding the median onset of postoperative systemic inflammatory response syndrome, which occurred the next day (P ≤ .001). Peak procalcitonin and C-reactive protein occurrence were significantly delayed at 24 hours (P = .012) and 48 hours (P = .012). There was no mortality 30 days postoperatively. CONCLUSION: Interleukin 6 is a reliable predictor of postoperative systemic inflammatory response syndrome, and it is able to detect postoperative system inflammatory response syndrome before the onset of related clinical symptoms. When identifying patients at high risk, it would be beneficial to include interleukin 6 in conventional postoperative monitoring, particularly after extended surgical resection.

The origin points of the knee collateral ligaments: an MRI study on paediatric patients during growth.

PURPOSE: Different femoral origins for both the medial collateral ligament (MCL) and the lateral collateral ligament (LCL) have been reported in the growing skeleton (epiphyseal and metaphyseal). Knowledge about the exact attachment sites is mandatory for anatomically correct reconstruction. This study assesses the femoral origins of the knee collateral ligaments in skeletally immature individuals using magnetic resonance imaging (MRI). METHODS: MRIs of 336 knee joints (median age 15 years (range 2-18 years), m = 209 and f = 127) were retrospectively analysed to assess the distances between the femoral origins of the MCL and LCL to the distal femoral growth plate. In 175 patients, the body sizes were additionally retrieved from medical records. RESULTS: Both MCL and LCL ligament origins were invariably located on the epiphysis. Mean MCL origin-growth plate distance was 9.6 mm (SD 2.1 mm; range 2.2-13.6 mm) in boys and 8.6 mm (SD 1.5 mm; range 3.4-12.0 mm) in girls. Mean LCL origin-growth plate distance was 9.3 mm (SD 1.8 mm; range 4.3-13.0 mm) in boys and 8.2 mm (SD 1.5 mm; range 3.4-11.8 mm) in girls. The distance between the growth plate and both collateral ligaments as well as the length of the LCL correlated positively with patients' age and body size (MCL R(2) = 0.673 and 0.556, LCL R (2) = 0.734 and 0.645, LCL length R(2) = 0.589 and 0.741; all p < 0.001). CONCLUSIONS: During growth, the femoral origins of the MCL and the LCL are constantly located on the distal femoral epiphysis. There is a linear increase in the distances from the ligaments' origins to the growth plate according to age and body size. This new information may be of clinical importance for reconstructive surgery of the knee's collateral ligaments.

Extra-virgin olive oil diet and mild physical activity prevent cartilage degeneration in an osteoarthritis model: an in vivo and in vitro study on lubricin expression.

Mediterranean diet includes a relatively high fat consumption mostly from monounsaturated fatty acids mainly provided by olive oil, the principal source of culinary and dressing fat. The beneficial effects of olive oil have been widely studied and could be due to its phytochemicals, which have been shown to possess anti-inflammatory properties. Lubricin is a chondroprotective glycoprotein and it serves as a critical boundary lubricant between opposing cartilage surfaces. A joint injury causes an initial flare of cytokines, which decreases lubricin expression and predisposes to cartilage degeneration such as osteoarthritis. The aim of this study was to evaluate the role of extra-virgin olive oil diet and physical activity on inflammation and expression of lubricin in articular cartilage of rats after injury. In this study we used histomorphometric, histological, immunocytochemical, immunohistochemical, western blot and biochemical analysis for lubricin and interleukin-1 evaluations in the cartilage and in the synovial fluid. We report the beneficial effect of physical activity (treadmill training) and extra-virgin olive oil supplementation, on the articular cartilage. The effects of anterior cruciate ligament transection decrease drastically the expression of lubricin and increase the expression of interleukin-1 in rats, while after physical activity and extra-virgin olive oil supplemented diet, the values return to a normal level compared to the control group. With our results we can confirm the importance of the physical activity in conjunction with extra-virgin olive oil diet in medical therapy to prevent osteoarthritis disease in order to preserve the articular cartilage and then the entire joint.

Post-traumatic caspase-3 expression in the adjacent areas of growth plate injury site: a morphological study.

The epiphyseal plate is a hyaline cartilage plate that sits between the diaphysis and the epiphysis. The objective of this study was to determine the impact of an injury in the growth plate chondrocytes through the study of histological morphology, immunohistochemistry, histomorphometry and Western Blot analyses of the caspase-3 and cleaved PARP-1, and levels of the inflammatory cytokines, Interleukin-6 (IL-6) and Tumor Necrosis Factor alpha (TNF-α), in order to acquire more information about post-injury reactions of physeal cell turnover. In our results, morphological analysis showed that in experimental bones, neo-formed bone trabeculae-resulting from bone formation repair-invaded the growth plate and reached the metaphyseal bone tissue (bone bridge), and this could result in some growth arrest. We demonstrated, by ELISA, increased expression levels of the inflammatory cytokines IL-6 and TNF-α. Immunohistochemistry, histomorphometry and Western Blot analyses of the caspase-3 and cleaved PARP-1 showed that the physeal apoptosis rate of the experimental bones was significantly higher than that of the control ones. In conclusion, we could assume that the inflammation process causes stress to chondrocytes that will die as a biological defense mechanism, and will also increase the survival of new chondrocytes for maintaining cell homeostasis. Nevertheless, the exact stimulus leading to the increased apoptosis rate, observed after injury, needs additional research to understand the possible contribution of chondrocyte apoptosis to growth disturbance.

Towards a better understanding of bone bridge formation in the growth plate - an immunohistochemical approach.

The growth plate at the end of long bones is the cartilaginous organ responsible for longitudinal bone growth in children. Trauma to the growth plate, i.e. fractures, can severely impair longitudinal bone growth, leading to growth disorders due to destruction of the epiphyseal circulation and formation of a bone bridge. From the clinical experience it is known that in some patients this bone bridge eventually disappears during the growth process. However, the molecular mechanisms involved in bone bridge formation and dissolution have not been clarified yet. The aim of this study was to investigate the spatial and temporal protein level of molecules potentially involved in these processes, i.e. RANKL, OPG, DKK-1, Coll 10, BMP-2 and IL-6, in an experimental rat model using an immunohistochemical approach. The results from our study suggest that bone bridge formation might be an early event starting immediately after growth plate injury and involving several pro-osteoblastic molecules, i.e. IL-6, BMP-2 as well as OPG and Coll X. In the late studied time points 3- and 9-month post-injury expression of anti-osteoblastic proteins, i.e. DKK1 and RANKL, was increased. This indicates that bone bridge dissolution might be a late event and potentially linked to Wnt signaling inhibition and RANK/RANKL signaling activation.

Sesquiterpene lactones downregulate G2/M cell cycle regulator proteins and affect the invasive potential of human soft tissue sarcoma cells.

Soft tissue sarcomas (STS) represent a rare group of malignant tumors that frequently exhibit chemotherapeutic resistance and increased metastatic potential. Many studies have demonstrated the great potential of plant-derived agents in the treatment of various malignant entities. The present study investigates the effects of the sesquiterpene lactones costunolide and dehydrocostus lactone on cell cycle, MMP expression, and invasive potential of three human STS cell lines of various origins. Both compounds reduced cell proliferation in a time- and dose-dependent manner. Dehydrocostus lactone significantly inhibited cell proliferation, arrested the cells at the G2/M interface and caused a decrease in the expression of the cyclin-dependent kinase CDK2 and the cyclin-dependent kinase inhibitor p27(Kip1). In addition, accumulation of cells at the G2/M phase transition interface resulted in a significant decrease in cdc2 (CDK1) together with cyclin B1. Costunolide had no effect on the cell cycle. Based on the fact that STS tend to form daughter cell nests and metastasize, the expression levels of matrix metalloproteinases (MMPs), which play a crucial role in extracellular matrix degradation and metastasis, were investigated by Luminex® technology and real-time RT-PCR. In the presence of costunolide, MMP-2 and -9 levels were significantly increased in SW-982 and TE-671 cells. Dehydrocostus lactone treatment significantly reduced MMP-2 and -9 expression in TE-671 cells, but increased MMP-9 level in SW-982 cells. In addition, the invasion potential was significantly reduced after treatment with both sesquiterpene lactones as investigated by the HTS FluoroBlock™ insert system.

RANKL is downregulated in bone cells by physical activity (treadmill and vibration stimulation training) in rat with glucocorticoid-induced osteoporosis.

The aim of this study was to investigate bone tissue and plasma levels of RANKL and OPG in rats with prednisolone-induced osteoporosis and to evaluate the outcomes of physical activity on the skeletal system by treadmill and vibration platform training. Osteoporosis is a disease characterised by low bone mass and structural deterioration of bone tissue leading to bone fragility. Vibration exercise is a new and effective measure to prevent muscular atrophy and osteoporosis. The animals were divided into 5 groups. 1: control rats; 2: rats with osteoporosis receiving prednisolone; 3: rats receiving prednisolone and treadmill training; 4: rats receiving prednisolone and vibration stimulation training; 5: rats receiving prednisolone, treadmill and vibration stimulation training. For bone evaluations we used whole-body scans, histology and histomorphometric analysis. RANKL and OPG expression was evaluated by immunohistochemistry and biochemical analysis. After treatment, our data demonstrated that RANKL expression was significantly increased in groups 2 and 3 and decreased in groups 4 and 5. Conversely, OPG expression was significantly decreased in groups 2 and 3 and increased in groups 4 and 5. In conclusion, our findings suggest that mechanical stimulation inhibits the activity of RANKL. This finding provides new insights into the occurrence and progression of osteoporosis.

The influence of ultrasound guidance in the rate of success of acromioclavicular joint injection: an experimental study on human cadavers.

BACKGROUND: Injections of the acromioclavicular joint (ACJ) are performed routinely in patients with ACJ arthritis, both diagnostically and therapeutically. The aim of this prospective controlled study was to estimate the frequency of successful intra-articular ACJ injections with the aid of sonographic guidance versus non-guided ACJ injections. MATERIALS AND METHODS: A total of 80 cadaveric ACJs were injected with a solution containing methylene blue and subsequently dissected to distinguish intra- from peri-articular injections. In 40 cases the joint was punctured with sonographic guidance, whereas 40 joints were injected in the control group without the aid of ultrasound. RESULTS: The rate of successful intra-articular ACJ injection was 90% (36 of 40) in the guided group and 70% (28 of 40) in the non-guided group. Ultrasound was significantly more accurate for correct intra-articular needle placement (P = .025). DISCUSSION: The use of ultrasound significantly improves the accuracy of ACJ injection.

Drilling, not a benign procedure: laboratory simulation of true drilling depth.

INTRODUCTION: Drilling is an integral part of almost all boney operations. Various anatomical structures coursing close to the bone are at risk if the drill bit projects beyond the far cortex. Aim of this study was to evaluate and quantify the depth to which surgeons over drill beyond the far cortex. MATERIALS AND METHODS: During an AO course 153 (41 females, 112 males) surgeons and physicians were invited to participate in this study. Each participant performed 3 bicortical drillings on generic artificial bone. Polystyrene plates were mounted on the far cortex of the bone to allow for exact measurement of the over penetration of the drill bit. RESULTS: A total of 462 bicortical drilling manoeuvres were analysed. The average projection of the drill bit beyond the far cortex was 6.31 mm. No significant statistical correlation was noted between the specialty or the experience of the participant and depth of over drilling. CONCLUSIONS: It is remarkable that the mean and the range of far cortex over-penetration was quite similar amongst surgeons of differing grades and experience. The results of this study should return to mind to pay attention when drilling particularly in anatomical sites where nerve and vessels coursing close to the far cortex.

Bone-implant interface strength and osseointegration: Biodegradable magnesium alloy versus standard titanium control.

Previous research on the feasibility of using biodegradable magnesium alloys for bone implant applications mainly focused on biocompatibility and corrosion resistance. However, successful clinical employment of endosseous implants is largely dependent on biological fixation and anchorage in host bone to withstand functional loading. In the present study, we therefore aimed to investigate whether bone-implant interface strength and osseointegration of a novel biodegradable magnesium alloy (Mg-Y-Nd-HRE, based on WE43) is comparable to that of a titanium control (Ti-6Al-7Nb) currently in clinical use. Biomechanical push-out testing, microfocus computed tomography and scanning electron microscopy were performed in 72 Sprague-Dawley rats 4, 12 and 24 weeks after implantation to address this question. Additionally, blood smears were obtained from each rat at sacrifice to detect potential systemic inflammatory reactions. Push-out testing revealed highly significantly greater maximum push-out force, ultimate shear strength and energy absorption to failure in magnesium alloy rods than in titanium controls after each implantation period. Microfocus computed tomography showed significantly higher bone-implant contact and bone volume per tissue volume in magnesium alloy implants as well. Direct bone-implant contact was verified by histological examination. In addition, no systemic inflammatory reactions were observed in any of the animals. We conclude that the tested biodegradable implant is superior to the titanium control with respect to both bone-implant interface strength and osseointegration. These results suggest that the investigated biodegradable magnesium alloy not only achieves enhanced bone response but also excellent interfacial strength and thus fulfils two critical requirements for bone implant applications.

Accuracy of anterolateral versus posterolateral subtalar injection.

INTRODUCTION: Injections into the subtalar joint may be performed for diagnostic or therapeutic reasons. The anterolateral approach is most commonly utilised for this purpose. We evaluated the success of an intra-articular puncture by using the anterolateral in comparison to the posterolateral approach. METHODS: Sixty-eight cadaver adult feet were used for performing injections into the subtalar joint without fluoroscopic or ultrasound guidance. Methylene blue dye was infiltrated into 34 of the 68 subtalar joints through an anterolateral approach and into 34 through an posterolateral approach. An arthrotomy was then performed to confirm the placement of the dye within the joint. RESULTS: Twenty-three of the anterolateral injections (67.6%) were successful as were 31 of 34 (91.2%) of the posterolateral. The posterolateral approach showed a greater accuracy with a statistically significance (p = 0.016). CONCLUSION: Unintended peri-articular injection can cause complications and an unsuccessful aspiration can delay diagnosis. Comparing the anterolateral to the posterolateral approach with regards to the rate of successful intra-articular puncture of the subtalar joint without the use of imaging there is a greater accuracy with the PL with statistically significance.

Morphology of the tibialis anterior muscle and its implications in minimally invasive plate osteosynthesis of tibial fractures.

We examined the variation in the origin of the tibialis anterior muscle from the lateral aspect of the tibial shaft and interosseous membrane as well as the variation in the morphology of its musculotendinous junction. Forty cadaveric lower leg specimens (20 right and 20 left) were dissected to reveal the anterior compartment. The origin of the tibialis anterior muscle and its relation to the lateral tibial shaft and interosseous membrane were determined. The position of the musculotendinous junction relative to the medial malleolus was also measured. Tibial length ranged from 29.5 to 45 cm (mean, 36.5+/-3.1 cm). The distal limit of the muscle origin was 5.9 to 20.5 cm (mean, 12.1+/-3.3 cm) from the tip of the medial malleolus. The distance between the musculotendinous junction and the medial malleolus ranged from 1.4 to 10.8 cm (mean, 6.1+/-1.9 cm). The attachment of the muscle belly ends between 15.3 and 31.8 cm (mean, 24.4+/-4.1 cm) distally from the joint line at the knee. There was no statistical correlation between tibial length and muscle morphology.This variation warrants consideration in the percutaneous insertion of screws in the distal end of long plates, as the neurovascular bundle may be injured in patients with a shorter muscle belly. We advocate an open distal approach to protect the neurovascular bundle during insertion of the plate and distal screws.

Role of Neuroprotein S-100B in the Diagnostic of Pediatric Mild Brain Injury.

Traumatic brain injury is one of the leading causes of death and disability in children and adolescents. Patients with moderate or severe lesions can be readily recognized clinically, require immediate radiologic diagnostics by computed tomography (CT) or magnetic resonance imaging (MRI), admission to intensive care units, and, in some cases, will go on to require neurosurgical intervention. Patients with mild traumatic brain injuries (MTBIs) are diagnostically challenging. Often, the event is unobserved and head injury can only be suspected. Clinical symptoms are unreliable and clinical findings from neurological examination have to be interpreted with care. As a small percentage of MTBI patients progress to have a life-threatening intracranial hemorrhage, the recognition of this group of patients and their judicious and timely management is, therefore, an important goal. Subjecting every MTBI patient to a cranial CT scanning results in high costs and unnecessary exposure to ionizing radiation. Admitting all MTBI patients for observation and performing CTs only in case of clinical deterioration is costly and a substantial drain on resources, not to mention the radiation exposure and a source of stress for the majority of patients. Current European guidelines for diagnostics and therapy in MTBI patients are only partially applicable to the pediatric population. This article reviews the clinical problem, treatment options and guidelines, as well as diagnostic tools, with special focus on neuroprotein S-100B in pediatric and adolescent patients with MTBIs.

Transitional fractures of the distal tibia: a minimal access approach for osteosynthesis.

BACKGROUND: Transitional fractures typically occur in patients with partially closed growth plates. In case of displacements >2 mm, osteosynthesis is recommended. Open reduction and stabilization with lag screws is the most common approach. Infection and paraesthesia are common complications of this method. This study describes an alternative approach by closed reduction and cannulated screw fixation. METHODS: All patients with transitional fractures treated by closed reduction and cannulated screw fixation were identified. All patients with >1 year after implant removal were included in this investigation. Of 27 patients treated by this technique, 21 met the inclusion criteria and were sent a standardized questionnaire including the Foot Function Index (FFI). All cases with impairments in the FFI were invited for a follow-up examination. RESULTS: Postoperative complications occurred in two patients (8.3%): one reported paraesthesia of the hallux and one showed skin irritations above the screw insertion. Average follow-up time was 3.8 years after implant removal. Of 21 patients who returned the questionnaire, three patients (14.3%) had impairment in the FFI and were invited for clinical follow-up: one patient showed mild signs of osteoarthritis without visible gaps of the joint surface, one patient had minimally restricted pronation, and one had neither clinical nor radiologic correlates for the impairment reported. Sports activity was reduced in one patient. CONCLUSION: If closed reduction can be achieved fixation with cannulated screws proved to be a satisfactory method with little scars and good clinical results.

[Elastic Stable Intramedullary Nailing (ESIN) of forearm fractures]. / Elastisch-stabile intramedulläre Marknagelung (ESIN) von Unterarmfrakturen.

OBJECTIVE: Fracture stabilization and restoration of bony anatomy with elastic stable intramedullary nailing (ESIN). INDICATIONS: Diaphyseal forearm fractures with displacements > 10 degrees . In cases of narrowing of the marrow cavity functional deficits can be encountered even in displacements < 10 degrees . CONTRAINDICATIONS: Distal metaphyseal fractures. Undislocated unstable fractures with no need for repositioning. Grade III open fractures. Greenstick fractures in patients < 5 years. SURGICAL TECHNIQUE: After skin incision 2 cm proximal to the distal radial epiphysis, the cortical bone is transfixed diagonally toward proximal (ascending). The ulnar bone is transfixed from proximal to distal (descending). For that, a small incision 2 cm distal to the olecranon apophysis is made. To reduce the risk of refractures in case of greenstick fractures at the forearm, bones should be broken completely after introduction of the wires. Furthermore, implant removal is recommended approximately 6-8 months postoperatively. POSTOPERATIVE MANAGEMENT: No additional fixation is required, allowing immediate functional treatment with early return to school. RESULTS: Operative treatment of forearm shaft fractures with ESIN was analyzed in 77 children. Average duration of surgery was 44 min (10-140 min). After an average of 7 months (1-13 months), the nails were removed. Postoperative complications were analyzed in 74 patients (96%). In three patients (4%), a superficial pin site infection emerged. One child (1%) fell on his arm again and broke his distal radius during ESIN treatment, and one patient (1%) showed deflected nails after a refall on the arm 1 week after surgery. Assessment of functional outcome in 70 patients revealed only two cases (3%) with minimal functional deficit.