Role of the Binding Energy on Nondipole Effects in Single-Photon Ionization.

We experimentally study the influence of the binding energy on nondipole effects in K-shell single-photon ionization of atoms at high photon energies. We find that for each ionization event, as expected by momentum conservation, the photon momentum is transferred almost fully to the recoiling ion. The momentum distribution of the electrons becomes asymmetrically deformed along the photon propagation direction with a mean value of 8/(5c)(E_{γ}-I_{P}) confirming an almost 100 year old prediction by Sommerfeld and Schur [Ann. Phys. (N.Y.) 396, 409 (1930)10.1002/andp.19303960402]. The emission direction of the photoions results from competition between the forward-directed photon momentum and the backward-directed recoil imparted by the photoelectron. Which of the two counteracting effects prevails depends on the binding energy of the emitted electron. As an example, we show that at 20 keV photon energy, Ne^{+} and Ar^{+} photoions are pushed backward towards the radiation source, while Kr^{+} photoions are emitted forward along the light propagation direction.

The role of perinatal palliative care following prenatal diagnosis of major, incurable fetal anomalies: a multicentre prospective cohort study.

OBJECTIVE: To describe prenatal decision-making processes and birth plans in pregnancies amenable to planning perinatal palliative care. DESIGN: Multicentre prospective observational study. SETTING: Nine Multidisciplinary Centres for Prenatal Diagnosis of the Paris-Ile-de-France region. POPULATION: All cases of major and incurable fetal anomaly eligible for TOP where limitation of life-sustaining treatments for the neonate was discussed in the prenatal period between 2015 and 2016. METHODS: Cases of congenital defects amenable to perinatal palliative care were prospectively included in each centre. Prenatal diagnosis, decision-making process, type of birth plan, birth characteristics, pregnancy and neonatal outcome were collected prospectively and anonymously. MAIN OUTCOME MEASURE: Final decision reached following discussions in the antenatal period. RESULTS: We identified 736 continuing pregnancies with a diagnosis of a severe fetal condition eligible for TOP. Perinatal palliative care was considered in 102/736 (13.9%) pregnancies (106 infants); discussions were multidisciplinary in 99/106 (93.4%) cases. Prenatal birth plans involved life-sustaining treatment limitation and comfort care in 73/736 (9.9%) of the pregnancies. The main reason for planning palliative care at birth was short-term inevitable death in 39 cases (53.4%). In all, 76/106 (71.7%) infants were born alive, and 18/106 (17%) infants were alive at last follow-up, including four with a perinatal palliative care birth plan. CONCLUSIONS: Only a small proportion of severe and incurable fetal disorders were potentially amenable to limitation of life-sustaining interventions. Perinatal palliative care may not be considered a universal alternative to termination of pregnancy. TWEETABLE ABSTRACT: Perinatal palliative care is planned in 10% of continuing pregnancies with a major and incurable fetal condition eligible for TOP.

Embolization of tumor cells is rare in patients with systemic cancer and cerebral large vessel occlusion.

BACKGROUND AND PURPOSE: Stroke is a dreaded complication in patients with cancer. Besides paraneoplastic coagulopathy, chemotherapy, radiotherapy and tumor-directed invasive procedures, circulating cancer cells may contribute to thrombus formation and embolic stroke. However, the incidence of tumor cells within the blood clots of cancer patients with stroke is unknown and the role of circulating tumor cells in the formation of cerebrovascular thrombi remains unclear. METHODS: All patients who had undergone cerebrovascular thrombectomy at the University Hospital Zurich between 2014 and 2017 were screened for history of cancer. Clinical information was retrieved from the local stroke registry and the electronic charts and thrombi underwent a thorough histopathological re-review. RESULTS: Thirty-two of 182 patients (18%) with thrombectomy had a history of cancer. The majority of patients had advanced stage cancer. However, even after extensive histopathological re-review, only one specimen revealed tumor cells in the thrombus: a 75-year-old patient with acute occlusion of the middle cerebral artery who had been diagnosed with non-small-cell lung cancer 8.1 months prior to stroke. CONCLUSIONS: The presence of cancer cells in clots from cerebrovascular thrombectomy, indicative of a direct involvement of circulating tumor cells in the causation of stroke, is rare.

Full-field characterization of helical Bloch modes guided in twisted coreless photonic crystal fiber.

It was recently reported that a photonic crystal fiber (PCF) with no structural core guides light if a permanent chiral twist is introduced by spinning the fiber preform during the draw. The intriguing guidance mechanism behind this novel effect has many remarkable features; for example, it intrinsically supports circularly polarized helical Bloch modes (HBMs) that carry multiple optical vortices, making twisted PCFs of interest in fields such as optical micro-manipulation, imaging, quantum optics, and optical communications. Here we report for the first time, to the best of our knowledge, that a twisted coreless PCF supports not just one but a family of guided HBMs, each member of which has a unique transverse field distribution and harmonic spectrum. By making detailed interferometric measurements of the near-field phase and amplitude distributions of HBMs, and expanding them as a series of Bessel beams, we are able to extract the amplitude of each azimuthal and radial HBM harmonic. Good agreement is found with the numerical solutions of Maxwell's equations. The results shed light on the properties of this curious new optical phenomenon.

Bevacizumab may improve quality of life, but not overall survival in glioblastoma: an epidemiological study.

Background: The vascular endothelial growth factor antibody bevacizumab (Avastin®), received approval for the treatment of recurrent glioblastoma in many countries including the USA and Switzerland, but not the European Union, in 2009. Here, we explored the hypothesis that the approval of bevacizumab improved outcome with glioblastoma on a population level. Patients and methods: The prognostic significance of epidemiological, molecular genetic, and clinical data including treatment for glioblastoma patients diagnosed from 2010 to 2014 in the Canton of Zurich, Switzerland, was retrospectively analyzed using log-rank test and Cox proportional hazards models. Data were compared with data for the years 2005-2009. Results: In total, 310 glioblastoma patients were identified in the years 2010-2014. Median overall survival was 13.5 months for patients with known isocitrate dehydrogenase (IDH) wild-type (wt) (IDH1R132H-non-mutant) tumors (N = 248), compared with 11.3 months for IDH wt patients (P = 0.761) before (2005-2009). In the IDH wt cohort, bevacizumab use at any time increased from 19% in 2005-2009 to 49% in 2010-2014. Multivariate analysis did not identify bevacizumab exposure at any time to be associated with survival. Yet, upon the second-line treatment, baseline doses of corticosteroids were reduced by more than half in 83% of patients on bevacizumab compared with 48% of the patients treated with bevacizumab-free regimens (P = 0.007). Conclusion: This epidemiological study of a small, but clinically well-annotated patient cohort fails to support the assumption that the strong increase of bevacizumab use since 2010 improved survival in glioblastoma although clinical benefit associated with decreased steroid use may have been achieved.

Bevacizumab plus hypofractionated radiotherapy versus radiotherapy alone in elderly patients with glioblastoma: the randomized, open-label, phase II ARTE trial.

Background: The addition of bevacizumab to temozolomide-based chemoradiotherapy (TMZ/RT â†’ TMZ) did not prolong overall survival (OS) in patients with newly diagnosed glioblastoma in phase III trials. Elderly and frail patients are underrepresented in clinical trials, but early reports suggested preferential benefit in this population. Patients and methods: ARTE was a 2 : 1 randomized, multi-center, open-label, non-comparative phase II trial of hypofractionated RT (40 Gy in 15 fractions) with bevacizumab (10 mg/kg×14 days) (arm A, N = 50) or without bevacizumab (arm B, N = 25) in patients with newly diagnosed glioblastoma aged ≥65 years. The primary objective was to obtain evidence for prolongation of median OS by the addition of bevacizumab to RT. Response was assessed by RANO criteria. Quality of life (QoL) was monitored by the EORTC QLQ-C30/BN20 modules. Exploratory studies included molecular subtyping by 450k whole methylome and gene expression analyses. Results: Median PFS was longer in arm A than in arm B (7.6 and 4.8 months, P = 0.003), but OS was similar (12.1 and 12.2 months, P = 0.77). Clinical deterioration was delayed and more patients came off steroids in arm A. Prolonged PFS in arm A was confined to tumors with the receptor tyrosine kinase (RTK) I methylation subtype (HR 0.25, P = 0.014) and proneural gene expression (HR 0.29, P = 0.025). In a Cox model of OS controlling for established prognostic factors, associations with more favorable outcome were identified for age <70 years (HR 0.52, P = 0.018) and Karnofsky performance score 90%-100% (HR 0.51, P = 0.026). Including molecular subtypes into that model identified an association of the RTK II gene methylation subtype with inferior OS (HR 1.73, P = 0.076). Conclusion: Efficacy outcomes and exploratory analyses of ARTE do not support the hypothesis that the addition of bevacizumab to RT generally prolongs survival in elderly glioblastoma patients. Molecular biomarkers may identify patients with preferential benefit from bevacizumab. Clinical trial registration number: NCT01443676.

Multimodality imaging evaluation before transcatheter aortic valve implantation: incidence of contrast medium-induced acute kidney injury, risk factors and prognosis.

AIM: To evaluate the incidence, risk factors, and prognostic implications of contrast medium-induced acute kidney injury (CI-AKI) in patients undergoing transcatheter aortic valve implantation (TAVI) evaluation. MATERIALS AND METHODS: Datasets from 98 out of 207 consecutive patients referred for multidetector computed tomography (MDCT) for TAVI evaluation were eligible for evaluation and were analysed retrospectively. The incidence of CI-AKI was correlated to outcome and to potential risk factors: kidney function (estimated glomerular filtration rate [eGFR]), heart failure, diabetes, amount of contrast medium, and duration of examination period. RESULTS: CI-AKI occurred in 67 patients (68.4%) and mainly correlated with eGFR (p=0.01) and the amount of contrast medium as a function of eGFR (p=0.04). CI-AKI occurred before TAVI in 36 (53.7%) patients of which 13 (19.4%) did not undergo TAVI. In-hospital all-cause mortality was 21.4%, and of those 21 patients, 18 (85.7%) had CI-AKI and nine (42.9%) did not undergo TAVI. One-year all-cause mortality was 39.8%, and of those 39 patients who died within 1 year, 31 (79.5%) had CI-AKI. CONCLUSION: CI-AKI mostly occurs already before TAVI as a consequence of pre-procedural imaging, which therefore represents the main contributor for CI-AKI in relation to TAVI. Regarding the observation that some patients will ultimately have no benefit because TAVI is not performed and the poor prognosis linked to CI-AKI should encourage improvement in patient selection when referring to pre-procedural imaging.

[Basic principles of diagnosis and treatment of gliomas]. / Grundlagen zur Diagnose und Therapie von Gliomen.

BACKGROUND: Traditionally, gliomas were classified based on histopathological features alone. The revised World Health Organization (WHO) classification of tumors of the central nervous system from 2016 integrated molecular features into the histopathological diagnosis. OBJECTIVE: To summarize key aspects of the WHO classification from 2016 and implications for the clinical management of glioma patients. An overview of novel treatment approaches is also provided. RESULTS: Oligodendrogliomas are defined independently of their histopathological appearance by the simultaneous presence of a mutation in the isocitrate dehydrogenase (IDH)-1 or IDH-2 gene and co-deletion of chromosome arms 1p and 19q. Astrocytomas are classified based on the presence or absence of mutations in IDH. Astrocytic tumors with wild-type IDH comprise approximately 90% of glioblastomas, the most common malignant primary brain tumor in adults. The extent of resection is a favorable prognostic factor in diffuse gliomas. Postoperatively, most patients are treated with a combination of radiotherapy and alkylating agent chemotherapy. In IDH wild-type astrocytic tumors, hypermethylation of the promoter of the DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT) gene is predictive for benefit from the alkylating agent temozolomide. Most novel treatment approaches that are currently being assessed in clinical trials aim at reprogramming the immune system to specifically eradicate tumor cells, but the efficacy of such approaches in gliomas remains to be demonstrated. DISCUSSION: To date the classical treatment modalities comprising surgery, radiotherapy and chemotherapy remain the mainstay of glioma treatment. The integration of molecular features into the classification of gliomas is a basis for personalized treatment approaches.

Mid-Term Survival of Total Knee Arthroplasty in Patients with Posttraumatic Osteoarthritis.

PURPOSE OF THE STUDY There is limited evidence on survival and complication rates in patients after total knee arthroplasty for posttraumatic osteoarthritis. The failure mechanisms leading to revision remain an issue of constant debate. The purpose of this study was to analyze the mid-term survival of primary total knee arthroplasties as well as to evaluate complications and failure mechanisms in patients with posttraumatic knee osteoarthritis. MATERIAL AND METHODS This retrospective study included 79 patients with an average age of 59 years at the time of primary total knee arthroplasty. A functional and radiographic assessment was obtained during outpatient clinical follow-up at 3 and 12 months postoperatively and yearly intervals after that. Survival rates were calculated using Kaplan-Meier analyses. The mean postoperative follow-up was 69 months. RESULTS At 69 month the revision-free survival rate was 88.6%. In nine cases (11.4%) a revision procedure was performed. The leading cause of revision was a periprosthetic infection (n = 6, 66.6%). An age of fewer than 55 years at the time of total knee arthroplasty had a significant influence on implant survival (p = 0.018) with superior survival in favor of the older patient population. At most recent follow-up, a mean Knee Society Score of 82 points and an average Function Score of 77 points were observed. CONCLUSIONS Periprosthetic joint infection is the primary failure mechanism leading to a revision in patients with total knee arthroplasty for posttraumatic osteoarthritis. Apart from the increased infection rate, total knee arthroplasties in patients with posttraumatic osteoarthritis revealed results that were comparable to patients with primary osteoarthritis. Key words:posttraumatic knee osteoarthritis, total knee replacement, survival, complications, revision, outcome.

Microstructural Changes of Tensor Fasciae Latae and Gluteus Medius Muscles Following Total Hip Arthroplasty: A Prospective Trial.

PURPOSE OF THE STUDY Although total hip arthroplasty (THA) is one of the most successful orthopedic operations, the soft tissue trauma towards the periarticular musculature during surgical approaches remains a critical concern. However, the actual microstructural proof of muscle trauma on the level of the myofiber due to the surgical approach has never been claimed. MATERIAL AND METHODS Patients undergoing THA were prospectively enrolled and either operated by a direct lateral (DL) or a anterolateral minimally invasive approach (ALMI). Intraoperatively and at 6 months follow-up a needle biopsy was taken from the gluteus medius muscle and the tensor fasciae latae. Pre- and post-operative fiber diameter and composition, of gluteal medius muscle (GMM) and the tensor fasciae latae muscle (TFLM) were compared in both surgical approaches. RESULTS A total of 19 patients (12 F; 7 M) were included in this study. The average pre-operative fiber diameter or fiber type composition did not differ significantly in the GMM and TFLM, nor did it vary among patients with different approaches. The muscle fiber diameter significantly increased post-operatively in the TFLM, in both, the DL (p = 0.043) and the ALMI (p = 0.043) approach. There was a trend towards more pronounced muscle fiber changes in the DL (TFLM: p = 0.077; GMM: p = 0.150), compared to the ALMI. DISCUSSION AND CONCLUSIONS Our results show microstructural changes to the periarticular musculature following THA by a compensatory hypertrophy of the TFLM and GMM. These adaptions directly next to the surgical trauma were observed in DL and AMLI. Key words: total hip arthroplasty, skeletal muscle, muscle biopsy, iatrogenic trauma, muscle scar.

Patterns of care in recurrent glioblastoma in Switzerland: a multicentre national approach based on diagnostic nodes.

Despite moderate improvements in outcome of glioblastoma after first-line treatment with chemoradiation recent clinical trials failed to improve the prognosis of recurrent glioblastoma. In the absence of a standard of care we aimed to investigate institutional treatment strategies to identify similarities and differences in the pattern of care for recurrent glioblastoma. We investigated re-treatment criteria and therapeutic pathways for recurrent glioblastoma of eight neuro-oncology centres in Switzerland having an established multidisciplinary tumour-board conference. Decision algorithms, differences and consensus were analysed using the objective consensus methodology. A total of 16 different treatment recommendations were identified based on combinations of eight different decision criteria. The set of criteria implemented as well as the set of treatments offered was different in each centre. For specific situations, up to 6 different treatment recommendations were provided by the eight centres. The only wide-range consensus identified was to offer best supportive care to unfit patients. A majority recommendation was identified for non-operable large early recurrence with unmethylated MGMT promoter status in the fit patients: here bevacizumab was offered. In fit patients with late recurrent non-operable MGMT promoter methylated glioblastoma temozolomide was recommended by most. No other majority recommendations were present. In the absence of strong evidence we identified few consensus recommendations in the treatment of recurrent glioblastoma. This contrasts the limited availability of single drugs and treatment modalities. Clinical situations of greatest heterogeneity may be suitable to be addressed in clinical trials and second opinion referrals are likely to yield diverging recommendations.

Serial testing for latent tuberculosis infection in transplant candidates: a retrospective review.

BACKGROUND: Accurately identifying latent tuberculosis (TB) infection (LTBI) in liver and renal transplant candidates is important because of the risks associated with both treatment of LTBI and reactivation of disease in this population. Many programs advocate yearly screening of patients awaiting organ transplantation. The reproducibility of serial interferon-gamma release assay (IGRA) testing in transplant candidates has not been studied. METHODS: We conducted a retrospective longitudinal study of patients listed for liver or kidney transplantation between January 1, 2005 and February 1, 2012 at the University of Illinois Medical Center at Chicago. Data collected included demographics, transplant type, IGRA results, treatment received, and mortality. RESULTS: The study population was comprised of 795 adults; 79 (10%) had at least 1 indeterminate result; indeterminate results were less common in men (P = 0.01) and more common in liver transplant candidates (P < 0.001). The reversion frequency was 27% with a rate of 158.1 reversions in 1000 person-years. A higher magnitude of initial TB response values was predictive of consistently positive results (P < 0.001). The conversion frequency was 15% with a rate of 82.6 conversions in 1000 person-years. Among those who converted, the values of the IGRA varied, with 48% having a TB response of <1 IU/mL, 41% 1-5 IU/mL, and only 10% >5 IU/mL. CONCLUSIONS: A significant number of conversions and reversions occur during serial IGRA testing of transplant candidates. Delineating true-positive converters from false-positives is an issue that warrants further study.

[Management of extensor mechanism injuries following total knee arthroplasty]. / Verletzungen und Rekonstruktion des Streckapparates nach Knie-TEP.

Extensor mechanism injuries in total knee arthroplasty include disruption of the quadriceps tendon, disruption of the patellar tendon, and/or patellar fractures. While these injuries are rare, they are a devastating complication to manage. This review summarizes the anatomy of the extensor mechanism, risk factors for extensor mechanism injuries, and the prevalence and diagnosis of extensor mechanism injuries. In addition, this review outlines non-operative and operative management options. A new surgical approach for the reconstruction and augmentation of the extensor mechanism with the use of a synthetic mesh is described in detail. In multiple publications and in our own experience this newly developed technique shows promising results.

[Quadriceps tendon insufficiency and rupture : Treatment options in total knee arthroplasty]. / Quadrizepssehneninsuffizienzen und -rupturen : Verfahren zur Behandlung in der Knieendoprothetik.

Quadriceps tendon injuries and insufficiencies in total knee arthroplasty are rare, but are followed by a devastating complication that left untreated leads to a complete loss of function of the knee. This review article summarizes the functional anatomy, risk factors, and the prevalence and diagnosis of quadriceps tendon injuries, in addition to the possible management options for partial and complete ruptures. The treatment options are adapted according to the extent of the loss of function (partial, complete) and the duration of the injury (acute vs chronic). Furthermore, the choice of treatment should take into account the quality and availability of primary tissue, the patient's general health, along with their likely functional requirements. Conservative treatment is often justified in partial ruptures with good results. Complete ruptures require surgical intervention and multiple operative techniques are described. Treatment options for acute ruptures include direct primary repair with autogenous or synthetic tissue augmentation. In the case of chronic insufficiency and a lack of soft-tissue surroundings, reconstruction with the aid of a muscle flap or allograft tissue can be considered. All surgical intervention techniques used so far have been fraught with complications and rarely lead to satisfactory results. A new surgical approach to the reconstruction and augmentation of the extensor mechanism consists of the use of a synthetic mesh. The technique is described here in detail.

[Periprosthetic fractures following total hip and knee arthroplasty: Risk factors, epidemiological aspects, diagnostics and classification systems]. / Periprothetische Frakturen nach Hüft- und Knietotalendoprothesenimplantation: Risikofaktoren, epidemiologische Aspekte, Diagnostik und Klassifikationssysteme.

Periprosthetic fractures following hip and knee arthroplasty are potentially severe complications. As a fundament in diagnostic and therapeutic procedures, specific classification systems are necessary to ensure an optimal individualized treatment of these sometimes complicated fractures. This review article summarizes the epidemiological aspects, risk factors and diagnostics of periprosthetic hip and knee fractures. The most frequently used location related fracture classifications systems are explained. In addition, the recently introduced unified classification system (UCS), which is applicable to any location of periprosthetic fractures, is described in detail. Initial studies have shown a reliable applicability of the UCS to periprosthetic hip and knee fractures.

Latent tuberculosis in kidney and liver transplant patients: a review of treatment practices and outcomes.

BACKGROUND: The standard treatment of latent tuberculosis infection (LTBI) is associated with toxicities and data are limited on tolerability among patients with advanced organ disease listed for transplant. Alternate options are available, but they have yet to be studied in this population. METHODS: A retrospective review of the treatment of LTBI among kidney and/or liver transplant candidates was conducted to assess factors impacting therapy initiation, tolerability, and completion of therapy. RESULTS: Of 174 eligible patients, treatment of LTBI was initiated in 129, of which 91 were listed for kidney transplant and 38 were listed for liver or liver/kidney transplant. Infectious Diseases consultation was independently associated with treatment initiation when controlling for waitlisted organ and receipt of hemodialysis (odds ratio [OR] 81.14, 95% confidence interval [CI] 23.94-274.94, P < 0.001). Documented completion of first-line therapy was 47% overall, and 49% and 39%, respectively, among kidney and liver/kidney candidates (P = not significant). On multivariable analysis, controlling for baseline aspartate aminotransferase and waitlisted organ, first-line receipt of rifampin was associated with lower rates of treatment completion (OR 0.19, 95% CI 0.05-0.77, P = 0.02). CONCLUSION: Based on medical record documentation, completion of first-line therapy was <50% in this cohort, although this is likely an underestimate, as 34% of patients had no chart documentation that therapy was completed. Approximately 20% of patients did not complete first-line therapy because of adverse effects.

[Chemotherapy of brain tumors in aduts]. / Chemotherapie von Hirntumoren bei Erwachsenen.

The treatment of patients with brain tumors has long been the domain of neurosurgery and radiotherapy but chemotherapy is now well established as an additional treatment option for many tumor entities in neuro-oncology. This is particularly true for patients with newly diagnosed and relapsing glioblastoma and anaplastic glioma as well as the treatment of medulloblastoma and primary lymphoma of the central nervous system (CNS). In addition to purely histopathological features, treatment decisions including those for chemotherapy are now based increasingly more on molecular tumor profiling. Within the group of gliomas these markers include the methylation status of the O-6-methylguanine-DNA methyltransferase (MGMT) promoter and the 1p/19q status, which reflects the loss of genetic material on chromosome arms 1p and 19q. The presence of a 1p/19q codeletion is associated with a better prognosis and increased sensitivity to alkylating chemotherapy in patients with anaplastic gliomas.

[Complications after minimally invasive total hip arthroplasty]. / Komplikationen nach minimal-invasiver Hüftendoprothetik.

BACKGROUND: The goal of minimally invasive surgery in total hip arthroplasty (MIS-THA) is reduction of surgical trauma without any limitations regarding exposure of the femur and acetabulum to achieve reproducible results. Despite improved instrumentation the implementation of these techniques is associated with a risk of higher complication rates. AIM: The article describes specific and unspecific complications of MIS-THA and gives hints and tips on how to avoid them. MATERIAL AND METHODS: In a retrospective study 152 THA revisions following MIS-THA were examined and an error analysis was performed. RESULTS: The study of 152 MIS-THA revisions included 87 female and 65 male patients. A gender-specific incidence of complications could not be found. The most common indication for revision surgery was due to recurrent dislocation. An increased incidence of fractures of the greater trochanter was observed using the anterolateral approach with the patient in a supine position. DISCUSSION: The MIS-THA procedure contributes to excellent early rehabilitation when performed correctly. The muscle preserving aspect can be counted as an advantage particularly for young patients. This patient collective has a high risk to undergo revision surgery.

[Treatment of Mason type II radial head fractures by percutaneous reduction]. / Die Behandlung von Radiusköpfchenfrakturen Typ Mason II durch perkutane Drahtreposition.

BACKGROUND: The therapeutic algorithm for the treatment of Mason type II radial head fractures is still controversially discussed. This study describes the technique of percutaneous fracture reduction without additional internal fixation of the radial head as an alternative to open reduction and presents the results of the method. MATERIAL AND METHODS: The data from 26 out of 30 patients with a Mason type II radial head fracture who had been consecutively treated with percutaneous fracture reduction were evaluated retrospectively. The analysis comprised the disabilities of shoulder and hand (DASH) score, the Mayo elbow performance score (MEPS) and data from the radiological examinations. RESULTS: The average follow-up time was 21 months (range 6-47 months). In 22 cases (85 %) an anatomical reduction could be achieved, 2 cases (8 %) showed a complete redislocation of the fragment and 2 cases (8 %) a partial redislocation. The average DASH score was 5.6 points (range 0-56) and the average MEPS was 93.8 (range 60-100). Only 4 patients (15 %) reported persisting functional impairment with a DASH score >10. CONCLUSIONS: The method of percutaneous reduction of radial head fractures without additional internal fixation in Mason type II fractures has been demonstrated to be a good alternative to open reduction.