Cervical spine injuries in spinal ankylosing disorders: results of single-stage posterior stabilization without posterolateral fusion.

Patients with long-segment cervical spinal fusion resulting from spinal ankylosing disorders (SADs) are at high risk for highly unstable cervical spine fractures necessitating surgery as the treatment of choice; however, without an existing gold standard. Specifically, patients without concomitant myelo- pathy, representing a rare entity, may benefit from a minimized surgical approach of a single-stage posterior stabilization without bone grafting for posterolateral fusion. This retrospective monocenter study in a Level I trauma center included all patients treated with navigated posterior stabilization without posterolateral bone grafting between January 2013 and January 2019 for cervical spine fractures in preexisting SADs without myelopathy. The outcomes were analyzed based on complication rates, revision frequency, neurologic deficits, and fusion times and rates. Fusion was evaluated by X-ray and computed tomography. 14 patients (11 male, 3 female) with a mean age of 72.7 ± 17.6 years were included. Five fractures were at the upper and nine at the subaxial cervical spine (predominantly C5-7). There was one surgery-specific complication of postoperative paresthesia. There was no infection, implant loosening, or dislocation, and no revision surgery necessary. All fractures healed after a median time of 4 months and 12 months being the latest time of fusion in one patient. Single-stage posterior stabilization without posterolateral fusion is an alternative for patients with SADs and cervical spine fractures without myelopathy. They can benefit from a minimization of surgical trauma while having equal times of fusion and no increased rate of complications.

A Feasibility Pilot Study on the Use of Telemedicine for the Examination of the Knee Joint. / Eine Pilotuntersuchung zur Machbarkeit der Videosprechstunde bei muskuloskelettalen Beschwerden des Kniegelenks.

BACKGROUND: In times of a pandemic threat, such as COVID-19, and the need for reduced direct doctor-patient contact, internet-based telemedicine has attracted more and more attention as a surrogate service. Suspending the diagnosis and treatment of non-virus related diseases for longer periods of time is not a viable option since this would only exacerbate problems on the patient and national level. The need for alternative treatment modalities increased rather quickly. So far, telemedical applications have mainly focused on teleradiological diagnosis, follow-up and monitoring of psychiatric and internal diseases, as well as geriatric patient care. As far as these authors are aware, orthopaedic physical examination of the knee joint, including trauma work-up, has not been the subject of any studies to date. This feasibility study explores how video consultation can be designed and implemented in the context of history taking and physical examination in knee joint complaints. MATERIAL AND METHOD: 21 patient actors (PA) with simulated complaints of the knee joint were examined individually for each diagnosis, first via video consultation and then directly by a specialist (SP). One PA group has a medical background, the other was made up of laypersons. The time was measured for both types of consultation. The physician documented the detected symptoms, the quality of implementation of the self-examination steps, and the derived diagnosis on an assessment form. After completion of both consultation sessions, the PAs were handed a questionnaire on the respective examination modality. RESULTS: With the video consultation the examination lasted 8.63 (± 2.5) minutes on average and with the regular consultation in person 5.63 (± 1.7) minutes (p < 0.001). For the group with medical background the examination lasted 7.67 (± 1.4) minutes on average, while for the lay group the video consultation took 9.7 (± 3.1) minutes (p = 0.049). With increased age, the video consultation was prolonged (p = 0.032; r = 0.47). The mean value for self-examination of leg axis, gait pattern and degrees of freedom was 9.32 (± 0.4) of 10 points. The following functional tests resulted in lower mean values (points): Payr 7.2 (± 2.3), Merke 5.9 (± 2.8), no-touch Lachmann 6.4 (± 2.7), gravity sign-recurvatum 6.7 (± 2.4). The mean grade by the PAs for the feasibility of self-examination was 2.43 (± 0.98) out of 5 points. CONCLUSION: The video consultation for musculoskeletal complaints of the knee joint allows exploratory remote examination and helps to minimise the number of patients in hospitals and practices. It takes longer for the physician to perform and does not permit functional testing for ligament injuries of the knee joint. In its present form, telemedical examination is not able to fully replace personal consultation.

Clinical and patient reported outcome in total ankle replacement compared to ankle fusion in end-stage haemophilic arthropathy.

BACKGROUND: Ankle arthropathy is a frequent complication of haemophilia, reducing the patients' quality of life. Despite intensive conservative therapy, end-stage arthropathy requires surgical treatment, either by ankle fusion (AF) or total ankle replacement (TAR). METHODS: Eleven consecutive AFs were performed in nine patients and 11 TARs were implemented in 10 patients. Outcomes were assessed clinically by AOFAS score and radiologically by the Pettersson and Gilbert scores. RESULTS: The mean age of the patients in these groups were 35.7 years and 49.4 years, respectively. Of the 11 ankles that underwent fusion, 10 showed bony consolidation not later than 12 weeks after surgery, whereas one still showed non-union after 6 months. VAS pain scores decreased significantly in both groups. Mean AOFAS scores also improved significantly, from 28.1 before to 80.3 after AF and from 21.5 before to 68.0 after ankle replacement. No perioperative complications were observed in either group. Late deep infection was observed in two patients that underwent TAR, which required removal of the implant. CONCLUSION: Our data indicate that both AF and TAR result in significantly reduced pain in patients with haemophilia with end-stage haemophilic arthropathy. While TAR is associated with a higher risk of deep infection and minimal persistent pain, it preserves the pre-operative range of motion. AF on the other hand is associated with the risk of non-union and a longer post-operative recovery period but results in greater pain reduction.

Evaluation of the Feasibility of a Telemedical Examination of the Hip and Pelvis - Early Lessons from the COVID-19 Pandemic. / Evaluation der Durchführbarkeit einer telemedizinischen Untersuchung des Hüftgelenks und des Beckens ­ frühe Lehren aus der COVID-19-Pandemie.

INTRODUCTION: Due to the current COVID-19 pandemic, the German Health Ministry has issued restrictions applying to the field of orthopaedics and trauma surgery. Besides postponement of elective surgeries, outpatient consultations have been drastically reduced. Parallel to these developments, an increase in telemedical consultations has reflected efforts to provide sufficient patient care. This study aims to evaluate the feasibility of a clinical examination of the hip joint and pelvis by way of a telemedical consultation. MATERIALS AND METHODS: Twenty-nine patients of a German university clinic were recruited and assessed in both telemedical and conventional examinations. Agreement between the two examinations was then assessed, and connections between the observed agreement and patient-specific factors such as age, BMI and ASA classification were investigated. RESULTS: The inspections agreed closely with a mean Cohen's kappa of 0.76 ± 0.37. Palpation showed adequate agreement with a mean Cohen's kappa of 0.38 ± 0.19. Function showed good agreement with a mean Cohen's kappa of 0.61 ± 0.26 and range of motion showed adequate agreement with a mean Cohen's kappa of 0.36 ± 0.19. A significant positive correlation was observed between the number of deviations in the different examinations and age (p = 0.05), and a significant positive correlation was shown between the number of non-feasible examinations and age (p < 0.01), BMI (p < 0.01) and ASA classification score (p < 0.01). DISCUSSION: Inspection and function can be reliably evaluated, whereas the significance of palpation, provocation and measurement of range of motion is limited. The small sample size puts limitations on the significance of a statistically relevant correlation between patient-specific factors such as age, BMI and ASA classification score and valid and successful implementation of a telemedical examination. The authors recommend targeted patient selection. If, however, patients are being evaluated who are very old (> 75 years), obese (BMI > 30) or with multiple comorbidities (ASA 3 and above), caution is advised. Large, prospective studies are needed in the future to fully validate telemedical consultations in the fields of orthopaedics and trauma surgery. CONCLUSION: A telemedical examination of the hip joint and pelvis can be performed with certain limitations. Patient-specific factors such as age, BMI, and extent of comorbidities appear to have a relevant impact on validity and execution of the examination. Patients with multiple comorbidities (ASA 3 and above), advanced age (> 75 years) or obesity (BMI > 30) should, whenever possible, be examined in a conventional outpatient setting.

Basic Clinical Examination of the Foot and Ankle. / Klinische Basisuntersuchungen am Fuß und Sprunggelenk.

Successful treatment of foot and ankle diseases requires an accurate diagnosis. In addition to differentiated history taking, clinical examination is the most important component in the diagnosis of foot and ankle diseases. The present video explains the common provocation tests and functional tests that are used in the basic clinical examination of the foot and ankle complex. In addition to general inspection and palpation, the focus is on different diagnostic tests and clinical signs that improve diagnostic accuracy. The present basic clinical examination methods allow a structured approach to clinical issues and can be a good basis, if supplemented by further specific and individual tests.

Feasibility study of preoperative microvessel evaluation and characterization in perforator flaps using various modes of color-coded duplex sonography (CCDS).

BACKGROUND: Color-coded duplex sonography (CCDS) is useful for perforator flap design showing the highest sensitivity in identifying microvessels. This prospective study evaluates the feasibility of different ultrasound (US) modes applied by the microsurgeon in daily practice suggesting quantifiable reference values. METHODS: Twenty-four patients aged between 17 and 68 years (mean 43.3 ± 14.2 years) with 18 anterolateral thigh (ALT) and 6 superficial circumflex iliac artery (SCIP) flaps were included. Indications were traumatic (n = 12), infectious (n = 6), ischemic (n = 4), or tumor-associated defects (n = 2). Different US modes were evaluated regarding applicability using multifrequency linear probes (5-15 MHz). Vessels diameter, peak systolic velocity (PSV), end diastolic velocity (EDV), and resistance index (RI) were measured. Preoperative results were correlated to intraoperative findings. RESULTS: In the examined patient group with 24 perforator flaps a 100% correlation was seen when comparing perforators detected with CCDS/PD with intraoperative findings using optimized US settings. Sensitivity, PPV, and accuracy of CCDS were 100% respectively. Mean PSV of 16.99 ± 6.07 cm/s, mean EDV of 5.01 ± 1.84 cm/s and RI of 0.7 ± 0.07 were measured in microvessels (PW-mode). CCDS proved to be superior compared to PD in correct diameter assessment showing a mean diameter of 1.65 ± 0.45 mm, compared to PD-mode 1.31 ± 0.24 mm. Mean PSV and EDV were higher in ALT than in SCIP flaps, RI was slightly higher in SCIP flaps (p > .05). There were no significant differences in size of different flaps' perforators (p > .05). CONCLUSION: CCDS represents a highly valuable tool in the daily practice of free flap reconstructions using optimized low flow US settings and multifrequency linear probes.

Characterization of synovial fluid from periprosthetic infection in revision total joint arthroplasty by single-molecule microscopy.

Periprosthetic joint infection is among the most common and severe complications in total joint arthroplasty. Today, a combination of different methods is used for diagnosis because no single method with sufficient sensitivity and specificity is available. In this study, we explored the usability of single-molecule microscopy to characterize synovial fluid samples from periprosthetic joint infections. Patients (n = 27) that needed revision arthroplasty underwent the routine diagnostic procedures for periprosthetic joint infection of the University Hospital in Bonn. Additionally, the diffusion rate of two probes, dextran and hyaluronan, was measured in small volumes of periprosthetic synovial fluid samples using single-molecule microscopy. To evaluate the suitability of single-molecule microscopy to detect PJI the AUC for both markers was calculated. The diffusion rate of hyaluronan in periprosthetic synovial fluid from patients with septic loosening was faster than in samples from patients with aseptic loosening. Single-molecule microscopy showed excellent diagnostic performance, with an area under the receiver operating characteristic curve of 0.93, and allowed the detection of periprosthetic joint infection in patients that would be challenging to diagnose with current methods. For the first time, single-molecule microscopy was used to detect periprosthetic joint infection. Our results are encouraging to study the value of single-molecule microscopy in a larger patient cohort. The speed and accuracy of single-molecule microscopy can be used to further characterize synovial fluid, potentially allowing intraoperative diagnosis of periprosthetic joint infections in the future.

Significance of the Marginal Mandibular Branch in Relation to Facial Palsy Reconstruction: Assessment of Microanatomy and Macroanatomy Including Axonal Load in 96 Facial Halves.

BACKGROUND: The marginal mandibular branch (MMB) of the facial nerve provides lower lip symmetry apparent during human smile or crying and is mandatory for vocal phonation. In treating facial palsy patients, so far, little attention is directed at the MMB in facial reanimation surgery. However, isolated paralysis may occur congenital, in Bell's palsy or iatrogenic during surgery, prone to its anatomical course. A variety of therapies address symmetry with either weakening of the functional side or reconstruction of the paralyzed side. To further clarify the histoanatomic basis of facial reanimation procedures using nerve transfers, we conducted a human cadaver study examining macroanatomical and microanatomical features of the MMB including its axonal capacity. METHODS: Nerve biopsies of the MMB were available from 96 facial halves. Histological processing, digitalization, nerve morphometry investigation, and semiautomated axonal quantification were performed. Statistical analysis was conducted with P < 0.05 as level of significance. RESULTS: The main branch of 96 specimens contained an average of 3.72 fascicles 1 to 12, and the axonal capacity was 1603 ± 849 (398-5110, n = 85). Differences were found for sex (P = 0.018), not for facial sides (P = 0.687). Diameters were measured with 1130 ± 327 µm (643-2139, n = 79). A significant difference was noted between sexes (P = 0.029), not for facial sides (P = 0.512.) One millimeter in diameter corresponded to 1480 ± 630 axons (n = 71). A number of 900 axons was correlated with 0.97 mm (specificity, 90%; sensitivity, 72%). CONCLUSIONS: Our morphometric results for the MMB provide basic information for further investigations, among dealing with functional reconstructive procedures such as nerve transfers, nerve grafting for direct neurotization or babysitter procedures, and neurectomies to provide ideal power and authenticity.

An Analysis of Aesthetic Refinements in 120 Secondary Cleft Rhinoplasties.

BACKGROUND: Secondary cleft nose rhinoplasty remains a challenging procedure. Cartilage memory and scar contraction are problematic factors. The need for more detailed procedures for secondary reconstruction in this patient population has arisen. Contemporary refinements demonstrate a highly structured approach. We conducted a retrospective study evaluating the aesthetic results of cleft patients who underwent secondary rhinoplasty. METHODS: In a retrospective study, a photometric analysis of cleft patients operated in the period 2003-2011 was conducted. Reconstructive methods were documented. Pre- and postoperative photographs of cleft rhinoplasty patients were evaluated using a standardized protocol. Nostril width ratio, columellar angle, tip projection ratio, and nasolabial angle served as objective instruments. The Unilateral Cleft Lip Surgical Outcomes Evaluation score was chosen for external photometric rating and rated blindly by 2 external individual plastic surgeons as independent nonbiased reviewers. The interrater and intrarater reliabilities were calculated using the Cohen kappa coefficient (κ). RESULTS: A total of 120 secondary rhinoplasties in 85 uni- and bilateral cleft patients could be included. Mean follow-up was 20 months. A total of 60 (71%) patients needed additional bone grafting (chin/pelvis), and 23 (27%) patients a LeFort I osteotomy. In one third of the secondary rhinoplasties, a medial and/or lateral osteotomy was performed (34%). In one fourth (24%), an external septoplasty was considered necessary. In 55% (47 patients) of the cases, a columellar strut was used. Excluding bone grafts, a total of 173 other grafts (mean of 2 grafts/patient) were applied. Postoperative measurements for nostril width ratio and columellar angle were statistically significant. A structured approach with contemporary refinements is described in detail. Intra- and interrater reliabilities for photometric assessment according to the Unilateral Cleft Lip Surgical Outcomes Evaluation score are shown. CONCLUSIONS: A structured approach for secondary cleft rhinoplasty yields satisfying, reproducible, and stable results.

Soft Tissue Sarcoma - a Current Review of the Diagnostic and Treatment Strategies. / Weichteilsarkome ­ eine Übersicht aktueller evidenzbasierter Behandlungskonzepte.

Soft tissue sarcomas are a heterogeneous group of neoplasias that due to their often clinically silent appearance often remain undetected or experience delayed treatment. Especially soft tissue swelling is often misinterpreted by patients and doctors and trivialized or verified with an incorrect biopsy technique. The hereby evoked complications for the patients are serious and may be reduced by simply following the available guidelines. The treatment of soft tissue sarcomas requires a close interdisciplinary coordination between specialists in tumor orthopedics, oncology, radiology, pathology and radiotherapy. On the basis of a selective literature review, the following article points out the current evidence on the treatment and illustrates a treatment algorithm.

Anatomical study of the zygomatic and buccal branches of the facial nerve: Application to facial reanimation procedures.

The facial nerve is responsible for any facial expression channeling human emotions. Facial paralysis causes asymmetry, lagophthalmus, oral incontinence, and social limitations. Facial dynamics may be re-established with cross-face-nerve-grafts (CFNG). Our aim was to reappraise the zygomaticobuccal branch system relevant for facial reanimation surgery with respect to anastomoses and crossings. Dissection was performed on 106 facial halves of 53 fresh frozen cadavers. Study endpoints were quantity and relative thickness of branches, correlation to "Zuker's point", interconnection patterns and crossings. Level I and level II branches were classified as relevant for CFNG. Anastomoses and fusion patterns were assessed in both levels. The zygomatic branch showed 2.98 ± 0.86 (range 2-5) twigs at level II and the buccal branch 3.45 ± 0.96 (range 2-5), respectively. In the zygomatic system a single dominant branch was present in 50%, two co-dominant branches in 9% and three in 1%. In 66% of cases a single dominant buccal twig, two co-dominant in 12.6%, and three in 1% of cases were detected. The most inferior zygomatic branch was the most dominant branch (P = 0.003). Using Zuker's point, a facial nerve branch was found within 5 mm in all facial halves. Fusions were detected in 80% of specimens. Two different types of fusion patterns could be identified. Undercrossing of branches was found in 24% at levels I and II. Our study describes facial nerve branch systems relevant for facial reanimation surgery in a three-dimensional relationship of branches to each other. Clin. Anat. 32:480-488, 2019. © 2019 Wiley Periodicals, Inc.

Bone Metastases - Pathophysiology, Diagnostic Testing and Therapy (Part 2). / Knochenmetastasen ­ Pathophysiologie, Diagnostik und Therapie (Teil 2).

The second part of this review deals with the several options for the surgical therapy of bone metastases according to their anatomical site and the patient's individual prognosis. Although metastases to the bone - with few exceptions - are normally given palliative therapy, patients nowadays reach survival times of several months to years, depending on the underlying tumour entity. Scoring systems are suitable to estimate the patient's prognosis and fracture risk. The indication for operation has to be adapted to these parameters. In order to preserve a high quality of life, a limb saving procedure has to be aimed at. The options include the resection of the metastasis with stabilisation, the sole stabilisation of the affected bone, and wide resection with limb reconstruction using a modular tumor endoprosthesis. With today's anaesthesiological peri- and intraoperative care, a vast number of surgical implants and bone augmentations are available. However, what is important is not the practicability of the procedure, but the oncological justification and patient-adapted selection of surgical therapy.

Multiple Myeloma - Current Standards in Surgical Treatment. / Multiples Myelom ­ aktuelle Standards der operativen Therapie.

BACKGROUND: Multiple myeloma is a haematological blood cancer in elderly patients, in which neoplastic cell populations cause osteolytic destruction in the bone skeleton. More than 50% of all patients sustain pathological fractures during the course of their disease. Of all malignant lesions of the spine, multiple myeloma is the most frequent spinal tumour and accounts for approximately 15% of all cases. 8 - 10% of the patients develop neurological deficits. In addition to systemic antineoplastic therapy, surgical treatment is often required in order to reconstruct and stabilise bone defects associated with multiple myeloma, as well as to address tumour-related complications. METHODS: A comprehensive literature search was performed in PubMed using the keywords "multiple myeloma" and "surgery" or "fracture". This served to evaluate the available primary and secondary literature on the current status of the surgical therapy of multiple myeloma. Systematic reviews, meta-analyses and clinical studies and international recommendations for therapy were included - from 1975 until the spring of 2018. DISCUSSION: Stabilising surgery is essential in order to retain and restore function and mobility in bone sections affected by myeloma and for tumour-related osseous defects due to pathological fracture or instability. Absolute and relative indications for surgical treatment are distinguished and are based on the extent and localisation of bone lesions, manifest fractures, accompanying side effects and complications such as neurological deficits and bone pain that is intractable to conservative treatment. The range of options in surgical treatment of myeloma-related bone damage within the upper and lower extremities ranges from hybrid stabilisation procedures combining bone cement and various implants, to conventional and modular tumour prostheses systems. In spinal surgery, minimally invasive procedures such as kyphoplasty or vertebroplasty, as well as selective decompressive operations, dorsal spinal fusion and vertebral replacement are performed in cases of osseous defects and related fractures or instabilities. The surgical treatment and time of operation is determined by the general individual risk profile and prognosis of the patient with multiple myeloma. The surgical approach should have the objective of a final and load stable solution for the patient, which takes into account the frequent long-term course of the disease. Radiotherapy is often recommended after surgery. CONCLUSION: In therapy of multiple myeloma, surgical treatment is often required in order to reduce distress and retain the function and flexibility of myeloma affected bone sections and the mobility and quality of life of the cancer patient. The range of surgical strategies is complex and demanding.

[Bone Metastases - Pathophysiology, Diagnostic Testing and Therapy (Part 1)]. / Knochenmetastasen ­ Pathophysiologie, Diagnostik und Therapie (Teil 1).

In Germany and other European countries, cancer is the second most common cause of death after cardiovascular disease. Although 5-year survival rates for several types of cancer have significantly improved over the last 30 years, metastasis to the bone almost always leads to incurable disease. Aside from the rare primary bone tumours, the treatment of bone metastases now accounts for a major part of tumour orthopaedic workload and requires close interdisciplinary coordination between specialists in oncology, radiology and the discipline of the primary tumour entity. Due to improvements in oncological treatment regimes, long survival times can be achieved. Therefore, the management of so-called "SRE" (skeletal-related events) has gained importance, even in palliative situations. On the basis of a selective literature review, the following article points out the underlying pathophysiological processes of bone metastases and outlines different diagnostic approaches and their relevance in the current clinical setting.

[Multiple Myeloma - Current Status in Diagnostic Testing and Therapy]. / Multiples Myelom ­ aktuelle Standards in Diagnostik und Therapie.

Background Multiple myeloma is a haematological blood cancer of the bone marrow and is classified by the World Health Organisation (WHO) as a plasma cell neoplasm. In multiple myeloma, normal plasma cells transform into malignant myeloma cells and produce large quantities of an abnormal immunoglobulin called monoclonal protein or M protein. This ultimately causes multiple myeloma symptoms such as bone damage or kidney problems. The annual worldwide incidence of multiple myeloma is estimated to be 6 - 7/100,000 and accounts for 1% of all cancer. In Germany, there are about 6,000 cases of newly diagnosed multiple myeloma per annum. In the current era of new agents, such as immunomodulatory drugs and proteasome inhibitors and antibodies, enormous progress has been achieved in the therapy of multiple myeloma. In orthopaedics, it is essential to be able to recognise the of alarming symptoms of multiple myeloma in clinical routine and to be aware of basic diagnostic features to confirm this disease. Surgical treatment of myeloma-related bone lesions - such as stabilisation of pathological fractures - is an important domain of tumour orthopaedic surgery. Methods A comprehensive literature search was performed in PubMed using the keywords "multiple myeloma" and "diagnostic" or "therapy". This served to evaluate the available primary and secondary literature on the current status of the diagnostic testing and therapy of multiple myeloma. Systematic reviews, meta-analyses and clinical studies as well as international recommendations in therapy were included until the spring of 2016. Results There are now very sensitive screening methods for the diagnosis of multiple myeloma. Accurate diagnosis is generally based on several factors, including physical evaluation, patient history, symptoms, and diagnostic testing results. The standards for initial diagnostic tests are determined by blood and urine tests as well as a bone marrow biopsy and skeletal imaging, such as X-rays, CT scans and MRI scans. Major and minor criteria are required to confirm the diagnosis of multiple myeloma and help to determine the classification and staging of multiple myeloma, and whether it is smoldering myeloma (asymptomatic), symptomatic myeloma, or a monoclonal gammopathy of undetermined significance (MGUS). Multiple myeloma treatment options have increased significantly over the last 10 years. Standard of basic myeloma treatment consists of high dose chemotherapy in combination with autologous stem cell transplantation. Several factors may determine multiple myeloma treatment, such as age and general health, results of laboratory and cytogenetic (genomic) tests as well as symptoms and disease complications. After evaluation of these factors, an individual and often multimodal treatment plan is created and implemented in interdisciplinary cooperation. Conventional treatment options have to be evaluated for older patients (> 70 - 75 years), who are not eligible for high dose chemotherapy and autologous stem cell transplantation due to their age and/or severe comorbidities. It is essential to include supportive therapy in the integral treatment concept, in order to control pain or retain function or mobility. Supportive drugs such as bisphosphonates but also radiation therapy and orthopaedic surgery may be required in order to manage complications of the disease as well as side effects of treatment. Conclusion Current studies show promising results in the treatment of multiple myeloma, due to new agents such as immunomodulatory drugs, proteasome inhibitors and antibodies, which may improve prognosis and survival rate among myeloma patients in the future. However treatment algorithms have become more complex and expensive.

Silver-coated endoprosthetic replacement of the proximal humerus in case of tumour-is there an increased risk of periprosthetic infection by using a trevira tube?

BACKGROUND AND OBJECTIVES: The aim of our study was to evaluate if there is an increased risk of periprosthetic infection (PJI) in patients following replacement of the proximal humerus by using a modular tumour prosthesis in combination with a trevira tube. METHODS: Thirty patients were treated by using a modular tumour endoprosthesis (MUTARS®) following intra-articular resection of the proximal humerus. Fifteen patients received treatment by using a trevira tube. In 15 further cases the use of a trevira tube was not necessary. The mean follow-up time was 26 months (range: 24 months to 84 months). Both, Enneking score and range of motion (ROM), was evaluated. Further radiographs were obtained in two planes. RESULTS: The survival rate one year after surgery was 83 % and 63 % after two years. We recorded a 96 % survival of the limb two years after surgery. We also observed only one case of periprosthetic joint infection (PJI) in the entire follow-up period in one patient who received treatment with a trevira tube. The mean Enneking score was 20 points (range 8 to 26 points). ROM was equal in both study groups. In total 20 % of the treated patients (n = 6) suffered complications. CONCLUSIONS: Replacement of the proximal humerus by using a trevira tube in combination with a modular tumour endoprosthesis is a safe and viable treatment option for both, bone tumours and metastases. There is no statistically significant increased risk of infection by using trevira tube even among immunosuppressed patients. LEVEL OF EVIDENCE: Level 3, retrospective comparative study.

Maximizing prediction probability PK as an alternative semiparametric approach to estimate the plasma effect-site equilibration rate constant ke0.

BACKGROUND: The k(e)(0) value is the first order rate constant determining the equilibration of drugs between plasma or end-tidal concentration and effect-site (e.g., brain) concentration. Parametric and semiparametric approaches have been used for estimating individual k(e)(0) values and describing the drug-response curve. In this study, we introduce a new semiparametric approach calculating k(e)(0) values for isoflurane, sevoflurane, and desflurane by maximizing the prediction probability P(K). METHODS: Data from 45 patients scheduled for a radical prostatectomy were analyzed. After lumbar epidural catheterization, patients received remifentanil and propofol solely for induction of anesthesia. Thereafter, epidural analgesia was initiated, and isoflurane, sevoflurane, or desflurane (15 patients each) was added to maintain unconsciousness. At least 45 min later, end-tidal concentrations were varied between 0.5 and 2 minimum alveolar anesthetic concentration. We estimated an individual k(e)(0) value for each patient by optimizing the prediction probability P(K) (P(K)-based k(e)(0)) or by minimizing the area within the hysteresis loop (area-based k(e)(0)). Data are mean +/- sd. RESULTS: Both semiparametric approaches led to comparable k(e)(0) values with 0.18 +/- 0.06 min(-1) (P(K) based) and 0.15 +/- 0.04 min(-1) (area based) for isoflurane and 0.17 +/- 0.08 min(-1) (P(K) based) and 0.16 +/- 0.11 min(-1) (area based) for sevoflurane. k(e)(0) values for desflurane (P(K) based: 0.30 +/- 0.17min(-1); area based: 0.32 +/- 0.25 min(-1)) were significantly higher than for isoflurane and sevoflurane. CONCLUSION: Maximizing the prediction probability P(K) for estimating k(e)(0) seems to be a promising method that researchers could use on an exploratory basis.