[Reconstruction of large osteochondral defects of the distal femur and proximal tibia : Adaptation of fresh frozen allografts using 3D-printed models]. / Rekonstruktion großer osteochondraler Defekte des distalen Femurs und der proximalen Tibia : Anpassung frisch gefrorener Allografts unter Zuhilfenahme 3D-gedruckter Kunststoffmodelle.

The reconstruction of large osteochondral defects is still a challenge in musculoskeletal surgery. Fresh frozen allografts are a frequently used resource for the treatment of such tissue defects. Furthermore, 3D-printed models enable multiple options in the preoperative planning and intraoperative adaptation of the allografts, so that healing is optimal and the best functional outcome for the patient is achieved.

[Injuries of the biceps-labrum complex : Principles, pathologies and treatment concepts]. / Verletzungen des Bizeps-Labrum-Komplexes : Grundlagen, Pathologien und Behandlungskonzepte.

BACKGROUND: The biceps-labrum complex is prone to acute lesions and degenerative changes due to its anatomical structure and the high load it has to endure. Pathological changes of these structures are common pain generators and can significantly impair shoulder function. Anatomically, the biceps-labrum complex can be divided into three zones: inside, junction and bicipital tunnel. DIAGNOSTIC PROCEDURE: Despite the focused physical examination and advancements in imaging techniques, the exact localization of pathologies remains challenging. Arthroscopy can be used to accurately diagnose inside and junctional pathologies but extra-articular changes in the region of the bicipital tunnel can only be partially visualized. TREATMENT: In cases of unsuccessful conservative treatment and correct indications, a high level of patient satisfaction can be surgically achieved. In young patients an anatomical reconstruction of inside lesions or tenodesis of the long head of the biceps tendon is performed; however, even tenotomy is a valuable option and can achieve equally satisfactory results. Unaddressed pathological changes of the bicipital tunnel can lead to persistence of pain. In clinical procedures performing tenodesis, both the different techniques and the implants used have been found to show similar results. This article describes the anatomical principles, pathological changes, the focused clinical instrumental diagnostics and discusses the different treatment philosophies as well as the outcome according to the recent literature.

Potential roles of nitrate and live yeast culture in suppressing methane emission and influencing ruminal fermentation, digestibility, and milk production in lactating Jersey cows.

Concern over the carbon footprint of the dairy industry has led to various dietary approaches to mitigate enteric CH4 production. One approach is feeding the electron acceptor NO3-, thus outcompeting methanogens for aqueous H2. We hypothesized that a live yeast culture (LYC; Saccharomyces cerevisiae from Yea-Sacc 1026, Alltech Inc., Nicholasville, KY) would stimulate the complete reduction of NO3- to NH3 by selenomonads, thus decreasing the quantity of CH4 emissions per unit of energy-corrected milk production while decreasing blood methemoglobin concentration resulting from the absorbed intermediate, NO2-. Twelve lactating Jersey cows (8 multiparous and noncannulated; 4 primiparous and ruminally cannulated) were used in a replicated 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments. Cattle were fed diets containing 1.5% NO3- (from calcium ammonium nitrate) or an isonitrogenous control diet (containing additional urea) and given a top-dress of ground corn without or with LYC, with the fourth week used for data collection. Noncannulated cows were spot measured for CH4 emission by mouth using GreenFeed (C-Lock Inc., Rapid City, SD). The main effect of NO3- decreased CH4 by 17% but decreased dry matter intake by 10% (from 19.8 to 17.8 kg/d) such that CH4:dry matter intake numerically decreased by 8% and CH4:milk net energy for lactation production was unaffected by treatment. Milk and milk fat production were not affected, but NO3- decreased milk protein from 758 to 689 g/d. Ruminal pH decreased more sharply after feeding for cows fed diets without NO3-. Acetate:propionate was greater for cows fed NO3-, particularly when combined with LYC (interaction effect). Blood methemoglobin was higher for cattle fed NO3- than for those fed the control diet but was low for both treatments (1.5 vs. 0.5%, respectively; only one measurement exceeded 5%), indicating minimal risk for NO2- accumulation at our feeding level of NO3-. Although neither apparent organic matter nor neutral detergent fiber digestibilities were affected, apparent N digestibility had an interaction for NO3- × LYC such that apparent N digestibility was numerically lowest for diets containing both NO3- and LYC compared with the other 3 diets. Under the conditions of this study, NO3- mitigated ruminal methanogenesis but also depressed dry matter intake and milk protein yield. Based on the fact that few interactions were detected, LYC had a minimal role in attenuating negative cow responses to NO3- supplementation.

Rumen microbial responses to supplemental nitrate. I. Yeast growth and protozoal chemotaxis in vitro as affected by nitrate and nitrite concentrations.

Nitrates have been fed to ruminants, including dairy cows, as an electron sink to mitigate CH4 emissions. In the NO3- reduction process, NO2- can accumulate, which could directly inhibit methanogens and some bacteria. However, little information is available on eukaryotic microbes in the rumen. Protozoa were hypothesized to enhance nitrate reductase but also have more circling swimming behavior, and the yeast Saccharomyces cerevisiae was hypothesized to lessen NO2- accumulation. In the first experiment, a culture of S. cerevisiae strain 1026 was evaluated under 3 growth phases: aerobic, anoxic, or transition to anoxic culture. Each phase was evaluated with a control or 1 of 3 isonitrogenous doses, including NO3-, NO2-, or NH4+ replacing peptone in the medium. Gas head phase, NO3-, or NH4+ did not influence culture growth, but increasing NO2- concentration increasingly inhibited yeast growth. In experiment 2, rumen fluid was harvested and incubated for 3 h in 2 concentrations of NO3-, NO2-, or sodium nitroprusside before assessing chemotaxis of protozoa toward glucose or peptides. Increasing NO2- concentration decreased chemotaxis by isotrichids toward glucose or peptides and decreased chemotaxis by entodiniomorphids but only toward peptides. Live yeast culture was inhibited dose-responsively by NO2- and does not seem to be a viable mechanism to prevent NO2- accumulation in the rumen, whereas a role for protozoal nitrate reductase and NO2- influencing signal transduction requires further research.

Rumen microbial responses to supplemental nitrate. II. Potential interactions with live yeast culture on the prokaryotic community and methanogenesis in continuous culture.

Nitrates have been fed to ruminants, including dairy cows, as an electron sink to mitigate CH4 emissions. In the NO3- reduction process, NO2- can accumulate, which could directly inhibit methanogens and possibly other microbes in the rumen. Saccharomyces cerevisiae yeast was hypothesized to decrease NO2- through direct reduction or indirectly by stimulating the bacterium Selenomonas ruminantium, which is among the ruminal bacteria most well characterized to reduce both NO3- and NO2-. Ruminal fluid was incubated in continuous cultures fed diets without or with NaNO3 (1.5% of diet dry matter; i.e., 1.09% NO3-) and without or with live yeast culture (LYC) fed at a recommended 0.010 g/d (scaled from cattle to fermentor intakes) in a 2 × 2 factorial arrangement of treatments. Treatments with LYC had increased NDF digestibility and acetate:propionate by increasing acetate molar proportion but tended to decrease total VFA production. The main effect of NO3- increased acetate:propionate by increasing acetate molar proportion; NO3- also decreased molar proportions of isobutyrate and butyrate. Both NO3- and LYC shifted bacterial community composition (based on relative sequence abundance of 16S rRNA genes). An interaction occurred such that NO3- decreased valerate molar proportion only when no LYC was added. Nitrate decreased daily CH4 emissions by 29%. However, treatment × time interactions were present for both CH4 and H2 emission from the headspace; CH4 was decreased by the main effect of NO3- until 6 h postfeeding, but NO3- and LYC decreased H2 emission up to 4 h postfeeding. As expected, NO3- decreased methane emissions in continuous cultures; however, contrary to expectations, LYC did not attenuate NO2- accumulation.

[Typical alterations of frozen shoulder in MRI examinations]. / Typische Veränderungen bei der "frozen shoulder" in der bildgebenden MRT-Untersuchung.

Magnetic resonance imaging (MRI) is routinely used for the diagnostic assessment of diseases of the shoulder joint. Depending on the clinical presentation native imaging, intravenous (IV) or intra-articular injection of contrast medium can be performed (MR arthrography). Advances in imaging technology nowadays enable early detection of characteristic changes in the clinical picture of frozen shoulder. These changes typically include thickening of the coracohumeral ligament, the axillary pouch and the capsule at the rotator interval. Furthermore, obliteration of the subcoracoidal fat pad can also be observed. The MRI examinations also show a hyperintensity in the T2-weighted imaging and a contrast enhancement of the joint capsule. The alterations can show a temporal correlation with the clinical symptoms of the patient.

[Torsional malalignment of the humerus]. / Torsionsfehlstellungen am Humerus.

The torsion of the humerus describes the physiological rotation of the humerus around its longitudinal axis. Various clinical and radiological methods for measurement have been described. The computed tomography method is currently the gold standard. The angle between the humeral head axis and the transepicondylar axis is measured. This angle is called retroversion. Values of retroversion vary between 10° and 40°. For the treatment of many humeral pathologies, a precise reconstruction of the anatomical retroversion is required. The retroversion of the humerus has to be considered in shoulder arthroplasty, in fracture situations and also in planning correction of posttraumatic deformities. If an orientation to the original anatomical landmarks of the humerus is no longer possible, an orientation to the contralateral side is recommended.

[Shoulder dislocations in elderly patients]. / Schulterluxationen des älteren Patienten.

In contrast to shoulder dislocations in younger patients, anterior shoulder dislocation in the elderly is often associated with concomitant injuries to the rotator cuff and fractures. There is also frequent involvement of the brachial plexus or peripheral nerves. After closed reduction and a short period of immobilization, physiotherapy should be performed to restore mobility and strength. The evaluation of the rotator cuff is essential for further treatment decisions. The majority of patients are classically treated conservatively. Elderly patients with accompanying rotator cuff lesions and failed conservative therapy can benefit from a surgical intervention. Reconstructive interventions of the rotator cuff should be principally considered; however, some individuals may benefit from a reverse prosthesis in this elderly subgroup of patients. The challenge for the treating surgeon is to exactly define the structural injury of the shoulder (which may include pre-existing lesions) and to select the optimal treatment option.

Switching from a percutaneous to a transcutaneous bone anchored hearing system: the utility of the fascia temporalis superficialis pedicled flap in case of skin intolerance.

OBJECTIVES: To present the option to use a Fascia Temporalis Superficialis pedicled flap for the implantation of a transcutaneous magnetic osseointegrated auditory implant in selected revision procedures. BACKGROUND: Osseointegrated auditory implants represent a reliable option for patients. Skin intolerance and aesthetic issue are two clear limitations of percutaneous system. Magnetic transcutaneous devices have been developed to overcome such drawbacks. The current new experience of such a device shows that they are well tolerated in primary cases. However, switching from a previous percutaneous system raises the question of skin tolerance. Hence, previous implanted abutments with skin penetration and skin reduction are more likely cause to skin intolerance and complication. METHODS: We described here the option to use a Fascia Temporalis Superficialis flap to cover the implanted magnet. CONCLUSION: When switching from percutaneous osseointegrated auditory implant to transcutaneous system in case of high risk of skin intolerance, this procedure may provide sufficient tissue coverage to prevent skin intolerance, pain and delayed extrusion.

Quality of life in bimodal hearing users (unilateral cochlear implants and contralateral hearing aids).

The main objective was to evaluate the bimodal self-rated benefits on auditory performance under real conditions and the quality of life in two groups of cochlear-implanted adults, with or without a contralateral hearing aid. The secondary objective was to investigate correlations between the use of a hearing aid and residual hearing on the non-implanted ear. This retrospective study was realized between 2000 and 2010 in two referral centers. A population of 183 postlingually deaf adults, implanted with a cochlear experience superior to 6 months, was selected. The Speech, Spatial, and other Qualities of Hearing Scale were administered to evaluate the auditory performances, and the Nijmegen Cochlear Implant Questionnaire to evaluate the quality of life. The population was divided into two groups: a group with unilateral cochlear implants (Cochlear Implant-alone, n = 54), and a bimodal group with a cochlear implant and a contralateral hearing aid (n = 62). Both groups were similar in terms of auditory deprivation duration, duration of cochlear implant use, and pure-tone average on the implanted ear. There was a significant difference in terms of pure-tone average on low and low-to-mid frequencies on the non-implanted ear. The scores on both questionnaires showed an improvement in the basic sound perception and quality of social activities for the bimodal group. The results suggest that the bimodal stimulation (cochlear implant and contralateral hearing aid) improved auditory perception in quiet and the quality of life domain of social activities.

[Posttraumatic nonunions and malunions of the proximal humerus. Possibilities and limitations of corrective osteotomy]. / Posttraumatische Fehlstellungen und Pseudarthrosen des proximalen Humerus. Möglichkeiten und Grenzen der Korrekturosteotomie.

BACKGROUND: According to the future demographic trends the incidence of proximal humeral fractures and subsequent posttraumatic malunions and nonunions of the proximal humerus are expected to substantially increase. OBJECTIVES: This article reviews the indications, techniques and outcomes of corrective osteotomy for the treatment of posttraumatic nounions and malunions of the proximal humerus. METHODS: A selective literature search was performed and personal surgical experiences are reported. RESULTS: Malunions of the proximal humerus can occur after both surgical and conservative management of fractures. Due to the complex anatomy of the proximal humerus, malunions have to be systematically assessed regarding epiphyseal and metaphyseal malpositioning. Furthermore, the objective anatomical disorder has to be completely correlated with the subjective patient complaints. The associated soft tissue structures, such as the glenohumeral joint capsule and ligaments, long head of the biceps tendon, rotator cuff and muscles inserting in the metaphysis, can independently cause discomfort to the patient and need to be meticulously identified as such. CONCLUSION: A variety of corrective surgical strategies are available, which are indicated depending on the location and extent of the malunion. The depicted single-cut osteotomy technique represents an elegant therapeutic option for multidimensional deformities of the proximal humerus. Nonunions of the proximal humerus can usually be successfully managed with autologous cancellous bone grafting and locking plate osteosynthesis.

[Posttraumatic arthritis of the glenohumeral joint. Joint-preserving therapy options]. / Posttraumatische Arthrosen des Glenohumeralgelenks. Gelenkerhaltende Therapieoptionen.

BACKGROUND: The management of glenohumeral osteoarthritis in younger patients with high activity levels remains a challenge to orthopedic surgeons. The clinical results of joint replacement surgery are commonly unsatisfactory in this particular cohort with the associated problem of limited longevity of the implant. OBJECTIVES: This paper reviews the indications, techniques and outcomes of joint-preserving arthroscopic surgery for the treatment of osteoarthritis of the shoulder. METHODS: A selective literature search was performed and personal surgical experiences are reported. RESULTS: Besides significant pain reduction, improved range of motion and increased patient satisfaction, arthroscopic surgery can delay the need for total shoulder arthroplasty. A comprehensive approach that addresses all concomitant pathologies of the shoulder joint is of particular importance. Recent studies have shown that a glenohumeral joint space of less than 2 mm predicts significantly poorer results with arthroscopic therapy. CONCLUSION: Arthroscopic procedures are a good option to treat young, active patients with osteoarthritis of the shoulder. Patient selection and setting a consensus for appropriate preoperative expectations are of particular relevance.

[Development of compartment syndrome after intravenous administration of an X-ray contrast medium. Recommendations on acute therapy regimens]. / Kompartmentsyndrom nach paravasaler Applikation von Röntgenkontrastmittel. Empfehlung zum akuten Therapieregime.

The incidence of extravasation of contrast medium is reported in the literature to be between 0.2 % and 0.9 %. A rare consequence of this could be compartment syndrome of the affected limb which requires immediate treatment.We report the case of a patient who developed acute compartment syndrome of the forearm after intravenous injection of radiographic contrast medium in a radiovolar vein during a computed tomography (CT) scan for multiple trauma. The clinical symptoms with pain, loss of range of motion and sensitivity functions, measurement of compartment pressure and radiological images confirmed the diagnosis. After emergency dermatofasciotomy of the forearm the full range of motion and sensitivity functions could be restored.

[Biodegradable screw versus a press-fit bone plug fixation for ACL reconstruction: a prospective randomized study]. / Biodegradierbare Schraube vs. einer Press-fit-Verankerung für VKB-Rekonstruktionen : Eine prospektive randomisierte Studie.

BACKGROUND: Press-fit fixation of a tendon graft has been advocated in order to achieve tendon to bone healing. HYPOTHESIS: Fixation of a tendon graft with a porous bone scaffold limits bone tunnel enlargement compared with a biodegradable interference screw fixation. METHODS: Between 2005 and 2006, 20 patients (17 men, 3 women) were enrolled in this study for primary reconstruction of the ACL. Patients were randomized to either obtain graft fixation in the tibial tunnel by means of an interference screw (I) or a press-fit fixation with a porous bone cylinder (P). Three months after surgery, a CT scan of the knee was performed and tunnel enlargement was analysed in the coronal and sagittal planes for the proximal, middle and distal thirds of the tunnel. After 6 months, 1 and 2 years, International Knee Documentation Committee (IKDC), Tegner and Lysholm scores of both groups were compared. RESULTS: The bone tunnel enlargement was 106.9±10.9% for group P and 121.9±9.0% for group I (P<0.02) in the AP plane and 102.8±15.2% vs 121.5±10.1% in the coronal plane (P<0.01). IKDC, Tegner, and Lysholm scores improved in both groups from pre- to postoperative assessment without significant differences between the two groups. There was a trend to higher knee stability in group P after 3 months (0.6±1.4 mm vs 1.81±.5 mm, P=0.08). CONCLUSIONS: Both interference screw and a press-fit fixation lead to a high number of good or very good outcomes after ACL reconstruction. Tibial press-fit fixation decreases the amount of proximal bone tunnel enlargement. Press-fit fixation decreases the amount of proximal bone tunnel enlargement and improves bone to tendon contact.

[Fractures of the lateral clavicle and acromion]. / Frakturen der lateralen Klavikula und des Akromions.

Fractures of the lateral clavicle and the acromion are uncommon and represent a separate entity. Fractures of the lateral clavicle demonstrate a high rate of problems, such as non-union, malunion and functional impairment when treated nonoperatively. The aim of any treatment option is full restoration of shoulder function by achieving fracture healing without significant malpositioning. Unstable fracture patterns have to be identified and should be fixed using an appropriate technique, which include plating, K-wire fixation and arthroscopic techniques which bring the dislocated fragments into contact. Dislocated fractures of the acromion can usually be treated by plating.

[Is routine implant removal after trauma surgery sensible?]. / Ist eine routinemäßige Implantatentfernung nach unfallchirurgischen Eingriffen sinnvoll?

We present a literature review about implant removal after operative extremity and spine fracture treatment. The indication for implant removal procedures has become less frequent in recent years, but is still more common in Europe than for example in North America. The time required to perform a implant removal can easily exceed the planned amount. Implant removal can result in significant complications like soft tissue damage, fractures, infections, and other problems. Not only because of these problems, the decision on whether or not to remove the implant should be made with great care. Therefore good communication with the patient and thorough information about risks and benefits are essential.

Accuracy of high tibial osteotomy: comparison between open- and closed-wedge technique.

High tibial osteotomy is an established technique for the treatment of varus malaligned knees. This study analyses the difference between the amount of correction in the preoperative planning and the postoperative result. Furthermore, it compares the difference of the accuracy between open-wedge osteotomy and closed-wedge osteotomy. About 61 patients were either treated with open-wedge or closed-wedge high tibial osteotomy. Preoperative planning and postoperative analysis were performed with a special planning software. The influence of operative technique, aetiology, age, number of previous surgeries, amount of correction and accuracy of the correction compared to the preoperative planning were analysed. The overall postoperative mechanical axis differed form preoperative planning by 2.1° ± 1.7°. The accuracy in the open-wedge group (1.7° ± 1.6°) was significantly higher than in the closed-wedge group (2.6° ± 1.8°; P = 0.038). In patients with congenital varus deformity, the accuracy of the correction was significantly higher than in patients with post-traumatic deformity. The authors recommend open-wedge technique in combination with fixed-angle plates for high tibial osteotomy.

The role of preoperative MRI in knee arthroscopy: a retrospective analysis of 2,000 patients.

The aim of this study was to investigate, to what extent routine preoperative MRI scans could set the indications for knee arthroscopies and reduce the number of diagnostic arthroscopies. For this retrospective cohort study, 1,000 patients who had knee arthroscopies documented in 1994/1995 were compared with 1,000 patients that were treated in 2004/2005. The preoperative diagnoses that gave indications for knee arthroscopy were compared with the intraoperative findings. The congruence of preoperative diagnosis with the intraoperative findings was evaluated comparing both study populations. The number of patients who were referred to orthopaedic trauma surgeons with MRI increased from 24% to 56%. A high congruence of preoperative diagnosis and intraoperative findings was found in 49% in 1994/1995 and 55% in 2004/2005. However, regarding the most important outcome parameter, the number of diagnostic arthroscopies, no improvement was found (3% in both periods). The presented data suggests that MRI scans are not routinely necessary as an indication for knee arthroscopy, as clinical examination and plain radiograph are sufficient. However, MRI scans do allow a more detailed characterization of the expected findings and can therefore be helpful in therapy planning.

[Proximal humeral fractures-Where do we stand today? : Comments on the "Proximal fracture of the humerus evaluation by randomization (PROFHER)" study]. / Die proximale Humerusfraktur ­ Wo stehen wir heute? : Ein Kommentar zur "Proximal fracture of the humerus evaluation by randomization (PROFHER)"-Studie.

The PROFHER study is a multicenter randomized controlled trial of 250 out of 1250 patients assessed for eligibility with dislocated proximal humeral fractures with involvement of the surgical neck. These patients were randomized either for surgery or conservative treatment. Patients with comorbidities that precluded surgery, lack of mental capacity, luxation fractures or clear indications for surgery from the authors' perspective were excluded. To evaluate the outcome, standardized self-assessment methods were used (patient reported outcome [PRO]), including the Oxford shoulder score (OSS). The results showed no differences in the primary and secondary self-assessment outcome scores after both 2 and 5 years. Although no significant differences could be detected between both groups, no clear statement could be deduced from the PROFHER study with respect to which patients would benefit from an operative treatment. Nevertheless, the PROFHER study provides a valuable and important addition to the literature on this heavily debated topic. The purpose of this review is to critically evaluate the PROFHER study within the existing literature regarding inclusion of patients, fracture treatment and evaluation of the results.