Monocytes Do Not Transdifferentiate into Proper Osteoblasts

Recent publications suggested that monocytes might be an attractive cell type to transdifferentiate into various cellular phenotypes. Aim was, therefore, to evaluate the potential of blood monocytes to transdifferentiate into osteoblasts. Monocytes isolated from peripheral blood were subjected to two previously published treatments to obtain unique, multipotent cell fractions, named programmable cells of monocytic origin (PCMOs) and monocyte-derived mesenchymal progenitor cells (MOMPs). Subsequently, MOMPs and PCMOs were treated with osteogenic differentiation medium (including either vitamin D or dexamethasone) for 14 days. Regarding a variety of surface markers, no differences between MOMPs, PCMOs, and primary monocytes could be detected. The treatment with osteogenic medium neither resulted in loss of hematopoietic markers nor in adoption of mesenchymal phenotype in all cell types. No significant effect was observed regarding the expression of osteogenic transcription factors, bone-related genes, or production of mineralized matrix. Osteogenic medium resulted in activation of monocytes and appearance of osteoclasts. In conclusion, none of the investigated monocyte cell types showed any transdifferentiation characteristics under the tested circumstances. Based on our data, we rather see an activation and maturation of monocytes towards macrophages and osteoclasts

All-suture anchors for distal biceps tendon repair: a preliminary outcome study

Introduction: The aim of this study was to retrospectively evaluate the clinical outcome of double intramedullary all-suture anchors’ fixation for distal biceps tendon ruptures. Materials and methods: A retrospective case series of patients who underwent primary distal biceps tendon repair with all-suture anchors was conducted. Functional outcome was assessed at a minimum follow-up of at 12 months based on the assessments of the Mayo Elbow Performance Score (MEPS), Andrews–Carson Score (ACS), Quick Disabilities of the Arm, Shoulder, and Hand questionnaire (QuickDASH), and the Visual Analog Scale (VAS) for pain. Maximum isometric strength test for flexion and supination as well as postoperative range of motion (ROM) were determined for both arms. Results: 23 patients treated with all-suture anchors were assessed at follow-up survey (mean age 56.5 ± 11.4 years, 96% male). The follow-up time was 20 months (range Q$_{0.25}$–Q$_{0.75}$, 15–23 months). The following outcome results were obtained: MEPS 100 (range Q$_{0.25}$–Q$_{0.75}$, 100–100); ACS 200 (range Q$_{0.25}$–Q$_{0.75}$, 195–200); QuickDASH 31 (range Q$_{0.25}$–Q$_{0.75}$, 30–31); VAS 0 (range Q$_{0.25}$–Q$_{0.75}$, 0–0). The mean strength compared to the uninjured side was 95.6% (range Q$_{0.25}$–Q$_{0.75}$, 80.9–104%) for flexion and 91.8 ± 11.6% for supination. There was no significant difference in ROM or strength compared to the uninjured side and no complications were observed in any patient. Conclusion: Distal biceps tendon refixation using all-suture anchors provides good-to-excellent results in terms of patient-reported and functional outcome. This repair technique appears to be a viable surgical option, although further long-term results are needed

Quercetin Protects Primary Human Osteoblasts Exposed to Cigarette Smoke through Activation of the Antioxidative Enzymes HO-1 and SOD-1

Smokers frequently suffer from impaired fracture healing often due to poor bone quality and stability. Cigarette smoking harms bone cells and their homeostasis by increased formation of reactive oxygen species (ROS). The aim of this study was to investigate whether Quercetin, a naturally occurring antioxidant, can protect osteoblasts from the toxic effects of smoking. Human osteoblasts exposed to cigarette smoke medium (CSM) rapidly produced ROS and their viability decreased concentration- and time-dependently. Co-, pre- and postincubation with Quercetin dose-dependently improved their viability. Quercetin increased the expression of the anti-oxidative enzymes heme-oxygenase- (HO-) 1 and superoxide-dismutase- (SOD-) 1. Inhibiting HO-1 activity abolished the protective effect of Quercetin. Our results demonstrate that CSM damages human osteoblasts by accumulation of ROS. Quercetin can diminish this damage by scavenging the radicals and by upregulating the expression of HO-1 and SOD-1. Thus, a dietary supplementation with Quercetin could improve bone matter, stability and even fracture healing in smokers

Proximal radius fracture morphology following axial force impact: a biomechanical evaluation of fracture patterns

Abstract Background The most common location for articular fractures of the radial head is often reported to be the anterior lateral aspect of the radial head with the arm in neutral position. However, these findings mainly base on clinical observations rather than precise biomechanical measurements. The purpose of this study was to evaluate the formation of proximal radius fractures, the association between axial forces and fracture morphology, energy to failure and bone stiffness in a biomechanical in-vitro setup. Methods 18 fresh-frozen cadaveric radii performed axial load compression with 10 mm/min loading until bone failure. Energy to failure and bone stiffness were recorded. Proximal radial head fracture morphology and affection of the anterolateral quadrant were optically analyzed. Results All radii survived a compression load of 500 N. The mean compressive forces that lead to failure were 2,56 kN (range 1,30 – 7,32). The mean stiffness was 3,5 kN/mm (range 2,0 – 4,9). 11 radial neck fractures and 7 radial neck and radial head multifragment fractures were documented. The anterolateral quadrant was involved in 78% of tested radii. Conclusion The anterolateral quadrant of the radial head (in neutral position of the forearm) is confirmed to be the most common location for articular radial head fractures in a biomechanical setting. In case of a fall on the outstretched arm radial neck fractures should be securely ruled out due to prior occurrence to radial neck and head fractures

Indication and technique for arthroscopic stabilization of anterior shoulder instability with multidirectional laxity

<jats:title>Abstract</jats:title><jats:p>As concomitant hyperlaxity has been identified as an independent risk factor for failure following anterior shoulder stabilization, the treatment of this special pathology remains challenging. There is a broad consensus that a clear differentiation to multidirectional instability and isolated anteroinferior instability should be ensured to avoid unsatisfactory outcomes. Typical features of this patient collective include positive clinical tests for anteroinferior instability and multidirectional shoulder hyperlaxity, findings of an anterior labral lesion and general capsular redundancy in the radiologic assessment, while tests for posterior instability are negative. Surgical treatment should consist of an anteroinferior capsulolabroplasty with concomitant posteroinferior plication to reduce pathological capsular volume. Although there is a lack of clinical evidence, biomechanical investigations suggest that a four-anchor construct with three anterior anchors and one posteroinferior anchor may be sufficient to restore glenohumeral stability. This surgical approach is presented and discussed in the current article.</jats:p&gt

Traumatische posteriore Luxation als seltene Ursache einer multidirektionalen Schulterinstabilität im Profisport

<jats:title>Zusammenfassung</jats:title><jats:p>Die multidirektionale Instabilität der Schulter als Folge einer traumatischen posterioren Luxation ist selten und in der Literatur nur unzureichend beschrieben. Hier präsentiert wird der Fall eines 28-jährigen Anschiebers aus dem deutschen Bob-Olympia-Kader, der eine weichteilige multidirektionale Instabilität in Folge einer traumatischen posterioren Luxation beim Mountainbiken erlitt. Die Stabilisierung des Schultergelenks erfolgte arthroskopisch mittels kombinierter anteriorer und posteriorer Labrumrefixation.</jats:p&gt

Subpectoral Biceps Tenodesis: All-Suture Anchor Onlay Technique

Surgical management for biceps pathologies has advanced to provide stronger fixation and to be less invasive. The long head of the biceps tendon has been recognized as a common contributor to anterior shoulder pain and is often associated with other glenohumeral pathologies such as SLAP lesions, rotator cuff tears, and subacromial impingement. Both tenotomy and tenodesis have shown to be effective in ameliorating pain associated with the long head of the biceps tendon. However, decreased muscle function and cosmetic concerns are seen at higher rates after tenotomy compared with tenodesis. One option for the treatment of biceps tendon pathology includes mini-open subpectoral biceps tenodesis. Lower reoperation rates are observed after subpectoral biceps tenodesis than after suprapectoral biceps tenodesis, with thoughts that releasing the tendon from its sheath and the bicipital groove relieves the patient of most associated pain. The purpose of this Technical Note is to describe in detail our preferred operative technique for mini-open subpectoral biceps tenodesis using an onlay technique with all-suture anchor fixation

The influence of radio frequency ablation on intra-articular fluid temperature in the ankle joint - a cadaver study

Abstract Background Radio frequency ablation devices have found a widespread application in arthroscopic surgery. However, recent publications report about elevated temperatures, which may cause damage to the capsular tissue and especially to chondrocytes. The purpose of this study was the investigation of the maximum temperatures that occur in the ankle joint with the use of a commercially available radio frequency ablation device. Methods Six formalin-fixed cadaver ankle specimens were used for this study. The radio frequency device was applied for 120 s to remove tissue. Intra-articular temperatures were logged every second for 120 s at a distance of 3, 5 and 10 mm from the tip of the radio frequency device. The irrigation fluid flow was controlled by setting the inflow pressure to 10 mmHg, 25 mmHg, 50 mmHg and 100 mmHg, respectively. The controller unit voltage setting was set to 1, 5 and 9. Results Maximum temperatures exceeding 50 °C/122 °F were observed for all combinations of parameters, except for those with a pressure of 100 mmHg pressure. The main critical variable is the pressure setting, which is highly significant. The controller unit voltage setting showed no effect on the temperature measurements. The highest temperature was 102.7 °C/215.6 °F measured for an irrigation flow of 10 mmHg. The shortest time span to exceed 50 °C/122 °F was 3 s. Conclusion In order to avoid temperatures exceeding 50 °C/122 °F in the use of radio frequency devices in arthroscopic surgeries of the ankle joint, it is recommended to use a high irrigation flow by setting the pressure difference across the ankle joint as high as feasible. Even short intervals of a low irrigation flow may lead to critical temperatures above 50 °C/122 °F. Level of Evidence Level II, diagnostic study