[Bicycle accidents in the course of time in Münster, Germany : Analysis of changes in bicycle accidents over the past 10 years]. / Münsteraner Fahrradunfälle im Wandel der Zeit : Analyse der Entwicklung der Fahrradunfälle in den letzten 10 Jahren.

BACKGROUND: Bicycles have been a popular means of transport for many years. Especially in times of increased climate discussion, the bicycle has moved further into focus as an environmentally friendly and cost-effective means of transport. Bike lanes and roads are becoming more crowded and new means of transport such as pedelecs or e­scooters are emerging. METHODS: A total of four studies by Münster University Hospital on bicycle accidents and the official accident statistics of the Münster police were compared. In the period from 2009 to 2019, three studies were conducted that considered all bicycle accidents and one study that only considered pedelec riders separately. RESULTS: The age distribution as well as main causes of accidents remained almost the same over the years. The number of pedelec accidents has increased. Pedelec riders have a higher average age and a higher proportion of intensive care stays; however, this cohort also has a high rate of helmet wearers. Overall, the willingness to wear a helmet seems to have increased. CONCLUSION: It should be considered that with increasing bicycle traffic, safety measures must be increased accordingly. In this respect, accident prevention should focus on three major areas, engineering, education and enforcement.

[Paronychia and Felons - Surgical Treatment]. / Infektionen am Fingerendglied.

Infections of the distal phalanx are the most common of all hand infections. There are dorsal localised infections, which develop in the area of the nail and are called paronychia, and palmar infections, which affect the fingertip and are the typical felons. The acute paronychia must be specifically opened depending on the site of infection. This requires precise anatomical knowledge of nail structure. Chronic paronychia usually have other causes and treatment is much more difficult. Felons are often extremely painful. There is a complex system of fibrous septa and swelling is limited. If the septa are destroyed a spread into the bones or the flexor tendon sheath is possible.

[Pyogenic Flexor Tenosynovitis]. / Infektionen der Beugesehnenscheide.

Pyogenic flexor tenosynovitis (PFT) is still the most serious infections of the hand. If the typical cardinal signs of PFT according to Kanavel exist, the indication for surgery should be made immediately. The consequential damage of a delayed surgery with enormous restrictions on the movement of the fingers due to the destruction of the sliding layers and massive adhesions are so serious that conservative therapy attempts are very difficult to justify. The results of Hand therapy after delayed surgery are often disappointing. The rapid surgical intervention and the early opening and relief as well as the irrigation of the tendon sheath can end the disease, the destruction of the sliding layers and the severe pain almost immediately. Quick recognition and quick action are important. With early intervention, normal hand function can often be completely restored.

[Extensor tendon injuries of fingers in the region of the metacarpophalangeal joint (zone V)]. / Strecksehnenverletzungen der Finger im Bereich der Grundgelenke (Zone V).

Due to the exposed situation of the extension side of the metacarpophalangeal joint when the fingers are bent, injuries in this region are not uncommon. The extensor apparatus lies directly below the skin and the various parts can be easily injured. Due to the complex anatomical structure, the different clinical appearances and the various forms of treatment, injuries of the extensor tendons in the region of the metacarpophalangeal joint must be examined in a very differentiated manner. The not uncommonly occurring deviation phenomenon makes all injuries in zone V suspicious and special attention must be paid to them. The alarming multitude of revision surgeries with tenolysis, arthrolysis and restoration of the balance of extensor tendons or centering show that these operations are much more demanding than the way they are appreciated in the literature and by many surgeons (beginner's operation). The article presents the surgical treatment with suture techniques and reconstruction possibilities as well as the aftercare, in addition to the special anatomy and diagnostics.

Development and first biomechanical validation of a score to predict bone implant interface stability based on clinical qCT scans.

Sufficient implant anchoring in osteoporotic bone is one major challenge in trauma and orthopedic surgery. In these cases, preoperative planning of osteosynthesis is becoming increasingly important. This study presents the development and first biomechanical validation of a bone-implant-anchorage score based on clinical routine quantitative computer tomography (qCT) scans. 10 pairs of fresh frozen femora (mean age 77.4 years) underwent clinical qCT scans after placing 3 referential screws (for matching with the second scan). Afterwards, three 4.5 mm cortical screws (DePuy Synthes, Zuchwil, Switzerland) were placed in each distal femur in the dia-metaphyseal transition followed by the second CT scan. The femur was segmented using thresholding and its outer shape was visualized as a surface model. A 3D model of the cortex screw in STL format was used to model the screw surface precisely. For each femur, the 3 cortex screw models were exactly positioned at the locations previously determined using the second CT scan. The BMD value was calculated at the center of each triangle as an interpolation from the measured values at the three vertices (triangle corners) in the CT. Scores are based on the sum of all the triangles' areas multiplied by their BMD values. Four different scores were calculated. A screw pull-out test was performed until loss of resistance. A quadratic model adequately describes the relation between all the scores and pull-out values. The square of the best score explains just fewer than 70% of the total variance of the pull-out values and the standardized residual which were approximately normally distributed. In addition, there was a significant correlation between this score and the peak pull-out force (p < 0.001). The coefficient of determination was 0.82. The presented score has the potential to improve preoperative planning by adding the mechanical to the anatomical dimension when planning screw placement.