Intramedullary nailing without interlocking screws for femoral and tibial shaft fractures

Background

Intramedullary fixation is the treatment of choice for diaphyseal fractures of the femur and tibia. Locking the implant can sometimes be cumbersome and time consuming. In our institution, fractures with axial and rotational stability are treated with intramedullary nailing without interlocking.

Methods

All consecutive patients presented in the University Medical Center Utrecht from October 2003 to August 2009 with acute traumatic diaphyseal fractures of the tibia or femur that were considered axial and rotational stable were included. They underwent internal fixation using intramedullary nails without interlocking. Patient records were evaluated for duration of surgery, perioperative complications, consolidation time and re-operations.

Results

Twenty-nine long bone fractures were treated in 27 patients: 20 men and 7 women, with an average age of 28.9 years (range 15.6–54.4). There were 12 femoral fractures and 17 tibial fractures. Sixteen fractures were closed and 13 were open (10 Gustilo 1, 3 Gustilo 2). The mean operating time was 43 min (range 18–68 min) for tibial fractures and 55 min (range 47–150 min) for femoral fractures. Postoperative complications occurred in six patients. Two patients (three fractures) were lost to follow-up. Healing occurred in 25 of the 26 remaining fractures (96 %) without additional interventions. One tibia was secondarily converted to a standard locked nail because of axial and rotational instability. All patients returned to their pre-injury level of activity.

Conclusion

The use of intramedullary nailing without interlocking is associated with minimal complications in selected fractures. The advantages include a short operating time and the simplicity of its application.     

Histometric analysis of ligature-induced periodontal defects in beagle dogs- evaluation following ligature removalLongitudinal

The aim of the present study was to investigate the sequence of events that takes place in ligature-induced periodontal defects following removal of the ligature.
In eight beagle dogs the dentogingival fibres around six lower premolars (₂P₂, ₃P₃, ₄P₄) were cut to the level of the alveolar bone. Closely adapted copper bands were then cemented around the teeth. After 3 weeks the copper bands were replaced by cotton floss ligatures which were left in place for 11 weeks.
The dogs were sacrificed on different dates so that it was possible to analyse defects 3, 7, 15, or 31 weeks after ligature removal. Contralateral defects one week after ligature removal served as controls. Micrographic color slides of the histological sections were analyzed using a Ferranti-Cetec digitizer.
Mean values for loss of attachment in the 15 and 31 weeks specimens were greater than in the control defects, suggesting that apical positioning of the junctional epithelium was irreversible. However, alveolar bone height tended to increase with experimental time, indicating bone repair. In the 15 and 31 weeks specimens junctional epithelium was occasionally found between the root surface and the alveolar bone
It was concluded that the model does not show all the histological characteristics of naturally occurring periodontitis even in those dogs examined 31 weeks after removal of ligatures.     

Predictability of probing depths in ligature-induced periodontal defects in beagle dogs

The aim of the present study was to evaluate the predictability of a method of creating periodontal defects in dogs. The dentogingival fibres around the lower premolars of 12 beagle dogs were cut to the level of the alveolar bone and closely adapted copper bands were cemented to the teeth. After 3 weeks the copper bands were replaced by cotton ligatures which were left in place for 11 weeks. After this active phase the ligatures were removed, and the defects were allowed to heal for varying periods up to 30 weeks. Probing depths were recorded at different stages of the experiment. Indications for predictability were: 1° the magnitude of the standard deviations of the mean probing depths and 2° the differences between results from contralateral areas. Relatively deep defects were obtained immediately after creation, but the magnitude of the standard deviation of the mean indicated wide variations in probing depths. Following ligature removal probing depths decreased but were of a more uniform depth. These results indicate that variation of probing depths in artificial periodontal defects is rather high immediately after creation but decreases drastically during the healing phase. It was concluded that in young adult beagle dogs predictable periodontal defects, 3.0–3.5 millimeters in depth, can be produced artificially provided that the initial deeper artificially created defects are allowed to heal for at least 3 months.     

Pharmacological manipulation of memory reconsolidation: towards a novel treatment of pathogenic memories

Well-consolidated memories, when retrieved, may return to a transiently fragile state, and need to be consolidated again in order to be maintained. This process has been referred to as memory reconsolidation and presumably serves to modify or strengthen memory traces. In recent years, our understanding of the neurobiological mechanisms underlying this phenomenon has increased rapidly. Here, we will briefly review some of the pharmacological evidence, stressing a crucial role for the brain's major neurotransmitter systems, such as glutamate and noradrenaline, in memory reconsolidation. Pharmacological intervention of reconsolidation processes may have clinical relevance, especially for the treatment of psychiatric disorders that are characterized by pathological memories, including post-traumatic stress disorder and addictive behaviour.     

Double modification of adenovirus fiber with RGD and polylysine motifs improves coxsackievirus-adenovirus receptor-independent gene transfer efficiency

Adenoviral vectors based on serotype 5 (Ad5) have been widely used to deliver therapeutic genes to different organs and tissues. However, many tissues are poorly infected with Ad5 because of low-level expression of its primary receptor, coxsackievirus-adenovirus receptor (CAR). Two motifs, RGD and polylysine (pK7), have been shown to enhance Ad5 infection via CAR-independent pathways when incorporated into fiber separately. Because the two motifs bind to different cell surface proteins (RGD motif binds to integrins, and pK7 binds to heparan sulfate-containing receptors), we hypothesized that the two motifs function additively to improve gene transfer efficiency. In this study, we sought to improve infectivity of Ad5 by incorporating both RGD and pK7 motifs into fiber. We created an Ad5 vector containing an RGD motif in the HI loop and a pK7 motif at the C terminus of fiber (Ad5.RGD.pK7). Compared with unmodified and singly modified Ad5 vectors Ad5.RGD and Ad5.pK7, the doubly modified Ad5 demonstrated the highest infectivity in both CAR-positive and CAR-negative cells. The enhanced infectivity appeared to be mediated by additive effects of the two motifs. More importantly, Ad5.RGD.pK7 lost the natural CAR-dependent pathway while employing novel targeting mechanisms. This strategy thus may be used to overcome CAR deficiency and to achieve vector retargeting.     

The skin in primary immunodeficiency disorders

Primary immunodeficiency disorders comprise serious and rare diseases, predominantly in children. The skin may be involved in a primary immunodeficiency and the cutaneous alterations such as infections, eczematous dermatitis, erythroderma, autoimmune dermatoses and vasculitis may be the basis for the ultimate diagnosis. Dermatologists may realize something is wrong with the immunity of their patient and prompt diagnosis of the defect can lead to lifesaving treatment. Since atypical presentations of well known dermatoses are common in immunodeficiency disorders, histopathology and bacterial, fungal or viral tests of the skin lesions are often indispensable. The knowledge of skin findings in primary immunodeficiency diseases may help dermatologists to play a role in the early detection of these diseases. Key findings constitute specific skin symptoms combined with unusual or severe infections.