Klinische und radiologische Ergebnisse nach bipolarer Radiuskopfprothese

Background

Radial head arthroplasty is considered to be the treatment of choice in non-reconstructable radial head fractures in the acute fracture situation. Despite the promising short-term results in the current literature, replacement of the radial head remains controversially discussed as long-term results are still missing. In our study, we report our 7.8-year results after treatment with the bipolar radial head prosthesis of Judet.

Materials and methods

Between 1997 and 2004, 34 patients were treated with Judet??s bipolar radial head prosthesis in our department. After a mean of 94 months (range 15?C139), 28 of these 34 patients could be re-examined. While 20 patients were treated with radial head arthroplasty primarily in a fracture situation, 7 patients were treated secondarily after failure of fixation. One patient was treated for a tumor of the proximal radius.

Results

According to the Mayo Elbow Performance Score, 16 patients achieved an excellent, 10 patients a good, 1 patient a fair, and 1 patient a poor result. The mean Disabilities of the Arm, Shoulder and Hand Questionnaire (DASH) score was 12.0 (range 0?C50.1). There was no distinct difference between primary and secondary implantation in terms of the clinical outcome. The elbow flexion averaged 125° (range 100?C150°); the mean extension deficit was 20° (range 0?C60°). The mean pronation was 66° (range 0?C90°) with a mean supination of 67° (range 0?C90°). The most common complications were osteoarthritis of the ulnohumeral joint (n=18) and degenerative changes of the humeral capitellum with erosions (n=12). Finally, 3 patients suffered a dislocation after the surgical intervention, 1 patient had an infection, and 1 patient developed a radioulnar synostosis.

Conclusion

Despite major primary complications and the high incidence of radiographic signs of degenerative changes, mainly good clinical results were achieved after 7.8 years with Judet??s bipolar prosthesis.     

Distale Humerusfraktur beim ?lteren Menschen

The intraarticular fracture of the distal humerus in an elderly patient remains a challenge for trauma surgeons. In case of severe co-morbidities and/or osteoporosis stable fixation with screws and plates is difficult and in some cases can be impossible. Even if osteosynthesis is feasible the clinical outcome is still incalculable due to delayed or non-union of the fracture fragments. Endoprosthetic replacement of the elbow joint for comminuted distal humerus fractures has been used for almost 20?years. The clinical results are predominantly excellent or good and better predictable than those of osteosynthesis. There still is no guideline when a prosthesis for the elbow joint should be used. We reviewed the literature and outline the current recommendations for diagnostics and surgical therapy for distal humerus fractures in the elderly.     

Pediatric fractures of the carpal scaphoid: a retrospective clinical and radiological study

A retrospective study was undertaken of 22 carpal scaphoid fracture patients younger than 18 years. Of these, 17 patients received conservative treatment, and 5 received treatment involving screw fixation with or without a bone graft from the iliac crest. Clinical outcomes were evaluated using the Cooney score. Radiographs were analyzed with respect to the site of the fracture, the course of the fracture gap, displacement, and time to union. According to the Cooney score, in 94% of patients, good or excellent results were obtained. A total of 94% of patients considered their result as good or excellent. All fractures healed. Malunion was evident in 1 case.     

Survival trends and predictors of mortality in severe pelvic trauma: estimates from the German Pelvic Trauma Registry Initiative

Study objective

To determine longitudinal trends in mortality, and the contribution of specific injury characteristics and treatment modalities to the risk of a fatal outcome after severe and complex pelvic trauma.

Methods

We studied 5048 patients with pelvic ring fractures enrolled in the German Pelvic Trauma Registry Initiative between 1991 and 1993, 1998 and 2000, and 2004 and 2006. Complete datasets were available for 5014 cases, including 508 complex injuries, defined as unstable fractures with severe peri-pelvic soft tissue and organ laceration. Multivariable mixed-effects logistic regression analysis was employed to evaluate the impact of demographic, injury- and treatment-associated variables on all-cause in-hospital mortality.

Results

All-cause in-hospital mortality declined from 8% (39/466) in 1991 to 5% (33/638) in 2006. Controlling for age, Injury Severity Score, pelvic vessel injury, the need for emergency laparotomy, and application of a pelvic clamp, the odds ratio (OR) per annum was 0.94 (95% confidence interval [CI] 0.91–0.96). However, the risk of death did not decrease significantly in patients with complex injuries (OR 0.98, 95% CI 0.93–1.03). Raw mortality associated with this type of injury was 18% (95% CI 9–32%) in 2006.

Conclusion

In contrast to an overall decline in trauma mortality, complex pelvic ring injuries remain associated with a significant risk of death. Awareness of this potentially life-threatening condition should be increased amongst trauma care professionals, and early management protocols need to be implemented to improve the survival prognosis.     

Biomechanical comparison of bending and torsional properties in retrograde intramedullary nailing of humeral shaft fractures.

OBJECTIVE: To establish whether the bending and torsional stiffness of an implanted nail are influenced by nail design and nail-bolt interface, this study compared two implanted retrograde nail systems: the AO/ASIF unreamed humeral nail (UHN) and the Russell-Taylor (RT) nail. DESIGN: Pair randomization. SETTING: Mechanical laboratory testing. SPECIMENS: Twelve pairs of freshly harvested cadaveric humeri. METHODS: Transverse fractures were simulated with a standardized midshaft osteotomy and a three-millimeter gap. Both nails were proximally and distally interlocked. The RT nail has a single interlock at its base and tip. The UHN has double interlocking both proximally and distally. The screw hole design of the RT nail features slots, whereas the UHN has round screw holes. MAIN OUTCOME MEASURES: Anteroposterior and mediolateral bending stiffness and torsional stiffness. RESULTS: The RT nail showed higher bending stiffness in anteroposterior and mediolateral bending. Large differences were seen in the torsional characteristics: for the first 30 degrees, the RT nail showed a much lower resistance against torsion than the UHN. Analysis of variance of stiffness at four, six, and eight newton-meters showed statistical significance (p < 0.0001). Torsional stiffness, defined as the slope of a straight line approximated to between 75 and 100 percent of the maximum torque, was very similar in both nails. CONCLUSION: The torsional differences between the two nail systems are attributable to the nail-bolt interface of the RT nail. This dynamic system allows a clinically relevant degree of movement. The greater resistance to rotatory forces of the UHN is explained by the fact that the interlocking at its tip and base creates a static rather than a dynamic system.     

Azetabulumfrakturen

Ohne Zusammenfassung     

Repositionstechniken in der Marknagelosteosynthese

Die Unfallchirurgie - Die Marknagelung wurde ursprünglich für die Stabilisierung von Schaftfrakturen der langen Röhrenknochen entwickelt. Neue Nageldesigns und multiple...     

Generation and characterization of a humanized PPARδ mouse model

BACKGROUND AND PURPOSE

Humanized mice for the nuclear receptor peroxisome proliferator-activated receptor δ (PPARδ), termed PPARδ knock-in (PPARδ KI) mice, were generated for the investigation of functional differences between mouse and human PPARδ and as tools for early drug efficacy assessment.

EXPERIMENTAL APPROACH

Human PPARδ function in lipid metabolism was assessed at baseline, after fasting or when challenged with the GW0742 compound in mice fed a chow diet or high-fat diet (HFD).

KEY RESULTS

Analysis of PPARδ mRNA levels revealed a hypomorph expression of human PPARδ in liver, macrophages, small intestine and heart, but not in soleus and quadriceps muscles, white adipose tissue and skin. PPARδ KI mice displayed a small decrease of high-density lipoprotein-cholesterol whereas other lipid parameters were unaltered. Plasma metabolic parameters were similar in wild-type and PPARδ KI mice when fed chow or HFD, and following physiological (fasting) and pharmacological (GW0742 compound) activation of PPARδ. Gene expression profiling in liver, soleus muscle and macrophages showed similar gene patterns regulated by mouse and human PPARδ. The anti-inflammatory potential of human PPARδ was also similar to mouse PPARδ in liver and isolated macrophages.

CONCLUSIONS AND IMPLICATIONS

These data indicate that human PPARδ can compensate for mouse PPARδ in the regulation of lipid metabolism and inflammation. Overall, this novel PPARδ KI mouse model shows full responsiveness to pharmacological challenge and represents a useful tool for the preclinical assessment of PPARδ activators with species-specific activity.