Erythropoietin does not improve fracture healing in aged mice.

Fracture healing in the elderly is associated with a declined healing potential caused by multiple factors including a delay of vascularization. Erythropoietin (EPO) has been demonstrated to improve vascularization and fracture healing in adult mice. We, therefore, hypothesized that EPO in aged mice also improves fracture healing. For this purpose, EPO was given daily in a femoral fracture model in aged mice and compared to vehicle-treated controls using radiological, biomechanical, histomorphometric and Western blot techniques. Blood analyses revealed significantly higher concentrations of hemoglobin and a higher hematocrit in EPO-treated animals at 14 and 35 days after fracture. Micro-computed tomography (µCT) indicated that the fraction of bone volume/tissue volume within the callus did not differ between the two groups. However, µCT showed a 3-fold increased tissue mineral density (TMD) in the callus of EPO-treated animals compared to controls. The callus TMD of the EPO-treated animals was also 2-fold higher when compared to the TMD of the unfractured contralateral femur. Interestingly, biomechanical analyses revealed a reduced bending stiffness in femurs of EPO-treated animals at day 35. The histomorphometrically analyzed callus size and callus composition did not show significant differences between the study groups. However, Western blot analyses exhibited an increased expression of osteoprotegerin (OPG), but in particular of receptor activator of NF-κB ligand (RANKL) in the callus of the EPO-treated animals. Further histological analyses of the callus tissue showed that this was associated with an increased number of newly formed blood vessels and a higher number of tartrate-resistant acid phosphatase (TRAP)+ cells. Conclusion: In fracture healing of aged mice EPO treatment increases callus TMD as well as OPG and RANKL expression, indicating an accelerated bone turnover when compared to controls. However, EPO does not improve fracture healing in aged mice. The process of fracture healing may be altered by EPO due to a deterioration of the microcirculation caused by the worsened rheological properties of the blood and due to an increased bone fragility caused by the accelerated bone turnover. Thus, EPO may not be used to improve fracture healing in the elderly.

[A new continuous gait analysis system for ankle fracture aftercare]. / Ein neues, kontinuierliches Ganganalysesystem zur Nachbehandlung von Sprunggelenkfrakturen.

BACKGROUND: Correct aftercare following lower extremity fractures remains a controversial issue. Reliable, clinically applicable weight-bearing recommendations have not yet been defined. The aim of the current study was to establish a new gait analysis insole during physical therapy aftercare of ankle fractures to test patients' continuous, long-term compliance to partial weight-bearing restrictions and investigate whether patients can estimate their weight-bearing compliance. MATERIALS AND METHODS: The postoperative gait of 14 patients after operative treatment of Weber B-type ankle fractures was monitored continuously for six weeks (OpenGO, Moticon GmbH, Munich). All patients were instructed and trained by physical therapists on how to maintain partial weight-bearing for this time. Discontinuous (three, six and twelve weeks) clinical (patient questionnaire, visual analogue pain score [VAS]) and radiographic controls were performed. RESULTS: Despite the set weight-bearing limits, individual ranges for overall weight-bearing (range 5-107% of the contralateral side) and patient activity (range 0-366 min/day) could be shown. A good correlation between weight-bearing and pain was seen (rs = -0.68; p = <0.0001). Patients significantly underestimated their weight-bearing time over the set limit (2.3 ± 1.4 min/day vs. real: 12.6 ± 5.9 min/day; p < 0.01). CONCLUSIONS: Standardized aftercare protocols and repeated training alone cannot ensure compliance to postoperative partial weight-bearing. Patients unconsciously increased weight-bearing based on their pain level. This study shows that new, individual and possibly technology-assisted weight-bearing regimes are needed. The introduced measuring device is feasible to monitor and steer patient weight-bearing during future studies.

[Saw Injuries to the Hand - Epidemiological Aspects]. / Sägeverletzungen der Hand ­ epidemiologische Aspekte.

Background: No current studies regarding saw injuries have been published in German literature for quite some time. Despite awareness measures and safety instructions, saw accidents along with crush injuries are the most common causes of severe hand injuries. Approximately 12,000 circular saw injuries occur in Germany each year. Since professional providers have increased prices due to the rising energy costs and a wide range of different home appliance saws are available, increasing use has been made of portable circular saws in the do-it-yourself market sector. Patients and methods: At our hospital, we evaluated the data of 51 male patients with saw injuries. The present study investigated factors that may contribute to accidents involving saws. Results: 80 % of the accidents occurred at home, usually on weekends or after work. 51 % of the accidents happened while patients cut firewood. In 84 % of the cases, an electric table saw was used. The majority of severe hand injuries were sustained with lower priced saws. Injuries occurred most frequently between 11 a. m. and 2 p. m., primarily with injuries to bones, tendons, blood vessels and nerves. Replantable amputations or partial amputations occured rarely. In 37 % of the patients, anatomical reconstruction using osteosynthesis and/or microsurgical techniques was performed successfully. Conclusions: Saw injuries to the hand are sustained almost exclusively by men. Serious injuries from low-priced table saws and due to the lack of protective covering are predominant. Preventive measures and mandatory training could reduce the number of saw injuries in the years to come. The results obtained by us largely confirm the data from previous publications.

[Salvage procedure for painful proximalisation of the 1st metacarpal after trapeziectomy using the Mini TightRope®]. / Die Rettungsoperation mittels Mini TightRope® bei schmerzhafter Proximalisierung des 1. Mittelhandknochens nach Trapezektomie.

PURPOSE: This study analyses our results after revision surgery for failed trapezectomy and suspension arthroplasty with painful proximalisation of the 1(st) metacarpal using the Mini TightRope(®). PATIENTS AND METHODS: In a prospective observational study, 5 patients (4 women and 1 man) with an average age of 62 years were treated with the Mini TightRope(®) for revision of a failed Epping arthroplasty with painful proximalisation of the first ray. The mean time between initial surgery and revision was 23.1 (12.5-31.5) months; the mean follow-up was 25±7.7 (12-32) months. The pain level (visual analogue scale - VAS), pinch grip, and qDASH score were evaluated preoperatively and postoperatively. In addition, the Conolly score was used postoperatively. Directly after surgery and at the last follow-up exam, the degree of proximalisation of the first metacarpal was measured radiologically. RESULTS: At the last follow-up, there was significant mean pain relief during everyday stress, from 5.2 preoperatively to 1.6 (p<0.01) postoperatively, and a significant increase in pinch grip, from 0.5 kg to 3 kg (p<0.01). qDASH improved significantly, from 54 to 20 (p<0.001). The Conolly score showed 2 good and 3 fair results. Renewed proximalisation could not be entirely prevented, but was limited to an average of 2 mm. CONCLUSION: Mini TightRope(®) revision surgery after failed trapezectomy and suspension arthroplasty showes good results with significant pain reduction and gain of function. Renewed proximalisation of the first ray cannot be completely avoided.

Obesity does not affect the healing of femur fractures in mice.

Obesity is reported to be both protective and deleterious to bone. Lipotoxicity and inflammation might be responsible for bone loss through inhibition of osteoblasts and activation of osteoclasts. However, little is known whether obesity affects the process of fracture healing. Therefore, we studied the effect of high fat diet-induced (HFD) obesity on callus formation and bone remodelling in a closed femur fracture model in mice. Thirty-one mice were fed a diet containing 60kJ% fat (HFD) for a total of 20 weeks before fracture and during the entire postoperative observation period. Control mice (n=31) received a standard diet containing 10kJ% fat. Healing was analyzed using micro-CT, biomechanical, histomorphometrical, immunohistochemical, serum and protein biochemical analysis at 2 and 4 weeks after fracture. HFD-fed mice showed a higher body weight and increased serum concentrations of leptin and interleukin-6 compared to controls. Within the callus tissue Western blot analyses revealed a higher expression of transcription factor peroxisome proliferator-activated receptor y (PPARy) and a reduced expression of runt-related transcription factor 2 (RUNX2) and bone morphogenetic protein (BMP)-4. However, obesity did not affect the expression of BMP-2 and did not influence the receptor activator of nuclear factor κB (RANK)/RANK ligand/osteoprotegerin (OPG) pathway during fracture healing. Although the bones of HFD-fed animals showed an increased number of adipocytes within the bone marrow, HFD did not increase callus adiposity. In addition, radiological and histomorphometric analysis could also not detect significant differences in bone formation between HFD-fed animals and controls. Accordingly, HFD did not affect bending stiffness after 2 and 4 weeks of healing. These findings indicate that obesity does not affect femur fracture healing in mice.

[Purpura fulminans of the adult--a hematological emergency]. / Purpura fulminans des Erwachsenen--ein hämatologischer Notfall.

HISTORY AND CLINICAL FINDINGS: A 51-year-old female patient with history of longterm drug abuse, was admitted to our hospital with large, stocking-shaped areas of painful, non-displaceable confluent bruising reaching up to the groin. INVESTIGATIONS: The emergency laboratory tests showed leucopenia, thrombocytopenia and anemia as well as a distinct protein C deficiency. DIAGNOSIS, TREATMENT AND COURSE: Purpura fulminans was diagnosed and treated with an initial dose of protein C. The patient survived and the skin necrosis can be treated. CONCLUSION: Purpura fulminans is an internistic and dermatological emergency situation which can lead to shock through consumptive coagulopathy. The serious course of disease can be prevented by rapid treatment with protein C.

[The effects of tobacco smoke on alveolar macrophages - an in vivo mouse lung model for short-term smoking]. / Die Auswirkungen von Tabakrauch auf Alveolarmakrophagen - ein In-vivo-Kurzzeitrauchmodell zur Mauslunge.

BACKGROUND: The effect of cigarette smoke (CS) on the phagocytosis of alveolar macrophages is discussed controversially on the basis of in vitro experiments. In this short report we describe the in vivo observations that we have performed. METHODS: For this purpose mice were exposed to CS for three consecutive days. One day later the fluorescent microspheres were administered intratracheally and the lung surface was investigated using long-distance fluorescence microscopy. RESULTS: We found that the numbers of neutrophils which engulfed particles was increased in the CS group as compared to controls. The overall phagocytic activity was not significantly different after CS exposure. CONCLUSIONS: In conclusion the phagocytosis of alveolar macrophages and neutrophils after short time CS exposure was not affected. Further investigations will need to look for the effects of long-term CS exposure and the phagocytosis of living bacteria.