Jörn Zwingmann

Computer-navigated iliosacral screw insertion reduces malposition rate and radiation exposure.

AbstractInsertion of percutaneous iliosacral screws with fluoroscopic guidance is associated with a relatively high screw malposition rate and long radiation exposure. We asked whether radiation exposure was reduced and screw position improved in patients having percutaneous iliosacral screw insertion using computer-assisted navigation compared with patients having conventional fluoroscopic screw placement. We inserted 26 screws in 24 patients using the navigation system and 35 screws in 32 patients using the conventional fluoroscopic technique. Two subgroups were analyzed, one in which only one iliosacral screw was placed and another with additional use of an external fixator. We determined screw positions by computed tomography and compared operation time, radiation exposure, and screw position. We observed no difference in operative times. Radiation exposure was reduced for the patients and operating room personnel with computer assistance. The postoperative computed tomography scan showed better screw position and fewer malpositioned screws in the three-dimensional navigated groups. Computer navigation reduced malposition rate and radiation exposure. Level of Evidence: Level II, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Chondrogenesis of Adipose-Derived Adult Stem Cells in a Poly-Lactide-Co-Glycolide Scaffold

Adult adipose-derived stem cells (ASCs) are considered to be an alternative cell source for cell-based cartilage repair because of their multiple differentiation potentials. This article addresses the chondrogenic differentiation of ASCs seeded into poly-lactide-co-glycolide (PLGA) scaffolds after implantation in a subcutaneous pocket of nude mice. Human ASCs were seeded into PLGA (polylactic acid:polyglycolic acid = 90:10) scaffolds and cultured in transforming growth factor beta 1 (TGF-beta1)-containing medium for 3 weeks in vitro. Then specimens were implanted into a subcutaneous pocket of severe combined immunodeficiency mice and harvested after 8 weeks. Chondrospecific messenger RNA (mRNA) expression was analyzed using reverse transcriptase polymerase chain reaction. Corresponding extracellular matrix (ECM) synthesis was demonstrated using immunohistochemical staining. Chondrospecific marker molecules such as collagen type II and type X, cartilage oligomeric matrix protein, and aggrecan subsequently increased during the 3 weeks period in vitro. After a further 8 weeks, in vivo samples pretreated with TGF-beta1 continued expressing collagen type II and aggrecan mRNA, and collagen type II was found within the ECM using immunohistochemistry. Chondrospecific mRNA was not detected in control samples. ASC-seeded PLGA scaffolds express a stable chondrogenic phenotype in a heterotopic model of cartilage transplantation and represent a suitable tool for tissue engineering of cartilage.

Percutaneous Iliosacral Screw Insertion: Malpositioning and Revision Rate of Screws With Regards to Application Technique (Navigated Vs. Conventional)

BACKGROUND Conventional percutaneous iliosacral screw placement in pelvic surgery is considered to be a highly demanding operative technique with a high rate of screw malpositions, which may be associated with the risk of neurologic damage or inefficient stability. In the conventional technique, the correct entry point for the screw and the small target corridor for the iliosacral screw may be difficult to visualize using an image intensifier. We tried to find out in this study whether the positioning of percutaneous screw implantations could be optimized by evaluating the rate and grade of malpositions and whether the needed revisions could be reduced by using computer navigation and three-dimensional (3D) image intensifier. METHODS A group of 54 patients with 63 screws implanted using computer navigation was compared with 87 patients with 131 screws implanted using the conventional fluoroscopic technique. The exact screw position was controlled in a postoperative computed tomography scan, and the grade of malposition of every screw was investigated and compared. RESULTS A complete intraosseous screw position was found in 42% of cases using the conventional technique and was significantly less compared with 81% using a 3D image intensifier in combination with a navigation system. Moreover, the revision rate of 1.6% was significantly less in the navigated group compared with 19% in the conventional group. CONCLUSIONS The results indicate that 3D-computer navigation of the percutaneous iliosacral screw insertion can facilitate surgical performance in respect to reducing screw malposition and revision rates.

bFGF influences human articular chondrocyte differentiation

BACKGROUND The possible functional role of basic fibroblast growth factor (bFGF) in regulating the mitotic and metabolic activity of primary human articular chondrocytes was investigated. METHODS [EF1]Chondrocytes were enzymatically isolated from femoral head cartilage, and were cultured in vitro in monolayer. bFGF-dependent cell proliferation, production of collagen type II and aggrecan were monitored 10 days after isolation. Furthermore, effect of bFGF on cell cycle, cell morphology, and mRNA expression of integrins and chondrogenic markers determined by real time PCR were analyzed. RESULTS bFGF concentrations in supernatants of primary human articular chondrocytes peaked immediately after isolation and then declined. In a dose-dependent manner, bFGF enhanced cell amplification and viability. BFGF induced a decrease in the apoptotic cell population, while the number of proliferating cells remained unchanged. Supplementation of cell culture with bFGF reduced collagen type II mRNA by 49%, but increased expression of the integrin alpha(2) by 70%. bFGF did not significantly regulate the integrins alpha(1), alpha(5), alpha(10), alpha(v) and type I collagen. bFGF reduced the amount of collagen type II by 53%, which was correlated with diminished mRNA production. Monolayer cultured chondrocytes secreted significant amounts of aggrecan that decreased over time. Secretion of this cartilage-specific marker was further reduced by the addition of bFGF. DISCUSSION These findings highlight the potential role of bFGF as an endogenous chondrocyte mediator that can enhance cell amplification and regulate cell differentiation.

Survival and neurologic outcome after traumatic out-of-hospital cardiopulmonary arrest in a pediatric and adult population: a systematic review

IntroductionThis systematic review is focused on the in-hospital mortality and neurological outcome of survivors after prehospital resuscitation following trauma. Data were analyzed for adults/pediatric patients and for blunt/penetrating trauma.MethodsA systematic review was performed using the data available in Ovid Medline. 476 articles from 1/1964 - 5/2011 were identified by two independent investigators and 47 studies fulfilled the requirements (admission to hospital after prehospital resuscitation following trauma). Neurological outcome was evaluated using the Glasgow outcome scale.Results34 studies/5391 patients with a potentially mixed population (no information was found in most studies if and how many children were included) and 13 paediatric studies/1243 children (age ≤ 18 years) were investigated. The overall mortality was 92.8% (mixed population: 238 survivors, lethality 96.7%; paediatric group: 237 survivors, lethality 86.4% = p < 0.001).Penetrating trauma was found in 19 studies/1891 patients in the mixed population (69 survivors, lethality: 96.4%) and in 3 pediatric studies/91 children (2 survivors lethality 97.8%).44.3% of the survivors in the mixed population and 38.3% in the group of children had a good neurological recovery. A moderate disability could be evaluated in 13.1% in the mixed population and in 12.8% in children. A severe disability was found in 29.5% of the survivors in the mixed patients and in 38.3% in the group of children. A persistent vegetative state was the neurological status in 9.8% in the mixed population and in 10.6% in children.For each year prior to 2010, the estimated log-odds for survival decreased by 0.022 (95%-CI: [0.038;0.006]). When jointly analyzing the studies on adults and children, the proportion of survivors for children is estimated to be 17.8% (95%-CI: [15.1%;20.8%]). The difference of the paediatric compared to the adult proportion is significant (p < 0.001).ConclusionsChildren have a higher chance of survival after resuscitation of an out-of-hospital traumatic cardiac arrest compared to adults but tend to have a poorer neurological outcome at discharge.

Intra- and postoperative complications of navigated and conventional techniques in percutaneous iliosacral screw fixation after pelvic fractures: Results from the German Pelvic Trauma Registry

BACKGROUND Percutaneous iliosacral screw placement following pelvic trauma is a very demanding technique involving a high rate of screw malpositions possibly associated with the risk of neurological damage or inadequate stability. In the conventional technique, the screws correct entry point and the small target corridor for the iliosacral screw may be difficult to visualise using an image intensifier. 2D and 3D navigation techniques may therefore be helpful tools. The aim of this multicentre study was to evaluate the intra- and postoperative complications after percutaneous screw implantation by classifying the fractures using data from a prospective pelvic trauma registry. The a priori hypothesis was that the navigation techniques have lower rates of intraoperative and postoperative complications. METHODS This study is based on data from the prospective pelvic trauma registry introduced by the German Society of Traumatology and the German Section of the AO/ASIF International in 1991. The registry provides data on all patients with pelvic fractures treated between July 2008 and June 2011 at any one of the 23 Level I trauma centres contributing to the registry. RESULTS A total of 2615 patients were identified. Out of these a further analysis was performed in 597 patients suffering injuries of the SI joint (187×with surgical interventions) and 597 patients with sacral fractures (334×with surgical interventions). The rate of intraoperative complications was not significantly different, with 10/114 patients undergoing navigated techniques (8.8%) and 14/239 patients in the conventional group (5.9%) for percutaneous screw implantation (p=0.4242). Postoperative complications were analysed in 30/114 patients in the navigated group (26.3%) and in 70/239 patients (29.3%) in the conventional group (p=0.6542). Patients who underwent no surgery had with 66/197 cases (33.5%) a relatively high rate of complications during their hospital stay. The rate of surgically-treated fractures was higher in the group with more unstable Type-C fractures, but the fracture classification had no significant influence on the rate of complications. DISCUSSION In this prospective multicentre study, the 2D/3D navigation techniques revealed similar results for the rate of intraoperative and postoperative complications compared to the conventional technique. The rate of neurological complications was significantly higher in the navigated group.

Association between expression of the Bone morphogenetic proteins 2 and 7 in the repair of circumscribed cartilage lesions with clinical outcome

BackgroundAlthough there is much known about the role of BMPs in cartilage metabolism reliable data about the in vivo regulation in natural and surgically induced cartilage repair are still missing.MethodsLavage fluids of knee joints of 47 patients were collected during surgical therapy. 5 patients had no cartilage lesion and served as a control group, the other 42 patients with circumscribed cartilage defects were treated by microfracturing (19) or by an Autologous Chondrocyte Implantation (23). The concentrations of BMP-2 and BMP-7 were determined by ELISA. The clinical status was evaluated using the IKDC Score prior to and 1 year following the operation.ResultsHigh level expression in the control group was found for BMP-2, concentrations of BMP-7 remained below detection levels. No statistical differences could be detected in concentrations of BMP-2 or BMP-7 in the lavage fluids of knees with cartilage lesions compared to the control group. Levels of BMP-7 did not change after surgical cartilage repair, whereas concentrations of BMP-2 statistically significant increased after the intervention (p < 0.001). The clinical outcome following cartilage regenerating surgery increased after 1 year by 29% (p < 0.001). The difference of the IKDC score after 1 year and prior to the operation was used to quantify the degree of improvement following surgery. This difference statistically significant correlated with initial BMP-2 (R = 0.554, p < 0.001) but not BMP-7 (R = 0.031, n.s.) levels in the knee joints.ConclusionsBMP-2 seems to play an important role in surgically induced cartilage repair; synovial expression correlates with the clinical outcome.

Influence of Arm Positioning on Radiation Dose for Whole Body Computed Tomography in Trauma Patients

BACKGROUND Multislice whole body computed tomography is regarded as the method of choice for primary investigation of hemodynamically stable patients with multiple injuries. However, a disadvantage of this method is the high level of radiation to which the patient is exposed. Various recommendations on how to position the patients arms during whole body computed tomography have been given in the literature, but conclusive data are missing. Therefore, the aim of our study was to investigate the relationship between different arm positions and radiation dose in patients undergoing whole body computed tomography. METHODS In a retrospective analysis of available data derived from former whole body computed tomography screening of patients with multiple injuries, we calculated the effective radiation dose and scanning time for different arm positions (both arms up, both arms at sides, right arm up, and left arm up). Statistical analysis was performed using the independent t test with 95% confidence intervals. Statistical significance was set at 0.05. RESULTS The data evaluated had been recorded for 956 patients during a period of 18 months. Of these patients, 710 were included in the study. In 487 cases (68%), both arms were up; in 82 cases (12%), down by the sides; in 90 cases (13%), the right arm was up; and in 44 cases (6%), the left arm was up. Overall, the radiation dose was statistically significantly higher with both arms at sides (24.69 mSv ± 6.91 mSv) than with both arms up (19.18 mSv ± 4.99 mSv; p < 0.0000001). Statistically significant differences in effective radiation dose were not found for either the right arm up (23.52 mSv ± 5.23 mSv; p = 0.211) or the left arm up (22.53 mSv ± 5.4 mSv; p = 0.076) compared with both arms down at sides. Comparison of scan lengths for the thorax or abdomen did not yield any significant differences between arms down and any other arm position. Analysis of scanning times did not reveal any significant differences for whole body computed tomography with both arms down (07:31 minutes ± 02:53 minutes) compared with both arms up (07:30 minutes ± 02:04 minutes; p = 0.94), right arm up (07:15 minutes ± 01:43 minutes; p = 0.582), or left arm up (07:18 minutes ± 01:24 minutes; p = 0.707). CONCLUSION Based on our retrospective investigation, it can be recommended with reference to whole body computed tomography screening that the arms should be in the arms-up position during thorax or abdomen scanning of a severely injured patient, provided there are no clear clinical indications of shoulder injury. For the patient, this position is associated with a significantly reduced radiation dose without noticeable loss of time.

Stimulation of chondrocytes in vitro by gene transfer with plasmids coding for epidermal growth factor (hEGF) and basic fibroblast growth factor (bFGF)

Human epidermal growth factor (hEGF) and basic fibroblast growth factor (bFGF) influence critical characteristics of chondrocytes. The effects on metabolism and differentiation were evaluated following transfection using specific plasmids coding for both cytokines. Chondrocytes were isolated from femoral head cartilage of patients undergoing a hip arthroplasty for femoral neck fracture. Following collagenase-digestion, cells were cultured in monolayers, and cell proliferation, glucosaminoglycan-production and collagen type II expression were monitored 10 days after isolation. Addition of recombinant hEGF and bFGF resulted in a significant increase in cell proliferation and glucosaminoglycan production. Chondrocytes were transfected with vectors coding for either hEGF or bFGF and the production of these proteins was measured in supernatants by ELISA. Expression kinetics showed different patterns: hEGF was detectable 2.5 days following transfection and peaked at day 5.5, whereas bFGF-production reached its maximum 1.5 days after transfection, declining thereafter. Chondrocytes endogenously produced significant amounts of bFGF within 5 days following isolation. Proliferation of hEGF-transfected cells increased up to 81%; bFGF-transfection caused an increase up to 76%. Similarly, glucosaminoglycan-production was enhanced up to 120% by hEGF-transfection and 37% by bFGF transfection, respectively. Collagen type II production decreased following transfection with both plasmids. Temporary in vitro gene transfer of the growth factors hEGF and bFGF provides a method to stimulate chondrocyte proliferation and induces signs of dedifferentiation, which would limit a reasonable clinical application.

Lower Health-Related Quality of Life in Polytrauma Patients: Long-Term Follow-Up After Over 5 Years

AbstractAlthough trauma-associated mortality has fallen in recent decades, and medical care has continued to improve in many fields, the quality of life after experiencing polytrauma has attracted little attention in the literature. This group of patients suffer from persisting physical disabilities. Moreover, they experience long-term social, emotional, and psychological effects that limit/lower considerably their quality of life.We analyzed retrospective data on 147 polytraumatized patients by administering written questionnaires and conducting face-to-face interviews 6 ± 0.8 years after the trauma in consideration of the following validated scores: Glasgow Outcome Scale, European Quality of Life Score, Short Form-36, Trauma Outcome Profile, and Beck Depressions Inventory II.Our analysis of these results reveals that polytraumatized patients suffer from persistent pain and functional disabilities after >5 years. We also observed changes in their socioeconomic situation, as well as psychological after-effects.The rehabilitation of this particular group of patients should not only address their physical disabilities. The psychological after-effects of trauma must be acknowledged and addressed for an even longer period of time.