Quality of orthodontic care-A multicenter cohort study in Germany : Part 1: Evaluation of effectiveness of orthodontic treatments and predictive factors.

AIMS: Orthodontic care and its effectiveness have increasingly become the focus of political and public attention in the recent past. Therefore, this multicenter cohort study aimed to report about the effectiveness of orthodontic treatments in Germany and to identify potential influencing factors. METHODS: A total of 586 patients from seven German study centers were screened for this cohort study, of which 361 patients were recruited at the end of their orthodontic treatment. Of these, 26 patients had missing study models and/or missing treatment information. Thus, 335 participants were included. The severity of malocclusion was rated using the Peer Assessment Rating (PAR) Index at baseline (T0) retrospectively and-prospectively-after the retention period (T1). Practitioner-, treatment- and patient-related information were analyzed in order to detect potential predictive factors for treatment effectiveness. RESULTS: Study participants (202 female and 133 male) were on average 14.8 (standard deviation [SD] ± 6.1) years old at start of active treatment. Average PAR score at T0 was 25.96 (SD ± 10.75) and mean posttreatment PAR score was 3.67 (SD ± 2.98) at T1. An average decrease of total PAR score by 22.30 points (SD ± 10.73) or 83.54% (SD ± 14.58; p < 0.001) was detected. Furthermore, 164 treatments (49.1%) were categorized as 'greatly improved' but only 3 treatments (0.9%) as 'worse or no different'; 81.5% of all cases finished with a high-quality treatment outcome (≤5 PAR points at T1). Logistic regression analyses detected staff experience as a significant predictive factor for high-quality results (odds ratio 1.27, p = 0.001, 95% confidence interval 1.11-1.46). CONCLUSION: The improvement rate among this selected German cohort indicated an overall very good standard of orthodontic treatment. Staff experience proved to be a predictive factor for high-quality results.

Blood transfusion and venous thromboembolism trends and risk factors in primary and aseptic revision total hip and knee arthroplasties: A nationwide investigation of 736,061 cases.

BACKGROUND: Over the last years, new transfusion guidelines and pharmaceuticals have been introduced in primary and revision total hip and knee arthroplasty (P-THA, P-TKA, R-THA, R-TKA). In the US, a substantial decrease in transfusions has been observed in recent years. Little data exists on the subject in Europe. In this context we aimed to analyze: (1) Is there also a significant decrease in blood transfusion for these procedures in Germany? (2) Which patient and hospital related factors are associated with the risk of blood transfusion? (3) Is there a trend in complications, especially venous thromboembolism and stroke events that can be linked to tranexamic acid use? HYPOTHESIS: There is a significant trend in decreasing blood transfusions in hip and knee arthroplasty. METHODS: Using nationwide healthcare insurance data for inpatient hospital treatment, 736,061 cases treated between January 2011 and December 2017 were included (318,997 P-THAs, 43,780 R-THAs, 338,641 P-TKAs, 34,643 R-TKAs). Multivariable logistic regression was used to model the odds of transfusion as a function of the year of surgery. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated. RESULTS: In each cohort the odds of transfusion decreased over time (2017 vs. 2011 (reference): P-THA: OR 0.42 (95%CI: 0.39-0.45), P-TKA: OR 0.41 (95%CI: 0.37-0.46), R-THA: OR 0.52 (95%CI: 0.47-0.58), R-TKA: OR 0.53 (95%CI: 0.46-0.61). Patient-related risk factors for blood transfusion included older age, female gender, lower Body Mass Index, comorbidities such as renal failure, cardiac arrhythmia, congestive heart failure, valvular disease, coagulopathy, depression, and antithrombotic medication prior to surgery. Venous thromboembolism or stroke events did not increase over the study period. DISCUSSION: The incidence of blood transfusions in primary and revision TKA and THA decreased over the study period. This may be due to new transfusion guidelines and the introduction of novel pharmaceuticals such as tranexamic acid. A further improved patient blood management and a focus on vulnerable patient groups might lead to a further future reduction of transfusions, especially in R-THA. LEVEL OF EVIDENCE: III; comparative observational study.

Low Hospital Volume Increases Re-Revision Rate Following Aseptic Revision Total Knee Arthroplasty: An Analysis of 23,644 Cases.

BACKGROUND: Along with rising numbers of primary total knee arthroplasty (TKA), the number of revision total knee arthroplasties (R-TKAs) has been increasing. R-TKA is a complex procedure requiring special instruments, implants, and surgical skills. Therefore it is likely that hospitals with more R-TKAs have more experience with this type of surgery and therefore fewer complications. The purpose of this study is to evaluate the relationship between hospital volume and re-revision rate following R-TKA. METHODS: Using nationwide healthcare insurance data for inpatient hospital treatment, 23,644 aseptic R-TKAs in 21,573 patients treated between January 2013 and December 2017 were analyzed. Outcomes were 90-day mortality, 1-year re-revision rate, and in-house adverse events. The effect of hospital volumes on outcomes were analyzed by means of multivariate logistic regression. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated. RESULTS: Hospital volume had a significant effect on 1-year re-revision rate (≤12 R-TKA/a: OR 1.44, CI 1.20-1.72; 13-24 R-TKA/a: OR 1.43, CI 1.20-1.71; 25-52 R-TKA/a: OR 1.13, CI 0.94-1.35; ≥53 R-TKA/a: reference). Ninety-day mortality and major in-house adverse events decreased with increasing volume per year, but after risk adjustment this was not statistically significant. CONCLUSION: We found evidence of higher risk for re-revision surgery in hospitals with fewer than 25 R-TKA per year. It might contribute to improved patient care if complex elective procedures like R-TKA which require experience and a specific logistic background were performed in specialized centers.

Evaluation of the value of re-wetting prior to resin infiltration of post-orthodontic caries lesions.

OBJECTIVES: Assessment of the influence of colour changes during the re-wetting process as a possible predictor for the final result after resin infiltration to mask post-orthodontic white spot lesions. MATERIALS AND METHODS: Resin infiltration (ICON; DMG, Hamburg, Germany) was performed according to the manufacturer's recommendation with the exception of repeated, at maximum three etching procedures based on the subjective decision of the dentist during a so called re-wetting process using ethanol. The masking effect by ethanol as well as after resin infiltration was evaluated by digital images taken before, for nine seconds during re-wetting and one week after treatment using CIE L*a*b* colour space. RESULTS: Twenty-nine patients (16 female) with a total of 221 lesions (ICDAS 2) were included (mean age 16 years). Mean time after debonding the orthodontic appliances was ten weeks. Colour changes during re-wetting, evaluated in the first ten patients (71 lesions) showed a significant correlation between the minimum ΔE observed during re-wetting and the final ΔE after resin infiltration (r = 0.65, p < 0.001; Spearman correlation). The main drop in ΔE becomes visible after three seconds when performing the re-wetting process. Regarding the 221 lesions, resin infiltration significantly reduced the colour difference between sound and lesion areas from a baseline ΔE (25th/75th percentiles) of 10.9 (8.2/13.2) to a ΔE of 4 (2.1/5.8) after one week (p < 0.001). The number of etching procedures correlated significantly with baseline ΔE (p < 0.05). CONCLUSIONS: The minimum ΔE observed during the re-wetting process seems to be a useful predictor for the final result of resin infiltration of post-orthodontic caries lesions. More prominent lesions with higher ΔE at baseline seem to require more erosion of the surface layer. In general, a significant and considerable clinical reduction of ΔE could be observed. CLINICAL SIGNIFICANCE: We corroborate that resin infiltration technique is a very useful method to mask caries lesions having developed during treatment with fixed orthodontic appliances. Colour changes while re-wetting the lesions with ethanol seem to be a valuable indicator for the number of required etching procedures.

Potential impact of lingual retainers on oral health: comparison between conventional twistflex retainers and CAD/CAM fabricated nitinol retainers : A clinical in vitro and in vivo investigation.

PURPOSE: To evaluate the impact of a novel computer-fabricated lingual nitinol retainer compared to a conventional lingual flexible spiral wire twistflex retainer on oral health. METHODS: The study was based on a retrospective controlled clinical study with pilot character, an in vitro investigation of material-dependent biofilm formation and an analysis of biofilm formation after intraoral incubation. Sixty-one patients with completed fixed orthodontic treatment and retention phase for at least 6 months with twistflex retainers (group 1, n = 31) or computer-aided design/computer-aided manufacturing (CAD/CAM) nitinol retainers (group 2, n = 30) were included and examined regarding plaque index (PI), gingival index (GI), probing depths, bleeding on probing (BOP) and marginal recessions (MR). Material-dependent biofilm formation of twistflex, untreated nitinol and electropolished nitinol wire samples were assessed (1) in vitro: using optical density (OD) measurement of 10 samples of each and (2) in vivo: using histomorphometric analysis of 18 samples of each. RESULTS: Patients treated with nitinol retainers had significant better oral health indices (PI1 = 1.29 ± 0.06, PI2 = 0.94 ± 0.06; GI1 = 0.71 ± 0.05, GI2 = 0.56 ± 0.04; BOP1 = 0.11 ± 0.01, BOP2 = 0.08 ± 0.01; PD1 = 1.79 ± 0.03 mm, PD2 = 1.59 ± 0.04 mm) except for MR (0.08 ± 0.03 mm versus 0.08 ± 0.02 mm) compared to twistflex retainers. After 24 h intraoral incubation nitinol retainers demonstrated significant less biofilm formation compared to twistflex retainers. In the in vitro investigation the temporary significant differences between the groups were compensated in the end. CONCLUSIONS: Based on the results it can be assumed that nitinol-made CAD/CAM developed lingual retainers have a positive effect on oral health.

Obesity Increases the Risk of Postoperative Complications and Revision Rates Following Primary Total Hip Arthroplasty: An Analysis of 131,576 Total Hip Arthroplasty Cases.

BACKGROUND: The aim of our study is to evaluate the association of body mass index (BMI) and the risk of postoperative complications, mortality, and revision rates following primary total hip arthroplasty given other potentially confounding patient characteristics in a large cohort study. METHODS: Using nationwide billing data for inpatient hospital treatment of the biggest German healthcare insurance, 131,576 total hip arthroplasties in 124,368 patients between January 2012 and December 2014 were included. Outcomes were 90-day mortality, 1-year revision procedures (with and without removal or exchange of implants), 90-day surgical complications, 90-day femoral fractures, and overall complications. The effect of BMI on outcome was analyzed using multivariable logistic regression. Risk-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. RESULTS: BMI had a significant effect on overall complications (30-34 in kg/m2: OR 1.1, CI 1.0-1.2, P = .014; 35-39: OR 1.5, CI 1.3-1.6, P < .001; ≥40: OR 2.1, CI 1.9-2.3, P < .001; <30: reference). The OR for 1-year revision procedures (30-34: OR 1.2, CI 1.1-1.4, P = .001; 35-39: OR 1.6, CI 1.4-1.8, P < .001; ≥40: OR 2.4, CI 2.1-2.7, P < .001; <30: reference) and 90-day surgical complications increased with every BMI category. For mortality and periprosthetic fractures there was a higher risk only for patients with BMI ≥40. CONCLUSION: BMI increases the risk of revision rates in a liner trend. Therefore, the authors believe that patients with a BMI >40 kg/m2 should be sent to obesity medicine physicians in order to decrease the body weight prior elective surgery.

Simulation of three surgical techniques combined with two different bone-borne forces for surgically assisted rapid palatal expansion of the maxillofacial complex: a finite element analysis.

Surgically assisted rapid palatal expansion (SARPE) is a common treatment to correct transverse maxillary deficiencies. Finite element analysis was simulated for six designs of SARPE based on a computed tomography scan of a human skull: median osteotomy with palatal (type A) or alveolar ridge (type B) bone-borne force, additional lateral osteotomy with palatal (type C) or alveolar ridge (type D) bone-borne force, and additional pterygomaxillary separation with palatal (type E) or alveolar ridge (type F) bone-borne force. The transverse expansion was about 1.0mm. The distribution of von Mises stress and the displacement were evaluated. The largest stress distribution was after types A and B, followed by types C and D, and finally types E and F. Displacement increased simultaneously. Palatal bone-borne forces (types A, C, and E) led to higher stress distributions in the midface and maxilla, but to a more parallel expansion compared with alveolar ridge-borne forces (types B, D, and F). The largest bony displacements at the midpalatal suture were anterior in all models. Increased weakening of the bony pillar of the facial skeleton and the use of palatal bone-borne forces leads to a decrease in stress distribution in the midface and to a more parallel transverse expansion of the maxilla.

Maxillary advancement versus mandibular setback in class III dentofacial deformity: are there any differences in aesthetic outcomes?

A retrospective evaluation of maxillary advancement and mandibular setback in class III patients was performed and their aesthetic outcomes compared. Patients with a sella-nasion-A-point angle (SNA) of 80-84° were selected. Pre- and postoperative lateral cephalograms were obtained for 34 class III patients; these were divided into two groups according to the surgical procedure performed: mandibular setback group (n=17) and maxillary advancement group (n=17). The pre- and postoperative cervical length, lip-chin-throat angle, lower/upper lip thickness, distance from the lower/upper lip to the aesthetic line, soft tissue angle, facial contour angle, and nasolabial angle of the two groups were compared. Significant differences were observed for cervical length (P=0.0003) and sex (P=0.003) when comparing maxillary advancement with mandibular setback. Although the preoperative cervical length was similar in the two groups, it increased significantly after maxillary advancement and decreased after mandibular setback. In this study, the differences in aesthetic outcomes depending on the surgical procedure performed were considered. Some aesthetically important parameters proved to be superior after maxillary advancement when compared to mandibular setback, even with the maxilla in the normal position.

Novel lingual retainer created using CAD/CAM technology: evaluation of its positioning accuracy.

OBJECTIVES: Permanent retention is currently the method of choice to stabilize orthodontic treatment results. Frequently, permanent retention schemes are adopted to prevent posttreatment changes in the esthetic zone of the anterior teeth. With increasingly prolonged times of intraoral device use, and retention to be provided in the maxilla despite limited space, the demands placed on well-planned and precise retainer positioning are becoming more exacting. The aim of the present study was to analyze the intraoral precision of lingual retainers made using computer-aided design and machining (CAD/CAM). MATERIALS AND METHODS: A custom manufacturer (Retaintechnology; Cologne, Germany) employing innovative CAD/CAM technology was commissioned to fabricate 16 lingual retainers. Following intraoral insertion using the manufacturer's recommended transfer system, impressions of the intraoral situations were taken and scanned for digitization. On this basis, the intraoral retainer positions were compared to the preceding virtual setups by superimposition with the manufacturer's datasets. Three-dimensional processing software (Geomagic Qualify 2012; Geomagic) was used to analyze the retainers, based on a total of 80 interproximal sites, for deviations from their planned positions along the horizontal (x-), sagittal (y-), and vertical (z-) axes. These deviations of the achieved from the intended positions were considered clinically relevant if ≥ 0.5 mm and, based on this premise, were subjected to a t-test with statistical software (Prism; GraphPad). RESULTS: The intraoral retainer positions were found to correlate closely with the preceding virtual setups (i.e., the positions as they had been planned by the custom manufacturer). Positional deviations were significantly less than 0.5 mm. They were very small in the horizontal and sagittal planes and moderately larger in the vertical plane. CONCLUSION: Highly precise intraoral results may be achieved by transferring three-dimensional virtual setups for lingual retainers to the actual patients. This CAD/CAM strategy of making retainers can offer high predictability even in anatomically demanding regions and in the presence of limited space.

Maxillary expansion therapy with plates featuring a transverse screw: implications of patient compliance with wear-time and screw activation requirements.

OBJECTIVE: The goal of the present work was to determine the influence of screw activation rates and electronically tracked wear times on transverse maxillary expansion with removable orthodontic appliances. METHODS: In all, 28 patients were included in an open prospective observational study covering approximately 6 months of maxillary transverse expansion. In each of these patients, the maxillary plate appliance used for treatment was fitted with a wear-time sensor to document wear time for the duration of the study. Patients were instructed to activate the transverse expansion screw in their plate appliance by 0.2 mm/week. The resultant gap-width increases were monitored with a caliper over three follow-up appointments scheduled at 2-month intervals. RESULTS: Largely linear increases in gap width due to screw activation were only noted within the first 4 months of treatment. The mean increases in gap width fell short of the values that were anticipated after calculations. Longer daily wear times were, on average, associated with larger gap widths. CONCLUSION: Treatment can be objectively monitored by referring to wear-time tracking and by measuring increases in gap width, thus, ensuring that the appliance fits well. In this way, the process can be customized to serve individual needs and to better utilize the full potential of therapy.

Methods to evaluate compliance of patients with removable appliances-survey results.

OBJECTIVES: Are removable appliances still being routinely used in orthodontic offices? Which methods do clinicians use to assess compliance with wear requirements, and how effective are these methods considered to be? SUBJECTS AND METHODS: A questionnaire inquiring about types of treatment, methods of assessing patient compliance with removable appliances, and the perceived effectiveness of these methods was mailed to a sample of 375 members of the German Orthodontic Society ("Deutschen Gesellschaft für Kieferorthopädie", DGKFO). RESULTS: The rate of returned questionnaires was 29%. Almost all respondents (99%) indicated that they used removable appliances and reported having a "relatively high" proportion of patients currently undergoing such treatment. The most widely used methods of compliance assessment were questioning patients and parents (96%) and examining clinical parameters associated with the dentition and the appliance's fit (95-100%). While these parameters were considered "highly effective", questioning the patients and parents was regarded as "less effective" despite its frequent application. CONCLUSION: Removable appliances continue to be a standard method of orthodontic treatment. While patient compliance with wear requirements is mainly assessed via indirect clinical methods, the effectiveness of these parameters remains unclear.

Perthes' or Perthes' resembling disease in 13-month-old boy.

Onset of Perthes' disease is reported frequently from the age of 2 years. Latest publications showed cases with onset of this disease in infancy at ages of 17 and 18 months. We report the case of a 13-month-old boy, who presented with left-sided limping. Radiological examination showed reduced height and fragmentation of the femoral head. Magnetic resonance imaging showed the typical signs of an avascular necrosis. Follow-up was done after 3, 7 and 15 months. Plain radiography showed the femoral head in a state of reparation. This is the youngest documented case of Legg-Calvé-Perthes' disease and is discussed under consideration of the current literature.

Go east: phylogeographies of Mauremys caspica and M. rivulata- discordance of morphology, mitochondrial and nuclear genomic markers and rare hybridization.

In recent years many cases of hybridization and introgression became known for chelonians, requiring a better understanding of their speciation mechanisms. Phylogeographic investigations offer basic data for this challenge. We use the sister species Mauremys caspica and M. rivulata, the most abundant terrapins in the Near and Middle East and South-east Europe, as model. Their phylogeographies provide evidence that speciation of chelonians fits the allopatric speciation model, with both species being in the parapatric phase of speciation, and that intrinsic isolation mechanisms are developed during speciation. Hybridization between M. caspica and M. rivulata is very rare, suggesting that the increasing numbers of hybrids in other species are caused by human impact on environment (breakdown of ecological isolation). Genetic differentiation within M. caspica and M. rivulata resembles the paradigm of southern genetic richness and northern purity of European biota. However, in west Asia this pattern is likely to reflect dispersal and vicariance events older than the Holocene. For M. caspica three distinct Pleistocene refuges are postulated (Central Anatolia, south coast of Caspian Sea, Gulf of Persia). Morphologically defined subspecies within M. caspica are not supported by genetic data. This is one of the few studies available about the phylogeography of west and central Asian species.

Haemorrhagic shock in mice--intracellular signalling and immunomodulation of peritoneal macrophages' LPS response.

Haemorrhagic shock leads to decreased proinflammatory cytokine response which is associated with an increased susceptibility to bacterial infections. In the present study, the effect of GM-CSF on lipopolysaccharide (LPS)-induced TNF-alpha release and MAPkinase activation was analysed on the background of a possible immunostimulating activity of this substance. Male BALB/c mice were bled to a mean arterial blood pressure of 50 mmHg for 45 min followed by resuscitation. Peritoneal macrophages were isolated 20 h after haemorrhage and incubated with 10 ng/ml GM-CSF for 6h before LPS stimulation. TNF-alpha synthesis was studied in the culture supernatants using ELISA. Phosphorylation of ERK, p38MAPK and IkappaBalpha was detected by Western blotting. LPS-induced TNF-alpha production of peritoneal macrophages was significantly decreased 20 h after haemorrhage in comparison to the corresponding cells of sham-operated mice. In parallel the phosphorylation of IkappaBalpha was less in LPS-stimulated peritoneal macrophages from haemorrhagic mice. LPS-induced phosphorylation of ERK1/2 was also decreased in peritoneal macrophages isolated after haemorrhagic shock. In contrast, p38MAPK was phosphorylated more intensely after LPS-stimulation in macrophages collected from shocked mice. GM-CSF incubation elevated LPS-induced TNF-alpha response of macrophages from both sham-operated and shocked mice which was accompanied by an elevated IkappaB and ERK phosphorylation. In general, GM-CSF treatment in vitro enhanced peritoneal macrophages LPS-response both in terms of TNF-alpha synthesis and IkappaB and MAPK signalling, but the levels always stayed lower than those of GM-CSF-treated cells from sham-operated animals. In conclusion, GM-CSF preincubation could partly reactivate the depressed functions of peritoneal macrophages and may therefore exert immunostimulating properties after shock or trauma.

Interpretation of surface EMGs in children with cerebral palsy: An initial study using a fuzzy expert system.

Surface EMG detected simultaneously at different muscles has become an important tool for analysing the gait of children with cerebral palsy (CP), as it offers essential information about muscular coordination. However, the interpretation of surface EMG is a difficult task that assumes extensive knowledge and experience. As such, this noninvasive procedure is not frequently used in the general clinical routine. An Artificial Intelligence (AI) system for interpreting surface EMG signals and the resulting muscular coordination patterns could overcome these limitations. To support such interpretation, an expert system based on fuzzy inference methodology was developed. The knowledge-base of the system implemented 15 rules, from which the fuzzy inference methodology performs a prediction of the effectiveness of the muscular coordination during gait. Our aim was to assess the feasibility and value of such an expert system in clinical applications. Surface EMG signals were recorded from the tibialis anterior, soleus muscle, and gastrocnemius muscles of children with CP to assess muscular coordination patterns of ankle movement during gait. Nineteen children underwent 114 surface EMG measurements. Simultaneously, the gait cycles of each patient were determined using foot switches and videotapes. From the EMG signals, the effectiveness of the ankle movement was predicted by the expert system, and predictions were classified using a three-point ordinal scale. In 91 cases (80%), the clinical findings matched the predictions of the expert system. In 23 cases (20%) the predictions of the expert system differed from the clinical findings with 12 cases revealing worse and 11 cases revealing better results in comparison to the clinical findings. As this study is a first attempt to verify the feasibility and correctness of this expert system, the results are promising. Further study is required to assess the correlation with the kinematic data and to include the whole leg.

Efficacy of topical diclofenac diethylamine gel in osteoarthritis of the knee.

OBJECTIVE: To assess the efficacy and safety of topical diclofenac diethylamine gel, 1.16%, 4 g applied qid for 3 weeks to relieve the symptoms of osteoarthritis (OA) of the knee. METHODS: Patients with OA of the knee washed out their OA medications for at least 5 drug half-lives. Patients with adequately high baseline pain scores were randomized to apply either double-blind active or placebo gel for 3 weeks. Acetaminophen (up to 2 g/day) was supplied as rescue medication. In a diary, patients recorded compliance to dosing and use of rescue medication and assessed daily pain on movement, spontaneous pain, and pain relief. At weekly site visits, patients completed the Western Ontario and McMaster (WOMAC) Osteoarthritis Index Questionnaire, which includes assessment of pain, stiffness, and physical function, and assessed pain intensity "right now." At the final visit, a global assessment of treatment efficacy was completed. RESULTS: Of 238 randomized patients, 237 were included in the intent to treat efficacy analysis. Treatments differed significantly for daily pain on movement at Day 5, and continued on most days through end of study. Peak differences were achieved in the second week. On the primary outcome, average pain on movement over Days 1-14, diclofenac gel was significantly superior to placebo gel. Scores for all 3 WOMAC indices for diclofenac gel treatment were significantly superior to placebo at Weeks 2 and 3. A significant difference was achieved on pain intensity "right now" at all 3 weeks. At the end of the study, patients rated diclofenac gel as significantly more effective in treating the pain of OA of the knee (p = 0.03) compared to placebo. There were no safety issues concerning adverse events or laboratory values. CONCLUSION: Diclofenac gel was effective and safe for relief of symptoms of OA of the knee over 3 weeks of dosing.

Efficacy and safety of a novel moldable, resorbable, and degradable sealant of bone surfaces for hemostasis after bone graft harvesting from the iliac crest.

STUDY DESIGN: A prospective, controlled, open, randomized multicenter study. OBJECTIVE: The study's objective was to demonstrate equivalence of a novel, moldable, resorbable, and degradable synthetic polymer (Bone Seal) compared with a collagen fleece (Lyostypt) in efficacy and safety for topical hemostasis after iliac crest bone graft harvesting. SUMMARY OF BACKGROUND DATA: Harvesting cortico-cancellous bone from the iliac crest is a well established procedure in orthopedic and particularly in spine surgery. It is associated with significant morbidity at the donor site where hematoma formation may cause impaired wound healing and infections in up to 10% of cases. METHODS: A total of 112 patients were included in the safety analysis. Safety was determined by a compound wound healing score and the incidence of adverse clinical effects. One hundred and eight patients were studied for equivalence in efficacy using a compound bleeding score. The handling properties and the application to the bone surface of either device were measured with two additional compound scores. RESULTS: The mean bleeding scores in the final analysis was 4.5 +/- 1.3 for the Bone Seal group and 4.2 +/- 1.3 for the collagen fleece group. Bone Seal was better applicable to the bleeding bone surfaces than the collagen fleece, even though its handling was more complicated. Wound healing and the incidences of adverse clinical events were comparable in either study group. CONCLUSIONS: Bone Seal is an effective and safe hemostatic material for sealing bleeding bone surfaces after iliac crest bone graft harvesting. By virtue of its hemostatic efficacy, Bone Seal is preventive for wound healing disorders.