Search PubMed⌕ Search

Biomedical subjects

C Fink

Publications and source records attributed to C Fink.

At least 55 records · Page 3Linked to original sources

Chronic lateral epicondylitis of the elbow: A prospective study of low-energy shockwave therapy and low-energy shockwave therapy plus manual therapy of the cervical spine.

OBJECTIVE: To compare the effects of extracorporeal shockwave therapy (ESWT) alone with a combination of ESWT and manual therapy of the cervical spine in treating chronic tennis elbow. DESIGN: Prospective, matched single-blind control trial. SETTING: University hospital clinic. PATIENTS: Thirty patients with unilateral chronic tennis elbow, an unsuccessful conservative therapy during the 6 months before referral, and clinical signs of cervical dysfunction (eg, pressure pain at the C4-5 and/or C5-6 level, protraction of the head). INTERVENTIONS: Three times at weekly intervals all patients received 1000 shockwave impulses of an energy flux density of.16mJ/mm(2) at the lateral elbow. Additionally, they underwent manual therapy of the cervical spine and the cervicothoracic junction 10 times (group I). For each patient, a control matched by age (3-yr range) and gender at first conservative treatment was drawn at random from 127 patients who had undergone low-energy shockwave therapy in the same unit in the past 3 years (group II). Follow-up examinations took place at 12 weeks and at 12 months. MAIN OUTCOME MEASURES: The Roles and Maudsley outcome score at 12 months, defining an excellent or good result with no or only occasional discomfort without limitation of activity and range of motion. RESULTS: Neither group differed statistically before the study, with a poor rating for all patients (p >.05). At 12 months, there was still no significant difference, with the outcome being excellent or good in 56% in group I, and in 60% in group II (p >.05). Each group showed significant improvement compared with the respective prestudy evaluation (p <.0001). CONCLUSION: ESWT may be an effective conservative treatment method for unilateral chronic tennis elbow. The efficacy of additional cervical manual therapy for lateral epicondylitis remains questionable.

Adult↗

Tibial tunnel enlargement following anterior cruciate ligament reconstruction with patellar tendon autograft.

PURPOSE: The purpose of this study was to prospectively evaluate changes in the tibial bone tunnel following endoscopic anterior cruciate ligament (ACL) reconstruction with patellar tendon autograft. We used computed tomography (CT) sequentially to monitor the time course of these changes over a 2-year period and correlated the results to clinical outcome and instrumented laxity measurements. TYPE OF STUDY: Case series. METHODS: Thirty-four patients (11 women, 23 men; mean age, 26.4 +/- 4.5 years) who underwent endoscopic patellar tendon ACL reconstruction, were evaluated clinically according to IKDC, Lysholm, and Tegner scores as well as with respect to changes in tibial tunnel morphology over a 2-year period. Subsequent CT scans were performed at 1 and 6 weeks and at 3, 6, 12, and 24 months postoperatively. The tibial bone tunnel was measured in the sagittal and coronal planes at 5 different levels (L1 to L5). RESULTS: The diameters of the tibial tunnel increased an average overall by 30.6% in the sagittal plane and 16.4% in the coronal plane within 2 years. The enlargement was significantly higher (P <.05) in the mid portion of the tunnel (L 2/3: 44.0% and 47.9% in the sagittal and 29.8% and 29.9% in the coronal plane, respectively), which resulted in a uniform cavity-type appearance. The percentage of change in tunnel size was significantly higher (P <.05) within the first 6 weeks following surgery compared with all other time intervals. No correlation between the amount of tunnel enlargement and the clinical results or between tunnel enlargement and KT-1000 measurements could be detected. CONCLUSIONS: Endoscopic ACL reconstruction is associated with tibial tunnel enlargement, which is already present within weeks following surgery. However, no negative effects on the clinical results were found over a 24-month period in our study population.

Adult↗

The effect of dynamic mechanical compression on nitric oxide production in the meniscus.

OBJECTIVE: The menisci play an important role in the biomechanics of the knee, and loss of meniscal function has been associated with progressive degenerative changes of the joint in rheumatoid arthritis as well as in osteoarthritis. However, little is known about the underlying mechanisms that link meniscal injury or degeneration to arthritis. Meniscal fibrochondrocytes respond to environmental mediators such as growth factors and cytokines, but the influence of mechanical stress on their metabolic activity is not well understood. Nitric oxide (NO) is believed to play a role in mechanical signal transduction, and there is also significant evidence of its role in cartilage and meniscus degeneration. The goal of this study was to determine if meniscal fibrochondrocytes respond to mechanical stress by increasing NO production in vitro. DESIGN: Explants of lateral and medial porcine menisci were dynamically compressed in a precisely controlled manner, and NO production, nitric oxide synthase antigen expression and cell viability were measured. The relative responses of the meniscal surface and deep layers to dynamic compression were also investigated separately. RESULTS: Meniscal NO production was significantly (P< 0.01) increased by dynamic compression in both the medial and lateral menisci. Dynamically compressed menisci contained inducible nitric oxide synthase antigen, while uncompressed menisci did not. Significant (P< 0.05) zonal differences were observed in basal and compression-induced NO production. DISCUSSION: Our findings provide direct evidence that dynamic mechanical stress influences the biological activity of meniscal cells. These results suggest that NO production in vivo may be in part regulated by mechanical stress acting upon the menisci. Since NO affects matrix metabolism in various intraarticular tissues, alterations in the distribution and magnitude of stress in the menisci may have important metabolic as well as biomechanical consequences on joint physiology and function.

Animals↗

Long-term outcome of operative or nonoperative treatment of anterior cruciate ligament rupture--is sports activity a determining variable?

The purpose of this study was to evaluate the long-term clinical outcome of operative versus nonoperative treatment of anterior cruciate ligament (ACL) deficiency and to define its relationship with sports activity. Forty-six patients (37 male, 9 female, mean age, 33.6 +/- 8.0 years) who underwent open ACL reconstruction using patellar tendon autograft and 25 patients (18 male, 7 female, mean age, 32.3 +/- 9.9 years) who were treated nonoperatively were evaluated by the same two examiners at 5 - 7 and 10 - 13 years following injury. The evaluations included objective and subjective scoring (Lysholm, OAK, IKDC), instrumented testing (Cybex, KT 1000), radiographic evaluation, and assessments of sports activity, with respect to type, frequency and associated symptoms. According to Lysholm, OAK and IKDC scores, the operative group performed significantly (p < 0.05) better and was able to maintain increased involvement in sports, although both groups participated less over time. However, risks for degenerative joint changes were similar for both the operative and the nonoperative group. A significant (p < 0.05) correlation between participation in high-risk pivoting sports, such as soccer or basketball and osteoarthritic changes could be found for the nonoperative group, only. Sports activity represents an important variable not only affecting the outcome, but also influencing treatment decisions following ACL injuries.

Adult↗

[Prospective study to compare high-resolution computed tomography and magnetic resonance imaging in the detection of pancreatic neoplasms: use of intravenous and oral MR contrast media].

PURPOSE: To compare thin-section hydro-CT and MRI in the detection of pancreatic neoplasms. Evaluation of an oral, superparamagnetic contrast agent (OMP) for pancreatic MRI. MATERIAL AND METHODS: 45 patients with suspected pancreatic neoplasms were examined with consecutive thin-section helical CT (Hydro-CT, 3/6/3, 130 ml Ultravist, Schering) and MRI (1.0 T, breath-holding, T1w-GRE, T1w-GRE fat-sat, T2w-TSE). The MRI protocol included precontrast studies, studies after oral administration of OMP (Abdoscan, Nycomed Amersham) and studies after administration of OMP and Gadodiamide i.v. (Omniscan, Nycomed Amersham). All images were assessed by two independent radiologists in a blinded fashion. Radiologic diagnosis was correlated with histology or clinical follow-up (> or = 3 month). RESULTS: 39 patients could be included in analysis. In 13 cases a pancreatic neoplasm was proven by histology. Thin-section hydro-CT and MRI showed no statistically significant differences for the detection of pancreatic neoplasia. The sensitivity of helical hydro-CT was superior compared to MRI (88.5% vs. 65.44/73.1%/76.9%). The specificity of MRI was superior compared to helical hydro-CT (86.5% vs. 94.2%/90.4%/88.5%). CONCLUSION: Thin-section hydro-CT and MRI show similar results for the detection of pancreatic neoplasms. Compared to thin-section helical CT, MRI still has the drawbacks of much more time consumption and, still, lower spatial resolution. The use of an oral, superparamagnetic contrast agent added no advantage for pancreatic MRI.

Administration, Oral↗

Predictors of left ventricular function after acute myocardial infarction: effects of time to treatment, patency, and body mass index: the GUSTO-I angiographic experience.

BACKGROUND: Despite the significant survival benefit associated with successful reperfusion therapy for acute myocardial infarction, global indices of outcome left ventricular function, such as ejection fraction, have often demonstrated little or no improvement. Although these measurements are confounded by numerous clinical, physiologic, and angiographic variables, no comprehensive analysis of this issue in a large series of patients is available. We used the Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries (GUSTO-I) database to better understand this phenomenon by determining independent predictors of left ventricular function and their interplay with regard to outcome ventricular function and improvement in function during the initial postinfarction week. METHODS: Ninety-minute and 5- to 7-day posttreatment global and regional indices derived from left ventriculograms were analyzed from a population of 676 patients. These observations were combined with clinical data to describe independent determinants of ventricular function outcome. RESULTS: Clinical factors predictive of global and regional ventricular function as well as improvement in function between 90 minutes and 5 to 7 days included time to treatment, early infarct-related artery flow grade, and body mass index. These same factors contribute significantly to compensatory hyperkinesis of the noninfarct zone, which is critical to maintenance of global ventricular function during this time period. CONCLUSIONS: The ventricular function benefits of early complete reperfusion after myocardial infarction are readily demonstrable after adjustment for multiple covariables and include (1) maintenance of global ventricular function and (2) prevention or delay in ventricular dilatation.

Aged↗

The incidence of combined facial and cervical spine injuries.

BACKGROUND: The association between facial and cervical spine injuries has been documented. However, only severe spinal injuries were included in previous analyses. It was the purpose of this study to evaluate the incidence of and risk factors for these injury combinations including the complete injury spectrum. METHODS: Between 1995 and 1997, 4,907 patients with cervical spine injuries were treated at our hospital. One hundred five (2.14%) of these patients had suffered a concomitant facial injury. This group was compared with the group of patients with cervical spine injury but without facial trauma. RESULTS: The majority of cases (98%) consisted of minor lesions to both regions. With increasing severity of cervical spine trauma, the risk for facial injury increased. Age and male gender represent significant (p < 0.05) risk factors for combined injuries. CONCLUSION: Patients sustaining cervical spine trauma have a small but real chance of injuring their face as well. The cervical spine must be examined carefully, whenever facial injuries are present.

Adolescent↗

Experimental preseeding of the STARFlex atrial septal occluder device with autologous cells.

Devices used in interventional cardiology are permanent implants. However, most of the devices fulfill only a temporary function. For example, atrial septal defect (ASD) occluders serve as mechanical shields until complete in- and overgrowth of the occluding device by endogenous tissue from the defect edges has occurred. Thereafter, the foreign body material of the devices is no longer needed and bears potential long-term adverse effects. The concept of "biodegradable" occluder devices that act as transient mechanical shields to close the defects and as scaffolds for overgrowth with autologous tissue is, therefore, tempting. Since rapid and complete ingrowth as well as coverage by firm tissue is a prerequisite for any such "biological" occluder devices, the feasibility and short-term in vivo response to STARFlex devices preceeded with autologous cells was studied in an experimental sheep model. The experiments demonstrated that autologous cell preceeding of cardiovascular implants is technically feasible. Cells survived the mechanical stress of device implantation. A precoating of conventional STARFlex occluders led to an increased cellular density after cell seeding of the device, an increased resistance of the precultured cytolayer against mechanical stress, and a significantly higher poststress viability of "implanted" cells. Experimental closure of ASD using autologous-cell preseeded STARFlex devices was uncomplicated. In the sheep model this led to rapid, complete, and firm ingrowth of the device into the adjacent atrial tissue. A thicker layer of young fibrous granulation tissue in organization was found on the preceeded devices compared with the unseeded control group after 4 weeks in vivo. Currently, an increased thrombogenicity limits in vivo application.

Cell Transplantation↗

A novel approach to temporary stenting: degradable cardiovascular stents produced from corrodible metal-results 6-18 months after implantation into New Zealand white rabbits.

OBJECTIVE: To determine whether corrodible materials may be safely used as biodegradable cardiovascular implants. DESIGN: Corrodible iron stents (> 99.8% iron) were produced from pure iron and laser cut with a stent design similar to a commercially available permanent stent (PUVA-AS16). A total of 16 NOR-I stents were implanted into the native descending aorta of 16 New Zealand white rabbits (mean luminal diameter at the implantation site 3.4 mm, balloon diameter to vessel diameter ratio 1.13). RESULTS: No thromboembolic complications and no adverse events occurred during the follow up of 6-18 months. All stents were patent at repeat angiography after 6 (n = 9), 12 (n = 5), and 18 months (n = 2) with no significant neointimal proliferation, no pronounced inflammatory response, and no systemic toxicity. CONCLUSIONS: This initial in vivo experience suggests that degradable iron stents can be safely implanted without significant obstruction of the stented vessel caused by inflammation, neointimal proliferation, or thrombotic events.

Absorbable Implants↗

Intramedullary screw fixation of Jones fractures.

BACKGROUND: Jones fractures of the fifth metatarsal can be stabilized using intramedullary screw fixation techniques. A range of screw diameters from 4.5 mm to 6.5 mm can be used, but the optimal screw for this procedure has yet to be defined. In clinical practice, we have observed that failure is more likely when smaller diameter screws are used. METHODS: Experimental Jones fractures were created in 23 pairs of human cadaver fifth metatarsals, which were fixed using either 5.0 mm or 6.5 mm screws. Fracture stiffness and pull-out strengths were measured for either screw type and their relationships with bone mineral density and medullary canal diameter were determined. RESULTS: There was no significant difference in the bending stiffness of fractures stabilized with 5.0 mm and 6.5 mm screws; however, different mechanisms of failure were noted for either screw type. Poor thread purchase within the medullary canal was noted with the 5.0 mm screws, while excellent purchase was noted with 6.5 mm screws. Pull-out strength testing revealed significantly higher pullout strengths for the larger 6.5 mm screws. There was no significant difference in bone mineral density or medullary canal diameter between right and left metatarsals. CONCLUSIONS: Fifth metatarsals can often accommodate a 6.5 mm screw for the stabilization of Jones fractures. Larger diameter screws did not result in greater fracture stiffness in our model, but did result in significantly greater pull-out strengths. CLINICAL RELEVANCE: Larger diameter screws may be more appropriate for intramedullary screw fixation of Jones fractures.

Biomechanical Phenomena↗

Long-term results of arthroscopic partial lateral meniscectomy in knees without associated damage.

We evaluated the outcome of partial lateral meniscectomy of 31 knees in 29 patients whose knees were otherwise normal. The mean follow-up was 10.3 years. According to the Lysholm score, 14 knees were rated as excellent, four as good, five as fair and eight as poor, with a mean score of 80.5 points. Radiologically, only one lateral compartment was classified as grade 0, eight as grade 1, nine as grade 2, 11 as grade 3, and two as grade 4 according to Tapper and Hoover. No significant (p < 0.05) correlation was found between the amount of tissue resected and the subjective, clinical and radiological outcome. Although early results of lateral meniscectomy may be satisfactory, we have demonstrated that in the long term there was a high incidence of degenerative changes, a high rate of reoperation (29%) and a relatively low functional outcome score.

Adult↗

Three-dimensional engineered heart tissue from neonatal rat cardiac myocytes.

A technique is presented that allows neonatal rat cardiac myocytes to form spontaneously and coherently beating 3-dimensional engineered heart tissue (EHT) in vitro, either as a plane biconcaval matrix anchored at both sides on Velcro-coated silicone tubes or as a ring. Contractile activity was monitored in standard organ baths or continuously in a CO(2) incubator for up to 18 days (=26 days after casting). Long-term measurements showed an increase in force between days 8 and 18 after casting and stable forces thereafter. At day 10, the twitch amplitude (TA) of electrically paced EHTs (average length x width x thickness, 11 x 6 x 0.4 mm) was 0.51 mN at length of maximal force development (L(max)) and a maximally effective calcium concentration. EHTs showed typical features of neonatal rat heart: a positive force-length and a negative force-frequency relation, high sensitivity to calcium (EC(50) 0.24 mM), modest positive inotropic (increase in TA by 46%) and pronounced positive lusitropic effect of isoprenaline (decrease in twitch duration by 21%). Both effects of isoprenaline were sensitive to the muscarinic receptor agonist carbachol in a pertussis toxin-sensitive manner. Adenovirus-mediated gene transfer of beta-galactosidase into EHTs reached 100% efficiency. In summary, EHTs retain many of the physiological characteristics of rat cardiac tissue and allow efficient gene transfer with subsequent force measurement.

Adenoviridae↗

Transcatheter retrieval and repositioning of an Amplatzer device embolized into the left atrium.

A transcatheter technique is described for stabilization and retrieval of an embolized Amplatzer device, which was inadvertently deployed in the left atrium of a 2-year-old girl with hemodynamically significant atrial septal defect within the fossa ovalis. Since surgery was not available for immediate device retrieval, transcatheter means were chosen to prevent embolization of the device into the mitral valve. After stabilizing the device by creating a guidewire circuit through the wire mesh of the right atrial disk, the Amplatzer device was repositioned through the interatrial defect by snaring the microscrew. No residual shunting and perfect device position was recorded during Doppler echocardiography directly after the procedure as well as 1, 2, and 120 days after the intervention. Cathet. Cardiovasc. Intervent. 51:297-300, 2000.

Cardiac Catheterization↗

[Surgical stabilization of per- and subtrochanteric femoral fractures with the gamma nail].

BACKGROUND: From 1992 through 1997 96 patients with per- or subtrochanteric femur fractures were treated with a Gamma nail. We retrospectively evaluated the influence of patient age, additional diseases, type of fracture, time of operation, type of implant (short/long Gamma nail) and surgical approach (open/closed reduction) on the mobility of the patients, healing of the fractures on radiographs, and possible complications. PATIENTS AND METHODS: The average patient age was 72.5 years (range 27 to 101). There were 27 male and 69 female patients. Surgery was performed 1.19 (0-10) days after injury. At 3, 6, and 12 months after surgery radiographs of the involved hip joint and femur were obtained and the degree of mobility was assessed. RESULTS: Additional diseases, type of fracture, time of operation, type of implant (short/long Gamma nail) and surgical approach (open/closed reduction) did not influence mobility of the patients, healing of the fractures on radiographs or rate of complications. It was more difficult to mobilize older patients (P < 0.001). After 1 year 97% of all fractures had healed on radiographs. In 15 patients (18%) complications occurred due to technical errors using the Gamma nail. DISCUSSION: With the Gamma nail stable osteosynthesis of per- and subtrochanteric femur fractures is obtained independently of the fracture classification. Patients can be mobilized immediately. Technical errors must be avoided.

Adult↗

[Transplant fixation by anterior cruciate ligament reconstruction. Metal vs. bioabsorbable polyglyconate interference screw. A prospective randomized study of 40 patients].

To overcome some of the potential problems (e.g. hardware removal during revision surgery) of metal interference screws used for patellar tendon anterior cruciate ligament reconstruction, bioabsorbable screws have recently been introduced. Forty patients who underwent endoscopic ACL reconstruction using patella tendon autograft were included in the study, they were randomized intraoperatively to either Group A (femoral bone block fixation: polyglyconate screw; tibial: metal screw) or Group B (both bone blocks fixed with metal interference screws). The patients were evaluated clinically preoperatively as well as 6 weeks, 3 months 12 months and 24 months post op. Lysholm Score at 24 months was 98.1 +/- 2.3 for Group A and 97.7 +/- 3.0 for Group B. Tegner Score was 7.4 +/- 1.1 for Group A and 7.5 +/- 0.8 for Group B. Two years post op overall IKDC-Score for group A was 5.6% normal, 88.8% nearly normal and 5.6% abnormal. The result for group B was 11.1%, 77.8% and 11.1%, respectively. KT-1000 (at 89 N) at two years revealed a side to side difference of 1.5 +/- 0.3 mm (Group A) and 1.6 +/- 0.7 (Group B). The results of the two groups did not show significant differences at any stage of follow up. In our study polyglyconate interference screw fixation for patellar tendon grafts has not found to be associated with increased clinical complications. It provided equivalent fixation and clinical results compared to metal screws.

Absorbable Implants↗

[Early postoperative dysfunction of a modified Blalock-Taussig shunt: successful therapy with angioplasty and stent implantation in the subclavian artery].

A newborn with pulmonary atresia with ventricular septal defect and transposition of the great arteries was palliated with a modified Blalock-Taussig shunt at 5 days of age. Three days postoperatively arterial oxygen saturations dropped significantly. Thrombosis of the shunt was suspected. Angiography revealed stenosis of the proximal subclavian artery related to the creation of the shunt. The patient was successfully treated with angioplasty and stent implantation into the stenotic subclavian artery. Follow-up angiography 3 months after stent deployment showed a completely patent subclavian artery and unobstructed blood flow across the modified Blalock-Taussig shunt.

Angiography↗