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1.
Eye (Lond) ; 35(10): 2834-2839, 2021 10.
Article in English | MEDLINE | ID: mdl-33257804

ABSTRACT

PURPOSE: The purpose of this study is to investigate potential factors predicting complete recovery of visual acuity following surgery for macula off retinal detachment (RD). PATIENTS AND METHODS: Retrospective review of patients operated for macula-off RD at Jules-Gonin Eye Hospital between January 2015 and December 2016. The study included patients with visual acuity recovery of 0 LogMAR. A control group of 83 patients with comparable baseline characteristics but partial recovery of visual acuity after vitrectomy for macula-off RD was used for statistical comparison analysis. RESULTS: Seventy-four patients, 46 males (62%) and 28 females (38%), were included. Mean age was 65 years (standard deviation: 12). Median follow-up was 6 months (interquartile range: 3). Fifty patients (68%) were pseudophakic. Median pre-op best-corrected visual acuity (BCVA) was 2 LogMAR (interquartile range: 1.22). Forty-three of the patients (58%) had preoperative BCVA equivalent of count fingers or less. The majority of the patients (91%) had up to 3-day duration of macular detachment (MD) before surgery. In comparison only 18% of the group of patients with partial recovery of visual acuity after vitrectomy for macula-off RD had been operated within 3 days of MD (p < 0.0001). In 63% of the 40 cases in whom an optical coherence tomography (OCT) of the fovea could be interpreted, OCT image showed a retained foveal depression of the detached retina, whereas only 35% of the 46 control eyes with adequate OCT imaging showed a retained foveal depression (p = 0.01). CONCLUSIONS: In our study, patients had significantly better chances of complete visual acuity recovery when operated within 3 days of MD in comparison to more delayed surgery. Additionally, preservation of the foveal depression of the detached retina appeared to be a common characteristic among patients demonstrating complete visual recovery.


Subject(s)
Macula Lutea , Retinal Detachment , Aged , Female , Humans , Macula Lutea/diagnostic imaging , Male , Retinal Detachment/surgery , Retrospective Studies , Tomography, Optical Coherence , Visual Acuity , Vitrectomy
2.
Scand J Med Sci Sports ; 28(1): 4-15, 2018 Jan.
Article in English | MEDLINE | ID: mdl-28449312

ABSTRACT

Chronic painful Achilles tendinopathy (AT) is a common disorder among athletes. Sclerotherapy (ST) and prolotherapy (PT) are two promising options among the numerous other conservative therapies. As their efficacy and potential adverse effects (AE) are still unclear, we systematically searched, analyzed, and synthesized the available literature on ST and PT for treating AT. Electronic databases, Google Scholar and articles' reference lists were searched according to PRISMA guidelines. Eligibility criteria were set up according to the PICOS-scheme including human and animal studies. Three authors independently reviewed the results and evaluated methodological quality (Coleman Methodology Score and Cochrane Risk of Bias Assessment). The initial search yielded 1104 entries. After screening, 18 articles were available for qualitative synthesis, six of which were subjected to meta-analysis. The mean Coleman Score of the 13 human studies was 50. Four RCTs were ranked as having a low risk of selection bias. Three of those reported a statistically significant drop in the visual analog scale (VAS) score, one a significant increase in the VISA-A Score. 12 of 13 human studies reported positive results in achieving pain relief and patient satisfaction, whereas only one study's finding differed. Meta-analysis revealed an unambiguous result in favor of the intervention (weighted mean difference D=-4.67 cm, 95% CI -5.56 to -3.76 cm [P<.001]). Only one serious AE and two minor AEs were reported in the entire literature. This systematic review suggests that ST and PT may be effective treatment options for AT and that they can be considered safe. Long-term studies and RCTs are still needed to support their recommendation.


Subject(s)
Achilles Tendon/physiopathology , Prolotherapy , Sclerotherapy , Tendinopathy/therapy , Animals , Humans , Pain Management
3.
BMC Musculoskelet Disord ; 18(1): 344, 2017 Aug 08.
Article in English | MEDLINE | ID: mdl-28789628

ABSTRACT

BACKGROUND: The prevalence of patellar tendinopathy is elevated in elite soccer compared to less explosive sports. While the burden of training hours and load is comparably high in youth elite players (age < 23 years), little is known about the prevalence of patellar tendinopathy at this age. There is only little data available on the influence of age, the amount of training, the position on the field, as well as muscular strength, range of motion, or sonographical findings in this age group. The purpose of the present study was to examine the above-mentioned parameters in all age groups of a German youth elite soccer academy. METHODS: One hundred nineteen male youth soccer players (age 15,97 ± 2,24 years, height 174, 60 ± 10,16 cm, BMI 21, 24 ± 2,65) of the U-13 to U-23 teams were part of the study. Data acquisition included sport specific parameters such as footwear, amount of training hours, leg dominance, history of tendon pathologies, and clinical examination for palpatory pain, indurations, muscular circumference, and range of motion. Subjective complaints were measured with the Victorian Institute of Sport Assessment Patellar (VISA-P) Score. Furthermore, sonographical examinations (Aplio SSA-770A/80; Toshiba, Tokyo, Japan) with 12-MHz multifrequency linear transducers (8-14 MHz) of both patellar tendons were performed with special emphasis on hyper- and hypo echogenic areas, diameter and neovascularization. RESULTS: The prevalence of patellar tendinopathies was 13.4%. Seventy-five percent of the players complained of pain of their dominant leg with onset of pain at training in 87.5%. The injured players showed a medium amount of 10.34 ± 3.85 training hours and a medium duration of symptoms of 11.94 ± 18.75 weeks. Two thirds of players with patellar tendinopathy were at the age of 15-17 (Odds ratio 1.89) while no differences between players of the national or regional league were observed. In case of patellar tendinopathy, VISA-P was significantly lower in comparison to healthy players (mean ± SD 76.80 ± 28.56 points vs. 95.85 ± 10.37). The clinical examination revealed local pain at the distal patella, pain at stretching, and thickening of the patellar tendon (p = 0.02). The mean tendon diameter measured 2 cm distally to the patella was 4.10 ± 0.68 mm with a significantly increased diameter of 0.15 mm in case of an underlying tendinopathy (p = 0.00). The incidence of hypo-echogenic areas and neovascularizations was significantly elevated in players with patellar tendon syndrome (PTS) (p = 0.05). CONCLUSION: The prevalence of patellar tendinopathy in youth elite soccer is relatively high in comparison to available data of adult players. Especially players at the age of 15 to 17 are at considerable risk. Tendon thickening, hypo-echogenic areas, and neovascularization are more common in tendons affected by PTS.


Subject(s)
Patellar Ligament/diagnostic imaging , Patellar Ligament/injuries , Soccer/injuries , Tendinopathy/diagnostic imaging , Ultrasonography, Doppler , Adolescent , Case-Control Studies , Germany/epidemiology , Humans , Male , Tendinopathy/epidemiology , Ultrasonography, Doppler/methods
4.
Am J Surg ; 214(5): 945-955, 2017 Nov.
Article in English | MEDLINE | ID: mdl-28683896

ABSTRACT

BACKGROUND: Improved resection techniques has decreased mortality rate following liver resections(LRx). Sealants are known as effective adjuncts for haemostasis after LRx. We compared biliostatic effectiveness of two sealants in a standardized porcine model of LRx. MATERIAL AND METHODS: We accomplished left hemihepatectomy on 27 pigs. The animals were randomized in control group(n = 9) with no sealant and treatment groups (each n = 9), in which resection surfaces were covered with TachoSil® and TissuFleece®/Tissucol Duo®. After 5 days the volume of ascites(ml), bilioma and/or bile leakages and degree of intra-abdominal adhesions were analysed. RESULTS: Proportion of ascites was lower in TissuFleece/Tissucol Duo® group. The ascites volume was lower in TachoSil® group. In sealant groups, increased adhesion specially in the TachoSil® group was seen. A reduction of the "bilioma rate" was seen in sealant groups, which was significantly lower in TissuFleece®/Tissucol Duo® group. CONCLUSION: In a standardized condition sealants have a good biliostatic effect but with heterogeneous potentials. This property in combination with the cost-benefit analysis should be the focus of future prospective studies.


Subject(s)
Bile , Collagen/therapeutic use , Fibrin Tissue Adhesive/therapeutic use , Fibrinogen/therapeutic use , Hepatectomy , Postoperative Complications/prevention & control , Surgical Sponges , Thrombin/therapeutic use , Animals , Drug Combinations , Materials Testing , Models, Animal , Random Allocation , Swine
5.
BMC Musculoskelet Disord ; 18(1): 162, 2017 04 19.
Article in English | MEDLINE | ID: mdl-28420360

ABSTRACT

BACKGROUND: Avulsion fractures of the pelvic apophyses typically occur in adolescent athletes due to a sudden strong muscle contraction while growth plates are still open. The main goals of this systematic review with meta-analysis were to summarize the evidence on clinical outcome and determine the rate of return to sports after conservative versus operative treatment of avulsion fractures of the pelvis. METHODS: A systematic search of the Ovid database was performed in December 2016 to identify all published articles reporting outcome and return to preinjury sport-level after conservative or operative treatment of avulsion fractures of the pelvis in adolescent patients. Included studies were abstracted regarding study characteristics, patient demographics and outcome measures. The methodological quality of the studies was assessed with the Coleman Methodology Score (CMS). RESULTS: Fourteen studies with a total of 596 patients met the inclusion criteria. The mean patient age was 14.3 ± 0.6 years and 75.5% of patients were male. Affected were the anterior inferior iliac spine (33.2%), ischial tuberosity (29.7%), anterior superior iliac spine (27.9%), iliac crest (6.7%) lesser trochanter (1.8%) and superior corner of the pubic symphysis (1.2%). Mean follow-up was 12.4 ± 11.7 months and most of the patients underwent a conservative treatment (89.6%). The overall success rate was higher in the patients receiving surgery (88%) compared to the patients receiving conservative treatment (79%) (p = 0,09). The rate of return to sports was 80% in conservative and 92% in operative treated patients (p = 0,03). Overall, the methodological quality of the included studies was low, with a mean CMS of 41.2. CONCLUSION: On the basis of the present meta-analysis, the overall success and return to sports rate was higher in the patients receiving surgery. Especially in patients with fragment displacement greater 15 mm and high functional demands, surgical treatment should be considered.


Subject(s)
Athletic Injuries/therapy , Conservative Treatment/statistics & numerical data , Fractures, Avulsion/therapy , Orthopedic Procedures/statistics & numerical data , Pelvic Bones/injuries , Return to Sport/statistics & numerical data , Adolescent , Clinical Decision-Making , Female , Fractures, Avulsion/surgery , Humans , Male , Treatment Outcome
6.
Br J Sports Med ; 51(4): 260-263, 2017 Feb.
Article in English | MEDLINE | ID: mdl-27797733

ABSTRACT

OBJECTIVE: The aim of this study was to translate, culturally adapt and validate the Oslo Sports Trauma Research Centre (OSTRC) Questionnaire on Health Problems into the German context. METHODS: A slightly modified back-translation method was used to translate the questionnaire. Validation was done in 24 high-level Paralympic athletes followed over 20 consecutive weeks. RESULTS: The translated version of the questionnaire showed a very high internal consistency and good test-retest reliability (Cronbach's α 0.92, intraclass correlation coefficient 0.91). Additionally, we observed high acceptance and compliance from our cohort of athletes, whose mean weekly response rate was 91.5%. Overall, 114 training days were lost because of illness or injury within the 20 weeks and, on average, 5 athletes per week (20.8%) reported health problems. CONCLUSIONS: This study demonstrates that the translated German version of the OSTRC Questionnaire is a reliable and valid tool with high internal consistency for the medical monitoring of German athletes. The OSTRC-G now offers the opportunity for a continued surveillance of high-level German athletes.


Subject(s)
Athletic Injuries/epidemiology , Bicycling/injuries , Cumulative Trauma Disorders/epidemiology , Surveys and Questionnaires , Translations , Adult , Athletes , Female , Germany , Humans , Male , Middle Aged , Reproducibility of Results
7.
Klin Monbl Augenheilkd ; 233(4): 444-7, 2016 Apr.
Article in English | MEDLINE | ID: mdl-27116505

ABSTRACT

BACKGROUND: Without treatment, the natural history of central retinal vein occlusion (CRVO) can result in severe loss of vision. MATERIAL AND METHODS: This was a retrospective study of 10 eyes with CRVO treated with pars plana vitrectomy (PPV), combined with radial optic neurotomy. The patients completed a minimum of 5 years follow-up. RESULTS: Median age at the time of surgery was 67 ± 14 years. Median follow-up was 79 ± 9 months. Ischaemic changes were present in 4 patients pre-operatively. Baseline median logMAR BCVA was 2.00 ± 0.76 and improved significantly to a median of 0.35 ± 0.54 (p < 0.0001, two tailed t test) at 5 years follow-up. The baseline median central macular thickness (CMT) was 645 ± 108 µm and improved significantly, to a median of 203 ± 72 µm (p < 0.0001, two tailed t test). One of the patients developed neovascular complications during the follow-up period. CONCLUSIONS: Our results compare very favorably with the natural history of CRVO. All patients demonstrated a trend to improved visual acuity, while only one of the patients developed neovascular complications. These results provide information on the potential long-term effect of PPV in patients with CRVO and may help to reassess the place of the surgical management of CRVO in patients who do not respond to medical treatment.


Subject(s)
Decompression, Surgical/methods , Neurosurgical Procedures/methods , Optic Nerve/surgery , Retinal Vein Occlusion/diagnosis , Retinal Vein Occlusion/surgery , Vision Disorders/prevention & control , Aged , Aged, 80 and over , Female , Humans , Longitudinal Studies , Male , Middle Aged , Retinal Vein Occlusion/complications , Retrospective Studies , Treatment Outcome , Vision Disorders/etiology , Visual Acuity , Vitrectomy/methods
8.
Orthop Traumatol Surg Res ; 101(2): 221-5, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25736198

ABSTRACT

BACKGROUND: A common method to restore the sagittal alignment and stabilize the spinal column is a dorso-ventral spondylodesis. It is assumed that correction loss after posttraumatic spondylodesis results from inadequate incorporation of the autologous iliac crest graft. MATERIALS AND METHODS: Retrospective documentation of patients with unstable vertebral body fractures of the thoracic or lumbar spine with concomitant rupture of at least one adjacent intervertebral disk who received surgical treatment at our institution from 2000 to 2006. Followed by analysis of the computer tomography documentation of a total of 142 patients with unstable vertebral body fracture stabilized by posterior internal fixator and anterior iliac crest spondylodesis. RESULTS: The following mean angle changes were derived from the second series of CT scans performed on average 283 days after anterior spondylodesis: vertebral wedge angle (VWA): 2.1°; segmental kyphotic angle: 4.9°; adjusted-SKA: 4.8°; sagittal index (SI): -0.04; segmental-scoliotic-angle (SSA): 0°; adjusted-SSA: 0°. Changes in VWA, both SKAs and SI postoperatively and prior to ME, were statistically significant (P<0.05). The McAfee fusion assessment of the graft showed: full fusion: cranial 64%, caudal 47%; partial fusion: cranial 20.5%, caudal 29%; lysis: cranial 8.5%, caudal 17%; graft resorption: 7%. No correlation was found between the above-mentioned angle changes and fusions grade. DISCUSSION: The importance of radiological evidence of fusion deficiency is questionable, because the extent of fusion only has a minimal effect on correction loss. LEVEL OF EVIDENCE: Level IV.


Subject(s)
Bone Transplantation/methods , Lumbar Vertebrae/injuries , Osseointegration , Spinal Fractures/surgery , Spinal Fusion/methods , Thoracic Vertebrae/injuries , Adolescent , Adult , Aged , Aged, 80 and over , Female , Follow-Up Studies , Humans , Lumbar Vertebrae/diagnostic imaging , Lumbar Vertebrae/surgery , Male , Middle Aged , Reoperation , Retrospective Studies , Spinal Fractures/diagnostic imaging , Thoracic Vertebrae/diagnostic imaging , Thoracic Vertebrae/surgery , Tomography, X-Ray Computed , Transplantation, Autologous , Young Adult
9.
Injury ; 46(6): 985-9, 2015.
Article in English | MEDLINE | ID: mdl-25771445

ABSTRACT

INTRODUCTION: The relatively high complication rate after fixation of olecranon fractures has led to an increasing application of anatomically pre-contoured locking plate systems. The purpose of the present study was to conduct a biomechanical comparison of olecranon osteosyntheses by applying the Olecranon VA-LCP and the 3.5mm LCP Hook Plate (LCP, locking compression plate) to an unstable fracture model under high-cycle loading conditions. METHODS: After creating an unstable fracture (Schatzker type B), osteosynthesis was performed on eight pairs of fresh-frozen cadaveric ulnae by application of either the Olecranon VA-LCP (Synthes, Solothurn, Switzerland) or the 3.5mm LCP Hook Plate (Synthes, Solothurn, Switzerland). Loading (50,000 alternating loads, cyclic and sinusoidal 10-300 N) was conducted by application of tensile load with the elbow in 90° flexion to simulate the tensile strength of the triceps brachii. For statistical analysis, angular displacement in the region of the humeral trochlea was taken as a measure of olecranon dislocation. RESULTS: In Group 1 (Olecranon VA-LCP), a median angular displacement of 0.36° (minimum 0.10°; maximum 0.80°) was observed after 500 alternating loads. In Group 2 (3.5-mm LCP Hook Plate), the medial displacement was 0.80° (minimum 0.13°; maximum 2.72°). The difference was nonsignificant (p = 0.128). The mean value for angular displacement in Group 1 after 50,000 cycles was 0.80° (minimum 0.31°; maximum 1.99°), whereas in Group 2 a mean angular displacement of 2.02° (minimum 0.71°; maximum 6.40°) was recorded. The difference was statistically significant (p = 0.017). In Group 2, implant failure in the form of proximal plate pullout occurred in one construct after 756 cycles. CONCLUSION: A significantly higher biomechanical stability can be achieved in the fixation of unstable olecranon fractures by application of the Olecranon VA-LCP rather than the 3.5mm LCP Hook Plate.


Subject(s)
Bone Plates , Fracture Fixation, Internal/methods , Fracture Fixation, Intramedullary/methods , Fractures, Comminuted/surgery , Olecranon Process/surgery , Ulna Fractures/surgery , Biomechanical Phenomena , Cadaver , Humans , Prosthesis Design , Tensile Strength
10.
Orthopade ; 43(11): 1000-7, 2014 Nov.
Article in German | MEDLINE | ID: mdl-25288100

ABSTRACT

BACKGROUND: Open wedge high tibial osteotomy (HTO) is an increasingly more common surgical method. A typical problem of this procedure is fracture of the lateral hinge. OBJECTIVES: The aims of this article are to present the special issue of fractures of the lateral hinge after HTO and to discuss surgical hints on how to prevent and treat this problem. METHODS: The results of recently published clinical studies are summarized and tips from own clinical experiences are given. RESULTS: Type II fractures of the lateral hinge are unstable and can create a major problem. Using short spacer plates results in a problem of stability for all types of fractures. CONCLUSION: The classification into Takeuchi grades I-III has been proven to be suitable for fractures of the lateral hinge. The TomoFix plate is a safe implant to stabilize the osteotomy in type I and III fractures with which healing can be achieved with no problems. Type II fractures can be stabilized with the TomoFix plate; however, an autologous bone graft has to be taken into consideration. For fractures of the lateral hinge short spacer plates are not recommended due to stability issues.


Subject(s)
Fracture Fixation, Internal/methods , Osteoarthritis, Knee/complications , Osteoarthritis, Knee/surgery , Osteotomy/adverse effects , Tibial Fractures/etiology , Tibial Fractures/surgery , Fracture Fixation, Internal/instrumentation , Humans , Osteoarthritis, Knee/diagnosis , Osteotomy/methods , Tibia/surgery , Treatment Outcome
11.
Technol Health Care ; 22(6): 909-13, 2014.
Article in English | MEDLINE | ID: mdl-25335971

ABSTRACT

BACKGROUND: Fracture of the distal humerus is a fairly rare injury and makes high demands on the treating surgeon. Prerequisites for a good outcome are anatomical reconstruction and osteosynthesis stable enough for exercises. A method permitting early restoration of function is especially important for patients with osteoporosis. The extensive surgical approach necessary for open reduction is associated with a high number of wound healing disorders and infections with a frequency of 11% being reported in the literature. Although open reduction and internal fixation in double-plating technique is unavoidable for complex intraarticular fractures, an alternative, minimally invasive and, consequently, tissue-preserving procedure is desirable for simpler fractures. OBJECTVE: To investigate this issue further an angular stable nail system developed for the distal radius was implanted as a stabilizer and the construct tested biomechanically as part of a feasibility study. METHODS: Distal humerus fractures were stabilized by insertion of a distal radius nail, namely, the Targon DR (Aesculap, Tuttlingen) and a K-wire. To test the hypothesis six cadaveric bones fixed in formalin were tested biomechanically for displacement, implant failure, and stiffness. Displacement was determined by means of an ultrasound-based system. RESULTS: An average displacement of 1.6 mm ± 0.7 was recorded at a maximum compression force of 100 N in extension and an average displacement of 1.4 mm ± 0.9 in flexion. Implant failure was not observed for any of the constructs. CONCLUSIONS: The study presented here permits the conclusion that a minimally invasive procedure is possible at the distal humerus and does ensure adequate stability. Although the nail was not specifically designed for the humerus, current findings form the basis for a promising approach that will be pursued further after modification of the nail design.


Subject(s)
Fracture Fixation, Intramedullary/methods , Fractures, Bone/surgery , Humerus/injuries , Minimally Invasive Surgical Procedures , Bone Nails , Bone Wires , Feasibility Studies , Humans , Mechanical Phenomena , Pilot Projects
13.
Osteoporos Int ; 24(10): 2701-6, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23702701

ABSTRACT

SUMMARY: The aim of this study is to identify osteoporosis values, beyond which there is a high risk of osteosynthesis failure. Bone mineral density (BMD) of 30 cadaveric femora with a pertrochanteric fracture osteotomy was correlated to the risk of cut out after osteosynthesis on a biomechanical testing approach. For a BMD less than 250 mg/cm(3), there is a high risk of fixation failure after surgical treatment of pertrochanteric fractures. This value can be regarded as a reference value for future experimental and clinical studies. INTRODUCTION: Despite continuous modification of intramedullary load carriers for the surgical stabilization of trochanteric fractures, cut out remains the most frequent complication. The aim of this experimental study was to identify threshold osteoporosis values, beyond which there is a high risk of osteosynthesis failure. METHODS: Bone mineral density (BMD) of 30 cadaveric femora was recorded for the femoral head by QCT measurement. Subsequently, a standardized osteotomy mimicking an unstable trochanteric type fracture was stabilized by intramedullary nailing. The constructs were loaded axially at a force of 2,100 N up to 20,000 cycles. Cut out at the femoral head was documented by radiograph. Statistical evaluation of the cohort group was performed by calculation of relative risk in relation to the BMD values. RESULTS: In total, there were six cases of cut out after 10,000 cycles. The incidence of cut out for BMD less than 250 mg/cm(3) was 0.55 (5 of 9) and for BMD greater than 250 mg/cm(3), it was 0.05 (1 of 21). Therefore, the relative risk of cut out for BMD <250 mg/cm(3) is 11× greater than for a BMD >250 mg/cm(3). After 20,000 cycles, an additional test caused one cut out (relative risk of cut out for a BMD <250 mg/cm(3) 5.8). CONCLUSIONS: For a BMD less than 250 mg/cm(3), there is a high risk of fixation failure after surgical treatment of pertrochanteric fractures. Although this value is based on an experimental in vitro study design with all its associated limitations, it can be regarded as a reference value for future experimental and clinical studies.


Subject(s)
Fracture Fixation, Intramedullary/adverse effects , Hip Fractures/surgery , Osteoporosis/physiopathology , Osteoporotic Fractures/surgery , Bone Density/physiology , Femur Head/diagnostic imaging , Femur Head/physiopathology , Hip Fractures/diagnostic imaging , Hip Fractures/physiopathology , Humans , Osteoporotic Fractures/diagnostic imaging , Osteoporotic Fractures/physiopathology , Reference Values , Risk Assessment/methods , Stress, Mechanical , Tomography, X-Ray Computed , Treatment Failure , Weight-Bearing
14.
Injury ; 44(6): 784-90, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23395417

ABSTRACT

BACKGROUND: Current recommendations with regard to central or caudal positioning of the femur head carrier in the management of trochanteric fractures are contradictory. METHODS: A standardised pertrochanteric osteotomy was stabilised in 15 pairs of cadaver femurs by means of intramedullary osteosynthesis (5xPFN-A-Synthes, 5xIntertan-Smith&Nephew, 5xTargon-PF-Aesculap). For each pair randomised central (group A) or caudal (group B) implantation of the femoral neck component was performed. Subsequently, the constructs were axially loaded to 2100N. In the absence of cut out after 20,000 cycles, load was increased to a maximum force of 3100N. Angular displacement was recorded based on ultrasound. Migration of the load carrier in the femoral head was monitored radiologically. FINDINGS DISPLACEMENT: No significant difference between groups (p>0.15) was found for the first 50 load cycles. A significantly greater degree of varus deformity was observed in group A (p=0.049) after 2000 load cycles and became more apparent as the number of load cycles increased (after 6000 cycles p=0.039, after 20,000 cycles p=0.034, after 22,000 cycles p=0.016). Angular displacement in the other two planes did not differ significantly across groups. CUT OUT: Migration of the load carrier in the femoral head was not significantly different for the two groups. Overall cut out occurred in 9 constructs, 3 in group A and 6 in group B. The difference in cut-out rate was not significant (p=0.213, chi-squared test). CONCLUSION: Biomechanical superiority can be shown for caudal positioning of the femoral neck load carrier in terms of reduced varus deformity. The incidence of cut out is however unaffected by the position of the load carrier.


Subject(s)
Fracture Fixation, Intramedullary/methods , Hip Fractures/surgery , Osteotomy/methods , Biomechanical Phenomena , Bone Screws , Cadaver , Female , Humans , Male , Mechanical Phenomena , Weight-Bearing
15.
Article in English | MEDLINE | ID: mdl-22149414

ABSTRACT

In order to evaluate stabilisation systems in trochanteric femoral fractures with finite element (FE) analysis, a realistic model is required. For this purpose, a new model of a femur with all the relevant muscles and the hip capsule ligaments is set up. The pelvic and tibial bones are modelled as rigid bodies so as to take all the muscles attached to the femur into account. Fracture zones in the proximal femur are defined. Following the modelling of the geometry, the isotropic material behaviour and the load application, a numerical calculation of the femur is carried out. The static iterated FE simulation shows good agreement with in vivo data for the one-leg-stance phase during walking and Pauwels' one-leg stance regarding the displacement of the femoral head (2.9 and 5.2 mm, respectively) and the resulting hip force (253% and 294% bodyweight, respectively). In the modelled fracture zones without osteosynthesis, shear is higher than axial strain. The reduction of shear among others could be a criterion for judging the quality of a stabilisation implant.


Subject(s)
Femur/anatomy & histology , Hip Joint/anatomy & histology , Models, Anatomic , Adult , Biomechanical Phenomena , Female , Femur/physiology , Finite Element Analysis , Hip Joint/physiology , Humans , Ligaments/anatomy & histology , Ligaments/physiology , Muscles/anatomy & histology , Muscles/physiology , Pelvis/anatomy & histology , Pelvis/physiology , Stress, Mechanical
16.
Eye (Lond) ; 27(2): 163-71, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23196647

ABSTRACT

Most uveal melanomas are treated with radiotherapy. An adequate understanding of the effects of radiation on the tumour and the healthy ocular tissues is necessary. Ionizing radiation damages cell membranes, organelles, and DNA. Irradiated cells are lysed or undergo apoptosis, necrosis, and senescence. These effects occur in tumour cells and vascular endothelial cells, resulting in tumour shrinkage, ischaemia, infarction, exudation, and fibrosis, which can cause exudative maculopathy, serous retinal detachment, rubeosis, and neovascular glaucoma (ie, 'toxic tumour syndrome'). Such abnormalities must be distinguished from collateral damage to healthy ocular tissues that receive high doses of radiation, and these include radiation-induced retinopathy, optic neuropathy, choroidopathy, cataract, and scleral necrosis. Radiation retinopathy can be treated effectively with photodynamic therapy, anti-angiogenic agents, and intravitreal steroid injections. In some patients, optic neuropathy may improve with intravitreal steroids or anti-angiogenic agents. Neovascular glaucoma resolves with intra-cameral bevacizumab. Exudative retinal detachment can regress with intra-vitreal steroid injections. Cataract is treated in the usual manner. Scleral necrosis, if severe, may require grafting, possibly using a lamellar flap from the same eye. Depending on the bulk of the residual toxic tumour, treatment can consist of intra-vitreal steroids and/or anti-angiogenic agents, transpupillary thermotherapy or photodynamic therapy to the tumour, or surgical removal of the tumour by endo- or exo-resection. Measures aimed at preventing collateral damage include eccentric placement of ruthenium plaques or iodine seeds and delivery of a notched proton beam. The decision to treat a uveal melanoma with radiotherapy requires the ability to manage iatrogenic side effects and complications.


Subject(s)
Eye/radiation effects , Melanoma/radiotherapy , Organs at Risk/radiation effects , Radiation Injuries/therapy , Uveal Neoplasms/radiotherapy , Humans , Radiation Injuries/prevention & control
17.
Sportverletz Sportschaden ; 25(3): 167-72, 2011 Sep.
Article in German | MEDLINE | ID: mdl-21922439

ABSTRACT

Although paracycling is a growing discipline in high level competitive sports as well as in posttraumatic rehabilitation, epidemiological data of resulting injuries is still missing. Therefore, 19 athletes of the German national paracycling team were asked about their injuries during the 2008 season using a standardized questionnaire. Overall, 18 (94.7 %) of 19 athletes reported overuse injuries; most commonly localized at the back (83.3 %), neck/shoulder (77.8 %), knee (50 %), groin/buttock (50 %) and hands/wrists (38.9 %). Altogether, 18 accidents were registered, corresponding to an injury rate of 0,95 acute injuries per athlete per year (0,07 / 1000 km). The most common acute injuries were abrasions (69.2 %) and contusions (61.5 %), whereas fractures were stated only twice (11.8 %). The anatomical distribution of overuse injuries in disabled cyclists confirms the results of studies in able-bodied cycling, although the incidences in low-back pain and neck/shoulder pain is clearly higher in disabled cycling, as well as the rate of traumatic injuries.


Subject(s)
Athletic Injuries/epidemiology , Athletic Injuries/etiology , Bicycling/injuries , Cumulative Trauma Disorders/epidemiology , Cumulative Trauma Disorders/etiology , Disabled Persons , Musculoskeletal System/injuries , Adult , Competitive Behavior , Female , Germany , Humans , Male , Musculoskeletal Pain/epidemiology , Musculoskeletal Pain/etiology , Risk Factors , Surveys and Questionnaires
18.
Proc Inst Mech Eng H ; 225(7): 710-7, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21870378

ABSTRACT

The aim of this study was the biomechanical evaluation of the reversed less invasive stabilization system (LISS) internal fixation as a joint-preserving salvage procedure for trochanteric fractures. Five LISS plates and five dynamic condylar screws (DCS) were tested using synthetic femora (Sawbones) with an osteotomy model similar to a type-A2.3 pertrochanteric fracture. The constructs were subjected to axial loading up to 1000 N for five cycles. Then, the force was continuously increased until fixation failure. For the evaluation of the biomechanical behaviour, the stiffness levels were recorded and the osteotomy gap displacement was mapped three-dimensionally. The average stiffness for the constructs with LISS plates was 412 N/mm (with a standard deviation (SD) of 103N/mm) and 572N/mm (SD of 116 N/mm) for the DCS constructs (p=0.051). Local displacement at the osteotomy gap did not yield any significant differences. The LISS constructs failed at a mean axial compression of 2103N (SD of 519N) and the DCS constructs at a mean of 2572N (SD of 372N) (p=0.14). It is concluded that the LISS plate offers a reliable fixation alternative for salvage procedures.


Subject(s)
Fracture Fixation, Internal/instrumentation , Hip Fractures/surgery , Biomechanical Phenomena , Bone Plates , Bone Screws , Equipment Failure Analysis , Hip Fractures/physiopathology , Humans , Osteotomy , Stress, Mechanical
19.
Klin Monbl Augenheilkd ; 228(4): 288-92, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21484631

ABSTRACT

BACKGROUND: Submacular hemorrhage is a manifestation of neovascular age-related macular degeneration (AMD) that has a very poor natural history leading to severe visual loss. We have evaluated the safety and efficacy of intravitreal ranibizumab in the treatment of predominantly hemorrhagic AMD. PATIENTS AND METHODS: A retrospective study of patients with predominantly hemorrhagic AMD treated with intravitreal ranibizumab at the Jules Gonin Eye Hospital between December 2006 and December 2008 was undertaken. Baseline and monthly follow-up exams included visual acuity (VA), fundus exam and optical coherence tomography (OCT) while fluorescein and indocyanine green angiography were performed at least every three months. RESULTS: The study included 8 eyes. The mean follow-up was 13 months (SD: 6.3). The mean number of intravitreal injections administered for each patient was 6.4 (SD: 2). 50 % of the patients demonstrated stable or improved VA. The size of hemorrhage at baseline was inversely correlated to the final VA (two-tailed p value = 0.038) and positively correlated to the final central macular thickness (two-tailed p value = 0.021). Anticoagulation treatment was inversely correlated to the time of hemorrhage resolution (two-tailed p value = 0.039). CONCLUSIONS: Intravitreal ranibizumab may be an effective treatment for predominantly hemorrhagic lesions due to neovascular AMD.


Subject(s)
Antibodies, Monoclonal/administration & dosage , Choroid Hemorrhage/drug therapy , Choroid Hemorrhage/etiology , Exudates and Transudates/drug effects , Macular Degeneration/complications , Macular Degeneration/drug therapy , Aged , Aged, 80 and over , Antibodies, Monoclonal, Humanized , Female , Humans , Intravitreal Injections , Male , Middle Aged , Ranibizumab , Treatment Outcome
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