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Patients with hip fractures are older and often present many co-morbidities, including dementia.These patients cannot answer quality of life questionnaires and are generally excluded from trials.We hypothesized that a significant number of patients are being excluded from these studies and thismay impact outcomes. This was a two part study; the first analyzing databases of two ongoing large-scale multi-centred hip fracture trials and the second being a systematic review. The FAITH andHEALTH studies were analyzed for exclusion incidence directly related to dementia. The second partconsisted of a systematic search of all relevant studies within the last 20 years. In the FAITH study, atotal of 1690 subjects were excluded, 375 (22.2%) of which were due to dementia or cognitiveimpairment. In the HEALTH study, 575 were excluded with dementia/cognitive impairmentrepresenting 207 patients (36%). Following the systematic review, 251 articles were identified 17 ofwhich were retained. The overall prevalence of dementia was 27.9% (range 2–51%). Only two studiescompared demented and non-demented groups. In these studies significant increases in bothmortality and complications were found. In summary, when investigating hip fractures, choosingappropriate objective endpoints is essential to ensure results are also applicable to patients withdementia.

Contains fulltext : 88459.pdf (Publisher’s version ) (Open Access) BACKGROUND AND PURPOSE: Total hip arthroplasties in young patients have lower long-term survival rates than in older patients. We evaluated the use of a unique treatment protocol in patients aged between 40 and 50 years. In all cases we used a cemented THA, and for acetabular deficiencies we also used impacted bone grafts together with a cemented cup. METHODS: In 140 consecutive patients who were between 40 and 50 years of age at index surgery, 168 cemented total hip prostheses were evaluated after a mean follow-up time of 10 (2-19) years. Acetabular deficiencies were reconstructed with wire meshes and impacted bone grafts with a cemented cup (70 hips). During follow-up, 18 patients died (27 hips); in this group 3 hips (3 patients) had been revised. None of the patients were lost to follow-up. In all surviving patients, clinical assessment was performed with hip-score questions and all radiographs were evaluated. RESULTS: All clinical questionnaires showed an improved clinical hip score. 29 hips (17%) were revised after a mean of 8 (0.3-18) years. Kaplan-Meier survival analysis showed a survival of 88% (95% CI: 82-94) after 10 years with revision of either component for any reason. Survival with endpoint revision for aseptic loosening of either component was 94% (95% CI: 90-99) after 10 years. INTERPRETATION: Cemented implants in young patients have satisfying long-term results. Reconstruction of acetabular deficiencies with impacted bone grafts show promising results. 01 april 2010

Contains fulltext : 88074.pdf (Publisher’s version ) (Open Access) PURPOSE: We investigated the hypothesis that many total hip arthroplasty revisions that are classified as aseptic are in fact low-grade infections missed with routine diagnostics. METHODS: In 7 Dutch hospitals, 176 consecutive patients with the preoperative diagnosis of aseptic loosening of their total hip arthroplasty were enrolled. During surgery, between 14 and 20 tissue samples were obtained for culture, pathology, and broad-range 16S rRNA PCR with reverse line blot hybridization. Patients were classified as either not being infected, suspected of having infection, or infected according to strict, predefined criteria. Each patient had a follow-up visit after 1 year. RESULTS: 7 patients were classified as infected, 4 of whom were not identified by routine culture. 15 additional patients were suspected of having infection. 20 of these 22 patients received a cemented prosthesis, fixated with antibiotic-loaded bone cement. All 22 patients received prophylactic systemic antibiotics. 7 of them reported complaints one year after surgery, but only one showed signs of early loosening. However, additional surgery was not performed in any of the patients. INTERPRETATION: Although the proportions were not as high as previously reported in the literature, between 4% and 13% of patients with the preoperative diagnosis of aseptic loosening were infected. However, as thorough debridement was performed during surgery and prophylactic antibiotics were used, the diagnosis of infection did not have any obvious clinical consequences, as most patients performed well at the 1-year follow-up. Whether this observation has implications for long-term implant survival remains to be seen. 01 december 2010

Contains fulltext : 71115.pdf (Publisher’s version ) (Closed access) Bone morphogenetic proteins (BMPs) accelerate bone repair in experimental and clinical conditions. Impacted Morsellized Cancellous Bone grafts (MCB) are successfully used to reconstruct bone defects after failed hip implants. The main question in this study was if BMP-7 (OP-1) mixed with MCB could accelerate the incorporation of MCB and prevents the formation of a soft tissue interface after remodeling of the MCB. A large loaded defect in the acetabulum of goats was reconstructed with a wire mesh and with MCB or MCB mixed with OP-1. After 6 weeks, no differences were found in the revascularization process, in the number of osteoclasts resorbing the MCB, and in the thickness and appearance of the fibrous interface between MCB with or without OP-1. After 6 weeks, enchondral bone had formed in the bone graft layer and on the periosteal anterior and superior rim in the OP-1 group only. More periosteal bone and more bone in the holes of the mesh had been formed in most OP-1 goats. Most MCB was replaced by new lamellar bone after 15 weeks in both groups. We speculate that during or directly after impaction most of the OP-1 is released from the carrier inducing an early effect outside the reconstructive layer at the periosteal side of the acetabulum. Probably most OP-1 has left the reconstruction by the time new vessels and progenitors reached the bone graft. These results do not support the use of OP-1 in impaction bone grafting in patients.

Contains fulltext : 49343.pdf (Publisher’s version ) (Closed access) BACKGROUND: The purpose of this study was to evaluate the clinical and radiographic outcomes of revision of the femoral component of a hip arthroplasty with use of an impaction bone-grafting technique and a cemented polished stem. METHODS: Thirty-three consecutive femoral reconstructions that were performed between March 1991 and February 1996 with use of the X-change femoral revision system, fresh-frozen morselized allograft, and a cemented polished Exeter stem were followed prospectively. Femoral bone stock defects were classified according to the Endoklinik classification. The average age of the patients at the time of the femoral component revision was sixty-three years. No patient was lost to follow-up, which was performed at a minimum of eight years, but eight patients had died. None of the deaths was related to the surgery. RESULTS: No femoral reconstruction had been rerevised at a mean of 10.4 years postoperatively. There was one unrecognized intraoperative fracture, which healed following nonoperative treatment. There were three postoperative femoral fractures, all through cortical defects at the level of the tip of the prostheses. All fractures healed after plate fixation, and all femoral implants were left in situ. The average subsidence of the stem within the cement mantle was 3 mm; seven stems migrated 5 mm. The average Harris hip score improved from 49 points prior to surgery to 85 points (range, 68 to 100 points) at the time of this review. Subsidence did not affect the Harris hip score. Kaplan-Meier analysis, with an end point of femoral revision for any reason, showed a survival rate of 100% (one-sided 95% confidence interval, 100% to 91.3%). CONCLUSIONS: Femoral revision with use of an impaction bone-grafting technique and a cemented polished stem resulted in an excellent prosthetic survival rate at eight to thirteen years postoperatively. The major problem that occurred was a femoral fracture in four patients.

Item does not contain fulltext Reconstructing large loaded bone defects with ceramic bone graft extenders is tempting considering the expected future donor bone shortage. However, whether there are negative effects is unknown. Standardized large defects in the acetabulum of goats were created and subsequently reconstructed with metal mesh and impacted morselized cancellous bone grafts or a 50/50% volume mixture of tricalcium phosphate-hydroxyapatite granules and morselized cancellous bone grafts using the bone impaction grafting technique. Subsequently, a cemented total hip prosthesis was inserted. Clinically, no differences were observed between groups. Most of the morselized cancellous bone graft had been resorbed and incorporated into new bone after 15 weeks. The large tricalcium phosphate-hydroxyapatite granules were integrated, the smaller crushed tricalcium phosphate-hydroxyapatite granules were surrounded by osteoclasts or engulfed by macrophages and giant cells. The cement penetration into the reconstructive layer and the quality of the bone based on a semiquantitative score were similar in both groups. We found no suggestion of tricalcium-hydroxyapatite granule-induced third-body wear in this short-term followup study. No negative effects were observed in this study, and therefore, it seems reasonable to use tricalcium-hydroxyapatite granules in a 50/50% volume mix with morselized cancellous bone graft as a bone graft extender in acetabular revision surgery with the bone impaction grafting technique.

Item does not contain fulltext This study assesses femoral neck shortening and its effect on gait pattern and muscle strength in patients with femoral neck fractures treated with internal fixation. Seventy-six patients from a multicenter randomized controlled trial participated. Patient characteristics and Short Form 12 and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were collected. Femoral neck shortening, gait parameters, and maximum isometric forces of the hip muscles were measured and differences between the fractured and contralateral leg were calculated. Variables of patients with little or no shortening, moderate shortening, and severe shortening were compared using univariate and multivariate analyses. Median femoral neck shortening was 1.1 cm. Subtle changes in gait pattern, reduced gait velocity, and reduced abductor muscle strength were observed. Age, weight, and Pauwels classification were risk factors for femoral neck shortening. Femoral neck shortening decreased gait velocity and seemed to impair gait symmetry and physical functioning. In conclusion, internal fixation of femoral neck fractures results in permanent physical limitations. The relatively young and healthy patients in our study seem capable of compensating. Attention should be paid to femoral neck shortening and proper correction with a heel lift, as inadequate correction may cause physical complaints and influence outcome.

Item does not contain fulltext Despite the worldwide usage of the cemented Contemporary acetabular component (Stryker), no published data are available regarding its use in patients aged < 50 years. We undertook a mid- to long-term follow-up study, including all consecutive patients aged < 50 years who underwent a primary total hip replacement using the Contemporary acetabular component with the Exeter cemented stem between January 1999 and January 2006. There were 152 hips in 126 patients, 61 men and 65 women, mean age at surgery 37.6 years (16 to 49 yrs). One patient was lost to follow-up. Mean clinical follow-up of all implants was 7.6 years (0.9 to 12.0). All clinical questionnaire scores, including Harris hip score, Oxford hip score and several visual analogue scales, were found to have improved. The eight year survivorship of all acetabular components for the endpoints revision for any reason or revision for aseptic loosening was 94.4% (95% confidence interval (CI) 89.2 to 97.2) and 96.4% (95% CI 91.6 to 98.5), respectively. Radiological follow-up was complete for 146 implants. The eight year survival for the endpoint radiological loosening was 93.1% (95% CI 86.2 to 96.6). Three surviving implants were considered radiologically loose but were asymptomatic. The presence of acetabular osteolysis (n = 17, 11.8%) and radiolucent lines (n = 20, 13.9%) in the 144 surviving cups indicates a need for continued observation in the second decade of follow-up in order to observe their influence on long-term survival. The clinical and radiological data resulting in a ten-year survival rate > 90% in young patients support the use of the Contemporary acetabular component in this specific patient group. Cite this article: Bone Joint J 2013;95-B:1617-25.

Item does not contain fulltext In a previous report, we presented our results of forty-two acetabular reconstructions, performed with use of impaction bone-grafting and a cemented polyethylene cup, in thirty-seven patients who were younger than fifty years and had a minimum of fifteen years of follow-up. The present update study shows the results after twenty to twenty-eight years. Eight additional cups had to be revised--four because of aseptic loosening, three because of wear, and one during a revision of the stem. Three additional cups were considered loose on radiographs. Survivorship of the acetabular reconstructions, with an end point of revision for any reason, was 73% after twenty years and 52% after twenty-five years. With revision for aseptic loosening as the end point, survival was 85% after twenty years and 77% after twenty-five years; for signs of loosening on radiographs, survival was 71% at twenty years and 62% at twenty-five years. In conclusion, our previous results have declined but the technique of using impacted morselized bone graft and a cemented cup is useful for the purpose of restoring bone stock in young patients whose acetabular defects require primary or revision total hip arthroplasty.

Item does not contain fulltext Hip resurfacing arthroplasty was introduced as an alternative to the conventional total hip arthroplasty which had shown suboptimal results in younger patients. Application of the resurfacing technique in younger patients has increased over the last few years. To date, no randomized controlled trials with a minimum follow-up span of 10 years comparing hip resurfacing to conventional hip replacement have been conducted in patients under 55 years of age. Australian and English hip registries demonstrate high revision rates after 5 years for some brands of resurfacing implants. In addition to these disappointing revision rates, the complication of aseptic lymphocytic vasculitis caused by metal particles evoking a local tissue reaction has been increasingly reported. The resurfacing procedure recently received some negative media attention in the Netherlands, leading to confusion among patients. In order to ease patient doubts, it is important to correctly inform them as to the type of implant used, for example, by means of the website or an information card.

Contains fulltext : 87356.pdf (Publisher’s version ) (Closed access) OBJECTIVE: To determine the follow-up outcomes of open lateral clavicle resection 1 year postoperatively in patients with acromioclavicular osteoarthritis. The operation involves resection of a small part of the lateral clavicle. DESIGN: Prospective descriptive. METHOD: Data were collected from all patients who had undergone an open lateral clavicle resection in the period July 1999 to June 2008 and who were examined preoperatively and 1 year postoperatively. This concerned 23 operations in 22 patients. The Constant score for the functionality of the shoulder was determined and visual analogue scales (VAS) were used to determine the pain and satisfaction concerning the operated shoulder. The results were evaluated with the paired t-test and the non-parametric Wilcoxon test. RESULTS: The mean length of the lateral clavicle resection was 7.8 mm. Preoperatively the mean Constant score was 64 (SD: 14) and 1 year after the operation 86 (SD: 14; p < 0.001). Ninety-one percent had an increase in the postoperative Constant score compared with the preoperative score. The median VAS score for pain decreased from 70 (95% CI: 60-77) preoperatively to 25 (0-48) 1 year postoperatively (p < 0.001). The median VAS score for satisfaction increased from 40 (40-50) preoperatively to 85 (68-100) (p < 0.001). CONCLUSION: The open lateral clavicle resection was a treatment option to reduce the symptoms in patients with acromioclavicular osteoarthritis in whom conservative treatment and medication proved to be insufficient.

Contains fulltext : 87341.pdf (Publisher’s version ) (Closed access) OBJECTIVE: To determine the long-term results of primary cemented total hip arthroplasty in patients under the age of 40. In cases of acetabular defects, initial reconstruction with bone impaction grafting was performed. DESIGN: Cohort analysis. METHODS: Details of patients under the age of 40 who underwent primary cemented total hip arthroplasty between 1 January 1988 and 30 June 2004 were analysed. The primary goal of this study was to determine the time until revision surgery. Kaplan Meier analysis was used to calculate prosthesis survival. RESULTS: A total of 175 total hip arthroplasties in 130 patients were included in the study. Acetabular reconstruction using bone impaction grafting was performed on 84 hips (48%). The average age at surgery was 31 years. Six patients (8 hips) died during follow-up; none of these had undergone revision surgery. Average follow-up was 8.1 years (range: 2.0-18.5). In total, 24 hips (14%) were revised. Reasons for revision were: septic loosening (n = 8), recurrent dislocations (n = 4), traumatic loosening (n = 1) and aseptic loosening (n = 11). The 10-year prosthesis survival was 83% (95% CI: 76-90) with the endpoint 'revision for any reason' and 92% (95% CI: 86-98) with the endpoint 'revision for aseptic loosening'. Aseptic survival of the cups with and without bone impaction grafting was 95% (95% CI: 89-100) and 90% (95% CI: 81-99) (p = 0.73), respectively. CONCLUSION: Hip replacement with cemented total hip arthroplasty in patients under the age of 40 produced good long-term results. Acetabular deficiencies reconstructed with bone impaction grafting also produced good results in this group of patients.

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Contains fulltext : 70712.pdf (Publisher’s version ) (Closed access) We evaluated the outcome of 104 consecutive primary cemented Exeter femoral components in 78 patients (34 men, 44 women) under the age of 40 years who underwent total hip replacement between October 1993 and May 2004. The mean age at operation was 31 years (16 to 39). No hip was lost to follow-up, but three patients (four hips) died. None of the deaths were related to the surgery. At a mean follow-up of 6.2 years (2 to 13), three femoral components had been revised for septic loosening. Using Kaplan-Meier survival analysis, the seven-year survival of the component with revision for any reason as the endpoint was 95.8% (95% confidence interval 86.67 to 98.7). The seven-year survival with aseptic femoral loosening as the endpoint was 100% (95% confidence interval 100). The cemented Exeter femoral component in patients under the age of 40 shows promising medium-term results. As it is available in a wide range of sizes and offsets, we could address all types of anatomical variation in this series without the need for custom-made components.

Contains fulltext : 53064.pdf (Publisher’s version ) (Closed access) OBJECTIVE: Determination of long-term results of hip replacements in patients who, at the time of operation, were under the age of 50. Procedures whereby an existing acetabulum defect was filled with bone chips that were impacted into a strong layer, after which a cemented total hip prosthesis was implanted. DESIGN: Descriptive. METHOD: Prospectively collected data from patients who were under the age of 50, and had undergone a hip replacement operation at our hospital between 1 July 1979 and 31 December 1987 were analysed. Data were collected up to 31 December 2002. The main outcome was time to revision. Survival was calculated by the Kaplan-Meier method. RESULTS: The study group consisted of 25 patients, 17 women and 8 men with 29 prosthetic hips. The average age at operation was 37.6 years (range: 20-49). Follow-up time was 15-23 years (median: 18.7 years). 1 patient (1 hip) was lost to follow-up. 3 patients (4 hips) died within 15 years after the operation; none of them had undergone revision. 4 revisions had been performed: I septic loosening (14 years p.o.) and 3 aseptic loosenings (6, 15, 20 years p.o.). The cumulative survival with the end-point 'revision for any reason' was 96% (95% CI: 88-100) at to years and 88% (95% CI: 74-100) at 20 years; after exclusion of the septic loosening the survival at 20 years was 92% (95% CI: 80-100). CONCLUSION: Hip replacement including a reconstruction technique for an acetabulum defect in patients under the age of 50 was regarded as successful if after 10 years, at least 90% of the prostheses were still in situ.

Contains fulltext : 52140.pdf (Publisher’s version ) (Closed access) OBJECTIVE: To describe the complications within 2 years after revision of failed total hip prostheses. DESIGN: Descriptive. METHOD: Using prospective registration, data were collected on the complications that had occurred in patients who had undergone hip revision in 2002 and 2003 on the orthopaedic department at the University Medical Centre St. Radboud in Nijmegen, The Netherlands. RESULTS: The study group consisted of 67 patients, 47 women and 20 men, with an average age at time of revision of 62 (SD: 15.3). 67 revisions of total hip prostheses were performed: 64% underwent first revision and 36% re-revision. In 40% a cup revision only was performed, in 15% a femoral revision and 45% underwent total revision. The most frequent indications for revision were aseptic loosening (76%) and recurrent dislocation (13%). In 19% of the procedures a peroperative complication occurred, 2 patients died during follow up although not from operation-related causes, and in 51% of remaining patients a complication occurred within 2 years after surgery. The most frequently seen complications were dislocation (8%) and deep infection (5%). 2 of 3 deep infections were re-infections of earlier septic revisions. The most frequent complication was luxation. Together with recurrent dislocation, deep infection was the most frequent indication for a re-operation. The re-operation percentage was 12. 3 out of the 5 luxations that occurred were re-revised due to recurrent dislocation. CONCLUSION: Hip revision procedures are associated with a high rate of complications within 2 years of implantation. The data are comparable with the limited amount of published data.

Contains fulltext : 51605.pdf (Publisher’s version ) (Closed access) Bone impaction grafting has been advocated for reconstruction of femoral head osteonecrosis. However, bone grafts do not prevent the progression of collapse and subsequent disabling osteoarthritis in late-stage osteonecrosis. We hypothesized reconstruction of large subchondral defects with a mix of impacted morsellized cancellous bone grafts and calcium phosphate cement would afford mechanical stability allowing remodeling into new bone without femoral head collapse. In a pilot study we created a critically sized subchondral defect model in 15 goats following the trapdoor procedure. Defects were left empty (n = 3), filled with morsellized cancellous bone grafts (n = 6), or filled with a mixture of morsellized cancellous bone and calcium phosphate cement (n = 6). No defects collapsed by sacrifice at 12 weeks. Defects filled with morsellized cancellous bone showed complete incorporation and remodeling to a normal trabecular structure. In the morsellized cancellous bone/calcium phosphate cement group, most of the calcium phosphate cement was resorbed in 12 weeks and the mixture was largely replaced by fibrous or fatty marrow. Although the specific mixture did not confirm our hypothesis, we suspect a slower resorbing calcium phosphate cement remains a promising material to mix with morsellized cancellous bone to treat late stages of femoral head osteonecrosis.

Contains fulltext : 52780.pdf (Publisher’s version ) (Closed access) Reconstruction of bone defects with impacted morsellized cancellous bone grafts (MCB) is a popular method. Because of a shortage of human bone, mixing with biomaterials may be attractive. Ceramics may be used as bone graft extenders. In this study, various volume mixtures of biphasic tri-calciumphosphate/hydroxyl-apatite (TCP-HA) granules (1.5-2 mm) with MCB were examined in a non-loaded defect model in rabbits. Direct post-operatively, many 10-150 microm TCP-HA particles were present due to impaction. Irrespective to the group, after 8 weeks, virtually all MCB was resorbed and most TCP-HA granules were osseous-integrated with newly formed bone. The cross-sectional areas of TCP-HA after 8 weeks was generally smaller compared with direct post-operatively and the number of small 10-150 microm TCP-HA particles seemed reduced. Macrophages and giant cells were sparse after 8 weeks. In conclusion, the osteoconductivity of various mixtures of MCB and TCP-HA granules is not dependent on the ratio of TCP-HA over MCB. The reduced number of the 10-150microm TCP-HA particles after 8 weeks, may suggest that a cellular mediated resorption process of TCP-HA granules took place. Based on these favorable biological findings subsequent in-vivo experiments are warranted in load-bearing conditions to investigate whether these findings hold for joint reconstruction purposes.

Contains fulltext : 50724.pdf (Publisher’s version ) (Closed access)

Contains fulltext : 47852.pdf (Publisher’s version ) (Closed access) BACKGROUND: The purpose of this study was to evaluate the clinical and radiographic outcomes of revision of the femoral component of a hip arthroplasty with use of an impaction bone-grafting technique and a cemented polished stem. METHODS: Thirty-three consecutive femoral reconstructions that were performed between March 1991 and February 1996 with use of the X-change femoral revision system, fresh-frozen morselized allograft, and a cemented polished Exeter stem were followed prospectively. Femoral bone stock defects were classified according to the Endoklinik classification. The average age of the patients at the time of the femoral component revision was sixty-three years. No patient was lost to follow-up, which was performed at a minimum of eight years, but eight patients had died. None of the deaths was related to the surgery. RESULTS: No femoral reconstruction had been rerevised at a mean of 10.4 years postoperatively. There was one unrecognized intraoperative fracture, which healed following nonoperative treatment. There were three postoperative femoral fractures, all through cortical defects at the level of the tip of the prostheses. All fractures healed after plate fixation, and all femoral implants were left in situ. The average subsidence of the stem within the cement mantle was 3 mm; seven stems migrated > or =5 mm. The average Harris hip score improved from 49 points prior to surgery to 85 points (range, 68 to 100 points) at the time of this review. Subsidence did not affect the Harris hip score. Kaplan-Meier analysis, with an end point of femoral revision for any reason, showed a survival rate of 100% (one-sided 95% confidence interval, 100% to 91.3%). CONCLUSIONS: Femoral revision with use of an impaction bone-grafting technique and a cemented polished stem resulted in an excellent prosthetic survival rate at eight to thirteen years postoperatively. The major problem that occurred was a femoral fracture in four patients.

Contains fulltext : 49342.pdf (Publisher’s version ) (Closed access)

Contains fulltext : 65587_propefofn.pdf (Publisher’s version ) (Open Access) Contains fulltext : 70688.pdf (Publisher’s version ) (Open Access) Heterotopic ossification (HO) is formation of bone where it normally is not present. The incidence of HO after THA among different studies varies between 10 and 90%. Larger studies using the same or similar grading systems show considerably smaller variations, with HO ranging between 35 and 60%. Two different forms of prophylaxis of HO are being applied. The first is radiation therapy, which can be applied directly before or directly after the operation with similar results. The second mode of prophylaxis is by non-steroidal anti-inflammatory drugs (NSAIDs). Although indomethacin and several other NSAIDs are effective in preventing heterotopic ossification (HO) after primary total hip arthroplasty, side effects are frequently observed. Approximately 30% of all patients on traditional NSAIDs suffer from gastrointestinal side effects. In this thesis the next research questions were formulated: 1 Can the duration of treatment with indomethacin to prevent HO after THA be shortened? 2 Are the prophylactic effects of COX-2 selective NSAIDs on the development of HO after THA similar to that of indomethacin? 3 Do Non-Steroidal Anti-Inflammatory Drugs impair bone ingrowth? 4 Is it possible to measure the local inflammatory response after THA by means of cytokine levels at the site of surgery? RU Radboud Universiteit Nijmegen, 06 oktober 2008 Promotor : Kampen, A. van Co-promotores : Schreurs, B.W., Rijnberg, W.J. 143 p.

Contains fulltext : 49618.pdf (Publisher’s version ) (Open Access) RU Radboud Universiteit Nijmegen, 06 april 2006 Promotor : Veth, R.P.H. Co-promotores : Buma, P., Schreurs, B.W., Verdonschot, N.J.J. 210 p.

Contains fulltext : 49146.pdf (Publisher’s version ) (Open Access) Je evenwicht verliezen - het gebeurt iedereen wel eens. Meestal loopt het goed af en val je niet, omdat je nog tijdig je balans weet te corrigeren. Hoe doe je dat? Promovendus Christian Grüneberg heeft met name gekeken naar de motorische reacties waarmee plotselinge externe verstoringen in de balans worden opgevangen. Door proefpersonen met behulp van een korset op verschillende manieren te 'verstijven', blijkt dat controle van de armen en de romp van essentieel belang is voor een stabiele staande houding. Tevens tonen de resultaten aan dat een toename van de rompstijfheid - in het bijzonder in de zijwaartse richting - een verklaring voor rompinstabiliteit bij ouderen zou kunnen zijn. RU Radboud Universiteit Nijmegen, 01 maart 2005 Promotores : Duysens, J.E.J., Allum, J.H.J., Veth, R.P.H. Co-promotor : Schreurs, B.W. 132 p.