The aim of the thesis was to contribute to a better understanding of the influence of differences in implant design and surgical techniques on the migration of total knee arthroplasties (TKAs) and,... Show moreThe aim of the thesis was to contribute to a better understanding of the influence of differences in implant design and surgical techniques on the migration of total knee arthroplasties (TKAs) and, more broadly, the effect of using Radiostereometric Analysis (RSA) and other markers to detect early loosening. In this thesis, we compared various types of TKAs in different randomized controlled trials. Additionally, we investigated whether the positioning of TKAs relative to the patient's specific leg axis (e.g., neutral, varus, or valgus alignment) affects the stability of the prosthesis. We also analyzed, by combining registry data with data from a meta-analysis, whether TKAs evaluated with migration analysis (radiostereometric analysis; RSA) yield better results than TKAs that have not been previously examined with RSA. Finally, we conducted a systematic review to explore whether there are markers that can indicate loosening/failure of a prosthesis. Show less
Purpose - The aim of this prospective randomised controlled study was to compare wear characteristics and functional outcome between deep-dished mobile bearing (MB) and fixed bearing (FB) cemented... Show morePurpose - The aim of this prospective randomised controlled study was to compare wear characteristics and functional outcome between deep-dished mobile bearing (MB) and fixed bearing (FB) cemented total knee arthroplasty (TKA). We hypothesised that deep-dished MB reduces polyethylene wear and improves patient-reported outcome measures.MethodsA total of 50 patients were randomised to receive a MB or FB tibia component of the same cemented TKA design. Patients were evaluated over a 5-year follow-up period. Medial and lateral wear were assessed using model-based Roentgen Stereophotogrammetric Analysis (RSA) and compared with the direct postoperative minimal joint space measurement. Functional outcome was assessed by the clinician-derived KSS and OKS, WOMAC, LEAS, and FJS-12. All data were derived using a general linear mixed model.Results - At 5-year follow-up, decreased wear in the MB compared to the FB group was observed on the lateral side (0.07 +/- 0.17 mm, p = 0.026), but not on the medial side (0.31 +/- 0.055 mm, p = 0.665). Functional outcomes improved with a statistical significant effect over time, with no significant differences between groups (all p > 0.17).ConclusionThis model-based RSA study with 5-year follow-up showed that cemented deep-dished MB reduced lateral polyethylene wear as compared to FB in a single TKA system, whilst clinical outcomes were comparable. Longer follow-up is needed to establish clinical implications of these altered wear patterns and determine type of wear. Show less
Improving implant longevity is an eminent challenge in joint replacement surgery with aseptic loosening as the major reason for early failure necessitating revision surgery in both total hip and... Show moreImproving implant longevity is an eminent challenge in joint replacement surgery with aseptic loosening as the major reason for early failure necessitating revision surgery in both total hip and total knee arthroplasty (THA and TKA). Analysis of implant fixation by measuring migration with roentgen stereophotogrammetric analysis (RSA) has shown that the loosening process starts at very early onset after implantation. Implants showing relative high migration during the first post-operative year are prone to failure and subsequent revision later on. However, it is still not crystallized how specific implant characteristics or the surgical procedure affect the implant migration pattern and what degree of initial migration is acceptable without jeopardizing longevity of implant fixation at 10-20 years. In this thesis the migration pattern in relation to longevity of both cemented and cementless stems in THA, the influence of mobile-bearings in TKA on migration and survival, and methods to instantly evaluate implant fixation by inducible displacement have been studied. Show less
The longevity of total knee implants may be impaired by aseptic loosening of the components within the bone. Aseptic loosening remains the leading cause of revision surgery. In the past decades,... Show moreThe longevity of total knee implants may be impaired by aseptic loosening of the components within the bone. Aseptic loosening remains the leading cause of revision surgery. In the past decades, many implant design aspects and surgical techniques have been changed in an attempt to decrease the risk of loosening. Given that radiostereometric analysis (RSA) is a highly accurate method to detect early implant migration which is predictive for late loosening, new implant designs should ideally be tested with RSA before widespread introduction onto the market. In this thesis, we present the results of four randomized controlled trials studying the effect of such changes in design on implant migration with use of RSA. We also pooled several RSA studies to be able to analyze the effect of other possible risk factors, including patient characteristics and surgical technique. We show that slight changes in implant design may increase the risk of loosening considerably, while other factors that are often thought to be associated with an increased risk (such as a high body mass index) do not appear to have a large effect. Show less
This thesis describes several aspects of diagnostic and therapeutic possibilities of mitochondrial function in clinical pharmacological. During several clinical studies in healthy volunteers, pre... Show moreThis thesis describes several aspects of diagnostic and therapeutic possibilities of mitochondrial function in clinical pharmacological. During several clinical studies in healthy volunteers, pre-frail elderly and Huntington’s disease patients, we used phosphorous magnetic resonance spectroscopy as the main method to measure mitochondrial function in vivo. Other in vivo methods included Near Infrared Spectroscopy and the novel Protoporphorin-9 Triplet State Lifetime Technique, besides in vitro ELISA methods to measure activity of separate complexes of the mitochondrial electron transport chain. Using these modalities, we showed mitochondrial dysfunction in pre-frail elderly, emphasizing the importance of an active lifestyle in the prevention of sarcopenia and frailty. Using the mitotoxicity of simvastatin, and its reversibility by ubiquinol, we validated the first proof-of-pharmacology model in healthy volunteers to evaluate efficacy of novel mitochondrial function improving compounds. We also described the importance of measuring (mitochondrial) oxygen consumption as a means to measure mitotoxicity of commonly described medications. Lastly, we evaluated the safety and efficacy of the novel compound SBT-020 in a placebo-controlled, double-blinded, randomized controlled trial in mild to moderate Huntington’s disease patients and compared central to peripheral mitochondrial function for the first time, gaining inside into therapeutic possibilities in this complex and devastating disease. Show less
Our aim was to assess the effect of perioperative interventions targeting psychological distress on clinical outcome after total knee arthroplasty (TKA). We searched studies on the effect of... Show moreOur aim was to assess the effect of perioperative interventions targeting psychological distress on clinical outcome after total knee arthroplasty (TKA). We searched studies on the effect of perioperative interventions focused on psychological distress used in conjunction with TKA on pain, function, and quality of life (QoL) on PubMed, Embase.com, PsycINFO/OVID, CENTRAL, the Cochrane Database of Systematic Reviews, Scopus, and Web of Science. We included 40 studies (22 RCTs, ten cohort studies, and eight quasi-experimental studies) with a total of 3846 patients. We graded the quality of evidence as low for pain and function and as moderate for QoL. Patients receiving music, education, cognitive behavioural therapy, guided imagery, pain coping skills training, Reiki, occupational therapy with self-monitoring, and biofeedback-assisted progressive muscles relaxing training had lower pain scores or declined opioid prescriptions after TKA. Pain coping skills training, audio recording-guided imagery scripts, video promoting self-confidence, psychological therapies by video, Reiki, music, occupational therapy with self-monitoring, education, and psychotherapy improved postoperative functional outcome. Education through an app improved QoL after TKA. The studies in our systematic review show that perioperative interventions targeting psychological distress for patients receiving TKA seem to have a positive effect on postoperative pain, function, and QoL. RCTs with strict methodological safeguards are still needed to determine if perioperative interventions focused on psychological distress should be used in conjunction with TKA. These studies should also assess which type of intervention will be most effective in improving patient-reported outcome measures and declining opioid prescriptions. Show less
Purpose The aim of this study was to evaluate the anthropometric differences between knees of Indonesian Asians and Dutch Caucasians and the fit of nine different knee implant systems. Methods A... Show morePurpose The aim of this study was to evaluate the anthropometric differences between knees of Indonesian Asians and Dutch Caucasians and the fit of nine different knee implant systems. Methods A total of 268 anteroposterior (AP) and lateral knee preoperative radiographs from 134 consecutive patients scheduled for total knee arthroplasty at two different centres in Jakarta and Leiden were included. Both patient groups were matched according to age and sex and included 67 Asians and 67 Caucasians. We assessed the radiographic differences between the Asian and Caucasian anthropometric data. The dimensions of the nine knee implant designs (Vanguard, Genesis II, Persona Standard, Persona Narrow, GK Sphere, Gemini, Attune Standard, Attune Narrow, and Sigma PFC) were compared with the patients' anthropometric (distal femur and proximal tibia) measurements. Results The Dutch Caucasian patients had larger mediolateral (ML) and AP femoral and tibial dimensions than the Indonesian Asians. The aspect ratios of the distal femur and tibia were larger in Asians than in Caucasians. The AP and ML dimensions were mismatched between the tibial components of the nine knee systems and the Asian anthropometric data. Both groups had larger ML distal femoral dimensions than the knee systems. Conclusion Absolute and relative differences in knee dimensions exist not only between Asian and Caucasian knees but also within both groups. Not all TKA systems had a good fit with the Asian and Caucasian knee phenotypes. An increase in the range of available knee component sizes would be beneficial, although TKA remains an adequate compromise. Show less
This thesis aimed to contribute to the optimal use of non-surgical treatment and timing of surgery among hip and knee OA and sciatica patients in two different ways. First, if guidelines are... Show moreThis thesis aimed to contribute to the optimal use of non-surgical treatment and timing of surgery among hip and knee OA and sciatica patients in two different ways. First, if guidelines are specific on non-surgical and (timing of) surgical treatment, the focus was on implementation strategies to improve guideline uptake in hip and knee OA and sciatica care. Across the different studies carried out in this thesis, knowledge, attitude of health care providers and organization of care seem to be relevant for any implementation of evidence based guideline recommendations in a multidisciplinary setting. Future implementation studies can start focusing on these topics. However, if guidelines are not available or not specific on e.g. optimal timing of total hip or knee arthroplasty (THA/TKA), additional evidence is needed. Therefore, the second part of this thesis focused on studying criteria and determinants to reach the best possible outcomes after THA and TKA, as information in the literature is lacking on optimal timing of surgery. Pooling multiple cohort studies in the Netherlands showed that preoperative status is the most important variable for outcome after both THA and TKA, i.e. patients with better preoperative quality of life, functioning and less pain had better postoperative outcomes. Show less
