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Neuromusculoskeletal models can be used to evaluate aberrant muscle function in cerebral palsy (CP), for example by estimating muscle and joint contact forces during gait. However, to be accurate, models should include representative musculotendon parameters. We aimed to estimate personalised parameters that capture the mechanical behaviour of the plantarflexors in children with CP and typically developing (TD) children. Ankle angle (using motion capture), torque (using a load-cell), and medial gastrocnemius fascicle lengths (using ultrasound) were measured during slow passive ankle dorsiflexion rotation for thirteen children with spastic CP and thirteen TD children. Per subject, the measured rotation was input to a scaled OpenSim model to simulate the torque and fascicle length output. Musculotendon model parameters were personalised by the best match between simulated and experimental torque–angle and fascicle length-angle curves according to a least-squares fit. Personalised tendon slack lengths were significantly longer and optimal fibre lengths significantly shorter in CP than model defaults and than in TD. Personalised tendon compliance was substantially higher in both groups compared to the model default. The presented method to personalise musculotendon parameters will likely yield more accurate simulations of subject-specific muscle mechanics, to help us understand the effects of altered musculotendon properties in CP.

BACKGROUND: Developmental Dysplasia of the Hip (DDH) is one of the most common pediatric orthopedic disorders, affecting 1-3% of all newborns. The optimal treatment of centered DDH is currently under debate. This randomized controlled trial aims to study the (cost-)effectiveness of active monitoring versus abduction treatment for infants with centered DDH. METHODS: This is a multicenter, parallel-group, open-label, non-inferiority randomized controlled trial studying the (cost-)effectiveness of active monitoring versus abduction treatment for infants with centered DDH in fourteen hospitals in the Netherlands. In total, 800 infants with centered DDH (Graf IIa-/IIb/IIc), aged 10-16 weeks, will be randomly allocated to the active monitoring or abduction treatment group. Infants will be followed up until the age of 24 months. The primary outcome is the rate of normal hips, defined as an acetabular index lower than 25 degrees on an antero-posterior radiograph, at the age of 12 months. Secondary outcomes are the rate of normal hips at the age of 24 months, complications, time to hip normalization, the relation between baseline patient characteristics and the rate of normal hips, compliance, costs, cost-effectiveness, budget impact, health-related quality of life (HRQoL) of the infant, HRQoL of the parents/caregivers, and parent/caregiver satisfaction with the treatment protocol. DISCUSSION: The outcomes of this randomized controlled trial will contribute to improving current care-as-usual for infants with centered DDH. TRIAL REGISTRATION: Dutch Trial Register, NL9714, registered September 6, 2021. https://clinicaltrialregister.nl/en/trial/29596.

Background: Only a few papers are published on the safety and effectiveness of acute burn care in low-income countries. A cohort study was therefore carried out to determine such outcomes.Methods: The study was conducted in a rural Tanzanian hospital in 2017–2018. All patients admitted with burns were eligible. Complications were scored during admission as an indication for safety. Survivors of severe burn injuries were evaluated for time of reepithelialization, graft take, disability (WHODAS2.0) and quality of life (EQ5D-3L) up to 3 months post-injury, as an indication of effectiveness.Results: Patients presented on average at 5 days after injury (SD 11, median 1, IQR 0–4). Three patients died at admission. The remaining 79 were included in the cohort. Their median age was 3 years (IQR 2–9, range 0.5–49), mean TBSA burned 12% (SD10%) and mortality rate 11.4%. No surgery-related mortality or life-threatening complications were observed. Skin grafting was performed on 29 patients at a delayed stage (median 23 days, IQR 15–47). Complications of skin grafts included partial (25% of procedures) and complete graft necrosis (8% of procedures). The mean time to reepithelialization was 52 (SD 42) days after admission. Disability and quality of life improved from admission to 3 months after injury (pConclusion: In this resource-limited setting patients presented after a delay and with multiple complications. The mortality during the first two weeks after admission was high. Surgery was found to be safe and effective. A significant improvement in disability and quality of life was observed.

Bone defects caused by systemic or local factors cannot heal spontaneously. The repair of critical-sized bone defects in clinical practice remains challenging due to limited clinically available bone-defect filling material. To stimulate bone regeneration and resolve this clinical challenge, bone tissue engineering approaches have been developed during the past decades. Osteocytes have multiple functions in bone tissue. They can sense fluid shear stress as a result of mechanical loading, translating the mechanical stress into the production of biochemical signaling molecules. These effective biomolecules further regulate bone resorption and bone formation. Thus, it may well be that osteocytes not only regulate bone turnover but are also able to enhance osteogenesis of stem cells, suggesting a novel yet unrecognized role of osteocytes in governing bone tissue regeneration. In Chapter 2, we reviewed osteocyte functions in bone, as well as the interaction of osteocytes with other bone cells, and their role in bone remodeling. We hypothesize that osteocytes may have a pivotal role in bone regeneration as well, and thus that bone regeneration may be enhanced effectively and rapidly by optimal usage and stimulation of osteocytes. Currently available synthetic bone grafts are biocompatible and osteoconductive, but the majority of these biomaterials lack osteoinductivity. Biomaterials coated with various growth factors, proteins, and/or drugs promote the expansion and osteogenic differentiation of precursor cells. However, these growth factors or drugs might cause local and systemic adverse effects that hinder the clinical application for bone regeneration. Therefore, the search for safe and effective biomaterials to promote bone regeneration is still ongoing. In Chapter 3, we concluded that our results indicate a possible role of k-carrageenan in pre-osteoblast adhesion, spreading, migration, metabolic activity, proliferation, and osteogenic differentiation. This study fully explored the influence of k-carrageenan on cell function from different aspects that are needed for bone regeneration. The current results suggest that k-carrageenan might be a promising factor to functionalize bone graft and for enhanced osseointegration of implants. The search for cost-effective bioactive agents that can be incorporated in biomimetic calcium phosphate coating on an implant surface to improve implant osseointegration is still ongoing. k-Carrageenan could be a potent factor to improve implant osteoinductivity and osseointegration when incorporated in a calcium phosphate coating on titanium implants. In Chapter 4, we successfully incorporated k-carrageenan in an octa-calcium phosphate (OCP) coating on a titanium surface using a biomimetic co-precipitation technique. We found that k-carrageenan in the OCP coating increased pre-osteoblast spreading, proliferation, and metabolic activity, as well as alkaline phosphatase (ALP) activity, matrix mineralization, and osteogenic gene expression suggesting that k-carrageenan-functionalized OCP coating might improve osseointegration of titanium dental or orthopedic implants. Confined cell-cell and/or cell-scaffold interactions in three-dimensional (3D)-printed scaffolds containing β-tricalcium phosphate (TCP) limit bone regeneration and large bone defect repair. Stem cell culture systems have attracted considerable attention as a way to better mimic the complex interactions between individual cells and scaffolds that occur in vivo. Spheroids might be a promising strategy to improve cell-cell and/or cell-scaffold interactions to achieve ideal bone regeneration. In Chapter 5, we successfully developed self-assembled stem cells from human exfoliated deciduous teeth (SHEDs) µ-spheroids that enhanced the osteogenic potential of 3D-printed hydroxypropyl methylcellulose/polyethylenimine/β-TCP composite scaffolds in vitro and in vivo, suggesting that SHEDs µ-spheroids may be promising in bone tissue engineering for bone regeneration. Collectively, natural polymers and osteogenic cells do affect bone tissue regeneration. Bone regeneration modulated by osteocytes, k-carrageenan, and SHEDs µ-spheroids is promising in bone tissue engineering. Investigation of these processes provides further opportunities to learn and elucidate the mechanisms involved, leading to the development of new strategies for bone regeneration.

Background: Antibiotic use prior to biopsy acquisition in people with diabetes and osteomyelitis of the foot (DFO) might influence bacterial yield in cultures or induce bacterial resistance. Obtaining reliable culture results is pivotal to guide antibiotics for conservative treatment of DFO. Methods: We prospectively analysed cultures of ulcer bed and percutaneous bone biopsies of people with DFO and investigated if antibiotics administered prior to (

Background: Children with cerebral palsy often show deviating calf muscle activation patterns during gait, with excess activation during early stance and insufficient activation during push-off. Research question: Can children with cerebral palsy improve their calf muscle activation patterns during gait using one session of biofeedback-driven gaming? Methods: Eighteen children (6–17 y) with spastic cerebral palsy received implicit game-based biofeedback on electromyographic activity of the calf muscle (soleus or gastrocnemius medialis) while walking on a treadmill during one session. Biofeedback alternately aimed to reduce early stance activity, increase push-off activity, and both combined. Early stance and push-off activity and the double-bump-index (early stance divided by push-off activity) were determined during baseline and walking with feedback. Changes were assessed at group level using repeated measures ANOVA with simple contrast or Friedman test with post-hoc Wilcoxon signed rank test, as well as individually using independent t-tests or Wilcoxon rank sum tests. Perceived competence and interest-enjoyment were assessed through a questionnaire. Results: Children successfully decreased their electromyographic activity during early stance feedback trials (relative decrease of 6.8 ± 12.2 %, P = 0.025), with a trend during the combined feedback trials (6.5 ± 13.9 %, P = 0.055), and increased their electromyographic activity during push-off feedback trials (8.1 ± 15.8 %, P = 0.038). Individual improvements were seen in twelve of eighteen participants. All children experienced high levels of interest-enjoyment (8.4/10) and perceived competence (8.1/10). Significance: This exploratory study suggests that children with cerebral palsy can achieve small within-session improvements of their calf muscle activation pattern when provided with implicit biofeedback-driven gaming in an enjoyable manner. Follow-up gait training studies can incorporate this method to assess retention and long-term functional benefits of electromyographic biofeedback-driven gaming.

Introduction: Video-based clinical rating plays an important role in assessing dystonia and monitoring the effect of treatment in dyskinetic cerebral palsy (CP). However, evaluation by clinicians is time-consuming, and the quality of rating is dependent on experience. The aim of the current study is to provide a proof-of-concept for a machine learning approach to automatically assess scoring of dystonia using 2D stick figures extracted from videos. Model performance was compared to human performance.Methods: A total of 187 video sequences of 34 individuals with dyskinetic CP (8–23 years, all non-ambulatory) were filmed at rest during lying and supported sitting. Videos were scored by three raters according to the Dyskinesia Impairment Scale (DIS) for arm and leg dystonia (normalized scores ranging from 0–1). Coordinates in pixels of the left and right wrist, elbow, shoulder, hip, knee and ankle were extracted using DeepLabCut, an open source toolbox that builds on a pose estimation algorithm. Within a subset, tracking accuracy was assessed for a pretrained human model and for models trained with an increasing number of manually labeled frames. The mean absolute error (MAE) between DeepLabCut’s prediction of the position of body points and manual labels was calculated. Subsequently, movement and position features were calculated from extracted body point coordinates. These features were fed into a Random Forest Regressor to train a model to predict the clinical scores. The model performance trained with data from one rater evaluated by MAEs (model-rater) was compared to inter-rater accuracy.Results: A tracking accuracy of 4.5 pixels (approximately 1.5 cm) could be achieved by adding 15–20 manually labeled frames per video. The MAEs for the trained models ranged from 0.21 ± 0.15 for arm dystonia to 0.14 ± 0.10 for leg dystonia (normalized DIS scores). The inter-rater MAEs were 0.21 ± 0.22 and 0.16 ± 0.20, respectively.Conclusion: This proof-of-concept study shows the potential of using stick figures extracted from common videos in a machine learning approach to automatically assess dystonia. Sufficient tracking accuracy can be reached by manually adding labels within 15–20 frames per video. With a relatively small data set, it is possible to train a model that can automatically assess dystonia with a performance comparable to human scoring.

Balance recovery after tripping often requires an active adaptation of foot placement. Thus far, few attempts have been made to actively assist forward foot placement for balance recovery employing wearable devices. This study aims to explore the possibilities of active forward foot placement through two paradigms of actuation: assistive moments exerted with the reaction moments either internal or external to the human body, namely ‘joint’ moments and ‘free’ moments, respectively. Both paradigms can be applied to manipulate the motion of segments of the body (e.g., the shank or thigh), but joint actuators also exert opposing reaction moments on neighbouring body segments, altering posture and potentially inhibiting tripping recovery. We therefore hypothesised that a free moment paradigm is more effective in assisting balance recovery following tripping. The simulation software SCONE was used to simulate gait and tripping over various ground-fixed obstacles during the early swing phase. To aid forward foot placement, joint moments and free moments were applied either on the thigh to augment hip flexion or on the shank to augment knee extension. Two realizations of joint moments on the hip were simulated, with the reaction moment applied to either the pelvis or the contralateral thigh. The simulation results show that assisting hip flexion with either actuation paradigm on the thigh can result in full recovery of gait with a margin of stability and leg kinematics closely matching the unperturbed case. However, when assisting knee extension with moments on the shank, free moment effectively assist balance but joint moments with the reaction moment on the thigh do not. For joint moments assisting hip flexion, placement of the reaction moment on the contralateral thigh was more effective in achieving the desired limb dynamics than placing the reaction on the pelvis. Poor choice of placement of reaction moments may therefore have detrimental consequences for balance recovery, and removing them entirely (i.e., free moment) could be a more effective and reliable alternative. These results challenge conventional assumptions and may inform the design and development of a new generation of minimalistic wearable devices to promote balance during gait.

Objective: Children and adults with talipes equinovarus (TEV) have smaller calves and shorter feet compared to non-affected controls. Do these changes have a prenatal onset?. Methods: A prospective cohort study (January 2020–July 2021) was conducted with serial ultrasonographic measurements at 20 and 28 weeks gestation and measurements directly and 6 weeks after birth. Calf circumference and width, foot length and length of humerus, ulna, radius, femur, tibia and fibula were measured in TEV and were compared to a control population. Calculated sample size necessitated a minimal population of 10 cases with TEV and 50 controls. Results: Twenty cases with TEV and 62 controls were included. Fetal calf circumference (p

Background Foot and ankle joint kinematics are measured during clinical gait analyses with marker-based multi-segment foot models. To improve on existing models, measurement errors due to soft tissue artifacts (STAs) and marker misplacements should be reduced. Therefore, the aim of this study is to define a clinically informed, universally applicable multi-segment foot model, which is developed to minimize these measurement errors. Methods The Amsterdam foot model (AFM) is a follow-up of existing multi-segment foot models. It was developed by consulting a clinical expert panel and optimizing marker locations and segment definitions to minimize measurement errors. Evaluation of the model was performed in three steps. First, kinematic errors due to STAs were evaluated and compared to two frequently used foot models, i.e. the Oxford and Rizzoli foot models (OFM, RFM). Previously collected computed tomography data was used of 15 asymptomatic feet with markers attached, to determine the joint angles with and without STAs taken into account. Second, the sensitivity to marker misplacements was determined for AFM and compared to OFM and RFM using static standing trials of 19 asymptomatic subjects in which each marker was virtually replaced in multiple directions. Third, a preliminary inter- and intra-tester repeatability analysis was performed by acquiring 3D gait analysis data of 15 healthy subjects, who were equipped by two testers for two sessions. Repeatability of all kinematic parameters was assessed through analysis of the standard deviation (σ) and standard error of measurement (SEM). Results The AFM was defined and all calculation methods were provided. Errors in joint angles due to STAs were in general similar or smaller in AFM (≤2.9°) compared to OFM (≤4.0°) and RFM (≤6.7°). AFM was also more robust to marker misplacement than OFM and RFM, as a large sensitivity of kinematic parameters to marker misplacement (i.e. > 1.0°/mm) was found only two times for AFM as opposed to six times for OFM and five times for RFM. The average intra-tester repeatability of AFM angles was σ:2.2[0.9°], SEM:3.3 ± 0.9° and the inter-tester repeatability was σ:3.1[2.1°], SEM:5.2 ± 2.3°. Conclusions Measurement errors of AFM are smaller compared to two widely-used multi-segment foot models. This qualifies AFM as a follow-up to existing foot models, which should be evaluated further in a range of clinical application areas.

biBackground:/i/bBecause the behavioral variant of frontotemporal dementia (bvFTD) shows major clinical overlap with primary psychiatric disorders (PPD) that affect similar neuroanatomical circuits, a common genetic vulnerability between FTD and PPD was hypothesized.biAims:/i/bWe studied whether PPD are more prevalent in families of patients with sporadic frontotemporal dementia compared with healthy controls (HC), subjects with Alzheimer's disease (AD), and individuals with bipolar disorder (BD).biMethods:/i/bIn this case-control study performed between January 2013 and February 2019, we investigated the first-degree family history concerning depression, psychosis (including schizophrenia), BD, and autism spectrum disorder for 73 bvFTD patients, 153 patients with BD, 108 patients with AD, and 101 HC with a semistructured questionnaire (QFTD-NL 1.0) according toiDSM-IV/i,iDSM-5/i, oriICD-10/icriteria.biResults:/i/bPatients with bvFTD had a 2.58-fold higher odds of having a first-degree family member with depression compared to HC (iP/i = .04). Furthermore, they showed 3.26-fold higher odds of having a first-degree relative with psychosis compared to HC (iP/i = .09).biConclusions:/i/bOur results implicate a link between dementia, including sporadic bvFTD, and depression. Further study into the genetic overlap between bvFTD and PPD might provide clues to targeting common disease mechanisms.

Despite the high incidence of developmental dysplasia of the hip (DDH), treatment is very diverse. Therefore, the Dutch Orthopedic Society developed a clinical practice guideline with recommendations for optimal and uniform treatment of DDH. This article summarizes the guideline on centered DDH (i.e. Graf types 2A–C). The guideline development followed the criteria of Appraisal of Guidelines for Research and Evaluation II. A systematic literature review was performed to identify randomized controlled trials and comparative cohort studies including children Out of 430 potentially relevant articles, 5 comparative studies were included. Final guideline recommendations were (1) initially observe 3-month-old patients with centered DDH, start abduction treatment if the hip does not normalize after 6–12 weeks; (2) prescribe a Pavlik harness to children 6 months; (3) assess patients every 6 weeks; and (4) discontinue the abduction device when the hip has normalized or when the child is 12 months. This paper presents a summary of part 1 of the first evidence-based guideline for treatment of centered DDH in children

Purpose Different bacteria lead to divers diabetic foot infections (DFIs), and some bacteria probably lead to higher amputation and mortality risks. We assessed mortality and amputation risk in relation to bacterial profiles in people DFI and investigated the role of sampling method. Methods We included people (> 18 years) with DFI in this retrospective study (2011–2020) at a Dutch tertiary care hospital. We retrieved cultures according to best sampling method: (1) bone biopsy; (2) ulcer bed biopsy; and (3) swab. We aggregated data into a composite determinant, consisting of unrepeated bacteria of one episode of infection, clustered into 5 profiles: (1) Streptococcus and Staphylococcus aureus; (2) coagulase-negative Staphylococcus, Cutibacterium, Corynebacterium and Enterococcus; (3) gram-negative; (4) Anaerobic; and (5) less common gram-positive bacteria. We calculated Hazard Ratio’s (HR’s) using time-dependent-Cox regression for the analyses and investigated effect modification by sampling method. Results We included 139 people, with 447 person-years follow-up and 459 episodes of infection. Sampling method modified the association between bacterial profiles and amputation for profile 2. HR’s (95% CI’s) for amputation for bacterial profiles 1–5: 0.7 (0.39–1.1); stratified analysis for profile 2: bone biopsy 0.84 (0.26–2.7), ulcer bed biopsy 0.89 (0.34–2.3), swab 5.9*(2.9–11.8); 1.3 (0.78–2.1); 1.6 (0.91–2.6); 1.6 (0.58–4.5). HR’s (95% CI’s) for mortality for bacterial profiles 1–5: 0.89 (0.49–1.6); 0.73 (0.38–1.4); 2.6*(1.4–4.8); 1.1(0.58–2.2); 0.80(0.19–3.3). Conclusions In people with DFI, there was no association between bacterial profiles in ulcer bed and bone biopsies and amputation. Only in swab cultures, low-pathogenic bacteria (profile 2), were associated with a higher amputation risk. Infection with gram-negative bacteria was associated with a higher mortality risk. This study underlined the possible negative outcome of DFI treatment based on swabs cultures.

This study investigates patients’ access to surgical care for burns in a low- and middle-income setting by studying timeliness, surgical capacity, and affordability. A survey was conducted in a regional referral hospital in Manyara, Tanzania. In total, 67 patients were included. To obtain information on burn victims in need of surgical care, irrespective of time lapsed from the burn injury, both patients with burn wounds and patients with contractures were included. Information provided by patients and/or caregivers was supplemented with data from patient files and interviews with hospital administration and physicians. In the burn wound group, 50% reached a facility within 24 hours after the injury. Referrals from other health facilities to the regional referral hospital were made within 3 weeks for 74% in this group. Of contracture patients, 74% had sought healthcare after the acute burn injury. Of the same group, only 4% had been treated with skin grafts beforehand, and 70% never received surgical care or a referral. Together, both groups indicated that lack of trust, surgical capacity, and referral timeliness were important factors negatively affecting patient access to surgical care. Accounting for hospital fees indicated patients routinely exceeded the catastrophic expenditure threshold. It was determined that healthcare for burn victims is without financial risk protection. We recommend strengthening burn care and reconstructive surgical programs in similar settings, using a more comprehensive health systems approach to identify and address both medical and socioeconomic factors that determine patient mortality and disability.

Objectives: In this cadaveric study, the accuracy of CAS guided mandibular and maxillary reconstruction including immediate dental implant placement in different Brown defect classes is assessed. Materials and methods: The virtual planning and surgical procedure was conducted according to a newly proposed Amsterdam UMC reconstruction protocol. Postoperative evaluation was performed according to a previously proposed evaluation guideline. Results: Fourteen mandibular and 6 maxillary reconstructions were performed. Average mandibular angle deviations were 1.52°±1.32, 1.85°±1.58, 1.37°±1.09, 1.78°±1.37, 2.43°±1.52 and 2.83°±2.37, respectively for the left and right axial angles, left and right coronal angles and left and right sagittal angles. A total of 62 dental implants were placed in neomandibles with an average dXYZ values of 3.68 ± 2.21 mm and 16 in neomaxillas with an average dXYZ values of 3.24 ± 1.7 mm. Conclusion: Promising levels of accuracy were achieved for all mandibular angles. Dental implant positions approached the preoperative preferred positions well, within the margin to manufacture prosthetic devices.

© 2022 The AuthorsBackground: Gait adaptability is of utmost importance for keeping balance during gait in patients with knee osteoarthritis, also after total knee arthroplasty (TKA). The aims of this explorative study are: (1) assess the effect of age, knee osteoarthritis and TKA on gait adaptability; (2) assess changes in gait adaptability pre-to post-TKA and (3) their relation to functional outcomes. Methods: Gait adaptability was measured using a Target Stepping Test (TST) in knee osteoarthritis patients before (preTKA) and 12 months after TKA (postTKA) and compared to asymptomatic old (AsOld) and young adults (AsYng). TST imposed an asymmetrical gait pattern with projected stepping targets at high walking speed. Gait adaptability was determined through stepping accuracy on the targets. The Oxford Knee Score (OKS) and Timed-Up-and-Go test (TUG) measured patients’ physical function. Results: 12 preTKA, 8 postTKA, 18 AsYng, 21 AsOld were tested. Age showed no effect on TST-stepping accuracy. PreTKA showed worse TST-stepping accuracy compared to AsYng and AsOld (7.7; 6.2 cm difference). PostTKA showed an improvement of 52% in TST-stepping accuracy compared to preTKA (3.2 cm). Higher stepping accuracy preTKA predicted higher stepping accuracy post-TKA. In addition, low preTKA stepping accuracy predicted more improvement postTKA. Pre-to post-TKA improvement of stepping accuracy was related to improvement on the TUG (Beta = 0.17, p = 0.024), but not to OKS. Conclusions: Gait adaptability is improved following TKA in knee osteoarthritis patients and no longer significantly worse than asymptomatic adults. The relation of gait adaptability to function is shown by its relation to the TUG and shows to have predictive value pre-to post-TKA.

Background: The Foot Profile Score (FPS) is a single score that summarises foot posture and dynamic foot motion during the gait cycle based on the kinematic data of the Oxford Foot Model. The FPS enables clinicians and researchers to quantify foot abnormalities during gait, to monitor change in foot/ankle motion over time, and to measure the outcome of intervention. With the creation of a new outcome measure, it is important to test its responsiveness in a clinical population for whom it may be sensitive to change. Aim: To evaluate the responsiveness of the FPS in a clinical population following isolated foot and ankle surgery. Methods: Using previous work completed to validate the FPS, we defined the minimal clinically important difference (MCID) for the FPS. Using this MCID, we applied it to a clinical population of 37 children with cerebral palsy, spastic hemiplegia, comparing their FPS before and after foot and ankle surgery. A regression analysis looked at potential relationships between the change in FPS and their pre-operative FPS, age at surgery, and time since surgery. Results: An MCID of 2.4 degrees was calculated through regression analysis. The mean change from the pre-operative FPS to the post-operative FPS was 4.6 (SD 3.7 with a range from −0.1 to 13.4). Twenty-eight children (76%) had a change in their FPS greater than the MCID. A regression analyses only showed a clear regression between pre-operative FPS and change in FPS (R2 = 0.58 p < 0.01).

Summary Purpose The use of free vascularized fibula grafts (FVFG) in complex spinal deformity surgery intends to allow for life-long stability of the spine with good long-term clinical outcome. However, these long-term outcomes of this technique are still lacking. The objective of this study is to report the long-term postoperative outcomes and establish the long-term viability of this method for spinal reconstruction. Methods A retrospective cohort study was conducted in all patients who underwent spinal reconstructive surgery utilizing a FVFG at a tertiary medical centre. Questionnaires taken from the participants were the Numeric Pain Rating Scale (NPRS), Oswestry Low Back Pain Disability (also known as Oswestry Disability Index (ODI)), Scoliosis Research Society 22r (SRS-22), the EQ-5D-5L and a self-assembled questionnaire regarding donor site comorbidities and patient satisfaction. Results Over a period of 24 years (1995–2019), we used FVFG for spinal reconstruction in 31 patients. A total of 25 patients were included in this study, 8 patients were deceased at the time of this study, and sixteen patients responded to the questionnaires. Patient satisfaction was rated 6.8 out of 10, the average SRS-22r score was 3.6, EQ-5D-5L score was 0.725, and the ODI score showed a minimal disability (0–20%) postoperatively. Overall complication-free survival was 8.9 years. Nine patients underwent a re-operation in the spinal area; five for the removal of the spinal instrumentation. Conclusion Patients reported satisfied and good long-term outcomes following FVFG surgical procedure for complex spinal deformities. Therefore, considering the alternatives, this procedure provides a good long-term solution for complex spinal deformity surgery.

In this article, author name “T.R.I. den Dungen” should be corrected to “T.R.I. van den Dungen”. The original article has been corrected.

Background Osteoradionecrosis of the jaw is a severe complication of radiotherapy in head and neck cancer patients. If conservative treatment and surgical debridement have been unsuccessful, the preferred treatment for symptomatic mandibular osteoradionecrosis (mORN) is radical surgery and subsequent reconstruction with a free vascularized flap. This study aims to assess the outcomes of free vascularized flap reconstruction in mORN. Methods A retrospective study was conducted on all patients who underwent a free vascularized flap reconstruction for mORN between 1995 and 2021 in Amsterdam UMC – VUmc, The Netherlands. Results In our cohort study, three of the twenty-eight flap reconstructions failed (10.7%). No recurrences of mORN were observed during a mean follow-up of 8 years. Conclusions The success rate of free vascularized flap reconstruction for mORN is high. The fibula is the preferred free flap for mandibular reconstruction in mORN cases. However, this type of surgery is at risk for complications and patients need to be informed that these complications may require surgical re-intervention. Level of evidence: Level IV, Therapeutic; Risk/Prognostic.

OBJECTIVE: The aims of this study were to visualize and quantify relative bone positions in the feet of individuals with cerebral palsy (CP) with a foot deformity and compare bone positions with those of typically developed (TD) controls. MATERIALS AND METHODS: Weight-bearing CT images of 14 individuals with CP scheduled for tendon transfer and/or bony surgery and of 20 TD controls were acquired on a Planmed Verity WBCT scanner. Centroids of the navicular and calcaneus with respect to the talus were used to quantify foot deformities. All taluses were aligned and the size and dimensions of the individuals' talus were scaled to correct for differences in bone sizes. In order to visualize and quantify variations in relative bone positions, 95% CI ellipsoids and standard deviations in its principle X-, Y-, and Z-directions were determined. RESULTS: In individuals with CP (age 11-17), a large variation in centroid positions was observed compared to data of TD controls. Radiuses of the ellipsoids, representing the standard deviations of the 95% CI in the principle X-, Y-, and Z-directions, were larger in individuals with CP compared to TD controls for both the calcaneus (3.16 vs 1.86 mm, 4.26 vs 2.60 mm, 9.19 vs 3.60 mm) and navicular (4.63 vs 1.55 mm, 5.18 vs 2.10 mm, 16.07 vs 4.16 mm). CONCLUSION: By determining centroids of the calcaneus and navicular with respect to the talus on WBCT images, normal and abnormal relative bone positions can be visualized and quantified in individuals with CP with various foot deformities.

The findings in this thesis underlined the confounding nature of ulnar-sided wrist pain. It is crucial to be aware of the complex overlap and interaction of the pathologies at the ulnar wrist, to guide accurate diagnosis. Relevant diagnostic imaging can assist in establishing the right diagnosis and exclude other pathology. However, it must be noted that each modality has its own specific indications and set of advantages and disadvantages. Furthermore, it may be difficult to differentiate structural sources of ulnar-sided wrist pain from unrelated incidental findings, which once again highlights the importance of taking a thorough history and performing a detailed physical examination. We stated that PROMs can assist in the development of a treatment plan to meet the specific preferences and needs of a particular patient, as they quantify care from the patient’s perspective. In this thesis we found relatively high rates of complications and reoperations after ulnar-sided wrist surgery. However, these high rates did not always necessarily lead to inferior patient-reported outcomes. We believe that psychological factors and coping strategies have a great influence on level of pain and physical functioning. Advances in medical imaging technology with the use of artificial intelligence (AI) in radiology and new techniques such as 4D-CT, may allow improved assessment of wrist kinematics and pathology in ulnar-sided wrist pain. Furthermore, there is growing evidence for a strong influence of psychosocial factors on PROMs across a range of upper-extremity disorders. We believe that that there is more to generating optimal outcomes than resolving pathophysiology, restoring anatomy, and focusing on the technical components alone. More large-scale and prospective studies are required to compare several ulnar-sided wrist procedures, ideally with implementation and a great focus on the influence of psychological and social factors.

Background Massive perivillous fibrin deposition (MPFD) is associated with adverse pregnancy outcomes and is mainly caused by maternal factors with limited involvement of fetal or genetic causes. We present one consanguineous couple with six fetuses developing Fetal Akinesia Deformation Sequence (FADS) and MPFD, with a possible underlying genetic cause. This prompted a literature review on prevalence of FADS and MPFD. Methods Fetal ultrasound examination, motor assessment, genetic testing, postmortem examination, and placenta histology are presented (2009–2019). Literature was reviewed for the association between congenital anomalies and MPFD. Results All six fetuses developed normally during the first trimester. Thereafter, growth restriction, persistent flexed position, abnormal motility, and contractures in 4/6, consistent with FADS occurred. All placentas showed histologically confirmed MPFD. Genetic analyses in the five available cases showed homozygosity for two variants of unknown significance in two genes, VARS1 (OMIM*192150) and ABCF1 (OMIM*603429). Both parents are heterozygous for these variants. From 63/1999 manuscripts, 403 fetal outcomes were mobilized. In 14/403 fetuses, congenital abnormalities in association with MPFD were seen of which two fetuses with contractures/FADS facial anomalies. Conclusion The low prevalence of fetal contractures/FADS facial anomalies in association with MPFD in the literature review supports the possible fetal or genetic contribution causing FADS and MPFD in our family. This study with literature review supports the finding that fetal, fetoplacental, and/or genetic components may play a role in causing a part of MPFDs., The low prevalence of fetal contractures/FADS facial anomalies in association with MPFD in the literature review supports the possible fetal or genetic contribution causing FADS and MPFD in our family. This study with literature review supports the finding that fetal, fetoplacental and/or genetic components may play a role in causing a part of MPFDs.

Background Fracture reverse shoulder arthroplasty (fRSA) in geriatric, complex dislocated proximal humerus fractures is becoming the standard treatment next to conservative treatment. fRSA is a multifaceted, reasonably challenging procedure of which functional outcomes and complication rates are likely to depend on the experience of the surgeon. The goal of this study was to determine whether there is a learning curve for fRSA. Methods All patients with a dislocated multipart proximal humerus fracture that were treated with an fRSA between 2013 and 2019 in a specialized institution were included. The functional outcomes (Constant Shoulder Score, Oxford Shoulder Score, and range of motion), complications, and operation time of fRSA were assessed with linear regression plots and cumulative summation analysis to establish whether a learning curve was present. Results In this cohort study, 50 patients were included. They had a mean age of 77.1 years and were treated with an fRSA by one trauma surgeon. Learning curves were distinguished for functional outcomes, complications, and operation time based on learning targets for daily activity and the mean complications and operation time. Results indicated that an optimal treatment is achieved after performing 20 fRSAs. Conclusion The results show that functional outcomes of PHFs treated with an fRSA improve with surgical experience. Also, outcomes are getting less variable after about 20 procedures. Surgeons starting this procedure should be aware of the learning curve and, therefore, should consider guidance from an experienced surgeon to swiftly optimize functional outcomes and prevent unnecessary complications.

Background: Muscle weakness is characteristic of knee osteoarthritis. Muscle steadiness may be an important adjunct to knee muscle strength in improving physical function in knee osteoarthritis. However, the role of muscle steadiness is uncertain. Aims: To determine the associations of knee extensor muscle steadiness with maximal voluntary torque and physical function in patients with knee osteoarthritis. Methods: Baseline data from 177 patients in a randomized clinical trial were used. Isokinetic knee extension torque was processed into maximal voluntary torque [Nm]. Muscle steadiness was expressed as the coefficient of variance [%] and as peak power frequency [Hz]. Physical function was assessed using the Western Ontario and McMaster Universities Osteoarthritis Index, the Get-Up-and-Go and Stair-climb tests. Associations were determined using regression analyses and adjusted for confounders. Findings: Lower muscle steadiness (i.e., higher coefficient of variance and peak power frequency) was associated with lower maximal voluntary torque (B = − 7.38, [−10.8, −3.95], R2 = 0.10 and B = −14.71, [−28.29, −1.13], R2 = 0.03, respectively). Higher coefficient of variance was associated with lower self-reported physical function (B = 1.14, [0.11,2.17], R2 = 0.03) and remained significant after adjusting for potential confounders. Peak power frequency was not associated with physical function. Interpretation: Low muscle steadiness was weakly associated with low muscle strength and poorer self-reported physical function. Muscle steadiness and muscle strength seem to be different attributes of muscle function. There is no convincing evidence that muscle steadiness is an important adjunct in studying physical function in patients with knee osteoarthritis.