Surgical approach to forearm pronation deformity in patients with cerebral palsy: a systematic review.

Background: Pronation deformity in patients with cerebral palsy can have a major impact on upper limb functionality. There is lack of consensus in the literature about the preferred surgical technique to address this deformity. Study aim: To evaluate and synthesize the outcome of different surgical techniques for pronation deformity in patients with cerebral palsy. Methodology: The databases MEDLINE and Embase were searched for publications up to December 2021. Articles were considered eligible for inclusion when the included patients had a pronation deformity caused by cerebral palsy and results of surgical intervention for pronation deformity were examined. Evaluation of the quality of the retrieved study was conducted using the MINORS tool. Meta-analysis was not possible due to the heterogeneity of interventions and reported outcomes. Results: Nineteen studies, involving 475 patients and eight different techniques were included. All studies reported gain of active supination in most patients. The effect of surgery on functional gain was less clear and there was a large heterogeneity of reported functional outcome measures. There were 46 reported complications. Overall quality of study design was poor, illustrated by the average MINOR score of 6.9/16. Overall, there is a high risk of bias due to poor internal and external validity of the studies. Conclusion: Despite positive reports on gain in supination and functionality after most procedures addressing pronation deformity in CP patients, no conclusions can be drawn concerning the preferred technique due to the low quality of the evidence.

An improved method for assessing the technical accuracy of optical tracking systems for orthopaedic surgical navigation.

BACKGROUND: Optical tracking systems (OTSs) are essential components of many modern computer assisted orthopaedic surgery (CAOS) systems but patient movement is often neglected in the evaluation of the accuracy. The aim of this study was to develop a representative test to assess the accuracy of OTSs including patient movement and demonstrate the effect of pointer design and OTS choice. METHOD: A mobile phantom with dynamic reference base (DRB) attached was designed and constructed. The point registration trueness and precision were evaluated for measurements with both a static and moving phantom. RESULTS: The trueness of the total target registration error (TTRE) was 1.4 to 2.7 times worse with a moving phantom compared to a static phantom. CONCLUSION: The accuracy of OTSs for CAOS applications should be evaluated by measurements with a moving phantom as the evaluation of the TTRE with a static frame significantly underestimates the measurement error.

A study on the efficacy of AFO stiffness prescriptions.

PURPOSE: Ankle foot orthosis (AFO) stiffness is a key characteristic that determines how much support or restraint an AFO can provide. Thus, the goal of the current study is twofold: (1) to quantify AFO prescriptions for a group of patients; (2) to evaluate what impact these AFO have on the push-off phase. METHOD: Six patients were included in the study. Three patients were prescribed an AFO for ankle support and three patients were prescribed an AFO for ankle and knee support. Two types of AFO - a traditional polypropylene AFO (AFOPP) and a novel carbon-selective laser sintered polyamide AFO (AFOPA), were produced for each patient. AFO ankle stiffness was measured in a dedicated test rig. Gait analysis was performed under shod and orthotic conditions. RESULTS: Patient mass normalized AFOPP stiffness for ankle support ranged from 0.042 to 0.069 N·m·deg-1·kg-1, while for ankle and knee support it ranged from 0.081 to 0.127 N·m·deg-1·kg-1. On the group level, the ankle range of motion and mean ankle velocity in the push-off phase significantly decreased in both orthotic conditions, while peak ankle push-off power decreased non-significantly. Accordingly, on the group level, no significant improvements in walking speed were observed. However, after patient differentiation into good and bad responders it was found that in good responders peak ankle push-off power tended to be preserved and walking speed tended to increase. CONCLUSIONS: Quantification of AFO stiffness may help to understand why certain orthotic interventions are successful (unsuccessful) and ultimately lead to better AFO prescriptions. Implications for rehabilitation AFO ankle stiffness is key characteristic that determines how much support or restraint an AFO can provide. In a typical clinical setting, AFO ankle stiffness is not quantified. AFO has to meet individual patient's biomechanical needs. More objective AFO prescription and more controlled AFO production methods are needed to increase AFO success rate.

Three-dimensional correction of fibular hemimelia using a computer-assisted planning : technical report and literature review.

The purpose of this survey in Belgium and the Netherlands was to assess treatment variation in glenohumeral osteoarthritis between experienced and less experienced orthopedic surgeons, and to investigate perioperative treatment after shoulder arthroplasty in a large group of orthopedic surgeons. Orthopedic surgeons specialized in shoulder surgery were invited to complete a survey between November 2013 and February 2015. Seventy-one percent of the approached surgeons com-pleted the survey. Less experienced surgeons (< 6 years) and surgeons from the Netherlands find patient characteristics (e.g. smoking p=0.01) more relevant than more experienced surgeons (≥ 6 years) and surgeons from Belgium. Less experienced surgeons will less likely (p=0.001) perform resurfacing arthroplasty compare to experienced surgeons. The less and the experienced surgeons use similar indications for a reverse shoulder arthroplasty regarding age limit and cuff arthropathy without osteoarthritis. Less experienced surgeon will more likely (p=0.003) prescribe a low molecular weight heparin during the hospital stay after a shoulder arthroplasty. In this survey, we found a decrease in the use of resurfacing arthroplasty and a strong increase in the use of reverse shoulder arthroplasty. Besides, there is little consensus concerning pre-operative planning, patient characteristics, surgical technique, and patient reported outcome measures. Level of evidence: IV.

A validated computational framework to evaluate the stiffness of 3D printed ankle foot orthoses.

The purpose of this study was to create and validate a standardized framework for the evaluation of the ankle stiffness of two designs of 3D printed ankle foot orthoses (AFOs). The creation of four finite element (FE) models allowed patient-specific quantification of the stiffness and stress distribution over their specific range of motion during the second rocker of the gait. Validation was performed by comparing the model outputs with the results obtained from a dedicated experimental setup, which showed an overall good agreement with a maximum relative error of 10.38% in plantarflexion and 10.66% in dorsiflexion. The combination of advanced computer modelling algorithms and 3D printing techniques clearly shows potential to further improve the manufacturing process of AFOs.

Computational and experimental evaluation of the mechanical properties of ankle foot orthoses: A literature review.

BACKGROUND: Ankle foot orthoses are external medical devices applied around the ankle joint area to provide stability to patients with neurological, muscular, and/or anatomical disabilities, with the aim of restoring a more natural gait pattern. STUDY DESIGN: This is a literature review. OBJECTIVES: To provide a description of the experimental and computational methods present in the current literature for evaluating the mechanical properties of the ankle foot orthoses. METHODS: Different electronic databases were used for searching English-language articles realized from 1990 onward in order to select the newest and most relevant information available. RESULTS: A total of 46 articles were selected, which describe the different experimental and computational approaches used by research groups worldwide. CONCLUSION: This review provides information regarding processes adopted for the evaluation of mechanical properties of ankle foot orthoses, in order to both improve their design and gain a deeper understanding of their clinical use. The consensus drawn is that the best approach would be represented by a combination of advanced computational models and experimental techniques, capable of being used to optimally mimic real-life conditions. CLINICAL RELEVANCE: In literature, several methods are described for the mechanical evaluation of ankle foot orthoses (AFOs); therefore, the goal of this review is to guide the reader to use the best approach in the quantification of the mechanical properties of the AFOs and to help gaining insight in the prescription process.

Test-retest reliability of three dimensional gait analysis: including a novel approach to visualising agreement of gait cycle waveforms with Bland and Altman plots.

BACKGROUND/AIM: Estimating the measurement error (reliability) of three dimensional gait analysis (3DGA) is crucial to interpretation of gait data. The purpose of this study was to investigate the intra-rater reliability of 3DGA and apply a novel method of visualising reliability of gait cycle waveforms. METHODS: A test re-test design was employed. A convenience sample of 30 healthy adults (18F; 12 M: mean age 30 ± 6.8 years) participated. Subjects walked along a 10 m walkway at their preferred gait speed and 3DGA data were collected using a VICON(®) 3DGA system. Testing was performed by the same investigator on two separate days within two weeks. Data from 10 trials were averaged and analysed. ANALYSIS: The intraclass correlation coefficient (ICC), the standard error of measurement (SEM), minimal detectable change (MDC) and limits of agreement were calculated for kinetic and kinematic data. Bland and Altman plots were applied to gait cycle waveforms. RESULTS: Spatio-temporal parameters such as cadence, step length, velocity, step time and step width were highly repeatable generating ICC's of 0.90 and above and low SEM/MDC. Range of joint movement across the gait cycle was generally more reliable than either minimum or maximum values and higher ICCs were obtained for movement in the sagittal plane. For kinematic data the standard error of measurement was low (≤ 5) for the majority of parameters. Transverse plane measurements showed poor reliability with lowest ICC's. ICCs for kinetic data ranged from 0.51 to 0.81. CONCLUSIONS: Reliability of 3DGA has been estimated for our gait laboratory. Bland and Altman plots of gait cycle waveforms provide a useful addition to reliability analysis.

The clinical relevance of selecting resting data at different points in an energy cost of walking test in cerebral palsy.

AIM: Energy cost of walking (ECOW) is defined as 'walking oxygen consumption minus resting oxygen consumption divided by speed', where 'resting' data can be obtained either at the start or cessation of a test. This study aimed to ascertain when resting data should be taken during an ECOW test in children with cerebral palsy (CP). METHOD: Resting oxygen consumption per unit mass (VO(2) ) and heart rate were recorded in children without physical impairment (18 males, 13 females; mean age 11 y [SD 2 y 1 mo]) and children with diplegic CP (18 males, 13 females; mean age 11 y [SD 2 y 6 mo, Gross Motor Function Classification System levels I and II]) at three stages, namely pre- and posttest sitting and pretest standing before and after an 8-minute ECOW test using the Cosmed K4b. RESULTS: Heart rate and VO(2) differed significantly between groups and stages (p ≤ 0.05) except for heart rate in standing and posttest sitting in the unimpaired children and for VO(2) during pretest sitting between groups. These differences impacted on the calculation of non-dimensional net oxygen cost (NDNOC) and physiological cost index (PCI) in CP but not in the unimpaired group. PCI was correlated with NDNOC in CP but not in the unimpaired cohort. INTERPRETATION: Pretest sitting resting data appear to be the most appropriate for use in the calculation of NDNOC and PCI. PCI may still have relevance in pathology where walking efficiency is compromised.

Energy cost of walking: A comparison of two recognised methods for defining steady state in a group of unimpaired children and children with cerebral palsy.

Measurement of VO(2) based 'energy cost of walking' indices provide quantitative information that can be used clinically to ascertain progress and relative functional impairment in pathology. The accuracy and validity of these indices relies on being able to identify periods of steady state conditions, since it is only in steady state that there is a direct and predictable relationship between VO(2) consumption and energy expenditure. This paper presents a comparison of two new mathematically based approaches that have recently gained recognition as methods for identifying steady state during an energy cost assessment. The first applies a mathematically defined threshold for steady state within a (non-treadmill) walking trial. This method is compared with a statistically based approach that relies on the calculation of the correlation coefficient, Kendall's Tau to define steady state data. To examine the impact of both methods on the calculation of the energy cost of walking, each was applied to the calculation of two oxygen based energy cost of walking parameters, the non-dimensional net oxygen cost and the net oxygen cost with speed normalised to height in a cohort of unimpaired subjects and children with cerebral palsy. The results revealed that overall there were no clinically significant differences between the two methods. It is suggested that the methods can be used interchangeably to calculate the energy cost of walking.

Energy cost of walking: solving the paradox of steady state in the presence of variable walking speed.

Measurement of the energy cost of walking in children with cerebral palsy is used for baseline and outcome assessment. However, such testing relies on the establishment of steady state that is deemed present when oxygen consumption is stable. This is often assumed when walking speed is constant but in practice, speed can and does vary naturally. Whilst constant speed is achievable on a treadmill, this is often impractical clinically, thus rendering an energy cost test to an element of subjectivity. This paper attempts to address this issue by presenting a new method for calculating energy cost of walking that automatically applies a mathematically defined threshold for steady state within a (non-treadmill) walking trial and then strips out all of the non-steady state events within that trial. The method is compared with a generic approach that does not remove non-steady state data but rather uses an average value over a complete walking trial as is often used in the clinical environment. Both methods were applied to the calculation of several energy cost of walking parameters of self-selected walking speed in a cohort of unimpaired subjects and children with cerebral palsy. The results revealed that both methods were strongly correlated for each parameter but showed systematic significant differences. It is suggested that these differences are introduced by the rejection of non-steady state data that would otherwise have incorrectly been incorporated into the calculation of the energy cost of walking indices during self-selected walking with its inherent speed variation.

The effect of simulating weight gain on the energy cost of walking in unimpaired children and children with cerebral palsy.

OBJECTIVE: To examine the effect of simulating weight gain on the energy cost of walking in children with cerebral palsy (CP) compared with unimpaired children. DESIGN: Repeated measures, matched subjects, controlled. SETTING: University hospital clinical gait and movement analysis laboratory. PARTICIPANTS: Children (n=42) with CP and unimpaired children (n=42). INTERVENTIONS: Addition of 10% of body mass in weight belt. MAIN OUTCOME MEASURES: Energy cost of walking parameters consisting of walking speed, Physiological Cost Index, Total Heart Beat Index, oxygen uptake (VO2), gross oxygen cost, nondimensional net oxygen cost, and net oxygen cost with speed normalized to height were measured by using a breath-by-breath gas analysis system (K4b2) and a light beam timing gate system arranged around a figure 8 track. Two walking trials were performed in random order, with and the other without wearing a weighted belt. RESULTS: Children with CP and their unimpaired counterparts responded in fundamentally different ways to weight gain. The unimpaired population maintained speed and VO2 but the children with CP trended toward a drop in their speed and an increase in their VO2. The oxygen consumption of children with CP showed a greater dependence on mass than the unimpaired group (P=.043). CONCLUSIONS: An increase of a relatively small percentage in body mass began to significantly impact the energy cost of walking in children with CP. This result highlights the need for weight control to sustain the level of functional walking in these children.

The impact of muscular variation on the neurodynamic test for the median nerve in a healthy population with Langer's axillary arch.

OBJECTIVE: The neurodynamic test of the median nerve (ULNT1) is frequently used to assess the mechanics and physiology of the brachial plexus and median nerve. The present study looks for a positive ULNT1 in a healthy population with Langer's axillary arch (LAA) and analyzes whether LAA affects the elbow extension range of motion (EE-ROM) of the ULNT1. METHOD: Of 640 volunteers screened, 26 LAA sides were finally included. Additional history taking revealed "minor symptoms" in some subjects. Minor symptoms do not qualify as a disorder because there is no interference with daily activities and no medical advice is sought. This study investigates whether the ULNT1 can (re)produce minor symptoms or abnormal responses in subjects with LAA. The EE-ROM was compared between the subjects' left and right side, and the subtraction angle-which is the effect of placing the cervical spine in contralateral lateral flexion-was compared between LAA sides and controls. RESULTS: Langer's axillary arch sides showed a significant increase in the occurrence of minor symptoms and positive ULNT1, but no influence was observed on the EE-ROM. CONCLUSIONS: These findings suggest that LAA may be capable of transiently provoking the axillary neurovascular bundle. The unaffected EE-ROM may be the consequence of a vascular origin of the minor symptoms or the consequence of an ulnar nerve/medial cord response to the ULNT1.