Publications by authors named "Brigitte M Jolles"

65 Publications

Longitudinal Femoral Cartilage T2 Relaxation Time and Thickness Changes with Fast Sequential Radiographic Progression of Medial Knee Osteoarthritis-Data from the Osteoarthritis Initiative (OAI).

J Clin Med 2021 Mar 21;10(6). Epub 2021 Mar 21.

Swiss BioMotion Lab, Department of Musculoskeletal Medicine (DAL), Lausanne University Hospital and University of Lausanne (CHUV-UNIL), 1011 Lausanne, Switzerland.

This study tested for longitudinal changes in femoral cartilage T2 relaxation time and thickness in fast-progressing medial femorotibial osteoarthritis (OA). From the Osteoarthritis Initiative (OAI) database, nineteen knees fulfilled the inclusion criteria, which included medial femorotibial OA and sequential progression from Kellgren-Lawrence grade (KL) 1 to KL2 to KL3 within five years. Median T2 value and mean thickness were calculated for six condylar volumes of interest (VOIs; medial/lateral anterior, central, posterior) and six sub-VOIs (medial/lateral anterior external, central, internal). T2 value and thickness changes between severity timepoints were tested using repeated statistics. T2 values increased between KL1 and KL2 and between KL1 and KL3 in the medial compartment ( ≤ 0.02), whereas both increases and decreases were observed between the same timepoints in the lateral compartment ( ≤ 0.02). Cartilage thickness decreased in VOI/subVOIs of the medial compartment from KL1 to KL2 and KL3 ( ≤ 0.014). Cartilage T2 value and thickness changes varied spatially over the femoral condyles. While all T2 changes occurred in the early radiographic stages of OA, thickness changes occurred primarily in the later stages. These data therefore support the use of T2 relaxation time analyses in methods of detecting disease-related change during early OA, a valuable period for therapeutic interventions.
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http://dx.doi.org/10.3390/jcm10061294DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8003903PMC
March 2021

Advantages of patient-specific cutting guides with disposable instrumentation in total knee arthroplasty: a case control study.

J Orthop Surg Res 2021 Mar 15;16(1):188. Epub 2021 Mar 15.

Department of Orthopaedics and Traumatology, Lausanne University Hospital and University of Lausanne (UNIL), Lausanne, Switzerland.

Background: Total knee arthroplasty (TKA) is most frequently planned using conventional two-dimensional weight-bearing lower limb radiographs and is performed with conventional femoral and tibial cutting guides. Questions have been raised about the accuracy of conventional TKA instrumentation and planning for an anatomically standard or complex joint. Use of computed tomography (CT)-based three-dimensional (3D) templating and patient-specific cutting guides printed in 3D has shown improved postoperative lower limb alignment parameters. This case-control study compared costs and operative times of using CT-based, patient-specific, single-use instruments versus conventional metal instruments for TKA.

Methods: In this case-control, retrospective chart review, all TKAs were performed by one senior surgeon, using the F.I.R.S.T. posterior-stabilised knee prosthesis (Symbios, CH), with a similar protocol and identical operating room setup. Group A included 51 TKAs performed with patient-specific cutting guides and conventional metal instruments. Group B included 49 TKAs performed with patient-specific cutting guides and patient-specific, single-use instrumentation. Operation duration, number of instrumentation trays and sterilisation costs were evaluated.

Results: The groups were similar for age, body mass index, hip-knee-ankle angle and operation duration. The mean number of instrumentation trays was 8.0 ± 0.8 for group A (controls) and 5.1 ± 0.9 for group B (p<0.001). The mean sterilisation costs were 380 ± 47 Swiss Francs (CHF) for group A and 243 ± 55 CHF for group B (p<0.001), for a mean cost reduction of 130.50 CHF per intervention in group B. The time interval between two consecutive surgeries was 24 min for group A and 18 min for group B. There were no adverse events or complications, instrument-related or otherwise.

Conclusion: Compared to conventional instrumentation, use of patient-specific, single-use instruments for TKA reduced the number of instrumentation trays by more than one-third and saved 36% in sterilisation costs. If fabrication costs of single-use instruments are included by the company, the total cost is significantly diminished. There was no operative time advantage for single-use instrumentation.
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http://dx.doi.org/10.1186/s13018-021-02310-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7958711PMC
March 2021

Relationship between psychological factors and spinal motor behaviour in low back pain: a systematic review and meta-analysis.

Pain 2021 Mar;162(3):672-686

Swiss BioMotion Lab, Department of Musculoskeletal Medicine, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland.

Abstract: This meta-analysis investigated whether more negative psychological factors are associated with less spinal amplitude of movement and higher trunk muscle activity in individuals with low back pain. Furthermore, it examined whether pain intensity was a confounding factor in this relationship. We included studies that provided at least 1 correlation coefficient between psychological (pain-related fear, catastrophizing, depression, anxiety, and self-efficacy) and spinal motor behaviour (spinal amplitude and trunk muscle activity) measures. In total, 52 studies (3949 participants) were included. The pooled correlation coefficients (95% confidence interval; number of participants) were -0.13 (-0.18 to -0.09; 2832) for pain-related fear, -0.16 (-0.23 to -0.09; 756) for catastrophizing, -0.08 (-0.13 to -0.03; 1570) for depression, -0.08 (-0.30 to 0.14; 336) for anxiety, and -0.06 (-0.46 to 0.36; 66) for self-efficacy. The results indicated that higher levels of pain-related fear, catastrophizing, and depression are significantly associated with reduced amplitudes of movement and larger muscle activity and were consistent across subgroup and moderation analyses. Pain intensity did not significantly affect the association between these psychological factors and spinal motor behaviour and had a very small independent association with spinal motor behaviour. In conclusion, the very small effect sizes found in the meta-analyses question the role of psychological factors as major causes of spinal movement avoidance in low back pain. Experimental studies with more specific and individualized measures of psychological factors, pain intensity, and spinal motor behaviour are recommended.
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http://dx.doi.org/10.1097/j.pain.0000000000002065DOI Listing
March 2021

Analyzing Femorotibial Cartilage Thickness Using Anatomically Standardized Maps: Reproducibility and Reference Data.

J Clin Med 2021 Jan 26;10(3). Epub 2021 Jan 26.

Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA.

Alterations in cartilage thickness (CTh) are a hallmark of knee osteoarthritis, which remain difficult to characterize at high resolution, even with modern magnetic resonance imaging (MRI), due to a paucity of standardization tools. This study aimed to assess a computational anatomy method producing standardized two-dimensional femorotibial CTh maps. The method was assessed with twenty knees, processed following three common experimental scenarios. Cartilage thickness maps were obtained for the femorotibial cartilages by reconstructing bone and cartilage mesh models in tree-dimension, calculating three-dimensional CTh maps, and anatomically standardizing the maps. The intra-operator accuracy (median (interquartile range, IQR) of -0.006 (0.045) mm), precision (0.152 (0.070) mm), entropy (7.02 (0.71) and agreement (0.975 (0.020))) results suggested that the method is adequate to capture the spatial variations in CTh and compare knees at varying osteoarthritis stages. The lower inter-operator precision (0.496 (0.132) mm) and agreement (0.808 (0.108)) indicate a possible loss of sensitivity to detect differences in a setting with multiple operators. The results confirmed the promising potential of anatomically standardized maps, with the lower inter-operator reproducibility stressing the need to coordinate operators. This study also provided essential reference data and indications for future research using CTh maps.
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http://dx.doi.org/10.3390/jcm10030461DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7865848PMC
January 2021

Three-Dimensional Quantification of Bone Mineral Density in the Distal Femur and Proximal Tibia Based on Computed Tomography: In Vitro Evaluation of an Extended Standardization Method.

J Clin Med 2021 Jan 5;10(1). Epub 2021 Jan 5.

Swiss BioMotion Lab, Department of Musculoskeletal Medicine, Lausanne University Hospital and University of Lausanne (CHUV-UNIL), CH-1011 Lausanne, Switzerland.

While alterations in bone mineral density (BMD) are of interest in a number of musculoskeletal conditions affecting the knee, their analysis is limited by a lack of tools able to take full advantage of modern imaging modalities. This study introduced a new method, combining computed tomography (CT) and computational anatomy algorithms, to produce standardized three-dimensional BMD quantification in the distal femur and proximal tibia. The method was evaluated on ten cadaveric knees CT-scanned twice and processed following three different experimental settings to assess the influence of different scans and operators. The median reliability (intraclass correlation coefficient (ICC)) ranged from 0.96 to 0.99 and the median reproducibility (precision error (RMSSD)) ranged from 3.97 to 10.75 mg/cc for the different experimental settings. In conclusion, this paper presented a method to standardize three-dimensional knee BMD with excellent reliability and adequate reproducibility to be used in research and clinical applications. The perspectives offered by this novel method are further reinforced by the fact it relies on conventional CT scan of the knee. The standardization method introduced in this work is not limited to BMD and could be adapted to quantify other bone parameters in three dimension based on CT images or images acquired using different modalities.
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http://dx.doi.org/10.3390/jcm10010160DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7796434PMC
January 2021

Decreasing the ambulatory knee adduction moment without increasing the knee flexion moment individually through modifications in footprint parameters: A feasibility study for a dual kinetic change in healthy subjects.

J Biomech 2020 10 20;111:110004. Epub 2020 Aug 20.

Lausanne University Hospital and University of Lausanne (CHUV-UNIL), Department of Musculoskeletal Medicine, Swiss BioMotion Lab, Lausanne, Switzerland. Electronic address:

Gait retraining is gaining in interest to reduce loading associated to knee osteoarthritis (OA) progression. So far, interventions focused on reducing the peak knee adduction moment (pKAM) and it remains unclear if this can be done individually without increasing the peak knee flexion moment (pKFM). Additionally, while modifying foot progression angle (FPA) and step width (SW) is common, little is known about modifications in stride length (SL). This study aimed at characterizing the feasibility of a dual kinetic change, consisting in reducing the pKAM by at least 10% without increasing the pKFM. It also aimed to evaluate the added value of SL modifications in achieving the dual kinetic change. Gait trials with modifications in FPA, SW and SL were recorded for 11 young healthy subjects in a laboratory equipped with an augmented-reality system displaying instruction footprints on the floor. All participants achieved the dual kinetic change with at least one of the modifications. Seven participants achieved it with FPA modification, three with SW modification, and seven with SL modification. In conclusion, this study showed that it is feasible to achieve the dual kinetic change individually through subject-specific modifications in footprint parameters, suggesting that, in the future, gait retraining could aim for more specific kinetic changes than simply pKAM reductions. Modifying SL allowed achieving the dual kinetic change, stressing out the value of this parameter for gait retraining, in addition to FPA and SW. Finally, an augmented-reality approach was introduced to help footprint parameter modifications in the framework of knee OA.
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http://dx.doi.org/10.1016/j.jbiomech.2020.110004DOI Listing
October 2020

Changes in ambulatory knee adduction moment with lateral wedge insoles differ with respect to the natural foot progression angle.

J Biomech 2020 04 24;103:109655. Epub 2020 Jan 24.

Lausanne University Hospital and University of Lausanne (CHUV-UNIL), Department of Musculoskeletal Medicine, Swiss BioMotion Lab, Lausanne, Switzerland. Electronic address:

Lateral wedge insoles (LWI) have been proposed to reduce the knee adduction moment (KAM) during walking; a biomechanical modification notably sought in case of medial knee osteoarthritis. However, the inter-individual inconsistency in KAM changes with LWI limits their therapeutic use. Although the foot progression angle (FPA) has been frequently discussed in KAM modifications literature, there is a lack of data regarding a possible relationship between this gait measure and changes in KAM with LWI. This study aimed to test if KAM changes with LWI differ with respect to the natural FPA and to compare KAM-related variables between individuals walking with smaller and larger natural FPA. Twenty-two healthy participants (14 males, 24 ± 3 years, 22.7 ± 2.7 kg/m) underwent gait analysis with and without LWI. They were divided into two groups based on their natural FPA, and changes in KAM 1st peak, KAM impulse, and KAM-related variables were compared between groups. KAM 1st peak and impulse decreased with LWI in the smaller natural FPA group (p ≤ 0.006), while only KAM impulse decreased in the larger natural FPA group (p < 0.001). The difference in KAM 1st peak changes was explained by a less reduced lever arm in participants walking with larger natural FPA. In conclusion, this study brought new insight into the variability in KAM response to LWI. If the findings are confirmed in patients with medial knee osteoarthritis, the FPA could become a simple measure to help identify the patients more likely to reduce their KAM with LWI.
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http://dx.doi.org/10.1016/j.jbiomech.2020.109655DOI Listing
April 2020

Lumbar and thoracic kinematics during step-up: Comparison of three-dimensional angles between patients with chronic low back pain and asymptomatic individuals.

J Orthop Res 2020 06 7;38(6):1248-1256. Epub 2020 Jan 7.

Swiss BioMotion Lab, Department of Musculoskeletal Medicine, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland.

While alterations in spinal kinematics have been repeatedly observed in patients with chronic low back pain (CLBP), their exact nature is still unknown. Specifically, there is a need for comprehensive assessments of multisegment spinal angles during daily-life activities. The purpose of this exploratory study was to characterize three-dimensional angles at the lower lumbar, upper lumbar, lower thoracic, and upper thoracic joints in CLBP patients and asymptomatic controls during stepping up with three different step heights. Spinal angles of 10 patients with nonspecific CLBP (six males; 38.7 ± 7.2 years old, 22.3 ± 1.6 kg/m ) and 11 asymptomatic individuals (six males; 36.7 ± 5.4 years old, 22.9 ± 3.8 kg/m ) were measured in a laboratory using a camera-based motion capture system. Seven out of the 12 angle curves had characteristic patterns, leading to the identification of 20 characteristic peaks. Comparing peak amplitudes between groups revealed statistically significantly smaller sagittal- and frontal-plane angles in the patient group at the upper lumbar joint with the two higher steps and at the lower lumbar joint with the higher step. Significantly reduced angles were also observed in sagittal plane at the upper thoracic joint with the two smaller steps. Moreover, a higher number of significant differences between groups was detected with the two higher steps than with the smallest step. In conclusion, this study showed the value of a comprehensive description of spinal angles during step-up tasks and provided insights into the alterations with CLBP. These preliminary results support prior research suggesting that CLBP rehabilitation should facilitate larger amplitudes of motion during functional activities.
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http://dx.doi.org/10.1002/jor.24575DOI Listing
June 2020

Are the Cumulated Ambulation Score and Risk Assessment and Prediction Tool useful for predicting discharge destination and length of stay following total knee arthroplasty?

Eur J Phys Rehabil Med 2019 Dec 22;55(6):816-823. Epub 2019 Jul 22.

Department of Musculoskeletal Medicine, Vaudois University Hospital Center CHUV, Lausanne, Switzerland.

Background: Postoperative management of patients undergoing total knee arthroplasty (TKA) is continually changing. Costs related to TKA are driven by implant cost, operating room cost, hospital length of stay (LOS), and rehabilitation approach. Discharges to rehabilitation centers have declined significantly in recent years.

Aim: We evaluated the usefulness of the Cumulated Ambulation Score (CAS) and Risk Assessment and Prediction Tool (RAPT) to predict discharge destination and estimate hospital LOS of patients undergoing TKA.

Design: Prospective cohort study.

Setting: University hospital inpatients.

Population: Patients undergoing elective primary TKA.

Methods: Consecutive patients were prospectively evaluated. Outcome measures were discharge destination and LOS dichotomized at the median (LOS<8 versus LOS≥8). Patients completed five outcome questionnaires and knee range of motion was measured preoperatively. RAPT was considered continuous, and also dichotomized (RAPT≤9 versus RAPT>9; RAPT9). CAS was dichotomized (CAS<11 versus CAS≥11; CAS11). Surgical technique and aftercare were similar for all patients.

Results: Sixty-four patients (37 females), mean age 69.3±10.2 years were evaluated. CAS11 and discharge destination were strongly associated: 75.9% of patients with CAS≥11 were discharged home; 85.7% of patients with CAS<11 were discharged to a rehabilitation center (P<0.001). 80.7% of patients with RAPT≤9 were discharged to a rehabilitation center, versus 36.4% of patients with RAPT>9 (P=0.002). Odds ratios for discharge home were 18.9 (CAS11) and 7.3 (RAPT). CAS11 and RAPT were not related to LOS.

Conclusions: The CAS and RAPT can assist clinicians in estimating the discharge destination and developing patient care plans following TKA. However, predicting LOS with such tools alone was inaccurate.

Clinical Rehabilitation Impact: Use of the CAS and RAPT can inform discharge destination and patient care plans following TKA and has the potential to optimise resources and costs. However, due to social and organizational constraints on discharge, predicting LOS with such tools alone revealed to be inaccurate.
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http://dx.doi.org/10.23736/S1973-9087.19.05568-0DOI Listing
December 2019

Gait events during turning can be detected using kinematic features originally proposed for the analysis of straight-line walking.

J Biomech 2019 Jun 11;91:69-78. Epub 2019 May 11.

Lausanne University Hospital and University of Lausanne (CHUV-UNIL), Department of Musculoskeletal Medicine, Swiss BioMotion Lab, Lausanne, Switzerland. Electronic address:

There is a growing interest for turning biomechanics notably because it is a more challenging task than straight-line walking during which some gait impairments are increased. Detecting heel-strike (HS) and toe-off (TO) events using the trajectory of markers attached to the feet is common in straight-line gait analysis and could reveal very useful to evaluate turning maneuvers. Yet, a comprehensive evaluation is missing, making difficult the selection of features for temporal analysis of turning. This study aimed to compare features of foot marker trajectories to detect HS and TO. Twenty healthy participants, 10 young (5 males, 23 ± 1 years old, 21.3 ± 2.2 kg/m) and 10 elderly (4 males, 72 ± 5 years old, 26.4 ± 6.4 kg/m), performed quarter, half, and full turns as well as straight-line walking in a gait lab. Fourteen features, adapted from straight-line walking literature, were used to detect HS and TO based on marker trajectories. Force plate measures served as reference. One HS and one TO feature were found particularly suitable. Overall, they detected more than 99% of the 1788 events recorded, with accuracies and precisions of -3.9 ms and 9.0 ms for HS and -7.8 ms and 10.7 ms for TO, respectively. Differences in accuracy and precision were observed among walking conditions and groups, but remained small, generally below 4.0 ms. In conclusion, this study identified kinematic features that can be used to analyze both turning and straight-line walking. Further assessment could be necessary with pathologies inducing severe degradation of gait patterns.
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http://dx.doi.org/10.1016/j.jbiomech.2019.05.006DOI Listing
June 2019

Comprehensive description of T2 value spatial variations in non-osteoarthritic femoral cartilage using three-dimensional registration of morphological and relaxometry data.

Knee 2019 Jun 8;26(3):555-563. Epub 2019 May 8.

Department of Musculoskeletal Medicine (DAL), Lausanne University Hospital (CHUV), Lausanne, Switzerland.

Purpose: The aim of this study was to develop and assess a method of quantifying cartilage T2 relaxation times in a series of volumes of interest (VOIs) covering the entire cartilage of the femoral condyles. Subsequently, the method was used to test for T2 spatial variations in non-osteoarthritic (OA) knees.

Methods: Ten non-OA subjects (five female, average 30 years) were enrolled after informed consent. Three-dimensional bone and cartilage models were created by double echo steady state (DESS) morphological magnetic resonance image (MRI) segmentation, and the models were semi-manually registered with multi-slice, multi-echo (MSME) T2 MRI. Mean T2 values were calculated for 12 VOIs derived from cartilage thickness literature and their respective superficial and deep layers.

Results: Analyses showed that intra- and inter-rater reliabilities of the presented method were "good" to "excellent" in more than 90% of the VOIs. Additionally, several spatial differences in T2 values were observed, including, for the medial condyle, higher T2 values in the anterior and central VOIs versus in the posterior VOI (p < .05). T2 values were also generally higher in the superficial versus deep layers (p < .05).

Conclusions: The presented MRI T2 analysis method is reliable and provides a comprehensive quantification of spatial heterogeneity of healthy cartilage compositional properties. This method can be further applied to better understand knee OA pathophysiology and potentially define clinically relevant diagnostic features of the disease.
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http://dx.doi.org/10.1016/j.knee.2019.03.006DOI Listing
June 2019

Gait analysis following single-shot hyaluronic acid supplementation: a pilot randomized double-blinded controlled trial.

Pilot Feasibility Stud 2019 22;5:56. Epub 2019 Apr 22.

Centre Hospitalier Universitaire Vaudois (CHUV), Site Hôpital Orthopédique, Avenue Pierre Decker 4, CH-1011 Lausanne, Switzerland.

Objectives: Viscosupplementation with new-generation, polyol-containing, cross-linked hyaluronic acid (HA) gels reduces joint inflammation in patients with knee osteoarthritis. Gait analysis is a complementary outcome measure to standard patient-reported scores and physical measures for testing the effect of HA injection. This three-arm, prospective, randomized, controlled, double-blind, feasibility pilot study investigated which gait parameters are more sensitive following a single bolus injection of polyol-containing HA for knee osteoarthritis.

Methods: Twenty-two patients with Ahlbäck grade II-III knee osteoarthritis were randomly allocated into three groups: (1) HA + mannitol ( = 9), (2) HA + sorbitol ( = 5), and (3) saline placebo ( = 8). Patients were assessed by blinded observers prior to injection and at 4 weeks post-injection (4W). Outcome measures included the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee Society score (KSS), EuroQol in five-dimensions (EQ-5D), VAS pain, and VAS stiffness. Gait was assessed over 30 m using a portable inertial-based data logger (Physilog®).

Results: Differences between 4W and baseline were statistically significant for the mannitol-containing viscosupplement, with a median increase of 0.076 m/s on gait speed ( = 0.039), 0.055 m on stride length ( = 0.027), and 15 points on the KSS ( = 0.047). In contrast, the HA + sorbitol and saline groups demonstrated no significant changes from baseline to 4W in any gait parameters or self-reported outcome measures (all  > 0.3). The observed increase in gait speed is approximately 13% greater than the mean difference between healthy subjects and those with knee osteoarthritis, is clinically important, and thus is a sensitive gait parameter.

Conclusions: This study demonstrated gait speed and stride length are the most relevant gait parameters to investigate when assessing the effect of polyol-containing HA viscosupplementation. This study supports the need for a larger, randomized, controlled, clinical trial to assess the effect of a single-bolus HA injection versus multiple injections in people with knee osteoarthritis using both gait performance and self-reported parameters of knee function.

Trial Registration: This study was retrospectively registered at clinicaltrials.gov on August 20, 2018, and assigned #NCT03636971.

Level Of Evidence: I.
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http://dx.doi.org/10.1186/s40814-019-0443-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6475965PMC
April 2019

Patellar bone strain after total knee arthroplasty is correlated with bone mineral density and body mass index.

Med Eng Phys 2019 06 9;68:17-24. Epub 2019 Apr 9.

Laboratory of Biomechanical Orthopedics, Ecole Polytechnique Fédérale de Lausanne, Station 9, 1015 Lausanne, Switzerland. Electronic address:

Patella-related complications after total knee arthroplasty (TKA) remain a major clinical concern. Previous studies have suggested that increased postoperative patellar bone strain could be related to such complications, but there is limited knowledge on patellar strain after TKA. The objective of this study was to predict patellar bone strain after TKA and evaluate correlations with various preoperative data. Fourteen TKA patients with a minimum follow-up of one year were included in this study. Using preoperative CT datasets, preoperative planning, and postoperative X-rays, a method is presented to generate patient-specific finite element models after virtual TKA. Patellar kinematics and forces were predicted during a squat movement, and patellar bone strain was evaluated at 60° of knee flexion. Strain varied greatly among patients, but was strongly negatively correlated (r = -0.85, p < 0.001) with bone mineral density (BMD) and moderately positively (r  = 0.54, p  =  0.05) with body mass index (BMI). The BMI/BMD ratio explained 87% of strain, and should be further investigated as a potential risk factor for clinical complications. This study represents a preliminary step towards the identification of patients at risk of patellar complications after TKA.
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http://dx.doi.org/10.1016/j.medengphy.2019.03.017DOI Listing
June 2019

Corrigendum to "Chronic low back pain patients walk with locally altered spinal kinematics" [J. Biomech. 60 (2017) 211-218].

J Biomech 2019 01 2;83:329. Epub 2019 Jan 2.

Physiotherapy Department, HESAV School of Health Sciences, HES-SO University of Applied Sciences and Arts Western Switzerland, Lausanne, Switzerland.

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http://dx.doi.org/10.1016/j.jbiomech.2018.12.033DOI Listing
January 2019

Effect of lateral wedge length on ambulatory knee kinetics.

Gait Posture 2018 06 27;63:114-118. Epub 2018 Apr 27.

Swiss BioMotion Lab, Department of Musculoskeletal Medicine, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland. Electronic address:

Background: Lateral wedge insoles (LWI) were proposed to treat medial knee osteoarthritis through reductions of the ambulatory knee adduction moment (KAM). Limited attention was however paid to the LWI length, resulting in unclear understanding of its effect on KAM reductions. The knee flexion moment (KFM) was also shown to be important in knee osteoarthritis, but little is known about the effect of LWI length on it.

Research Question: This study aimed to compare the KAM and KFM of healthy subjects walking with four different lengths of LWI, explicitly without LWI and with LWI below the hindfoot (HF), below the hindfoot and forefoot (HF + FF) and below the hindfoot, forefoot and hallux (HF + FF + HX) segments.

Methods: Nineteen healthy participants (63% male; 24 ± 3 years old) walked in an instrumented gait lab with LWI of four different lengths. Repeated one-way ANOVAs and post-hoc t-tests were used to compare knee kinetics among LWI lengths.

Results: The peak value of the KAM during the first half of stance and the KAM impulse differed with respect to the LWI length (p < 0.001). A length of at least HF + FF, but not necessarily longer, was needed to decrease both KAM parameters compared to walking without LWI. The LWI length had no effect on the peak value of the KFM during the first half of stance (p = 0.86).

Significance: The results in this study could contribute to better selections of LWI for medial knee osteoarthritis and suggested that the length of the LWI could be a critical factor that should be considered in future research.
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http://dx.doi.org/10.1016/j.gaitpost.2018.04.044DOI Listing
June 2018

Cartilage can be thicker in advanced osteoarthritic knees: a tridimensional quantitative analysis of cartilage thickness at posterior aspect of femoral condyles.

Br J Radiol 2018 Jul 16;91(1087):20170729. Epub 2018 Apr 16.

3 Department of Musculoskeletal Medicine, Swiss BioMotion Lab, Centre Hospitalier Universitaire Vaudois and University of Lausanne , Lausanne , Switzerland.

Objective: To test, through tridimensional analysis, whether (1) cartilage thickness at the posterior aspect of femoral condyles differs in knees with medial femorotibial osteoarthritis (OA) compared to non-OA knees; (2) the location of the thickest cartilage at the posterior aspect of femoral condyles differs between OA and non-OA knees.

Methods: CT arthrograms of knees without radiographic OA (n = 30) and with severe medial femorotibial OA (n = 30) were selected retrospectively from patients over 50 years of age. The groups did not differ in gender, age and femoral size. CT arthrograms were segmented to measure the mean cartilage thickness, the maximal cartilage thickness and its location in a region of interest at the posterior aspect of condyles.

Results: For the medial condyle, mean and maximum cartilage thicknesses were statistically significantly higher in OA knees compared to non-OA knees [1.66 vs 1.46 mm (p = 0.03) and 2.56 vs 2.14 mm (p = 0.003), respectively]. The thickest cartilage was located in the half most medial aspect of the posterior medial condyle for both groups, without significant difference between groups. For the lateral condyle, no statistically significant difference between non-OA and OA knees was found (p ≥ 0.17).

Conclusion: Cartilage at the posterior aspect of the medial condyle, but not the lateral condyle, is statistically significantly thicker in advanced medial femorotibial OA knees compared to non-OA knees. The thickest cartilage was located in the half most medial aspect of the posterior medial condyle. These results will serve as the basis for future research to determine the histobiological processes involved in this thicker cartilage. Advances in knowledge: This study, through a quantitative tridimensional approach, shows that cartilage at the posterior aspect of the medial condyles is thicker in severe femorotibial osteoarthritic knees compared to non-OA knees. In the posterior aspect of the medial condyle, the thickest cartilage is located in the vicinity of the center of the half most medial aspect of the posterior medial condyle. These results will serve as the basis for future research to determine the histobiological processes involved in this thicker cartilage.
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http://dx.doi.org/10.1259/bjr.20170729DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6221770PMC
July 2018

A gait retraining system using augmented-reality to modify footprint parameters: Effects on lower-limb sagittal-plane kinematics.

J Biomech 2018 01 11;66:26-35. Epub 2017 Nov 11.

Swiss BioMotion Lab, Department of Musculoskeletal Medicine, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland. Electronic address:

Improving lower-limb flexion/extension angles during walking is important for the treatment of numerous pathologies. Currently, these gait retraining procedures are mostly qualitative, often based on visual assessment and oral instructions. This study aimed to propose an alternative method combining motion capture and display of target footprints on the floor. The second objectives were to determine the error in footprint modifications and the effects of footprint modifications on lower-limb flexion/extension angles. An augmented-reality system made of an optoelectronic motion capture device and video projectors displaying target footprints on the floor was designed. 10 young healthy subjects performed a series of 27 trials, consisting of increased and decreased amplitudes in stride length, step width and foot progression angle. 11 standard features were used to describe and compare lower-limb flexion/extension angles among footprint modifications. Subjects became accustomed to walk on target footprints in less than 10 min, with mean (± SD) precision of 0.020 ± 0.002 m in stride length, 0.022 ± 0.006 m in step width, and 2.7 ± 0.6° in progression angle. Modifying stride length had significant effects on 3/3 hip, 2/4 knee and 4/4 ankle features. Similarly, step width and progression angle modifications affected 2/3 and 1/3 hip, 2/4 and 1/4 knee as well as 3/4 and 2/4 ankle features, respectively. In conclusion, this study introduced an augmented-reality method allowing healthy subjects to modify their footprint parameters rapidly and precisely. Walking with modified footprints changed lower-limb sagittal-plane kinematics. Further research is needed to design rehabilitation protocols for specific pathologies.
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http://dx.doi.org/10.1016/j.jbiomech.2017.10.030DOI Listing
January 2018

Knee Implant Loosening Detection: A Vibration Analysis Investigation.

Ann Biomed Eng 2018 Jan 24;46(1):97-107. Epub 2017 Oct 24.

Laboratory of Movement Analysis and Measurement, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.

Knee implant loosening is mainly caused by the weakness of the prosthesis-bone interface and is the main reason for surgical revisions. However, pre-operative diagnosis is difficult due to lack of accurate tests. In this study, we developed a vibration-based system to detect the loosening of the tibial implant of an instrumented knee prosthesis. The proposed system includes an instrumented vibrator for transcutaneous stimulation of the bone in a repeatable manner, and accelerometer sensors integrated into the implants to measure the propagated vibration. A coherence-based detection technique was proposed to distinguish the loosened implants from the secure ones. Fourteen ex vivo lower limbs were used, on which the knee prosthesis was implanted, and harmonic-forced vibration was applied on the tibia. The input-output coherence measure provided 92.26% accuracy, a high sensitivity (91.67%) and specificity (92.86%). This technique was benchmarked against power spectrum based analysis of the propagated vibration to the implant. In particular, loosening detection based on new peak appearance, peak shift, and peak flattening in power spectra showed inferior performance to the proposed coherence-based technique. As such, application of vibration on our instrumented knee prosthesis together with input-output coherence analysis enabled us to distinguish the secure from loose implants.
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http://dx.doi.org/10.1007/s10439-017-1941-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5754435PMC
January 2018

Chronic low back pain patients walk with locally altered spinal kinematics.

J Biomech 2017 07 5;60:211-218. Epub 2017 Jul 5.

Swiss BioMotion Lab, Department of Musculoskeletal Medicine, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland.

Various studies have reported alterations of spinal kinematics in patients with chronic low back pain (CLBP) during gait. However, while recent findings stressed the importance of multi-segment analysis, most of prior gait studies modelled the lumbar spine as one segment, when it was not the entire trunk that was considered as a single segment. Therefore, there is a need for comprehensive multi-segment research that could improve our understanding of CLBP pathomechanism and thus possibly contribute to better care for CLBP. This study aimed at characterizing the angle patterns at the lower lumbar (LLS), upper lumbar (ULS), lower thoracic (LTS) and upper thoracic (UTS) joints in the three anatomical planes and at comparing CLBP patients and asymptomatic subjects. Spinal kinematics of 11 CLBP patients and 11 controls was measured using a marker-based motion capture system and described according to a previously proposed multi-segment biomechanical model. Characteristic patterns were observed at the UTS, LTS and ULS joints in the transverse plane and at the UTS, ULS and LLS joints in the frontal plane. CLBP patients walked with smaller frontal-plane LLS range of motion than controls. The results also suggested that patients had more asymmetrical LTS motion in the transverse plane. In conclusion, this work extended prior literature by showing specific CLBP-related alterations in multi-segment spinal kinematics during gait. Further research is necessary to understand the factors influencing kinematics alterations and how treatment strategies might improve motor behaviour in CLBP patients.
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http://dx.doi.org/10.1016/j.jbiomech.2017.06.042DOI Listing
July 2017

Gait analysis of patients with knee osteoarthritis highlights a pathological mechanical pathway and provides a basis for therapeutic interventions.

EFORT Open Rev 2016 Oct 13;1(10):368-374. Epub 2017 Mar 13.

Swiss BioMotion Laboratory, Department of Musculoskeletal Medicine, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland.

Knee osteoarthritis (OA) is a painful and incapacitating disease affecting a large portion of the elderly population, for which no cure exists. There is a critical need to enhance our understanding of OA pathogenesis, as a means to improve therapeutic options.Knee OA is a complex disease influenced by many factors, including the loading environment. Analysing knee biomechanics during walking - the primary cyclic load-bearing activity - is therefore particularly relevant.There is evidence of meaningful differences in the knee adduction moment, flexion moment and flexion angle during walking between non-OA individuals and patients with medial knee OA. Furthermore, these kinetic and kinematic gait variables have been associated with OA progression.Gait analysis provides the critical information needed to understand the role of ambulatory biomechanics in OA development, and to design therapeutic interventions. Multidisciplinary research is necessary to relate the biomechanical alterations to the structural and biological components of OA. Cite this article: Favre J, Jolles BM. Analysis of gait, knee biomechanics and the physiopathology of knee osteoarthritis in the development of therapeutic interventions. 2016;1:368-374. DOI: 10.1302/2058-5241.1.000051.
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http://dx.doi.org/10.1302/2058-5241.1.000051DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5367582PMC
October 2016

Heightened clinical utility of smartphone versus body-worn inertial system for shoulder function B-B score.

PLoS One 2017 20;12(3):e0174365. Epub 2017 Mar 20.

School of Health Sciences, Queen Margaret University, Edinburgh, Scotland.

Background: The B-B Score is a straightforward kinematic shoulder function score including only two movements (hand to the Back + lift hand as to change a Bulb) that demonstrated sound measurement properties for patients for various shoulder pathologies. However, the B-B Score results using a smartphone or a reference system have not yet been compared. Provided that the measurement properties are comparable, the use of a smartphone would offer substantial practical advantages. This study investigated the concurrent validity of a smartphone and a reference inertial system for the measurement of the kinematic shoulder function B-B Score.

Methods: Sixty-five patients with shoulder conditions (with rotator cuff conditions, adhesive capsulitis and proximal humerus fracture) and 20 healthy participants were evaluated using a smartphone and a reference inertial system. Measurements were performed twice, alternating between two evaluators. The B-B Score differences between groups, differences between devices, relationship between devices, intra- and inter-evaluator reproducibility were analysed.

Results: The smartphone mean scores (SD) were 94.1 (11.1) for controls and 54.1 (18.3) for patients (P < 0.01). The difference between devices was non-significant for the control (P = 0.16) and the patient group (P = 0.81). The analysis of the relationship between devices showed 0.97 ICC, -0.6 bias and -13.2 to 12.0 limits of agreement (LOA). The smartphone intra-evaluator ICC was 0.92, the bias 1.5 and the LOA -17.4 to 20.3. The smartphone inter-evaluator ICC was 0.92, the bias 1.5 and the LOA -16.9 to 20.0.

Conclusions: The B-B Score results measured with a smartphone were comparable to those of an inertial system. While single measurements diverged in some cases, the intra- and inter-evaluator reproducibility was excellent and was equivalent between devices. The B-B score measured with a smartphone is straightforward and as efficient as a reference inertial system measurement.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0174365PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5358877PMC
August 2017

Multi-segment analysis of spinal kinematics during sit-to-stand in patients with chronic low back pain.

J Biomech 2016 07 20;49(10):2060-2067. Epub 2016 May 20.

Swiss BioMotion Lab, Department of Musculoskeletal Medicine, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland.

While alterations in spinal kinematics have been frequently reported in patients with chronic low back pain (CLBP), a better characterization of the kinematics during functional activities is needed to improve our understanding and therapeutic solutions for this condition. Recent studies on healthy subjects showed the value of analyzing the spine during sit-to-stand transition (STST) using multi-segment models, suggesting that additional knowledge could be gained by conducting similar assessments in CLBP patients. The objectives of this study were to characterize three dimensional kinematics at the lower lumbar (LLS), upper lumbar (ULS), lower thoracic (LTS) and upper thoracic (UTS) joints during STST, and to test the hypothesis that CLBP patients perform this movement with smaller angle and angular velocity compared to asymptomatic controls. Ten CLBP patients (with minimal to moderate disability) and 11 asymptomatic controls with comparable demographics (52% male, 37.4±5.6 years old, 22.5±2.8kg/m(2)) were tested using a three-dimensional camera-based system following previously proposed protocols. Characteristic patterns of movement were identified at the LLS, ULS and UTS joints in the sagittal plane only. Significant differences in the form of smaller sagittal-plane angle and smaller angular velocity in the patient group compared to the control group were observed at these three joints. This indicated a more rigid spine in the patient group and suggested that CLBP rehabilitation could potentially be enhanced by targeting movement deficits in functional activities. The results further recommended the analysis of STST kinematics using a pelvis-lumbar-thoracic model including lower and upper lumbar and thoracic segments.
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http://dx.doi.org/10.1016/j.jbiomech.2016.05.015DOI Listing
July 2016

Reliability of the Knee Smartphone-Application Goniometer in the Acute Orthopedic Setting.

J Knee Surg 2017 Mar 24;30(3):223-230. Epub 2016 May 24.

Department of Musculoskeletal Medicine, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland.

The standard goniometer (SG) is the most commonly used tool to assess range of motion (ROM) in patients with knee restrictions. Several medical applications have been designed to measure joint ROM. Little data are available on their reliability in the postoperative clinical setting. The purpose of this study was to assess whether a smartphone accelerometer-based knee goniometer application (App) is as reliable as the SG to measure knee ROM in clinical settings. A total of 60 subjects were included in this cross-sectional reliability trial. Overall, 20 healthy subjects (HS) and 20 acute postoperative patients (PO) underwent three active and three passive measurements in knee flexion and extension, using the SG and the smartphone knee goniometer App. To determine the fatigability of postoperative patients, a third group of 20 patients underwent a single active measurement in knee flexion and extension (PO1). Measurements were performed by three clinicians. For intraobserver reliability, mean intraclass correlation coefficient (ICC) values were higher for the App in all circumstances (overall mean SG 0.85, App 0.91), indicating an excellent correlation. For interobserver reliability, the highest ICC scores were in the PO1 group, with the App more consistent than the SG in all movements. Interobserver reliability was lower in the PO group versus PO1. Interobserver reliability was better for active ROM than for passive measurements. The overall concordance coefficient was very good to excellent with active measurements (range, 0.60-0.97). In conclusion, the App is a reliable tool for use in acute orthopedic care and offers better intra- and interobserver correlation scores for a single active measurement.
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http://dx.doi.org/10.1055/s-0036-1584184DOI Listing
March 2017

Effect of Manual Lymphatic Drainage After Total Knee Arthroplasty: A Randomized Controlled Trial.

Arch Phys Med Rehabil 2016 05 30;97(5):674-82. Epub 2016 Jan 30.

Orthopedics and Traumatology Department, University Hospital of Lausanne - University of Lausanne, Lausanne, Switzerland.

Objective: To evaluate the effects of manual lymphatic drainage (MLD) on knee swelling and the assumed consequences of swelling after total knee arthroplasty (TKA).

Design: Randomized controlled trial.

Setting: Primary care hospital.

Participants: Two groups of 30 patients were randomized before TKA surgery (N=60; 65% women [39]; mean age, 70.7±8.8y; weight, 77.8±11.3kg; size, 1.64±0.08m; body mass index, 29.9±4.1kg/m(2)).

Interventions: Participants received either 5 MLD treatments or a placebo, added to rehabilitation, in between the second day and the seventh day after surgery.

Main Outcome Measures: Swelling was measured by blinded evaluators before surgery and at second day, seventh day, and 3 months using bioimpedance spectroscopy and volume measurement. Secondary outcomes were active and passive range of motion, pain, knee function, and gait parameters.

Results: At seventh day and 3 months, no outcome was significantly different between groups, except for the knee passive flexion contracture at 3 months, which was lower and less frequent in the MLD group (-2.6°; 95% confidence interval, -5.0° to -0.21°; P=.04; absolute risk reduction, 26.6%; 95% confidence interval, 0.9%-52.3%; number needed to treat, 4). The mean pain level decreased between 5.8 and 8.2mm on the visual analog scale immediately after MLD, which was significant after 4 of 5 MLD treatments.

Conclusions: MLD treatments applied immediately after TKA surgery did not reduce swelling. It reduced pain immediately after the treatment. Further studies should investigate whether the positive effect of MLD on knee extension is replicable.
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http://dx.doi.org/10.1016/j.apmr.2016.01.006DOI Listing
May 2016

Unexpected wear of an unicompartimental knee arthroplasty in oxidized zirconium.

Acta Orthop Belg 2015 Dec;81(4):790-5

Unicompartimental knee arthroplasty is a successful procedure for the treatment of localized osteoarthritis to one compartment of the knee with good long-term results. However, several modes of failure of unicompartimental knee arthroplasty have been described, namely aseptic or septic loosening, progression of disease, wear, and instability. Metallosis after unicompartimental knee arthroplasty is rarely reported and is most often related with polyethylene wear or break. We report on a case of rapid failure of unicompartimental knee arthroplasty in oxidized zirconium associated with metallosis secondary to the dislocation of the polyethylene.
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December 2015

Measurement properties of the smartphone-based B-B Score in current shoulder pathologies.

Sensors (Basel) 2015 Oct 22;15(10):26801-17. Epub 2015 Oct 22.

Laboratory of Movement Analysis and Measurement, Ecole Polytechnique Fédérale de Lausanne (EPFL), ELH 135 (Bâtiment ELH), Station 11, 1015 Lausanne, Switzerland.

This study is aimed at the determination of the measurement properties of the shoulder function B-B Score measured with a smartphone. This score measures the symmetry between sides of a power-related metric for two selected movements, with 100% representing perfect symmetry. Twenty healthy participants, 20 patients with rotator cuff conditions, 23 with fractures, 22 with capsulitis, and 23 with shoulder instabilities were measured twice across a six-month interval using the B-B Score and shoulder function questionnaires. The discriminative power, responsiveness, diagnostic power, concurrent validity, minimal detectable change (MDC), minimal clinically important improvement (MCII), and patient acceptable symptom state (PASS) were evaluated. Significant differences with the control group and significant baseline-six-month differences were found for the rotator cuff condition, fracture, and capsulitis patient groups. The B-B Score was responsive and demonstrated excellent diagnostic power, except for shoulder instability. The correlations with clinical scores were generally moderate to high, but lower for instability. The MDC was 18.1%, the MCII was 25.2%, and the PASS was 77.6. No floor effect was observed. The B-B Score demonstrated excellent measurement properties in populations with rotator cuff conditions, proximal humerus fractures, and capsulitis, and can thus be used as a routine test to evaluate those patients.
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http://dx.doi.org/10.3390/s151026801DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4634494PMC
October 2015

Soft tissue artifact distribution on lower limbs during treadmill gait: Influence of skin markers' location on cluster design.

J Biomech 2015 Jul 17;48(10):1965-71. Epub 2015 Apr 17.

Laboratory of Movement Analysis and Measurement (LMAM), EPFL, Lausanne, Switzerland. Electronic address:

Segment poses and joint kinematics estimated from skin markers are highly affected by soft tissue artifact (STA) and its rigid motion component (STARM). While four marker-clusters could decrease the STA non-rigid motion during gait activity, other data, such as marker location or STARM patterns, would be crucial to compensate for STA in clinical gait analysis. The present study proposed 1) to devise a comprehensive average map illustrating the spatial distribution of STA for the lower limb during treadmill gait and 2) to analyze STARM from four marker-clusters assigned to areas extracted from spatial distribution. All experiments were realized using a stereophotogrammetric system to track the skin markers and a bi-plane fluoroscopic system to track the knee prosthesis. Computation of the spatial distribution of STA was realized on 19 subjects using 80 markers apposed on the lower limb. Three different areas were extracted from the distribution map of the thigh. The marker displacement reached a maximum of 24.9 mm and 15.3 mm in the proximal areas of thigh and shank, respectively. STARM was larger on thigh than the shank with RMS error in cluster orientations between 1.2° and 8.1°. The translation RMS errors were also large (3.0 mm to 16.2 mm). No marker-cluster correctly compensated for STARM. However, the coefficient of multiple correlations exhibited excellent scores between skin and bone kinematics, as well as for STARM between subjects. These correlations highlight dependencies between STARM and the kinematic components. This study provides new insights for modeling STARM for gait activity.
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http://dx.doi.org/10.1016/j.jbiomech.2015.04.007DOI Listing
July 2015

Bioimpedance spectroscopy for swelling evaluation following total knee arthroplasty: a validation study.

BMC Musculoskelet Disord 2015 Apr 25;16:100. Epub 2015 Apr 25.

CHUV-UNIL, Orthopedics and Traumatology Department, CHUV-UNIL, Avenue du Bugnon 21, 1011, Lausanne, Switzerland.

Background: The evaluation of swelling is important for the outcome of total knee arthroplasty (TKA) surgery. The circumference or volume measurements are applicable at the bedside of the patient but are altered by muscular atrophy and the post-surgical dressing. Bioimpedance spectroscopy might overcome these limitations; however, it should be validated. This study aimed to explore the validity, the reliability and the responsiveness of bioimpedance spectroscopy for measuring swelling after TKA.

Methods: The degree of swelling in 25 patients undergoing TKA surgery was measured using bioimpedance spectroscopy (BIS R0), knee circumference and limb volume. The measurements were performed on D-1 (day before surgery), D + 2 (2 days after surgery) and D + 8 (8 days after surgery). The BIS R0 measurements were repeated twice, alternating between two evaluators. The percentage of the difference between the limbs was calculated for BIS R0, circumference and volume. The intra- and inter-observer intraclass correlation coefficients (ICCs), limits of agreement (LOA), effect size (Cohen's d), correlations between the methods and diagnostic sensitivity were calculated.

Results: BIS R0, circumference and volume detected swelling < 3.5% at D-1. The swelling at D2 and D8 was greater with BIS R0 [mean (SD) 29.9% (±9.8) and 38.27 (±7.8)] than with volume [14.7 (±9.5) and 14.9 (±8.2)] and circumference [11.1 (±5.7) and 11.7 (±4.1)]. The BIS R0 intra- and inter-evaluator ICCs ranged from 0.89 to 0.99, whereas the LOA were < 5.2%. The BIS R0 correlation was 0.73 with volume and 0.75 with circumference. The BIS R0 Cohen's d was 3.32 for the D-1-D2 evolution. The diagnostic sensitivity was 83% D2 and 96% at D8.

Conclusion: Bioimpedance is a valid method for the evaluation of swelling following TKA. BIS R0 also demonstrated excellent intra- and inter-evaluator reliability. The diagnostic sensitivity and responsiveness is superior to that of concurrent methods. BIS R0 is an efficient method for post-surgical follow up at the bedside of the patient. The measurement of BIS R0 is a straightforward, valid, reliable and responsive method for lower limb swelling following TKA surgery that could be used in clinics and research.

Trial Registration: ClinicalTrials.gov Identifier: NCT00627770.
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http://dx.doi.org/10.1186/s12891-015-0559-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4422299PMC
April 2015

Alteration and recovery of arm usage in daily activities after rotator cuff surgery.

J Shoulder Elbow Surg 2015 Sep 29;24(9):1346-52. Epub 2015 Mar 29.

Department of Orthopaedic and Trauma Surgery, Centre Hospitalier Universitaire Vaudois (CHUV) and University of Lausanne, Lausanne, Switzerland.

Background: The objective measurement of dominant/nondominant arm use proportion in daily life may provide relevant information on healthy and pathologic arm behavior. This prospective case-control study explored the potential of such measurements as indicators of upper limb functional recovery after rotator cuff surgery.

Methods: Data on dominant/nondominant arm usage were acquired with body-worn sensors for 7 hours. The postsurgical arm usage of 21 patients was collected at 3, 6, and 12 months after rotator cuff surgery in the sitting, walking, and standing postures and compared with a reference established with 41 healthy subjects. The results were calculated for the dominant and nondominant surgical side subgroups at all stages. The correlations with clinical scores were calculated.

Results: Healthy right-handed and left-handed dominant arm usage was 60.2% (±6.3%) and 53.4% (±6.6%), respectively. Differences in use of the dominant side were significant between the right- and left-handed subgroups for sitting (P = .014) and standing (P = .009) but not for walking (P = .328). The patient group showed a significant underuse of 10.7% (±8.9%) at 3 months after surgery (P < .001). The patients recovered normal arm usage within 12 months, regardless of surgical side. The arm underuse measurement was weakly related to function and pain scores.

Conclusion: This study provided new information on arm recovery after rotator cuff surgery using an innovative measurement method. It highlighted that objective arm underuse measurement is a valuable indicator of upper limb postsurgical outcome that captures a complementary feature to clinical scores.
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http://dx.doi.org/10.1016/j.jse.2015.01.017DOI Listing
September 2015

[Single use custom made instrumentation, the future of total knee arthroplasty?].

Rev Med Suisse 2014 Dec;10(455):2424-8

It is expected that the number of total knee arthroplasties should be multiplied by 7 in twenty years. Until now, this procedure required a large number of surgical trays. Three-dimensional preoperative planning, persona-lized cutting guides, and disposable instrumentation kits can now help to optimize this procedure by providing a unique single-use surgical kit per patient. This type of instrumentation leads to improvements in precision, operative time, turnover time, sterilization and maintenance costs, and could help reduce infectious risks. This technology is a step towards personalized orthopedic surgery, and opens new perspectives on a future with implants entirely customized for each patient.
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December 2014