Automatic gait events detection with inertial measurement units: healthy subjects and moderate to severe impaired patients.

BACKGROUND: Recently, the use of inertial measurement units (IMUs) in quantitative gait analysis has been widely developed in clinical practice. Numerous methods have been developed for the automatic detection of gait events (GEs). While many of them have achieved high levels of efficiency in healthy subjects, detecting GEs in highly degraded gait from moderate to severely impaired patients remains a challenge. In this paper, we aim to present a method for improving GE detection from IMU recordings in such cases. METHODS: We recorded 10-meter gait IMU signals from 13 healthy subjects, 29 patients with multiple sclerosis, and 21 patients with post-stroke equino varus foot. An instrumented mat was used as the gold standard. Our method detects GEs from filtered acceleration free from gravity and gyration signals. Firstly, we use autocorrelation and pattern detection techniques to identify a reference stride pattern. Next, we apply multiparametric Dynamic Time Warping to annotate this pattern from a model stride, in order to detect all GEs in the signal. RESULTS: We analyzed 16,819 GEs recorded from healthy subjects and achieved an F1-score of 100%, with a median absolute error of 8 ms (IQR [3-13] ms). In multiple sclerosis and equino varus foot cohorts, we analyzed 6067 and 8951 GEs, respectively, with F1-scores of 99.4% and 96.3%, and median absolute errors of 18 ms (IQR [8-39] ms) and 26 ms (IQR [12-50] ms). CONCLUSIONS: Our results are consistent with the state of the art for healthy subjects and demonstrate a good accuracy in GEs detection for pathological patients. Therefore, our proposed method provides an efficient way to detect GEs from IMU signals, even in degraded gaits. However, it should be evaluated in each cohort before being used to ensure its reliability.

Return to Sport and Duty in French Military Personnel after Medial Opening Wedge High Tibial Osteotomy.

INTRODUCTION: Medial opening wedge high tibial osteotomy (MOWHTO) is a surgical option for medial femorotibial osteoarthritis, which preserves articular cartilage by correcting the extra-articular deformities of the lower limbs that cause osteoarthritis. This is an increasingly popular treatment in a population with high functional demand, such as the French military population. The aim of this study was to evaluate the rate of return to work and military activities at 6 months postsurgery and at last follow-up in this military population following MOWHTO.The hypothesis of this study was that MOWHTO enabled a majority of service members to return to the same level of activity within 6 months of surgery. MATERIALS AND METHODS: This was a retrospective, multicenter study including all French military personnel operated on for MOWHTO alone for osteoarthritis of medial compartment between 2008 and 2018 in different Military Teaching Hospitals. We excluded civilian patients. For each patient, a questionnaire was used to collect epidemiological, professional, sports, and functional data. The primary endpoint was the rate of return to work at 6 months postsurgery. We also studied the recovery of sports activities and functional results at a 6.6-year follow-up by standardized questionnaires (Tegner activity scale, Lysholm, IKDC subjective (International Knee Documentation Commitee)). RESULTS: Twenty-four MOWHTOs were performed during this period in a cohort of 22 French military personnel. Return to work at 6 months was possible in 20/24 cases (83.3%). Of the four patients who did not return to work at 6 months, two changed their activities, while the other two returned to their jobs after 6 months. The rate of resumption of sporting activities at an equal or higher level was 50% (11/22). There was no difference between pre- and postoperative Tegner Activity Scale scores at the longest follow-up (P = .08). The mean postoperative Lysholm scores were 73.5 (standard deviation 17.8) and IKDC 59 (standard deviation 8.7). No intraoperative complications were found, and one case of postoperative infection was found. CONCLUSIONS: A total of 83% of the operated soldiers were able to return to their professional activities in less than 6 months. We observed a functional improvement at the last follow-up. Comparing these results with data from civilian populations, the rate of occupational recovery is comparable. However, the return to sport is much better in the series of nonmilitary patients with approximately 90% return to work and sport in the year following surgery. MOWHTO improves the functional results of the knee, enabling a return to work and sport in most cases in young, active populations such as the French military.

Return to military duty following anterior cruciate ligament reconstruction is associated with preoperative Body Mass Index and postoperative physiotherapy.

PURPOSE: To determine the rate and time of return to duty following anterior cruciate ligament reconstruction (ACLR) in military members, and to determine whether their outcomes are influenced by patient characteristics or surgical parameters. METHODS: We prospectively assessed 280 military members that underwent ACLR. 27 were excluded due to multi-ligamentous injuries or revision surgery, two did not provide informed consent and 62 were lost to follow-up. Patient demographics, pre-injury physical workload, complications and whether/when patients resumed duty and sports were noted, as well as clinical outcomes at a minimum follow-up of one year, including Knee Injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee score (IKDC), Lysholm, and Tegner scale. RESULTS: The final cohort of 189 military members (82% men) had mean age of 25.5 ± 3.4 (range,19-38) at ACLR. At 3.3 ± 1.6 years (range, 1.0-6.3), the Tegner score was 6.1 ± 2.0, Lysholm was 87.0 ± 13.7, IKDC was 80.1 ± 15.7, and KOOS was 81.1 ± 14.8. Only 144 patients (76%) resumed duty, at 9.5 ± 5.3 months (range,1-28), and 141 patients (75%) resumed sport, at 10.2 ± 6.2 months (range,1-35). Multivariable analysis revealed that return to duty was less likely in patients with higher BMI (OR,0.89;p = 0.025), but more likely in patients that followed military physiotherapy (OR,2.76;p = 0.017) and with higher pre-injury physical workload (OR,3.93;p = 0.010). CONCLUSION: At a follow-up of 3.3 ± 1.6 years, 76% returned to duty at 9.5 ± 5.3 months, and 75% returned to their main sport at 10.2 ± 6.2 months. Patients with higher BMI are significantly less likely to resume military duty and sports; those that followed military physiotherapy were most likely to resume duty, while those that had greater pre-injury physical workload were more likely to both resume duty and sport.

Innovative multidimensional gait evaluation using IMU in multiple sclerosis: introducing the semiogram.

Background: Quantifying gait using inertial measurement units has gained increasing interest in recent years. Highly degraded gaits, especially in neurological impaired patients, challenge gait detection algorithms and require specific segmentation and analysis tools. Thus, the outcomes of these devices must be rigorously tested for both robustness and relevancy in order to recommend their routine use. In this study, we propose a multidimensional score to quantify and visualize gait, which can be used in neurological routine follow-up. We assessed the reliability and clinical coherence of this method in a group of severely disabled patients with progressive multiple sclerosis (pMS), who display highly degraded gait patterns, as well as in an age-matched healthy subjects (HS) group. Methods: Twenty-two participants with pMS and nineteen HS were included in this 18-month longitudinal follow-up study. During the follow-up period, all participants completed a 10-meter walk test with a U-turn and back, twice at M0, M6, M12, and M18. Average speed and seven clinical criteria (sturdiness, springiness, steadiness, stability, smoothness, synchronization, and symmetry) were evaluated using 17 gait parameters selected from the literature. The variation of these parameters from HS values was combined to generate a multidimensional visual tool, referred to as a semiogram. Results: For both cohorts, all criteria showed moderate to very high test-retest reliability for intra-session measurements. Inter-session quantification was also moderate to highly reliable for all criteria except smoothness, which was not reliable for HS participants. All partial scores, except for the stability score, differed between the two populations. All partial scores were correlated with an objective but not subjective quantification of gait severity in the pMS population. A deficit in the pyramidal tract was associated with altered scores in all criteria, whereas deficits in cerebellar, sensitive, bulbar, and cognitive deficits were associated with decreased scores in only a subset of gait criteria. Conclusions: The proposed multidimensional gait quantification represents an innovative approach to monitoring gait disorders. It provides a reliable and informative biomarker for assessing the severity of gait impairments in individuals with pMS. Additionally, it holds the potential for discriminating between various underlying causes of gait alterations in pMS.

Return to sport after surgery for osteochondral lesions of the talar dome. Results of a multicenter prospective study on 58 patients.

INTRODUCTION: Osteochondral lesions of the talar dome (OLTD) are most often found in patients for whom the return to sports activities is the main issue. Two types of surgery have been distinguished at present, bone marrow stimulation techniques and mosaicplasty techniques. The size of the lesion indicating the need for bone marrow stimulation as the required surgical procedure has recently been decreased (<1cm). The main objective of this study was therefore to evaluate the return to sport after OLTD surgery. Our hypothesis is that surgery of osteochondral lesions of the talar dome allows the resumption of sports activities in the majority of cases. MATERIAL AND METHODS: This multicenter prospective study was conducted across 10 French centers specializing in foot and ankle surgery. All patients aged 18 to 65 with symptomatic OLTD resistant to thorough medical treatment for at least 6 months, justifying surgery, were included from June 2018 to September 2019. In addition to the usual demographic data, the practice of sport and level (professional, competitive, leisure) were systematically investigated preoperatively. A common protocol for surgical management and postoperative follow-up had previously been established according to the arthrographic stage of the lesion. The most recent recommendations based on size, but also depth, were taken into account. The primary endpoint was return to sport. RESULTS: A final functional evaluation with the AOFAS (American Orthopedic Foot & Ankle Society) score was performed at a minimum of 12 months. Of 58 sports patients, 70.6% returned to sport (41/58) with an average delay of 4.3 months. A high AOFAS functional score (p=0.02) and a stage 1 lesion (p=0.006) were the only preoperative criteria significantly associated with a return to sport. No other factor was predictive of a return to sport. CONCLUSION: Our prospective study shows that 70.6% of sports patients returned to sport after OLTD surgery according to a surgical protocol and standardized follow-up. LEVEL OF EVIDENCE: II.

Management of combat-sustained radial nerve injury during World War I: The case of Louis-Ferdinand Céline.

The radial nerve conveys sensory and motor information to and from the upper limb, and radial nerve injury can induce functional disability, as demonstrated by the case of the renowned French writer Louis-Ferdinand Céline (1894-1961), who sustained a gunshot injury to his right arm in October 1914. Radial nerve injuries treated during World War I inspired the publication of several medical handbooks and medical theses, such as that of the military surgeon Major Robert Bretton (1889-1956). The aim of this paper is, via Céline's injury, to explore the management of radial nerve injury during and since World War I. It is important to consider the historical perspective in order to improve radial nerve injury management so as to adapt to modern warfare.

A Machine Learning Pipeline for Gait Analysis in a Semi Free-Living Environment.

This paper presents a novel approach to creating a graphical summary of a subject's activity during a protocol in a Semi Free-Living Environment. Thanks to this new visualization, human behavior, in particular locomotion, can now be condensed into an easy-to-read and user-friendly output. As time series collected while monitoring patients in Semi Free-Living Environments are often long and complex, our contribution relies on an innovative pipeline of signal processing methods and machine learning algorithms. Once learned, the graphical representation is able to sum up all activities present in the data and can quickly be applied to newly acquired time series. In a nutshell, raw data from inertial measurement units are first segmented into homogeneous regimes with an adaptive change-point detection procedure, then each segment is automatically labeled. Then, features are extracted from each regime, and lastly, a score is computed using these features. The final visual summary is constructed from the scores of the activities and their comparisons to healthy models. This graphical output is a detailed, adaptive, and structured visualization that helps better understand the salient events in a complex gait protocol.

Nerve transfer in the spastic equino varus foot: Anatomical feasibility study.

PURPOSE: We want to evaluate the feasibility of transferring a motor branch of the anterior tibial muscle (ATM) to the extensor digitorum longus (EDL) to evaluate this procedure in patients with spastic equinovarus foot (EVF) following post-stroke hemiplegia. METHODS: Ten cadaveric dissections from five fresh frozen human cadavers were performed to establish the anatomic feasibility of transferring a motor branch of the deep peroneal nerve, usually destinated to the ATM, to the branch of the EDL to manage spastic EVF. RESULTS: Six cases (60%) presented three branches destinated to the ATM, one case (10%) presented give branches, and three cases (30%) had four branches. In all specimens, the coaptation between the motor branch to the ATM, referred as the "effector" branch, and the branch of the EDL "receiver" branch was feasible without tension and did not require any intraneural dissection. CONCLUSION: This anatomical study confirms the feasibility of transferring a motor branch from the ATM to the EDL to correct a spastic EVF.

Evaluation methods to assess the efficacy of equinovarus foot surgery on the gait of post-stroke hemiplegic patients: A literature review.

Introduction: The aim of this study was to realize a systematic review of the different ways, both clinical and instrumental, used to evaluate the effects of the surgical correction of an equinovarus foot (EVF) deformity in post-stroke patients. Methods: A systematic search of full-length articles published from 1965 to June 2021 was performed in PubMed, Embase, CINAHL, Cochrane, and CIRRIE. The identified studies were analyzed to determine and to evaluate the outcomes, the clinical criteria, and the ways used to analyze the impact of surgery on gait pattern, instrumental, or not. Results: A total of 33 studies were included. The lack of methodological quality of the studies and their heterogeneity did not allow for a valid meta-analysis. In all, 17 of the 33 studies involved exclusively stroke patients. Ten of the 33 studies (30%) evaluated only neurotomies, one study (3%) evaluated only tendon lengthening procedures, 19 studies (58%) evaluated tendon transfer procedures, and only two studies (6%) evaluated the combination of tendon and neurological procedures. Instrumental gait analysis was performed in only 11 studies (33%), and only six studies (18%) combined it with clinical and functional analyses. Clinical results show that surgical procedures are safe and effective. A wide variety of different scales have been used, most of which have already been validated in other indications. Discussion: Neuro-orthopedic surgery for post-stroke EVF is becoming better defined. However, the method of outcome assessment is not yet well established. The complexity in the evaluation of the gait of patients with EVF, and therefore the analysis of the effectiveness of the surgical management performed, requires the integration of a patient-centered functional dimension, and a reliable and reproducible quantified gait analysis, which is routinely usable clinically if possible.

Foreign body removal by a lung-sparing bronchotomy.

This tutorial shows how to remove an aspirated foreign body via a lung-sparing operation using a transverse bronchotomy through a transthoracic approach.  An 18-year-old woman was admitted for treatment of an aspirated foreign body. A pushpin was impacted in a subsegmental branch of the right lower lobe of her bronchus. The problem was managed successfully using a conservative surgical approach:  The foreign body was removed from the lower-lobe bronchus, thereby avoiding the need for a lung resection. Starting with a posterolateral thoracotomy by harvesting a pedicled flap, the surgeon exposed and opened the bronchus to remove the impacted foreign body. The bronchial suture was covered by the pedicled flap.  The endoscopic removal of aspirated foreign bodies, which is considered the first-line treatment, can be challenging and can lead to airway injury or stenosis. Described at the beginning of 20th century, transthoracic bronchotomy for foreign body removal remains a life-saving and lung-sparing procedure that should not be overlooked.

Masquelet technique in military practice: specificities and future directions for combat-related bone defect reconstruction.

Because of its simplicity, reliability, and replicability, the Masquelet induced membrane technique (IMT) has become one of the preferred methods for critical bone defect reconstruction in extremities. Although it is now used worldwide, few studies have been published about IMT in military practice. Bone reconstruction is particularly challenging in this context of care due to extensive soft-tissue injury, early wound infection, and even delayed management in austere conditions. Based on our clinical expertise, recent research, and a literature analysis, this narrative review provides an overview of the IMT application to combat-related bone defects. It presents technical specificities and future developments aiming to optimize IMT outcomes, including for the management of massive multi-tissue defects or bone reconstruction performed in the field with limited resources.

Tibia fracture management in low-resource settings using the External Fixation and Traction Device of the Guinean Military Health Service.

INTRODUCTION: The authors analyzed results over a 7-year period for a locally manufactured external fixation and traction device (EFTD) used in tibial fracture. Three models were used, depending on the medical and technological context of the healthcare structure in question. The aim of the present study was to reports results for tibial fracture treated by EFTD in low-resource settings. MATERIALS AND METHODS: A multicenter observational study was conducted for the period 2008-2015 in a series of 34 tibial fractures (22 right, 12 left, with 1 bilateral) in 33 young adults (28 male, 5 female; mean age, 42.2 years). Nineteen were closed fractures and 15 open. The 11 recent open fractures comprised 2 Cauchoix-Duparc type I, 3 type II and 6 type III; the 4 older open fractures were infected. Four patients were lost to follow-up. RESULTS: Seventeen of the patients with closed fracture had very good results, in 75% (6/8) of shaft fractures and 55.55% (5/9) of complex metaphyseal-epiphyseal fractures. In infected fractures older than 48h, there were good results in 25% of cases. In recent open fractures, there were 100% (2/2), 66.6% (2/3) and 20% (1/5) good results for types I, II and III respectively. Five patients showed malunion, well-tolerated functionally. Mean time to bone healing was 16 weeks (range, 12-72 weeks). CONCLUSION: In developing countries, the pitfall in treating open fractures is delayed surgery due to patients' socioeconomic situation and to underequipment. The EFTD is a promising technique, readily available at low cost, easy to implement and with minimal iatrogenesis. LEVEL OF EVIDENCE: IV, prospective observational study.

Arthroscopic lateral ankle ligament reinsertion with reinforcement by a minimally invasive extensor retinaculum flap for chronic ankle instability.

The past decade has seen the development of numerous arthroscopic techniques for ankle ligament repair or reconstruction in the treatment of chronic lateral ankle instability. Arthroscopy allows the assessment and treatment of intra-articular pathologies and is associated with faster functional recovery. The open surgery technique described by Blanchet, combining reinsertion of the lateral collateral ligament with reinforcement by an extensor retinaculum flap, has long proven its effectiveness. The aim of this article is to describe this technique under arthroscopy.

Open Screw Fixation of Large Anterior Glenoid Rim Fractures Using a Deltopectoral Approach With Subscapularis Splitting.

Anterior glenoid rim fracture is a consequence of the humeral head impacting the glenoid fossa. The management of large glenoid fractures involving more than 20% of the articulating glenoid requires surgical treatment. The 2 main techniques are open reduction internal fixation (ORIF) by screws and arthroscopic treatment using suture anchors or transcutaneous screws. Next to the technical equipment, a surgeon requires extensive experience to achieve good results with the arthroscopic technique. The main disadvantage using the ORIF technique is the detachment of the subscapularis muscle, which is often criticized for causing functional deficits of the subscapularis. Our study demonstrates the feasibility of the ORIF technique through a deltopectoral approach and splitting of the subscapularis. To our knowledge, subscapularis splitting has never been described to treat glenoid fractures.

Acetabular reconstruction after advanced acetabular metastasis resection: Modified Harrington technique with a Kerboull reinforcement device.

The surgical treatment of acetabular bone metastases rests on total hip arthroplasty (THA). In the event of major bone defects, the reconstruction may prove challenging. Two complicating factors are the need to obtain a mechanically stable acetabulum and the unfeasibility of using an autograft to increase the bone stock. The technique described in 1981 by Harrington involves implanting steel rods to reinforce the pelvis before sealing the prosthetic cup. We have now been using this technique for several years, and based on our accumulated experience we introduced several substantial modifications. The most important among them is the use of a Kerboull acetabular reinforcement device (KARD) in addition to the iliac pins. This reinforcement of the acetabulum, which is widely used for THA, serves as the basis for guiding the reconstruction, while also facilitating the sealing of the prosthetic cup. Furthermore, we use centrally threaded rods to avoid secondary displacement. Finally, we routinely use a dual-mobility cemented cup to decrease the risk of dislocation. Here, we describe our acetabular reconstruction technique based on a modified Harrington technique, which is used for acetabular reconstruction in patients with advanced acetabular metastases managed at our French referral centre.

Management of musculoskeletal tumours of the extremity in low-resource settings.

BACKGROUND: Management of extremity tumor is particularly challenging in low-resource settings where patients are often referred with late presentations. First, diagnostic means are limited, with CT scan, MRI, and pathology usually not being available. Limitations are also related to therapeutic means, as the absence of adjuvant therapy (chemotherapy and radiotherapy) may preclude any improvement in overall survival despite a curative surgical treatment. OBJECTIVE: The authors suggest a kind of "toolbox" combining a diagnostic guide, based on clinical examination and X-rays, and therapeutic advice adapted to this context of care. The objective is to help the surgeon to better categorize the tumor to decide whether or not to operate or act in a relevant way. CONCLUSION: The authors do not aim to provide recommendations but rather an inventory of what the isolated surgeon should know to decide on the best treatment strategy which, however, can only be symptomatic.

Military Orthopedic Surgeons Are Not Just Traumatologists.

INTRODUCTION: Each French military orthopedic surgeon is both an orthopedic surgeon and a trauma surgeon. Their mission is to support the armed forces in France and on deployment. The aim of this study was to describe the type of orthopedic surgery performed for the armed forces in France. Our hypothesis was that scheduled surgery was more common than trauma surgery. METHODS: We conducted a retrospective descriptive analysis of the surgical activity for military patients in the orthopedic surgery departments of the four French military platform hospitals. All surgical procedures performed during 2020 were collected. We divided the procedures into the following categories: heavy and light trauma, posttraumatic reconstruction surgery, sports surgery, degenerative surgery, and specialized surgery. Our primary endpoint was the number of procedures performed per category. RESULTS: A total of 827 individuals underwent surgery, 91 of whom (11%) were medical returnees from deployment. The surgeries performed for the remaining 736 soldiers present in metropolitan France (89%) consisted of 181 (24.6%) trauma procedures (of which 86.7% were light trauma) and 555 (75.4%) scheduled surgery procedures (of which 60.8% were sports surgery). Among the medical returnees, there were 71 traumatology procedures (78%, of which 87.3% were light traumatology) and 20 procedures corresponding to surgery usually carried out on a scheduled basis (22%, of which 95% were sports surgery). CONCLUSION: Military orthopedic surgeons are not just traumatologists; their activity for the armed forces is varied and mainly consists of so-called programmed interventions.

Application of the Masquelet technique in austere environments: experience from a French forward surgical unit deployed in Chad.

PURPOSE: We sought to evaluate the results of the Masquelet-induced membrane technique (IMT) for long bone defect reconstruction within the limited-resource setting of a French forward surgical unit deployed in Chad. METHODS: A prospective and observational study was conducted in all patients with a traumatic segmental bone defect in any anatomical location treated by IMT from November 2015 to December 2019. Although IMT was applied by various orthopedic surgeons with variable expertise, all followed the same surgical protocol. Endpoint assessment was performed 12 months after IMT application. RESULTS: Sixteen patients with a mean age of 32.7 years were included in the study. Bone defects were located on the tibia (n = 8), the femur (n = 6) or the radius (n = 2). Thirteen bone defects were infected. After debridement, the mean bone defect length was 4.3 cm. External fixation of the tibia and femur was predominant in both stages. Bone union was achieved in only 8 of the 16 cases at a mean time of 7.6 months. All failures were related to persistent infection or insufficient fixation stability in the second stage. CONCLUSIONS: This series is the first to report IMT use in a forward surgical unit. Despite frequent complications, local patients can benefit from this procedure, which is the only available method for bone reconstruction in areas with limited medical resources. A rigorous technical completion at both stages is crucial to limit septic or mechanical failures.