Inertial measurement units to evaluate the efficacity of Equino Varus Foot surgery in post stroke hemiparetic patients: a feasibility study

 From this earlier research is this comment: So did they truly come up with an accurate assessment of the surgery? Go ask your competent? doctor that question.

Evaluation methods to assess the efficacy of equinovarus foot surgery on the gait of post-stroke hemiplegic patients: A literature review November 2022

 Comment: Neuro-orthopedic surgery for post-stroke EVF is becoming better defined. However, the method of outcome assessment is not yet well established.

Inertial measurement units to evaluate the efficacity of Equino Varus Foot surgery in post stroke hemiparetic patients: a feasibility study

• Nicolas de l’Escalopier,
• Cyril Voisard,
• Sylvain Jung,
• Mona Michaud,
• Albane Moreau,
• Nicolas Vayatis,
• Philippe Denormandie,
• Alix Verrando,
• Claire Verdaguer,
• Alain Moussu,
• Aliénor Jequier,
• Christophe Duret,
• Laurence Mailhan,
• Laure Gatin,
• Laurent Oudre &
• Damien Ricard 

Journal of NeuroEngineering and Rehabilitation volume 21, Article number: 182 (2024) Cite this article

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Abstract

Introduction

This study evaluates the gait analysis obtained by Inetial Measurement Units (IMU) before and after surgical management of Spastic Equino Varus Foot (SEVF) in hemiplegic post-stroke patients and to compare it with the functional results obtained in a monocentric prospective cohort.

Methods

Patients with post-stroke SEVF, who underwent surgery in a single hospital between November 2019 and December 2021 were included. The follow-up duration was 6 months and included a functional analysis using Goal Attainment Scaling (GAS) and a Gait analysis using an innovative Multidimensional Gait Evaluation using IMU: the semiogram.

Results

20 patients had a gait analysis preoperatively and at 6 months postoperatively. 90% (18/20) patients had a functional improvement (GAS T score ≥ 50) and 50% (10/20) had an improvement in walking technique as evidenced by the cessation of the use of a walking aid (WA). In patients with functional improvement and modification of WA the change in the semiogram area was + 9.5%, sd = 27.5%, and it was + 15.4%, sd = 28%. In the group with functional improvement without change of WA. For the 3 experiences (two patients) with unfavorable results, the area under the curve changed by + 2.3%, -10.2% and − 9.5%. The measurement of the semiogram area weighted by average speed demonstrated very good reproducibility (ICC(1, 3) = 0.80).

Discussion

IMUs appear to be a promising solution for the assessment of post-stroke hemiplegic patients who have undergone SEVF surgery. They can provide a quantified, objective, reliable in individual longitudinal follow up automated gait analysis solution for routine clinical use. Combined with a functional scale such as the GAS, they can provide a global analysis of the effect of surgery.

Introduction

A frequent chronic complication of post-stroke hemiplegia is the occurrence of a Spastic Equino Varus Foot (SEVF) deformity. This deformity is the cause of significant discomfort in walking and increases the risk of falling. The medical management is based on the use of botulinum toxin and rehabilitation [1]. If medical measures fail, “neuro-orthopaedic” surgery is required to correct dynamic and static deformities [2]. About 18% of stroke survivors will have a SEVF [3], and 59% of these will require surgical management [1].The preoperative evaluation is delicate and relies on consultation between the different actors of the management [4, 5]. Neuro orthopaedic surgery for SEVF encompasses a combination of tendon and nerve procedures performed by a single team [6, 7]. In most cases, the result is satisfactory, allowing the patient to have a plantigrade support for a more stable and fluid gait, sometimes without the need for technical aids. However, precise assessment of the effect of surgery on walking remains difficult and complex to reproduce [8].

The performance of a neuro-orthopaedic surgical procedure in these patients not only has an analytical local impact, but also has a more global repercussion. While the outcome of the procedure can be easily observed during the open chain analytical examination, its repercussion on the patient’s global approach remains extremely difficult to evaluate and quantify. Gait assessment of hemiplegic post-stroke patients with SEVF is a real challenge in clinical practice. There is currently no simple, reproducible, objective, and quantifiable way to assess gait in its entirety in clinical practice [8]. For this reason the evaluation of the result is therefore mainly based today on a subjective functional evaluation, with the Goal Attainment Scale (GAS) appearing as the most reliable tool [9,10,11]. It allows to know if the functional contract established with the patient during the preoperative phase has been fulfilled. Although it provides effective individual-level analysis, it is not very precise when it comes to comparing different treatments [12].

Thus, it seems essential to complete this functional evaluation with a global, quantified and objective evaluation of the repercussion of this procedure on the patients’ gait [13].

For several years, the use of inertial measurement units (IMUs) has made it possible to obtain a gait analysis that can be easily deployed in clinical routine [14]. The parameters used have proved highly effective in the longitudinal follow-up of patients suffering from neurological diseases such as Multiple Sclerosis or Parkinsons disease [15,16,17,18]. In post stroke patients, several parameters have shown good reliability [19,20,21]. However, IMUs have never been used in post-operative evaluation in this population. The semiogram is a radar diagram providing an immediate and intuitive view of all the gait data obtained by calculating 17 mathematical parameters validated in the literature and divided into 7 clinical criteria [22, 23]. It offers an instantaneous analysis of gait, which clinicians can conveniently interpret. By combining relevant parameters found in the literature [24, 25], it enables a comprehensive approach based on clinical criteria that can be easily used by the clinician. It therefore seems to us to be a relevant tool for easy use in clinical practice in this indication as a complement of GAS. Indeed it allows for a more detailed and quantified analysis, making it possible, for example, to compare two different interventions, or to assess changes in outcome longitudinally, which is not possible with GAS.

In order to assess the reliability and consistency of semiogram in the peri-operative evaluation of post-stroke SEVF, we compare in this article the results obtained with the semiogram and the functional evaluation usually performed [8]. Validation of IMU analysis by this method will inevitably have the same limitations as GAS, but it remains the best option for comparing clinical data with instrumental data. The originality of our study lies in this mixed approach, as there is currently no way of asserting that an improvement observed instrumentally is necessarily associated with an improvement felt by the patient.

Our main objective is to evaluate the gait analysis obtained by IMU before and after surgical management of SEVF in hemiplegic post-stroke patients and to compare it with the functional results obtained in a monocentric prospective cohort.

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