Hip and knee effects after implantation of a drop foot stimulator

Article type: Research Article

Authors: Yao, Daiwei^{a; 1} | Lahner, Matthias^{b; 1} | Jakubowitz, Eike^c | Thomann, Anna^c | Ettinger, Sarah^a | Noll, Yvonne^d | Stukenborg-Colsman, Christina^a | Daniilidis, Kiriakos^{e; *}

Affiliations: [a] Department of Orthopaedic Surgery, Hannover Medical School, Hannover 30625, Germany | [b] Department of Orthopaedic Surgery and Traumatology, University Hospital Bochum, Bochum 44791, Germany | [c] Laboratory for Biomechanics and Biomaterials, Department of Orthopaedic Surgery, Hannover Medical School, Hannover 30625, Germany | [d] Clinical Trail Management, Hannover Medical School, Hannover 30625, Germany | [e] Sporthopaedicum Straubing, Foot and Ankle Surgery, Straubing 94315, Germany

Correspondence: [*] Corresponding author: Kiriakos Daniilidis, Sporthopaedicum Straubing, Foot and Ankle Surgery, Bahnhofplatz 27, Straubing 94315, Germany. Tel.: +49 (0) 9421 99570; Fax: +49 (0) 511 9957199; E-mail:kraj@gmx.net

Note: [1] Daiwei Yao and Matthias Lahner contributed equally to this work.

Abstract: BACKGROUND: An active ankle dorsiflexion is essential for a proper gait pattern. If there is a failure of the foot lifting, considerable impairments occur. The therapeutic effect of an implantable peroneus nerve stimulator (iPNS) for the ankle dorsiflexion is already approved by recent studies. However, possible affection for knee and hip motion after implantation of an iPNS is not well described. OBJECTIVE: The objective of this retrospective study was to examine with a patient cohort whether the use of iPNS induces a lower-extremity flexion withdrawal response in the form of an increased knee and hip flexion during swing phase. METHODS: Eighteen subjects (12 m/6 w) treated with an iPNS (ActiGait®, Otto Bock, Duderstadt, Germany) were examined in knee and hip motion by gait analysis with motion capture system (Vicon Motion System Ltd®, Oxford, UK) and Plug-in-Gait model after a mean follow up from 12.5 months. The data were evaluated and compared in activated and deactivated iPNS. RESULTS: Only little changes could be documented, as a slight average improvement in peak knee flexion during stand phase from 1.0° to 2.5° and peak hip flexion in stance from 3.1° to 2.1° In contrast, peak knee flexion during swing appeared similar (25.3° to 25.7°) same as peak hip flexion during swing. In comparison with the healthy extremity, a more symmetric course of the knee flexion during stand phase could be shown. CONCLUSIONS: No statistical significant improvements or changes in hip and knee joint could be shown in this study. Only a more symmetric knee flexion during stand phase and a less hip flexion during stand phase might be hints for a positive affection of iPNS for knee and hip joint. It seems that the positive effect of iPNS is only based on the improvement in ankle dorsiflexion according to the recent literature.

Keywords: Stroke, implantable peroneus nerve stimulator, gait pattern, knee and hip motion

DOI: 10.3233/THC-171297

Journal: Technology and Health Care, vol. 25, no. 3, pp. 599-606, 2017