Selective neural electrical stimulation restores hand and forearm movements in individuals with complete tetraplegia.

BACKGROUND: We hypothesized that a selective neural electrical stimulation of radial and median nerves enables the activation of functional movements in the paralyzed hand of individuals with tetraplegia. Compared to previous approaches for which up to 12 muscles were targeted through individual muscular stimulations, we focused on minimizing the number of implanted electrodes however providing almost all the needed and useful hand movements for subjects with complete tetraplegia. METHODS: We performed acute experiments during scheduled surgeries of the upper limb with eligible subjects. We scanned a set of multicontact neural stimulation cuff electrode configurations, pre-computed through modeling simulations. We reported the obtained isolated and functional movements that were considered useful for the subject (different grasping movements). RESULTS: In eight subjects, we demonstrated that selective stimulation based on multicontact cuff electrodes and optimized current spreading over the active contacts provided isolated, compound, functional and strong movements; most importantly 3 out of 4 had isolated fingers or thumb flexion, one patient performed a Key Grip, another one the Power and Hook Grips, and the 2 last all the 3 Grips. Several configurations were needed to target different areas within the nerve to obtain all the envisioned movements. We further confirmed that the upper limb nerves have muscle specific fascicles, which makes it possible to activate isolated movements. CONCLUSIONS: The future goal is to provide patients with functional restoration of object grasping and releasing with a minimally invasive solution: only two cuff electrodes above the elbow. Ethics Committee / ANSM clearance prior to the beginning of the study (inclusion period 2016-2018): CPP Sud Méditerranée, #ID-RCB:2014-A01752-45, first acceptance 10th of February 2015, amended 12th of January 2016. TRIAL REGISTRATION: (www.clinicaltrials.gov): #NCT03721861, Retrospectively registered on 26th of October 2018.

Composite reverse shoulder arthroplasty can provide good function and quality of life in cases of malignant tumour of the proximal humerus.

PURPOSE: Management of proximal humeral tumours remains a surgical challenge. No study to date has assessed the quality of life scores following the composite reverse shoulder arthroplasty for this indication. We, therefore, evaluated function and quality of life following reconstruction with allograft for malignant tumour of the humerus. METHODS: A series of six cases of humeral tumour treated by a single surgeon in a single centre was reviewed after a mean follow-up of 5.9 years. The tumours included two chondrosarcomas, one plasmocytoma and three metastases. Resection involved bone epiphysis, metaphysis and diaphysis in five cases (S3S4S5A) and epiphysis and metaphysis in one case (S3S4A). For reconstruction, an allograft composite reverse shoulder arthroplasty was used in all the cases. Outcomes were assessed with range of motion, the QuickDash score and the Short Form 12 (SF-12) Health Survey. Radiographs assessed osseointegration and complications. RESULTS: At the final follow-up, the mean shoulder range of motion were respectively 95°, 57° and 11° for forward flexion, abduction and external rotation. Mean QuickDASH score improved from 28 to 41 and VAS-pain scores improved from 5.1 to 2.3. The post-operative MSTS score was 73% and the Constant score was 46.1/100. The SF-12 PCS and MCS scores were also improved, respectively from 44.4 and 39.7 to 45.5 and 56.1. The mean satisfaction score was 8.1/10. CONCLUSIONS: Composite reverse shoulder arthroplasty is a viable alternative for reconstruction after resection of malignant humeral tumour. Although total tumour resection was the most important objective, the functional and quality of life scores were satisfactory.