Biomedical Engineering Device Development

Integrated brain training is a real game-changer for ACL rehab. 🤔 In sports, athletes perform in dynamic, unpredictable settings, making split-second decisions while executing complex movements. That's a far cry from the controlled environment of typical rehab sessions. 💡 Rehab focuses on task-oriented exercises and internal feedback, but it might be missing the mark. From recent research it even seems that classic rehabilitation induces as much, if not more, of the neuroplasticity than the injury itself, increasing the risk of re-injury (Grooms, in press).   🏋️♀️ There’s a need for an implicit and dual-task approach in ACL rehab, starting from the early stages. The video highlights the integration of this approach into ACL rehab.   🔴 SL squat right leg; Pass left; Count -1.  🟢 Step-up right leg; Pass left; Count +1.  🟣 SL RDL right leg; Count -2.  🔵 SL squat left; Header.  🟡 Step-up left leg; Header; Count +2.  🩵 SL RDL left leg.   1️⃣ Neuromuscular deficits and muscle weakness occur at different central nervous system levels (Cortical, subcortical and spinal level) in ACL patients (Tayfur 2020, Bodkin 2019). These deficits in central activation are linked to poor recuperation of quadriceps activation and strength (Criss 2023). These neural deficits not only prevent effective strengthening, but also contribute to secondary injury risk (Capin 2016). Impaired strength and central nervous system excitability persist for months to years after ACL surgery, suggesting the need for integrated brain training during the early stages of ACL rehab (Kuenze 2015). Traditional concentric exercises cannot overcome the inhibited cortical drive to the muscle and therefore fails to adequately activate muscles and restore neuromuscular control (Lepley 2015).     2️⃣ There's a link between how our brains work and the risk of ACL injuries. Brain activity related to visual, proprioceptive and attentional integration are crucial factors in rehab and prevention of ACL injury (Grooms 2022). Interestingly, athletes with high-risk landing biomechanics following ACL rehab exhibit a brain activation pattern shifted toward increased visual-proprioceptive and spatial processing to organize movement. However, this heightened reliance on attentional and sensory processing for movement coordination might compromise their ability to effectively maintain neuromuscular control in high-pressure sports situations involving opponents or the ball (common scenarios for ACL injuries) (Villa 2020) The current task-oriented rehab methods might actually reinforce these less effective brain activation patterns rather than fixing them. It is paramount to design rehab programs that challenge both the body and the brain, simulating the unpredictable situations athletes face during games. By integrating tasks that require perception, quick decision-making and neuromuscular control, we are able to retrain the brain and reduce the risk of injuries (Chaaban 2023, Grooms 2017). #acl

A great way to fix focal scoliosis: the Straight-Ahead TLIF technique where a TLIF cage is placed on the lateral annular ring in scoliotic segments. I’ve shown a few similar cases with long-term followup on LinkedIn previously. This case today reminded me why I love the technique: 1) Simple technique. No fancy lateral or oblique approaches, no fancy retractors, no Neuromonitoring needed. 2) No navigation needed. Not every hospital around the world has access to navigation or fancy robotics. Using simple, freehand or fluoroscopic technique allows for safe and rapid screw placement. 3) Low radiation exposure to patient and room. We did 7 total fluoro shots during the case. 4) Wolff’s Law at work: Bone adapts to stress, thus bone on the collapsed scoliosis side is sclerotic and very resistant to cage subsidence. Placing the cage directly on the hardened sclerotic bone resists collapse intraop and postop. 5) Laterally placed cage leaves a huge area for bone graft in the disc space for fusion. Miriam Hospital Brown Orthopedics University Orthopedics International Spine Study Group (ISSG) Bassel George Diebo, MD Eren O. Kuris MD Bryce Basques, MD Alan Job, MD Mohammad Daher Joseph Nassar Heather Schmutzler RN, BSN, ONC Ashley Knebel Andrew Xu Manjot Singh Chris McDonald, MD Sarah Criddle Krista Acciaioli Simbarashe Peresuh, MD Spinal Alignment Solutions (SAS) Medtronic Cranial and Spine Therapies Spineart

I want to share a brief conversation about the iMAS TLIF. Those of you who have come and participated in surgery with me understand my obsession with 'early accuracy'. First tenet, start each and every phase of the case with best of capability three dimensional accuracy. There is a tendency to wait for the implant, and I would argue that at that point it is too late and you will be fighting yourself. So my iMAS process has a sequence that guides the TLIF. Preop planning marking fluoroscopically sets up the precision. Incision and exposure of the segment with minimal tissue trauma on the way in is key to outpatient capabilities. Before any retractors have been applied, I apply headless screws under AP fluoro. The goal is not to 'be in the pedicle', the goal is to be exactly where I want to be in the pedicle and why. The medial head of the inferior segmental screw has a measurable distance to the medial pedicle, which is the lateral wall of the central canal. I create two small holes at top of disc space and bottom of disc space 1-2 mm lateral to that wall. Connect those holes cephalocaudal, then run an imaginary drill line from the B hole (upper hole) parallel to the unexposed foramenal nerve root. The base of the trapezoid is at the superior endplate of the disc space, with special care to remove any and all inferior bone protrusions, any of which will displace all the tools, templates, tools, towards the foramenal nerve root. The perfect iMAS facetectomy is a modification of the original Kambin's triangle and not the Kambin's triangle itself. My patients are never relaxed, and I test for nerve stimulation before any movement into the disc space through that tunnel to ensure zero nerve engagement. The goal is to not see the nerve at this point. Your process goes where your mind and eyes go, so I am purely focused on the space between the thecal sac and the traversing nerve root. Disc prep is done interventionally with dynamic lateral fluoroscopy at the anterior 2/3rd of the disc space. My third generation of steerable cage is manufactured by Biedermann Motech, it is called Telix K, and I love large, broad surface area, etched titanium cages that allow for perfect placement with technical precision. It is simple, versatile, and has large channels for bone in growth and is extremely specific in its application capabilities in a variety of severe clinical situations. The template is the most important phase of the placement. It sets the course, the trail of the final implant as it gently cuts small grooves into the endplate and maximum precision is focused at this phase of the prep. The implant is a passenger and passively delivers to the spot acquired and confirmed, fluoroscopically, by the template. A typical one level segmental case has four screws and the TLIF done in the first 20 minutes, allowing the indirect decompression to substantially improve the access for the best possible direct decompression. #tlif #imas #spine

Does endoscopic / percutaneous fusion actually work? Does an endoscopically placed TLIF cage result in fusion and does it have high risk of subsidence? I have heard these skeptic remarks many times! Two years ago, I posted a case of a 52 years-old lady with a spondylolysthesis with a central canal stenosis at L4/L5 that I treated with an endoscopic / percutaneous TLIF and full-endoscopic decompression (ULBDE). Post-operatively, she was immediately pain-free and was discharged from the hospital in less than 24 hours with minimal blood loss and no need for post-operative opioid medication. Back when I posted this case, I received several comments expressing concerns on a supposedly (under-)sizing of the cage, proper endplate preparation, risk of subsidence and/or not fusing using this surgical technique (Henry Fabian Jr., MD, MBA @Ion Branea, etc.). Here, I am presenting the 2 year follow-up of this patient that is reporting a VAS back 0, VAS leg 0 and ODI score of 5/50 with evidence of post-operative fusion at the CT scan and standing X-ray images. The patient is still very happy with the outcome of the surgery. My mistake back then was probably to post an intra-operative fluoroscopy image instead of a post-op standing image. For the purpose of the endsocopic/percutaneous TLIF, we developed a new fusion dilator with MaxMoreSpine that shields the exiting nerve root and protects it during the TLIF cage placement. This new fusion dilator is not tubular, hence it has no diameter constraint (like the regular endoscopic tubes)! Using this dilator it is possible to endoscopically/percutaneously insert a regular TLIF cage used in open surgery (in this case it was SPINEART's Juliet TO cage) and not just those fancy but really expensive endoscopic expandable cages. Moreover, it is also possible to use standard disk preparation instruments for open surgery (no need for endoscopic instrumentation). A percutaneous TLIF procedure usually takes approx. 20 to 25 minutes, it can be done with fluoroscopy only (no endoscope needed unless you want to) through a 1.5 cm skin incision and allows preserving the facet, resulting in less bleeding, no post-op opioid medication and early hospital discharge (usually less than 24 hours). Would I have done anything different for this case? Looking back, today I would probably still go for endoscopic TLIF using a large-footprint cage to add more lordosis. This is something I have been working on with Mareike Siedler and SIGNUS - The Spine Sign and I will be showing you my results in my next posts. Have a good start into the new year everyone! #endoscopicsurgery #TLIF #spine #spinesurgery #maxmorespine #Vertaconnect #Signus #fusiondilator #endoscopy

🔬 New publication in Arthroscopy Techniques 🎯 The Quad 2.0 Technique: A Single Rectus Femoris Autograft Solution for Combined ACL and Double-Bundle ALL Reconstruction Proud to share our latest surgical innovation: the Quad 2.0 technique, using a single rectus femoris tendon autograft for anatomical reconstruction of both the anterior cruciate ligament (ACL) and the anterolateral ligament (ALL) — particularly suited for revision ACL surgeries. 💡 Why is it a breakthrough? • Avoids additional femoral/tibial tunnels for ALL • Preserves hamstring tendons • Reduces donor site morbidity and anterior knee pain • Effective in multiligament knee injuries • Optimizes valgus stability • Allograft-free revision strategy A precise, reproducible, and minimally invasive technique for challenging ACL cases. 📎 Open access article: https://lnkd.in/e7s98K_N With: Victor Sonnery-Cottet, Dany Mouarbes Ali Alayane MD, FEBOT ,Regis Pailhe #ACLreconstruction #Quad20 #ALLreconstruction #KneeSurgery #Orthopedics #SportsMedicine #Innovation #CHUToulouse #Cavaignac #Arthroscopy

Anterior cruciate ligament (ACL) tear is common in sports and accidents, and accounts for over 50% of all knee injuries. ACL reconstruction (ACLR) is commonly indicated to restore the knee stability, prevent anterior–posterior translation, and reduce the risk of developing post-traumatic osteoarthritis. However, the outcome of biological graft healing is not satisfactory with graft failure after ACLR. Tendon graft-to-bone tunnel healing and graft mid-substance remodeling are two key challenges of biological graft healing after ACLR. Mounting evidence supports excessive inflammation due to ACL injury and ACLR, and tendon graft-to-bone tunnel motion negatively influences these two key processes. To tackle the problem of biological graft healing, we believe that an inductive approach should be adopted, starting from the endpoint that we expected after ACLR, even though the results may not be achievable at present, followed by developing clinically practical strategies to achieve this ultimate goal. We believe that mineralization of tunnel graft and ligamentization of graft mid-substance to restore the ultrastructure and anatomy of the original ACL are the ultimate targets of ACLR. Hence, strategies that are osteoinductive, angiogenic, or anti-inflammatory should drive graft healing toward the targets. This paper reviews pre-clinical and clinical literature supporting this claim and the role of inflammation in negatively influencing graft healing. The practical considerations when developing a biological therapy to promote ACLR for future clinical translation are also discussed.

🦿 From Prosthesis to Physiology: The First Tissue-Integrated #Bionic Knee! In a new Science Magazine study, MIT Media Lab researchers introduced the osseointegrated mechanoneural #prosthesis (OMP) — a system that fuses: 🔹 Bone-anchored stability with a titanium implant 🔹 Muscle-to-muscle communication restored through the AMI surgical technique 🔹 Neural integration, transmitting signals directly to a robotic knee 📊 Results from early trials:  • Participants navigated stairs, terrain, and obstacles with natural control  • Movements were smoother, faster, and biomimetic  • Most strikingly, users reported the prosthesis felt like part of their body — not a tool This shift from external attachment to biological integration signals a new era in prosthetics: one where technology is not worn, but embodied. 👏 Huge congratulations to Ethan Chun, Christopher Shallal, Rickard Brånemark, Sean Boerhout, Michael Nawrot, Matt Carney, Hugh Herr, and the entire team for making this possible. Article link here: https://lnkd.in/esqfVvY3 #Bionics #Neuroengineering #Rehabilitation #DigitalHealth #Prosthetics #BiomedicalEngineering

For the first time, a small group of below-knee amputees can control their prosthetic legs using neural signals, achieving a natural gait. This breakthrough, detailed in 𝑵𝒂𝒕𝒖𝒓𝒆 𝑴𝒆𝒅𝒊𝒄𝒊𝒏𝒆, involved a specialized amputation surgery and a non-invasive surface electrode connection to a robotic prosthetic leg. “What happens then is quite miraculous,” said Hugh Herr of the MIT Media Lab. “Patients with this neural interface can walk naturally and navigate obstacles without conscious thought.” The surgery creates an agonist-antagonist myoneural interface (AMI), connecting muscle pairs and synthetic elements to establish a two-way body-machine connection. Muscle-sensing electrodes send signals to a computer in the prosthetic limb, which interprets them as joint movements and provides proprioception. Daniel Ferris of the University of Florida praised the approach as novel and effective. Testing showed AMI users walked more naturally, benefiting movement, energy use, and social interactions. AMI surgeries are now standard at Brigham and Women’s Hospital, with around 60 patients worldwide. Hugh Herr aims for neural integration and embodiment of prosthetics, predicting commercialization within five years. This study is a significant step toward that goal. Read more: https://lnkd.in/eWkGUJ2w

Our paper with Cara Welker and Kevin Best entitled "Improving Sit/Stand Loading Symmetry and Timing Through Unified Variable Impedance Control of a Powered Knee-Ankle Prosthesis" was recently published in IEEE Transactions on Neural Systems & Rehabilitation Engineering! Individuals using passive prostheses typically rely heavily on their biological limb to complete sitting and standing tasks, leading to slower completion times and increased rates of osteoarthritis and lower back pain. Powered prostheses can address these challenges, but have control methods that divide sit-stand transitions into discrete phases, limiting user synchronization across the motion and requiring long manual tuning times. This paper extends our preliminary work using a thigh-based phase variable to parameterize optimized data-driven impedance parameter trajectories for sitting, standing, and walking, with only two classification modes. We decouple the stand-to-sit and sit-to-stand equilibrium angles through a knee velocity-dependent scaling term, reducing the model fitting error by approximately half compared to our previous results. We then experimentally validate the controller with three individuals with above-knee amputation performing sitting and standing transitions to/from three different chair heights. We show that our controller implemented on a powered knee-ankle prosthesis produced biomimetic joint mechanics, resulting in significantly reduced sit/stand loading asymmetry and time to complete a 5x sit-to-stand task compared to participants’ passive prostheses. Integration with a previously developed walking controller also allowed sit/walk transitions between different chair heights. The controller’s biomimetic assistance may reduce the overreliance on the biological limb caused by inadequate passive prostheses, helping improve mobility for people with above-knee amputations. Supplemental Video: https://lnkd.in/g7d8PiZJ Open-Access Paper: https://lnkd.in/gxfz54nP