2022 Fall | Page 2 | Biomechanics in the Wild

Strengthening the Spine with Pedicle Screws

How are pedicle screws being used to strengthen the vertebrae in spinal fusion surgeries?

Xray of human spine with misaligned vertabrae. Then shows same spine that is aligned using pedicle screws. — Image from *Seattle Neuro.* Pedicle screws are inserted in the right image to align the unstable vertebrae originally shown left.

In the US alone, over 300,000 spinal fusion surgeries are performed every year to correct for fractures, deformations, or spinal instabilities. These surgeries are often performed by inserting a pedicle screw into the damaged vertebrae to increase the strength of the fusion. These screws are most often used in cases where the bone in the surrounding area is already weak, which decreases the likelihood of success in the surgery. Essentially, pedicle screws are used in damaged bones to increase their strength, in turn increasing the likelihood of success in a high-risk patient.

Twists and Curves: Spinal Analysis and the Correction of Scoliosis

For anyone who had braces as a kid, you know how miserable the process can be. From rubber bands to the restrictions on what foods you could enjoy, having braces was a real pain. However, once the braces came off, it was all worth it to have perfectly straight teeth. While many adolescents go through orthodontic bracing to straighten crooked teeth, there are some who go through a similar process to correct the curvature of their spines.

Pressed and stressed: How understanding tumor biomechanics may be the future for treating patients with triple-negative breast cancer

Despite unstinting interventions such as chemotherapy and surgical tumor removal, approximately 40% of patients with stage I-III triple-negative breast cancer (TNBC) will experience tumor recurrence. Fortunately, not all hope is lost. The advent of immune checkpoint blockade (ICB) immunotherapy—a type of therapy that uses one’s own immune cells to kill the cancer—has shown great promise for the treatment of TNBC. However, as Dr. Azra Raza says in her book, The First Cell: And the Human Costs of Pursuing Cancer to the Last, these “immune approaches are not universally curative and, at present, help very few patients.”

Do Humans Get Weaker in Outer Space?

We have entered an era of renewed excitement regarding human space travel. The international community has lofty goals for the future of human spaceflight: returning to the Moon, sending crewed missions to Mars and other planets, and even colonizing space to save the human race when Earth is no longer habitable. These goals are beyond exciting, but before we can safely accomplish any of them, we must understand the biological consequences of space travel. For instance, it is well documented that space travel causes muscle atrophy, or deterioration. What causes this atrophy, and can how it be prevented?

Live fast die young: Rate of Living Theory

The rate of living theory proposed by Max Rubner (1908) suggests that animals have a finite number of heartbeats till they die. The initial observation was that the large animals which have slower RHR (resting heart rate) live more than small animals which have faster RHR. Taylor (1980) explained this phenomenon with the “cost of generating force” hypothesis which suggests the amount of oxygen consumed by running animals is proportional to their weight. It was stated that producing one newton of force on the ground is more costly for smaller animals than for bigger ones because smaller animals must take shorter steps using faster, less economical muscle fibers than bigger animals do. Additionally, their larger area and volume ratio causes them to lose more heat. Therefore, small animals require more oxygen (per kg of body mass) to be delivered to the tissues in the body. However, the total number of heartbeats of most animals -large or small- tends to be approximately the same, around a billion, and humankind is stated as the exception with 2.24 billion heartbeats. Anyhow, if we consider it in terms of broad orders of magnitude, there does appear to be a tragic connection between living quickly and passing away soon for all species, large and small.

Sensing tension in the brain tumor microenvironment

According to Azra Raza, a Professor of Medicine at Columbia University in New York, high-grade brain cancer called glioblastoma is “one of the most aggressive, ruthless killers known to mankind”. Indeed, despite recent advances in cancer therapies, glioblastoma remains incurable with a median survival of 15 months which has not improved substantially in the last 20 years. This poor prognosis is, in part, due to the highly immunosuppressive microenvironment that allows tumors to evade anti-tumor immune response and promotes resistance to immunotherapy – a kind of therapy that uses your body’s own immune system to find and eliminate tumor cells.

Deer Science, what’s changing my antlers and why are they important to you?

A deer is a mammal that is recognizable by the majority of people. Typically, the male deer or buck has the unique attribute of antlers. Antlers are made up of bone that develops, grows, and falls off each year.

Want Your Ticket to the Top?

Rock climbing may just be the greatest exercise activity. It’s a holistic workout with an infectiously supportive community that involves plenty of problem solving and a good understanding of body movement and biomechanics. If you ever find yourself on the climbing wall, you will inevitably encounter a sequence of moves that seemingly proves to be too difficult or complicated. Whether you’re a veteran or a beginner, below are just a few of the countless biomechanical techniques and tips to keep in mind when coordinating and executing your attempts; they could be the difference between plateauing and finally topping out on that elusive route.

Category: 2022 Fall

How are pedicle screws being used to strengthen the vertebrae in spinal fusion surgeries?