Orthopedic Devices: From the Baseball Diamond to the Operating Room

I'm Christian Azaret, a 17-year-old student who fell in love with biomedical engineering for a very personal reason. I play baseball, and a few years ago, I tore the ulnar collateral ligament (UCL) in my throwing arm. The diagnosis was every pitcher's nightmare: I needed Tommy John surgery.

What followed was a long recovery, a lot of physical therapy, and eventually, a fascination with the technology that put me back on the mound. My surgeon, Dr. James "Beamer" Carr II, a sports medicine orthopedic surgeon at Hospital for Special Surgery (HSS) who served as a team physician for the New York Mets, used a cutting-edge approach that combined traditional UCL reconstruction with an internal brace, a suture tape augmentation designed to prevent repeat tears. The instruments and implants he used looked like they belonged in a machine shop, not a hospital. I wanted to understand every piece of it.

This past summer, I had the incredible opportunity to observe orthopedic surgeons in the operating room, including Dr. Domingo Delgado, a board-certified orthopedic surgeon at Holy Cross Hospital in Fort Lauderdale, Florida, with over 35 years of experience. I watched them use robotic arms, power tools, and protective gear that looked like something out of a science fiction movie. This article breaks down what I learned, and why orthopedic devices are one of the most exciting areas of biomedical engineering.

Quick Summary

• Orthopedic devices include surgical implants (plates, screws, joint replacements), power tools (saws, drills, reamers), electrosurgical units like the Bovie, and robotic-assisted systems like the Mako
• Surgeons wear specialized surgical helmet systems to protect themselves from bone fragments, blood aerosols, and tissue debris during joint replacement surgery
• The Mako robotic-arm system uses CT scans and 3D modeling to help surgeons plan and execute joint replacements with precision
• My Tommy John surgery, performed by Dr. James "Beamer" Carr II, a Mets team physician, used a cutting-edge internal brace augmentation to prevent repeat UCL tears

What Are Orthopedic Devices?

Orthopedic devices are medical tools and implants designed to treat conditions of the musculoskeletal system, including bones, joints, ligaments, tendons, and muscles. They range from simple screws and plates that hold broken bones together to complex robotic systems that assist surgeons in replacing entire joints.

The FDA regulates orthopedic implants as medical devices, classifying them by risk level. Depending on the specific device, its intended use, and the level of risk it poses to the patient, orthopedic devices can fall into different FDA classes, from low-risk Class I devices to high-risk Class III devices that require premarket approval (FDA).

Orthopedic Surgical Implants

Surgical implants are the hardware that stays in your body after surgery. Here are the main types:

Plates and Screws

Bone plates and screws are the workhorses of orthopedic trauma surgery. When a bone breaks, a surgeon may attach a metal plate to the outside of the bone using screws to hold the fragments in place while they heal. These are commonly made from titanium or stainless steel alloys, materials chosen because they are strong, non-toxic, and don't corrode inside the body (BMES).

Intramedullary Nails

For fractures of long bones like the femur (thigh bone) or tibia (shin bone), surgeons often use intramedullary nails, which are metal rods inserted into the hollow canal of the bone. These rods provide internal support and alignment. Recent advances include antibiotic-coated nails that release infection-fighting medication at the implant site. A comparative study showed gentamicin-coated nails reduced infection rates from approximately 18% to 3% compared to uncoated nails (NIH/PMC).

In April 2024, the FDA approved the first antibacterial coating technology for orthopedic implants, Onkos Surgical's NanoCept coating, specifically designed for tumor and revision arthroplasty cases, representing a breakthrough in implant safety (NIH/PMC).

Total Joint Replacements

When a joint is too damaged to repair, surgeons replace it entirely. Total joint replacement involves removing damaged bone and cartilage and replacing them with metal, ceramic, or plastic components. The most common types are:

• Total knee replacement: replaces the surfaces of the femur and tibia where they meet at the knee
• Total hip replacement: replaces the ball of the femur and the socket of the pelvis
• Total shoulder replacement: replaces the ball of the humerus and the socket of the scapula

These implants must be biocompatible, meaning non-toxic, non-carcinogenic, chemically inert, and mechanically strong enough to withstand millions of steps over a lifetime. BMES notes that newer biomaterials even incorporate living cells to provide a true biological and mechanical match for living tissue (BMES).

My Tommy John Surgery: A Personal Look at Orthopedic Implants

Tommy John surgery, formally known as ulnar collateral ligament (UCL) reconstruction, is the procedure that rebuilt my elbow and got me back on the pitcher's mound. It was first performed in 1974 by Dr. Frank Jobe on Los Angeles Dodgers pitcher Tommy John, who successfully returned to pitching after the surgery (Johns Hopkins Medicine).

Here's how it works:

1. Harvesting the graft: The surgeon takes a tendon from elsewhere in the body (often the palmaris longus tendon from the forearm, or a hamstring tendon) to replace the torn UCL. A donor tendon can also be used.
2. Accessing the elbow: An incision is made near the inside of the elbow to access the UCL. The surgeon moves muscles and tissues aside to reach the damaged ligament.
3. Drilling the bones: Holes are drilled into two bones: the humerus (upper arm bone) and the ulna (forearm bone). These are the bones that the original UCL connected.
4. Threading the graft: The tendon graft is threaded through the drilled holes in a figure-eight or docking pattern, replacing the torn ligament.
5. Securing the graft: The graft is held in place using sutures, buttons, or screws, the same types of orthopedic fixation hardware used in other bone surgeries.

The whole procedure takes about 60 to 90 minutes under general anesthesia, and it's typically outpatient, so I went home the same day (Johns Hopkins Medicine).

Recovery: The Long Road Back

Recovery from Tommy John surgery is a marathon, not a sprint:

For me, the recovery was long but worth it. Dr. Carr's use of the internal brace was a key reason my recovery went well, as the brace provided immediate stability to protect the healing ligament and reduce the risk of a repeat tear. That recovery time is what got me thinking about biomedical engineering: what if the implants, the tools, or the surgical techniques could be improved even further to speed up healing?

The Internal Brace: A Breakthrough in UCL Repair

One of the most exciting advances in orthopedic surgery, and the technology that Dr. Carr used in my procedure, is the internal brace. This is a collagen-coated suture tape (made by Arthrex) that is anchored at each end of the native UCL to augment the repaired or reconstructed ligament. Think of it as a seatbelt for the healing ligament: it doesn't do the work of the ligament, but it provides backup support if excessive force is applied while the tissue heals (NIH/PMC).

Here's how it works:

1. The surgeon repairs or reconstructs the UCL using the standard technique (graft tendon threaded through drilled holes in the humerus and ulna).
2. A high-strength FiberTape, a flat, woven suture material, is attached to SwiveLock anchors at each end of the native UCL's footprint on the bone.
3. The tape is tensioned to match the native ligament's tension during elbow movement, ensuring it doesn't over-constrain the joint.
4. The internal brace reinforces the repair, offloading stress from the healing ligament and providing immediate mechanical stability.

Studies have shown that UCL repair with internal brace augmentation is more resistant to gap formation under cyclic loading than traditional reconstruction alone, meaning the ligament is less likely to stretch or re-tear during healing. Biomechanical studies have demonstrated that the internal brace replicates the zero-time strength of a traditional UCL reconstruction while providing greater stability at low cyclic loads (NIH/PMC).

Faster Return to Play

One of the biggest advantages of the internal brace is a shorter recovery time. Studies by Dugas et al. found that athletes who underwent UCL repair with internal brace augmentation returned to the same or higher level of competition at a mean time of 6.7 months, with 92% of athletes successfully returning to play, compared to the traditional 9 to 12+ months required after standard UCL reconstruction (PubMed, NIH/PMC).

The technique preserves the patient's native anatomy and proprioception (the body's sense of joint position), avoids the morbidity of harvesting a second tendon graft, and requires less bone tunneling. It's particularly well-suited for younger athletes with avulsion-type injuries where the ligament pulls away from the bone, rather than mid-substance tears where the ligament frays in the middle (JOSPT).

Why This Matters to Me

When Dr. Carr explained the internal brace to me and my family, he described it as added insurance, a way to protect the repair while it healed and reduce the chance that I'd need a second surgery. As a baseball player, the fear of re-injury is always in the back of your mind. Knowing that there was an engineered device, a suture tape and two anchors, reinforcing the ligament that I'd just torn gave me confidence during my rehabilitation.

That's when it clicked for me: this is what biomedical engineers do. They design materials, devices, and techniques that give patients like me a better chance at a full recovery. The internal brace isn't just a piece of tape, it's a carefully engineered system of suture material, anchor design, and biomechanical principles, all working together to solve a real medical problem.

Tools of the Trade: Surgical Power Instruments

When I first walked into the OR this summer, I was struck by how much it looked like a high-tech workshop. Orthopedic surgeons use specialized power tools to cut, drill, and shape bone with precision:

Oscillating Saws

The oscillating saw is the most iconic orthopedic tool. Unlike a circular saw that spins continuously, an oscillating saw blade moves back and forth in a small arc, typically just a few degrees. This design cuts bone cleanly while minimizing damage to surrounding soft tissue. The small range of motion means that if the blade contacts flexible tissue like muscle, the tissue tends to move with the blade rather than being cut, making it safer for use near delicate structures.

Sagittal Saws

Similar to oscillating saws, sagittal saws move in a front-to-back (sagittal) plane. They're used for making precise bone cuts during joint replacement surgery, such as resurfacing the end of the femur for a knee replacement.

Drills and Reamers

Orthopedic drills are used to create holes in bone for screws, pins, and grafts, just like the holes drilled in my humerus and ulna during my Tommy John surgery. Reamers are larger drill-like tools used to widen the medullary canal (the hollow center of a long bone) so an intramedullary nail can be inserted.

Screwdrivers and Wire Drivers

These specialized tools drive bone screws and insert Kirschner wires (K-wires), which are thin metal pins used to temporarily hold bone fragments in place during healing.

All of these power tools come in electric, battery-powered, and pneumatic (air-driven) versions. Major medical device companies produce integrated systems that combine multiple attachments, including drills, saws, and reamers, into a single handpiece platform, giving surgeons a toolkit that can handle everything from small bone work to major joint replacement.

The Bovie: Electrosurgical Unit

The Bovie, or electrosurgical unit (ESU), is one of the most widely used tools in modern surgery. Invented by William T. Bovie and introduced to clinical practice in the 1920s by neurosurgeon Harvey Cushing, it uses high-frequency alternating current (300 kHz to 3 MHz) to cut tissue and control bleeding simultaneously. In cutting mode, a continuous waveform vaporizes cells to cleanly divide tissue. In coagulation mode, an intermittent pulsed waveform seals blood vessels. A blend mode combines both, allowing the surgeon to cut while controlling bleeding at the same time (PubMed, AORN).

In orthopedic surgery, the Bovie is used to cut through tendons, ligaments, and other soft tissues, and to coagulate blood vessels during surgical exposure. Its main advantage over a scalpel is the ability to cut and coagulate at the same time, reducing blood loss, improving visibility, and shortening operating time. Surgeons typically use a scalpel for the initial skin incision and switch to the Bovie for deeper dissection, as it does cause some thermal damage to surrounding tissue (PubMed, AORN).

Protecting the Team: The Surgical Helmet System

One of the first things I noticed in the OR was what the surgeons and nurses were wearing. During joint replacement surgery, the entire surgical team wears what looks like a space suit: a helmet with a clear face shield and a hood that covers the head and neck, connected to a battery-powered ventilation system.

This is the surgical helmet system (SHS), and it has a fascinating history. The concept was pioneered by Sir John Charnley, a British orthopedic surgeon who revolutionized hip replacement surgery in the 1960s. Charnley designed a body exhaust system (BES), a negative-pressure setup with intake and outtake tubing that blew air away from the surgical site, keeping any bacteria shed by the surgical team away from the patient (International Journal of Spine Surgery).

The BES was adopted after a landmark 1982 multicenter study by Lidwell et al. showed that surgeries performed in ultraclean air with the body exhaust system had about one-quarter the infection rate of conventional ventilation (International Journal of Spine Surgery).

The bulky tubing was later replaced by the modern surgical helmet system, a portable helmet and hood that creates a sterile barrier across the surgeon's face and neck. Today, it's commonly used in orthopedic joint replacement surgery (International Journal of Spine Surgery).

Why it matters: During orthopedic surgery, especially joint replacement, there's a lot of aerosolized material flying around. Bone dust from sawing, blood mist from drilling, and tissue debris can all become airborne. The surgical helmet protects the surgical team from these fluids and particles while also protecting the patient from bacteria that might shed from the team's skin or respiratory system.

When I was observing in the OR, I could see how the surgical helmet created a barrier between Dr. Delgado and the surgical team and the aerosolized bone dust that filled the air during the sawing and drilling. It was a powerful reminder that biomedical engineering isn't just about the implants and the robots, it's also about protecting the people who do the work.

The Mako Robotic-Arm System: A Game Changer

The most impressive technology I saw in the OR this summer was the Mako robotic-arm assisted surgery system, made by Stryker. Mako combines a robotic arm with advanced software to help surgeons perform joint replacements with a level of precision that's simply not possible by hand.

How Mako Works

Mako operates in three steps (Stryker):

1. Scan: Before surgery, a CT scan is taken and used to create a 3D virtual model of the patient's unique joint anatomy. The surgeon can evaluate bone structure, alignment, and surrounding tissue.
2. Plan: Using the 3D model, the surgeon creates a personalized surgery plan, choosing implant size, positioning, and alignment based on the patient's specific anatomy.
3. Mako Can: During surgery, the surgeon guides the robotic arm, which uses AccuStop technology to help the surgeon stay aligned with the personalized surgical plan. The system is designed to help the surgeon execute the procedure according to the preoperative plan.

What Mako Is Used For

Mako is available for (Stryker):

• Total hip replacement
• Total knee replacement
• Partial knee replacement
• Shoulder replacement
• Spine surgery

Why Mako Matters

Stryker reports that in hip and knee surgeries, Mako has been shown to help protect healthy bone, lead to less pain, and result in shorter recovery times compared to traditional manual surgery. Stryker also reports that for partial knee replacement, Mako has been shown to shorten hospital stays (Stryker).

The technology has been used in joint replacement procedures for over two decades, and it represents a perfect example of what biomedical engineering is all about: combining engineering precision with medical expertise to improve patient outcomes.

What I Saw in the OR

When I watched a Mako-assisted total knee replacement, the surgeon spent the first part of the procedure reviewing the 3D model on a screen, adjusting the implant position. Then, during the actual bone cuts, the robotic arm moved with the surgeon's hand while the AccuStop technology helped keep the cutting aligned with the preoperative plan.

The precision of the system was remarkable, it was like watching a master craftsman with tools that knew exactly where the planned boundaries were.

Putting It All Together: The Orthopedic OR Ecosystem

What struck me most during my summer in the OR was how all these technologies work together as a system:

Each piece is a biomedical engineering solution to a real surgical problem. The surgical helmet solves contamination. The oscillating saw solves soft-tissue protection. The Mako solves precision. The antibiotic coating solves infection. Together, they make modern orthopedic surgery safer, more accurate, and more effective than ever before.

What This Means for Students

My Tommy John surgery was the worst thing that happened to me on a baseball field, but it turned out to be the best thing that happened to my career interests. It showed me that biomedical engineering isn't abstract. It's real tools, used by real surgeons, to fix real people. And there's so much room for improvement.

If you're a student interested in orthopedic devices, here are some things you can do:

1. Learn the anatomy: Understanding bones, joints, and ligaments is essential. Take biology and anatomy courses.
2. Study materials science: Implants are all about materials. Learn about metals, polymers, and ceramics.
3. Explore robotics: Systems like Mako are robots. Learn to code and study robotics.
4. Observe if you can: Reach out to local hospitals or orthopedic practices. Many are happy to host curious students.
5. Build something: Try designing a 3D-printed bone model or a simple mechanical joint. Hands-on projects teach you more than any textbook.

What's Next on This Blog?

In the next article, we'll explore Surgical Devices & Robotics in more depth, going beyond Mako to look at the da Vinci system, surgical navigation, and other robotic platforms that are transforming the operating room.

Until then, keep building, keep learning, and keep asking "how does that work?"

This article was written by Christian Azaret, a 17-year-old student and baseball player whose Tommy John surgery, performed by Dr. James "Beamer" Carr II, a team physician for the New York Mets, sparked a passion for biomedical engineering. The BME Blueprint is a student-run blog exploring the world of BME, one field at a time.