By Dr. Matthew Sloan | The Joint Replacement Podcast, Episode 59
Every year, hundreds of thousands of patients undergo hip replacement surgery. Most will never know who designed the implant that becomes a permanent part of their body.
We often assume these devices are developed by large medical device companies, with teams of engineers, scientists, and orthopedic surgeons working together.
But what happens when one surgeon decides he can design something better?
In Episode 59 of The Joint Replacement Podcast, I sat down with Dr. Kurtis Biggs, a fellowship-trained hip and knee replacement surgeon from Naples, Florida, who did exactly that.
After performing thousands of joint replacements, Dr. Biggs developed his own hip replacement implant, the Xerxes femoral stem, taking it from a sketch at his kitchen counter to FDA clearance and ultimately into the operating room.
His story provides a fascinating perspective on orthopedic innovation, but it also raises an important question: Just because we can design a new implant, how do we know it’s actually better?
From a Kitchen Counter Sketch to a Hip Replacement Implant
Dr. Biggs began his journey working with a group of surgeons on an implant development team.
Although the experience exposed him to the engineering and manufacturing process, he became frustrated that some of the suggestions from practicing surgeons weren’t incorporated into the final design.
Rather than accepting the limitations of the available implants, he decided to create his own.
He started with a drawing at his kitchen counter.
His goals were straightforward:
- Design a shorter, anatomically curved femoral stem.
- Better reproduce the natural anatomy of the proximal femur.
- Restore the hip’s normal center of rotation and offset.
- Reduce unwanted contact between the implant and surrounding bone.
- Make implantation easier, particularly through the direct anterior approach.
He hired an engineer to convert his drawings into computer-aided design models, then developed 3D-printed prototypes.
Over the following years, his project progressed through mechanical testing, cadaver studies, regulatory review, and manufacturing.
Unlike many orthopedic innovations funded by major corporations, much of this development was initially self-funded.
Working with Signature Orthopedics, an Australian medical device manufacturer, he eventually brought his design to market.
Dr. Biggs reports receiving FDA 510(k) clearance in July 2023, with the first implantation taking place on September 6, 2024.
The process took approximately five years.
What Makes One Hip Replacement Stem Different From Another?
To understand why Dr. Biggs designed a new implant, it helps to understand the components of a total hip replacement.
A typical total hip replacement includes four primary components:
- Acetabular shell: A metal socket implanted into the pelvis.
- Liner: Usually a highly cross-linked polyethylene insert that fits inside the socket.
- Femoral head: Typically a ceramic or metal ball that articulates with the liner.
- Femoral stem: The implant inserted into the thighbone to support the new ball.
Although the bearing surfaces receive significant attention, femoral stem design is equally important.
Surgeons must consider how the stem fits inside the bone, distributes mechanical forces, restores leg length and hip offset, and achieves durable fixation.
Why does hip anatomy matter?
The human femur is not simply a straight tube.
It has natural curvature, variations in shape, and a unique relationship between the femoral neck and shaft.
Traditional femoral stems often use tapered or wedge-shaped designs to achieve fixation.
These implants have decades of clinical experience supporting their use and can provide excellent outcomes.
However, Dr. Biggs wondered whether a more anatomically shaped stem could reproduce the hip’s natural geometry with fewer compromises.
His Xerxes stem incorporates a curved design and separate right- and left-sided components.
The objective is to better accommodate the proximal femur while restoring both lateral and anterior hip offset.
These features are intended to improve implant positioning and potentially reduce unwanted bony contact or impingement.
Whether these theoretical benefits translate into meaningful improvements in long-term patient outcomes remains an important unanswered question.
When a Hip Replacement Surgeon Becomes a Hip Replacement Patient
One of the most interesting parts of our conversation was learning that Dr. Biggs has undergone a total hip replacement himself.
Although he reports having an excellent overall result, he occasionally experiences discomfort near the posterior portion of his femur.
He believes this may be related to contact between his existing straight femoral stem and the surrounding bone.
That personal experience influenced his design philosophy.
He wanted to develop a stem that curved away from the posterior femoral cortex, potentially reducing unwanted contact.
This is an example of how orthopedic innovation can emerge from both clinical experience and firsthand patient experience.
However, it’s important to distinguish a plausible mechanical explanation from a proven clinical benefit. Pain after hip replacement can have multiple causes, and changing stem geometry does not guarantee that such symptoms will be prevented.
What Does It Take to Get a New Hip Implant FDA Cleared?
Many patients assume that if a medical device receives FDA clearance, it must have been tested in thousands of patients.
That is not necessarily how orthopedic implant clearance works.
Many new orthopedic devices enter the market through the FDA’s 510(k) regulatory pathway.
This process evaluates whether a new device is substantially equivalent to an existing legally marketed device, known as a predicate device.
Depending on the device, manufacturers may submit mechanical testing, fatigue testing, design comparisons, biocompatibility information, and sometimes clinical data.
A device may receive clearance without large randomized clinical trials establishing superior patient outcomes.
This distinction is critical.
FDA clearance does not establish that a new implant is superior to existing alternatives.
Dr. Biggs described the extensive engineering, testing, documentation, and regulatory responsibilities involved in bringing his stem to market.
He even recounted an FDA inspection conducted at his kitchen table, where his medical device company was registered.
His experience illustrates that developing an implant is only the beginning. Manufacturers must also maintain quality systems, monitor complaints, document changes, and continue evaluating device performance after it enters clinical use.
What Have the First 130 Hip Replacements Shown?
At the time of our interview, Dr. Biggs reported approximately 130 implantations of the Xerxes femoral stem.
His early experience included:
- One periprosthetic fracture following a fall approximately six weeks after surgery.
- One case of stem subsidence, which subsequently required revision.
- One intraoperative fracture requiring cable fixation.
- No reported dislocations.
He also described encouraging observations regarding implant fit, posterior thigh discomfort, and trochanteric symptoms.
However, these observations require important context.
This is an early, relatively small clinical experience without a randomized comparison group.
A series of approximately 130 patients cannot establish whether a new implant is safer, more durable, or more effective than established femoral stems.
Moreover, rare complications and longer-term problems such as aseptic loosening may not become apparent until significantly more patients have been followed for many years.
These early results are interesting, but they should be considered preliminary clinical observations rather than proof of superiority.
Could Better Implant Design Make Anterior Hip Replacement Easier?
Dr. Biggs designed his stem primarily with the direct anterior approach in mind.
During anterior hip replacement, surgeons access the joint from the front of the hip, working through an intermuscular interval.
Femoral exposure can sometimes be challenging, especially in patients with certain anatomical characteristics or limited mobility.
Dr. Biggs explained that his curved femoral stem follows the natural anatomy of the femur and may allow insertion with less manipulation of the surrounding soft tissues.
He also described modifications to the implant’s shoulder intended to preserve more proximal femoral bone.
These are potentially useful technical features.
However, ease of implantation is not the same as improved clinical outcomes.
An important next step would be studying whether these design differences reduce operative complications, soft tissue trauma, postoperative pain, or recovery time compared with established implants.
Cemented vs. Cementless Hip Replacement: Which Is Better?
Another important part of our discussion involved implant fixation.
Femoral stems can generally be secured using two approaches.
Cementless fixation relies on a mechanical press-fit into the bone, followed by biological bone attachment to the implant surface.
Cemented fixation uses bone cement to secure the implant within the femoral canal.
Both approaches have a long history of successful use.
Implant selection depends on multiple factors, including patient age, bone quality, femoral anatomy, fracture risk, and the surgeon’s experience.
Dr. Biggs described his preference for cementless fixation and discussed how bone quality influences his implant selection.
His current Xerxes stem is collarless, with plans for a collared version.
A collar is a component near the proximal end of the femoral stem that can provide additional support against the femoral neck cut.
There is ongoing interest in whether collared stems may reduce certain early mechanical complications in selected patients.
Ultimately, neither cemented nor cementless fixation is universally superior for every patient.
The goal is to choose an implant and fixation method appropriate for the individual’s anatomy and clinical circumstances.
How Long Should a Modern Hip Replacement Last?
This is one of the most common questions patients ask before surgery.
Dr. Biggs explained that he often discusses an expected lifespan of 20 to 30 years with patients undergoing modern hip replacement.
But implant longevity is not a fixed expiration date.
A hip replacement does not suddenly stop functioning after a specific number of years.
Its durability depends on several factors, including implant design, surgical technique, fixation, patient characteristics, activity, and complications.
Published long-term studies demonstrate that many hip replacements remain functioning for decades.
For example, a systematic review published in The Lancet in 2019 found that approximately 58% of hip replacements in the registry datasets analyzed remained in place at 25 years.
These results reflect historical implant designs and patient populations, and they should not be interpreted as the expected survival of every modern implant.
Newer materials and improvements in manufacturing may continue to improve durability, but we still need long-term data to establish their performance.
For patients, an important question is not simply how long a replacement might last, but how long a specific implant design has been studied and what its long-term revision rates look like.
Are Medical Device Companies Limiting Innovation?
Perhaps one of the most thought-provoking parts of our discussion involved the relationship between orthopedic surgeons and implant manufacturers.
Dr. Biggs described the challenges of bringing a new design to market, including manufacturing costs, instrument availability, inventory management, and the difficulty of convincing other surgeons to adopt an unfamiliar device.
Large manufacturers must balance innovation against practical considerations such as cost, manufacturing complexity, regulatory requirements, and distribution.
That does not necessarily mean these companies oppose innovation.
Manufacturing reliable orthopedic implants at scale requires substantial resources, engineering expertise, and quality control.
At the same time, surgeons working directly with patients may identify problems that could be addressed through design modifications.
The challenge is determining which changes represent meaningful improvements and which simply add complexity without measurable clinical benefits.
Innovation matters, but innovation must ultimately be judged by patient outcomes.
How Do We Know Whether a New Hip Implant Is Actually Better?
This was one of the most important questions I asked Dr. Biggs.
Many existing femoral stems have excellent clinical track records.
If a new implant is going to replace a well-established design, what evidence should convince surgeons and patients that it offers something better?
There are several outcomes I would want to evaluate:
- Revision rates: Does the new implant have fewer failures requiring additional surgery?
- Periprosthetic fractures: Does its geometry reduce fractures during or after implantation?
- Subsidence and loosening: Does the stem achieve reliable and durable fixation?
- Patient-reported outcomes: Do patients experience less pain and better function?
- Dislocation and impingement: Does restoring anatomy translate into improved hip stability?
- Recovery: Does easier implantation produce faster or more comfortable rehabilitation?
- Long-term survival: Does the implant perform as well as or better than established alternatives after 10, 15, or 20 years?
Ideally, these questions would be answered through well-designed comparative clinical studies, independent evaluation, and long-term joint replacement registry data.
Early experience is valuable, but it is only the first step.
A device can be innovative, mechanically sophisticated, and easier for a surgeon to implant without necessarily producing better outcomes for patients.
What Should Patients Ask About Their Hip Replacement Implant?
If you’re considering hip replacement surgery, it’s reasonable to ask your surgeon about the implant being recommended.
Some important questions include:
- What implant design do you recommend, and why?
- How long has this implant been used clinically?
- Are there published clinical studies or registry data supporting its performance?
- Is the implant appropriate for my bone quality and anatomy?
- What are the potential benefits and risks compared with other established options?
You do not necessarily need the newest implant on the market.
In fact, an implant with a long history of excellent outcomes may be a better choice than a recently introduced design that has not yet established its long-term performance.
The most important consideration is whether the implant is appropriate for you and whether your surgeon has the experience to use it safely and effectively.
Final Thoughts: The Future of Hip Replacement Innovation
Dr. Kurtis Biggs’ story is a remarkable example of surgeon-driven innovation.
He identified aspects of existing implants that he believed could be improved, developed a new design, invested years of work and personal resources, navigated the regulatory process, and ultimately implanted the device in patients.
During our conversation, he described the surreal moment of closing the incision after implanting his own design for the first time.
After years of development, the implant was no longer a sketch, a computer model, or a prototype.
It was now part of someone’s body.
That moment captures both the excitement and responsibility of medical device innovation.
As orthopedic surgeons, we should always be looking for ways to improve patient outcomes. But we must also remain appropriately skeptical of new technology until its benefits are supported by meaningful evidence.
The question is not simply whether we can build a better hip replacement. It’s whether we can prove that we have.
That’s ultimately what matters to our patients.
Listen to Episode 59 of The Joint Replacement Podcast
Can One Surgeon Design a Better Hip Replacement? Featuring Dr. Kurtis Biggs
Join Dr. Matthew Sloan and Dr. Kurtis Biggs for an inside look at orthopedic implant design, FDA clearance, clinical outcomes, and the future of hip replacement innovation.
Watch on YouTube or listen on Spotify.
Learn more about Dr. Matthew Sloan and The Joint Replacement Podcast at MatthewSloanMD.com.
About the Author
Dr. Matthew Sloan is a board-certified, fellowship-trained orthopedic surgeon specializing in hip and knee replacement and Director of Robotics for Orthopedic Surgery at Emerson Health in Concord, Massachusetts. He hosts The Joint Replacement Podcast, an educational resource featuring evidence-based conversations about joint replacement surgery, emerging technologies, patient outcomes, and orthopedic innovation.
References
- U.S. Food and Drug Administration. Premarket Notification 510(k): Substantial Equivalence.
- U.S. Food and Drug Administration. Medical Device Safety and the 510(k) Clearance Process.
- U.S. Food and Drug Administration. General Information About Hip Implants.
- American Association of Hip and Knee Surgeons (AAHKS). Total Hip Replacement: Patient Education.
- Evans JT, Evans JP, Walker RW, Blom AW, Whitehouse MR, Sayers A. How long does a hip replacement last? A systematic review and meta-analysis of case series and national registry reports with more than 15 years of follow-up. The Lancet. 2019;393:647–654. Read the study.
Editorial note: Details regarding the Xerxes implant’s development timeline, regulatory history, design rationale, and early clinical outcomes are based on statements made by Dr. Biggs during Episode 59. These specific claims and results have not been independently verified for this article. This content is for educational purposes and does not constitute individualized medical advice.