Spinal Implant

Improving Lumbar Fusion Patient Outcomes
Spinal Implant User Testing

User Experience Researcher

PrinterPrezz

Skills: Interviews/Field Studies/ Prototyping

Team: Melissa Keller, Rhett Larson, Lindsey Milisits, Malavika Shankar

Project Duration: 10 months (2019-2020)

3D Printed Spinal Implant Design

Improving lumbar fusion patient outcomes with a novel titanium spinal interbody device.

Problem Space

Chronic back pain affects 57 million people nationwide and is the leading cause of spinal fusion surgery. Approximately 20% of spinal fusions fail, leaving one-fifth of patients with persisting back pain, the need for a subsequent surgery, and other complications in their daily life. Repeat surgeries account for $4.2B in US healthcare spending. My team designed and developed a spinal implant for lumbar fusion surgery and business plan utilizing a human centered design approach aimed to improve patient outcomes and decrease healthcare spending.

Design Strategy & Research Process

I collaborated with PrinterPrezz, a 3D printing orthopedic medi-facturing company, to design and execute this project.

Discover

Problem: Inadequate clinical outcomes for patients requiring spinal fusion surgeries

Define

Understand clinical unmet need through interviews with orthopedic surgeons and field visits to observe surgery

Develop

Prototype & iterate based on research, validate and test, create a plan to train and support users

Deliver

Generate clinical data to scale and deliver solution that works, generate business model

Meet our End User, Dr. Smith

Experienced Orthopedic Surgeon aged 40-65
Conducts 2 surgeries per day on average, each lasts several hours
Knowledgeable of competition that holds most market share
Cautious of new techniques
Develops close relationships with medical device representatives
Follows patients for years
Highly influences hospital purchasing of orthopedic devices

Customer Interviews & Field Studies

Given that the surgeon selects the most appropriate product for surgery, operates with the device, and influences hospital purchasing, the end user for our product is the surgeon, not the patient. I interviewed 6 orthopedic surgeons about their job, relationship with stakeholders, experience with spinal implants, goals and challenges with lumbar fusion surgeries, and desires for new implants. In addition, I put on scrubs and observed several lumbar fusion surgeries to obtain personal insight into the procedures and challenges with the operation.

"It's helpful to have the option to externally fixate the device, though it is not always used. Not all implants accommodate this feature"

"I value knowledgeable, punctual, and helpful representatives that are prepared with appropriate inventory"

"An implant must be strong in one direction, have a graft window, and be easy to manipulate with one hand"

"I have no financial gain on which implant to use - the outcomes are what matter"

Customer Journey

Orthopedic surgeons are involved in every aspect of the spinal implant journey. The below map details the activities, pain points, and emotions the surgeon experiences from selecting a product to use for an operation through surgery and to post op.

Listen

Design The Right Thing

Interviews conducted with 6 orthopedic surgeons and 3 field studies to observe surgery revealed the following:

Needs:

Physicians need an

ergonomic and easy to handle product

Product needs to work with familiar system
Core needs to promote bone growth
Too many posterior devices, need lateral approach

Pain Points:

When product breaks or chips upon impact
Device does not glide easily with little force
When there is no option for fixation
Unknowledgeable reps

Reframe

Problem Definition

Technology:

How might we design

an implant that maintains strength & promotes bone growth?

Physician Experience:

How might we obtain buy in from physicians despite the saturated market?

Create

Design Things Right

The creation process involved the following steps:

Rapid Iterative Prototyping:

Iterate design drawings with paper and pencil
Co-design & prioritize end user feedback
Apply 3D printing constraints
Print several options to test in person

Validation & Testing:

Test designs with orthopedic surgeons in practice surgery
Iterate as needed
Conduct mechanical testing to confirm product viability
Generate cost and performance metrics
Plan for rep training

Product Development

Technology Ideation & Prototyping

The engineering team created several low fidelity implant designs based off of research collected in the first phase. I then facilitated a co-design session between the engineers and volunteer surgeons to ideate several additional design options. From this collaborative experience, our team decided to prioritize the following design features:

an anisotropic lattice (strong in one direction and resistant to compression fatigue)
a large graft window (to distribute force and combat subsidence)
a bulleted nose (to aid smooth placement and reduce impact failure)
integrated fixation (to stabilize vertebrae and increase rate of bone fusion)

This lattice structure, patented by PrinterPrezz, was an essential part of the design development and incorporated into each geometric concept

Example of final design iteration drawn by hand, with CAD, and preparing for 3D printing

Physician Experience Ideation

The first goal was to develop innovative technology that will improve clinical outcomes and ultimately decrease the need for repeat surgeries.

From our user research, we quickly identified a second goal of improving the physician experience in order to facilitate adoption of our product. The team brainstormed several approaches to differentiate our product from a customer experience perspective.

To create a successful product that would reach patients and ultimately improve clinical outcomes, we created a plan to develop a customer journey video to pitch the product and a training curriculum for representatives to understand the surgery and troubleshoot in the operating room in order to deliver more value to the physician - representative relationship.

Validation & Testing

User Testing: My team 3D printed several plastic prototypes of our design. We took these prototypes back to the surgeons to give them the chance to touch, hold, and feel the design. We talked through a theoretical surgery procedure and had the surgeons demonstrate how their surgical tools and access system would integrate with the prototypes. From the array of prototypes, the surgeons provided feedback on size, feel, and product features that they anticipate to fail or be beneficial. Presenting prototypes in person was immensely helpful in shaping the final design that would theoretically be tested in clinical trials down the line.

Insights obtained from user testing:

oval shaped products can easily slip when maneuvering with one hand
- ---> led to rectangular cage
flush fixation holes are challenging to secure
- ---> led to slightly angled screw inserts
challenging to keep sizes aligned during surgery
- ---> led to package tray design with visible size labels on container and product

Mechanical Testing: The team converged on a final design after user testing several 3D printed plastic prototypes with orthopedic surgeons.

Solution & Impact

User experience research was crucial for designing a product that would be adopted by a surgeon and prevent the need for reoperation on a patient. Our product design centered around promoting bone growth while exhibiting strength. These factors will allow the surgeon to operate without complication, and improve patient outcomes. Through our user interviews and field studies, we learned that in order to differentiate our product from the saturated market, training and deploying a medical device sales team, that is fluent in articulating the advantages of our technology and able to build trusting relationships with surgeons, is a crucial aspect for success. In addition, my team and I also developed a comprehensive business strategy through market sizing, competitive analysis, regulatory pathway development, manufacturing and operational planning, clinical trial design, reimbursement strategy, and exit opportunity analysis.

Our Solution

Offers

Technological Advantage

Novel 3D printing manufacturing process allows for customized sizing and lattice structure for enhanced bone growth
Superior clinical data to entice physicians to utilize our product over competitors, despite being a small company

Improved Physician Experience

Knowledgeable medical device reps trained on products and able to troubleshoot in surgery to build physician trust
Implant package designed intuitively for ease of use during operation and to decrease waste

Impact & Value to Stakeholders

Hospitals

Fewer reoperations resulting in cost saving opportunities

A 10% decrease in patient complications will result in $500 M hospital savings

Physicians

Lower risk of failure during operation, enhanced ease of use, and trustworthy representative relationship

Patients

Hope to improve patient outcomes and quality of life by 10%

Decrease the need to have subsequent surgery and rehabilitation

Product Roadmap

*Singapore selected as additional launch location due to its use of FDA and global medical tourism

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CMU CARNIVAL BOOTH

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Improving Lumbar Fusion Patient Outcomes
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