Next Generation Personalized Restoration Technology :
The Bodycad Unicompartmental Knee System
The First Truly Patient Specific Implant Design
Introducing Bodycad’s revolutionary Unicompartmental Knee System, designed to optimize personalized restorations of the patient’s unique anatomical features and kinematics. The BUKS is based on proprietary 3D rendering of medical images of the patient’s anatomy. Recent studies of Unicompartmental Knee Arthroplasty (UKA) have demonstrated favorable outcomes, shorter hospital stays versus total knee arthroplasty, and lower 30-day readmissions.5, 6 In addition, there is clinical evidence that modest improvements in implant survivorship for younger patients will increase the cost-effectiveness of the treatment.7 The BUKS is designed to advance and improve upon this body of clinical evidence.
The BUKS Optimization
- Designed to preserve bone and soft tissue
- Minimizes bone loss
- Includes instrumentation that is patient specific, intuitive and accurate
- Provides an unconstrained design for a full range of motion
- Engineered to fit the patient’s anatomy and kinematics
- Has the potential for improved clinical results and patient satisfaction
- Procedure in a box provides potentially greater efficiency and quality improvements to all stakeholders
- Offers a unique and accurate resection solution which reduces issues related to saw blades
There's Nothing Standard About It
It Starts with Imaging
Imaging technology is evolving and innovating all the time. MRI and CT access and utility is becoming more abundant across the globe. Bodycad believes that we need to be adaptable to the latest imaging modalities for the restoration. Bodycad’s proprietary imaging algorithms allow us to rapidly and automatically produce a 3D anatomic model. We have the capability to adapt and incorporate CT, MRI and long standing X-Ray data into our PREP. Our preferred imaging modality MRI and a coronal x-ray but we do have the capability to utilize CT, MRI and long standing interchangeably. MRI and a coronal long film are required in the US per our FDA clearance. To assist surgeons and imaging centers with providing Bodycad with the best quality images we have the Bodycad Unicompartmental Knee System Imaging Guide as a reference.
|Bone model imaging||MRI|
|Alignment imaging||None||Coronal Long Film*||Full leg CT|
|Mechanical axis angle
Hip knee ankle angle
Mechanical axis deviation
|Varus / valgus||Relative||•||•|
|* Required in the US|
|Bone model imaging||CT|
|Alignment imaging||None||Coronal Long Film||Full leg CT|
|Mechanical axis angle
Hip knee ankle angle
Mechanical axis deviation
|Varus / valgus||Relative||•||•|
Better Precision and Accuracy
The BUKS is designed with precision in mind. Evaluation of the precision and accuracy of implanting the BUKS tibial and femoral components in cadaver knees showed it to be the most precise of any current or traditional method. The Bodycad study reviewed 10 cadaver cases performed by three surgeons of varying levels of experience with UKA. Reported implant positioning accuracy results show that using conventional, robotic and navigated methods is not as accurate as Bodycad’s method on cadaveric models. 11, 12, 13, 14, 15
(Cobb et al.2006)
(Cobb et al.2006)
(N.J.Dunbar et al.2012)
|Bodycad Cadaveric Accuracy Study|
|Translation Error (mm)||2.2||1.1||1.3||0.9|
|Rotation Error (degrees)||5.5||2.4||2.4||2.2|
Our proprietary, novel method of bone resection uses a patient-specific drill guide that provides for surgeon control of depth and accuracy. This reduces adverse issues associated with saw blade deflection, positional errors, and heat generation.16, 17, 18, 19, 20 One important factor in achieving precise placement of the BUKS is the provision for adjunctive fixation for both the tibial and femoral components. The final step in implanting the BUKS is securing the bone screws, which increases bone cement compression and insures complete and accurate seating in accordance with the surgical plan.
Clinical Outcomes for Personalized Arthroplasty
A personalized restoration has the potential for improved clinical results versus off-the-shelf products. A recent multi-center study of 120 custom UKA knees found improved range of motion, higher functional outcome scores, and lower pain scores. Patient satisfaction was high, with 99% of patients saying they were satisfied – 89% were very or extremely satisfied with the results of the procedure and 89% said the movement of the knee felt natural. Two years after surgery, only 2 patients had undergone revision for tibial loosening.1 In a quote from an orthopaedic surgeon’s in-press publication for The Journal of Arthroplasty, the following statement was made : “Patients really feel more stable with their custom knee replacements especially when they do activities like bending or walking down stairs which some patients with off-the-shelf knee replacements have difficulty with due to mid-flexion instability.” 2
Potential Quality and Economic Improvements for Personalized Arthroplasty
The potential for quality and economic improvements for personalized restorations versus off-the-shelf solutions has started to emerge in the clinical body of evidence. Reduced blood loss and swelling, decreased length of stay, and discharge optimization may lead to a better economic case for patient-specific solutions. One study concluded that the “differences in blood loss and swelling may be explained by the lack of femoral canal preparation and the ability to completely cover all cut bone surfaces in the customized TKR group.” 3 Another study documented a decrease of 1.1 days Length of Stay (LOS), a 36% increase in the 24hr discharge rate, and a higher percentage of patients discharged directly to home versus off-the-shelf solutions.4 These quality improvements should translate to considerable upgrades in episode of care efficiencies and cost effectiveness.
Anatomical Fit and Bone Preservation
The titanium tibial baseplate of the BUKS fits and covers the bone resection. It has recently been documented that a custom UKA provides significantly greater cortical rim surface area coverage compared to off-the-shelf implants: 77% versus 43% medially and 60% versus 37% laterally. In addition, significantly less cortical rim overhang and under coverage were measured.8 This increased coverage of resected bone may lead to decreased blood loss. The matching of the tibial baseplate to resected bone is inherent to the Bodycad design and manufacturing process, which translates into optimal coverage all of the time. The femoral component is also designed to match closely the anatomy of the patient’s femur. The femur is prepared by denuding the surface of cartilage and osteophytes, keeping bone removal to a minimum. This is important because studies have shown that a femoral component overhang of more than 3mm nearly doubles the odds of clinically important knee pain two years after total knee arthroplasty.9
Bodycad’s solution is to re-establish the normal kinematics of the patient’s articulation by using a proprietary algorithm to best match the patient’s movement and anatomy. The Bodycad PREP Tech uses this information to develop an articulation specific to each patient. The results of one study postulate that knees with patient-specific implants generate kinematics more closely resembling normal knee kinematics than standard knee designs.10 Each and every Bodycad kinematic solution undergoes finite element analysis (FEA) to validate the design kinematics and contact stresses on the surface of the polyethylene insert. The polyethylene insert is available in 6mm to 10mm thicknesses in 1mm increments giving the surgeon flexibility for proper balancing of the knee.
Efficient Surgical Work Flow and Lower Asset Intensity
A personalized arthroplasty greatly reduces inventory of instruments, eliminates implant inventory, and reduces costs of reprocessing instruments and unused implants because the delivery comes in a self-contained kit. This procedure in a box provides all the patient-specific instruments and implants. Traditional off-the-shelf products require a significant amount of asset intensity and human resources to ensure all components and instruments arrive on time into the operating room theatre, and instruments are cleaned and prepared for the next surgery. The reduction of asset intensity has the potential to increase the efficiency of the work flow in the hospital and operating theatre. These reductions may lead to improved cost benefits for all stakeholders. The BUKS kit is better suited for procedures performed in an out-patient surgery center, as well as for the bundled care approach, as it drives overall efficiency for the episode of care.
- Barnes, CL, et al. “Customized, Individually Made Unicondylar Knee Replacement: A Prospective Multicenter Study of 2-Year Clinical Outcomes.” 2nd Annual Pan Pacific Orthopaedic Congress, Kona, Hawaii (July 22-25, 2015).
- “ConForMIS iTotal CR Outperformed Off the Shelf Implants.” Press Release (October 20th, 2016).
- Kurtz, et al. “Patient-Specific Knee Replacement Implants Preserve Bone and Decrease Blood Loss and Swelling.” BASK Annual Meeting, Poster Exhibit (2013).
- Buch, et al. “Clinical Study Presentation of an Independent, Prospective, Single-Center Investigator-Initiated Study of the iTotal CR Knee.” ICJR Pan Pacific Orthopaedic Congress (August 2016).
- Berger, Richard A., et al. “Results of Unicompartmental Knee Arthroplasty at a Minimum of Ten Years of Follow-Up.” The Journal of Bone & Joint Surgery - American Volume 87, 5 (May 2005): 999-1006.
- Drager, Jusin, et al. “Shorter Hospital Stay and Lower 30-Day Readmission after Unicondylar Knee Arthroplasty Compared to Total Knee Arthroplasty.” The Journal of Arthroplasty 31, 2 (February 2016): 356-361.
- Ghomrawi, Hassan, Ashley Eggman and Andrew D. Pearle. “Effect of Age on Cost-Effectiveness of Unicompartmental Knee Arthroplasty Compared with Total Knee Arthroplasty in the U.S.” The Journal of Bone & Joint Surgery - American Volume 97, 5 (March 2015): 396-402.
- Carpenter, Dylan P., et al. “Tibial Plateau Coverage in UKA: A Comparison of Patient Specific and Off-The-Shelf Implants.” The Journal of Arthroplasty 29, 9 (September 2014): 1694-1698.
- Mahoney, Ormonde M. and Tracy Kinsey. “Overhang of the Femoral Component in Total Knee Arthroplasty: Risk Factors and Clinical Consequences.” The Journal of Bone & Joint Surgery - American Volume 92, 5 (May 2010): 1115-1121.
- Patil, Shantanu, et al. “Patient -Specific Implants with Custom Cutting Blocks Better Approximate Natural Knee Kinematics than Standard TKA without Custom Cutting Blocks.” The Knee 22, 6 (August 2015).
- Internal Bodycad Test RAP-BP001-41, Bodycad UKS, “Prosthesis Position Accuracy Evaluation of Cadaver Specimen’s”. (December 2016).
- Karia, Monil, et al. “Robotic Assistance Enables Inexperienced Surgeons to Perform Unicompartmental Knee Arthroplasties on Dry Bone Models with Accuracy Superior to Conventional Methods.” Advances in Orthopedics vol. 2013.
- Cobb, J., et al. “Hands-On Robotic Unicompartmental Knee Replacement: A Prospective, Randomised Controlled Study of the Acrobot System.” The Bone & Joint Journal 88-B, 2 (February 2006): 188–197.
- Dunbar, Nicholas J., et al. “Accuracy of Dynamic Tactile-Guided Unicompartmental Knee Arthroplasty.” The Journal of Arthroplasty 27, 5 (May 2012): 803–808.e1.
- Smith, Julie R., Philip E. Riches and Philip J. Rowe. “Accuracy of a Freehand Sculpting Tool for Unicondylar Knee Replacement.” The International Journal of Medical Robotics and Computer Assisted Surgery 10, 2 (June 2014): 162-169.
- Goran, Augustin, et al. “Cortical Bone Drill and Thermal Osteonecrosis.” Clinical Biomechanics 27, 4 (May 2012): 313-325.
- Ohmori, Takaaki, et al. “The Accuracy of Initial Bone Cutting in Total Knee Arthroplasty.” Open Journal of Orthopaedics 5, 10 (October 2015): 297-304.
- Paskos, Christopher, et al. “Bone Cutting Errors in Total Knee Arthroplasty.” The Journal of Arthroplasty 17, 6 (September 2002): 698-705.
- Tawy,Gwenllian F., Philip J. Rowe, and Philip E. Riches. “Thermal Damage Done on Bone by Burring and Sawing With and Without Irrigation in Knee Arthroplasty.” The Journal of Arthroplasty 31, 5 (May 2016): 1102-1108.
- Toksvig-Larsen, Søren, Leif Ryd and Anders Lindstrand. “Temperature Influence in Different Orthopaedic Saw Blades.” The Journal of Arthroplasty 7, 1 (March 1992): 21-24.