ROSA® Knee System

Individualized alignment and ligament balancing technique with the ROSA® robotic system for total knee arthroplasty.

Rossi SMP, Benazzo F.  Int Orthop. 2023 Mar;47(3):755-762. doi: 10.1007/s00264-022-05671-z. Epub 2023 Jan 4. PMID: 36596998.

Key Takeaway: The ROSA Knee System is showing a favorable gap balancing technique and the possibility to create individualized alignment. 

The ROSA® robotic system has been recently introduced in the market and presents specific and peculiar features to optimize ligament balancing and an individualized alignment of the implant in a three dimensional prospective.

Imageless robotic-assisted total knee arthroplasty is accurate in vivo: a retrospective study to measure the postoperative bone resection and alignment

Schrednitzki D, Horn CE, Lampe UA, Halder AM. Arch Orthop Trauma Surg. 2022 Oct 21. doi: 10.1007/s00402-022-04648-2. Epub ahead of print. PMID: 36269397.

Key Takeaway: The imageless mode of ROSA Knee is accurate in vivo. 

The use of the ROSA Knee imageless pathway is accurate in terms of coronal alignment and bone resections. This is consistent with published studies. The present paper is the first to show that the accuracy previously reported only in cadavers can also be achieved in patients.

Image-Free Robotic-Assisted Total Knee Arthroplasty Results in Quicker Recovery but Equivalent One-Year Outcomes Compared to Conventional Total Knee Arthroplasty.

Khan IA, Vaile JR, DeSimone CA, Parsell DE, Heinze JD, Alessi A, Xu W, Shah RP, Pickering T, Cafferky NL, Lonner JH. J Arthroplasty. 2023 Feb 18:S0883-5403(23)00131-6. doi: 10.1016/j.arth.2023.02.023. Epub ahead of print. PMID: 36801477.

Key Takeaway: ROSA® Knee has resulted in a faster recovery following total knee arthroplasty in regards to KOOS JR scores.

Image-free RA-TKA reduces pain and improves early functional recovery compared to C-TKA at 4 to 6 weeks, but functional outcomes at 1 year are equivalent based on the MCID and PASS for KOOS-JR.

Earlier Gains in Active Range of Motion Following Robotic-Assisted Total Knee Arthroplasty Compared with Conventional Instrumentation.

Fary, C. Tripuraneni K, Klar B, Ren AN, Abshagen S, Verheul R. Orthopaedic Proceedings. 2023;105-B(SUPP_2):43-43. doi:doi:10.1302/1358-992X.2023.2.043.

Key Takeaway: ROSA® Knee has resulted in a faster recovery following total knee arthroplasty in regards to range-of-motion.

raTKA resulted in greater AROM flexion gains in the early postoperative period than cTKA. Additional research is needed to understand if these earlier gains in AROM are associated with improved patient satisfaction and continued improvements with time.

A new robotically assisted technique can improve outcomes of total knee arthroplasty comparing to an imageless navigation system

Mancino F, Rossi SMP, Sangaletti R, Lucenti L, Terragnoli F, Benazzo F. Arch Orthop Trauma Surg. 2022

Key Takeaway : Imageless robotic TKA demonstrates improved ROM and less pain at 12 months following TKA compared to imageless navigation.

Introduction of ROSA robotic-arm system for total knee arthroplasty is associated with a minimal learning curve for operative time

Bolam SM, Tay ML, Zaidi F, et al. Journal of Experimental Orthopaedics. 2022;9(1):86.

Key Takeaway : The most pertinent finding of this study was that there was a learning curve of between 5 and 15 cases associated with the introduction of this RA TKA system. There was no significant increase in operative time in the RA TKA group compared to the conventional TKA group. There were no post-operative complications associated with the introduction of this system.

An anatomo-functional implant positioning technique with robotic assistance for primary TKA allows the restoration of the native knee alignment and a natural functional ligament pattern, with a faster recovery at 6 months compared to an adjusted mechanical technique. 

Parratte S, Van Overschelde P, Bandi M, Ozturk BY, Batailler C. Knee Surg Sports Traumatol Arthrosc. 2022.

Key Takeaway : Faster recovery using an anatomo-functional implant positioning (AFIP) technique for robotic total knee arthroplasty compared to an adjusted mechanical alignment (aMA) technique.

“The AFIP concept allowed the restoration of the native knee anatomy and alignment with a natural ligament pattern.

With a more physiological target for ligament balancing, robotically-assisted AFIP technique had equivalent clinical outcomes at 12 months compared to aMA, with a faster recovery”

Comparative outcomes between a new robotically assisted and a manual technique for total knee arthroplasty in patients with osteoarthritis: a prospective matched comparative cohort study. 

Kenanidis E, Paparoidamis G, Milonakis N, Potoupnis M, Tsiridis E. European Journal of Orthopaedic Surgery & Traumatology. 2022.

Key Takeaway: raTKA was associated with the same complication risk, less pain level, better patient satisfaction, and PROMs on 6-month follow-up than the mTKA group.

“One of the first comparative clinical studies evaluating outcome differences between ROSA raTKA and mTKA”, and the “results indicate that raTKA may help enhance the early functional recovery of TKA patients and promote a better satisfaction level in the early postoperative period.”

Total Knee Arthroplasty With Robotic Surgical Assistance Results in Less Physician Stress and Strain Than Conventional Methods

Haffar A, Krueger CA, Goh GS, Lonner JH. 2022 Jun;37(6S):S193-S200.

Key Takeaway: Robotic assistance may help to increase surgical efficiency and reduce physician workload

Total energy expenditure was lower in robotic TKA than conventional TKA. Average heart rate was lower in robotic TKA. Robotic TKA resulted in less lumbar flexion and a reduction in the time spent in demanding lumbar flexion. Neck rotation was significantly reduced by robotic TKA.

Is sequential bilateral robotic total knee arthroplasty a safe procedure? A matched comparative pilot study.

Batailler C, Anderson MB*, Flecher X, Ollivier M, Parratte S. Archives of Orthopaedic and Trauma Surgery 2022.

Key Takeaway: Sequential bilateral TKA performed with robotic assistance more accurately restores knee alignment with similar perioperative outcomes and better Knee Society functional scores at six months postoperative compared to conventional instrumentation, despite a longer surgical time.

Bilateral sequential TKA is a valid option for improving accuracy and early outcomes, without posing an additional risk of complications.

A Personal Journey through, and review of, the Landscape of Surgical Robotics in Knee Arthroplasty: My Transition from Mako® to NAVIO™ and finally to the ROSA® Knee System

Lonner H. Jess, Journal of Orthopaedic Experience & Innovation 2022.

Key Takeaway: The potential of the confluence of the ROSA Knee System and analytics platforms to simplify the surgical procedure, improve accuracy, and provide a vehicle for mass customization and individualization of care for each patient is a noteworthy advance.

Dr. Lonner concludes that the value of contemporary knee robotics may not yet be fully appreciated, which is emphasized by the prospects of advancing AI with pre, intra, and post-operative data in order to further optimize outcomes for TKA. He feels that robotics in arthroplasty is on the verge of becoming “self-evident”.

The initial learning curve for the ROSA® Knee System can be achieved in 6-11 cases for operative time and has similar 90-day complication rates with improved implant alignment compared to manual instrumentation in total knee arthroplasty.

Vanlommel, Luc, Enrico Neven, Mike B. Anderson*, Liesbeth Bruckers, Jan Truijen. Journal of Experimental Orthopaedics (2021) 8:119

Key Takeaway: The data demonstrated a relatively rapid learning curve for operative times associated with adoption of this novel robotic system.

As the digital age of medicine continues to develop, advanced technologies may disrupt the industry, but should not disrupt the care provided. This cutting guide positioning robotic system can be integrated relatively quickly with a rapid initial learning curve (6-11 cases) for operative times, similar 90-day complication rates, and improved component positioning compared to mTKA. Proficiency of the system requires additional analysis, but it can be expected to improve over time.

Using Standard X-ray Images to Create 3D Digital Bone Models and Patient-Matched Guides for Aiding Implant Positioning and Sizing in Total Knee Arthroplasty

Massé, Vincent and Raju S. Ghate. Computer Assisted Surgery, 26:1, 31-40, published online 15 Mar 2021

Key Takeaway: X-Atlas™ imaging technology could effectively predict implant sizing.

The X-Atlas™ imaging technology proved to be accurate to reconstruct a 3D bone model and results have shown that it might provide benefits to surgeons seeking improved planning and precision without the problems of obtaining 3D imaging.

Registration of Bony Landmarks and Soft Tissue Laxity During Robotic Total Knee Arthroplasty is Highly Reproducible.

Charette, R., Sarpong, N., Weiner, T., Shah, R., Cooper, J.  Surg Technol Int. 2022

Key Takeaway: High reproducibility of bony landmarks and tissue laxity among robotic TKA experienced and novice surgeons.

Excellent intra-rater reliability for both rTKA experienced (ICC = 0.952) and inexperienced (ICC = 0.925) surgeons. Excellent inter-rater reliability between rTKA experienced and inexperienced surgeons for both imageless and image-based. Excellent reliabilities for soft tissue laxities suggest that inherent differences in tension applied by physicians during the dynamic stress evaluation will not affect the ROSA Knee System gap analysis.[The] results show a high repeatability of registration of anatomic landmarks and gap assessment among observers using this robotic system for both image-based and [imageless] software.

High accuracy of a new robotically assisted technique for total knee arthroplasty: an in vivo study. 

Rossi SMP, Sangaletti R, Perticarini L, Terragnoli F, Benazzo F. Knee Surg Sports Traumatol Arthrosc 2022

Key Takeaway: The ROSA Knee system demonstrated a high degree of in vivo accuracy.

The average difference between planned and validated measures were below 1 mm or under 1 degree with SD < 1.

The average difference between planned HKA and measured was 1.2 ± 1.1 degrees.

“…using this new surgical robot in total knee arthroplasty [makes it] possible to perform accurate bone cuts and to achieve the planned angles and resections.”

ROSA® Hip System

The learning curve for a novel, fluoroscopy-based robotic-assisted total hip arthroplasty system. 

Buchan GBJ, Hecht CJ 2nd, Lawrie CM, Sculco PK, Kamath AF. Int J Med Robot. 2023 Apr 14:e2518. doi: 10.1002/rcs.2518. Epub ahead of print. PMID: 37058696.

Key Takeaway: Adoption of fluoroscopy-based RA-THA is associated with a brief learning curve of 12 cases.

Implementation of fluoroscopy-based RA-THA was associated with a learning curve of 12 cases. A 6-min increase in operative time was seen during the learning phase compared to the proficiency phase (44.3 ± 4.4 vs. 38.0 ± 7.1 min; p < 0.001), with a 3-min longer robotic cup impaction sequence during the learning phase (7.8 ± 1.9 vs. 4.8 ± 1.3 min; p < 0.001).

Equivalent radiation exposure with robotic total hip replacement using a novel, fluoroscopic-guided (CT-free) system: case–control study versus manual technique.

Buchan G, Ong C, Hecht C, et al. Journal of Robotic Surgery. 2023/03/13 2023;doi:10.1007/s11701-023-01554-6

Key Takeaway: The novel CT-free robotic system likely poses no clinically significant increase in radiation exposure to the patient compared to manual approaches.

No learning curve was detected by CUSUM analysis with respect to the number of fluoroscopic images taken during the adoption of the robotic THA system. While statistically significant, in comparison to published literature, the radiation exposure of the CT-free robotic THA system was comparable to that of unassisted manual THA approach and less than that of CT-based robotic approaches. Thus, the novel CT-free robotic system likely poses no clinically significant increase in radiation exposure to the patient compared to manual approaches.

Improved accuracy and fewer outliers with a novel CT‑free robotic THA system in matched‑pair analysis with manual THA

Kamath, Atul, F., Sridhar M. Durbhakula, Trevor Pickering, Nathan L. Caferky, Trevor G. Murray, Michael A. Wind Jr., Stéphane Méthot*. Journal of Robotic Surgery. Published online: 28 October 2021.

Key Takeaway: ROSA Hip demonstrated more accurate acetabular cup positioning and resulted in fewer outliers compared to manual THA.

For all parameters studied – including cup inclination and version, leg length discrepancy and cup placement compared to target – the robotic group had an improved accuracy and lower variance (fewer outliers) vs conventional instrumentation.

SignatureTM ONE Surgical Planning 

Patient-specific targeting guides compared with traditional instrumentation for glenoid component placement in shoulder arthroplasty: a multi-surgeon study in 70 arthritic cadaver specimens

imac27inches-no logo
Throckmorton, MD, Thomas W, Lawrence V. Gulotta, MD, Frank O. Bonnarens, MD, Stephen A. Wright, MD, Jeffrey L. Hartzell, MD, William B. Rozzi, MD, Jason M. Hurst, MD, Simon P. Frostick, MD, John W. Sperling, MD, MBA. J Shoulder Elbow Surg (2015).

Key Takeaway: Signature ONE planner and patient-specific guides were significantly more accurate (P=.01) for the combined vectors of version and inclination compared to conventional instruments.

Accuracy of 3-Dimensional Planning, Implant Templating, and Patient-Specific Instrumentation in Anatomic Total Shoulder Arthroplasty

imac27inches-no logo
Iannotti, MD, Joseph P., PhD, Kyle Walker, MD, Eric Rodriguez, MS, Thomas E. Patterson, PhD, Bong-Jae Jun, PhD, and Eric T. Ricchetti, MD. J Bone Joint Surg Am. 2019;101:446-57. 

Key Takeaway: Signature preoperative planning and patient-specific instrumentation improves the accuracy of glenoid implant placement in TSA.


Recovery Curves for Patient Reported Outcomes and Physical Function After Total Hip Arthroplasty.

Sato, EH, et al. The Journal of Arthroplasty. Published online April 15, 2023. DOI:

Key Takeaway: This study provides a unique and valuable visual aid to assist with patient counseling and setting perioperative expectations.

Patients can be counseled that the greatest proportional improvement in PROMs is within one month after THA, while function surpasses pre-operative baselines by three-months, and gait quality may not improve until after one-year. This can help set realistic expectations and target interventions toward patients deviating from the norm.

Use of a Smartphone-Based Care Platform After Primary Partial and Total Knee Arthroplasty: 1-Year Follow-Up of a Prospective Randomized Controlled Trial.

Jacob S. Alexander, Roberta E. Redfern, Paul J. Duwelius, Keith R. Berend, Adolph V. Lombardi, David A. Crawford,  The Journal of Arthroplasty, 2023, ISSN 0883-5403,

Key Takeaway: This study demonstrates that the use of a smartphone-based care platform after primary knee arthroplasty resulted in significantly less visits to physiotherapy and the ED when compared to the control group.

Implementation of this smartphone/smart watch care platform showed similar outcomes to traditional care models at 1 year postoperative. Traditional physiotherapy and ED visits were seen at much lower rates in this cohort, demonstrating a lower usage of health care resources. This application could assist in alleviating the need for health care dollars by reducing postoperative costs, enhancing communication across the health care team, and permitting such resources to be more properly distributed.

Patients’ Perceptions of Remote Monitoring and App-based Rehabilitation Programs: A Comparison of Total Hip and Knee Arthroplasty

Booth, Matthew W. et al. The Journal of Arthroplasty, Published online April 20, 2023. DOI:

Key Takeaway: Patients found remote monitoring with mymobility easy to use, increased motivation, and recommend it to other patients undergoing lower extremity arthroplasty. 

Remote monitoring technologies for THA, TKA, and UKA provide patients motivation to conduct their rehabilitation programs, and patients would recommend it to other patients undergoing similar procedures. The THA patients felt that these technologies could eventually even completely replace in-person rehabilitation programs, but all patients recommend a combination of technology and in-person rehabilitation postoperatively. This study showed an overwhelmingly positive experience of patients utilizing remote monitoring rehabilitation technologies.

2021 Mark Coventry Award: Use of a Smartphone-Based Care Platform After Primary Partial and Total Knee Arthroplasty: A Prospective Randomized Controlled Trial

Crawford, David et al. Bone Joint J 2021;103-B (6 Supple A) : 3-12 

Key Takeaway: Equivalent outcomes and significantly fewer PT visits with mymobility for TKA/PKA

The purpose of this study was to determine the non-inferiority of a smartphone-based exercise educational care management system after primary knee arthroplasty compared with a traditional in-person physiotherapy rehabilitation model. The data found that mymobility is clinically non-inferior to the standard of care for all outcomes. mymobility users demonstrated a significant reduction of physical therapy utilization post-operatively. Further, mymobility users trended lower on ED visits than control group, though not statistically significant. This platform could aid in decreasing post-operative costs, while improving patient engagement and communication with the healthcare team.

Early Outcomes of Primary Total Hip Arthroplasty with Use of a Smartphone-Based Care Platform: A Prospective Randomized Controlled Trial

Crawford, David et al Bone Joint J 2021;103-B (7 Supple B):91-97.

Key Takeaway: Equivalent outcomes and significantly fewer PT visits with mymobility for THA

The purpose of this study was to determine the non-inferiority of a smartphone-based exercise educational care management system after primary total hip arthroplasty compared with a traditional in-person physiotherapy rehabilitation model. The data found that mymobility is clinically non-inferior to the standard of care for all outcomes. mymobility users demonstrated a significant reduction of physical therapy utilization post-operatively. Further, mymobility users trended lower on ED visits than the control group and hospital readmissions, though not statistically significant. This platform could aid in decreasing post-operative costs, while improving patient engagement and communication with the healthcare team.

Feasibility of Passively Collected Gait Parameters Using a Smart-Phone Based Care Platform Following Total Hip and Knee Arthroplasty

M. Anderson*, D. Van Andel*, J. Foran, I. Mance, E. Arnold. Orthopaedic Proceedings Vol. 103-B, No. SUPP_9, Published online 15 June 2021.

Key Takeaway: mymobility enables remote gait quality measurements

The purpose of this study was to assess the recovery of gait quality following primary total hip and knee arthroplasty using a smart-phone based care management platform. The recovery curves reflect previous curves captured by traditional gait analysis methods as well as functional and patient reported outcome scores. Capturing real-world gait quality metrics through the phone may provide further insights into objective recovery data not captured by traditional in-clinic assessments.

The Recovery Curve for Physical Activity Following Primary Knee Arthroplasty Using Passively Collected Objective Measures with a Smart-phone Based Care Platform and Smart Watch

M. Anderson*, D. Van Andel*, C.L. Israelite, C. Nelson. Orthopaedic Proceedings. Volume 103-B, No. SUPP_9, Published online 15 June 2021 

Key Takeaway: Objective and reliable data with mymobility

The purpose of this study was to characterize the recovery of physical activity following knee arthroplasty by means of step counts and flight counts (flights of stairs) measured using a smart-phone based care platform.  This data demonstrated a recovery curve similar to previously reported curves for patient reported outcome measures in the arthroplasty arena. Patients and surgeons may use this information to help set goals for recovery following total and partial knee arthroplasty using objective activity measures.

OrthoIntel Orthopedic Intelligence Platform

An Orthopaedic Intelligence Application Successfully Integrates Data from a Smartphone-based Care Management Platform and a Robotic Knee System Using a Commercial Database.

Lonner, J.H., Anderson, M.B.*, Redfern, R.E.* et al. International Orthopaedics (SICOT) (2022).

Key Takeaway: mymobility can be integrated with ROSA Knee to passively collect data throughout the episode-of-care. Associations between intra-operative decisions regarding laxity and post-operative outcomes were identified.

There were higher step counts at six-weeks post-operatively in knees with >2mm increased laxity in both the lateral compartment in extension and medial compartment in flexion (p<0.05). Knees balanced in flexion within <0.5mm had higher KOOS JR scores at six-weeks post-operative (p=0.034) compared to knees balanced within 0.5 – 1.5mm. Knees with laxity balanced between 0.5 and 1.5 mm and those with more than 1.5 mm of laxity between medial and lateral compartments in extension had significantly greater step counts at six-weeks. The study has a relatively small sample size (n=131).

The focus of this paper was on the feasibility of data collection throughout the episode of care. These associations are intriguing, and the clinical relevance needs further investigation.

OptiVu™ Mixed Reality

Looking through the Lens: The Reality of Telesurgical Support with Interactive Technology Using Microsoft’s HoloLens 2. 

Kees van der Putten*, Mike B. Anderson*, and Rutger C. van Geenen. Case Reports in Orthopedics, vol. 2022, Article ID 5766340, 5 pages, 2022. 

Key Takeaway: Microsoft HoloLens 2 was used for unplanned remote assistance for telesurgical support.

This case study demonstrates the ability to use the HoloLens 2 with Microsoft Dynamics 365 Remote Assist Software to provide immediate telesurgical support by an industry representative, the PM, to the operating surgeon approximately 100 km apart. The data is transferred via an encrypted and secured cloud-based program and provided the PM a real-time surgeon viewpoint of the operating theatre, including direct line of site to the operative knee, the operating instruments, and even the surgeon’s hands.

*Authored, in part, by a Zimmer Biomet clinical employee
Funded, in part, by Zimmer Biomet

This material is intended for healthcare professionals. Distribution to any other recipient is prohibited. Zimmer Biomet does not practice medicine. For indications, contraindications, warnings, precautions, potential adverse effects and patient counselling information, see the package insert or contact your local representative; visit for additional product information. Not all patients are candidates for the use of this product and surgeons should evaluate individually to determine which patients are appropriate for therapy at home.

All names used in the mymobility app examples are fictitious. No identification with actual patients or health care professionals is intended or should be inferred. Apple, Apple Watch, iPhone, HealthKit and Mac are trademarks of Apple, Inc., registered in the U.S. and other countries. Patients must have compatible hardware and be clinically appropriate for remote care to use mymobility. WalkAI Exceptions are visible through the mymobility® clinician experience and are only for patients using the mymobility app with an iOS device. ©2022 Zimmer Biomet