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Zimmer, Inc.

Zimmer® Computer Assisted Solutions (CAS)

Computer Assisted Surgery

Zimmer Computer Assisted Surgery techniques combine advanced computer technology with a surgeon's skills to help improve the outcomes of knee and hip replacement surgery.

CAS, also known as Surgical Navigation, is defined as a surgery that is performed using a computer as a guiding and validation tool. The same way a car navigation system guides a driver from point A to point B, Zimmer's surgical navigation system provides the surgeon with important information during a surgery.

The system provides precise positional guidance when removing damaged surfaces of bones, based on a patient's anatomy, and suggests the appropriate implant size to be used and helps to determine its correct positioning.

Benefits of Surgical Navigation for Knee and Hip Replacements
In addition to assisting the surgeon's intra-operative decisions during a hip or a knee replacement procedure, Zimmer CAS system can offer a number of additional benefits, including:

  • Smaller incisions and increased visibility during the procedure to help achieve:
    • Less pain and a shorter recovery time for the patient1
    • Shorter hospital stay 1,2
    • Less scarring 1,3  (5.1 inches to 3.5 inches)
  • Less invasive techniques which are associated with:
    • Reduced bleeding and transfusion rates 3,13
    • Reduced risk of emboli during a knee replacement5
    • Less disruption of tissue6

It has been shown that surgical navigation can help to provide a more accurate alignment7,8,9, of the implanted joint that can enhance its overall function 8,10. This, in turn, should provide the patient with:

  • A longer lasting implant 8,10
  • A reduced risk of dislocation after hip replacement8

The accuracy of implant positioning through the Zimmer CAS system should also help reduce the risk of leg length discrepancy 11,12 that can cause limping after a hip replacement.

If you and your surgeon have explored all non-surgical treatments for your joint problems, a partial or a total knee or hip replacement can help you relieve your pain and get you back to living an active life.

Benefits Of Surgical Navigation For Knee And Hip Replacements

CAS graph

In addition to assisting the surgeon's intra-operative decisions during a hip or a knee replacement procedure, Zimmer CAS system can offer a number of additional benefits, including:

  • Smaller incisions and increased visibility during the procedure to help achieve:
    • Less pain and a shorter recovery time for the patient1
    • Shorter hospital stay 1,2
    • Less scarring 1,3  (5.1 inches to 3.5 inches)
  • Less invasive techniques which are associated with:
    • Reduced bleeding and transfusion rates 3,13
    • Reduced risk of emboli during a knee replacement5
    • Less disruption of tissue6

It has been shown that surgical navigation can help to provide a more accurate alignment7,8,9, of the implanted joint that can enhance its overall function 8,10. This, in turn, should provide the patient with:

  • A longer lasting implant 8,10
  • A reduced risk of dislocation after hip replacement8

The accuracy of implant positioning through the Zimmer CAS system should also help reduce the risk of leg length discrepancy 11,12 that can cause limping after a hip replacement.

If you and your surgeon have explored all non-surgical treatments for your joint problems, a partial or a total knee or hip replacement can help you relieve your pain and get you back to living an active life.

ORTHOsoft® Total Hip Replacement (THR)

HIP NAVIGATION AT ITS SIMPLEST: ORTHOsoft LEG LENGTH AND OFFSET

The ORTHOsoft® hip navigation proposes an efficient and accurate way to measure a critical variable in the success of THR. Discrepancy in leg length and offset after THR may cause limping and lead to patient dissatisfaction. Leg length discrepancy is the most frequent source of litigation following hip arthroplasty13,14.

The ORTHOsoft System's user-friendly time-saving navigation workflow allows the surgeon to start the surgery in lateral (without having to modify the patient's position during the procedure), while only using one pelvic reference.

Pain, instability and stiffness are all described as direct or indirect consequences of leg length discrepancy15.The fast and reliable intra-operative feedback of the Zimmer CAS navigation system can potentially improve patient recovery after a hip replacement procedure.

Perform the measurement of leg length and offset with Zimmer CAS navigation and effectively address discrepancies by using the modular stem and neck M/L Taper Hip with Kinectiv® Technology.

HIP NAVIGATION WITH EXTENDED PERFORMANCE: ORTHOsoft CUP NAVIGATION

Optimal placement of the acetabular and femoral components is determinant in the success of total hip arthroplasty10. ORTHOsoft® hip navigation provides a complete workflow that helps the surgeon precisely fit the implant to the patient's specific anatomy.

A unique system, designed to increase the efficiency of the procedure, adapts to most surgeons' conventional techniques. ORTHOsoft® hip navigation provides optimized view of the implant component position, with a real time positioning of the cup to deliver a precise implant positioning experience.

Surgical navigation helps provide a more accurate implant alignment 7,8,9 that can enhance implant function and longevity.8,9 Enhance your technique and provide your THR patients with an implant that will potentially last longer and reduce the risk of dislocation after hip replacement.

ORTHOsoft® Partial Hip Resurfacing Replacement (PHR)

NAVIGATE A CHALLENGING AND GROWING TYPE OF SURGERY with ORTHOsoft PARTIAL HIP RESURFACING

Partial hip resurfacing offers potential advantages to selected patients-especially young, active, highly-demanding patients. Among the proposed benefits of resurfacing are the following: bone retention for future revisions, less stress shielding and fewer dislocations than conventional hip arthroplasties.

Avoid the notching of the femoral bone and achieve an accurate placement of the femoral hip component are the main challenges of this procedure.

ORTHOsoft PHR planning device allows the surgeon to fine-tune the anterversion/retroversion, varus/valgus and translation to optimize the final guide wire position. Real time data on instrument positioning compared to the target allows immediate and accurate adjustment to implant position.  

The application aims to achieve a reduced or equal operative time, while increasing the overall accuracy of the procedure. Even in their first attempt, surgeons were able to reach a high degree of accuracy by using navigation for a resurfacing procedure16.

  • The ORTHOsoft PHR was shown to reduce outliers by 38% from 33 in a non-navigated group to zero outliers in the navigated group 17
  • The ORTHOsoft PHR was shown to reduce notching by 4.5%, from four cases in a non- navigated group to zero in the navigated group17
  • Computer guided method provided ranges of error of up to eight times less than the conventional alignment jigs in the coronal plan 18

These results are associated with a lower risk of dislocation and fracture. Zimmer CAS navigation was shown to reduce hospital length of stay, allowing patients to go back faster to the activities they like 15,19.

To get more information on the ORTHOsoft PHR, contact your local Zimmer sales representative or click here to Get Trained on Zimmer CAS Navigation software.

Click here to find a surgeon trained on the Zimmer CAS ORTHOsoft PHR application.

References

  1. Dutton A.Q., YEO S.J., Yand K.Y., Lo N.N., & Chong H.C. (2008), Computer-Assisted Minimally Invasive Total Knee Arthroplasty Compared with Standard Total Knee Arthroplasty. A Prospective Randomized Study. J Bone Join Surg, 90-A:2-9.
  2. Zanasi S., Minimally Invasive Computer-Assisted Total Knee Arthroplasty through a Subvastus Approach, (2006), Orthosupersite.com.
  3. Coon T.M., Tria A.J., and Lavernia C., & Randall L (2005) The Economics of Minimally Invasive Total Knee Surgery, Semin Arthro, 16 :235-238.
  4. Kalairajah Y., Simpson D., Cossey A.J., Verrall G.M., & Spriggins A.J. (2005) Blood loss after total knee replacement. Effects of computer assisted surgery. J Bone Join Surg Br, 87-B(11):1480-1482.
  5. Kalairajah Y., Cossey A.J., Verrall G.M., Ludbrook G., & Spriggins A.J. (2006) Are systemic emboli reduced in computer-assisted knee surgery? A prospective randomized, clinical trial. J Bone Join Surg, 88-B(2):198-202.
  6. Kennon R.E., Keggi J.M., Wetmore R.S., Zatorski L.E., Huo M.H., & Keggi K.J (2003), Total Hip Arthroplasty Through a Minimally Invasive Anterior Surgical Approach, J Bone Join Surg. Am., 85:39-48.
  7. Kalteis T., Handel M., Bathis H., Perlick L., Tingart M., & Griftka J. (2006) Imageless navigation for insertion of the acetabular component in total hip arthroplasty. Is it as accurate as CT-Based navigation? J Bone Join Surg BR, 88B(2):163-167.8).
  8. Skiorski J.M., & Chauhan S. (2003) Computer-Assisted Orthopaedic Surgery: Do we need CAOS? J Bone Join Surg,85-B:319-23.
  9. Haaker R.G., Stockheim M., Kamp M, Proff G., Breitenfelder J, & Ottersbach A. (2005) Computer-assisted navigation increases precision of component placement in total knee arthroplasty, Clin Orthop. 433:152-9.
  10. Noble P.C., Sugano N., Johnston J.D., Thompson M.T., Conditt M.A., Engh C.A. Sr, & Mathis K.B. Computer Simulation: How can it help the surgeon optimize implant position? CORR. 2003 Dec; (417):242-52.
  11. Ganapathi M., Vendittoli P.A., & Lavigne M. (2008), Limb length and femoral offset reconstruction during THA using CT-Free computer navigation, CAOS Congress, February 7-9, Glasgow, UK.
  12. Konyves A., & Bannister G.C. (2005), The importance of leg length discrepancy after total hip arthroplasty, J Bone Join Surg. 87-B(2):155-157.
  13. White AB. AAOS committee on professional liability: study on 119 closed malpractice involoving hip replacement. AAOS bulletin, July 1994.
  14. Hoffman A.A. & Skrzynski M.C. Led length inequality and nerve palsy in total hip arthroplasty; a laywer awaits! Orthopaedics. 2000;9;943-944.
  15. Confalonieri et al. (2008) Leg length discrepancy, dislocation rate, and offset in total hip replacement using a short modular stem: navigation vs conventional freehand, Oct;31(10 Suppl 1). pii: orthosupersite.com/view.asp?rID=35541.
  16. Cobb J.P. et al. (2007) Navigation reduces the learning curve in resurfacing total hip arthroplasty. Clinical Orthopedics related Res.
  17. Ganapathi et al. (2007), Femoral Component Positioning in Hip Resurfacing With and Without Navigation, Clin Orthop Relat Res.
  18. Olsen et al. (2010), A comparison of conventional guidewire alignment jigs with imageless computer navigation in hip resurfacing arthroplasty, J Bone Joint Surg. Am 2010 Aug 4;92(9):1834-41.
  19. Vogt P. & Schueler M. (2007) Navigation beim Durom Cup: Ein erster Erfhrungsbericht, SGO Congress, September 19-21, Montreux, France.