Robotic Surgery and Computer Navigation in Orthopaedics



  • The term “Robot” is derived from the Polish word, “robota”, which means, “forced labour” and is used to describe a machine that carries out multiple tasks automatically or with a minimum of external impulse, especially one that is programmable
  • Two systems for Robotic Surgery exist: 1)Autonomous 2) Haptic (Tactile) System
  • Haptic systems allow the surgeon to drive, or use the robot to perform the operation
  • Constant input of the surgeon is mandatory for efficient functioning of the system
  • In autonomous systems, the surgeon performs the approach, sets up the machine and then engages the robot to complete the surgery without the surgeons help

Proposed advantages of Robotic Surgery include:-

  1. Ability to perform MIS
  2. Improved accuracy of implant placement
  3. Improved radiological alignment of extremities


  • Commercially available tactile systems for Unicondylar knee replacement: Robotic Arm Interactive Orthopaedic System (RIO, Mako Surgical Corp.)
  • Uses preoperative CT scans to generate 3D computer model of the knee
  • Helps for preoperative planning
  • Surgeon will intraoperatively mark the bony surfaces of the femur and tibia allowing the preoperative model to be merged into the active anatomy of the knee
  • The knee is taken through a full range of motion, the flexion-extension gaps assessed, component size and implant placement finalized and a cutting zone is created for the robot
  • The system’s algorithm is wholly based on the preoperative planning and templating
  • While manipulating the burr, for resection of bone, the surgeon can view the 3D model on the monitor
  • Resection of bone is confined to the predefined cutting space on the forced controlled tip of the rotating burr
  • In any case if the surgeons goes beyond the cutting zone, the safety system automatically stops the burr

Robot assisted Unicondylar Knee Replacement(UKR) Systems

  • In 2010 Roche et al..described the use in 43 cases, where he measured 344 radiological parameters. There were only 3 abnormal parameters.
  • Roche proposed advantages like smaller incisions, short recovery and rehabilitation time, hence can be performed as an out-patient procedure

 Acrobot Systems

  • Cobb et al..used Acrobot systems (UK), and compared Robot assisted UKR versus Conventional UKR
  • They found that in patients who underwent Robot assisted UKR, there were better AKS scores(American Knee Society) , increased operating time,  tibiofemoral alignment and implant positioning within 2 degree of preoperative plan in all patients
  • In the conventional UKR group, only 40% of patients achieved tibiofemoral alignment within 2 degree of the preplanned position


  • Autonomous robotic systems complete the surgery without assistance of a surgeon
  • Though the robot operated independently, the surgeon is in control of an emergency shut-off switched
  • ROBODOC was such a system that was developed in the 1980s and was introduced into surgical practice in 1992(Curexo Technology, California)
  • ROBODOC was very popular in Germany with many trials conducted in THA demonstrating good component positioning, but soon fell into disrepute amidst safety concerns
  • A hybrid system has been developed in Carnegie Mellon University, Pittsburgh, Pennsylvania
  • In this system the Mini Bone Attached Robotic System(MBARS), mounts on to the femur and completes the bony resection in TKR
  • Praxiteles (Praxim, France) is another similar robotic system developed in France.

ROBOTIC Surgery: Pitfalls

  • The setup required for performing robotic surgery is expensive. Also contant software upgradations and calibrations will add to the cost. It may still be cost efficient in high volume institutions
  • Though proposed advantages like short hospital stay, less blood loss, greater accuracy are present, long term outcomes studies are necessary to demonstrate superiority and cost efficiency of Robotic surgery in routine practice
  • Robots, can identify bony anatomy well. But the nuances of soft tissue dissection are not still identified by a robot.
  • The autonomous robotic system, the ROBODOC fell into disrepute because it was associated with increased risk of infection, blood loss, neurological damage and perhaps an increased rate of litigation
  • Currently, high quality level I studies including Randomised Control Trials are not available for the use of Robotic Surgery in Clinical Practice.

PASSIVE SURGERY SYSTEMS (computer navigation)

These systems are used during surgery for

1) assessing joint irregularities and joint biomechanics;

2) to make recommendations on how to continue with the procedure,(eg.,ligament balancing)

3) to monitor the accuracy of the bone cuts.


  • The navigation systems have several cameras to track surgical instrumentation, boney geometry and alignment
  • The cameras communicate with instruments and boney landmarks through light-emitting diodes(LEDs)
  • The surgeon always has the option to override the information given by the computer
  • The surgeon is not limited to “predefined cutting zones”, as in robotic surgery
  • It is useful for surgeons in the early learning curve
  • Many authors have reported superior alignment of the femoral and tibial components, tibial slope and the mechanical axis  using passive surgery systems
  • Accuracy in restoring rotational alignment has been questioned while using computer navigation in TKA


  1. Banks SA. Haptic robotics enable a systems approach to design of a minimally invasive modular knee arthroplasty. Am J Orthop (Belle Mead NJ) 2009;38(Suppl):23–27.
  2. Roche MW, Augustin D, Conditt MA. Accuracy of robotically assisted UKA. J Bone Joint Surg [Br] 2010;92-B(Suppl):127.
  3. Bargar WL. Robots in orthopaedic surgery: past, present, and future. Clin Orthop 2007;463:31–36
  4. Wolf A, Jaramaz B, Lisien B, DiGioia AM. MBARS: mini bone-attached robotic system for joint arthroplasty. Int J Med Robot 2005;1:101–121.
  5. Plaskos C, Cinquin P, Lavallee S, Hodgson AJ. Praxiteles: a miniature bonemounted robot for minimal access total knee arthroplasty. Int J Med Robot 2005;1:67–79.
  6. Park SE, Lee CT. Comparison of robotic-assisted and conventional manual implantation of a primary total knee arthroplasty. J Arthroplasty 2007;22:1054–1059.
  7. Jenny JY, Clemens U, Kohler S, et al. Consistency of implantation of a total knee arthroplasty with a non-image-based navigation system: a case-control study of 235 cases compared with 235 conventionally implanted prostheses. J Arthroplasty 2005;20:832–839.
  8. Cobb J, Henckel J, Gomes P, et al. Hands-on robotic unicompartmental knee replacement: a prospective, randomised controlled study of the acrobot system. J Bone Joint Surg [Br] 2006;88-B:188–197.

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