MAKOplasty® Total Hip Replacement Enables More Accurate Implant Placement

September 23, 2013

Accuracy is important in any medical procedure, and particularly for joint replacement procedures in which orthopedic implants must be positioned and aligned to move together smoothly. Fortunately, MAKOplasty assists surgeons in achieving greater accuracy in cup placement than traditional manual surgeries, according to a recent study.1

Here’s how it works. During any total hip replacement, the hip’s ball and socket joint is reconstructed. The diseased bone in the pelvic socket, called the acetabulum, and the femoral head are removed. The acetabulum socket is fitted with a cup implant and liner, and the femoral head at the top of the leg bone is replaced with a new head and stem component.

With MAKOplasty, the surgeon-controlled RIO® robotic arm system is used to plan and support the execution of the hip replacement procedure. Before surgery, the implant alignment and positioning are pre-planned based on a CT scan of the patient’s own hip. During surgery, the RIO system provides the surgeon with constant visualization, data and measurements, and the surgeon-controlled robotic arm is used by the surgeon as a smart tool to prepare the pelvic bone.

A clinical study evaluated 77 MAKOplasty hip procedures performed by four different surgeons, and compared their accuracy to data from a study previously published by Massachusetts General Hospital (MGH), which evaluated 1,823 manual hip replacements. Using the same measures of accuracy, almost twice as many of the cup implants were placed in the acceptable safe zone during MAKOplasty procedures as compared with the manual procedures in the MGH study.1, 2

In total hip replacement procedures, poor implant positioning can lead to complications such as impingement, 3, 4 dislocations, 5 and reduced life expectancy of the implants.5, 6

  1. Malchau H, Padgett D, Dounchis J, Illgen R, Marchand R. A multicentric evaluation of acetabular cup positioning in robotic-assisted THA. 42nd Annual Course: Advances in Arthroplasty, October 2-5, 2012, Boston, MA.
  2. Callanan MC, Jarrett B, Bragdon CR, Zurakowski D, Rubash HE, Freiberg AA, Malchau H. The John Charnley Award: Risk factors for cup malpositioning: Quality improvement through a joint registry at a tertiary hospital. Clin Orthop Relat Res. 2011;469(2):319-329.
  3. Kluess D, Martin H, Mittelmeier W, Schmitz KP, Bader R. Influence of femoral head size on impingement, dislocation and stress distribution in total hip replacement. Med Eng Phys. 2007;29:465-71.
  4. Barrack RL, Lavernia C, Ries M, Thornberry R, Tozakoglou E. Virtual reality computer animation of the effect of component position and design on stability after total hip arthroplasty. Orthop Clin North Am. 2001;32:569-77,vii.
  5. Kennedy JG, Rogers WB, Soffe KE, Sullivan RJ, Griffen DG, Sheehan LJ. Effect of acetabular component orientation on recurrent dislocation, pelvic osteolysis, polyethylene wear, and component migration. J. Arthroplasty 1998;13:530-4.
  6. Lewinnek GE, Lewis JL, Tarr R, Compere CL, Zimmerman JR. Dislocations after total hip-replacement arthroplasties. J Bone Joint Surg Am. 1978;60:217-20.