Learning that a robotic arm will assist with your hip replacement naturally raises questions. Is a machine performing the surgery? What role does your surgeon play? These are common concerns, and the answers are reassuring. This guide walks you through each stage of a Mako procedure, from your first CT scan to your final follow-up, so you know exactly what to expect.
Why Mako Is Called Surgeon Guided Technology
Mako is a robotic arm system from Stryker that pairs 3D CT-based planning with AccuStop haptic technology.1 Surgical robots generally fall into two groups. Autonomous systems carry out steps on their own, while haptic systems are guided by the surgeon's hand.4 Mako belongs to the second group. Your surgeon holds and moves the arm, and the arm responds with resistance when a tool nears the edge of your plan. You can read more about Mako robotic hip replacement and how it fits within total hip replacement.
Mako can be used with more than one surgical approach, including the posterior approach and the direct anterior approach (DAA), where your surgeon reaches the hip joint from the front. Your surgeon will recommend the approach that suits your anatomy, their experience, and your needs.
Stage 1: Imaging That Maps Your Unique Hip
Your journey starts with a CT scan. The software uses it to build a 3D model of your pelvis and upper thighbone.2 In one published posterior approach technique, the team also takes side view spine X-rays while you sit and stand, because the way your pelvis tilts can affect how stable a new hip feels in daily life.3 This is important whether your pain comes from hip osteoarthritis, avascular necrosis, or another condition.
Stage 2: Building a Plan Around Your Anatomy and Movement
With your 3D model on screen, your surgeon chooses implant sizes and positions before surgery begins. The planning view shows details such as leg length and combined offset, which describe how your new joint will sit compared with your natural hip.2 The software can also factor in how your spine and pelvis move between sitting and standing.2,3 For people with unusual anatomy, such as hip dysplasia or a complex primary hip replacement, this careful preparation can be especially useful.
Stage 3: Registration Links Your Plan to the Operating Room
Once surgery begins, the system must learn exactly where your bones are. In the posterior technique described in the literature, small pins are placed in the pelvis to hold a tracking array, and a small marker is placed on the thighbone so initial leg length and offset can be recorded.3 Your surgeon then performs bone registration, which links the 3D model to your real anatomy.3 This setup adds some time, and a review noted that registration and calibration likely contributed to slightly longer average operating times.6
The details of this setup, such as where tracking markers and pins are placed, can differ between the posterior approach and the direct anterior approach (DAA). Your surgeon will explain what to expect for your procedure.
Stage 4: Preparing the Socket Within Haptic Boundaries
Next comes the hip socket. Your surgeon guides the robotic arm while it holds the reamer, and a stereotactic boundary helps keep the reaming and cup insertion aligned with your plan.2 The system also offers a single ream option, which may reduce the need for several sequential reams.2 Your surgeon then impacts the cup into the planned position.3 The arm does not push forward on its own. It simply resists movement outside the planned zone.
Stage 5: Positioning, Testing, and Fine Tuning
After the socket, your surgeon prepares the thighbone, places trial components, and moves your hip to test stability. Leg length and offset are rechecked through the robotic system before the final implants go in.3 Studies suggest this approach can help with implant positioning. One study found more cups within a target safe zone with robotic assistance, though its authors stressed that long term clinical benefit was not proven.5 A 2025 review reported similar positioning findings with low complication rates in both groups.6
Who Makes the Decisions During Your Surgery
Throughout every stage, your surgeon is in control. This includes choosing the surgical approach. Whether you have a posterior approach, a direct anterior approach (DAA), or another technique, the same principle applies: the surgeon leads and the robotic arm supports. Stryker describes Mako as designed to support surgeon control and confidence, not to replace surgical judgment.1 Technology cannot remove surgical risk, and no method guarantees a specific result. Your health, bone quality, and commitment to rehab all shape recovery. If your knee is the concern instead, you can explore robotic assisted knee replacement and robotic assisted partial knee surgery, or compare options on the robotic assisted hip replacement page.
Frequently Asked Questions
Is the robot doing the surgery during a Mako hip replacement?
No, the surgeon performs the operation and guides the robotic arm by hand. Mako is considered a haptic, surgeon guided system rather than an autonomous robot.1,4
Can Mako be used with the direct anterior approach (DAA)?
Yes. Mako is a planning and guidance system, not a specific incision. Surgeons use it with different approaches, including the direct anterior approach (DAA) and the posterior approach. Which one is right for you depends on your anatomy, your condition, and your surgeon’s expertise.
Why do I need a CT scan before Mako surgery?
The CT scan creates a 3D model of the hip that the surgeon uses to plan implant size and position. This plan is then followed during the procedure.2,3
What does registration mean in robotic hip replacement?
Registration is the step that matches the patient's real bone to the 3D model on screen. It uses tracking markers and points on the bone so the system knows where the anatomy is.3
Does Mako make hip replacement more accurate?
Research suggests it can improve how closely implants match the plan. Studies show more cups placed within target zones, though long term benefits are still being studied.5,6
Your Next Step Toward a More Comfortable Hip
Knowing what happens at each stage can make surgery feel far less mysterious. If hip pain is holding you back, you can request an appointment online or find the nearest of the practice locations to discuss whether robotic arm assisted surgery, and which approach (posterior, direct anterior, or other), may be a good fit for you.
Reference Links:
- https://www.stryker.com/us/en/joint-replacement/systems/Mako_SmartRobotics_Overview.html
- Mako Total Hip Clinical Summary
- Schwabe MT, Gibian JT, Bartosiak KA, et al. Robotic assisted total hip arthroplasty through the posterior approach. JBJS Essential Surgical Techniques.
- Lang JE, Mannava S, Floyd AJ, et al. Robotic systems in orthopaedic surgery. Journal of Bone and Joint Surgery British Volume.
- Domb BG, El Bitar YF, Sadik AY, et al. Comparison of robotic assisted and conventional acetabular cup placement in THA: a matched pair controlled study. Clinical Orthopaedics and Related Research.
- Loke RWK, Lim YH, Chan YK, et al. MAKO robotic assisted compared to conventional total hip arthroplasty for hip osteoarthritis: a systematic review and meta analysis - Journal of Orthopaedic Surgery and Research
AUTHOR: Dr. Nick R. Johnson, MD – Fellowship-Trained Orthopedic Surgeon
Dr. Nick R. Johnson, MD, is a fellowship-trained orthopedic surgeon specializing in hip and knee reconstruction, including complex primary and revision joint replacement. A native of Oklahoma, Dr. Johnson combines advanced surgical expertise with a compassionate, patient-centered approach to care. With specialized training in adult reconstruction and the management of periprosthetic joint infections, he is dedicated to delivering personalized treatment plans that restore mobility, relieve pain, and improve long-term outcomes.
Credentials & Recognition
Dr. Johnson earned his Bachelor of Science in Biomedical Studies and Doctor of Medicine from the University of Oklahoma. During medical school, he was selected for a prestigious Orthopedic Research Fellowship at the Mayo Clinic, where he trained under leading experts in the field. He completed his orthopedic surgery residency at Carolinas Medical Center in Charlotte, North Carolina, followed by a fellowship in Adult Reconstruction at OrthoCarolina. His advanced training focused on complex hip and knee replacement, revision surgery, and infection management.
Dr. Johnson is a member of the American Academy of Orthopaedic Surgeons (AAOS) and the American Association of Hip and Knee Surgeons (AAHKS), as well as Alpha Omega Alpha (AOA), a national medical honor society recognizing excellence in scholarship, leadership, and professionalism. His academic and clinical achievements reflect a strong commitment to advancing orthopedic care and maintaining the highest standards in patient outcomes.
Clinical Expertise
Dr. Johnson specializes in primary and revision hip and knee replacement, complex joint reconstruction, and the treatment of periprosthetic joint infections. He is particularly skilled in managing challenging cases and developing individualized surgical strategies tailored to each patient’s unique anatomy and needs.
Medical Disclaimer: This information is for educational purposes only and does not constitute medical advice. For diagnosis and treatment recommendations, please consult with Dr. Johnson.