What is Augmented Reality Navigation Total Hip Replacement?
Augmented reality navigation total hip replacement is an innovative, FDA-approved total hip arthroplasty (replacement) system. It is a head-mounted augmented reality (AR) platform in which the surgeon can view 3D models of the patient’s unique anatomy, implants, and surgical instruments inside the body in real-time (instantaneously) during the surgery.
In layman’s terms, the augmented reality (AR)-guided system gives your surgeon “x-ray vision” into the body and improves surgical efficiency and accuracy in total hip replacement. Projecting the critical bone, implant, and instrument models inside the patient’s body effectively provides the surgeon with “x-ray vision” to view beyond what can be viewed through the incision and allows the surgeon to confirm the exact achievement of the objectives of surgery in a smooth, intuitive way.
Hip arthroplasty or hip replacement surgery is a procedure in which the worn-out or damaged parts of the hip joint are removed and replaced with artificial hip components called prostheses or implants made of metal, ceramic, or plastic.
Anatomy of the Hip
The hip joint is one of the body's largest weight-bearing joints and is the point where the thighbone (femur) and pelvis (acetabulum) join. It is a ball-and-socket joint in which the head of the femur forms the ball, and the pelvic acetabulum forms the socket. The joint surface is covered by smooth articular cartilage that cushions and enables frictionless movement of the joint. The bones are held together by bands of tissue called ligaments that provide stability to the joint.
Indications for Augmented Reality Navigation Total Hip Replacement
Augmented reality navigation total hip replacement is usually indicated for individuals with osteoarthritis of the hip joint that is not responsive to conservative treatment. Osteoarthritis is a degenerative joint disease that causes breakdown and eventual loss of cartilage in the joint, causing a painful rubbing of bone surfaces with movement. Other hip conditions that your surgeon may recommend an augmented reality navigation system for hip arthroplasty include severe hip joint fracture or trauma and failed/revision hip replacement.
How Does Augmented Reality Navigation Total Hip Replacement Work?
During standard hip arthroplasty surgery, surgeons use 2D X-rays of a patient’s anatomy to plan the procedure. AR-guided hip arthroplasty relies instead on CT scans obtained before surgery. The 3-dimensional nature of a CT scan provides more details about a patient’s anatomy than X-rays by themselves. It also allows a computer model of the femur and pelvis to be generated. This model is utilized to create a surgical plan that specifies the position, orientation, and size of the hip arthroplasty components. The computer model and plan are loaded into the AR headset, enabling the surgeon to visualize them directly while doing the surgery.
During the surgery, the surgeon temporarily installs a small tracking device on the patient’s pelvic bone. When the AR lenses pair with the tracker, the patient’s anatomical information is projected inside the body. With this, the surgeon can see the patient's unique hip anatomy to accurately place the implant. As opposed to robotic and traditional navigation systems, this AR-based surgical platform does not require large, heavy external workstations, screens, or cameras. The small footprint of the AR system means it can be effortlessly placed across operating rooms, promoting greater surgical team efficiency and cost savings.
Preparation for Augmented Reality Navigation Total Hip Replacement
The preoperative preparation is similar to most hip joint replacement procedures. But contrary to traditional techniques, augmented reality navigation hip replacement involves careful planning and utilizes a series of CT scans to generate 3D images of an individual’s unique hip anatomy. These images enable the surgeon to design a personalized plan tailored to an individual and help to determine the precise implant size, restoration of femoral offset, level of the neck cut, head size, and center of rotation of the new hip prior to performing the surgery.
In addition, preparation for the augmented reality navigation total hip replacement may involve the following steps:
- A review of your medical history and a physical examination by your doctor to check for any medical issues that need to be addressed prior to surgery.
- Diagnostic tests such as blood work and imaging to help detect any abnormalities that could compromise the safety of the procedure.
- You will be asked if you have allergies to medications, anesthesia, or latex.
- You should inform your doctor of any medications or supplements that you are taking or any conditions you have such as heart or lung disease.
- You may be asked to avoid medications such as blood thinners or anti-inflammatories for a specific period prior to surgery.
- You should refrain from alcohol or tobacco at least a few days prior to the surgery and several days after as they can hinder the healing process.
- You should not consume solids or liquids at least 8 hours prior to surgery.
- You should arrange for someone to drive you home after surgery.
- A signed informed consent will be obtained from you after the pros and cons of the surgery have been explained.
Procedure for Augmented Reality Navigation Total Hip Replacement
Augmented reality navigation total hip replacement surgery is performed under general anesthesia with you appropriately positioned on the operating table. A surgical cut is made over the hip to expose the hip joint, and the femur is dislocated from the acetabulum. The surface of the socket is cleaned and the damaged or arthritic bone is removed using a reamer. Augmented reality navigation software provides the surgeon with real-time 3-D images of the mapped patient’s hip joint and the surgical instruments during surgery. The data for the images is provided by the tracking device fixed to the bones of the joint and the surgical instruments. When the AR lenses pair with the tracker, the patient’s anatomical information is projected inside the body. The surgeon analyzes the patient's unique hip anatomy to precisely resurface and cut the bones of the hip joint and fix the implant accurately according to the pre-operative surgical plan. Once the surgery is completed, the incision is closed with sutures and covered with a sterile dressing.
Postoperative Care and Recovery
In general, postoperative care and recovery after an augmented reality navigation hip replacement surgery involve the following:
- You will be transferred to the recovery area where your nurse will closely observe you for any allergic/anesthetic reactions and monitor your vital signs.
- Most patients may need to stay in the hospital for a day or two before discharge to home.
- You may experience pain, swelling, and discomfort in the hip area. Pain and anti-inflammatory medications are provided as needed for comfort.
- Antibiotics are also prescribed to address the risk of surgery-related infection.
- You will be placed on assistive devices such as crutches with instructions on restricted weight-bearing for a specified period of time. You are encouraged to walk with assistance as frequently as possible to prevent blood clots.
- Instructions on surgical site care and bathing will be provided to keep the wound clean and dry.
- Refrain from strenuous activities for the first few months and lifting heavy weights for at least 6 months. A gradual increase in activities over a period of time is recommended.
- An individualized physical therapy regimen will be designed to help strengthen hip muscles and optimize hip function once you are off crutches.
- Most patients are able to resume their normal activities in 3 to 4 weeks after surgery; however, a return to sports or high-intensity activities may take 6 months or longer.
- You should refrain from driving until you are fully fit and receive your doctor’s consent.
- A periodic follow-up appointment will be scheduled to monitor your progress.
Risks and Complications
Augmented reality navigation total hip replacement surgery is a relatively safe procedure; however, as with any surgery, there are risks and complications that can occur, such as:
- Damage to surrounding soft tissues
- Allergic/anesthetic reactions
- Blood clots or deep vein thrombosis (DVT)
- Leg-length inequality