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What is ROSA Partial Knee Replacement?

Picture of ROSA Partial Knee Replacement

The term ROSA refers to Robotic Surgical Assistant. ROSA partial knee replacement surgery is a robotic-assisted surgical procedure in which only the damaged portion of the knee joint is removed and replaced with an implant or prostheses.

The knee can be divided into three compartments: patellofemoral, the compartment in front of the knee between the kneecap and thighbone, medial compartment, on the inside portion of the knee, and lateral compartment which is the area on the outside portion of the knee joint. In total knee replacement, all worn out or damaged surfaces of the knee joint are removed and replaced with new artificial parts. Partial knee replacement is a surgical option if the damage is confined to a single compartment of your knee.

ROSA - developed by Zimmer Biomet - enables surgeons to carry out partial knee replacement surgery with greater precision and a higher standard of care. The ROSA robotic knee system comprises state-of-the art features, including real-time information to assist surgeons with bone resections, assessment of soft tissue condition, and precise placement of the implant intraoperatively based on the patient’s unique knee anatomy. It utilizes a camera and optical trackers that are secured to the patient's leg to know the exact position of the knee during surgery.

Anatomy of the Knee

The knee is made up of the femur (thighbone), tibia (shinbone), and patella (kneecap). The lower end of the femur meets the upper end of the tibia at the knee joint. A small disc of bone called the patella rests on a groove on the front side of the femoral end. The fibula, another bone of the lower leg, forms a joint with the shinbone. The bones are held together by protective tissues, ligaments, tendons, and muscles. Synovial fluid within the joint aids in the smooth movement of the bones over one another. The meniscus, a soft crescent-shaped area of cartilage between the femur and tibia, serves as a cushion and helps absorb shock during motion.

Indications for ROSA Partial Knee Replacement

The ROSA partial knee replacement surgery is indicated for patients with early-to-mid-stage osteoarthritis of the knee exhibiting symptoms such as pain, swelling, locking, and stiffness, that are not responsive to conservative treatment. Osteoarthritis is a degenerative joint disease that causes breakdown and eventual loss of cartilage in the knee joint making the bones rub against each other leading to painful movement.

Preparation for ROSA Partial Knee Replacement

The preoperative preparation is similar to most partial knee replacement procedures. But contrary to traditional partial knee replacement techniques, the ROSA Knee System utilizes a series of X-rays to generate 3D images of an individual’s unique knee anatomy. This 3D image enables the surgeon to design a personalized plan based on the specifics of an individual’s knee anatomy prior to performing partial knee replacement surgery.

In addition, preparation for ROSA partial knee replacement procedure may involve the following steps:

  • A review of your medical history and a physical examination are performed by your doctor to check for any medical issues that need to be addressed prior to surgery.
  • Depending on your medical history, social history, and age, you may need to obtain dental clearance and undergo tests such as blood work 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, vitamins, 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, aspirin, 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 weeks after as it can hinder the healing process.
  • You should not consume any solids or liquids at least 8 hours prior to surgery.
  • You need to arrange for someone to drive you home after surgery.
  • Signed informed consent will be obtained from you after the pros and cons of the surgery have been explained in detail.

Procedure for ROSA Partial Knee Replacement

In general, the partial knee replacement procedure using the ROSA knee system is similar to that of a traditional partial knee replacement, but performed with the help of a robotic assistant. The robotic system does not perform the procedure on its own. The surgery is performed entirely by your surgeon by prompting the robotic hands as per the personalized plan developed by your surgeon. The ROSA knee system is only an additional tool to guide your surgeon to ensure greater accuracy in the placement of the knee implants. It cannot replace the skills of your experienced surgeon.

The ROSA partial knee replacement surgery is usually done under general anesthesia with you appropriately placed on the operating table. An incision is made over the affected knee to expose the knee joint. The ROSA knee system functions like a high-tech GPS system utilizing optical trackers and a mini-camera attached to your leg to determine the damaged areas of the joint that need to be removed for the precise placement of the knee implant. The robotic system makes adjustments even with the slightest movement of your legs ensuring the surgical plan designed by your surgeon is carried out without any changes and with a high degree of precision. In partial knee resurfacing, only the diseased portion of your knee is removed, preserving the surrounding healthy bone and tissue. An implant is then secured over the prepared portion of your knee joint. Throughout the procedure, your surgeon is provided with real-time data by the ROSA Knee System, which enhances your surgeon’s skill enabling accurate placement of the knee implant. With the new implant in place, the knee is taken through a range of movements. The muscles are then approximated, the incision closed, and covered with a sterile dressing.

Postoperative Care and Recovery

Recovery is fairly quick as it is a minimally invasive procedure. In general, postoperative care and recovery after ROSA partial knee replacement procedure 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 as you recover.
  • Most patients may need to stay in the hospital for 2 to 3 days before being discharged home.
  • You may notice pain, swelling, and discomfort in the knee 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.
  • Eating a healthy diet rich in vitamin D and iron is strongly advised to promote healing and a faster recovery.
  • 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 protocol will be designed to help strengthen knee muscles and optimize knee function once you are off crutches.
  • Most patients are able to resume their normal activities in 3 to 4 weeks after surgery; however, returning to sports or high-intensity activities may take at least 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.

Benefits of ROSA Partial Knee Replacement

Being a minimally invasive procedure, the ROSA partial knee replacement surgery offers the following benefits:

  • Smaller incisions
  • Shorter hospital stay
  • Less postoperative pain
  • Minimal muscle trauma and reduced scarring
  • Precise placement of the implant
  • Increased longevity of the implant
  • Quicker return to normal activities
  • Lower risk of postoperative complications
  • Better range of motion
  • Increased knee stability

Risks and Complications

ROSA partial knee replacement is a relatively safe procedure; however, as with any surgery, there are risks and complications that can occur, such as:

  • Pain
  • Bleeding
  • Infection
  • Stiffness or instability in the knee
  • Blood clots or deep vein thrombosis (DVT)
  • Allergic/anesthetic reactions
  • Damage to adjacent soft-tissue structures
  • Implant fracture/failure
  • Dislocation (rarely)

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Useful Links

  • Picture of American Academy of Orthopaedic Surgeons
  • Picture of American College of Sports Medicine
  • Picture of American Orthopaedic Society for Sports Medicine
  • Picture of Arthroscopy Association of North America