Abstract
Introduction:
UKA allows replacement of a single compartment in patients who have isolated osteoarthritis. However, limited visualization of the surgical site and lack of patient-specific planning provides challenges in ensuring accurate alignment and placement of the prostheses. Robotic technology provides three-dimensional pre-op planning, intra-operative ligament balancing and haptic guidance of bone preparation to mitigate the risks inherent with current manual instrumentation. The aim of this study is to examine the clinical outcomes of a large series of robot-assisted UKA patients.
Methods:
The results of 500 consecutive medial UKAs performed by a single surgeon with the use of a metal backed, cemented prosthesis installed with haptic robotic guidance. The average age of the patients at the time of the index procedure was 71.1 years (range was 40 to 93 years). The average height was 68 inches (range 58″–77″) and the average weight was 192.0 pounds (range 104–339 pounds). There were 309 males and 191 females. The follow-up ranges from 2 weeks to 44 months.
Results:
Surgical Technique: The technique evolved from a one night stay with a tourniquet and a retinacular “T'd” arthrotomy, to a same day surgical procedure with a 2.5–3 inch straight medial arthrotomy that is muscle sparing and tourniquet free allowing all patients to go home the same day with only 2–3 weeks of formal physical therapy post op, less pain medication and a quicker return to their preoperative range of motion.
Clinical Outcomes: All patients increased their ROM by 3–6 months postop. The return to preoperative ROM was seen by 6 weeks with an increased ROM of 5–10 degrees by 1 year. 6 out of 500 patients were converted to a TKA (1.2%). Two for deep infection (one had severe venous stasis disease preop), Three for medial pain despite stable, well aligned implants, and one who developed pain at around 6 weeks that had a large scar band that formed across the top of the tibial poly causing pain with weight bearing.
Conclusion:
This evolved surgical technique along with the use of the sophisticated, patient-specific preoperative and intraoperative planning software combined with haptically guided bone resection allowed most patients, regardless of age, to have their procedure performed as an outpatient. This new technique can provide significant savings to the healthcare system in terms of costs of hospital days, costs of rehabilitation, costs in pain medication and quality of life in the acute post operative period with no increased risk of failure, loosening, malalignment, DVT, PE, infection, return to the OR, readmissions, or manipulation.
