Himchan Hospital Announces SCIE-class Paper on Korea's First Mako Robot Hip Artificial Joint Surgery...Present accurate leg length measurement criteria

May 14, 2025

Machorobot artificial joint surgery by medical staff at Himchan Hospital.

The orthopedic surgery team at Himchan Hospital announced on the 14th that it published a research paper on Makorobot hip joint surgery in an SCIE-level international journal for the first time in Korea.

This paper contains the results of a study that presented a new reference point for accurate leg length measurement during hip artificial joint surgery using a macorobot.

The hip joint is the area where the pelvic bone meets the femur, and artificial joint surgery is performed in case of severe arthritis, bloodless necrosis of the femur head, or femur fracture. After hip artificial joint surgery, side effects such as dislocation or difference in leg length after surgery may rarely occur. In particular, if both leg lengths are different after surgery, the stability of the hip joint may be reduced and back pain or walking disorder may be caused. If the stability of the joint is poor, hip collision and dislocation can occur, and the life of the artificial joint can be shortened due to wear and tear due to damage to the joint surface.

To compensate for these problems, robotic surgery machines are also being applied to hip artificial joint surgery. It is increasing the possibility of using robots to insert artificial joints in more accurate positions and reduce errors in leg length to reduce the dislocation rate. This study is evaluated as presenting a new reference point to make leg length measurements more accurate during robotic surgery.

Through this paper, the first author, Lee Dong-nyeong, head of the medical center, and a research team proved the effectiveness of using a Macorobot as an index to evaluate the difference in leg length during hip artificial joint surgery (pre-replacement surgery), not the existing patella as a reference point. In the case of the existing method of holding the lower (lower) of the patella as a reference point, the position of the reference point may fluctuate slightly due to the traction applied to the leg during surgery, and the length of the patella tendon may vary depending on the movement of the knee joint, resulting in errors in the measurement value. These factors can lead to difficulty in precise leg length measurements in millimeters, which can affect patient satisfaction after surgery.

The research team compared a total of 78 patients, including 26 patients with general hip artificial joint surgery and macorobotic hip artificial joint surgery using the lower patella or outer femur as a reference point, and found that robotic surgery using the outer femur as a reference point had the least difference in leg length when comparing X-ray images after surgery.

Lee Dong-nyeong, head of the medical center (Orthopedic Surgeon), said "When performing robotic hip joint artificial joint surgery, it is necessary to accurately identify changes in leg length before and after artificial joint insertion to reduce side effects after surgery. At this time, a measurement instrument (sensor) is attached by holding a reference point to measure the leg length. If the external femur is used as a reference point rather than the lower part of the knee patella, which is susceptible to the patient's obesity and movement, we expect to supplement these points and measure leg length more quickly and accurately,' he said, adding that "We plan to further solidify clinical usefulness through further research on more patients in the future."

In April, the paper titled 「Usefulness of the lateral femoral epithelium as a landmark for evaluation of leg length in robot-assisted total hip arthroplasty」, which contains the results of this study, was published in the Journal of Clinical Medicine, a world-renowned SCIE-class journal.

Meanwhile, Himchan Hospital took the lead in introducing the Makorobot surgical device into domestic medical care in 2020 and performed 11,514 cases, the largest number of surgeries in Korea, until December last year. In particular, the number of surgeries for two years in 2023 and 2024 was the highest in the world, receiving a plaque of appreciation from Makorobot's Korean branch, Korea Striker. Based on various surgical cases, a total of nine international papers related to Makorobot artificial joint surgery have been published so far, and six of them have been adopted in SCIE-level international journals, showing remarkable research results.