[Virtual image-guided minimal incision sugary unicondylar knee arthroplasty]

To investigate the curative effect of virtual image-guided minimal incision sugary unicondylar knee arthroplasty (MIS-UKA).

Twenty-six patients of knee osteoarthritis (with 26 knees) received virtual image-guided MIS-UKA and followed up for (8.2 +/- 2.4) months. The incision length, operative time, hemorrhage, and 48 h drainage were calculated. The patients were evaluated by hand injury severity score (HISS) system knee score. X-ray film of the whole lower limb was taken to observe the line of force and range of motion of knee.

MIS-UKA was successfully performed on the 26 knees with the average incision length of 7.4 +/- 0.6 cm, the average operative time of 78 +/- 12 min, the average hemorrhage of 114 +/- 18 ml, and the 48 h drainage of 122 +/- 13 ml. Two weeks after the operation, the average HISS hip score was 98, higher than that before the operation (72), the hip-knee-ankle angle was 0.8 degree +/- 0.6 degree, larger than that before the operation (7.6 degrees +/- 1.8 degrees), the flexion contraction angle was 1.8 degrees +/- 1.1 degrees, smaller than that before the operation (6.8 degrees +/- 1.6 degrees), and the joint range of motion of knee was 132.6 degrees +/- 3.5 degrees, larger than that before the operation (107.5 degrees +/- 6.2 degrees). No infection, prosthesis cacothesis, and patellofemoral joint pain were found.

The surgical navigation system surmounts the disadvantage of small visual field, observes the line of force of the lower limbs, knee joint rotational apposition, and ligament balance dynamically with digital 3D bone mode, provide geometry and morphology data, and rebuilds knee joint vitodynamically and anatomically, and heightens the accuracy of prostheses replacement, thus having important clinic value in MIS-UKA.