Usefulness of robot-assisted total knee arthroplasty in patients with retained hardware: A report of two cases

Abstract

Total knee arthroplasty (TKA) is technically demanding in patients with pre-existing hardware around the knee. We report two cases of knee osteoarthritis in patients with retained hardware who would have difficulty undergoing conventional TKA. Robot-assisted TKA can be a useful treatment for knee osteoarthritis in patients with retained hardware.

Keywords: osteoarthritis; retained hardware; robot‐assisted surgery; total knee arthroplasty.

FIGURE 1

(A and B). Bilateral Kellgren‐Lawrence (K‐L) grade IV osteoarthritic changes in an 81‐year‐old woman who failed to respond to conservative management. Three years prior, she had undergone open reduction and internal fixation with an internal medullary nail for a shaft fracture of the left femur. (C) A preoperative standing anteroposterior (AP) radiograph of the bilateral lower extremities shows a right hip‐knee‐ankle (HKA) angle of 6.2° and a left HKA angle of 11.5°

FIGURE 2

(A and B) An 81‐year‐old woman underwent bilateral robot‐assisted total knee arthroplasty (TKA) without removal of retained hardware. (C) A 4‐week postoperative standing AP radiograph shows a right HKA angle of 2.7° and a left HKA angle of 2.9°

FIGURE 3

(A and B) Bilateral K‐L grade IV osteoarthritic changes in a 69‐year‐old woman. Five years prior, she had undergone bilateral high tibial osteotomy to treat medial osteoarthritis. (C) A preoperative standing AP radiograph shows a right HKA angle of 12.6° and a left HKA angle of 16.5°. (D and E) A preoperative CT scan of the right (D) and left knees (E) shows metal plates covered with bone (yellow arrow)

FIGURE 4

(A and B) A 69‐year‐old woman underwent bilateral robot‐assisted total TKA after removal of proximal screws that interfered with tibial component fixation. (C) A 4‐week postoperative standing AP radiograph shows a right HKA angle of 0.2° and a left HKA angle of −1.9°