Effectiveness of Periarticular Pin Tracker Placement Through a Single Main Incision in Robotic-Assisted Total Knee Arthroplasty: Technical Note and Short-Term Results

Abstract

Background and Objectives: Robotic-assisted total knee arthroplasty (TKA) is gaining popularity worldwide, leading to a potential increase in the number of pin tracker-related complications. This study determined the effectiveness of periarticular pin tracker placement in the distal femur and proximal tibia through a single main incision during robotic-assisted TKA over a minimum follow-up period of 6 months. Materials and Methods: A consecutive series of 149 TKAs was performed in 108 patients using the triathlon posterior-stabilized total knee prosthesis with a robotic-assisted system at our hospital from December 2023 to February 2024. Clinical outcomes and complications associated with pin tracker sites, including pin-site infection, neurovascular injury, hematoma, soft-tissue morbidity, and pin-site fracture, were assessed. Results: The mean Knee Society knee score improved from 42.5 preoperatively to 76.3 points at the final follow-up, whereas the mean Knee Society function score improved from 43.1 preoperatively to 78.1 points at the final follow-up (both p < 0.05). No patient experienced any minor or major complications related to the use of pin trackers in the distal femur and proximal tibia. Conclusions: This periarticular technique that uses pin trackers in the distal femur and proximal tibia through a single main incision could be a useful option for orthopedic surgeons while performing robotic-assisted TKA.

Keywords: complications; pin tracker; robotic-assisted system; total knee arthroplasty.

Figure 1

Anterior view of the femoral and tibial pins and trackers through a single incision.

Figure 2

Positioning of the knee joint at approximately 130° of flexion. (a) Tibial checkpoint (arrow) was placed next to the medial aspect of the patellar ligament. (b) Femoral checkpoint (arrow) was placed around the medial epicondyle (star).

Figure 3

(a) Tibial first insertion point (thick arrow) was located 3 cm inferior to the anteromedial joint line (thin arrow) and 1.5 cm medial to the patellar ligament. (b) First tibial pin was directed 45° to the posterolateral aspect of the tibia in the coronal plane and horizontally in the axial plane.

Figure 4

(a) Tibial second insertion point (arrow) was located 2.0 cm medial to the patellar ligament. The second tibial pin was inserted in the same direction as the first pin. (b) After removing the pin guide, the pelvic tracker used in robotic hip surgery was fitted.

Figure 5

Medial view of the femoral pins and tracker.

Figure 6

(a) If the original tibial tracker is positioned on the medial proximal tibia, surgery is impossible due to impingement on the robotic saw. (b) Unlike the original tibial tracker, the pelvic tracker did not impinge on the robotic saw because it was displaced distally from the pins.