Distal Femoral Tracker Pin Placement Prevents Delayed Pin Tract-Induced Fracture in Robotic-Assisted Total Knee Arthroplasty: Results of Minimum 1-Year Follow-Up

Abstract

The purpose of this study was to determine the outcomes of the placement of a pin tracker in the distal femur in robotic-assisted total knee arthroplasty (TKA) over a minimum follow-up period of 1 year. A consecutive series of 81 TKAs were performed in 59 patients using a robotic-assisted system (Mako) at our hospital. The mean follow-up period was 1.1 years (range, 1–1.2 years). No periprosthetic fracture at a pin tracker site was reported at a minimum of 1 year of follow-up. No patients reported minor or major complications associated with the distal femoral pins. In addition, unicortical pin-site drilling marks in all patients disappeared on one-postoperative-year follow-up radiographs. Our technique, which used unicortical pin placement in the distal femur in robotic-assisted TKA, demonstrated that it was a safe and reliable method at a minimum follow-up period of 1 year. The level of evidence is IV.

Robotic Total Knee Arthroplasty: An Update

“…Among them, femoral and tibial tracker pin positioning used for calibration are at risk of resulting in iatrogenic fractures and may be responsible for local complications, such as pin-tract infections [ 69 ]. Conversely, accurate distal femoral pin positioning in the medial sagittal plane does not result in iatrogenic fractures [ 70 ]. On the other hand, other authors reported in a retrospective study that R-TKA was associated with a decreased complication rate, including deep vein thrombosis and pulmonary embolism, anemia, and decreased opioid consumption, compared to T-TKA [ 71 ].…”

Where are We Now and What are We Hoping to Achieve with Robotic Total Knee Arthroplasty? A Critical Analysis of the Current Knowledge and Future Perspectives

“…Despite being unusual, several complications have been associated with robotic-assisted technique including superficial pin site infections, pin-track osteomyelitis, pin-track site stress fracture, vascular injury, hematoma, myositis ossificans, and even mechanical failures related to pin-use. In order to reduce the risk of fractures at pin sites, Baek et al 44 reported success on using unicortical pins in MAKO assisted TKA with 0 cases (out of 81 TKAs) of pin-related complications at 1-year follow-up. Thomas et al 45 recently reported that the overall pin site complication rate was 1.4% over 7336 knees (range, 0.3% to 8%), with intraoperative and postoperative complications occurring at 1.4% and 1.1%, respectively.…”