Component position alignment with patient-specific jigs in total knee arthroplasty

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Medical Imaging

Background:

• Improper mechanical alignment and rotational axis are common causes of implant failure in total knee arthroplasty (TKA).
• Conventional and computer-assisted TKA methods have limitations.
• Patient-specific jigs (PSJ) present a potential alternative for TKA component alignment.

Purpose of the Study:

• To evaluate the accuracy and reproducibility of component orientation in TKA using patient-specific jigs (PSJ).
• To compare the efficacy of PSJ with conventional and computer-assisted surgery in TKA.

Main Methods:

• A prospective case series of 261 patients undergoing TKA for osteoarthritis was conducted.
• Preoperative MRI and specialized software were used to generate patient-specific femoral and tibial jigs.
• Postoperative computed tomography (CT) was utilized to measure component alignment.

Main Results:

• 96.2% of patients achieved target femoral rotational alignment.
• 92.7% of tibial coronal alignment was within ±3 degrees of the tibial medullary axis.
• 76.6% of posterior tibial slopes and 81.2% of overall mechanical axes were within acceptable ranges.

Conclusions:

• Patient-specific jigs demonstrate good accuracy for component alignment in TKA compared to conventional methods.
• Improvements in tibial alignment guides are needed to further enhance PSJ accuracy and reproducibility.