Abstract:

BACKGROUND: With the development of precision medicine, knee replacement under navigation has been paid more and more attention. Precision medicine allows for more accurate implant placement and better limb alignment. However, precision medicine can also make surgery much longer.

OBJECTIVE: To evaluate the application of Aesculap Ortho-Pilot non-image-dependent wireless navigation in total knee arthroplasty.

METHODS: Data of 42 patients with unilateral knee osteoarthritis admitted to the First Affiliated Hospital of Anhui Medical University from April to November 2017 were retrospectively collected. First total knee arthroplasty was conducted by the same surgeon. According to surgical methods, the patients were divided into two groups: the navigation group (n=21) received a total knee arthroplasty under the assistance of Ortho-Pilot non-image-dependent wireless navigation, and the non-navigation group (n=21) received a regular total knee arthroplasty. Operation time and drainage volume were recorded in both groups. X-ray film of weight bearing was taken 12 months after operation. Mechanical axis of the lower extremity, the mechanical proximal medial proximal angle of the mechanical shaft of the tibia, the distal lateral angle of the femoral mechanical axis, sagittal tibial component angle and the number of alignment deviation of the lower extremity (>3°) were compared between the two groups. Knee range of motion and Hospital for Special Surgery knee score were evaluated. This study was approved by the Ethics Committee of First Affiliated Hospital of Anhui Medical University.

RESULTS AND CONCLUSION: (1) Operation time was longer in the navigation group than in the non-navigation group (P < 0.05). Postoperative drainage was less in the navigation group than in the non-navigation group (P < 0.05). (2) At postoperative 12 months, the variables of mechanical axis of the lower extremity, lateral angle of the distal end of the mechanical axis of the femur, and angular separation of the component of the sagittal tibia were smaller in the navigation group than in the non-navigation group (P < 0.05). There was no significant difference in the quantity of lower limb alignment > 3° and the variables of medial angular separation of proximal end of the mechanical axis of the tibia between the two groups (P > 0.05). (3) At postoperative 12 months, the range of motion was larger in the navigation group than in the non-navigation group (P < 0.05). There was no significant difference in Hospital for Special Surgery knee score between the two groups (P > 0.05). (4) Results suggested that total knee arthroplasty assisted by computer navigation can improve the accuracy of lower limb alignment, accuracy of prosthesis placement and knee range of motion. However, the operation time was improved, so the advantages and disadvantages should be considered comprehensively.

Key words: knee arthroplasty, navigation, knee, computer-assisted, lower limb alignment, arthroplasty, knee motion range, tissue engineering, alignment error