The radiological outcomes of patient-specific instrumentation versus conventional total knee arthroplasty

• Published in: Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA Vol. 22; no. 3; pp. 630 - 635
• Main Authors: Chen, Jerry Yongqiang, Yeo, Seng Jin, Yew, Andy Khye Soon, Tay, Darren Keng Jin, Chia, Shi-Lu, Lo, Ngai Nung, Chin, Pak Lin
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-03-2014; Springer Nature B.V
• Subjects: Aged; Ankle; Arthroplasty, Replacement, Knee - methods; Female; Humans; Joint replacement surgery; Knee; Knee Joint - diagnostic imaging; Knee Joint - surgery; Learning curves; Male; Medicine; Medicine & Public Health; Middle Aged; Operative Time; Orthopedics; Osteoarthritis, Knee - diagnostic imaging; Osteoarthritis, Knee - surgery; Patients; Postoperative Period; Prospective Studies; Prostheses; Radiography; Surgeons; Surgery, Computer-Assisted - methods; Surgical techniques; Tibia - diagnostic imaging; Tibia - surgery; Torsion, Mechanical; Transplants & implants; Treatment Outcome; Indiana; United States > US; Singapore; Patient-specific instrumentation; Total knee arthroplasty; Lower limb alignment; Implant placement
• ISSN: 0942-2056; 1433-7347
• DOI: 10.1007/s00167-013-2638-1

Purpose
The aim of this study was to investigate the post-operative radiological outcomes of patient-specific instrumentation (PSI) surgery versus conventional total knee arthroplasty (TKA).
Methods
Sixty patients scheduled for a primary TKA were prospectively divided into PSI or conventional technique. Coronal and sagittal radiographic long limb films were taken post-operatively. The accepted values for normal alignment were 180° ± 3° for hip-knee-ankle angle; 90° ± 3° for coronal femoral component angle or coronal tibia component angle; 0° to 3° flexion for sagittal femoral component angle and 0° to 7° posterior slope for sagittal tibia component angle.
Results
For hip-knee-ankle angle, there were 21 % more outliers in the PSI group compared to the conventional group (
p
 = 0.045). Most of these outliers had valgus deformity in the PSI group and varus deformity in the conventional group (
p
 = 0.045). For implant placement, there was no difference in the proportion of outliers between the two groups. There was also no difference in the duration of surgery.
Conclusions
This study showed that PSI surgery is associated with a larger proportion of outliers for lower limb alignment. PSI surgery as an alternative to conventional TKA is not advisable.
Level of evidence
II.