A Comparative Study Between Patient-Specific Instrumentation and Conventional Technique in TKA

Patient-specific instrumentation (PSI) was developed to improve the accuracy of component positioning through custom cutting blocks constructed based on preoperative 3-dimensional imaging in total knee arthroplasty (TKA). The purpose of this study was to compare the clinical and radiological outcomes between the patients who underwent PSI-assisted TKA or conventional TKA. Sixty-four patients (64 knees) underwent TKA by a single surgeon: 32 patients (32 knees) underwent TKA with PSI, 32 patients (32 knees) underwent TKA with conventional instrumentation. The mean age of the patients was 67.6 years, and the mean follow-up duration is 26.2 months. Patients were evaluated preoperatively and after surgery. The current authors evaluated clinical outcomes including knee range of motion, Hospital for Special Survey scale, Western Ontario and McMaster University Osteoarthritis Index, and Knee Society pain and function scores. The current authors also compared radiological outcomes including mechanical axis and coronal and sagittal alignment. The current authors found no significant differences in any clinical outcomes between the PSI-assisted TKA group and the conventional TKA group. In terms of radiological outcomes, the PSI-assisted TKA group had fewer alignment outliers. The current authors found that PSI-assisted TKA restores limb alignment better than conventional TKA, but PSI does not confer a substantial advantage in early functional outcomes after TKA. Further follow-up is needed to ascertain the long-term impact of these findings. [Orthopedics. 2016; 39(3):S83-S87.].