Abstract
Objective
Patient-specific instrumentation (PSI) is a novel technique in total knee arthroplasty (TKA) which potentially permits more accurate alignment of the components; however, there is no consensus in literature regarding the accuracy and reliability of PSI as many studies have shown controversial and inconsistent results of various PSI systems. A 24-month follow-up study was carried out to compare perioperative clinical outcomes, radiological limb alignment and component positioning, as well as functional outcomes following TKA between PSI and conventional instrumentation (CI).
Methods
During September 2011 and August 2012, 90 consecutive patients were scheduled to undergo unilateral TKA with either PSI or CI. TruMatch® Personalised Solutions was used in this study, and a senior surgeon performed all operations. Patients were clinically assessed before, 6-month and 24-month after surgery.
Results
There were 42 patients who underwent TKA with PSI and 48 patients with CI, with no preoperative demographic and clinical difference. There was significant improvement in maximal extension for both groups at both of the two follow-ups, compared to baseline. While the CI group maintained similar maximal flexion angle, PSI group had significant decrease in maximal flexion angle, at both follow-ups. Overall, there was no significant improvement in the range of motion for both groups over the 24-month period after surgery. At 6 and 24 months postoperatively, there were similarly significant improvements in the mean scores of Oxford Knee Score, Knee Society Score, and Physical Component Sscore of the SF-36 Health Survey for both groups. At 24 months postoperatively, no significant differences were detected between PSI and CI groups in all clinical and functional outcomes. Radiographic results showed that the lower limb mechanical alignment and coronal component positioning were satisfactory and similar between the two groups. There were no differences in operating time, haemoglobin loss, transfusion rate and length of hospitalisation between PSI and CI, perioperatively.
Conclusion
In conclusion, CT-based PSI showed comparable clinical and functional outcomes at 24 months after TKA compared with CI. There were no significant differences between the two types of instruments in achieving alignment restoration, component positioning, and perioperative clinical outcomes in terms of operating time and blood loss.
