Study Summary

158 obese patients undergoing primary total knee arthroplasty (TKA) were randomized to receive patient-specific instrumentation (PSI) or standard of care (SOC) conventional instrumentation. The outcomes of interest were radiographic alignment parameters, including the medial proximal tibial angle (MPTA), anatomic femoral-tibial angle (FTA), and lateral distal femoral angle (LDFA). Secondary outcomes included patient-reported outcome measures such as the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee Society Score (KSS), and 12-Item Short Form Survey (SF-12), surgical characteristics, complications, and revision rates. Outcomes were assessed through a minimum follow-up of 5 years. Overall, the results of the study revealed no clinically meaningful differences in radiographic alignment, functional outcomes, complications, or revision rates between PSI and SOC. These findings suggest that PSI does not provide a significant long-term clinical advantage over conventional instrumentation in obese patients undergoing primary TKA.