Radiographic Predictors of Patient Satisfaction Following Primary Total Knee Arthroplasty.

BACKGROUND: Predicting satisfaction following total knee arthroplasty (TKA) continues to be a clinical challenge. We sought to quantify radiographic variables associated with clinical improvement and satisfaction following TKA.

METHODS: We reviewed a consecutive series of primary TKAs performed by a single surgeon with a minimum 2-year follow-up. Radiographic variables assessed included preoperative and postoperative mechanical axis alignment, osteophyte size and location, and the presence of tibial or patella subluxation. Measurements were taken using a calibrated ruler and goniometer using digital radiographs. Knee Society Scores (KSS), satisfaction, and range of motion (ROM) were prospectively collected.

RESULTS: A total 155 TKAs were followed with a minimum 2.3 year follow-up (mean: 4.2 ± 0.85). Eleven were not satisfied, 9 were satisfied with minor complaints, and 131 were completely satisfied after TKA. Increasing size of patella and lateral compartment osteophytes, particularly greater than 5 mm, was significantly associated with improvement in KSS knee scores (p < 0.05). Patient satisfaction was also strongly associated with these variables and appeared independent of mechanical axis alignment. A regression model demonstrated that lateral patella osteophytes and lateral compartment osteophytes continued to have a significant.