Long-term Follow-up of Patellar Nonresurfacing in Total Knee Arthroplasty.

BACKGROUND

We aimed to confirm the long-term effect of patellar nonresurfacing (patellar decompression) in preventing anterior knee pain after total knee arthroplasty (TKA) and to investigate the possible complications.

METHODS

Among patients who underwent primary TKA after being diagnosed as having advanced osteoarthritis (Kellgren-Lawrence grade 4) at our institution from January 2004 to December 2010, 121 patients who were followed up for more than 7 years were included in this study. Patients who underwent TKA with and without patellar decompression were classified as the study group and control group, respectively. A clinical knee rating score was used to compare the postoperative clinical outcomes between groups. To identify complications after patellar decompression, simple radiographs (weight-bearing anteroposterior and lateral views, patella in 30° and 45° axial views, and whole scanogram) were taken during follow-up.

RESULTS

There were no complications such as patellar fracture, osteonecrosis, and subluxation. At 2 years after surgery, the prevalence of anterior knee pain was 12.7% and 18.0% in the study group and control group, respectively (p = 0.42), and the number of patients with patellofemoral osteoarthritis grade II or over was lower in the study group (p = 0.03). At 7 years after surgery, the prevalence of anterior knee pain was 18.3% and 24.0% in the study group and control group, respectively (p = 0.45), and there was no statistically significant intergroup difference in the number of patients with patellofemoral osteoarthritis grade II or over (p = 0.11).

CONCLUSIONS

Patellar nonresurfacing TKA reduces anterior knee pain in the early postoperative period. The procedure can be considered a relatively safe option with fewer complications; however, its effectiveness appears to decrease over time.