Published results showed use of a specific prosthesis in total knee replacement yielded excellent midterm to long-term outcomes.
Researchers assessed patient satisfaction, range of movement and Knee Society Score (KSS) among 621 primary TKAs performed with the NexGen Legacy Posterior Stabilized prosthesis (Zimmer Inc.). Follow-up occurred at 1, 3, 5, 7 and 10 years postoperatively.
Results showed improvements in Knee Society score from 29.94 preoperatively to 88.74 at 3-year follow-up. Researchers found no further significant improvements in KSS at 5-, 7- or 10-year follow-up. Although the functional component of the KSS increased from a preoperative mean of 49.8 to 68.58 at 1-year follow-up, researchers noted a significant reduction at each subsequent visit. At 1-year follow-up, patients experienced a significant improvement in the pain component of the KSS, but no further improvements at subsequent visits, according to results.
Patients experienced a significant increase in satisfaction with their operated knees, with 92.8% of patients reporting satisfaction at 1-year follow-up and 96.2% of patients reporting satisfaction at 3-year follow-up. However, researchers found no further significant improvements on further visits. Results showed improvements in mean range of movement from 88.3° preoperatively to 104.3° at 3-year follow-up.
At 14 years, patients had a survivorship of 96.5% when revision for any reason was used as the end point and of 98.9% when aseptic loosening alone was used as the end point, according to results of a Kaplan-Meier analysis. Researchers found female patients had a significantly higher survival rate compared with male patients when revision for any reason was used as the end point, while patients younger than 70 years of age had reduced survivorship compared with patients older than 70 years of age. The most common cause for revision was infection, according to results, and 5.3% of patients complained of anterior knee pain at 1-year follow-up. However, researchers noted this reduced to 3.2% by 3-year follow-up.
“In conclusion, the design modifications in the femoral component from its predecessor, the [Insall-Burstein] IB II prosthesis, appear to have been beneficial for the NexGen [Legacy Posterior Stabilized] LPS, with an almost negligible incidence of anterior knee pain or patellofemoral complications in this study,” the authors wrote. “Coupled with the excellent mid[term] to long-term results observed here, the NexGen LPS prosthesis holds promise for patients in need of a total knee arthroplasty.” – by Casey Tingle
Disclosures: The authors report no relevant financial disclosures.