Early Clinical Outcomes of a New Posteriorly Stabilized Total Knee Arthroplasty Prosthesis: Comparisons with Two Established Prostheses

PURPOSE: We sought to determine whether early clinical performance of new posterior stabilized (PS) knee system, the Vega-PS (Aesculap), is better than that of two established total knee arthroplasty (TKA) prostheses, the E.motion-PS (Aesculap) and the Genesis II (Smith & Nephew) in terms of functional outcomes, patient satisfaction, and incidence of adverse events. MATERIALS AND METHODS: We compared the clinical outcomes of 206 consecutive TKAs using Vega-PS with those of 205 TKAs using E.motion-PS and 216 TKAs using Genesis II at 2 years of follow-up. RESULTS: Overall, the knees with the Vega-PS had better functional outcome scores than the knees with the E.motion-PS, but had similar outcome scores to the knees with the Genesis II, as evident from the American Knee Society knee score (94.2 vs. 92.5 vs. 93.2), Western Ontario McMaster Universities Osteoarthritis (WOMAC) stiffness index (1.8 vs. 2.3 vs. 2.0), WOMAC function index (11.8 vs. 16.8 vs. 18.5), Short Form 36 (SF-36) physical component summary score (41.9 vs. 39.3 vs. 41.6), and SF-36 mental component summary score (50.0 vs. 45.8 vs. 46.9). Patient satisfaction was higher in the Vega-PS and Genesis II groups than the E.motion-PS group. No notable group differences were found in terms of the incidence of adverse events. CONCLUSIONS: The Vega-PS, a newly developed PS fixed bearing prosthesis, had comparable or superior clinical performance in comparison with the two established fixed or mobile bearing PS prostheses.

Anterolateral Portal Is Less Painful than Superolateral Portal in Knee Intra-Articular Injection

PURPOSE: Intra-articular knee injections are commonly performed in clinical practice for treating various knee joint disorders such as osteoarthritis and rheumatoid arthritis. When selecting the portal for injection, not only intra-articular needle accuracy but also procedural pain should be taken into consideration. The purpose of this study was to determine whether injection through anterolateral portal provokes less pain and provides better pain relief compared to superolateral portal. MATERIALS AND METHODS: A total of 60 patients with primary osteoarthritis of the knee receiving intra-articular injections were randomized into 2 groups according to the type of portal approach; anterolateral or superolateral. All patients received hyaluronic acid (20 mg) and triamcinolone (40 mg) as the first injection followed by second and third injections of hyaluronic acid on a weekly basis. Underlying knee pain, procedural pain, and knee pain at 4 weeks were evaluated using visual analogue scale (VAS). RESULTS: Injection through anterolateral portal provoked less pain (VAS, 1.5+/-1.3) than the superolateral portal (VAS, 1.5 vs. 2.7; p=0.004). No differences were found in the degree of pain relief at weeks between the two groups (p=0.517). CONCLUSIONS: We recommend the use of anterolateral portal for intra-articular knee injection as it provokes less pain and comparably short-term pain relief than the superolateral portal.