Journal List > J Korean Orthop Assoc > v.48(6) > 1013266

Chon, Song, Sun, Jang, and Lee: Comparison of Two Year Follow-Up Results in High Flexion Total Knee Arthroplasty with Lospa and Scorpio NRG



The purpose of this study is to evaluate the clinical and radiologic results after high flexion Lospa (Corentec Inc.) and Scorpio NRG (Stryker Inc.) total knee arthroplasty.

Materials and Methods

We prospectively compared 205 knees in 128 patients who underwent arthroplasty using Lospa (group A) and 164 knees in 102 patients who underwent arthroplasty using Scorpio NRG (group B) from September 2010 to March 2012 at Department of Orthopaedic Surgery, Sun General Hospital (Daejeon, Korea). Mean follow-up period was 23 months in group A and 24 months in group B. The radiologic analysis included the change of mechanical axis deviation and femoro-tibial angle, implant position (α, β, γ, δ), and patellar tilt. The clinical results were evaluated according to hospital for special surgery (HSS), knee society score (KSS), and range of motion.


Mechanical axis deviations were change in varus from 34.8 mm to 2.6 mm (p=0.02) in group A, and change in varus from 34.3 mm to 3.1 mm (p=0.04) in group B; no statistically significant difference was observed between them (p=0.13). Femoro-tibial angles were varus 4.3° to valgus 6.6° (p=0.02) in group A, and varus 4.4° to valgus 6.5° (p=0.03) in group B; no significant difference was observed between them (p=0.25). No significant difference in implant position was observed between the two groups (p=0.25 in α, p=0.17 in β, p=0.12 in γ, p=0.17 in δ). Mean HSS improved from 48.5 to 93.6 (p=0.02) in group A, and from 41.4 to 94.4 (p=0.01) in group B.


Lospa total knee arthroplasty showed excellent early radiologic, clinical results and no statistically significant difference in the results was observed between Lospa and Scorpio NRG.

Figures and Tables

Figure 1
Deep flexion favoring design of (A) Lospa total knee arthroplasty requires cutting of the posterior condyle to 10 mm compared with 8 mm of (B) Scorpio NRG.
Figure 2
A 72-year-old female showed (A) advanced osteoarthritis on both knees with left knee subluxation. She underwent Lospa total knee arthroplasty and demonstrated well positioned implants. (B) The α angle was measured between the parallel to the femoral condyles and a line drawn along the femoral shaft axis. The β angle was calculated between the parallel to the tibial metal baseplate and a line drawn along the tibial axis shaft. (C) Whereas sagittal tibial δ and femoral γ angles were measured on lateral knee radiographs with the patient lying and the knee flexion.
Table 1
Demography of Group A (Lospa) and Group B (Scorpio NRG)

Values are presented as mean±standard deviation or number.

Table 2
Comparison of Mean Mechanical Axis Deviation (MAD) and Tibia-Femoral (T-F) Angle in Group A (Lospa) and Group B (Scorpio NRG)

Values are presented as median (range).

Table 3
Comparison of Mean Postoperative Implant Position in Group A (Lospa) and Group B (Scorpio NRG)

Values are presented as median (range).

Table 4
Comparison of Mean HSS, KSS, and Average Range of Motion in Group A (Lospa) and Group B (Scorpio NRG)

Values are presented as *median (range) or average (range). HSS, Hospital for Special Surgery; KSS, Knee Society Score; ROM, range of motion.


This article was announced at 2012 The Korean Orthopedic Association Annual Fall Congress.


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