Investigation of Range of Motion of Nexgen LPS Flex Knee Prosthesis: Comparison of Mobile-Bearing and Fixed-Bearing Prostheses

• Published in: Orthopedics & Traumatology Vol. 56; no. 2; pp. 258 - 262
• Main Authors: Kido, Hidehiko, Shirasawa, Kenzo, Irie, Manabu, Yamashita, Akihisa, Ogata, Junya, Mitsuyasu, Hiroaki
• Format: Journal Article
• Language: Japanese
• Published: West-Japanese Society of Orthopedics & Traumatology 2007
• Subjects: deep flexion; fixed bearing; mobile bearing; total knee arthroplasty
• ISSN: 0037-1033; 1349-4333
• DOI: 10.5035/nishiseisai.56.258

We investigated the postoperative range of motion and short-term outcome of LPS Flex TKA performed in our department, and compared 55 mobile-bearing and 30 fixed-bearing knees. The postoperative range of motion improved earlier in the mobile group than in the fixed group, but there was no significant difference in percentage flexion achieved at final observation between the two groups, with 105.0% for the mobile group and 105.7% for the fixed group, indicating good short-term outcome for both. Deep flexion can be achieved not only with mobile bearing but as a result of various factors such as surgical techniques. In particular, we found that good surgical techniques (ensuring posterior clearance) and the accurate balance adjustment of the soft tissue to achieve deep flexion markedly improved the postoperative percentage of flexion. The advantages of mobile bearing are the attainment of both deep flexion and durability, though results of in vivo kinetic analysis are still unclear. Thus careful follow-up of cases is necessary, though good long-term outcome can be expected.