The intra-operative joint gap in cruciate-retaining compared with posterior-stabilised total knee replacement

T. Matsumoto, MD, PhD, Orthopaedic Surgeon1; R. Kuroda, MD, PhD, Orthopaedic Surgeon, Associate Professor1; S. Kubo, MD, PhD, Orthopaedic Surgeon1; H. Muratsu, MD, PhD, Orthopaedic Surgeon2; K. Mizuno, MD, PhD, Orthopaedic Surgeon1; and M. Kurosaka, MD, PhD, Professor1

Journal of Bone and Joint Surgery - British Volume, Vol 91-B, Issue 4, 475-480.  doi: 10.1302/0301-620X.91B4.21862  Copyright © 2009 by British Editorial Society of Bone and Joint Surgery

Abstract: We have developed a new tensor for total knee replacements which is designed to assist with soft-tissue balancing throughout the full range of movement with a reduced patellofemoral joint. Using this tensor in 40 patients with osteoarthritis we compared the intra-operative joint gap in cruciate-retaining and posterior-stabilised total knee replacements at 0°, 10°, 45°, 90° and 135° of flexion, with the patella both everted and reduced.

While the measurement of the joint gap with a reduced patella in posterior-stabilised knees increased from extension to flexion, it remained constant for cruciate-retaining joints throughout a full range of movement. The joint gaps at deep knee flexion were significantly smaller for both types of prosthetic knee when the patellofemoral joint was reduced (p < 0.05).

1 Department of Orthopaedic Surgery Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
2 Department of Orthopaedic Surgery Nippon Steel Hirohata Hospital, 3-1, Yumesaki-cho, Hirohata-ku, Himeji 671-1122, Japan.
Correspondence should be sent to Dr T. Matsumoto; e-mail: mastun@m4.dion.ne.jp