Session V - Femur


Fri., 10/21/05 Femur, Paper #18, 10:30 am

Stabilization of Knee Dislocations Using a Hinged External Fixator - A Prospective Randomized Study

James P. Stannard, MD (a-Smith+Nephew, Inc.);
Stephen L. Brown, MD (n); James T. Robinson, BS (n);
Robert R. Lopez-Ben, MD (n); Gerald McGwin, Jr., PhD (n);
David A. Volgas, MD (n);
University of Alabama at Birmingham, Birmingham, Alabama, USA

Purpose: This study was conducted to evaluate the use of a hinged external fixator supplementing reconstruction following knee dislocation. Our hypothesis was that using the external fixator would decrease ligament laxity following reconstruction.

Methods: Patients with knee dislocations were randomized into either Group A (controls) and treated with a knee brace following ligament reconstruction, or Group B, which had a Compass Knee Hinge (CKH) external fixator. Range of motion (ROM) was begun on the first postoperative day. Outcomes included physical examination (ROM, ligament stability, analog pain scale), KT-2000 results, and outcome scores (Lysholm knee score and International Knee Documentation Committee [IKDC] score).

Results: 65 patients with 70 knee dislocations have been enrolled in our study to date, with 35 (37 knees) in Group A and 30 (33 knees) in Group B. 21 patients (22 dislocations with 71 torn ligaments) in Group A and 22 patients (24 dislocations with 77 torn ligaments) in Group B have a minimum of 24-month follow-up. With this follow-up, 6 patients in Group A (29%) had a failure of 16 (23%) ligament reconstructions and required a total of 8 revision reconstruction procedures. One patient (5%) in Group B had a failure of two (3%) ligaments requiring one revision reconstruction. The difference in outcome when comparing patients was significant (P<0.05). The difference in outcome when comparing total ligament reconstructions was also significant, with

P<0.01. Mean ROM for patients in Group A was 1 - 115 compared to 1 - 126 in Group B. Final IKDC and Lysholm scores following revision reconstruction were comparable for both groups. 83% of the patients had IKDC results in Group A (normal) or Group B (near normal), and the mean Lysholm knee score was 84.

Conclusion/Significance: Knee dislocations are severe injuries associated with a high rate of complications and adverse outcomes, including pain, stiffness and instability. The published prevalence of instability following surgical stabilization ranges from 18% to 61%, with a mean of 37%. Our data indicate that the temporary use of a hinged external fixator may lead to improved ligament stability and decreased need for revision surgery with no adverse impact on ROM or complication rates. Based on our data, we recommend the use of the CKH for approximately 6 weeks as a supplement to ligament reconstruction if an early and aggressive motion rehabilitation protocol is employed.

If noted, the author indicates something of value received. The codes are identified as a-research or institutional support; b-miscellaneous funding; c-royalties; d-stock options; e-consultant or employee; n-no conflicts disclosed, and *disclosure not available at time of printing.