2015 ISAKOS Biennial Congress ePoster #1354

Subjective Evaluation of Knee Flexor Muscle Weakness Following Anterior Cruciate Ligament Reconstruction Using Hamstring Autograft

Masaya Hayashi, MD, PhD, Kawaguchi, Saitama JAPAN
Masayuki Shimaya, MD, PhD, Kawaguchi, Saitama JAPAN
Sadahiro Cho, MD, Soka, Saitama JAPAN
Takashi Ogiuchi, MD, Kawaguchi, Saitama JAPAN
Hideya Yoshimura, MD, PhD, Kawaguchi, Saitama JAPAN
Daisuke Hatsushika, MD, PhD, Kawaguchi, Saitama JAPAN
Mari Uomizu, MD, Bunkyo Ku, Tokyo JAPAN
Mai Katakura, MD, PhD, Tokyo, Japan JAPAN
Akiho Hoshino, MD, Kawaguchi, Saitama JAPAN
Sadao Niga, MD, PhD, Saitama, Saitama JAPAN

Kawaguchi Kogyo General Hospital, Kawaguchi-city, Saitama, JAPAN

FDA Status Not Applicable

Summary: Harvesting hamstring tendons has a potential risk of postoperative weakness of the knee bending force, and this study showed that additional gracilis tendon harvesting increased the rate of consciousness of hamstring weakness of the operated side but it had less to do with clinical results except some sporting events.

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Abstract:

Introduction

Hamstring tendons are common graft sources for ACL reconstruction surgery; however, harvesting hamstring tendons has a potential risk of postoperative weakness of the knee bending force. Some athletes were conscious of hamstring muscle weakness during their sports activities, especially with their knees in full flexion position. In this study, we investigated patient’s consciousness of hamstring weakness after ACL reconstruction, and its relationship with other clinical results.

Materials And Methods

Five hundred eleven patients who received arthroscopically assisted single-bundle ACL reconstruction using multistrand hamstring autograft for unilateral, isolated ACL injuries between 2001 and 2010 were retrospectively reviewed. For the graft, the ipsilateral semitendinosus tendon was initially harvested (ST), and if it was not enough in volume, gracilis tendon from the same side was additionally harvested (STG).
Range of motion (ROM), KT-1000 side-to-side difference, Lysholm score, flexor force of the knee measured by Cybex isokinetic dynamometer, conscious or unconscious of hamstring weakness during sporting activities, and knee flexion lag were evaluated at postoperative follow-ups. Knee flexion lag was defined as a side-to-side difference of heel height during their knee in maximal flexion in one leg standing position.
Patients were divided into two groups by subjective evaluation of hamstring muscle weakness: Conscious and Unconscious of hamstring weakness (CHW and UHW group). And we statistically analyzed the relationship of these two groups to other clinical results.

Results

The follow-up period was 19.6 (12 - 60) months, and the mean age at the time of the surgery was 21.9 (13 - 46) years old. STG harvested group was 25% of the total. CHW group was 12% of the total. Looking into the graft material, rate of CHW was significantly higher in the STG group (17%) than that of the ST group (10%).
There were no significant differences between CHW and UHW groups in ROM and side-to-side difference with KT-1000. The mean Lysholm score of the UHW group (96.3±5.8) was significantly higher than that of the CHW group (95.2±5.2). There was no statistical difference between CHW and UHW groups in knee flexor force measured by Cybex. On the other hand, there exists significant deference in flexion lag between the two groups, 1.6±2.3 cm for UHW group and 2.3±2.7 cm for CHW group. Among the sporting events, CHW positive ratio was highest in judo (27%), followed by soccer (11%), futsal (11%) and basketball (6%).

Discussion

In this study, patients who were conscious of hamstring weakness were relatively small (12% of the total), but additional gracilis tendon harvesting increased the complication 70% more than semitendinosus tendon harvesting alone. Among sporting events, Judo players showed highest CHW rate (27%). That may be because maximum flexion of the knee is important during reaping opponent’s leg in Judo match.
We found that knee flexion lag was more closely related to the CHW than measured knee flexion force, and we think that’s because knee flexion lag was evaluated with their knee in full flexed position.