2017 ISAKOS Biennial Congress ePoster #1178

 

Effects of Gracilis Tendon Harvest on Thigh Muscle Strength

Anne Flies, cand. med., Berlin GERMANY
Heide Boeth, MSc, Dipl Ing, Berlin GERMANY
Natascha Kraus, MD, Dr. med., Berlin GERMANY
Sebastian Kopf, MD, PhD, Prof., Brandenburg An Der Havel, Brandenburg GERMANY

Charité-University Medicine Berlin, Berlin, GERMANY

FDA Status Not Applicable

Summary

Clinical trial to evaluate the consequences of isolated gracilis tendon harvest from uninjured knees on thigh muscle strength.

Abstract

The gracilis tendon is one of the most commonly used autologous tendon grafts in orthopaedic surgery. Previous studies analyzed predominantly the effects of gracilis and/or semitendinosus harvest on thigh muscle strength after rupture, reconstruction and rehabilitation. However, all of these three incidents influence the outcome. Thus, the purpose of the present study was to evaluate the effect of isolated gracilis tendon harvest from uninjured knees on thigh muscle strength.
Patients between 18 to 60 years with harvest of their gracilis tendon for reconstruction of the acromioclavicular joint have been included in this study. Exclusion criteria were previous surgeries or injuries of their knees as well as inability to perform the evaluated exercises. Maximum strength of characteristic functions of the gracilis muscle was evaluated using an isokinetic dynamometer: (1) knee flexion in prone position (for flexion angles > 90°), (2) knee flexion in sitting position (for flexion angles < 90°), (3) internal rotation of the lower leg and (4) hip adduction. The contralateral knee was used as control. In addition, the subjective outcome of the knee was assessed using the subjective knee evaluation form from the IKDC-2000. The D'Agostino & Pearson Test was used to test for a Gaussian distribution. For parametric data the dependent t-test or Pearson correlation was used, otherwise the Wilcoxon Test or Spearman correlation was used.
To date, fourteen patients have been evaluated. The mean age was 41 years [standard deviation (SD) 13 years] and time to follow up was 49 months (SD 23). For all four exercises tested, the affected limb showed a deficit in comparison to the healthy contralateral side without reaching any statistical significance. In particular, for knee flexion in prone position the deficit was 2.1 Nm (SD ± 7.3; p = 0,31), while it represented 2.2 Nm (SD 11.8; p = 0.49) during sitting position. During internal rotation and hip adduction, deficits of 1.8 Nm (SD 9.7; p = 0.44) and 1.9 Nm (SD 19.0; p = 0.76) of the affected leg were obtained, respectively. Maximum strength of the injured and uninjured leg during knee flexion in sitting position (r = 0.7283; p = 0.0046, and r = 0.6527; p = 0.0139, respectively) as well as adduction (r = 0.7283; p = 0.0046, and r = 0.5840; p = 0.0006) correlated positively and statistically significant with the subjective knee evaluation form of the IKDC-2000. For knee flexion in prone position and internal rotation, no statistically significant correlation with the IKDC-2000 was found.
The present study shows that gracilis tendon harvest in healthy knees does lead to muscle strength deficit of the thigh, but without statistical significance. This could indicate that there is no relevant muscle strength deficit after gracilis tendon harvest and that the other thigh muscles compensate its function. However, it should be taken into consideration that these data only represent preliminary data, and that it is influenced by the fact that every patient has a dominant leg. In addition, it was shown that a higher muscle strength of both thighs correlates with a better subjective outcome. These data support the use of the gracilis tendon as autologous graft for reconstruction surgery.