Rectus femoris and vastus intermedius thickness measurement by ultrasound before and after anterior cruciate ligament reconstruction in athletes

Background Most anterior cruciate ligament (ACL) injuries which are common in violent sports require anterior cruciate ligament reconstruction (ACLR) to restore knee joint stabilization. Rectus femoris (RF) and vastus intermedius (VI) weakness are among the notable changes after ACLR. This weakness can be hazardous to the patient as it could decrease functional activity and thus increases the chances of re-injury. The objectives of the current study were to measure the (RF) thickness, (VI) thickness and the total (RF + VI) thickness on (ACL) reconstructed limb and the non-reconstructed limb of athletes using ultrasound and to compare the results pre-operatively and 6–8 months post-operative. Results The reconstructed limb showed a significant decrease in (RF), (VI) and the total thickness in the 1st, 2nd and 3rd measurements compared to that of non- reconstructed limb post-operatively. In both limbs, the decrease of (VI) thickness was significantly higher than (RF) thickness in the 1st, 2nd and 3rd measurements ( p < 0.001, p < 0.001 and p < 0.001 respectively). Conclusions Ultrasound can be used to assess quadriceps atrophy (including the individual muscles) found after ACLR. Ultrasound is an affordable and easily available modality as compared to MRI and CT scans for the assessment of RF and VI muscle weakness in athletes with ACLR during the rehabilitation period and can guide selective rehabilitation protocols if wasting is identified early.