The Effects of Semitendinosus and Gracilis Harvest in Anterior Cruciate Ligament Reconstruction

PURPOSE: There is significant debate concerning the morbidity of hamstring harvest for use during anterior cruciate ligament (ACL) reconstruction. We hypothesized that harvest of the semitendinosus and gracilis tendons for ACL reconstruction would result in no measurable hamstring weakness, but that abnormalities of the semitendinosus and gracilis muscle would be observed on magnetic resonance imaging (MRI) scans. TYPE OF STUDY: Case series. METHODS: Nine patients undergoing ACL reconstruction with doubled semitendinosus and gracilis tendons had MRI cross-sectional area measurements of both limbs made from axial images and muscle contour was studied on coronal images at 3 and 12 months. The semitendinosus, semimembranosus, gracilis, sartorius, and biceps muscles were evaluated. Isokinetic testing was performed on the operative and nonoperative legs at 60 degrees and 180 degrees per second at 6 and 12 months postoperatively. RESULTS: The gracilis cross-sectional area at 1 year averaged 2 cm2 on the operative side and 3.7 cm2 on the contralateral side. The semitendinosus averaged 2.1 cm2 on the operative side and 6.6 cm2 on the contralateral side at 1 year. Both of these differences were statistically significant (P < .05). In most cases, the semitendinosus muscle was retracted. Distally, the gracilis and occasionally the semitendinosus were blending with the gastrocnemius or sartorial fascia. The gracilis and semitendinosus in 1 case extended to near the original attachment site. Hamstring strength testing revealed a 26% deficit on the operative side at 60 degrees/second at 6 months and 16% at 180 degrees/second. At 12 months the mean 60 degrees/second deficit was 21% and the deficit at 180 degrees/second was 13%. CONCLUSIONS: At 1 year, the semitendinosus and gracilis muscles showed significant and persistent atrophy on the operative side and frequent retraction of the semitendinosus muscle belly. There were also hamstring strength deficits persisting at 1 year after the use of the tendons for ACL reconstruction. LEVEL OF EVIDENCE: Level IV.