Histological findings of tendon-bone healing following anterior cruciate ligament reconstruction with hamstring grafts.

摘要

BACKGROUND: The purpose of the study was the histological examination of tendon-bone healing of hamstring grafts after anterior cruciate ligament (ACL) reconstruction. METHODS: During five arthroscopies done 6-14 months after ACL reconstructions, biopsies of the wall of the former drilled femoral canal were obtained. Four patients were primarily operated on using a suspending device (Endobutton, Acufex Microsurgical, Mansfield, MA, USA, and Transfix, Arthrex, Naples, FL, USA) for femoral fixation, one patient was reconstructed with a biodegradable interference screw directly inserted between the tendon and the wall of the canal. Biopsies were obtained using a tube harvester during re-arthroscopy. Three grafts were stable, two grafts were unstable, and revision of the ACL was performed. RESULTS: Histologically, in the four cases of reconstruction with a button or a rectangular pin, biopsies resembled granulation tissue without insertion of fibers between the tendon tissue and the bony wall. A wide area of woven bone was noted adjacent to the pre-existing lamellar bone. In contrast, the tendon-bone junction in the knee reconstructed with a biodegradable interference screw resembled a zone of metaplastic fibrous cartilage between the tendon graft and the lamellar bone. Collagen fibers connecting the tendon-bone interface occurred under polarized light microscopy. CONCLUSION: We conclude that the use of hamstring grafts for ACL reconstruction can lead to different histological pattern of tendon-bone healing. Micromotion of the hamstring graft inside the drilled canal can be play a role in tendon-bone healing.