Hybrid Graft Anterior Cruciate Ligament Reconstruction: A Predictable Graft for Knee Stabilization

Abstract

Trauma to the anterior cruciate ligament (ACL) is a season-ending injury and involves months of activity modification and rehabilitation. The annual incidence of ACL tears in the United States is approximately 200,000, which allows for a broad range of individualized treatment options. Various surgical techniques, including transtibial and independent tunnel drilling, allograft and autograft tissue, and various implants, have been described in the literature. This article describes the indications and technique for a hybrid soft tissue graft for ACL reconstruction. Autologous grafts eliminate the risk of disease transmission and have recently been shown to have a lower rerupture rate, particularly in younger, active patients; however, the harvesting of autologous hamstring grafts carries a risk of donor-site morbidity, iatrogenic injury of the graft, and inadequate graft size. In contrast to a traditional autologous soft tissue graft, the hybrid graft allows for graft size customization for a desired reconstruction, especially in cases where autograft hamstrings may be iatrogenically damaged or of inadequate size when harvested. The goal of a hybrid graft ACL reconstruction is to provide a favorable-sized graft with clinical outcomes comparable with autologous soft tissue grafts. In contrast to a traditional autologous soft tissue graft, this technique provides another option in the event of unforeseen deficiencies or complications associated with harvesting and preparation of the autologous gracilis and semitendinosis soft tissue graft.

Failure Rate and Clinical Outcomes of Anterior Cruciate Ligament Reconstruction Using Autograft Hamstring Versus a Hybrid Graft

“…32 The clinical protocol for group assessment and graft selection was based on the size of the autograft hamstring at the time of the surgical procedure. A soft tissue hybrid ACL reconstruction, involving a combination of the autograft hamstring and tibialis anterior or tibialis posterior allograft soft tissue as previously described, 26 was performed when quadruple-stranded autograft hamstring tissue was inadequate or iatrogenically damaged during harvesting to achieve a minimum desired graft size of 8 mm in diameter. If the harvested autograft hamstring tissue was less than 8 mm, it was used in total and hybridized to fit the appropriate aperture fixation femoral implant (Cayenne Medical, Scottsdale, AZ) as determined by the surgeon for the individual patient (Table 1).…”

“…26 The clinical study received approval through the Main Campus Institutional Review Board. Strict inclusion and exclusion criteria were used.…”

“…All patients were scheduled for autograft hamstring and also consented for the possibility of a hybrid graft should the surgeon determine the patient's hamstring tissue alone not be sufficient for the reconstruction when measured at the time of graft preparation during surgery. 26 Soft tissue allografts used by the research hospital are tibialis grafts sterilized without radiation using a BioCleanse tissue sterilization process (RTI Surgical, Alachua, FL). 32 The clinical protocol for group assessment and graft selection was based on the size of the autograft hamstring at the time of the surgical procedure.…”

“…1,16 Several recent studies have shown a 4 times higher probability of rerupture for all patients after allograft ACL reconstructions when compared with autograft reconstructions 3,4,25 and up to 5 times higher probability specifically in patients under 25 years of age. 12,[26][27][28] A hybrid graft combining both autograft hamstring and allograft soft tissue is a viable reconstructive option for surgeons who desire performing ACL reconstruction using a soft tissue graft. 26 It provides surgeons the ability to customize graft size by augmenting autograft hamstrings with soft tissue allografts.…”

“…12,[26][27][28] A hybrid graft combining both autograft hamstring and allograft soft tissue is a viable reconstructive option for surgeons who desire performing ACL reconstruction using a soft tissue graft. 26 It provides surgeons the ability to customize graft size by augmenting autograft hamstrings with soft tissue allografts. 5,6,8,29,30 Hybrid grafts may be used as a primary graft for reconstructions or to enhance autologous hamstring tissue when it is iatrogenically damaged or is of insufficient size when harvested.…”