Pretreatment of periosteum with TGF-β1 in situ enhances the quality of osteochondral tissue regenerated from transplanted periosteal grafts in adult rabbits

SummaryObjectiveTo compare the efficacy of in situ transforming growth factor-beta1 (TGF-β1)-pretreated periosteum to untreated periosteum for regeneration of osteochondral tissue in rabbits.MethodsIn the pretreatment group, 12 month-old New Zealand white rabbits received subperiosteal injections of 200ng of TGF-β1 percutaneously in the medial side of the proximal tibia, 7 days prior to surgery. Control rabbits received no treatment prior surgery. Osteochondral transverse defects measuring 5mm proximal to distal and spanning the entire width of the patellar groove were created and repaired with untreated or TGF-β1-pretreated periosteal grafts. Post-operatively the rabbits resumed normal cage activity for 6 weeks.ResultsComplete filling of the defects with regenerated tissue was observed in both the TGF-β1-pretreated and control groups with reformation of the original contours of the patellar groove. The total histological score (modified O’Driscoll) in the TGF-β1-pretreated group, 20 (95% Confidence Interval (CI), 19–21), was significantly higher (P=0.0001) than the control group, 18 (16–19). The most notable improvements were in structural integrity and subchondral bone regeneration. No significant differences in glycosaminoglycan or type II collagen content, or equilibrium modulus were found between the surgical groups. The cambium of the periosteum regenerated at the graft harvest site was significantly thicker (P=0.0065) in the TGF-β1-pretreated rabbits, 121μm (94–149), compared to controls, 74μm (52–96), after 6 weeks.ConclusionsThis study demonstrates that in situ pretreatment of periosteum with TGF-β1 improves osteochondral tissue regeneration at 6-weeks post-op compared to untreated periosteum in 12 month-old rabbits

Anatomic Considerations in Hamstring Tendon Harvesting for Ligament Reconstruction

Hamstring tendon autograft remains a popular graft choice for anterior cruciate ligament reconstruction. Although the technique of hamstring autograft harvest is relatively straightforward, it is critical to pay attention to several technical steps to avoid iatrogenic anatomic or neurovascular damage as well as to reduce the risk of premature amputation of the graft when using a tendon stripper. We describe a technique of hamstring autograft harvesting using only 2 anatomic references that makes it a simple and reproducible technique for surgeons, especially those in training