Fresh-frozen Complete Extensor Mechanism Allograft versus Autograft Reconstruction in Rabbits

Abstract

Different clinical results have been reported in the repair of extensor mechanism disruption using fresh-frozen complete extensor mechanism (CEM) allograft, creating a need for a better understanding of fresh-frozen CME allograft reconstruction. Here, we perform histological and biomechanical analyses of fresh-frozen CEM allograft or autograft reconstruction in an in vivo rabbit model. Our histological results show complete incorporation of the quadriceps tendon into the host tissues, patellar survival and total integration of the allograft tibia, with relatively fewer osteocytes, into the host tibia. Vascularity and cellularity are reduced and delayed in the allograft but exhibit similar distributions to those in the autograft. The infrapatellar fat pad provides the main blood supply, and the lowest cellularity is observed in the patellar tendon close to the tibia in both the allograft and autograft. The biomechanical properties of the junction of quadriceps tendon and host tissues and those of the allograft patellar tendon are completely and considerably restored, respectively. Therefore, fresh-frozen CEM allograft reconstruction is viable, but the distal patellar tendon and the tibial block may be the weak links of the reconstruction. These findings provide new insight into the use of allograft in repairing disruption of the extensor mechanism.

Hypoxia-Induced Mesenchymal Stem Cells Exhibit Stronger Tenogenic Differentiation Capacities and Promote Patellar Tendon Repair in Rabbits

“…Rabbits were suffocated at 4 weeks after surgery for biomechanical analysis as described in our previous study [ 27 ]. The patella-patellar tendon-tibial tubercle was harvested and stored at −80°C.…”

Treatment of a Neglected Patellar Tendon Rupture with a Modified Surgical Technique: Ipsilateral Semitendinosus Autograft Reconstruction with Suture Tape Augmentation

“…Allograft reconstruction has an increased risk of infection and weakness secondary to radiation of the tendon graft. In addition, animal models have demonstrated that allograft extensor mechanism reconstruction shows a reduction in vascularity and cellularity when histologically compared to autograft reconstruction [ 26 ]. We also elected to use nonabsorbable sutures because we believe they add strength and longevity to the repair, which have been seen in a literature review of acute patellar tendon repair and an Achilles tendon repair model [ 27 , 28 ].…”

Allograft of the knee extensor in cases of patellar tendon rupture in total arthroplasty patients

“…2 , 3 Several treatment options are available, including the use of a complete knee extensor allograft, as described by Noronha et al 8 in isolated patellar tendon ruptures and by Emerson et al 9 in ruptures observed in patients who have undergone total knee arthroplasty. Chen et al 10 demonstrated that allograft integration is more time-consuming, but equally effective, and preserves the biomechanical properties. These data are in line with those described with the use of bone-tendon-bone allograft for anterior cruciate ligament reconstruction.…”