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Alexander Y Shin - One of the best experts on this subject based on the ideXlab platform.
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mesenchymal stem cells and local tacrolimus delivery synergistically enhance neurite extension
Biotechnology and Bioengineering, 2021Co-Authors: Sara Saffari, Tiam M Saffari, Katelyn Chan, Gregory H Borschel, Alexander Y ShinAbstract:BACKGROUND The aim of this study was to investigate the combined effect of mesenchymal stem cells (MSC) and local delivery of tacrolimus (FK506) on nerve regeneration when applied to nerve Autografts and decellularized allografts. METHODS A three-dimensional in vitro compartmented cell culture system consisting of a neonatal dorsal root ganglion adjacent to a nerve graft was used to evaluate the regenerating neurites into the peripheral nerve scaffold. Nerve Autografts and allografts were treated with (i) undifferentiated MSCs, (ii) FK506 (100 ng/mL) or (iii) both (N = 9/group). After 48 hours, neurite extension was measured to quantify nerve regeneration and stem cell viability was evaluated. RESULTS Stem cell viability was confirmed in all MSC-treated grafts. Neurite extension was superior in Autografts treated with FK506, and MSCs and FK506 combined (p < 0.001 and p = 0.0001, respectively), and Autografts treated with MSCs (p = 0.12) were comparable to untreated Autografts. In allografts, FK506 treatment and combined treatment were superior to controls (p < 0.001 and p = 0.0001, respectively), and treatment with MSCs (p = 0.09) was comparable to controls. All Autograft groups were superior compared to their respective allograft treatment group (p < 0.05) in neurite extension. CONCLUSIONS Alone, either MSC or FK506 treatment improved neurite outgrowth, and combined they further enhanced neurite extension in both Autografts and allografts.
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return of motor function after segmental nerve loss in a rat model comparison of autogenous nerve graft collagen conduit and processed allograft axogen
Journal of Bone and Joint Surgery American Volume, 2012Co-Authors: Guilherme Giusti, Wouter F Willems, Thomas Kremer, Patricia F Friedrich, Allen T Bishop, Alexander Y ShinAbstract:Background: An effective alternative to nerve Autograft is needed to minimize morbidity and solve limited-availability issues. We hypothesized that the use of processed allografts and collagen conduits would allow recovery of motor function that is equivalent to that seen after the use of Autografts. Methods: Sixty-five Lewis rats were divided into three experimental groups. In each group, a unilateral 10-mm sciatic nerve defect was repaired with nerve Autograft, allograft treated by AxoGen Laboratories, or a 2.0-mm-inner-diameter collagen conduit. The animals were studied at twelve and sixteen weeks postoperatively. Evaluation included bilateral measurement of the tibialis anterior muscle force and muscle weight, electrophysiology, assessment of ankle contracture, and peroneal nerve histomorphometry. Muscle force was measured with use of our previously described and validated method. Results were expressed as a percentage of the values on the contralateral side. Two-way analysis of variance (ANOVA) corrected by the Ryan-Einot-Gabriel-Welsch multiple range test was used for statistical investigation (α = 0.05). Results: At twelve weeks, the mean muscle force (and standard deviation), as compared with that on the contralateral (control) side, was 45.2% ± 15.0% in the Autograft group, 43.4% ± 18.0% in the allograft group, and 7.0% ± 9.2% in the collagen group. After sixteen weeks, the recovered muscle force was 65.5% ± 14.1% in the Autograft group, 36.3% ± 15.7% in the allograft group, and 12.1% ± 16.0% in the collagen group. Autograft was statistically superior to allograft and the collagen conduit at sixteen weeks with regard to all parameters except histomorphometric characteristics (p < 0.05). The collagen-group results were inferior. All Autograft-group outcomes improved from twelve to sixteen weeks, with the increase in muscle force being significant. Conclusions: The use of Autograft resulted in better motor recovery than did the use of allograft or a collagen conduit for a short nerve gap in rats. A longer evaluation time of sixteen weeks after segmental nerve injuries in rats would be beneficial as more substantial muscle recovery was seen at that time. Clinical Relevance: On the basis of this study, the enthusiasm for use of processed allograft nerve grafts in motor nerve reconstruction should be tempered until additional studies are performed.
Anthony A Schepsis - One of the best experts on this subject based on the ideXlab platform.
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ORIGINAL ARTICLE Prospective Comparison of Auto and Allograft Hamstring Tendon Constructs for ACL Reconstruction
2015Co-Authors: Cory M. Edgar, Sanjeev Kakar, Hugh Jones, Anthony A SchepsisAbstract:Abstract Although allograft use for primary anterior cruciate ligament reconstruction has continued to increase during the last 10 years, concerns remain regarding the long-term function of allografts (primarily that they may stretch with time) and clinical efficacy compared with Autograft tendons. We attempted to address these issues by prospectively comparing identical quadrupled hamstring Autografts with allograft constructs for primary anterior cruciate ligament reconstruction in patients with a mini-mum followup of 3 years. Eighty-four patients (37 with Autografts and 47 with allografts) were enrolled; the mean followup was 52 ± 11 months for the Autograft group and 48 ± 8 months for the allograft group. Outcome mea-surements included objective and subjective International Knee Documentation Committee scores, Lysholm scores, Tegner activity scales, and KT-1000 arthrometer mea-surements. The two cohorts were similar in average age, acute or chronic nature of the anterior cruciate ligament rupture, and incidence of concomitant meniscal surgeries. At final followup, we found no difference in terms of Tegner, Lysholm, KT-1000, or International Knee Docu-mentation Committee scores. Five anterior cruciate ligament reconstructions failed: three in the Autograft group and two in the allograft group. Our data suggest laxity is not increased in allograft tendons compared with Autografts and clinical outcome scores 3 to 6 years after surgery are similar. Level of Evidence: Level II, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence
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prospective comparison of auto and allograft hamstring tendon constructs for acl reconstruction
Clinical Orthopaedics and Related Research, 2008Co-Authors: Cory Edgar, Scott Zimmer, Sanjeev Kakar, Hugh P Jones, Anthony A SchepsisAbstract:Although allograft use for primary anterior cruciate ligament reconstruction has continued to increase during the last 10 years, concerns remain regarding the long-term function of allografts (primarily that they may stretch with time) and clinical efficacy compared with Autograft tendons. We attempted to address these issues by prospectively comparing identical quadrupled hamstring Autografts with allograft constructs for primary anterior cruciate ligament reconstruction in patients with a minimum followup of 3 years. Eighty-four patients (37 with Autografts and 47 with allografts) were enrolled; the mean followup was 52 ± 11 months for the Autograft group and 48 ± 8 months for the allograft group. Outcome measurements included objective and subjective International Knee Documentation Committee scores, Lysholm scores, Tegner activity scales, and KT-1000 arthrometer measurements. The two cohorts were similar in average age, acute or chronic nature of the anterior cruciate ligament rupture, and incidence of concomitant meniscal surgeries. At final followup, we found no difference in terms of Tegner, Lysholm, KT-1000, or International Knee Documentation Committee scores. Five anterior cruciate ligament reconstructions failed: three in the Autograft group and two in the allograft group. Our data suggest laxity is not increased in allograft tendons compared with Autografts and clinical outcome scores 3 to 6 years after surgery are similar.
Katja Skaza - One of the best experts on this subject based on the ideXlab platform.
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quality of life and clinical outcome comparison of semitendinosus and gracilis tendon versus patellar tendon Autografts for anterior cruciate ligament reconstruction an 11 year follow up of a randomized controlled trial
American Journal of Sports Medicine, 2011Co-Authors: Matjaz Sajovic, Andrej Strahovnik, Mojca Z Dernovsek, Katja SkazaAbstract:Background: There are still controversies about graft selection for primary anterior cruciate ligament reconstruction. Prospective, randomized long-term studies are needed to determine the differences between the graft materials.Hypothesis: Eleven years after anterior cruciate ligament reconstruction there is no difference in functional outcome and quality of life between patients with patellar tendon or hamstring tendon Autografts; however, the patients with patellar tendon Autograft would have a higher prevalence of osteoarthritis.Study Design: Randomized controlled trial; Level of evidence, 2.Methods: From June 1999 to March 2000, 64 patients were included in this prospective study. A single surgeon performed primary arthroscopically assisted anterior cruciate ligament reconstruction in an alternating sequence. In 32 patients, anterior cruciate ligament reconstruction was performed with hamstring tendon Autograft (semitendinosus and gracilis [STG] group) while in the other 32 patients the reconstructio...
Akira Kawai - One of the best experts on this subject based on the ideXlab platform.
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Clinical Study Intercalary Reconstruction after Wide Resection of Malignant Bone Tumors of the Lower Extremity Using a Composite Graft with a Devitalized Autograft and a Vascularized Fibula
2020Co-Authors: Koichi Ogura, Minoru Sakuraba, Shimpei Miyamoto, Tomohiro Fujiwara, Hirokazu Chuman, Akira KawaiAbstract:Introduction. Although several intercalary reconstructions after resection of a lower extremity malignant bone tumor are reported, there are no optimal methods which can provide a long-term reconstruction with fewest complications. We present the outcome of reconstruction using a devitalized Autograft and a vascularized fibula graft composite. Materials and Methods. We conducted a retrospective review of 11 patients (7 males, 4 females; median age 27 years) undergoing reconstruction using a devitalized Autograft (pasteurization ( = 6), deep freezing ( = 5)) and a vascularized fibula graft composite for lower extremity malignant bone tumors (femur ( = 10), tibia ( = 1)). Results. The mean period required for callus formation and bone union was 4.4 months and 9.9 months, respectively. Four postoperative complications occurred in 3 patients: 2 infections (1 pasteurized Autograft, 1 frozen Autograft) and 1 fracture and 1 implant failure (both in pasteurized Autografts). Graft removal was required in 2 patients with infections. The mean MSTS score was 81% at last follow-up. Conclusions. Although some complications were noted in early cases involving a pasteurized Autograft, our novel method involving a combination of a frozen Autograft with a vascularized fibula graft and rigid fixation with a locking plate may offer better outcomes than previously reported allografts or devitalized Autografts
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intercalary reconstruction after wide resection of malignant bone tumors of the lower extremity using a composite graft with a devitalized Autograft and a vascularized fibula
Sarcoma, 2015Co-Authors: Koichi Ogura, Minoru Sakuraba, Shimpei Miyamoto, Tomohiro Fujiwara, Hirokazu Chuman, Akira KawaiAbstract:Introduction. Although several intercalary reconstructions after resection of a lower extremity malignant bone tumor are reported, there are no optimal methods which can provide a long-term reconstruction with fewest complications. We present the outcome of reconstruction using a devitalized Autograft and a vascularized fibula graft composite. Materials and Methods. We conducted a retrospective review of 11 patients (7 males, 4 females; median age 27 years) undergoing reconstruction using a devitalized Autograft (pasteurization (n = 6), deep freezing (n = 5)) and a vascularized fibula graft composite for lower extremity malignant bone tumors (femur (n = 10), tibia (n = 1)). Results. The mean period required for callus formation and bone union was 4.4 months and 9.9 months, respectively. Four postoperative complications occurred in 3 patients: 2 infections (1 pasteurized Autograft, 1 frozen Autograft) and 1 fracture and 1 implant failure (both in pasteurized Autografts). Graft removal was required in 2 patients with infections. The mean MSTS score was 81% at last follow-up. Conclusions. Although some complications were noted in early cases involving a pasteurized Autograft, our novel method involving a combination of a frozen Autograft with a vascularized fibula graft and rigid fixation with a locking plate may offer better outcomes than previously reported allografts or devitalized Autografts.
Jaskarndip Chahal - One of the best experts on this subject based on the ideXlab platform.
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a comparison of quadriceps tendon Autograft with bone patellar tendon bone Autograft and hamstring tendon Autograft for primary anterior cruciate ligament reconstruction a systematic review and quantitative synthesis
Clinical Journal of Sport Medicine, 2019Co-Authors: Prabjit Ajrawat, Tim Dwyer, Daniel B Whelan, John Theodoropoulos, Lucas Murnaghan, Manoj Bhargava, Darrell Ogilvieharris, Jaskarndip ChahalAbstract:OBJECTIVE There is growing enthusiasm for the increased use of quadriceps tendon (QT) Autograft for primary anterior cruciate ligament reconstruction (ACLR). The purpose of this analysis was to synthesize and quantitatively assess the available evidence comparing QT Autograft with hamstring tendon (HT) and bone-patellar tendon-bone (BPTB) Autografts, regarding functional outcomes, knee stability, anterior knee pain, and revision rates. DATA SOURCES A search in MEDLINE, EMBASE, PubMed, and the Cochrane Central Register of Controlled Trials for eligible studies up to May 2018 was conducted. Two reviewers selected studies based on inclusion criteria and assessed methodological quality. Outcomes analyzed were anterior knee pain, graft failure rates, knee stability, functional outcomes, and adverse events. Pooled analyses were performed for continuous and dichotomous variables where appropriate. MAIN RESULTS Ten studies (1 randomized trial and 9 nonrandomized cohorts) met our inclusion criteria, which included 1398 patients. The analysis showed no statistical difference in anterior knee pain when comparing QT and HT Autografts, but a significant difference between QT and BPTB Autografts [odds ratio, 0.15 (95% confidence interval, 0.08-0.27); P < 0.001]. There were no differences between all 3 Autografts in revision rates, knee stability, and patient-reported functional outcomes. CONCLUSIONS Quadriceps tendon Autograft is a suitable graft alternative for primary ACLR, as it achieves good clinical outcomes with a low incidence of anterior knee pain. Given the limited quality of the included studies, there is a need for a well-designed multicenter randomized control trial comparing QT Autograft with other primary ACL Autografts to confirm our findings. LEVEL OF EVIDENCE Level IV systematic review.
