human
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Purpose To assess by magnetic resonance imaging ( MRI ) if adult non-cultivated bone marrow stem cells accelerate tendon-to-bone healing in the femoral tunnel , after hamstring anterior cruciate ligament ( ACL ) reconstruction . Methods Forty-three patients underwent ACL reconstruction and were prospect ively r and omized into two groups : 20 patients in the experimental group ( group A ) with adult non-cultivated bone marrow stem cells and 23 patients in the control group ( group B ) without adult non-cultivated bone marrow stem cells . All patients underwent MRI of the knee at three months after surgery to evaluate the signal-to-noise ratio of the interzone . Results There was no difference in the signal-to-noise ratio of the interzone on MRI between the experimental and the control group . Conclusions Adult non-cultivated bone marrow stem cells do not seem to accelerate graft-to-bone healing in ACL reconstruction . The clinical relevance of this finding is that adult non-cultivated bone marrow stem cells apparently have a limited role in ACL reconstruction . Level of evidence II PURPOSE To compare the tunnel enlargement of  double-bundle ( DB ) anterior cruciate ligament reconstruction ( ACLR )  with and without suturing of autologous ruptured tissue to hamstring graft in patients with subacute anterior cruciate ligament injury . METHODS Ten patients with subacute ( ≤3 months after injury ) anterior cruciate ligament rupture were r and omly allocated to undergo DB ACLR with suturing of the ruptured tissue to hamstring graft ( n = 5 ) or conventional DB ACLR ( n = 5 ) . When autologous ruptured tissue was used , remnant ruptured tissue was then harvested , divided into 4 pieces , placed between the loops at the distal and proximal portions of the graft , and secured with the suture . As the primary endpoint , tunnel volume assessment by  3-dimensional multi-detector row computed tomography ( MDCT ) was performed 1 year after ACLR . To assess the efficacy of these procedures , the Lysholm score , anterior tibial translation ( measured with a KT-1000 arthrometer [ MEDmetric , San Diego , CA ] ) , and rotational instability ( measured by the pivot-shift test ) were evaluated after 2 years . RESULTS Tunnel volume enlargement between 3 weeks and 1 year after ACLR as assessed by 3-dimensional MDCT was significantly less for ACLR using ruptured tissue than for conventional ACLR , especially at the femoral site ( P < .05 ) . However , the postoperative Lysholm score , anterior stability of the knee measured with the KT-1000 arthrometer , and rate of negative manual pivot-shift test results did not differ significantly between the 2 groups . There was no correlation to the clinical outcomes in terms of tunnel size . CONCLUSIONS The Lysholm score , anterior laxity measured with the KT-1000 arthrometer , and rotational instability according to the pivot-shift test did not differ significantly between ACLR using ruptured tissue and the conventional technique . However , ACLR using ruptured tissue produced less femoral tunnel enlargement as assessed by MDCT , warranting further long-term follow-up to eluci date its effectiveness . LEVEL OF EVIDENCE Level II , prospect i ve comparative study Background Bone morphogenetic proteins induce new bone both in patients with bone defects and at extraskeletal sites in animals . After anterior cruciate ligament rupture , tendon graft fixation into a bone tunnel is a widely used method for anterior cruciate ligament reconstruction . Hypothesis Bone morphogenetic protein–7 applied to the bone-tendon interface enables better integration of a free tendon graft into the surrounding bone . Study Design Controlled laboratory study . Methods The anterior cruciate ligament was reconstructed using a free tendon graft in the right rear knees of 30 one-year-old male sheep .  Recombinant human bone morphogenetic protein–7 ( 25 μg ) was applied r and omly to the bone-tendon interface in 15 animals , and a vehicle was applied in 15 control animals . At 3 weeks , 10 animals from each group were sacrificed , and the remaining sheep were sacrificed at 6 weeks after surgery . Subsequently , histologic analysis and mechanical testing were performed . In another group of 20 sheep , the same procedure was used and mechanical testing was performed after 3 weeks . Results More new bone was formed at the bone-tendon interface in the knees treated with bone morphogenetic protein–7 as compared histologically with similar areas in control animals , creating areas of dense trabecular network with significantly greater invasion of the tendon fibrous tissue into the bone marrow space . Mechanical testing showed greater strain resistance to force ( 368 N ) in the knees treated with bone morphogenetic protein–7 than in control specimens ( 214 N ) . There was no difference between mechanical testing of sample s from 3 and 6 weeks after surgery . Conclusion Bone morphogenetic protein–7 promotes complete tendon graft integration into the newly formed surrounding trabecular bone in the reconstruction of the anterior cruciate ligament . Clinical Relevance Bone morphogenetic protein–7 in tendon graft integration might be successfully used in reconstructive surgery of ligaments Background : There is controversy regarding the efficacy of remnant tissue preservation on graft healing in anterior cruciate ligament ( ACL ) reconstruction . Hypothesis : The preserved remnant tissue will ( 1 ) adhere to the graft surface and undergo a remodeling process , ( 2 ) accelerate graft revascularization , ( 3 ) increase the number of graft mechanoreceptors by 4 weeks , and ( 4 ) improve anteroposterior knee laxity and structural properties of the graft by 12 weeks . Study Design : Controlled laboratory study . Methods : Forty-two sheep were r and omly divided into 2 groups of 21 animals . In group I , the ACL was completely removed . In group II , the ACL was transected at the midsubstance but not debrided . ACL reconstruction was performed using a semitendinosus tendon autograft in both groups . Histological changes of the grafted tendon and the remnant tissue were evaluated at 4 and 12 weeks after surgery . Biomechanically , anterior translation and knee joint stiffness under an anterior drawer force and the structural properties of the femur-graft-tibia complex were evaluated . Results : The preserved remnant tissue was histologically distinct from the graft at 4 weeks , while the tissue partially adhered to the graft surface at 12 weeks . The ACL remnant tissue significantly accelerated revascularization in the grafted tendon at 4 weeks and significantly increased the number of mechanoreceptors at 4 and 12 weeks . In addition , remnant preservation significantly improved anterior translation ( 9.3 ± 2.1 mm and 5.4 ± 1.7 mm at 60 ° of knee flexion in groups I and II , respectively ) and knee joint stiffness at 12 weeks . However , there were no significant differences in the structural properties between the 2 groups at 4 and 12 weeks after surgery . Conclusion : Preservation of the ACL remnant tissue in ACL reconstruction enhanced cell proliferation , revascularization , and regeneration of proprioceptive organs in the reconstructed ACL and reduced anterior translation . However , remnant preservation did not improve the structural properties of the graft . Clinical Relevance : These results imply that preservation of the ACL remnant tissue may improve graft healing after ACL reconstruction PURPOSE Our purpose was ( 1 ) to compare the structural integrity and healing capacity of the acutely repaired anterior cruciate ligament ( ACL ) remnants and ( 2 ) to determine whether the short-term postoperative biomechanical results of the acute remnant-repairing anterior cruciate ligament reconstruction ( ACLR ) were superior to the conventional ACLR . METHODS An acute complete ACL femoral detachment model was created in 50 rabbits . The rabbits were immediately r and omly allocated into the remnant-repairing ACLR group ( group 1 , n = 25 ) and the conventional ACLR group ( group 2 , n = 25 ) . Each animal in both groups was subjected to unilateral ACLR with semitendinosus tendon autografts . During ACLR , the ACL remnants were acutely repaired with the femoral-tensioning technique in group 1 , whereas the ACL remnants were debrided in group 2 . The outcomes of the remnant were macroscopically evaluated in group 1 . The remnant 's structural integrity and remnant-to-graft healing capacity were divided into 3 categories ( grade A , good ; grade B , fair ; or grade C , poor ) according to 2 distinct criteria . Biomechanical tests including the anterior tibial translation test at 30 ° and 90 ° of knee flexion and tensile tests were compared between groups . All the macroscopic evaluations and biomechanical tests were performed postoperatively at week 12 . RESULTS The macroscopic evaluations of the ACL remnants in group 1 ( n = 25 ) showed that the remnants ' structural integrity was grade A ( well-maintained continuity with an adequate amount of tissue and tension on probing ) in 10 specimens ( 40 % ) , grade B ( fairly maintained continuity with thin and slack fibers detected ) in 5 ( 20 % ) , and grade C ( resorption with no remnant left in situ ) in 10 ( 40 % ) . The remnant-to-graft healing capacities among the specimens with surviving remnants ( grade s A and B for structural integrity , n = 15 ) were all classified as grade C ( an obvious remnant-to-graft interval through the entire length of the graft ) . For the biomechanical tests , there were no significant differences between the groups ( 25 in each group ) with respect to the anterior tibial translation test at 30 ° ( P = .15 ) and 90 ° ( P = .91 ) of knee flexion and stiffness ( P = .66 ) , ultimate failure load ( P = .11 ) , and elongation at failure ( P = .92 ) . CONCLUSIONS In our rabbit model of ACL femoral detachment , the acutely repaired ACL remnants showed a high resorption rate , low healing capacity , and poor biomechanical properties . The acute remnant-repairing ACLR had no evident superiority over the conventional ACLR  in rabbits . CLINICAL RELEVANCE The findings did not support the contention that the remnant-repairing ACLR , even performed in the acute setting , could produce better postoperative knee joint stability outcomes than the conventional ACLR PURPOSE To determine whether the use of platelet-rich plasma gel ( PRPG ) affects magnetic resonance imaging ( MRI ) findings in the anterior cruciate ligament ( ACL ) graft during the first year after reconstruction . METHODS A prospect i ve single-blinded study of 50 ACL reconstructions in 50 patients was performed . In group A ( study group ) PRPG was added to the graft with a st and ardized technique , and in group B ( control group ) no PRPG was added . An  MRI study  was performed postoperatively between 3 and 9 months in group A and between 3 and 12 months in group B. The imaging analysis was performed in a blind protocol by the same radiologist . RESULTS The mean heterogeneity score value at the time of MRI , assigned by the radiologist , was 1.14 in group A and 3.25 in group B. Both groups were comparable in terms of sex and age ( P < .05 ) . The mean time to obtain a completely homogeneous intra-articular segment in group A ( PRPG added ) was 177 days after surgery , and it was 369 days in group B. Using the quadratic predictive model , these findings show that group A ( PRPG added ) needed only 48 % of the time group B required to achieve the same MRI image ( P < .001 ) . CONCLUSIONS ACL reconstruction with the use of PRPG achieves complete homogeneous grafts assessed by MRI , in 179 days compared with 369 days for ACL reconstruction without PRPG . This represents a time shortening of 48 % with respect to ACL reconstruction without PRPG The aim of this study was to investigate whether augmented remnant repair could enhance polyethylene terepthalate ( PET ) artificial ligament graft ligamentization . 12 female goats underwent ACL reconstruction with PET artificial ligament graft in the right knees . Right knees in 6 goats were reconstructed with augmented remnant repair ( Remnant group ) , whereas the other 6 goats had no augmented remnant repair  comprised the Control group . 3 goats in each group were r and omly sacrificed at 6 months and 12 months respectively after surgery . The intra-articular parts of the reconstructed grafts were harvested for histological evaluation . Well-vascularized tissue ingrowth within the artificial ligament was observed in the remnant group at 12 months postoperatively . Collagen-I content of graft was significantly higher in the Remnant group than in the Control group at each time point ( p<0.05 ) . The relative expression of collagen-III positive area of the remnant-preserved group was significantly higher than that of the Control group at 12 months ( p=0.005 ) . The vascular endothelial growth factor (VEGF)-positive or CD31-positive area in the graft appeared higher in the Remnant group compared with the Control group at 6 months . Remnant repair enhanced the revascularization and remodeling of the PET artificial ligament in ACL reconstruction Background : Although  anterior cruciate ligament ( ACL ) reconstruction  is the treatment gold st and ard for ACL injury , it does not reduce the risk of posttraumatic osteoarthritis . Therefore , new treatments that minimize this postoperative comp 
    Output:
    
agent
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Purpose To assess by magnetic resonance imaging ( MRI ) if adult non-cultivated bone marrow stem cells accelerate tendon-to-bone healing in the femoral tunnel , after hamstring anterior cruciate ligament ( ACL ) reconstruction . Methods Forty-three patients underwent ACL reconstruction and were prospect ively r and omized into two groups : 20 patients in the experimental group ( group A ) with adult non-cultivated bone marrow stem cells and 23 patients in the control group ( group B ) without adult non-cultivated bone marrow stem cells . All patients underwent MRI of the knee at three months after surgery to evaluate the signal-to-noise ratio of the interzone . Results There was no difference in the signal-to-noise ratio of the interzone on MRI between the experimental and the control group . Conclusions Adult non-cultivated bone marrow stem cells do not seem to accelerate graft-to-bone healing in ACL reconstruction . The clinical relevance of this finding is that adult non-cultivated bone marrow stem cells apparently have a limited role in ACL reconstruction . Level of evidence II PURPOSE To compare the tunnel enlargement of  double-bundle ( DB ) anterior cruciate ligament reconstruction ( ACLR )  with and without suturing of autologous ruptured tissue to hamstring graft in patients with subacute anterior cruciate ligament injury . METHODS Ten patients with subacute ( ≤3 months after injury ) anterior cruciate ligament rupture were r and omly allocated to undergo DB ACLR with suturing of the ruptured tissue to hamstring graft ( n = 5 ) or conventional DB ACLR ( n = 5 ) . When autologous ruptured tissue was used , remnant ruptured tissue was then harvested , divided into 4 pieces , placed between the loops at the distal and proximal portions of the graft , and secured with the suture . As the primary endpoint , tunnel volume assessment by  3-dimensional multi-detector row computed tomography ( MDCT ) was performed 1 year after ACLR . To assess the efficacy of these procedures , the Lysholm score , anterior tibial translation ( measured with a KT-1000 arthrometer [ MEDmetric , San Diego , CA ] ) , and rotational instability ( measured by the pivot-shift test ) were evaluated after 2 years . RESULTS Tunnel volume enlargement between 3 weeks and 1 year after ACLR as assessed by 3-dimensional MDCT was significantly less for ACLR using ruptured tissue than for conventional ACLR , especially at the femoral site ( P < .05 ) . However , the postoperative Lysholm score , anterior stability of the knee measured with the KT-1000 arthrometer , and rate of negative manual pivot-shift test results did not differ significantly between the 2 groups . There was no correlation to the clinical outcomes in terms of tunnel size . CONCLUSIONS The Lysholm score , anterior laxity measured with the KT-1000 arthrometer , and rotational instability according to the pivot-shift test did not differ significantly between ACLR using ruptured tissue and the conventional technique . However , ACLR using ruptured tissue produced less femoral tunnel enlargement as assessed by MDCT , warranting further long-term follow-up to eluci date its effectiveness . LEVEL OF EVIDENCE Level II , prospect i ve comparative study Background Bone morphogenetic proteins induce new bone both in patients with bone defects and at extraskeletal sites in animals . After anterior cruciate ligament rupture , tendon graft fixation into a bone tunnel is a widely used method for anterior cruciate ligament reconstruction . Hypothesis Bone morphogenetic protein–7 applied to the bone-tendon interface enables better integration of a free tendon graft into the surrounding bone . Study Design Controlled laboratory study . Methods The anterior cruciate ligament was reconstructed using a free tendon graft in the right rear knees of 30 one-year-old male sheep .  Recombinant human bone morphogenetic protein–7 ( 25 μg ) was applied r and omly to the bone-tendon interface in 15 animals , and a vehicle was applied in 15 control animals . At 3 weeks , 10 animals from each group were sacrificed , and the remaining sheep were sacrificed at 6 weeks after surgery . Subsequently , histologic analysis and mechanical testing were performed . In another group of 20 sheep , the same procedure was used and mechanical testing was performed after 3 weeks . Results More new bone was formed at the bone-tendon interface in the knees treated with bone morphogenetic protein–7 as compared histologically with similar areas in control animals , creating areas of dense trabecular network with significantly greater invasion of the tendon fibrous tissue into the bone marrow space . Mechanical testing showed greater strain resistance to force ( 368 N ) in the knees treated with bone morphogenetic protein–7 than in control specimens ( 214 N ) . There was no difference between mechanical testing of sample s from 3 and 6 weeks after surgery . Conclusion Bone morphogenetic protein–7 promotes complete tendon graft integration into the newly formed surrounding trabecular bone in the reconstruction of the anterior cruciate ligament . Clinical Relevance Bone morphogenetic protein–7 in tendon graft integration might be successfully used in reconstructive surgery of ligaments Background : There is controversy regarding the efficacy of remnant tissue preservation on graft healing in anterior cruciate ligament ( ACL ) reconstruction . Hypothesis : The preserved remnant tissue will ( 1 ) adhere to the graft surface and undergo a remodeling process , ( 2 ) accelerate graft revascularization , ( 3 ) increase the number of graft mechanoreceptors by 4 weeks , and ( 4 ) improve anteroposterior knee laxity and structural properties of the graft by 12 weeks . Study Design : Controlled laboratory study . Methods : Forty-two sheep were r and omly divided into 2 groups of 21 animals . In group I , the ACL was completely removed . In group II , the ACL was transected at the midsubstance but not debrided . ACL reconstruction was performed using a semitendinosus tendon autograft in both groups . Histological changes of the grafted tendon and the remnant tissue were evaluated at 4 and 12 weeks after surgery . Biomechanically , anterior translation and knee joint stiffness under an anterior drawer force and the structural properties of the femur-graft-tibia complex were evaluated . Results : The preserved remnant tissue was histologically distinct from the graft at 4 weeks , while the tissue partially adhered to the graft surface at 12 weeks . The ACL remnant tissue significantly accelerated revascularization in the grafted tendon at 4 weeks and significantly increased the number of mechanoreceptors at 4 and 12 weeks . In addition , remnant preservation significantly improved anterior translation ( 9.3 ± 2.1 mm and 5.4 ± 1.7 mm at 60 ° of knee flexion in groups I and II , respectively ) and knee joint stiffness at 12 weeks . However , there were no significant differences in the structural properties between the 2 groups at 4 and 12 weeks after surgery . Conclusion : Preservation of the ACL remnant tissue in ACL reconstruction enhanced cell proliferation , revascularization , and regeneration of proprioceptive organs in the reconstructed ACL and reduced anterior translation . However , remnant preservation did not improve the structural properties of the graft . Clinical Relevance : These results imply that preservation of the ACL remnant tissue may improve graft healing after ACL reconstruction PURPOSE Our purpose was ( 1 ) to compare the structural integrity and healing capacity of the acutely repaired anterior cruciate ligament ( ACL ) remnants and ( 2 ) to determine whether the short-term postoperative biomechanical results of the acute remnant-repairing anterior cruciate ligament reconstruction ( ACLR ) were superior to the conventional ACLR . METHODS An acute complete ACL femoral detachment model was created in 50 rabbits . The rabbits were immediately r and omly allocated into the remnant-repairing ACLR group ( group 1 , n = 25 ) and the conventional ACLR group ( group 2 , n = 25 ) . Each animal in both groups was subjected to unilateral ACLR with semitendinosus tendon autografts . During ACLR , the ACL remnants were acutely repaired with the femoral-tensioning technique in group 1 , whereas the ACL remnants were debrided in group 2 . The outcomes of the remnant were macroscopically evaluated in group 1 . The remnant 's structural integrity and remnant-to-graft healing capacity were divided into 3 categories ( grade A , good ; grade B , fair ; or grade C , poor ) according to 2 distinct criteria . Biomechanical tests including the anterior tibial translation test at 30 ° and 90 ° of knee flexion and tensile tests were compared between groups . All the macroscopic evaluations and biomechanical tests were performed postoperatively at week 12 . RESULTS The macroscopic evaluations of the ACL remnants in group 1 ( n = 25 ) showed that the remnants ' structural integrity was grade A ( well-maintained continuity with an adequate amount of tissue and tension on probing ) in 10 specimens ( 40 % ) , grade B ( fairly maintained continuity with thin and slack fibers detected ) in 5 ( 20 % ) , and grade C ( resorption with no remnant left in situ ) in 10 ( 40 % ) . The remnant-to-graft healing capacities among the specimens with surviving remnants ( grade s A and B for structural integrity , n = 15 ) were all classified as grade C ( an obvious remnant-to-graft interval through the entire length of the graft ) . For the biomechanical tests , there were no significant differences between the groups ( 25 in each group ) with respect to the anterior tibial translation test at 30 ° ( P = .15 ) and 90 ° ( P = .91 ) of knee flexion and stiffness ( P = .66 ) , ultimate failure load ( P = .11 ) , and elongation at failure ( P = .92 ) . CONCLUSIONS In our rabbit model of ACL femoral detachment , the acutely repaired ACL remnants showed a high resorption rate , low healing capacity , and poor biomechanical properties . The acute remnant-repairing ACLR had no evident superiority over the conventional ACLR  in rabbits . CLINICAL RELEVANCE The findings did not support the contention that the remnant-repairing ACLR , even performed in the acute setting , could produce better postoperative knee joint stability outcomes than the conventional ACLR PURPOSE To determine whether the use of platelet-rich plasma gel ( PRPG ) affects magnetic resonance imaging ( MRI ) findings in the anterior cruciate ligament ( ACL ) graft during the first year after reconstruction . METHODS A prospect i ve single-blinded study of 50 ACL reconstructions in 50 patients was performed . In group A ( study group ) PRPG was added to the graft with a st and ardized technique , and in group B ( control group ) no PRPG was added . An  MRI study  was performed postoperatively between 3 and 9 months in group A and between 3 and 12 months in group B. The imaging analysis was performed in a blind protocol by the same radiologist . RESULTS The mean heterogeneity score value at the time of MRI , assigned by the radiologist , was 1.14 in group A and 3.25 in group B. Both groups were comparable in terms of sex and age ( P < .05 ) . The mean time to obtain a completely homogeneous intra-articular segment in group A ( PRPG added ) was 177 days after surgery , and it was 369 days in group B. Using the quadratic predictive model , these findings show that group A ( PRPG added ) needed only 48 % of the time group B required to achieve the same MRI image ( P < .001 ) . CONCLUSIONS ACL reconstruction with the use of PRPG achieves complete homogeneous grafts assessed by MRI , in 179 days compared with 369 days for ACL reconstruction without PRPG . This represents a time shortening of 48 % with respect to ACL reconstruction without PRPG The aim of this study was to investigate whether augmented remnant repair could enhance polyethylene terepthalate ( PET ) artificial ligament graft ligamentization . 12 female goats underwent ACL reconstruction with PET artificial ligament graft in the right knees . Right knees in 6 goats were reconstructed with augmented remnant repair ( Remnant group ) , whereas the other 6 goats had no augmented remnant repair  comprised the Control group . 3 goats in each group were r and omly sacrificed at 6 months and 12 months respectively after surgery . The intra-articular parts of the reconstructed grafts were harvested for histological evaluation . Well-vascularized tissue ingrowth within the artificial ligament was observed in the remnant group at 12 months postoperatively . Collagen-I content of graft was significantly higher in the Remnant group than in the Control group at each time point ( p<0.05 ) . The relative expression of collagen-III positive area of the remnant-preserved group was significantly higher than that of the Control group at 12 months ( p=0.005 ) . The vascular endothelial growth factor (VEGF)-positive or CD31-positive area in the graft appeared higher in the Remnant group compared with the Control group at 6 months . Remnant repair enhanced the revascularization and remodeling of the PET artificial ligament in ACL reconstruction Background : Although  anterior cruciate ligament ( ACL ) reconstruction  is the treatment gold st and ard for ACL injury , it does not reduce the risk of posttraumatic osteoarthritis . Therefore , new treatments that minimize this postoperative comp 
    Output:
    