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: Objective To investigate whether the cartilage regenerative effects of intra-aricular platelet-rich plasma ( PRP ) are different , according to the severity of osteoarthritis ( OA ) , in a collagenase-induced knee OA rabbit model . Method New Zeal and white rabbits ( N=21 ) were r and omly divided into three groups . Three different doses ( 0.25 mg , group 1 ; 0.5 mg , group 2 ; and 1.0 mg , group 3 ) of collagenase were injected twice into both knees of each group under an ultrasound guidance . The mean platelet concentration of the PRP fraction was 2,664±970 × 103/µl and was enriched 8.2-times , compared with the whole blood . PRP ( 0.3 ml ) was injected into the left knee and saline ( 0.3 ml ) into the right knee at 4 weeks , and macroscopic and histological scores of both injected knees were evaluated at 9 weeks after the first collagenase injection . Results Macroscopic and histological scores of group 3 were significantly higher than those of group 1 and 2 ( p<0.05 ) . Macroscopic and histological scores of the PRP-injected knees were significantly lower than those of the saline-injected knees , in all groups ( p<0.05 ) . Differences of gross morphologic and histologic scores between saline- and PRP-injected knees in group 3 were significantly higher than those in group 1 and 2 ( p<0.05 ) . Conclusion Intra-articular PRP injection  influences cartilage regeneration in all severities of rabbit knee OA , and the cartilage regenerative power  of PRP injection in moderate knee OA was greater than that in mild or very mild OA . A large pre clinical trial is needed to establish the validity of our study Background : Arthrosis is particularly prevalent in the knee . Infiltration treatment for gonarthrosis is among the most widely used techniques in orthopaedic practice . Purpose : To compare the clinical response of hyaluronic acid ( HA ) and platelet-rich plasma ( PRP ) treatment in 2 groups of patients affected by gonarthrosis . Study Design : R and omized controlled trial ; Level of evidence , 1 . Methods : A total of 120 patients affected by clinical ly and radiographically documented gonarthrosis were included in this study . The gonarthrosis was grade d using the Kellgren-Lawrence radiographic classification scale . The 120 patients were r and omized into 2 study groups in a 1:1 ratio : 60 patients received 4 intra-articular injections of PRP ( specifically , autologous conditioned plasma [ ACP ] , 5.5 mL ) , and 60 patients received 4 intra-articular injections of HA ( 20 mg/2 mL ) . An unblinded physician performed infiltration once a week for 4 weeks into the knee affected by clinical ly relevant gonarthrosis ( in both groups ) . All patients were evaluated with the Western Ontario and McMaster ( WOMAC ) score before the infiltration and at 4 , 12 , and 24 weeks after the first injection . Results : Treatment with a local injection of ACP had a significant effect shortly after the final infiltration and a continuously improving sustained effect up to 24 weeks ( WOMAC score , 65.1 and 36.5 in the HA and ACP groups , respectively ; P < .001 ) , where the clinical outcomes were better compared with the results with HA . In the HA group , the worst results were obtained for grade III gonarthrosis , whereas the clinical results obtained in the ACP group did not show any statistically significant difference in terms of the grade of gonarthrosis . The mean WOMAC scores for grade III gonarthrosis were 74.85 in the HA group and 41.20 in the ACP group ( P < .001 ) . Conclusion : Treatment with ACP showed a significantly better clinical outcome than did treatment with HA , with sustained lower WOMAC scores . Treatment with HA did not seem to be effective in the patients with grade III gonarthrosis In recent years biological strategies are being more widely used to treat cartilage lesions . One of the most exploited novel treatments is Platelet-rich Plasma ( PRP ) , whose high content of growth factors is supposed to determine a regenerative stimulus to cartilaginous tissue . Despite many promising in vitro and in vivo studies , when discussing clinical application a clear indication for the use of PRP can not be assessed . There are initial encouraging clinical data , but only a few r and omized controlled trials have been published , so it is not possible to fully endorse this kind of approach for the treatment of cartilage pathology . Furthermore , study comparison is very difficult due to the great variability in PRP preparation methods , cell content and concentration , storage modalities , activation methods and even application protocol s. These factors partially explain the lack of high quality controlled trials up to now . This paper discusses the main aspects concerning the basic biology of PRP , the principal sources of variability , and summarizes the available literature on PRP use , both in surgical and conservative treatments . Based on current evidence , PRP treatment should only be indicated for low- grade cartilage degeneration and in case of failure of more traditional conservative approaches PURPOSE The aim of our study is to compare the efficacy of platelet-rich plasma ( PRP ) and viscosupplementation ( hyaluronic acid [ HA ] ) intra-articular injections for the treatment of knee cartilage degenerative lesions and osteoarthritis ( OA ) . METHODS The study involved 150 patients affected by cartilage degenerative lesions and early and severe OA . Fifty symptomatic patients were treated with 3 autologous PRP intra-articular injections and were evaluated prospect ively at enrollment and at 2- and 6-month follow-up . The results obtained were compared with 2 homogeneous groups of patients treated with HA injections . One group was treated with injections of high-molecular weight HA ; the other group was treated with low-molecular weight ( LW ) HA .  International Knee Documentation Committee and EQ VAS scores were used for clinical evaluation ; adverse events and patient satisfaction were also recorded . RESULTS At 2 months ' follow-up , the PRP and LW HA groups showed a similar improvement , with higher results compared with the high-molecular weight HA group ( P < .005 ) . At 6 months ' follow-up , better results were observed in the PRP group ( P < .005 ) . PRP and LW HA treatments offered similar results in patients aged over 50 years and in the treatment of advanced OA . PRP showed a better performance compared with HA in younger patients affected by cartilage lesions or early OA . CONCLUSIONS Autologous PRP injections showed more and longer efficacy than HA injections in reducing pain and symptoms and recovering articular function . Better results were achieved in younger and more active patients with a low degree of cartilage degeneration , whereas a worse outcome was obtained in more degenerated joints and in older patients , in whom results similar to those of viscosupplementation have been observed . LEVEL OF EVIDENCE Level II , prospect i ve comparative study Background Platelet Rich Plasma ( PRP ) , a blood-derived product rich in growth factors , is a promising treatment for cartilage defects but there is still a lack of clinical evidence . The aim of this study is to show , through a r and omized double blind prospect i ve trial , the efficacy of this procedure , by comparing PRP to Hyaluronic Acid ( HA ) injections for the treatment of knee chondropathy or osteoarthritis ( OA ) . Methods 109 patients ( 55 treated with HA and 54 with PRP )  were treated and evaluated at 12 months of follow-up . The patients were enrolled according to the following inclusion criteria : age > 18 years , history of chronic ( at least 4 months ) pain or swelling of the knee and imaging findings of degenerative changes of the joint ( Kellgren-Lawrence Score up to 3 ) . A cycle of 3 weekly injections was administered blindly . All patients were prospect ively evaluated before and at 2 , 6 , and 12 months after the treatment by : IKDC , EQ-VAS , TEGNER , and KOOS scores . Range of motion and knee circumference changes were measured over time . Adverse events and patient satisfaction were also recorded . Results Only minor adverse events were detected in some patients , such as mild pain and effusion after the injections , in particular in the PRP group , where a significantly higher post-injective pain reaction was observed ( p=0.039 ) . At the follow-up evaluations , both groups presented a clinical improvement but the comparison between the two groups showed a not statistically significant difference in all scores evaluated . A trend favorable for the PRP group was only found in patients with low grade articular degeneration ( Kellgren-Lawrence score up to 2 ) . Conclusions Results suggest that PRP injections offer a significant clinical improvement up to one year of follow-up . However , conversely to what was shown by the current literature , for middle-aged patients with moderate signs of OA , PRP results were not better than those obtained with HA injections , and thus it should not be considered as first line treatment . More promising results are shown for its use in low grade degeneration , but they still have to be confirmed Background : Nonoperative options for osteochondral lesions ( OCLs ) of the talar dome are limited , and currently , there is a lack of scientific evidence to guide management . Purpose : To evaluate the short-term efficacy and safety of platelet-rich plasma ( PRP ) compared with hyaluronic acid ( HA ) in reducing pain and disability caused by OCLs of the ankle . Study Design : R and omized controlled trial ; Level of evidence , 2 . Methods : Thirty-two patients aged 18 to 60 years were allocated to a treatment by intra-articular injections of either HA ( group 1 ) or PRP ( plasma rich in growth factors [ PRGF ] technique , group 2 ) for OCLs of the talus . Thirty OCLs , 15 per arm , received 3 consecutive intra-articular therapeutic injections and were followed for 28 weeks . The efficacy of the injections in reducing pain and improving function was assessed at each visit using the American Orthopaedic Foot and Ankle Society ( AOFAS ) Ankle-Hindfoot Scale ( AHFS ) ; a visual analog scale ( VAS ) for pain , stiffness , and function ; and the subjective global function score . Results : The majority of patients were men ( n = 23 ; 79 % ) . The AHFS score improved from 66 and 68 to 78 and 92 in groups 1 and 2 , respectively , from baseline to week 28 ( P < .0001 ) , favoring PRP ( P < .05 ) . Mean VAS scores ( 1 = asymptomatic , 10 = severe symptoms ) decreased for pain ( group 1 : 5.6 to 3.1 ; group 2 : 4.1 to 0.9 ) , stiffness ( group 1 : 5.1 to 2.9 ; group 2 : 5.0 to 0.8 ) , and function ( group 1 : 5.8 to 3.5 ; group 2 : 4.7 to 0.8 ) from baseline to week 28 ( P < .0001 ) , favoring PRP ( P < .05 for stiffness , P < .01 for function , P > .05 for pain ) . Subjective global function scores , reported on a scale from 0 to 100 ( with 100 representing healthy , preinjury function ) improved from 56 and 58 at baseline to 73 and 91 by week 28 for groups 1 and 2 , respectively ( P < .01 in favor of PRP ) . Conclusion : Osteochondral lesions of the ankle treated with intra-articular injections of PRP and HA result ed in a decrease in pain scores and an increase in function for at least 6 months , with minimal adverse events .  Platelet-rich plasma treatment led to a significantly better outcome than HA A biodegradable , hyaluronian-based biocompatible scaffold was used for autologous chondrocyte transplantation . This prospect i ve study analyzes a clinical outcome of 70 consecutive patients treated by arthroscopic autologous chondrocyte transplantation at minimum 24 months follow up ( 47 of these patients achieved minimum 36 months follow-up and 21 patients minimum 48 months follow-up ) in order to establish clear indication criteria for this type of treatment . 31 of these patients presented isolated chondral lesions , while 39 patients with associated lesions ( 23 ACL lesions , 28 meniscal lesions , 1 varus knee ) were treated during the same surgical procedure with cartilage harvesting . A statistically significant clinical improvement was shown just at 24 months and the second-look arthroscopy demonstrated a complete coverage of the grafted area with a hyaline cartilage-like tissue in 12 of 15 analyzed patients . A better clinical outcome was observed in young , well-trained patients and in traumatic lesions . Other factors , such as defect size , localization , previous and associated surgery did not influence significantly the results . This matrix autologous chondrocyte transplantation procedure simplifies the surgical procedure and can be performed arthroscopically , thus reducing surgical morbidity and recovery time Purpose To compare the safety and efficacy of two different approaches of platelet-rich plasma ( PRP ) production methods as intra-articular injection treatment for knee cartilage degenerative lesions and osteoarthritis ( OA ) . Methods The study involved 144 symptomatic patients affected by cartilage degenerative lesions and OA . Seventy-two patients were treated with 3  injections of platelet concentrate prepared with a single-spinning procedure ( PRGF ) , the other  
    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: Objective To investigate whether the cartilage regenerative effects of intra-aricular platelet-rich plasma ( PRP ) are different , according to the severity of osteoarthritis ( OA ) , in a collagenase-induced knee OA rabbit model . Method New Zeal and white rabbits ( N=21 ) were r and omly divided into three groups . Three different doses ( 0.25 mg , group 1 ; 0.5 mg , group 2 ; and 1.0 mg , group 3 ) of collagenase were injected twice into both knees of each group under an ultrasound guidance . The mean platelet concentration of the PRP fraction was 2,664±970 × 103/µl and was enriched 8.2-times , compared with the whole blood . PRP ( 0.3 ml ) was injected into the left knee and saline ( 0.3 ml ) into the right knee at 4 weeks , and macroscopic and histological scores of both injected knees were evaluated at 9 weeks after the first collagenase injection . Results Macroscopic and histological scores of group 3 were significantly higher than those of group 1 and 2 ( p<0.05 ) . Macroscopic and histological scores of the PRP-injected knees were significantly lower than those of the saline-injected knees , in all groups ( p<0.05 ) . Differences of gross morphologic and histologic scores between saline- and PRP-injected knees in group 3 were significantly higher than those in group 1 and 2 ( p<0.05 ) . Conclusion Intra-articular PRP injection  influences cartilage regeneration in all severities of rabbit knee OA , and the cartilage regenerative power  of PRP injection in moderate knee OA was greater than that in mild or very mild OA . A large pre clinical trial is needed to establish the validity of our study Background : Arthrosis is particularly prevalent in the knee . Infiltration treatment for gonarthrosis is among the most widely used techniques in orthopaedic practice . Purpose : To compare the clinical response of hyaluronic acid ( HA ) and platelet-rich plasma ( PRP ) treatment in 2 groups of patients affected by gonarthrosis . Study Design : R and omized controlled trial ; Level of evidence , 1 . Methods : A total of 120 patients affected by clinical ly and radiographically documented gonarthrosis were included in this study . The gonarthrosis was grade d using the Kellgren-Lawrence radiographic classification scale . The 120 patients were r and omized into 2 study groups in a 1:1 ratio : 60 patients received 4 intra-articular injections of PRP ( specifically , autologous conditioned plasma [ ACP ] , 5.5 mL ) , and 60 patients received 4 intra-articular injections of HA ( 20 mg/2 mL ) . An unblinded physician performed infiltration once a week for 4 weeks into the knee affected by clinical ly relevant gonarthrosis ( in both groups ) . All patients were evaluated with the Western Ontario and McMaster ( WOMAC ) score before the infiltration and at 4 , 12 , and 24 weeks after the first injection . Results : Treatment with a local injection of ACP had a significant effect shortly after the final infiltration and a continuously improving sustained effect up to 24 weeks ( WOMAC score , 65.1 and 36.5 in the HA and ACP groups , respectively ; P < .001 ) , where the clinical outcomes were better compared with the results with HA . In the HA group , the worst results were obtained for grade III gonarthrosis , whereas the clinical results obtained in the ACP group did not show any statistically significant difference in terms of the grade of gonarthrosis . The mean WOMAC scores for grade III gonarthrosis were 74.85 in the HA group and 41.20 in the ACP group ( P < .001 ) . Conclusion : Treatment with ACP showed a significantly better clinical outcome than did treatment with HA , with sustained lower WOMAC scores . Treatment with HA did not seem to be effective in the patients with grade III gonarthrosis In recent years biological strategies are being more widely used to treat cartilage lesions . One of the most exploited novel treatments is Platelet-rich Plasma ( PRP ) , whose high content of growth factors is supposed to determine a regenerative stimulus to cartilaginous tissue . Despite many promising in vitro and in vivo studies , when discussing clinical application a clear indication for the use of PRP can not be assessed . There are initial encouraging clinical data , but only a few r and omized controlled trials have been published , so it is not possible to fully endorse this kind of approach for the treatment of cartilage pathology . Furthermore , study comparison is very difficult due to the great variability in PRP preparation methods , cell content and concentration , storage modalities , activation methods and even application protocol s. These factors partially explain the lack of high quality controlled trials up to now . This paper discusses the main aspects concerning the basic biology of PRP , the principal sources of variability , and summarizes the available literature on PRP use , both in surgical and conservative treatments . Based on current evidence , PRP treatment should only be indicated for low- grade cartilage degeneration and in case of failure of more traditional conservative approaches PURPOSE The aim of our study is to compare the efficacy of platelet-rich plasma ( PRP ) and viscosupplementation ( hyaluronic acid [ HA ] ) intra-articular injections for the treatment of knee cartilage degenerative lesions and osteoarthritis ( OA ) . METHODS The study involved 150 patients affected by cartilage degenerative lesions and early and severe OA . Fifty symptomatic patients were treated with 3 autologous PRP intra-articular injections and were evaluated prospect ively at enrollment and at 2- and 6-month follow-up . The results obtained were compared with 2 homogeneous groups of patients treated with HA injections . One group was treated with injections of high-molecular weight HA ; the other group was treated with low-molecular weight ( LW ) HA .  International Knee Documentation Committee and EQ VAS scores were used for clinical evaluation ; adverse events and patient satisfaction were also recorded . RESULTS At 2 months ' follow-up , the PRP and LW HA groups showed a similar improvement , with higher results compared with the high-molecular weight HA group ( P < .005 ) . At 6 months ' follow-up , better results were observed in the PRP group ( P < .005 ) . PRP and LW HA treatments offered similar results in patients aged over 50 years and in the treatment of advanced OA . PRP showed a better performance compared with HA in younger patients affected by cartilage lesions or early OA . CONCLUSIONS Autologous PRP injections showed more and longer efficacy than HA injections in reducing pain and symptoms and recovering articular function . Better results were achieved in younger and more active patients with a low degree of cartilage degeneration , whereas a worse outcome was obtained in more degenerated joints and in older patients , in whom results similar to those of viscosupplementation have been observed . LEVEL OF EVIDENCE Level II , prospect i ve comparative study Background Platelet Rich Plasma ( PRP ) , a blood-derived product rich in growth factors , is a promising treatment for cartilage defects but there is still a lack of clinical evidence . The aim of this study is to show , through a r and omized double blind prospect i ve trial , the efficacy of this procedure , by comparing PRP to Hyaluronic Acid ( HA ) injections for the treatment of knee chondropathy or osteoarthritis ( OA ) . Methods 109 patients ( 55 treated with HA and 54 with PRP )  were treated and evaluated at 12 months of follow-up . The patients were enrolled according to the following inclusion criteria : age > 18 years , history of chronic ( at least 4 months ) pain or swelling of the knee and imaging findings of degenerative changes of the joint ( Kellgren-Lawrence Score up to 3 ) . A cycle of 3 weekly injections was administered blindly . All patients were prospect ively evaluated before and at 2 , 6 , and 12 months after the treatment by : IKDC , EQ-VAS , TEGNER , and KOOS scores . Range of motion and knee circumference changes were measured over time . Adverse events and patient satisfaction were also recorded . Results Only minor adverse events were detected in some patients , such as mild pain and effusion after the injections , in particular in the PRP group , where a significantly higher post-injective pain reaction was observed ( p=0.039 ) . At the follow-up evaluations , both groups presented a clinical improvement but the comparison between the two groups showed a not statistically significant difference in all scores evaluated . A trend favorable for the PRP group was only found in patients with low grade articular degeneration ( Kellgren-Lawrence score up to 2 ) . Conclusions Results suggest that PRP injections offer a significant clinical improvement up to one year of follow-up . However , conversely to what was shown by the current literature , for middle-aged patients with moderate signs of OA , PRP results were not better than those obtained with HA injections , and thus it should not be considered as first line treatment . More promising results are shown for its use in low grade degeneration , but they still have to be confirmed Background : Nonoperative options for osteochondral lesions ( OCLs ) of the talar dome are limited , and currently , there is a lack of scientific evidence to guide management . Purpose : To evaluate the short-term efficacy and safety of platelet-rich plasma ( PRP ) compared with hyaluronic acid ( HA ) in reducing pain and disability caused by OCLs of the ankle . Study Design : R and omized controlled trial ; Level of evidence , 2 . Methods : Thirty-two patients aged 18 to 60 years were allocated to a treatment by intra-articular injections of either HA ( group 1 ) or PRP ( plasma rich in growth factors [ PRGF ] technique , group 2 ) for OCLs of the talus . Thirty OCLs , 15 per arm , received 3 consecutive intra-articular therapeutic injections and were followed for 28 weeks . The efficacy of the injections in reducing pain and improving function was assessed at each visit using the American Orthopaedic Foot and Ankle Society ( AOFAS ) Ankle-Hindfoot Scale ( AHFS ) ; a visual analog scale ( VAS ) for pain , stiffness , and function ; and the subjective global function score . Results : The majority of patients were men ( n = 23 ; 79 % ) . The AHFS score improved from 66 and 68 to 78 and 92 in groups 1 and 2 , respectively , from baseline to week 28 ( P < .0001 ) , favoring PRP ( P < .05 ) . Mean VAS scores ( 1 = asymptomatic , 10 = severe symptoms ) decreased for pain ( group 1 : 5.6 to 3.1 ; group 2 : 4.1 to 0.9 ) , stiffness ( group 1 : 5.1 to 2.9 ; group 2 : 5.0 to 0.8 ) , and function ( group 1 : 5.8 to 3.5 ; group 2 : 4.7 to 0.8 ) from baseline to week 28 ( P < .0001 ) , favoring PRP ( P < .05 for stiffness , P < .01 for function , P > .05 for pain ) . Subjective global function scores , reported on a scale from 0 to 100 ( with 100 representing healthy , preinjury function ) improved from 56 and 58 at baseline to 73 and 91 by week 28 for groups 1 and 2 , respectively ( P < .01 in favor of PRP ) . Conclusion : Osteochondral lesions of the ankle treated with intra-articular injections of PRP and HA result ed in a decrease in pain scores and an increase in function for at least 6 months , with minimal adverse events .  Platelet-rich plasma treatment led to a significantly better outcome than HA A biodegradable , hyaluronian-based biocompatible scaffold was used for autologous chondrocyte transplantation . This prospect i ve study analyzes a clinical outcome of 70 consecutive patients treated by arthroscopic autologous chondrocyte transplantation at minimum 24 months follow up ( 47 of these patients achieved minimum 36 months follow-up and 21 patients minimum 48 months follow-up ) in order to establish clear indication criteria for this type of treatment . 31 of these patients presented isolated chondral lesions , while 39 patients with associated lesions ( 23 ACL lesions , 28 meniscal lesions , 1 varus knee ) were treated during the same surgical procedure with cartilage harvesting . A statistically significant clinical improvement was shown just at 24 months and the second-look arthroscopy demonstrated a complete coverage of the grafted area with a hyaline cartilage-like tissue in 12 of 15 analyzed patients . A better clinical outcome was observed in young , well-trained patients and in traumatic lesions . Other factors , such as defect size , localization , previous and associated surgery did not influence significantly the results . This matrix autologous chondrocyte transplantation procedure simplifies the surgical procedure and can be performed arthroscopically , thus reducing surgical morbidity and recovery time Purpose To compare the safety and efficacy of two different approaches of platelet-rich plasma ( PRP ) production methods as intra-articular injection treatment for knee cartilage degenerative lesions and osteoarthritis ( OA ) . Methods The study involved 144 symptomatic patients affected by cartilage degenerative lesions and OA . Seventy-two patients were treated with 3  injections of platelet concentrate prepared with a single-spinning procedure ( PRGF ) , the other  
    Output:
    