Platelet rich plasma in arthroscopic rotator cuff repair: a prospective RCT study, 2-year follow-up. Platelet-rich plasma injection for chronic Achilles tendinopathy: a randomized controlled trial. Platelet-rich plasma vs hyaluronic acid to treat knee degenerative pathology: study design and preliminary results of a randomized controlled trial Patellar Tendon Healing With Platelet-Rich Plasma Ongoing Positive Effect of Platelet-Rich Plasma Versus Corticosteroid Injection in Lateral Epicondylitis Ultrasound guided injections of platelets rich plasma for muscle injury in professional athletes. Comparative study. Platelet-Rich Plasma Versus Focused Shock Waves in the Treatment of Jumper’s Knee in Athletes Treatment of Lateral Epicondylitis With Platelet-Rich Plasma, Glucocorticoid, or Saline Has platelet-rich plasma any role in anterior cruciate ligament allograft healing? Platelet-rich plasma prevents blood loss and pain and enhances early functional outcome after total knee arthroplasty: a prospective randomised controlled study Increased vascularization during early healing after biologic augmentation in repair of chronic rotator cuff tears using autologous leukocyte- and platelet-rich fibrin (L-PRF): a prospective randomized controlled pilot trial. Platelet-rich plasma injections for the treatment of refractory Achilles tendinopathy: results at 4 years. Growth factor-based therapies provide additional benefit beyond physical therapy in resistant elbow tendinopathy: a prospective, single-blind, randomised trial of autologous blood injections versus platelet-rich plasma injections
HYPOTHESIS Local application of autologous platelet rich plasma ( PRP ) improves tendon healing in patients undergoing arthroscopic rotator cuff repair . STUDY DESIGN Prospect i ve , r and omized , controlled , double blind study ; considering an alpha level of 5 % , a power of 80 % , 22 patients for group are needed . MATERIAL S AND METHODS Fifty-three patients who underwent shoulder arthroscopy for the repair of a complete rotator cuff tear were r and omly divided into 2 groups , using a block r and omization procedure . A treatment group ( N = 26 ) consisted of those who received an intraoperative application of PRP in combination with an autologous thrombin component . A control group ( N = 27 ) consisted of those who did not receive that treatment . Patients were evaluated with vali date d outcome scores . A magnetic resonance image ( MRI ) was performed in all cases at more than 1 year post-op . All patients had the same accelerated rehabilitation protocol . RESULTS The 2 groups were homogeneous . The pain score in the treatment group was lower than the control group at 3 , 7 , 14 , and 30 days after surgery ( P < .05 ) . On the Simple Shoulder Test ( SST ) , University of California ( UCLA ) , and Constant scores , strength in external rotation , as measured by a dynamometer , were significantly higher in the treatment group than the control group at 3 months after surgery ( strength in external rotation [ SER ] : 3 ± 1.6 vs 2.1 ± 1.3 kg ; SST : 8.9 ± 2.2 vs 7.1 ± 2.7 ; UCLA : 26.9 ± 3 vs 24.2 ± 4.9 ; Constant : 65 ± 9 vs 57.8 ± 11 ; P < .05 ) . There was no difference between the 2 groups after 6 , 12 , and 24 months . The follow-up MRI showed no significant difference in the healing rate of the rotator cuff tear . In the subgroup of grade 1 and 2 tears , with less retraction , SER in the PRP group was significant higher at 3 , 6 , 12 , and 24 months postoperative ( P < .05 ) . CONCLUSION The results of our study showed autologous PRP  reduced pain in the first postoperative months . The long-term results of subgroups of grade 1 and 2 tears suggest that PRP positively affected cuff rotator healing CONTEXT Tendon disorders comprise 30 % to 50 % of all activity-related injuries ; chronic degenerative tendon disorders ( tendinopathy ) occur frequently and are difficult to treat . Tendon regeneration might be improved by injecting platelet-rich plasma ( PRP ) , an increasingly used treatment for releasing growth factors into the degenerative tendon . OBJECTIVE To examine whether a PRP injection would improve outcome in chronic midportion Achilles tendinopathy . DESIGN , SETTING , AND PATIENTS A stratified , block-r and omized , double-blind , placebo-controlled trial at a single center ( The Hague Medical Center , Leidschendam , The Netherl and s ) of 54 r and omized patients aged 18 to 70 years with chronic tendinopathy 2 to 7 cm above the Achilles tendon insertion . The trial was conducted between August 28 , 2008 , and January 29 , 2009 , with follow-up until July 16 , 2009 . INTERVENTION Eccentric exercises ( usual care ) with either a PRP injection ( PRP group ) or saline injection ( placebo group ) . R and omization was stratified by activity level . MAIN OUTCOME MEASURES The vali date d Victorian Institute of Sports Assessment -Achilles ( VISA-A ) question naire , which evaluated pain score and activity level , was completed at baseline and 6 , 12 , and 24 weeks . The VISA-A score ranged from 0 to 100 , with higher scores corresponding with less pain and increased activity . Treatment group effects were evaluated using general linear models on the basis of intention-to-treat . RESULTS After r and omization into the PRP group ( n = 27 ) or placebo group ( n = 27 ) , there was complete follow-up of all patients . The mean VISA-A score improved significantly after 24 weeks in the PRP group by 21.7 points ( 95 % confidence interval [ CI ] , 13.0 - 30.5 ) and in the placebo group by 20.5 points ( 95 % CI , 11.6 - 29.4 ) . The increase was not significantly different between both groups ( adjusted between-group difference from baseline to 24 weeks , -0.9 ; 95 % CI , -12.4 to 10.6 ) . This CI did not include the predefined relevant difference of 12 points in favor of PRP treatment . CONCLUSION Among patients with chronic Achilles tendinopathy who were treated with eccentric exercises , a PRP injection compared with a saline injection did not result in greater improvement in pain and activity . TRIAL REGISTRATION clinical trials.gov Identifier : NCT00761423 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 : The patellar tendon has limited ability to heal after harvesting its central third . Platelet-rich plasma ( PRP ) could improve patellar tendon healing . Hypothesis : Adding PRP to the patellar tendon harvest site would improve donor site healing and improve clinical outcome at 6 months after anterior cruciate ligament ( ACL ) reconstruction with a patellar tendon graft . Study Design : R and omized controlled trial ; Level of evidence , 1 . Methods : Twenty-seven patients were r and omly divided to receive ( n = 12 ) or not receive ( n = 15 ) PRP in the patellar tendon harvest site during ACL reconstruction . The primary outcome was magnetic resonance imaging ( MRI ) assessment of patellar tendon healing ( gap area ) after 6 months . Secondary outcomes were question naires and isokinetic testing of ACL reconstruction with a patellar tendon graft comparing both groups . Results : Patellar tendon gap area was significantly smaller in the PRP group ( 4.9 ± 5.3 mm2 ; 95 % confidence interval [ CI ] , 1.1 - 8.8 ) than in the control group ( 9.4 ± 4.4 mm2 ; 95 % CI , 6.6 - 12.2 ; P = .046 ) . Visual analog scale score for pain was lower in the PRP group immediately postoperatively ( 3.8 ± 1.0 ; 95 % CI , 3.18 - 4.49 ) than in the control group ( 5.1 ± 1.4 ; 95 % CI , 4.24 - 5.90 ; P = .02 ) . There were no differences after 6 months in question naire and isokinetic testing results comparing both groups . Conclusion : We showed that PRP had a positive effect on patellar tendon harvest site healing on MRI after 6 months and also reduced pain in the immediate postoperative period . Question naire and isokinetic testing results were not different between the groups at 6 months Background : Platelet-rich plasma ( PRP ) has been shown to be a general stimulation for repair and 1-year results showed promising success percentages . Purpose : This trial was undertaken to determine the effectiveness of PRP compared with corticosteroid injections in patients with chronic lateral epicondylitis with a 2-year follow-up . Study Design : R and omized controlled trial ; Level of evidence , 1 . Methods : The trial was conducted in 2 Dutch teaching hospitals . One hundred patients with chronic lateral epicondylitis were r and omly assigned to a leukocyte-enriched PRP group ( n = 51 ) or the corticosteroid group ( n = 49 ) . R and omization and allocation to the trial group were carried out by a central computer system . Patients received either a corticosteroid injection or an autologous platelet concentrate injection through a peppering needling technique . The primary analysis included visual analog scale ( VAS ) pain scores and Disabilities of the Arm , Shoulder and H and ( DASH ) outcome scores . Results : The PRP group was more often successfully treated than the corticosteroid group ( P < .0001 ) . Success was defined as a reduction of 25 % on VAS or DASH scores without a reintervention after 2 years . When baseline VAS and DASH scores were compared with the scores at 2-year follow-up , both groups significantly improved across time ( intention-to-treat principle ) . However , the DASH scores of the corticosteroid group returned to baseline levels , while those of the PRP group significantly improved ( as-treated principle ) . There were no complications related to the use of PRP . Conclusion : Treatment of patients with chronic lateral epicondylitis with PRP  reduces pain and increases function significantly , exceeding the effect of corticosteroid injection even after a follow-up of 2 years . Future decisions for application of PRP for lateral epicondylitis should be confirmed by further follow-up from this trial and should take into account possible costs and harms as well as benefits AIM Professional athletes require faster recovery after trauma . The aim of our study was to evaluate the efficacy of ultrasound guided platelets rich plasma ( PRP ) treatment for acute muscle injury comparing with traditional conservative therapy . MATERIAL S AND METHODS Thirty consecutive men ( mean age 24 years old ) professional athletes with acute local muscle injury were enrolled . All patients underwent US and sonoelastography examination . Patients were r and omly assigned to 2 groups : group A received targeted PRP injection under US guidance and additionally conservative treatment and group B received conventional conservative treatment only . The pain was assessed according to visual analogue scale ( 0 to 10 ) , muscle function according to pain on resisted ﬂexion or strength , and range of motion . Both groups were further evaluated in the days 1 , 7 , 14 , 21 , and 28 after treatment starting . US criteria for regeneration were considered to be the disappearance of hypoechoic areas of muscle damage , fibrous tissue more stiff on sonoelastography , and neovascularity appearances . RESULTS The pain relief was more important in group A compared to group B starting from day 1 and continuing in the next 3 evaluation sessions ( p<0.05 ) . At the end of observation ( 28 day ) , 93 % of pain regression was declared by patients in group A vs 80 % of regression of pain in group B ( p>0.05 ) . Assessing the physical evolution in the 7th and 14th days significant changes in strength ( p<0.05 ) and range of motion ( p<0.05 ) for PRP treatment group was observed . After 28 days no significant differences between groups were observed concerning the pain on resisted ﬂexion and strength ( p>0.05 ) but the range of movement improved better in group A compared with group B ( p < 0.05 ) . Subjective global function scores improved significantly in group A compared with group B on the 28th day ( p<0.05 ) . The mean time for the physical recovery movement volume and the ability to practice sport was 10+/-1.2 days in group A and 22+/-1.5 days in group B. CONCLUSIONS Injections of PRP under ultrasound guidance had asignificantly higher level of pain relief , physical recovery , and faster regeneration compared with conventional conservative treatment in acute muscle trauma in professional athletes Background : Tendinopathies represent a serious challenge for orthopaedic surgeons involved in treatment of athletes . Purpose : To compare the effectiveness and safety of platelet-rich plasma ( PRP ) injections and focused extracorporeal shock wave therapy ( ESWT ) in athletes with jumper ’s knee . Study Design : R and omized controlled trial ; Level of evidence , 1 . Methods : Forty-six consecutive athletes with jumper ’s knee were selected for this study and r and omized into 2 treatment groups : 2 autologous PRP injections over 2 weeks under ultrasound guidance ( PRP group ; n = 23 ) , and 3 sessions of focused extracorporeal shock wave therapy ( 2.400 impulses at 0.17 - 0.25 mJ/mm2 per session ) ( ESWT group ; n = 23 ) . The outcome measures were Victorian Institute of Sports Assessment –Patella ( VISA-P ) question naire , pain visual analog scale ( VAS ) , and modified Blazina scale . A review er who was blinded as to the group allocation of participants performed outcome assessment s before treatment and at 2 , 6 , and 12 months after treatment . Nonparametric tests were used for within-group ( Friedman/Wilcoxon test ) and between-group ( Kruskal-Wallis/Fisher test ) testing , and the significance level was set at .05 . Results : The 2 groups were homogeneous in terms of age , sex , level of sports participation , and pretreatment clinical status . Patients in both groups showed statistically significant improvement of symptoms at all follow-up assessment s. The VISA-P , VAS , and modified Blazina scale scores showed no significant differences between groups at 2-month follow-up ( P = .635 , .360 , and .339 , respectively ) . The PRP group showed significantly better improvement than the ESWT group in VISA-P , VAS scores at 6- and 12-month follow-up , and modified Blazina scale score at 12-month follow-up ( P < .05 for all ) . Conclusion : Therapeutic injections of PRP lead to better midterm clinical results compared with focused ESWT in the treatment of jumper ’s knee in athletes Background : Lateral epicondylitis ( LE ) is a common musculoskeletal disorder for which an effective treatment strategy remains unknown . Purpose : To examine whether a single injection of platelet-rich plasma ( PRP ) is more effective than placebo ( saline ) or glucocorticoid in reducing pain in adults with LE after 3 months . Study Design : R and omized controlled trial ; Level of evidence , 1 . Methods : A total of 60 patients with chronic LE were r and omized ( 1:1:1 ) to receive either a blinded injection of PRP , saline , or glucocorticoid . The primary end point was a change in pain using the Patient-Rated Tennis Elbow Evaluation ( PRTEE ) question naire at 3 months . Secondary outcomes were ultrasonographic changes in tendon thickness and color Doppler activity . Results : Pain reduction at 3 months ( primary end point ) was observed in all 3 groups , with no statistically significant difference between the groups ; mean differences were the following : glucocorticoid versus saline : −3.8 ( 95 % CI , −9.9 to 2.4 ) ; PRP versus saline : −2.7 ( 95 % CI , −8.8 to 3.5 ) ; and glucocorticoid versus PRP : −1.1 ( 95 % CI , −7.2 to 5.0 ) . At 1 month , however , glucocorticoid  reduced pain more effectively than did both saline and PRP ; mean differences were the following : glucocorticoid versus saline : −8.1 ( 95 % CI , −14.3 to −1.9 ) ; and glucocorticoid versus PRP : −9.3 ( 95 % CI , −15.4 to −3.2 ) . Among the secondary outcomes , at 3 months , glucocorticoid was more effective than PRP and saline in reducing color Doppler activity and tendon thickness . For color Doppler activity , mean differences were the following : glucocorticoid versus PRP : −2.6 ( 95 % CI , −3.1 to −2.2 ) ; and glucocorticoid versus saline : −2.0 ( 95 % CI , −2.5 to −1.6 ) . For tendon thickness , mean differences were the following : glucocorticoid versus PRP : −0.5 ( 95 % CI , −0.8 to −0.2 ) ; and glucocorticoid versus saline : −0.8 ( 95 % CI , −1.2 to −0.5 ) . Conclusion : Neither injection of PRP nor glucocorticoid was superior to saline with regard to pain reduction in LE at the primary end point at 3 months . However , injection of glucocorticoid had a short-term pain-reducing effect at 1 month in contrast to the other therapies . Injection of glucocorticoid in LE reduces both color Doppler activity and tendon thickness compared with PRP and saline PURPOSE The aim of this study was to evaluate and compare the clinical and inflammatory parameters with the addition of platelet-derived growth factor ( PDGF ) in primary anterior cruciate ligament ( ACL ) reconstruction with bone-patellar tendon-bone allograft .  METHODS We prospect ively r and omized 100 patients undergoing arthroscopic patellar tendon allograft ACL reconstruction  to a group in whom platelet-enriched gel was used ( n = 50 ) and a non-gel group ( n = 50 ) . The platelet concentration was 837 x 10(3)/mm(3 ) , and the gel was introduced inside the graft and the tibial tunnel . Demographic data were comparable between groups . The mean follow-up was 24 months for both groups and included a history , clinical evaluation with the International Knee Documentation Committee score , radiographs , and magnetic resonance imaging . RESULTS There were no differences in the number of associated injuries . The results did not show any statistically significant differences between the groups for inflammatory parameters ( perimeters of the knee and C-reactive protein level ) , magnetic resonance imaging appearance of the graft , and clinical evaluation scores ( visual analog scale , International Knee Documentation Committee , and KT-1000 arthrometer [ MEDmetric , San Diego , CA ] ) . CONCLUSIONS At this time , the therapeutic role of PDGF in ACL reconstruction remains unclear . The use of PDGF , on the graft and inside the tibial tunnel , in patients treated with bone-patellar tendon-bone allografts has no discernable clinical or biomechanical effect at 2 years ' follow-up . More clinical studies will be needed to show the efficacy and use of these factors in daily practice in ACL reconstruction . LEVEL OF EVIDENCE Level I , prospect i ve , r and omized , double-blind study Purpose The purpose of this study was to determine whether platelet-rich plasma ( PRP ) might prevent blood loss and postoperative pain and expedite wound healing following total knee arthroplasty ( TKA ) . Methods Forty consecutive patients with knee arthritis who were matched for age , sex and body mass index ( BMI ) were r and omly allocated to either receive or not receive PRP application over the wound , including capsule , medial and lateral recesses , during TKA . Postoperative haemoglobin , blood loss , blood transfusion , visual analogue scale ( VAS ) score , wound score , Knee Society Score ( KSS ) and Western Ontario and McMaster Osteoarthritis Index ( WOMAC ) score were recorded and evaluated . Results The platelet-rich plasma and control groups comprised 17 and 23 patients , respectively . The PRP group recorded significantly less reduction in haemoglobin and need for blood transfusion ( p = 0.00 and p = 0.001 , respectively ) , experienced less pain ( p = 0.00 ) and required fewer narcotics than the control ( p = 0.00 ) . There was significant difference in range of motion ( ROM ) at three months ( p = 0.01 ) , no significant difference in wound scores ( p = 0.311 ) and significant difference in KSS and WOMAC scores at 12 weeks ( p = 0.00 , 0.00 ) . However no significant difference was found at six months . Conclusions PRP has significant effect in preventing blood loss , postoperative pain and need for narcotics after TKA and has a positive effect on short-term clinical outcome HYPOTHESIS We hypothesized that arthroscopic rotator cuff repairs using leukocyte- and platelet-rich fibrin ( L-PRF ) in a st and ardized , modified protocol is technically feasible and results in a higher vascularization response and watertight healing rate during early healing . METHODS Twenty patients with chronic rotator cuff tears were r and omly assigned to 2 treatment groups . In the test group ( N = 10 ) , L-PRF was added in between the tendon and the bone during arthroscopic rotator cuff repair . The second group served as control ( N = 10 ) . They received the same arthroscopic treatment without the use of L-PRF . We used a double-row tension b and technique . Clinical examinations including subjective shoulder value , visual analog scale , Constant , and Simple Shoulder Test scores and measurement of the vascularization with power Doppler ultrasonography were made at 6 and 12 weeks . RESULTS There have been no postoperative complications . At 6 and 12 weeks , there was no significant difference in the clinical scores between the test and the control groups . The mean vascularization index of the surgical tendon-to-bone insertions was always significantly higher in the L-PRF group than in the contralateral healthy shoulders at 6 and 12 weeks ( P = .0001 ) . Whereas the L-PRF group showed a higher vascularization compared with the control group at 6 weeks ( P = .001 ) , there was no difference after 12 weeks of follow-up ( P = .889 ) . Watertight healing was obtained in 89 % of the repaired cuffs . DISCUSSION / CONCLUSIONS Arthroscopic rotator cuff repair with the application of L-PRF is technically feasible and yields higher early vascularization . Increased vascularization may potentially predispose to an increased and earlier cellular response and an increased healing rate BACKGROUND Chronic Achilles tendinopathy is responsible for a severe reduction in physical performance and persistent pain . There is currently a number of therapeutic options and the local administration of growth factors is an emerging treatment strategy . In particular , platelet-rich plasma ( PRP ) is a widely used way to provide a local regenerative stimulus for tendon healing . The aim of this study was to document the mid-term results obtained after treating recalcitrant Achilles tendinopathy with injections of high concentrate , leucocyte-rich PRP . MATERIAL S AND METHODS Twenty-seven patients ( mean age : 44.6 years ; 22 men and 5 women ) affected by chronic mid-portion Achilles tendinopathy ( 7 bilateral , for a total of 34 tendons ) , refractory to previous treatments , were enrolled . Patients were treated with three ultrasound-guided intra-tendinous injections of PRP at 2-week intervals . Patients were prospect ively evaluated at baseline , and then at 2 , 6 , and up to a mean of 54.1 months of follow-up ( minimum 30 months ) , using the following tools : Blanzina , VISA-A , EQ-VAS for general health , and Tegner scores . RESULTS The VISA-A score showed a significant improvement : the baseline score of 49.9±18.1 increased to 62.9±19.8 at 2 months ( p=0.002 ) , with a further improvement at 6 months ( 84.3±17.1 , p<0.0005 ) , and stable results at 4.5 years ( 90.0±13.9 ) . The EQ-VAS score also showed a similar positive trend . An evaluation of the activity level confirmed these findings , showing a significant improvement in the Tegner score over time ( p=0.017 for the final evaluation ) . The longer duration of symptoms before treatment was associated with a slower return to sport ( p=0.041 ) . DISCUSSION PRP injections produced good overall results for the treatment of chronic recalcitrant Achilles tendinopathy with a stable outcome up to a medium-term follow-up . Longer symptom duration was related with a more difficult return to sporting activity Background Growth factor technologies are increasingly used to enhance healing in musculoskeletal injuries , particularly in sports medicine . Two such products ; platelet-rich plasma ( PRP ) and autologous blood , have a growing body of supporting evidence . No previous trial has directly compared the efficacy of these two methods . Hypothesis Growth factor administration improves tissue regeneration in patients who have failed to respond to conservative therapy . Study design A prospect i ve , double-blind , r and omised trial . Methods Elbow tendinopathy patients who had failed conservative physical therapy were divided into two patient groups : PRP injection ( N=80 ) and  autologous blood injection ( ABI ) ( N=70 ) . Each patient received two injections at 0 and 1 month . Patient-related tennis elbow evaluation ( PRTEE ) was recorded by a blinded investigator at 0 , 1 , 3 and 6 months . The main outcome measure was PRTEE , a vali date d composite outcome for pain , activities of daily living and physical function , utilising a 0–100 scale . Results At 6 months the authors observed a 66 % success rate in the PRP group versus 72 % in the ABI group , p = NS . There was a higher rate of conversion to surgery in the ABI group ( 20 % ) versus the PRP group ( 10 % ) . Conclusion In patients who are resistant to first-line physical therapy such as eccentric loading , ABI or PRP injections are useful second-line therapies to improve clinical outcomes . In this study , up to seven out of 10 additional patients in this difficult to treat cohort benefit from a surgery-sparing intervention
INTRODUCTION In recent years , platelet rich plasma ( PRP ) has been receiving increasing attention for the treatment of soft tissue injuries .
These numerous applications have raised a great deal of questions and debate about the effectiveness of this method .
This study aim ed to determine the efficacy of PRP in improving sports injuries and subsequently throw some light on these controversies .