Baseline clinical and MRI risk factors for hamstring reinjury showing the value of performing baseline MRI and delaying return to play: a multicentre, prospective cohort of 330 acute hamstring injuries.

OBJECTIVES: Studies identifying clinical and MRI reinjury risk factors are limited by relatively small sample sizes. This study aimed to examine the association between baseline clinical and MRI findings with the incidence of hamstring reinjuries using a large multicentre dataset. METHODS: We merged data from four prospective studies (three randomised controlled trials and one ongoing prospective case series) from Qatar and the Netherlands. Inclusion criteria included patients with MRI-confirmed acute hamstring injuries (<7 days). We performed multivariable modified Poisson regression analysis to assess the association of baseline clinical and MRI data with hamstring reinjury incidence within 2 months and 12 months of follow-up. RESULTS: 330 and 308 patients were included in 2 months (31 (9%) reinjuries) and 12 months (52 (17%) reinjuries) analyses, respectively. In the 2-month analysis, the presence of discomfort during the active knee extension test was associated with reinjury risk (adjusted risk ratio (ARR) 3.38; 95% CI 1.19 to 9.64). In the 12 months analysis, the time to return to play (RTP) (ARR 0.99; 95% CI 0.97 to 1.00), straight leg raise angle on the injured leg (ARR 0.98; 95% CI 0.96 to 1.00), the presence of discomfort during active knee extension test (ARR 2.52; 95% CI 1.10 to 5.78), the extent of oedema anteroposterior on MRI (ARR 0.74; 95% CI 0.57 to 0.96) and myotendinous junction (MTJ) involvement on MRI (ARR 3.10; 95% CI 1.39 to 6.93) were independently associated with hamstring reinjury. CONCLUSIONS: Two clinical findings (the presence of discomfort during active knee extension test, lower straight leg raise angle on the injured leg), two MRI findings (less anteroposterior oedema, MTJ involvement) and shorter time to RTP were independently associated with increased hamstring reinjury risk. These findings may assist the clinician to identify patients at increased reinjury risk following acute hamstring injury. TRIAL REGISTRATION NUMBERS: NCT01812564; NCT02104258; NL2643; NL55671.018.16.

Proximal hamstring tendon avulsions: comparable clinical outcomes of operative and non-operative treatment at 1-year follow-up using a shared decision-making model.

OBJECTIVE: To prospectively evaluate 1-year clinical and radiological outcomes after operative and non-operative treatment of proximal hamstring tendon avulsions. METHODS: Patients with an MRI-confirmed proximal hamstring tendon avulsion were included. Operative or non-operative treatment was selected by a shared decision-making process. The primary outcome was the Perth Hamstring Assessment Tool (PHAT) score. Secondary outcome scores were Proximal Hamstring Injury Questionnaire, EQ-5D-3L, Tegner Activity Scale, return to sports, hamstring flexibility, isometric hamstring strength and MRI findings including proximal continuity. RESULTS: Twenty-six operative and 33 non-operative patients with a median age of 51 (IQR: 37-57) and 49 (IQR: 45-56) years were included. Median time between injury and initial visit was 12 (IQR 6-19) days for operative and 21 (IQR 12-48) days for non-operative patients (p=0.004). Baseline PHAT scores were significantly lower in the operative group (32±16 vs 45±17, p=0.003). There was no difference in mean PHAT score between groups at 1 year follow-up (80±19 vs 80±17, p=0.97). Mean PHAT score improved by 47 (95% CI 39 to 55, p<0.001) after operative and 34 (95% CI 27 to 41, p<0.001) after non-operative treatment. There were no relevant differences in secondary clinical outcome measures. Proximal continuity on MRI was present in 20 (95%, 1 recurrence) operative and 14 (52%, no recurrences) non-operative patients (p=0.008). CONCLUSION: In a shared decision-making model of care, both operative and non-operative treatment of proximal hamstring tendon avulsions resulted in comparable clinical outcome at 1-year follow-up. Operative patients had lower pretreatment PHAT scores but improved substantially to reach comparable PHAT scores as non-operative patients. We recommend using this shared decision model of care until evidence-based indications in favour of either treatment option are available from high-level clinical trials.

Foot Orthoses Enhance the Effectiveness of Exercise, Shockwave, and Ice Therapy in the Management of Medial Tibial Stress Syndrome.

OBJECTIVE: Our aim was to assess the effects of adding arch-support foot-orthoses (ASFO) to a multimodal therapeutic intervention on the perception of pain and improvement of recovery from medial tibial stress syndrome (MTSS) in recreational runners. DESIGN: A prospective randomized controlled trial. SETTING: Sport training and medical centers. PARTICIPANTS: Fifty female recreational runners with MTSS were randomized into 2 groups. INTERVENTIONS: Runners either received ASFO or sham flat noncontoured orthoses. Both groups received a multimodal therapeutic intervention, including ice massage, ankle muscle exercises, and extracorporeal shockwave therapy. MAIN OUTCOME MEASURES: Pain during bone pressure using a numerical Likert scale (0-10), MTSS severity using an MTSS scale, perceived treatment effect using the global rating of change scale, and quality of life using the short Form-36 questionnaire were determined at week 6, 12, and 18. RESULTS: Pain intensity and MTSS severity were lower, and the perceived treatment effect and physical function were better in the ASFO than in the sham flat noncontoured orthoses group at week 6 and week 12. Cohen's dz effect size for between-group differences showed a medium difference. However, arch-support foot-orthoses did not add to the benefits of multimodal therapeutic intervention on pain, MTSS severity and perceived treatment effect at week 18. CONCLUSIONS: Adding ASFO to a therapeutic intervention leads to an earlier diminishment of pain and MTSS severity, and improved PF and perceived therapeutic effects.

Autologous stem cell therapy in knee osteoarthritis: a systematic review of randomised controlled trials.

OBJECTIVE: Stem cell therapy is increasingly used for knee osteoarthritis (KOA). We aimed to review the evidence of autologous mesenchymal stem cell therapy on pain, function and severity on imaging in KOA. DESIGN: Systematic review of randomised controlled trials (RCTs). ELIGIBILITY CRITERIA: RCTs evaluating autologous mesenchymal stem cell (MSC) therapy on patient-reported outcome measures and disease severity. DATA SOURCES: Seven databases were searched until 31 December 2020. RISK OF BIAS AND DATA SYNTHESIS: Risk of bias was assessed using the ROB V.2. We used Grading of Recommendations Assessment, Development and Evaluation to appraise the certainty of the evidence. Data were synthesised descriptively. RESULTS: Fourteen RCTs were included. A total of 408 patients with KOA received MSC therapy derived from bone marrow, adipose tissue or activated peripheral blood. After 1 year, 19 of 26 (73%) clinical outcome measures improved with MSCs compared with control. In the MSC group, patients improved by 1.8-4.4 points on the Visual Analogue Scale (0-10) and 18-32 points of the Knee Osteoarthritis Outcome Score (0-100). Four studies showed better disease severity on imaging after MSC compared with control at 1 year. Ten of 14 (71%) RCTs were at high risk of bias on all outcomes. No serious adverse events were reported after MSC therapy during a maximum of 4 years follow-up. CONCLUSION: We found a positive effect of autologous MSC therapy compared with control treatments on patient-reported outcome measures, and disease severity. The certainty of this evidence was low to very low. PROSPERO REGISTRATION NUMBER: CRD42019120506.

Effect of Platelet-Rich Plasma Injections vs Placebo on Ankle Symptoms and Function in Patients With Ankle Osteoarthritis: A Randomized Clinical Trial.

Importance: Approximately 3.4% of adults have ankle (tibiotalar) osteoarthritis and, among younger patients, ankle osteoarthritis is more common than knee and hip osteoarthritis. Few effective nonsurgical interventions exist, but platelet-rich plasma (PRP) injections are widely used, with some evidence of efficacy in knee osteoarthritis. Objective: To determine the effect of PRP injections on symptoms and function in patients with ankle osteoarthritis. Design, Setting, and Participants: A multicenter, block-randomized, double-blinded, placebo-controlled clinical trial performed at 6 sites in the Netherlands that included 100 patients with pain greater than 40 on a visual analog scale (range, 0-100) and tibiotalar joint space narrowing. Enrollment began on August 24, 2018, and follow-up was completed on December 3, 2020. Interventions: Patients were randomly assigned (1:1) to receive 2 ultrasonography-guided intra-articular injections of either PRP (n = 48) or placebo (saline; n = 52). Main Outcomes and Measures: The primary outcome was the validated American Orthopaedic Foot and Ankle Society score (range, 0-100; higher scores indicate less pain and better function; minimal clinically important difference, 12 points) over 26 weeks. Results: Among 100 randomized patients (mean age, 56 years; 45 [45%] women), no patients were lost to follow-up for the primary outcome. Compared with baseline values, the mean American Orthopaedic Foot and Ankle Society score improved by 10 points in the PRP group (from 63 to 73 points [95% CI, 6-14]; P < .001) and 11 points in the placebo group (from 64 to 75 points [95% CI, 7-15]; P < .001). The adjusted between-group difference over 26 weeks was -1 ([95% CI, -6 to 3]; P = .56). One serious adverse event was reported in the placebo group, which was unrelated to the intervention; there were 13 other adverse events in the PRP group and 8 in the placebo group. Conclusions and Relevance: Among patients with ankle osteoarthritis, intra-articular PRP injections, compared with placebo injections, did not significantly improve ankle symptoms and function over 26 weeks. The results of this study do not support the use of PRP injections for ankle osteoarthritis. Trial Registration: Netherlands Trial Register: NTR7261.

Effectiveness of an e-health tennis-specific injury prevention programme: randomised controlled trial in adult recreational tennis players.

BACKGROUND: Despite reported injury rates of up to 3 per 1000 hours exposure, there are no evidence-based prevention programmes in tennis. PURPOSE: To evaluate the effectiveness of an e-health prevention programme for reducing tennis injury prevalence. STUDY DESIGN: Two-arm, researcher-blinded randomised controlled trial. METHODS: Adult tennis players of all playing levels were randomised in an unsupervised programme lasting 12 weeks (TennisReady group or control group). The primary outcome was the overall injury prevalence over a 16-week period, measured at 2 weekly intervals with the Oslo Sports and Trauma Research Centre questionnaire. Estimates for the primary outcome and associated 95% CIs were obtained using generalised estimating equation models. Secondary outcome scores included prevalence of substantial injuries, overall incidence, adherence and time-loss injuries. RESULTS: A total of 579 (83%) (TennisReady n=286, control n=293) participants were included in the primary analysis. The mean injury prevalence was 37% (95% CI 33% to 42%) in the TennisReady vs 38% (95% CI 34% to 42%) in the control group (adjusted p-value 0.93). The prevalence of substantial injuries was 11% (95% CI 9% to 14%) in the TennisReady vs 12% (95% CI 9% to 15%) in the control group (p value of 0.79). Analysis of the secondary outcome scores showed no difference between groups. The mean prevalence rates between high (8%) and low (92%) adherent groups were 32% (95% CI 23% to 44%) and 37% (95% CI 33% to 42%), respectively (p value 0.36). CONCLUSION: Providing an unsupervised e-health tennis-specific exercise programme did not reduce the injury rates and should not be implemented. TRIAL REGISTRATION NUMBER: NTR6443.

Is high soleus muscle activity during the stance phase of the running cycle a potential risk factor for the development of medial tibial stress syndrome? A prospective study.

To assess the impact of lower-leg muscle activity during the stance phase of running on the development of medial tibial stress syndrome (MTSS), in 123 healthy participants (18.2 ± 0.8 years), dynamic and static foot posture, and soleus and tibialis anterior muscle activity during the stance phase of running were measured before a 17-week track- and field-course. After the course, MTSS was identified in 20.5% of the participants. MTSS participants had a higher body mass (ES = 1.13), body mass index (BMI) (ES = 1.31), lower previous vigorous physical activity level (ES = 0.84) and VO2max (ES = 0.61), greater dynamic foot pronation (ES = 0.66), higher soleus peak EMG amplitude during the absorption (ES = 0.60) and propulsion phases (ES = 0.56) of running, and a history of MTSS (OR = 6.38) (p < 0.05). Stepwise logistic regression showed BMI, dynamic foot index, soleus peak EMG amplitude during propulsion, MTSS history and previous vigorous physical activity were predictors of MTSS. The model predicted 96.6% of the healthy participants and 56.5% of the MTSS participants and correctly classified 88.4% of overall cases. Coaches and sports-medicine professionals that screen for injury risk should consider adopting a comprehensive evaluation that includes these parameters.

Microcrack-associated bone remodeling is rarely observed in biopsies from athletes with medial tibial stress syndrome.

The pathology of medial tibial stress syndrome (MTSS) is unknown. Studies suggest that MTSS is a bony overload injury, but histological evidence is sparse. The presence of microdamage, and its potential association with targeted remodeling, could provide evidence for the pathogenesis of MTSS. Understanding the pathology underlying MTSS could contribute to effective preventative and therapeutic interventions for MTSS. Our aim was to retrospectively evaluate biopsies, previously taken from the painful area in athletes with MTSS, for the presence of linear microcracks, diffuse microdamage and remodeling. Biopsies, previously taken from athletes with MTSS, were evaluated at the Department of Anatomy and Cell Biology at the Indiana University. After preparing the specimens by en bloc staining, one investigator evaluated the presence of linear microcracks, diffuse microdamage and remodeling in the specimens. A total of six biopsies were evaluated for the presence of microdamage and remodeling. Linear microcracks were found in 4 out of 6 biopsies. Cracking in one of these specimens was artefactual due to the biopsy procedure. No diffuse microdamage was seen in any of the specimens, and only one potential remodeling front in association with the microcracks. We found only linear microcracks in vivo in biopsies taken from the painful area in 50% of the athletes with MTSS, consistent with the relationship between linear cracks and fatigue-associated overloading of bone. The nearly universal absence of a repair reaction was notable. This suggests that unrepaired microdamage accumulation may underlie the pathophysiological basis for MTSS in athletes.

Intramuscular tendon injury is not associated with an increased hamstring reinjury rate within 12 months after return to play.

BACKGROUND: Acute hamstring injury that includes intramuscular tendon injury has been suggested to be associated with increased reinjury risk. These observations were based on a relatively small number of retrospectively analysed cases. OBJECTIVE: To determine whether intramuscular tendon injury is associated with higher reinjury rates in acute hamstring injury. METHODS: MRIs of 165 athletes with an acute hamstring injury were obtained within 5 days of injury. Treatment consisted of a standardised criteria-based rehabilitation programme. Standardised MRI parameters and intramuscular tendon injury, the latter subdivided into tendon disruption and waviness, were scored. We prospectively recorded reinjuries, defined as acute onset of posterior thigh pain in the same leg within 12 months after return to play. RESULTS: Participants were predominantly football players (72%). Sixty-four of 165 (39%) participants had an index injury with intramuscular hamstring tendon disruption, and waviness was present in 37 (22%). In total, there were 32 (19%) reinjuries. There was no significant difference (HR: 1.05, 95% CI 0.52 to 2.12, P=0.898) in reinjury rate between index injuries with intramuscular tendon disruption (n=13, 20%) and without tendon disruption (n=19, 20%). There was no significant difference in reinjury rate (X²(1)=0.031, P=0.861) between index injuries with presence of waviness (n=7, 19%) and without presence of waviness (n=25, 20%). CONCLUSION: In athletes with an acute hamstring injury, intramuscular tendon injury was not associated with an increased reinjury rate within 12 months after return to play.

Effects of Natural Between-Days Variation in Sleep on Elite Athletes' Psychomotor Vigilance and Sport-Specific Measures of Performance.

Performance capacity in athletes depends on the ability to recover from past exercise. While evidence suggests that athletic performance decreases following (partial) sleep deprivation and increases following sleep extension, it is unclear to which extent natural variation in sleep impacts performance. Sleep quantity and, for the first time, sleep stages were assessed among 98 elite athletes on three non-consecutive nights within a 7-day monitoring period, along with performance tests that were taken on standardized times each following morning. Performance assessment included psychomotor performance (10-minute psychomotor vigilance task) and sport-specific tests of fine (e.g., accuracy) and gross motor skills (e.g., endurance, power). Mixed-effects models were employed to assess the effect of sleep quantity (total sleep time (TST), sleep onset latency (SOL), wake after sleep onset, sleep efficiency) and sleep stage duration (light, deep, REM) on performance. Average TST was 7:30 ± 1:05 hours, with a mean variation of 57 minutes across days. Longer TSTs were associated with faster reaction times (p = 0.04). Analyses indicated small and inconsistent effects of sleep quantity (TST, SOL) and sleep staging (light sleep) on gross motor performance, and no effects on fine motor skill performance. Results indicate that natural variation in sleep quantity impacts psychomotor vigilance to a greater extent than athletic performance. Small or absent effects can be a consequence of the rather small variation in non-manipulated sleep. It is suggested that one night of compromised sleep may not be immediately problematic, but that more extreme sleep loss or accumulated sleep debt may have more severe consequences.

No evidence for the use of stem cell therapy for tendon disorders: a systematic review.

INTRODUCTION: Stem cells have emerged as a new treatment option for tendon disorders. We systematically reviewed the current evidence for stem cell therapy in tendon disorders. METHODS: Randomised and non-randomised controlled trials, cohort studies and case series with a minimum of 5 cases were searched in MEDLINE, CENTRAL, EMBASE, CINAHL, PEDro and SPORTDiscus. In addition, we searched grey literature databases and trial registers. Only human studies were included and no time or language restrictions were applied to our search. All references of included trials were checked for possibly eligible trials. Risk of bias assessment was performed using the Cochrane risk of bias tool for controlled trials and the Newcastle-Ottawa scale for case series. Levels of evidence were assigned according to the Oxford levels of evidence. RESULTS: 4 published and three unpublished/pending trials were found with a total of 79 patients. No unpublished data were available. Two trials evaluated bone marrow-derived stem cells in rotator cuff repair surgery and found lower retear rates compared with historical controls or the literature. One trial used allogenic adipose-derived stem cells to treat lateral epicondylar tendinopathy. Improved Mayo Elbow Performance Index, Visual Analogue Pain scale and ultrasound findings after 1-year follow-up compared with baseline were found. Bone marrow-derived stem cell-treated patellar tendinopathy showed improved International Knee Documentation Committee, Knee injury and Osteoarthritis Outcome Score subscales and Tegner scores after 5-year follow-up. One trial reported adverse events and found them to be mild (eg, swelling, effusion). All trials were at high risk of bias and only level 4 evidence was available. CONCLUSIONS: No evidence (level 4) was found for the therapeutic use of stem cells for tendon disorders. The use of stem cell therapy for tendon disorders in clinical practice is currently not advised.

Stem cell injections in knee osteoarthritis: a systematic review of the literature.

OBJECTIVE: Stem cell injection for knee osteoarthritis (KOA) is an emerging new therapy, and we aimed to review its evidence of efficacy. DESIGN: Systematic review. ELIGIBILITY CRITERIA: Criteria for eligibility were randomised controlled trials (RCTs) and non-RCT on the efficacy of stem cell injections in KOA. All references were checked for missed articles. DATA SOURCES: MEDLINE, EMBASE, CINAHL, Web of Science, Cochrane Library, PEDro and SPORTDiscus were searched. A grey literature search was performed. No restrictions were imposed to our search strategy. RISK OF BIAS AND DATA SYNTHESIS: Risk of bias was assessed using the Cochrane risk of bias tool. Descriptive synthesis was performed using the levels of evidence according to the Oxford Levels of Evidence. RESULTS: Five RCTs and one non-RCT were found. Bone-marrow-derived stem cells, adipose-derived mesenchymal stem cells and peripheral blood stem cells were used. All trials were at high risk of bias, resulting in level-3 evidence. All five RCTs reported superior efficacy for patient-reported outcomes (Visual Analogue Scale, Western Ontario and McMaster Universities Arthritis Index, Tegner, Lysolm, International Knee Documentation Committee, Knee Injury and Osteoarthritis Outcome Score, Lequesne) compared with controls at final follow-up (range 24-48 months). Superior radiological outcomes were found favouring stem cell injection. Superior histological outcomes and/or improved arthroscopically scored healing rates were reported in two trials. No serious adverse events were reported. CONCLUSION: Six trials with high risk of bias showed level-3 or level-4 evidence in favour of stem cell injections in KOA. In the absence of high-level evidence, we do not recommend stem cell therapy for KOA.

The prognostic value of MRI in determining reinjury risk following acute hamstring injury: a systematic review.

BACKGROUND: A challenge for sports physicians is to estimate the risk of a hamstring re-injury, but the current evidence for MRI variables as a risk factor is unknown. OBJECTIVE: To systematically review the literature on the prognostic value of MRI findings at index injury and/or return to play for acute hamstring re-injuries. DATA SOURCES: Databases of PubMed, Embase, MEDLINE, Scopus, CINAHL, Google Scholar, Web of Science, LILACS, SciELO, ScienceDirect, ProQuest, SPORTDiscus and Cochrane Library were searched until 20 June 2016. STUDY ELIGIBILITY CRITERIA: Studies evaluating MRI as a prognostic tool for determining the risk of re-injury for athletes with acute hamstring injuries were eligible for inclusion. DATA ANALYSIS: Two authors independently screened the search results and assessed risk of bias using standardised criteria from a consensus statement. A best-evidence synthesis was used to identify the level of evidence. Post hoc analysis included correction for insufficient sample size. RESULTS: Of the 11 studies included, 7 had a low and 4 had a high risk of bias. No strong evidence for any MRI finding as a risk factor for hamstring re-injury was found. There was moderate evidence that intratendinous injuries were associated with increased re-injury risk. Post hoc analysis showed moderate evidence that injury to the biceps femoris was a moderate to strong risk factor for re-injury. CONCLUSION: There is currently no strong evidence for any MRI finding in predicting hamstring re-injury risk. Intratendinous injuries and biceps femoris injuries showed moderate evidence for association with a higher re-injury risk. SYSTEMATIC REVIEW REGISTRATION: Registration in the PROSPERO International prospective register of systematic reviews was performed prior to study initiation (registration number CRD42015024620).

Effectiveness of Shockwave Treatment Combined With Eccentric Training for Patellar Tendinopathy: A Double-Blinded Randomized Study.

OBJECTIVE: To evaluate the effectiveness of a combined treatment of focused shockwave therapy (ESWT) and eccentric training compared with sham-shockwave therapy (placebo) and eccentric training in participants with patellar tendinopathy (PT) after 24 weeks. DESIGN: Randomized controlled trial. SETTING: Sports medicine departments of a university hospital and a general hospital in the Netherlands. PARTICIPANTS: Fifty-two physically active male and female participants with a clinical diagnosis of PT (mean age: 28.6 years; range, 18-45) were randomly allocated to the ESWT (n = 22) or sham shockwave (n = 30). INTERVENTIONS: Extracorporeal shockwave therapy and sham shockwave were applied in 3 sessions at 1-week intervals with a piezoelectric device. All participants were instructed to perform eccentric exercises (3 sets of 15 repetitions twice a day) for 3 months on a decline board at home. MAIN OUTCOME MEASURES: The Victorian Institute of Sport Assessment-Patella (VISA-P) scores (primary), pain scores during functional knee loading tests, and Likert score (secondary) were registered at baseline and at 6, 12, and 24 weeks after the start with the ESWT or sham-shockwave treatment. RESULTS: No significant differences for the primary and secondary outcome measures were found between the groups. In the ESWT/eccentric group, the VISA-P increased from 54.5 ± 15.4 to 70.9 ± 17.8, whereas the VISA-P in the sham-shockwave/eccentric group increased from 58.9 ± 14.6 to 78.2 ± 15.8 (between-group change in VISA-P at 24 weeks -4.8; 95% confidence interval, -12.7 to 3.0, P = 0.150). CONCLUSIONS: This study showed no additional effect of 3 sessions ESWT in participants with PT treated with eccentric exercises. The results should be interpreted with caution because of small sample size and considerable loss to follow-up, particularly in the ESWT group.

The medial tibial stress syndrome score: a new patient-reported outcome measure.

BACKGROUND: At present, there is no validated patient-reported outcome measure (PROM) for patients with medial tibial stress syndrome (MTSS). AIM: Our aim was to select and validate previously generated items and create a valid, reliable and responsive PROM for patients with MTSS: the MTSS score. METHODS: A prospective cohort study was performed in multiple sports medicine, physiotherapy and military facilities in the Netherlands. Participants with MTSS filled out the previously generated items for the MTSS score on 3 occasions. From previously generated items, we selected the best items. We assessed the MTSS score for its validity, reliability and responsiveness. RESULTS: The MTSS score was filled out by 133 participants with MTSS. Factor analysis showed the MTSS score to exhibit a single-factor structure with acceptable internal consistency (α=0.58) and good test-retest reliability (intraclass correlation coefficient=0.81). The MTSS score ranges from 0 to 10 points. The smallest detectable change in our sample was 0.69 at the group level and 4.80 at the individual level. Construct validity analysis showed significant moderate-to-large correlations (r=0.34-0.52, p<0.01). Responsiveness of the MTSS score was confirmed by a significant relation with the global perceived effect scale (ß=-0.288, R(2)=0.21, p<0.001). CONCLUSIONS: The MTSS score is a valid, reliable and responsive PROM to measure the severity of MTSS. It is designed to evaluate treatment outcomes in clinical studies.

Atrophy and Depigmentation After Pretibial Corticosteroid Injection for Medial Tibial Stress Syndrome: Two Case Reports.

INTRODUCTION: No reports have been published on the results of corticosteroid injections for medial tibial stress syndrome (MTSS). CASE PRESENTATION: The authors present 2 cases of women with MTSS who showed atrophy and depigmentation of the skin after pretibial corticosteroid injections. Case 1 is an 18-y-old woman presenting with pain in her lower leg for 12 mo. No improvement was noticed after conservative treatment, so she received local injections with corticosteroids. Five months later physical examination showed tissue atrophy and depigmentation around the injection sites. Case 2 is a 22-y-old woman who presented with pain in both lower legs for 24 mo. Several conservative treatment options failed, so she received local injections with corticosteroids. Physical examination revealed tissue atrophy and depigmentation around the injection sites. CONCLUSION: No positive effect of injections with corticosteroids was found in 2 cases of MTSS. Furthermore, considerable tissue atrophy and hypopigmentation of the skin was observed.

Efficacy of platelet-rich plasma injections in osteoarthritis of the knee: a systematic review and meta-analysis.

BACKGROUND: The effectiveness of platelet-rich plasma (PRP) injections for osteoarthritis (OA) is still controversial. We investigated the effect of PRP injections in patients with knee OA based on decreasing pain, improving function, global assessment and changes regarding joint imaging. METHODS: We performed a comprehensive, systematic literature search in computerised databases (MEDLINE, EMBASE, CINAHL, CENTRAL, Web of Science and PEDro) until June 2014 for randomised or non-randomised controlled trials. These were graded for risk of bias and a level of evidence was provided. If possible, meta-analysis was performed. RESULTS: Ten trials were included. In these, intra-articular PRP injections were more effective for pain reduction (mean difference (MD) -2.45; 95% CI -2.92 to -1.98; p value <0.00001 and MD -2.07; 95% CI -2.59 to -1.55; p value <0.00001, single and double PRP injections, respectively) compared with placebo at 6 months postinjection. Intra-articular PRP injections were compared with hyaluronic acid and showed a statistically significant difference in favour of PRP on pain reduction based on the visual analogue scale and numeric rating scale (standardised mean difference -0.92; 95% CI -1.20 to -0.63; p value <0.00001) at 6 months postinjection. Almost all trials revealed a high risk of bias. CONCLUSIONS: On the basis of the current evidence, PRP injections reduced pain more effectively than did placebo injections in OA of the knee (level of evidence: limited due to a high risk of bias). This significant effect on pain was also seen when PRP injections were compared with hyaluronic acid injections (level of evidence: moderate due to a generally high risk of bias). Additionally, function improved significantly more when PRP injections were compared with controls (limited to moderate evidence). More large randomised studies of good quality and low risk of bias are needed to test whether PRP injections should be a routine part of management of patients with OA of the knee.

Efficacy of rehabilitation (lengthening) exercises, platelet-rich plasma injections, and other conservative interventions in acute hamstring injuries: an updated systematic review and meta-analysis.

BACKGROUND: Our 2012 review on therapeutic interventions for acute hamstring injuries found a lack of high-quality studies. The publication of new studies warranted an update. OBJECTIVES: To update and reanalyse the efficacy of conservative treatments for hamstring injury. DATA SOURCES: PubMed, EMBASE, Web of Science, Cochrane library, CINAHL and SPORTDiscus were searched till mid-February 2015. STUDY ELIGIBILITY CRITERIA: Randomised controlled trials (RCTs) on the effect of conservative interventions versus a control group or other intervention for hamstring injuries (HI) were included. DATA ANALYSIS: The search results were screened independently by two authors. Risk of bias assessment was performed using a modified Downs and Black scale with a maximum score of 28. Meta-analysis was performed, where possible. MAIN RESULTS: 10 RCTs (526 participants), including 6 new RCTs, were identified. Two RCTs were of good/excellent quality, the rest were fair or poor (median Downs and Black score 16 (IQR 9)). Meta-analysis of two studies on rehabilitation (lengthening) exercises showed a significantly reduced time to return to play (HR 3.22 (95% CI 2.17 to 4.77), p<0.0001) but no difference in risk of re-injury. Meta-analysis of three studies investigating platelet-rich plasma (PRP) showed no effect when compared to control (HR 1.03 (95% CI 0.87 to 1.22), p=0.73). Limited evidence was found that progressive agility and trunk stability training may reduce re-injury rates. CONCLUSIONS: Meta-analysis showed superior efficacy for rehabilitation exercises. PRP injection had no effect on acute hamstring injury. Limited evidence was found that agility and trunk stabilisation may reduce re-injury rates. The limitations identified in the majority of RCTs should improve the design of new hamstring RCTs.

Rationale, secondary outcome scores and 1-year follow-up of a randomised trial of platelet-rich plasma injections in acute hamstring muscle injury: the Dutch Hamstring Injection Therapy study.

BACKGROUND: Platelet-rich plasma (PRP) injections are an experimental treatment for acute muscle injuries. We examined whether PRP injections would accelerate return to play after hamstring injury. The methods and the primary outcome measure were published in the New England Journal of Medicine (NEJM) as 'Platelet-rich plasma injections in acute muscle injury' (2014). This article shares information not available in the NEJM letter or online supplement, especially the rationale behind the study and the secondary outcome measures including 1 year re-injury data. METHODS: We performed a multicentre, randomised, double-blind, placebo-controlled trial in 80 competitive and recreational athletes with acute hamstring muscle injuries. Details can be found in the NEJM (http://www.nejm.org/doi/full/10.1056/NEJMc1402340). The primary outcome measure was the time needed to return to play during 6 months of follow-up. Not previously reported secondary outcome scores included re-injury at 1 year, alteration in clinical and MRI parameters, subjective patient satisfaction and the hamstring outcome score. RESULTS: In the earlier NEJM publication, we reported that PRP did not accelerate return to play; nor did we find a difference in the 2-month re-injury rate. We report no significant between-group difference in the 1-year re-injury rate (HR=0.89; 95% CI, 0.38 to 2.13; p=0.80) or any other secondary outcome measure. CONCLUSIONS: At 1-year postinjection, we found no benefit of intramuscular PRP compared with placebo injections in patients with acute hamstring injuries in the time to return to play, re-injury rate and alterations of subjective, clinical or MRI measures.

Clinical findings just after return to play predict hamstring re-injury, but baseline MRI findings do not.

BACKGROUND: Acute hamstring re-injuries are common and hard to predict. The aim of this study was to investigate the association between clinical and imaging findings and the occurrence of hamstring re-injuries. METHODS: We obtained baseline data (clinical and MRI findings) of athletes who sustained an acute hamstring injury within 5 days of initial injury. We also collected data of standardised clinical tests within 7 days after return to play (RTP). The number of re-injuries was recorded within 12 months. We analysed the association between the possible predictive variables and re-injuries with a multivariate Cox proportional-hazards regression model. RESULTS: Eighty patients were included at baseline and 64 patients could be included in the final analysis because data after RTP were not available in 16 cases. There were 17 re-injuries (27%). None of the baseline MRI findings were univariately associated with re-injury. A higher number of previous hamstring injuries (adjusted OR (AOR) 1.33; 95% CI 1.11 to 1.61), more degrees of active knee extension deficit after RTP (AOR 1.13; 95% CI 1.03 to 1.25), isometric knee flexion force deficit at 15° after RTP (AOR 1.04; 95% CI 1.01 to 1.07) and presence of localised discomfort on hamstring palpation after RTP (AOR 3.95; 95% CI 1.38 to 11.37) were significant independent predictors of re-injury. Athletes with localised discomfort on hamstring palpation just after RTP were consequently almost four times more likely to sustain a re-injury. CONCLUSIONS: The number of previous hamstring injuries, active knee extension deficit, isometric knee flexion force deficit at 15° and presence of localised discomfort on palpation just after RTP are associated with a higher hamstring re-injury rate. None of the baseline MRI parameters was a predictor of hamstring re-injury. TRIAL REGISTRATION NUMBER: ClinicalTrial.gov number NCT01812564.