Editorial Commentary: Designing Patient-Reported Outcome Measures That Have High Clinical Utility and Minimum Responder Burden: When Less Is More.

Patient-reported outcome measures provide important information regarding the subjective status of a patient's health. Preference is often given to the use of condition-specific measures for symptoms, pain, and function, although it is also recognized that measures pertaining to quality of life and psychological status are highly relevant. The challenge is to develop a comprehensive set of outcome measures that do not overly burden the patient. The development of short-form versions of commonly used scales plays an important part in this endeavor. Of note, such short forms show a remarkable degree of data consilience for different injury types and patient samples. This suggests that there are a core set of responses, specifically psychological responses, that are relevant to patients who desire to return to sport, irrespective of the type of injury or condition. Moreover, patient-reported outcomes are highly useful when they inform other relevant outcomes. Recent research shows that relevant patient-reported outcome scores in the shorter term predict return to sport in the longer term, which is of high clinical utility. Finally, psychological factors are potentially modifiable, and scores allowing early identification of patients who may find the resumption of sport challenging allow intervention with a goal of improving the final outcome.

Anterior Knee Pain Following Primary Unilateral Total Knee Arthroplasty With Posterior-Stabilized Prosthesis and Patellar Resurfacing: Prevalence and Clinical Implications.

BACKGROUND: Anterior knee pain following total knee arthroplasty (TKA) is associated with patient dissatisfaction. Factors related to postoperative anterior knee pain and its impact on patient outcomes are poorly understood. The following are the aims of this study: (1) to report the prevalence of anterior knee pain before and after TKA using a posterior-stabilized prosthesis with routine patellar resurfacing; (2) to investigate the association of preoperative clinical factors with the presence of anterior knee pain after TKA; and (3) to explore the association of postoperative anterior knee pain with postoperative self-reported function and quality of life. METHODS: This retrospective study included 506 patients who had undergone elective primary unilateral TKA with a posterior-stabilized prosthesis and patellar resurfacing. Outcome measures prior to and 12 months after TKA included self-reported anterior knee pain, knee function, and quality of life. RESULTS: Prevalence of anterior knee pain was 72% prior to and 15% following TKA. Patients who had preoperative anterior knee pain had twice the risk of experiencing anterior knee pain after TKA than patients who did not have preoperative anterior knee pain (risk ratio: 2.37, 95% CI 1.73-2.96). Greater severity of preoperative anterior knee pain and worse self-reported function were associated with the presence of postoperative anterior knee pain (rho = 0.15, P < .01; rho = 0.13, P < .01, respectively). Preoperative age, gender, and quality of life were not associated with postoperative anterior knee pain. Greater severity of postoperative anterior knee pain was associated with worse knee function at 12 months postoperative (rho = 0.49, P < .01). CONCLUSION: One in 7 patients reported anterior knee pain 12 months following posterior-stabilized and patella-resurfaced TKA. The presence of preoperative anterior knee pain and worse self-reported function are associated with postoperative anterior knee pain.

Editorial Commentary: Why the Mind Matters in Anterior Cruciate Ligament Injury Recovery: Psychological Readiness and Return to Sport.

Following anterior cruciate ligament injury and surgery, it is important that we prepare athletes to return to sport not only from a physical perspective but also a psychological one. Typically, we are concerned for an athlete who has low confidence or high anxiety. However, can being too psychologically ready to return to sport also be a bad thing? While the optimal psychological profile will vary from person to person, evidence is emerging that more extreme responses may have detrimental consequences and increase the risk of further injury.

Anterior Cruciate Ligament Injury and Knee Osteoarthritis: An Umbrella Systematic Review and Meta-analysis.

OBJECTIVE: To conduct a systematic review of reviews to summarize the (1) risk for development and (2) prevalence of knee osteoarthritis (OA) after anterior cruciate ligament (ACL) injury and surgical treatment and (3) compare prevalence rates between surgical and nonsurgical treatment of ACL injury. DATE SOURCES: Five electronic databases were searched using medical subject heading and text words up to February 2020 to identify English language reviews. STUDY SELECTION: Studies were included if they were a systematic review or meta-analysis. DATA EXTRACTION: Thirteen eligible reviews were included, and the main outcome extracted was knee OA prevalence or risk data and any meta-analysis results. DATA SYNTHESIS: Results from reviews were combined with a summary meta-analysis based on odds ratios (ORs) or proportions. There was a near 7-fold and 8-fold increase in the odds for the development of knee OA post ACL injury [OR = 6.81 (5.70-8.13)] and ACL reconstruction [OR = 7.7, (6.05-9.79)]. Data were too heterogenous to specify a point estimate prevalence for OA after ACL injury, but OA prevalence was estimated at 36% (19.70-53.01) at near 10 years after reconstruction surgery. A significantly higher prevalence of OA was found for those who received surgical treatment at a minimum 10-year follow-up [OR = 1.40 (1.17-1.68)]. CONCLUSIONS: This study combines all data from previous systematic reviews into a single source to show that ACL injury markedly increases the risk for development of knee OA, which is likely to be present in the long term in approximately a third of patients who have reconstruction surgery. Surgical treatment does not reduce OA prevalence in the longer term compared with nonsurgical treatment.

Differences in accuracy and consistency in elite lawn bowlers.

The aim of this study was to determine whether there are differences in the accuracy and consistency of repeated lawn bowl deliveries between different bowling conditions and to describe the bias of bowls that missed the target (jack). Twenty-seven elite lawn bowl athletes were recruited to partake in the study. Participants delivered 16 bowls in four conditions: (i) forehand and (ii) backhand towards a target 23 metres away and (iii) forehand and (iv) backhand towards a target 27 metres away. The resting position of each bowl relative to the jack was described in terms of absolute displacement, width displacement and length displacement. For each participant and each condition, the average absolute displacement of deliveries was calculated as a measure of accuracy; the average width and length displacement was used to describe the bias of deliveries; and the bivariate variable error of absolute displacement was calculated as a measure of consistency. The forehand towards a target 23 metres away was significantly less accurate and consistent when compared with other conditions. There was a bias for greater width displacement of both forehand deliveries (p < 0.001). Analysing lawn bowls in this detail provides specific areas for coaching to improve lawn bowling performance.

Knee strength deficits following anterior cruciate ligament reconstruction differ between quadriceps and hamstring tendon autografts.

PURPOSE: To compare patient reported outcomes and functional knee recovery following anterior cruciate ligament (ACL) reconstruction using either a quadriceps tendon (QT) or hamstring tendon (HT) autograft. METHODS: Thirty-five QT patients (age 20; range 15-34 years) participated in this study and were matched for gender, age and pre-injury activity level to 70 HT (age 20; range 15-32 years) patients. The following assessments were performed at 6 and 12 months post-operatively; standardized patient-reported outcome measures (IKDC, KOOS-QOL, ACL-RSI, Marx activity, anterior knee pain), knee range of motion (passive and active), anterior knee laxity, hop tests (single and triple crossover hop for distance), and isokinetic strength of the knee extensors and flexors. All dependent variables were analysed using a two-way mixed ANOVA model, with within (Time; 6 and 12 months) and between-subject (Graft; QT and HT) factors. RESULTS: Patient reported outcome measures and hop performance improved between 6 and 12 months (p < 0.001), however no significant differences in either patient-reported outcomes or hop performance were found between the two grafts. Isokinetic strength testing showed both groups improved their peak knee extensor strength in the operated limb between 6 and 12 months (p < 0.001), but the QT group had significantly lower knee extensor strength symmetry at both time points compared to HT at 60 deg/s (p < 0.001) and 180 deg/s (p < 0.01). In contrast, the QT group had significantly greater knee flexor strength symmetry at both time points compared to HT at 60 deg/s (p < 0.01) and 180 deg/s (p = 0.01), but knee flexor strength limb symmetry did not significantly improve over time in either group. CONCLUSION: Recovery of knee function following either QT or HT ACL reconstruction continues between 6 and 12 months after surgery. However, knee extensor strength deficits in the QT group and knee flexor strength deficits in the HT persisted at 12 months. This may have implications for decisions regarding return to sport. LEVEL OF EVIDENCE: III.

Association Between Knee Moments During Stair Navigation and Participant-Related Factors in Individuals With Anterior Cruciate Ligament Reconstruction: A Cross-Sectional Study.

CONTEXT: Altered knee joint mechanics may be related to quadriceps muscle strength, time since surgery, and sex following anterior cruciate ligament reconstruction (ACLR). The aim of this study was to investigate the association between knee moments, with participant-related factors during stair navigation post-ACLR. DESIGN: Cross-sectional study. METHODS: A total of 30 participants (14 women) with ACLR, on average 7.0 (SD 4.4) years postsurgery were tested during stair ascent and descent in a gait laboratory. Motion capture was conducted using a floor-embedded force plate and 11 infrared cameras. Quadriceps concentric and eccentric muscle strength was measured with an isokinetic dynamometer at 60°/s, and peak torques recorded. Multiple regression analyses were performed between external knee flexion and adduction moments, respectively, and quadriceps peak torque, sex, and time since ACLR. RESULTS: Higher concentric quadriceps strength and female sex accounted for 55.7% of the total variance for peak knee flexion moment during stair ascent (P < .001). None of the independent variables accounted for variance in knee adduction moment (P = .698). No significant associations were found for knee flexion and adduction moments during for stair descent. CONCLUSION: Higher quadriceps concentric strength and sex explains major variance in knee flexion moments during stair ascent. The strong association between muscle strength and external knee flexion moments during stair ascent indicate rehabilitation tailored for quadriceps may optimize knee mechanics, particularly for women.

Editorial Commentary: Anterior Cruciate Ligament Suture Repair Could Have High Failure Rates in Active Athletes of All Ages.

When it comes to anterior cruciate ligament (ACL) injury and surgery, age is a proxy for early return to strenuous sports. In addition, premature return to sport is a risk factor for reinjury after ACL surgery. Thus, when considering ACL suture repair as an alternative to ACL graft reconstruction, we must consider that failure rates may be influenced by patient demographic variables, particularly age and activity. In the end, treatment options for young patients who are highly active and eager to make a timely return to sport after ACL injury require careful evaluation.

Time of Season and Game Segment Is Not Related to Likelihood of Lower-Limb Injuries: A Meta-Analysis.

OBJECTIVE: Fatigue due to game play is often cited as a factor in musculoskeletal injuries; however, it is unclear whether or not this view is supported by published research findings. Given the importance researchers and practitioners place on the potential effects of game play with respect to injury, it is important to understand what inferences can be drawn from the collective research in this realm. This meta-analysis will consider the time of season and segment of the game, as it relates anterior cruciate ligament (ACL), groin, and hamstring injury occurrence. DATA SOURCES: Database searches were run in PubMed, MEDLINE, SportDiscus, CINAHL, and Ausport, in addition to the inclusion of articles identified manually. STUDY SELECTION: Search terms were chosen to identify articles related to each of the 3 injuries of interest. There were no date limitations placed on the articles, as such, all published articles listed in the databases up to November 2017 were eligible for selection if they met the search criteria. DATA EXTRACTION: Initial searches yielded 1349 articles, and this was eventually reduced to 15 articles deemed suitable for inclusion in the meta-analysis, which provided 21 data sets. DATA SYNTHESIS: Comparing the first half with the second half of the season, there were no differences in ACL, groin, or hamstring injury occurrences [ACL: odds ratio (OR), 1.27; confidence interval (CI), 0.43-3.78, groin: OR, 1.79; CI, 0.63-5.06, and hamstring: OR, 1.16; CI, 0.88-1.53]. Similarly, there were no differences in injury occurrence between the first and second halves of the game for the ACL or hamstring injuries (ACL: OR, 0.43; CI, 0.47-7.92, hamstring: OR, 0.85; CI, 0.58-1.24). CONCLUSIONS: Findings from this meta-analysis determined that time in season or time in game does not influence risk of the ACL, groin, or hamstring injury. Commonly, many studies did not provide sufficient detail to be included in the meta-analysis. Consequently, it is recommended that future studies report data related to the timing of the injury within the season or game.

Knee muscle strength after quadriceps tendon autograft anterior cruciate ligament reconstruction: systematic review and meta-analysis.

PURPOSE: Restoration of knee muscle strength is associated with better outcomes following anterior cruciate ligament (ACL) reconstruction, but little is known about the outcome of strength following quadriceps tendon autograft (QT) ACL reconstruction in relation to other graft types. The aim of this review was to evaluate strength outcomes of the knee extensors and knee flexors following QT ACL reconstruction compared to (1) the non-reconstructed contralateral limb and (2) alternative ACL graft types. METHODS: Four electronic databases were searched up until 21st February 2020. Summary meta-analyses were performed comparing knee strength outcomes following QT ACL reconstruction to the contralateral limb by way of limb symmetry index (LSI). Comparative meta-analyses were performed comparing QT ACL reconstruction to alternative ACL grafts for the two most frequently reported strength outcome measures which were peak knee extensor torque LSI, and peak knee flexor torque LSI at the following post-operative periods: 3, 5-8, 9-15, 24, 36-60 months. RESULTS: In total, 18 studies met the inclusion criteria. Knee strength outcomes of 952 QT ACL reconstructions were included and compared to either the contralateral limb or 1 of 4 alternative ACL graft types; 245 hamstring tendon autograft (HT), 143 patellar tendon autograft (PT), 45 quadriceps tendon allograft, and 21 tibialis anterior allograft. Knee extensor strength LSI following QT ACL reconstruction did not reach 90% even at 24 months post-operatively. Conversely, knee flexor strength LSI following QT ACL reconstruction exceeded 90% at the 9-15 months post-operative period. Knee extensor strength at 5-8 months following QT ACL reconstruction appears similar to PT but weaker than HT ACL reconstruction. In addition, peak knee flexor LSI was significantly greater at 5-8 months in QT ACL reconstruction patients compared to HT patients. CONCLUSION: The decision to utilize a QT graft for ACL reconstruction should include consideration of strength outcomes. Knee extensor strength recovery following QT ACL reconstruction appears not to be restored before 24 months. LEVEL OF EVIDENCE: Level IV.

Psychological readiness is related to return to sport following hip arthroscopy and can be assessed by the Hip-Return to Sport after Injury scale (Hip-RSI).

PURPOSE: Psychological readiness may play an important role in the return to sport (RTS) process following hip arthroscopy (HA), but there are limited tools for the measurement of this construct. The aim of this study was to modify the Swedish version of the Anterior Cruciate Ligament-Return to Sport after Injury (ACL-RSI) scale for use in HA patients and evaluate its psychometric properties. METHODS: Content validity of a modified version of the Swedish ACL-RSI (Hip-RSI) was evaluated through 127 HA patient responses and relevance ratings by an expert panel (35 patients, 9 surgeons, 11 physiotherapists). Items with low relevance were omitted. Construct validity was assessed by the association of Hip-RSI scores to hip-related sporting function (HAGOS sport) and quality of life (iHOT12). Hip-RSI scores were compared between patients who had not returned, or returned to sport participation, previous sport, and sport performance. RESULTS: Item reduction resulted in a 6-item Hip-RSI scale with adequate content validity for the target population. Construct validity of the full and the item-reduced scale was demonstrated by correlation to HAGOS sport and iHOT12 (r 0.631-0.752). A gradient increase in Hip-RSI scores was found for patients returning to sport participation, previous sport, and sport performance. CONCLUSION: The short version of the Swedish Hip-RSI is a valid tool for the assessment of psychological readiness to RTS and can be recommended to be used in HA patients. Higher psychological readiness to RTS, assessed by the Hip-RSI, is found with increasing levels of return to sports following HA. LEVEL OF EVIDENCE: III.

The effectiveness of preoperative rehabilitation programmes on postoperative outcomes following anterior cruciate ligament (ACL) reconstruction: a systematic review.

BACKGROUND: To explore the effectiveness of preoperative rehabilitation programmes (PreHab) on postoperative physical and psychological outcomes following anterior cruciate ligament reconstruction (ACLR). METHOD: A systematic search was conducted from inception to November 2019. Randomised controlled trials (RCTs) published in English were included. Risk of bias was assessed using Version 2 of the Cochrane risk-of-bias tool, and the Grading of Recommendations Assessment system was used to evaluate the quality of evidence. RESULTS: The search identified 739 potentially eligible studies, three met the inclusion criteria. All included RCTs scored 'high' risk of bias. PreHab in all three RCTs was an exercise programme, each varied in content (strength, control, balance and perturbation training), frequency (10 to 24 sessions) and length (3.1- to 6-weeks). Statistically significant differences (p < 0.05) were reported for quadriceps strength (one RCT) and single leg hop scores (two RCTs) in favour of PreHab three months after ACLR, compared to no PreHab. One RCT reported no statistically significant between-group difference for pain and function. No RCT evaluated post-operative psychological outcomes. CONCLUSION: Very low quality evidence suggests that PreHab that includes muscular strength, balance and perturbation training offers a small benefit to quadriceps strength and single leg hop scores three months after ACLR compared with no PreHab. There is no consensus on the optimum PreHab programme content, frequency and length. Further research is needed to develop PreHab programmes that consider psychosocial factors and the measurement of relevant post-operative outcomes such as psychological readiness and return to sport. TRIAL REGISTRATION: PROSPERO trial registration number. CRD42020162754 .

Is There Value and Validity for the Use of Return to Sport Test Batteries After Anterior Cruciate Ligament Injury and Reconstruction?

Is there value and validity for the use of return-to-sport (RTS) test batteries? With regard to RTS testing, there has been marked interest and rapid growth in studies that document RTS criteria after anterior cruciate ligament reconstruction. A set of criteria or "test-battery" is typically used to "clear" the athlete for RTS. Although most RTS testing is done with aim of assessing safety, the same measurements can be as used to determine the amount of functional capacity regained. It is suggested that RTS test batteries incorporate multiple domains of risk factors. If testing "works," patients who pass should have a lower risk of reinjury than patients who fail but nonetheless return to sport. More recent studies have attempted to cover a broad range of risk factors, with as many as 15 to 20 RTS tests. This is possibly due to a lack of clear evidence as to what are the most important risk factors for second injury. As a result, few patients pass these combined criteria. Findings from a meta-analysis showed that there is a low rate of passing RTS testing (23%). The findings from this and a second meta-analyses are quite similar, as both showed there was no effect of passing RTS test batteries on overall subsequent anterior cruciate ligament injury. There was a 7% to 9% reduction in risk difference of graft injuries with passing of RTS; however, there was a 4% to 9% risk difference or 176% to 235% increased risk of a contralateral injury with passing of RTS criteria. There remain several problems with RTS test batteries, which include low rates of meeting thresholds, many athletes return without meeting RTS thresholds, evidence for predictive value is limited, small sample sizes in many studies (only 2 studies >100 patients), and many studies don't document RTS rates. Additional issues include questions as to whether testing should be staged, how to monitor progression of rehabilitation, and should these RTS batteries be tailored to age groups?

Anterior cruciate ligament grafts display differential maturation patterns on magnetic resonance imaging following reconstruction: a systematic review.

PURPOSE: The appearance of anterior cruciate ligament (ACL) grafts on magnetic resonance imaging (MRI) is related to graft maturity and mechanical strength after ACL reconstruction (ACLR). Accordingly, the purpose of this review was to quantitatively analyze reports of serial MRI of the ACL graft during the first year following ACLR; the hypothesis tested was that normalized MRI signal intensity would differ significantly by ACL graft type, graft source, and postoperative time. METHODS: PubMed, Scopus, and CINAHL were searched for all studies published prior to June 2018 reporting MRI signal intensity of the ACL graft at multiple time points during the first postoperative year after ACLR. Signal intensity values at 6 and 12 months post-ACLR were normalized to initial measurements and analyzed using a least-squares regression model to study the independent variables of postoperative time, graft type, and graft source on the normalized MRI signal intensity. RESULTS: An effect of graft type (P = 0.001) with interactions of graft type * time (P = 0.012) and graft source * time (P = 0.001) were observed. Post hoc analyses revealed greater predicted normalized MRI signal intensity of patellar tendon autografts than both hamstring (P = 0.008) and hamstring with remnant preservation (P = 0.001) autografts at postoperative month 12. CONCLUSION: MRI signal varies with graft type, graft source, and time after ACLR. Enhanced graft maturity during the first postoperative year was associated with hamstring autografts, with and without remnant preservation. Serial MRI imaging during the first postoperative year may be clinically useful to identify biologically or mechanically deficient ACL grafts at risk for failure. LEVEL OF EVIDENCE: IV.

The Japanese version of the anterior cruciate ligament-return to sport after injury (ACL-RSI) scale has acceptable validity and reliability.

PURPOSE: The anterior cruciate ligament-return to sports after injury (ACL-RSI) scale assesses the psychological impact of returning to sports (also referred to as psychological readiness) after ACL reconstruction. The aim of this study was to evaluate important measurement properties of the Japanese version of ACL-RSI scale. METHODS: Ninety-three participants who underwent ACL reconstruction filled out the Japanese version of ACL-RSI scale, the Tampa scale for kinesiophobia (TSK), the International Knee Documentation Committee-Subjective Knee Form (IKDC-SKF), and Knee injury and Osteoarthritis Outcome Score (KOOS). To assess test re-test reliability, 50 of the 93 participants re-answered the Japanese version of ACL-RSI scale within 10 days. Floor and ceiling effects, internal consistency, construct validity, and reliability of the Japanese version of ACL-RSI scale were analysed. RESULTS: There were no floor and ceiling effects. The Japanese version of ACL-RSI scale showed good internal consistency (Cronbach's alpha = 0.912). It was positively correlated with total points of IKDC-SKF and the Lysholm score, and with the all sub-categories of the KOOS, and it was negatively correlated with the TSK. Reliability of the Japanese version of ACL-RSI scale was satisfactory. CONCLUSION: The Japanese version of ACL-RSI scale has acceptable measurement properties. It can be a useful for evaluation of psychological readiness for return to sports in Japanese athletes who undergo primary ACL reconstruction. Information provided by the Japanese version of the ACL-RSI scale may also help to identify athletes who find return to sport a challenge, and guide conversations regarding treatment and rehabilitation plans. LEVEL OF EVIDENCE: II.

Translation, cross-cultural adaptation, validation, and measurement properties of the Spanish version of the anterior cruciate ligament-return to sport after injury (ACL-RSI-Sp) scale.

PURPOSE: To translate into Spanish and validate the anterior cruciate ligament-return to sport after injury (ACL-RSI) scale, and to evaluate the psychological factors that have the greatest impact on the return to play among Spanish football players. METHODS: The ACL-RSI was first translated into Spanish by two teams of bilingual experts. At the time of discharge, 114 amateur and semi-professional football players who underwent ACL reconstruction answered a questionnaire regarding demographic and injury-related data, along with the translated ACL-RSI, the Knee Injury and Osteoarthritis Outcome Score (KOOS), the Tampa Scale for Kinesiophobia (TSK-11SV) and the injury-psychological readiness to return to sport (I-PRRS). Statistical analysis included reliability tests (Cronbach's alpha and test-retest), construct validity and exploratory factor analysis. RESULTS: The ACL-RSI-Sp showed excellent internal consistency (Cronbach's α = 0.9), temporal stability (test-retest r = 0.9) and significant moderate correlations with the KOOS subscales of symptoms (r = 0.4; p < 0.01), pain (r = 0.4; p < 0.01), daily life (r = 0.4; p < 0.01), "sport" (r = 0.5; p < 0.01) and quality of life (r = 0.6; p < 0.01). Significant moderate and strong correlations were also observed for the ACL-RSI-Sp with the TSK (r = - 0.5; p < 0.01) and the I-PRRS (r = 0.8; p < 0.01), respectively. Confidence in performance (1) and fear and insecurity (2) explained 62.6% of the total variance in ACL-RSI-Sp. CONCLUSIONS: The ACL-RSI-Sp was a valid and reliable instrument to evaluate the relevant psychological factors in the return to sports of Spanish football players after ACL reconstruction. Players' confidence in performance and fear and insecurity were the most important factors influencing the return to play in this population. LEVEL OF EVIDENCE: Level IV.

Clinical outcomes after anterior cruciate ligament injury: panther symposium ACL injury clinical outcomes consensus group.

PURPOSE: A stringent outcome assessment is a key aspect for establishing evidence-based clinical guidelines for anterior cruciate ligament (ACL) injury treatment. The aim of this consensus statement was to establish what data should be reported when conducting an ACL outcome study, what specific outcome measurements should be used and at what follow-up time those outcomes should be assessed. METHODS: To establish a standardized approach to assessment of clinical outcome after ACL treatment, a consensus meeting including a multidisciplinary group of ACL experts was held at the ACL Consensus Meeting Panther Symposium, Pittsburgh, PA; USA, in June 2019. The group reached consensus on nine statements by using a modified Delphi method. RESULTS: In general, outcomes after ACL treatment can be divided into four robust categories-early adverse events, patient-reported outcomes, ACL graft failure/recurrent ligament disruption and clinical measures of knee function and structure. A comprehensive assessment following ACL treatment should aim to provide a complete overview of the treatment result, optimally including the various aspects of outcome categories. For most research questions, a minimum follow-up of 2 years with an optimal follow-up rate of 80% is necessary to achieve a comprehensive assessment. This should include clinical examination, any sustained re-injuries, validated knee-specific PROs and Health-Related Quality of Life questionnaires. In the mid- to long-term follow-up, the presence of osteoarthritis should be evaluated. CONCLUSION: This consensus paper provides practical guidelines for how the aforementioned entities of outcomes should be reported and suggests the preferred tools for a reliable and valid assessment of outcome after ACL treatment. LEVEL OF EVIDENCE: V.

Current Perspectives of the Australian Knee Society on Rehabilitation and Return to Sport After Anterior Cruciate Ligament Reconstruction.

CONTEXT: The importance of rehabilitation and evaluation prior to return to sport (RTS) in patients undergoing anterior cruciate ligament reconstruction has been reported. OBJECTIVE: This study sought to investigate current perspectives of Australian orthopedic surgeons on rehabilitation and RTS evaluation. DESIGN: Survey. PARTICIPANTS: Members of the Australian Knee Society. MAIN OUTCOME MEASURES: A 14-question survey was disseminated to Australian Knee Society members (orthopedic surgeons) to investigate (1) preferred graft choice, (2) estimated retear rate, (3) importance of preoperative and postoperative rehabilitation, and (4) preferred timing of RTS and evaluation prior to RTS discharge. RESULTS: Of all 85 Australian Knee Society members contacted, 86% (n = 73) responded. Overall, 66 respondents (90.4%) preferentially used hamstring tendon autografts. All surgeons estimated their retear rate to be ≤15%, with 31 (42.5%) <5%. Twenty-eight surgeons (38.4%) reported no benefit in preoperative rehabilitation. The majority of surgeons (82.2%-94.5%) reported that postoperative rehabilitation was important within various periods throughout the postoperative timeline. Most surgeons did not permit RTS until ≥9 months (n = 56, 76.7%), with 17 (23.3%) allowing RTS between 6 and 9 months. The most highly reported considerations for RTS clearance were time (90.4%), functional capacity (90.4%), and strength (78.1%). Most commonly, knee strength and/or function was assessed via referral to a preferred rehabilitation specialist (50.7%) or with the surgeon at their practice (11.0%). CONCLUSIONS: This survey revealed variation in beliefs and practices surrounding rehabilitation and RTS evaluation. This is despite the current evidence demonstrating the benefit of preoperative and postoperative rehabilitation, as well as the emerging potential of RTS assessments consisting of strength and functional measures to reduce reinjury rates.

"What's my risk of sustaining an ACL injury while playing sports?" A systematic review with meta-analysis.

OBJECTIVE: To estimate the incidence proportion (IP) and incidence rate (IR) for ACL injury in athletes. DESIGN: Systematic review with meta-analysis DATA SOURCES: The PubMed, CINAHL and SPORTDiscus electronic databases were searched from inception to 20 January 2017. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Studies were included if they reported total number of participants/population by sex, total number of ACL injuries by sex and total person-time by sex. RESULTS: Fifty-eight studies were included. The IP and IR of ACL injury in female athletes were 3.5% (1 out of every 29 athletes) and 1.5/10 000 athlete-exposures over a period of 1 season-25 years. The IP and IR of ACL injury in male athletes were 2.0% (1 out of every 50 athletes) and 0.9/10 000 athlete-exposures over a period of 1-25 years. Female athletes had a higher relative risk (RR) for ACL injury compared with males (RR=1.5; 95% CI 1.2 to 1.9; P<0.01) and a higher incidence rate ratio (IRR) of ACL injury compared with males over 1 season-25 years (IRR=1.7; 95% CI 1.4 to 2.2; P<0.010). When accounting for participation level, the disparity in the IR between female and male athletes was highest for amateur athletes compared with intermediate and elite athletes (IRR=2.1; 95% CI 1.3 to 3.4; P<0.01; I²=82%). Amateur female athletes remained at higher risk of ACL injury than did with amateur male athletes. In studies where follow-up length was <1 year, female athletes had a higher IR of ACL injury than did to males (IRR=1.7; 95% CI 1.3 to 2.2; P<0.01). Where follow-up was 1 year and beyond, there was no sex difference in the IR of ACL injury (IRR=2.1; 95% CI 0.9 to 4.8; P=0.06; I²=65%). SUMMARY/CONCLUSIONS: One in 29 female athletes and 1 in 50 male athletes ruptured their ACL in a window that spanned from 1season to 25 years. The IR of ACL injury among female athletes in a season was 1.7 times higher than the IR of ACL injury among male athletes and the IP of ACL injury among female athletes was 1.5 times higher than the IP of ACL injury among male athletes. The reported sex disparity in ACL injury rates is independent of participation level and length of follow-up.

'What's my risk of sustaining an ACL injury while playing football (soccer)?' A systematic review with meta-analysis.

OBJECTIVE: To estimate the incidence proportion (IP) and incidence rate (IR) of ACL injury in football players. DESIGN: Systematic review with meta-analysis. DATA SOURCES: PubMed, CINAHL and SPORTDiscus electronic databases were searched from inception to 20 January 2017. ELIGIBILITY CRITERIA FOR SELECTING STUDY: Studies that reported the total number of participants/population by sex, total number of ACL injuries by sex and total person-time by sex were included. RESULTS: Twenty-eight studies were included. The IP and IR of ACL injury in female football players were 2.0% (95% CI 1.2% to 3.1%) and 2.0/10 000 athlete exposures (AEs) (95% CI 1.6 to 2.6; I2=91%) over a period of one season to 4 years. The IP and IR of ACL injury in male players were 3.5% (95% CI 0.7% to 8.2%) and 0.9/10 000 AEs (95% CI 0.7 to 1.1; I2=94%). Studies that evaluated matched cohorts of female and male players showed no difference in IP (relative risk=1.2; 95% CI 0.9 to 1.6; P=0.47) over a period of one season to 4 years. Women were at greater risk than men (incidence rate ratio (IRR)=2.2; 95% CI 1.6 to 3.1; I2=83%; P<0.001). When accounting for participation level, the difference in IR between women and men was greatest for intermediate players (IRR=2.9; 95% CI 2.4 to 3.6) compared with amateur (IRR=2.6; 95% CI 1.4 to 4.8) and elite (IRR=2.0; 95% CI 1.1 to 3.4) players. SUMMARY/CONCLUSION: Overall, more men sustained ACL injury in football. There was no difference in the relative risk of ACL injury between female and male football players in a window that spanned one season to 4 years. The IR of ACL injury among women was 2.2 times higher than the IR of ACL injury among men. The reported sex disparity in ACL injury was independent of participation level.