After Anterior Cruciate Ligament Reconstruction Surgery Research Articles

Effects of sex differences on osteoarthritic changes after anterior cruciate ligament reconstruction in rats

The prevalence of primary osteoarthritis is higher in females than males. However, it remains unclear if there are sex differences in the incidence of post-traumatic osteoarthritis after anterior cruciate ligament (ACL) reconstruction. In this study, we aimed to investigate the effects of sex on osteoarthritic changes after ACL reconstruction using an animal model. Rats were divided into the following four groups: male control, male ACL reconstruction, female control, and female ACL reconstruction. ACL reconstruction surgery was performed on the right knees of rats in the ACL reconstruction groups, while rats in the control groups did not undergo knee surgery. At 1, 4, and 12 weeks after surgery, cartilage degeneration in the medial tibial plateau and osteophyte formation in the proximal tibia were histologically assessed. After ACL reconstruction, an increase in the Mankin score, cartilage fissures, and osteophyte formation were detected within 12 weeks in both male and female rats, with similar degrees of these changes between males and females. However, changes in cartilage thickness and chondrocyte density after ACL reconstruction differed between males and females. Cartilage thickening was observed in male rats but not in female rats. The increase in chondrocyte density in the anterior region was detected in both males and females but was more pronounced in female rats. In conclusion, osteoarthritic changes were observed after ACL reconstruction in both male and female rats, but differences in changes in cartilage thickness and chondrocyte density were observed between males and females.

Quadriceps and Hamstrings Activation Peaks Earlier as Athletes Repeatedly Hop, but There are Differences Depending on ACL Reconstruction Technique.

After Anterior Cruciate Ligament Reconstruction (ACLR) athletes face the challenge of regaining their previous competitive level while avoiding re-injury and early knee joint cartilage degeneration. Quadriceps and hamstrings strength reductions and neuromuscular alterations potentially related to risk of re-injury are present after ACLR and relate to deficits in muscle activation. Cross-sectional laboratory study. To examine quadriceps and hamstrings muscle activation during repeated hops in healthy pivoting-sport athletes and those who had undergone ACLR (bone-tendon-bone and semitendinosus graft) who had met functional criteria allowing return to training. Surface electromyography (SEMG) was recorded from vastus medialis and lateralis and medial and lateral hamstrings bilaterally during 30 seconds' repeated hopping in male athletes on average eight months after ACLR surgery (5-12 months). All patients underwent hamstring (HS) (n=24) or bone-tendon-bone (BTB) reconstruction (n=20) and were compared to healthy controls (n=31). The SEMG signals were normalized to those obtained during maximal voluntary isometric contraction. A significant time shift in peak muscle activation (earlier) was seen for: vastus medialis and vastus lateralis activation in the control group, in the BTB group's healthy (but not injured) leg and both legs of the HS group. A significant time shift in peak muscle activation was seen for lateral hamstrings (earlier) in all but the BTB group's injured leg and the medial hamstrings in the control group only. Lower peak activation levels of the vastus lateralis (p\<0.001) and vastus medialis (p\<0.001) were observed in the injured compared to healthy legs and lower peak lateral hamstrings activity (p\<0.009) in the injured leg compared to control leg. Decline in medial hamstring peak activation (p\<0.022) was observed between 1st and 3rd phase of the hop cycle in all groups. Repeated hop testing revealed quadriceps and hamstring activation differences within ACLR athletes, and compared to healthy controls, that would be missed with single hop tests. 3.

Effect of knee bracing on clinical outcomes following anterior cruciate ligament reconstruction: A prospective randomised controlled study

While there is a consensus against bracing after anterior cruciate ligament (ACL) reconstruction, the question of its potential benefits, especially in cases involving meniscus repair, as well as its routine use by the majority of clinicians, remains a topic of debate. This study aims to assess the effectiveness of bracing in relation to clinical scores after ACL reconstruction, regardless of meniscus surgery. This randomised controlled study involved patients aged 15-55 years who underwent arthroscopic ACL reconstruction surgery. All eligible patients were assigned into two groups: one group received an adjustable frame with a four-point fixation knee brace for a four-week period, while the other did not.A single experienced surgeon performed standard anatomical single-bundle ACL reconstruction. All patients, irrespective of whether they underwent meniscus repair, followed the same rehabilitation protocol. Knee functional questionnaires, including the International Knee Documentation Committee (IKDC) score, Lysholm score, Tegner Activity Scale, Visual Analogue Scale (VAS), and examinations, were collected preoperatively, at six months, one year, and two years postoperatively. The study employed an intention-to-treat analysis and multilevel mixed-effects generalised linear models to compare continuous outcomes between the groups, adjusting for the times of follow-up. A total of 84 patients (42 patients per group) comprised of 75 males (89 %) and average age of 30±9.4 years old. Patient-reported function, physical examination findings, and surgical characteristics were comparable between the two groups. (P-value >0.05) Both groups demonstrated significant improvement in IKDC and Lysholm scores at the end of the two-year follow-up period. (P-value <0.0001) In multivariate analysis, bracing was significantly associated with lower Tegner activity scale than the non-brace group after adjustment for VAS and time (coefficient -0.49, 95 % confidence interval -0.87, -0.10, P-value=0.013). None of the graft ruptures were reported, and there was no significant difference of return to sports between the groups at the end of the follow-up. The study suggests that knee bracing after ACL reconstruction, regardless of any additional meniscus procedures, fails to enhance subjective or objective outcomes and could potentially have a negative impact on the Tegner activity scale, although the difference is not clinically significant. The routine use of a postoperative brace should be discontinued. Level I, Randomised controlled trial with no negative criteria.

Effect of bone marrow aspiration concentrate and platelet-rich plasma combination in anterior cruciate ligament reconstruction: a randomized, prospective, double-blinded study

BackgroundThe effect of bone marrow aspirate concentrate (BMAC) and platelet-rich plasma (PRP) combination in enhancing graft maturation and tendon–bone tunnel interfacial healing after anterior cruciate ligament (ACL) reconstruction remains unclear. We hypothesised that BMAC and PRP combination could lead to better clinical results and better graft maturation/interface healing than PRP alone or conventional ACL reconstruction without any other biologic augmentation.MethodsIn this randomised double-blind prospective study, patients undergoing ACL reconstruction surgery were randomly assigned into three groups: (1) control group (without any biologic augmentation), (2) PRP treatment group, and (3) combined BMAC and PRP (BMAC + PRP) group. Moreover, they were evaluated using the clinical functional score, laxity examination, and magnetic resonance imaging (MRI) analysis.ResultsNo significant difference was observed in the improvement of functional scores among groups. However, laxity improvement at 24 weeks showed a significant difference with the BMAC + PRP group having the lowest laxity. MRI analysis showed no significant change in whole graft maturation among groups. In particular, the BMAC + PRP group showed delayed signal peak and higher graft signal at 24 weeks compared with the other two groups; however, the difference was not significant. With regard to tendon–bone interfacial healing, the BMAC + PRP group showed significantly wider tendon–bone interface in the femoral bone tunnel at 24 weeks compared with the other two groups. Moreover, the BMAC + PRP group showed significantly higher peri-tunnel edema signal in the femoral bone tunnel at 12 weeks compared with the other two groups.ConclusionPRP alone and BMAC and PRP combination showed limited enhancing effect in clinical function, graft maturation and tendon–bone interfacial healing compared with control (no additional treatment). When BMAC is used in ACL reconstruction, the possibility of greater inflammation in the early stage to graft maturation and bone tunnel healing should be considered.

Association of Psychological Readiness to Return to Sports With Subjective Level of Return at 12 Months After ACL Reconstruction.

Return-to-sports (RTS) rates after anterior cruciate ligament (ACL) reconstruction (ACLR) differ according to the level at which patients return. It is unclear whether the level of RTS is affected by psychological readiness to return. To examine the association between psychological readiness to RTS and subjective RTS level 12 months after ACLR. Case-control study; Level of evidence, 3. A total of 47 patients who underwent unilateral primary ACLR surgery were enrolled. Assessments at 6 and 12 months postoperatively consisted of knee strength testing (isokinetic quadriceps and hamstring strength), the International Knee Documentation Committee Subjective Knee Evaluation Form (IKDC-SKF), and the Anterior Cruciate Ligament-Return to Sport after Injury (ACL-RSI) scale to measure psychological readiness to RTS. Patients were assigned to 1 of 3 subgroups based on their subjective assessment of RTS level at 12 months postoperatively: RTS at or above preinjury level (RTS≥Pre; n = 19), RTS below preinjury level (RTS<Pre; n = 24), or no RTS (n = 4). Two-way mixed-model analysis of variance was used to examine the effects of RTS subgroup, postoperative time point, and group × time interaction with patient characteristics, knee strength, and IKDC-SKF and ACL-RSI scores. Multivariate logistic regression analysis was performed to determine which factors were associated with RTS subgroupings. Significant differences were found among the RTS≥Pre, RTS<Pre, and no-RTS groups in age, ACL-RSI score at 6 and 12 months, quadriceps strength at 6 and 12 months, and IKDC-SKF score at 6 and 12 months (P < .001 for all). Multivariate logistic regression analysis revealed that RTS at or above preinjury level was associated with higher ACL-RSI score at 12 months postoperatively (odds ratio [OR], 1.11; 95% CI, 1.05-1.20; P = .003) and younger age (OR, 0.80; 95% CI, 0.61-0.92; P = .012). The ACL-RSI score was significantly different among the study groups, and the ACL-RSI score at 12 months postoperatively and younger age were associated with RTS at or above preinjury level.

Factors Affecting Graft Remodeling and Anterior Cruciate Ligament Reconstruction: MRI Study of 180 Knees

Background: Several factors affect the retear rate after anterior cruciate ligament (ACL) reconstruction, but there are few data on which factors affect graft remodeling. Purpose: To determine which factors are associated with the remodeling of an ACL graft. Study Design: Case-control study; Level of evidence, 3. Methods: A retrospective longitudinal study was conducted to investigate the relationship between various exposure factors and the occurrence of an “event”: graft remodeling measured with the signal-to-noise quotient (SNQ). Data were collected prospectively and analyzed retrospectively for this study. The endpoint was the SNQ on magnetic resonance imaging at postoperative 1 year. The effect of the following parameters on SNQ was investigated: sex, smoking habits, age at surgery, body mass index, time to surgery, time to return to sports, type of sport (in-line, pivot, contact), type of graft (free semitendinosus [ST] or attached ST), and addition of lateral tenodesis. Results: An overall 180 patients were enrolled (90 with each technique). The following factors were significantly and independently associated with the SNQ: attached ST graft (β = −2.624668; P < .001), age at the time of surgery (β = −0.7948476; P = .012), and time elapsed between the injury event and surgery (β = −0.7137424; P = .046). Conclusion: Leaving the ST graft attached distally, being older at the time of surgery, and having more time elapse between the injury event and ACL reconstruction surgery were significantly associated with better graft remodeling.

Development and validation of a clinical prediction model for return to work after arthroscopic anterior crucial ligament reconstruction

BackgroundOccupational reintegration after anterior cruciate ligament (ACL) rupture is an important clinical issue including economic and health-related perspectives. This study aims to develop and validate a clinical prediction model of return to work in patients with ACL reconstruction surgery considering evidence-based clinical, anthropometric and occupational factors. MethodsData of 562 patients with an ACL rupture receiving an arthroscopic ACL reconstruction were used for analysis. A model for the binary outcome of experiencing an inability to work period of less or more than 14 days (model 1), and a model for finding predictor variables that are linearly associated with a continuous longer inability to work period of over 14 days (model 2) was calculated. Pre-operative determinants including patient characteristics and peri-operative factors were used as predictors for both models. ResultsFor model 1, the highest increase in odds was observed for the occupational type of work, followed by injury of the medial collateral ligament together with partial weight bearing. Small protective effects were observed for female sex, meniscal suture and work with light occupational strain. The type of occupational work, together with revision surgery, a longer duration of limited range of motion and the presence of cartilage therapy were risk factors for longer inability to work. Discrimination and calibration statistics were satisfactory in internal validation. ConclusionWithin the framework of clinical consideration, these prediction models will serve as an estimator for patients, their treating physicians and the socioeconomic partners to forecast the individual cost and benefit of ACL injury.

The pathological technical and tactical movements of a soccer player during return to sport predicts a second anterior cruciate ligament injury

Background: Return to sport after Anterior Cruciate Ligament (ACL) reconstruction remains a difficult decision-making process that is not structured on shared and homogeneous assessments. This greatly elevates the risk factors for second injuries. Objective: Highlight football-specific gestural, pathological, technical-tactical patterns that contribute to new ACL injuries (ipsilateral graft rupture or contralateral rupture of the native ACL). Material and method: For the purpose of this literature review, peer-reviewed and nonpeer-reviewed indexed journals were consulted from 1979 to the present. Studies were identified by searching them on PubMed/MEDLINE databases. The following search terms were used: “second ACL injury,” “cutting maneuver and ACL”, “sidestep cutting technique and ACL” “Valgus knee in sport” “change of direction and ACL injury” “pressing soccer” tackle in soccer”. The literature search was directed, also, to the Gray Literature. Result: An immediate pressing or re-aggression on the adversary, tackle, or cutting maneuver is clinically read as moments of risk factors, injury, or re-injury, for both the ball bearer and the defender. We found how a good deal of literature emphasizes how side-to-side gestural asymmetries, during technical and tactical movements, present during return to sport can elevate risk factors for second ACL injuries. During ball recovery, 4 main game situations have been found to elevate the risk factors of knee capsular ligament injuries: (1) during tactical moments of collective pressing or individual pressure; (2) in the postural rebalancing phase after moments of instability following the kicking of the ball; (3) dysfunctional moments from gestural instability, in landing, after a header in single-pedal support; (4) during a tackle by direct contact or indirect contact on the joint. Conclusion: Residual pathological movement’s side-to-side asymmetries and postural-dysfunctional pictures related to specific gestures after ACL reconstructive surgery are predictive factors of second ipsilateral ACL injury or injury to the contralateral limb. Given, however, the subjective interpretation of movement quality assessments, their relative reliability and validity in the diagnostic and therapeutic use of complex sports gestures, pressing, and cutting maneuvers, during the process of return to sport should be analyzed together and clinical assessments to identify other and consistent predictors of second ACL injuries.

Effects of joint immobilization and treadmill exercise on marrow adipose tissue and trabecular bone after anterior cruciate ligament reconstruction in the rat proximal tibial epiphysis

Marrow adipose tissue (MAT) adversely affects bone metabolism under certain conditions. Although mechanical stress is an important factor in regulating MAT and bone mass, how stress from different rehabilitation protocols after anterior cruciate ligament (ACL) reconstruction affects trabecular bone and MAT is unclear. We aimed to examine the effects of joint immobilization and treadmill exercise on trabecular bone and MAT after ACL reconstruction. Rats received unilateral knee ACL transection and reconstruction surgery. After surgery, rats were reared without intervention, with joint immobilization, or with treadmill exercise (12 m/min, 60 min/day, six days/week), with untreated rats as controls. At two or four weeks after starting experiments, we examined histological changes in trabecular bone and MAT in the proximal tibial epiphysis. After ACL reconstruction, there were no significant changes in trabecular bone area and MAT area at both time points. Joint immobilization after ACL reconstruction resulted in reduced trabecular bone area and MAT accumulation due to adipocyte hyperplasia and hypertrophy within four weeks. Treadmill exercise after ACL reconstruction did not affect any parameters in trabecular bone and MAT. We detected a moderate negative correlation between trabecular bone area and MAT area. Therefore, MAT accumulation induced by joint immobilization may contribute, at least in part, to reducing trabecular bone area. To minimize trabecular bone loss and MAT accumulation, joint immobilization after ACL reconstruction should be minimized. Exercise after ACL reconstruction did not alter trabecular bone and MAT.

Ultrasonography for quantitative assessment of knee joint effusions-useful tool for objective evaluation of rehabilitation progress?

We sought to externally validate ultrasonography (US) for quantification of suprapatellar effusion size to improve diagnosis and individualised rehabilitation strategies in knee rehabilitation after anterior cruciate ligament reconstruction (ACLR) surgery. US was performed on 35 patients as part of the ongoing CAMOPED study. Data were collected in ACLR and post surgery in defined intervals up to oneyear post-operation. The palpatory assessment was graded using the International Knee Documentation Committee (oIKDC). In a total of 164 sonographies, a strong correlation between palpatory and US effusion (r = 0.83, p < 0.01) with lower deviations in US quantification compared to palpatory quantification Y = 1.15 + 0.15* x was seen. Threshold values could be determined for the detection of effusions by palpation and for the differentiation between mild and moderate/severe effusions (effusion depth: 2.6mm and resp. 5.8mm, respectively). As demonstrated in this multicenter study, the size of suprapatellar effusions can be easily quantified with high accuracy using standardised bedside ultrasound. Especially in moderate to severe effusions, US provides a practical and reliable tool for outcome measurement superior to palpatory assessment with the goal of optimising individual recommendations during the rehabilitation course. Furthermore, for the first time, it has been possible to define sonographic threshold values for the detection of effusion and differentiation of mild vs. moderate/severe effusion by means of palpation.

How limb dominance influences limb symmetry in ACL patients: effects on functional performance

BackgroundTiming for return to sport (RTS) after anterior cruciate ligament (ACL) injury is paramount for the avoidance of a secondary injury. A common criterion in RTS decision-making is the limb symmetry index (LSI) which quantifies (a)symmetries between the affected and unaffected limb. Limb dominance is one of many factors that may contribute to the recovery of the LSI after ACL reconstruction. The purpose of this study was to examine how limb dominance affects the LSI of functional performance tasks nine months following ACL reconstruction (time of RTS).MethodsAt time of return to sport, n = 100 patients (n = 48 injured the dominant limb, n = 52 injured the non-dominant limb, n = 34 female, n = 66 male) with ACL reconstruction surgery performed isokinetic strength measurements of the knee extensors and flexors, and drop jumps (DJ), single leg hop for distance (SHD) and 6 m timed hop (6MTH) testings.ResultsThe findings indicated that injury of the dominant leg led to significantly higher LSI values in maximal isokinetic knee extensor strength (p = 0.030). No significant differences were observed for maximal isokinetic knee flexor strength, DJ, SHD or 6MTH performance. Stratifying for sex revealed no significant differences. Simple regression analyses demonstrated that LSI in maximal knee extensor strength significantly predicted LSIs in DJ and SHD while explaining 14% and 18% of the respective variance.ConclusionsGiven that limb dominance affects the LSI of muscle strength suggests that a differentiated interpretation of the LSI with respect to limb dominance should be considered for a safe return to sport. Monoarticular knee extensor strength and multiarticular hop test performance are interrelated and thus can show asymmetries which are not maladaptive but established during years of habituation or training.

Altered movement strategy during functional movement after an ACL injury, despite ACL reconstruction.

Knee joint functional deficits are common after anterior cruciate ligament (ACL) injury, but different assessment methods of joint function seem to provide contradicting information complicating recovery monitoring. We previously reported improved perceived knee function and functional performance (forward lunge ground contact time) in patients with an ACL injury from pre to 10 months post ACL reconstruction without improvement in knee-specific biomechanics. To further investigate this discrepancy, we additionally analyzed knee extensor and flexor muscle strength, and movement quality in the forward lunge (subjective and objective evaluations) and performed a full lower limb biomechanical analysis of the forward lunge movement. We included 12 patients with an ACL injury (tested before and after ACL reconstructive surgery) and 15 healthy controls from the previous study to the current investigation. Outcome measures were obtained pre and ~11 months post ACL reconstruction for the patients and at a single time point for the controls. Objective movement quality in the patients with an ACL injury showed an improvement from their pre reconstruction surgery visit to the post reconstruction visit but this was not observable in the subjective evaluation. Knee extensor muscle strength declined after the ACL reconstruction by 29% (p = 0.002) and both knee extensors (p < 0.001) and flexors (p = 0.027) were weaker in the patients post ACL reconstruction compared to healthy controls. ACL injured patients had an altered movement strategy in the forward lunge with reduced knee extensors contribution and increased hip extensor contribution compared to the controls both before and after the reconstruction. The altered movement strategy was associated with knee extensor muscle strength. This explorative study with a limited sample size found that clinicians should be aware that significant functional deficits in the knee extensor muscles, both in isolated muscle strength testing and during a functional movement, may be present although patients perceive an improvement in their knee function and present good functional performance without obvious movement quality issues.

Effects of Joint Immobilization and Treadmill Exercise on Articular Cartilage After ACL Reconstruction in Rats.

Background:The development of osteoarthritis after anterior cruciate ligament (ACL) reconstruction (ACLR) is an important issue. However, the appropriate rehabilitation protocol to prevent cartilage degeneration due to postoperative osteoarthritis is unclear.Purpose:To examine the effects of joint immobilization and treadmill exercise on articular cartilage after ACLR.Study Design:Controlled laboratory study.Methods:A total of 55 rats received unilateral knee ACL transection and reconstruction surgery using tail tendon autografts. After surgery, rats were reared without intervention, with joint immobilization, or with daily treadmill exercise (12 m/minute, 60 minutes/day, 6 days/week). Treadmill exercise was initiated at 3 or 14 days postoperatively. After 2 weeks of immobilization, the fixation device was removed from some of the immobilized rats, and the knee was allowed to move freely for 2 weeks. Untreated, age-matched rats (n = 8) were used as controls. At 2 or 4 weeks after starting the experiment, cartilage degeneration in the medial tibial plateau was histologically assessed using a modified Mankin score, cartilage thickness, chondrocyte density, and immunohistochemistry for cyclooxygenase-2 (COX-2) in the anterior, middle, and posterior regions.Results:After ACLR, cartilage degeneration in the anterior region characterized by increased Mankin score, accompanied with increased COX-2 expression, was detected. Joint immobilization after ACLR facilitated cartilage degeneration, which is detected by histological changes such as reductions in cartilage thickness, chondrocyte density, and high Mankin scores. Enhanced COX-2 expression in all degenerated cartilage regions was also detected. It was found that 2 weeks of remobilization could not restore cartilage degeneration induced by 2 weeks of immobilization after ACLR. Treadmill exercise after ACLR did not affect most articular cartilage parameters, regardless of the timing of exercise.Conclusion:Our results indicated that (1) immobilization after ACLR accelerates cartilage degeneration, even when applied only for 2 weeks, and (2) mild exercise during early phases after ACLR does not facilitate cartilage degeneration.Clinical Relevance:To reduce cartilage degeneration, periods of joint immobilization after ACLR should be minimized. Mild exercise during the early phases after ACLR will not negatively affect articular cartilage.

Anterior-cruciate-ligament reconstruction does not alter the knee-extensor moment arm during gait

BackgroundThe ability of the quadriceps muscles to extend the knee depends on the moment arm of the knee-extensor mechanism, which is described by the moment arm of the patellar tendon at the knee. The knee-extensor moment may be altered by a change in quadriceps force, a change in the patellar tendon moment arm (PTMA), or both. A change in quadriceps muscle strength after anterior-cruciate-ligament-reconstruction (ACLR) surgery is well documented, however, there is limited knowledge about how this procedure affects the PTMA. Research questionDoes ACLR surgery alter the moment arm of the knee-extensor mechanism during gait? MethodsWe measured the PTMA in both the ACLR knee and the uninjured contralateral knee in 10 young active individuals after unilateral ACLR surgery. Mobile biplane X-ray imaging was used to measure the three-dimensional positions of the femur, tibia and patella during level walking and downhill walking over ground. The PTMA was found from the location of the instantaneous axis of rotation at the knee and the line-of-action of the patellar tendon. ResultsThere was a small but statistically significant difference in the mean PTMA calculated over one cycle of level walking between the ACLR knee and the contralateral knee, with the mean PTMA in the ACLR knee being 1.5 mm larger (p < 0.01). In downhill walking, statistically significant differences were found in the range 15°– 25° of knee flexion, where the PTMA was 4.7 mm larger in the ACLR knee compared to the contralateral knee (p < 0.01). SignificanceSignificant differences were evident in the mean PTMA between the ACLR knee and the contralateral knee in both activities, however, the magnitudes of these differences were relatively small (range: 3–10%), indicating that ACLR surgery successfully restores the moment arm of the knee-extensor mechanism during dynamic activity.

Psychological Readiness to Return to Sport After Anterior Cruciate Ligament Reconstruction in the Adolescent Athlete.

Psychological readiness to return to sport has been shown to be associated with future play after anterior cruciate ligament (ACL) reconstruction surgery but has not been extensively studied in adolescent athletes. To investigate the psychometric properties of the Anterior Cruciate Ligament-Return to Sport after Injury (ACL-RSI) scale in adolescent athletes at multiple time points after ACL reconstruction surgery and determine whether psychological readiness scores at 6 months predict return to competition sport at 12 months. Case series. Private orthopaedic clinic. A total of 115 adolescent athletes (65 girls, 50 boys) 17 years and younger who had undergone primary unilateral ACL reconstruction. The ACL-RSI scale was administered at 6 and 12 months after surgery, and return-to-sport status was also documented. Factor analysis was undertaken and predictive validity assessed using between-groups comparisons and receiver operating characteristic (ROC) curve statistics. The ACL-RSI scores increased between 6 and 12 months (55 to 71; P < .001, effect size = 0.98). No floor or ceiling effects were present, and the scale had high internal consistency (Cronbach α at 6 months = 0.91 and at 12 months = 0.94). Principal component analysis showed that 2 factors were present: the first represented performance confidence and risk appraisal and the second, emotions. For the full-scale ACL-RSI, scores at 6 months had acceptable predictive ability for a return to play at 12 months (area under the ROC curve = 0.7, P = .03). When the 2 identified factors were analyzed separately, the emotions factor also had acceptable predictive ability (area under the ROC curve = 0.73, P = .009), but the confidence in performance and risk appraisal factors had poor predictive ability (area under the ROC curve = 0.59, P = .09). Greater psychological readiness was associated with return to sport in adolescent athletes after ACL reconstruction, with the athletes' emotional response appearing to be more influential than their confidence in their performance or their appraisal of risk.

Why More Is Better: Integrating Sports Rehabilitation With Group-based Strength &amp; Conditioning After ACL Reconstruction

Current return to sport (RTS) timelines after anterior cruciate ligament reconstruction (ACLR) suggest a minimum of 9 months before returning to competitive sports. Time, quadriceps limb symmetry index (qLSI) deficits and movement mechanics are recognized as indicators of RTS surgical limb performance and re-injury risk reduction. Current isolated therapy models may not provide appropriate skilled rehabilitation leaving individuals with impairments near the end of their care. PURPOSETo examine the effects of combined therapy and group-based strength training on known RTS strength criteria following ACLR surgery. METHODSTwenty-two individuals (17 +/- 2 years) having undergone ACLR (CON) were age, sex and graft harvest matched with individuals who participated in a group-based strength and conditioning program between 3 and 9 months post-surgery (ACLRSC). 900 flexion isometric dynamometer strength testing was administered at 3, 6 & 9 months post-surgery. Individuals maximally kicked out for five seconds and was repeated 3 times. Dependent strength variables were average peak torque (Nm), relative torque (Nm/kg) and qLSI (%). ACLRSC completed strength sessions between 3 and 9 month testing (40 +/- 1 visits). The primary quadriceps specific stimulus was closed kinetic chain, semi supported, single leg squat exercises beginning with an asymmetrical loading ratio of 3:1 of exercise sets and progressed to 2:1 and 3:2 for the surgical limb compared to nonsurgical. Independent samples t-tests were used to determine differences in strength variables per group. RESULTSNo significant differences between groups at all time points in surgical limb average peak torque or relative torque (p > .05) was. No difference was found in qLSI at 3 or 6 (p > .05) months. However, at 9 months post-surgery qLSI was significantly higher in the ACLRSC group compared to CON (p = 0.03). CONCLUSIONIndividuals who completed combined therapy and training during rehabilitation reach RTS qLSI criteria at 9 months post-surgery compared to those who do not complete additional training. This model of combined therapy and group-based strength training proves to increase positive functional outcomes after ACLR. It further justifies the importance of a team based, patient centered, objective measure driven rehabilitation model.

Wide Variability in Return-to-Sport Criteria used by Team Physicians After Anterior Cruciate Ligament Reconstruction in Elite Athletes—A Qualitative Study

PurposeThe purpose of this study is to explore currently used readiness to return to sport (RTS) criteria after anterior cruciate ligament reconstruction (ACLR) used in elite athletes to gain novel insights into the RTS decision-making process of professional team physicians.MethodsEighteen qualitative semistructured interviews with professional team physicians were conducted by a single trained interviewer. The interviews were used to identify team physician concepts and themes regarding the criteria used to determine RTS after ACLR. General inductive analysis and a coding process were used to identify themes and subthemes arising from the data. A hierarchical approach in coding helped to link themes.ResultsThe most important RTS criteria included muscle strength, followed by satisfactory functional testing including hop tests, a satisfactory clinical examination, joint stability, psychological readiness, time since the ACLR surgery, absence of joint effusion, subjective feeling of knee stability, pain-free return to sporting movements, completion of a sport-specific rehabilitation, and at last allied team support.ConclusionsThis study identified 4 main themes, including (1) objective findings, (2) informative feedback of the team members, (3) subjective findings, and (4) type of sport and time to surgery as having the most influence on RTS decision after ACLR. However, interviews showed that even among professional team physicians, the main criteria to RTS in these categories were inconsistent. A definitive set of conclusive guidelines could not be established and would be a fruitful and useful area for future research through further quantitative studies and international consensus meetings along the foundation of the presenting study.Level of EvidenceV, evidence-based practices, qualitative study.

A Psychological Support Intervention to Help Injured Athletes "Get Back in the Game": Design and Development Study.

BackgroundAfter a serious knee injury, up to half of athletes do not return to competitive sport, despite recovering sufficient physical function. Athletes often desire psychological support for the return to sport, but rehabilitation clinicians feel ill-equipped to deliver adequate support.ObjectiveWe aimed to design and develop an internet-delivered psychological support program for athletes recovering from knee ligament surgery.MethodsOur work for developing and designing the Back in the Game intervention was guided by a blend of theory-, evidence-, and target population–based strategies for developing complex interventions. We systematically searched for qualitative evidence related to athletes’ experiences with, perspectives on, and needs for recovery and return to sport after anterior cruciate ligament (ACL) injury. Two reviewers coded and synthesized the results via thematic meta-synthesis. We systematically searched for randomized controlled trials reporting on psychological support interventions for improving ACL rehabilitation outcomes in athletes. One reviewer extracted the data, including effect estimates; a second reviewer checked the data for accuracy. The results were synthesized descriptively. We conducted feasibility testing in two phases—(1) technical assessment and (2) feasibility and usability testing. For phase 1, we recruited clinicians and people with lived experience of ACL injury. For phase 2, we recruited patients aged between 15 and 30 years who were within 8 weeks of ACL reconstruction surgery. Participants completed a 10-week version of the intervention and semistructured interviews for evaluating acceptability, demand, practicality, and integration. This project was approved by the Swedish Ethical Review Authority (approval number: 2018/45-31).ResultsThe following three analytic themes emerged from the meta-synthesis (studies: n=16; participants: n=164): (1) tools or strategies for supporting rehabilitation progress, (2) barriers and facilitators for the physical readiness to return to sport, and (3) barriers and facilitators for the psychological readiness to return to sport. Coping strategies, relaxation, and goal setting may have a positive effect on rehabilitation outcomes after ACL reconstruction (randomized controlled trials: n=7; participants: n=430). There were no trials of psychological support interventions for improving the return to sport. Eleven people completed phase 1 of feasibility testing (technical assessment) and identified 4 types of software errors, which we fixed. Six participants completed the feasibility and usability testing phase. Their feedback suggested that the intervention was easy to access and addressed the needs of athletes who want to return to sport after ACL reconstruction. We refined the intervention to include more multimedia content and support access to and the use of the intervention features.ConclusionsThe Back in the Game intervention is a 24-week, internet-delivered, self-guided program that comprises 7 modules that complement usual rehabilitation, changes focus as rehabilitation progresses, is easy to access and use, and includes different psychological support strategies.

Low-Level Laser Therapy Attenuates Arthrogenic Contracture Induced by Anterior Cruciate Ligament Reconstruction Surgery in Rats

Therapeutic approaches to treat joint contracture after anterior cruciate ligament (ACL) reconstruction have not been established. Arthrofibrosis accompanied by joint inflammation following ACL reconstruction is a major cause of arthrogenic contracture. In this study, we examined whether anti-inflammatory treatment using low-level laser therapy (LLLT) can prevent ACL reconstruction-induced arthrogenic contracture. Rats underwent ACL transection and reconstruction surgery in their right knees. Unoperated left knees were used as controls. After surgery, rats were reared with or without daily LLLT (wavelength: 830 nm; power output: 150 mW; power density: 5 W/cm2; for 120 s/day). We assessed the passive extension range of motion (ROM) after myotomy at one and two weeks post-surgery; the reduction in ROM represents the severity of arthrogenic contracture. ROM was markedly decreased by ACL reconstruction at both time points; however, LLLT partially attenuated the decrease in ROM. One week after ACL reconstruction, the gene expression of the proinflammatory cytokine interleukin-1beta in the joint capsule was significantly upregulated, and this upregulation was significantly attenuated by LLLT. Fibrotic changes in the joint capsule, including upregulation of collagen type I and III genes, shortening of the synovium, and thickening were caused by ACL reconstruction and seen at both time points. LLLT attenuated these fibrotic changes as well. Our results indicate that LLLT after ACL reconstruction could attenuate the formation of arthrogenic contracture through inhibition of inflammation and fibrosis in the joint capsule. Thus, LLLT may become a novel therapeutic approach for ACL reconstruction-induced joint contracture.

Conflicting time-dependent effects of treadmill exercise on joint contracture after anterior cruciate ligament reconstruction in rats

We examined the time-dependent differences in the effects of treadmill exercise on joint contracture after anterior cruciate ligament (ACL) reconstruction. Rats received ACL reconstructive surgery. After surgery, rats were reared with or without treadmill exercise (60 min/day) starting at 3 days (when inflammatory reactions are active) or 14 days (when inflammatory reactions have subsided) post-surgery. Untreated rats were used as controls. Data were collected at two or four weeks post-surgery. The range of motion (ROM) decreased following surgery at both time points and treadmill exercise during the first two weeks post-surgery further decreased the ROM. Moreover, treadmill exercise during first two weeks post-surgery upregulated the pro-inflammatory cytokine interleukin-1β gene in the joint capsule and aggravated joint capsule fibrosis. For exercise started at 14 days post-surgery, the ROM recovered to control levels at four weeks post-surgery. In addition, delayed exercise contributed to resolving inflammatory and fibrotic reactions. Treadmill exercise initiated soon after surgery aggravates joint contracture via enhanced inflammatory and fibrotic reactions in the joint capsule. Conversely, exercise initiated after active inflammation has subsided facilitates joint capsule reorganization and increases joint ROM. Therefore, aggressive exercise should be started only after active inflammation is resolved to improve joint contracture following ACL reconstruction.