Functional performance 6 months after ACL reconstruction can predict return to participation in the same preinjury activity level 12 and 24 months after surgery

Time course of Quadriceps thickness changes over six months post-anterior cruciate ligament reconstruction: Unveiling critical impairments in vastii muscles

Vastii muscle adaptation caused by Quadriceps weakness observed after an Anterior Cruciate Ligament reconstruction (ACLr) remain debatable. We described the time course of changes in Quadriceps thickness, strength, and thigh circumference over six months following an ACLr. Quadriceps thicknesses, Quadriceps strength, and thigh circumference were measured preoperative, 3, and 6 months post-ACLr surgery in 103 patients (77 men and 26 women). Limbs and time were compared with repeated-measures ANOVA and the Intra-class correlation coefficient was determined (α = 5 %). From 0 to 3 months post-surgery, Quadriceps strength (p < 0.05), and VI (p < 0.05) and VL (p < 0.001) thicknesses were reduced. From 3 to 6 months, Quadriceps strength (p < 0.05), total Quadriceps thickness (p < 0.001), and VI (p < 0.001) and VL (p < 0.05) thicknesses increased. VM and RF thicknesses increase to 3 months after ACLr (p < 0.05). Quadriceps strength, circumference at 5 cm, VI, VL, VM, and total Quadriceps thickness remain lower than the contralateral limb 6 months following an ACLr (p < 0.05). Quadriceps thickness adapts heterogeneously, with VI and VL atrophying for up to three months, developing the highest Quadriceps weakness. By 6 months, VI does not recover its thickness proportion, and VI and VL do not return to pre-surgery conditions. Both vastii muscles align with Quadriceps strength changes over six months posterior ACLr.

Physical therapists' perspectives and clinical practice on assessment, rehabilitation, and return to sport criteria after anterior cruciate ligament injury and reconstruction in Saudi Arabia

Background and objectivesTo explore the physical therapists' (PTs) perspectives and clinical practice on assessment, rehabilitation, and return to sports (RTS) criteria and to investigate their associations with gender, level of educational qualification, years of clinical experience, and the number of individuals treated after ACL injury and reconstruction (ACLR) in Saudi Arabia (SA).MethodsThis descriptive cross-sectional study surveyed 206 participants through an online survey covering demographics, ACLR rehabilitation importance, clinical measurements, practice, progression criteria, return to running, and RTS.ResultsMost PTs (84.9%) see an individual post-ACLR for the first time within the first week. About 24.8% of PTs preferred starting open kinetic chain (OKC) exercises one to seven days immediately post-ACLR. The timing of returning to running post-ACLR is variable among participants. Between six to nine months, 39.8% of PTs allowed an individual post-ACLR to RTS. Over 40% of participants did not use patient-reported outcome measures (PROMs) to clear an individual post-ACLR to RTS or evaluate psychological readiness. About 76.2% recommended an ACL injury prevention program at discharge.ConclusionMost PTs in SA inconsistently follow evidence-based ACLR rehabilitation practices. Education and training programs are needed to bridge the evidence-to-practice gap in post-ACLR care.

Return to sport at the pre-injury level following anterior cruciate ligament reconstruction is influenced by patients' perceived knee status and psychological readiness, and does not correlate with functional ability

OBJECTIVES

The purposes of this study were to (1) prospectively evaluate clinical and functional outcomes of athletes following anterior cruciate ligament (ACL) reconstruction up to 12 months after surgery, (2) to identify the correlations between functional and subjective tests, and (3) to determine which factors influence patients' capability to resume sports at pre-injury level.

METHODS

Patients who underwent ACL reconstruction using doubled autologous hamstring graft were prospectively assessed pre-operatively, 6, and 12 months after surgery using International Knee Documentation Committee (IKDC) Subjective Knee Form, Tegner activity level, and ACL-Return to Sport after Injury (ACL-RSI) scale. Jumping ability was instrumentally assessed using a test battery including bipodalic squat jump (SJ), bipodalic countermovement jump (CMJ), monopodalic CMJ, and monopodalic side-hop test.

RESULTS

Thirty-three patients were available for clinical evaluation at 12-months follow-up. Average age was 34.0 years (SD 11.5, range 19-50). Male/female ratio was 31:2. Mean overall IKDC, and ACL-RSI scores increased from 52.5 to 47.1 preoperatively, to 89.9 (SD: 12.2, range 36.8-100) and 81.3 (SD 21.7, range 10-98.3), respectively at last follow-up (p ​< ​0.001). Monopodalic jump tests showed improvements at 12-month evaluation compared to 6-month follow-up (p ​< ​0.01). No statistically significant correlation was reported for ACL-RSI and jump limb symmetry index (LSI) (p ​= ​0.08 vs. CMJ; p ​= ​0.07 vs. side-hop test). No differences were observed in terms of jump LSI between patients who returned to pre-injury activity level and those who did not (p ​= ​0.11 for CMJ, p ​= ​0.09 for side-hop test). A significantly higher IKDC score at 6 months was observed in patients who did not return to pre-injury levels (p ​= ​0.009). Patients who did not return to pre-injury activity reported lower ACL-RSI scores at 12-months follow-up (p ​= ​0.007).

CONCLUSIONS

One year after ACL reconstruction, an improvement in jumping ability was observed, while a persistence of lower limbs asymmetries when performing jump tests was noted at 6-months follow-up. The ability to perform vertical jumps was not influenced by psychological outcomes 12 months following surgery. Higher values of subjective knee score and psychological readiness weakly correlated to return to sport at preinjury level, while no correlation was reported concerning jumping performance.

The "11 to Perf Score", a Test for Professional Players Returning to Soccer After Anterior Cruciate Ligament Reconstruction

Rupture of the anterior cruciate ligament (ACL) is common among soccer players. Although there are no strict recommendations for the return to sport, more and more practitioners are having their patients perform isokinetic and even composite tests. However, these tests have not yet been shown to be predictive of re-injury, and are not specific to professional footballers. Objectives: The "11 to Perf" is a test designed to help professional footballers return to sport after ACL reconstruction. Its originality lies in its integration of soccer practice with specific tests. The aim of this article is to present the "11 to Perf" evaluation method. Methods: A prospective cohort study was conducted at the Centre National du Football (FIFA center) in Clairefontaine, including professional footballers who have undergone anterior cruciate ligament surgery and rehabilitation. Tests include clinical assessments, jumping, agility, psychological and isokinetic tests and match simulation. Conclusions: The "11 to Perf" is a composite test designed to assess the return to sport of professional footballers after ACL reconstruction. Its predictive capacity for recurrence should be assessed in the future.

Prediction of 12-Month Clinical Outcomes Postsurgery Based on 3-Month Knee Examination After Primary Anterior Cruciate Ligament Reconstruction

CONTEXT

Active management of modifiable factors during the early rehabilitation stage can help patients who have undergone anterior cruciate ligament (ACL) reconstruction successfully return to sports. This study aimed to determine predictors for performance on the single-leg hop test and Tegner activity score 12-month post-ACL reconstruction, based on knee function assessed 3-month postsurgery.

DESIGN

Prospective cohort study.

METHODS

Ninety-one patients who underwent ACL reconstruction were recruited. Multivariate logistic regression analysis was performed to identify predictors of the one hop test and Tegner activity score 12-month postsurgery, based on a knee examination performed 3 months after ACL reconstruction. Factors evaluated at 3 months included the Biodex balance system anteroposterior and mediolateral indexes; Y balance test anterior, posteromedial, and posterolateral reaches; knee extensors and flexors peak torque per body weight; and knee extensors and flexors average power per body weight.

RESULTS

The knee extensor peak torque per body weight (PT/BW) and Biodex balance system-mediolateral index with cutoff values of 132 N·m/kg and 0.45, respectively were identified as predictors for achieving a limb symmetric index within 10% on the hop test. Furthermore, achieving a Tegner activity score over 6 was predicted by Y balance test-posteromedial reach and knee flexors average power per body weight, with cutoff values of 92.5 cm and 122 W/kg, respectively.

CONCLUSION

Three months following ACL reconstruction, knee extensor peak torque, and mediolateral balance predicted performance on the hop test, while dynamic posteromedial balance and knee flexors average power predicted rotational ability, at the 12-month assessment.

Follow-up Treatment after Cartilage Therapy of the Knee Joint - a Recommendation of the DGOU Clinical Tissue Regeneration Working Group

The first follow-up treatment recommendation from the DGOU's Clinical Tissue Regeneration working group dates back to 2012. New scientific evidence and changed framework conditions made it necessary to update the follow-up treatment recommendations after cartilage therapy.As part of a multi-stage member survey, a consensus was reached which, together with the scientific evidence, provides the basis for the present follow-up treatment recommendation.The decisive criterion for follow-up treatment is still the defect localisation. A distinction is made between femorotibial and patellofemoral defects. In addition, further criteria regarding cartilage defects are now also taken into account (stable cartilage edge, location outside the main stress zone) and the different methods of cartilage therapy (e. g. osteochondral transplantation, minced cartilage) are discussed.The present updated recommendation includes different aspects of follow-up treatment, starting with early perioperative management through to sports clearance and resumption of contact sports after cartilage therapy has taken place.

Drop Vertical Jump Landing Mechanics Are Similar Between Patients With Quadriceps Tendon and Patellar Tendon Autografts After Anterior Cruciate Ligament Reconstruction

Purpose

To compare the biomechanics of a drop vertical jump (DVJ) landing task and functional outcomes among patients with anterior cruciate ligament reconstruction (ACLR) with quadriceps tendon (QT) and patellar tendon (PT) autografts.

Methods

Physically active patients who underwent primary ACLR with either a QT or PT autograft were included in this study. All were within 6 months to 2 years after surgery and cleared for return to physical activity. Subjects completed DVJs in a biomechanics laboratory. Peak vertical ground reaction force (VGRF) and lower-extremity joint sagittal and frontal plane kinematics and kinetics were collected and analyzed. Mann-Whitney U tests were used to compare the surgical limbs of the QT and PT autograft groups for kinematic and kinetic variables. Wilcoxon rank-sum tests were used to compare the surgical and nonsurgical limbs for both the QT and PT autograft groups.

Results

Twenty-four physically active individuals who underwent primary ACLR with QT (n = 14) or PT (n = 10) autografts completed DVJs in a biomechanics laboratory. There were no statistically significant biomechanical differences between the QT and PT groups. Peak VGRF differed between the surgical and nonsurgical limbs for the QT (surgical and nonsurgical, 1.10 and 1.30 N) and PT (surgical and nonsurgical, 1.10 and 1.35 N) groups. Specifically, both groups demonstrated lower VGRFs in the surgical limb compared with the nonsurgical limb (P < .05). Additional medium and large effect sizes were found when comparing kinetic variables between limbs within both surgical groups.

Conclusions

Regardless of the graft-specific surgical technique, patients who undergo ACLR are returning to activity with movements that resemble an offloading pattern of the surgical limb. Coupled with the finding of an absence of differences in kinematic and kinetic variables between the QT and PT autograft groups suggests that the QT graft may be a viable alternate graft source for ACLR.

Level of Evidence

Level III, retrospective comparative study.

Verbal instructions for attentional focus influence the results of tests for return to sport after anterior cruciate ligament reconstruction

This cross-sectional study investigated the influence of attentional focus verbal instructions on test results for return to sport (RTS) after ACL-R. Sixty subjects (53 male and 7 female, age 27.52 ± 7.63 years, body mass 77.56 ± 12.41 kg, height 162.04 ± 43.90 cm, and surgery time 11.15 ± 4.55 months) were evaluated in the single hop test (SHT), 6 m timed hop test (6mTHT), and "T" agility test. Participants performed the tests following randomly determined verbal instructions that induced neutral focus (NF), internal focus (IF), and external focus (EF). EF increased hop distance in SHT compared to NF (p = 0.001, effect size = 0.57) and IF (p = 0.037, effect size = 0.57) and there was no difference between IF and NF (p = 0.418). In 6mTHT, NF and EF increase velocity compared to IF (p = 0.001, effect size = 0.49, p = 0.001, effect size = 0.49, respectively). In the "T" agility test, the NF increased velocity when compared to the EF (p = 0.001, effect size = 0.62) and the IF (p = 0.001, effect size = 0.62), without difference between IF and EF (p = 0.071). In summary, attentional focus in patients under ACL-R can influence hops and agility.

Factors Associated with Return to Sport After Anterior Cruciate Ligament Reconstruction: A Focus on Athletes Who Desire Preinjury Level of Sport

In most previous studies investigating return to preinjury level of sport (RTPS) after anterior cruciate ligament reconstruction (ACLR), whether patients continue aiming for RTPS not only before but also after ACLR was unclear because environmental and social factors were not considered. Herein, we aimed to evaluate factors associated with RTPS among athletes who desired to achieve RTPS even after ACLR, excluding patients who no longer desire this goal owing to environmental and social factors. Ninety-two patients who underwent primary double-bundle ACLR with a minimum 2-year follow-up and desired to achieve RTPS before surgery were retrospectively enrolled. Twelve (13%) patients who no longer desired to achieve RTPS after ACLR owing to environmental and social factors were excluded. Sixty-nine patients were included in the final cohort. At the final follow-up, the patients were split into two groups: those who achieved (R group) or did not achieve (N group) RTPS based on patient self-assessment. The Knee Injury and Osteoarthritis Outcome Score (KOOS) and Lysholm scores were also determined. The anterior tibial translation in the Lachman test and acceleration and external rotational angular velocity (ERAV) in the pivot shift test were measured at the hardware removal operation. Significant differences were observed for preinjury level of sports between the groups (p < 0.05). The rate of RTPS in competitive athletes was lower than that in recreational athletes (20/46: 43% vs. 16/22: 73%; p =.037). Lysholm score, KOOS symptom, pain, and quality of life showed higher values in the R group than in the N group (p < 0.050). Acceleration was significantly lower in the R group than in the N group (p = 0.028). Competitive level of sports is a risk factor for failure to achieve RTPS. The postoperative functional outcomes in the group that achieved RTPS showed more favorable results. These results provide important information to enable the surgeons to consider the appropriate surgical plan for competitive athletes who desire to achieve RTPS after ACLR.

A Qualitative Study of Factors Perceived to Influence Physical Activity among Young Athletes after ACL Reconstruction

Background

Despite evidence of alarming declines in physical activity levels after anterior cruciate ligament reconstruction (ACLR), very little is known about how young athletes perceive their experiences with engagement in sports and physical activity in the years following ACLR.

Hypothesis/Purpose

The purpose of this study was to answer the research question, "what are the lived experiences and perceptions of factors that facilitate or hinder physical activity among young athletes following ACLR?".

Study Design

Qualitative Study.

Methods

Ten participants were included in this qualitative study at a median of 5.9 (4.3-10.2) years after adolescent ACLR. Using an interpretive phenomenological methodology, semi-structured interviews were conducted with each participant. Data collection focused on participants' lived experiences related to physical activity participation in the years after ACLR. Iterative coding with two independent coders and a peer debriefing process were used to identify themes from the data.

Results

Factors perceived to influence physical activity after ACLR spanned all levels of the socioecological framework. Three overarching themes were generated during thematic analysis: 1) navigation of barriers (common obstacles, injury-related limitations, unique adaptations), 2) movement motives (ingrained desire to move, external motivators, internal motivation), and 3) movement mindset (envisions for future physical activity, perceived impact of injury, belief in the power of sports).

Conclusion

The themes identified in this study indicate that the adolescent ACLR experience has the potential to significantly influence one's physical activity into young adulthood, both positively and negatively. These findings serve as an important foundation for future studies to explore the psychological and environmental factors identified as important to one's physical activity participation in the years following adolescent ACLR.

Level of Evidence

Level 3.

Predicting the Recovery of Isokinetic Knee Strength 6 Months After Anterior Cruciate Ligament Reconstruction

Background

The limb symmetry index (LSI) is a metric of strength restoration. It is key to successfully return to sports after anterior cruciate ligament (ACL) reconstruction. The threshold for return to sports is generally considered an LSI of ≥85%.

Purpose

To develop a statistical model for predicting the recovery of knee extension and flexion strength (with LSI ≥85%) at 6 months after ACL reconstruction.

Study Design

Case-control study; Level of evidence: 3.

Methods

Patients who underwent arthroscopic ACL reconstruction between November 2015 and December 2020 were included. The patients were classified into 2 groups: "pass" if the LSI at 6 months postoperatively was ≥85% and "fail" if the LSI was <85%. Factors in 25 categories with 74 levels, including patient characteristics, periarticular procedures, intra-articular lesions and treatment, and perioperative management, were collected. A multivariable logistic regression combined with backward variable elimination was used to determine the predictive parameters for recovery of knee extension and flexion strength.

Results

A total of 948 patients were included. Graft site, preoperative isokinetic strength, treatment of meniscal injury, and injured side (left vs right) were identified as general predictors for both knee extension and flexion strength. For knee extension strength, age at injury and partial weightbearing duration were identified as additional predictors. For knee flexion strength, type of meniscal injury, surgeon volume, cartilage procedures, and periarticular procedures were identified as additional predictors. The Nagelkerke R 2 of the final model was 0.178, and the c-statistic was 0.716 (95% CI, 0.676-0.754). The Hosmer-Lemeshow test indicated good calibration (P = .879).

Conclusion

Several factors including preoperative isokinetic strength, treatment of meniscal injuries, left vs. right side and graft site were found to predict recovery of ≥85% LSI in knee extension and flexion strength. Despite the numerous factors that were analyzed, the predictive power was moderate (c-statistic = 0.716), indicating there were other nonincluded factors that significantly influence strength performance at 6 months postoperatively.

Single-bundle ACL combined with ALL reconstruction yields comparable outcomes in patients with varied anatomical risk factors for ACL graft failure

BACKGROUND

Anterior cruciate ligament (ACL) graft failure is influenced by factors such as meniscal tears and tibial plateau slope. Combined anterior cruciate ligament (ACL) and anterolateral ligament (ALL) reconstruction has reduced failure rates; however, its efficacy in high-risk patients remains unclear. This study hypothesized that combined ACL and ALL reconstruction would yield similar clinical outcomes in patients with varying risks of ACL failure.

PATIENTS AND METHODS

A total of 76 patients who underwent primary single-bundle ACL reconstruction combined with ALL reconstruction between June 2018 and June 2021 were included. The medial tibial slope (MTS), lateral tibial slope (LTS), and anterior tibial translation (ATT) were measured using magnetic resonance imaging and plain radiography of the knee joint. The meniscal lesions were assessed during surgery. Preoperative clinical assessments and final follow-up were conducted using patient-reported outcome measurements (PROMs), including the International Knee Documentation Committee (IKDC) evaluation, Lysholm knee scoring scale, and Tegner Activity scale. PROMs were collected at least two years postoperatively.

RESULTS

The average follow-up was 32.5 ± 7.4 months. There were no significant differences in postoperative IKDC score, Lysholm score, or Tegner activity score between patients with or without medial meniscus injury (p = 0.155, 0.914, and 0.042, respectively), with or without lateral meniscus injury (p = 0.737, 0.569, and 0.942, respectively), medial tibial slope > 12° or ≤ 12° (p = 0.290, 0.496, and 0.988, respectively), or lateral tibial slope > 7.4° or ≤ 7.4° (p = 0.213, 0.625, and 0.922, respectively). No significant correlations were found between anterior tibial translation and postoperative IKDC (R = -0.058, p = 0.365), Lysholm (R = -0.017, p = 0.459), or Tegner activity scores (R = -0.147, p = 0.189).

CONCLUSION

Our study demonstrates that single-bundle ACL reconstruction combined with ALL reconstruction provides reliable and comparable clinical outcomes in patients with high-risk factors for ACL graft failure, such as increased tibial slope or meniscal injury. Our results suggest that the indications for ALL reconstruction may be expanded to include patients with a high tibial slope or meniscal injury, because these factors have been shown to contribute to increased rotational instability and high rates of ACL graft failure. Future prospective randomized controlled trials with large patient cohorts and long follow-up periods are needed to validate these findings and establish clear guidelines for patient selection and surgical decision-making.

LEVEL OF EVIDENCE

Level 3.

Reasons for Not Returning to Pre-injury Sport Level After ACL-Reconstruction

The study aimed to identify athlete-reported reasons for not returning to pre-injury sports level after anterior cruciate ligament reconstruction (ACLR) and to identify the factors associated with these reasons. Ninety-one athletes with 2 years post-ACLR indicated whether or not they had returned to their pre-injury sport level (same frequency, duration, and intensity). Athletes who did not return were asked to provide the reasons. Athletes' characteristics and injury-related factors were used to determine factors associated with the reasons for not returning. Only nine athletes (10%) returned to pre-injury sport level after ACLR. The most common reasons for not returning were lack of confidence or concerns about re-injury (48.8%), followed by continued post-surgical impairments in the reconstructed knee (39%). Having episodes of the knee giving way after ACLR was the only significant predictor of post-surgical impairments (48.8%; OR=8.3, 95%CI=2.48-27.42, p=0.001). Lack of confidence, concerns about re-injury, or post-surgical impairments in the reconstructed knee were the most frequently reported reasons for not returning to pre-injury sports level with 2 years post-ACLR. Reported dynamic knee instability was the only factor associated with ongoing post-surgical knee impairments after ACLR. Rehabilitation programs should address athletes' psychological responses and resolve knee impairments to optimize return to pre-injury sport level after ACLR.

Functional Return-to-Sport Testing Demonstrates Inconsistency in Predicting Short-Term Outcomes Following Anterior Cruciate Ligament Reconstruction: A Systematic Review

PURPOSE

To systematically review the relationship between functional testing at the time of return to sport (RTS) and short-term outcomes, such as second anterior cruciate ligament (ACL) tear and return to a preinjury level of sport, among athletes who underwent anterior cruciate ligament reconstruction (ACLR).

METHODS

A systematic literature search was performed in MEDLINE, EMBASE, Scopus, and Web of Science to identify studies examining athletes who underwent functional RTS testing and were followed for at least 12 months following ACLR. Studies were screened by 2 reviewers. A standardized template was used to extract information regarding study characteristics, ACLR information, functional test results, and risk factors associated with retear or reduced RTS.

RESULTS

Of the 937 studies identified, 22 met the inclusion criteria. The average time between ACLR and RTS testing was 8.5 months. Single leg hop for distance performance had no association with retear risk in any study and no association with RTS rates in most studies. Quadriceps strength had conflicting results in relation to retear risk, whereas it had no relationship with RTS rates. Rates of reinjury and RTS were similar between patients who passed and did not pass combined hop and strength batteries. Asymmetric knee extension and hip moments, along with increased knee valgus and knee flexion angles, demonstrated increased risk of retear.

CONCLUSIONS

Individual hop and strength tests that are often used in RTS protocols following ACLR may have limited and inconsistent value in predicting ACL reinjury and reduced RTS when used in isolation. Combined hop and strength test batteries also demonstrate low sensitivity and negative predictive value, highlighting conflicting evidence to suggest RTS testing algorithm superiority.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I-IV studies.

Return to the Pre-Injury Level of Sport after Anterior Cruciate Ligament Reconstruction: A Practical Review with Medical Recommendations

Returning to sport after anterior cruciate ligament reconstruction (ACLR) can be a challenging and complex process for the athlete, with the rate of return to the pre-injury level of sport observed to be less than athlete expectations. Of the athletes that do return to sport (RTS), knee re-injury rates remain high, and multiple studies have observed impaired athletic performance upon RTS after ACLR as well as reduced playing time, productivity, and career lengths. To mitigate re-injury and improve RTS outcomes, multiple RTS after ACLR consensus statements/clinical practice guidelines have recommended objective RTS testing criteria to be met prior to medical clearance for unrestricted sports participation. While the achievement of RTS testing criteria can improve RTS rates after ACLR, current criteria do not appear valid for predicting safe RTS. Therefore, there is a need to review the various factors related to the successful return to the pre-injury level of sport after ACLR, clarify the utility of objective performance testing and RTS criteria, further discuss safe RTS decision-making as well as present strategies to reduce the risk of ACL injury/re-injury upon RTS. This article provides a practical review of the current RTS after ACLR literature, as well as makes medical recommendations for rehabilitation and RTS decision-making after ACLR.

Bone-patellar tendon-bone autograft is associated with a higher rate of return to preinjury levels of performance in high-level athletes than anterior cruciate ligament reconstruction using hamstring autograft

PURPOSE

Return to preinjury levels of performance (RTP) is the main goal after anterior cruciate ligament reconstruction (ACL-R) for athletes when ACL graft rupture is a career-threatening event. The purpose of this study was to elucidate the associated factors for RTP and subsequent ACL injury after ACL-R using bone-patellar tendon-bone (BPTB) or hamstring (HT) autograft in high-level athletes with a minimum postoperative follow-up of 24 months.

METHODS

This retrospective study included 157 patients who had preinjury Tegner activity level of 9 and underwent primary ACL-R using BPTB (average age, 16.9 years; 35 males and 36 females) or HT (average age, 17.2 years; 49 males and 37 females). The mean follow-ups were 33.6 months in BPTB and 44.5 months in HT, respectively. The data were obtained based on routine clinical follow-ups and telephone interviews performed by the surgeon. Multivariate logistic regression analysis was conducted to determine the association of patient variables with RTP and subsequent ACL injury.

RESULTS

Ninety-nine patients (63.1%) were able to RTP. The rate of RTP in BPTB (74.6%) was significantly higher than that of HT (53.5%) (p < 0.05). The overall average timing of RTP after ACL-R was 10.0 months while that was significantly earlier in BPTB (9.7 months) than in HT (10.5 months) (p < 0.05). Twenty-three (14.6%) and 21 patients (13.4%) had ACL graft ruptures and ACL injuries in the contralateral knees, respectively. Multivariate analyses showed that BPTB (odds ratio [OR], 2.590; 95% confidence interval [CI], 1.300-5.160; p = 0.007) was associated with a higher potential for RTP after ACL-R. The incidence of ACL graft rupture after ACL-R decreased with BPTB (OR, 0.861; 95% CI, 0.770-0.962; p = 0.009).

CONCLUSIONS

The use of BPTB autograft was associated with a higher rate of RTP and a lower incidence of ACL graft rupture compared to ACL-R using HT autograft.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Are lower limb symmetry and self-reported symptoms associated with functional and neuromuscular outcomes in Brazilian adults with anterior cruciate ligament reconstruction? A cross-sectional study

INTRODUCTION

After anterior cruciate ligament (ACL) reconstruction, determining readiness to return to participation is challenging. The understanding of which neuromuscular performance parameters are associated with limb symmetry and self-reported symptoms may be useful to improve monitoring the rehabilitation towards adequate decision-making to return.

OBJECTIVES

To compare the ACL-operated and injury-free lower limbs regarding functional performance; and to investigate whether lower limb strength and functional performance are associated with self-reported symptoms and functional lower limb symmetry.

METHOD

Thirty-four participants were included. Functional performance was assessed by using the Y-Balance test, Single-leg Hop, and Functional Movement Screen. An isokinetic dynamometer was used to evaluate the strength levels in open and closed kinetic chains. The functional lower limb symmetry was calculated considering the single-leg hop test results for each lower limb.

RESULTS

There were no differences in dynamic balance (Y-Balance) between the operated and injury-free limbs. The operated limb presented a worst performance in the single-leg hop. Self-reported symptoms prevalence and lower limb symmetry were associated with knee extension strength and functional performance (Y-Balance).

CONCLUSION

Individuals submitted to ACL-reconstruction presented worse functional performance in the operated limb compared to the injury-free limb. Both knee strength and dynamic balance were associated with limb symmetry and self-reported symptoms.

Limb asymmetries persist 6 months after anterior cruciate ligament reconstruction according to the results of a jump test battery

Objectives

Test batteries used to assess a patient's return-to-sports (RTS) following anterior cruciate ligament reconstruction (ACLR) are currently undergoing continual development, although no consensus exist on tests to be administered to athletes before allowing return to play. A simple standardized jump test battery was developed to objectively evaluate knee function following ACLR, thereby aiding in RTS decision-making.

Methods

Thirty-three patients who underwent ACLR were prospectively assessed pre-operatively, 6, and 12 months after surgery. Knee function was assessed using a device for optical detection using a test battery consisting of three jump tests: monopodalic countermovement jump (CMJ), drop jump, and monopodalic side-hop. Limb symmetry index (LSI) was reported for all tests at all time points. LSI ≥90% was defined as RTS criteria.

Results

At 12-month evaluation, mean LSI significantly improved compared to 6-month follow up (p < 0.01), and also compared to baseline (p < 0.01), reporting a mean value of 92.6% for CMJ, 90.6 for drop jump and 96.9% for side hop test. Most patients fulfilled the RTS criteria 12 months after surgery (LSI ≥90%). The percentages of patients demonstrating LSI ≥90% at 6 months was 7/33 (21.2%) for CMJ, 12/33 (36.4%) for drop jump, and 11/33 (33.3%) for side-hop test. One year after surgery, percentages grew up to 66.6% (22/33), 63.6% (21/33), and 81.8% (27/33) respectively.

Conclusion

Six months after ACLR, knee functional performance was unsatisfactory in most patients, whereas a significantly higher percentage of patients met RTS criteria 1 year after surgery. The results of the jump test battery proposed in this study support the idea that timing for resumption of cutting and pivoting sports should be delayed later than 6 months, as still limb asymmetries persist at this time point.

The optimal window for reconstruction of the anterior cruciate ligament (ACL) with respect to quadriceps atrophies lies within 21 to 100 days

PURPOSE

The study's objective was to determine the optimal window for anterior cruciate ligament (ACL) reconstruction with respect to quadriceps atrophies and clinical outcome.

METHODS

For this retrospective, comparative study, 115 patients aged under 35 were included, who received an ACL reconstruction between 2011 and 2016. They were divided into four groups, depending on the time to surgery, to determine the optimal window for reconstruction: (group 1: ≤21 d, group 2: <21d-56d≥, group 3: >56d-100d≥, group 4: >100d). Follow-up was performed one month postoperatively, after a mean of 4.9 (±5.3) months, and after a mean of 3.5 (±1.4) years. Primary endpoints included quadriceps muscle status, range of motion (ROM), pain, swelling, the International Knee Documentation Committee Subjective Knee Form (IKDC), the Lysholm-Score, the Knee Injury and Osteoarthritis Outcome Score (KOOS), and the Tegner-Activity-Scale (TAS).

RESULTS

Significantly more quadriceps atrophies were observed in group 1 and group 4, representing reconstructions earlier than 21 and later than 100 days (29% and 41% vs. 9%; p = 0.032). The measurements of knee extension (p = 0.082) and ROM (p = 0.123) were comparable in all groups. Group 1 showed the least pain (0% vs. 15%; p = 0.285) and swelling (0% vs. 23%; p = 0.077) compared to all other groups one month postoperatively. A comparison of postoperative clinical scores revealed no significant differences, with group 1 exhibiting the lowest TAS levels.

CONCLUSION

In patients who underwent ACL reconstruction within three weeks or after more than 100 days, a significantly higher incidence of quadriceps atrophy was observed, possibly attributable to the initial inflammatory phase or the delayed reconstruction affecting quadriceps function. However, this impairment may not be observable in elite athletes who undergo reconstruction within hours of the injury.

Sports activity level after ACL reconstruction is predicted by vastus medialis or vastus medialis obliquus thickness, single leg triple hop distance or 6-m timed hop, and quality of life score

PURPOSE

Recovery after anterior cruciate ligament reconstruction (ACLR) may take > 2 years, and younger athletes have higher re-injury risk. The purpose of this prospective longitudinal study was to determine how the early to mid-term Tegner Activity Level Scale (TALS) scores of athletically active males ≥ 2 years post-ACLR follow-up was predicted by bilateral isokinetic knee extensor and flexor torque, quadriceps femoris thickness, single leg hop test performance, and self-reported knee function (Knee Injury and Osteoarthritis Outcome Score (KOOS); International Knee Documentation Committee (IKDC) Subjective Assessment score).

METHODS

After ACLR with a hamstring tendon autograft and safely returning to sports at least twice weekly, 23 men (18.4 ± 3.5 years of age) were evaluated at final follow-up (mean = 4.5, range = 2-7 years). Exploratory forward stepwise multiple regression was used to determine the relationship between independent surgical and non-surgical lower limb variables peak concentric isokinetic knee extensor-flexor torque at 60°/sec and 180°/sec, quadriceps femoris muscle thickness, single leg hop test profile results, KOOS subscale scores, IKDC Subjective Assessment scores, and time post-ACLR on TALS scores at final follow-up.

RESULTS

Subject TALS scores were predicted by KOOS quality of life subscale score, surgical limb vastus medialis obliquus (VMO) thickness, and surgical limb single leg triple hop for distance (SLTHD) performance. Subject TALS scores were also predicted by KOOS quality of life subscale score, non-surgical limb vastus medialis (VM) thickness, and non-surgical limb 6 m single leg timed hop (6MSLTH) performance.

CONCLUSION

TALS scores were influenced differently by surgical and non-surgical lower extremity factors. At ≥ 2 years post-ACLR, ultrasound VM and VMO thickness measurements, single leg hop tests that challenge knee extensor function, and self-reported quality of life measurements predicted sports activity levels. The SLTHD test may be better than the 6MSLTH for predicting long-term surgical limb function.

The Effect of Staged Versus Usual Care Physiotherapy on Knee Function Following Anterior Cruciate Ligament Reconstruction

CONTEXT

The long duration and high cost of anterior cruciate ligament reconstruction (ACLR) rehabilitation can pose barriers to completing rehabilitation, the latter stages of which progress to demanding sport-specific exercises critical for a safe return to sport. A staged approach shifting in-person physiotherapy sessions to later months of recovery may ensure patients undergo the sport-specific portion of ACLR rehabilitation. Design/Objective: To compare postoperative outcomes of knee function in patients participating in a staged ACLR physiotherapy program to patients participating in usual care physiotherapy through a randomized controlled trial.

METHODS

One hundred sixty-two patients were randomized to participate in staged (n = 80) or usual care physiotherapy (n = 82) following ACLR and assessed preoperatively and postoperatively at 2 weeks, 6 weeks, 3 months, and 6 months. The staged group completed the ACLR rehabilitation protocol at home for the first 3 months, followed by usual care in-person sessions. The usual care group completed in-person sessions for their entire rehabilitation. Outcome measures included the Lower Extremity Functional Scale, International Knee Documentation Committee Questionnaire, pain, range of motion, strength, and hop testing.

RESULTS

There were no statistically significant between-group differences in measures of knee function at 6 months postoperative. Patients in the usual care group reported significantly higher International Knee Documentation Committee scores at 3 months postoperative (mean difference = 5.8; 95% confidence interval,  1.3 to 10.4; P = .01).

CONCLUSION

A staged approach to ACLR rehabilitation does not appear to impede knee function at 6 months postoperative but may result in worse patient reported outcomes at early follow-ups.

The Influence of Quadriceps Strength and Rate of Torque Development on the Recovery of Knee Biomechanics During Running After Anterior Cruciate Ligament Reconstruction

BACKGROUND

After anterior cruciate ligament reconstruction (ACLR), altered surgical knee biomechanics during running is common. Although greater quadriceps strength is associated with more symmetrical running knee kinetics after ACLR, abnormal running mechanics persist even after resolution of quadriceps strength deficits. As running is a submaximal effort task characterized by limited time to develop knee extensor torque, quadriceps rate of torque development (RTD) may be more closely associated with recovery of running knee mechanics than peak torque (PT).

PURPOSE

To assess the influence of recovery in quadriceps PT and RTD symmetry on knee kinematic and kinetic symmetry during running over the initial 2 years after ACLR.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 39 Division I collegiate athletes (106 testing sessions; 19 female) completed serial isometric performance testing and running analyses between 3 and 24 months after ACLR. Athletes performed maximal and rapid isometric knee extension efforts with each limb to assess PT and RTD between-limb symmetry indices (PTLSI and RTDLSI), respectively. Peak knee flexion difference (PKFDIFF) and peak knee extensor moment limb symmetry index (PKEMLSI) during running were computed. Multivariable linear mixed-effects models assessed the influence of PTLSI and RTDLSI on PKFDIFF and PKEMLSI over the initial 2 years after ACLR.

RESULTS

Significant main effects of RTDLSI (P < .001) and time (P≤ .02) but not PTLSI (P≥ .24) were observed for both PKFDIFF and PKEMLSI models. For a 10% increase in RTDLSI, while controlling for PTLSI and time, a 0.9° (95% CI, 0.5°-1.3°) reduction in PKFDIFF and a 3.5% (95% CI, 1.9%-5.1%) increase in PKEMLSI are expected. For every month after ACLR, a 0.2° (95% CI, 0.1°-0.4°) reduction in PKFDIFF and a 1.3% (95% CI, 0.6%-2.0%) increase in PKEMLSI are expected, controlling for PTLSI and RTDLSI.

CONCLUSION

Quadriceps RTDLSI was more strongly associated with symmetrical knee biomechanics during running compared with PTLSI or time throughout the first 2 years after ACLR.

Monitoring External Workload With Wearable Technology After Anterior Cruciate Ligament Reconstruction: A Scoping Review

Background

Current sports medicine and rehabilitation trends indicate an increasing use of wearable technology. The ability of these devices to collect, transmit, and process physiological, biomechanical, bioenergy, and environmental data may aid in anterior cruciate ligament reconstruction (ACLR) workload monitoring and return-to-sport decision-making. In addition, their ease of use allows assessments to occur outside the clinical or laboratory settings and across a broader timeline.

Purpose

To (1) determine how wearable technology can assess external workload deficits between limbs (involved and uninvolved) and between groups (healthy controls vs patients with ACLR) during physical activity (PA) or sport and (2) describe the types of sensors, sensor specifications, assessment protocols, outcomes of interest, and participant characteristics from the included studies.

Study Design

Scoping review; Level of evidence, 4.

Methods

In February 2023, a systematic search was performed in the MEDLINE, EMBASE, CINAHL, SPORTDiscus, Scopus, IEEE Xplore, Compendex, and ProQuest Dissertations and Theses Global databases. Eligible studies included assessments of PA or sports workloads via wearable technology after ACLR.

Results

Twenty articles met eligibility criteria and were included. The primary activity assessed was activities of daily living, although rehabilitation, training, and competition were also represented. Accelerometers, global positioning system units, pedometers, and pressure sensor insoles were worn to collect external workload data, which was quantified as kinetic, kinematic, and temporospatial data. Daily steps (count) and moderate to vigorous PA (min/day or week) were the most common units of measurement. A limited number of studies included outcomes related to between-limb asymmetries.

Conclusion

The findings of this scoping review highlight the versatility of wearable technologies to collect patients' kinetic, kinematic, and temporospatial data and assess external workload outcomes after ACLR. In addition, some wearable technologies identified deficits in workload compared with healthy controls and between reconstructed and unaffected limbs.

Differences in psychological readiness for return to sport after anterior cruciate ligament injury is evident in thigh musculature motor unit characteristics

Background

Following anterior cruciate ligament (ACL) injury, many athletes that undergo surgery and 6-9 months of rehabilitation struggle to return to sport. Evidence suggests that psychological factors contribute to this failure to return-to-sport.

Objective

Determine the motor control relationship between thigh musculature motor unit characteristics and psychological readiness to return to sport between ACL-injured and healthy controls.

Study design

A longitudinal cohort study.

Methods

Athletes longitudinally completed the ACL Return to Sport after Injury (ACL-RSI) survey and isometric strength measures with a measurement of electromyography (EMG) of the vastus lateralis, vastus medialis, biceps femoris, and semitendinosus. A score cut-off of 61 on the ACL-RSI was used to divide ACL-injured groups. EMG was decomposed to provide each identified motor unit's characteristics (amplitude, average firing rate, etc).

Results

Data demonstrated increased average firing rate for hamstrings (p<0.001), decreased average firing rate for vastus lateralis (p<0.001) and decreased motor unit size for both the quadriceps and hamstrings at return-to-sport post-ACL reconstruction compared with sex-matched and age-matched healthy controls (p<0.001). Furthermore, there were marked differences in disparate ACL-RSI scores between ACL-injured athletes.

Conclusions

At return to sport, ACL-injured athletes have major alterations of thigh musculature motor control, with smaller motor units used by those with low ACL-RSI scores. This study uniquely demonstrates objective thigh muscle motor unit characteristics that coincide with subjective reports of psychological readiness. This information will be important to address psychomotor complexes of injury for future rehabilitation protocols.

American Academy of Orthopaedic Surgeons Clinical Practice Guideline Summary: Management of Anterior Cruciate Ligament Injuries

Management of Anterior Cruciate Ligament Injuries : Evidence-based Clinical Practice Guideline is based on a systematic review of published studies for the treatment of anterior cruciate ligament injurie in both skeletally mature and immature patients. This guideline contains eight recommendations and seven options to assist orthopaedic surgeons and all qualified physicians managing patients with ACL injuries based on the best current available evidence. It is also intended to serve as an information resource for professional healthcare practitioners and developers of practice guidelines and recommendations. In addition to providing pragmatic practice recommendations, this guideline also highlights gaps in the literature and informs areas for future research and quality measure development.

Hip Abductor and External Rotator Strengths Correlate With Hop Symmetry in Men Athletes 2 Years After Anterior Cruciate Ligament Reconstruction

CONTEXT

Hip muscle strength and hop performance limb symmetries after anterior cruciate ligament reconstruction (ACLR) are not well studied. This study aimed to determine the differences in hip abductors' (ABD) and external rotators' (ER) muscle strength measures between limbs, and the relationship between hip ABD and ER muscle strengths and hop performance limb symmetry indices (LSIs) 2 years after ACLR.

DESIGN

Cross-sectional study.

METHODS

Forty (level I/II) men athletes 2 years after unilateral ACLR completed 4 single-legged hop tests and involved hip ABD and ER strength testing (maximum voluntary isometric contraction [MVIC]; isokinetic peak torque [PKTQ] at 60°, 180°, and 300°/s; and isotonic peak velocity at 75% of their MVICs). Muscle strength measures were normalized to body mass, and hop performances were reported as LSIs. Paired t test was used to determine strength differences between limbs, and the Pearson correlation coefficient was used to assess the relationship between involved hip muscle strength measures and hop performance LSIs.

RESULTS

Hip ER-MVIC (involved: 60.26 [12.01], uninvolved: 63.68 [13.17] N·m/kg) and ER eccentric PKTQ at 60°/s (involved: 32.59 [9.28]; uninvolved: 35.73 [10.50] N·m/kg) were significantly different between limbs (P ≤ .018). Single-hop LSI correlated with hip ER-PKTQ at 180°/s (r = .354) and 300°/s (r = .324, P ≤ .041), while triple-hop LSI correlated with hip ER-MVIC (r = .320), concentric ER-PKTQ at 180°/s (r = .355), eccentric ER-PKTQ at 60°/s (r = .314), and hip ABD-PKTQ at 60°/s (r = .364) and 300°/s (r = .336, P ≤ .049).

CONCLUSIONS

Men athletes demonstrated symmetrical hop performance and hip muscle strengths, except for ER hip's MVIC and isokinetic eccentric peak torque at 60°/s 2 years after ACLR. Hop performance LSIs had a few, yet positive moderate relationships with involved hip ABDs and ER strength measures. This may indicate that hip ABD and ER muscle strength measures contribute to athletes' hop performances 2 years after ACLR. Post-ACLR rehabilitation programs might incorporate hip muscle strengthening training to improve athletes' functional performances.

Return to Sport After Anterior Cruciate Ligament Reconstruction Requires Evaluation of >2 Functional Tests, Psychological Readiness, Quadriceps/Hamstring Strength, and Time After Surgery of 8 Months

PURPOSE

The purpose of this study was to examine the factors commonly used to determine readiness for return to sport (RTS) in the ACL reconstruction (ACL-R) patient population and assess which were most influential to successfully returning to sport and avoiding re-tear.

METHODS

The PUBMED, EMBASE and Cochrane Library databases were queried for studies related to RTS in ACL-R. Inclusion and exclusion criteria were applied to identify studies with greater than 1-year outcomes detailing the rate of return and re-tear given a described RTS protocol. Data of interest were extracted, and studies were stratified based on level of evidence and selected study features. Meta-analysis or subjective synthesis of appropriate studies was used to assess more than 25 potentially significant variables effecting RTS and re-tear.

RESULTS

After initial search of 1503 studies, 47 articles were selected for inclusion in the final data analysis, including a total of 1432 patients (31.4% female, 68.6% male). A meta-analysis of re-tear rate for included Level of Evidence 1 studies was calculated to be 2.8%. Subgroups including protocols containing a strict time until RTS, strength testing, and ≥2 dynamic tests demonstrated decreased RTS and re-tear heterogeneity from the larger group. Time to RTS, strength testing, dynamic functional testing, and knee stability were also found to be among the most prevalent reported criteria in RTS protocol studies.

CONCLUSIONS

This study suggests a multifactorial clinical algorithm for successful evaluation of RTS. The "critical criteria" recommended by the authors to be part of the postoperative RTS criteria include time since surgery of 8 months, use of >2 functional tests, psychological readiness testing, and quadriceps/hamstring strength testing in addition to the modifying patient factors of age and female gender.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I-IV studies.

Patient-Reported Measures Associated with the Return to Pre-Injury Levels of Sport 2 Years after Anterior Cruciate Ligament Reconstruction

The International Knee Documentation Committee Subjective Knee Form (IKDC2000) and the Knee Injury and Osteoarthritis Outcome Score (KOOS) are knee-specific measures. However, their association with a return to sports after anterior cruciate ligament reconstruction (ACLR) is unknown. This study aimed to investigate the association between the IKDC2000 and the KOOS subscales and the return to the same pre-injury level of sport two years after ACLR. Forty athletes that were two years post-ACLR participated in this study. Athletes provided demographic information, filled out the IKDC2000 and KOOS subscales, and indicated whether they returned to any sport and whether they returned to the same pre-injury level (same duration, intensity, and frequency). In this study, 29 (72.5%) athletes returned to play any sport and eight (20%) returned to the same pre-injury level. The IKDC2000 (r: 0.306, p = 0.041) and KOOS quality of life (KOOS-QOL) (r: 0.294, p = 0.046) significantly correlated with the return to any sport, but it was age (r: -0.364, p = 0.021), BMI (r: -0.342, p = 0.031), IKDC2000 (r: 0.447, p = 0.002), KOOS-pain (r: 0.317, p = 0.046), KOOS sport and recreation function (KOOS-sport/rec)(r: 0.371, p = 0.018), and KOOS QOL (r: 0.580, p > 0.001) that significantly correlated with a return to the same pre-injury level. High KOOS-QOL and IKDC2000 scores were associated with returning to any sport, and high KOOS-pain, KOOS-sport/rec, KOOS-QOL, and IKDC2000 scores were all associated with returning to the same pre-injury level of sport.

Association between knee function and kinesiophobia 6 months after anterior cruciate ligament reconstruction

[Purpose] Kinesiophobia after anterior cruciate ligament reconstruction has been identified as an inhibitor of return to sports. This study aimed to clarify the relationship between kinesiophobia and knee function 6 months after anterior cruciate ligament reconstruction when the patient intends to return to sports. [Participants and Methods] A total of 66 patients who underwent primary anterior cruciate ligament reconstruction (mean age 17.3 ± 2.6 years, 17 males and 49 females, Tegner activity score ≥7) were included in the study. The 11-item version of Tampa scale of kinesiophobia was used to evaluate kinesiophobia 6 months postoperatively. Knee function was evaluated with knee extension muscle strength, tibial anterior displacement, heel buttock distance, heel height difference, anterior knee pain score, and single-leg hop test. The relationship between Tampa scale of kinesiophobia, patient characteristics, and knee function was investigated. [Results] A low Anterior knee pain score and low single-leg hop test, male gender, and age were significant factors associated with kinesiophobia. [Conclusion] Kinesiophobia was associated with a low anterior knee pain score and low single-leg hop test 6 months after anterior cruciate ligament reconstruction. Patients with a low single-leg hop test score or severe pain may need rehabilitation to reduce kinesiophobia.

Translation, cross-cultural adaptation and validation of the Italian version of the knee outcome survey - activities of daily living scale

PURPOSE

The Knee Outcome Survey - Activities of Daily Living Scale (KOS-ADLS) is a joint-specific questionnaire measuring symptoms and functional limitations experienced by individuals with painful knee disorders. The original version of the KOS-ADLS has been shown to be reliable, valid and responsive to change. The purpose of this study was to perform a translation and cross-cultural adaptation of the KOS-ADLS into Italian and to assess its reliability and validity.

METHODS

In accordance with standard procedures, the original version of the KOS-ADLS was translated and cross-culturally adapted into Italian (KOS-ADLS-I). Then, the KOS-ADLS-I was administered to 150 patients with knee disorders. A subsample of patients compiled the KOS-ADLS-I again after five/seven days later to evaluate test-retest reliability. Symptoms and function-oriented questionnaires were also completed to evaluate construct validity. Structural validity (Explanatory Factor Analysis [EFA]), internal consistency (Cronbach's alpha), test-retest reliability (Intraclass Correlation Coefficient [ICC]), measurement error (Standard Error of the Measurement [SEM], Minimal Detectable Change [MDC]), and construct validity (hypothesis testing) were assessed.

RESULTS

The cross-cultural adaptation procedure revealed no major problems. EFA revealed a unidimensional structure. Internal consistency was high (Cronbach's alpha = 0.976) and the test-retest reliability was excellent (ICC = 0.990, 95%CI: 0.980-0.995) with low measurement error (SEM = 2.6 points; MDC = 7.1 points). The construct validity resulted to be satisfactory, as 100% a-priori hypothesis were met.

CONCLUSIONS

The KOS-ADLS-I is a reliable and valid questionnaire for the assessment of symptoms and functional limitations in individuals with musculoskeletal knee disorders and it can be used in clinical practice and research.

Unilateral tests of lower-limb function as prognostic indicators of future knee-related outcomes following anterior cruciate ligament injury: a systematic review and meta-analysis of 13 150 adolescents and adults

OBJECTIVE

To investigate the prognostic capacity of individual hop tests, hop test batteries and other unilateral functional performance tests following anterior cruciate ligament (ACL) injury.

DESIGN

Systematic review with meta-analysis.

DATA SOURCES

Six databases searched up to June 2021.

ELIGIBILITY CRITERIA

Studies reporting associations between unilateral lower-limb function (eg, hop tests) following ACL injury and future (≥3 months) knee-related outcomes.

RESULTS

Of 42 included studies (13 150 participants), all assessed the single-forward hop test and 32 assessed a repeated-forward hop test (crossover hop, triple hop, 6m-timed hop), mostly within a year after ACL injury/reconstruction. Results of meta-analyses indicated that higher single-forward and repeated-forward hop limb symmetry were associated with higher odds of return-to-sport 1-3 years post-ACL reconstruction (OR 2.15; 95% CI 1.30 to 3.54; OR 2.11; 95% CI 1.23 to 3.60, respectively). Higher single-forward and repeated-forward hop limb symmetry was associated with better self-reported symptoms and function 1-37 years after ACL injury (OR 2.51; 95% CI 1.62 to 3.88; OR 4.28; 95% CI 1.65 to 11.08, respectively). Higher limb symmetry on a repeated-forward hop does not appear to be associated with higher odds of successful rehabilitation without ACL reconstruction (OR 1.51; 95% CI 0.94 to 2.44). Achieving ≥90% limb symmetry on the single-forward hop was associated with reduced odds of knee osteoarthritis 5-37 years after ACL injury (OR 0.46; 95% CI 0.23 to 0.94).

CONCLUSION

Very low certainty evidence suggests single-forward and repeated-forward hop tests are prognostic indicators for important knee-related outcomes in individuals after ACL injury and may help stratify individuals at risk of poor outcomes to target rehabilitation interventions.

PROSPERO REGISTRATION NUMBER

CRD42018092197.

Morphometric risk factors effects on anterior cruciate ligament injury

OBJECTIVES

This study aims to compare the morphometric differences between patients with and without an anterior cruciate ligament (ACL) injury and to investigate the anatomical risk factors associated with ACL injury.

PATIENTS AND METHODS

Between February 2020 and February 2022, a total of 100 patients (57 males, 43 females; mean age: 36.2±6.8 years; range, 18 to 45 years) who were operated for isolated non-contact ACL tear as the patient group and a total of 100 healthy individuals (58 males, 42 females; mean age: 35.0±6.9 years; range, 18 to 45 years) without an ACL tear as the control group were included. Magnetic resonance imaging scans of the knee joint were included in the study. Morphological variables of the ACL, distal femur, proximal tibia, and menisci were measured.

RESULTS

The mean ACL inclination angle and medial meniscus bone angle were 37.7±3.8 and 20.2±2.9 in the patient group and 48.1±3.3 and 25.0±2.9 in the control group. According to the results of multivariate analysis, those with small ACL inclination angle and medial meniscus bone angle were more likely to have ACL tear (odds ratio: 0.128, intraclass correlation coefficient: 0.038-0.430, p=0.001).

CONCLUSION

Small ACL inclination angle and medial meniscus bone angle can be a risk factor for ACL tear.

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

BACKGROUND

Timing 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).

METHODS

At 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.

RESULTS

The 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.

CONCLUSIONS

Given 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.

Primary surgery versus primary rehabilitation for treating anterior cruciate ligament injuries: a living systematic review and meta-analysis

OBJECTIVE

Compare the effectiveness of primarily surgical versus primarily rehabilitative management for anterior cruciate ligament (ACL) rupture.

DESIGN

Living systematic review and meta-analysis.

DATA SOURCES

Six databases, six trial registries and prior systematic reviews. Forward and backward citation tracking was employed.

ELIGIBILITY CRITERIA

Randomised controlled trials that compared primary reconstructive surgery and primary rehabilitative treatment with or without optional reconstructive surgery.

DATA SYNTHESIS

Bayesian random effects meta-analysis with empirical priors for the OR and standardised mean difference and 95% credible intervals (CrI), Cochrane RoB2, and the Grading of Recommendations Assessment, Development and Evaluation approach to judge the certainty of evidence.

RESULTS

Of 9514 records, 9 reports of three studies (320 participants in total) were included. No clinically important differences were observed at any follow-up for self-reported knee function (low to very low certainty of evidence). For radiological knee osteoarthritis, we found no effect at very low certainty of evidence in the long term (OR (95% CrI): 1.45 (0.30 to 5.17), two studies). Meniscal damage showed no effect at low certainty of evidence (OR: 0.85 (95% CI 0.45 to 1.62); one study) in the long term. No differences were observed between treatments for any other secondary outcome. Three ongoing randomised controlled trials were identified.

CONCLUSIONS

There is low to very low certainty of evidence that primary rehabilitation with optional surgical reconstruction results in similar outcome measures as early surgical reconstruction for ACL rupture. The findings challenge a historical paradigm that anatomic instability should be addressed with primary surgical stabilisation to provide optimal outcomes.

PROSPERO REGISTRATION NUMBER

CRD42021256537.

Reliability of wearable sensors-based parameters for the assessment of knee stability

Anterior cruciate ligament (ACL) rupture represents one of the most recurrent knee injuries in soccer players. To allow a safe return to sport after ACL reconstruction, standardised and reliable procedures/criteria are needed. In this context, wearable sensors are gaining momentum as they allow obtaining objective information during sport-specific and in-the-field tasks. This paper aims at proposing a sensor-based protocol for the assessment of knee stability and at quantifying its reliability. Seventeen soccer players performed a single leg squat and a cross over hop test. Each participant was equipped with two magnetic-inertial measurement units located on the tibia and foot. Parameters related to the knee stability were obtained from linear acceleration and angular velocity signals. The intraclass correlation coefficient (ICC) and minimum detectable change (MDC) were calculated to evaluate each parameter reliability. The ICC ranged from 0.29 to 0.84 according to the considered parameter. Specifically, angular velocity-based parameters proved to be more reliable than acceleration-based counterparts, particularly in the cross over hop test (average ICC values of 0.46 and 0.63 for acceleration- and angular velocity-based parameters, respectively). An exception was represented, in the single leg squat, by parameters extracted from the acceleration trajectory on the tibial transverse plane (0.60≤ICC≤0.76), which can be considered as promising candidates for ACL injury risk assessment. Overall, greater ICC values were found for the dominant limb, with respect to the non-dominant one (average ICC: 0.64 and 0.53, respectively). Interestingly, this between-limb difference in variability was not always mirrored by LSI results. MDC values provide useful information in the perspective of applying the proposed protocol on athletes with ACL reconstruction. Thus, The outcome of this study sets the basis for the definition of reliable and objective criteria for return to sport clearance after ACL injury.

Cross-sectional study on relationships between physical function and psychological readiness to return to sport after anterior cruciate ligament reconstruction

BACKGROUND

Information about specific factors of physical function that contribute to psychological readiness is needed to plan rehabilitation for a return to sports. The purpose of this study was to identify specific physical functions related to the psychological readiness of patients aiming to return to sports 6 months after reconstruction. We hypothesized that the knee strength is a factor related to the Anterior Cruciate Ligament-Return to Sport after Injury scale (ACL-RSI) cutoff score for a return to sports.

METHODS

This was a cross-sectional study. Fifty-four patients who had undergone primary reconstruction using hamstring tendon participated in this study. Psychological readiness was measured using the ACL-RSI in patients at 6 months after reconstruction. To identify specific physical functions related to the ACL-RSI score, participants were divided into groups with ACL-RSI scores of ≥ 60 or < 60. Non-paired t-tests or the Mann-Whitney test were performed to analyze group differences in objective variables in physical function: (1) knee strength in both legs; (2) leg anterior reach distance on both sides; and (3) single-leg hop (SLH) distances in three directions for both legs.

RESULTS

Significant differences between groups were identified in knee flexion strength (60°/s) for the uninvolved limb, hamstring-to-quadriceps ratio (60°/s) for the uninvolved limb, knee flexion strength (180°/s) for the involved limb, limb symmetry index (LSI) of leg anterior reach distance, the ratio of the distance to the height of the patient and LSI of SLH distances in lateral and medial directions.

CONCLUSION

This study revealed that at 6 months after reconstruction, increased knee flexion strength (ratio of peak torque measured to body mass of the patient), hamstring-to-quadriceps ratio, leg anterior reach distance LSI, and lateral and medial SLH appear important to exceed the ACL-RSI cutoff for a return to sports. The present results may be useful for planning post-operative rehabilitation for long-term return to sports after reconstruction.

Association Between Meeting Return-to-Sport Criteria and Psychological Readiness to Return to Sport After Anterior Cruciate Ligament Reconstruction

Background:

The relationship between meeting return-to-sport criteria and psychological readiness after anterior cruciate ligament (ACL) reconstruction is unknown.

Purposes:

To examine (1) whether patients who met 1 of the criteria for return to sport had higher psychological readiness than those who did not meet any of the criteria and (2) if those who met more criteria had higher psychological readiness.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

This study included 144 patients who underwent unilateral ACL reconstruction. All patients had regularly participated in some sport activities before an ACL rupture. At 12 months postoperatively, each patient completed 3 knee function tests (isokinetic quadriceps strength, isokinetic hamstring strength, and single-leg hop distance) and 2 self-reported measures (International Knee Documentation Committee [IKDC] 2000 subjective form and ACL–Return to Sport after Injury [ACL-RSI] scale); the ACL-RSI scale was used to measure psychological readiness to return to sport. The 4 criteria for return to sport were a limb symmetry index (LSI) ≥90% for each of the 3 function tests in addition to an IKDC score ≥90. Multivariate regression analysis was used to determine the association between meeting the individual criteria and the ACL-RSI score. In addition, the patients were divided into 5 groups according to the number of criteria met, and the Kruskal-Wallis and Steel-Dwass tests were used to compare the ACL-RSI scores among the groups.

Results:

Overall, 23 patients (16.0%) met none of the criteria for return to sport, 27 (18.7%) met 1 of the criteria, 34 (23.6%) met 2 criteria, 35 (24.3%) met 3 criteria, and 25 (17.4%) met all 4 criteria. Meeting the criteria for the hamstring strength LSI (P = .002), single-leg hop distance LSI (P = .004), and IKDC subjective score (P < .001) was each associated with higher ACL-RSI scores. Significant differences in ACL-RSI scores were found between patients who met none versus 2, 3, and 4 of the return-to-sport criteria (P < .001 for all) and between patients who met 1 versus 4 criteria (P < .001).

Conclusion:

Meeting return-to-sport criteria was positively associated with psychological readiness, and the patients who met multiple criteria had higher psychological readiness.

Evidence for isokinetic and functional testing in return to sport decisions following ACL surgery

The rupture and reconstruction of the anterior cruciate ligament (ACL) of the knee are associated with an increased risk of functional instability, a reduction in sports performance, and a higher risk of future additional injuries. Competitive athletes who participate in sports that require pivoting, cutting, and jumping are at particularly high risk for ACL rupture. The return to sport progression continuum after surgery includes sports-specific rehabilitation, evaluation of strength and function, gradual participation in exercise training with progressively challenging activities in the field of play, participation in sports at a lower level, and finally a return to preinjury-level sports competition. This narrative review evaluates the evidence that supports the use of quadriceps and hamstrings isokinetic strength testing and sports-specific functional skills assessments to evaluate progress with rehabilitation after ACL surgery. Strength evaluations, hop tests, agility tests, and the limb symmetry index are described, as well as the associations of quadriceps and hamstrings muscle strength and functional test results with successful return to sports and the risk of ACL graft rupture and contralateral knee injuries. Suggestions for future research directions are presented including the importance of presurgery testing, standardization of test batteries, and comparison of test results with normative data.

Anterior Cruciate Ligament Reconstruction Recovery and Rehabilitation: A Systematic Review

BACKGROUND

The success of anterior cruciate ligament (ACL) reconstruction is influenced by effective rehabilitation. Previously published, comprehensive systematic reviews evaluating rehabilitation after ACL reconstruction have studied Level-I and II evidence published through 2012. Interval studies continue to evaluate the efficacy of various rehabilitative modalities.

METHODS

A total of 824 articles from 2012 to 2020 were identified using multiple search engines. Fifty Level-I or II studies met inclusion criteria and were evaluated using the Consolidated Standards of Reporting Trials (CONSORT) criteria and National Institutes of Health (NIH) Study Quality Assessment Tools.

RESULTS

Accelerated rehabilitation can be effective for patients with semitendinosus-gracilis grafts. Blood flow restriction (BFR) training with high-intensity exercise is not effective for ACL reconstruction recovery. Postoperative bracing does not offer any advantages or improve limb asymmetry. Cryotherapy is an effective analgesic when used perioperatively. The early introduction of open kinetic chain exercises may improve ACL reconstruction outcomes, and high-intensity plyometric exercise is not effective. Estimated pre-injury capacity (EPIC) levels may be more accurate than the Limb Symmetry Index (LSI) when using functional test results to predict reinjury rates, and hip external rotation strength may be the most accurate predictor of the hop test performance. Nerve blocks can provide postoperative analgesia with minimal complication risk. Neuromuscular electrical stimulation is effective when used independently and in combination with rehabilitative exercises. Psychological readiness should be evaluated both objectively and subjectively before allowing patients to safely return to sport. Electromyography biofeedback may help to regain muscular function, and whole-body vibration therapy can improve postural control. Supervised rehabilitation is more effective than unsupervised rehabilitation.

CONCLUSIONS

Various rehabilitative modalities following ACL reconstruction are effective in improving surgical outcomes and return-to-sport rates. Further evidence and improved study design are needed to further validate modalities including accelerated rehabilitation, BFR training, functional testing, and return-to-sport criteria.

LEVEL OF EVIDENCE

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Knee strength symmetry at 4 months is associated with criteria and rates of return to sport after anterior cruciate ligament reconstruction

BACKGROUND

Strength limb symmetry index (LSI) is a useful criterion to help in return-to-sport performance (RTP) after anterior cruciate ligament reconstruction (ACLR).

OBJECTIVES

We aimed to assess whether knee extensor and flexor LSI values at 4 months after ACLR are associated with those recommended at 8 months after ACLR for RTP (80%, 85% and 90%) and with successful RTP after 2 years.

METHODS

This was prospective cohort study of 113 participants who underwent primary ACLR. Personal factors such as demographic and sport information, injury and surgery characteristics were collected at 6 weeks after surgery. Isokinetic strength LSI (60°/s) was calculated at 4 months (LSI[4m]) and 8 months (LSI[8m]) for knee extensors (Q-LSI) and flexors (H-LSI). Participants were followed at 2 years after ACLR to determine their self-reported RTP. Multiple linear regression analysis was used to determine associations between personal factors and LSI at 4 and 8 months. Associations between passing the optimal cut-off thresholds and RTP were tested with chi-square tests and odds ratios (ORs) with effect sizes (ES).

RESULTS

Among the 113 participants (mean age 25.2 [SD 9.7] years; 42% females), extended tourniquet time and lower level of pre-injury sport were associated with lower Q-LSI[4m] and H-LSI[4m]. Bone-patellar tendon-bone graft was associated with lower Q-LSI[4m] and Q-LSI[8m], and older age was associated with lower Q-LSI[4m]. For knee extensors, Q-LSI[4m] >59% was associated with Q-LSI[8m] >80% (OR= 31.50, p <0.001, large ES) and increased odds of successful RTP (60% vs 31%, OR= 3.45, p= 0.003, medium ES). For knee flexors, H-LSI[4m] >72% was associated with H-LSI[8m] >90% (OR= 6.03, p <0.001, large ES) and increased odds of successful RTP (53% vs 23%, OR= 3.76, p= 0.013, small-to-medium ES).

CONCLUSIONS

After primary ACLR, 4-month post-operative strength symmetry was negatively associated with age, pre-injury sport and tourniquet time and bone-patellar tendon-bone graft. Four-month post-operative LSI was associated with 8-month post-operative LSI, and Q-LSI[4m] >59% or H-LSI[4m] >72% was associated with increased RTP rates after 2 years. CLINICALTRIALS.GOV: : NCT04071912.

Biomechanical Markers of Forward Hop-Landing After ACL-Reconstruction: A Pattern Recognition Approach

Biomechanical changes after anterior cruciate ligament reconstruction (ACLR) may be detrimental to long-term knee-joint health. We used pattern recognition to characterise biomechanical differences during the landing phase of a single-leg forward hop after ACLR. Experimental data from 66 individuals 12-24 months post-ACLR (28.2 ± 6.3 years) and 32 controls (25.2 ± 4.8 years old) were input into a musculoskeletal modelling pipeline to calculate joint angles, joint moments and muscle forces. These waveforms were transformed into principal components (features), and input into a pattern recognition pipeline, which found 10 main distinguishing features (and 8 associated features) between ACLR and control landing biomechanics at significance \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\alpha =0.05$$\end{document}α=0.05. Our process identified known biomechanical characteristics post-ACLR: smaller knee flexion angle; less knee extensor moment; lower vasti, rectus femoris and hamstrings forces. Importantly, we found more novel and less well-understood adaptations: smaller ankle plantar flexor moment; lower soleus forces; and altered patterns of knee rotation angle, hip rotator moment and knee abduction moment. Crucially, we identified, with high certainty, subtle aberrations indicating landing instability in the ACLR group for: knee flexion and internal rotation angles and moments; hip rotation angles and moments; and lumbar rotator and bending moments. Our findings may benefit rehabilitation and assessment for return-to-sport 12–24 months post-ACLR.

A Compound Hop Index for Assessing Soccer Players' Performance

Athletes regularly have to pass a series of tests, among which one of the most frequently used functional performance measures are single-leg hop tests. As the collected individual results of tests constitute a large amount of data, strategies to decrease the amount of data without reducing the number of performed tests are being searched for. Therefore, the study aimed to present an effective method to reduce the hop-test battery data to a single score, namely, the Compound Hop Index (CHI) in the example of a soccer team. A male, first-league soccer team performed a battery of commonly used single-leg hop tests, including single hop and triple hop for distance tests and the six-meter timed hop test. Gathered data, including Limb Symmetry Indexes of the three tests, normalized to body height for the single- and triple-hop-tests distance separately for right and left legs, and the time of the six-meter timed hop test separately for right and left legs were standardized to z-scores. Consecutively, the z-scores were averaged and formed CHI. The developed CHI represents a novel score derived from the average of z-scores that significantly reduces, clarifies, and organizes the hop performance-measures data.

Age, time from injury to surgery and hop performance after primary ACLR affect the risk of contralateral ACLR

PURPOSE

To evaluate factors affecting the risk of contralateral anterior cruciate ligament reconstruction (ACLR) within 5 years of primary ACLR.

METHODS

Primary ACLRs performed at Capio Artro Clinic, Stockholm, Sweden, during the period 2005-2014, were reviewed. The outcome of the study was the occurrence of contralateral ACLR within 5 years of primary ACLR. Univariable and multivariable logistic regression analyses were employed to identify preoperative [age, gender, body mass index (BMI), time from injury to surgery, pre-injury Tegner activity level], intraoperative [graft type, medial meniscus (MM) and lateral meniscus (LM) resection or repair, cartilage injury] and postoperative [limb symmetry index (LSI) for quadriceps and hamstring strength and single-leg-hop test performance at 6 months] risk factors for contralateral ACLR.

RESULTS

A total of 5393 patients who underwent primary ACLR were included. The incidence of contralateral ACLR within 5 years was 4.7%. Univariable analysis revealed that age ≥ 25 years, BMI ≥ 25 kg/m², time from injury to surgery ≥ 12 months and the presence of a cartilage injury reduced the odds, whereas female gender, pre-injury Tegner activity level ≥ 6, quadriceps and hamstring strength and a single-leg-hop test LSI of ≥ 90% increased the odds of contralateral ACLR. Multivariable analysis showed that the risk of contralateral ACLR was significantly affected only from age ≥ 25 years (OR 0.40; 95% CI 0.28-0.58; P < 0.001), time from injury to surgery ≥ 12 months (OR 0.48; 95% CI 0.30-0.75; P = 0.001) and a single-leg-hop test LSI of ≥ 90% (OR 1.56; 95% CI 1.04-2.34; P = 0.03).

CONCLUSION

Older age (≥ 25 years) and delayed primary ACLR (≥ 12 months) reduced the odds, whereas a symmetrical (LSI ≥ 90%) 6-month single-leg-hop test increased the odds of contralateral ACLR within 5 years of primary ACLR. Knowledge of the factors affecting the risk of contralateral ACLR is important when it comes to the appropriate counselling for primary ACLR. Patients should be advised regarding factors affecting the risk of contralateral ACLR.

LEVEL OF EVIDENCE

Level III.

Return to play testing following anterior cruciate reconstruction - A systematic review & meta-analysis

PURPOSE

The purpose of this study is to systematically review the evidence regarding return to sport evaluation following ACL reconstruction and evaluate the relationship between testing and secondary ACL injury.

METHODS

A systematic review of the literature with PubMed, Ovid MEDLINE, Cochrane Reviews, was performed on June, 2020 based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies were included if they compared outcomes following passing and failing RTP testing subsequent to ACLR. Clinical outcomes were compared, with all statistical analysis performed using Review Manager Version 5.3. Correlation was calculated with Spearman testing.

RESULTS

Overall, 8 studies with 1224 patients were included in the analysis. Overall, 34.3% (420/1224) patients passed the RTP testing. Those who passed the RTP testing had a statistically significant 47% lower rate of ACL graft re-rupture compared to those who did not pass the RTP testing (p = 0.03). However, there was a slightly higher, albeit not statistically significant, rate of contralateral ACL rupture in those who passed the RTP testing compared to those who did not (p = 0.42). There was a strong positive correlation between a high rate of patients passing the ACL RTP testing in studies and ACL graft rupture rate in those who failed (0.80).

CONCLUSION

Passing RTP testing following ACLR results in a lower rate of ACL graft rupture, but not contralateral ACL injury. Further evaluation and standardization of RTP testing is necessary in order to increase reliability in identifying patients at risk for re-injury after ACLR.

LEVEL OF EVIDENCE

Level of Evidence III.

Anterolateral Ligament Reconstruction Does Not Delay Functional Recovery, Rehabilitation, and Return to Sport After Anterior Cruciate Ligament Reconstruction: A Matched-Pair Analysis From the SANTI (Scientific ACL Network International) Study Group

PURPOSE

To determine whether the addition of an anterolateral ligament reconstruction (ALLR) resulted in delayed functional recovery (based on the Knee Santy Athletic Return to Sport [K-STARTS] score) at 6 months after anterior cruciate ligament reconstruction (ACLR).

METHODS

A retrospective analysis of prospectively collected data from consecutive patients who underwent an ACLR between September 2017 and December 2020 was conducted. Patients who received an isolated hamstring autograft (isolated ACLR group) were propensity matched in a 1:1 ratio to patients who received a hamstring autograft ACLR combined with an ALLR (ACLR-ALLR group). Outcome measures included the Tegner Activity Scale and the K-STARTS test-a validated composite return-to-sports test (including the Anterior Cruciate Ligament-Return to Sport After Injury scale, Qualitative Assessment of Single-Leg Landing tool, limb symmetry index, and ability to change direction using the Modified Illinois Change of Direction Test).

RESULTS

The study included 111 matched pairs. At 6 months postoperatively, there were no significant differences between groups in the overall K-STARTS score (65.4 for isolated ACLR vs 61.2 for ACLR-ALLR, P = .087) or the Tegner Activity Scale score (3.7 for isolated ACLR vs 3.8 for ACLR-ALLR, P = .45). In addition, an evaluation of the subscales of the K-STARTS score revealed no disadvantage across the domains of neuromuscular control, limb symmetry index, agility, or psychological readiness to return to sport when an ALLR was performed.

CONCLUSIONS

The addition of ALLR at the time of ACLR does not delay functional recovery. Specifically, at 6 months postoperatively, there was no disadvantage in patients undergoing ALLR-ACLR, when compared with those undergoing isolated ACLR, with respect to neuromuscular control, limb symmetry indices (hop tests), agility, or psychological readiness to return to sport.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Influence of Patient Demographics and Surgical Characteristics on Pass Rates of Return-to-Activity Tests in Anterior Cruciate Ligament-Reconstructed Patients Before Physician Clearance

OBJECTIVE

To identify the frequency of passing return-to-activity tests after anterior cruciate ligament reconstruction (ACLR) and to investigate the influence of patient-specific factors on pass rates. We hypothesized that isolated strength tests would be most difficult to pass and that graft type would be the most influential factor.

DESIGN

Cross-sectional.

SETTING

Laboratory.

PARTICIPANTS

Eighty patients with a history of primary, unilateral ACLR, and 80 healthy controls participated.

INTERVENTIONS

Bilateral isokinetic strength, isometric strength, and single-leg hop tests were recorded during a single visit. The International Knee Documentation Committee (IKDC) Subjective Knee Evaluation measured subjective knee function, and the Tegner Activity Scale measured physical activity level.

MAIN OUTCOME MEASURES

Pass rates were calculated for 3 thresholds of absolute between-limb asymmetry: 0% to 10%, 11% to 15%, and 16% to 20%. Pass rates were compared by sex (male and female), graft type (patellar and hamstrings), meniscal procedure (yes and no), physical activity level (</≥ median Tegner), and time from surgery (</≥ 6 months).

RESULTS

Isokinetic quadriceps strength was consistently most difficult to pass, whereas the 6-meter timed hop and crossover hop tests were easiest. Graft type had the greatest influence on pass rates (isometric quadriceps and hamstring strength, hamstrings-to-quadriceps ratio), followed by time from surgery (6-meter timed hop and crossover hop), physical activity (IKDC), and meniscal procedure (6-meter timed hop).

CONCLUSIONS

Isokinetic quadriceps strength was the most difficult test to pass, and single-leg hop tests were the easiest. Patient-specific factors including graft type, time from surgery, physical activity level, and meniscal procedure may influence the ability to meet return-to-activity criterion after ACLR.

Prognostic Factors for Patient-Reported Outcomes at 32 to 37 Years After Surgical or Nonsurgical Management of Anterior Cruciate Ligament Injury

Background:

Knowledge to inform the identification of individuals with a poor long-term prognosis after anterior cruciate ligament (ACL) injury is limited. Identifying prognostic factors for long-term outcomes after ACL injury may inform targeted interventions to improve outcomes for those with a poor long-term prognosis.

Purpose:

To determine whether ACL treatment (early augmented or nonaugmented ACL repair plus rehabilitation, rehabilitation alone, or rehabilitation plus delayed ACL reconstruction [ACLR]) and 4-year measures (quadriceps and hamstrings strength, single-leg hop, knee laxity, flexion and extension deficit, self-reported knee function, activity level) are prognostic factors for patient-reported outcomes at 32 to 37 years after acute ACL injury.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

A total of 251 patients aged 15 to 40 years with acute ACL rupture between 1980 and 1985 were allocated to early ACL repair (augmented or nonaugmented) plus rehabilitation or to rehabilitation alone, based on birth year. One hundred ninety of 234 completed 32- to 37-year follow-up questionnaires (response rate, 81%); 18 people were excluded, resulting in 172 patients available for analysis (mean age, 59 ± 6 years; 28% female). Potential prognostic factors assessed 4 years after ACL injury were ACL treatment (early ACL repair, rehabilitation alone, or delayed ACLR), isokinetic quadriceps and hamstrings strength, single-leg hop performance, knee flexion and extension deficit, knee laxity, Tegner activity scale, and Lysholm score. Outcomes included Knee injury and Osteoarthritis Outcome Score (KOOS) subscales and the Anterior Cruciate Ligament Quality of Life (ACL-QOL) measure. Linear regression adjusted for age, sex, baseline meniscal injury, and contralateral ACL injury was used to assess potential prognostic factors for 32- to 37-year outcomes. Multiple imputation accounted for missing data.

Results:

A fair/poor Lysholm score (vs excellent/good) at 4 years was a prognostic factor for worse KOOS Pain (adjusted regression coefficient, −12 [95% confidence interval (CI), −19 to −4]), KOOS Symptoms (−15 [95% CI, −23 to −7]), KOOS Sport and Recreation (−19 [95% CI, −31 to −8]), and ACL QOL (−9 [95% CI, −18 to −1]) scores. A 4-year single-leg hop limb symmetry index <90% was a prognostic factor for worse KOOS Pain (adjusted regression coefficient, −9 [95% CI, −17 to −1]) and ACL QOL (−13 [95% CI, −22 to −3]) scores at long-term follow-up. A lower activity level, delayed ACLR, and increased knee laxity were prognostic factors in the crude analysis. Rehabilitation alone versus early repair, quadriceps and hamstring strength, and flexion and extension deficit were not related to 32- to 37-year outcomes.

Conclusion:

Reduced self-reported knee function and single-leg hop performance 4 years after ACL injury were prognostic factors for worse 32- to 37-year outcomes. Estimates exceeded clinically important thresholds, highlighting the importance of assessing these constructs when managing individuals with ACL injuries.

Registration:

NCT03182647 (ClinicalTrials.gov identifier).

Return to sport following anterior cruciate ligament reconstruction: the argument for a multimodal approach to optimise decision-making: current concepts

Existing literature is varied in the methods used to make this determination in the treatment of athletes who have undergone recent anterior cruciate ligament (ACL) reconstruction. Some authors report using primarily time-based criteria, while others advocate for physical measures and kinematic testing to inform decision-making. The goal of this paper is to elucidate the most current medical evidence regarding identification of the earliest point at which a patient may safely return to sport. The present review therefore seeks to examine the evidence from a critical perspective-breaking down the biology of graft maturation, effect of graft choice, potential for image-guided monitoring of progression and results associated with time-based versus functional criteria-based return to play-to justify a multifactorial approach to effectively advance athletes to return to sport. The findings of the present study reaffirm that time is a prerequisite for the biological progression that must occur for a reconstructed ligament to withstand loads demanded by athletes during sport. Modifications of surgical techniques and graft selection may positively impact the rate of graft maturation, and evidence suggests that imaging studies may offer informative data to enhance monitoring of this process. Aspects of both functional and cognitive testing have also demonstrated utility in prior studies and consequently have been factored into modern proposed methods of determining the athlete's readiness for sport. Further work is needed to definitively determine the optimal method of clearing an athlete to return to sport after ACL reconstruction. Evidence to date strongly suggests a role of a multimodal algorithmic approach that factors in time, graft biology and functional testing in return-to-play decision-making after ACL reconstruction.Level of evidence: level V.

The Role of Psychological Readiness in Return to Sport Assessment After Anterior Cruciate Ligament Reconstruction

BACKGROUND

Knowledge about the predictive value of return to sport (RTS) test batteries applied after anterior cruciate ligament reconstruction (ACLR) is limited. Adding assessment of psychological readiness has been recommended, but knowledge of how this affects the predictive ability of test batteries is lacking.

PURPOSE

To examine the predictive ability of a RTS test battery on return to preinjury level of sport and reinjury when evaluation of psychological readiness was incorporated.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

A total of 129 patients were recruited 9 months after ACLR. Inclusion criteria were age ≥16 years and engagement in sports before injury. Patients with concomitant ligamentous surgery or ACL revision surgery were excluded. Baseline testing included single-leg hop tests, isokinetic strength tests, the International Knee Documentation Committee (IKDC) Subjective Knee Form 2000, a custom-made RTS questionnaire, and the Anterior Cruciate Ligament-Return to Sport after Injury (ACL-RSI) scale. The RTS criteria were IKDC 2000 score ≥85% and ≥85% leg symmetry index on hop and strength test. At a 2-year follow-up evaluation, further knee surgery and reinjuries were registered and the RTS questionnaire was completed again. Regression analyses and receiver operating characteristic analyses were performed to study the predictive ability of the test battery.

RESULTS

Out of the 103 patients who completed the 2-year follow-up, 42% returned to their preinjury level of sport. ACL-RSI 9 months after surgery (odds ratio [OR], 1.03) and age (OR, 1.05) predicted RTS. An ACL-RSI score <47 indicated that a patient was at risk of not returning to sport (area under the curve 0.69; 95% CI, 0.58-0.79), with 85% sensitivity and 45% specificity. The functional tests did not predict RTS. Six patients sustained ACL reinjuries and 7 underwent surgery for other knee complaints/injuries after RTS testing. None of the 29 patients who passed all RTS criteria, and were therefore cleared for RTS, sustained a second knee injury.

CONCLUSION

ACL-RSI and age were predictors of 2-year RTS, while functional tests were not informative. Another main finding was that none of the patients who passed the 85% RTS criteria sustained another knee injury.

Is It Time We Better Understood the Tests We are Using for Return to Sport Decision Making Following ACL Reconstruction? A Critical Review of the Hop Tests

There has been a move towards a criterion-based return to play in recent years, with 4 single-leg hop tests commonly used to assess functional performance. Despite their widespread integration, research indicates that relationships between ‘passing’ ‘hop test criteria and successful outcomes following rehabilitation are equivocal, and, therefore, require further investigation. This critical review includes key information to examine the evolution of these tests, their reliability, relationships with other constructs, and sensitivity to change over time. Recommendations for how measurement and administration of the tests can be improved are also discussed. The evidence presented in this review shows that hop tests display good reliability and are sensitive to change over time. However, the use of more than 2 hop tests does not appear to be necessary due to high collinearity and no greater sensitivity to detect abnormality. The inclusion of other hop tests in different planes may give greater information about the current function of the knee, particularly when measured over time using both relative and absolute measures of performance. It is recommended that the contralateral limb be tested prior to surgery for a more relevant benchmark for performance, and clinicians are strongly advised to measure movement quality, as hop distance alone appears to overestimate the recovery of the knee.