Time to Reflect on Return to Sport Timing Following ACL Reconstruction

The time of return to sport following anterior cruciate ligament (ACL) reconstruction is a commonly discussed topic within clinical settings and the sports medicine literature. Emerging science has demonstrated protective effects of delaying the time of sport clearance on athlete reinjury. Though a single time cutoff is unlikely to be applicable for all athletes, large inconsistencies in the time of return to sport clearance are present in both the literature and within prescribed clinical protocols. A multitude of patient factors, such as perceived function, objective function, confidence, post-operative goals, among others, are vital for how athletes are progressed and released for sport participation. This Current Opinion article is constructed to discuss the time to return to sport after ACL reconstruction-factors that may influence timing decisions, how time is assessed within the scientific literature-and to promote discussion on this common topic within the sports medicine and athletic communities. The aim of the article is not to establish defined clinical time cutoffs for this population.

Prolonged Physiotherapy after Anterior Cruciate Ligament Reconstruction Does Not Improve Muscular Strength and Function

Background: After the rupture of the anterior cruciate ligament (ACL), surgery is proposed in the case of knee instability or for athletes who want to return to a pivotal and/or contact sport. The current trend is to extend physiotherapy sessions until a patient's return to sport. We aimed to assess the interest in prolonging the physiotherapy sessions up to 4 postoperative months to restore muscle knee strength and function. Methods: From a historical cohort, 470 patients (24.3 ± 8.7 years) were included; 312 (66%) were males. They all had undergone a primary ACL reconstruction with a hamstring procedure. The number of physiotherapy sessions was established at 4 postoperative months. The main study parameters to assess the benefit of prolonged physiotherapy were the isokinetic limb symmetry index (LSI) for the quadriceps and the hamstrings as well as the Lysholm score. Results: At 4 postoperative months, 148 patients (31.4%) still had physiotherapy sessions. This group had performed 49 ± 14 physiotherapy sessions at the time of evaluation compared to 33 ± 9 sessions performed by the group that stopped physiotherapy at 3 months post-ACL reconstruction. The isokinetic knee LSI and the Lysholm score were not different between the two groups. Continued physiotherapy sessions were associated with female gender, previous high sport level, meniscal repair, lateral tenodesis and outpatient rehabilitation at the beginning of the rehabilitation management, while knee pain complications were not associated. Conclusions: No significant correlation was found between the number of physiotherapy sessions and the knee strength LSI or the Lysholm score. Prolonging patient physiotherapy sessions after 3 months post-ACL reconstruction seems ineffective in improving knee strength recovery and function.

Quadriceps Strength and Knee-Related Symptom State 6 Months After Anterior Cruciate Ligament Reconstruction

CONTEXT

Isometric quadriceps strength metrics and patient-reported outcomes are commonly used in return-to-sport assessments in those with anterior cruciate ligament reconstruction (ACLR). Patients may experience clinical knee-related symptoms aggravating enough to seek additional medical care after ACLR. In addition to seeking additional medical care, these patient-reported clinical knee-related symptoms may also influence function after ACLR. However, whether an association exists between these common quadriceps metrics and the patient-reported clinical knee-related symptom state is unknown.

OBJECTIVE

To determine if meeting isometric quadriceps strength and symmetry criteria is associated with acceptable clinical knee-related symptoms at 5 to 7 months post-ACLR.

DESIGN

Cross-sectional study.

SETTING

Laboratories.

PATIENTS OR OTHER PARTICIPANTS

We classified individuals at 5 to 7 months post-ACLR based on their isometric ACLR and uninvolved-limb quadriceps strength or quadriceps strength symmetry. We also dichotomized participants based on the Englund et al criteria for unacceptable clinical knee-related symptoms.

MAIN OUTCOME MEASURE(S)

Quadriceps strength variables were compared between groups using analysis of covariance, and the relative risk of a participant in each quadriceps strength group reporting acceptable clinical knee-related symptoms was determined using binary logistic regression.

RESULTS

A total of 173 individuals participated. The isometric quadriceps strength and limb symmetry index were different (P < .001) between quadriceps strength groups. Those categorized as both strong and symmetric had a 1.28 (95% CI = 0.94, 1.74) and individuals categorized as symmetric only had a 1.29 (95% CI = 0.97, 1.73) times greater relative risk of reporting acceptable clinical knee-related symptoms compared with the neither strong nor symmetric group.

CONCLUSIONS

The majority of individuals (85%) recovering from ACLR failed to meet either the clinical quadriceps strength or symmetry criteria at 5 to 7 months post-ACLR. Quadriceps strength and quadriceps strength symmetry are clinically important but may not be primary determinants of the clinical knee-related symptom state within the first 6 months post-ACLR.

Influence of interim functional assessments on patient outcomes at the time of return to activity following ACL-reconstruction

OBJECTIVE

To compare patient outcomes at the time of the return to activity (RTA) progression between those with a prior interim assessment and those without.

DESIGN

Retrospective, Cohort Study.

SETTING

Controlled Laboratory.

PARTICIPANTS

Patients following Anterior Cruciate Ligament Reconstruction (ACLR) were recruited through an ongoing RTA assessment program. Patients were stratified into two testing groups = "Single RTA test": only assessment between 6 and 9 months post-ACLR and "Repeat RTA test": prior assessment performed >2-months before their RTA assessment. Patients were matched based on time post-surgery, age, activity level, and graft type.

MAIN OUTCOME MEASURE

Self-reported knee function and isokinetic knee flexor and extensor strength/symmetry were compared between groups.

RESULTS

392 patients were identified. Once matched, 138 patients (21.1 ± 7.0 years, 7.3 ±0 .9 mo post-ACLR) were analyzed. Repeat RTA test patients demonstrated higher measures of self-reported knee function (P = .04) and greater knee flexion strength (P = .006) and symmetry (P = .05).

CONCLUSION

Patients with interim functional assessments reported greater self-reported knee function and higher hamstring strength at the time of RTA compared to patients that completed their only assessment within this time point. Early functional assessments may identify individualized deficits that can be addressed while patients are under supervision of rehabilitation specialists.

Longitudinal Changes in Ultrasound-Assessed Femoral Cartilage Thickness in Individuals from 4 to 6 Months Following Anterior Cruciate Ligament Reconstruction

OBJECTIVE

Diagnostic ultrasound provides a valid assessment of cartilage health that has been used to observe cross-sectional cartilage thickness differences post-ACLR (anterior cruciate ligament reconstruction), but has not been used longitudinally during early recovery post-ACLR.

DESIGN

The purpose of this study was to assess longitudinal changes in femoral cartilage thickness via ultrasound in individuals at 4 to 6 months post-ACLR and compared to healthy controls. Twenty participants (50% female, age = 21.1 ± 5.7 years) completed testing sessions 4 and 6 months post-ACLR. Thirty healthy controls (57% female, age = 20.8 ± 3.8 years) without knee injury history completed 2 testing sessions (>72 hours apart). Femoral cartilage ultrasound images were captured bilaterally in ACLR participants and in the dominant limb of healthy controls during all sessions. Average cartilage thicknesses in the medial, intercondylar, and lateral femoral regions were determined using a semi-automated processing technique.

RESULTS

When comparing cartilage thickness mean differences or changes over time, individuals post-ACLR did not demonstrate between limb differences (P-range = 0.50-0.92), limb differences compared to healthy controls (P-range = 0.19-0.94), or changes over time (P-range = 0.22-0.72) for any femoral cartilage thickness region. However, participants demonstrated cartilage thickening (45%) or thinning (35%) that exceeded minimal detectable change (MDC) from 4 to 6 months post-ACLR, respectively.

CONCLUSIONS

Using MDC scores may help better identify within-subject femoral cartilage thickness changes longitudinally post-ACLR due to bidirectional cartilage thickness changes.

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.

Patient function in serial assessments throughout the post-ACL reconstruction progression

OBJECTIVE

To assess the changes in patient strength and function from 4- to 6-month assessments following ACLR, determine relationships between changes in strength to changes in subjective function, and identify factors that predict patients that fail to increase in strength.

DESIGN

Prospective, Cohort Study.

SETTING

Controlled Laboratory.

PARTICIPANTS

Forty-seven patients(27 female, 24.3 ± 11.1 years) completed a battery of performance assessments at approximately 4- and 6-months following primary ACLR (4.03 ±0 .49 and 6.46 ±0 .68 months).

MAIN OUTCOME MEASURES

Subjective scores and isokinetic knee flexor and extensor strength were compared across visits. Patients were categorized per their ability to increase in strength beyond a previously defined threshold(0.22 Nm/kg). Binary logistic regression models were used to determine predictors of patients that failed to meet strength changes.

RESULTS

Patients demonstrated improvements in patient-reported outcomes and strength measures between visits(P's < 0.05). Higher age (B = -0.073, P = .039), lower pre-injury activity levels (B = 0.61, P = .022), and higher limb symmetry indexes (B = -0.044, P = .05) at 4-months were predictors of patients that did not achieve improvements in quadriceps strength between assessments.

CONCLUSIONS

From 4- to 6-months post-ACLR, increases in subjective function, strength and symmetry were observed. High quadriceps symmetry at interim assessments without consideration of the magnitude of strength values could overestimate recovery of quadriceps function.

The Influence, Barriers to and Facilitators of Anterior Cruciate Ligament Rehabilitation Adherence and Participation: a Scoping Review

Background

Outcomes following anterior cruciate ligament (ACL) reconstruction are considered poor. There are many factors which may influence patient outcomes. As such, the purpose of this review was to report on the influence, barriers to and facilitators of rehabilitation adherence and participation after ACL reconstruction, providing information to help clinicians and patients make quality decisions to facilitate successful rehabilitation.

Methods

A systematic search of five electronic databases was undertaken in identifying studies from inception to 18 July 2019. The search included English language articles reporting on the influence, barriers to and facilitators of adherence and participation in rehabilitation of patients who have undergone ACL reconstruction. Data extraction and synthesis of included studies were undertaken.

Results

Full text articles (n = 180) were assessed for eligibility following screening of titles and abstracts (n = 1967), yielding 71 studies for inclusion. Forty-four articles investigated ‘rehabilitation prescription and participation’ and 36 articles investigated ‘rehabilitation barriers and facilitators’. The results indicate that a moderately or minimally supervised rehabilitation program is at least as effective as a fully supervised high-frequency rehabilitation program, although a longer duration of supervised rehabilitation is associated with improvement in a multitude of functional outcomes. A number of psychological factors associated with rehabilitation adherence were also identified. The most commonly investigated concepts were self-motivation, athletic identity and social support. Patients perceived the therapeutic relationship, interaction with family and friends, self-motivation, fear of reinjury, organisation/lack of time and interpersonal comparison as the most common barriers to and facilitators of rehabilitation.

Conclusions

A longer duration of supervised rehabilitation is associated with an increased chance of meeting functional and return to sport criteria; however, the optimal supervised rehabilitation frequency is yet to be determined. Identification of the barriers to and facilitators of adherence and participation in ACL rehabilitation provides an opportunity for further research to be conducted to address personal, environmental and treatment-related factors, with the aim to improve rehabilitation outcomes.

Patient-Reported and Quantitative Outcomes of Anatomic Anterior Cruciate Ligament Reconstruction With Hamstring Tendon Autografts

Background:

The pivot-shift test has become more consistent and reliable and is a meaningful outcome measurement after anterior cruciate ligament reconstruction (ACLR).

Purpose/Hypothesis:

The purpose of this investigation was to assess patient-reported outcomes (PROs) and the quantitative pivot shift (QPS) preoperatively, at time zero immediately after anatomic ACLR, and after 24 months as well as the relationship between PROs and the QPS. It was hypothesized that anatomic ACLR would restore rotatory stability measured by the pivot-shift test and that QPS measurements would be positively correlated with PROs.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

The ACL-injured and contralateral uninjured knees from 89 of 107 (83.2%) enrolled patients at 4 international centers were evaluated using a standardized pivot-shift test. Tibial acceleration was assessed with an inertial sensor, and lateral compartment translation was measured using an image analysis system preoperatively, at time zero immediately postoperatively, and at follow-up after 2 years. PROs were assessed at 12 and 24 months postoperatively with the International Knee Documentation Committee (IKDC) subjective knee form, Cincinnati Knee Rating System (CKRS), Marx activity rating scale, and activity of daily living score (ADLS).

Results:

The mean patient age at surgery was 27 years (range, 15-45 years). A positive pivot shift preoperatively (side-to-side difference in tibial acceleration, 2.6 ± 4.0 m/s²; side-to-side difference in anterior tibial translation, 2.0 ± 2.0 mm) was reduced at time zero postoperatively (side-to-side difference in tibial acceleration, –0.5 ± 1.3 m/s²; side-to-side difference in anterior tibial translation, –0.1 ± 1.0 mm). All PROs improved from preoperatively to final follow-up at 24 months: from 56.5 to 85.5 points for the IKDC (P = .0001), from 28.8 to 32.4 points for the CKRS (P = .04), from 11.2 to 7.9 points for the Marx (P < .0001), and from 75.7 to 91.6 points for the ADLS (P < .0001). Neither preoperative nor time zero postoperative rotatory laxity assessed by the pivot-shift test correlated with PROs at 24-month follow-up. A graft retear was observed in 4 patients (4.5%) within 2 years of follow-up.

Conclusion:

Anatomic ACLR resulted in significantly improved and acceptable PROs at 2-year follow-up and a low failure rate. Anatomic ACLR restored QPS measurements of anterior tibial translation and tibial acceleration to those of the contralateral knee immediately after surgery while still under anesthesia, but there was no correlation between the QPS preoperatively or at time zero after ACLR and PROs at 2-year follow-up.

Diagnostic Validity of an Isokinetic Testing to Identify Partial Anterior Cruciate Ligament Injuries

OBJECTIVE

To assess the diagnostic validity of an isokinetic testing to detect partial injuries on the anterior cruciate ligament (ACL).

DESIGN

Prospective diagnostic study.

SETTINGS

Orthopedic clinic, physiotherapy clinic, orthopedic hospital, and diagnostic/image clinic.

PARTICIPANTS

Consecutive patients (n = 29) with unilateral knee complaint submitted to physical examination, magnetic resonance images (MRIs), and isokinetic testing prior to surgery of ACL reconstruction.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

The isokinetic torque curves data from extensor and flexor muscles were converted to frequency domain by fast Fourier transformation and compared with healthy contralateral limb. Differences were categorized as unstable knees and these conclusions were compared with patient's physical examinations (doctor's conclusion on ACL integrity) and MRIs (as the radiologist conclusions on ACL integrity). After surgery, all intraoperatively confirmed partial injured patient's data were collected. The diagnostic accuracy measures to compare the conclusions of all 3 professionals included sensitivity, specificity, positive predictive value, negative predictive value, disease prevalence, positive likelihood ratio, and accuracy-all using a confidence interval of 95%.

RESULTS

Compared with MRI, the sensitivity of isokinetic test for an ACL partial injury was 90.00%, specificity 83.33%, positive predictive value 52.94%, negative predictive value 97.56%, and accuracy 84.48%. Compared with physical examination, the sensitivity of isokinetic test for an ACL partial injury was 85.71%, specificity 78.43%, positive predictive value 35.29%, negative predictive value 97.56%, and accuracy 79.31%.

CONCLUSIONS

This method of isokinetic data analysis through fast Fourier transformation can be used to improve diagnostic accuracy of a difficult detection injury. Even present, a partial ACL injury can produce a stable knee during isokinetic testing and could be used to detect candidates for conservative treatment based on strengthening exercises, reducing surgery risks, and financial and social impact on patient's life.

Relationship Between Pain Catastrophizing and 6-Month Outcomes Following Anterior Cruciate Ligament Reconstruction

BACKGROUND

Pain catastrophizing predicts poor outcomes following orthopedic procedures for patients with chronic conditions; however, limited research has focused on acute injuries. This study aimed to quantify the progression of Pain Catastrophizing Scale (PCS) scores from injury to 6-months post-anterior cruciate ligament reconstruction (ACLR) and determine if preoperative or 6-month PCS scores were related with self-reported pain or function 6 months post-ACLR. The authors hypothesized PCS scores would minimally fluctuate and would be related with worse outcomes 6-months post-ACLR.

METHODS

All 48 participants (27 male/21 female; aged 22.7 [4.6] y, body mass index 24 [3.3]) included in this secondary analysis of a randomized control trial sustained an ACL injury during sports activity. Participants completed the PCS and Pain Visual Analog Scale (VAS) at 5 time points: within 7 days of injury (INITIAL), day of surgery, 2 weeks postoperative (2W), 6 weeks postoperative (6W), and 6 months postoperative (6M). They completed the Knee Injury and Osteoarthritis Outcome Score (KOOS) at 6M. Wilcoxon signed-rank tests and Spearman rank-order correlations were used for analysis.

RESULTS

PCS scores were not fixed (INITIAL: 11.6 [10.8], day of surgery: 2.5 [3.7], 2W: 8.0 [7.8], 6W: 3.7 [6], 6M: 0.8 [2.3]). They fluctuated in response to injury and ACLR similar to Pain VAS scores. Preoperative PCS scores were not related with 6M outcomes; however, 6M PCS scores were significantly related with 6M Pain VAS and KOOS subscales.

CONCLUSIONS

PCS scores fluctuated in response to injury and ACLR. Preoperative PCS scores were not related with 6M outcomes; however, 6M PCS scores correlated with pain and function at 6M. High pain catastrophizing appears to be a natural response immediately following acute ACL injury and ACLR, but may not be indicative of a poor postoperative result. PCS scores 6-months following ACLR may provide useful information regarding self-reported pain and function.

The effects of patellar tendon vibration on quadriceps strength in anterior cruciate ligament reconstructed knees

OBJECTIVES

To examine the immediate effects of prolonged patellar tendon vibration on quadriceps strength in anterior cruciate ligament reconstructed (ACLR) knees with bone-patellar tendon-bone (BTB) grafts and non-BTB grafts, and healthy control knees.

DESIGN

Pretest-posttest design.

SETTING

Laboratory.

PARTICIPANTS

Young adult participants were stratified into one of three groups: non-BTB graft (n = 25), BTB graft (n = 26), and controls without ACLR (n = 21).

MAIN OUTCOME MEASURES

Maximum voluntary isometric contraction (MVIC) knee extension torque was measured at baseline and following a 20-min vibration intervention applied locally to the patellar tendon.

RESULTS

Our findings suggest there was no difference in the effects of vibration on knee extension torque between the three groups. Knee extension torque significantly increased (effect size = 0.52 [0.18 to 0.81]) from baseline to post-vibration across all three groups (0.30 ± 0.26 Nm/kg, 21.8 ± 20.0%). Both ACLR groups demonstrated significantly lower knee extension torque compared the control group.

CONCLUSIONS

The vibration intervention had a net excitatory effect on quadriceps strength in all three groups and there were no differences in the magnitude of change between the three groups. Vibration could become a useful tool for enhancing quadriceps strength in ACLR and healthy knees.