Factors Affecting the Achievement of a Patient-Acceptable Symptom State 1 Year After Anterior Cruciate Ligament Reconstruction: A Cohort Study of 343 Patients From 2 Registries

Several factors predict the achievement of the patient acceptable symptom state and minimal clinically important difference for patient-reported outcome measures following anterior cruciate ligament reconstruction: A systematic review

PURPOSE

To summarize the predictors of the patient acceptable symptom state (PASS), minimal clinically important difference (MCID) and minimal important change (MIC) for patient-reported outcome measures (PROMs) following anterior cruciate ligament reconstruction (ACLR).

METHODS

MEDLINE, PubMed and Embase were searched from inception to 5 January 2024. The authors adhered to PRISMA/R-AMSTAR guidelines, and the Cochrane Handbook for Systematic Reviews of Interventions. Data on statistical associations between predictive factors and PROMs were extracted. Inverse odds ratios (ORs) and confidence intervals (reverse group comparison) were calculated when appropriate to ensure comparative consistency.

RESULTS

Thirteen studies comprising 21,235 patients (48.1% female) were included (mean age 29.3 years). Eight studies comprising 3857 patients identified predictors of PASS, including lateral extra-articular tenodesis (LET) (OR = 11.08, p = 0.01), hamstring tendon (HT) autografts (OR range: 2.02-2.63, p ≤ 0.011), age over 30 (OR range: 1.37-2.28, p ≤ 0.02), male sex (OR range: 1.03-1.32, p ≤ 0.01) and higher pre-operative PROMs (OR range: 1.04-1.21). Eight studies comprising 18,069 patients identified negative predictors of MCID or MIC, including female sex (OR = 0.93, p = 0.034), absence of HT autografts (OR = 0.70, p < 0.0001), higher pre-operative PROMs (OR = 0.76-0.84, p ≤ 0.01), meniscectomy (OR = 0.67, p = 0.014) and collision sports (OR = 0.02-0.60, p ≤ 0.05).

CONCLUSION

Higher pre-operative PROMs, age over 30, male sex, LETs and HT autografts predicted PASS achievement. Lower pre-operative PROMs, male sex, non-collision sports, and lack of meniscectomies predicted MCID/MIC achievement. This review provides a comprehensive understanding of the predictors of clinically significant post-ACLR outcomes, thus improving clinical decision-making and the management of patient expectations.

LEVEL OF EVIDENCE

Level IV.

Demographic and surgical characteristics in patients who do not achieve minimal important change in the KOOS Sport/Rec and QoL after ACL reconstruction: a comparative study from the Swedish National Knee Ligament Registry

OBJECTIVES

This study aimed to compare demographic and surgical characteristics between patients who do and do not achieve minimal important change (MIC) in the Knee injury and Osteoarthritis Outcome Score (KOOS) Sports and Recreation (Sport/Rec) and Quality of Life (QoL) subscales 1 year after anterior cruciate ligament reconstruction.

DESIGN

Comparative cross-sectional.

SETTING

The MIC for the KOOS Sport/Rec subscale was ≥12.1 and ≥18.3 for the KOOS QoL subscale from before surgery to 1-year follow-up using data from the Swedish National Knee Ligament Registry.

PARTICIPANTS

In total 16 131 patients were included: 11 172 (69%) with no MIC for the Sport/Rec scale, and 10 641 (66%) for the QoL.

RESULTS

Patients with no MIC for Sport/Rec and QoL had a higher body mass index (BMI) (24.8±3.5 vs 24.6±3.3 and 24.7±3.5 vs 24.6±3.2, respectively, p<0.0001), were younger (years) at time of surgery (28.5±10.3 vs 29.1±10.8 and 27.4±9.8 vs 29.7±11.0, respectively, p=0.0002 and <0.0001), had longer time from injury to surgery (months) (Sports/Rec 22.0±38.5 vs 19.3±36.6, respectively, p=0.0002), and greater rates of concomitant cartilage injuries especially to the lateral femoral condyle (22.7% vs 19.4% and 23.3% vs 19.0%, respectively, p=0.001 and p=0.005) compared with patients who achieved the MIC. A smaller proportion of patients treated with a hamstring tendon autograft had no MIC (91.4%) compared with patients with MIC (94.1%).

CONCLUSIONS

Patients with no MIC for KOOS Sport/Rec and QoL subscales had a higher BMI, longer time from injury to surgery and were younger at the time of surgery compared with patients who did achieve MIC. Although differences were small, they may reframe management strategies with patients who have these characteristics.

Registry-based cohort study comparing percentages of patients reaching PASS for knee function outcomes after revision ACLR compared to primary ACLR

OBJECTIVES

Reaching the Patient-Acceptable Symptom State (PASS) threshold for the Knee injury and Osteoarthritis Outcome Score (KOOS) has previously been reported to successfully identify individuals experiencing clinical success after anterior cruciate ligament reconstruction (ACLR). Thus, the objectives of this study were to examine and compare the percentages of patients meeting PASS thresholds for the different KOOS subscales 1 year postoperatively after primary ACLR compared with revision ACLR (rACLR) and multiply revised ACLR (mrACLR), and second, to examine the predictors for reaching PASS for KOOS Quality of Life (QoL) and Function in Sport and Recreation (Sport/Rec) after mrACLR.

DESIGN

Prospective observational registry study.

SETTING

The data used in this study was obtained from the Swedish National Ligament Registry and collected between 2005 and 2020.

PARTICIPANTS

The study sample was divided into three different groups: (1) primary ACLR, (2) rACLR and (3) mrACLR. Data on patient demographic, injury and surgical characteristics were obtained as well as mean 1-year postoperative scores for KOOS subscales and the per cent of patients meeting PASS for each subscale. Additionally, the predictors of reaching PASS for KOOS Sport/Rec, and QoL subscales were evaluated in patients undergoing mrACLR.

RESULTS

Of the 22 928 patients included in the study, 1144 underwent rACLR and 36 underwent mrACLR. Across all KOOS subscales, the percentage of patients meeting PASS thresholds was statistically lower for rACLR compared with primary ACLR (KOOS Symptoms 22.5% vs 32.9%, KOOS Pain 84.9% vs 92.9%, KOOS Activities of Daily Living 23.5% vs 31.4%, KOOS Sport/Rec 26.3% vs 45.6%, KOOS QoL 26.9% vs 51.4%). Percentages of patients reaching PASS thresholds for all KOOS subscales were comparable between patients undergoing rACLR versus mrACLR. No predictive factors were found to be associated with reaching PASS for KOOS QoL and KOOS Sport/Rec 1 year postoperatively after mrACLR.

CONCLUSION

Patients undergoing ACLR in the revision setting had lower rates of reaching acceptable symptom states for functional knee outcomes than those undergoing primary ACLR.

LEVEL OF EVIDENCE

Prospective observational registry study, level of evidence II.

Greater self-efficacy, psychological readiness and return to sport amongst paediatric patients compared with adolescents and young adults, 8 and 12 months after ACL reconstruction

PURPOSE

The purpose of this study was to evaluate differences in rehabilitation-specific outcomes between paediatric patients, adolescents and young adults within the first 2 years after anterior cruciate ligament (ACL) reconstruction. A further aim was to determine whether patient age was associated with an increased risk of not achieving symmetrical muscle function within the first 2 years after ACL reconstruction.

METHODS

The patient data in the present study were extracted from the rehabilitation outcome registry, Project ACL. Patients aged 11-25 years registered for primary ACL reconstruction with a hamstring tendon autograft between April 1, 2013 and November 23, 2020 were included. A total of 691 patients met the inclusion criteria and were included in the study; 41 paediatric patients (females 11-13, males 11-15 years), 347 adolescents (females 14-19, males 16-19 years) and 303 young adults (females 20-25, males 20-25 years).

RESULTS

The comparison between groups revealed that 70% of paediatric patients, 39% of adolescents and 35% of young adults had returned to knee-strenuous sport at 8 months and that 90% of paediatric patients, 71% of adolescents and 62% of young adults had returned to sport at 12 months. Paediatric patients also reported higher scores compared with both the other patient groups on the Knee Self-Efficacy Scale (K-SES) and the Anterior Cruciate Ligament Return to Sport after Injury scale (ACL-RSI) at 8 and 12 months.

CONCLUSIONS

A larger proportion of paediatric patients had returned to sport compared with adolescents and young adults 8 and 12 months after ACL reconstruction. Paediatric patients also reported higher self-efficacy and greater psychological readiness to return to sport at 8 and 12 months than the other two groups. No differences in terms of muscle function tests when comparing paediatric patients, adolescents and young adults were found.

LEVEL OF EVIDENCE

II.

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

BACKGROUND

Occupational reintegration after anterior cruciate ligament (ACL) rupture is an important clinical issue including economic and health-related perspectives. This study aims to develop and validate a clinical prediction model of return to work in patients with ACL reconstruction surgery considering evidence-based clinical, anthropometric and occupational factors.

METHODS

Data of 562 patients with an ACL rupture receiving an arthroscopic ACL reconstruction were used for analysis. A model for the binary outcome of experiencing an inability to work period of less or more than 14 days (model 1), and a model for finding predictor variables that are linearly associated with a continuous longer inability to work period of over 14 days (model 2) was calculated. Pre-operative determinants including patient characteristics and peri-operative factors were used as predictors for both models.

RESULTS

For model 1, the highest increase in odds was observed for the occupational type of work, followed by injury of the medial collateral ligament together with partial weight bearing. Small protective effects were observed for female sex, meniscal suture and work with light occupational strain. The type of occupational work, together with revision surgery, a longer duration of limited range of motion and the presence of cartilage therapy were risk factors for longer inability to work. Discrimination and calibration statistics were satisfactory in internal validation.

CONCLUSION

Within the framework of clinical consideration, these prediction models will serve as an estimator for patients, their treating physicians and the socioeconomic partners to forecast the individual cost and benefit of ACL injury.

Lower rate of acceptable knee function in adolescents compared with young adults five years after acl reconstruction: results from the swedish national knee ligament register

Background

The number of studies with a large cohort of patients that primarily focus on patient-reported outcomes after ACL reconstruction in children and adolescents is limited. The purpose of the present study was to determine whether patient age affects the proportion of patients that achieve a patient-acceptable symptom state (PASS) on the Knee injury and Osteoarthritis Outcome Score (KOOS) subscales one, two, five and 10 years after an ACL reconstruction.

Methods

The patient data in the present study were extracted from the Swedish National Knee Ligament Register (SNKLR). Patients aged between five and 35 years that underwent a primary ACL reconstruction between 1 January 2005 and 31 December 2017 and had completed the KOOS questionnaire at the one-, two-, five- or 10-year follow-up were included. A total of 2,848 patients met the inclusion criteria and were included in the study; 47 paediatric patients (females 5–13, males 5–15 years), 522 adolescents (females 14–19, males 16–19 years) and 2,279 young adults (females 20–35, males 20–35 years). The results from the KOOS were presented as the mean and 95% confidence interval (CI) for the mean. For comparisons between groups, the chi-square test was used for non-ordered categorical variables. For pairwise comparisons between groups, Fisher’s exact test (2-sided) was used for dichotomous variables. All the statistical analyses was set at 5%.

Results

Adolescents reported a significantly lower score than young adults on the KOOS4 at the two- (68.4 vs. 72.1; P < 0.05), five- (69.8 vs. 76.0; P < 0.05) and 10-year follow-ups (69.8 vs. 78.2; P < 0.05). Moreover, a significantly smaller proportion of adolescents achieved a PASS on each of the KOOS subscales when compared with young adults at the five-year follow-up (Symptoms: 83.3% vs. 91.6%; Pain: 42.9% vs. 55.3%; Function in daily living: 31.4% vs. 41.1%; Function in sports and recreational activities: 42.3% vs. 55.7%; Knee-related quality of life: 50.0% vs. 65.0%; P < 0.05).

Conclusions

A significantly smaller proportion of adolescents achieved a PASS on each of the KOOS subscales when compared with young adults five years after ACL reconstruction. The results of the present study provide important information for physicians and physiotherapists treating young patients after an ACL injury and they can aid in providing realistic expectations in terms of the mid- and long-term outcomes.

Level of evidence

Prospective Observational Register/Cohort Study, Level II.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05727-6.

Scoping Review on ACL Surgery and Registry Data

Purpose of Review

To present an overview of registry-based anterior cruciate ligament (ACL) research, as well as provide insight into the future of ACL registries.

Recent Findings

During the past decades, the ACL registries have had an important role in increasing our understanding of patients with ACL injuries and their treatment. The registry data has deepened our understanding of factors that have been associated with an increased risk of sustaining an ACL injury and for evaluation of treatment factors and their impact on patient-related outcomes. Recently, registry-based ACL research using artificial intelligence (AI) and machine learning (ML) has shown potential to create clinical decision-making tools and analyzing outcomes. Thus, standardization of collected data between the registries is needed to facilitate the further collaboration between registries and to facilitate the interpretation of results and subsequently improve the possibilities for implementation of AI and ML in the registry-based research.

Summary

Several studies have been based on the current ACL registries providing an insight into the epidemiology of ACL injuries as well as outcomes following ACL reconstruction. However, the current ACL registries are facing future challenges, and thus, new methods and techniques are needed to ensure further good quality and clinical applicability of study findings based on ACL registry data.

Determining the Substantial Clinical Benefit Values for Patient-Reported Outcome Scores After Primary ACL Reconstruction

Background:

Little is known about the threshold of patient-reported outcomes (PROs) at which patients perceive to have attained a substantial clinical benefit (SCB) after anterior cruciate ligament reconstruction (ACLR).

Purpose:

To determine the SCB value of PROs 1 year after ACLR in the general population and to determine factors that predict SCB attainment.

Study Design:

Case series; Level of evidence, 4.

Methods:

The Lysholm, International Knee Documentation Committee Subjective Knee Evaluation Form (IKDC-SKF), Tegner, and Anterior Cruciate Ligament–Return to Sport after Injury (ACL-RSI) scores were examined postoperatively in 88 patients who underwent ACLR. At the 12-month follow-up visit, the patients answered 2 independent anchor questions about daily discomfort and functional recovery. Receiver operating characteristic (ROC) curve analysis was used to differentiate PRO scores between patients who responded as having no difficulty versus some difficulty with daily knee discomfort (anchor question 1) and between patients with substantial recovery versus nonsubstantial recovery of knee function (anchor question 2). The area under the ROC curve (AUC) was calculated to assess reliability, and the differences between the AUC values were compared. Multivariate logistic regression analyses were performed to determine predictors affecting SCB attainment.

Results:

There were 76 patients enrolled in this study. The 12-month Lysholm, IKDC-SKF, Tegner, and ACL-RSI scores that corresponded to the SCB were 88.0, 85.1, 6.5, and 64.2 for anchor question 1 and 84.5, 77.7, 5.5, and 57.1 for anchor question 2, respectively. The AUC values obtained from the ROC curve analyses showed acceptable to excellent reliability (anchor question 1: Lysholm, 0.90; IKDC-SKF, 0.86; Tegner, 0.71; ACL-RSI, 0.92; anchor question 2: Lysholm, 0.80; IKDC-SKF, 0.90; Tegner, 0.82; ACL-RSI, 0.82) and were all statistically significant ( P < .001 to P = .028). For all PROs, younger age (Odds Ratio (OR), 0.88-0.94; P < .001 to P = .027) and greater muscle strength (OR, 1.03-1.07; P < .001 to P = .023) were predictive factors of SCB attainment.

Conclusion:

The postoperative Lysholm, IKDC-SKF, Tegner, and ACL-RSI scores showed acceptable to excellent reliability in predicting the SCB after ACLR in the general population. Age at surgery and thigh muscle strength influenced SCB attainment for all PROs.

Greater proportion of patients report an acceptable symptom state after ACL reconstruction compared with non-surgical treatment: a 10-year follow-up from the Swedish National Knee Ligament Registry

Objectives

To compare the proportion of patients with anterior cruciate ligament (ACL) injury reporting an acceptable symptom state, between non-surgical and surgical treatment during a 10-year follow-up.

Methods

Data were extracted from the Swedish National Knee Ligament Registry. Exceeding the Patient Acceptable Symptom State (PASS) for the Knee injury and Osteoarthritis Outcome Score (KOOS) was the primary outcome. The PASS and KOOS₄ (aggregated KOOS without the activities of daily living (ADL) subscale) were compared cross-sectionally at baseline and 1, 2, 5 and 10 years after ACL injury, where patients treated non-surgically were matched with the maximum number of patients with ACL reconstruction for age, sex and activity at injury.

Results

The non-surgical group consisted of 982 patients, who were each matched against 9 patients treated with ACL reconstruction (n=8,838). A greater proportion of patients treated with ACL reconstruction exceeded the PASS in KOOS pain, ADL, sports and recreation, and quality of life compared with patients treated non-surgically at all follow-ups. With respect to quality of life, significantly more patients undergoing ACL reconstruction achieved a PASS compared with patients receiving non-surgical treatment at all follow-ups except at baseline, with differences ranging between 11% and 25%; 1 year −25.4 (−29.1; −21.7), 2 years −16.9 (−21.2; −12.5), 5 years −11.0 (−16.9; −5.1) and 10 years −24.8 (−36.0; −13.6). The ACL-reconstructed group also reported statistically greater KOOS₄ at all follow-ups.

Conclusion

A greater proportion of patients treated with ACL reconstruction report acceptable knee function, including higher quality of life than patients treated non-surgically at cross-sectional follow-ups up to 10 years after the treatment of an ACL injury.

Generalized joint hypermobility does not influence 1-year patient satisfaction or functional outcome after ACL reconstruction

PURPOSE

The purpose of this study was to evaluate whether generalized joint hypermobility (GJH) influences postoperative results, including return to sport, patientreported outcomes, functional performance (hop tests), muscular strength, and the occurrence of ACL re-injury, in patients 1 year after anterior cruciate ligament (ACL) reconstruction.

METHODS

Data was extracted from a regional rehabilitation-specific registry containing information on patients with ACL injury. Patients between the ages of 16-50 years previously undergoing ACL reconstruction with available 1 year follow-up data were eligible for inclusion. Generalized joint hypermobility was assessed using the Beighton score (BS). Patients were examined one year postoperatively in terms of return to sport, patient-reported outcome, hop tests, muscular strength and the occurrence of reinjury. For purpose of analysis, patients were allocated into two groups, depending on the existence of GJH. The KOOS subscale of sports and recreation was considered the primary outcome. Analyses were performed both dichotomously and by using adjusted logistic regression, to consider potential confounders.

RESULTS

A total of 356 patients (41% males) were included, of which 76 (24% male) were categorized as having GJH. Patients with GJH had an inferior limb symmetry index preoperatively in terms of knee extension (mean 81.6 [SD 16.4] vs. 91.4 [SD 15.9], p = 0.02) and flexion strength (mean 91.9 vs. 99.1, p = 0.047) compared to patients without GJH. There was no difference between the groups in terms of the primary outcome, nor in any of the other postoperative outcomes. Nine patients (11.8%) in the group with GJH suffered ACL re-injury, compared with 13 patients (4.6%) in the control group (n.s.).

CONCLUSION

One year after ACL reconstruction the existence of GJH did not affect postoperative patient satisfaction, strength or functional outcome. No conclusive statements can be made regarding the influence of GJH on the risk of ACL re-injury in this particular study.

LEVEL OF EVIDENCE

Level II.

Registry Studies Use Inconsistent Methods to Account for Patients Lost to Follow-up, and Rates of Patients LTFU Are High

PURPOSE

To determine methods described in the literature to account for patients lost to follow-up (LTFU) in registry studies and whether rates of patient LTFU are within acceptable margins.

METHODS

A scoping review, where a literature search is conducted for studies from 9 arthroscopy registries, was performed on EMBASE, MEDLINE, and the annual reports of each registry. Inclusion criteria included studies with information on patient-reported outcome measures and being based on 9 national registries identified. Exclusion criteria included review articles, conference abstracts, studies not based on registry data, and studies from regional, claims-based, or multicenter registries. Studies were then divided into categories based on method of LTFU analysis used.

RESULTS

Thirty-six articles were identified for the final analysis. Categories for LTFU analysis included dropout analyses (n = 10), referencing validation studies (n = 12), contacting nonresponders (n = 4), and sensitivity analyses (n = 1). Referencing validation studies was the most common method (n = 12). Majority (n = 35) of the studies exceeded the recommended maximum rates for LTFU.

CONCLUSIONS

Registry studies use inconsistent methods to account for patient LTFU, and rates of patients LTFU are unacceptably high.

CLINICAL RELEVANCE

The impact of patients LTFU in studies related to arthroscopic intervention is unknown. A universal method for accounting for patient follow-up is needed.

Effect of Concomitant Meniscal Lesions and Meniscal Surgery in ACL Reconstruction With 5-Year Follow-Up: A Nationwide Prospective Cohort Study From Norway and Sweden of 8408 Patients

Background

Increased knowledge of the factors predicting outcome after anterior cruciate ligament reconstruction (ACLR) is needed.

Purpose

To determine the effect of concomitant meniscal lesions, and the surgical management thereof, on patient-reported outcomes 5 years after ACLR.

Study Design

Prospective cohort study; Level of evidence, 2.

Methods

A total of 15,706 patients who underwent primary unilateral ACLR between 2005 and 2008 were enrolled prospectively and evaluated longitudinally. All patients were part of the Norwegian and Swedish national knee ligament registries. Outcomes at 5-year follow-up were evaluated with the Knee injury and Osteoarthritis Outcome Score (KOOS). A multivariable linear regression model was used to assess possible effects on prognosis, as measured by KOOS, of a concomitant meniscal lesion and its associated surgical treatment.

Results

At a mean follow-up of 5.1 ± 0.2 years, KOOS data were available from 8408 patients: 4774 (57%) patients with no and 3634 (43%) patients with concomitant meniscal lesions (mean patient age, 33.8 ± 10.7 years). Patients with concomitant meniscal lesions reported equal crude mean scores compared with patients without meniscal lesions in all KOOS subscales 5 years after ACLR. The mean improvement in scores from preoperative to the 5-year follow-up was greater for patients with a concomitant meniscal lesion for the KOOS Pain, Activities of Daily Living (ADL), and Sport and Recreation subscales. In the adjusted regression analyses, using patients without concomitant meniscal lesions as the reference, neither no treatment nor resection or repair of medial meniscal lesions were significantly associated with KOOS scores 5 years after ACLR. Except for the ADL subscale, in which a repaired lateral meniscal lesion was associated with better outcome, no significant associations between any of the lateral meniscal lesion treatment categories and KOOS outcome at 5-year follow-up were identified.

Conclusion

Concomitant meniscal lesions at the time of ACLR conferred no negative effects on patient-reported outcomes 5 years after ACLR. The improvement in selected KOOS subscales from preoperative to the 5-year follow-up was significantly greater for patients with concomitant meniscal lesions than for patients without such lesions.

Evaluation of the Responsiveness of the Anterior Cruciate Ligament Return to Sport After Injury (ACL-RSI) Scale

Background

The Anterior Cruciate Ligament Return to Sport After Injury (ACL-RSI) scale is a reliable and valid tool for evaluation of psychological readiness to return to sport after ACL injury, but its responsiveness to change has not been extensively evaluated.

Purpose

To determine the responsiveness of the ACL-RSI scale.

Study Design

Cohort study (diagnosis); Level of evidence, 2.

Methods

The ACL-RSI scale and the knee confidence question from the Knee injury and Osteoarthritis Outcome Score-Quality of Life subscale was completed at 6 and 12 months after ACL reconstruction surgery. Responsiveness was assessed using distribution and anchor-based methods for the full- and short-form versions of the scale and subgroup analyzed for sex. From distribution statistics, the standardized response mean (SRM) and the smallest detectable change (SDC) were calculated. Using the anchor-based method, the minimally important change (MIC) that was associated with an improvement in knee confidence was determined using receiver operating characteristic analysis.

Results

A total of 441 patients (257 men, 184 women; mean age of 25 years) were included in this study. An SRM of 0.7 was found for both versions, indicating a moderate level of responsiveness. The MIC was 13.4 points for the full-form version and 15.1 points for the short-form version. These values were larger than SDC values at the group level but not at the individual patient level. Responsiveness was similar between male and female patients.

Conclusion

The ACL-RSI scale had sufficient responsiveness to investigate the efficacy of an intervention at a group level, but it may be more limited at an individual patient level.

Effects of Temperature and Volume of Intraoperative Normal Saline Irrigation on Postoperative Pain, Swelling, and Serum Markers of Inflammation in Patients After Elective, Arthroscopic, Single-Bundle Surgical Reconstruction of the Anterior Cruciate Ligament: A Retrospective, Single-Center Study

BACKGROUND Arthroscopic single-bundle surgical reconstruction of the anterior cruciate ligament (ACL) is often performed electively after 3 weeks of mobilization therapy. The present single-center retrospective study aimed to investigate the effects of temperature and volume of intraoperative normal saline irrigation on postoperative pain and swelling and on serum markers of inflammation following elective, arthroscopic, single-bundle surgical reconstruction of the ACL. MATERIAL AND METHODS Clinical data from 716 patients with non-acute ACL injuries who met the criteria between March 2015 and May 2020 were retrospectively analyzed. The patients were broken into 5 groups, depending on the volume or temperature of intraoperative irrigation with normal saline. At specific times after surgery, pain, knee swelling, and skin temperature were assessed. Postoperative levels of serum C-reactive protein (CRP), interleukin (IL)-1, IL-6, and IL-10 also were measured. RESULTS Visual analog scale (VAS) scores for pain, rates of swelling, and skin temperature differed significantly among the 5 groups at all postoperative time points (P<0.001). The VAS scores(P=0.322) and ratings for swelling (P=0.245), and skin temperature (P=0.093) were not significantly different among the volume groups. There were no significant differences in the VAS scores (P=0.055), swelling ratings (P=0.570), or skin temperatures (P=0.321) among the groups that received irrigation with normal saline at different temperatures. There were no significant differences in postoperative serum levels of CRP, IL-1, IL-6, or IL-10 among the groups (P>0.05). CONCLUSIONS Irrigation with different volumes and temperatures of normal saline did not have a significant effect on postoperative pain, swelling, or serum markers of inflammation.

Clinical Outcomes After Anterior Cruciate Ligament Injury: Panther Symposium ACL Injury Clinical Outcomes Consensus Group

A stringent outcome assessment is a key aspect of establishing evidence-based clinical guidelines for anterior cruciate ligament (ACL) injury treatment. To establish a standardized assessment of clinical outcome after ACL treatment, a consensus meeting including a multidisciplinary group of ACL experts was held at the ACL Consensus Meeting Panther Symposium, Pittsburgh, Pennsylvania, USA, in June 2019. The aim was to establish a consensus on what data should be reported when conducting an ACL outcome study, what specific outcome measurements should be used, and at what follow-up time those outcomes should be assessed. The group reached consensus on 9 statements by using a modified Delphi method. In general, outcomes after ACL treatment can be divided into 4 robust categories: early adverse events, patient-reported outcomes (PROs), ACL graft failure/recurrent ligament disruption, and clinical measures of knee function and structure. A comprehensive assessment after ACL treatment should aim to provide a complete overview of the treatment result, optimally including the various aspects of outcome categories. For most research questions, a minimum follow-up of 2 years with an optimal follow-up rate of 80% is necessary to achieve a comprehensive assessment. This should include clinical examination, any sustained reinjuries, validated knee-specific PROs, and health-related quality of life questionnaires. In the midterm to long-term follow-up, the presence of osteoarthritis should be evaluated. This consensus paper provides practical guidelines for how the aforementioned entities of outcomes should be reported and suggests the preferred tools for a reliable and valid assessment of outcome after ACL treatment.

Subjective Knee Function and Risk of Failure Are Equivalent for Men and Women at 5 Years After Meniscus Repair

PURPOSE

To determine whether subjective knee function or risk of repair failure differ between men and women at mean 5 years following meniscal repair with or without concomitant anterior cruciate ligament reconstruction.

METHODS

A total of 235 patients (97 women, 138 men; mean age, 29.1 years; standard deviation, 11.3) were assessed for meniscus repair failure and postoperative knee function at mean 5.8 years follow-up. Knee symptoms were assessed with International Knee Documentation Committee Subjective (IKDC-S) scores. Postoperative activity scores were assessed with Marx activity score. Independent effects of patient age and activity level on meniscus failure risk and patient-reported outcomes were determined by multivariate analysis with adjustment for age, body mass index, anterior cruciate ligament status, tear pattern, and number of implants used at the time of surgery.

RESULTS

Failures occurred in 18.9% of men and 21.0% of women with no difference in mean time to failure (P = .75) or risk of failure for men vs women (P = .57) in the univariate analysis. Male sex was not an independent risk factor for failure after adjustment for patient age, body mass index, concomitant anterior cruciate ligament status, tear pattern, or number of implants used (P = .16). Marx activity scores at follow-up were higher among men in multivariate analysis (P = .009). Men and women had similar IKDC-S scores at follow-up in the unadjusted (P = .25) and multivariate analyses (P = .21).

CONCLUSIONS

Following meniscus repair, both sexes report similar subjective knee function, though men have higher self-reported activity scores. Meniscus repair failure risk does not differ between men or women at mid-term follow up.

LEVEL OF EVIDENCE

Level III, retrospective case-control study.

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

PURPOSE

A stringent outcome assessment is a key aspect for establishing evidence-based clinical guidelines for anterior cruciate ligament (ACL) injury treatment. The aim of this consensus statement was to establish what data should be reported when conducting an ACL outcome study, what specific outcome measurements should be used and at what follow-up time those outcomes should be assessed.

METHODS

To establish a standardized approach to assessment of clinical outcome after ACL treatment, a consensus meeting including a multidisciplinary group of ACL experts was held at the ACL Consensus Meeting Panther Symposium, Pittsburgh, PA; USA, in June 2019. The group reached consensus on nine statements by using a modified Delphi method.

RESULTS

In general, outcomes after ACL treatment can be divided into four robust categories-early adverse events, patient-reported outcomes, ACL graft failure/recurrent ligament disruption and clinical measures of knee function and structure. A comprehensive assessment following ACL treatment should aim to provide a complete overview of the treatment result, optimally including the various aspects of outcome categories. For most research questions, a minimum follow-up of 2 years with an optimal follow-up rate of 80% is necessary to achieve a comprehensive assessment. This should include clinical examination, any sustained re-injuries, validated knee-specific PROs and Health-Related Quality of Life questionnaires. In the mid- to long-term follow-up, the presence of osteoarthritis should be evaluated.

CONCLUSION

This consensus paper provides practical guidelines for how the aforementioned entities of outcomes should be reported and suggests the preferred tools for a reliable and valid assessment of outcome after ACL treatment.

LEVEL OF EVIDENCE

V.

How Should We Define Clinically Significant Improvement on Patient-Reported Outcomes Measurement Information System Test for Patients Undergoing Knee Meniscal Surgery?

PURPOSE

The purpose of the study was to define the minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptomatic state (PASS) thresholds for the Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function (PF) computerized adaptive test (CAT) instrument in patients undergoing arthroscopic meniscal surgery.

METHODS

The PROMIS PF CAT was administered preoperatively and postoperatively to patients undergoing arthroscopic meniscal surgery. At 6 months postoperatively, patients graded their knee function based on a domain-specific anchor question. A satisfaction anchor question was used to indicate achievement of the PASS. Receiver operating characteristic analysis determined the relevant psychometric values. Cutoff analysis was performed to find preoperative patient-reported outcome scores predicting achievement of clinically significant outcomes (CSOs).

RESULTS

A total of 73 patients (41.1% female patients) were included, with a mean age of 44.9 ± 12.8.0 years and average follow-up period of 24.0 ± 1.2 weeks. The MCID on the PROMIS PF CAT was calculated to be 2.09 (area under the curve [AUC], 0.75; 95% CI, 0.57-0.94). Net score improvement equivalent to achievement of SCB was found to be 6.50 (AUC, 0.77; 95% CI, 0.55-0.99). The PASS was found to be 46.1 (AUC, 0.86; 95% CI, 0.76-0.96). A preoperative score below 37.6 on the PROMIS PF CAT predicted achievement of the MCID (AUC, 0.76; 95% CI, 0.62-0.87), whereas scores above 41.9 predicted achievement of the PASS (AUC, 0.77; 95% CI, 0.65-0.90). Higher baseline functional status and the absence of pre-existing arthritis were also found to be statistically significant predictors of achieving CSOs.

CONCLUSIONS

Our study defined the MCID, SCB, and PASS for the PROMIS PF CAT. We found that a preoperative score below 37.6 was predictive of achieving a meaningful clinical change with surgery whereas a preoperative score above 41.9 was predictive of patients who would attain an acceptable postoperative health state. In addition, exercising more days per week and the absence of arthritis increased the likelihood of achieving postoperative CSOs.

LEVEL OF EVIDENCE

Level III, retrospective cohort.

Age, gender, quadriceps strength and hop test performance are the most important factors affecting the achievement of a patient-acceptable symptom state after ACL reconstruction

PURPOSE

To assess the percentage of patients achieving an acceptable symptom state 2 years after primary anterior cruciate ligament reconstruction (ACLR) and to identify factors affecting its achievement, in a large cohort.

METHODS

Patients who underwent primary ACLR at Capio Artro Clinic, Stockholm, Sweden, from 2005 to 2015, were identified in our clinic registry. Patients who had completed the Knee injury and Osteoarthritis Outcome Score (KOOS) at the 2-year follow-up were included. The primary outcome was the achievement of a patient-acceptable symptom state (PASS) for each KOOS subscale. A multivariate logistic regression analysis was used to determine whether patient age, gender, time from injury to surgery, pre-injury Tegner activity level, graft type, cartilage injury, the presence of medial meniscus (MM) or lateral meniscus (LM) resection or repair and the recovery of 6-month symmetrical (limb symmetry index [LSI] of ≥ 90%) isokinetic quadriceps or hamstring strength and single-leg-hop test performance were factors associated with the achievement of a PASS for each KOOS subscale.

RESULTS

A total of 2335 primary ACLRs were included. More than 60% of the patients reported a PASS on four of the five KOOS subscales. Age ≥ 30 years and an LSI of ≥ 90% for 6-month isokinetic quadriceps strength increased the odds of achieving a PASS across all KOOS subscales. Female gender reduced the odds of achieving a PASS on the Pain (OR 0.76; 95% CI 0.62-0.94; P = 0.01), activities of daily living (ADL) (OR 0.79; 95% CI 0.64-0.97; P = 0.02) and sport and recreation (OR 0.72; 95% CI 0.58-0.89; P = 0.003) subscales. The presence of an MM repair reduced the odds of achieving a PASS on the Pain (OR 0.59; 95% CI 0.36-0.96; P = 0.03) subscale. Hamstring tendon (HT) autograft rather than bone-patellar tendon-bone (BPTB) autograft showed increased odds (OR 2.02; 95% CI 1.31-3.10; P = 0.001), whereas a cartilage injury showed reduced odds (OR 0.73; 95% CI 0.55-0.97; P = 0.03) of achieving a PASS on the sport and recreation subscale. An LSI of ≥ 90% for 6-month single-leg-hop test performance increased the odds of achieving a PASS on the ADL (OR 1.37; 95% CI 1.09-1.71; P = 0.005), Sport and Recreation (OR 1.40; 95% CI 1.11-1.77; P = 0.004), and quality of life (OR 1.28; 95% CI 1.00-1.63; P = 0.04) subscales.

CONCLUSION

More than 60% of the patients reported an acceptable symptom state on four of the five KOOS subscales 2 years after primary ACLR. Age ≥ 30 years and female gender were the non-modifiable factors that consistently increased and reduced, respectively, the odds of achieving a PASS. A symmetrical 6-month isokinetic quadriceps strength and single-leg-hop test performance were the modifiable factors that consistently increased the opportunity of achieving a PASS 2 years after primary ACLR.

LEVEL OF EVIDENCE

III.

Prospective Evaluation of the Patient Acceptable Symptom State to Identify Clinically Successful Anterior Cruciate Ligament Reconstruction

BACKGROUND

The length of most patient-reported outcome measures creates significant response burden, which hampers follow-up rates. The Patient Acceptable Symptom State (PASS) is a single-item, patient-reported outcome measure that asks patients to consider all aspects of life to determine whether the state of their joint is satisfactory; this measure may be viable for tracking outcomes on a large scale.

HYPOTHESIS

The PASS question would identify clinically successful anterior cruciate ligament reconstruction (ACLR) at 1-year follow-up with high sensitivity and moderate specificity. We defined "clinically successful" ACLR as changes in preoperative to postoperative scores on the Knee injury and Osteoarthritis Outcome Score (KOOS) pain subscale and the KOOS knee-related quality of life subscale in excess of minimal clinically important difference or final KOOS pain or knee-related quality of life subscale scores in excess of previously defined PASS thresholds.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 2.

METHODS

Patients enrolled in a prospective longitudinal cohort completed patient-reported outcome measures immediately before primary ACLR. At 1-year follow-up, patients completed the same patient-reported outcome measures and answered the PASS question: "Taking into account all the activity you have during your daily life, your level of pain, and also your activity limitations and participation restrictions, do you consider the current state of your knee satisfactory?"

RESULTS

A total of 555 patients enrolled in our cohort; 464 were eligible for this study. Of these, 300 patients (64.7%) completed 1-year follow-up, of whom 83.3% reported satisfaction with their knee after surgery. The PASS question demonstrated high sensitivity to identify clinically successful ACLR (92.6%; 95% CI, 88.4%-95.6%). The specificity of the question was 47.1% (95% CI, 35.1%-59.5%). The overall agreement between the PASS and our KOOS-based criteria for clinically successful intervention was 81.9%, and the kappa value indicated moderate agreement between the two methods (κ = 0.44).

CONCLUSION

The PASS question identifies individuals who have experienced clinically successful ACLR with high sensitivity. The limitation of the PASS is its low specificity, which we calculated to be 47.1%. Answering "no" to the PASS question meant that a patient neither improved after surgery nor achieved an acceptable final state of knee health. The brevity, interpretability, and correlation of the PASS question with significant improvements on various KOOS subscales make it a viable option in tracking ACLR outcomes on a national or global scale.