Clinical, Functional, and Physical Activity Outcomes 5 Years Following the Treatment Algorithm of the Delaware-Oslo ACL Cohort Study

Use of the Uninvolved Limb as Comparator When Calculating Return to Sports Hop Test Symmetry After ACL Reconstruction

BACKGROUND

Horizontal hop testing is a reliable measure included in test batteries after anterior cruciate ligament (ACL) reconstruction (ACLR). Hop test results are typically expressed as limb symmetry indexes (LSIs) comparing the involved limb with the uninvolved limb. Using the uninvolved limb as a comparative measure has been questioned due to concerns that performance may be reduced in this limb also and may not be a stable comparison across time, leading to a falsely inflated LSI. Here, we report changes in uninvolved limb hop scores over 5 timepoints after ACLR.

HYPOTHESIS

Uninvolved limb hop scores would be similar between preoperative rehabilitation and 2 years after ACLR.

STUDY DESIGN

Cohort study.

LEVEL OF EVIDENCE

Level III.

METHODS

Level I and II athletes were enrolled after isolated ACL injury. Participants completed a preoperative hop testing battery after impairment resolution, preoperative rehabilitation, and 6 months, 1 year, and 2 years after ACLR. Linear mixed-effects models were performed separately for each hop and each limb to characterize change in scores over time. Pairwise comparisons for fixed effects of timepoint and estimated marginal means are reported.

RESULTS

A total of 182 athletes (25.0 ± 8.8 years, 44% female) were enrolled a mean of 54 days from ACL injury. For each hop, the uninvolved limb hop distance was statistically different from the impairment resolution timepoint only to various follow-up timepoints (P ≤ 0.009). If athletes underwent preoperative rehabilitation, uninvolved limb hop distance was stable throughout the duration of rehabilitation until 2 years, apart from timed hop from 6 months to 2 years (P = 0.04).

CONCLUSION

The uninvolved limb is a stable comparison for calculating hop test LSIs as part of return-to-sport decisions.

CLINICAL RELEVANCE

These results increase confidence in using symmetry as an outcome and are important for clinicians lacking preinjury hop testing data.

Treatment Decision-Making for Anterior Cruciate Ligament Rupture From the Perspective of Physical Therapists in Australia: A Mixed Methods Study

IMPORTANCE

In Australia, few people with acute anterior cruciate ligament (ACL) rupture are managed with rehabilitation alone despite clinical trials demonstrating similar outcomes to ACL reconstruction (ACLR). The reasons for the low uptake of rehabilitation alone for the treatment of acute ACL rupture in Australia are unclear.

OBJECTIVES

The objectives of this study were to evaluate physical therapists' beliefs and the information they provide to patients about treatment options for ACL rupture, and to explore ACL rupture treatment decision-making from the perspective of physical therapists.

DESIGN

The design was a mixed-methods convergent parallel design comprising an Australia-wide survey (n = 246) and semi-structured interviews (n = 10).

PARTICIPANTS

Participants included physical therapists who manage people with ACL rupture in Australia.

MAIN OUTCOMES

The survey contained 41 items that assessed demographics, treatment of ACL rupture, referral pathways, treatment beliefs, and the information provided to patients with ACL rupture.

RESULTS

Physical therapists' beliefs about treatment options varied and did not always reflect the information they provided to patients. Although 60% agreed that ACLR and rehabilitation-alone result in similar outcomes on average, only 37% reported regularly informing patients about this. To return to pivoting/contact sport, 23% believed that ACLR was required and 79% informed patients that ACLR was the best treatment to do so. Physical therapists felt that rehabilitation-alone is underutilized as a treatment for ACL rupture. Physical therapists encountered barriers to offering and providing rehabilitation-alone for ACL rupture, reflected in 7 qualitative themes: preference for surgery reflecting societal beliefs; more weight given to surgeon's opinion; unbalanced information from surgeon; referral pathways; uncertain recovery timeline; beliefs about treatment suitability; and knowledge and experience.

CONCLUSIONS

Physical therapists had mixed beliefs about treatment options and the information provided to patients was not always evidence based. Physical therapists felt that nonsurgical management was underutilized, and experienced barriers to offering and providing non-surgical management of ACL rupture in clinical practice.

RELEVANCE

Informed decision-making can only occur if accurate, evidence-based information about ACL rupture treatment options is provided to patients. These findings may be used to guide professional development for physical therapists and inform strategies to improve evidence uptake by physical therapists.

More knee reinjuries after ACL reconstruction compared to nonsurgical treatment of the ACL. A 2-year follow-up of the NACOX prospective cohort study

PURPOSE

To describe knee reinjuries and surgeries within 2 years after an acute anterior cruciate ligament (ACL) injury, in patients treated with or without ACL reconstruction (ACLR).

METHODS

Two years follow-up of 275 patients (52% females, mean age 25.2 [SD 7.0] years) about knee reinjuries and surgeries were analysed from the prospective NACOX cohort study, aiming to describe recovery after an acute ACL injury treated according to clinical routine. Knee reinjury was defined as increase or new symptoms due to new trauma. At 2 years after injury, 169 (61%) had undergone an ACLR. Results are presented with descriptive statistics and risk ratios (RR).

RESULTS

Thirty-two patients sustained reinjuries within 2 years; 6 in the non-ACLR group, and 26 in the ACLR group (7 before and 19 after ACLR). Twelve patients in the ACLR group sustained a graft rupture and three did an ACL revision. Patients with non-ACLR, aged 21-25 years, had a 5.9-fold higher risk for reinjury than those aged 15-20 years (RR 5.9 [1.3-26.9]; p = 0.012). Twenty-four patients had surgery in the non-ACLR group and 36 patients in the ACLR group (excluding primary ACLR), where six were before ACLR and 30 were after ACLR.

CONCLUSION

Twelve percent sustained a knee reinjury and 21% underwent knee surgery within 2 years after the index ACL injury. There was a higher reinjury incidence in the ACLR group, but no difference in incidence of surgeries. Thus, ACLR did not reduce the risk of traumatic reinjuries or surgeries, which is important for treatment decision considerations.

LEVEL OF EVIDENCE

Level I.

Prehabilitation prior to anterior cruciate ligament reconstruction is a safe and effective intervention for short- to long-term benefits: A systematic review

PURPOSE

Comprehensively explore current practices in preoperative rehabilitation (prehabilitation) for anterior cruciate ligament reconstruction (ACLR) and assess corresponding clinical outcomes and complication rates.

METHODS

A systematic search of EMBASE, MEDLINE, Cochrane and PubMed was conducted from inception to 1 November 2024. All studies reporting outcomes and/or complications following prehabilitation and ACLR were included. Screening and data abstraction were designed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Revised Assessment of Multiple Systematic Reviews guidelines.

RESULTS

Thirty-six studies with 2326 patients undergoing prehabilitation and ACLR were included. Weighted averages of all clinical outcomes met or surpassed patient acceptable symptom state (PASS) thresholds and return to sports (RTS) criteria. There were no preoperative complications following prehabilitation. Major post-operative complications included graft failure (4.6%), contralateral ACL rupture (1.0%), surgical site infection (0.6%), deep infection (0.4%), non-ACL ligament injury (0.5%), reoperation for hardware removal (0.3%), muscle rupture (0.1%), patellar subluxation (0.1%) and patellar rupture (0.1%).

CONCLUSION

Current prehabilitation practices for ACLR emphasize impairment resolution, ROM restoration, and neuromuscular exercises. Safety of current practices is supported by the absence of preoperative complications and similar post-operative complication rates compared to patients undergoing standard care. Clinical outcomes of patients undergoing prehabilitation were shown to meet and surpass PASS thresholds and RTS criteria, expedite post-operative recovery, and maintain functional improvements up to 10 years post-operation, suggesting that prehabilitation is a safe and effective intervention yielding short- to long-term benefits. There is a need for further high-quality randomized controlled trials and large prospective cohort studies comparing the effect of prehabilitation on post-operative outcomes, reporting specific exercise details and protocol progression.

LEVEL OF EVIDENCE

Level II.

Clinical, Functional, Sports Participation, and Osteoarthritis Outcomes After ACL Injury: Ten-Year Follow-up Study of the Delaware-Oslo ACL Cohort Treatment Algorithm

BACKGROUND

Anterior cruciate ligament reconstruction (ACLR) is often recommended for treatment of an ACL injury; however, the literature reports similar outcomes for those undergoing rehabilitation alone. We assessed the clinical, functional, sports participation, and osteoarthritis outcomes following our treatment algorithm, and compared 10-year outcomes among participants who chose progressive rehabilitation alone, early ACLR, or delayed ACLR.

METHODS

We included 276 participants who had a unilateral ACL injury without substantial concomitant knee injuries in a prospective cohort study. Treatment choice was based on shared decision-making after a 5-week progressive rehabilitation program. At the 10-year follow-up, we assessed patient-reported outcomes (International Knee Documentation Committee Subjective Knee Form [IKDC-SKF], Knee injury and Osteoarthritis Outcome Score [KOOS], and patient acceptable symptom state [PASS] achievement), quadriceps strength, hop performance, sports participation, and weight-bearing radiographs.

RESULTS

Sixty-nine percent of the participants (191 participants; 99 male and 92 female; 6 African American, 7 Asian, 59 Caucasian, 119 unknown) attended the 10-year follow-up, including 98% (53) of 54 participants who had rehabilitation alone, 68% (114) of 167 with early ACLR, and 69% (24) of 35 with delayed ACLR. Among the entire cohort, 78% (126 of 162) reported having a PASS, 72% (109 of 151) had symmetrical quadriceps strength, ≥85% (≥116 of ≤137) had a symmetrical hop performance, 93% (162 of 174) were still engaged in some kind of sports, only 1% (1 of 139) had symptomatic osteoarthritis, and 12% (17 of 139) had radiographic evidence of osteoarthritis. We found similar outcomes after rehabilitation alone and early ACLR. The participants who underwent delayed ACLR had similar outcomes to the other 2 groups except for significantly lower KOOS Sports scores, KOOS Quality of Life scores, and hop performance (p ≤ 0.03). Participants who had rehabilitation alone were older, less active, and more likely to have concomitant lateral meniscal injuries than those who underwent ACLR.

CONCLUSIONS

Participants who followed our treatment algorithm after ACL injury had high percentages of satisfaction and of symmetrical quadriceps strength and hop performance, high sports participation rates, and low prevalences of osteoarthritis. Participants who chose progressive rehabilitation alone, despite being older and less active, had similar clinical, functional, sports participation, and osteoarthritis outcomes compared with those who chose early ACLR. Participants who underwent delayed ACLR scored lower on KOOS Sports, KOOS Quality of Life, and hop performance compared with both other groups.

LEVEL OF EVIDENCE

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

The Impact of Time to Anterior Cruciate Ligament Reconstruction on Return to Duty Among Active Duty Military Personnel

INTRODUCTION

After an anterior cruciate ligament (ACL) injury, service members often undergo ACL reconstruction (ACLR) to restore knee stability, which is critical for performing physically demanding and unconventional military-specific tasks. Despite advancements in surgical techniques and rehabilitation protocols, a large portion of service members will not fully return to duty (RTD) post-ACLR and will receive a permanent profile restriction (PP) or undergo a medical evaluation board (MEB). The timing of ACLR is a modifiable factor that can potentially impact RTD and remains underexplored in this population. This study aimed to assess the relationship between the timing of ACLR and its impact on RTD and meniscal procedures performed at index ACLR.

METHODS

This retrospective observational study was conducted among active duty military personnel who underwent primary ACLR at Madigan Army Medical Center between October 1, 2016, and December 31, 2022. The primary outcome was the number of RTD, PP, or MEB outcomes. Secondary outcomes included the incidence and type of meniscal procedure performed at index ACLR. Kruskal-Wallis analyses were employed to assess the relationships between time to ACLR and RTD, as well as the incidence and type of meniscal procedure performed. After separating time to ACLR into four distinct time-based groups (0-3 months, 3-6 months, 6-12 months, and >12 months), a chi-squared test with post hoc analysis via Dunn's test with Bonferroni correction was conducted to identify a time interval from injury to ACLR that impacted RTD.

RESULTS

Initial analysis to assess the relationship between time to ACLR and outcome (RTD, PP, or MEB) were significant (P = .02). Subsequent analyses performed between 4 distinct time-based groups (0-3 months, 3-6 months, 6-12 months, and >12 months) were also significant (P = .03). Pairwise comparisons revealed an 80% rate of RTD in the 0-3 month group compared to a 53% RTD rate in 3-6 month group (P = .006). However, comparisons between the 3-6 month and 6-12 month group (P = .68) and between the 6-12 month and greater than 12 month groups were not significant (P = .80).Additionally, time to ACLR significantly differed between service members who did not undergo any concurrent meniscal procedure to those who had a meniscal debridement (P = .002), and to those who underwent meniscal repair (P = .02). There was no significant difference in time to ACLR between those who underwent debridement versus repair (P = .22). Patients without any meniscal procedure had an average surgery time of 175 days, compared to 240 days for those undergoing meniscal repair and 295 days for those with meniscal debridement.

CONCLUSION

The findings from this novel study suggest that ACLR within 3 months after injury can improve the likelihood of RTD without limitations. The timing of ACLR can also impact the incidence and type of meniscal procedures, as patients who did not undergo any concomitant meniscal procedures underwent ACLR within 6 months after injury. This study offers valuable insight into the importance of earlier ACLR among service members to improve RTD rates and decrease additional concomitant meniscal procedures.

Higher incidence of postoperative complications in patients with simultaneous patellar tendon and anterior cruciate ligament ruptures following single surgery: a case series and literature review

BACKGROUND

Patients with simultaneous ruptures of the patellar tendon (PT) and anterior cruciate ligament (ACL) underwent PT repair and ACL reconstruction in a single or staged surgery. However, due to the limited cases, the design of previous studies was mostly case report with varying conclusions regarding recommended surgical strategy selection, the optimal surgical strategy remains a subject of debate.

METHODS

We conducted a retrospective case series and literature review, including 10 cases from local institution and 27 cases from 17 studies. Demographic information, injury causes, surgical strategies, combined injuries, whether to return to (pre-injury level) sports, postoperative complications, Lysholm score and International Knee Documentation Committee (IKDC) score were identified retrospectively or reviewed from previous studies. The Fisher's exact test was used to compare the incidence of postoperative complications between different surgical strategy groups, and linear logistic regression was used to analyze factors influencing postoperative knee function scores.

RESULTS

Of the 37 patients, 15 patients (40.5%) underwent single surgery and 22 patients (59.5%) underwent staged surgery. Postoperative complications occurred in 5 (33.3%) patients after single surgery and in none after staged surgery, with the former being significantly more frequent than the latter (P = 0.007). Linear regression of postoperative knee function scores showed that surgical strategy did not significantly affect postoperative Lysholm and IKDC scores (P = 0.327 and P = 0.348, respectively).

CONCLUSIONS

This study demonstrates that staged surgery significantly reduces postoperative complications compared to single surgery in patients with simultaneous PT and ACL ruptures and should be considered the preferred approach, especially when an expedited return to sports is not a priority.

Feasibility and Cost-Effectiveness of Daycare Anterior Cruciate Ligament Reconstruction - A Retrospective Case Series

Introduction

Multiple reviews of the applicability, cost-effectiveness, and safety of daycare reconstruction of anterior cruciate ligament have been published in French, American, and British setups, but have not been described in our population.

Materials and methods

In this study, 25 patients who underwent Anterior Cruciate Ligament Reconstruction (ACLR) as a daycare surgery in our setup were assessed retrospectively. Post-operatively patients were reviewed for pain, complications, conversion from daycare to inpatients, readmission within two weeks post ACLR and cost-effectiveness.

Results

None of the patients required readmission within two weeks post-operatively, two patients were admitted on request from Surgical Day Care (SDC) to inpatient postoperatively, two patients developed urinary retention. Daycare ACLR was also cost-effective, as shown by cost analysis a reduction of cost by 26.9 %.

Conclusion

Daycare ACLR is safe, feasible, and cost-effective treatment modality for young patients and can provide a substantial cost saving.

Bridge-Enhanced Anterior Cruciate Ligament Restoration: 6-Year Results From the First-in-Human Cohort Study

Background

Bridge-enhanced anterior cruciate ligament restoration (BEAR) combines suture repair of the anterior cruciate ligament (ACL) with an extracellular matrix implant plus autologous blood to facilitate native ACL healing.

Purpose/Hypothesis

The purpose of this study was to compare the 6-year follow-up outcomes of patients who underwent the BEAR procedure with those of a nonrandomized concurrent control group receiving autograft ACL reconstruction (ACLR) in the first-in-human safety study of the BEAR implant (BEAR I trial). Based on the 2-year results, it was hypothesized that isometric hamstring strength after the BEAR procedure would be greater than that after ACLR and that there would be no other differences in outcomes at 6 years.

Study Design

Cohort study, Level of evidence, 2.

Methods

Ten patients underwent BEAR and 10 received ACLR with a 4-stranded hamstring autograft. Outcomes assessed included the record of subsequent surgeries, the International Knee Documentation Committee (IKDC) Subjective Knee Score, IKDC physical examination grade, the Knee injury and Osteoarthritis Outcome Score, instrumented knee laxity, functional outcomes (ie, muscle strength assessments and hop testing), and qualitative magnetic resonance imaging assessment. Comparisons between treatments were based on computations of the mean differences and the associated 95% CIs.

Results

One patient in the BEAR group and 3 patients in the ACLR group were lost to follow-up. In the period between 2 and 6 years, 1 patient in each group underwent revision surgery. There were no differences between groups at the 6-year follow-up in any of the outcome measures except for isometric hamstring strength, which was approximately equal to that of the contralateral knee in the BEAR group and <44% of that in the contralateral knee in the ACLR group (P < .01).

Conclusion

This preliminary study suggests that the outcomes of BEAR and ACLR with a hamstring tendon graft may be similar at the 6-year follow-up and warrants investigation of the BEAR procedure in a larger cohort of patients.

Ingelsrud L, Roos EM, Silbernagel KG, Snyder-Mackler L, Risberg MA. Patient Acceptable Symptom State Thresholds for IKDC-SKF and KOOS at the 10-Year Follow-up After Anterior Cruciate Ligament Injury: A Study From the Delaware-Oslo ACL Cohort

Background

Clinicians need thresholds for the Patient Acceptable Symptom State (PASS) and Treatment Failure to interpret group-based patient-reported outcome measures after anterior cruciate ligament (ACL) injury. Validated thresholds that are crucial for accurately discerning patient symptom state and facilitating effective interpretation have not been determined for long-term follow-up after ACL injury.

Purpose

To calculate and validate thresholds for PASS and Treatment Failure for the International Knee Documentation Committee Subjective Knee Form (IKDC-SKF) and the Knee injury and Osteoarthritis Outcome Score (KOOS) subscales at the 10-year follow-up after ACL injury.

Study Design

Cohort study; Level of evidence, 3.

Methods

A total of 163 participants with unilateral ACL injury (treated with reconstruction or rehabilitation alone) from the Delaware-Oslo ACL Cohort were included. Thresholds for PASS were calculated for IKDC-SKF and KOOS subscales using anchor-based predictive modeling and receiver operating characteristic (ROC) analysis. Too few participants had self-reported Treatment Failure to calculate thresholds for that outcome. Nonparametric bootstrapping was used to derive 95% CIs. The criterion validity of the predictive modeling and ROC-derived thresholds were assessed by comparing actual patient-reported PASS outcome with the calculated PASS outcome for each method of calculation and calculating their positive and negative predictive values with respect to the anchor questions.

Results

A total of 127 (78%) participants reported satisfactory symptom state. Predictive modeling PASS thresholds (95% CIs) were 76.2 points (72.1-79.4 points) for IKDC-SKF, 85.4 points (80.9-89.2 points) for KOOS Pain, 76.5 points (67.8-84.7 points) for KOOS Symptoms, 93.8 points (90.1-96.9 points) for KOOS activities of daily living, 71.6 points (63.4-77.7 points) for KOOS Sports, and 59.0 points (53.7-63.9 points) for KOOS quality of life (QoL). Predictive modeling thresholds classified 81% to 93% of the participants as having satisfactory symptom state, whereas ROC-derived thresholds classified >50% as unsatisfied. The thresholds for IKDC-SKF, KOOS Sports, and KOOS QoL resulted in the most accurate percentages of PASS among all identified thresholds and therefore demonstrate the highest validity.

Conclusion

Predictive modeling provided valid PASS thresholds for IKDC-SKF and KOOS at the 10-year follow-up after ACL injury. The thresholds for IKDC-SKF, KOOS Sports, and KOOS QoL should be used when determining satisfactory outcomes. ROC-derived thresholds result in substantial misclassification rates of the participants who reported satisfactory symptom state.

The Delaware-Oslo ACL Cohort treatment algorithm yields superior outcomes to usual care 9-12 years after anterior cruciate ligament reconstruction

PURPOSE

Patient-reported outcomes were compared between participants who followed the treatment algorithm of the Delaware-Oslo ACL Cohort, consisting of progressive preoperative and postoperative rehabilitation, patient education, clinical testing and shared decision-making about treatment choice, and those who followed usual care 9-12 years after anterior cruciate ligament reconstruction (ACLR).

METHODS

Participants with primary ACLR were included from the Norwegian arm of the Delaware-Oslo ACL Cohort and the Norwegian Knee Ligament Registry (usual care). The Knee Injury and Osteoarthritis Outcome Score (KOOS) subscale scores and the International Knee Documentation Committee-Subjective Knee Form (IKDC-SKF) scores were compared. KOOS scores for the usual care group were converted to IKDC-SKF scores with recently published validated crosswalk. The percentages of participants with scores above predefined thresholds for patient acceptable symptom state (PASS) were also calculated.

RESULTS

Eighty of 100 (80%) participants from the Delaware-Oslo ACL Cohort and 1588 of 3248 (49%) from the usual care group participated in the follow-up. Participants from the Delaware-Oslo ACL Cohort had higher KOOS subscale (p < 0.001) and IKDC-SKF scores (p < 0.001), and a higher percentage reached PASS (84%-96% vs. 62%-76%, p ≤ 0.002) for KOOS Pain, symptoms, activities of daily living and sports compared to the usual care group. No significant differences were found for KOOS quality of life scores (not significant [n.s.]) or PASS percentages (80% vs. 74%, n.s.).

CONCLUSION

Participants with ACLR who followed the Delaware-Oslo ACL Cohort treatment algorithm had reduced knee symptoms, superior function and higher percentages of satisfactory outcomes than participants who followed usual care.

LEVEL OF EVIDENCE

Level II.

Deep Learning Approach for Diagnosing Early Osteonecrosis of the Femoral Head Based on Magnetic Resonance Imaging

BACKGROUND

The diagnosis of early osteonecrosis of the femoral head (ONFH) based on magnetic resonance imaging (MRI) is challenging due to variability in the surgeon's experience level. This study developed an MRI-based deep learning system to detect early ONFH and evaluated its feasibility in the clinic.

METHODS

We retrospectively evaluated clinical MRIs of the hips that were performed in our institution from January 2019 to June 2022 and collected all MRIs diagnosed with early ONFH. An advanced convolutional neural network (CNN) was trained and optimized; then, the diagnostic performance of the CNN was evaluated according to its accuracy, sensitivity, and specificity. We also further compared the CNN's performance with that of orthopaedic surgeons.

RESULTS

Overall, 11,061 images were retrospectively included in the present study and were divided into three datasets with ratio 7:2:1. The area under the receiver operating characteristic curve, accuracy, sensitivity, and specificity of the CNN model for identifying early ONFH were 0.98, 98.4, 97.6, and 98.6%, respectively. In our review panel, the averaged accuracy, sensitivity, and specificity for identifying ONFH were 91.7, 87.0, and 94.1% for attending orthopaedic surgeons; 87.1, 84.0, and 89.3% for resident orthopaedic surgeons; and 97.1, 96.0, and 97.9% for deputy chief orthopaedic surgeons, respectively.

CONCLUSION

The deep learning system showed a comparable performance to that of deputy chief orthopaedic surgeons in identifying early ONFH. The success of deep learning diagnosis of ONFH might be conducive to assisting less-experienced surgeons, especially in large-scale medical imaging screening and community scenarios lacking consulting experts.

Clinically Relevant Subgroups Among Athletes Who Have Ruptured Their Anterior Cruciate Ligaments: A Delaware-Oslo Cohort Study

OBJECTIVE

To identify subgroups of individuals with anterior cruciate ligament (ACL) injuries based on patient characteristics, self-reported outcomes, and functional performance at baseline, and to associate subgroups with long-term outcomes after ACL rupture.

METHODS

A total of 293 participants (45.7% male, mean ± SD age 26.2 ± 9.4 years, days from injury 58 ± 35) were enrolled after effusion, pain, and range of motion impairments were resolved and quadriceps strength was at least 70% of the uninvolved limb. Mixture modeling was used to uncover latent subgroups without a prior group classification using probabilistic assignment. Variables include demographics, functional testing, and self-reported outcome measures. Radiographic evidence of osteoarthritis (OA; i.e., Kellgren/Lawrence grade of ≥1) in the involved knee at 5 years after injury was the primary outcome of interest. Chi-square tests assessed differences in the presence of radiographic OA in the involved knee between subgroups at 5 years after ACL rupture. Secondary outcomes of interest included radiographic OA in the uninvolved knee, return to preinjury sport by 2 years, operative status, and clinical OA (classified using Luyten et al criteria) at 5 years.

RESULTS

Four distinct subgroups exist after ACL rupture (younger good self-report, younger poor self-report, older poor self-report, older good self-report) with 30%, 31%, 47%, and 53%, respectively, having involved knee OA. The percentage of radiographic OA was not significantly different between the groups (P = 0.059).

CONCLUSION

The prevalence of OA in all subgroups is highly concerning. These results suggest there are unique subgroupings of individuals that may guide treatment after ACL rupture and reconstruction by providing support for developing a patient-centered approach.

Knee osteoarthritis, joint laxity and PROMs following conservative management versus surgical reconstruction for ACL rupture: a meta-analysis

INTRODUCTION

Patients whose rupture of the anterior cruciate ligament (ACL) can be managed conservatively or undergo reconstruction surgery.

SOURCE OF DATA

Current scientific literature published in Web of Science, PubMed and Scopus.

AREAS OF AGREEMENT

Several studies published by July 2022 compare surgical and conservative management following ACL rupture. The latest evidence suggests that surgical management may expose patients to an increased risk of early-onset knee osteoarthritis (OA).

AREAS OF CONTROVERSY

The state of art does not recommend a systematic ACL reconstruction to all patients who tore their ACL. After the initial trauma, surgical reconstruction may produce even greater damage to the intra-articular structures compared to conservative management.

GROWING POINTS

The state of art does not recommend systematic surgical reconstruction to all patients who tore their ACL. The present study compared surgical reconstruction versus conservative management for primary ACL ruptures in terms of joint laxity, patient reported outcome measures (PROMs) and rate of osteoarthritis.

AREAS TIMELY FOR DEVELOPING RESEARCH

ACL reconstruction provides significant improvement in joint laxity compared to conservative management, but is associated with a significantly greater rate of knee osteoarthritis, despite similar results at PROM assessment.

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.

Four Distinct 5-Year Trajectories of Knee Function Emerge in Patients Who Followed the Delaware-Oslo ACL Cohort Treatment Algorithm

BACKGROUND

Impairments and dysfunction vary considerably after anterior cruciate ligament (ACL) injury, and distinct subgroups may exist.

PURPOSE

(1) To identify subgroups of patients with ACL injury who share common trajectories of patient-reported knee function from initial presentation to 5 years after a treatment algorithm where they chose either ACL reconstruction (ACLR) plus rehabilitation or rehabilitation alone. (2) To assess associations with trajectory affiliation.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

We included 276 patients with a acute first-time complete unilateral ACL injury. All patients underwent a 5-week neuromuscular and strength training program before a shared decision-making process about treatment. Within their latest attended follow-up, 62% of patients had undergone early ACLR (<6 months after the 5-week program), 11% delayed ACLR (>6 months after the 5-week program), and 27% progressive rehabilitation alone. Patients completed the International Knee Documentation Committee Subjective Knee Form (IKDC-SKF) at inclusion, after the 5-week program, and at 6 months, 1 year, 2 years, and 5 years after ACLR or completion of the 5-week program (patients treated with rehabilitation alone). We used group-based trajectory modeling to identify trajectories of IKDC-SKF and multinomial logistic regression to assess associations with trajectory affiliation.

RESULTS

Four distinct trajectories of IKDC-SKF were identified: Low (n = 22; 8.0% of the cohort), Moderate (n = 142; 51.4%), High (n = 105; 38.0%), and High Before Declining (n = 7; 2.5%). The High trajectory had higher scores at inclusion than the Moderate trajectory, but both improved considerably within 1 year and had thereafter stable high scores. The High Before Declining trajectory also started relatively high and improved considerably within 1 year but experienced a large deterioration between 2 and 5 years. The Low trajectory started low and had minimal improvement. New knee injuries were important characteristics of the High Before Declining trajectory, concomitant meniscal injuries were significantly associated with following the Low (vs Moderate) trajectory, and early/preoperative quadriceps strength and hop symmetry (measured at inclusion) were significantly associated with following the High (vs Moderate) trajectory.

CONCLUSION

We identified 4 distinct 5-year trajectories of patient-reported knee function, indicating 4 subgroups of patients with ACL injury. Importantly, 88% of the patients who followed our treatment algorithm followed the Moderate and High trajectories characterized by good improvement and high scores. Due to eligibility criteria and procedures in our cohort, we can only generalize our model to athletes without major concomitant injuries who follow a similar treatment algorithm. Concomitant meniscal injuries and new knee injuries were important factors in the unfavorable Low and High Before Declining trajectories. These associations were exploratory but support the trajectories' validity. Our findings can contribute to patient education about prognosis and underpin the importance of continued secondary injury prevention.

Greater Psychological Readiness to Return to Sport, as Well as Greater Present and Future Knee-Related Self-Efficacy, Can Increase the Risk for an Anterior Cruciate Ligament Re-Rupture: A Matched Cohort Study

PURPOSE

To determine the psychological characteristics and strength outcomes of patients who sustained an early anterior cruciate ligament (ACL) re-rupture after their primary ACL reconstruction and cross-sectionally compare them with a matched cohort of patients who did not sustain a reinjury during the first 2 years after primary ACL reconstruction.

METHODS

In this matched cohort study, data for quadriceps and hamstring strength and 3 hop tests and answers to standardized patient-reported outcomes (the Anterior Cruciate Ligament Return to Sport after Injury scale and a short version of the Knee Self-Efficacy Scale) were extracted from a rehabilitation outcome registry. Data for patients suffering a re-rupture were extracted, and patients were matched in terms of sex, age, and activity level with patients not suffering an ACL re-rupture within 2 years of primary reconstruction. The groups were compared 10 weeks and 4, 8, and 12 months after the primary reconstruction.

RESULTS

A total of 36 patients suffering an ACL re-rupture were matched with 108 patients not suffering a re-rupture after ACL reconstruction. Patients who suffered an ACL re-rupture had greater psychological readiness, that is, greater confidence in performance, lesser negative emotions, and lesser risk appraisal, to return to sport (RTS) at 8 months (81.2 vs 67.9 [95% Δconfidence interval {CI} 2.7-23.8) P = .014) and at 12 months (95.2 vs 67.1, (95% ΔCI 14.3-41.8) P ≤ .001), and greater knee-related self-efficacy at 8 months (8.6 vs 8.0 [95% ΔCI 0.1-1.2], P = .021) and 12 months (9.4 vs 8.1, [95% ΔCI 0.3-2.2] P = .012) after primary ACL reconstruction, compared with the matched group.

CONCLUSIONS

A stronger psychological profile, defined by a greater psychological readiness to RTS and knee-related self-efficacy, may be associated with an ACL re-rupture within 2 years of the primary reconstruction.

LEVEL OF EVIDENCE

Matched cohort study, level III.

RetroBRACE: clinical, socioeconomic and functional-biomechanical outcomes 2 years after ACL repair and InternalBrace augmentation in comparison to ACL reconstruction and healthy controls-experimental protocol of a non-randomised single-centre comparative study

INTRODUCTION

Despite good clinical outcomes reported in the literature, to date, scientific evidence for the functional and biomechanical benefit of primary anterior cruciate ligament (ACL) repair with augmentation is scarce. We present an experimental protocol for a detailed multimodal (clinical, socioeconomic, functional and biomechanical) comparative study in patients after primary ACL repair and InternalBrace augmentation, patients after ACL reconstruction and healthy controls.

METHODS AND ANALYSIS

In this non-randomised single-centre comparative study with prospective data collection with three arms (patients 2 years after ACL repair and InternalBrace augmentation; patients 2 years after ACL reconstruction using hamstring autografts; and healthy controls), 30 participants per study arm will be included. The study is designed as non-inferiority study with three arms. Required sample size was estimated based on data reported in the literature on muscle strength, proprioception and balance parameters, resulting in at least 28 participants per group. Outcome parameters include patient-reported outcome measures (EQ-5D-5L, Tegner Activity Scale, Knee Injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee and ACL-Return to Sports Injury Scale), socio-economic parameters, anterior tibial translation, range of motion and functional-biomechanical data of the lower extremities. Functional-biomechanical parameters include proprioception, isokinetic muscle strength, single-leg balance, walking, running and single-leg hops with additional lower extremity 3D joint kinematics and kinetics and muscle activity. These parameters will be compared between limbs in patients, between groups and to the current literature.

ETHICS AND DISSEMINATION

The results of this study will be disseminated through peer-reviewed publications and presentations at national and international conferences. Ethical approval was obtained by the regional ethics board (Ethics Committee Northwest Switzerland EKNZ 2020-00551), and the study is registered at clinicaltrials.gov.Trial registration numberNCT04429165.

Low Rates of Radiographic Knee Osteoarthritis 5 Years After ACL Reconstruction or Rehabilitation Alone: The Delaware-Oslo ACL Cohort Study

BACKGROUND

Patients and clinicians often struggle to choose the optimal management strategy for posttraumatic knee osteoarthritis (OA) after an anterior cruciate ligament (ACL) injury. An evaluation of radiographic outcomes after a decision-making and treatment algorithm applicable in clinical practice can help to inform future recommendations and treatment choices.

PURPOSE

To describe and compare 5-year radiographic outcomes and knee pain in individuals who had gone through our decision-making and treatment algorithm and chosen (1) early (<6 months) ACL reconstruction (ACLR) with pre- and postoperative rehabilitation, (2) delayed (>6 months) ACLR with pre- and postoperative rehabilitation, or (3) progressive rehabilitation alone.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

We included 276 patients with unilateral ACL injury from a prospective cohort study. Patients chose management using a shared decision-making process and treatment algorithm, and 5-year postoperative radiographs of the index and contralateral knees were assessed using the Kellgren and Lawrence (K&L) classification and minimum joint space width measurements. We defined radiographic tibiofemoral OA as K&L grade ≥2 and knee pain as a Knee injury and Osteoarthritis Outcome Score for Pain ≤72. To further explore early radiographic changes, we included alternative cutoffs for radiographic knee OA using K&L grade ≥2/osteophyte (definite osteophyte without joint space narrowing) and K&L grade ≥1.

RESULTS

At 5 years, 64% had undergone early ACLR; 11%, delayed ACLR; and 25%, progressive rehabilitation alone. Radiographic examination was attended by 187 patients (68%). Six percent of the cohort had radiographic tibiofemoral OA (K&L grade ≥2) in the index knee; 4%, in the contralateral knee. Using the alternative cutoffs at K&L grade ≥2/osteophyte and K&L grade ≥1, the corresponding numbers were 20% and 33% in the index knee and 18% and 29% in the contralateral knee. Six percent had a painful index knee. There were no statistically significant differences in any radiographic outcomes or knee pain among the 3 management groups.

CONCLUSION

There were no statistically significant differences in any 5-year radiographic outcomes or knee pain among the 3 management groups. Very few of the patients who participated in our decision-making and treatment algorithm had knee OA or knee pain at 5 years.