The Importance of Patient Sex in the Outcomes of Anterior Cruciate Ligament Reconstructions: A Systematic Review and Meta-analysis

Sexual Dimorphisms in Anterior Cruciate Ligament Injury: A Current Concepts Review

Background:

Although most anterior cruciate ligament (ACL) injuries occur in male athletes, female athletes are consistently observed to be at a higher risk for sports-specific ACL injury.

Purpose:

To provide a thorough review of what is known about the sexual dimorphisms in ACL injury to guide treatment and prevention strategies and future research.

Study Design:

Narrative review.

Methods:

We conducted a comprehensive literature search for ACL-related studies published between January 1982 and September 2017 to identify pertinent studies regarding ACL injury epidemiology, prevention strategies, treatment outcomes, and dimorphisms. By performing a broad ACL injury search, we initially identified 11,453 articles. After applying additional qualifiers, we retained articles if they were published in English after 1980 and focused on sex-specific differences in any of 8 different topics: sex-specific reporting, difference in sports, selective training, hormonal effects, genetics, neuromuscular and kinematic control, anatomic differences, and outcomes.

Results:

A total of 122 articles met the inclusion criteria. In sum, the literature review indicated that female athletes are at significantly higher risk for ACL injuries than are their male counterparts, but the exact reasons for this were not clear. Initial studies focused on intrinsic differences between the sexes, whereas recent studies have shifted to focus on extrinsic factors to explain the increased risk. It is likely both intrinsic and extrinsic factors contribute to this increased risk, but further study is needed. In addition to female patients having an increased risk for ACL injuries, they are less likely than are male patients to undergo reconstructive surgery, and they experience worse postsurgical outcomes. Despite this, reconstructive surgery remains the gold standard when knee stability, return to sports, and high functional outcome scores are the goal, but further research is needed to determine why there is disparity in surgical rates and what surgical techniques optimize postsurgical outcomes for female patients.

Conclusion:

Male athletes often predominated the research concerning ACL injury and treatment, and although sex-specific reporting is progressing, it has historically been deficient. ACL injuries, prevention techniques, and ACL reconstruction require further research to maximize the health potential of at-risk female athletes.

Current trends in the anterior cruciate ligament part II: evaluation, surgical technique, prevention, and rehabilitation

Clinical evaluation and management of anterior cruciate ligament (ACL) injury is one of the most widely researched topics in orthopedic sports medicine, giving providers ample data on which to base their practices. The ACL is also the most commonly treated knee ligament. This study reports on current topics and research in clinical management of ACL injury, starting with evaluation, operative versus nonoperative management, and considerations in unique populations. Discussion of graft selection and associated procedures follows. Areas of uncertainty, rehabilitation, and prevention are the final topics before a reflection on the current state of ACL research and clinical management of ACL injury. Level of evidence V.

Long-term evaluation of pediatric ACL reconstruction: high risk of further surgery but a restrictive postoperative management was related to a lower revision rate

INTRODUCTION

The guidelines regarding rehabilitation after pediatric anterior cruciate ligament reconstruction (ACLR) are sparse. The aim of the study was to retrospectively describe the long-term outcome regarding further surgery and with special emphasis on the revision rate after two different postoperative rehabilitation programs following pediatric ACLR.

MATERIAL AND METHODS

193 consecutive patients < 15 years of age who had undergone ACLR at two centers, A (n = 116) and B (n = 77), in 2006-2010 were identified. Postoperative rehabilitation protocol at A: a brace locked in 30° of flexion with partial weight bearing for 3 weeks followed by another 3 weeks in the brace with limited range of motion 10°-90° and full weight bearing; return to sports after a minimum of 9 months. B: immediate free range of motion and weight bearing as tolerated; return to sports after a minimum of 6 months. The mean follow-up time was 6.9 (range 5-9) years. The mean age at ACLR was 13.2 years (range 7-14) years. The primary outcome measurement in the statistical analysis was the occurrence of revision. Multivariable logistic regression analysis was performed to investigate five potential risk factors: surgical center, sex, age at ACLR, time from injury to ACLR and graft diameter.

RESULTS

Thirty-three percent had further surgery in the operated knee including a revision rate of 12%. Twelve percent underwent ACLR in the contralateral knee. The only significant variable in the statistical analysis according to the multivariable logistic regression analysis was surgical center (p = 0.019). Eight percent of the patients at center A and 19% of the patients at B underwent ACL revision.

CONCLUSIONS

Further surgery in the operated knee could be expected in one third of the cases including a revision rate of 12%. The study also disclosed a similar rate of contralateral ACLR at 12%. The revision rate following pediatric ACLR was lower in a center which applied a more restrictive rehabilitation protocol.

LEVEL OF EVIDENCE

Case-control study, Level III.

"I don't opt out of things because I think I will get a sore knee, but I don't expose myself to stupid risks either": patients' experiences of a second ACL injury-an interview study

PURPOSE

The purpose of this qualitative study was to describe women's experiences with anterior cruciate ligament reconstruction (ACLR) and a subsequent ACL rupture, and to identify potential facilitators and barriers for coping with rehabilitation after the second injury.

METHODS

Eight women between 17 and 36 years (mean 26, SD 6.5) who had experienced ACLR, followed by another ACL rupture, participated in the study. Semi-structured interviews were conducted, and data were analyzed using qualitative content analysis.

RESULTS

One overarching theme, "Rehabilitation after a second ACL injury-A lifelong adaptive coping process", emerged from analyses. Undergoing a second rehabilitation is described as a process of adaptation, beginning with the first injury and still ongoing, more than 5 years later. Participants applied different coping strategies to adapt to these life-altering injuries, but the common denominator was of major life adjustments with no return to previous activity levels. Initially, after the reinjury, it was about coping with the catastrophe of the dreaded second injury. Over time, they accepted their "new" life and reset their recovery/rehabilitation goal not just as "return to sport" but rather as a "personal life goal".

CONCLUSION

Undergoing a second ACL injury is a long process that challenges the patient's coping skills. Given these results, rehabilitation programs need to be more person centred according to the patients-adjusted life goals.

Sex-Specific Differences Following Lateral Ankle Ligament Repair

BACKGROUND

Chronic ankle instability is a common condition that can be treated with lateral ankle ligament repair. These procedures have a reported success rate greater than 85% in the literature, but little has been reported about the differences in postoperative outcomes between males and females. The purpose of this study was to evaluate sex-specific outcomes following lateral ankle ligament repair.

METHODS

In this systematic review and meta-analysis, we used Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria to search for articles on electronic databases and included studies in which study participants underwent primary lateral ligament repair and sex-specific outcomes were evaluated. Functional postoperative outcomes for males and females were recorded and statistically analyzed.

RESULTS

Out of 2768 studies, 7 (0.25%) met inclusion criteria and were analyzed in this review. These studies included 618 patients (402 males [65%] and 216 females [35%]) who underwent primary lateral ligament repair for ankle instability. Karlsson score (P = .1582) and American Orthopaedic Foot & Ankle Society (AOFAS) score (P = .1586) analyses found no statistically significant difference between males and females. Postoperative success rate-defined as a "good" or "excellent" Karlsson score (>81)-was not found to be significantly different between males and females (P = .9374).

CONCLUSION

There was no difference in postoperative mean Karlsson scores, AOFAS scores, or success rates between males and females who underwent primary lateral ankle ligament repair.

LEVEL OF EVIDENCE

Level IV, therapeutic.

Terminal knee extension deficit and female sex predict poorer quadriceps strength following ACL reconstruction using all-soft tissue quadriceps tendon autografts

PURPOSE

The all-soft tissue quadriceps tendon (QT) autograft is becoming increasingly popular for ACL reconstruction (ACLR); however, studies reporting strength recovery and early outcomes after QT autograft are limited with patient samples composed of predominantly males. The primary purpose was to characterize early, sex-specific recovery of strength, range of motion (ROM), and knee laxity in a large cohort of patients undergoing primary ACLR with standardized harvest technique of the all-soft tissue QT autograft. The secondary purpose was to examine the influence of demographic factors and clinical measures on 6-month quadriceps strength.

METHODS

Patients 14-25 years who underwent primary, unilateral ACLR with all-soft tissue QT autografts were prospectively followed. Knee laxity and ROM were collected at 6 weeks, 3 and 6 months; while, quadriceps normalized torques and limb symmetry indices (LSI) were collected at 3 and 6 months using isokinetic dynamometry at 60°/s. Two-way ANOVAs with repeated measures were conducted to determine recovery over time and between sexes. Stepwise linear multiple regressions were conducted to determine predictors of 6-month quadriceps strength.

RESULTS

Three-hundred and twenty patients were included (18 ± 3 years; 156 males:164 females; BMI = 24 ± 4 kg/m²) with no early graft failures within the study period. For strength, there were significant main effects of time (p < 0.001) and sex (p < 0.001), indicating similar improvement from 3 to 6 months with males demonstrating greater quadriceps LSI (6 months: 72.1 vs 63.3%) and normalized strength (6 months: 2.0 vs 1.6 Nm/kg). A significantly higher proportion of females had knee extension ROM deficits ≥ 5° compared to males at 6 weeks (61 vs 39%; p = 0.002). Female sex and 3-month extension ROM deficits were identified as significant predictors of 6-month quadriceps LSI (R² = 0.083; p < 0.001). Female sex, BMI, and 6-week extension ROM deficits were identified as significant predictors of 6-month normalized quadriceps strength (R² = 0.190; p < 0.001).

CONCLUSIONS

Females had decreased quadriceps strength and greater extension ROM deficits at 3 and 6 months following ACLR using all-soft tissue QT autografts. Female sex, higher BMI, and loss of extension ROM were independent predictors of poorer quadriceps strength at 6 months. There were no early graft failures, and laxity remained within normal ranges for both males and females. Surgeons and rehabilitation clinicians should be aware of the increased risk of postoperative loss of extension ROM in females and its implications on quadriceps strength recovery.

LEVEL OF EVIDENCE

III.

Revision Anterior Cruciate Ligament Reconstruction with the All-Soft Tissue Quadriceps Tendon Autograft Has Acceptable Early and Intermediate-Term Outcomes

PURPOSE

The purposes were to (1) examine early to intermediate-term clinical outcomes and complications of revision anterior cruciate ligament reconstruction (ACLR) using all-soft tissue quadriceps tendon (QT) autografts, and (2) compare quadriceps strength between patients who had hamstring versus patella tendon autografts in their previous reconstruction.

METHODS

One hundred patients (52 males/48 females; 22.6 ± 8.0 years) undergoing revision ACLR with all-soft tissue QT autografts were prospectively followed. All revision procedures were performed by a single surgeon, using a minimally invasive graft harvest technique and suspensory fixation. Subjective assessment of knee function was obtained before and after surgery with the International Knee Documentation Committee (IKDC) survey. Postoperative knee laxity and isokinetic quadriceps strength were collected at regular intervals. Strength was reported as limb symmetry index (LSI; surgical side divided by nonsurgical side). Complications including hematomas, postoperative loss of knee extension, and graft failures were recorded. To determine clinical significance (P ≤ .05), outcomes were compared using analysis of variance or paired samples t-tests.

RESULTS

The mean IKDC scores significantly improved (54.3 ± 13.0 vs 82.8 ± 13.8), with an average follow-up of 42.2 ± 21.2 months. There were no significant changes in knee laxity side-to-side differences: 6 weeks (1.2 ± 1.5 mm), 3 months (1.2 ± 1.8 mm), 6 months (1.4 ± 1.6 mm). Quadriceps LSIs significantly improved from 71.6% ± 19.3% at 6 months to 81.5% ± 19.3% at 12 months for 60°/s isokinetic testing and 76.6% ± 16.4% at 6 months to 83.9% ± 16.9% at 12 months for 180°/s testing. Graft harvest site hematomas developed in 2 patients, postoperative loss of knee extension in 4 patients, and graft failure in 11 patients. No significant differences in quadriceps or hamstrings LSIs were noted between patients with previous hamstring versus patella tendon autografts (P > .050).

CONCLUSION

Revision ACLR with all-soft tissue QT autografts has acceptable early and intermediate-term outcomes with reasonable complication rates (11/80 patients with follow-up). Secondary insult to the extensor mechanism via QT autograft harvest does not adversely affect strength after prior patellar tendon versus hamstring autograft.

LEVEL OF EVIDENCE

Level IV, cases series subgroup analysis.

Sources of Individual Differences in Pain

Pain is an immense clinical and societal challenge, and the key to understanding and treating it is variability. Robust interindividual differences are consistently observed in pain sensitivity, susceptibility to developing painful disorders, and response to analgesic manipulations. This review examines the causes of this variability, including both organismic and environmental sources. Chronic pain development is a textbook example of a gene-environment interaction, requiring both chance initiating events (e.g., trauma, infection) and more immutable risk factors. The focus is on genetic factors, since twin studies have determined that a plurality of the variance likely derives from inherited genetic variants, but sex, age, ethnicity, personality variables, and environmental factors are also considered.

Assessing Physical Activity After ACL Injury: Moving Beyond Return to Sport

CONTEXT

Return to sport is widely utilized by sports medicine researchers and clinicians as a primary outcome of interest for successful recovery when working with young patients who have undergone anterior cruciate ligament (ACL) reconstruction (ACLR). While return-to-sport outcomes are effective at tracking progress post-ACLR, they are limited because they do not necessarily capture physical activity (PA) engagement, which is important to maintain knee joint health and reduce the risk of noncommunicable diseases. Therefore, there is a critical need (1) to describe current PA participation and measurement recommendations; (2) to appraise common PA measurement approaches, including patient-reported outcomes and device-based methodologies; and (3) to provide clinical recommendations for future evaluation.

EVIDENCE ACQUISITION

Reports of patient-reported or device-based PA in patients with ACL injury were acquired and summarized based on a PubMed search (2000 through July 2020). Search terms included physical activity OR activity AND anterior cruciate ligament OR ACL.

STUDY DESIGN

Clinical review.

LEVEL OF EVIDENCE

Level 5.

RESULTS

We highlight that (1) individuals with ACLR are 2.36 times less likely to meet the US Department of Health and Human Services PA recommendations even when reporting successful return to sport, (2) common patient-reported PA assessments have significant limitations in the data that can be derived, and (3) alternative patient-reported and device-based assessments may provide improved assessment of PA in this patient population.

CONCLUSION

Clinicians and researchers have relied on return to sport status or self-reported PA participation via surveys. These approaches are not consistent with current recommendations for PA assessment and do not allow for comparison with contemporary PA recommendations or guidelines. Return to sport, patient-reported outcome measures, and device-based assessment approaches should be used in complementary manners to comprehensively assess PA participation after ACLR. However, appropriate techniques should be used when assessing PA in adult and adolescent populations.

Clinical Trial Registry Use in Orthopaedic Surgery Systematic Reviews

BACKGROUND

Results from systematic reviews and meta-analyses, which have the highest level of evidence (Level I), often drive clinical decision-making and health policy. Often, unpublished trial data are omitted from systematic reviews, raising concerns about the extent of the reliability and validity of results that have been drawn from systematic reviews. We aimed to determine the extent to which systematic review authors include searches of clinical trial registries for unpublished data when conducting systematic reviews in orthopaedic surgery.

METHODS

Systematic reviews and/or meta-analyses were gathered from the top 5 orthopaedic surgery journals based on the h5-index from Google Scholar Metrics. Systematic reviews that had been published in the Cochrane Database of Systematic Reviews, which requires the inclusion of a clinical trial registry search, served as controls. For the primary outcome, each systematic review from the top 5 orthopaedic journals was screened to determine whether the authors of each study searched for unpublished data in clinical trial registries. We then compared the rate of registry searches with those in the control group. For the secondary analysis, a search of ClinicalTrials.gov was performed for unpublished trial data for 100 randomized systematic reviews.

RESULTS

All 38 of the Cochrane systematic reviews (100%) included clinical trial registry searches, while the top 5 orthopaedic journals had only 31 of 480 studies (6.5%) that looked at clinical trial registries. The secondary analysis yielded 59 of 100 systematic review articles (59.0%) that could have included unpublished clinical trial data from ≥1 studies to their sample.

CONCLUSIONS

Systematic reviews that have been published in the top orthopaedic surgery journals seldom included a search for unpublished clinical trial data.

CLINICAL RELEVANCE

The exclusion of clinical trial registry searches potentially contributes to publication bias within the orthopaedic literature. Moving forward, systematic review authors should include clinical trial registry searches for unpublished clinical trial data to provide the most accurate representation of the available evidence for systematic reviews and meta-analyses.

Sex differences in postural orientation errors and association with objective and patient-reported function in patients with ACL injury: an exploratory cross-sectional study

Objectives

There is limited research on sex differences in postural orientation (ie, alignment between body segments) in people with knee injury measured with a clinically applicable method. An understanding of the relationship between postural orientation and physical function may help guide decision making in rehabilitation. The aims were to evaluate (1) sex differences in visual assessment of Postural Orientation Errors (POEs) and (2) the association between POEs and objective and patient-reported physical function, in men and women with anterior cruciate ligament reconstruction (ACLR).

Methods

Twenty-four women and 29 men (mean 26.7 (SD 6.5) years) with ACLR were included. Six POEs (lower extremity and trunk) were scored from a video of five tasks with varying difficulty to compute POE scores (total and subscores). Objective physical function was evaluated with the single-leg hop for distance and side hop. Patient-reported physical function was evaluated using patient-reported outcome measures (PROMs).

Results

Women had significantly more POEs than men (median difference 5.5–25, p≤0.028). More POEs were associated with shorter hop distance and fewer side hops in women (r_s= −0.425 to −0.518, p<0.038), but not in men (r_s<0.301, p>0.05). No associations were found between POE scores and PROMs, in either sex (r_s< –0.246, p>0.05).

Conclusions

Women with ACLR seem to have more POEs compared with men, indicating worse postural orientation. More POEs were associated with worse hop performance, suggesting that POE scores may be used as criteria for rehabilitation progression. The lack of associations between POE scores and PROMs indicate that these measures complement each other.

Current Concept Review: Inclusion and Analysis of Diverse Study Populations in Orthopaedic Research

As disparities in healthcare access and outcomes have been increasingly identified across medical specialties, the importance of recognizing and understanding the diversity of our patient populations and the influence of individual characteristics such as age, sex, gender, race, and ethnicity on clinical outcomes has been emphasized. Orthopaedic literature has advanced dramatically in the quality and quantity of research generated over the past 25 years, yet a consistent, sustained focus on studying musculoskeletal health in the context of these unique patient-specific variables has not been maintained. The result of this inattention may be the provision of orthopaedic care that is ill-suited for the individual patient whose biologic characteristics, life experiences, and cultural constructs differ from that of the typical research subject. The recent proliferation of meta-analyses-whose intention is to optimize statistical power-likely compounds the problem because improper, inconsistent, or absent categorization of patients in research articles precludes meaningful subgroup analysis. This article describes the current variability in demographic reporting in the orthopaedic literature, highlights the importance of complete, consistent demographic reporting and subgroup analysis, and reviews specific examples of orthopaedic conditions that illustrate how clinical outcomes may be affected by patient-specific variables such as age, sex, gender, race, and ethnicity.

Effect of Patient Height and Sex on the Patellar Tendon and Anterior Cruciate Ligament

Background:

Graft-tunnel mismatch is an avoidable complication in anterior cruciate ligament (ACL) reconstruction. Patient height and sex may be predictors of patellar tendon length (PTL) and intra-articular ACL length (IAL). Understanding these relationships may assist in reducing graft-tunnel mismatch during ACL reconstruction with bone–patellar tendon–bone (BTB) autograft.

Purpose:

To determine the association of patient height and sex with PTL and IAL.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

Magnetic resonance imaging (MRI) studies were obtained on the healthy knees of 100 male and 100 female patients. Patients with prior surgery, open physes, significant degenerative changes, ACL rupture, or extensor mechanism injury were excluded. Three independent readers measured PTL, IAL, and Caton-Deschamps Index (CDI) on MRI. Bivariate and linear regression analysis was performed to detect the association of anthropometric data with anatomic parameters measured on MRI studies.

Results:

The mean age and body mass index were not significantly different between the male and female patients; however, male patients were significantly taller than female patients (1.75 vs 1.72 m, respectively; P < .001). There was a substantial agreement between the 3 readers for all parameters (κ > 0.75). Overall, female patients had significantly longer PTL (47.38 vs 43.92 mm), higher CDI (1.146 vs 1.071), and shorter IAL (33.05 vs 34.39 mm) (P < .001 for all). Results of the linear regression analysis demonstrated that both height and female sex were predictive of longer PTL. Further, height was independently predictive of IAL but sex was not.

Conclusion:

PTL was correlated more with patient sex than height. IAL was also correlated with patient sex. Longer BTB grafts are expected to be harvested in female patients compared with male patients of the same height despite shorter IAL. These associations should be considered during BTB ACL reconstruction to minimize graft-tunnel mismatch.

Clinical Risk Profile for a Second Anterior Cruciate Ligament Injury in Female Soccer Players After Anterior Cruciate Ligament Reconstruction

BACKGROUND

The risk of a second anterior cruciate ligament (ACL) injury when participating in pivoting sports after ACL reconstruction is high. Risk factors associated with a second ACL injury are complex.

PURPOSE

To investigate the combinations of various clinical risk factors associated with second ACL injury in female soccer players with a primary unilateral ACL reconstruction, using Classification and Regression Tree (CART) analysis.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

A total of 117 active female soccer players (mean ± SD age, 20 ± 2 years) were included. Athletes were enrolled 19 ± 9 months after ACL reconstruction and were prospectively followed for 2 years. At baseline, all players underwent assessment of knee and ankle joint range of motion (ROM), participated in functional tests (postural control, hop performance, and movement asymmetries in the lower limbs and trunk), and answered questionnaires (patient-reported knee function, knee-related quality of life, psychological and personality factors). A clinical prediction model using CART was developed.

RESULTS

A total of 28 players (24%) sustained a second ACL injury (21 ipsilateral and 7 contralateral ruptures) while playing soccer. CART analysis selected 9 of 19 independent variables associated with second ACL injury: the 5-jump test, knee collapse on the non-ACL reconstructed leg in a drop vertical jump, tuck jump, limb symmetry index on side hop and the single hop for distance, side difference in ankle dorsiflexion ROM, and scores for the questionnaires ACL-Return to Sport After Injury and the Swedish Universities Scales of Personality subscales of Stress Susceptibility and Adventure Seeking. The accuracy of the model was 89%, with 100% sensitivity and 76% specificity. CART analysis indicated that the interaction of longer jumps in the 5-jump test (>916 cm) with more side difference in ankle dorsiflexion ROM (>-2.5°) and more knee valgus collapse in the nonreconstructed knee (>-1.4 cm) (relative risk, 4.03; 95% CI, 2.21-7.36) best predicted an increased likelihood of a second ACL injury.

CONCLUSION

The risk profiles selected by CART could accurately identify female soccer players at high risk for a second ACL injury. There was an interaction between functional performance, clinical assessment, and psychological factors, and it is reasonable to include these factors in return-to-sport decisions and in athlete screening after ACL injury.

Quadriceps Strength After Anterior Cruciate Ligament Reconstruction Compared With Uninjured Matched Controls: A Systematic Review and Meta-analysis

Background:

The limb symmetry index may overestimate the recovery of quadriceps muscle strength after anterior cruciate ligament reconstruction. Comparison of individuals who have had anterior cruciate ligament reconstruction with age-, sex-, and activity-matched individuals might be more appropriate to guide rehabilitation interventions.

Purpose:

To compare the quadriceps strength between the injured limb of people with anterior cruciate ligament reconstruction and the limb of an age-, sex-, and activity-matched control group.

Study Design:

Systematic review; Level of evidence, 3.

Methods:

MEDLINE, CINAHL, EMBASE, SCOPUS, and SPORTDiscus were searched between inception and April 2019. Studies were included if they reported the peak quadriceps strength for persons with anterior cruciate ligament reconstruction and age-, sex-, and activity-matched control groups measured using isometric or isokinetic dynamometry. Risk of bias was assessed, and meta-analyses and metaregression (for effect of time since surgery) were performed.

Results:

A total of 2759 studies were identified and 21 were included for analyses. Quadriceps strength was lower in the limbs with anterior cruciate ligament reconstruction compared with the limb from matched controls within 6 months of anterior cruciate ligament reconstruction (standardized mean difference [SMD], –1.42; 95% CI, –1.62 to –1.23), 6 to 18 months after anterior cruciate ligament reconstruction (SMD, –0.92; 95% CI, –1.18 to –0.66), and >18 to 48 months after anterior cruciate ligament reconstruction (SMD, –0.38; 95% CI, –0.79 to 0.03). Results of the metaregression were significant, with the difference between anterior cruciate ligament reconstruction and matched controls decreasing with time since surgery (P < .001).

Conclusion:

In people with anterior cruciate ligament reconstruction, the injured limb had lower quadriceps strength compared with the limb of age-, sex-, and activity-matched controls up to 4 years after surgery. Clinicians should consider comparison with matched cohorts for return to sports decision making.

Anterior cruciate ligament injury: towards a gendered environmental approach

BACKGROUND

The anterior cruciate ligament (ACL) injury rate for girls/women has not changed in over 20 years, and they remain 3-6 times more likely to experience injury compared with boys/men. To date, ACL injury prevention and management has been approached from a sex-based biological point of view which has furthered our understanding of injury risk factors, mechanisms, and prevention and rehabilitation programmes. However, the traditional sex-based approach does not take into account the growing recognition of how sex and gender (a social construct) are 'entangled' and influence each other.

OBJECTIVE

This paper discusses the curious absence of gender as an influencer in the dialogue surrounding ACL injuries. We propose adding gender as a pervasive developmental environment as a new theoretical overlay to an established injury model to illustrate how gender can operate as an extrinsic determinant from the presport, training and competition environments through to ACL injury and the treatment environment.

APPROACH

We draw on social epidemiological theories of the embodiment of gender and health to provide plausible examples of how gender may influence ACL injury, and demonstrate the opportunity for new, interdisciplinary research in the field.

CONCLUSION

Over 20 years of research has failed to decrease the ACL injury rate disparity between girls/women and boys/men. Embedding gender in the study of ACL injury will heighten awareness of possible influences outside the traditional biological elements, challenge us to think about the inextricable 'entanglement' of sex and gender, and inform more effective approaches to ACL injury prevention and treatment.

Functional outcome of implant-free bone-patellar tendon autograft versus hamstring autograft in arthroscopic anterior cruciate ligament reconstruction: A prospective study

Introduction

The use of implant in anterior cruciate ligament (ACL) reconstruction has been associated with several drawbacks including graft injury, implant osteolysis, implant migration and soft tissue irritation. Implant-free ACL reconstruction surgery offers additional benefits of cost-effective, improved graft incorporation and ease of revision surgery. Our study aimed to compare the functional outcome of ACL reconstruction by using bone-patellar tendon autograft with press-fit fixation technique and hamstring autografts with implant.

Methods

A prospective cohort study design was used. Between March 2013 and March 2014, 12 patients underwent patella tendon-bone graft fixated by press-fit fixation technique (implant-free), while 24 patients underwent ACL reconstruction using implant-fixated hamstring tendon graft. Objective functional outcome was measured by using rolimeter, and subjective functional outcome was measured according to the functional score of IKDC, Tegner-Lysholm and KOOS.

Results

Both techniques have shown no significant difference in terms of functional outcome, whether assessed by rolimeter measurement, IKDC score, Tegner-Lysholm, KOOS score between implant group and implant-free group, preoperatively and postoperatively.

Discussion

Our study results are in line with several other studies with various follow-up time and systematic review. With the right technique, graft harvesting of patella tendon-tibial tuberosity bone block can be successfully performed, and associated donor site morbidity can be avoided.

Conclusion

Patients who underwent ACL reconstruction using implant-free technique by press-fit fixation had comparable outcome with ACL reconstruction with implant, objectively and subjectively. This technique should be further revisited and reevaluated.

Knee laxity, lateral meniscus tear and distal femur morphology influence pivot shift test grade in ACL injury patients

PURPOSE

Although several factors have been considered to be associated with pivot shift test grade in ACL injured patients, a conclusion regarding which factors contribute to the pivot shift test grade has not been reached. The purpose of this study was to identify factors associated with preoperative pivot shift test grade.

METHODS

Three hundred and sixty-six consecutive patients who underwent ACL reconstruction in our hospital were enrolled in the study. Patients were divided into two groups on the basis of preoperative pivot shift test grade (Mild: grade 0-3, Severe: grade 4-6). First, 13 independent variables (age, gender, period from injury to surgery, hyperextension, KT measurement, contralateral side pivot shift test grade, medial and lateral tibial slope, lateral condyle length, lateral condyle height, distal femoral condyle offset, medial and lateral meniscus tear) were analyzed by one-way ANOVA and Chi-squared test. Binary Logistic regression was then performed based on the results of univariate analyses (independent variables of p < 0.2 were included).

RESULTS

Hyperextension, lateral meniscus tear, contralateral side pivot shift test grade, distal femoral condyle offset and KT measurement were identified as risk factors for preoperative pivot shift grade via logistic regression analysis.

CONCLUSION

The current study revealed that hyperextension, lateral meniscus tear, contralateral side pivot shift test grade, distal femoral condyle offset and anterior instability were associated with preoperative pivot shift grade. Patients with above factors that cannot be modified during surgery may need special consideration when ACL reconstruction is performed, as greater preoperative pivot shift has been proven to be a risk factor for residual pivot shift after ACL reconstruction.

LEVEL OF EVIDENCE

III.

Recovery of preoperative absolute knee extension and flexion strength after ACL reconstruction

Background

The recovery of muscle function after an Anterior Cruciate Ligament (ACL) reconstruction is most commonly reported as limb-to-limb differences using the Limb Symmetry Index (LSI), which is not free from limitations. The purpose of this study was to compare the proportion of patients who recover their Preoperative Absolute Muscle Strength (PAMS) 8 and 12 months after ACL reconstruction with the proportion of patients who recover their symmetrical knee strength. A secondary aim was to assess the relationship between psychological Patient-Reported Outcomes (PROs) and recovering PAMS at 8 and 12 months after ACL reconstruction and rehabilitation.

Method

Preoperative, 8- and 12-month results from quadriceps and hamstring strength tests and PROs for 117 patients were extracted from a rehabilitation registry. Individual preoperative peak torques from strength tests were compared with results from the 8- and 12-month follow-ups respectively. Patients were defined as having recovered their PAMS upon reaching 90% of their preoperative peak torque for both quadriceps and hamstring strength. Patients were defined as having recovered their LSI upon reaching a value ≥90% when comparing the results for their injured knee with those of their healthy knee. Correlations between the recovery of PAMS and PROs at 8 and 12 months were analyzed.

Results

There was no difference in the proportion of patients who recovered their PAMS compared with patients who recovered their LSI. In all, 30% and 32% of the patients who recovered their LSI had not recovered their PAMS at 8 months and 12 months respectively. In the patients who had recovered their PAMS, 24% and 31% had not recovered their symmetrical LSI at 8 months and 12 months respectively. There was no significant correlation between the recovery of PAMS and psychological PROs.

Conclusion

The use of both PAMS and LSI provides more detailed information on the recovery of muscle strength after ACL reconstruction. The recovery of PAMS was not correlated with psychological traits, which implies that both PROs and PAMS are important when evaluating patients after ACL reconstruction.

Trial registration

 This trial was not registered.

Anterior cruciate ligament studies in south-east asia over the past 10 years: A systematic review

Purpose

There was numerous articles that discussed about anterior cruciate ligament (ACL). There was no study that wrapped up all about ACL in South-east asia country. This study aims to apply bibliometric tools to orthopaedics publications on ACL in South-east asia country.

Methods

We searched English full text with keyword “ACL” OR “Anterior Cruciate Ligament” AND “injury” OR “tear” OR “rupture” that published from January 1st^, 2010 to December 31st^, 2019 on PubMed, EMBASE, and Cochrane Library. We included article with at least has one author affiliation in the South-east asia country.

Results

A total of 12,570 articles were analyzed, and 64 articles were included. Study type analysis revealed that clinical research (n = 28; 43.7%) was the most frequent study type. The journal of knee surgery, sports traumatology, arthroscopy (KSSTA) and Orthopaedic Journal of Sports Medicine had the highest number of publications in general (n = 6; 9.4%). Sholahuddin Rhatomy (n = 4) was the top author with highest number in the first author order and Lingaraj Krishna (n = 12) was the top author with highest number of published article. Most of studies (n = 32; 50.0%) were published in high index journal with impact factor >1.0.

Conclusion

ACL articles in South-east asia had high quality publication that proved by high impact journal publisher. There has been a steady increase in the article number since 2010 in South-east asia. This article quantifies the increased interest and could act as a baseline for future studies to compare.

•

Summarized the ACL publication in South-East Asia Country over the past 10 years.

•

There was high number of publication among knee surgeon in South-East Asia.

•

High impact factor journal publisher.

Meniscus or Cartilage Injury at the Time of Anterior Cruciate Ligament Tear Is Associated With Worse Prognosis for Patient-Reported Outcome 2 to 10 Years After Anterior Cruciate Ligament Injury: A Systematic Review

OBJECTIVES

(1) To assess prognostic factors for patient-reported outcome measures (PROMs) and physical activity 2 to 10 years after anterior cruciate ligament reconstruction (ACLR) or anterior cruciate ligament (ACL) injury, and (2) to assess differences in prognostic factors between patients treated with ACLR and with rehabilitation alone.

DESIGN

Prognosis systematic review.

LITERATURE SEARCH

Systematic searches were performed in PubMed, Web of Science, and SPORTDiscus.

STUDY SELECTION CRITERIA

We selected prospective cohort studies and randomized clinical trials that included adults or adolescents undergoing either ACLR or rehabilitation alone after ACL rupture. Studies had to assess the statistical association between potential prognostic factors (factors related to patient characteristics, injury, or knee symptoms/function measured at baseline or within 1 year) and outcomes (PROMs and physical activity).

DATA SYNTHESIS

Our search yielded 997 references. Twenty studies met the inclusion criteria. Seven studies with low or moderate risk of bias remained for data synthesis.

RESULTS

Moderate-certainty evidence indicated that concomitant meniscus and cartilage injuries were prognostic factors for worse PROMs 2 to 10 years after ACLR. Very low-certainty evidence suggested that body mass index, smoking, and baseline PROMs were prognostic factors for worse outcome. Very low-certainty evidence suggested that female sex and a worse baseline Marx Activity Rating Scale score were prognostic factors for a worse Marx Activity Rating Scale score 2 to 10 years after ACLR. There was a lack of studies on prognostic factors after rehabilitation alone.

CONCLUSION

Concomitant meniscus and cartilage injuries were prognostic factors for worse long-term PROMs after ACLR. The certainty was very low for other prognostic factors. J Orthop Sports Phys Ther 2020;50(9):490-502. Epub 1 Aug 2020. doi:10.2519/jospt.2020.9451.

Rates of revision and surgeon-reported graft rupture following ACL reconstruction: early results from the New Zealand ACL Registry

PURPOSE

There remains a lack of consensus on the patient factors associated with graft rupture following anterior cruciate ligament (ACL) reconstruction. This study aimed to identify the rate of revision and surgeon-reported graft rupture and clarify the patient risk factors for failure.

METHODS

Analysis was conducted on prospective data captured by the New Zealand ACL registry. All primary isolated ACL reconstructions recorded between April 2014 and December 2018 were reviewed to identify the rate of revision and surgeon-reported graft rupture. Univariate and multivariate survival analysis was performed to identify patient factors associated with revision and graft rupture.

RESULTS

A total of 7402 primary isolated ACL reconstructions were reviewed and had a mean follow-up time of 23.1 (SD ± 13.9) months. There were 258 surgeon-reported graft ruptures (3.5%) of which 175 patients underwent subsequent revision ACL reconstruction (2.4%). Patients younger than 18 years had the highest risk of revision (adjusted HR = 7.29, p < 0.001) and graft rupture (adjusted HR = 4.26, p < 0.001) when compared to patients aged over 36 years. Male patients had a higher risk of revision (adjusted HR = 2.00, p < 0.001) and graft rupture (adjusted HR = 1.70, p < 0.001) when compared to their female counterparts. Patients who underwent ACL reconstruction within 6 months of their injury had a two times increased risk of revision compared to patients who had surgery after 12 months (adjusted HR = 2.15, p = 0.016).

CONCLUSION

Younger age, male sex and a shorter injury-to-surgery time interval increased the risk of revision, while younger age and male sex increased the risk of surgeon-reported graft rupture.

LEVEL OF EVIDENCE

II.

Females Have Earlier Muscle Strength and Functional Recovery After Bridge-Enhanced Anterior Cruciate Ligament Repair

Background: While a sex effect on outcomes following anterior cruciate ligament (ACL) reconstruction surgery has been previously documented, less is known following bridge-enhanced ACL repair (BEAR). We hypothesized that female sex would have significantly worse early functional outcomes and higher retear rates following primary repair of the ACL enhanced with a tissue-engineered scaffold. Methods: Sixty-five patients (28 males and 37 females), age 14-35 with a complete ACL tear underwent primary repair of the ACL enhanced with a tissue-engineered scaffold (bridge-enhanced ACL repair) within 45 days of injury. International Knee Documentation Committee (IKDC) and Knee Injury and Osteoarthritis Outcome (KOOS) scores, as well as instrumented anteroposterior (AP) laxity through KT-1000 testing and functional outcome measures were obtained at time points up to 2 years postoperatively and compared between males and females using mixed model repeated measures analyses and chi square tests. Results: There was no significant sex difference on the postoperative IKDC Subjective Score at 3, 6, 12, or 24 months or any of the five KOOS scores at 12 and 24 months. Instrumented AP laxity testing demonstrated mean (standard deviation) side-to-side differences that were similar in the two sexes at 2 years; 1.7 (2.7) mm and 1.5 (3.7) mm in females and males, respectively, p = 0.72. At 6 months postoperatively, males had a larger deficit in hamstring strength on the operated leg (14.0% vs. 1.7%; p = 0.03) and a larger deficit in quadriceps strength on the operated leg (11.3% vs. 2.0%; p = 0.004); however, no sex difference was noted at 12 or 24 months. Females demonstrated superior single leg hop testing at 6 and 12 months ([91.3% vs. 78.1%, p = 0.001], [96.9% vs. 87.0%, p = 0.01] respectively). There were no significant sex differences on ipsilateral (males; 14.3% vs. females; 13.9%, p = 1.00) or contralateral (males; 3.6% vs. females; 2.8%, p = 1.00) ACL reinjury rates. Conclusions: Female subjects had better hamstring and quadriceps strength indices at 6 months than males as well as better hop test results at the 6 and 12-month time period. Despite this, there was no significant sex difference on patient-reported outcomes and objective AP laxity testing at time points up to 2 years postoperatively. Impact statement This is the first study comparing sex specific outcomes following the bridge-enhanced ACL repair technique (BEAR). The results of this study suggest that females have earlier recovery of both muscle strength and functional outcomes compared to their male counterparts. This is an important finding when considering future modifications to postoperative care and rehabilitation in females and males following this tissue-engineered BEAR technique.

The Affect of Patient Sex and Graft Type on Postoperative Functional Outcomes After Primary ACL Reconstruction

Background:

Graft choice in anterior cruciate ligament reconstruction (ACLR) and postoperative rehabilitation may affect strength recovery differently in men than women and therefore affect a timely and successful return to sport.

Purpose:

To compare knee extensor and flexor strength between men and women who underwent isolated ACLR with either patellar tendon or hamstring tendon (HST) autografts.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

A total of 166 patients (87 women, 79 men) with primary unilateral and uncomplicated ACLRs were recruited for participation. A total of 100 patients had bone–patellar tendon–bone (BPTB) autografts and 66 had HST autografts. At 6 months postoperatively, all patients completed the Tegner activity scale and International Knee Documentation Committee Subjective Knee Evaluation as well as underwent bilateral isokinetic (90 deg/s) tests of the knee extensor and flexor groups. Outcomes were recorded in a single session as part of a return-to-sport test battery. Surgical notes were obtained to determine the type of autograft and nerve block used at the time of ACLR.

Results:

There was a significant sex × graft type interaction for mass-normalized knee flexor torque (P = .017). Female patients with an HST graft had a significantly lower knee flexor torque compared with female patients with a BPTB graft (0.592 ± 0.49 N·m/kg vs 0.910 ± 0.24 N·m/kg; Cohen d [95% CI] = 0.91 [0.45, 1.36]). They also had a significantly lower knee flexor torque when compared with male patients with an HST graft (0.592 ± 0.49 N·m/kg vs 0.937 ± 0.35 N·m/kg; Cohen d [95% CI]= 0.88 [0.45, 1.31]). There were significant main effects for graft type with knee flexion (P = .001) and extension (P = .008) symmetry. Patients with a BPTB graft demonstrated lower knee extensor symmetry (65.7% ± 17.0%) and greater knee flexor symmetry (98.7% ± 18.0%) compared with patients with an HST graft (extension: 77.1% ± 32%, Cohen d [95% CI] = 0.47 [0.16, 0.79]; flexion: 82.9% ± 33.3%, Cohen d [95% CI] = 0.63 [0.31, 0.95]). We also observed a significant main effect for sex (P = .028) and graft type (P = .048) for mass-normalized knee extensor strength. Female participants and patients of either sex with BPTB grafts had lower knee extensor strength compared with male participants and patients with HST grafts, respectively.

Conclusion:

At approximately 6 months after ACLR, female patients reconstructed with HST autografts demonstrated weaker HST strength compared with female patients with a BPTB autograft. There were no differences in HST strength between graft types in male patients. Female patients appear to be recovering HST strength differently than male patients when using an HST autograft. These findings may have implications in surgical planning, postoperative rehabilitation, and return-to-sport decision making.

Greater medial tibial slope is associated with increased anterior tibial translation in females with an ACL-deficient knee

PURPOSE

The purpose of the study was to determine the correlation between medial tibial slope (MTS) and anterior tibial translation (ATT) in female patients with an ACL-deficient knee. It was hypothesized that female patients with a greater medial tibial slope had an increased anterior tibial translation compared to males.

METHODS

MTS and ATT were analysed in 276 patients (138 females and 138 males) with a complete ACL rupture from 2012 to 2016. The mean age was 32 ± 12 years. Previous surgery or additional ligament injury was excluded. CT scan was used for measuring MTS. Meniscal findings were reported. Anterior tibial translation and side to side difference (SSD) were measured by bilateral Telos™ stress radiography with knee flexion of 20°.

RESULTS

There was no significant difference in ATT between females (5.4 ± 3.9) and males (5.8 ± 4.2), nor was there a difference in MTS between females (9.8 ± 2.8) and males (9.8 ± 2.7). A positive correlation was found between MTS and ATT absolute (r = 0.35, p < 0.001) and side to side difference (r = 0.12, p = 0.03). MTS greater or equal to 11° significantly increased the ATT (p < 0.05). For each degree of increase of the MTS, increases in ATT absolute of 0.6 mm and SSD of 0.18 mm were observed. Greater MTS was identified as a risk factor for an increase of ATT in females (r = 0.37, p < 0.001) but not in males (r = - 0.1, n.s). Increases of 1° of MTS increased ATT 0.57 mm in female patients (p < 0.001). MTS was influential in ATT despite the presence (r = 0.28 [0.11, 0.44], p = 0.001) or absence (r = 0.48 [0.35, 0.6], p < 0.001) of meniscal lesions.

CONCLUSIONS

Greater medial tibial slope is associated with increased anterior tibial translation in females with ACL-deficient knees compared to males, despite the presence or absence of meniscal lesions. This could be due to a quadriceps/hamstring imbalance in females and the ability of the hamstring muscles to moderate ATT.

LEVEL OF EVIDENCE

III.

Physical prognostic factors predicting outcome following anterior cruciate ligament reconstruction: protocol for a systematic review

INTRODUCTION

Injuries of the anterior cruciate ligament (ACL) are a common musculoskeletal complication and can cause significant reduction in patient function and quality of life. Many undergo ACL reconstruction, with high-quality rehabilitation key to successful outcome. Knowledge of physical prognostic factors, such as quadriceps strength, is crucial to inform rehabilitation and has important implications for outcome following ACL reconstruction. However, these factors predicting outcome are poorly defined. Therefore, the aim of this systematic review is to establish physical prognostic factors predictive of outcome in adults following ACL reconstruction. Outcome will be subdivided into two groups of outcome measures, patient-reported and performance-based. Physical prognostic factors of interest will reflect a range of domains and may be modifiable/non-modifiable. Results will help decide most appropriate management and assist in planning and tailoring preoperative and postoperative rehabilitation.

METHODS AND ANALYSIS

This systematic review protocol is reported according to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols. MEDLINE, CINAHL and EMBASE databases, key journals and grey literature will be searched from inception to July 2019. Prospective cohort studies including participants aged ≥16 years who have undergone ACL reconstruction will be included, with articles focusing on multi-ligament reconstructions and ACL repair surgery, or not published in English excluded. Two independent reviewers will conduct searches, assess study eligibility, extract data, assess risk of bias (Quality in Prognostic Studies tool) and quantify overall quality of evidence (modified Grading of Recommendations, Assessment, Development and Evaluation guidelines). If possible, a meta-analysis will be conducted, otherwise a narrative synthesis will ensue focusing on prognostic factors, risk of bias of included studies and strength of association with outcomes.

ETHICS AND DISSEMINATION

Findings will be published in a peer-reviewed journal, presented at conferences and locally to physiotherapy departments. Ethical approval is not required for this systematic review.

PROSPERO REGISTRATION NUMBER

CRD42019127732.

Knee Extension Deficit in the Early Postoperative Period Predisposes to Cyclops Syndrome After Anterior Cruciate Ligament Reconstruction: A Risk Factor Analysis in 3633 Patients From the SANTI Study Group Database

BACKGROUND

Cyclops syndrome is characterized by a symptomatic extension deficit attributed to impingement of a cyclops lesion within the intercondylar notch. The syndrome is an important cause of reoperation after anterior cruciate ligament reconstruction (ACLR). It has been suggested that remnant-preserving ACLR techniques may predispose to cyclops syndrome, but there is very limited evidence to support this. In general terms, risk factors for cyclops syndrome are not well-understood.

PURPOSE

To determine the frequency of and risk factors for reoperation for cyclops syndrome in a large series of patients after ACLR.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

A retrospective analysis of prospectively collected data was performed, including all patients who underwent primary ACLR between January 2011 to December 2017. Patients undergoing major concomitant procedures were excluded. Demographic data, intraoperative findings (including the size of preserved remnants), and postoperative outcomes were recorded. Those patients who underwent reoperation for cyclops syndrome were identified, and potential risk factors were evaluated in multivariate analysis.

RESULTS

A total of 3633 patients were included in the study, among whom 65 (1.8%) underwent reoperation for cyclops syndrome. Multivariate analysis demonstrated that preservation of large remnants did not predispose to cyclops lesions (odds ratio [OR], 1.11; 95% CI, 0.63-1.93). The most important risk factor was extension deficit in the early postoperative period. If present at 3 weeks postoperatively, it was associated with a >2-fold increased risk of cyclops syndrome (OR, 2.302; 95% CI, 1.268-4.239; P < .01), which was increased to 8-fold if present 6 weeks after ACLR (OR, 7.959; 95% CI, 4.442-14.405; P < .0001). None of the other potential risk factors evaluated were found to be significantly associated with an increased frequency of cyclops syndrome.

CONCLUSION

Failure to regain full extension in the early postoperative period was the only significant risk factor for cyclops syndrome after ACLR in a large cohort of patients. Other previously hypothesized risk factors, such as preservation of a large anterior cruciate ligament remnant, did not predispose to the development of this debilitating postoperative complication.

Return to Sport Tests' Prognostic Value for Reinjury Risk after Anterior Cruciate Ligament Reconstruction: A Systematic Review

INTRODUCTION

Return to sports (RTS) clearance after anterior cruciate ligament (ACL) reconstruction typically includes multiple assessments. The ability of these tests to assess the risk of a reinjury remains unknown.

PURPOSE

To assess and rate RTS self-reported function and functional tests on prognostic value for reinjury risk after ACL reconstruction and RTS.

STUDY DESIGN

Systematic review on level 2 studies.

METHODS

PubMed, Web of Knowledge, Cochrane Library, and Google Scholar databases were searched for articles published before March 2018. Original articles in English or German that examined reinjury risks/rates after primary (index) ACL injury, ACL reconstruction, and RTS were included. All RTS functional tests used in the included studies were analyzed by retrieving an effect size with predictive value (odds ratio, relative risk (risk ratio), positive predictive value, positive likelihood ratio, or hazard rate).

RESULTS

A total of 276 potential studies were found; eight studies (moderate to high quality) on 6140 patients were included in the final analysis. The reinjury incidence recorded in the included studies ranged from 1.5% to 37.5%. Four studies reported a combination of isokinetic quadriceps strength at different velocities and a number of hop tests as predictive with various effect sizes. One reported isokinetic hamstring to quadriceps ratio (hazard rate = 10.6) as predictive. Two studies reported functional questionnaires (knee injury and osteoarthritis outcome score and Tampa Scale of Kinesiophobia-11; RR = 3.7-13) and one study showed that kinetic and kinematic measures during drop vertical jumps were predictive (odds ratio, 2.3-8.4) for reinjury and/or future revision surgery.

CONCLUSIONS

Based on level 2 evidence, passing a combination of functional tests with predetermined cutoff points used as RTS criteria is associated with reduced reinjury rates. A combination of isokinetic strength and hop tests is recommended during RTS testing.

High Risk of Further Anterior Cruciate Ligament Injury in a 10-Year Follow-up Study of Anterior Cruciate Ligament-Reconstructed Soccer Players in the Swedish National Knee Ligament Registry

PURPOSE

To follow up on soccer players 10 years after a primary anterior cruciate ligament (ACL) reconstruction to find out how many players returned to play soccer, what influenced their decision, and if there are any differences in additional ACL injuries (graft failure and/or contralateral ACL injury) between those who returned to play and those who did not.

METHODS

The study cohort consists of 1661 soccer players from the Swedish National Knee Ligament Registry. A questionnaire was sent to each player regarding their return to play and additional knee injuries that may have occurred 10 years after their primary ACL. The results are based on the 684 responders. Data such as age, sex, surgical procedural data, associated injuries, patient-reported outcome measures, and additional knee surgeries were collected from the registry.

RESULTS

In this study, 51% returned to play soccer. For those who did not return to play, the primary reason was knee related (65.4% of the cases). The most common knee-related reasons for not returning were pain and/or instability (50%; n = 109), followed by fear of reinjury (32%; n = 69). Players who return to soccer have a significantly higher risk of additional ACL injury. Of the players who returned to play soccer, 28.7% (odds ratio [OR] 2.3, P < .001) had additional ACL injury, 9.7% (OR 2.9, P < .001) had a graft failure and 20.6% (OR 2.1, P < .001) had a contralateral ACL injury.

CONCLUSIONS

Players that return to soccer have a significantly higher risk of sustaining further ACL injury. Only half of the soccer players return to play after ACL reconstruction, and in two-thirds of those who did not return, the reason was knee related. The high risk of sustaining additional knee injury is of serious concern to the player's future knee health and should be considered when deciding on a return to play.

LEVEL OF EVIDENCE

Level III retrospective case-control study.

Japanese Orthopaedic Association (JOA) clinical practice guidelines on the management of anterior cruciate ligament injury - Secondary publication

BACKGROUND

This clinical guideline presents recommendations for the management of patients with anterior cruciate ligament (ACL) injury, endorsed by the Japanese Orthopaedic Association (JOA) and Japanese Orthopaedic Society of Knee, Arthroscopy and Sports Medicine (JOSKAS).

METHODS

The JOA ACL guideline committee revised the previous guideline based on "Medical Information Network Distribution Service Handbook for Clinical Practice Guideline Development 2014", which proposed a desirable method for preparing clinical guidelines in Japan. Furthermore, the importance of "the balance of benefit and harm" was also emphasized. This guideline consists of 21 clinical questions (CQ) and 23 background questions (BQ). For each CQ, outcomes from the literature were collected and evaluated systematically according to the adopted study design.

RESULTS

We evaluated the objectives and results of each study in order to make a decision on the level of evidence so as to integrate the results with our recommendations for each CQ. For BQ, the guideline committee proposed recommendations based on the literature.

CONCLUSIONS

This guideline is intended to be used by physicians, orthopedic surgeons, physical therapists, and athletic trainers managing ACL injuries. We hope that this guideline is useful for appropriate decision-making and improved management of ACL injuries.

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.

Trends in Recurrent Anterior Cruciate Ligament Injuries Differ From New Anterior Cruciate Ligament Injuries in College and High School Sports: 2009-2010 Through 2016-2017

Background:

Knee injuries are common and result in extended time missed from sports participation. Little is known regarding the comparative characteristics of recurrent versus first-time anterior cruciate ligament (ACL) injuries sustained during athletic events and how they are influenced by sex, sports participation level, and game-time features.

Purpose:

To evaluate the characteristics (sex, sports level, and game timing [ie, early vs late in the game]) of recurrent ACL injury in National Collegiate Athletic Association (NCAA) and high school athletes compared with first-time ACL injury.

Study Design:

Descriptive epidemiology study.

Methods:

Athletic trainers reported ACL injury occurrences and characteristics for collegiate athletes during the 2009-2010 through 2016-2017 academic years and for high school athletes during the 2011-2012 through 2013-2014 academic years. Logistic regression was used to estimate odds ratios (ORs) and 95% CIs for recurrent versus first-time ACL injury. The number of ACL injuries, proportions, and ORs were calculated by sex, competition level, and time in game played. Results were also classified according to injury mechanism: noncontact, overuse, or surface contact.

Results:

A total of 705 ACL injuries were reported, including 644 first-time injures and 61 recurrent injuries. When restricting to noncontact ACL injuries, 416 were reported (373 first-time injuries and 43 recurrent injuries). The odds of a recurrent versus new ACL injury in NCAA student-athletes were 4.6 times that of high school student-athletes (95% CI, 1.41-15.24; P = .01). When restricting to noncontact ACL injuries, the odds of a recurrent versus new ACL injury during postseason and preseason were 4.5 and 2.8 times that during the regular season, respectively. Athletes in limited-contact and noncontact sports had greater odds of a recurrent versus new ACL injury compared with athletes playing football and other contact and collision sports. There was no significant difference in the odds of a recurrent ACL injury by sex or time in game.

Conclusion:

Based on the current study, the odds of recurrent ACL injuries are associated with the level of competition but not associated with sex or timing of game play. Determinants of reinjury after primary ACL reconstruction will help advance care for young injured athletes who continue to participate in competitive sports.

Incidence and risk factors for cyclops syndrome after anterior cruciate ligament reconstruction: A systematic literature review

BACKGROUND

Cyclops syndrome after anterior cruciate ligament (ACL) reconstruction is due to a fibrous nodule that develops in the anterior part of the intercondylar notch and prevents full knee extension. The primary objective of this systematic literature review was to evaluate the incidence of symptomatic cyclops lesion after ACL reconstruction. The secondary objective was to identify risk factors for cyclops syndrome.

HYPOTHESIS

Cyclops syndrome is common after ACL reconstruction and has several risk factors reported in the literature.

METHODS

A systematic literature review was performed by searching the PubMed, Medline, CINAHL, Cochrane, and Embase databases with the key terms 'cyclops' and 'ACL reconstruction'. The data thus retrieved were evaluated independently by two investigators. All articles in English or French that reported the incidence and risk factors of cyclops syndrome after ACL reconstruction were included.

RESULTS

The search retrieved the titles and abstracts of 79 articles, of which 20 were selected to be read in full; among these, 10 were included in the study. The incidence of symptomatic cyclops lesion ranged from 1.9% to 10.9%. Identified risk factors were as follows: pre-operatively, knee inflammation and/or motion restriction at the time of ACL reconstruction; intra-operatively, narrow intercondylar notch and excessively anterior position of the tibial tunnel; and post-operatively, persistent hamstring muscle spasm.

DISCUSSION

Development of a cyclops lesion is common after ACL reconstruction, occurs early, and may require further surgery. The knowledge of the risk factors provided by this study may improve the ability to devise effective preventive measures.

LEVEL OF EVIDENCE

II, systematic literature review.

Effects of a functional lower extremity fatigue protocol and a 5-minute recovery period on the performance of a single leg hop test for distance in healthy participants

BACKGROUND

Hop tests evaluate lower extremity sport-specific performance after various interventions and as predictors of injury. The purpose of this study was to investigate the effect of a functional low-cost fatigue protocol and a 5-minute post fatigue recovery on the single-leg hop test for distance (SLHD) in healthy young adult college students, including a between-gender comparison.

METHODS

Sixty young healthy adults (37 male-23 female), without any musculosketal complaints or previous injury or surgery in any of their lower limbs, participated in the experiment. Three practice trials were initially performed, followed by three pre-fatigue formal trials of the SLHD. After the fatigue protocol, three more trials were conducted prior to a 5-min recovery period, followed by another 3 trials. The reliability of the non-fatigued SLHD was also tested in a random sample of the cohort.

RESULTS

Test-retest reliability was high (ICC2,3=0.91, SEM=7.9 cm). Mean decrease in performance between pre-fatigue and post-fatigue values was statistically significant for the whole group (-6.4%) and the male (-7.1%), however not the female participants. Mean increase between post-fatigue and 5-minute recovery trials, however, was significant for all (14.7%), as well as for the male (17.5%) and female (10.2%) participants. The 5-minute recovery trials were significantly increased even compared to the pre-fatigue trials for the whole group (6.6%) and the male participants (8.5%).

CONCLUSIONS

The particular fatigue protocol moderately affected SLHD values, mostly for the male participants of the population recruited. Mean increase between prefatigue and 5-minute postfatigue recovery data can be accounted mainly by post-activation potentiation.

Dynamic knee control and movement strategies in athletes and non-athletes in side hops: Implications for knee injury

Athletes exposed to rapid maneuvers need a high level of dynamic knee stability and robustness, while also controlling whole body movement, to decrease the risk of non-contact knee injury. The effects of high-level athletic training on such measures of movement control have not, however, been thoroughly evaluated. This study investigated whether elite athletes (who regularly perform knee-specific neuromuscular training) show greater dynamic knee robustness and/or different movement strategies than non-athletic controls, in relation to overall knee function. Thirty-nine women (19 athletes, 20 controls) performed standardized rebound side hops (SRSH) while a motion capture system synchronized with two force plates registered three-dimensional trunk, hip, and knee joint angles and moments. Dynamic knee robustness was evaluated using finite helical axis (FHA) inclination angles extracted from knee rotation intervals of 10°, analyzed with independent t tests. Angle and moment curves were analyzed with inferential methods for functional data. Athletes had superior knee function (less laxity, greater hop performances, and strength) but presented similar FHA inclination angles to controls. Movement strategies during the landing phase differed; athletes presented larger (a) hip flexion angles (during 9%-29% of the phase), (b) hip adduction moments (59%-99%), (c) hip internal rotation moments (83%-89%), and (d) knee flexion moments (79%-93%). Thus, elite athletes may have a greater ability than non-athletes to keep the knee robust while performing SRSH more efficiently through increased engagement of the hip. However, dynamic knee robustness associated with lower FHA inclination angles still show room for improvement, thus possibly decreasing knee injury risk.

Wrist Flexion Exercise Increases the Width of the Medial Elbow Joint Space During a Valgus Stress Test

OBJECTIVES

The medial elbow is stabilized during valgus loading by the ulnar collateral ligament, the flexor pronator mass (FPM), and the radial head. Impairment of the FPM can occur as a result of repeated wrist flexion activity. The purpose of this study was to determine the effect of repeated elbow flexion exercise on medial elbow stability.

METHODS

Thirty volunteers were included in this study. Ultrasound images of the medial joint space of the nondominant elbow of the participants were collected during a valgus stress test. The images were collected before and immediately after a wrist flexion exercise protocol.

RESULTS

The wrist flexion strength measure decreased (7.5%) after the exercise protocol (t = 3.840; P = .001). The medial elbow width increased between unstressed (mean ± SD, 2.8 ± 0.1 mm) and stressed (3.6 ± 0.1 mm) conditions (P < .001). The stress-by-fatigue interaction was significant (P = .048). The medial elbow width increased after fatigue (0.9 ± 0.09 mm) while remaining unchanged in the unstressed condition.

CONCLUSIONS

This study found an effect of repeated wrist flexion exercise on decreasing the stability of the medial elbow. Future research needs to explore the mechanisms leading to the decrease in medial elbow stability and to identify the effect of FPM fatigue on the development of medial elbow pain associated with activities.

Demographic and surgical factors affect quadriceps strength after ACL reconstruction

PURPOSE

To investigate the effects of graft source, time since surgery, age, and sex on unilateral and symmetry-based measures of knee extension strength among individuals with ACL reconstruction (ACLR).

METHODS

Three hundred and eight individuals aged 13-40 years old with primary, unilateral ACLR in the last 60 months were enrolled in this multi-site clinical measurement study. Participants completed bilateral knee extension maximal voluntary isometric contraction (MVIC) torque assessments which were normalized to body mass (Nm/kg) and limb symmetry indices (LSI) were calculated. The effects of graft source (patellar tendon autograft; hamstring tendon autograft), time since surgery (≤ 12 months; >12 mo.), age (≤ 18 years; >18 years), and sex were evaluated using separate ANCOVAs.

RESULTS

A significant interaction was present between time since surgery and graft source for LSI (P = 0.01) as participants with patellar tendon autografts ≤ 12 months post-ACLR experienced the greatest asymmetry (LSI = 69.2 ± 24.5%). Significant interactions were present between time since surgery and sex for involved limb (P = 0.01) and uninvolved limb MVIC torque (P = 0.05) with females ≤ 12 months post-ACLR being weakest (involved MVIC = 1.81 ± 0.70 N m/kg; uninvolved MVIC = 2.40 ± 0.68 N m/kg). Participants ≤ 18-year-old displayed weaker involved limb (P < 0.001) and contralateral limb (P < 0.001) MVIC torque as compared to participants > 18-year-old during the first year after ACLR.

CONCLUSIONS

Graft source, sex, age, and time since surgery effect quadriceps strength and symmetry after ACLR. Surgical and demographic factors should be considered when developing treatment approaches to optimize quadriceps function prior to re-integration into pre-injury levels of physical activity.

LEVEL OF EVIDENCE

IV.

Cross-education does not improve early and late-phase rehabilitation outcomes after ACL reconstruction: a randomized controlled clinical trial

PURPOSE

Limited evidence suggests that cross-education affords clinical benefits in the initial 8 weeks after anterior cruciate ligament (ACL) reconstruction, but it is unknown if such cross-education effects are reproducible and still present in later phases of rehabilitation. We examined whether cross-education, as an adjuvant to standard therapy, would accelerate the rehabilitation up to 26 weeks after ACL reconstruction by attenuating quadriceps weakness.

METHODS

ACL-reconstructed patients were randomized into experimental (n = 22) and control groups (n = 21). Both groups received standard care after ACL reconstruction. In addition, the experimental group strength trained the quadriceps of the non-operated leg during weeks 1-12 after surgery (i.e., cross-education). Self-reported knee function was assessed with the Hughston Clinic Knee score as the primary outcome. Secondary outcomes were maximal quadriceps and hamstring strength and single leg hop distance. All outcomes were measured 29 ± 23 days prior to surgery, as a reference, and at 5-week, 12-week, and 26-week post-surgery.

RESULTS

Both groups scored 12% worse on self-reported knee function 5-week post-surgery (95% CI 7-17) and showed 15% improvement 26-week post-surgery (95% CI - 20 to - 10). No cross-education effect was found. Interestingly, males scored 8-10% worse than females at each time point post-surgery. None of 33 secondary outcomes showed a cross-education effect. At 26-week post-surgery, both legs improved maximal quadriceps (5-14%) and hamstring strength (7-18%), and the non-injured leg improved 2% in hop distance. The ACL recovery was not affected by limb dominance and age.

CONCLUSION

26 weeks of standard care improved self-reported knee function and maximal leg strength relative to pre-surgery and adding cross-education did not further accelerate ACL recovery.

LEVEL OF EVIDENCE

I.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION

This randomized controlled clinical trial is registered at the Dutch trial register ( http://www.trialregister.nl ) under NTR4395.

Quadriceps Strength and Volitional Activation After Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-analysis

Context:

Quadriceps function is a significant contributor to knee joint health that is influenced by central and peripheral factors, especially after anterior cruciate ligament reconstruction (ACLR).

Objective:

To assess differences of unilateral quadriceps isometric strength and activation between the involved limb and contralateral limb of individuals with ACLR and healthy controls.

Data Sources:

Web of Science, SportDISCUS, PubMed, CINAHL, and the Cochrane Database were all used during the search.

Study Selection:

A total of 2024 studies were reviewed. Twenty-eight studies including individuals with a unilateral history of ACLR, isometric knee extension strength normalized to body mass, and quadriceps activation measured by central activation ratios (CARs) through a superimposed burst technique were identified for meta-analysis. The methodological quality of relevant articles was assessed using a modified Downs and Black scale. Results of methodological quality assessment ranged from low to high quality (low, n = 10; moderate, n = 8; high, n = 10).

Study Design:

Meta-analysis.

Level of Evidence:

Level 2.

Data Extraction:

Means, standard deviations, and sample sizes were extracted from articles, and magnitude of between-limb and between-group differences were evaluated using a random-effects model meta-analysis approach to calculate combined pooled effect sizes (ESs) and 95% CIs. ESs were classified as weak (d < 0.19), small (d = 0.20-0.49), moderate (d = 0.50-0.79), or large (d > 0.80).

Results:

The involved limb of individuals with ACLR displayed lower knee extension strength compared with the contralateral limb (ES, –0.78; lower bound [LB], –0.99; upper bound [UB], –0.58) and healthy controls (ES, –0.76; LB, –0.98; UB, –0.53). The involved limb displayed a lower CAR compared with healthy controls (ES, –0.84; LB, –1.18; UB, –0.50) but not compared with the contralateral limb (ES, –0.15; LB, –0.37; UB, 0.07). The ACLR contralateral limb displayed a lower CAR (ES, –0.73; LB, –1.39; UB, –0.07) compared with healthy control limbs but similar knee extension strength (ES, –0.24; LB, –0.68; UB, –0.19).

Conclusion:

Individuals with ACLR have bilateral CAR deficits and involved limb strength deficits that persist years after surgery. Deficits in quadriceps function may have meaningful implications for patient-reported and objective outcomes, risk of reinjury, and long-term joint health after ACLR.

5-Year Survival of Pediatric Anterior Cruciate Ligament Reconstruction With Living Donor Hamstring Tendon Grafts

BACKGROUND

It is well accepted that there is a higher incidence of repeat anterior cruciate ligament (ACL) injuries in the pediatric population after ACL reconstruction (ACLR) with autograft tissue compared with adults. Hamstring autograft harvest may contribute to the risk for repeat ACL injuries in this high functional demand group. A novel method is the use of a living donor hamstring tendon (LDHT) graft from a parent; however, there is currently limited research on the outcomes of this technique, particularly beyond the short term.

PURPOSE/HYPOTHESIS

The purpose was to determine the medium-term survival of the ACL graft and the contralateral ACL (CACL) after primary ACLR with the use of an LDHT graft from a parent in those aged less than 18 years and to identify factors associated with subsequent ACL injuries. It was hypothesized that ACLR with the use of an LDHT provides acceptable midterm outcomes in pediatric patients.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Between 2005 and 2014, 247 (of 265 eligible) consecutive patients in a prospective database, having undergone primary ACLR with the use of an LDHT graft and aged less than 18 years, were included. Outcomes were assessed at a minimum of 2 years after surgery including data on ACL reinjuries, International Knee Documentation Committee (IKDC) scores, and current symptoms, as well as factors associated with the ACL reinjury risk were investigated.

RESULTS

Patients were reviewed at a mean of 4.5 years (range, 24-127 months [10.6 years]) after ACLR with an LDHT graft. Fifty-one patients (20.6%) sustained an ACL graft rupture, 28 patients (11.3%) sustained a CACL rupture, and 2 patients sustained both an ACL graft rupture and a CACL rupture (0.8%). Survival of the ACL graft was 89%, 82%, and 76% at 1, 2, and 5 years, respectively. Survival of the CACL was 99%, 94%, and 86% at 1, 2, and 5 years, respectively. Survival of the ACL graft was favorable in patients with Tanner stage 1-2 at the time of surgery versus those with Tanner stage 3-5 at 5 years (87% vs 69%, respectively; hazard ratio, 3.7; P = .01). The mean IKDC score was 91.7. A return to preinjury levels of activity was reported by 59.1%.

CONCLUSION

After ACLR with an LDHT graft from a parent in those aged less than 18 years, a second ACL injury (ACL graft or CACL injury) occurred in 1 in 3 patients. The 5-year survival rate of the ACL graft was 76%, and the 5-year survival rate of the CACL was 86%. High IKDC scores and continued participation in sports were maintained over the medium term. Importantly, there was favorable survival of the ACL graft in patients with Tanner stage 1-2 compared with patients with Tanner stage 3-5 over 5 years. Patients with Tanner stage 1-2 also had a significantly lower incidence of second ACL injuries over 5 years compared with those with Tanner stage 3-5, occurring in 1 in 5 patients. Thus, an LDHT graft from a parent is an appropriate graft for physically immature children.

Greater Laxity in the Anterior Cruciate Ligament-Injured Knee Carries a Higher Risk of Postreconstruction Pivot Shift: Intraoperative Measurements With a Navigation System

BACKGROUND

The presence of pivot shift after anterior cruciate ligament (ACL) reconstruction is correlated with worse clinical outcomes. An orthopaedic navigation system is a useful tool for quantifying laxity in the ACL-deficient knee.

PURPOSE

To investigate the relationship between preoperative knee laxity measured by a navigation system and postoperative pivot shift (PPS) after ACL reconstruction.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

One hundred patients who underwent primary ACL reconstruction (62 hamstring tendon grafts, 38 patellar tendon grafts) were grouped according to the presence or absence of pivot shift at the 2-year follow-up, and the groups were compared retrospectively. Before surgery, knee laxity was assessed with a navigation system to quantify posterior tibial reduction (PTR) during pivot-shift tests and anterior tibial translation (ATT) during Lachman tests. PTR and ATT cutoff values were determined by receiver operator characteristic (ROC) analysis.

RESULTS

Preoperative PTR and ATT were significantly larger for patients with PPS (PPS-positive group) than those without (PPS-negative group). In the ROC analysis, the PTR had an area under the curve of 0.871 (95% CI, 0.763-0.979; P < .0001) for predicting a PPS; this was larger than that obtained for the ATT, which had an area under the curve of 0.825 (95% CI, 0.705-0.946; P = .001). Because the ROC curve of the ATT had 2 peaks, the ATT alone was not a suitable predictor for PPS. Based on the ROC curve, the optimal PTR cutoff value was 7 mm, with 88.9% sensitivity and 71.4% specificity for PPS (adjusted odds ratio = 19.7; 95% CI, 2.1-187.9; P = .009). Setting the cutoff value as a combination of the PTR (≧7 mm) and ATT (≧12 mm) improved the specificity (88.9% sensitivity and 84.6% specificity; adjusted odds ratio = 149.8; 95% CI, 5.9-3822.7; P = .002) over that with the PTR alone.

CONCLUSION

ACL injuries in knees with a large PTR had a higher risk of PPS. When reconstructing the ACL in a knee with a high degree of laxity, surgeons may need to adopt strategies to prevent PPS.

Ten-Year Risk Factors for Inferior Knee Injury and Osteoarthritis Outcome Score After Anterior Cruciate Ligament Reconstruction: A Study of 874 Patients From the Swedish National Knee Ligament Register

BACKGROUND

Factors relating to the patient and anterior cruciate ligament (ACL) reconstruction may help to identify prognostic factors of long-term outcome after reconstruction.

PURPOSE

To determine 10-year risk factors for inferior knee function after ACL reconstruction.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Prospectively collected data from the Swedish National Knee Ligament Register were extracted for patients who underwent ACL reconstruction between January 2005 and December 2006. Patients who had no data at the 10-year follow-up for the Knee injury and Osteoarthritis Outcome Score (KOOS) were excluded. Multivariable proportional odds regression modeling was used to assess 10-year patient- and surgery-related risk factors across all the KOOS subscales and the KOOS₄ (mean score of 4 subscales: pain, knee-related symptoms, function in sport and recreation, and knee-related quality of life).

RESULTS

A total of 874 (41%) patients were included (male, 51.5%; median age at the time of ACL reconstruction, 27.5 years [range, 11.2-61.5 years]). An increase in the severity of concomitant articular cartilage injuries resulted in a reduced KOOS on 4 subscales (odds ratio, 0.64-0.80; P < .05). A higher preoperative KOOS pain score increased the odds of a higher score on the pain, symptoms, and sport subscales and the KOOS₄. In addition, a higher preoperative body mass index was a significant risk factor for lower scores on 3 KOOS subscales and the KOOS₄. No patient- or surgery-related predictor was significant across all KOOS subscales.

CONCLUSION

This 10-year risk factor analysis identified several factors that can affect long-term knee function after ACL reconstruction. Most risk factors were related to preoperative patient-reported outcome and potentially modifiable. On the other hand, most of the surgery-related risk factors were nonmodifiable. Nevertheless, this information may be helpful to physicians and physical therapists counseling patients on their expectations of outcome after ACL reconstruction.

Patient Characteristics and Predictors of Return to Sport at 12 Months After Anterior Cruciate Ligament Reconstruction: The Importance of Patient Age and Postoperative Rehabilitation

Background:

Preventing and mitigating the risk of reinjury after anterior cruciate ligament reconstruction (ACLR) rest on variables including age, surgical restoration of knee stability, adequate physical function, and thorough and complete postoperative rehabilitation, but to what degree these factors influence return to sport is unclear.

Purpose:

To investigate factors predictive of return to sport 12 months after ACLR. The factors specifically evaluated were strength, hop function, self-reported knee function, patient age, and quality of postoperative rehabilitation.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

This study evaluated 113 patients approximately 12 months after ACLR using a rehabilitation grading tool, the subjective International Knee Documentation Committee (IKDC) form, and a return-to-sport battery consisting of maximal isokinetic quadriceps and hamstring strength and 4 functional hop tests. Mann-Whitney U tests and chi-square analyses were used to determine differences between patients who had or had not returned to sport. A subsequent binary logistic hierarchical regression determined the factors predictive of a patient’s return to sport. In those patients who had returned to sport, relationships between either age or level of rehabilitation and passing the return-to-sport battery were also investigated.

Results:

Complete rehabilitation (adjusted odds ratio [OR], 7.95; P = .009), age ≤25 years (adjusted OR, 3.84; P = .024), and higher IKDC scores (P < .001) were predictive of return to sport at 12 months. In participants who had returned to sport, 21% passed the return-to-sport battery compared with only 5% who did not. Of those who had returned to sport, 37% who underwent complete rehabilitation passed the return-to-sport battery as opposed to 5% who underwent incomplete rehabilitation. In patients aged ≤25 years, only 48% underwent complete rehabilitation, despite having returned to sport. Additionally, in this group of patients, 40% underwent complete rehabilitation and passed the physical performance battery as opposed to only 4% who did not undergo complete rehabilitation.

Conclusion:

Younger patients and higher subjective IKDC scores were predictive of return to sport. Patients who completed 6 months of rehabilitation incorporating jumping and agility tasks had a higher rate of return to sport, suggesting that postoperative rehabilitation is important in predicting return to sport. Specialists and physical therapists alike should stress the importance of thorough postoperative rehabilitation and adequate neuromuscular strength and function to patients whose goals are to return to sport.

Combined Tibial Tubercle Osteotomy and Medial Patellofemoral Ligament Reconstruction for Recurrent Lateral Patellar Instability in Patients With Multiple Anatomic Risk Factors

PURPOSE

To report the outcomes for combined tibial tubercle osteotomy (TTO) and medial patellofemoral ligament (MPFL) reconstruction and assess for potential risk factors for recurrent instability and/or poor outcomes.

METHODS

The medical record at our institution was reviewed for patients treated with MPFL reconstruction and TTO for recurrent lateral patellar instability from 1998 to 2014. Preoperative imaging was assessed for trochlear dysplasia according to the Dejour classification (high grade = B, C, D) and the presence of patella alta using the Caton-Deschamps ratio (>1.2). The indication for combined MPFL reconstruction and TTO was MPFL insufficiency and a lateralized tibial tubercle. Outcomes were determined by recurrent instability, return to sport, and Kujala and International Knee Documentation Committee (IKDC) scores.

RESULTS

Thirty knees in 28 patients (14 M, 14 F) with a mean age of 22.6 ± 9.1 years (range, 13-51 years) were included with a mean follow-up of 48 ± 28 months (24-123 months). Seventy-three percent (22/30) had high-grade trochlear dysplasia, and 63% (19/30) had patella alta. One patient had a postoperative dislocation and 1 had a subluxation event. The Caton-Deschamps ratio decreased by a mean of 0.2 (P = .001), leaving 30% with postoperative patella alta. The mean postoperative scores were as follows: Tegner = 5 ± 2, Kujala = 89 ± 16 (45-100), and IKDC = 85 ± 17 (44-100). Eighty-three percent (15/18) returned to their preoperative sport. Female gender was a risk factor for lower IKDC (77.3 vs. 92.6, P = .01) and Kujala (82.2 vs. 95.0, P = .03) scores. Medialization greater than 10 mm was directly correlated to lower IKDC (P = .02) and Kujala (P = .01) scores.

CONCLUSIONS

The combination of MPFL reconstruction and TTO in patients with trochlear dysplasia results in low recurrence of instability. Patients on average had good subjective outcomes and were able to return to sport. Female gender and tibial tubercle medialization greater than 10 mm were associated with worse outcomes.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Factors associated with additional anterior cruciate ligament reconstruction and register comparison: a systematic review on the Scandinavian knee ligament registers

Objective

To present an overview of the Scandinavian knee ligament registers with regard to factors associated with additional ACL reconstruction, and studies comparing the Scandinavian registers with other knee ligament registers.

Design

Systematic review.

Data sources

Four electronic databases: PubMed, EMBASE, the Cochrane Library and AMED were searched, and 157 studies were identified. Two reviewers independently screened titles, abstracts and full-text studies for eligibility. A modified version of the Downs and Black checklist was applied for quality appraisal.

Eligibility criteria for selecting studies

Eligible studies were those published since the establishment of the Scandinavian registers in 2004, which reported factors associated with additional ACL reconstruction and compared data from other registers.

Results

Thirty-one studies met the inclusion criteria and generally displayed good reporting quality. Adolescent age (<20 years) was the most common factor associated with additional ACL reconstruction. The choice of hamstring tendon graft compared with patella tendon, transportal femoral tunnel drilling, smaller graft diameter and utilisation of suspensory fixation devices were associated with additional ACL reconstruction. Concomitant cartilage injury decreased the likelihood of additional ACL reconstruction. Patient sex alone did not influence the likelihood. The demographics of patients undergoing ACL reconstruction in the Scandinavian registers are comparable to registers in other geographical settings. However, there are differences in surgical factors including the presence of intra-articular pathology and graft choice.

Summary

The studies published from the Scandinavian registers in general have a high reporting quality when regarded as cohort studies. Several factors are associated with undergoing additional ACL reconstruction. The results from the registers may help facilitate treatment decisions.

Sex Differences in the Residual Patellar Tendon After Harvesting Its Central Third for Anterior Cruciate Ligament Reconstruction

OBJECTIVES

Some studies have found that sex can affect the clinical results after anterior cruciate ligament reconstruction. We hypothesized that sex would significantly affect the healing of the postoperative patellar tendon. This study evaluated the patellar tendon after bone-patellar tendon-bone autograft harvest, specifically with regard to sex-dependent differences.

METHODS

At 6 months postoperatively, an ultrasonographic evaluation was performed. We measured the residual donor site gap width between tendon tissues and the thickness of newly formed nontendinous tissue in the gap. In addition, the cross-sectional area of tendon tissue was measured. The ratios between the operated and contralateral sides were calculated, and the sexes were compared. A paired Student t test was performed, with P < .05 considered statistically significant.

RESULTS

The population of 52 patients (32 male and 20 female) had a mean age ± SD of 23 ± 8 years. We observed no significant sex-dependent differences in the residual donor site gap and the thickness of newly formed nontendinous tissue when calculating ratios to the contralateral tendon. The mean cross-sectional area of tendon tissue was 101 ± 26 mm² (male, 114 ± 26 mm² ; female, 80 ± 16 mm² ). When the ratios to the contralateral tendon were calculated, male patients had significantly higher cross-sectional area ratios than female patients (male, 124% ± 20%; female, 100% ± 19%, P = .024).

CONCLUSIONS

We have reported a dramatic increase in the cross-sectional area of patellar tendon tissue during the first 6 months after anterior cruciate ligament reconstruction with a bone-patellar tendon-bone autograft, which was more prominent in male patients than in female patients. This difference might have contributed to the sex-dependent variation in clinical outcomes.