Relationships between objective assessment of ligament stability and subjective assessment of symptoms and function after anterior cruciate ligament reconstruction

Diagnosis and treatment of anterior cruciate ligament injuries: Consensus of Chinese experts part II: Graft selection and clinical outcome evaluation

Background

In the recent decade, there has been substantial progress in the technologies and philosophies associated with diagnosing and treating anterior cruciate ligament (ACL) injuries in China. The therapeutic efficacy of ACL reconstruction in re-establishing the stability of the knee joint has garnered widespread acknowledgment. However, the path toward standardizing diagnostic and treatment protocols remains to be further developed and refined.

Objective

In this context, the Chinese Association of Orthopaedic Surgeons (CAOS) and the Chinese Society of Sports Medicine (CSSM) collaboratively developed an expert consensus on diagnosing and treating ACL injury, aiming to enhance medical quality through refining professional standards.

Methods

The consensus drafting team invited experts across the Greater China region, including the mainland, Hong Kong, Macau, and Taiwan, to formulate and review the consensus using a modified Delphi method as a standardization approach. As members of the CSSM Lower Limb Study Group and the CAOS Arthroscopy and Sports Medicine Study Group, invited experts concentrated on two pivotal issues: "Graft Selection" and "Clinical Outcome Evaluation" during the second part of the consensus development.

Results

This focused discussion ultimately led to a strong consensus on nine specific consensus terms.

Conclusion

The consensus clearly states that ACL reconstruction has no definitive "gold standard" graft choice. Autografts have advantages in healing capability but are limited in availability and have potential donor site morbidities; allografts reduce surgical trauma but incur additional costs, and there are concerns about slow healing, quality control issues, and a higher failure rate in young athletes; synthetic ligaments allow for early rehabilitation and fast return to sport, but the surgery is technically demanding and incurs additional costs. When choosing a graft, one should comprehensively consider the graft's characteristics, the doctor's technical ability, and the patient's needs. When evaluating clinical outcomes, it is essential to ensure an adequate sample size and follow-up rate, and the research should include patient subjective scoring, joint function and stability, complications, surgical failure, and the return to sport results. Medium and long-term follow-ups should not overlook the assessment of knee osteoarthritis.

Young men undergoing anterior cruciate ligament reconstruction with patellar tendon autograft and anteromedial drilling outperform at 5- to 10-year follow-up in terms of graft stability and activity levels compared to those undergoing reconstruction with hamstring autograft and transtibial drilling

OBJECTIVE

To compare 5- to 10-year outcomes of anterior cruciate ligament (ACL) reconstruction in young men performed with bone-patellar tendon bone (BPTB) autograft and anteromedial portal to reconstruction with hamstring autograft and transtibial technique. It was hypothesised that in young adult men, at 5- to 10-year follow-up, superior restoration of knee laxity and activity levels would be demonstrated using BPTB autograft and anteromedial portal technique.

METHODS

Ninety-four men who had ACL reconstruction with BPTB autograft and anteromedial portal were eligible for comparison to 106 men who had reconstruction with hamstring autograft and transtibial technique. Inclusion criteria were: (1) age 18-35 years, (2) ACL tear caused by sports trauma only, (3) no concomitant ligament reconstruction and (4) 5- to 10-year follow-up. Outcome measures compared between the two groups included Lachman and pivot shift tests, KT side-to-side difference, Tegner and Marx scores, International Knee Documentation Committee (IKDC)-subjective score, Knee Osteoarthritis Outcome Scale (KOOS), Short Form (SF)-36, and single hop test for distance. P value ​< ​0.05 indicated statistical significance.

RESULTS

Forty-five patients with BPTB and 55 patients with hamstring ACL reconstruction were available for in-person assessment at 5-10 years after surgery. Outcomes in the BPTB group compared to the hamstring group showed KT difference 1.4 ​± ​1.9 mm vs. 2.8 ​± ​2.3 mm (p ​< ​0.01), pivot shift grade 2-3 in 4% vs. 34% (p ​< ​0.01), return to preinjury Tegner level in 51% vs. 36% (p ​= 0.1) and to preinjury Marx score in 29% vs. 11% (p ​= 0.02), and IKDC-subjective 88 ​± ​10 vs. 82 ​± ​13 vs (p ​< ​0.01), respectively. Statistically significant inter-relationships were found between KT side-to-side difference and the Tegner, Marx and IKDC-subjective scores at follow-up (r ​= ​-0.314, p ​< ​0.01; r ​= ​-0.263, p ​< ​0.01; r ​= ​-0.218, p ​= ​0.03, respectively).

CONCLUSION

Young men undergoing ACL reconstruction with patellar tendon autograft and anteromedial drilling outperform at 5- to 10-year follow-up in terms of graft stability and activity levels compared to young men undergoing reconstruction with hamstring autograft and transtibial drilling.

LEVEL OF EVIDENCE

III (Retrospective cross-sectional comparative study).

Serial Assessment of Factors Associated With Patient-Reported Outcomes up to 2 Years After ACL Reconstruction Using Autologous Hamstring Tendon: Results From the TMDU MAKS Study

Background

Understanding the factors related to patient-reported outcomes (PROs) after anterior cruciate ligament reconstruction (ACLR) can lead to more effective interventions.

Purpose/Hypothesis

The purpose of this study was to identify factors associated with PRO scores after ACLR. It was hypothesized that concomitant meniscal treatment and postoperative range of motion (ROM) would be associated with early postoperative PRO scores and that postoperative physical findings would be associated with 2-year postoperative PRO scores.

Study Design

Cohort study; Level of evidence, 2.

Methods

We examined the data from the Tokyo Medical and Dental University Multicenter Arthroscopic Knee Surgery (TMDU MAKS) Study for patients who underwent primary ACLR with autologous hamstring tendon grafts; 1252 patients in the TMDU MAKS Study were eligible for inclusion. The International Knee Documentation Committee (IKDC) subjective score, Knee injury and Osteoarthritis Outcome Score (KOOS), and Lysholm score of the patients at 3 months (n = 675), 1 year (n = 660), and 2 years (n = 375) postoperatively were assessed using multiple regression to evaluate the strength of the relationship between PRO scores and the following predictor variables: patient-specific factors, treatment-specific factors, and physical findings.

Results

Improvement in all PROs significantly exceeded the minimal important change at 1 and 2 years postoperatively. Older age and female sex were predictive of lower PRO scores up to 2 years postoperatively. Concurrent meniscal treatment and limited range of knee motion were predictive of lower PRO scores at 3 months and 1 year postoperatively. A tighter knee (ie, less anterior translation) on the injured side compared with the contralateral knee was predictive of lower KOOS-Quality of Life and IKDC scores at 2 years postoperatively. At all 3 postoperative time points, greater side-to-side difference in knee ROM was predictive of lower PRO scores.

Conclusion

Inferior PRO scores were associated with concomitant meniscal treatment and limited postoperative ROM until 1 year postoperatively and with older age and female sex up to 2 years postoperatively. PRO scores were associated with knee stability at all assessed time points.

Subjective grade of apprehension during the pivot-shift test reflects patient-reported outcomes more than conventional pivot-shift test grade after ACL reconstruction

PURPOSE

To investigate whether the pivot-shift test reflects patient-reported outcomes 1 year after anterior cruciate ligament (ACL) reconstruction based on a multicentre prospective cohort study.

METHODS

This study included patients who underwent primary ACL reconstruction using the hamstring tendons. The pivot-shift test grades were determined according to the International Knee Documentation Committee (IKDC) form as 0, 1+, 2+ or 3+. In addition, patients' subjective apprehension during the pivot-shift test were classified as 0 (no-apprehension), 1+ (mild-apprehension), 2+ (moderate-apprehension) or 3+ (severe-apprehension). In this study, a positive pivot-shift test was defined as grade 1+ or higher.

RESULTS

A total of 837 patients were enroled in this study. One year postoperatively, there was no significant difference in the Knee injury and Osteoarthritis Outcome Score (KOOS), IKDC score, Lysholm knee scale and Tegner activity scale between the positive (118 patients) and negative (719 patients) groups of the conventional IKDC grading of the pivot-shift test. However, when divided into two groups based on the apprehension grading of the pivot-shift test after surgery, the postoperative scores were significantly lower in the apprehension-positive group (114 patients) than those in the apprehension-negative group (723 patients) on the Tegner activity scale and KOOS Symptom, Sports/Rec and Quality of Life subscales.

CONCLUSIONS

Patients' subjective apprehension during the pivot-shift test after ACL reconstruction was significantly associated with the postoperative Tegner activity scale and three subscales of the KOOS. However, there was no association between the conventional IKDC grading of the pivot-shift test and any patient-reported outcomes postoperatively.

LEVEL OF EVIDENCE

Level II.

Steep medial posterior tibial slope angle and ramp lesion are independent risk factors for an increase in quantitatively measured pivot shift in patients with ACL-deficient knees

Background

Delayed anterior cruciate ligament (ACL) reconstruction often causes residual anterolateral rotatory instability (ALRI) and consequent knee osteoarthritis, warranting the recommendation of early ACL reconstruction within 6 months after injury. Nonetheless, some cases show notable instability, even shortly after injury. The purpose of this study was to identify risk factors for an increase in quantitatively measured pivot shift in patients with ACL-deficient knees within 6 months after injury.

Methods

Patients with primary ACL reconstruction within 6 months after injury and quantitative triaxial accelerometer measurements of preoperative pivot shift were included. Descriptive statistics were calculated for 11 independent variables (age, gender, time from injury to surgery, KT-1000, knee extension angle, lateral and medial posterior tibial slope angle, medial and lateral meniscus tears, ramp lesion and Tegner active scale). A single regression analysis was performed on the 11 items and acceleration during the pivot shift, and a multiple regression analysis was performed for items with p value less than 0.1.

Results

Overall, 111 patients met the inclusion criteria. Single regression analysis showed that medial posterior tibial slope angle, medial meniscus tear and ramp lesion were significantly correlated with acceleration during the pivot shift (p < 0.001, p = 0.04 and p = 0.001). Multiple regression analysis identified medial posterior tibial slope angles and ramp lesions as independent factors for increased preoperative pivot shift (p = 0.005 and 0.01).

Conclusion

A steep medial posterior tibial slope angle and ramp lesion were independent risk factors for increased quantitatively measured pivot shift in patients with ACL-deficient knees.

Level of Evidence

Level IV, case series study.

A High Grade of Postoperative Knee Laxity Is Associated With an Increased Hazard of Revision Surgery: A Cohort Study of 4697 Patients With Primary ACL Reconstruction

BACKGROUND

There is still debate regarding the association between arthrometric knee laxity measurements and subjective knee outcome and revision surgery after primary anterior cruciate ligament reconstruction (ACLR).

PURPOSE

To assess whether arthrometric knee laxity (measured with the KT-1000 arthrometer) 6 months after primary ACLR was associated with the 1-, 2-, and 5-year subjective knee outcomes or revision ACLR at a 5-year follow-up.

STUDY DESIGN

Cohort study, Level of evidence 3.

METHODS

Patients who underwent primary ACLR with a hamstring tendon autograft at the authors' institution between January 1, 2005, and December 31, 2017, with no concomitant ligamentous injuries, were identified. Anterior knee laxity (KT-1000 arthrometer, 134 N) was assessed 6 months postoperatively. The Knee injury and Osteoarthritis Outcome Score (KOOS) was collected preoperatively and 1, 2, and 5 years postoperatively. Patients who underwent revision ACLR at any institution in the country within 5 years of primary surgery were identified through the Swedish National Knee Ligament Registry.

RESULTS

A total of 4697 patients (54.3% male) with available KT-1000 arthrometer measurements were included (normal: side-to-side [STS] ≤2 mm, 3015 [64.2%]; nearly normal: STS 3-5 mm, 1446 [30.8%]; abnormal: STS >5 mm, 236 [5.0%]). The only significant difference in subjective knee outcome between the groups was for the KOOS Symptoms subscale at the 1-year follow-up (STS ≤2 mm, 79.9 ± 16.2; STS 3-5 mm, 82.5 ± 14.8; STS >5 mm, 85.1 ± 14.2; P < .001). No other significant differences between the groups were found preoperatively or at 1, 2, or 5 years postoperatively for any of the KOOS subscales. The hazard for revision ACLR within 5 years of the primary surgery was significantly higher for the groups with an STS of 3 to 5 mm (6.6%; 95/1446) (hazard ratio [HR], 1.42; 95% CI, 1.07-1.87; P = .01) and an STS >5 mm (11.4%; 27/236) (HR, 2.61; 95% CI, 1.69-4.03; P < .001) compared with the group with an STS ≤2 mm (3.8%; 116/3015).

CONCLUSION

A high grade of postoperative knee laxity (STS 3-5 mm and STS >5 mm) 6 months after primary ACLR was associated with an increased hazard of revision ACLR within 5 years, but it was not associated with an inferior subjective knee outcome.

Wearable sensor systems measure differences in knee laxity between healthy and affected knees during dynamic exercise activities: A systematic review

Purpose

Knee laxity can be experienced as knee instability which may lead to a limitation in the activity of patients. Current methods to determine knee instability are performed in a static setting, which does not always correlate with dynamic knee laxity during activities. Wearables might be able to measure knee laxity in a dynamic setting and could be of added value in the diagnosis and treatment of excessive knee laxity. Therefore, the aim of this systematic review is to provide an overview of the wearables that have been developed and their ability to measure knee laxity during dynamic activities.

Methods

The PRISMA guidelines for systematic reviews were followed. A literature search was conducted in EMBASE, PubMed and Cochrane databases. Included studies assessed patients with knee instability using a non-invasive wearable sensor system during dynamic activity, with comparison to a reference system or healthy knees. Data extraction was performed by two authors via a predefined format. The risk of bias was assessed by The Dutch checklist for diagnostic tests.

Results

A total of 4734 articles were identified. Thirteen studies were included in the review. The studies showed a great variety of patients, sensor systems, reference tests, outcome measures and performed activities. Nine of the included studies were able to measure differences in patients with knee instability, all including a tri-axial accelerometer. Differences were not measurable in all parameters and activities in these studies.

Conclusions

Wearables, including at least a tri-axial accelerometer, seem promising for measuring dynamic knee laxity in the anterior-posterior and mediolateral direction. At this stage, it remains unclear if the measured outcomes completely reflect the knee instability that patients experience in daily life.

Level of Evidence

Level III.

Clinical Outcomes of Modified Suture Buttons for Tibial Side Fixation in Anterior Cruciate Ligament Reconstruction: A Retrospective Comparative Study

Introduction Restoring knee joint stability and resuming sports activities are important objectives of anterior cruciate ligament (ACL) reconstruction. The maintenance of anterior knee stability after ACL reconstruction is contingent on graft tension. Various devices and techniques have been used to achieve robust tibial graft tendon fixation, and their advantages and disadvantages are established. However, a gold standard has not been established. Therefore, we aimed to determine whether anterior knee joint stability and clinical outcomes of graft tendon fixation could be improved using a recently modified suture button (MSB) compared with using an adjustable suspensory fixator (ASF) at 1 year after double-bundle ACL reconstruction. Methods This study retrospectively analyzed postoperative data derived from 79 patients at a single center between January 2016 and December 2021. The patients were assigned to groups that underwent double-bundle ACL reconstruction with tibial fixation using an MSB (n = 30) that maintains tension while tying sutures, or an ASF (n = 49). We then compared complications, clinical outcomes and knee joint stability at 1 year postoperatively. Rates of postoperative infection, graft rupture, implant removal and residual anterior knee laxity (AKL) were compared between the groups using chi-square tests. Patient-reported outcome measures (PROM) based on Forgot Joint Score-12, Knee Injury and Osteoarthritis Outcome, and Lysholm Knee scores were compared using Mann-Whitney U tests. Results One patient in the MSB group developed postoperative infection. Rates of graft rupture and implant removal in the MSB and ASF groups were 3.3% and 4.1%, and 3.6% and 10.2%, respectively. None of the PROMs differed between the groups. The proportions of postoperative AKL were 3.6% and 14.9% in the MSB and ASF groups, respectively. A trend towards lower postoperative AKL in the MSB group did not reach statistical significance (p = 0.25). Conclusions The incidence of AKL at a year after ACL reconstruction using the MSB was 3%. Postoperative AKL and clinical outcomes were comparable between the MSB and ASF groups. A low AKL rate and positive postoperative outcomes indicated that MSB could be an option for tibial-side fixation in ACL reconstruction.

Anterior Cruciate Ligament-Injured Knees With Meniscal Ramp Lesions Manifest Greater Anteroposterior and Rotatory Instability Compared With Isolated Anterior Cruciate Ligament-Injured Knees

PURPOSE

To investigate the effects of ramp lesion (RL) and its repair on knee instability in patients with anterior cruciate ligament (ACL) injury by quantitatively assessing anteroposterior and rotational knee instability before and after ACL reconstruction.

METHODS

All primary double-bundle ACL reconstructions using hamstring autografts between 2016 and 2021 were evaluated retrospectively. Patients with RLs without other meniscal injuries were included in group R, whereas those with isolated ACL injuries constituted group C. RL was repaired using all-inside devices in all patients in group R. Knee instability, including the amount of anterior tibial translation (ATT), and the acceleration and external rotational angular velocity of the knee joint (ERAV) during the pivot-shift test were assessed at the time of surgery. The pivot-shift test grade was recorded.

RESULTS

A total of 73 patients were included in this study. Preoperatively, group R (n = 23) had significantly greater pivot-shift grades (P = .039), ATT (6.0 mm, group R; 4.5 mm, group C, P < .001), acceleration (6.8, 2.8; P = .037), and ERAV (3.9, 2.8; P = .001) than group C (n = 50). Intraoperatively, ATT (-1.0 mm, -1.0 mm; P < .001), acceleration (1.2, 1.1; P < .001), and ERAV (1.4, 1.2; P < .001) were significantly decreased compared with the preoperative values in both groups. No significant differences in these values were observed between groups R and C.

CONCLUSIONS

ACL-injured knees accompanied by RLs exhibited significantly greater anteroposterior and rotatory instability than knees with isolated ACL injuries; increased knee instability can be effectively addressed by performing RL repair in conjunction with ACL reconstruction. The quantitative assessments employed-specifically measuring ATT, acceleration, and ERAV during the pivot-shift test-have allowed us to delineate these aspects of knee instability with greater precision.

LEVEL OF EVIDENCE

Level Ⅲ, retrospective comparative study.

Association Between MRI Signal Intensity of the Repaired Lateral Meniscus and Residual Anterolateral Knee Laxity After ACL Reconstruction

Background

Anterolateral knee laxity (ALLx) has been linked to tears of the lateral meniscus (LM) and anterior cruciate ligament (ACL) injury.

Purpose

To investigate the longitudinal relationship between the signal intensity (SI) of the repaired LM on magnetic resonance imaging (MRI) and residual ALLx after ACL reconstruction (ACLR).

Study Design

Cohort study; Level of evidence, 3.

Methods

Included were 87 patients who underwent double-bundle ACLR and lateral meniscal repair (mean age, 23.5 years; body mass index, 23.7 kg/m2; 56 women) at a single institution between 2010 and 2019. Proton density-weighted (PDW) and T2-weighted (T2W) MRI was performed at 3, 6, and 12 months postoperatively, and the SI ratio (SIR) was calculated as (SI of the repaired LM)/(SI of the posterior cruciate ligament). At the 12-month follow-up, ALLx was evaluated using the pivot-shift test; an International Knee Documentation Committee grade ≥1 indicated residual ALLx.

Results

Overall, 12 patients (13.8%) exhibited ALLx at 12 months postoperatively. At 3 months postoperatively, the SIR on PDW images (SIR-PDW) was significantly higher in patients with ALLx versus those without ALLx (1.98 ± 0.77 vs 1.49 ± 0.52, respectively; P = .007); there was no difference in the SIR on T2W images between the groups. SIR-PDW at 3 months postoperatively was correlated negatively with patient age (r = -0.308, P = .004). When patients were stratified into a younger (≤22 years; n = 53; ALLx = 7 [13.2%]) and an older (>22 years; n = 34; ALLx = 5 [14.7%]) group, the area under the receiver operating characteristic curves (AUCs) for SIR-PDW in the younger group were statistically significant for predicting the prevalence of ALLx at all follow-up times (AUCs, 0.733-0.788) with optimal cutoff values of 2.00 at 3 months, 1.50 at 6 months, and 1.50 at 12 months. Logistic regression analysis revealed that if younger patients consistently had higher SIR-PDW values than the cutoff values, they were more likely to have residual ALLx (odds ratios, 10.24-23.57).

Conclusion

For younger patients who underwent both ACLR and lateral meniscal repair, higher MRI SI of the repaired LM was associated with a higher prevalence of residual ALLx.

Factors Associated With Residual Pivot Shift After ACL Reconstruction: A Quantitative Evaluation of the Pivot-Shift Test Preoperatively and at Minimum 12-Month Follow-up

Background

Postoperative residual rotatory laxity remains despite improvement in surgical techniques for anterior cruciate ligament (ACL) reconstruction (ACLR).

Purpose

To evaluate factors associated with residual pivot shift after ACLR by quantitative measurement of the pivot shift before and after surgery.

Study Design

Case-control study; Level of evidence, 3.

Methods

A total of 97 patients who underwent primary double-bundle ACLR between June 2016 and March 2021 and underwent surgery to remove staples, with at least 12 months of follow-up evaluation, were enrolled. Quantitative measurements were performed under general anesthesia immediately before ACLR (preoperatively), after temporary fixation of the ACL graft (intraoperatively), and immediately before staple removal (postoperatively). The laxity of pivot shift was assessed using inertial sensors to measure acceleration and external rotational angular velocity (ERAV). Descriptive data were assessed for associations with postoperative acceleration and ERAV in a univariate analysis. A multiple linear regression analysis was performed to identify factors associated with postoperative acceleration and ERAV.

Results

Anterior tibial translation, acceleration, and ERAV increased from intra- to postoperatively (P < .05). Factors significantly associated with postoperative acceleration were age (β = -0.238; P = .021), lateral posterior tibial slope (PTS) (β = 0.194; P = .048), and preoperative acceleration (β = 0.261; P = .008). Factors significantly affecting postoperative ERAV were age (β = -0.222; P = .029), ramp lesions (β = 0.212; P = .027), and preoperative ERAV (β = 0.323; P = .001).

Conclusion

Greater preoperative laxity in the pivot shift was the factor having the most significant association with residual pivot shift after ACLR using quantitative measurements under general anesthesia. Younger age, higher lateral PTS, and concomitant ramp lesions were significant predictors of residual pivot shift. These findings can help pre- and intraoperative decision-making regarding whether an anterolateral structure augmentation should be added.

Must a Knee with Anterior Cruciate Ligament Deficiency and High-grade Pivot Shift Test Present an Increase in Internal Rotation?

Objective:  Rupture of the anterior cruciate ligament (ACL) is one of the most common injuries in athletes and is often associated with damage to anterolateral structures. This combination of injuries presents itself clinically as a high-grade pivot shift test. The hypothesis of this study is that patients with ACL deficiency and high-grade pivot shift test should have an increased internal knee rotation. Methods:  Twenty-two patients were tested. After effective spinal anesthesia, two tests were performed with the patient in supine position. First, the bilateral pivot shift test was performed manually, and its grade was recorded. Then, with the knee flexed to 90 degrees, the examiner drew the projection of the foot in a neutral position and in maximum internal rotation, and the angle of internal rotation was measured from the axes built between the central point of the heel and the hallux. Results:  In the ACL-deficient knee, it was observed that there is a statistically significant average internal rotation (IR) delta of 10.5 degrees between the groups when not adjusted for age, and 10.6 degrees when adjusted for age. Conclusions:  Knees with ACL deficiency and with pivot shift test grade I do not show increased internal rotation in relation to knees with intact ACL. Knees with ACL deficiency and with pivot shift test grades II and III show increased internal rotation in comparison to healthy knees.

The Role of Anterolateral Ligament Reconstruction or Lateral Extra-articular Tenodesis for Revision Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-analysis of Comparative Clinical Studies

BACKGROUND

After its success in restoring rotational stability and reducing failure rates in primary anterior cruciate ligament reconstruction (ACLR), lateral extra-articular tenodesis (LET) or anterolateral ligament reconstruction (ALLR) has been endorsed for use in revision ACLR surgery, where failure rates are historically higher.

PURPOSE

To perform a systematic review and meta-analysis on whether the addition of a LET or ALLR results in superior clinical outcomes and stability compared with isolated revision ACLR (iACLR).

STUDY DESIGN

Meta-analysis; Level of evidence, 4.

METHODS

The Cochrane Controlled Register of Trials, PubMed, Medline, and Embase were used to perform a systematic review and meta-analysis of comparative studies using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) criteria with the following search terms: ("extra-articular" OR "tenodesis" OR "anterolateral ligament" OR "iliotibial") AND ("anterior cruciate ligament") AND ("revision" OR "re-operation"). Data pertaining to all patient-reported outcome measures (PROMs), rotational stability, and postoperative complications were extracted from each study.

RESULTS

After abstract and full-text screening, 10 clinical comparative studies were included. There were 793 patients, of whom 390 had an iACLR while 403 had an ACLR augmented with a LET or an ALLR (augmented ACLR [aACLR]). The mean time for assessment of PROMs was 35 months. The aACLR group had superior International Knee Documentation Committee (IKDC) scores (standardized mean difference [SMD], 0.27; 95% CI, 0.01 to 0.54; P = .04), rotational stability (odds ratio [OR], 2.77; 95% CI, 1.91 to 4.01; P < .00001), and lower side-to-side difference (OR, -0.53; 95% CI, -0.81 to -0.24; P = .0003) than those without the augmentation. Furthermore, they were less likely to fail (OR, 0.44; 95% CI, 0.24 to 0.80; P = .007). Subgroup analysis in the higher-grade laxity cohort (grade ≥2) revealed an even greater IKDC score (SMD, 0.51; 95% CI, 0.16 to 0.86; P = .005) and an improved Lysholm score (SMD, 0.45; 95% CI, 0.24 to 0.67; P < .0001) in the aACLR group.

CONCLUSION

Revision aACLR with a LET or an ALLR can improve subjective IKDC scores, restore rotational stability, and reduce failure rates compared with iACLR. Although controversy remains on the necessity of augmenting all revision ACLRs, the present meta-analysis advocates adding a lateral procedure, particularly in those with a higher-grade pivot shift.

Conservative Treatment Using Platelet-Rich Plasma for Acute Anterior Cruciate Ligament Injuries in Highly Active Patients: A Retrospective Survey

Background The recommended treatment for anterior cruciate ligament (ACL) injuries in active, sports-oriented patients is reconstructive surgery in order to regain stability and prevent secondary meniscal injuries. However, ACL reconstruction requires a long recovery period and poses issues such as decreased muscle strength due to tendon harvesting and postoperative osteoarthritis (OA) progression, thereby raising significant expectations for the advancement of conservative treatments. Recent studies have shown that platelet-rich plasma (PRP) therapy, which utilizes the tissue repair-promoting property of platelets, is effective for ACL injuries. Methods We administered PRP therapy within six weeks after ACL injury in patients who expressed the desire for an early return to sports through conservative care. After the treatment, patients wore a simple brace that limited deep flexion but placed no restrictions on weight bearing. Four months was the standard goal established for returning to pre-injury condition, and, depending on the target level, timing, and knee condition, we adjusted the additional PRP treatments and rehabilitation approach, gradually authorizing the patients' return to sport. We assessed the ligament repair status by magnetic resonance imaging (MRI) just before the full return to sports. A retrospective survey was conducted to evaluate the status of ligament repair and the condition of return-to-sport in patients with ACL injuries who underwent conservative treatment using PRP. Results The average patient age was 32.7 years and the average treatment was 2.8 PRP sessions. MRI evaluations confirmed that ligament continuity was regained in all cases. All the patients returned to their pre-injury level (Tegner Activity Scale 7.0) in an average of 139.5 days, but there was one instance of re-rupture following the return to sports. Conclusion All patients with ACL injury who underwent PRP therapy regained ligament continuity and returned to sport successfully with only one case of re-rupture.

Optimising the Early-Stage Rehabilitation Process Post-ACL Reconstruction

Outcomes following anterior cruciate ligament reconstruction (ACLR) need improving, with poor return-to-sport rates and a high risk of secondary re-injury. There is a need to improve rehabilitation strategies post-ACLR, if we can support enhanced patient outcomes. This paper discusses how to optimise the early-stage rehabilitation process post-ACLR. Early-stage rehabilitation is the vital foundation on which successful rehabilitation post-ACLR can occur. Without high-quality early-stage (and pre-operative) rehabilitation, patients often do not overcome major aspects of dysfunction, which limits knee function and the ability to transition through subsequent stages of rehabilitation optimally. We highlight six main dimensions during the early stage: (1) pain and swelling; (2) knee joint range of motion; (3) arthrogenic muscle inhibition and muscle strength; (4) movement quality/neuromuscular control during activities of daily living (5) psycho-social-cultural and environmental factors and (6) physical fitness preservation. The six do not share equal importance and the extent of time commitment devoted to each will depend on the individual patient. The paper provides recommendations on how to implement these into practice, discussing training planning and programming, and suggests specific screening to monitor work and when the athlete can progress to the next stage (e.g. mid-stage rehabilitation entry criteria).

Concomitant Lateral Meniscus Tear is Associated with Residual Rotatory Knee Instability 1 Year after Anterior Cruciate Ligament Reconstruction: Case-cohort Study

Lateral meniscus tear (LMT) accompanied by anterior cruciate ligament (ACL) injuries has been reported to provoke rotatory instability of the affected knee joint. Unfortunately, these previous papers did not determine whether LMT-derived rotatory knee instability is residual because only preoperative or time zero data exists. This study aimed to longitudinally investigate how the prevalence of comorbid LMT is associated with residual rotatory knee instability (RKI) 1 year after ACL reconstruction (ACLR). A total of 327 patients who underwent double-bundle ACLR (average age: 23.4 years, body mass index: 23.5 kg/m2, 215 females). The patients were divided into three groups based on arthroscopy: 1) intact lateral meniscus (LM); 2) unrepaired LMT; 3) repaired LMT. At the 1-year follow-up, the pivot-shift test was performed. The prevalence of RKI, determined according to IKDC grades (grade ≥1 denoted RKI), was compared with chi-square or Fisher's exact tests. Thirty-eight patients (11.6%) had RKI; 203 subjects (62.1%) showed LMT, and 124 patients were diagnosed with an intact LM. Out of the 203 patients, 79 (38.9%) underwent LM repair. RKI was more prevalent in the LMT group than in the intact group (13.8% versus 8.1%, p = 0.117; Odds ratio: 1.499 [95%CI: 0.864 - 2.600]). In addition, the prevalence of RKI was significantly higher in the LM-repair group than in the intact-LM group (17.7% versus 8.1%, p = 0.038; Odds Ratio: 2.455 [95%CI: 1.032 - 5.842]). Medial meniscus tear (MMT) was detected in 113 patients (34.6%); RKI prevalence was not statistically different between the intact-MM group and the MMT group (12.2% versus 10.6%, p = 0.681). The current cohort study clarified that LMT comorbid with ACL injury was longitudinally associated with increased RKI prevalence 1 year after ACLR. Therefore, patients who underwent both ACLR and LM repair demonstrated a significantly higher prevalence of residual RKI.

Modified Lemaire Lateral Extra-Articular Tenodesis Using an Inlay Technique and All-Suture Knotless Anchor Fixation

Appreciation of persistent anterolateral rotatory instability and graft failure after anterior cruciate ligament (ACL) reconstruction procedures has led surgeons to adopt the addition of lateral extra-articular tenodesis (LET) in both the revision and primary setting. Multiple techniques have been shown to eliminate anterolateral rotatory instability and reduce forces on the ACL graft, which has translated to lower re-rupture rates and improved patient outcomes. The risk of ACL/LET tunnel convergence can potentially compromise the fixation of one or both graft reconstructions. This article describes a technique for LET fixation which minimizes the depth of the LET femoral bone socket and utilizes low-profile implants thus mitigating this risk.

Greater Knee Rotatory Instability After Posterior Meniscocapsular Injury Versus Anterolateral Ligament Injury: A Proposed Mechanism of High-Grade Pivot Shift

Background

For anterolateral rotatory instability as a result of secondary soft tissue injuries in anterior cruciate ligament (ACL)-deficient knees, there is increasing interest in secondary stabilizers to prevent internal rotation (IR) of the tibia.

Purpose

To determine which secondary stabilizer is more important in anterolateral rotatory instability in ACL-deficient knees.

Study Design

Controlled laboratory study.

Methods

The lower extremities of 10 fresh-frozen cadavers (20 extremities) without anterior-posterior or rotational instability were included. Matched-pair randomization was performed, with each side per specimen assigned to 1 of 2 groups. In group 1, the ACL was sectioned, followed by the anterolateral ligament (ALL); in group 2, the ACL was sectioned, followed by sequential sectioning of the posterolateral meniscocapsular complex (PLMCC) and posteromedial meniscocapsular complex (PMMCC). The primary outcome was the change in relative tibial IR during a simulated pivot-shift test with 5 N·m of IR torque and 8.9 N of valgus force. The secondary outcomes were the International Knee Documentation Committee grade in the pivot-shift test and the incidence of the grade 3 pivot shift.

Results

In group 1, compared with baseline, the change in relative tibial IR at 0° of knee flexion was 1.4° (95% CI, -0.1° to 2.9°; P = .052) after ALL release. In group 2, it was 2.5° (95% CI, 0.4° to 4.8°; P = .007) after PLMCC release and 4.1° (95% CI, 0.5° to 7.8°; P = .017) after combined PLMCC and PMMCC release. Combined PLMCC and PMMCC release resulted in greater change of tibial IR with statistical significance at 0°, 15°, and 30° of knee flexion (P = .008, .057, and .004, respectively) compared with ALL release. The incidence of grade 3 pivot shifts was 10% in group 1 and 90% in group 2.

Conclusion

Posterior meniscocapsular laxity caused an increase in relative tibial IR as much as ALL injury in ACL-deficient knees in our simulated laboratory test, and greater anterolateral rotatory instability occurred with posterior meniscocapsular injury compared with ALL injury.

Clinical Relevance

Repair of the injured posterior meniscocapsular complex may be an important treatment option for reducing anterolateral rotatory instability in the ACL-deficient knee.

Bayesian Calibration of Computational Knee Models to Estimate Subject-Specific Ligament Properties, Tibiofemoral Kinematics, and Anterior Cruciate Ligament Force With Uncertainty Quantification

High-grade knee laxity is associated with early anterior cruciate ligament (ACL) graft failure, poor function, and compromised clinical outcome. Yet, the specific ligaments and ligament properties driving knee laxity remain poorly understood. We described a Bayesian calibration methodology for predicting unknown ligament properties in a computational knee model. Then, we applied the method to estimate unknown ligament properties with uncertainty bounds using tibiofemoral kinematics and ACL force measurements from two cadaver knees that spanned a range of laxities; these knees were tested using a robotic manipulator. The unknown ligament properties were from the Bayesian set of plausible ligament properties, as specified by their posterior distribution. Finally, we developed a calibrated predictor of tibiofemoral kinematics and ACL force with their own uncertainty bounds. The calibrated predictor was developed by first collecting the posterior draws of the kinematics and ACL force that are induced by the posterior draws of the ligament properties and model parameters. Bayesian calibration identified unique ligament slack lengths for the two knee models and produced ACL force and kinematic predictions that were closer to the corresponding in vitro measurement than those from a standard optimization technique. This Bayesian framework quantifies uncertainty in both ligament properties and model outputs; an important step towards developing subject-specific computational models to improve treatment for ACL injury.

Comparison of clinical outcomes between anterior cruciate ligament reconstruction with over-the-top route procedure and anatomic single-bundle reconstruction in pediatric patients

The purpose of this study is to evaluate the clinical results of over-the-top route (OTTR) reconstruction for pediatric anterior cruciate ligament (ACL) injuries and compare them with results of anatomic single-bundle reconstruction (SBR), which used the bone tunnel technique and was performed early after epiphyseal closure (age ≤15 years). This study included pediatric patients aged 11-15 years who underwent ACL reconstruction. The mean age at surgery was 13.4 years (11-15 years), including 14 men and 29 women. Operative procedures were determined according to growth plate closure. In all cases, the tibial side was reconstructed using a bone tunnel procedure. On the femoral side, we selected the OTTR procedure (group O) with open physis. Where the physis was closed, we selected the anatomical SBR (group B). The clinical results were evaluated with manual examination, the side-to-side difference (SSD) in tibial anterior translation using the Kneelax 3, and knee function score. There were no significant differences in the Lachman and pivot-shift tests, SSD in tibial anterior translation with Kneelax 3, or knee function score between the two groups before or after the surgery. Growth disturbance was not observed on either the femoral or tibial side in group O. The OTTR method provided comparable results with the bone tunnel anatomical method in manual examination, Kneelax 3, and knee clinical function scores, suggesting that the OTTR method is very useful for pediatric ACL reconstructions. Level of evidence: III; retrospective study.

Surgical Treatment for Avulsion Fractures of the Anterolateral Ligament Associated with Periarticular Fractures of the Knee

The existence and anatomy of the anterolateral ligament (ALL) of the knee are a somewhat controversial topic in orthopaedic surgery. The fixation of the avulsion fracture of the ALL (Segond fracture), associated with periarticular knee fractures, is rarely given much consideration while the major fracture fragments are reconstructed. This study aims to confirm the existence of ALL and evaluate the clinical outcomes of surgical management for avulsion fractures, involving its insertion, when associated with periarticular knee fractures. Twenty-three patients (16 males and 7 females) with avulsion fractures of the ALL associated with periarticular knee fractures were fixed with a spider plate, cannulated screw, or suture anchor. Eight patients were diagnosed with distal femoral fracture, 10 with tibial plateau fracture, and 5 with tibial eminence avulsion fracture. All patients underwent X-rays at follow-up. Clinical and functional outcomes were assessed with the pivot-shift test, objective and subjective International Knee Documentation Committee (IKDC) score, Lysholm score, and Tegner activity scale. The ALL was found and identified as a distinct ligamentous structure in all patients. Prior to Segond repair, patients had significantly more instability, as determined by pivot-shift test, than seen postoperatively (p < 0.0001). At final follow-up, the mean subjective IKDC score was 83.2 ± 10.3. Fourteen patients were graded A, 6 were graded B, and 3 was graded C on the IKDC objective score. The mean Lysholm score was 85.4 ± 12.2. The mean Tegner score was 7.5 ± 1.2. This study confirmed that the ALL is a distinct structure in the anterolateral portion of the knee. The fixation of the avulsion fracture of the ALL associated with periarticular knee fractures can be an effective procedure without specific complications. Long-term and comparative follow-up studies are necessary to confirm the effects.

Risk factors of residual pivot-shift after anatomic double-bundle anterior cruciate ligament reconstruction

INTRODUCTION

Although anterior cruciate ligament reconstruction (ACLR) is considered a successful procedure, residual pivot-shift after surgery remains to be solved. The purpose of this study was to comprehensively evaluate the risk factors of residual pivot-shift after anatomic double-bundle (DB) ACLR.

MATERIALS AND METHODS

A total of 164 patients who underwent primary anatomic DB-ACLR between January 2014 and December 2019 and screw removal after the index ACLR in our hospital were included in this retrospective case-control study. The manual pivot-shift test was performed under general anesthesia during screw removal surgery, and patients with grade 1 or higher pivot-shift were classified as the positive pivot-shift group, and those with grade 0 were defined as the negative pivot-shift group. Univariate and logistic regression analyses were performed to identify the factors associated with postoperative residual pivot-shift. Assessment included sex, age, time to surgery, preoperative Tegner activity scale, preoperative pivot-shift grade, preoperative anterior tibial translation by the KT-2000 arthrometer measurement, meniscus injury and its surgical procedure, knee hyperextension, cartilage damage, Segond fracture, medial and lateral posterior tibial slope, lateral-medial slope asymmetry, participation in pivoting sport/activity at the time of injury, and return to sports at postoperative one year line.

RESULTS

Postoperative positive pivot-shift was observed in 14 (8.5%) of 164 patients. The KT-2000 measurement at 1-year postoperatively was significantly higher in the residual pivot-shift-positive group than in the negative group (P < 0.05). Logistic regression analysis revealed that age of patients < 20 years [P < 0.05, odds ratio (OR): 6.1)], preoperative pivot-shift grade (P < 0.05, OR: 4.4), and hyperextended knee (P < 0.05, OR: 11.8) were risk factors of postoperative pivot-shift. There were no statistically significant differences between other variables.

CONCLUSIONS

Patients < 20 years of age, with high-grade preoperative pivot-shift, or hyperextended knees had a higher risk of residual postoperative pivot-shift.

Functional Outcomes of Anterior Cruciate Ligament Reconstruction Using Titanium Adjustable Loop Button and Poly-L-co-DL-Lactic Acid-Beta Tricalcium Phosphate (PLDLA-bTCP) Interference Screws: A Single-Center, Retrospective, Observational Study

Background The anterior cruciate ligament (ACL) reconstruction is a standard surgery in patients with instability of the knee caused by ACL insufficiency. Several differential procedures using grafts and implants such as loops, buttons, and screws have been described. This study aimed to assess the functional outcomes of ACL reconstruction surgery using titanium adjustable loop buttons and poly-L-co-DL-lactic acid-beta tricalcium phosphate (PLDLA-bTCP) interference screws. Methodology This was a retrospective, observational, single-center, and clinical study. A total of 42 patients who underwent ACL reconstruction at a tertiary trauma center in northern India between 2018 and 2022 were recruited. Data including demographics, details of the injury, surgery, implants, and surgical outcomes were collected from the patients' medical records. Further, post-surgery details such as re-injury, adverse events, International Knee Documentation Committee (IKDC) profiles, and Lysholm knee score were recorded from the enrolled patients through a telephonic follow-up. Pain score and Tegner activity scale were used to compare the knee status before and after surgery. Results At the time of surgery, the mean age of the recruited patients was 31.1 ± 8.8 years, with a male preponderance of 93%. About 57% of patients had left knee injuries. The common symptoms were instability (67%), pain (62%), swelling (14%), and giving away (5%). During surgery, titanium adjustable loop button and PLDLA-bTCP interference screw implants were used in all patients. The mean follow-up time was 21.2 ± 14.2 months. Based on patient responses, the mean IKDC and Lysholm scores were found to be 54.02 ± 5.93 and 94.4 ± 4.73, respectively. Further, the proportion of patients reporting pain decreased from 62% before surgery to 21% after surgery. The mean Tegner score revealed a significant increase in the activity levels of the patients post-surgery compared to pre-surgery (p < 0.05). Lastly, no adverse events or re-injuries were reported in any of the patients during follow-up. Conclusions Our findings revealed a significant improvement in Tegner activity levels and pain scores after surgery. In addition, patient-reported IKDC and Lysholm scores fell under the category of good knee status and function, suggesting a satisfactory functional outcome of ACL reconstruction. Hence, titanium adjustable loop and PLDLA-bTCP interference screws may be a good choice of implants for successful ACL reconstruction surgery.

Pivot shift intraoperative quantitative assessment using a smartphone accelerometer in ACL deficient knees

PURPOSE

The Pivot Shift (PS) test is a complex clinical sign that assesses the internal rotation and anterior tibial translation, which occurs abnormally in ACL deficient-knees. Because of the high inter-observer variability, different devices have been designed to characterize this complex movement in quantitative variables. The objective of this pilot study is to validate the reproducibility of intraoperative quantitative assessment of the PS with a smartphone accelerometer.

METHODS

Twelve ACL-injured knees were included and compared with the contralateral uninjured side. The PS was measured by two independent observers utilizing a smartphone accelerometer and graded according to the IKDC classification. Measurements were taken preoperatively, intraoperatively and postoperatively. Intraoperative readings were taken during each stage of reconstruction or repair of meniscoligamentous lesions including meniscal lesions, ramp lesions, ACL reconstruction and lateral tenodesis. Reproducibility of the measurements were evaluated according to an intraclass correlation coefficient (ICC).

RESULTS

The intra-observer reliability was good for the first examiner and excellent for the second examiner, with the ICC 0.89 [0.67, 0.98] p < 0,001 and ICC 0.97 [0.91, 1.0] p < 0,001 respectively. The inter-observer reliability was excellent between the two observers with the ICC 0.99 [0.97, 1.0] p < 0,001. The mean tibial acceleration measured 3.45 m.s² (SD = 1.71) preoperatively on the injured knees and 1.03 m.s² (SD = 0.36) on the healthy knees, demonstrating a significant difference following univariate analysis p < 0.001. Postoperatively, no significant difference was observed between healthy and reconstructed knees The magnitudes of tibial acceleration values were correlated with the PS IKDC grade.

CONCLUSION

The smartphone accelerometer is a reproducible device to quantitatively assess the internal rotation and anterior tibial translation during ACL reconstruction surgery. The measurements are influenced by the different surgical steps. Other larger cohort studies are needed to evaluate the specific impact of each step of the ACL reconstruction and meniscal repair on this measurement. An external validation using other technologies are needed to validate the reliability of this device to assess the PS test.

LEVEL OF EVIDENCE

Level IV, case series, pilot study.

Lateral Extra-Articular Tenodesis Staple Risks Penetration of Anterior Cruciate Ligament Reconstruction Tunnel

Purpose

To identify the risk of anterior cruciate ligament (ACL) femoral tunnel penetration with the use of a staple for lateral extra-articular tenodesis (LET) graft fixation and to determine whether this varied between 2 different techniques for ACL femoral tunnel drilling.

Methods

Twenty paired, fresh-frozen, cadaver knees underwent ACL reconstruction with a LET. Left and right knees were randomized to ACL reconstruction with femoral tunnel creation by use of either a rigid guide pin and reamer through the accessory anteromedial portal or by the use of a flexible guide pin and reamer through the anteromedial portal. Immediately after tunnel creation, the LET was performed and fixated with a small Richard's staple. Fluoroscopy was used to obtain a lateral view of the knee to determine staple position, and visualization of the ACL femoral tunnel was performed with the arthroscope to investigate penetration of the staple into the femoral tunnel. The Fisher exact test was conducted to determine whether there was any difference in tunnel penetration between tunnel creation techniques.

Results

The staple was noted to penetrate the ACL femoral tunnel in 8 of 20 (40%) extremities. When stratified by tunnel creation technique, the Richards staple violated 5 of 10 (50%) of the tunnels made via the rigid reaming technique compared with 3 of 10 (30%) of those created with a flexible guide pin and reamer (P = .65).

Conclusions

A high incidence of femoral tunnel violation is seen with lateral extra-articular tenodesis staple fixation.

Level of Evidence

Level IV, controlled laboratory study.

Clinical Relevance

The risk of penetrating the ACL femoral tunnel with a staple for LET graft fixation is not well understood. Yet, the integrity of the femoral tunnel is important for the success of ACL reconstruction. Surgeons can use the information in this study to consider adjustments to operative technique, sequence, or fixation devices used when performing ACL reconstruction with concomitant LET to avoid the potential for disruption of ACL graft fixation.

Bilateral changes in knee joint laxity during the first year after non-surgically treated anterior cruciate ligament injury

OBJECTIVES

Analyse changes in knee laxity between 3, 6, 12 and 24 months after non-surgically treated ACL injury and to analyse associations between knee laxity and knee function, self-reported knee stability, ACL-Return to Sport after Injury (ACL-RSI), fear and confidence at different timepoints during recovery.

DESIGN

Prospective cohort study.

PARTICIPANTS

125 patients (67 males, mean age 25.0 ± 7.0 years) with acute ACL injury.

MAIN OUTCOME

Laxity was measured using KT-1000 arthrometer. Self-reported knee function was assessed using the International Knee Documentation Committee Subjective Knee Form (IKDC-SKF). Confidence and fear were assessed with questions from the ACL-RSI scale. Subjectively knee stability was assessed using SANE.

RESULTS

Knee laxity increased bilaterally from 3 to 12 months, and in the non-involved knee from 3 to 24 months (p˂0.05), although mean change was below 1 mm. Side-to-side difference in knee laxity was correlated with IKDC-SKF (r = -0.283) and knee stability in rehabilitation/sport activities (r = -0.315) at 6 months, but not with confidence/fear.

CONCLUSION

Knee laxity increased bilaterally during the first year after non-surgically treated ACL injury, though, the mean change in knee laxity was below 1 mm and the clinical significance is unknown. Knee laxity was weakly associated with knee function and perceived knee stability.

LEVEL OF EVIDENCE

Level II TRIAL REGISTRATION: NCT02931084.

Transepicondylar distance measured on MRI can predict the length of the graft required for different anterior cruciate ligament reconstruction (ACLR) techniques useful for revision surgery

Background

The aim of this study is to find a correlation between linear measurements and the graft length required for different anterior cruciate ligament (ACL) revision techniques, to extract formulas to predict required graft length during the preoperative planning.

Methods

At time 0 and 30 days later, two observers measured eight linear distances on standard 2D knee magnetic resonance imaging (MRI), and nine curved distances on 3D MRI sequences, corresponding to different techniques for ACL revision, anatomic anterolateral ligament (ALL) reconstruction, and lateral extrarticular tenodesis (LET). Intra- and interobserver reliability was tested for 2D and 3D measurements. The correlation between 2D and 3D measurements was tested. The 2D measurements with highest repeatability and reproducibility, and with strongest correlation with 3D measurements were used to extract formulas to calculate the graft length from 2D values.

Results

Fifty MRIs acquired with both 2D and 3D sequences were used. The intra- and interobserver reliability of linear 2D measurement was high, with the transepicondylar distance (TD) showing the highest reproducibility and repeatability. The intra- and interobserver reliability of 3D measurements was lower than 2D, but acceptable for all measurements except for ALL reconstruction. The TD showed the strongest correlation with 3D measurements. The formulas extracted to calculate the graft length from the TD proved to be accurate.

Conclusion

Accurate formulas were created to calculate the graft length needed for different ACL revision techniques and ALL reconstruction/LET techniques from TD. These formulas can be used during preoperative planning of ACL revision cases.

Variation in Kaplan fiber insertion to the distal femur and surgical implications: A cadaveric anatomical study comparing Asian and Caucasian knees

BACKGROUND

The iliotibial band together with its attachment to the distal femur, known eponymously as the Kaplan fibers, has been shown to contribute to anterolateral rotatory stability of the knee. However, there remains paucity of data regarding the detailed anatomy of the Kaplan fibers to aid us in anatomical-based surgical reconstruction of these structures. The aim of our study was to identify and compare the presence and quantitative anatomy of the Kaplan fibers in Caucasian and Asian cadavers.

METHODS

Twenty paired fresh-frozen Asian and 20 unpaired embalmed Caucasian cadaveric knees were dissected using a standard outside-in technique. The presence, qualitative and quantitative measurements of any distal femoral attachments of the iliotibial band were recorded. Mean values of its dimensions were calculated and compared between the Caucasian and Asian groups.

RESULTS

A consistent supracondylar attachment of the iliotibial band was found in all Caucasian knees and in 19 of 20 Asian knees. The fibers were noted to have two variations with regard to their insertion to the distal femur, either as a single limb or as a double limb attachment, averaging between 30 mm and 40 mm from the lateral femoral epicondyle. No statistically significant difference was noted in dimensions of the fibers between the Caucasian and Asian groups.

CONCLUSIONS

The Kaplan fibers are a consistent attachment of the iliotibial band at the distal femur in both Caucasian and Asian knees with two different patterns of insertion. Surgical reconstructions should aim to recreate these attachments to be as anatomically based as possible.

A high level of knee laxity after anterior cruciate ligament reconstruction results in high revision rates

PURPOSE

The literature indicates a lack of consensus on the correlation between knee laxity after anterior cruciate ligament reconstruction (ACLR) and subjective clinical outcomes and the need for revision surgery. Therefore, using high-volume registry data, this study aimed to describe the relationship between objective knee laxity after ACLR and subjective symptom and functional assessments and the need for revision surgery. The hypothesis was that greater postoperative knee laxity would correlate with inferior patient-reported outcomes and a higher risk for revision surgery.

METHODS

In this study, 17,114 patients in the Danish knee ligament reconstruction registry were placed into three groups on the basis of objective side-to-side differences in sagittal laxity one year after surgery: group A (≤ 2 mm), Group B (3-5 mm) and Group C (> 5 mm). The main outcome measure was revision rate within 2 years of primary surgery, further outcome measures were the knee injury and osteoarthritis outcome score (KOOS) as well as Tegner activity score.

RESULTS

The study found the risk for revision surgery was more than five times higher for Group C [hazard ratio (HR) = 5.51] than for Group A. The KOOS knee-related Quality of Life (QoL) sub-score exhibited lower values when comparing Groups B or C to Group A. In addition, the KOOS Function in Sport and Recreation (Sport/Rec) sub-score yielded lower values for groups B and C in comparison with Group A.

CONCLUSION

These results indicate that increased post-operative sagittal laxity is correlated with an increased risk for revision surgery and might correlate with poorer knee-related QoL, as well as a decreased function in sports. The clinical relevance of the present study is that high knee laxity at 1-year follow-up is a predictor of the risk of revision surgery.

LEVEL OF EVIDENCE

III.

The Spectrum of Anterior Cruciate Ligament Reconstruction Options for the Pediatric and Adolescent Patient: A Narrative Review

As youth sports participation has increased in recent years, injuries to the anterior cruciate ligament (ACL) have become increasingly common in pediatric patients. Historically, ACL reconstruction was delayed in pediatric patients to avoid physeal damage with the potential for leg-length discrepancy or angular deformity. Current research shows that delaying reconstruction or choosing nonoperative management is associated with increased rates of meniscal and chondral injuries, persistent knee instability, and low rates of return to previous activity. Early ACL reconstruction using techniques to avoid physeal growth disturbance is now widely accepted among physicians. The purpose of this review was to describe the pediatric ACL in terms of the relevant anatomy and biomechanics, physical examination, and diagnostic imaging. In addition, the importance of skeletal age and possible physeal injury is discussed in the context of ACL reconstruction options by skeletal age and remaining growth potential.

Effects of remnant preservation in anterior cruciate ligament reconstruction: A systematic review and meta-analysis

Background

Compared with standard anterior cruciate ligament (ACL) reconstruction, it is controversial whether anterior cruciate ligament reconstruction (ACLR) with remnant preservation can lead to better clinical outcomes. We conducted a systematic study and meta-analysis to assess the differences in clinical efficacy between the two.

Method

We searched for clinical randomized controlled studies and cohort studies included in the Cochrane library, PubMed, and Embase from March 2012 to March 2022 in English. The included studies were ACLR with or without remant preservation, and the data were extracted and the quality of the included studies was assessed by two authors, respectively. Revman 5.4 was used for statistical analysis and conclusions were presented.

Result

Ten articles containing a total of 777 patients were finally included. There was no significant difference in postoperative Lachman test [OR = 1.66, 95%CI (0.79, 3.49), P = 0.18 > 0.05], Tegner score [SMD = −0.13, 95%CI (−0.47, 0.22), P = 0.46 > 0.05], synovial coverage rate by second-look arthroscopy [OR = 1.55, 95%CI (0.66, 3.65), P = 0.32 > 0.05], the rate of cyclops lesion [OR = 3.92, 95%CI (0.53, 29.29), P = 0.18 > 0.05], joint range of motion [SMD = 0.27, 95%CI (−0.13, 0.68), P = 0.19 > 0.05] and re-injury rate [OR = 0.57, 95%CI (0.18, 1.74), P = 0.32 > 0.05] between the two groups. There were statistically significant differences in postoperative Lysholm score [SMD = 0.98, 95% CI (0.32, 1.64), P = 0.004 < 0.05], International Knee Documantation Committee grade (IKDC grade) [OR = 2.19, 95%CI (1.03, 4.65), P = 0.04 < 0.05], Pivot shift test [OR = 1.71, 95%CI (1.06, 2.77), P = 0.03 < 0.05], KT1000/2000 arthrometer side-to-side difference [SMD = −0.22, 95%CI (−0.42, −0.03), P = 0.02 < 0.05], operation time [SMD = 11.69, 95%CI (8.85, 14.54), P = 0.00001 < 0.05] and degree of tibial tunnel enlargement [SMD = −0.66, 95%CI (−1.08, −0.23), P = 0.002 < 0.05].

Conclusion

This meta-analysis concluded that remnant preservation significantly had better results in terms of patient functional score (Lysholm, IKDC), knee stability (Pivot shift test, postoperative side-to-side anterior laxity) and tibial tunnel enlargement. In terms of complications (incidence of Cyclops lesions, range of motion, re-injury rate), no significant differences were seen between the two groups. Although many studies concluded that remnant preservation could bring better synovial coverage, this meta-analysis indicated that there is insufficient evidence to support it, possibly due to different remnant preservation procedures.The potential risks associated with longer operation times are also worth considering.

The presence of high-grade pivot shift test preoperatively is associated with inferior functional outcomes

BACKGROUND

The effect of high-grade preoperative pivot shift test on outcomes of anterior cruciate ligament (ACL) reconstruction surgery is not very well established. The present study was conducted to study the factors associated with high-grade pivot shift test and effect of high-grade preoperative pivot shift test on functional outcomes after ACL reconstruction surgery.

METHODS

Three hundred and sixty-two patients who underwent primary ACL reconstruction surgery were enrolled in the study. The pivot shift test was performed preoperatively under anesthesia in all patients. Side of the meniscal tear, if present at the time of ACL reconstruction, was documented. Patients were divided into two groups depending upon the grade of pivot shift test: group H, high-grade pivot shift (n = 84/362; 23%); and group L, low-grade pivot shift (n = 278/362; 77%). Patients were further divided into two groups depending upon the duration of injury: acute (<6 months) and chronic (>6 months). The functional assessment was done using Lysholm score and Tegner activity scale.

RESULTS

The presence of lateral meniscus tear (27/84 vs. 53/278) or both menisci tear (29/84 vs. 60/278) was associated with high-grade pivot shift (p < 0.05). Chronic ACL tears were also observed to be associated with high-grade pivot shift (p = 0.03). The mean Lysholm score in group H and group L patients was 93.8 ± 5.1 and 95.2 ± 5.3, respectively (p = 0.04). The mean post-op Tegner activity scale in group H was 6.8 and in group L was 7.3 (p = 0.0001). Also, 181/253 (71.5%) patients returned to same or higher level of sports activity in group L as compared to 33/72 (46%) patients in group H. The incidence of graft failure in groups H and L was 6.5% (5/77) and 1.6% (4/257; p = 0.03), respectively.

CONCLUSIONS

The high-grade pivot shift is associated with chronic ACL tear (>6 months) and concomitant lateral meniscus tear. The presence of high-grade pivot shift preoperatively is associated with inferior clinical outcomes and lower rate of return to sports.

LEVEL OF EVIDENCE

Level IV, case-control study.

Editorial Commentary: For Single-Bundle Anterior Cruciate Ligament Reconstruction, Graft Fixation Should Be Performed at a Medium Tension in Full Extension: Multiple Bundle Reconstruction May Require a Different Strategy

Successful anterior cruciate ligament reconstruction requires a multifaceted approach to replicate normal knee anatomy and biomechanics. Graft tensioning force and the angle at which this tension is applied intraoperatively are factors under the surgeon's control. The literature suggests the best tensioning strategy for single bundle reconstructions is at medium tension in full extension, while tensioning multiple bundles is best done at 20° at lower overall tension. Graft tensioning should be individualized with attention paid to graft choice and fixation. Generally, stiffer grafts are thought to require additional force to create the same amount of lengthening. For example, bone-patellar tendon-bone grafts tend to be stiffer than quadrupled hamstring grafts and the native anterior cruciate ligament. Hamstring grafts also are thought to exhibit greater stress relaxation over time, thus elongating and potentially causing increased laxity over time. Pretensioning may eliminate some postoperative graft creep, typically more of an issue with hamstring grafts.

Lateral extraarticular tenodesis improves stability in non-anatomic ACL reconstructed knees: in vivo kinematic analysis

PURPOSE

To carry out an in vivo kinematic analysis to determine whether adding a lateral extraarticular tenodesis (LET) for those patients with subjective instability and objective residual laxity after a transtibial (TT) anterior cruciate ligament reconstruction (ACLR) reduces anteroposterior and rotational laxity and to evaluate the 2-year follow-up clinical outcomes to analyze whether biomechanical changes determine clinical improvement or not.

METHODS

A total of 19 patients with residual knee instability after TT ACLR who underwent a modified Lemaire LET were prospectively evaluated for at least 2-year follow-up. Preoperative, intraoperative, and 6 and 24-month postoperative kinematic analyses were carried out using the KiRA accelerometer and KT1000 arthrometer to look for residual anterolateral rotational instability and residual anteroposterior instability. Functional outcomes were measured with the single-leg vertical jump test and the single-leg hop test. Clinical outcomes were evaluated using the IKDC 2000, Lysholm, and Tegner scores.

RESULTS

A significant reduction in anterolateral rotational instability was detected with the patient under anesthesia (from 3 ± 1.2 to 1.1 ± 1.1 m/s²; p < 0.05) as well as with the patient awake (from 2.1 ± 0.8 to 0.7 ± 1.4 m/s²; p < 0.05). A significant reduction in anteroposterior instability was only present under anesthesia (from 3.4 ± 1.9 to 2.1 ± 1.1 mm; p < 0.05), while no difference was present without anesthesia (from 2.3 ± 1.1 to 1.6 ± 1 mm; n.s.). Postoperative analysis of knee laxity did not show any significant variation from the first to the last follow-up. Both the single-leg vertical jump test and single-leg hop test improved significantly at the last follow-up (both p < 0.05). The mean values of both the IKDC and Tegner scores showed an improvement (p < 0.05 and p < 0.05, respectively), whereas that was not the case with the Lysholm score (n.s.).

CONCLUSIONS

The modified Lemaire LET can improve the kinematics of a non-anatomic ACL reconstructed knee with residual subjective and objective instability. These kinematic changes were able to lead to an improvement in subjective stability as well as the function of the knee in a small cohort of recreationally active patients. At 2-year follow-up, the kinematic changes as well as the level of activity of the patients and the IKDC score show their improvement sustained.

LEVEL OF EVIDENCE

Level IV.

Modified iliotibial band tenodesis versus lateral extracapsular tenodesis, to augment anterior cruciate ligament reconstruction: a 2-year randomized controlled trial

BACKGROUND

Residual instability following anterior cruciate ligament (ACL) reconstruction is associated with disruption of the anterolateral complex (ALC). Our goal was to conduct a randomized controlled trial comparing the effectiveness of modified Iliotibial tenodesis (MITBT) versus lateral extracapsular tenodesis (LET) to correct this residual instability.

METHODS

Group 1 underwent MITBT, Group 2 LET, added to the ACL reconstruction. Outcomes of interest were Tegner activity Scores (TAS), international knee documentation committee score (IKDC), knee osteoarthritis outcome score (KOOS), ACL related quality of life (ACL QoL), recurrent ACL rupture and meniscal tears. Follow-up was 2 years. Statistical analysis used chi-squared tests, frequency statistics and generalized linear models. We have followed the guidelines outlined in the CONSORT statement.

RESULTS

A total of 164 patients were randomized, 84 to Group 1, 80 to Group 2. Group 1 had higher TAS than Group 2, at 2 years (median 8, range 7-10 vs. median 7, range 5-9, P<0.001). Group 1 had higher ACL QoL scores at 1 and 2 years post-surgery (82.1, SD2.7 vs. 67.9, SD 4.0, P< 0.001 and 82.5, SD 2.6 vs. 68.8, SD 3.8, P<0.001, respectively), and higher KOOS Sport/recreation subscale at both 1 and 2 years (91.5, SD4.3 vs. 78.3, SD7.9, P<0.001 and 91.8, SD4.8 vs. 80.4, SD 9.5, P<0.001). Risk of recurrent ACL rupture (0% vs. 5%, P = 0.040-0.05) and medial meniscal tear (2.4% vs. 14%, P = 0.007-0.02) were lower in Group 1.

CONCLUSION

Augmentation of ACL reconstruction with the MITBT, rather than the LET, was associated with improved outcomes, and lower risks of recurrent ACL rupture and medial meniscal tears.

No Difference in Complication Rates or Patient-Reported Outcomes Between Bone–Patella Tendon–Bone and Quadriceps Tendon Autograft for Anterior Cruciate Ligament Reconstruction

Purpose

To compare subjective outcomes and complications of anterior cruciate ligament reconstruction (ACLR) using either bone–patellar tendon–bone (BPTB) or quadriceps tendon (QT) autograft.

Methods

A retrospective analysis of prospectively collected data identified consecutive cohorts of patients undergoing ACLR with either BPTB or QT autograft. Patients with less than 12-month follow-up and those undergoing concomitant osteotomies, cartilage restoration, and/or other ligament reconstruction procedures were excluded. Pre- and postsurgical patient-reported outcomes including International Knee Documentation Committee, Knee Injury and Osteoarthritis Outcome Score, Patient-Reported Outcomes Measurement Information System (PROMIS), Single Assessment Numeric Evaluation, Tegner, and Marx were compared between groups. Complications requiring reoperation were recorded.

Results

One hundred nineteen patients met inclusion criteria, including 39 QT autografts and 80 BPTB autografts. Demographic information was comparable between groups. Mean follow-up was comparable between groups (QT 22.4 ± 10.6 months vs BPTB 28.5 ± 18.5 months, P = .06). At minimum 12-month follow-up (range 12.0-100.8 months), patients in both groups demonstrated statistically significant improvements in International Knee Documentation Committee (QT 60.0%, P < .0001; BPTB 57.7%, P < .0001), all Knee Injury and Osteoarthritis Outcome Score domains, PROMIS Mobility T-Score (QT 27.2%, P = .0001; BPTB 23.2%, P < .0001), PROMIS Global Physical Health (QT 14.4%, P = .002; BPTB 13.4%, P = .001), PROMIS Physical Function (QT 29.6%, P < .0001; BPTB 37.1%, P < .0001), PROMIS Pain Interference (QT –16.5%, P < .0001; BPTB –20.8%, P < .0001), Single Assessment Numeric Evaluation, (QT 76.9%, P < .0001; BPTB 73.3%, P < .0001), Tegner (QT 92.9%, P = .0002; BPTB 101.4%, P < .0001), and Marx (QT –26.6%, P = .02; BPTB –32.0%, P = .0002) with no statistically significant differences between the 2 groups. Overall postoperative reoperation rate did not differ between groups (QT 12.8% vs BPTB 23.8%, P = .2). Revision ACL reconstruction rate did not differ between groups (QT 5.1% vs BPTB 7.5%, P = .6).

Conclusions

Patients undergoing autograft ACLR with either BPTB or QT demonstrated significant subjective improvements in patient-reported outcomes from preoperative values and no statistically significant differences in outcomes between the groups. Complication and revision ACLR rates were similar between the 2 groups.

Level of Evidence

III, retrospective cohort study.

Predictors of Graft Failure in Young Active Patients Undergoing Hamstring Autograft Anterior Cruciate Ligament Reconstruction With or Without a Lateral Extra-articular Tenodesis: The Stability Experience

BACKGROUND

Anterior cruciate ligament (ACL) reconstruction (ACLR) has higher failure rates in young active patients returning to sports as compared with older, less active individuals. Augmentation of ACLR with an anterolateral procedure has been shown to reduce failure rates; however, indications for this procedure have yet to be clearly defined.

PURPOSE/HYPOTHESIS

The purpose of this study was to identify predictors of ACL graft failure in high-risk patients and determine key indications for when hamstring ACLR should be augmented by a lateral extra-articular tenodesis (LET). We hypothesized that different preoperative characteristics and surgical variables may be associated with graft failure characterized by asymmetric pivot shift and graft rupture.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Data were obtained from the Stability 1 Study, a multicenter randomized controlled trial of young active patients undergoing autologous hamstring ACLR with or without a LET. We performed 2 multivariable logistic regression analyses, with asymmetric pivot shift and graft rupture as the dependent variables. The following were included as predictors: LET, age, sex, graft diameter, tear chronicity, preoperative high-grade knee laxity, preoperative hyperextension on the contralateral side, medial meniscal repair/excision, lateral meniscal repair/excision, posterior tibial slope angle, and return-to-sports exposure time and level.

RESULTS

Of the 618 patients in the Stability 1 Study, 568 with a mean age of 18.8 years (292 female; 51.4%) were included in this analysis. Asymmetric pivot shift occurred in 152 (26.8%) and graft rupture in 43 (7.6%). The addition of a LET (odds ratio [OR], 0.56; 95% CI, 0.37-0.83) and increased graft diameter (OR, 0.62; 95% CI, 0.44-0.87) were significantly associated with lower odds of asymmetric pivot shift. The addition of a LET (OR, 0.40; 95% CI, 0.18-0.91) and older age (OR, 0.83; 95% CI, 0.72-0.96) significantly reduced the odds of graft rupture, while greater tibial slope (OR, 1.15; 95% CI, 1.01-1.32), preoperative high-grade knee laxity (OR, 3.27; 95% CI, 1.45-7.41), and greater exposure time to sport (ie, earlier return to sport) (OR, 1.18; 95% CI, 1.08-1.29) were significantly associated with greater odds of rupture.

CONCLUSION

The addition of a LET and larger graft diameter were significantly associated with reduced odds of asymmetric pivot shift. Adding a LET was protective of graft rupture, while younger age, greater posterior tibial slope, high-grade knee laxity, and earlier return to sport were associated with increased odds of graft rupture. Orthopaedic surgeons should consider supplementing hamstring autograft ACLR with a LET in young active patients with morphological characteristics that make them at high risk of reinjury.

Anteromedial Tibial Attachment in Single-Bundle Anterior Cruciate Ligament Reconstruction Can Represent Normal Kinematics in Computer Simulation

Tunnel position during anterior cruciate ligament (ACL) reconstruction is considered as an important factor to restore normal knee kinematics and to gain better clinical outcomes. It is still unknown where the optimal femoral and tibial tunnel position is located in single-bundle (SB) ACL reconstruction. The purposes of this study were to analyze the knee kinematics with various graft positions and to propose the optimal graft position during SB ACL reconstruction. A musculoskeletal computer simulation was used to analyze knee kinematics. Four attachments on the femoral side (anteromedial [AM], mid, posterolateral [PL], and over-the-top positions) and three attachments on the tibial side (AM, middle, and PL positions) were determined. The middle-bundle attachment was placed at the midpoint of the AM and PL bundle attachments for the femoral and tibial attachments. SB ACL reconstruction models were constructed to combine each of the four femoral attachments with each of three tibial attachments. Kinematic comparison was made among a double-bundle (DB) model and 12 SB reconstruction models during deep knee bend and stair descent activity. The tunnel position of the tibia had greater effect of knee kinematics than that of the femur. AM tibial attachment models showed similar medial and lateral anteroposterior positions to the DB model for both activities. Axial rotation in the AM tibial attachment models was similar to the DB model regardless of the femoral attachment, whereas greater maximum axial rotation was exhibited in the PL tibial attachment models, especially during stair descent activity. AM tibial attachment can represent normal knee kinematics, whereas the PL tibial attachment can induce residual rotational instability during high-demand activities. The AM tibial tunnel is recommended for SB ACL reconstruction.

The effect of lateral extra-articular tenodesis on in vivo cartilage contact in combined anterior cruciate ligament reconstruction

PURPOSE

Lateral extra-articular tenodesis (LET) may confer improved rotational stability after anterior cruciate ligament reconstruction (ACLR). Little is known about how LET affects in vivo cartilage contact after ACLR. The aim of this study was to investigate the effect of LET in combination with ACLR (ACLR + LET) on in vivo cartilage contact kinematics compared to isolated ACLR (ACLR) during downhill running. It was hypothesised that cartilage contact area in the lateral compartment would be larger in ACLR + LET compared with ACLR, and that the anterior-posterior (A-P) position of the contact center on the lateral tibia would be more anterior after ACLR + LET than after ACLR.

METHODS

Twenty patients were randomly assigned into ACLR + LET or ACLR during surgery (ClinicalTrials.gov:NCT02913404). At 6 months and 12 months after surgery, participants were imaged during downhill running using biplane radiography. Tibiofemoral motion was tracked using a validated registration process. Patient-specific cartilage models, obtained from 3 T MRI, were registered to track bone models and used to calculate the dynamic cartilage contact area and center of cartilage contact in both the medial and lateral tibiofemoral compartments, respectively. The side-to-side differences (SSD) were compared between groups using a Mann-Whitney U test.

RESULTS

At 6 months after surgery, the SSD in A-P cartilage contact center in ACLR + LET (3.9 ± 2.6 mm, 4.4 ± 3.1 mm) was larger than in ACLR (1.2 ± 1.6 mm, 1.5 ± 2.0 mm) at 10% and 20% of the gait cycle, respectively (p < 0.01, p < 0.05). There was no difference in the SSD in cartilage contact center at 12 months after surgery. There was no difference in SSD of cartilage contact area in the medial and lateral compartments at both 6 and 12 months after surgery. There were no adverse events during the trial.

CONCLUSION

LET in combination with ACLR may affect the cartilage contact center during downhill running in the early post-operation phase, but this effect is lost in the longer term. This suggests that healing and neuromuscular adaptation occur over time and may also indicate a dampening of the effect of LET over time. (337 /350 words) LEVEL OF EVIDENCE: Level II.

Comparison of Clinical Outcomes after Revision Anterior Cruciate Ligament Reconstruction using a Bone-patellar Tendon-bone Autograft and that Using a Double-Bundle Hamstring Tendon Autograft

PURPOSE

 The purpose of this study was to compare clinical outcomes between revision anterior cruciate ligament reconstruction (ACLR) using a bone-patellar tendon-bone (BPTB) autograft and that using a double-bundle hamstring tendon (HT) autograft.

METHODS

 Consecutive cases of revision ACLRs were reviewed. The Lysholm knee scale and Knee Osteoarthritis Outcome Score (KOOS) were recorded at the final follow-up. The pivot shift test, Lachman test, and anterior knee laxity measurement using an arthrometer were evaluated before revision ACLR and at final follow-up. Contralateral knee laxity was also evaluated, and side-to-side differences noted. The Lysholm knee scale, KOOS, the pivot shift test, Lachman test, and anterior knee laxity were compared between HT versus BPTB autograft recipient groups using the Mann-Whitney test or the t-test.

RESULTS

 Forty-one patients who underwent revision ACLR and followed up for at least 2 years were included. The graft source was a BPTB autograft in 23 patients (BPTB group) and a double-bundle HT autograft in 18 patients (HT group). The mean postoperative follow-up period was 44 ± 28 months in the BPTB group and 36 ± 18 in the HT group (p = 0.38). The HT group had significantly higher KOOS in the pain subscale (less pain) than the BPTB group at the final follow-up (BPTB group 84.2 vs. HT group 94.4; p = 0.02). The BPTB group showed significantly smaller side-to-side difference in anterior knee laxity (superior stability) than the HT group (0.3 vs. 2.6 mm; p < 0.01). The percentage of patients with residual anterior knee laxity in the BPTB group was significantly lower than that in the HT group (9.5% vs. 46.7%; odds ratio, 8.3; p = 0.02).

STUDY DESIGN

 This was a level 3 retrospective study.

CONCLUSION

 Revision ACLR with a BPTB autograft was associated with superior results regarding restoration of knee joint stability as compared with that with a double-bundle HT autograft, whereas double-bundle HT autograft was superior to BPTB autograft in terms of patient-reported outcomes of pain. The rest of the patient-reported outcomes were equal between the two groups.

Recovery After ACL Reconstruction in Male Versus Female Adolescents: A Matched, Sex-Based Cohort Analysis of 543 Patients

Background:

Differences in postoperative recovery after anterior cruciate ligament reconstruction (ACLR) between men and women have been demonstrated in the adult population. Sex-based differences have been incompletely investigated in adolescents, which represent the subpopulation most affected by ACL injury.

Purpose/Hypothesis:

The purpose of this study was to compare the 6-month postoperative functional recovery after ACLR between adolescent boys and girls. It was hypothesized that significant differences in postoperative strength, dynamic balance, and functional hop test performance would be seen between the sexes.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Included in this study were athletes aged 12 to 19 years with closed or closing growth plates who underwent ACLR with hamstring autograft between May 2014 and May 2018 at a single institution. All athletes had undergone strength and functional testing between 5 and 8 months postoperatively. Exclusion criteria were previous knee surgery (contralateral or ipsilateral knee), concomitant injury/surgery other than meniscal tear/repair, allograft supplementation, and incomplete medical records. The limb symmetry index (LSI) for strength (measured with handheld dynamometer), as well as dynamic Y-balance and functional hop test performance, was compared between groups. To account for differences in physical characteristics between the sexes, 1-way between-group multivariate analysis of covariance was used to analyze the data.

Results:

Overall, 543 patients (211 boys, 332 girls) were included. There was no significant difference in age, body mass index, incidence of concomitant meniscal pathology, use of regional anesthesia, or time to functional testing between cohorts. Female athletes demonstrated a statistically significantly greater deficit in quadriceps strength LSI compared with male athletes (boys, +3.4%; girls, –2.3%; P = .011). Both male and female athletes demonstrated 33% hamstring strength deficits, with no statistically significant sex-based differences in dynamic balance or functional hop testing.

Conclusion:

Female athletes demonstrated greater quadriceps strength deficits than male athletes at 6 months after ACLR with hamstring autograft. Severe hamstring strength deficits persisted in both male and female patients at this time point. The correlation of such deficits to risk of ACL retear warrants continued study in the adolescent population and may support a delay in return to sports, which has been suggested in the more recent literature.

Anatomic double-bundle anterior cruciate ligament reconstruction could not achieve sufficient control of pivot-shift when accompanying tibial tunnel coalition

PURPOSE

To evaluate the effect of tibial tunnel coalition on knee rotatory laxity and clinical outcomes after double-bundle (DB) anterior cruciate ligament (ACL) reconstruction.

METHODS

Forty-one patients who underwent anatomic DB ACL reconstruction were included prospectively. Three-dimensional computed tomography of the knee joint was obtained at approximately 1 year postoperatively to determine if tunnel coalition occurred. After excluding seven cases of femoral tunnel coalition, two groups were established based on the existence of a tibial tunnel coalition. The pivot-shift test was quantitatively evaluated on the basis of tibial acceleration preoperatively and at 1 year postoperatively. Two subjective scores, the International Knee Documentation Committee (IKDC) subjective and Lysholm scores, were also collected. The pivot-shift measurement and subjective scores were compared between the ACL-reconstructed knees with and without tibial tunnel coalition. The independent t test, Pearson's chi-square test, and Student t tests were used in data analysis.

RESULTS

Twenty-one knees had tibial tunnel coalition (group C), whereas 13 knees did not have tunnel coalition(group N). Pivot-shift was significantly diminished postoperatively in both groups on the basis of the clinical examination and quantitative evaluations (p < 0.05). However, there was a small but significant difference in tibial acceleration demonstrating larger pivot-shift in group C (1.0 ± 0.6 m/s²) than in group N (0.5 ± 0.3 m/s², p < 0.05). No significant difference was observed in the IKDC subjective and Lysholm scores (both n.s.).

CONCLUSION

When the tibial tunnel coalition occurs after DB ACL reconstruction, knee rotatory laxity may not be restored in ACL-reconstructed knees, as expected in those without tunnel coalition. It is recommended that two tibial tunnels should be created separately when performing DB-ACL reconstruction to achieve better control of rotatory knee laxity.

LEVEL OF EVIDENCE

III.

Medial meniscus ramp and lateral meniscus posterior root lesions are present in more than a third of primary and revision ACL reconstructions

PURPOSE

The purpose of this study was (1) to describe the meniscus tear pattern in anterior cruciate ligament (ACL)-injured patients, with a special focus on medial meniscus (MM) ramp lesions and lateral meniscus (LM) root tears and (2) to determine whether patient and injury characteristics were associated with meniscus tear patterns.

METHODS

Data from 358 cases of ACL primary and revision reconstruction surgeries were extracted from a center-based registry. During arthroscopy, the presence of associated meniscus lesions was documented by systematically inspecting the anterior and posterior tibiofemoral compartments. With a special focus on MM ramp lesions and LM root tears, groups of different injury tear patterns were formed. Chi-square tests were used to determine whether these groups differed with respect to various patient and injury characteristics, including gender, previous ipsilateral ACL injuries, the injury's relation to sport, person contact during injury and the type of ACL tear. Median age at surgery and body mass index were compared between groups using the Kruskal-Wallis test. Significance was set at p < 0.05.

RESULTS

Two hundred and thirty-nine ACL injuries (67%) showed additional meniscal injuries, of which 125 (52%) involved the MM ramp and/or the LM root. Ramp lesions were more frequent in males (23% vs 12% in females, p < 0.01), in contact injuries (28% vs 16% in non-contact, p < 0.05) and in complete ACL tears (21% vs 5% in partial, p < 0.05). Combined injuries of the MM ramp and the LM root showed a higher percentage of contact injuries compared to non-contact injuries (10% vs 4%, p < 0.05).

CONCLUSION

Two-thirds of all ACL injuries showed a concomitant meniscus injury, of which half involved the biomechanically relevant, but previously often undiagnosed RLMM or the PRLM. These findings provide evidence that until recently about half of ACL-associated meniscus injuries were not properly identified. Ramp lesions were more frequent in males, contact injuries and in complete ACL tears. These findings stress the need for a systematic assessment and a better understanding of the pathomechanism of these specific injuries which may have an important impact on knee biomechanics and the outcome of ACL reconstruction.

LEVEL OF EVIDENCE

III.

Clinical Outcomes of Anterolateral Ligament Reconstruction or Lateral Extra-articular Tenodesis Combined With Primary ACL Reconstruction: A Systematic Review With Meta-analysis

BACKGROUND

Residual rotational instability after isolated anterior cruciate ligament reconstruction (ACLR) has been a challenge for many years. Anterolateral extra-articular procedures (AEAPs), including anterolateral ligament reconstruction (ALLR) or lateral extra-articular tenodesis (LET), are performed as a surgical option for additional rotational stability, but clear evidence for their usefulness is lacking.

PURPOSE

To conduct a systematic review and meta-analysis of the literature regarding the efficacy of AEAP in primary ACLR.

STUDY DESIGN

Systematic review; Level of evidence, 3.

METHODS

A literature search, data extraction, and quality assessment were conducted by 2 independent reviewers. MEDLINE, EMBASE, and the Cochrane Library were searched in April 2020, following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. A total of 3444 studies were screened, and 20 studies (11 randomized controlled trials and 9 nonrandomized studies) were evaluated. Functional outcomes, stability, and complications were compared between patients who underwent primary ACLR with AEAP and those who underwent isolated primary ACLR. For subgroup analysis, outcomes were compared according to AEAP technique (ALLR vs LET) and time from injury to surgery (≤12 vs >12 months). The methodological quality of the included studies was assessed using the Cochrane risk-of-bias tool, Jadad scale, and Newcastle-Ottawa Scale.

RESULTS

Compared with isolated ACLR, combined ACLR with AEAP led to improved pivot-shift grades and graft failure rates, regardless of the AEAP technique or of time from injury to surgery. A limited, marginal improvement in subjective function score was observed in patients who underwent AEAP combined with ACLR. In contrast to ALLR, patients who underwent LET combined with ACLR had an increased risk of knee stiffness and adverse events.

CONCLUSION

Our review suggests that when there is a need to improve rotational stability and subjective function, AEAP combined with primary ACLR can be considered regardless of time from injury. ALLR appeared to be a better option for improving rotational stability compared with LET.

Lateral Extra-articular Tenodesis Alters Lateral Compartment Contact Mechanics under Simulated Pivoting Maneuvers: An In Vitro Study

BACKGROUND

There is concern that utilization of lateral extra-articular tenodesis (LET) in conjunction with anterior cruciate ligament (ACL) reconstruction (ACLR) may disturb lateral compartment contact mechanics and contribute to joint degeneration.

HYPOTHESIS

ACLR augmented with LET will alter lateral compartment contact mechanics in response to simulated pivoting maneuvers.

STUDY DESIGN

Controlled laboratory study.

METHODS

Loads simulating a pivot shift were applied to 7 cadaveric knees (4 male; mean age, 39 ± 12 years; range, 28-54 years) using a robotic manipulator. Each knee was tested with the ACL intact, sectioned, reconstructed (via patellar tendon autograft), and, finally, after augmenting ACLR with LET (using a modified Lemaire technique) in the presence of a sectioned anterolateral ligament and Kaplan fibers. Lateral compartment contact mechanics were measured using a contact stress transducer. Outcome measures were anteroposterior location of the center of contact stress (CCS), contact force from anterior to posterior, and peak and mean contact stress.

RESULTS

On average, augmenting ACLR with LET shifted the lateral compartment CCS anteriorly compared with the intact knee and compared with ACLR in isolation by a maximum of 5.4 ± 2.3 mm (P < .001) and 6.0 ± 2.6 mm (P < .001), respectively. ACLR augmented with LET also increased contact force anteriorly on the lateral tibial plateau compared with the intact knee and compared with isolated ACLR by a maximum of 12 ± 6 N (P = .001) and 17 ± 10 N (P = .002), respectively. Compared with ACLR in isolation, ACLR augmented with LET increased peak and mean lateral compartment contact stress by 0.7 ± 0.5 MPa (P = .005) and by 0.17 ± 0.12 (P = .006), respectively, at 15° of flexion.

CONCLUSION

Under simulated pivoting loads, adding LET to ACLR anteriorized the CCS on the lateral tibial plateau, thereby increasing contact force anteriorly. Compared with ACLR in isolation, ACLR augmented with LET increased peak and mean lateral compartment contact stress at 15° of flexion.

CLINICAL RELEVANCE

The clinical and biological effect of increased anterior loading of the lateral compartment after LET merits further investigation. The ability of LET to anteriorize contact stress on the lateral compartment may be useful in knees with passive anterior subluxation of the lateral tibia.

A Surgical Algorithm According to Pivot-Shift Grade in Patients With ACL Injury: A Prospective Clinical and Radiological Evaluation

Background:

Some patients have a positive pivot-shift finding and rotational instability after anterior cruciate ligament (ACL) reconstruction (ACLR). Three major pathologies known to affect the pivot-shift examination include ACL tear, anterolateral ligament injury, and loss of posterior lateral meniscus root function.

Purpose:

To describe a surgical algorithm determining indications for lateral extra-articular tenodesis (LET) based on intraoperative pivot-shift examination to prevent postoperative pivot shift and rotational instability and to evaluate the 2-year clinical and functional outcomes.

Study Design:

Case series; Level of evidence, 4.

Methods:

The study included 47 consecutive patients (39 men and 8 women) who underwent operative treatment for ACL injury between 2016 and 2017. Pivot-shift examination was performed under anesthesia, and the pivot shift was graded as grade 1 (glide), grade 2 (clunk), or grade 3 (gross). According to the surgical algorithm, single-bundle ACLR was performed in patients with grade 1 pivot shift. In patients with grade 2 with loss of posterior lateral meniscus root function, concurrent lateral meniscal repair was performed, and in patients with grade 2 with an intact lateral meniscus posterior root, concurrent extra-articular iliotibial band tenodesis was performed. Patients with grade 3 underwent ACLR, lateral meniscal repair, and LET. Clinical and radiographic evaluations were performed.

Results:

The mean age was 27.2 years (range, 16-56 years). In total, 26 (55.3%) patients were evaluated as having pivot-shift grade 1; 16 (34%) patients, grade 2; and 5 (10.6%) patients, grade 3. A total of 7 (14.9%) patients underwent LET in addition to ACLR. Two of these patients had pivot-shift grade 2, and LET was performed since the lateral meniscus posterior root was intact. In 14 of 16 patients with grade 2, lateral meniscus root disruption was detected, and lateral meniscal repair was performed. One patient was excluded from the further follow-up because of graft failure. At a mean postoperative follow-up of 29 months in 46 patients, the pivot-shift examination was negative in all patients. The mean Lysholm and International Knee Documentation Committee subjective scores were 95.35 ± 4.40 and 82.87 ± 9.36, respectively. Radiographic evidence of osteoarthritis was not detected.

Conclusion:

Only 14.9% of patients needed LET. With proper ACL, lateral meniscal, and anterolateral ligament surgery, it was possible to prevent positive pivot-shift findings postoperatively.

Neither Residual Anterior Knee Laxity Up to 6 mm nor a Pivot Glide Predict Patient-Reported Outcome Scores or Subsequent Knee Surgery Between 2 and 6 Years After ACL Reconstruction

BACKGROUND

A primary goal of anterior cruciate ligament reconstruction (ACLR) is to reduce pathologically increased anterior and rotational laxity of the knee, but the effects of residual laxity on patient-reported outcomes (PROs) after ACLR remain unclear.

HYPOTHESIS

Increased residual laxity at 2 years postoperatively is predictive of a higher risk of subsequent ipsilateral knee surgery and decreases in PRO scores from 2 to 6 years after surgery.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

From a prospective multicenter cohort, 433 patients aged <36 years were identified at a minimum 2 years after primary ACLR. These patients underwent a KT-1000 arthrometer assessment and pivot-shift test and completed PRO assessments with the Knee injury and Osteoarthritis Outcome Score and International Knee Documentation Committee (IKDC) scores. Patients completed the same PROs at 6 years postoperatively, and any subsequent ipsilateral knee procedures during this period were recorded. Subsequent surgery risk and change in PROs from 2 to 6 years postoperatively were compared based on residual side-to-side KT-1000 arthrometer differences (<-1 mm, -1 to 2 mm, 2 to 6 mm, and >6 mm) in laxity at 2 years postoperatively. Multiple linear regression models were built to determine the relationship between 2-year postoperative knee laxity and 2- to 6-year change in PROs while controlling for age, sex, body mass index, smoking status, meniscal and cartilage status, and graft type.

RESULTS

A total of 381 patients (87.9%) were available for follow-up 6 years postoperatively. There were no significant differences in risk of subsequent knee surgery based on residual knee laxity. Patients with a difference >6 mm in side-to-side anterior laxity at 2 years postoperatively were noted to have a larger decrease in PROs from 2 to 6 years postoperatively (P < .05). No significant differences in any PROs were noted among patients with a difference <6 mm in side-to-side anterior laxity or those with pivot glide (IKDC B) versus no pivot shift (IKDC A).

CONCLUSION

The presence of a residual side-to-side KT-1000 arthrometer difference <6 mm or pivot glide at 2 years after ACLR is not associated with an increased risk of subsequent ipsilateral knee surgery or decreased PROs up to 6 years after ACLR. Conversely, patients exhibiting a difference >6 mm in side-to-side anterior laxity were noted to have significantly decreased PROs at 6 years after ACLR.

Association Between Psychological Readiness and Knee Laxity and Their Predictive Value for Return to Sport in Patients With Anterior Cruciate Ligament Reconstruction

BACKGROUND

Deciding when patients are ready to return to sport (RTS) after an anterior cruciate ligament (ACL) reconstruction (ACLR) is challenging. The understanding of which factors affect readiness and how they may be related is limited. Therefore, despite widespread use of RTS testing, there is a lack of knowledge about which tests are informative on the ability to resume sports.

PURPOSE

To examine whether there is an association between knee laxity and psychological readiness to RTS after ACLR and to evaluate the predictive value of these measures on sports resumption.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Patients aged ≥16 years engaged in physical activity/sports before injury were recruited at routine clinical assessment 9-12 months after ACLR. Exclusion criteria were concomitant ligament surgery at ACLR and/or previous ACL injury in the contralateral knee. At baseline, a project-specific activity questionnaire and the ACL-Return to Sport After Injury (ACL-RSI) scale were completed. Knee laxity was assessed by use of the Lachman test, KT-1000 arthrometer, and pivot-shift test. Two years after surgery, knee reinjuries and RTS status (the project-specific questionnaire) were registered. Associations between psychological readiness and knee laxity were evaluated with the Spearman rho test, and predictive ability of the ACL-RSI and knee laxity tests were examined using regression analyses.

RESULTS

Of 171 patients screened for eligibility, 132 were included in the study. There were small but significant associations between the ACL-RSI score and the Lachman test (rho = -0.18; P = .046) and KT-1000 arthrometer measurement (rho = -0.18; P = .040) but no association between the ACL-RSI and the pivot-shift test at the time of recruitment. Of the total patients, 36% returned to preinjury sport level by 2 years after surgery. Higher age, better psychological readiness, and less anterior tibial displacement (KT-1000 arthrometer measurement) were significant predictors of 2-year RTS (explained variance, 33%).

CONCLUSION

Small but significant associations were found between measurements of psychological readiness and anterior tibial displacement, indicating that patients with less knee laxity after ACLR feel more ready to RTS. ACL-RSI and KT-1000 arthrometer measurements were independent predictors of 2-year RTS and should be considered in RTS assessments after ACLR.