Noninjured Knees of Patients With Noncontact ACL Injuries Display Higher Average Anterior and Internal Rotational Knee Laxity Compared With Healthy Knees of a Noninjured Population

Does Generalized Joint Laxity Affect Postoperative Alignment and Clinical Outcomes Following Medial Opening-Wedge High Tibial Osteotomy?

BACKGROUND

The purpose of this study was to investigate whether generalized joint laxity affects the postoperative alignment and clinical outcomes of medial opening-wedge high tibial osteotomy (MOWHTO).

METHODS

A total of 198 patients who underwent MOWHTO was divided into two groups according to absence or presence of generalized joint laxity. Generalized joint laxity was measured using the Beighton and Horan criteria, and a score of 4 or more out of 9 was defined as generalized joint laxity. A weight bearing line (WBL) ratio of 55% to 70% was considered an acceptable postoperative lower limb alignment range; WBL over 70% was defined as overcorrection and less than 55% as undercorrection. The WBL ratio was investigated before and 2 years after surgery, and the Western Ontario McMaster University Osteoarthritis Index scale score (WOMAC) was evaluated for patient-reported outcomes (PRO) of MOWHTO. There were 147 (73.7%) patients in the nongeneralized joint laxity group and 51 (26.3%) in the generalized joint laxity group. Preoperatively, there was no difference between the two groups in hip-knee-ankle (HKA) angle or WBL ratio (all P > .05).

RESULTS

At 2 years postoperatively, the generalized joint laxity group showed significantly higher HKA angle and WBL ratio than the nongeneralized joint laxity group (all P < .05). There was a significant difference in the distribution ratio of undercorrection, normocorrection, and overcorrection patients between the two groups (P < .05). There were no differences between the two groups in preoperative and postoperative WOMAC scores (all, P > .05).

CONCLUSION

The generalized joint laxity significantly affected postoperative over correction of alignment following MOWHTO. However, there was no significant difference in PRO between the patients who did and did not have generalized joint laxity after MOWHTO until 2 years.

Positional MR imaging of normal and injured knees

OBJECTIVES

This study uses a practical positional MRI protocol to evaluate tibiofemoral translation and rotation in normal and injured knees.

METHODS

Following ethics approval, positional knee MRI of both knees was performed at 35° flexion, extension, and hyperextension in 34 normal subjects (mean age 31.1 ± 10 years) and 51 knee injury patients (mean age 36.4 ± 11.5 years, ACL tear n = 23, non-ACL injury n = 28). At each position, tibiofemoral translation and rotation were measured.

RESULTS

Normal knees showed 8.1 ± 3.3° external tibial rotation (i.e., compatible with physiological screw home mechanism) in hyperextension. The unaffected knee of ACL tear patients showed increased tibial anterior translation laterally (p = 0.005) and decreased external rotation (p = 0.002) in hyperextension compared to normal knees. ACL-tear knees had increased tibial anterior translation laterally (p < 0.001) and decreased external rotation (p < 0.001) compared to normal knees. Applying normal thresholds, fifteen (65%) of 23 ACL knees had excessive tibial anterior translation laterally while 17 (74%) had limited external rotation. None (0%) of 28 non-ACL-injured knees had excessive tibial anterior translation laterally while 13 (46%) had limited external rotation. Multidirectional malalignment was much more common in ACL-tear knees.

CONCLUSIONS

Positional MRI shows (a) physiological tibiofemoral movement in normal knees, (b) aberrant tibiofemoral alignment in the unaffected knee of ACL tear patients, and (c) a high frequency of abnormal tibiofemoral malalignment in injured knees which was more frequent, more pronounced, more multidirectional, and of a different pattern in ACL-tear knees than non-ACL-injured knees.

KEY POINTS

• Positional MRI shows physiological tibiofemoral translation and rotation in normal knees. • Positional MRI shows a different pattern of tibiofemoral alignment in the unaffected knee of ACL tear patients compared to normal control knees. • Positional MRI shows a high prevalence of abnormal tibiofemoral alignment in injured knees, which is more frequent and pronounced in ACL-tear knees than in ACL-intact injured knees.

Does the contralateral healthy ankle of patient with ipsilateral mechanical lateral ankle laxity show greater lateral ankle laxity? Evaluation of the anterior talofibular ligament by stress ultrasonography

Background

A number of studies have evaluated risk factors for lateral ankle sprain (LAS) or chronic lateral ankle instability (CLAI). However, the definitive risk factors for LAS or CLAI remain controversial. The purpose of this study was to evaluate whether the contralateral healthy ankles of subjects with ipsilateral mechanical lateral ankle laxity (group I) show greater lateral ankle laxity in comparison to the healthy ankles of bilateral healthy controls (group B).

Methods

From March 2020, anterior talofibular ligament (ATFL) lengths of young adult volunteers were cross-sectionally measured in non-stress and stress positions using a previously reported stress ultrasonography (US) procedure. The ATFL ratio (the ratio of stress ATFL/non-stress ATFL length) was calculated as an indicator of lateral ankle laxity. The manual anterior drawer test (ADT) was also performed. The US findings of healthy ankles from groups I and B were compared.

Results

A total of 154 subjects in group B (mean age, 24.5 ± 2.8 years; male/female, 84/70) and 40 subjects in group I (mean age, 24.4 ± 2.3 years; male/female, 26/14) were included in the study. There was no significant difference in the ADT between the groups. There were no significant differences in the non-stress ATFL length (19.4 ± 1.8 vs. 19.3 ± 1.9, p = 0.84), stress ATFL length (20.8 ± 1.8 vs. 20.9 ± 1.9, p = 0.66), length change (1.5 ± 0.6 vs. 1.6 ± 0.6, p = 0.12) and ATFL ratio (1.08 ± 0.03 vs. 1.08 ± 0.03, p = 0.13) between the groups.

Conclusion

No significant difference was detected between the contralateral healthy ankles of subjects with ipsilateral mechanical lateral ankle laxity and those of bilateral healthy controls.

The Long-term Chondroprotective Effect of Meniscal Allograft Transplant: A 10- to 14-Year Follow-up Study

BACKGROUND

The long-term chondroprotective effect of meniscal allograft transplant (MAT) and its superiority over meniscectomy have rarely been reported.

HYPOTHESIS

MAT would reduce osteoarthritis (OA) progression when compared with the meniscus-deficient knee. Graft extrusion distance would strongly affect the chondroprotective effect of the MAT.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 17 knees receiving MAT were followed up as the MAT group. The MAT group was further divided into the nonextrusion subgroup (n = 9) and the extrusion subgroup (n = 8) according to 3-mm extrusion on the magnetic resonance imaging (MRI) coronal section. A further 26 consecutive patients receiving meniscectomy in the same period were followed up as the ME group. The healthy control group consisted of healthy contralateral legs chosen from the MAT and ME groups (n = 27). Joint space width (JSW) narrowing was measured on radiographs. Three-dimensional MRI with a T2 mapping sequence was used to quantitatively analyze cartilage degeneration and meniscal allograft extrusion in 5 directions (0°, 45°, 90°, 135°, and 180°). The cartilage degeneration index (CDI) was calculated according to the size and degree of the chondral lesions on MRI scans. The correlation between the CDI increase and the extrusion distance was analyzed.

RESULTS

The mean follow-up time was 11.3 years (range, 10-14 years). The MAT group had moderate superiority in chondral protection with less JSW narrowing (0.58 ± 0.66 mm) and CDI increase (1132 ± 1589) compared with the ME group (JSW narrowing: 1.26 ± 1.13 mm, P = .025; CDI increase: 2182 ± 1958, P = .079). The JSW narrowing (0.71 ± 0.80 mm; P = .186) and CDI increase (2004 ± 1965; P = .830) of the extrusion subgroup were close to those of the ME group, demonstrating that a 3-mm extrusion led to complete loss of the meniscal chondroprotective effect. The nonextrusion group had significantly less JSW narrowing (0.48 ± 0.48 mm; P = .042) and CDI increase (358 ± 249; P = .011) than the ME group. The JSW narrowing of the healthy control group was 0.22 ± 0.27 mm. The cartilage T2 values of the extrusion subgroup were similar to those of the ME group, with more OA features, whereas the T2 values of the nonextrusion subgroup were closer to those of the healthy control group. The extrusion distance in the 90° direction (P = .002) and the follow-up time (P = .019) significantly affected the CDI increase in the multivariate regression model. The average extrusion distance in the 45°, 90°, and 135° directions better predicted chondroprotection compared with the other individual directions.

CONCLUSION

MAT had moderate advantages in chondroprotection compared with meniscectomy in the long term. Graft extrusion distance strongly affected the chondroprotective effect of MAT. The chondroprotective effect of the nonextruded meniscal allograft was close to that of the native meniscus, whereas the allografts with an extrusion >3 mm completely lost their function after meniscectomy.

The Ratio of Stress to Nonstress Anterior Talofibular Ligament Length on Ultrasonography: Normative Values

Background:

Stress ultrasonography (US) has been shown to be a valid procedure for evaluating chronic anterior talofibular ligament (ATFL) injury. The ratio of stress/nonstress ATFL length (ATFL ratio) as measured on US is clinically useful; however, there are no published normative data concerning this ratio.

Purpose:

To report a normative value of the ATFL ratio on US and evaluate the relationships between sex, generalized joint laxity (GJL), and the grade of anterior drawer test (ADT).

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

The ATFL lengths were prospectively measured in the stress and nonstress positions (manual maximal anterior drawer position) for participants with noninjured ankles from March 2020 to March 2021. GJL was defined as a Beighton score ≥4. A manual ADT was also performed. The ATFL ratio was calculated, and the relationships between sex, GJL, and ADT grade were evaluated.

Results:

A total of 333 ankles in 184 participants (mean age, 24.5 ± 2.7 years; range, 20-33 years) were eligible for the analysis. GJL was found in 69 ankles (20.7%). The mean ATFL ratio was 1.08 ± 0.04 (95% CI, 1.08-1.09; range, 1.01-1.24), and there was a significant difference between male (1.07 ± 0.04; 95% CI, 1.07-1.08; range, 1.02-1.23) and female (1.09 ± 0.04; 95% CI, 1.08-1.10; range, 1.01-1.24) ankles (P = .001). In male ankles, the ATFL ratio was significantly greater in participants with GJL (1.11 ± 0.06 vs 1.07 ± 0.03; P = .02) or a higher grade of ADT (grade 2 vs grade 1: 1.11 ± 0.06 vs 1.07 ± 0.03, P = .002). These findings were not observed in female ankles.

Conclusion:

The normative value of the ATFL ratio on stress US was 1.07 ± 0.04 in men and 1.09 ± 0.04 in women. The ATFL ratio was affected by the presence of GJL in men but not in women. These findings will be useful for future studies seeking to establish the cutoff value of the ATFL ratio for diagnosing chronic lateral ankle stability on stress US.

Altered Knee Laxity and Stiffness in Response to a Soccer Match Simulation in Players Returning to Sport Within 12 Months After Anterior Cruciate Ligament Reconstruction

BACKGROUND

The acute effects of exercise on anterior knee laxity (AKL) and anterior knee stiffness (AKS) have been documented in healthy participants, but only limited evidence has been provided for athletes cleared to return to sports after anterior cruciate ligament (ACL) reconstruction (ACLR).

PURPOSE/HYPOTHESIS

The purpose was to determine if 45 minutes of a soccer match simulation lead to acute changes in AKL and AKS in soccer players returning to sport within 12 months after ACLR. We hypothesized that the reconstructed knee of the ACLR group would exhibit an altered response to sport-specific exercise.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 13 soccer players cleared to return to sport after ACLR and 13 healthy control soccer players matched for age, physical activity level, limb dominance, and anthropometric characteristics were recruited. To assess the effects of a standardized soccer match simulation (Soccer Aerobic Field Test [SAFT45]) on AKL and AKS, an arthrometric evaluation was carried out bilaterally before and immediately after SAFT45. To conduct a comprehensive examination of the force-displacement curve, the absolute and side-to-side difference (SSD) values of both AKL and AKS were extracted at 67, 134, and 200 N.

RESULTS

The ACLR and control groups showed similar AKL and AKS at baseline (P > .05). In response to SAFT45, laxity increased bilaterally at all force levels by 14% to 17% only in the control group (P < .025). Similarly, AKS at 134 and 200 N decreased in response to SAFT45 only in the control group (10.5% and 20.5%, respectively; P < .025). After SAFT45, the ACLR group had 1.9 and 2.5 times higher SSDs of AKS at 67 and 134 N compared with the control group, respectively (P < .025), as well as a 1.9 times higher SSD of AKS at 134 N compared with baseline (P = .014).

CONCLUSION

Soccer players at the time of return to sport after ACLR showed an altered mechanical response to a sport-specific match simulation consisting of bilaterally unchanged AKL and AKS.

CLINICAL RELEVANCE

Soccer players showing altered AKL and AKS in response to exercise after ACLR may not be ready to sustain their preinjury levels of sport, thus potentially increasing the risk of second ACL injuries.

Reliability of a Robotic Knee Testing Tool to Assess Rotational Stability of the Knee Joint in Healthy Female and Male Volunteers

BACKGROUND

Several clinical tests exist to assess knee laxity. Although these assessments are the predominant tools of diagnosis, they are subjective and rely on the experience of the clinician. The robotic knee testing (RKT) device has been developed to quantitatively and objectively measure rotational knee laxity. The purpose of this study was primarily to determine the intra-tester reliability of rotational knee laxity and slack, the amount of rotation occurring between the two turning points of the load deformation curve, measured by the RKT device and investigate the differences between female and male measurements.

METHODS

Ninety-one healthy and moderately active volunteers took part in the study, of which twenty-five participated in the reliability study. Tibial rotation was performed using a servomotor to a torque of 6 N m, while measurements of motion in all 6° of freedom were collected. Reliability measurements were collected over 5 days at similar times of the day. Intra-class correlation coefficient (ICC) values and standard error of measurement (SEM) were determined across the load deformation curves. Linear mixed effects modelling was used to further assess the reliability of the measurement of external and internal tibial rotation using features of the curve (internal/external rotational laxity and slack). Measurements of internal/external rotational laxity and slack were compared between the sexes using the Student t test.

RESULTS

Pointwise axial rotation measurements of the tibia had good reliability [ICC (2,1) 0.83-0.89], while reliability of the secondary motions ranged between poor and good [ICC (2,1) 0.31-0.89]. All SEMs were less than 0.3°. Most of the variation of the curve features were accounted for by inter-subject differences (56.2-77.8%) and showed moderate to good reliability. Comparison of the right legs of the sexes revealed that females had significantly larger amounts of internal rotation laxity (females 6.1 ± 1.3° vs males 5.6 ± 0.9°, p = 0.037), external rotation laxity (females 6.0 ± 1.6° vs males 5.0 ± 1.2°, p = 0.002) and slack (females 19.2 ± 4.2° vs males 16.6 ± 2.9°, p = 0.003). Similar results were seen within the left legs.

CONCLUSIONS

Overall, the RKT is a reliable and precise tool to assess the rotational laxity of the knee joint in healthy individuals. Finally, greater amounts of laxity and slack were also reported for females.

Which Children Are at Risk for Contralateral Anterior Cruciate Ligament Injury After Ipsilateral Reconstruction?

BACKGROUND

Following anterior cruciate ligament (ACL) reconstruction, children are at significant risk for complications, including contralateral ACL rupture. The purpose of this study is to determine which children are at risk for a contralateral ACL tear after ipsilateral reconstruction.

METHODS

After review of medical records, we contacted patients who underwent primary ACL reconstruction between 2009 and 2016. Patients were included in the study if they were able to provide follow-up data either in person or remotely at least 2 years after surgery. Demographic data, sports participation, and intraoperative findings and techniques were recorded. All patients were also asked to confirm returning to sport information and postoperative complications (including contralateral ACL tear). Univariate analysis consisted of χ and independent samples t tests. Purposeful entry logistic regression was then conducted to control for confounding factors. Kaplan-Meier analysis was performed to assess contralateral ACL survival.

RESULTS

A total of 498 children with average follow-up of 4.3±2.1 years were included in the analysis. The mean age was 15.0±2.3 years and 262 patients (52.6%) were female. Thirty-five subjects (7.0%) sustained a contralateral ACL tear at a mean of 2.7±1.7 years following index reconstruction. Kaplan-Meier analysis revealed the median contralateral ACL survival time to be 8.9 years [95% confidence interval (CI): 8.3, 9.5 y]. In univariate analysis, 11.5% of female patients had a contralateral rupture compared with 2.1% of male patient (P<0.001). Patients with a contralateral tear had a mean age of 14.4±2.0 years compared with 15.1±2.3 years for those without an ACL injury in the opposite knee (P=0.04). After controlling for numerous factors in a multivariate model, female patients had 3.5 times higher odds of sustaining a contralateral ACL tear than male patients (95% CI: 1.1, 10.6; P=0.03). Each year of decreasing age raised the odds of contralateral injury by a factor of 1.3 (95% CI: 1.1, 1.6; P=0.02). Furthermore, children younger than 15 years had 3.1 times higher odds of contralateral rupture than those aged 15 and older (95% CI: 1.3, 7.2; P=0.01).

CONCLUSIONS

After adjusting for confounding factors in a multivariate model, female patients were at increased risk of contralateral ACL tear following ipsilateral reconstruction, as were younger children. Specifically, ACL rupture in the opposite knee was more likely in patients below the age of 15 years.

LEVEL OF EVIDENCE

Level III-prognostic study.

Patients With Failed Anterior Cruciate Ligament Reconstruction Have an Increased Posterior Lateral Tibial Plateau Slope: A Case-Controlled Study

PURPOSE

To compare knee anatomical parameters of patients with failed anterior cruciate ligament reconstruction (ACL-R) with those of a control group of sex-matched patients with successful ACL-R.

METHODS

Forty-three patients (34 male, 9 female) who experienced graft failure after ACL-R were enrolled in the failed group. These patients were matched to a control group of 43 patients who underwent primary ACL-R with a minimum follow-up of 24 months. On magnetic resonance imaging, the following parameters were evaluated: transepicondylar distance, lateral and medial femoral condyle widths, tibial plateau width, notch width index, and the ratio of width and height of the femoral notch, ratio between the height and depth of the lateral and medial femoral condyle, lateral and medial posterior tibial slopes, and anterior subluxation of the lateral and medial tibial plateau. Multivariate regression with backward elimination, including only the previously identified significant variables, defined the independent predictors for revision surgery.

RESULTS

The anatomical variables that were significantly different between the 2 study groups were lateral and medial posterior tibial slopes, anterior subluxation of the lateral and medial tibial plateau, medial tibial plateau width, lateral tibial plateau width, medial femoral condyle width, and transepicondylar distance; however, the multivariate regression analysis identified the lateral posterior tibial slope (LTPs), the anterior subluxation of the medial tibial plateau, and the medial femoral condyle width as significant independent predictors (P < .05). The LPTs had the highest coefficient and the highest sensitivity (88%) and specificity (84%) to identify failures when considering the optimal cutoff value of 7.4°.

CONCLUSIONS

Several anatomical parameters have been identified that differ significantly between patients with failed ACL-R and those without a documented failure. The most accurate predictor of ACL failure was an LTPs >7.4°, with a sensitivity of 88% and specificity of 84%. Surgeons should consider measuring LTPs during preoperative assessment of ACL-injured patients, and patients with values >7.4° should be considered at high risk of ACL-R failure.

LEVEL OF EVIDENCE

Level III retrospective prognostic trial.

"I never made it to the pros…" Return to sport and becoming an elite athlete after pediatric and adolescent anterior cruciate ligament injury-Current evidence and future directions

The management of anterior cruciate ligament (ACL) injuries in the skeletally immature and adolescent patient remains an area of controversy in sports medicine. This study, therefore, summarizes and discusses the current evidence related to treating pediatric and adolescent patients who sustain an ACL injury. The current literature identifies a trend towards ACL reconstruction as the preferred treatment option for ACL injuries in the young, largely justified by the risk of further structural damage to the knee joint. Worryingly, a second ACL injury is all too common in the younger population, where almost one in every three to four young patients who sustain an ACL injury and return to high-risk pivoting sport will go on to sustain another ACL injury. The clinical experience of these patients emphasizes the rarity of an athlete who makes it to elite level after a pediatric or adolescent ACL injury, with or without reconstruction. If these patients are unable to make it to an elite level of sport, treatment should possibly be modified to take account of the risks associated with returning to pivoting and strenuous sport. The surveillance of young athletes may be beneficial when it comes to reducing injuries. Further research is crucial to better understand specific risk factors in the young and to establish independent structures to allow for unbiased decision-making for a safe return to sport after ACL injury. Level of evidence V.

Correlation between quantitative pivot shift and generalized joint laxity: a prospective multicenter study of ACL ruptures

PURPOSE

To investigate whether an increased magnitude of quantitative rotatory knee laxity is associated with a greater level of generalized joint laxity in ACL-injured and contralateral knees.

METHODS

A total of 103 patients were enrolled across four international centers to undergo anatomic ACL reconstruction. Rotatory knee laxity was evaluated preoperatively, both in the awake state and under anesthesia, using the standardized pivot shift test. Two devices were used to quantify rotatory knee laxity; an inertial sensor, measuring the joint acceleration, and an image analysis system, measuring the lateral compartment translation of the tibia. The presence of generalized joint laxity was determined using the Beighton Hypermobility Score. The correlation between the level of generalized joint laxity and the magnitude of rotatory knee laxity was calculated for both the involved knee and the non-involved knee. Further, patients were dichotomized into low (0-4) or high (5-9) Beighton Score groups. Alpha was set at < 0.05.

RESULTS

Ninety-six patients had complete datasets, 83 and 13 in the low and high Beighton Score groups respectively. In anesthetized patients, there was a significant correlation between the degree of Beighton Score and quantitative pivot shift when analyzing the non-involved knee using the image analysis system (r = 0.235, p < 0.05). When analyzing the same knee, multivariate analysis adjusted for meniscal injury, age and gender revealed an increased odds ratio for patients with increased lateral compartment translation to be part of the high Beighton Score group (OR 1.86, 95% CI 1.10-3.17, p < 0.05). No other correlation was significant. When analyzing the dichotomized subgroups, no significant correlations could be established.

CONCLUSION

The findings in this study suggest that there is a weak correlation between generalized joint laxity and the contralateral healthy knee, indicating increased rotatory knee laxity in these patients. Generalized joint laxity does not appear to correlate with rotatory knee laxity in ACL-injured knees.

LEVEL OF EVIDENCE

Prospective cohort study; level of evidence, 2.

Clinical course and recommendations for patients after anterior cruciate ligament injury and subsequent reconstruction: A narrative review

Almost all athletes who have suffered an anterior cruciate ligament (ACL) injury expect a full return to sports at the same pre-injury level after ACL reconstruction (ACLR). Detailed patient information on the reasonable outcomes of the surgery may be essential to improve patient satisfaction.

Pre-operative rehabilitation before ACLR should be considered as an addition to the standard of care to maximise functional outcomes after ACLR.

We propose an optimised criterion-based rehabilitation programme within a biopsychosocial framework.

No benchmark exists for evaluating return-to-sport (RTS) readiness after ACLR. Therefore, the authors propose a multi-factorial RTS test battery. A combination of both physical and psychological elements should be included in the RTS test battery.

There is need for shared decision-making regarding RTS.

Cite this article: EFORT Open Rev 2017;2:410-420. DOI: 10.1302/2058-5241.2.170011

Global rotation has high sensitivity in ACL lesions within stress MRI

PURPOSE

This study aims to objectively compare side-to-side differences of P-A laxity alone and coupled with rotatory laxity within magnetic resonance imaging, in patients with total anterior cruciate ligament (ACL) rupture.

METHODS

This prospective study enrolled sixty-one patients with signs and symptoms of unilateral total anterior cruciate ligament rupture, which were referred to magnetic resonance evaluation with simultaneous instrumented laxity measurements. Sixteen of those patients were randomly selected to also have the contralateral healthy knee laxity profile tested. Images were acquired for the medial and lateral tibial plateaus without pressure, with postero-anterior translation, and postero-anterior translation coupled with maximum internal and external rotation, respectively.

RESULTS

All parameters measured were significantly different between healthy and injured knees (P < 0.05), with exception of lateral plateau without stress. The difference between injured and healthy knees for medial and lateral tibial plateaus anterior displacement (P < 0.05) and rotation (P < 0.001) was statistically significant. It was found a significant correlation between the global rotation of the lateral tibial plateau (lateral plateau with internal + external rotation) with pivot-shift, and between the anterior global translation of both tibial plateaus (medial + lateral tibial plateau) with Lachman. The anterior global translation of both tibial plateaus was the most specific test with a cut-off point of 11.1 mm (93.8 %), and the global rotation of the lateral tibial plateau was the most sensitive test with a correspondent cut-off point of 15.1 mm (92.9 %).

CONCLUSION

Objective laxity quantification of ACL-injured knees showed increased sagittal laxity, and simultaneously in sagittal and transversal planes, when compared to their healthy contralateral knee. Moreover, when measuring instability from anterior cruciate ligament ruptures, the anterior global translation of both tibial plateaus and global rotation of the lateral tibial plateau add diagnostic specificity and sensitivity. This work strengthens the evidence that the anterior cruciate ligament plays an important biomechanical role in controlling the anterior translation, but also both internal and external rotation. The high sensitivity and specificity of this device in objectively identifying and measuring the multiplanar instability clearly guides stability restoration clinical procedures. Level of evidence Cross-sectional study, Level III.

Nonmodifiable risk factors for anterior cruciate ligament injury

PURPOSE OF REVIEW

As anterior cruciate ligament (ACL) injury is becoming increasingly prevalent in the population of active children and young adolescents, it is crucial to be aware of both the modifiable and nonmodifiable factors that place this population at increased ACL injury risk. Historically, there has not been a definitive consensus on all of these risk factors-particularly the nonmodifiable ones.

RECENT FINDINGS

The present review has accumulated the most recent evidence for the nonmodifiable risk factors in ACL injury focusing particularly on female gender, generalized joint laxity, knee recurvatum, increased lateral tibial slope, decreased intercondylar notch width, structural lower extremity valgus, limb length discrepancy, family history, and history of contralateral knee ACL injury.

SUMMARY

Physicians should be aware of the nonmodifiable risk factors for ACL tears in active children and adolescents and should also encourage avoidance of modifiable risk factors in this population. Young athletes with nonmodifiable risk factors are at a particularly increased risk of recurrent injury following ACL reconstruction (ACLR). We believe that a primary extra-articular augmentation via iliotibial band tenodesis at the same time of ACLR may decrease the rate of reinjury for the high risk athlete with multiple nonmodifiable risk factors.

An Ecological Study of Anterior Cruciate Ligament Reconstruction, Part 1: Clinical Tests Do Not Correlate With Return-to-Sport Outcomes

BACKGROUND

Additional high-quality prospective studies are needed to better define the objective criteria used in relation to return-to-sport decisions after synthetic (ligament advanced reinforcement system [LARS]) and autograft (hamstring tendon [2ST/2GR]) anterior cruciate ligament (ACL) reconstruction in active populations.

PURPOSE

To prospectively investigate and describe the recovery of objective clinical outcomes after autograft (2ST/2GR) and synthetic (LARS) ACL reconstructions, as well as to investigate the relationship between these clinimetric test outcomes and return-to-sport activity (Tegner activity scale [TAS] score) at 12 and 24 months postoperatively.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 64 patients who underwent ACL reconstruction (32 LARS, 32 2ST/2GR autograft) and 32 healthy reference participants were assessed for joint laxity (KT-1000 arthrometer), clinical outcome (2000 International Knee Documentation Committee [IKDC] knee examination), and activity (TAS score) preoperatively and at 12, 16, 20, and 24 weeks and 12 and 24 months postoperatively.

RESULTS

There was no significant correlation observed between clinical results using the 2000 IKDC knee examination and TAS score at 24 months (r_s = 0.188, P = .137), nor were results for side-to-side difference (r_s = 0.030, P = .814) or absolute KT-1000 arthrometer laxity of the surgical leg at 24 months postoperatively (r_s = 0.076, P = .553) correlated with return-to-sport activity. Nonetheless, return-to-sport rates within the surgical cohort were 81% at 12 months and 83% at 24 months, respectively. No statistically significant differences were observed between physiological laxity of the uninjured knee within the surgical group compared with healthy knees within the reference group (P = .522).

CONCLUSION

The results indicate that although relatively high levels of return-to-sport outcomes were achieved at 24 months compared with those previously reported in the literature, correlations between objective clinical tests and return-to-sport outcomes may not occur. Clinical outcome measures may provide suitable baseline information; however, the results of this study suggest that clinicians may need to place greater emphasis on other outcome measures when seeking to objectively promote safe return to sport.

Objective measurements of static anterior and rotational knee laxity

Several devices allow to measure anterior and rotational static knee laxity. To date, the use of rotational laxity measurements in the daily clinical practice however remains to be improved. These measurements may be systematically integrated to the follow-up of knee injuries. Physiologic laxity measurements may particularly be of interest for the identification of risk factors in athletes. Furthermore, knee laxity measurements help to improve the diagnosis of knee soft tissue injuries and to follow up reconstructions. Further prospective follow-ups of knee laxity in the injured/reconstructed knees are however required to conclude on the best treatment strategy for knee soft tissue injuries.