Lesão parcial do ligamento cruzado anterior: diagnóstico e tratamento

Nanosurgical and Bioengineering Treatment of Human Anterior Cruciate Ligament Tears with Ultrasound-Guided Injection of Modified Platelet-Rich Plasma Using Human Cell Memory Based on Clinical, Ultrasound, MRI, and Nanoscope Analyses: A Double-Blind Randomized Trial

Background: Anterior cruciate ligament (ACL) tears account for 40% to 50% of all ligamentous knee injuries. Most patients with ACL ruptures undergo surgical treatment. There is currently no objective, well-documented, repeatable, and standardized nonsurgical method for ACL tear treatment. This study aimed to investigate ACL outcomes in patients who underwent a novel nanosurgery and bioengineering treatment (NSBT) for an ACL tear. Methods: This was a double-blind randomized trial including 44 patients with a history of traumatic knee injury and a confirmed ACL tear. The final sample comprised 40 patients who met all the eligibility criteria. The patients were divided into two groups: the treatment group (n = 30) and the control group (n = 10). The treatment group underwent nanosurgery with an ultrasound-guided injection of modified platelet-rich plasma (PRP) using human cell memory (RP-hCM). The control group was treated with an ultrasound-guided PRP injection into the joint capsule. At baseline and post-treatment, all patients underwent both ultrasonography and magnetic resonance imaging (MRI), and the following clinical variables were assessed: the WOMAC score, the Lysholm knee score, the visual analog scale score, and knee instability. In most patients, the clinical outcome was verified using nanoscopy. Results: The median WOMAC, VAS, and LKS scores, as well as knee instability, improved significantly 12 weeks after the procedure in the treatment group (p < 0.001). We found a significantly larger improvement in the assessed parameters in the treatment group compared to the control group (p < 0.001). In the treatment group, all the patients had good and very good clinical outcomes, while 90% of the patients had a normal ACL signal in a follow-up MRI scan. In the control group, a physical examination revealed no changes in knee stability after treatment. Conclusions: This study showed that there is a significant difference in patient experience and the duration of recovery for patients with ACL tears treated with NSBT. The novel nonsurgical method was shown to be repeatable, objective, well documented, standardized, and highly effective.

The Value of Ultrasound Diagnostic Imaging of Anterior Crucial Ligament Tears Verified Using Experimental and Arthroscopic Investigations

This study investigates the potential of the ultrasound imaging technique in the assessment of Anterior Cruciate Ligament (ACL) pathologies by standardizing the examination process. We focused on four key ultrasound parameters: the inclination of the ACL; swelling or scarring at the ACL's proximal attachment to the lateral femoral condyle; swelling or scarring of the ACL/posterior cruciate ligament (PCL) compartment complex with accompanying morphological changes in the posterior joint capsule; and dynamic instability, categorized into three ranges-0-2 mm, 3-4 mm, and ≥5 mm. The study group consisted of 25 patients with an ACL injury and 25 controls. All four tested parameters were found more frequently in the study group compared to the control (p < 0.0001). Our findings suggest that this standardized approach significantly augments the diagnostic capabilities of ultrasound, complementing clinical evaluation and magnetic resonance imaging (MRI) findings. The meticulous assessment of these parameters proved crucial in identifying subtle ACL pathologies, which might otherwise be missed in conventional imaging modalities. Notably, the quantification of dynamic instability and the evaluation of morphological changes were instrumental in early detection of ACL injuries, thereby facilitating more precise and effective treatment planning. This study underscores the importance of a standardized ultrasound protocol in the accurate diagnosis and management of ACL injuries, proposing a more comprehensive diagnostic tool for clinicians in the field of sports medicine and orthopedics.

BLU-DAT: a new reliable and accurate arthrometer for measuring anterior knee laxity

PURPOSE

Although many arthrometers have been developed to assess anterior knee laxity, reliability and diagnostic accuracy of these devices are still debated. The aim of the present study was to evaluate the validity of a new arthrometer in the outpatient setting, with the hypothesis that it had good validity in terms of reliability and diagnostic accuracy.

METHODS

Seventy-eight subjects (39 with ACL injury and 39 with normal ACL) were tested. ATT was assessed by means of the Lachman test at 30° of flexion with a new testing device (BLU-DAT) under three different loading conditions: 7 kg (69 N), 9 kg (88 N) and maximum (MMT). The tests were performed on both knees to obtain SSD. In the ACL injury group, the tests were performed by two examiners and one of them repeated a second test series. Inter- and intra-observer reliability were assessed with the intraclass correlation coefficients (ICCs) for the average SSD measures. In the normal-ACL group, the analysis was performed with the same testing setup. Side-to-side difference measures of the two groups at every loading condition were compared by Student's t test. Data of test series were dichotomized based on the threshold value of 3-mm SSD as pathological ATT and 2 × 2 contingency tables were used to assess diagnostic accuracy.

RESULTS

The ICCs for intra-observer reliability at 7-kg (69 N), 9-kg (88 N) and MMT measurements were 0.781, 0.855 and 0.913, respectively. The ICC for inter-observer reliability at 7-kg (69 N), 9-kg (88 N) and MMT measurements were 0.701, 0.845 and 0.834, respectively. Comparison between the two groups showed a significant mean difference ranging from 3.4 mm for 7-kg (69 N) load to 4.6 mm for MMT. Overall accuracy ranged from 84.6% for 7-kg load to 98.7% for MMT.

CONCLUSION

The BLU-DAT has proven to be an instrument with good intra- and inter-observer reliability and very good accuracy in the diagnosis of ACL injuries in the outpatient setting. So, the BLU-DAT can be a new useful tool in everyday clinical practice to assist in the diagnosis of ACL injury.

LEVEL OF EVIDENCE

II.

Retrospective analysis and risk of progression of partial anterior cruciate ligament injuries in a young population

BACKGROUND

The anterior cruciate ligament (ACL) is a common knee ligament injury. Partial ACL tears are common, and at least 10-27% of isolated ACL tears are diagnosed as partial tears. Patients with partial tears have high risk of progression of tears to complete tears, which may require surgical reconstruction. The risk factors associated with the progression to a complete tear are poorly understood.

METHODS

The present case-control study assessed the incidence and risk factors for the progression of conservatively treated partial ACL tears to complete tears in 351 patients younger than 45 years. The diagnosis of partial ACL tears was based on clinical evaluation, side-to-side difference on Rolimeter, and magnetic resonance imaging. These patients were managed conservatively and followed up for a mean of 17.5 months or until the progression of the tear into a complete tear, requiring surgery. The patients in whom the tear progressed to complete tear (group P) were compared with those in whom the tear remained stable for a minimum of 18-month follow-up period (group S).

RESULTS

Of the 351 partial ACL tear patients, 166 (47.3%) patients progressed to a complete tear at a mean duration of 17.5 months, whereas the tear in 185 (52.7%) patients remained stable and did not progress to a complete tear. Group P had mean international knee documentation committee (IKDC) scores and Tegner scores of 95.7 ± 3.7 and 7.6 ± 1.6, respectively, before the injury, and scores decreased to 52.4 ± 4.1 and 5.7 ± 2.2, respectively, at the 24-month follow-up.

CONCLUSION

Partial ACL tear progressed to a complete tear in 47.3% of evaluated patients. The associated risk factors were age less than 35 years, rigorous physical activities, high ACL-Return to Sport after Injury score during early rehabilitation days, early return to activity, and pivoting contact sports.

Full and Partial Mid-substance ACL Rupture Using Mechanical Tibial Displacement in Male and Female Mice

The anterior cruciate ligament (ACL) is the most commonly injured knee ligament. Surgical reconstruction is the gold standard treatment for ACL ruptures, but 20-50% of patients develop post-traumatic osteoarthritis (PTOA). ACL rupture is thus a well-recognized etiology of PTOA; however, little is known about the initial relationship between ligamentous injury and subsequent PTOA. The goals of this project were to: (1) develop both partial and full models of mid-substance ACL rupture in male and female mice using non-invasive mechanical methods by means of tibial displacement; and (2) to characterize early PTOA changes in the full ACL rupture model. A custom material testing system was utilized to induce either partial or full ACL rupture by means of tibial displacement at 1.6 or 2.0 mm, respectively. Mice were euthanized either (i) immediately post-injury to determine rupture success rates or (ii) 14 days post-injury to evaluate early PTOA progression following full ACL rupture. Our models demonstrated high efficacy in inciting either full or partial ACL rupture in male and female mice within the mid-substance of the ACL. These tools can be utilized for preclinical testing of potential therapeutics and to further our understanding of PTOA following ACL rupture.

Biological enhancement methods may be a viable option for ACL arthroscopic primary repair - A systematic review

BACKGROUND

Bioactive factors combined with advanced anterior cruciate ligament (ACL) primary repair technology have been used to treat ACL repairs. The current review was conducted to identify whether biological enhancement could enable superior clinical outcome, including side-to-side difference, failure rate, reoperation rate and subjective scores.

HYPOTHESIS

The implementation of ACL primary repair with biological enhancement will provide better clinical outcomes in terms of side-to-side differences, failure rate, reoperation rate and subjective scores than ACL primary repair alone.

MATERIALS AND METHODS

A systematic literature review was performed following PRISMA guidelines by searching all studies reporting outcomes of arthroscopic primary repair with or without biological augmentation published until April 19, 2020, in Medline, PubMed, Embase and the Cochrane Library. Primary metrics were side-to-side differences, failure rate and reoperation rate, as well as measurements of patient-reported outcomes at the last follow-up.

RESULTS

A total of 20 studies were finally included in this work, of which 3 were Grade I (15%), 3 studies were Grade III (15%), and 14 studies were Grade IV (70%) in terms of the level of evidence. There were 729 patients with a mean age of 30 (range: 8-68) years, and the mean follow-up period of which was 38 (range: 3-122) months. At the final follow-up, the postoperative side-to-side differences (the proportion of patients with a side-to-side difference less than 3mm) and patient-report outcomes were significantly better in the biological enhancement group. Nevertheless, there were no significant differences between the two groups in the rate of surgical failure, the rate of revision, or the positive Lachman test or pivot shift test.

CONCLUSION

Biologically enhanced arthroscopic ACL primary repair was superior to ACL primary repair alone in terms of postoperative side-to-side differences (proportion of patients with a side-to-side difference less than 3mm) and patient-reported outcomes. Thus, biologically enhanced arthroscopic ACL primary repair can be preferentially recommended over ACL arthroscopic primary repair alone.

LEVEL OF EVIDENCE

IV, systematic review.

Risk factors of young males with physically demanding occupations having accumulated damage of anterior cruciate ligament

Objective

To present the clinical characteristics of accumulated anterior cruciate ligament (ACL) damage among young male patients undergoing routine exercise, and to evaluate the related risk factors.

Methods

A retrospective study involving ACL‐accumulated damage from June 2015 to December 2019 was conducted. Baseline characteristics, such as age, body mass index (BMI), training parameters, and clinical signs, were recorded. The results of the radiologic examinations and related standardized tests were obtained to evaluate the research outcomes. These results were compared using Student's t‐test or Chi‐square test, and the impact of risk factors on the patient's injury were analyzed.

Results

A total of 86 men with accumulated ACL damage were included in this study. Exercise pain (86 [100%]), synovitis (80 [93.0%]), and intra‐articular effusion (79 [91.9%]) were the most common clinical symptoms. Loosening of ligaments, decreased tension, mild hyperplasia, and intercondylar fossa effusion were observed using radiography, magnetic resonance imaging, and arthroscopy. Age, BMI, training intensity, length of training, and knee hyperextension were identified as risk factors for accumulated ACL damage.

Conclusion

This study suggests that accumulated ACL damage has differentiated clinical symptoms, imaging features, and risk factors compared to common ACL injuries.

Efficacy of non-surgical management and functional outcomes of partial ACL tears. A systematic review of randomised trials

Background

The incidence of anterior cruciate ligament (ACL) injuries represents a large burden of knee injuries in both the general and sporting populations, often requiring surgical intervention. Although there is much research on complete ACL tears including outcomes and indications for surgery, little is known about the short- and long-term outcomes of non-operative, physiotherapy led intervention in partial ACL tears. The primary aim of this study was to evaluate studies looking at the effectiveness of physiotherapy led interventions in improving pain and function in young and middle-aged adults with partial ACL tears. Additionally, the secondary aim was to evaluate the completeness of exercise prescription in randomised trials for physiotherapy led interventions in the management in partial ACL tears.

Methods

A comprehensive and systematic search was performed on six databases (Medline, CINAHL, EMBASE, PEDro, Scopus, SPORTDiscus and Cochrane). The search strategy consisted of two main concepts: (i) partial ACL tears, and (ii) non-operative management. 7,587 papers were identified by the search. After screening of eligible articles by two independent reviewers, 2 randomised studies were included for analysis. The same two reviewers assessed the completeness of reporting using the Toigio and Boutellier mechanobiological exercise descriptions and Template for Intervention Description and Replication (TIDieR) checklist. Group mean standard deviations (SD) for the main outcomes was extracted from both papers for analysis. Prospero Registration Number: CRD42020179892.

Results

The search strategy identified two studies; one looking at Tai Chi and the other Pilates. The analysis indicated that Tai Chi was significant in reducing pain scores and both Tai Chi and Pilates were found to increase Muscle Peak Torque Strength (MPTS) at 180 degrees. Furthermore, Tai Chi showed a significant increase in proprioception.

Conclusions

Physiotherapy led interventions such as Pilates, and Tai Chi may improve pain, proprioception and strength in young and middle-aged adults with partial ACL tears, however full scale, high-quality randomised studies are required with long term outcomes recorded.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05278-w.

Knee Hyperextension Greater Than 5° Is a Risk Factor for Failure in ACL Reconstruction Using Hamstring Graft

Background:

The degree of knee hyperextension in isolation has not been studied in detail as a risk factor that could lead to increased looseness or graft failure after anterior cruciate ligament (ACL) reconstruction.

Purpose:

To analyze whether more than 5° of passive knee hyperextension is associated with worse functional outcomes and greater risk of graft failure after primary ACL reconstruction with hamstring tendon autograft.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

A cohort of patients who had primary ACL reconstruction with hamstring tendon autografts was divided into 2 groups based on passive contralateral knee hyperextension greater than 5° (hyperextension group) and less than 5° (control group) of hyperextension. Groups were matched by age, sex, and associated meniscal tears. The following data were collected and compared between the groups: patient data (age and sex), time from injury to surgery, passive knee hyperextension, KT-1000 arthrometer laxity, pivot shift, associated meniscal injury and treatment (meniscectomy or repair), contralateral knee ligament injury, intra-articular graft size, follow-up time, occurrence of graft failure, and postoperative Lysholm knee scale and International Knee Documentation Committee subjective form scores.

Results:

Data from 358 patients initially included in the study were analyzed; 22 were excluded because the time from injury to surgery was greater than 24 months, and 22 were lost to follow-up. From the cohort of 314 patients, 102 had more than 5° of knee hyperextension. A control group of the same size (n = 102) was selected by matching among the other 212 patients. Significant differences in the incidence of graft failure (14.7% vs 2.9%; P = .005) and Lysholm knee scale score (86.4 ± 9.8 vs 89.6 ± 6.1; P = .018) were found between the 2 groups.

Conclusion:

Patients with more than 5° of contralateral knee hyperextension submitted to single-bundle ACL reconstruction with hamstring tendons have a higher failure rate than patients with less than 5° of knee hyperextension.

Strong association of meniscus tears with complete Anterior Cruciate Ligament (ACL) injuries relative to partial ACL injuries

BACKGROUND

Anterior Cruciate Ligament (ACL) injuries are often associated with meniscus tears. These meniscus tears in long term may affect the functional outcomes after ACL reconstruction. The present study aims to identify the incidence and relative association of meniscus injuries in complete and partial ACL injuries.

METHODS

This was a retrospective study. Patients were divided into 2 groups; group I: partial ACL tear and group 2: complete ACL tear. Both groups were assessed for meniscal tears; either isolated medial/lateral or combined and odds ratio was measured between two groups.

RESULTS

A total of 43 and 219 patients were enrolled in group I and II respectively. The mean age (years) in group I and II were 25.32 ± 7.12 and 28.64 ± 10.84 respectively. There were a total of 5 and 28 females in group I and II respectively. Mean pre-injury Tegner score in group I and II was 7.02 ± 2.87 and 6.82 ± 3.14 respectively. Mean time from injury to surgery (months) in group I and II was 8.04 ± 6.43 and 7.62 ± 4.83 respectively. In group 1 There were a total of 6 with lateral meniscus tears, 9 with medial meniscus tears And 3 with combined meniscal tears in group 1 while in group 2, 47 had lateral meniscal tears, 71 had medial meniscal tears and 71 had combined tears. Group II patients had stronger association for isolated meniscal tears compared to group I, with an odds ratio of 5.05(p < 0.05). Combined meniscal tears had non-significant relation in two groups (p = 0.58).

CONCLUSION

Partial ACL injuries present with less risk of acquiring isolated meniscus tears, compared to complete ACL injuries.

Seeing Beyond Morphology-Standardized Stress MRI to Assess Human Knee Joint Instability

While providing the reference imaging modality for joint pathologies, MRI is focused on morphology and static configurations, thereby not fully exploiting the modality’s diagnostic capabilities. This study aimed to assess the diagnostic value of stress MRI combining imaging and loading in differentiating partial versus complete anterior cruciate ligament (ACL)-injury. Ten human cadaveric knee joint specimens were subjected to serial imaging using a 3.0T MRI scanner and a custom-made pressure-controlled loading device. Emulating the anterior-drawer test, joints were imaged before and after arthroscopic partial and complete ACL transection in the unloaded and loaded configurations using morphologic sequences. Following manual segmentations and registration of anatomic landmarks, two 3D vectors were computed between anatomic landmarks and registered coordinates. Loading-induced changes were quantified as vector lengths, angles, and projections on the x-, y-, and z-axis, related to the intact unloaded configuration, and referenced to manual measurements. Vector lengths and projections significantly increased with loading and increasing ACL injury and indicated multidimensional changes. Manual measurements confirmed gradually increasing anterior tibial translation. Beyond imaging of ligament structure and functionality, stress MRI techniques can quantify joint stability to differentiate partial and complete ACL injury and, possibly, compare surgical procedures and monitor treatment outcomes.

Structural Consequences of a Partial Anterior Cruciate Ligament Injury on Remaining Joint Integrity: Evidence for Ligament and Bone Changes Over Time in an Ovine Model

BACKGROUND

Severe injury to the knee joint often results in accelerated posttraumatic osteoarthritis (PTOA). In an ovine knee injury model, altered kinematics and degradation of the cartilage have been observed at 20 and 40 weeks after partial anterior cruciate ligament (ACL) transection (p-ACL Tx) surgery. However, changes to the integrity of the remaining intact intra-articular ligaments (posterolateral [PL] band and posterior cruciate ligament [PCL]) as well as the subchondral bone after anteromedial (AM) band Tx remain to be characterized.

PURPOSE

(1) To investigate histological alterations to the remaining intact intra-articular ligaments, the synovium, and the infrapatellar fat pad (IPFP) and (2) to quantify subchondral bone changes at the contact surfaces of the proximal tibia at 20 and 40 weeks after AM band Tx.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Mature female Suffolk cross sheep were allocated into 3 groups: nonoperative controls (n = 6), 20 weeks after partial ACL transection (p-ACL Tx; n = 5), and 40 weeks after p-ACL Tx (n = 6). Ligament, synovium, and IPFP sections were stained and graded. Tibial subchondral bone microarchitecture was assessed using high-resolution peripheral quantitative computed tomography.

RESULTS

p-ACL Tx of the AM band led to significant change in histological scores of the PL band and the PCL at 20 weeks after p-ACL Tx (P = .031 and P = .033, respectively) and 40 weeks after p-ACL Tx (P = .011 and P = .029) as compared with nonoperative controls. Alterations in inflammatory cells and collagen fiber orientation contributed to the greatest extent of the combined histological score in the PL band and PCL. p-ACL Tx did not lead to chronic activation of the synovium or IPFP. Trabecular bone mineral density was strongly inversely correlated with combined gross morphological damage in the top and middle layers of the subchondral bone in the lateral tibial plateau for animals at 40 weeks after p-ACL Tx.

CONCLUSION

p-ACL Tx influences the integrity (biology and structure) of remaining intact intra-articular ligaments and bone microarchitecture in a partial knee injury ovine model.

CLINICAL RELEVANCE

p-ACL Tx leads to alterations in structural integrity of the remaining intact ligaments and degenerative changes in the trabecular bone mineral density, which may be detrimental to the injured athlete's knee joint in the long term.

Anterior cruciate ligament injury patterns and their relationship to fatigue and physical fitness levels - a cross-sectional study

Anterior cruciate ligament (ACL) injury is one of the most common knee injuries that leads to many consequences such as early osteoarthritis and knee joint instability.To explore the association of the types of ACL tear (complete and partial) and side of injury (dominant vs nondominate) with types of playing surfaces, sports, shoes, and mechanism of injuries as well as to determine whether higher levels of fatigue and physical fitness are risk factors for complete ACL tear.This cross-sectional study used a questionnaire to collect information from young male adults with a confirmed ACL injury who were attending rehabilitation programs. The outcomes of interest were patterns of ACL injury, levels of fatigue before the injury on a 0 to 10 scale, and levels of physical fitness (hours per week). Mann-Whitney U and Kruskal Wallis tests were used to assess the differences between groups, while the odds ratios were calculated to evaluate risk factors for complete ACL tear.One hundred thirteen young male adults with a confirmed ACL injury were enrolled. Most of the reported ACL injuries in this study were complete tear (80.5%) and occurred more frequently in the dominant leg (74.6%) due to noncontact mechanism (63.6%). More ACL injuries happened while playing soccer (97.2%) on artificial turf (53.3%). The level of fatigue before ACL injury was significantly higher in partial ACL tear injuries compared to complete ACL tear injuries (P = .014). For every 1-point increase in the level of fatigue on a 0-10 scale, there was a 25% reduction in complete ACL injury risk (P = .023).The pattern of ACL types of tear and side of injury varies in different playing surfaces and mechanisms of injuries. Higher levels of fatigue seem to be associated with a partial tear of the ACL and reduction of a complete ACL tear risk factor.

Accuracy of collagen fibre estimation under noise using directional MR imaging

In tissues containing significant amounts of organised collagen, such as tendons, ligaments, menisci and articular cartilage, MR imaging exhibits a strong signal intensity variation caused by the angle between the collagen fibres and the magnetic field. By obtaining scans at different field orientations it is possible to determine the unknown fibre orientations and to deduce the underlying tissue microstructure. Our previous work demonstrated how this method can detect ligament injuries and maturity-related changes in collagen fibre structures. Practical application in human diagnostics will demand minimisation of scanning time and likely use of open low-field scanners that can allow re-orienting of the main field. This paper analyses the performance of collage fibre estimation for various image SNR values, and in relation to key parameters including number of scanning directions and parameters of the reconstruction algorithm. The analysis involved Monte Carlo simulation studies which provided benchmark performance measures, and studies using MR images of caprine knee samples with increasing levels of synthetic added noise. Tractography plots in the form of streamlines were performed, and an Alignment Index (AI) was employed as a measure of the detected orientation distribution. The results are highly encouraging, showing high accuracy and robustness even for low image SNR values.

Relative Surface Velocity of the Tibiofemoral Joint and Its Relation to the Development of Osteoarthritis After Joint Injury

The relative velocity of the tibiofemoral surfaces during gait before and after partial-ACL and full MCL transection (p-ACL/MCL Tx) was examined in an ovine model (N = 5) and the relation between the variation in the relative sliding velocity component and gross morphological damage was investigated. We defined the in vivo kinematics of the tibiofemoral joints by using an instrumented spatial linkage and then determining the relative velocity components on the reconstructed femoral condyle surfaces. One major finding was that the magnitude of the relative velocity components was relatively high during the initial stance period of the gait and oscillated with a decaying envelope. Interestingly, for most subjects, the highest value of relative sliding velocity occurred during the stance phase, and not swing. The magnitude of the relative velocity components was increased in 3/5 subjects during stance after an injury. For the lateral compartment, there was a significant correlation (p value = 0.005) between the joint gross morphological damage and the increase in the maximum relative sliding velocity during stance. For the medial compartment, there was a trend (p value < 0.1) between the joint gross morphological score and the increase in the maximum relative sliding velocity during stance, 20 weeks after injury. In conclusion, a connection between an increase in the relative surface velocity and gross morphological damage might be due to an increase in the normal stress and the plowing friction between the surfaces.

Triaxial accelerometer can quantify the Lachman test similarly to standard arthrometers

PURPOSE

To assess the relationship between the KiRA triaxial accelerometer and the KT-1000 measurements in the intact, anterior cruciate ligament (ACL) deficient, and ACL reconstructed knee joint for the quantification of the Lachman test. Moreover, the intra- and inter-examiner repeatability of the KiRA device will be determined. It was hypothesized that the side-to-side difference of the anterior tibial translation as measured by the KiRA device would be equivalent to the one measured by the KT-1000 during the Lachman test.

METHODS

Sixty patients were divided into three groups and have been prospectively included in the present study. Group_A composed of 20 patients with a diagnosis of an isolated ACL tear. Group_B composed of 20 patients who underwent ACL reconstruction with a Single-Bundle Lateral Plasty (SBLP) technique with at least 20 years of follow-up. Group_C was the control group and included 20 patients with no history of ACL lesion. Lachman test has been performed at manual-maximum load on both sides, the involved and the contralateral and analyzed with the two different devices.

RESULTS

The KiRA device in terms of side-to-side difference resulted not statistically different from the measurement of the KT-1000 arthrometer for the three study groups (n.s): Group_A: (4 ± 2 mm KiRA, 4 ± 2 mm KT1000), Group_B: (4 ± 2 mm KiRA, 4 ± 2 mm KT-1000), Group_C: (4 ± 2 mm KiRA, 4 ± 2 mm KT-1000), an excellent intra- (ICC = 0.88-0.89) and inter-examiner (ICC = 0.79) agreement was found for KiRA measurements.

CONCLUSION

The KiRA (I+, Italy) device offers a valid method to quantify the Lacham test.

LEVEL OF EVIDENCE

II.

Nearly 90% participation in sports activity 12 years after non-surgical management for anterior cruciate ligament injury relates to physical outcome measures

PURPOSE

Traditionally reconstructive surgery is recommended for patients planning to return to sport (RTS), especially to pivoting sports after anterior cruciate (ACL) rupture. Recent trends focus on delaying or avoiding surgery as some studies have found similar rates of RTS following both surgical and conservative management. This study aimed to establish long-term RTS levels in ACL-ruptured individuals treated conservatively, and to investigate the relationship between outcome measures and RTS, in particular, pivoting sports.

METHOD

Fifty-five patients from a cohort of 132 ACL-deficient patients were followed-up for  12 (IQR 8,19) years post injury. Mean-aged 42 years, 22 patients were females and 33 males, 35 had meniscal injuries. Patients were treated with physiotherapy focussing on strength and dynamic stability training and not reconstructive surgery. Return to sport was measured on a 6-point scale. Outcome measures included: objective stability, subjective stability, quadriceps and hamstring strength. Spearman's rho and Chi-square tests were used to assess the relationship between RTS and outcome measures.

RESULTS

Eighty-nine percent of ACL-deficient patients were currently participating in sport despite a 38% increase in anterior translation (p < 0.001) and a 7.5% loss of quadriceps strength (p = 0.004) compared to the contralateral side. Six patients (11%) did not RTS, ten (18%) returned to safe sports, five (9%) returned to running and 16 (29%) to non-strenuous sports involving limited twisting. Eighteen patients (33%) returned to pivoting sports, 12(22%) at recreational level and six (11%) at competitive level. The level of RTS was related to subjective stability (p = 0.002), and to quadriceps and hamstring strength of the injured leg (p < 0.001). Patients able to return to pivoting sports differed significantly from those not doing so in outcome measures including objective (p = 0.022) and subjective stability (p = 0.035), and quadriceps strength (p = 0.044).

CONCLUSIONS

Eighty-nine percent of ACL-ruptured individuals treated conservatively lead an active sporting life. One-third returned to pivoting sports.  Overall RTS was related to subjective and objective stability and quadriceps and to a lesser extent hamstring strength. This finding reinforced the importance of dynamic stability training as an initial treatment option in most cases.

LEVEL OF EVIDENCE

III.

Incidence and Risk Factors for a Partial Anterior Cruciate Ligament Tear Progressing to a Complete Tear After Nonoperative Treatment in Patients Younger Than 30 Years

Background:

Partial anterior cruciate ligament (ACL) tears are observed in 10% to 27% of isolated ACL tears. There is currently no consensus on diagnosis and treatment protocols, and the outcomes of nonoperative treatment remain undefined.

Purpose:

To assess the incidence and risk factors for the progression of partial ACL tears to complete ruptures after nonoperative treatment in active patients younger than 30 years.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

A total of 41 patients, all younger than 30 years and active in sports, were diagnosed with a partial ACL tear, with no associated meniscal or chondral lesions on magnetic resonance imaging (MRI). All were assigned to a nonoperative treatment program. The Lachman test, ≤4-mm side-to-side difference in laxity by Rolimeter, and MRI were utilized for the diagnosis. Tegner and International Knee Documentation Committee (IKDC) scores were assessed before and after the first lesion, and the Anterior Cruciate Ligament Return to Sport After Injury (ACL-RSI) score was assessed at last follow-up. Postinjury Tegner and IKDC scores were assessed before the second injury for patients progressing to a complete ACL tear and at last follow-up for patients without progression.

Results:

At a mean of 43 months (range, 24-96 months), the partial ACL injury progressed to a complete ACL tear in 16 (39%) patients. In the remaining 25 patients without progression, the mean Tegner and IKDC scores were 7.0 and 96.0 before the injury and 5.9 and 85.7, respectively, at last follow-up. The mean ACL-RSI score was 69.3. The Tegner and IKDC scores were significantly lower at final follow-up (P = .0002 and P < .0001, respectively). Only 18 (44%) patients returned to their preinjury level of sports activities. A significantly increased risk of progression to a complete ACL tear was seen in patients ≤20 years (odds ratio, 5.19; P = .037) or patients practicing pivoting contact sports (odds ratio, 6.29; P = .026). Meniscal lesions were found in 50% of patients with a partial tear that progressed to a complete ACL tear.

Conclusion:

A partial ACL injury progressed to a complete ACL tear in 39% of young active patients treated conservatively, with half of the complete tears presenting with a concomitant meniscal lesion at the time of reconstruction. Age ≤20 years and participation in pivoting contact sports were identified as significant risk factors for progression to a complete tear.

Detection of maturity and ligament injury using magic angle directional imaging

PURPOSE

To investigate whether magnetic field-related anisotropies of collagen may be correlated with postmortem findings in animal models.

METHODS

Optimized scan planning and new MRI data-processing methods were proposed and analyzed using Monte Carlo simulations. Six caprine and 10 canine knees were scanned at various orientations to the main magnetic field. Image intensities in segmented voxels were used to compute the orientation vectors of the collagen fibers. Vector field and tractography plots were computed. The Alignment Index was defined as a measure of orientation distribution. The knees were subsequently assessed by a specialist orthopedic veterinarian, who gave a pathological diagnosis after having dissected and photographed the joints.

RESULTS

Using 50% less scans than reported previously can lead to robust calculation of fiber orientations in the presence of noise, with much higher accuracy. The 6 caprine knees were found to range from very immature (< 3 months) to very mature (> 3 years). Mature specimens exhibited significantly more aligned collagen fibers in their patella tendons compared with the immature ones. In 2 of the 10 canine knees scanned, partial cranial caudal ligament tears were identified from MRI and subsequently confirmed with encouragingly high consistency of tractography, Alignment Index, and dissection results.

CONCLUSION

This method can be used to detect injury such as partial ligament tears, and to visualize maturity-related changes in the collagen structure of tendons. It can provide the basis for new, noninvasive diagnostic tools in combination with new scanner configurations that allow less-restricted field orientations.

Types of posterolateral corner injury associated with both bundle and selective-bundle ACL tears

BACKGROUND

It is unknown whether a selective-bundle tear of the anterior cruciate ligament (ACL) shows a different prevalence of posterolateral corner (PLC) injury than a both-bundle tear.

PURPOSE

The prevalence of injury of PLC stabilizer in relation to the type of combined ACL tear (both-bundle and selective-bundle tears) has been investigated.

MATERIAL AND METHODS

This retrospective study included 94 patients who were diagnosed with an ACL tear after knee joint magnetic resonance imaging and underwent arthroscopic surgery. We compared the prevalence of each lesion in relation to the type of ACL injury and the type of selective-bundle tear. We used Fischer exact tests to compare the prevalence of each lesion in relation to the type of ACL injury and the type of selective-bundle tear.

RESULTS

Both-bundle tears occurred in 55 cases (56%) and selective-bundle tears in 39 cases (44%). The most common PLC injury with an ACL tear was inferior popliteomeniscal fascicle (PMF) injury, followed by superior PMF injury. The prevalence of each PLC injury was higher for both-bundle tears than selective-bundle tears, with the exception of popliteus tendon injury diagnosed by reader 1 (P.H.J). However, these differences were statistically significant for superior PMF injury only ( p < 0.05). The prevalence of PLC injury was unrelated to the type of selective-bundle tear (anteromedial vs posterolateral).

CONCLUSION

Superior PMF injury is more common in both-bundle tears than selective-bundle tears. There is no statistically significant difference in the prevalence of PLC injury between both-bundle tears and selective-bundle tears.

Three-dimensional in vivo kinematics and finite helical axis variables of the ovine stifle joint following partial anterior cruciate ligament transection

Partial anterior cruciate ligament (p-ACL) rupture is a common injury, but the impact of a p-ACL injury on in vivo joint kinematics has yet to be determined in an animal model. The in vivo kinematics of the ovine stifle joint were assessed during 'normal' gait, and at 20 and 40 weeks after p-ACL transection (Tx). Gross morphological scoring of the knee was conducted. p-ACL Tx creates significant progressive post-traumatic osteoarthritis (PTOA)-like damage by 40 weeks. Statistically significant increases for flexion angles at hoof-strike (HS) and mid-stance (MST) were seen at 20 weeks post p-ACL Tx and the HS and hoof-off (HO) points at 40 weeks post p-ACL-Tx, therefore increased flexion angles occurred during stance phase. Statistically significant increases in posterior tibial shift at the mid-flexion (MF) and mid-extension (ME) points were seen during the swing phase of the gait cycle at 40 weeks post p-ACL Tx. Correlation analysis showed a strong and significant correlation between kinematic changes (instabilities) and gross morphological score in the inferior-superior direction at 40 weeks post p-ACL Tx at MST, HO, and MF. Further, there was a significant correlation between change in gross morphological combined score (ΔGCS) and the change in location of the helical axis in the anterior direction (ΔsAP) after p-ACL Tx for all points analyzed through the gait cycle. This study quantified in vivo joint kinematics before and after p-ACL Tx knee injury during gait, and demonstrated that a p-ACL knee injury leads to both PTOA-like damage and kinematic changes.

Knee hyperextension and a small lateral condyle are associated with greater quantified antero-lateral rotatory instability in the patients with a complete anterior cruciate ligament (ACL) rupture

PURPOSE

To identify factors associated with quantified rotatory stability (pivot-shift phenomenon) in the anterior cruciate ligament (ACL)-injured knee joint.

METHODS

A consecutive sample of 54 patients who were diagnosed with an ACL injury and admitted to our hospital to undergo ACL reconstruction were enrolled in this study. Antero-lateral rotatory laxity of the knee joint was quantified using a Kinematic Rapid Assessment device (KiRA; Orthokey LTD) under spinal block before initiating reconstruction of the ACL. Univariate and multivariate regressions were performed assuming relationships between patient characteristics (independent variables) and quantified antero-lateral rotatory stability (a dependent variable).

RESULTS

It was observed that a low BMI (t = - 1.659, n.s.), greater passive knee extension angle (t = 2.374, P = 0.023), and a narrower lateral femoral condyle width index (t = - 1.712, n.s.) could be candidates associated with the antero-lateral rotatory instability, using univariate analysis. Employing multivariate analysis controlling for these three variables, that the range of passive knee extension was found to be significantly associated with antero-lateral rotatory instability in the ACL-injured knee joint (t = 2.21, P = 0.035). Patients were then divided into two groups (pivot-shift negative versus positive groups) based on the KiRA-documented quantified pivot-shift test. Interestingly, 23.3% of patients were pivot-shift negative, even though their ACL was confirmed as a complete rupture by arthroscopic observations. The degree of passive knee extension was 2.3 ± 4.5 (mean ± SD) in the pivot-shift negative group, while it was 6.8 ± 6.6 in the pivot-shift positive group (n.s.). The lateral femoral condyle width index was 36.6 ± 2.0% in the pivot-shift negative group, and it was significantly wider than in the pivot-shift positive group (33.8 ± 2.6%, P = 0.0046). Finally, we estimated that the risk of positive pivot-shift depends on the degree of knee extension. The logistic regression analysis revealed that genu recurvatum significantly increased the odds ratio for positive pivot-shift (OR = 3.08, P = 0.047, 95% CI = 1.017-9.350).

CONCLUSIONS

This study revealed that greater antero-lateral rotatory instability in patients with a complete ACL rupture was associated with genu recurvatum and small lateral femoral condyle. These factors should be considered as predictors of a poor outcome from an ACL reconstruction due to a higher load on the ACL graft, and therefore, the attending physicians should modify the treatment strategies accordingly. This study indicates that joint hyperlaxity and bone morphology contribute to the rotational stability of the knee joint, in addition to the ACL and antero-lateral complex (ALC).

LEVEL OF EVIDENCE

IV.

"Over the Top" Augmentation for Partial Anterior Cruciate Ligament Tears Using Suspension Device for Tibial Fixation

A technique for augmentation of the partial anterior cruciate ligament is presented. The patient is positioned supine with the knee flexed 90°. After addressing intra-articular injuries, the autologous semitendinosus tendon is harvested and measured in a doubled manner; after that, the tibial tunnel is performed in the outside-in direction, of the same diameter of the doubled graft. Both ends of the graft are sutured together, after inserting it through the loop of a suspension device, which is attached in its augmentation piece. A lateral femoral incision is made, to approach the joint through the "over the top" position. A looped thread is introduced inside the joint with the aid of a hook. This thread pulls the graft's sutures through the "over the top" position. A femoral tunnel is then drilled in the lateromedial and caudocranial direction. The suspension device is attached to the anterior tibial cortex and the graft is pulled in the caudocranial direction to the femoral tunnel, where an interference screw is used for fixation.

Posttraumatic Osteoarthritis Development and Progression in an Ovine Model of Partial Anterior Cruciate Ligament Transection and Effect of Repeated Intra-articular Methylprednisolone Acetate Injections on Early Disease

BACKGROUND

Partial anterior cruciate ligament (p-ACL) ruptures are a common injury of athletes. However, few preclinical models have investigated the natural history and treatment of p-ACL injuries.

PURPOSE

To (1) demonstrate whether a controlled p-ACL injury model (anteromedial band transection) develops progressive gross morphological and histological posttraumatic osteoarthritis (PTOA)-like changes at 20 and 40 weeks after the injury and (2) investigate the efficacy of repeated (0, 5, 10, and 15 weeks) intra-articular injections of methylprednisolone acetate (MPA; 80 mg/mL) in the mitigation of potential PTOA-like changes after p-ACL transection.

STUDY DESIGN

Controlled laboratory study.

METHODS

Twenty-one 3- to 5-year-old female Suffolk-cross sheep were allocated to 4 groups: (1) nonoperative controls (n = 5), (2) 20 weeks after p-ACL transection (n = 5), (3) 40 weeks after p-ACL transection (n = 6), and (4) 20 weeks after p-ACL transection + MPA (n = 5). Gross morphological grading and histological analyses were conducted. mRNA expression levels for inflammatory, degradative, and structural molecules were assessed.

RESULTS

p-ACL transection led to significantly more combined gross damage ( P = .008) and significant aggregate histological damage ( P = .009) at 40 weeks after p-ACL transection than the nonoperative controls, and damage was progressive over time. Macroscopically, MPA appeared to slightly mitigate gross damage at 20 weeks after p-ACL transection in some animals. However, microscopic analysis revealed that repeated MPA injections after p-ACL transection led to significant loss in proteoglycan content compared with the nonoperative controls and 20 weeks after p-ACL transection ( P = .008 and P = .008, respectively).

CONCLUSION

p-ACL transection led to significant gross and histological damage by 40 weeks, which was progressive over time. Multiple repeated MPA injections were not appropriate to mitigate injury-related damage in a p-ACL transection ovine model as significant proteoglycan loss was observed in MPA-treated knees.

CLINICAL RELEVANCE

A p-ACL injury leads to slow and progressive PTOA-like joint damage, and multiple repeated injections of glucocorticoids may be detrimental to the knee joint in the long term.

Intra-ligamentary autologous conditioned plasma and healing response to treat partial ACL ruptures

INTRODUCTION

Conservative treatment of partial ACL ruptures is associated with a high failure rate, and often patients undergo ACL reconstruction. ACL preservation by trephination of the ACL origin and application of Autologous Conditioned Plasma (ACP) seems to be an intriguing new treatment option to favour ACL tissue healing and avoid traditional reconstruction. The aim of this study was to describe the mid-term outcomes of this new ACL preserving technique.

MATERIALS AND METHODS

Twenty-four patients (mean age 41.8 years) affected by partial rupture of one or both ACL bundles were included in the present trial. The partial ACL tears were arthroscopically assessed and classified according to a new five step grading system. All patients were treated by trephination of the femoral ACL stump and intra-ligamentary application of ACP. The postoperative outcome was evaluated by both subjective scores and stability testing up to a mean of 25.1 months' follow-up. Adverse events and failure rate were also documented.

RESULTS

Clinical outcome was good to excellent with IKDC subjective 82.7 (SD 11.8), Lysholm 87.6 (SD 8.1), Tegner 5.3 (SD 2.1), Cincinnati 88.7 (SD 14.8). The failure rate (i.e. persisting knee instability assessed clinically or by rolimeter) was 12.5%. At objective measurements, knee joints showed a firm endpoint in Lachman test, negative pivot shift phenomenon and a significant reduction in AP-laxity compared to pre-operative status by rolimeter testing (p = 0.002). Return to sport practice was achieved after mean 4.8 months (SD 4.1).

CONCLUSIONS

ACL stump trephination and concomitant intra-ligamentary application of ACP revealed promising results at mid-term follow-up to treat partial ACL lesions.

The effectiveness of Pilates for partial anterior cruciate ligament injury

PURPOSE

This study explored the effects of Pilates on the muscle strength, function, and instability of patients with partial anterior cruciate ligament (ACL) injuries in situations in which a non-surgical treatment option is preferred.

METHODS

Fifty participants 20-45 years of age who were diagnosed with isolated ACL injuries were included in the study. The participants were randomly assigned to either the Pilates exercise group (n = 24) or the control group (n = 26). The subjects in the Pilates exercise group performed basic mat exercises that focused on the muscle strength and flexibility of the lower limbs and core muscles during each class session, which met three times per week for 12 weeks. The control group did not receive any treatment or home exercise programme. All patients were evaluated using the Lysholm Knee Scale, the Cincinnati Knee Rating System, and isokinetic quadriceps and hamstring strength. Patient satisfaction regarding improvement in knee stability was assessed using the Global Rating of Change scale.

RESULTS

The Pilates group experienced significant improvement over the control group as measured by the difference in quadriceps strength at 12 weeks (p = 0.03). Both groups showed some clinical change over time, but the Pilates group improved for all outcome measurements at the 12-week follow-up, and the control group only improved for functional outcomes. Patient satisfaction with the level of knee stability based on the Global Rating of Change scale was higher in the Pilates group than in the control group.

CONCLUSION

Although both groups exhibited improvements in knee strength and functional outcomes, the results suggest that Pilates is a superior management approach over a control treatment for increasing quadriceps strength in participants with partial ACL injury. Pilates may provide clinicians a novel option when choosing a treatment for a partial ACL injury. Further study is needed to determine whether certain subgroups of individuals might achieve an added benefit with this approach.

LEVEL OF EVIDENCE

II.

Ligament-Derived Stem Cells: Identification, Characterisation, and Therapeutic Application

Ligament is prone to injury and degeneration and has poor healing potential and, with currently ineffective treatment strategies, stem cell therapies may provide an exciting new treatment option. Ligament-derived stem cell (LDSC) populations have been isolated from a number of different ligament types with the majority of studies focussing on periodontal ligament. To date, only a few studies have investigated LDSC populations in other types of ligament, for example, intra-articular ligaments; however, this now appears to be a developing field. This literature review aims to summarise the current information on nondental LDSCs including in vitro characteristics of LDSCs and their therapeutic potential. The stem cell niche has been shown to be vital for stem cell survival and function in a number of different physiological systems; therefore, the LDSC niche may have an impact on LDSC phenotype. The role of the LDSC niche on LDSC viability and function will be discussed as well as the therapeutic potential of LDSC niche modulation.

Use of pre-clinical surgically induced models to understand biomechanical and biological consequences of PTOA development

Post-traumatic osteoarthritis (PTOA) development is often observed following traumatic knee injuries involving key stabilising structures such as the cruciate ligaments or the menisci. Both biomechanical and biological alterations that follow knee injuries have been implicated in PTOA development, although it has not been possible to differentiate clearly between the two causal factors. This review critically examines the outcomes from pre-clinical lapine and ovine injury models arising in the authors' laboratories and differing in severity of PTOA development and progression. Specifically, we focus on how varying severity of knee injuries influence the subsequent alterations in kinematics, kinetics, and biological outcomes. The immediate impact of injury on the lubrication capacity of the joint is examined in the context of its influence on biomechanical alterations, thus linking the biological changes to abnormal kinematics, leading to a focus on the potential areas for interventions to inhibit or prevent development of the disease. We believe that PTOA results from altered cartilage surface interactions where biological and biomechanical factors intersect, and mitigating acute joint inflammation may be critical to prolonging PTOA development. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:454-465, 2017.