Chronic anterior cruciate ligament tears and associated meniscal and traumatic cartilage lesions: evaluation with morphological sequences at 3.0 T

Optimal measurement method for anterior instability on stress radiographs in anterior cruciate ligament tear: Considering the effect of static anterior tibial subluxation

INTRODUCTION

Accurate assessment of anterior cruciate ligament (ACL) function is vital for guiding treatment. Nevertheless, the presence of tibial subluxation in the neutral position of a patient with an ACL injury may potentially introduce a confounding factor. This study aims to investigate whether tibial subluxation in the neutral position affects the diagnosis of anterior instability in patients with ACL injuries, potentially impacting the reliability and diagnostic accuracy of stress radiography.

METHODS

This study included 88 patients: 30 with acute complete ACL tears (acute group), 28 with chronic complete ACL tears (chronic group), and 30 patients who underwent knee arthroscopic surgery other than ACL reconstruction (control group). Side-to-side differences (SSD) in stress radiography were measured using the Telos load status and the SSD of the gap between the Telos load and unload statuses. Diagnostic accuracy of the two methods was assessed using areas under the receiver operating characteristic curves (AUCs).

RESULTS

The load SSD (5.92 ± 5.28 mm) was higher than the load-unload SSD (4.27 ± 5.99 mm) in the chronic group (P = 0.017). The load SSD demonstrated a significantly higher diagnostic value than that of the load-unload SSD in the combined group (AUC = 0.920 vs. 0.830; P = 0.012) and chronic group (AUC = 0.913 vs. 0.754; P = 0.002). After adjusting the symptoms for radiographic duration from 6 to 3 months in the chronic group, the load SSD exhibited a significantly higher diagnostic value (AUC = 0.902) than that of the load-unload SSD (AUC = 0.740; P < 0.001).

CONCLUSION

The load SSD provides superior diagnostic accuracy compared to the load-unload SSD in ACL tear cases, where static anterior tibial subluxation may result in false negatives. Although load-unload SSD may have diagnostic value within the first 3 months post-injury, the load SSD method provides a reliable assessment of ACL function for patients beyond this timeframe.

Player Sex and Playing Surface Are Individual Predictors of Injuries in Professional Soccer Players

Background: The factors contributing to soccer injuries and their influence on the occurrence of injury are controversial and inconclusive. This study aimed to determine the association between player characteristics and playing factors with injuries in professional soccer players. Methods: One hundred and fifty-two professional soccer players completed a self-administered questionnaire that asked about demographic information and injury profile, the type of playing surface on which they sustained their injury, medical treatment, and the time lost due to soccer injury at the end of the soccer season. Results: The injury rate was 44.74% (n = 68; males: 61.50% (n = 56), females: 19.70% (n = 12)). Players’ age (OR: 1.15, 95%CI: 1.05−1.25, p < 0.002) and BMI (OR: 1.21, 95%CI: 1.06−1.38, p < 0.003) were significantly associated with soccer injuries. After adjusting for age and BMI, players’ sex (OR: 5.39, 95%CI: 2.11−13.75, p < 0.001), previous soccer injury (OR: 3.308, 95%CI: 2.307−29.920, p < 0.001), and playing surfaces (OR: 11.07, 95%CI: 4.53−27.03, p < 0.001) were the significant predictors of soccer injuries. Conclusion: Players’ age, BMI, sex, previous soccer injury, and playing surface were associated with injuries among professional soccer players. Old male athletes with high BMI, previous soccer injuries, and playing on natural grass were more likely to sustain soccer injuries than young female players with low BMI who had no previous injuries and played on synthetic surfaces.

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.

Articular cartilage status 2 years after arthroscopic ACL reconstruction in patients with or without concomitant meniscal surgery: evaluation with 3.0T MR imaging

PURPOSE

To assess articular cartilage changes in the knee joint as detected on 3.0T MR imaging after 2-year follow-up in patients who underwent arthroscopic anterior cruciate ligament reconstruction (ACLR) with or without concomitant meniscal surgery.

METHODS

A total of twenty-nine patients (mean age 30.3 ± 10 years), who underwent arthroscopic ACLR, received clinical and imaging follow-up at an average of 27.8 ± 4.8 months after surgery. Our patients were divided into two subgroups: eighteen patients with additional meniscal injuries at the time of arthroscopic ACLR who underwent meniscal surgery and eleven patients with intact menisci. The cartilage status of all knees at the time of arthroscopic ACLR was recorded. All patients underwent an MRI scan preoperatively and at follow-up with the same imaging protocol. Cartilage status of all knee compartments was evaluated at the time of follow-up by MR imaging and the ICRS classification.

RESULTS

Deterioration of the cartilage status was found at all knee compartments of our study group, with respect to the number of cartilage defects. The cartilage of the lateral femoral condyle (LFC) was most severely affected, followed by patellar and medial femoral condyle (MFC) cartilage. A statistically significant relation was found between surgery of the medial meniscus and the development of new cartilage defects in LFC (p = 0.01) and MFC (p = 0.03) after adjusting for the site of meniscal surgery. The cartilage of LFC and the status of the medial meniscus were also found to be significantly related (p = 0.04). Partial meniscectomy was found to be associated with an increased incidence of new cartilage defects when compared to either meniscal repair or absence of meniscal surgery, although it was not statistically significant.

CONCLUSION

Development of new cartilage lesions was evident after 2-year follow-up in patients with arthroscopic ACLR as detected by MR imaging. There was a multicompartmental pattern of cartilage involvement, and the lateral compartment was most severely affected. Partial meniscectomy at the time of arthroscopic ACLR could be suggested as an additional risk factor for the progression of chondral lesions.

LEVEL OF EVIDENCE

Prospective comparative study, Level II.

Risk Factors of False-Negative Magnetic Resonance Imaging Diagnosis for Meniscal Tear Associated With Anterior Cruciate Ligament Tear

PURPOSE

To identify risk factors that predict false-negative magnetic resonance imaging (MRI) diagnosis for meniscal tear coincident with anterior cruciate ligament injury using multivariate logistic regression.

METHODS

We reviewed the medical records of consecutive patients who underwent arthroscopic anterior cruciate ligament reconstruction from January 2006 through December 2014. Exclusion criteria were no meniscal tear or incomplete tear less than 10 mm in length, delay to surgery from initial injury more than 1 year, delay to surgery from preoperative MRI more than 4 weeks, revisions, fracture histories, and multiple ligament injuries. According to preoperative MRI diagnosis, the meniscal tears were sorted into true-positive MRI and false-negative MRI groups. Multivariate logistic regression was used to analyze risk factors including age, gender, body mass index, time from injury to MRI, knee instability, concomitant ligament injury, intra-articular effusion, bone contusion, cartilage injury, meniscal tear location, and meniscal tear pattern.

RESULTS

Enrolled 249 meniscal tears (159 medial and 90 lateral menisci) were sorted into true-positive MRI (n = 136) and false-negative MRI (n = 113) groups. As time from injury to MRI diagnosis increased, the risk of the false-negative MRI diagnosis decreased (adjusted odds ratio [OR], 0.859; 95% confidence interval [CI], 0.802-0.921). Meniscal tear location within the posterior one-third was a significant risk factor compared with tear within the anterior one-third (adjusted OR, 11.823; 95% CI, 2.272-61.519). Peripheral longitudinal tear pattern was also a significant risk factor (adjusted OR, 3.522; 95% CI, 1.256-9.878).

CONCLUSIONS

Significant risk factors for false-negative MRI included short time from injury to MRI diagnosis, meniscal tear location within the posterior one-third, and peripheral longitudinal tear pattern.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Anterior cruciate ligament remnant tissue harvested within 3-months after injury predicts higher healing potential

Background

No study has examined the possible factors associated with different characteristics of stem-like cells derived from anterior cruciate ligament (ACL) remnants. And the purpose of the study is to elucidate whether demographic factors are associated with healing potential of stem-like cells derived from the ACL remnants tissue.

Methods

Thirty-six ACL remnants were harvested from patients who received primary arthroscopic ACL reconstruction. Interval from injury to surgery, age, sex, and combined meniscal or chondral injuries were analyzed. Cells were isolated from remnant tissues and their healing potential was evaluated by: 1) characterization of surface markers (CD34, CD44, CD45, CD146, CD29, and Stro-1), 2) cell expansion, 3) osteogenic differentiation, and 4) endothelial differentiation. Finally, using multivariable logistic regression to evaluate the relation between demographic factors and healing potential parameters. Adjusted odds ratios (OR) were calculated, and the significant difference was set at p < 0.05.

Results

ACL remnant tissue harvested less than 90 days after injury predicted higher fractions of stem-like cells [CD34+ (OR = 6.043, p = 0.025), CD44 + (OR = 8.440, p = 0.011), CD45+ (OR = 16.144, p = 0.015), and CD146+ (OR = 9.246, p = 0.015)] and higher expansion potential (passage 3: OR = 9.755, p = 0.034; passage 10: OR = 33.245, p = 0.003). Regarding osteogenic differentiation, higher gene expression of Osteocalcin (OR = 22.579, p = 0.009), Alkaline phosphatase (OR = 6.527, p = 0.022), and Runt-related transcription factor 2 (OR = 5.247, p = 0.047) can also be predicted. Younger age predicted higher CD34+ levels (20 ≤ age <30 years, OR = 2.020, p = 0.027) and higher expansion potential at passage 10 (10 ≤ age <20 years, OR = 25.141, p = 0.026). There was no significant relation found between meniscal or chondral injuries and ACL healing potential.

Conclusion

Our results indicated that the ACL remnant tissue harvested within 3-months after injury yields higher healing potential, suggesting early surgical intervention may achieve better clinical results.

Increased meniscal loading after anterior cruciate ligament transection in vivo: a longitudinal study in sheep

INTRODUCTION

Meniscal injury has been well documented as a frequent consequence of both acute and chronic ACL deficiency. The purpose of this study was to evaluate the effect of ACL deficiency on meniscal loads in vivo and determine how these loads would change over time after ACL injury.

METHODS

The in vivo kinematics of the stifle joint of five sheep were measured during normal gait, as well as 4 and 20 weeks after ACL transection. A unique robotic testing platform was then programmed to reproduce all the previously recorded kinematics and the loads carried by medial and lateral menisci during gait were estimated.

RESULTS

The results demonstrated a significant increase in both medial and lateral meniscal loads 20 weeks following ACL transection, mainly during mid-stance phase of gait (p = 0.007 and p = 0.003, respectively), with interesting inter-subject variability. A moderate correlation (R(2) ≥ 0.5) between in situ meniscal loads and anterior tibial translations was also detected over time after injury, increased translations post injury generally corresponded to larger meniscal loads.

CONCLUSION

The dramatic increase in meniscal loads long term post ACL transection probably explains the meniscal changes or injuries reported clinically in many chronic ACL-deficient knees.

Decreased posterior cruciate and altered collateral ligament loading following ACL transection: a longitudinal study in the ovine model

Although ACL deficiency is shown to lead to joint degeneration, few quantitative data are reported on its effect on soft tissue structures surrounding the knee joint, specifically, the posterior cruciate and collateral ligaments. The kinematics of the stifle joint of sheep (N = 5) were measured during "normal" gait, as well as 4 and 20 weeks after ACL transection. These motions were reproduced using a unique robotic manipulator and the loads borne by PCL, MCL, and LCL during gait were determined. Our results demonstrated a significant decrease in mean PCL loads 20 weeks post-ACL injury, at hoof-strike (0% of gait, p = 0.034), hoof-off (66% of gait, p = 0.006), peak-swing (85% of gait, p = 0.026), and extension-before-hoof-strike (95% of gait, p = 0.028). Mean MCL loads did not significantly increase following ACL transection, maybe due to large between-animal variation. Finally, mean LCL loads indicated a significant decrease (p < 0.047) at 20 weeks across the entire gait cycle. From a clinical perspective, the load redistributions observed in cruciate and collateral ligaments following ACL injury indicate that these tissues can carry/adapt to the altered mechanical environment of the joint. The considerable variability in the magnitudes of change following ACL injury among animals also simulates clinical variability in humans after trauma.

Defining the terms acute and chronic in orthopaedic sports injuries: a systematic review

BACKGROUND

Although many authors report on acute injuries and chronic injuries in the orthopaedic literature, the actual terms are seldom explicitly defined.

HYPOTHESIS

Much of the literature pertaining to sports injuries that are acute or chronic does not define these terms. It is believed that definitions will provide clarity and specificity in future literature.

STUDY DESIGN

Systematic review.

METHODS

A systematic review of 116 articles was conducted to determine whether and how the terms acute and chronic were defined as they pertain to several commonly treated conditions: Achilles tendon rupture, distal biceps tendon rupture, pectoralis major tendon rupture, anterior cruciate ligament (ACL) tear, anterior shoulder instability, and acromioclavicular (AC) joint dislocation. Articles were isolated from various databases and search engines by use of keywords to identify relevant literature.

RESULTS

This study determined that the terms acute and chronic for each injury are defined, respectively, as follows: Achilles tendon rupture: <1 week, >4 weeks; distal biceps tendon rupture: <6 weeks, >12 weeks; pectoralis major tendon rupture: <6 weeks, >6 weeks; ACL tear: <6 weeks, >6 months; anterior shoulder instability: <2 weeks, >6 months; AC joint dislocation, <3 weeks, >6 weeks.

CONCLUSION

The current literature varies greatly in defining the terms acute and chronic in common sports injuries. The vast majority of authors imply these terms, based on the method of their studies, rather than define them explicitly. Injuries involving tendons showed greater consistency among authors, thus making a definition based on consensus easier to derive. The literature on ACL and shoulder instability in particular showed great variability in defining these terms, likely representing the more complex nature of these injuries and the fact that timing of surgery in the majority of patients does not particularly affect the complexity of the surgical approach and treatment.

CLINICAL RELEVANCE

Defining injuries as acute or chronic is clinically relevant in many cases, particularly concerning tendon injuries, where these terms have implications regarding the anatomic pathologic changes and tissue quality, which may necessitate augmentation and alter the initial surgical plan. In cases where these terms are less pertinent to operative treatment considerations, they bring clarity to the discussion of the acuity of the injury (as it pertains to time from insult).

Partial tears of the anterior cruciate ligament: diagnostic performance of isotropic three-dimensional fast spin echo (3D-FSE-Cube) MRI

PURPOSE

To compare the performance of 3D-FSE-Cube MRI to arthroscopy, the reference test for the diagnosis of partial anterior cruciate ligament (ACL) tears.

METHODS

A retrospective study was performed including all patients who underwent surgery for an ACL tear in our Sports Surgery Unit from January 2008 to December 2009. All patients underwent a preoperative MRI, conventional 2D or 3D-Cube. The diagnosis of a partial tear was based on the appearance of the ligament bundles and signal quality on MRI, and on the continuity of the fibers on arthroscopy and the quality of the remaining ligament. Sixty-four of the 312 included patients underwent MRI 3D-Cube and 248 conventional 2D-MRI. The series included 82 women and 223 men, mean age 33.3 ± 19.6 years. Arthroscopy did not reveal any normal ACL, 247/312 (79.2 %) complete tears, and 65/312 (20.8 %) partial tears, with 50/65 (76.9 %) involving the anteromedial bundle and 15/65 (23.1 %) the posterolateral.

RESULTS

The results of MRI 3D-Cube were as follows: sensitivity 95 % CI = 62.5 ± 23.7 %, specificity 95 % CI = 93.7 ± 6.9 %, likelihood ratio LR(+) = 9.9, LR(-) = 0.4 and accuracy 85.9 %. Results of conventional 2D-MRI were as follows: sensitivity 95 % CI = 10.2 ± 8.5 %, specificity 95 % CI = 96.5 ± 2.5 %, LR(+) = 2.9, LR(-) = 0.9 and accuracy 79.4 %. The diagnostic performance of MRI 3D-Cube was better than conventional 2D-MRI.

CONCLUSION

The diagnostic performance of MRI 3D-Cube in partial ACL tears was good and significantly better than conventional 2D-MRI. The likelihood of having a positive test was 9.9 times higher in a patient with a partial tear. A negative result did not exclude this diagnosis.