Partial Anterior Cruciate Ligament Tears Research Articles

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.

Management of Partial Tears of the Anterior Cruciate Ligament: A Review of the Anatomy, Diagnosis, and Treatment.

Partial anterior cruciate ligament (ACL) tears comprise an estimated 10% to 27% of isolated ACL injuries. Partial ACL tears may be challenging to clinically diagnose. We reviewed relevant studies focusing on the anatomy, diagnosis, imaging, and treatment of a partial injury with the goal of providing guidance to clinicians. Although a comprehensive patient history, thorough clinical examination, and imaging studies are helpful in arriving at a diagnosis, the benchmark for diagnosis remains visualization and examination of the ACL at the time of knee arthroscopy. Currently, limited data exist about the long-term outcomes of nonsurgical treatment. Some studies demonstrate that younger, active patients have the risk of progressing to a complete ACL rupture with conservative treatment. The decision to proceed with surgery is based on careful history and physical examination findings that suggest either a "functional" or "nonfunctional" ACL. Surgical treatment consists of augmenting the intact bundle with a selective bundle reconstruction versus a traditional ACL reconstruction. Selective bundle reconstruction has limited data available but is an option. The best evidence supports traditional ACL reconstruction for the surgical management of patients with documented nonfunctional partial tears of the ACL.

Clinical examination of partial ruptures of the anterior cruciate ligament: A retrospective case–control study

BackgroundAnterior drawer test, Lachman test including evaluation of the endpoint, and pivot shift test have been commonly applied clinically in diagnosing anterior cruciate ligament (ACL) injury but how they function in the appraisal of partial ACL tears is less known. The aims of this study were to examine the diagnostic values of the commonly used knee function tests on patients in detecting ACL injury including partial injury patterns, to assess each of the test's predictive values on the specific ACL injury pattern, and to assess if using multiple tests collectively for the diagnosis of the injury could improve diagnostic accuracy. MethodsWe evaluated 36 consecutive patients who underwent ACL single bundle augmentation surgery. Those patients were matched by gender and age to 36 patients with a complete rupture of the ACL. Data was obtained from the patients' records. The rupture pattern was confirmed by arthroscopy. An examination under anesthesia was routinely performed by two surgeons who were blinded to the rupture pattern prior to surgery. ResultsCollectively using both Lachman test and pivot shift test increases ability to distinguish between partial tears and complete ruptures. When comparing partial PL tears and complete ruptures the pivot shift test is more important than the Lachman test. In diagnosing a complete rupture, the evaluation of the endpoint during the Lachman test is more sensitive than the evaluation of the anterior tibial translation during the Lachman test. ConclusionBased on the findings of this study, a diagnostic algorithm has been implemented and is presented in this manuscript.

Histological and cellular evaluation of anterior cruciate ligament

BackgroundWe hypothesized that the torn anterior cruciate ligament (ACL) demonstrates a great healing response after initial trauma and has competent cells leading to the healing but differs in its response based on the type of tear and duration of injury. This study aimed to evaluate the histological and cellular responses to the injured ACL. MethodsFifty-two tissue samples from the ACL were harvested from patients undergoing arthroscopy. Detailed histological and cellular examinations were performed for ligament angiogenesis, fibrocytes, and synovial tissue infiltration. We compared the cellular response to injury in partially and completely ruptured ACLs. The duration of ACL injury and its response to cellular characteristics were also examined. Immunohistochemical studies using cluster of differentiation 34 (CD34) staining was used to evaluate endothelial cells and fibrocytes. ResultsWe found a significantly higher density of synovial and ligament angiogenesis and fibrocytes at the torn end of ACL (Mann–Whitney, P < 0.050). Numerous fibrocytes were identified in complete ACL tears versus partial tears (Mann–Whitney = 0.020). Increased cellular proliferation was identified at the ruptured end of ACL remnant (Kruskal–Wallis, P < 0.050). The cellular proliferation of ruptured ACL decreased after 12 months. ConclusionsBased on our findings of the time-dependent decrease in the cellular response at the torn ends of the ACL, we recommend early intervention, preservation of the ACL remnant, and primary ACL repair or augmented reconstruction.

Arthroscopic Primary Repair for Partial Proximal Anterior Cruciate Ligament Tear in Military Personnel.

To evaluate the short-term clinical outcomes of arthroscopic primary repair for partial proximal anterior cruciate ligament (ACL) tear in a young, active duty military population. Retrospective cohort study. A national tertiary-level medical and academic institution. Nineteen active duty military patients with partial proximal ACL tears and excellent tissue quality were included and 18 were finally analyzed. All patients underwent arthroscopic primary repair using a suture anchor technique between March 2014 and June 2016. Clinical outcomes were evaluated using anterior drawer test (ADT), Lachman test, pivot shift test, 3-km run test, 10 m × 5 shuttle run test, physical readiness test (PRT) score, Tegner activity score, Lysholm score, modified Cincinnati score, International Knee Documentation Committee (IKDC) subjective score, and magnetic resonance imaging. At final follow-up, 17 patients had negative ADT, Lachman, and pivot shift examination findings, and 1 patient had a 1+ ADT, negative Lachman, and pivot shift result. Mean 3-km run time at final follow-up was not statistically different from that preinjury (12:55 vs 12:39, P = 0.071), nor were the 10 m × 5 shuttle run time (23.4 vs 22.9, P = 0.235), PRT score (82.5 vs 85.1, P = 0.086), and Tegner activity score (7.8 vs 7.9, P = 0.083). Mean Lysholm score at final follow-up was significantly improved compared with that preoperative (93.1 vs 70.7, P < 0.001), so were the modified Cincinnati score (90.4 vs 58.6, P < 0.001) and IKDC subjective score (88.3 vs 67.4, P < 0.001). Arthroscopic primary repair can achieve short-term clinical success in high-demand military patients with partial proximal ACL tears and excellent tissue quality.

Anterior cruciate ligament reconstruction with remnant preservation: current concepts

Anterior cruciate ligament (ACL) tears are a common knee injury, and anatomic ACL reconstruction (ACLR) is now the standard of care to restore knee stability. Nevertheless, re-tear rates exceeding 5% are commonly reported, with an even higher percentage of patients unable to achieve preinjury knee function. As the torn ACL remnant contains elements (eg, cells, blood vessels and mechanoreceptors) essential to ACL function, it has been hypothesised that ACLR with remnant preservation may improve graft remodelling, in turn more quickly and completely restoring ACL structure and function. In this Current Concepts review, we summarise the present understanding of ACLR with remnant preservation, which includes selective bundle reconstruction of partial (one-bundle) ACL tears and single- and double-bundle ACLR with minimal to partial debridement of the torn ACL stump. Reported benefits of remnant preservation include accelerated graft revascularisation and remodelling, improved proprioception, decreased bone tunnel enlargement, individualised anatomic bone tunnel placement, improved objective knee stability and early mechanical support (with selective bundle reconstruction) to healing tissues. However, clinical studies of ACLR with remnant preservation are heterogeneous in the description of remnant characteristics and surgical technique. Presently, there is insufficient evidence to support the superiority of ACLR with remnant preservation over the standard technique. Future studies should better describe the ACL tear pattern, remnant volume, remnant quality and surgical technique. Progress made in understanding and applying remnant preservation may inform, and be reciprocally guided by, ongoing research on ACL repair. The goal of research on ACLR with remnant preservation is not only to achieve anatomic structural restoration of the ACL but also to facilitate biologic healing and regeneration to ensure a more robust and functional graft.

Is a Partial Anterior Cruciate Ligament Tear Truly Partial? A Clinical, Arthroscopic, and Histologic Investigation

(1) To determine whether examination under anesthesia (EUA) and/or magnetic resonance imaging (MRI) is an accurate means for determining patient selection for a selective-bundle reconstruction, (2) to determine whether the preoperative clinical assessment correlates with the arthroscopic examination, and (3) to examine histologically whether a partial anterior cruciate ligament (ACL) tear is truly partial in terms of vascular insult. This prospective, nonrandomized cohort study included 95 patients who underwent primary ACL reconstruction from January 2013 through May 2014. All patients underwent an EUA, MRI, and arthroscopic evaluation. In patients with partial ACL tears, the intact bundle was resected and underwent histologic examination. The χ2 test was used to compare EUA and MRI in the detection of partial tears. Of the 95 patients included, 40 (42%) had EUA findings consistent with a partial ACL tear whereas 22 (23%) had MRI findings interpreted as showing a partial ACL tear. Arthroscopic examination confirmed a partial ACL tear in only 11 patients (12%). The sensitivity of EUA and MRI in the detection of partial ACL tears was 100% and 90.9%, and the specificity was 65% and 85.7%, respectively. The χ2 test suggested statistically significant associations between the method of evaluation and diagnostic outcome [χ2(1)= 7.83, P= .005]. MRI was 1.24 times more likely to correctly identify a partial tear (95% confidence interval, 1.06-1.45). EUA was 2.23 times as likely to incorrectly identify a partial tear (95% confidence interval, 1.24-4.02). The histologic analysis showed increased numbers of lymphocytes, absent polymorphonuclear leukocytes, predominant fibroblasts, neovascularization, and variable collagen orientation. There is a disparity between EUA, MRI, and arthroscopic findings in the evaluation of partial ACL tears. Arthroscopy remains the gold standard for diagnosing the macroscopic integrity of the intact bundle. Microscopic analysis reveals that the integrity of the remaining intact ligament material is altered and may show a histologic response similar to a complete ACL rupture. Level III, prospective, nonrandomized cohort study.

Association between radiographic anterior cruciate ligament tear and joint symptoms: Data from the osteoarthritis initiative.

Symptomatic osteoarthritis (OA) in the knee is defined as the presence of OA radiographic features in combination with knee symptoms. Pain has not been shown to correlate meaningfully to radiographic severity. We aimed to determine the relationship between a tear of the anterior cruciate ligament (ACL) with knee symptoms and radiographic OA. A within-person, between-knee cross-sectional study of 37 participants from the Osteoarthritis Initiative (OAI) with a complete or partial ACL tear detected on magnetic resonance imaging in 1 knee (index knee) were included. Western Ontario and McMaster Universities Osteoarthritis Index(WOMAC), Knee Injury and Osteoarthritis Outcome Score (KOOS) and radiographs of both knees, 1 with an ACL tear and one without (control knee) were scored for OA severity (Kellgren-Lawrence Grading) and symptoms. A generalized estimating equation with linear regression was used to compare symptom scores within individuals as well as to radiographic severity. Thirty-seven individuals (40% female, average age=60.7years, body mass index=31.0kg/m2 ) reported no difference in knee symptoms (WOMAC pain odds ratio [OR] =1.92, 95%CI 0.699-5.248, P = .21; KOOS symptoms OR=2.12, 95%CI 0.740-6.065, P = .09), stiffness (OR=1.67, 95%CI 0.653-5.583, P = .35) or functional disability (OR=1 0.97, 95%CI 0.515-7.508, P = .32) in the knee that exhibited an ACL tear compared to the control knee. Only knee function and disability (WOMAC Disability OR=1.12, 95%CI 1.003-1.249, P = .04) were associated with radiographic severity between index and control knees. Individuals did not report an increase in knee pain, stiffness or disability in their ACL-deficient knee. Only disability was associated with worsening severity of radiographic OA in ACL-deficient knees.

Concurrent use of oblique sagittal and oblique coronal MRI: does it enhance the specificity and the accuracy of diagnosing complete and partial ACL tears?

BackgroundThe aim of the study was to evaluate the diagnostic efficacy of utilization of oblique sagittal and oblique coronal MRI techniques separately and concurrently in improving the diagnosis of anterior cruciate ligament (ACL) complete and partial tears. Between December 2017 and November 2018, 71 patients, with suspected ACL injury, were examined by MRI using four diagnostic approaches: standard routine images only (approach A), standard and oblique coronal images (approach B), standard and oblique sagittal images (approach C), and standard images with both oblique coronal and sagittal images (approach D). Two experienced musculoskeletal radiologists evaluated the MRI images separately and in a random order using the four methods, and findings were compared with arthroscopy results as a gold standard.ResultsThe diagnostic accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for approach A in diagnosis of partial ACL tear was significantly lower than that for approaches B, C, and D (p value < 0.05). The PPV and NPV for approaches B (82% and 85%) and C (83% and 87%) in diagnosis of partial ACL tear which were significantly lower than that for approach D (94% and 95%). The four approaches revealed no significant difference in diagnosis of complete ACL tear (p value > 0.05). Approach D demonstrated highest interobserver agreement (94% in complete and 88% in partial ACL tears) in comparison to B (79% in complete and 66% in partial) and C (85% in complete and 71% in partial) when combining oblique sagittal and oblique coronal images in identifying both complete and partial ACL tearsConclusionThe addition of oblique sagittal and coronal images improved diagnostic accuracy of detection of complete and partial ACL tears. The concurrent use of sagittal and coronal oblique images enhanced the diagnostic efficacy of diagnosis of partial ACL tears only.

Risk factors for passive anterior tibial subluxation on MRI in complete ACL tear

IntroductionIn anterior cruciate ligament (ACL) tear, passive spontaneous anterior tibial subluxation (ATS), with respect to the femur, is sometimes observed on MRI. In a case-control study, ATS>3.5mm showed 100% specificity (±3.6, 95% CI) for complete ACL tear. The aim of the present study was to assess the relation between ATS on MRI and associated lesions in complete ACL tear. The study hypothesis was that associated lesions are a risk factor for ATS. Material and methodsA retrospective study included patients operated on for complete ACL tear between 2010 and 2015. Exclusion criteria comprised associated posterior cruciate ligament tear, partial ACL tear, and history of knee surgery. Preoperative MRI was performed with the patient in supine position and the knee in 20° flexion in neutral rotation. ATS was measured by axial superimposition of the bicondylar slice on the slice through the tibial plateau. Associated lesions were assessed: medial and lateral menisci, collateral ligaments, posteromedial and posterolateral corners, tibiofemoral compartment cartilage and cancellous bone. Factors associated with ATS>3.5mm were analyzed. Ninety-one patients were included: mean age, 31.1±10.1 years; 34 female, 57 male. Mean time from injury to MRI was 7.8±11.7 months (range, 0.7–60 months). ResultsMean ATS was 4.7±2.3mm. Inter- and intra-observer reproducibility for ATS measurement were excellent. On preoperative MRI, 61.1% of patients showed bone edema, 48.4% medial meniscal tear, and 36.3% lateral meniscal tear. ATS was significantly greater in case of medial meniscal tear (5.4±2.3mm vs. 4±2.1mm; p=0.003). No significant differences were found according to other lesions. Fifty-four patients (59.3%) showed ATS>3.5mm; risk factors comprised medial meniscal tear (OR=2.6, 95%CI [1.1–6.2]; p=0.03) and injury-to-MRI time>9 months (OR=9.8, 95% CI [1.1–85.2]; p=0.04). ConclusionSpontaneous anterior tibial subluxation on MRI in complete ACL tear was significantly associated with medial meniscal tear and accident-to-MRI time. Level of evidenceIV, retrospective cohort study.

The effect of thermosensitive hydrogel platelet-rich-plasma complex in the treatment of partial tear of anterior cruciate ligament in rat model.

Background/ObjectiveThe treatment of anterior cruciate ligament (ACL) partial tear is controversial. The reconstructive surgery is invasive while the prevalence of subsequent insufficiency after conservative treatment has been reported to range from 11% to 62%. Therefore, a new method that promotes tissue regeneration is needed. The aim of this study was to observe the healing of ACL partial tear biomechanically and histologically after the administration of a thermosensitive hydrogel platelet-rich-plasma (PRP) complex.MethodsThe complex was prepared according to a previously published protocol. One hundred and fifty 12-week-old male Sprague-Dawley rats were included and they were allocated into 4 groups. Lesion control group (Group 1), treatment group (Group 2), gel-only group (Group 3) and intact group (Group 4). Biomechanical testing, histological analysis (H&E and immunohistochemical staining) and scoring was performed.ResultsOn gross observation, the treatment group showed a continuous ACL with slightly thickened synovium or a partially healed ACL at 6-week follow up. In the biomechanical testing at 6 weeks after surgery, the failure load of the treatment group was significantly superior when compared with the lesion control group (52.7±10.8N vs. 41.6±7.8N, p<0.01), but the failure load was not restored to level of the intact group (52.7±10.8N vs. 61.5±9.1N, p=0.037). The maturity index of wound sites showed no significant inter-group differences at any timepoints. However, an increased expression of vascular endothelial growth factor (VEGF) and pro-collagen I was detected.ConclusionThe thermosensitive hydrogel-PRP was shown to be effective in enhancing the healing of ACL partial tear in the rat model, and potentially this complex can be used as a treatment for patients with ACL partial tear.The translational potential of this articleThe thermosensitive hydrogel-PRP is potentially translated to clinical use to treat patients with ACL partial tear by injection under arthroscopy or ultrasound guiding.

Outcome analysis following arthroscopic augmentation with autologous hamstring graft in partial tear of the anterior cruciate ligament with preservation of an intact bundle: A case series

Background: The anatomic approach to anterior cruciate ligament (ACL) reconstruction has shifted management focus of the commonly encountered partial tear from resection and complete reconstruction to augmentation (i.e. selective bundle reconstruction with preservation of intact remnant bundle). The purpose of this study was to prospectively evaluate functional outcome after augmentation of partial ACL tears. Methods: Thirty-four patients with a partial ACL tear in whom a conservative trial failed were treated with either anteromedial or posteromedial single-bundle reconstruction, using an isolated semitendinosus graft and conserving the remnant bundle. Outcomes were evaluated clinically using the 2000 International Knee Documentation Committee [IKDC] knee examination forms, and manual laxity tests. Subjective evaluation was done using the 2000 IKDC subjective knee evaluation, Lysholm knee score, and 2000 IKDC functional score. Patient activity level was determined using the Tegner activity score. IKDC knee grades were assigned based on final evaluation on the 2000 IKDC knee examination forms. Results: At final follow-up 2000 IKDC knee examination grades significantly improved, with 21 in group B (61.8%) and 12 in group A (35.3%), while preoperatively most were classified as group C (76.5%). Similarly, IKDC subjective and Lysholm scores were significantly better after follow-up. The difference between mean Tegner activity level preinjury (6.029±0.9040) and at follow-up (5.67±1.006) was not significant. Conclusions: Selective bundle reconstruction with preservation of remnants restores knee stability and function. The results are encouraging, with excellent improvement in functional scores. Level of Evidence: Level IV.

Multi-Layered Basis Pursuit Algorithms for Classification of MR Images of Knee ACL Tear

Deep learning architectures have been extensively used in recent years for the classification of biomedical images to assist clinicians for diagnosis and treatment management of patients with different health conditions. These architectures have demonstrated expert level diagnosis, and in some cases, surpassed human experts in diagnosing health conditions. The automation tools based on deep learning frameworks have the potential to transform all stages of medical imaging pipeline from image acquisition to interpretation and analysis. One of the most common areas where these techniques are applied is knee MR image classification for different types of Anterior Cruciate Ligament (ACL) tears. If properly and timely managed, the diagnosis and treatment of ACL tear can avoid further degradation of patients’ knee joints and can also help slow the process of subsequent knee arthritis. In this work, we have implemented a novel classification framework based on multilayered basis pursuit algorithms inspired from recent research work in the area of the theoretical foundation of deep learning with the help of celebrated sparse coding theory. We implement an optimal multi-layered Convolutional Sparse Coding (ML-CSC) framework for classification of a labelled dataset of knee MR images with the coronal view and compare the results with traditional convolutional neural network (CNN) based classifiers. Empirical results demonstrate the effectiveness of the ML-CSC framework and show that the framework can successfully learn distinct features on a small dataset and achieve a good efficiency of more than 92% without employing regularization techniques and extensive training on large datasets. In addition to 95% average accuracy on the presence and absence of ACL tears, the framework also performs well on the imbalanced and challenging classification of partial ACL tear with 85% accuracy.

The Role of Diffusion-weighted Magnetic Resonance Imaging in the Evaluation of Anterior Cruciate and Posterior Cruciate Ligament Tears

Objective: The objective of our study was to determine the role of diffusion-weighted (DW) magnetic resonance imaging (MRI) in diagnosing and differentiating between complete and partial anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) tears and to compare it with conventional MRI sequences. Materials and Methods: We conducted a prospective study for a period of 2 years from October 2017 to October 2019 on 30 patients with clinically suspected ACL/PCL injuries of the knee. MRI of the knee joint was performed using conventional, and DW sequences and the findings on both the sequences were assessed independently and compared with the intraoperative or follow-up MRI findings. Results: As per operative and follow-up MRI findings, the sensitivity and specificity of conventional MRI were 60% and 33.33% with a positive and negative predictive value of 47.37% and 45.45%, respectively. On the other hand, the sensitivity and specificity of DW MRI were 70.00% and 33.33% with a positive and negative predictive value of 51.22% and 52.13%, respectively. P = 0.417 was statistically not significant. Conclusion: According to our study, adding DW sequence to conventional MR sequences yielded comparable results in diagnosis and differentiation between complete and partial ACL and PCL tears.

Rotatory Knee Laxity Exists on a Continuum in Anterior Cruciate Ligament Injury.

The purpose of this investigation was to compare the magnitude of rotatory knee laxity in patients with a partial anterior cruciate ligament (ACL) tear, those with a complete ACL tear, and those who had undergone a failed ACL reconstruction. It was hypothesized that rotatory knee laxity would increase with increasing injury grade, with knees with partial ACL tears demonstrating the lowest rotatory laxity and knees that had undergone failed ACL reconstruction demonstrating the highest rotatory laxity. A prospective multicenter study cohort of 354 patients who had undergone ACL reconstruction between 2012 and 2018 was examined. All patients had both injured and contralateral healthy knees evaluated using standardized, preoperative quantitative pivot shift testing, determined by a validated, image-based tablet software application and a surface-mounted accelerometer. Quantitative pivot shift was compared with the contralateral healthy knee in 20 patients with partial ACL tears, 257 patients with complete ACL tears, and 27 patients who had undergone a failed ACL reconstruction. Comparisons were made using 1-way analysis of variance (ANOVA) with post hoc 2-sample t tests with Bonferroni correction. Significance was set at p < 0.05. There were stepwise increases in side-to-side differences in quantitative pivot shift in terms of lateral knee compartment translation for patients with partial ACL tears (mean [and standard deviation], 1.4 ± 1.5 mm), those with complete ACL tears (2.5 ± 2.1 mm), and those who had undergone failed ACL reconstruction (3.3 ± 1.9 mm) (p = 0.01) and increases in terms of lateral compartment acceleration for patients with partial ACL tears (0.7 ± 1.4 m/s), those with complete ACL tears (2.3 ± 3.1 m/s), and those who had undergone failed ACL reconstruction (2.4 ± 5.5 m/s) (p = 0.01). A significant difference in lateral knee compartment translation was found when comparing patients with partial ACL tears and those with complete ACL tears (1.2 ± 2.1 mm [95% confidence interval (CI), 0.2 to 2.1 mm]; p = 0.02) and patients with partial ACL tears and those who had undergone failed ACL reconstruction (1.9 ± 1.7 mm [95% CI, 0.8 to 2.9 mm]; p = 0.001), but not when comparing patients with complete ACL tears and those who had undergone failed ACL reconstruction (0.8 ± 2.1 [95% CI, -0.1 to 1.6 mm]; p = 0.09). Increased lateral compartment acceleration was found when comparing patients with partial ACL tears and those with complete ACL tears (1.5 ± 3.0 m/s [95% CI, 0.8 to 2.3 m/s]; p = 0.0002), but not when comparing patients with complete ACL tears and those who had undergone failed ACL reconstruction (0.1 ± 3.4 m/s [95% CI, -2.2 to 2.4 m/s]; p = 0.93) or patients with partial ACL tears and those who had undergone failed ACL reconstruction (1.7 ± 4.2 m/s [95% CI, -0.7 to 4.0 m/s]; p = 0.16). An increasing lateral compartment translation of the contralateral, ACL-healthy knee was found in patients with partial ACL tears (0.8 mm), those with complete ACL tears (1.2 mm), and those who had undergone failed ACL reconstruction (1.7 mm) (p < 0.05). A progressive increase in rotatory knee laxity, defined by side-to-side differences in quantitative pivot shift, was observed in patients with partial ACL tears, those with complete ACL tears, and those who had undergone failed ACL reconstruction. These results may be helpful when assessing outcomes and considering indications for the management of high-grade rotatory knee laxity. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

The Push-Through Sign—Making the Decision for Selective-Bundle Anterior Cruciate Ligament Surgery

Partial anterior cruciate ligament (ACL) tears are often difficult to diagnose and treat. Recent interest in the literature has focused on performing selective-bundle ACL reconstruction in patients with symptomatic partial ACL tears when one of the ACL bundles is intact. However, the clinical examination, magnetic resonance imaging, and arthroscopic evaluation of partial ACL tears may not correlate, and proper assessment of the integrity of the intact portion of the ACL continues to be a challenge. If a selective-bundle ACL reconstruction is performed in a patient with an apparently intact but structurally damaged individual bundle, the outcome would be compromised by leaving the damaged bundle in place. This technical note provides a description of a simple and reliable arthroscopic method to aid in the diagnosis of a partial ACL tear. The use of this method to assess remaining ligamentous tissue will assist surgeons in deciding for or against selective-bundle ACL reconstruction.

Diagnostic accuracy of dynamic ultrasound imaging in partial and complete anterior cruciate ligament tears: a retrospective study in 247 patients

ObjectivesDynamic ultrasound (US) imaging shows promising possibilities for accurate imaging in diagnosing anterior cruciate ligament (ACL) tears and can be used as a point-of-care test. The aim of this study...

Selective bundle reconstruction in partial ACL tears leads to excellent long-term functional outcomes and a low percentage of failures

BackgroundThe optimal treatment of partial anterior cruciate ligament (ACL) tears continues to be debatable. Short-term results of selective bundle reconstruction have already been widely shown. The purpose of this study was to assess functional outcomes, subjective satisfaction and the failure rate of selective bundle reconstructions for partial ACL tears over a five to nine year follow-up period. MethodsPatients who underwent ACL selective bundle reconstruction between October 2008 and October 2012 were studied. Functional assessment was performed with the objective International Knee Documentation Committee (IKDC) ligament evaluation form, the Lysholm knee scale and the Tegner activity level scale. Cumulative failure and level of satisfaction have also been investigated. ResultsSeventy-six patients were included. The average follow-up period was 85 months (range 65–110). Thirty-four had AMB tear and 42 had PLB tears. An overall statistically significant improvement (p < 0.001) was obtained in terms of the subjective IKDC and the Lysholm questionnaire between preoperative and last follow-up. The same or no more than one level lower Tegner score was restored in 97.3% of the cases. Cumulative failure was observed in two patients (2.6%). Dissatisfied patient percentage was 15% (4/76). ConclusionsSelective bundle reconstruction in partial ACL tears leads to excellent long-term functional outcomes, a low percentage of failures and a high degree of subjective satisfaction in patients. Level of evidenceTherapeutic case series; level 4.

The effect of alignment on knee osteoarthritis initiation and progression differs based on anterior cruciate ligament status: data from the Osteoarthritis Initiative.

Knee alignment and anterior cruciate ligament (ACL) injury are risk factors for knee osteoarthritis (OA). The objective was to examine interactions between knee alignment and ACL status on cartilage volume loss in participants with or at risk of knee OA. Participants were from the Osteoarthritis Initiative, a longitudinal cohort study. Data were from baseline and 24- and 72-month follow-up visits. Participants with knee OA (progression subcohort) or at risk of knee OA (incidence subcohort) that had partial or full ACL tears (OA-ACL group; n=66) or an intact ACL (OA-only group, n=367) were selected. Femur-tibia angles from radiographs quantified knee alignment. Changes in tibial and femoral cartilage volumes were measured using magnetic resonance imaging. Hierarchical linear models examined if knee alignment, presence of ACL, and their interaction were related to cartilage volume loss after accounting for other variables. Interactions between alignment and ACL status were significantly related to cartilage volume loss in the lateral plateau (β=-20.19, 95% confidence interval [CI]=-34.65 to -5.73) and lateral condyle (β=-23.64, 95%CI=-43.06 to -4.23). Valgus alignment was related to lateral compartment cartilage loss in the OA-ACL group, but not in the OA-only group. Varus alignment was related to cartilage loss in the medial plateau (β=7.49, 95%CI=0.17 to 14.80) and medial condyle (β=19.70, 95%CI=5.96 to 33.44) in both groups. The impact of knee alignment on knee OA initiation and progression varies based on ACL status. Initial lateral compartment damage or changes in joint kinematics after ACL rupture might account for these findings.Key Points• The relationship between knee alignment and lateral compartment cartilage loss depended on the status of the anterior cruciate ligament in participants with knee osteoarthritis or at risk for knee osteoarthritis.• Valgus alignment was related to lateral compartment cartilage loss in participants with a deficient anterior cruciate ligament.• Varus alignment was related to medial compartment cartilage loss regardless of the status of the anterior cruciate ligament.

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.