ACL-deficient Knee Research Articles

The Dynamic Effect of Anterior Cruciate Ligament Deficiency on Patellar Height.

The anterior tibial translation (ATT) in case of Anterior Cruciate Ligament (ACL) tear can lead to dynamic alterations of the extensor apparatus biomechanics. The aim of this study is to evaluate the dynamic effect of isolated ACL deficiency on patellar height. The hypothesis is that the ATT of ACL-insufficient knees dynamically reduces patellar height. Skeletally mature patients who underwent ACL reconstruction using hamstring graft between January and December 2018 were included in this study.The Posterior Tibial Slope (PTS), Caton-Deschamps (CDI), modified Insall-Salvati (MISI), and Blackburne-Peel (BPI) indices were calculated in standard lateral and TELOS X-rays. The mean of the measurements calculated between two observers was used to compare these parameters. 95 patients (M: 57; F: 38; 95 knees) were included in the study with a mean age of 31.8years (16-56years old). Significant patellar height reduction (CDI: 0.11 [-0.32; 0.31]; MISI: 0.09 [-0.66; 0.30]) was reported in TELOS compared with standard lateral knee radiography (p < 0.001). 20.0% of the study knees reported an abnormal CDI and 84.2% (16/19 knees) of them reduced this index to within normal limits in TELOS. 20.0% of the knees with mild patella alta reduced CDI in TELOS but always remained above 1.2. The abnormal ATT in case of ACL-deficient knees results in a lowering effect of the patella in TELOS X-rays. In patients with ACL tear and anterior pain the reconstructive ligament surgery should be performed to avoid also chronic anterior knee pain. Basic Science Study (Case Series). The decrease in patellar height in stress-X-rays compared with standard lateral knee radiography in ACL deficient knees, should be considered as a possible contributing cause of anterior pain in these patients.

Association of Meniscus Injuries in Patients With Anterior Cruciate Ligament Injuries.

Introduction: In today's orthopaedic practice, meniscus and anterior cruciate ligament (ACL) injuries are prevalent. It is more common in sports injuries and automobile accidents. In patients with ACL tears, meniscus problems are also common. Several studies have linked meniscus injuries to the development of osteoarthritis in early stages. Early onset of osteoarthritis has been observed in ACL-repaired patients with meniscus tears. As a result, meniscus tears should be detected and corrected as soon as possible to avoid degenerative changes in the knee joint. The goal of the study was to see if there was a link between meniscus injuries and ACL injuries in our rural community.Methods: This retrospective study was conducted on 48 patients at the R.L. Jalappa Hospital & Research Centre from January 2012 to December 2019. Patients between the ages of 18-65 diagnosed with ACL tear with/without meniscus damage in their knees were included in the study. Patients with posterior cruciate ligament (PCL) tear, medial collateral ligament (MCL) or lateral collateral ligament (LCL) injury, previously operated index knees, and patients with more than grade 3 knee osteoarthritis (Kellgren and Lawrence classification) were excluded. Clinical assessment of patients with knee injuries, MRI and diagnostic arthroscopy of the knee joint details were collected. After obtaining the data, we estimated the incidence of meniscus injuries associated with chronic ACL injuries. We also calculated the percentage of side/laterality injury (medial meniscus or lateral meniscus) and part of meniscus injury (anterior horn, body, and posterior horn) in chronic ACL-deficient knees. Patient characteristics such as age and gender were correlated with functional knee assessment using a modified Lysholm score. P-value and chi-square tests were used to assess the data. P-value of less than 0.5 was considered significant.Results: Average age of the participants was 32.31 years. There were 42 men and six women in the group. Isolated medial meniscus, lateral meniscus, and combined medial and lateral meniscus had average ages of 31.83, 31.16, and 40.28 years, respectively. ACL injuries on the right side were seen in 23 patients the left side was seen in 25 patients. In comparison to the right side, the isolated medial meniscus injury on the left side was more severe. In case of a combination of medial and lateral meniscus tears, the right side suffered more damage than the left. Eleven patients had an isolated ACL tear without a meniscus injury, while the other 37 had a meniscus injury and an ACL tear. Excellent scores were observed in 11 cases, satisfactory scores in 26, and unsatisfactory in 11 cases. Age group was categorized into three groups, less than 30, 30-45, and more than 45 years. Excellent, satisfactory, and unsatisfactory scores were observed in seven, eleven, and seven patients on the left side and excellent, satisfactory, and unsatisfactory scores in four, fifteen, and four patients on the right side, respectively. P-value was not statistically significant when comparing outcomes by age, gender, or side.Conclusion: Meniscus injuries occurred 77% of the time when there was a persistent ACL injury. In comparison to a lateral meniscus injury, the incidence of medial meniscus injury associated with chronic ACL tear was higher. In comparison to the anterior horn and body of the medial meniscus, the majority of medial meniscus tears were found in the posterior horn.

Biplanar high tibial osteotomy for the combined correction of varus and posterior tibial slope malalignment

Varus malalignment combined with an increased posterior tibial slope (PTS) in the ACL deficient knee is a frequent pathology; yet, treatment for this condition remains challenging. The presented biplanar osteotomy technique allows to simultaneously address both components of malalignment in a single step. A detailed preoperative planning is best achieved by means of a digital planning software and constant intraoperative imaging is performed to verify the correction angle. A bony wedge is resected along with the extension osteotomy according to the preoperative planning and the medial-opening tibial osteotomy site is filled with bone allograft. Two bicortical lag screws are placed in anterior-posterior direction to secure the extension osteotomy, whereas a plate fixation is used for the medial-open osteotomy.

ACL Surgery Necessity in Non-Acute Patients (ACL SNNAP): a statistical analysis plan for a randomised controlled trial

BackgroundRupture of the anterior cruciate ligament (ACL) is a common injury, primarily affecting young, active individuals. Despite surgical intervention being the more common treatment for patients suffering ACL ruptures, current management is based on limited and generally low-quality evidence. We describe a statistical analysis plan (SAP) for the ACL SNNAP randomised controlled trial, which aims to investigate the necessity of surgical management in patients with ACL injuries.Methods/designACL SNNAP is a pragmatic, multi-centre, superiority, parallel-group randomised controlled trial in participants with a symptomatic non-acute ACL deficient knee. Participants are allocated in a 1:1 ratio to either non-surgical management (rehabilitation) or surgical management (reconstruction) with the aim of assessing the efficacy and cost-effectiveness. The primary outcome of the study is the Knee Injury and Osteoarthritis Outcome Score (KOOS4) at 18 months post-randomisation. The KOOS4 score at 18 months will be evaluated using a linear regression model adjusting for recruitment centre and baseline KOOS4 scores, allowing for intra-centre correlation. A secondary analysis of the primary outcome will be carried out using an area under the curve (AUC) approach using treatment estimates obtained from a mixed model using baseline, 6 months, 12 months, and 18 months post-randomisation outcome data. Secondary outcomes will be measured at 18 months and will include return to activity/level of sport participation, intervention-related complications, the EQ-5D-5L questionnaire, all 5 individual subscales of the KOOS questionnaire, the ACL-QOL score, expectations of return to activity and cost-effectiveness of the interventions. Missing primary outcome data will be investigated through a sensitivity analysis. Full details of the planned methods for the statistical analysis of clinical outcomes are presented in this paper. The study protocol for the ACL SNNAP trial has been published previously.DiscussionThe methods of analysis for the ACL SNNAP trial have been described here to minimise the risk of data-driven results and reporting bias. Any deviations from the analysis methods described in this paper will be described in full and justified in the publications of the trial results.Trial registrationISRCTN ISRCTN10110685. Registered on 16 November 2016

Intraoperative Laximetry-Based Selective Transtibial Anterior Cruciate Ligament Reconstruction Concomitant With Medial Open Wedge High Tibial Osteotomy for Treating Varus Knee Osteoarthritis With Anterior Cruciate Ligament Deficiency

High tibial osteotomy (HTO) is used in the treatment of varus knee osteoarthritis (KOA) in young and active patients. At times, a concomitant anterior cruciate ligament (ACL) deficiency is found, and there is no conclusive evidence comparing the osteotomy options for an ACL-deficient knee despite the popularity of medial opening-wedge (MOW) HTO in varus KOA with ACL deficiency. To minimize the incidence of an unnecessary ACL reconstruction with MOW-HTO, we developed an intraoperative laximetry-based selective technique for transtibial ACL reconstruction concomitant with MOW-HTO using a sterilizable metal laximeter. To successfully use the device required for this procedure, surgeons must understand the proper techniques. Hence, this Technical Note aims to give a comprehensive description of the technique.

Arthroscopic Repair of Posterior Root Tears of the Lateral Meniscus with All-Suture Anchor

Meniscus root tears are increasingly being recognized and treated because of improved awareness and diagnostics. These injuries commonly occur in combination with knee ligament injuries. Untreated posterior meniscus root teats have been demonstrated to increase contact pressure and decrease contact area, ultimately leading to unfavorable joint loading and development of early osteoarthritis. Posterior lateral meniscus root tears (PLMRTs) also have been reported to increase anterior tibial translation and pivot shift in anterior cruciate ligament–deficient knees. Therefore, it is crucial to repair meniscal root tears when possible to restore knee joint loading and kinematics. Several techniques for repair of the PLMRT have been described. In this Technical Note, we describe our preferred technique for repair of PLMRT using an all-suture anchor. This technique is reproducible, does not need a tunnel, mitigates bungee effect of transtibial technique, and the anchor can easily be inserted on the footprint without a need for a guide.

Increased posterior tibial slope is an independent risk factor of anterior cruciate ligament reconstruction graft rupture irrespective of graft choice

IntroductionAnterior cruciate ligament (ACL) reconstruction failure remains a commonly seen complication despite advances in technique and graft options. Recently, several studies have shown that the inclination of the tibial plateau in the sagittal plane affects the stability of the knee joint. The purpose of this study was to determine if an increased posterior slope of the tibia is associated with failure of ACL reconstruction irrespective of the graft used. MethodsFrom June 2002 to August 2003, a total of 100 patients with a symptomatic ACL-deficient knee were randomised to receive either a hamstring autograft or posterior tibialis allograft. All allografts were from a single tissue bank, aseptically processed, and fresh-frozen without terminal irradiation. ACL graft failures requiring reoperation with a minimum of 10-year follow-up were identified via telephone survey. Lateral radiographs of the knee of all patients were reviewed, and the slope of the tibia was measured using a standardised technique. Two fellowship-trained orthopaedic sports medicine specialists, one board-certified general orthopaedic surgeon, and two fellowship-trained musculoskeletal radiologists measured the tibial slope in all patients. ResultsAt a minimum of 10-year follow-up, there were four (8.3%) autograft and 13 (26.5%) allograft failures that required revision reconstruction. The overall average tibial slope of the nonfailure cohort was 9.4°. The overall average tibial slope of the failure cohort was 11.9° (P ​= ​0.0002). The average slope of the allograft failures was 11.5°compared with an average slope of 9.6° in the nonfailures (P ​= ​0.01). The average slope of the autograft failures was 13.1° compared with 9.3° in the nonfailures (P ​= ​0.011). The mean difference in tibial slope measurements was 0.665 (95% confidence interval: 0.569–0.750). The interrater reliability, as measured by the intraclass correlation coefficient, for tibial slope was 0.898 (95% confidence interval: 0.859–0.928). The Cronbach α was 0.904. ConclusionIn a prospective, randomised trial of ACL reconstructions using either autograft or allograft, failures were associated with a significantly increased slope of the tibia compared with the nonfailures at 10-year follow-up.

Biomechanics of the lateral meniscus: evidences from narrative review.

Lateral meniscus plays a crucial role in the knee stability and function. Although complex settings are required for lateral meniscus biomechanical assessment, such characteristics have been investigated over time to optimize the daily clinical practice surgical procedure. The aim of the present study was to provide an overview of literature knowledge regarding the biomechanics of lateral meniscus and give further insights about novel experimental analyses. Studies regarding lateral meniscus mobility, effect on knee laxity, and contact mechanics were included in the review. The effect of meniscal lesion, meniscal repair, partial meniscectomy, and meniscus allograft transplantation were retrieved for either in vivo, cadaveric, or in-silico computational settings. Knee laxity was evaluated both in presence of isolated meniscal tears and in anterior cruciate ligament (ACL) deficient knees. Surgical navigation systems and robots were mainly used for the investigations in vivo and in cadaveric studies, while accelerometers emerged as an alternative for ambulatory assessments. Contact mechanics was only assessed in cadaveric and computational studies. Great effort has been put into exploring lateral meniscus biomechanics from multiple perspectives. Strong evidence emerged regarding the importance of lateral meniscus repair: increased knee stability at high degrees of knee flexion and reduction of peak contact pressures on tibial cartilage were the most reported benefits. The meniscus allograft transplantation also emerged as a concrete solution for irreparable tears and further studies are needed to investigate its long-term influence on knee stability.

Significant slope reduction in ACL deficiency can be achieved both by anterior closing-wedge and medial open-wedge high tibial osteotomies: early experiences in 76 cases.

It has been proven that a steep tibial slope (TS) is a risk factor for anterior cruciate ligament (ACL) injury and graft insufficiency after ACL reconstruction (ACLR). Recently, there is an increasing number of case series on slope decreasing osteotomies after failed ACLR utilizing different techniques and strategies. Goal of the present study is to report on early experiences with slope decreasing osteotomies in ACL deficient knees with special emphasis on the amount of slope correction, technical details, and complications; and to further analyze differences of slope corrections between sole sagittal as well as combined coronal and sagittal realignment procedures. In addition, we wanted to study if sole sagittal corrections change the coronal alignment. Seventy-six patients with a minimum follow-up of 6 months were identified, who underwent a sole sagittal correction (anterior closed-wedge high tibial osteotomy (ACW-HTO)) or a combined procedure with an additional coronal realignment (medial open-wedge high tibial osteotomy (MOW-HTO)). In ACW-HTO, either infratuberosity or supratuberosity approaches were used. The medial TS was measured on lateral radiographs and the anatomical medial proximal tibial angle (aMPTA) was measured on anterior-posterior radiographs. Technical details and specific complications were recorded. Fifty-eight ACW-HTO and 18 MOW-HTO were performed. Regarding ACW-HTO, an infratuberosity (N = 48) or a supratuberosity (N = 10) approach was chosen. Sixty-seven patients had at least 1 previous ACLR. Mean TS changed from 14.5 ± 2.2° to 6.8 ± 1.9° (P < 0.0001). Mean TS of ACW-HTO was significantly reduced (14.6 ± 2.3° vs. 6.5 ± 1.9°; P < 0.0001), whereas in combined coronal and sagittal realignments, from 14.1 ± 1.9° to 7.6 ± 1.9° (P < 0.0001). The TS reduction in sole sagittal corrections was significantly higher compared to combined procedures (8.1 ± 1.6 vs. 6.4 ± 1.6°; P = 0.0002). Mean aMPTA in ACW-HTO changed from 87.1 ± 2.1° to 87.4 ± 2.8 (n.s.). However, there was a significant inverse correlation between the amount of sagittal correction and coronal alteration (r = -0.29; P = 0.028). There was one late implant infection, which occurred 5.5months after the index surgery. ACW-HTO and MOW-HTO facilitate significant slope reduction with a low-risk profile in patients with ACL insufficiency and a high tibial slope. AOW-HTO does not significantly alter coronal alignment in the majority of patients. IV.

Large lateral tibial slope and lateral-to-medial slope difference are risk factors for poorer clinical outcomes after posterolateral meniscus root tear repair in anterior cruciate ligament reconstruction

BackgroundMeniscus root tear is an uncommon but detrimental injury of the knee. Hoop stress is lost during meniscus root tear, which can lead to excessive tibiofemoral contact pressure and early development of osteoarthritis. Posterolateral meniscus root tears (PLRT) are more commonly associated with anterior cruciate ligament (ACL) tears. As the lateral compartment is less congruent than the medial compartment, it is more susceptible to a shearing force, which is increased in the ACL-deficient knee. In accordance with the compressive axial load, the increase in the tibial slope would generate a greater shearing force. The additional lateral compartment mobility caused by ACL tear should be reduced after ACL reconstruction (ACLR). However, there is a lack of evidence to conclude that ACLR can sufficiently limit the effect of large tibial slope (LTS) on the healing after PLRT repair. This study aimed to evaluate whether a steep LTS would be a risk factor for poorer clinical outcomes after PLRT repair concomitant with ACLR.MethodsIn this retrospective study, a chart review was conducted to identify patients with concomitant unilateral primary ACLR and PLRT repair. Patients with a partial tear or healed tear were excluded. Postoperative MRI and clinical assessments were performed at a mean follow up of 35 months. MRI data was used to measure the LTS, medial tibial slope (MTS), coronal tibial slope (CTS), the lateral-to-medial slope difference (LTS-MTS) and meniscus healing and extrusion. Functional outcomes were evaluated by patient-reported outcomes (International Knee Documentation Committee [IKDC], Lysholm and Tegner scores) and KT-1000 arthrometer assessment. Interobserver reproducibility was assessed by two reviewers.ResultsTwenty-five patients were identified for the analysis. Patients with larger LTS and larger LTS-MTS differences were shown to be correlated with poorer IKDC scores after surgery (R = -0.472, p = 0.017 and R = -0.429, p = 0.032, respectively). Herein, patients with LTS ≥ 6° or LTS-MTS ≥ 3° demonstrated poorer IKDC scores.ConclusionA large LTS (≥ 6°) and a large difference of LTS-MTS (≥ 3°) were shown to be risk factors for poorer functional and radiological outcomes for PLRT repair in patients after ACLR. Clinically, closer monitoring and a more stringent rehabilitation plan for patients with LTS ≥ 6° or LTS-MTS ≥ 3° would be recommended.

The Knee Injury and Osteoarthritis Outcome Score Does Not Have Adequate Structural Validity for Use With Young, Active Patients With ACL Tears.

The Knee Injury and Osteoarthritis Outcome Score (KOOS) is well known and commonly used to assess young, active patients with ACL injuries. However, this application of the outcome measure has been called into question. There is currently no evidence supporting the structural validity of the KOOS for this patient population. Structural validity refers to whether a questionnaire meant to provide scores on different subscales behaves as intended in the populations of interest. Structural validity should be assessed for all questionnaire measures with multiple items or subscales. Does the KOOS demonstrate adequate structural validity in young, active patients with ACL tears, when evaluated using (1) exploratory and (2) confirmatory factor analyses? Between January 2014 and March 2017, 1033 patients were screened for eligibility in the Stability 1 randomized controlled trial from nine centers in Canada and Europe. Patients were eligible if they had an ACL deficient knee, were between 14 and 25 years old, and were thought to be at higher risk of reinjury based on the presence of two or more of the following factors: participation in pivoting sports, presence of a Grade 2 pivot shift or greater, generalized ligamentous laxity (Beighton score of 4 or greater), or genu recurvatum greater than 10°. Based on this criteria, 367 patients were ineligible and another 48 declined to participate. In total, 618 patients were randomized into the trial. Of the trial participants, 98% (605 of 618) of patients had complete baseline KOOS questionnaire data available for this analysis. Based on study inclusion criteria, the baseline KOOS data from the Stability 1 trial represents an appropriate sample to investigate the structural validity of the KOOS, specifically for the young, active ACL deficient population.A cross sectional retrospective secondary data analysis of the Stability 1 baseline KOOS data was completed to assess the structural validity of the KOOS using exploratory and confirmatory factor analyses. Exploratory factor analysis investigates how all questionnaire items group together based on their conceptual similarity in a specific sample. Confirmatory factor analysis is similar but used often in a second stage to test and confirm a proposed structure of the subscales. These methods were used to assess the established five-factor structure of the KOOS (symptoms [seven items], pain [nine items], activities of daily living [17 items], sport and recreation [five items], and quality of life [four items]) in young active patients with ACL tears. Incremental posthoc modifications, such as correlating questionnaire items or moving items to different subscales, were made to the model structure until adequate fit was achieved. Model fit was assessed using chi-square, root mean square error of approximation (RMSEA) and an associated 90% confidence interval, comparative fit index (CFI), Tucker-Lewis index (TLI), as well as standardized root mean square residual (SRMR). Adequate fit was defined as a CFI and TLI > 0.9, and RMSEA and SRMR < 0.08. Structural validity of the KOOS was not confirmed when evaluated using (1) exploratory or (2) confirmatory factor analyses. The exploratory factor analysis, where the 42 KOOS items were allowed to group naturally, did not reflect adequate fit for a five-factor model (TLI = 0.828). Similarly, the confirmatory factor analysis used to investigate the KOOS structure as it was originally developed, revealed inadequate fit in our sample (RMSEA = 0.088 [90% CI 0.086 to 0.091]). Our analysis suggested a modified four-factor structure may be more appropriate in young, active ACL deficient patients; however, the final version presented here is not appropriate for clinical use because of the number and nature of post-hoc modifications required to reach adequate fit indices. The established five-factor structure of the KOOS did not hold true in our sample of young, active patients undergoing ACL reconstruction, indicating poor structural validity. We question the utility and interpretability of KOOS subscale scores for young, active patients with ACL tears with the current form of the KOOS. A modified version of the KOOS, adjusted for this patient population, is needed to better reflect and interpret the outcomes and recovery trajectory in this high-functioning group. A separate analysis with a defined a priori development plan would be needed to create a valid alternative.

Influence of Hamstring Facilitatory Taping on Knee Muscle Activation and Dynamic Balance in Patients with Anterior Cruciate Ligament Deficient Knee

Influence of Hamstring Facilitatory Taping on Knee Muscle Activation and Dynamic Balance in Patients with Anterior Cruciate Ligament Deficient Knee

Four-dimensional computed tomographic analysis of screw home movement in patients with anterior cruciate ligament deficient knee - a 3D-3D registration technique.

The tibia externally rotates to the femur during the last 20° of the knee extension motion. This kinematic phenomenon is well known as screw home movement (SHM). The purpose was to clarify the SHM in anterior cruciate ligament deficient (ACLD) knee using four-dimensional computed tomography (4DCT). Six patients with a unilateral isolated ACLD knee participated. In the static position, CT scan of the both limbs of the femur and tibia were performed. Then, 4DCT was performed around knee. In the CT gantry, subjects were positioned in supine position with 45° of knee flexion on a triangle pillow and were asked to extend the knee to full extension within 10s on each limb. The CT data were accumulated in digital imaging and communication in medicine (DICOM) data format. From the static CT and 4DCT DICOM data, three-dimensional surfaces of the knee joint were reconstructed. The whole tibia surface was matched into the partial tibia surface of that frame using 3D-3D registration technique. After the assessment of coordination system of the whole leg, knee flexion, abduction, and external rotation angle were calculated. Knee external rotation angle was significantly smaller on the ACLD side than on the contralateral unaffected side in 0-15° of knee flexion (P < 0.05 in 0, 5, 10, and 15 degrees), while the angle was similar during 15-60° of knee flexion. The absence of SHM in ACLD knee was detected using 3D-3D registration technique based on 4DCT.

Controversies in the management of anterior cruciate ligament injuries in skeletally immature patients: a literature review of current treatment options

Background: Despite an increasing incidence of injury, there continues to be a paucity of literature, when compared with adult cohorts, for anterior cruciate ligament (ACL) disruption in skeletally immature patients. The detrimental long-term effects of chondral or meniscal damage resulting from an ACL deficient and unstable knee, has led most contemporary orthopaedic surgeons to opt for surgical intervention rather than nonoperative management. However, high failure rates in the young and adolescent group after formal ACL reconstruction, along with the potential risks of physeal disturbance, have been highlighted as a cause for concern. The aim of this review was to provide the state of art management of ACL injuries in skeletally immature patients based on the current evidence. Methods: A literature review on the different management options of ACL injuries in skeletally immature patients was conducted. The authors searched PubMed entries from inception until April 2021. The search was performed with the search terms “ACL injuries” AND “skeletally immature”. Results: A comprehensive search related to the management of “ACL injuries” generated 13,157 results. Thus, search was narrowed to include the term “children” to focus our study on 570 papers. To further refine our search, we included the terms “ACL injuries” AND “skeletally immature,” which produced 327 results. Conclusion: This review highlights pros and cons of current treatment options, based on available evidence, including a detailed assessment of factors affecting the success of repairing the ACL. Overall, further Level 1 studies are necessary to improve the available evidence. Level of Evidence: Level I.

Comparison of Anterior Cruciate Ligament Tears Treated Nonoperatively Versus With Reconstruction: Risk of Subsequent Surgery

Background: Anterior cruciate ligament (ACL) tears can be devastating injuries, leading to joint instability, meniscal tears, and subsequent arthritis. It is unknown whether ACL reconstruction (ACLR) alters the natural history of joint degeneration in the ACL-deficient knee compared with nonoperative treatment, and few studies have examined outcomes in middle–aged patients. Purpose: The objective of this study was to compare the midterm risk of subsequent ipsilateral knee surgery in middle–aged patients after an ACL injury treated with initial conservative (nonoperative) management (CM) versus ACLR (operative management [OM]) within 6 months of the diagnosis. Study Design: Cohort study; Level of evidence, 3. Methods: We performed an electronic database search from 2011 to 2012 for all patients aged 35 to 55 years with an initial diagnosis of magnetic resonance imaging—confirmed ACL tear. Patients who elected CM and those who underwent ACLR within 6 months of the diagnosis (OM) were identified. Index patient and clinical characteristics were collected from the health record. All patients were longitudinally observed until August 31, 2017. The primary outcome was subsequent ipsilateral knee surgeries, and secondary outcomes included contralateral knee surgeries, deep surgical–site infections, and venous thrombotic events. Results: The mean follow–up was 4.8 ± 0.6 years. The CM group included 463 patients (40.2%) and the OM group included 690 patients (59.8%). The mean ages were 43.9 ± 5.7 years and 42.7 ± 5.3 years for patients in the CM and OM groups, respectively (P < .001). Obesity and smoking were significantly more common in the CM group. During the follow–up, 180 patients (38.9%) in the CM group underwent subsequent ipsilateral knee surgery compared with 73 (10.6%) patients in the OM group (P < .001). The mean time to the first ipsilateral procedure was 0.9 ± 1.1 years in the CM and 2 ± 1.5 years in the OM group (P < .001). Delayed ipsilateral ACLRs were performed in 81 patients in the CM group (17.5%); non-ACLR ipsilateral knee surgeries were performed in 156 patients in the CM group (33.7%). Contralateral knee surgery rates were similar. In a regression model, after controlling for age, sex, the Charlson Comorbidity Index score, and smoking status, it was found that normal body mass index and CM group were risk factors for undergoing subsequent knee surgery or ipsilateral non-ACLR surgery. Conclusion: Excluding delayed ACLR, subsequent ipsilateral knee surgeries were more common and occurred earlier in middle–aged patients with nonoperatively managed ACL tears compared with patients managed with reconstruction.

The crevice sign: a new indicator of meniscal instability in ACL reconstructions.

Meniscus preservation is key in knee surgery. The newly documented crevice sign indicates instability of the medial meniscus in ACL-deficient knees. Once the sign is visualised, it is imperative that the stability of the medial meniscus is assessed and potentially treated. It was hypothesized that there would be a strong correlation between the presence of an unstable medial meniscal tear in patients with the crevice sign in ACL-deficient knees. This was a multicenter prospective study carried out to evaluate the incidence of medial meniscal tears in patients with ACL-deficient knees and their correlation with a crevice sign. All patients (128) who had undergone ACL reconstruction between May 2020 and November 2020 were assessed arthroscopically for meniscal stability and divided in to two groups: stable (n = 84) and unstable (n = 44). Thereafter, the presence of the crevice sign was determined in each case. The populations were comparable in terms of sex and age (Table 1). Fisher's exact test showed a significant association between the presence of the crevice sign and the instability of the medial meniscus (p < 0.001). Descriptive statistics suggest that the presence of crevice sign was associated more frequently to MM instability (38.6% vs 1.2%; p < 0.001). The specificity of this test was 98.8% and its sensitivity was 38.6%. The positive predictive value (PPV) was 94.4% and the negative predictive value (NPV) was 75.5%. Table 1 Descriptions and comparisons of internal meniscus instability of patients by presence of crevice sign Internal meniscus instability (N = 44) Internal meniscus stability (N = 84) Total (N = 128) Gender N 44 84 128 Male 33 (75.0) 58 (69.0) 91 (71.1) Female 11 (25.0) 26 (31.0) 37 (28.9) Fisher's exact test (n.s.) Age (years) N 44 84 128 Mean (ET) 28.6 (9.4) 30.1 (10.2) 29.6 (9.9) Median (IIQ) 26.5 (22.0;34.5) 27.0 (22.5;37.0) 27.0 (22.0;36.0) [Min-Max] [14-54] [14-52] [14-54] Wilcoxon test bilateral (n.s.) Crevice sign N 44 84 128 Absent 27 (61.4) 83 (98.8) 110 (85.9) Present 17 (38.6) 1 (1.2) 18 (14.1) Fisher's exact test p < 0.001 CONCLUSION: The hypothesis was confirmed since medial meniscal instability was strongly correlated with the existence of the crevice sign and showed high specificity and PPV. III.

Not strong enough? Movements generated during clinical examination of sagittal and rotational laxity in a cadaver knee

ABSTRACT BACKGROUND: Injury to the anterior cruciate ligament (ACL) is associated with sagittal and rotational laxity, which is exacerbated by damage to the anterolateral capsuloligamentous structures, also known as the anterolateral ligament (ALL). The amount of laxity reported in biomechanical studies might be clinically insignificant during a surgeon's examination, possibly influencing clinical judgement. We aimed to measure whether the motion generated by clinicians in a cadaver model after the ACL and ALL were transected is clinically significant METHODS: A group of orthopaedic surgeons and trainees examined a cadaver knee for sagittal and rotational laxity at 30° and 90° with intact ligaments, after the ACL was transected, and after the ACL and ALL were transected. The examiners were blinded to the dissection process. Rotational and sagittal movements during these examinations were recorded by a computer-assisted surgery (CAS) system RESULTS: Twenty-four orthopaedic surgeons took part in the study. The median sagittal plane motion captured by CAS at 30° flexion was 7 mm (IQR 2 mm, p-value 0.32) in the intact knee, 9 mm (IQR 1 mm, p-value 0.34) after the ACL was cut and 9 mm (IQR 3 mm, p-value 0.63) after ACL and ALL were cut. The median arc of rotational motion at 30° was 19° (IQR 7°, p-value 0.12) in the intact knee, 24° (IQR 5°, p-value 0.56) after the ACL was cut, and 22° (IQR 6°, p-value 0.8) after the ACL and ALL were cut. None of the differences in these movements was significant CONCLUSION: The surgeons could not generate significant differences in sagittal or rotational motion in a cadaver model, which could be objectively detected by CAS, when examining the intact knee, ACL deficient (only), or combined ACL and ALL deficient knee. This challenges the utility of known clinical tests and calls for improved objective laxity assessment tools to provide input in clinical decision-making and measure outcomes of these injuries Level of evidence: Level 5 Keywords: knee, anterolateral ligament, anterior drawer's test, pivot shift, rotatory instability, anterior cruciate ligament, iliotibial band, Kaplan fibres

Combined procedures with unicompartmental knee arthroplasty: High risk of stiffness but promising concept in selected indications

Introduction: Unicompartmental knee arthroplasty (UKA) has traditionally been contraindicated in the presence of an ACL deficient knee, bi-compartmental disease, or significant coronal deformity due to concerns regarding increased risk of persisted pain, knee instability, tibial loosening, or progression of osteoarthritis. The aim of this study was to evaluate the outcomes of patients undergoing UKA with an associated surgical procedure in these specific indications. Method: This was a retrospective cohort study of patients undergoing UKA between December 2015 and October 2020. Patients were categorized into groups based on associated procedures: UKA + ACL, UKA + HTO, and bicompartmental arthroplasty. Outcomes were assessed using the Knee Society Score (KSS) knee and function scores and the Forgotten Joint Score. Radiological and complication analysis was performed at the last clinical follow-up. Results: Thirty-two patients (13 men and 19 women) were included. The mean age was 56.2 years ± 11.1 (range, 33–84) with a mean follow-up of 26.3 months ± 15 (7.3–61.1). There was a significant improvement between the pre-and postoperative KSS Knee (+34.3 ± 16.5 [12–69]), Function (+34.3 ± 18.6 [0–75]), and Total scores (+68.5 ± 29.4 [24–129]) (p = 0.001). Seven patients (21.8%) required an arthroscopic arthrolysis for persistent stiffness. Two patients (UKA + PFA and UKA + ACL) underwent revision to TKA. Patient satisfaction was 90%, and mean flexion at last follow-up was 122° ± 6 (120–140). The implant survival rate was 94%. Discussion: This study found performing UKA with an additional procedure to address relative contraindications to the arthroplasty in physically active patients with monocompartmental knee arthritis is an efficient strategy with good results at short-term follow-up. It should be reserved for patients where TKA is likely to have unsatisfactory results, and the patient has been fully counseled regarding the management options. Even if there is a high rate of complications with stiffness requiring a re-intervention, the final results are very satisfying with no impact of the reintervention on the clinical result in the short term.

Various Prosthetic ACL Grafts: A Review of Literature Various Prosthetic ACL Grafts: A Review of Literature

Satisfactory prosthetic replacement of the ACL has been a focus of orthopaedic research endeavours for the past thirty years. Desires to provide immediate mobility and strength to the ACL-deficient knee while avoiding the donor site morbidity caused by the commonly used autograft surgical techniques continually drive new research initiatives. Most of the grafts that have been developed to date have failed due to unsatisfactory long-term physiologic and functional performance. Most permanent ACL prostheses are prone to creep, fatigue, and mechanical failure within several years after implantation. Tissue ingrowth scaffolds and ligament augmentation devices require further refinement to provide effective mechanical support while avoiding stress shielding of the host tissue. In view of these factors, prosthetics are not widely used today in ACL reconstruction, and autogenous tissue grafts remain the gold standard used by the majority of surgeons. Perhaps development of resorbable, tissueinducing and cell-seeded biomaterials will improve the long-term biomechanical performance of the reconstructed anterior cruciate ligament. Advances in tissue engineering combined with developments in molecular biology and gene therapy may couple with the rapid gains in computer-assisted surgery to provide improved options for the ACL-deficient knee, with a greater potential to restore its pre-injury state.

Meniscal Ramp Lesions: Anatomy, Epidemiology, Diagnosis, and Treatment.

Injuries to the medial meniscus meniscocapsular junction, also known as ramp lesions, are common in the setting of anterior cruciate ligament injuries with a prevalence of 9% to 42%. Anatomically, ramp lesions involve disruption of the posterior meniscocapsular junction and meniscotibial ligaments. Biomechanically, ramp lesions are associated with an increase in anterior tibial translation and internal and external tibial rotation in anterior cruciate ligament-deficient cadaveric knees. Magnetic resonance imaging is useful in evaluating the meniscocapsular junction. Irregularity or increased signal near the posterior meniscocapsular junction and/or signal change indicative of posterior medial tibial plateau edema can suggest these injuries are present before surgical intervention. The current benchmark for diagnosis is arthroscopic visualization of the posterior medial meniscocapsular junction viewed through the intercondylar notch. Once a ramp lesion is identified, stability should be assessed by arthroscopic probing to determine the degree of anterior displacement. Optimal treatment has been debated in the literature, especially for stable ramp lesions, although good outcomes have been shown with and without repair. Repair is warranted for those lesions that are unstable to probing. Unfortunately, only limited literature available to guide clinicians on the optimal rehabilitation for ramp lesions.