Anterior Cruciate Ligament Reconstruction Failure Research Articles

Revision anterior cruciate ligament reconstruction and outcomes with different autografts in a population with kneeling customs.

This study was designed to evaluate, compare the mid-term functional outcome of revision anterior cruciate ligament reconstruction (ACLR) using different autografts and assess the cause of failure of primary ACLR in an Omani population with kneeling customs. Patients with failed primary ACLR who underwent revision ACLR using autografts were included in this retrospective study. The cause of primary ACLR failure and the functional outcome was assessed using the Tegner-Lyholm knee score and compared among bone patella tendon-bone (BPTB), quadriceps tendon (QT), semitendinosus gracilis (STG) autografts used. One hundred two patients (102 male) were included in the study with a minimum follow-up of 2 years. Thirty-one patients underwent revision with BPTB, 34 with STG and 19 with QT autografts. Majority of the patients (70.23%) achieved good-to-excellent functional outcome based on their Tegner-Lysholm scores. The functional outcome of different autografts was comparable to each other based on Kruskal-Wallis test. The causes of primary ACLR failure were failure due to trauma in 58.33% of patients, technical failure in 22.61% of patients, and nontraumatic failure in 19.04% of patients. The functional outcome of revision ACLR in this Middle Eastern Asian Omani population was good-to-excellent, with the patients experiencing no difficulty in performing activities of daily living, including kneeling activities. The outcome of different autografts, BTPB, QT, STSG is similar in high knee flexion patients with no autograft found to be superior. The findings of this study add to the literature on functional outcomes after primary and revision ACLR in a customary kneeling population.

Steep lateral tibial slope measured on magnetic resonance imaging is the best radiological predictor of anterior cruciate ligament reconstruction failure.

To identify the radiological predictive risk factors for anterior cruciate ligament reconstruction (ACLR) failure, compare the diagnostic accuracies of different parameters of conventional radiographs and magnetic resonance imaging (MRI), and determine the cutoff values for patients at higher risk. Twenty-eight patients who were diagnosed as ACLR failure via MRI or arthroscopic examination were included in the study group. They were matched to 56 patients who underwent primary ACLR with the same surgical technique and without graft failure at the minimum 24-month follow-up by age, sex, and body mass index. On true lateral whole-leg radiographs, the posterior tibial slope (PTS) referenced to the tibial mechanical axis (PTS-mechanical), PTS referenced to the tibial proximal anatomical axis (PTS-anatomical), and anterior tibial translation (ATT) were measured. On the sagittal slices of MRI, the medial tibial slope (MTS), medial tibial plateau (MTP) subluxation (MTPsublx), lateral tibial slope (LTS), and lateral tibial plateau (LTP) subluxation (LTPsublx) were obtained. Receiver operator characteristic (ROC) curves were constructed to compare the diagnostic performance and determine the cutoff values of different radiological parameters. The study group demonstrated higher values of PTS-mechanical (10.7° ± 2.9° vs 8.7° ± 1.9°, p = 0.003), PTS-anatomical (13.2° ± 2.8° vs 10.5° ± 2.5°, p < 0.001), ATT (10.7 ± 3.3mm vs 8.9 ± 2.2mm, p = 0.014), LTS (9.4° ± 2.1° vs 5.5° ± 2.5°, p < 0.001), and LTPsublx (8.2 ± 2.8mm vs 6.8 ± 1.9mm, p = 0.009) as compared with the control group. The area under the ROC curve of LTS was significantly larger than that of PTS-mechanical (p = 0.006) and PTS-anatomical (p = 0.020). Based on the maximum Youden indexes, the cutoff values of PTS-mechanical, PTS-anatomical, and LTS were 10.1° (sensitivity, 64.3%; specificity, 78.6%), 12.0° (sensitivity, 71.4%; specificity, 71.4%), and 7.7° (sensitivity, 85.7%; specificity, 80.4%), respectively. Due to the morphological asymmetry of the MTP and LTP, steep LTS measured on MRI is the best radiological predictor of ACLR failure. Detailed measurement of the LTS on MRI is recommended to evaluate the risk of ACLR failure prior to the surgery. III.

Histopathological Analysis of the Degree of Tendinosis in Failed Anterior Cruciate Ligament Grafts.

After reconstruction of the anterior cruciate ligament, the modification processes in the transplanted tendon tissue directly influence the biomechanical properties of the knee. The histopathological alterations in failed grafts have hardly been studied. Our study focused on examining the presence and extent of tendinosis (low or high grade) in the tendon tissue of failed anterior cruciate ligament reconstructions. We considered its relationship to the type of transplant, the symptoms, the arthroscopic appearance, the mode of trauma, and the timing of the failure. The tendon tissue of failed anterior cruciate ligament reconstructions in 30 patients was gathered during revision surgery and its histopathology was analysed for the occurrence of structural alterations. The classification of the tendinosis as low or high grade was semiquantitative based on five qualities. We used a standardised questionnaire to collect patient data and we used the Marburg Arthroscopy Score for the intraoperative evaluation of the graft. We found histological vitality and, except for two samples, structural alterations consistent with tendinosis, predominantly high grade, in all failed anterior cruciate ligament grafts. No direct link could be proved between the degree of tendinosis and the type of graft used, the symptoms (except for instability) or the timing of the graft failure, the mode of trauma, or the arthroscopic appearance of the failed plasty. However, the accumulation of high-grade tendinosis in patients with hamstring tendons, subjective instability, and graft failure between 1 to 5 years postoperatively was noteworthy. Structural alterations consistent with tendinosis could be detected, with different expressions, in the vital tendon tissue of anterior cruciate ligament reconstructions. This indicates that the graft is subject to repetitive microtrauma. However, it is still unclear how tendinosis influences the failure of anterior cruciate ligament reconstructions.

Clinical application of slope-reducing tibial osteotomy and anterior cruciate ligament revision in patients with abnormally increased posterior tibial slope

To investigate the effectiveness of slope-reducing tibial osteotomy and anterior cruciate ligament (ACL) revision in the treatment of patients with primary ACL reconstruction failure and abnormally increased posterior tibial slope (PTS). The clinical data of 9 patients with primary ACL reconstruction failure and abnormally increased PTS (≥17°) who met the selection criteria between January 2018 and January 2020 were retrospectively analyzed. There were 8 males and 1 female; the age ranged from 21 to 42 years, with a median age of 30 years. Lachman test was positive in 9 patients. Pivot-shift test was negative in 6 cases, degree Ⅰ positive in 2 cases, and degree Ⅱ positive in 1 case. The PTS was (17.78±1.09)° and the anterior tibial translation (ATT) was (11.58±1.47) mm. The International Knee Documentation Committee (IKDC) score was 51.0±3.8, Lysholm score was 49.7±4.6, and Tegner score was 3.7±0.7. The time from primary reconstruction to revision was 12-33 months, with an average of 19.6 months. Slope-reducing tibial osteotomy and ACL revision were performed. The improvement of knee function was evaluated by IKDC score, Lysholm score, and Tegner score; Lachman test and Pivot-shift test were used to evaluate the stability of knee joint. PTS and ATT were measured to observe the morphological changes of knee joint. All the incisions healed by first intention, and there was no complication such as incision infection, fat liquefaction, necrosis, deep vein thrombosis of lower extremities, and neurovascular injury. All 9 patients were followed up 12-36 months, with an average of 25.8 months. At last follow-up, Lachman test and pivot-shift test were negative. IKDC score was 85.0±4.0, Lysholm score was 87.7±2.8, Tegner score was 6.8±0.7, PTS reduced to (9.89±0.60)°, and ATT shortened to (0.91±0.29) mm, which were significantly improved when compared with those before operation ( P<0.05). Slope-reducing tibial osteotomy and ACL revision in the treatment of patients with primary ACL reconstruction failure and abnormally increased PTS has a satisfactory short-term effectiveness. It can improve the stability of knee joint and maintain the normal shape of knee joint.

Predicting subjective failure of ACL reconstruction: a machine learning analysis of the Norwegian Knee Ligament Register and patient reported outcomes

ObjectivesAccurate prediction of outcome following anterior cruciate ligament (ACL) reconstruction is challenging, and machine learning has the potential to improve our predictive capability. The purpose of this study was to determine if machine learning analysis of the Norwegian Knee Ligament Register (NKLR) can (1) identify the most important risk factors associated with subjective failure of ACL reconstruction and (2) develop a clinically meaningful calculator for predicting the probability of subjective failure following ACL reconstruction. MethodsMachine learning analysis was performed on the NKLR. All patients with 2-year follow-up data were included. The primary outcome was the probability of subjective failure 2 years following primary surgery, defined as a Knee Injury and Osteoarthritis Outcome Score (KOOS) Quality of Life (QoL) subscale score of <44. Data were split randomly into training (75%) and test (25%) sets. Four models intended for this type of data were tested: Lasso logistic regression, random forest, generalized additive model (GAM), and gradient boosted regression (GBM). These four models represent a range of approaches to statistical details like variable selection and model complexity. Model performance was assessed by calculating calibration and area under the curve (AUC). ResultsOf the 20,818 patients who met the inclusion criteria, 11,630 (56%) completed the 2-year follow-up KOOS QoL questionnaire. Of those with complete KOOS data, 22% reported subjective failure. The lasso logistic regression, GBM, and GAM all demonstrated AUC in the moderate range (0.67–0.68), with the GAM performing best (0.68; 95% CI 0.64–0.71). Lasso logistic regression, GBM, and the GAM were well-calibrated, while the random forest showed evidence of mis-calibration. The GAM was selected to create an in-clinic calculator to predict subjective failure risk at a patient-specific level (https://swastvedt.shinyapps.io/calculator_koosqol/). ConclusionMachine learning analysis of the NKLR can predict subjective failure risk following ACL reconstruction with fair accuracy. This algorithm supports the creation of an easy-to-use in-clinic calculator for point-of-care risk stratification. Clinicians can use this calculator to estimate subjective failure risk at a patient-specific level when discussing outcome expectations preoperatively. Level of evidenceLevel-III Retrospective review of a prospective national register.

Recognizing the better autograft and the factors influencing outcomes of revision anterior cruciate ligament reconstruction

Objectives: The outcome of revision anterior cruciate ligament reconstruction (ACLR) is inferior to that of the primary reconstruction and is influenced by multiple factors. The purpose of this study was to identify the better autograft suited for revision ACLR and to assess the factors influencing the outcome of revision. Methods: A total of 102 patients who underwent revision ACLR were enrolled in this study. The patients were grouped based on the type of autograft used for revision. The mechanism of injury and the cause of the primary ACLR failure, meniscal, and chondral status were noted. All patients’ Tegner Lysholm functional scores were assessed at 2 years of follow-up. Results: Almost 37.3% of the patients underwent revision ACLR with bone-patellar tendon bone, 41.3% with semitendinosus-gracilis, and 21.3% with quadriceps tendon autografts. The mean Tegner-Lysholm score was 85.4 ± 15.8, with the majority achieving good to excellent scores. Chondral defect of Grade 3/4 was associated with an inferior poorer functional outcome (P = 0.03). At a 2-year follow-up, the non-contact mechanism of primary ACLR failure was associated with worse scores compared to the contact mechanism of failure (P = 0.03). On comparison of Lysholm functional score between different autografts using the Kruskal-Wallis test, the p-value was insignificant (P = 0.9). Conclusion: Non-contact mechanism of primary ACLR failure and Grade 3/4 chondral defects was associated with a poorer functional outcome at 2 years post-revision ACLR. The overall functional outcome of revision ACLR was good to excellent in our Middle East Asian population, with no one autograft found to be superior to the other.

Reinjury Rates in Adolescent Patients 2 Years Following ACL Reconstruction

Background: Sports injuries have increased dramatically in the pediatric and adolescent population. Return-to-sport testing and criteria are increasingly utilized, however, the guidelines for return to play in adolescents are unclear. The purpose of this study was to compare strength and function at the time of the return-to-sport progression to those with and without a failed anterior cruciate ligament reconstruction (ACLR). Methods: A total of 105 adolescent patients with primary ACLR were assessed at the time of return to sport. We identified graft failures/contralateral injury through medical records, clinic visits, or phone interviews at minimum 2 years of postsurgical follow-up. All patients completed bilateral isokinetic strength tests of the knee extensor/flexor groups and hop tests. Strength was expressed as torque-normalized-to-mass (Nm/kg), and limb-symmetry-index was expressed as a percentage of the uninvolved limb’s strength. All patients completed outcome surveys. The χ2 analysis was used to compare failures between sexes and graft types. Independent sample t tests were used to compare knee extensor/flexor strength, symmetry, and hop test results between patients with and without secondary anterior cruciate ligament (ACL) injury. One-way analysis of variance was used to compare knee extensor/flexor strength and symmetry, hop test, and survey results between those (1) without secondary injury, (2) ACLR graft failure, and (3) contralateral ACL injury. Results: A total of 100 of 105 patients (95.2%) were included with 4±1.2 years of follow-up, with 28 (28%) sustaining subsequent injury (12% graft, 16% contralateral). Patients with graft failure demonstrated (1) stronger quadriceps strength (2.00±0.46 Nm/kg) compared with those with contralateral ACL injury (1.58±0.35 Nm/kg, P=0.039) and patients that did not have a secondary injury (1.58±0.44 Nm/kg, P=0.007), (2) greater quadriceps strength symmetry (85.7±0.11.2%) compared with patients without secondary injury ACL (72.9±17.9%, P=0.046), (3) a greater proportion of hamstring grafts compared with those without reinjury (P=0.028). Conclusions: Adolescent patients who sustained ACLR graft failure had greater and more symmetric quadriceps strength at the time of return to sport compared with patients with no secondary injury. Objective measures of quadriceps strength at the time of the return-to-sport progression may not solely identify individuals that have a secondary ACL injury. Study Design: Level IV—retrospective cohort study.

Increase in cartilage degeneration in all knee compartments after failed ACL reconstruction at 4\xa0years of follow-up

PurposeDegeneration of the cartilage after anterior cruciate ligament reconstruction (ACL-R) is known, and further deterioration can be expected in patients with tunnel malplacement or partial meniscal resection. It was hypothesized that there is a significant increase in cartilage degeneration after failed ACL-R.Material and methodsIsolated ACL revision surgery was performed in 154 patients at an interval of 46 ± 33 months (5–175 months) between primary and revision surgery. Cartilage status at the medial, lateral femorotibial, and patellofemoral compartments were assessed arthroscopically during primary and revision ACL-R in accordance with the Outerbridge classification. Tunnel placement, roof angle, and tibial slope was measured using anteroposterior and lateral radiographic views.ResultsCartilage degeneration increased significantly in the medial femorotibial compartment, followed by the lateral and patellofemoral compartments. There was a correlation between both cartilage degeneration in the patellofemoral compartment (PFC) (rs = 0.28, p = 0.0012) and medial tibial plateau (Rs = 0.24, p = 0.003) in relation to the position of tibial tunnel in the frontal plane. Worsening of the cartilage status in the medial femorotibial compartment, either femoral or tibial, was correlated with the tibial aperture site in the lateral view (Rs = 0.28, p < 0.001). Cartilage degeneration in the lateral compartment of the knee, on both femoral or tibial side, was inversely correlated with the femoral roof angle (Rs = −0.1985, p = 0.02). Meniscal tears, either at the medial or lateral site or at both, were found in 93 patients (60%) during primary ACL-R and increased to 132 patients (86%) during revision ACL-R.DiscussionAccelerated cartilage degeneration and high prevalence of meniscal lesions are seen in failed ACL-R. Tunnel placement showed significant impact on cartilage degeneration and may partially explain the increased risk of an inferior outcome when revision surgery is required after failed primary ACL-R.Level of evidence: Level IV—retrospective cohort study.

Predicting Anterior Cruciate Ligament Reconstruction Revision: A Machine Learning Analysis Utilizing the Norwegian Knee Ligament Register.

Several factors are associated with an increased risk of anterior cruciate ligament (ACL) reconstruction revision. However, the ability to accurately translate these factors into a quantifiable risk of revision at a patient-specific level has remained elusive. We sought to determine if machine learning analysis of the Norwegian Knee Ligament Register (NKLR) can identify the most important risk factors associated with subsequent revision of primary ACL reconstruction and develop a clinically meaningful calculator for predicting revision of primary ACL reconstruction. Machine learning analysis was performed on the NKLR data set. The primary outcome was the probability of revision ACL reconstruction within 1, 2, and/or 5 years. Data were split randomly into training sets (75%) and test sets (25%). Four machine learning models were tested: Cox Lasso, survival random forest, generalized additive model, and gradient boosted regression. Concordance and calibration were calculated for all 4 models. The data set included 24,935 patients, and 4.9% underwent a revision surgical procedure during a mean follow-up (and standard deviation) of 8.1 ± 4.1 years. All 4 models were well-calibrated, with moderate concordance (0.67 to 0.69). The Cox Lasso model required only 5 variables for outcome prediction. The other models either used more variables without an appreciable improvement in accuracy or had slightly lower accuracy overall. An in-clinic calculator was developed that can estimate the risk of ACL revision (Revision Risk Calculator). This calculator can quantify risk at a patient-specific level, with a plausible range from near 0% for low-risk patients to 20% for high-risk patients at 5 years. Machine learning analysis of a national knee ligament registry can predict the risk of ACL reconstruction revision with moderate accuracy. This algorithm supports the creation of an in-clinic calculator for point-of-care risk stratification based on the input of only 5 variables. Similar analysis using a larger or more comprehensive data set may improve the accuracy of risk prediction, and future studies incorporating patients who have experienced failure of ACL reconstruction but have not undergone subsequent revision may better predict the true risk of ACL reconstruction failure. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Three-in-One Procedure for Revision ACL Reconstruction

Revision anterior cruciate ligament (ACL) reconstruction is a challenge due to the unfavorable condition of the knee and the lack of autogenous graft tissue. Anterolateral structure (ALS) reconstruction of the knee has been proved effective to address the unfavorable condition in revision cases, and lateral extra-articular tenodesis (LET) is a special technique that can enhance anterolateral stability of the knee without graft tissue. We introduce a procedure that combines ACL and ALS reconstruction, as well as LET for failed ACL reconstruction. The critical point of this technique is using the anterior half of the iliotibial band to realize LET and to partially reconstruct the ACL. Our clinical experience indicates this technique is extremely useful in revision ACL reconstruction without enough free graft tissue. This technique will provide a reasonable choice in revision ACL reconstruction.

Tibial Tubercle Preserving Anterior Closing Wedge Proximal Tibial Osteotomy and ACL Tunnel Bone Grafting for Increased Posterior Tibial Slope in Failed ACL Reconstructions

Anterior cruciate ligament reconstruction (ACLR) failure is multifactorial, but it is known that increased posterior tibial slope (PTS) leads to a greater likelihood of ACLR failure. This technical note describes the senior author’s technique for performing an anterior closing wedge proximal tibial osteotomy, in which the osteotomy is made proximal to the tibial tubercle. This procedure is the first part of a staged surgery for patients with multiple failed ACLRs and increased sagittal plane PTS. Debridement of osteolytic reconstruction tunnels with bone grafting is also undertaken in preparation for a second-stage revision ACLR.

Anterior Closing Wedge Proximal Tibial Osteotomy and Revision Anterior Cruciate Ligament Reconstruction With Quadriceps Tendon Autograft

Background: Anterior cruciate ligament (ACL) ruptures are among the most common injuries in young athletes and active adults. Reconstruction of the ACL most often leads to good functional outcomes and return to full activities. However, a number of patients experience ACL graft failures requiring revision surgery. The reasons for ACL graft failure are often multifactorial, though recent attention has been given to elevated posterior tibial slope (PTS) as a risk factor for recurrent ACL injuries. Indications: In patients with 2 or more ACL reconstruction failures with a PTS ≥12 degrees, anterior closing wedge proximal tibia osteotomy (ACWPTO) may be indicated to reduce the risk of recurrent ACL graft failure and allow return to full activities. Technique Description: This surgical technique video demonstrates the ACWPTO using a case example in a young athlete. Preoperative templating on lateral radiograph is used to determine the amount of correction for the closing wedge. The osteotomy is completed using K-wires and a free hand biplanar cutting technique with the tibial tubercle left in place. This is performed with a concomitant revision ACL reconstruction using quadriceps tendon autograft. Results: There are 2 small cases series published with good clinical outcomes and return to sport activities. No ACL graft failures were reported in either study with short-term follow-up. Discussion: In this surgical technique video, we review the literature indicating elevated PTS as a risk factor in ACL injuries and recurrent ACL graft failures. We highlight important technique pearls and pitfalls to avoid complications during the surgical demonstration. Finally, we review postoperative rehabilitation guidelines and clinical outcomes within the existing literature. In patients with recurrent ACL graft failures, ACWPTO provides a safe and reliable technique to correct an elevated PTS and return patients back to full activities with reduced risk of ACL graft re-tear.

Posterior Slope Reducing Osteotomy With Concomitant Anterior Cruciate Ligament Reconstruction

Background: Modern techniques for graft choice, preparation, and fixation for anterior cruciate ligament (ACL) reconstruction demonstrate excellent longevity and return-to-play rates; however, up to 10% to 18% of cases continue to suffer reruptures, with even higher rates in specific subsets of patients. Indications: Normally, the posterior tibial slope is measured between 7° and 10°, with biomechanical and observational studies showing that posterior slope greater than 12° increases the risk of graft failure by 5× by allowing for increased anterior tibial translation, putting increased stress on the graft. The primary indication for a slope correction osteotomy with a revision ACL reconstruction is a patient with tibial slope greater than 12° who has failed prior ACL reconstruction. Technique Description: In our preferred technique, we illustrate a slope reducing anterior closing wedge proximal tibial osteotomy with concurrent revision ACL reconstruction rather than a staged ACL reconstruction. Results: The primary benefit of this technique is the ability to correct the tibial slope and reconstruct the ACL in one setting, which decreases recovery time, costs, and risks to the patients by eliminating an additional procedure. Discussion/Conclusion: In cases of ACL reconstruction failure, particularly in patients with multiple failures, an increased posterior tibial slope may be a contributing factor. Anterior closing wedge osteotomy has been shown to be an effective treatment, in patients with a native slope greater than 12°. A slope reducing anterior closing wedge proximal tibial osteotomy with concurrent revision ACL reconstruction rather than a staged ACL reconstruction has a wide array of benefits.

Early cost estimating model for new bioabsorbable orthopedic implant candidates: A theoretical study

An early health technology assessment (HTA) study was performed to assess the need for developing a new bioabsorbable implant for the treatment of specific orthopedic injuries. The Anterior Cruciate Ligament Reconstruction (ACLR) procedure was selected based on the need and potential impact of bioabsorbable implants in the treatment of ACL injuries. The economic model considers the possible health events after an ACLR (failures and other complications such as stiffness and pain). A decision tree approach was used, and several sensitivity analyses were performed using a Monte Carlo simulation. A cost estimating model was applied comparatively for currently available metal and bioabsorbable implants against a potential new bioabsorbable implant with improved performance. A reduction in stiffness and pain symptoms were considered as targets for these new implants performance, with reduced inflammation resulting from the use of materials with appropriate biological and mechanical properties.The current study estimates that, under the assumptions made, the introduction of a new bioabsorbable implant in ACLR surgeries may generate yearly cost savings. The model estimates positive cost-benefits of the new implant when it reduces the probability of failure by more than 30%, or reduces at least 14% the probability of complications of an inflammatory nature. The development of a new bioabsorbable orthopedic implant for ACLR is encouraged by this study identifying the need for new bioabsorbable implants with improved biological and mechanical performance.The results of this early HTA have made it possible to anticipate design needs and objectives for the research and development of new orthopedic bioabsorbable implants.

Low annual hospital volume of anterior cruciate ligament reconstruction is not associated with higher revision rates.

Surgery performed in low-volume centres has been associated with longer operating time, longer hospital stays, lower functional outcomes, and higher rates of revision surgery, complications and mortality. This has been reported consistently in the arthroplasty literature, but there is a paucity of data regarding the relationship between surgical volume and outcome following anterior cruciate ligament (ACL) reconstruction. The purpose was to compare ACL reconstruction failure rates between hospitals performing different annual surgical volumes. All patients from the Norwegian Knee Ligament Register having primary autograft ACL reconstruction between 2004 and 2016 were included. Hospital volume was divided into quintiles based on the number of ACL reconstructions performed annually, defined arbitrarily as: 1-12 (V1), 13-24 (V2), 25-49 (V3), 50-99 (V4) and ≥ 100 (V5) annual procedures. Kaplan-Meier estimated survival curves and survival percentages were calculated with revision ACL reconstruction as the end point. Secondary outcome measures included (1) mean change in Knee Injury and Osteoarthritis Outcome Score (KOOS) Quality of Life (QoL) and Sport subsections from pre-operative to 5-year follow-up and (2) subjective failure defined as KOOS QoL < 44. Twenty thousand eight hundred and fifty patients met the inclusion criteria and 1195 (5.7%) underwent subsequent revision ACL reconstruction over the study period. Revision rates were lower in the lower volume hospitals compared with the higher volume hospitals (p < 0.001). There was no clinically significant difference in improvement between pre-operative and 5-year follow-up KOOS scores between hospital volume categories, but a higher proportion of patients having surgery at lower volume hospitals reported a subjective failure. Patients in the lower volume categories (V1-3) were more often male and older compared to the higher volume hospitals (V4-5). Concomitant meniscal injuries and participation in pivoting sports were most common in V5 compared with V1 (p < 0.001). Median operative time decreased as hospital volume increased, ranging from 90min at V1 hospitals to 56min at V5 hospitals (p < 0.001). Patients having ACL reconstruction at lower volume hospitals had a lower rate of subsequent revision surgery relative to higher volume hospitals. However, complications occurred more frequently, operative duration was longer, and the number of patients reporting a subjective failure of ACL reconstruction was highest at these lower volume hospitals. Level III.

RISK FACTORS FOR FAILURE FOLLOWING ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION IN A PEDIATRIC POPULATION: A NOVEL PREDICTION ALGORITHM

Background:Pediatric anterior cruciate ligament (ACL) reconstruction is becoming increasingly common, however, there is limited literature on the risk factors for failure in this demographic.Hypothesis/Purpose:In the present study we sought to: 1. To determine the rate of pediatric ACL reconstruction (ACLR) failure requiring revision surgery in a nationally representative sample. 2. To determine the associated patient/injury-specific risk factors for ACLR failure. 3. To examine the differences in the rate and risks of failure between pediatric and adult patients.Methods:Patient records were drawn from Humana individual health plans and Medicare medical records. Adult and pediatric patients who underwent primary ACLR and subsequent reoperation for either ACL revision surgery or a revision meniscal procedure between 2011-2016 were identified. Multivariate regression was used to determine the significant risk factors for ACL revision and overall reoperation rates in pediatric and adult patients. A risk algorithm was developed to predict the risk of ACL revision following pediatric ACL reconstruction.Results:Pediatric patients were significantly more likely to require ACL revision within one year (OR=1.97, 95%CI 1.57-2.45, p<0.0001) and five years (OR=3.22, 95%CI 2.77-3.72, p<0.0001) following their index ACLR compared to adults. Survivorship of the index ACL procedure was significantly decreased in pediatric patients (log-rank test p<0.0001) (Figure 1). Pediatric patients were also at higher risk of sustaining a contralateral ACL tear compared to adults (5.9% vs. 1.4%, respectively, p<0.0001). Meniscus injury was a risk factor for overall re-operation (OR=2.18, 95%CI 1.67-2.89 p<0.0001) as well as ACL revision (OR=2.28, 95%CI=1.66-3.21, p<0.0001) in the pediatric cohort. This increased risk was sustained despite the type of meniscal tear intervention, with patients undergoing concurrent meniscal repair (OR=1.84, 95%CI 1.43-2.38, p<0.0001) or meniscectomy (OR=2.20, 95%CI 1.72-2.82, p<0.0001) having a higher likelihood of requiring a revision ACLR. Concomitant MCL injury but not LCL injury was a risk factor for ACL revision in this cohort (OR=1.70, 95%CI 1.31-2.19, p<0.0001). Male sex and (OR=0.78, 95%CI 0.63-0.96, p=0.0204) and being >14 years old (OR=0.62, 95%CI 0.45-0.86, p=0.0035) was associated with a decreased risk of overall reoperation. The risk algorithm demonstrated the highest probability for ACLR failure in females, less than 15 years of age, with concomitant meniscus and MCL injury, demonstrating a 36% risk of failure (Table 1).Conclusion:Compared to adults, pediatric patients have an increased likelihood of ACL revision surgery, contralateral ACL tears, and meniscal reoperation within 5 years of an index ACLR.Figure 1.

The reasons for revision surgery after reconstruction of the anterior cruciate ligament: a systematic review

Reconstruction of the anterior cruciate ligament (ACL) is a fairly successful surgical intervention that can achieve satisfactory results in 75-97 % of cases. In order to show the main categories of factors that can affect the functional outcomes of patients after ACL reconstruction and lead to unsatisfactory outcomes after surgery based on the literature data, we have run a search for English- and Russian-language publications in the electronic databases PubMed and RSCI for the period from 2000 to 2019 using the keywords: anterior cruciate ligament, ACL, revision, re-reconstruction, re-injury, re-rupture, graft failure. Out of 634 papers, 113 publications with the full text were selected. Inclusion criteria - more than 50 cases in the report; follow - up period of more than 2 years; the same groups of patients; assessment of knee joint function; application of various imaging options for the knee joint. 26 papers were included in this review. Based on the analysis of the multiple causes of failed ACL reconstruction outcomes were merged into four main groups: technical mistakes diagnosis and surgery (from 22 % to 79 %); re-injury (18 % to 79 %); biological factors (violation of the integration of the graft and its ligamental) (17 %); errors of rehabilitation and other (15 %). Thus, the review made it possible to systematize the causes of unsuccessful outcomes of ACL reconstruction and identify the most frequent.

Posterior tibial slope measurements based on the full-length tibial anatomic axis are significantly increased compared to those based on the half-length tibial anatomic axis.

This study aimed to compare the difference in posterior tibial slope (PTS) measurements based on the full-length and half-length tibial anatomic axes of the same group of patients. It was hypothesized that the obtained PTS values would be affected by the length of tibia chosen during the measurements. Full-length true lateral tibia radiographs were obtained for each patient who underwent anterior cruciate ligament reconstruction (ACLR) in our department. PTS measurements were obtained by measuring the angle between the full-length or half-length tibial anatomic axis and an average of the lateral and medial tibial plateau. The anatomic axis was defined as the center of the tibial diaphysis. The PTS measurements from the full-length and half-length true lateral tibia radiographs were obtained and compared. Additionally, the absolute difference and the relationship between the two PTS measurements were calculated and analyzed. A total of 200 ACL-injured patients were included in this study. The average PTS values using the anatomic axis were 15.9 ± 3.7° and 14.1 ± 3.7° on full-length and half-length true lateral tibial radiographs. There was a significant difference between the measurements with the full-length and half-length tibial radiographs (P < 0.01). Additionally, 49.5% (n = 99) of patients had ≥ 2.0° differences between the full-length and half-length anatomic axis PTS measurement techniques; meanwhile, a strong and significant linear relationship (r = 0.95; P < 0.001) was identified between the two PTS measurements. There were significant differences and linear relationships between PTS measurements that measured the anatomic axis from full-length and half-length true lateral tibia radiographs. Therefore, the obtained PTS values were strongly associated with the length of tibia chosen during the measurements. Surgeons should pay more attention to the measurement techniques and the tibial length when considering the role of PTS in ACL injury and ACLR failure. Knowledge of the association is very important for calculating potential closing wedge proximal tibial osteotomies to correct excessive PTS in the setting of ACLR failures. IV.

A Systematic Review of Risk Factors for Anterior Cruciate Ligament Reconstruction Failure.

Although most studies have introduced risk factors related to anterior cruciate ligament reconstruction failure, studies on combinations of high-risk factors are rare. To provide a systematic review of the risk factors of anterior cruciate ligament reconstruction failure to guide surgeons through the decision-making process, an extensive literature search was performed of the Medline, Embase and Cochrane Library databases. Studies published between January 1, 2009, and September 19, 2019, regarding the existing evidence for risk factors of anterior cruciate ligament reconstruction failure or graft failure were included in this review. Study quality was evaluated with the quality index. Ultimately, 66 articles met our criteria. There were 46 cases classified as technical factors, 21 cases as patient-related risk factors, and 14 cases as status of the knee joint. Quality assessment scores ranged from 14 to 24. This systematic review provides a comprehensive summary of the risk factors for anterior cruciate ligament reconstruction failure, including technical factors, patient-related factors, and the factors associated with the status of the knee joint. Emphasis should be placed on avoiding these high-risk combinations or correcting modifiable risk factors during preoperative planning to reduce the rate of graft rupture and anterior cruciate ligament reconstruction failure.

Higher Meniscal Slope Is a Risk Factor for Anterior Cruciate Ligament Injury in Skeletally Immature Patients

To evaluate the relation between the femoral intercondylar index, tibial slope, and meniscal slope between 3 different groups of skeletally immature patients: primary anterior cruciate ligament (ACL) injury (group 1), ACL reconstruction failure (group 2), and control group, without an ACL injury history (group 3). This retrospective study evaluated magnetic resonance imaging scans of the knees of 605 skeletally immature patients obtained between 2015 and 2020. The inclusion criteria were as follows: patients younger than 16 years who were skeletally immature and underwent knee magnetic resonance imaging for any reason. A total of 605 skeletally immature patients were included in the study. The ratio of patients with ACL injury (cases) to those without ACL injury (controls) was 1:2.5. Patients with ACL injury had significantly greater medial meniscal slope and lateral meniscal slope values than the control group without ACL injury (P < .001). There was no statistically significant difference between patients with primary ACL injury and those with ACL reconstruction failure for all measured variables. The medial and lateral meniscal slope values were significantly higher in skeletally immature patients with ACL injury than in the control group of patients without ACL injury. There was no statistically significant difference in measurements of the femoral intercondylar index, lateral meniscal slope, medial meniscal slope, lateral tibial slope, or medial tibial slope between patients with primary injury and those with ACL reconstruction failure. Level III, retrospective comparative trial.