Anterior cruciate ligament reconstruction in the elderly: 5-Year follow-up study.

BACKGROUND: Older adults remain active for longer and continue sports and activities that require rotation on one leg later in life. The rate of anterior cruciate ligament (ACL) tears is therefore increasing in those over 40 years old, with an associated increase in the rate of surgical reconstruction (ACLR), but there is limited literature on its effectiveness. Our aim was to compare the outcomes of elderly patients who have undergone ACLR with those of a younger group of patients. MATERIALS AND METHODS: Patients who underwent ACLR with bone-patella tendon-bone grafting (BPTB) at a level I trauma center between 2015 and 2017 were included in the study with a 5-year follow-up. Patients were divided into 4 groups: below 40 years, 40-49 years, 50-59 years and over 60 years. The graft function was evaluated by the International Knee Documentation Committee (IKDC) Objective Score, the anteroposterior (AP) displacement was measured by arthrometer (KT-1000; MEDMetric) and the Lysholm scale was used for subjective evaluation. RESULTS: 195 patients were included in the final analysis. The IKDC score showed significantly poorer scores in the 50-59 years and over 60 years group than in the younger groups, however in 83 % and 66 % of cases reached normal or nearly normal grades, respectively. A significant difference was found in the knee AP displacement (measured in mm) between the below 40 years group and 50-59 years as well as over 60 years old groups; however, the number of graft failure (laxity >5 mm) and elongation (>3 mm) did not increased in these senior groups. The patient-reported Lysholm scores in the 40-49 years, 50-59 years and 60 years groups was lower than in the below 40 years group, but the average score was "good". CONCLUSIONS: The long-term results of ACL reconstruction in older athletes are comparable to those of younger patients, both in terms of knee function and patient satisfaction. Furthermore, there is no difference in outcomes for older patients over the age of 40 compared to those in their 50 s or even 60 s. There is still insufficient published evidence to define an upper age limit for ACL reconstruction in older athletes.

Synthetic Grafts in Anterior Cruciate Ligament Reconstruction Surgery in Professional Female Handball Players-A Viable Option?

Anterior cruciate ligament (ACR) rupture is a frequent injury in professional sports players. We conducted a retrospective cohort study, including 41 professional female handball players, undergoing ACR reconstruction surgery, using a Ligament Advanced Reinforcement System (LARS) graft (n = 12) or a Soft Tissue (ST) graft (n = 29). After return-to-play, the patients were asked to take a survey, reporting subjective and objective performance indexes before the injury and after return-to-play. Time from surgery to first practice and to return-to-play were significantly shorter in the LARS group (3.92 ± 1.14 vs. 6.93 ± 2.19 months, p < 0.001 and 4.71 ± 1.2 vs. 8.81 ± 2.9, respectively). While there was no difference between postoperative mean time on court, number of goals/match, number of matches played at 6 months return-to-play and 50 m, 100 m and gate-to-gate sprint times, there was a significantly greater increase in preoperative times in the ST group than in the LARS group (1.45 ± 1.05 s vs. 0.21 ± 0.58 s slower than preoperatively, p < 0.001 for 50 m; 1.09 ± 0.95 s vs. 0.08 ± 1 s, p = 0.01 for 100 m; 1.66 ± 1 s vs. 0.21 ± 0.66 s for gate-to-gate). In conclusion, LARS grafts provide a faster recovery time and better functional outcome, significantly impacting the performance of professional handball players.

Anterior Cruciate Ligament Reconstruction Utilizing Double Adjustable-Loop Suspensory Fixation Devices Provides Good Clinical Outcomes in Patients under the Age of 40 Years at Two-Year Follow-Up.

Background: Anterior cruciate ligament reconstruction (ACLR) using double adjustable fixation gained popularity in the last decade due to its minimally invasive technique. However, suspensory fixation devices could be related to recurrent instability, poor clinical outcomes, and patient dissatisfaction. The present study aims to evaluate the clinical outcomes following ACLR using double adjustable-loop suspensory fixation devices in the demanding population of young patients. Methods: Between 2019 and 2022, 95 patients with knee post-traumatic anterior cruciate ligament insufficiency were treated with primary ACLR using semitendinosus quadrupled graft and double adjustable-loop suspensory fixation devices and followed for at least two years. Concomitant lesions were also treated at the same surgical time. The knee examination form of the International Knee Documentation Committee (IKDC) was used to assess clinical evaluation, and the return to physical activities using the Tegner Activity Scale was recorded. Patient-reported objective measures (PROMs) were also evaluated, including the IKDC subjective and Lysholm scores. Results: Sixty-six males and twenty-nine females with a mean age of 23.8 (range 18-37) and a mean BMI of 24.9 (SD ± 2.42) kg/m2 were included in this study. All patients were evaluated clinically as normal or nearly normal at the final follow-up. PROMs also significantly improved postoperatively (p < 0.05) compared to the preoperative values. The Tegner Activity Scale increased from 2 to 7, the IKDC mean score improved from 43.9 (±8.9) to 93.3 (±12.3), and the modified Lysholm from 47.3 (±11.1) to 92.9 (±16.6). No complications or adverse events were recorded. Conclusions: Anterior cruciate ligament reconstruction utilizing double adjustable-loop suspensory fixation devices provides good clinical and functional outcomes in young patients at a two-year follow-up.

Posterior Tibial Slope Measured on Plain Radiograph Versus MRI and Its Association With Revision Anterior Cruciate Ligament Reconstruction: A Matched Case-Control Study.

BACKGROUND: Posterior tibial slope (PTS) has been identified as a possible modifiable risk factor for anterior cruciate ligament (ACL) injury and ACL reconstruction (ACLR) failure. However, the findings in the literature are inconsistent. This may be explained by several different reasons, including different measurement methods, differing definitions of ACLR failure, and possible inclusion of suboptimal films. PURPOSE: To compare PTS values obtained using plain radiographs (XR-PTS) in a young (≤21 years of age), skeletally mature patient population with those obtained using magnetic resonance imaging (MRI), as well as to quantify the number of suboptimal lateral knee radiographs obtained across an integrated health care system and determine the potential effect of including these radiographs on summary statistics of XR-PTS. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: Skeletally mature adolescent and young adult patients ≤21 years of age were identified from the ACLR registry of Kaiser Permanente. The cases of concern were patients requiring revision ACLR. The controls were patients who had an ACLR and did not require a revision procedure. The XR-PTS measurements were made on plain radiographs by a single blinded reviewer. These results were compared with measurements obtained using MRI. The quality of each plain radiograph was evaluated by measuring posterior/distal femoral condylar overlap and length of tibial diaphysis captured on the radiograph. Summary statistics with and without inclusion of measurements made on suboptimal radiographs were calculated. RESULTS: Of the initial 634 patients with ACLR (317 case-control pairs), 561 (88.5%) had radiographs available and were included for the analysis comparing radiograph to MRI slope measurements. For the evaluation of slope between case and control pairs with radiograph information available, there were 257 case-control pairs; there were 124 pairs when those with suboptimal radiographs were excluded. There was no difference in MRI-measured lateral tibial posterior slope or medial tibial posterior slope for the 257 case-control pairs with XR-PTS information and for the 124 pairs with optimal radiographs. XR-PTS in the revision cohort was significantly steeper than in the control group when suboptimal radiographs were included in the analysis. There was no difference when patients with suboptimal radiographs were excluded. PTS measurements made on plain radiographs were larger than those made on MRI. There was a poor correlation between measurements made using these 2 modalities (r = 0.22 for radiograph and medial PTS). CONCLUSION: This study did not find a significantly steeper XR-PTS in patients who had to undergo revision ACLR when suboptimal radiographs were not included in the analysis. The present study's results confirmed the findings from a previous study of the same patient population that used MRI. However, there was poor correlation between PTS measurements made using plain radiograph and MRI.

No difference in laxity, proprioception and neuromuscular control after suture-tape augmented ACL repair of acute proximal avulsions versus ACL reconstruction using hamstring autografts in young, active population.

Purpose: The purpose of this study is to compare results of suture-tape augmented anterior cruciate ligament (ACL) repair (internal bracing [IB]) and ACL reconstruction (ACLR) with hamstring autograft in terms of laxity, proprioception and neuromuscular control. The hypothesis was that with strict indications IB may provide better results in proprioception and neuromuscular control. Methods: Patients with unilateral ACL injury treated with IB or ACLR with hamstring autograft were enroled in this retrospective study. Anterior tibial translation (ATT) in 30° and 90° of flexion was measured with Rolimeter. The joint position sense (JPS) test was performed in 30° and 60° of flexion using Biodex System 4Pro. The time-synchronized motion capture system and surface electromyography set were used during dynamic tasks to assess knee valgus and semitendinosus (ST) and biceps femoris (BF) activities. Comparisons between both techniques and operated versus contralateral healthy knees were performed. Results: The study groups involved 28 patients after ACLR (21.8 ± 4.8 years) and 20 patients after IB (25.8 ± 10.5 years) with the average follow-up 30 ± 18 and 28 ± 15 months, respectively. The ATT did not differ significantly between operated groups. In 30° of flexion ATT for ACLR was significantly higher in operated than in contralateral knee (5.8 ± 2.4 mm vs. 4.3 ± 1.3 mm, p < 0.001). The JPS test and dynamic knee valgus presented no significant differences. The ACLR group presented significantly higher ST (p = 0.048) and BF (p = 0.012) activity comparing operated to contralateral knee in dynamic tasks. Conclusion: Suture-tape augmented ACL repair and ACLR with hamstring autograft yield similar results in terms of laxity, proprioception and neuromuscular control. Level of Evidence: Level III: Retrospective comparative study.

Effects of an untreated medial meniscal ramp lesion on histological deterioration findings of the medial meniscus: A study in a porcine anterior cruciate ligament reconstruction model.

Purpose: To evaluate the effect of untreated medial meniscal ramp lesions (MMRLs) on the tendon graft after anterior cruciate ligament (ACL) reconstruction and histological findings of medial meniscus (MM) in a porcine a model. Methods: A total of 17 pigs were divided into two groups: (1) the untreated MMRL group (UM group, n = 9) and (2) intact MM group (n = 8) and euthanized 12 weeks after surgery. The specimens were then tested cyclically and loaded to failure. Side-to-side differences (SSDs) in translation under cyclic loading and structural properties were analyzed. Histological evaluation of the MM was also performed. Results: No significant differences in the SSD in translation during the cyclic testing (UM group, 0.3 ± 0.4 mm; intact MM group, 0.1 ± 1.4 mm), upper yield load (UM group, 476.3 ± 399.9 N; intact MM group, 643.2 ± 302.9 N), maximum load (UM group, 539.5 ± 265.8 N; intact MM group, 705.8 ± 282.6 N), linear stiffness (UM group, 63.5 ± 39.0 N/mm; intact MM group, 73.7 ± 60.1 N/mm) and elongation at failure (UM group, -4.6 ± 16.3 mm; intact MM group, 2.3 ± 6.6 mm) were observed. However, the UM group had significantly worse Modified Mankin's histological grading scores (1.8 ± 0.4 [1-2] vs. 0 ± 0 [0]; p < 0.001) and Modified Copenhaver classification scores (6.6 ± 2.4 [2-9] vs. 0.7 ± 1.1 [0-3]; p < 0.001) than did the intact MM group. Conclusion: Untreated MMRLs showed postoperative histological deterioration. Level of Evidence: Level IV.

Improvement of Posterior Cruciate Ligament Buckling and Anterior Tibial Subluxation by Anterior Scar Removal of the Posterior Cruciate Ligament: A Case Report.

Posterior cruciate ligament (PCL) buckling and anterior tibial subluxation are observed in patients with insufficient anterior cruciate ligament (ACL). Here, we report the case of a patient after ACL reconstruction in whom these symptoms were improved by anterior scar resection of buckled PCL. The patient was a 46-year-old man. Six years ago, he underwent ACL reconstruction; however, his condition was not satisfactory. Magnetic resonance imaging (MRI) showed intercondylar impingement of the graft, anterior tibial subluxation, and PCL buckling. Intercondylar notchplasty and resection of the anterior scar of PCL were performed arthroscopically. Postoperative MRI showed improvement in PCL buckling and anterior tibial subluxation. His symptoms improved, and he was able to jog one year after surgery.  Anterior scar resection of PCL may improve PCL buckling and anterior tibial subluxation after ACL reconstruction.

Evaluation under loading detects medial meniscus extrusion in patients with reconstructed anterior cruciate ligament and restricted knee extension.

PURPOSE: Some patients who undergo anterior cruciate ligament (ACL) reconstruction experience abnormal mechanical stress in the meniscus. Medial meniscal extrusion (MME) is reflected in the pathological condition of the meniscus, which expands owing to repetitive mechanical stress. Thus, the effect of the reconstructed ACL on increasing MME under weight-bearing conditions remains unclear. This study investigated the effect of ACL reconstruction on meniscal extrusion under non-weight-bearing and weight-bearing conditions. METHODS: Seventeen patients who underwent unilateral ACL reconstruction (ACL group) and 20 age-matched healthy volunteers (control group) were enrolled. Ultrasonography was performed in the supine, standing, and walking positions in preoperative and postoperative ACL patients. MME during walking was evaluated based on the dynamic behavior of extrusion, and kinetic and kinematic data were synchronously obtained. Moreover, the ACL group underwent magnetic resonance imaging (MRI) evaluation at two points: preoperatively and 12 months postoperatively, and the ultrasound findings were compared. RESULTS: MME in the supine position measured using both ultrasonography and MRI was not significantly different preoperatively and postoperatively in the ACL group. However, postoperative MME and dynamic behavior of extrusion under standing and walking conditions were significantly higher than those in the preoperative state (dynamic behavior: 0.9 ± 0.4 mm preoperatively, 1.2 ± 0.4 mm postoperatively). Moreover, the deficits in knee extension during walking persisted postoperatively and were significantly higher than those in the control group. CONCLUSION: MME in patients with ACL reconstruction including meniscus repair was different under mechanical stress compared to the non-weight bearing condition.

Analysis of the Biomechanical Behavior of an Animal Model of Triple Hamstring Graft Configuration for Combined ACL and ALL Reconstruction with a Single Femoral Tunnel and a Single Strand for ALL Reconstruction.

Objective To describe and biomechanically test a configuration, in an animal model that simulates the triple hamstring graft for combined anterior cruciate ligament (ACL) and anterolateral ligament (ALL) reconstruction, with a single femoral tunnel and a single strand for ALL reconstruction. Methods Deep flexor porcine tendons were used as the graft and fixed with titanium interference screws in a polyurethane block. The samples were divided into 3 groups: group 1 (control) - with a quadruple graft; group 2-with a simple triple graft; and group 3-with a braided triple graft. The tests were conducted using an EMIC DL 10000 (Instron Brasil Equipamentos Científicos Ltda., São José dos Pinhais, PR, Brazil) electromechanical universal testing machine. Results The samples in groups 1, 2, and 3 obtained mean peak forces of 816.28 ± 78.78 N, 506.95 ± 151.30 N, and 723.16 ± 316.15 N, respectively. In Group 3, braiding increased graft diameter by 9% to 14%, and caused a shortening of 4% to 8% compared with group 1, with an average peak force increase of ∼ 200 N ( p < 0.05). Regarding peak forces, there was no statistically significant difference between groups 1 and 3, indicating that quadruple and braided triple grafts showed similar strength results. Conclusion The triple-braided hamstring graft configuration for combined ACL and ALL reconstruction with a single femoral tunnel and a single strand for ALL reconstruction may become a biomechanically viable solution, with potential clinical application.

Bicruciate Reconstruction with Bilateral Hamstring Autografts: Technique and Functional Results.

Objective The purpose of this study was to evaluate the clinical and functional results of simultaneous reconstruction of the ACL and PCL with bilateral hamstring autografts. We hypothesized that this reconstruction technique results in less morbidity and has similar results to the ones published in the previous literature. Methods Eighteen patients with bicruciate lesions were selected and treated by arthroscopic surgery with autologous hamstring tendons in a single-stage procedure. The thicker semitendinosus tendon (ST) and the two gracilis tendons (G) were used for a 6-strand PCL reconstruction. The thinner ST was used for a 3-strand ACL reconstruction. The average patient age at surgery was 31 years, and the minimum follow-up was 2 years. Function of the operated knee was evaluated according to the Lysholm scale. Anterior knee laxity was examined with a KT-1000 arthrometer. Posterior laxity was evaluated using stress radiographies. Results Statistically significant improvements were found for all three measurements ( p < 0.001). Knee function by the Lysholm score increased from 43.8 ± 4.1 to 89.9 ± 3.8 post-surgery. The average anterior knee laxity improved from 5.2 + -0.8 mm initially to 2.4 + - 0.5 mm post-surgery. The posterior translation of the tibia relative to the femur decreased from 10 ± 3.4 mm to 3 ± 1.6 mm post-surgery. No patient showed loss of motion in extension or knee flexion. Conclusion The simultaneous bicruciate reconstruction with bilateral hamstring autograft is a valuable option to achieve good functional outcomes and ligamentous stability.

Knee temperature remains abnormal in patients successfully treated with anterior cruciate ligament reconstruction: An infrared thermography analysis.

Purpose: The aim of this study was to evaluate if the operated knee environment remains abnormal in patients successfully treated with anterior cruciate ligament reconstruction (ACL-R). Methods: Thirty asymptomatic patients were enrolled (28 men, 2 women, age 28.6 ± 6.54 years, body mass index: 24.9 ± 3.0 kg/m2) and evaluated at 42.2 ± 12.5 months after surgery. Patients were assessed with patient-reported outcome measurements and with a triaxial accelerometer. The temperature of the knees as well as four regions of interest were evaluated with an infrared thermographic camera FLIR T1020 (FLIR® Systems) according to a standardised protocol including a baseline evaluation and further evaluations immediately after exercise and after 5, 10 and 20 min. The temperature of the ACL-R knee was compared to that of the contralateral healthy knee for the purpose of the study. Results: The mean temperature of the knee was higher (p = 0.010) for the ACL-R knees (31.4 ± 1.4°C) compared to the healthy knees (31.1 ± 1.6°C), as well as for the patellar area (p = 0.005), the lateral area (p = 0.016) and the medial area (p = 0.014). The analysis of the response to the exercises of the ACL-R knees showed similar trends to the healthy knees but higher temperature values at all time points (p < 0.05). Patients who underwent ACL-R with concomitant meniscal treatment showed higher knee temperatures compared to ACL-R knees without concomitant meniscal treatment after 5 (p = 0.047), 10 (p = 0.027) and 20 min (p = 0.048). Conclusions: The temperature of asymptomatic knees previously treated with ACL-R is higher than the contralateral healthy knee, both at rest and after exercise, with a further increase in knees that underwent both ACL-R and meniscal treatment. These results suggest an inflammatory state persisting years after the surgery, which could predispose to the early onset of knee degeneration. Level of Evidence: III, Case-control study.

Steep medial posterior tibial slope angle and ramp lesion are independent risk factors for an increase in quantitatively measured pivot shift in patients with ACL-deficient knees.

Background: Delayed anterior cruciate ligament (ACL) reconstruction often causes residual anterolateral rotatory instability (ALRI) and consequent knee osteoarthritis, warranting the recommendation of early ACL reconstruction within 6 months after injury. Nonetheless, some cases show notable instability, even shortly after injury. The purpose of this study was to identify risk factors for an increase in quantitatively measured pivot shift in patients with ACL-deficient knees within 6 months after injury. Methods: Patients with primary ACL reconstruction within 6 months after injury and quantitative triaxial accelerometer measurements of preoperative pivot shift were included. Descriptive statistics were calculated for 11 independent variables (age, gender, time from injury to surgery, KT-1000, knee extension angle, lateral and medial posterior tibial slope angle, medial and lateral meniscus tears, ramp lesion and Tegner active scale). A single regression analysis was performed on the 11 items and acceleration during the pivot shift, and a multiple regression analysis was performed for items with p value less than 0.1. Results: Overall, 111 patients met the inclusion criteria. Single regression analysis showed that medial posterior tibial slope angle, medial meniscus tear and ramp lesion were significantly correlated with acceleration during the pivot shift (p < 0.001, p = 0.04 and p = 0.001). Multiple regression analysis identified medial posterior tibial slope angles and ramp lesions as independent factors for increased preoperative pivot shift (p = 0.005 and 0.01). Conclusion: A steep medial posterior tibial slope angle and ramp lesion were independent risk factors for increased quantitatively measured pivot shift in patients with ACL-deficient knees. Level of Evidence: Level IV, case series study.

ACL reconstruction combined with anterolateral structures reconstruction for treating ACL rupture and knee injuries: a finite element analysis.

Introduction: The biomechanical indication for combining anterolateral structures reconstruction (ASLR) with ACL reconstruction (ACLR) to reduce pivot shift in the knee remains unclear. This study aims to investigate knee functionality after ACL rupture with different combinations of injuries, and to compare the effectiveness of ALSR with ACLR for treating these injuries. Methods: A validated finite element model of a human cadaveric knee was used to simulate pivot shift tests on the joint in different states, including 1) an intact knee; 2) after isolated ACL rupture; 3) after ACL rupture combined with different knee injuries or defect, including a posterior tibial slope (PTS) of 20°, an injury to the anterolateral structures (ALS) and an injury to the posterior meniscotibial ligament of the lateral meniscus (LP); 4) after treating the different injuries using isolated ACLR; v. after treating the different injuries using ACLR with ALSR. The knee kinematics, maximum von Mises stress (Max.S) on the tibial articular cartilage (TC) and force in the ACL graft were compared among the different simulation groups. Results and discussion: Comparing with isolated ACL rupture, combined injury to the ALS caused the largest knee laxity, when a combined PTS of 20° induced the largest Max.S on the TC. The joint stability and Max.S on the TC in the knee with an isolated ACL rupture or a combined rupture of ACL and LP were restored to the intact level after being treated with isolated ACLR. The knee biomechanics after a combined rupture of ACL and ALS were restored to the intact level only when being treated with a combination of ACLR and ALSR using a large graft diameter (6 mm) for ALSR. However, for the knee after ACL rupture combined with a PTS of 20°, the ATT and Max.S on the TC were still greater than the intact knee even after being treated with a combination of ACLR and ALSR. The finite element analysis showed that ACLR should include ALSR when treating ACL ruptures accompanied by ALS rupture. However, pivot shift in knees with a PTS of 20° was not eliminated even after a combined ACLR and ALSR.

Patient Perception of Allograft Versus Autograft in ACL Reconstruction Using a Validated Online Survey Marketplace.

Background: Little is known regarding the opinions of the general population on anterior cruciate ligament (ACL) graft options. Purpose: To evaluate the general population's perception of the use of allografts versus autografts in ACL reconstruction using a previously validated online marketplace platform. Methods: A prospective 34-question survey was distributed via the online marketplace. After collecting baseline demographics, participant preferences for ACL reconstruction with an allograft or autograft were established. All respondents completed a preeducation survey, reviewed an evidence-based education sheet, and completed a posteducation survey to assess their understanding. Upon completion, participants were asked which graft they would prefer. Participants were then asked if they would be willing to change their preference based on surgeon recommendation. Finally, participants were asked to rank the factors from the education sheet that were most influential. Study Design: Cross-sectional study. Results: There were 491 participants that completed the survey (mean age, 39.9 years [range, 19-72 years]; 244 male, 241 female, and 6 nonbinary/third-gender participants). Before reading the education sheet, 276 (56%) reported no graft preferences, 146 (30%) preferred autograft, and 69 (14%) preferred allograft. After reading the provided sheet, 226 (46%) participants preferred autograft, 185 (38%) preferred allograft, and 80 (16%) had no preference. The mean score on the preeducation test was 45%, and the mean score on the posteducation test was significantly greater (61%; P < .01). Overall, 345 participants (83.9%) stated they would change their preference for autograft or allograft if their surgeon recommended it. Surgeon preference (n = 330; 67%), educational information provided (n = 117; 24%), and previous knowledge (n = 44; 9%) were the most important factors for making graft selections. The mean ages of the participants selecting each graft type before and after education were as follows: allograft (37.8 ± 10.1 vs 40.6 ± 11.8 years; P = .05), autograft (38 ± 11.5 vs 39.5 ± 10.1 years; P = .21), and no preference (41.5 ± 11.2 vs 39.4 ± 11.8 years; P = .16). Conclusion: Education resulted in a greater number of individuals' reporting a preference in graft type (either allograft or autograft) compared with preinformation questioning. In addition, 83.9% of the participants were willing to switch their graft choice if recommended by their surgeon.

Ensemble Algorithm for Risk Prediction of Clinical Failure After Anterior Cruciate Ligament Reconstruction.

Background: Patient-specific risk profiles of clinical failure after anterior cruciate ligament reconstruction (ACLR) are meaningful for preoperative surgical planning and postoperative rehabilitation guidance. Purpose: To create an ensemble algorithm machine learning (ML) model and ML-based web-based tool that can predict the patient-specific risk of clinical failure after ACLR. Study Design: Cohort study; Level of evidence, 3. Methods: Included were 432 patients (mean age, 26.8 ± 8.4 years; 74.1% male) who underwent anatomic double-bundle ACLR with hamstring tendon autograft between January 2010 and February 2019. The primary outcome was the probability of clinical failure at a minimum 2-year follow-up. The authors included 24 independent variables for feature selection and model development. The data set was split randomly into training sets (75%) and test sets (25%). Models were built using 4 ML algorithms: extreme gradient boosting, random forest, light gradient boosting machine, and adaptive boosting. In addition, a weighted-average voting (WAV) ensemble model was constructed using the ensemble-voting technique to predict clinical failure after ACLR. Concordance (area under the receiver operating characteristic curve [AUC]), calibration, and decision curve analysis were used to evaluate predictive performances of the 5 models. Results: Clinical failure occurred in 73 of the 432 patients (16.9%). The 8 most important predictors for clinical failure were follow-up period, high-grade preoperative knee laxity, time from injury to ACLR, participation in competitive sports, posterior tibial slope, graft diameter, age at surgery, and medial meniscus resection. The WAV ensemble algorithm achieved the best predictive performance based on concordance (AUC, 0.9139), calibration (calibration intercept, -0.1806; calibration slope, 1.2794; Brier score, 0.0888), and decision curve analysis (greatest net benefits) and was used to develop an web-based application to predict a patient's clinical failure risk of ACLR. Conclusion: The WAV ensemble algorithm was able to accurately predict patient-specific risk of clinical failure after ACLR. Clinicians and patients can use the web-based application during preoperative consultation to understand individual prediction outcomes.

Location of Measurement Matters: Unveiling Regional Dynamics and Sex Differences in Patellar Tendon Strain In Vivo.

Patellar tendinopathy is more prevalent in males versus female athletes and commonly presents in the medial region of the tendon. Separate measures of patellar tendon strain in the medial, central, and lateral regions of the tendon, however, have not been quantified. The purpose was to investigate the differences in tendon strain between the medial, lateral, and central regions of the patellar tendon in healthy men and women. Strain in the medial and lateral regions of the patellar tendon in healthy participants (10 males, 10 females) was evaluated using ultrasound during isometric quadriceps contractions at 20%, 40%, 60%, 80%, and 100% of maximum voluntary contraction (MVIC) in 60° and 90° of knee flexion. Central strain was also measured at 60% MVIC in 90° of knee flexion. Mixed models were used to determine strain between tendon regions and sex at 60% MVIC in 90° of knee flexion. Sequential modeling was used to fit region, sex, %MVIC, and angle to predict strain. The central region had less strain compared with both medial and lateral regions. The lateral region had higher strain compared with the medial region regardless of sex. Females had higher strain compared with males, regardless of region. Knee position did not influence tendon strain. Patellar tendon strain differs by region and sex. The varying prevalence between sex and in location of patellar tendinopathy may in part be explained by the unbalanced strains. Differential assessment of regional patellar tendon strain may be of importance for understanding injury risk and recovery with exercise.

Quadriceps tendon size does not affect postoperative strength recovery following quadriceps tendon anterior cruciate ligament reconstruction.

OBJECTIVE: The influence of quadriceps tendon (QT) size on postoperative quadriceps strength following QT anterior cruciate ligament reconstruction (ACLR) is unclear. Therefore, this study aimed to determine the relationship between QT morphology and postoperative quadriceps strength recovery following primary ACLR using a QT autograft. METHODS: Patients who underwent primary ACLR using QT autograft from 2014 to 2022 followed by a postoperative isometric strength measurement between 5 and 8 months were retrospectively reviewed. Using preoperative magnetic resonance imaging findings, the anterior-posterior (A-P) thickness, medial-lateral (M-L) width, and cross-sectional area (CSA) of the QT were measured. Postoperative residual CSA of QT was estimated based on the graft-harvest diameter. The quadriceps index (QI) was also calculated, which was determined by dividing the maximum isometric quadriceps torque on the involved side by the maximum quadriceps torque on the uninvolved side. Associations between the QI and QT morphology were assessed. Furthermore, multivariable logistic regression analysis with the addition of sex as a covariate was performed with the addition of each individual measure of QT morphology to determine the association with a QI â€‹≥80%. RESULTS: A total of 84 patients (mean age: 21.9 â€‹± â€‹7.3 years; 46 female) were included. Residual CSA showed a statistically significant positive correlation with the QI (r â€‹= â€‹0.221, p â€‹= â€‹0.043). There were no statistically significant correlations between QI and CSA, A-P thickness, or M-L width. Multivariable logistic analysis adjusting for sex demonstrated that each individual measure of QT morphology was not statistically significantly associated with a QI â€‹≥80%. CONCLUSION: A statistically significant correlation between measures of preoperative QT size and postoperative quadriceps strength were not detected in patients undergoing primary QT autograft ACLR. A smaller residual QT CSA based on QT harvest diameter was weakly associated with decreased quadriceps strength 5-8 months postoperatively, but this association was not independent of sex. Future studies examining the impact of QT morphology on quadriceps strength at longer follow-up intervals are needed. LEVEL OF EVIDENCE: IV.

Crossover effect of knee and ankle joint training on knee mechanics after ACL reconstruction: A randomized controlled trial.

BACKGROUND: Anterior cruciate ligament (ACL) rehabilitation is a common intervention after ACL reconstruction. Since different types of exercise can influence muscle and kinematic parameters in diverse ways, the training order between the knee and ankle joints may also change gait parameters. PURPOSE: This study aimed to investigate whether the training sequence of the knee and ankle joints (knee followed by ankle training or vice-versa) in an ACL reconstruction (ACLR) rehabilitation program has any effects on knee extension and flexion torques. METHODS: Forty-two men (aged 20-30 years) with ACLR participated in this study. They were randomly allocated to receive one of two interventions: (A) knee joint training followed by ankle training or (B) ankle joint training followed by knee training. After five weeks (four weeks of intervention and one-week washout), participants crossed from one group to another for an additional four weeks. Knee extension and flexion torques were assessed during the stance phase of the gait cycle before and after the intervention program. RESULTS: Two-way Mixed-design MANOVA showed that knee extension torque improved significantly in both groups after training (p = 0.001, Cohen's D = 0.65), while the knee flexion torque increased significantly only in group B (p= 0.001, Cohen's D = 0.97). When comparing both groups, patients of group B presented significant improvements in the post-training mean values of all tested variables compared with group A. CONCLUSION: Starting a post-ACLR rehabilitation program with ankle training followed by knee training is better to improve knee flexion and extension torques during the stance phase of the gait cycle than starting the program by training the knee first, followed by the ankle. Future studies using a mixed-gender sample and different types of ACLR operations are necessary to examine whether similar improvements will happen as well as to test their effects on many sports activities.

Rising rates of anterior cruciate ligament reconstruction in Australian adults: An analysis of Australian Medicare Benefits Schedule database.

PURPOSE: Anterior cruciate ligament (ACL) reconstruction is an evolving field, though there remains sparse epidemiological data on the treatment of ACL ruptures. The objective of this study is to analyse the trends in the rate of ACL reconstruction (ACLR) in adult patients over the past two decades in the Australian population. METHODS: The incidence of ACLR between 2001 and 2020 in patients 15 years and over was analysed using the Australian Medicare Benefits Schedule (MBS) database. The data reflect patients with private health coverage (45% of the Australian population). An offset term was introduced using national population data to account for population changes over the study period. RESULTS: A total of 160,353 ACLRs were performed in Australia under the MBS in the 20-year period from 2001 to 2020. An annual increase in the total volume and per capita rate of ACLRs was found (p < 0.05). The annual volume of cases increased by 82%, from 5512 in 2001 to a peak of 10,011 in 2017. This increase was seen across all age groups (p < 0.05) and both sexes (p < 0.05), with a greater proportion of reconstructions performed on males (n = 102,357, 64%) than females (n = 57,996, 36%). In 2020, the rate of adult ACLRs decreased to a level last seen in 2004, likely due to the effects of COVID-19. CONCLUSIONS: The incidence of ACLR in adult patients has increased in Australia over the 20-year study period. The trends noted provide information that can be used to guide resource allocation and health provision in the future. LEVEL OF EVIDENCE: Level IV.

Patients' joint perception after anterior cruciate ligament reconstruction as a reliable patient-reported outcome measure.

PURPOSE: This study aims to evaluate and compare patients' joint perception (PJP) with other commonly employed patient-reported outcome measures (PROMs) in a cohort of patients following anterior cruciate ligament reconstruction (ACLR). METHODS: A retrospective study was conducted on 108 patients who underwent ACLR between 2017 and 2021, with complete data available for visual analogue scale (VAS) pain, PJP, Forgotten Joint Score (FJS), Tegner Activity Scale, Lysholm Knee Scoring Scale, Anterior Cruciate Ligament Return to Sport After Injury (ACL-RSI), Single Assessment Numeric Evaluation (SANE), Cincinnati Knee Rating System (CKRS) and The Hospital for Special Surgery Anterior Cruciate Ligament Satisfaction Survey (HSS ACL-SS) at a mean follow-up of 3 years. Spearman's rank-order correlation was used to determine the correlations between clinical scores. A receiver operating characteristic (ROC) curve analysis was used to assess the discriminatory power of the chosen PROMs in detecting natural joint perception. Natural joint perception was defined as patients responding 'like a native or natural joint' or PJP = 1. This study hypothesized that PJP would demonstrate significant correlations with established PROMs, indicating its reliability and validity as a tool for assessing outcomes following ACLR. RESULTS: PJP showed significant correlations with all the reported PROMs, suggesting its potential as a valid and reliable assessment tool for evaluating ACLR outcomes. The ROC curve analysis indicated a good area under the curve for identifying natural joint perception using various PROMs. According to the PJP, nearly 20% of patients reported natural joint perception. CONCLUSION: This study evaluates PJP as a reliable tool for assessing patient outcomes following ACLR. Its significant correlation with other established PROMs underscores its potential as a valuable addition to the existing array of PROMs in ACLR. LEVEL OF EVIDENCE: Level III.