Surface Electromyography and Gait Features in Patients after Anterior Cruciate Ligament Reconstruction.

OBJECTIVE: An important reason for the poor recovery of anterior cruciate ligament (ACL) injuries is the poor recovery of muscle function. Therefore, we used surface electromyography (sEMG) and gait analysis to explore the muscle activation patterns and gait characteristics between lower limbs under different exercise states in patients, following anterior cruciate ligament reconstruction (ACLR). METHODS: Forty-one adults with unilateral ACL injuries in Binzhou Medical University Hospital from October 2022 to June 2023 were allocated to three groups according to the time after ACL reconstruction: group A (≤3 months, 16), group B (3 months-1 year, 13), and group C (>1 year, 12). Patients were tested by sEMG and gait, while straight leg raising (SLR), walking at normal speed, fast walking, and walking up and down the stairs. Two related sample tests were performed for the normalized root mean square (RMS) values and gait parameters. RESULTS: Muscle function changes varied in different training tasks. The RMS value of the involved side was more than the uninvolved side in biceps femoris and semitendinosus of group A (p < 0.010), and for the bilateral rectus femoris (RS), vastus medialis (VM), and vastus lateralis in group B, only the comparison of the RS was significant in group C during fast walking and going up and down the stairs. The ground impact (0.90 [0.63, 1.33] vs. 0.71 [0.43, 1.02], p = 0.035) of the uninvolved side was significantly decreased compared to those of the involved side in patients with ACLR when going down the stairs. CONCLUSION: Different muscles need to be focused on at different stages of the postoperative period. sEMG and gait analysis can guide the development of a rehabilitation program.

Relationship Between Single-Leg Vertical Jump and Drop Jump Performance, and Return to Sports After Primary Anterior Cruciate Ligament Reconstruction Using Hamstring Graft.

Background: After anterior cruciate ligament reconstruction (ACLR), asymmetry is likely to persist in single-leg (SL) vertical jump and drop jump performance than in SL hop distance. However, its relationship with the return to sport (RTS) remains unclear. Hypothesis/Purpose: This study aimed to determine the association between vertical jump performance after primary ACLR using hamstring tendon autograft and RTS at a pre-injury competitive level. Study design: Cross-sectional study. Methods: Patients who underwent primary ACLR using hamstring tendon autograft were recruited for this study. Participants who returned to pre-injury competition after ACLR were recruited at least eight months postoperatively. Knee condition was assessed, including joint laxity, range of motion, muscle strength, and knee pain intensity during sports activities. Performance variables were also assessed, including SL hop distance, jump height in SL vertical jump, and reactive strength index (RSI; jump height/contact time) in SL drop jump. Participants were asked to subjectively report whether they had returned to the same level of competition as pre-injury and their perceived sport performance intensity. Those who answered "Yes" to the dichotomous question and had a postoperative subjective athletic performance of > 80% were categorized into the Yes-RTS group. The primary outcome was the ability to achieve RTS at the preinjury level. Results: Sixty-five patients (female, 35; male, 30) at 13.0 (13.0) [median (interquartile)] months after ACLR participated in this study. Thirty-nine (60%) were assigned to the Yes-RTS group. Regarding knee conditions, the No-RTS group had a significantly higher knee pain intensity, as assessed using a numerical rating scale (p<0.001, effect size -0.45). In the performance tests, the No-RTS group exhibited a significantly lower limb symmetry index of RSI during the SL drop jump compared to the Yes-RTS group (p=0.002, effect size 0.81). Conclusion: Patients unable to achieve RTS after primary ACLR using hamstring grafts are more likely to exhibit asymmetric performance during the SL drop jump test, suggesting the significance of assessing jump symmetry when evaluating post-ACLR rehabilitation success. Level of Evidence: 3c.

CAN SENSORY DISTURBANCES DUE TO INJURY TO THE INFRAPATELLAR BRANCH OF THE SAPHENOUS NERVE BE PREVENTED BY AN OBLIQUE INCISION?

Objective: To evaluate the incidence of injuries to the infrapatellar branch of the saphenous nerve (IPBSN) after anterior cruciate ligament reconstruction (ACLR) with an oblique incision for hamstring graft harvesting. Methods: In total, 59 knees (from 57 patients) were evaluated in the follow-up of ACLR for six months. We drew a horizontal line parallel to the ground, passing through the most medial portion of the surgical incision and another, perpendicular to the first, starting at the tibial tuberosity (TT). We measured the length and angle of the cut, the distances from its most medial point to the perpendicular line, and from the TT to the horizontal line. Skin sensitivity was tested with a brush and the altered sensitivity area was measured. Patients were asked about difficulties in activities daily of living (ADL). Results: A total of 27 knees (45.7%) had sensory disorders, which persisted until the sixth postoperative month in 92.6% of them. The ADL were compromised in one knee (3.7%). No significant differences were found between the groups with and without changes in sensitivity regarding age, affected side, incision angle, or measured distances. The incision size was larger in the group without alteration in sensitivity. Conclusions: An oblique incision did not avoid IPBSN injuries. This condition rarely compromised the ADL. Level of Evidence II, Lesser Quality Prospective Study.

Objetivo: Avaliar a incidência de lesões do ramo infrapatelar do nervo safeno (RIPNS) na reconstrução do ligamento cruzado anterior (RLCA), com incisão oblíqua para a coleta do enxerto dos isquiotibiais. Métodos: 59 joelhos (57 pacientes) foram avaliados no pós-operatório da RCLA, por seis meses. Traçamos uma linha horizontal paralela ao solo, passando pela porção mais medial da incisão cirúrgica, e outra perpendicular à esta, iniciando na tuberosidade tibial (TT). Medimos o comprimento e a angulação do corte, as distâncias do ponto mais medial do corte à linha perpendicular e outra, da TT, à linha horizontal. A sensibilidade da pele foi testada com um pincel, e a área alterada foi mensurada. Os pacientes foram questionados sobre as dificuldades nas atividades diárias da vida (ADV). Resultados: 27 joelhos (45,7%) apresentaram distúrbios sensitivos, persistentes até o sexto mês pós-operatório em 92,6% deles. As ADV foram comprometidas em um joelho (3,7%). Não houve diferença significante entre os grupos com e sem alterações da sensibilidade, relativamente à idade, ao lado comprometido, ao ângulo da incisão ou às distâncias medidas. O tamanho da incisão foi maior no grupo sem alteração de sensibilidade. Conclusões: Uma incisão oblíqua não evitou lesões no RIPNS. Essa condição raramente comprometeu as ADV. Nível de Evidência II, Estudo Prospectivo de Menor Qualidade.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Quadriceps Activation After Anterior Cruciate Ligament Reconstruction: The Early Bird Gets the Worm!

Arthrogenic Muscle Inhibition (AMI) is a phenomenon observed in individuals with joint injury or pathology, characterized by a reflexive inhibition of surrounding musculature, altered neuromuscular control, and compromised functional performance. After anterior cruciate ligament reconstruction (ACLR) one of the most obvious consequences of AMI is the lack of quadriceps activation and strength. Understanding the underlying mechanisms of AMI is crucial for developing effective therapeutic interventions. The surgical procedure needed to reconstruct the ACL has biochemical et physiological consequences such as inflammation, pain, and altered proprioception. These alterations contribute to the development of AMI. Therapeutic interventions aimed at addressing AMI encompass a multidimensional approach targeting pain reduction, inflammation management, proprioceptive training, and quadriceps activation. Early management focusing on pain modulation through modalities like ice, compression, and pharmacological agents help mitigate the inflammatory response and alleviate pain, thereby reducing the reflexive inhibition of quadriceps. Quadriceps activation techniques such as neuromuscular electrical stimulation (NMES) and biofeedback training aid in overcoming muscle inhibition and restoring muscle strength. NMES elicits muscle contractions through electrical stimulation, bypassing the inhibitory mechanisms associated with AMI, thus facilitating muscle activation and strength gains. Comprehensive rehabilitation programs tailored to individual needs and stage of recovery are essential for optimizing outcomes in AMI. The objective of this clinical viewpoint is to delineate the significance of adopting a multimodal approach for the effective management of AMI, emphasizing the integration of pain modulation, proprioceptive training, muscle activation techniques, and manual therapy interventions. Highlighting the critical role of early intervention and targeted rehabilitation programs, this article aims to underscore their importance in restoring optimal function and mitigating long-term complications associated with AMI.

Assessing the Relationship of Psychological Sport Readiness, Single-leg Vertical Jump, and Non-Sagittal Single-Leg Hops to Quadriceps Strength After Anterior Cruciate Ligament Reconstruction.

Background: Limitations exist with current ACLR functional testing assessments that may be mitigated by including single-leg multi-directional testing. Hypothesis/Purpose: To compare Anterior Cruciate Ligament-Return to Sport after Injury Scale (ACL-RSI) scores, limb symmetry index (LSI) of the single-leg vertical jump (SLVJ), single-leg medial rotation hop (SLMRH), single-leg lateral hop (SLLH), and isokinetic quadriceps strength between participants with an ACLR and healthy controls and assess predictors of quadriceps strength asymmetry. It was hypothesized that ACL-RSI scores and LSIs for all tests would differ between ACLR and healthy control groups and within the ACLR group a strong correlation would exist between all outcome measures and quadriceps strength. Study Design: Cross-Sectional Study. Methods: Twenty-six participants with an ACLR (median 13 months after surgery) and twenty-six matched healthy controls were recruited to participate in this study. Performance was assessed via SLVJ, SLMRH, SLLH, and isokinetic quadriceps strength. Between-group comparisons were made with independent t-tests and Mann-Whitney U test. Within the ACLR group, bivariate correlation and multivariate regression analysis were performed to assess the relationship between the outcome measures and quadriceps strength asymmetry. Results: Significant between-limb differences were only identified in the ACLR group (p< 0.05): SLVJ LSI: 88.5%, SLMRH LSI: 93.6%, SLLH LSI: 92.7%, quadriceps strength LSI 80.9% - 83.9%, which were significantly lower (p <0.05) than the healthy control group. Within the ACLR group, a moderate-strong significant (p < 0.05) correlations existed with quadriceps strength and SLVJ (r=0.44-0.65), SLMRH (r =0.43-0.83), and SLLH (r=0.54-0.63); while ACL-RSI had a weak non-significant (p > 0.05) correlation with quadriceps strength (r= 0.12-0.30). Conclusion: Single-leg multidirectional test LSIs were less in ACLR participants than matched healthy controls and all were directly related to quadriceps strength. Psychological readiness to return to sport was not related to quadriceps strength.

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.

Serial Assessment of Factors Associated With Patient-Reported Outcomes up to 2 Years After ACL Reconstruction Using Autologous Hamstring Tendon: Results From the TMDU MAKS Study.

Background: Understanding the factors related to patient-reported outcomes (PROs) after anterior cruciate ligament reconstruction (ACLR) can lead to more effective interventions. Purpose/Hypothesis: The purpose of this study was to identify factors associated with PRO scores after ACLR. It was hypothesized that concomitant meniscal treatment and postoperative range of motion (ROM) would be associated with early postoperative PRO scores and that postoperative physical findings would be associated with 2-year postoperative PRO scores. Study Design: Cohort study; Level of evidence, 2. Methods: We examined the data from the Tokyo Medical and Dental University Multicenter Arthroscopic Knee Surgery (TMDU MAKS) Study for patients who underwent primary ACLR with autologous hamstring tendon grafts; 1252 patients in the TMDU MAKS Study were eligible for inclusion. The International Knee Documentation Committee (IKDC) subjective score, Knee injury and Osteoarthritis Outcome Score (KOOS), and Lysholm score of the patients at 3 months (n = 675), 1 year (n = 660), and 2 years (n = 375) postoperatively were assessed using multiple regression to evaluate the strength of the relationship between PRO scores and the following predictor variables: patient-specific factors, treatment-specific factors, and physical findings. Results: Improvement in all PROs significantly exceeded the minimal important change at 1 and 2 years postoperatively. Older age and female sex were predictive of lower PRO scores up to 2 years postoperatively. Concurrent meniscal treatment and limited range of knee motion were predictive of lower PRO scores at 3 months and 1 year postoperatively. A tighter knee (ie, less anterior translation) on the injured side compared with the contralateral knee was predictive of lower KOOS-Quality of Life and IKDC scores at 2 years postoperatively. At all 3 postoperative time points, greater side-to-side difference in knee ROM was predictive of lower PRO scores. Conclusion: Inferior PRO scores were associated with concomitant meniscal treatment and limited postoperative ROM until 1 year postoperatively and with older age and female sex up to 2 years postoperatively. PRO scores were associated with knee stability at all assessed time points.