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Purpose: The study aimed to obtain a comprehensive 3D visualization of knee specimens, including the cruciate ligaments and corresponding femoral and tibial bone insertions using a non-destructive micro-CT method. Methods: Knee specimens were fixed in anatomical positions and chemically dehydrated before being scanned using micro-CT with a voxel size of 17.5 μm. RGBA (red, green, blue, alpha) transfer functions were applied to virtually colorize each structure. Following micro-CT scanning, the samples were rehydrated, decalcified, and trimmed based on micro-CT 3D reconstructions as references. Histological evaluations were performed on the trimmed samples. Histological and micro-CT images were registered to morphologically and densitometrically assess the 4-layer insertion of the ACL into the bone. Results: The output of the micro-CT images of the knee in extension and flexion allowed a clear differentiation of the morphologies of both soft and hard tissues, such as the ACL, femoral and tibial bones, and cartilage, and the subsequent creation of 3D composite models useful for accurately tracing the entire morphology of the ligament, including its fiber and bundle components, the trajectory between the femur and tibia, and the size, extension, and morphology of its insertions into the bones. Conclusion: The implementation of the non-destructive micro-CT method allowed complete visualization of all the different components of the knee specimens. This allowed correlative imaging by micro-CT and histology, accurate planning of histological sections, and virtual anatomical and microstructural analysis. The micro-CT approach provided an unprecedented 3D level of detail, offering a viable means to study ACL anatomy. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to quantify the impact of concomitant meniscal lesions on knee laxity using a triaxial accelerometer in a large population of patients affected by anterior cruciate ligament (ACL) injury. Methods: A total of 326 consecutive patients (261 men and 65 women, mean age 31.3 ± 11.3) undergoing primary ACL reconstruction, were preoperatively evaluated through Lachman and pivot shift tests using a triaxial accelerometer to quantify knee laxity. An analysis based on the presence of meniscal tears assessed during surgery was performed to evaluate the impact of meniscal lesions on knee laxity. Results: The anterior tibial translation (Lachman test) presented significantly higher values in patients with medial meniscal lesions (7.3 ± 1.7 mm, p = 0.049) and both medial and lateral meniscal lesions (7.7 ± 1.6 mm, p = 0.001) compared to patients without concomitant meniscal lesions (6.7 ± 1.3 mm). Moreover, patients with both medial and lateral meniscal lesions presented significantly higher values of anterior tibial translation compared to patients with lateral meniscal lesions (p = 0.049). No statistically significant differences were found between the groups in terms of tibial acceleration (pivot shift test). Conclusion: This study demonstrated that the contribution of concomitant meniscal lesions to knee laxity can be objectively quantified using a triaxial accelerometer in ACL‐injured knees. In particular, medial meniscus lesions, alone or in association with lateral meniscus lesions, determine a significant increase of the anterior tibial translation compared to knees without meniscus tears. Level of Evidence: Level IV. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to determine the clinical and functional outcome of a salvage surgical approach with the combined procedures meniscal allograft transplantation (MAT), anterior cruciate ligament reconstruction (ACLR), and high tibial osteotomy (HTO), in a cohort of patients treated for complex knee lesions evaluated up to a mid-term follow-up. Methods: Eight patients (38.8 ± 4.6 years, 88% males) were treated arthroscopically with MAT without bone plugs combined with primary or revision ACLR and HTO and evaluated at basal, at a minimum of two years (short follow-up), and at a mean follow-up of 5.1 years (mid-term follow-up) with the VAS score for pain, Lysholm score, IKDC subjective score, WOMAC Osteoarthritis index, and Tegner score. Physical examination (Lachman and pivot-shift tests, arthrometer assessment) and radiographic evaluation (pre- and post-operative x-rays) were obtained. Complications and failures were also recorded. Results: A statistically significant improvement was observed from baseline to five years in all clinical scores. In particular, the IKDC subjective score improved from 33.3 ± 20.7 to 73.1 ± 18.4 at short follow-up (p < 0.05), up to 78.3 ± 9.8 at the final follow-up (p < 0.05). A similar trend was demonstrated with the Lysholm, VAS, WOMAC, and Tegner score, even though only one patient reached the pre-injury activity level. Two patients had a worsening of the Kellgren-Lawrence (KL) grade from preoperative (grade 1) to final follow-up (grade 2). No major complications and surgical failures were documented. Conclusion: The combined procedure of MAT, ACLR, and HTO presents few complications and failures and showed to be a valid option to reduce pain, recover knee function, and slow down the osteoarthritis process even in complex patients, with good and stable results up to a mid-term follow-up. [ABSTRACT FROM AUTHOR]

Purpose: Variations in femoral and tibial bony morphology have been associated with higher clinical grading and increased quantitative tibial translation, but not tibial acceleration, during the pivot shift test following anterior cruciate ligament (ACL) injury. The purpose of this study was to determine the impact of femoral and tibial bony morphology, including a measurement influenced by both parameters (the Lateral Tibiofemoral Articular Distance (LTAD)), on the degree of quantitative tibial acceleration during the pivot shift test and rates of future ACL injury. Methods: All patients who underwent primary ACL reconstruction from 2014 to 2019 by a senior orthopedic surgeon with available quantitative tibial acceleration data were retrospectively reviewed. All patients underwent a pivot shift examination under anesthesia with a triaxial accelerometer. Measurements of femoral and tibial bony morphology were performed by two fellowship-trained orthopedic surgeons using preoperative magnetic resonance imaging and lateral radiographs. Results: Fifty-one patients were included at a mean follow-up of 4.4 years. The mean quantitative tibial acceleration during the pivot shift was 13.8 m/s2 (range: 4.9–52.0 m/s2). A larger Posterior Condylar Offset Ratio (r = 0.30, p = 0.045), smaller medial-to-lateral width of the medial tibial plateau (r = − 0.29, p = 0.041), lateral tibial plateau (r = − 0.28, p = 0.042), and lateral femoral condyle (r = − 0.29, p = 0.037), and a decreased LTAD (r = − 0.53, p < 0.001) significantly correlated with increased tibial acceleration during the pivot shift. Linear regression analysis demonstrated an increase in tibial acceleration of 1.24 m/s2 for every 1 mm decrease in LTAD. Nine patients (17.6%) sustained ipsilateral graft rupture and 10 patients (19.6%) sustained contralateral ACL rupture. No morphologic measurements were associated with rates of future ACL injury. Conclusion: Increased convexity and smaller bony morphology of the lateral femur and tibia were significantly associated with increased tibial acceleration during the pivot shift. Additionally, a measurement, termed the LTAD, was found to have the strongest association with increased tibial acceleration. Based on the results of this study, surgeons can utilize these measurements to preoperatively identify patients at risk of increased rotatory knee instability. Level of evidence: Level IV. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to synthesize and quantitatively assess the outcomes of ACL Revision using a quadriceps tendon (QT) graft and to compare them with those of ACL Revisions performed with hamstring tendons (HT) graft. Methods: A comprehensive search based on the PRISMA protocol was performed across PubMed, Scopus, Embase, and Cochrane Library from inception until February 2022. Clinical studies reporting the outcomes of ACL Revision with QT autograft were included. Subjective and Objective IKDC, Tegner activity level, Lysholm knee score, KOOS score, VAS for pain, knee laxity (KT-1000/2000 arthrometer, Lachman test, and pivot-shift test), and graft failure were assessed. A systematic review and meta-analysis were performed and a quality assessment of the included studies was carried out with the MINORS score. Results: Seven studies met the selection criteria and were included in the systematic review for the qualitative synthesis of data. A pooled mean of all the variables was provided for the 7 studies, while 3 studies included a control group of ACL Revision with HT and were included in a meta-analysis. A total of 420 participants with a mean age of 28.9 ± 10.5 years and a mean postoperative follow-up of 39.3 ± 16.4 months were assessed. Of these, 277 patients underwent ACL Revision with QT and 143 patients underwent ACL Revision with HT. In the QT group, average graft failure was 9.8% compared to 17.4% in the HT group. KOOS Sport and pivot-shift test showed better postoperative outcomes in QT than HT, although it was not statistically significant (p = 0.052). Conclusion: The QT autograft was associated with an improved trend of rotatory laxity, PROMs and failure rate compared to HT autograft after revision ACL reconstruction. The QT autograft for revision ACL reconstruction is supported by the current literature. It is a viable graft that should be considered for both primary and revision ACL reconstruction. Level of evidence: Level IV. [ABSTRACT FROM AUTHOR]

This article presents with an evidence based approach, the kinematical rationale, biological evidence and the long term results of the "Over-The-Top" anterior cruciate ligament reconstruction with lateral plasty technique. This surgery was developed more than 25 years ago at the Rizzoli Institute by professor Marcacci and Zaffagnini and it is still widely performed in many orthopedic center worldwide. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study is to illustrate an overview of the registries currently operative in many countries to support the introduction of new prospective registries in other countries. Methods: The authors carried out a systematic web research in July 2021 to identify national ACL registries' annual reports and scientific literature on national ACL registries. The latest annual public registry reports were collected and analyzed in this study. Results: There are currently established national ACL registries in Norway, Denmark, Sweden, Luxembourg, New Zealand, the United Kingdom (UK), and the Kaiser Permanente National Anterior Cruciate Ligament Reconstruction Registry in the United States (US). Some differences can be found among the various registries due to the local healthcare system structure, data management rules, and general national laws. Conclusion: It is possible to develop accessible, cost-effective and entirely web-based ACL registries—as demonstrated by the Danish and Swedish registries—respecting the national legislation of different countries. This study supports the introduction of new ACL prospective registries in other countries to obtain valuable information for implementing daily clinical practice. Level of evidence: IV. [ABSTRACT FROM AUTHOR]

Purpose: Anterior cruciate ligament (ACL) ruptures are considered high burden injuries in sports with high pivotal activity, especially for professional footballers. A lack of evidence exists about long-term follow up of professional elite athletes who underwent ACL reconstruction. The purpose of the study is to analyze the return to play and the career of professional footballers who underwent ACL reconstruction with hamstrings, to evaluate re-rupture and reoperation at either indexed and contralateral knee, and to assess the long-term clinical subjective outcomes and satisfaction. Methods: Twenty-eight professional footballers that underwent 33 ACL reconstructions were retrospectively included in the study. All surgical interventions were performed using hamstring tendons graft and an over the top technique. Inclusion criteria were: inability to compete due to joint instability caused by total or subtotal ACL lesion, patients contracted to a professional football team at time of surgery. Exclusion criteria were: multi-ligament reconstruction or concomitant meniscal allograft transplantation. Patients were contacted by phone and a brief questionnaire about surgery was administered. Subsequently, a Lysholm knee scoring scale was obtained. After that, an online research was performed on publicly available websites in order to retrieve information of the patients included after surgery. Results: In all cases, ACL Reconstruction was performed with hamstring tendons using a non-anatomic Double-Bundle technique in 16 cases (49%), an Over-The-Top Single-Bundle technique in 9 cases (27%), and an Over-The-Top Single-Bundle plus Lateral Plasty technique in 8 cases (24%); moreover, a meniscal lesion was present in 20 cases (61%). Three (9%) of the 33 ACL reconstruction failed (2/16 Double-Bundle, 1/9 Single- Bundle, 0/8 Single-Bundle + Lateral Plasty; p = n.s.), with two of them within 12 months from surgery. Other procedures, mainly arthroscopic meniscectomies, were performed in 10 cases (30%). The first official match was played after an average of 8.0 ± 3.6 (4.6–18.2) months in 31 cases (94%). Patients were evaluated after 12.6 ± 3.3 years (6.7–17.5) from the indexed ACL reconstruction. The average Lysholm score was 94.2 ± 8.3. Conclusions: In our small case-series, professional soccer players were able to return to play at a competitive level with a hamstrings over the top technique. Patients with long careers had a high percentage of reoperation on the contralateral knee. Level of evidence: IV. [ABSTRACT FROM AUTHOR]

Anterior cruciate ligament (ACL) injuries are caused by both contact and non-contact injuries. However, it can be claimed that non-contact ones account approximately for 70% of all cases. Thus, several authors have emphasized the role of reduction of muscle strength as a modifiable risk factor referred to non-contact ACL injury, with the latter being targeted by specific training interventions. The present paper wants to review the available literature specifically on the relationship between dynamic knee valgus, gluteal muscles (GM) strength, apart from the potential correlation regarding ACL injury. After a research based on MEDLINE via PubMed, Google scholar, and Web of Science, a total of 29 articles were collected and thus included. Additionally, this review highlights the crucial role of gluteal muscles in maintaining a correct knee position in the coronal plane during different exercises, namely walking, running, jumping and landing. [ABSTRACT FROM AUTHOR]

Paediatric and adolescent ACL injuries are an emerging health burden, increasing at a higher rate than in adults. They compromise quality of life, affect knee structure and function, lead to the early development of osteoarthritis and are a serious economic burden due to shortened professional careers and subsequent surgeries. Up to 35% of children and adolescents will experience a second ACL injury and this population particularly at high risk of secondary intraarticular soft tissue degeneration and growth abnormalities. However, there is still a lack of high-quality outcome studies on this specific population and many knowledge gaps persist in the current treatment guidelines. It is currently unknown whether ACL reconstruction in this young population decreases the risk of irreversible secondary intraarticular soft tissue degeneration. Furthermore, it is not known whether return to high or elite level sports after paediatric ACL injury or reconstruction should be recommended. The relatively low number of paediatric ACL injuries seen in each hospital makes it necessary to conduct international multi-centre studies to collect robust data to provide evidence-based guidelines for the treatment of these injuries. The Paediatric Anterior Cruciate Ligament Initiative (PAMI) was thus started by the European Society of Sports Traumatology, Knee Surgery & Arthroscopy and opened for patient inclusion in 2018. This comprehensive overview of the first 2 years of the PAMI registry shows that the project is now well consolidated and accepted by the European orthopaedic community. Future challenges include ensuring additional external funding to ascertain long term sustainability and continuous dissemination of the knowledge acquired in scientific journals. [ABSTRACT FROM AUTHOR]

Purpose: The objective of this study was to report on a worldwide web-based survey among the ESSKA community developed to investigate current recommendations regarding ACL reconstruction surgical procedures. Methods: All contacts in the official mailing list of the ESSKA were contacted to investigate preferences regarding graft type, anterolateral ligament reconstruction, femoral tunnel drilling technique, single-bundle vs double-bundle technique, femoral and tibial fixation methods. Results: Eight-hundred and twenty responses were analyzed. Hamstrings autograft was the graft of choice in male patients for 634 (79%) and in female patients for 674 (84%) responders, while its preference for ACL reconstruction in professional athletes was for 401 (50%). 480 (63%) surgeons surveyed would include anterolateral ligament reconstruction only if diagnosed and remaining instability after ACL surgery or revision. 598 (75%) respondents were in favor of anteromedial portal for femoral tunnel drilling. The most popular femoral fixation technique was found to be cortical suspension (500–66%), while a compression system was preferred on the tibial side by 537 (71% of the sample). Conclusions: This survey study found that HT autograft, single-bundle reconstruction, anteromedial portal for femoral tunnel drilling, cortical suspension systems for femoral fixation and compression systems for tibial fixation represent the current standard of ACLR in a large community of orthopedic surgeons. The present study performed with surgeons who are members of the ESSKA community will help to comprehend the actual ACLR worldwide practice patterns. Due to low response rate, these results should be interpreted with caution and not to be intended to represent the state of the art of ESSKA community. Level of evidence: III. [ABSTRACT FROM AUTHOR]

Purpose: The role of the anterior cruciate ligament (ACL) in knee biomechanics in vivo and under weight-bearing is still unclear. The purpose of this study was to compare the tibiofemoral kinematics of ACL-deficient knees to healthy contralateral ones during the execution of weight-bearing activities. Methods: Eight patients with isolated ACL injury and healthy contralateral knees were included in the study. Patients were asked to perform a single step forward and a single leg squat first with the injured knee and then with the contralateral one. Knee motion was determined using a validated model-based tracking process that matched subject-specific MRI bone models to dynamic biplane radiographic images, under the principles of Roentgen stereophotogrammetric analysis (RSA). Data processing was performed in a specific software developed in Matlab. Results: Statistically significant differences (p < 0.05) were found for single leg squat along the frontal plane: ACL-deficient knees showed a more varus angle, especially at the highest knee flexion angles (40°–50° on average), compared to the contralateral knees. Furthermore, ACL-deficient knees showed tibial medialization along the entire task, while contralateral knees were always laterally aligned. This difference became statistically relevant (p < 0.05) for knee flexion angles included between 0° and about 30°. Conclusion: ACL-deficient knees showed an abnormal tibial medialization and increased varus angle during single leg squat when compared to the contralateral knees. These biomechanical anomalies could cause a different force distribution on tibial plateau, explaining the higher risk of early osteoarthritis in ACL deficiency. The clinical relevance of this study is that also safe activities used in ACL rehabilitation protocols are significantly altered in ACL deficiency. Level of evidence: III. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to report current rehabilitation recommendations after ACL reconstruction in ESSKA community, with a particular focus on the specific criteria utilized to guide activity progression Methods: A web-based survey was developed to investigate preferences between time-based and functional ACL reconstruction rehabilitation progression milestones of ESSKA community. Results: Eight hundred and twenty completed questionnaires were received. Responders were from 86 different countries worldwide, 63% of them from European countries. Functional criteria were considered more appropriate to decide if a patient can start specific activities/exercises by 67% of the responders. Good core and lower extremity neuromuscular control were the most often used functional criteria for decision-making regarding readiness for sport-specific rehabilitation (66%), sport-specific drills without (65%) and with contact (66%). Strength assessed with an isokinetic dynamometer was considered by about half of the responders a determinant to initiate sport-specific drills without (51%—isokinetic strength, LSI > 80%) and with contact (58%—isokinetic strength, LSI > 85–90%). To determine readiness for sport-specific drills, hop tests were used by 40% of respondents for drills without contact and 48% of respondents for drills with contact. Conclusion: The results of this survey involving mainly orthopaedic surgeons indicate that functional measures are considered more appropriate than milestones based on time from surgery to guide progression through the postoperative rehabilitation process after ACLR. The main clinical relevance of this study is that updated information on collective agreement could be useful for clinicians and physiotherapists to delineate their postoperative treatments after ACLR. These results should be interpreted with caution, as this sample represents only a small portion of ESSKA community involved in knee surgery and treating patients following ACLR. Level of evidence: III. [ABSTRACT FROM AUTHOR]

Purpose: The aim of the present study was to translate, cross-culturally adapt, and assess the psychometric properties of the Pedi-IKDC and Pedi-FABS scores in the Italian paediatric population with various knee pathologies. Methods: In accordance with the Paediatric Anterior Cruciate Ligament Monitoring Initiative (PAMI) research protocol, the original English versions of the questionnaires were translated into Italian. All patients aged 8–16 and scheduled for knee surgery were considered eligible in the study. An open-source platform was implemented to collect responses to the surveys which included general patient information, the questionnaires Pedi-IKDC, and Pedi-FABS. Two surveys were sent under stable clinical conditions before surgery (Q1 and Q2); a third survey was sent 3–4 months after surgery (Q3). The following properties were calculated: reliability, internal consistency, criterion validity, responsiveness, and floor/ceiling effects. Results: Eighty-nine patients completed Q1, 81 patients completed Q2, and 49 patients completed Q3. Both questionnaires demonstrated acceptable properties. Pedi-IKDC: standard error of measurement (SEM) = 4.4, smallest detectable change (SDC) = 12.3, interclass correlation coefficient (ICC) = 0.96, Cronbach alpha (α) = 0.92, moderate-to-low correlation to Pedi-FABS, effect size (ES) = 0.79, standardized response mean (SRM) = 0.86, floor = 0%, ceiling = 22%. Pedi-FABS: SEM = 2.1, SDC = 5.8, ICC = 0.94, Cronback alpha (α) = 0.93, moderate-to-low correlation to Pedi-IKDK, ES = 0.60, SRM = 0.51, floor = 19%, ceiling = 0%. Conclusions: The Italian version of Pedi-IKDC and Pedi-FABS is valuable tools for patient assessment, by demonstrating good psychometric properties. In clinical setting, these questionnaires can be used to properly evaluate outcomes in Italian pediatric patients with knee pathologies. Level of evidence: II. [ABSTRACT FROM AUTHOR]

Purpose: To assess the relationship between the KiRA triaxial accelerometer and the KT-1000 measurements in the intact, anterior cruciate ligament (ACL) deficient, and ACL reconstructed knee joint for the quantification of the Lachman test. Moreover, the intra- and inter-examiner repeatability of the KiRA device will be determined. It was hypothesized that the side-to-side difference of the anterior tibial translation as measured by the KiRA device would be equivalent to the one measured by the KT-1000 during the Lachman test.Methods: Sixty patients were divided into three groups and have been prospectively included in the present study. Group_A composed of 20 patients with a diagnosis of an isolated ACL tear. Group_B composed of 20 patients who underwent ACL reconstruction with a Single-Bundle Lateral Plasty (SBLP) technique with at least 20 years of follow-up. Group_C was the control group and included 20 patients with no history of ACL lesion. Lachman test has been performed at manual-maximum load on both sides, the involved and the contralateral and analyzed with the two different devices.Results: The KiRA device in terms of side-to-side difference resulted not statistically different from the measurement of the KT-1000 arthrometer for the three study groups (n.s): Group_A: (4 ± 2 mm KiRA, 4 ± 2 mm KT1000), Group_B: (4 ± 2 mm KiRA, 4 ± 2 mm KT-1000), Group_C: (4 ± 2 mm KiRA, 4 ± 2 mm KT-1000), an excellent intra- (ICC = 0.88-0.89) and inter-examiner (ICC = 0.79) agreement was found for KiRA measurements.Conclusion: The KiRA (I+, Italy) device offers a valid method to quantify the Lacham test.Level Of Evidence: II. [ABSTRACT FROM AUTHOR]

Purpose: Aim of this study is to document if combined meniscal allograft transplantation (MAT) and ACL reconstruction can improve knee function, reduce pain and allow patients with meniscal defect and ACL lesion to resume sport activities.Methods: Fifty MAT, arthroscopically performed without bone plugs and combined with one-stage primary or revision ACL reconstruction, with or without high tibial osteotomy (HTO), were included. Patients (aged 38.2 ± 10.6 years, 87% males) were evaluated at a mean follow-up of 5 years with Lysholm, Tegner and VAS scores. Patient satisfaction was also recorded, together with complications and failures.Results: VAS and Lysholm scores improved significantly (from 63.7 to 24.5 and from 60.6 to 82.7, respectively, p < 0.001), while the Tegner score did not reach pre-injury values (p < 0.001), but it improved significantly compared to pre-surgery values (from 2.8 to 4.6, p < 0.001). Medial MAT reported significantly better results compared to lateral MAT. Patients undergoing concomitant HTO reported a significantly higher decrease of VAS. Younger patients with higher pre-operative pain and lower activity level presented higher satisfaction. Eight patients needed a reoperation. Three patients were considered surgical failures while four were considered clinical failures, for a total of 15% failures.Conclusions: Meniscal allograft transplantation combined with ACL reconstruction represents a safe and suitable treatment, which should be considered as a suitable option in the clinical practice. All evaluated patient profiles, ACL injury in a patient with post-meniscectomy syndrome, failed ACL reconstruction in patients with a meniscus defect, and ACL reconstruction in patients with malalignment due to meniscal defect, benefited from the combined MAT procedure at medium-term follow-up.Level Of Evidence: IV. [ABSTRACT FROM AUTHOR]

Purpose: To assess, using model-based dynamic radiostereometric analysis (RSA), the biomechanical behaviour of a new design posterior-stabilized (PS) fixed-bearing (FB) total knee arthroplasty (TKA) in vivo while patients performing two common motor tasks. The hypothesis was that model-based dynamic RSA is able to detect different behaviour of the implant under weight-bearing and non-weight-bearing conditions.Methods: A cohort of 15 non-consecutive patients was evaluated by dynamic RSA 9 months after TKA implantation. The mean age of patients was 73.4 (65-72) years. The kinematic evaluations were performed using an RSA device (BI-STAND DRX 2) developed in our Institute. The patients were asked to perform two active motor tasks: sit-to-stand in weight-bearing condition; range of motion (ROM) while sitting on the chair. The motion parameters were evaluated using the Grood and Suntay decomposition and the low-point kinematics methods.Results: The dynamic RSA evaluation showed a significant difference (p < 0.05) between the biomechanical behaviour of the prosthesis during the two motor tasks. When subjected to the patient weight (in the sit-to-stand) the low point of the medial compartment had a shorter motion (5.7 ± 0.2 mm) than the lateral (11.0 ± 0.2 mm). This realizes a medial pivot motion as in the normal knee. In the ROM task, where the patient had no weight on the prosthesis, this difference was not present: the medial compartment had a displacement of 12.7 ± 0.2 mm, while the lateral had 17.3 ± 0.2 mm.Conclusions: Model-based RSA proved to be an effective tool for the evaluation of TKA biomechanics. In particular, it was able to determine that the fixed-bearing posterior-stabilized TKA design evaluated in this study showed a medial pivoting movement under weight-bearing conditions that was not present when load was not applied. Under loading conditions what drives the pattern of movement is the prosthetic design itself. By the systematic use of this study protocol future comparisons among different implants could be performed, thus contributing significantly to the improvement of TKA design.Level Of Evidence: IV. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to follow up, clinically and radiographically, skeletally immature patients who underwent ACL reconstruction with an all-epiphyseal "over-the-top" technique.Methods: Twenty athletes aged between 8 and 13 years were enrolled and retrospectively evaluated. The subjects underwent surgical ACL reconstruction between 2009 and 2013. The surgical technique consisted of a single-bundle all-epiphyseal ACL reconstruction with an extra-articular lateral tenodesis. The mean follow-up was 54 months [34-123] after surgery. Clinically, the patients were evaluated pre- and post-operatively with Lysholm and KOOS scores; sport activity level was evaluated using the pre-injury, pre-operative and post-operative Tegner scores. Objective IKDC was calculated post-operatively. The joint laxity was evaluated by KT1000 and Rolimeter arthrometers. Panoramic AP standing radiographs of the lower limbs and lateral knee radiographs were also taken at the follow-up to evaluate limb length discrepancies (LLD) and axial malalignment. Normally distributed parameters were presented as mean ± standard deviation, while the non-normally distributed parameters were presented as median [25° percentile, 75° percentile].Results: Clinical scores showed significant (P < 0.01) improvement: Lysholm and KOOS scores improved from 40 [22; 65] and 59 [42, 73], respectively, to 100 [95; 100] and 99 [97;100] after surgery. Tegner score improved from 2 [2; 2] pre-operatively to 7 [3; 9] at follow-up (P < 0.01). At follow-up, IKDC score was A for 19 patients and one who scored B. All patients returned to sport activity and had good stability at follow-up: the KT1000 showed a median side-to-side difference of 0.0 mm [- 0.4; 1.0] for the standard force evaluation and 0.0 mm [- 1.0; 0.8] for manual-maximum test. The Rolimeter showed median side-to-site difference of 0.0 mm [- 1.0; 0.8]. Three minor leg length discrepancies and axial deviations were observed at the radiograph: one patient had 0.6 cm lengthening and 4° of varus, one had 1 cm lengthening, and one had 3° of varus (in comparison with the non-operated limb). No re-injury was observed.Conclusion: This study demonstrates that the modified all-epiphyseal single-bundle "over-the-top" technique is a viable and safe option for ACL reconstruction in pediatric subjects. These results support once more that not only ACL reconstruction is a safe procedure in skeletally immature patients, but also it is highly recommended for those who want to pursue an active and sportive life.Level Of Evidence: Case series, IV. [ABSTRACT FROM AUTHOR]

Purpose: Lateral compartment acceleration and translation have been used to quantify rotatory knee laxity in the setting of anterior cruciate ligament (ACL) injury; however, their relationship remains elusive. The purpose of this study was to examine the correlation between lateral compartment acceleration and translation during pivot shift testing. It was hypothesized that a correlation would exist in ACL-injured and uninjured knees, irrespective of sex, but would be greatest in knees with combined ACL and lateral meniscus tear.Methods: Seventy-seven patients (34 females, 25.2 ± 9.0 years) undergoing primary single-bundle ACL reconstruction were prospectively enrolled in a 2-year study across four international centers. Patients underwent preoperative examination under anesthesia of the injured and uninjured knee using Image Analysis software and surface mounted accelerometer.Results: A moderate correlation between lateral compartment acceleration and translation was observed in ACL-injured knees [ρ = 0.36, p < 0.05), but not in uninjured knees (ρ = 0.17, not significant (n.s.)]. A moderate correlation between acceleration and translation was demonstrated in ACL-injured knees with lateral meniscus tears (ρ = 0.53, p < 0.05), but not in knees with isolated ACL-injury (ρ = 0.32, n.s.), ACL and medial meniscus tears (ρ = 0.14, n.s.), or ACL and combined medial and lateral meniscus tears (ρ = 0.40, n.s.). A moderate correlation between acceleration and translation was seen in males (ρ = 0.51, p < 0.05), but not in females (ρ = 0.21, n.s.). Largest correlations were observed in males with ACL and lateral meniscus tears (ρ = 0.75, p < 0.05).Conclusion: Lateral compartment acceleration and translation were moderately correlated in ACL-injured knees, but largely correlated in males with combined ACL and lateral meniscus tears. ACL and lateral meniscus injury in males might, therefore, be suspected when both lateral compartment acceleration and translation are elevated. Surgeons should have a greater degree of suspicion for high-grade rotatory knee laxity in ACL-injured males with concomitant lateral meniscus tears. Future studies should investigate how these two distinct components of rotatory knee laxity-lateral compartment acceleration and translation-are correlated with patient outcomes and affected by ACL surgery.Level Of Evidence: Prospective cohort study; Level of evidence II. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of the current prospective study was to assess the changes over time in patients tested at 6 months and 9 months after anterior cruciate ligament reconstruction (ACLR) with a return to sport (RTS) test battery. It was hypothesized that more patients passed RTS criteria at 9 months compared to 6 months.Methods: Sixty-two ACLR patients performed a test battery at an average of 6.5 ± 0.7 and 9.5 ± 0.9 months after ACLR. All patients underwent a standardized rehabilitation protocol. The test battery consisted of the following tests: a jump-landing task assessed with the Landing Error Scoring System (LESS), three single-leg hop tasks (single-leg hop test, triple-leg hop test, side hop test), isokinetic quadriceps and hamstring strength at 60, 180 and 300°/s and two questionnaires (IKDC and ACL-RSI). Cut off criteria were set as Limb Symmetry Index (LSI) > 90% (for isokinetic strength and for single-leg hop tasks), LESS < 5, IKDC score within 15th percentage of healthy subjects and ACL-RSI > 56 respectively.Results: At 6 months, two patients (3.2%) passed all criteria. At 9 months, seven patients (11.3%) passed all criteria. Patients improved in all RTS criteria over time except for the IKDC score. Twenty-nine patients (46.8%) did not pass the strength criterion at 60°/s at 9 months after ACLR.Conclusions: The percentages of patients passing all RTS criteria were low at both 6 and 9 months after ACLR. Quadriceps strength revealed persistent deficits and the lack of improvement in the IKDC score questionnaires shows insufficient self-reported knee function for RTS.Level Of Evidence: III. [ABSTRACT FROM AUTHOR]

The aim of the present Letter was to comment on the paper "Prediction of Knee Kinematics at Time of Noncontact Anterior Cruciate Ligament Injuries Based on Bone Bruises" from Shi et al. (Ann Biomed Eng, 2020, https://doi.org/10.1007/s10439-020-02523-y). Though the authors provided an extremely interesting paper on a debated topic in Sport Medicine, with a strong methodology and consistent results, caution should be used when drawing conclusions on Anterior Cruciate Ligament injury mechanism through the interpretation of such data. [ABSTRACT FROM AUTHOR]

Purpose: To determine how the incision technique for hamstring tendon (HT) harvest in anterior cruciate ligament (ACL) reconstruction affects the risk of injury to the IPBSN and clinical outcome.Methods: A systematic literature search of the MEDLINE/Pubmed, Cochrane Central Register of Controlled Trials (CENTRAL) and EBSCOhost electronic databases and clinicaltrials.gov for unpublished studies was performed to identify comparative studies investigating injury to the IPBSN after HT ACL reconstruction by comparing at least two different incision techniques. Data were extracted for the number of patients with evidence of any neurologic deficit corresponding to injury to the IPBSN, area of sensory deficit, the Lysholm score and patient satisfaction. The mean difference (MD) in study outcome between incision groups was assessed. The relative risk (RR) and the number needed to treat (NNT) were calculated. The Chi-square and Higgins' I2 tests were applied to test heterogeneity. Data were pooled using a Mantel-Haenszel random-effects model if the statistical heterogeneity was > 50% and a fixed-effects model if the statistical heterogeneity was < 50%. The risk of bias was evaluated according to the Cochrane Database questionnaire and the quality of evidence was graded according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) guidelines.Results: A total of eight studies (three randomized controlled trials (RCTs) and five comparative studies) were included, of which six compared vertical and oblique incisions, one horizontal and vertical incisions, and one compared all three techniques. HT harvest was performed through a vertical incision in 329 patients, through an oblique incision in 195 patients and through a horizontal incision in 151 patients. Considering the meta-analysis of the RCTs, the performance of a vertical incision significantly increased the risk of causing IPBSN deficiency compared with both oblique and horizontal incision [RR 1.65 (CI 1.10-2.49, p = 0.02) and RR 2.45 (CI 1.73-3.47, p < 0.0001), respectively]. A significantly larger area of sensory deficit was found with vertical incisions compared with oblique ones, with an MD of 22.91 cm2 (95% CI 7.73-38.08; p = 0.04). No significant differences were found between the incision techniques in relation to patient-reported outcomes. The same trend was obtained after the performing a meta-analysis of all eight included studies. The quality of evidence in this meta-analysis was determined as "low" to "moderate", mostly due to inadequate methods of randomization and high heterogeneity among the included studies.Conclusion: The performance of a vertical incision to harvest HTs for ACL reconstruction significantly increased the risk of iatrogenic injury to the IPBSN compared with both oblique and horizontal incisions.Level Of Evidence: Level I-III, meta-analysis of comparative studies. [ABSTRACT FROM AUTHOR]

Background: Soccer is considered the most popular sport in the world concerning both audience and athlete participation, and the incidence of ACL injury in this sport is high. The understanding of injury situations and mechanisms could be useful as substratum for preventive actions. Purpose: To conduct a video analysis evaluating the situations and mechanisms of ACL injury in a homogeneous population of professional male soccer players, through a search entirely performed on the YouTube.com Web site focusing on the most recent years. Methods: A video analysis was conducted obtaining videos of ACL injury in professional male soccer players from the Web site YouTube. Details regarding injured players, events and situations were obtained. The mechanism of injury was defined on the basis of the action, duel type, contact or non-contact injury, and on the hip, knee and foot position. Results: Thirty-four videos were analyzed, mostly from the 2014-2015 season. Injuries occurred mostly in the first 9 min of the match (26%), in the penalty area (32%) or near the side-lines (44%), and in non-rainy conditions (97%). Non-contact injuries occurred in 44% of cases, while indirect injuries occurred in 65%, mostly during pressing, dribbling or tackling. The most recurrent mechanism was with an abducted and flexed hip, with knee at first degrees of flexion and under valgus stress. Conclusions: Through a YouTube-based video analysis, it was possible to delineate recurrent temporal, spatial and mechanical characteristics of ACL injury in male professional soccer players. Level of evidence: Level IV, case series. [ABSTRACT FROM AUTHOR]

Purpose: To document the available evidence on the influence of cartilage lesions on the results of anterior cruciate ligament (ACL) surgery and their management to optimize the final outcome.Methods: A systematic review was performed on the PubMed database on articles dealing with cartilage lesions detected at the time of ACL reconstruction, by looking both for their influence on the clinical outcome and the results of their treatment. Reports on clinical, radiological, or second-look outcomes at any follow-up were included. Exclusion criteria were preclinical studies, reviews, or studies not reporting clinical, radiological, or second-look outcome after primary ACL reconstruction.Results: Thirty-seven studies were included for the final analysis. Twenty-seven focused on the influence of cartilage lesions on clinical outcome after ACL reconstruction in 47,837 patients. In total, 21/27 articles showed a correlation with a poorer outcome in terms of subjective, objective, and radiographic findings. Lesion location and depth influenced final results. Only 9.0 % of these defects were treated in the analysed studies, and only 10 manuscripts of overall low level evaluated the results of combined cartilage-ACL treatments.Conclusion: The majority of the literature supports the clinical relevance of cartilage lesions which are correlated with a poorer outcome after ACL reconstruction. Nonetheless, a large amount of chondral defects are actually not addressed, also considering the poor evidence for the benefits provided by cartilage treatments. In fact, only a few studies specifically focused on how to manage cartilage lesions found during ACL reconstruction and there is a lack of indications for the most appropriate treatment approach.Level Of Evidence: IV. [ABSTRACT FROM AUTHOR]

Purpose: The main goal of this work was to evaluate the pivot shift test in awake and anesthetized patients by using two different quantitative methodologies and comparing the results with the standard clinical grading, taking advantage of a multicenter international study.Methods: Patients between 16 and 50 years of age undergoing primary unilateral single-bundle anterior cruciate ligament (ACL) reconstruction were considered eligible. The pivot shift test was performed pre-operatively, with the patient awake and again with the patient under general anaesthesia. The pivot shift test was clinically graded as defined by the International Knee Documentation Committee. The instrumented assessment was performed by using two non-invasive acquisition systems; specifically, a system exploiting an inertial sensor and a video-based application developed on a commercial tablet using skin markers. Lateral compartment translation and the tibial acceleration reached during joint reduction were used as quantitative parameters.Results: A total of 103 patients were enrolled in the study. Statistically significant difference was found between the distributions of clinical grade evaluated in awake patients and those under general anaesthesia (P < 0.01). Comparing awake patients to those under general anaesthesia, lower values were found both for tibial acceleration (3.7 ± 1.5 vs 6.0 ± 4.6 m/s2, P < 0.01) and lateral compartment translation of the involved limb (2.2 ± 1.7 vs 3.0 ± 2.2 mm, P < 0.01).Conclusions: This study indicated that significant differences in the grading of the pivot shift test exist between awake and anesthetized patients, regardless of the use of quantitative instruments during the evaluation. Actual clinical assessment reported indeed its weakness, presenting subjective variability and dependence on tester's experience. However, several factors might influence the validity of awake examination such as experience level of examiner and cultural factors, as seen in this international multicenter study.Level Of Evidence: Prospective comparative study, Level II. [ABSTRACT FROM AUTHOR]

The article presents a historical perspective on the role of extra-articular aspects of surgical reconstruction to treat the anterior cruciate ligament (ACL)-deficient knee. Topics discussed include the concept of rotational laxity, techniques to address the notion that injuries to the anterolateral knee structures are important features of the continuum of pathology and rotary knee laxity in the setting of ACL deficiency.

Purpose: The aim of this study was to report Italian orthopaedic surgeons' management of choice for ACL reconstruction and rehabilitation, and to compare surgical applications and rehabilitation approaches of Italian surgeons to the current approaches of "ACL Study Group". A secondary purpose was to compare the preferences of subgroup based on graft choice, surgical techniques and experience.Methods: A web-based survey was developed to investigate the attitudes of members of a national association specialized in sports traumatology and knee surgery (SIGASCOT) regarding surgical techniques, routine post-operative applications, rehabilitation approaches and starting time of specific activities and exercises following ACL reconstruction.Results: The response rate was 17 % (131 questionnaires). The most popular graft type was hamstring tendon (81 % in male patients, and 91 % in female patients). The rate of continuous passive motion use was 55 %. Half surgeons routinely used a brace (49 %), usually a hinged brace. In total, 33.0 % of surgeons allowed patients to load the operated knee as much as tolerated within the first 2 weeks. Fifty-nine per cent of surgeons did not limit full flexion within the first 2 weeks. Most surgeons advise to wait until 4 months or more (97 %) for return to sports not requiring contact, and 6 months or more for full-contact sport (86 %).Conclusions: This survey demonstrates clear trends in the practice of ACL reconstruction and rehabilitation in Italy. The data obtained from the SIGASCOT members revealed a more conservative approach when compared to the current approaches of "ACL Study Group".Level Of Evidence: Cross-sectional survey, Level III. [ABSTRACT FROM AUTHOR]

Purpose of this paper is to provide an overview of the latest research on the anterolateral ligament (ALL) and present the consensus of the ALL Expert Group on the anatomy, radiographic landmarks, biomechanics, clinical and radiographic diagnosis, lesion classification, surgical technique and clinical outcomes. A consensus on controversial subjects surrounding the ALL and anterolateral knee instability has been established based on the opinion of experts, the latest publications on the subject and an exchange of experiences during the ALL Experts Meeting (November 2015, Lyon, France). The ALL is found deep to the iliotibial band. The femoral origin is just posterior and proximal to the lateral epicondyle; the tibial attachment is 21.6 mm posterior to Gerdy's tubercle and 4-10 mm below the tibial joint line. On a lateral radiographic view the femoral origin is located in the postero-inferior quadrant and the tibial attachment is close to the centre of the proximal tibial plateau. Favourable isometry of an ALL reconstruction is seen when the femoral position is proximal and posterior to the lateral epicondyle, with the ALL being tight upon extension and lax upon flexion. The ALL can be visualised on ultrasound, or on T2-weighted coronal MRI scans with proton density fat-suppressed evaluation. The ALL injury is associated with a Segond fracture, and often occurs in conjunction with acute anterior cruciate ligament (ACL) injury. Recognition and repair of the ALL lesions should be considered to improve the control of rotational stability provided by ACL reconstruction. For high-risk patients, a combined ACL and ALL reconstruction improves rotational control and reduces the rate of re-rupture, without increased postoperative complication rates compared to ACL-only reconstruction. In conclusion this paper provides a contemporary consensus on all studied features of the ALL. The findings warrant future research in order to further test these early observations, with the ultimate goal of improving the long-term outcomes of ACL-injured patients. Level of evidence Level V-Expert opinion. [ABSTRACT FROM AUTHOR]

Persistent rotatory knee laxity is increasingly recognized as a common finding after anterior cruciate ligament (ACL) reconstruction. While the reasons behind rotator knee laxity are multifactorial, the impact of the anterolateral knee structures is significant. As such, substantial focus has been directed toward better understanding these structures, including their anatomy, biomechanics, in vivo function, injury patterns, and the ideal procedures with which to address any rotatory knee laxity that results from damage to these structures. However, the complexity of lateral knee anatomy, varying dissection techniques, differing specimen preparation methods, inconsistent sectioning techniques in biomechanical studies, and confusing terminology have led to discrepancies in published studies on the topic. Furthermore, anatomical and functional descriptions have varied widely. As such, we have assembled a panel of expert surgeons and scientists to discuss the roles of the anterolateral structures in rotatory knee laxity, the healing potential of these structures, the most appropriate procedures to address rotatory knee laxity, and the indications for these procedures. In this round table discussion, KSSTA Editor-in-Chief Professor Jón Karlsson poses a variety of relevant and timely questions, and experts from around the world provide answers based on their personal experiences, scientific study, and interpretations of the literature. Level of evidence V. [ABSTRACT FROM AUTHOR]

Recent publications have generated renewed interest in the anatomy of the anterolateral capsule. Knowledge of the biomechanical function of the anterolateral components is lacking. Further research is required to evaluate the influence of the anterolateral capsule on rotatory laxity of the knee. The role of surgical procedures, such as an extra-articular tenodesis or lateral plasty, has to be defined based on quantification of the injury. This article seeks to summarize the current literature and discusses the role of the anterolateral capsule and reconstructive techniques in combined ligamentous knee trauma. Level of evidence V. [ABSTRACT FROM AUTHOR]

Purpose: Posterolateral corner structures functionally interact with the ACL. The aim of this study was to investigate the capability of an isolated ACL reconstruction control laxity parameters in a knee with combined ACL and PLC and the increase in terms of laxity produced by the resection of the PC in an ACL-deficient knee.Method: An in vitro cadaveric study was performed on seven knees. The joints were analysed in the following conditions: intact, after ACL resection, after popliteus complex resection, after ACL reconstruction and after LCL. Testing laxity parameters were recorded with an intra-operative navigation system and defined as: AP displacement at 30° and 90° of flexion (AP30 and AP90) applying a 130 N load and IE at 30° and 90° of knee flexion with a 5 N load.Results: Sectioning the ACL significantly increased the AP30 at 30° and 90° of knee flexion (p < 0.05). At 90° of knee flexion, the resection of the LCL determined a significant increase in terms of AP laxity (p < 0.05). At 90° has been found a significant difference for the IE laxity (p < 0.05) after PC resection. Sectioning the LCL produced a significant increase in IE laxity at 30° and 90° of knee flexion (p < 0.05).Conclusion: Isolated ACL reconstruction is able to control the AP laxity with a combined complete lesion of the PLC at 30° of knee flexion, but not at higher angle of knee flexion. Considering the IE rotations, the reconstruction was not sufficient not even to control a partial lesion of the PLC. These findings suggest that additional surgical procedures should be considerate even when facing combined PLC lesion. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to identify and summarize the evidence on the biomechanical parameters and the corresponding technologies which have been used to quantify the pivot shift test during the clinical and functional assessment of anterior cruciate ligament (ACL) injury and surgical reconstruction. Methods: Search strategy Internet search of indexed scientific articles on the PubMed database, Web of Science and references on published manuscripts. No year restriction was used. Selection criteria Articles included were written only in English and related to search terms: 'pivot shift' AND (OR 'ACL'). The reviewers independently selected only those studies that included at least one quantitative parameter for the analysis of the pivot shift test, including both in vitro and in vivo analyses performed on human joint. Those studies that analysed only clinical grading were excluded from the analysis. Analysis After evaluating the methodological quality of the articles, the parameters found were summarized. Results: Six hundred and eight studies met the inclusion criteria, and finally, 68 unique studies were available for the systematic review. Quantitative results were heterogeneous. The pivot shift test has been quantified by means of 25 parameters, but most of the studies focused on anterior-posterior translations, internal-external rotation and acceleration in anterior-posterior direction. Conclusion: Several methodologies have been identified and developed to quantify pivot shift test. However, clinical professionals are still lacking a 'gold standard' method for the quantification of knee joint dynamic laxity. A widespread adoption of a standardized pivot shift manoeuvre and measurement method to allow objective comparison of the results of ACL reconstructions is therefore desirable. Further development of measurement methods is indeed required to achieve this goal in a routine clinical scenario. Level of Evidence: Systematic review of-at least-level II studies, Level II. [ABSTRACT FROM AUTHOR]

Revision ACL presents many technical issues that are not seen in the primary ACL reconstruction. A variety of surgical techniques for revising ACL reconstruction have been described in the literature to address these concerns. The purpose of this article is to present a novel technique consisting in a non-anatomic double-bundle ACL revision reconstruction, using a fresh-frozen Achilles tendon allograft with soft tissue fixation. This technique is a valid treatment option when faced with a complex scenario such as ACL revision surgery. [ABSTRACT FROM AUTHOR]

Purpose: To assess the ability of anatomic double-bundle anterior cruciate ligament reconstruction in eliminating the pivot-shift phenomenon when identified by a quantitative measuring system (computer navigation or magnetic resonance imaging). Methods: Literature review. Medline, Google Scholar and Cochrane Reviews computerized databases research using the keywords 'pivot-shift,' 'anterior cruciate ligament reconstruction' and 'double bundle.' Twelve (7 in vitro and 5 in vivo) studies met the inclusion criteria. Results: There was a wide variation in the absolute value of translation and rotation measured after anatomic double-bundle anterior cruciate ligament reconstruction. There were also differences in fixation methods, pivot-shift execution conditions, applied stresses during the pivot-shift, calculation methods and reference systems utilized by measurement systems. Conclusions: The double-bundle reconstruction was shown to over-constrain the knee with respect to the intact value, especially closer to knee extension. This review demonstrated that anatomic double-bundle anterior cruciate ligament reconstruction is able to eliminate pathological translations and rotations during the pivot-shift phenomenon, as identified by quantitative measurement systems. Level of evidence: Review of Level III studies, Level III. [ABSTRACT FROM AUTHOR]

In this article, we discuss current topics for rotatory knee laxity. All tests for knee laxity have a value. Static knee laxity tests reveal information for each individual patient's laxity status, especially compared to the contralateral side. Static knee laxity tests are simple to do, and some of them are instrumented, therefore quantifiable. Dynamic knee laxity tests are more complex. Dynamic stereo radiography (DSX) is considered the gold standard. Utilizing DSX, information can be gained on 3-D kinematics, functional joint space, and joint contact patterns. The disadvantage is that DSX is expensive and can only be performed in a laboratory environment. The pivot shift test is a unique test, because it is dynamic and easily performed in the office. However, it is subjective and only recently quantifiable. Future endeavors will attempt to improve the value of the pivot shift test by standardizing the test and improving measurement technologies, while keeping the pivot shift test simple and non-invasive. [ABSTRACT FROM AUTHOR]

Purpose: The use of several different maneuvers for the pivot shift test has resulted in inconsistent quantitative measurements. The purpose of this study was to describe, analyze, and group several surgeon-specific techniques for the pivot shift test and to propose a standardized pivot shift test. Methods: Twelve expert surgeons examined a whole lower cadaveric extremity with their preferred technique and assigned a clinical grade, I-III. Anterior tibial translation and acceleration were measured using an electromagnetic system. The test was repeated after watching an instructional video focused on a standardized pivot shift technique. Measurements were repeated and compared with the preferred technique. Results: The expert surgeons utilized valgus stress unanimously in addition to fixed internal rotation (n = 5), fixed external rotation (n = 1), a motion-allowing technique ( n = 3), a dislocation-type maneuver ( n = 2), and a fixed anterior drawer type of maneuver in extension ( n = 1). Anterior tibial translation measured was on average 15.9 ± 3.7 mm. Average tibial acceleration was 3.3 ± 2.1 mm/s. Average clinical grading was 2.3 ± 0.5. There were no differences in average clinical grading when using high stress (2.5 ± 0.6) versus low stress (2.3 ± 0.5, n.s.), or using fixed rotation (2.2 ± 0.5) versus a motion-allowing technique (2.3 ± 0.6; n.s.). Conclusions: Clinical grading, tibial translation, and acceleration vary between examiners performing the pivot shift test. High forces and extremes of rotation are not necessary to produce a clinical detectable pivot shift. In the future, a standardized pivot shift test-which can be performed universally and utilizes only gentle forces allowing motion to occur-may be beneficial when assessing differences in outcome following ACL reconstruction. [ABSTRACT FROM AUTHOR]

Purpose: The variability of the pivot shift test techniques greatly interferes with achieving a quantitative and generally comparable measurement. The purpose of this study was to compare the variation of the quantitative pivot shift measurements with different surgeons' preferred techniques to a standardized technique. The hypothesis was that standardizing the pivot shift test would improve consistency in the quantitative evaluation when compared with surgeon-specific techniques. Methods: A whole lower body cadaveric specimen was prepared to have a low-grade pivot shift on one side and high-grade pivot shift on the other side. Twelve expert surgeons performed the pivot shift test using (1) their preferred technique and (2) a standardized technique. Electromagnetic tracking was utilized to measure anterior tibial translation and acceleration of the reduction during the pivot shift test. The variation of the measurement was compared between the surgeons' preferred technique and the standardized technique. Results: The anterior tibial translation during pivot shift test was similar between using surgeons' preferred technique (left 24.0 ± 4.3 mm; right 15.5 ± 3.8 mm) and using standardized technique (left 25.1 ± 3.2 mm; right 15.6 ± 4.0 mm; n.s.). However, the variation in acceleration was significantly smaller with the standardized technique (left 3.0 ± 1.3 mm/s; right 2.5 ± 0.7 mm/s) compared with the surgeons' preferred technique (left 4.3 ± 3.3 mm/s; right 3.4 ± 2.3 mm/s; both P < 0.01). Conclusion: Standardizing the pivot shift test maneuver provides a more consistent quantitative evaluation and may be helpful in designing future multicenter clinical outcome trials. Level of evidence: Diagnostic study, Level I. [ABSTRACT FROM AUTHOR]

The goal of anterior cruciate ligament (ACL) reconstruction surgery is to eliminate the pivot shift phenomenon. Different injury mechanisms and injury patterns may lead to specific knee laxity patterns. Computer navigation is helpful for the surgeon during examination under anesthesia. Surgical treatment may have to be altered if high-grade laxity is detected preoperatively for example by utilizing a computer navigation that is a helpful adjunct for surgeons during examination under anesthesia. A typical case for revision ACL reconstruction is presented. This article describes several techniques of laxity assessments. Based on the type and degree of pathologic laxity, a treatment algorithm has been developed. Level of evidence V. [ABSTRACT FROM AUTHOR]

Purpose: The pivot-shift phenomenon has been identified to be one of the essential signs of functional anterior cruciate ligament (ACL) insufficiency. However, the pivot-shift test remains a surgeon-subjective examination, lacking a general recognized quantitative measurement. The goal of the present study was to validate the use of an inertial sensor for quantifying the pivot-shift test, using a commercial navigation system. Methods: An expert surgeon intra-operatively performed the pivot-shift test on 15 consecutive patients before ACL reconstruction. A single accelerometer and a commercial navigation system simultaneously acquired limb kinematics. An additional optical tracker mounted on the accelerometer allowed following sensor movements. Anteroposterior (a-p) tibial acceleration obtained with the navigation system was compared with three-dimensional (3D) acceleration acquired by the accelerometer. The effect of skin artifacts and test-retest positioning were estimated. Repeatability of the acceleration parameter and waveform was analyzed. Correlation between the two measurements was also assessed. Results: Average root mean square (RMS) error in test-retest positioning reported a good value of 5.5 ± 2.9 mm. Mean RMS displacement due to soft tissue artifacts was 4.9 ± 2.6 mm. The analysis of acceleration range repetitions reported a good intra-tester repeatability (Cronbach's alpha = 0.86). Inter-patients similarity analysis showed a mean acceleration waveform correlation of 0.88 ± 0.14. The acceleration ranges demonstrated a good positive correlation between the two measurements (rs = 0.72, P < 0.05). Conclusion: This study showed good reliability of the new device and good correlation with the navigation system results. Therefore, the accelerometer is a valid method to assess dynamic joint laxity. Level of evidence: II. [ABSTRACT FROM AUTHOR]

The purposes of this paper are to summarize the concepts relating to the use of a combined intra-articular and extra-articular reconstructive procedure in the arthroscopic treatment of a torn ACL and to review several operative techniques utilizing gracilis and semitendinosus tendons that are currently in use to treat this instability. The highly satisfactory results obtained over the time show that a combination of intra- and extra-articular procedures for ACL reconstruction is a valid surgical option. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to compare subjective, objective and radiographic outcome of the lateralized single-bundle bone-patellar tendon-bone autograft with a non-anatomical double-bundle hamstring tendons autograft anterior cruciate ligament (ACL) reconstruction technique at long-term follow-up. Methods: Seventy-nine non-consecutive randomized patients (42 men; 37 women) with unilateral ACL insufficiency were prospectively evaluated, before and after ACL reconstruction by means of the above-mentioned techniques, with a minimum follow-up of 8 years (range 8-10 years; mean 8.6 years). In the double-bundle hamstrings technique, we used one tibial and one femoral tunnel combined with one 'over-the-top' passage, cortical staple's fixation and we left intact hamstrings' tibial insertion. Patients were evaluated subjectively and objectively, using IKDC score, Tegner level, manual maximum displacement test with KT-2000™ arthrometer. Radiographic evaluation was performed according to IKDC grading system, and re-intervention rate for meniscal lesions was also recorded. Results: The subjective and objective IKDC were similar in both groups while double-bundle hamstrings group showed significantly higher Tegner level ( P = 0.0007), higher passive range of motion recovery ( P = 0.0014), faster sport resumption ( P = 0.0052), lower glide pivot-shift phenomenon ( P = 0.0302) and lower re-intervention rate ( P = 0.0116) compared with patellar tendon group. Radiographic evaluation showed significant lower objective degenerative changes in double-bundle hamstrings group at final follow-up ( P = 0.0056). Conclusion: Although both techniques provide satisfactory results, double-bundle ACL reconstruction shows better functional results, with a faster return to sport activity, a lower re-operation rate and lower degenerative knee changes. [ABSTRACT FROM AUTHOR]

A biodegradable, hyaluronian-based biocompatible scaffold was used for autologous chondrocyte transplantation. This prospective study analyzes a clinical outcome of 70 consecutive patients treated by arthroscopic autologous chondrocyte transplantation at minimum 24 months follow up (47 of these patients achieved minimum 36 months follow-up and 21 patients minimum 48 months follow-up) in order to establish clear indication criteria for this type of treatment. 31 of these patients presented isolated chondral lesions, while 39 patients with associated lesions (23 ACL lesions, 28 meniscal lesions, 1 varus knee) were treated during the same surgical procedure with cartilage harvesting. A statistically significant clinical improvement was shown just at 24 months and the second-look arthroscopy demonstrated a complete coverage of the grafted area with a hyaline cartilage-like tissue in 12 of 15 analyzed patients. A better clinical outcome was observed in young, well-trained patients and in traumatic lesions. Other factors, such as defect size, localization, previous and associated surgery did not influence significantly the results. This matrix autologous chondrocyte transplantation procedure simplifies the surgical procedure and can be performed arthroscopically, thus reducing surgical morbidity and recovery time. [ABSTRACT FROM AUTHOR]

A variety of graft sources have been used for ACL reconstruction to improve functions and kinematics in ACL deficient knees. The two most commonly used autogenous grafts are the central third of the patellar tendon and the hamstring tendon constructs. The choice of different grafts and different construct influence the final clinical outcome of ACL reconstruction. The 3 groups, of 25 patients each, were generated by choosing the technique (PT tendon, 4 strand hamstring, and single hamstring plus extraarticular plasty) to utilize and followed for 5 years, with an alternate systematic sampling. Our comparison has shown significant kneeling pain in the patellar tendon with respect to the groups with hamstrings techniques. Single hamstring plus extraarticular plasty achieved subjective score significantly higher with respect to the other two groups as well as for the time to resume sport. The study confirms that patellar tendon and hamstring can be equivalent options for ACL reconstruction. This study demonstrated that a superior outcome as far as subjective clinical findings were concerned, was obtained in group III. Patients in the latter group were also able to return to sports sooner than those in the bone-patellar tendon graft group and the four-strand hamstring group. [ABSTRACT FROM AUTHOR]

This prospective study examined 50 patients who underwent ACL surgery using hamstring tendons with a modification including intra- and extra-articular reconstruction. All patients were athletes competing at a high level in various sports. Full return to sports was allowed at 4 months. IKDC score and KT-2000 were used for assessing clinical outcome at a mean of 6.4 years (5-7 years) Resumption of sport, Tegner activity score, and isokinetic test were also used. The IKDC score showed 92% of normal or nearly normal knees. Of the 50 patients 48 regained full extension, and only two had extension deficit between 0 degrees and 3 degrees. KT evaluation was less than 3 mm in 38 cases (76%), 3-5 mm in 9 (18%), and more than 5 mm in 3 (6%). In 90% of cases the patient resumed sport at the same level. The mean Tegner activity score was 8.1 (5-10). The isokinetic test showed no deficit for hamstring and quadriceps muscles. Removal of staples was necessary in eight cases (16%) due to femoral lateral bursitis. Acute reconstruction had significantly better clinical assessment of abnormal laxity and KT value. Men had significantly better results then women. This technique demonstrated a high reliability, low morbidity, low functional deficit and fast recovery using hamstring grafts. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate clinical ad radiological outcomes of anterior cruciate ligament (ACL) reconstruction with an immunochemically modified porcine patellar tendon xenograft controlled against human Achilles tendon allograft at 24-month minimum follow-up. Methods: 66 patients undergoing arthroscopic ACL reconstruction were randomized into 2 groups: 34 allografts and 32 xenografts treated to attenuate the host immune response. Follow-up was 24-month minimum. Anterior knee stability was measured as KT − 1000 side-to-side laxity difference (respect to the contralateral healthy knee). Functional performance was assessed by one-legged hop test. Objective manual pivot-shift test and subjective (IKDC, Tegner and SF-36) outcomes were collected. MRI and standard X-Ray were performed. Results: 61 subjects (32 allograft, 29 xenograft) were evaluated at 12 and 24 months. Six of the subjects in xenograft group (20.6%) got an infection attributed to a water-based pathogen graft contamination in processing. Intention-to-treat analysis (using the last observation carried forward imputation method) revealed higher KT − 1000 laxity in xenograft group at 24-month follow-up (P =.042). Also pivot-shift was higher in xenograft group at 12-month (P =.015) and 24-month follow-up (P =.038). Per-protocol analysis (missing/contaminated subjects excluded) did not revealed clinical differences between groups. Tibial tunnel widening in the allograft group was low, whereas xenograft tunnel widening was within the expected range of 20–35% as reported in the literature. No immunological reactivity was associated to xenograft group. Conclusions: High infection rate (20.6%) was reported in xenograft group. Both groups of patients achieved comparable clinical outcomes if missing/contaminated subjects are excluded. Improved harvesting/processing treatments in future studies using xenografts for ACL reconstruction are needed to reduce infection rate, otherwise xenograft should not be used in ACL reconstruction. Level of evidence: Multicenter and double-blinded Randomized Controlled Clinical Trial, Level I. [ABSTRACT FROM AUTHOR]

Background: Meniscus allograft transplantation (MAT) is a surgical procedure performed in patients complaining post-meniscectomy syndrome. Although the effectiveness of MAT on knee stability has been already demonstrated in cadaveric studies, its biomechanical role has been poorly evaluated in-vivo. Methods: A narrative review of the biomechanical effect of meniscectomy and MAT was performed. Furthermore, two cases were presented, of one patient who underwent Medial MAT and Anterior Cruciate Ligament (ACL) reconstruction, and one who underwent Lateral MAT. During the surgery, knee laxity was evaluated using a surgical navigation system. Results: AP laxity and IE rotation were reduced of 25% to 50% at both 30° and 90° of knee flexion after MAT transplantation. Discussion: In both cases, almost all the tests performed showed a reduction of knee laxity after meniscus transplant, when compared with pre-operative knee laxity. This assessment confirms the insights of previous in-vitro studies and underline a crucial role of MAT in knee biomechanics. [ABSTRACT FROM AUTHOR]

The author discusses the study "Individualized ACL reconstruction" by PH Araujo and others published in a 2014 issue of the periodical. The topics discussed include noninvasive assessment of pivot shift testing using computer software, grading of anterior cruciate ligament (ACL) injury, and the information on extraarticular tenodesis technique.

The authors comment on the issue on anterior cruciate ligament (ACL) of "Knee Surgery, Sports Traumatology, Arthroscopy," journal. They emphasize the value for researchers to always remember the words of an ancient Greek philosopher about wisdom in knowing that one knows nothing. Some of the questions that should be addressed to improve ACL injury treatment include biomechanics and kinematics of ACL.