Knee Anatomy & Biomechanics

Knee joint anatomy and biomechanics focusing on patellofemoral and tibiofemoral kinematics, maltracking, and the role of the finite helical axis in surgical planning.

Overview

Anatomic single- and double-bundle ACL reconstruction procedures are similarly effective for restoring near-normal dynamic knee function [1], yet neither technique fully restores normal knee kinematics [1]. Conventional non-anatomic ACL reconstruction techniques fail to restore normal dynamic knee function and do not prevent early osteoarthritis [9]. While restoring anatomy may be the key to success, high-quality prospective randomized trials with precise outcome measures are needed to validate benefits [9]. Combined flexion influences knee biomechanics, though its direct impact on clinical outcomes remains unclear [2].

In total knee arthroplasty, functional knee phenotypes enable a simple, detailed assessment of individual anatomy based on native alignment in young non-osteoarthritic patients [4] and could serve as a helpful tool to individualize the approach [4]. Functional alignment in total knee arthroplasty best achieves balanced gaps and minimal bone resections compared to mechanical and kinematic alignment strategies [77], whereas implant alignment to the mechanical axis or joint line anatomy alone does not guarantee a balanced total knee arthroplasty [77]. Surgical technique, implant design features such as posterior condylar offset and femoral position, and articular constraints significantly influence knee arthroplasty kinematics [76].

Current implant designs do not replicate the kinematics of a healthy knee [13], though anatomy-mimetic designs preserve natural kinematics in patient-specific mobile-bearing unicompartmental knee arthroplasty [10] and tibiofemoral conformity is important for preserving native knee kinematics [10]. Reconstructed knees may be subjected to significantly lower rotational loads compared with the intact knee during combined in vivo loading maneuvers [78]. Future implant generations allowing for changes in the functional flexion axis may give patients a more 'natural' feeling knee [64], but it remains unclear how much implant mismatch is tolerable or if anatomical designs will improve clinical outcomes [65].

Anatomy & Pathophysiology

Kinematics and Biomechanics

Knee alignment is dynamic and varies between individuals depending on posture [16]. While combined flexion influences knee biomechanics, its direct impact on clinical outcomes remains unclear [2]. Jump direction significantly alters biomechanics, with lateral jumps representing the most dangerous stop-jump variant [27]. Boys exhibit greater knee frontal moments than girls during the impact phase of cutting maneuvers [40]. Kinematics of normal knees during high flexion vary according to the specific activity performed [35].

Osseous Morphology and Alignment

Correlations between knee kinematics and morphologic measures of the femoral transcondylar axis indicate these metrics are valuable for characterizing how femur shape influences dynamic function [3]. Analysis of the sagittal curvature of the femoral trochlea may aid in understanding knee kinematics and developing physiological prostheses [32]. Subtle modifications to the knee joint line can trigger widespread kinematic adaptations, highlighting the integrated nature of gait biomechanics [6]. In patients with constitutional varus, mechanical alignment in total knee arthroplasty yields more balanced load distribution and kinematics closer to the native knee [5]. Conversely, the kinematically aligned knee demonstrates greater multi-planar mobility, higher sagittal moments, and a more physiological gait pattern compared to the mechanically aligned knee [29].

Implant Design and Function

Contemporary knee implant designs investigated did not replicate the kinematics of a healthy knee [13]. Tibiofemoral conformity is critical for preserving native knee kinematics in patient-specific mobile-bearing unicompartmental knee arthroplasty [10]. The BCS cohort demonstrated expected knee joint kinematics [8]. However, kinematics alone is not the most relevant parameter to predict or explain knee function after total knee arthroplasty [15]. Knee motion patterns observed during sit-to-stand and stand-to-sit activities differ from normal kinematics and are derived from the unique design of the Bi-Surface PS [28]. Femoral external rotation may result in worse knee biomechanics than internal rotation [38]. A method exists to investigate the effect of different implant positions on knee biomechanics after total knee arthroplasty using a VIVO joint simulator without modifying the physical setup [37].

Ligamentous Function and Reconstruction

Anatomic single-bundle and double-bundle ACL reconstruction are similarly effective for restoring near-normal dynamic knee function, though neither fully restores normal knee kinematics [1]. There are no differences in knee kinematics between double-bundle and single-bundle central femoral tunnel techniques [30]. The anterior cruciate ligament provides resistance to externally applied anterior tibial force but not to internal rotational torque during simulated weight-bearing flexion [39].

Classification

Functional Knee Phenotyping: This system enables a simple, detailed assessment of individual anatomy based on native coronal lower limb alignment in young non-osteoarthritic patients [4]. Phenotype analysis using this framework demonstrates a wide diversity of coronal alignment phenotypes among knees with anteromedial osteoarthritis [55].

CT-Based Morphological Classification: CT-based phenotyping establishes a 3D classification of arthritic knee anatomy into 4 foundational morphologies, with types 1 and 3 representing outliers present in 26% of knees undergoing total knee arthroplasty [46].

Other Considerations: Anatomic single- and double-bundle ACL reconstruction procedures are similarly effective for restoring near-normal dynamic knee function, though neither fully restores normal knee kinematics [1]. Correlations between knee kinematics and morphologic measures describing the position and orientation of the femoral transcondylar axis suggest these measures are valuable for characterizing the influence of femur shape on dynamic knee function [3]. Mechanical alignment in total knee arthroplasty results in more balanced load distribution and kinematics more closely resembling the native knee in patients with constitutional varus [5]. Static native tibial alignment in total knee arthroplasty optimizes whole-body gait kinematics, suggesting subtle modifications to the knee joint line contribute to widespread kinematic adaptations [6]. Knee alignment is different in different individuals and is dynamic in nature, changing with different postures [16]. The anatomy of the knee includes bone structure, vascular and nerve supply, ligamentous organization, and functional mechanics relevant to stability and injury [22]. An intricate relationship exists among the main medial knee structures and their individual components for static function to applied loads [49]. The terminology 'Functional Knee Positioning' underscores a 3D scope, a focus on anterior knee compartment geometry and function, and reliance on the soft tissue envelope as the 'DNA' of the knee [50]. The anatomy of the knee has been described in depth with the addition of the newly recognized anterolateral ligament [54]. Although the knee adduction moment was similar between hamstring and patellar tendon anterior cruciate ligament reconstructed knees, the overall magnitude of the moment was influenced by different biomechanical factors [56]. Asymmetric cylindrical features of the distal part of the femur dictate a single flexion-extension axis throughout a majority of the knee arc of motion [58]. While a difference in knee kinematics may not be observable with different graft fixation sequences in double-bundle anterior cruciate ligament reconstruction, fixation sequence can alter the in situ forces that the grafts bear under knee loading [59].

Clinical Presentation

A careful history and effective physical examination remain the foundation for diagnosing knee instability, requiring information from multiple tests to reach a final diagnosis [19]. For a large proportion of patients, a musculoskeletal examination without imaging is sufficient to diagnose or exclude common knee disorders [7]. Clinically relevant kinetics assist in determining both the clinical risk of injury and the likely presentation of singular or concomitant knee injuries [20].

Functional knee phenotypes enable a simple yet detailed assessment of a patient's individual anatomy and may serve as a helpful tool to individualize the approach to total knee arthroplasty [4]. Correlations between knee kinematics and morphologic measures describing the position and orientation of the femoral transcondylar axis suggest these measures are valuable for characterizing the influence of femur shape on dynamic knee function [3]. The application of functional knee phenotyping to knee osteoarthritis in Japan suggested the presence of racial morphological characteristics [44].

Diagnosis of abnormal knee hyperextension involves a combination of multiple ligament and soft tissue structures without one primary restraint [33]. Careful and systematic exploration of the posteromedial part of the knee is important for diagnosing meniscal ramp lesions, for which recent studies have provided important knowledge regarding anatomy, epidemiology, diagnosis, and biomechanical consequences [14]. Knowledge of the prevalence, size, shape, and location of the semimembranosus-tibial collateral ligament bursa aids in the differential diagnosis of medial knee pain [42]. Understanding typical patterns of bone and soft-tissue pathology in the valgus arthritic knee is critical for appropriate surgical planning [43].

Gait analysis provides key biomechanical markers relevant to common knee pathologies [31]. Patients with severe unilateral osteoarthritis of the knee are at risk from abnormal biomechanics in the contralateral knee and both hips [18]. In young patients, the pathogenesis of knee osteoarthritis is predominantly related to an unfavorable biomechanical environment at the joint, where mechanical demand exceeds the ability of a joint to repair and maintain itself, predisposing articular cartilage to premature degeneration [34].

Anatomic single- and double-bundle ACL reconstruction procedures are similarly effective for restoring near-normal dynamic knee function, though neither fully restores normal knee kinematics [1]. Combined flexion influences knee biomechanics, but its direct impact on clinical outcomes remains unclear [2]. The medial rotation knee exhibited motion patterns similar to those observed in the normal knee during tibiofemoral kinematic analysis of knee flexion, yet exhibited less tibial rotation than the normal knee [21]. High tibial slope correlates with increased posterior tibial translation in healthy knees [36].

Kinematic alignment recreates femoral trochlear geometry more closely than mechanical alignment in total knee arthroplasty, though variability across knees exists regarding this recreation, warranting further research to evaluate clinical implications [17]. Understanding intraosseous innervation of the human patella may improve understanding of the pathophysiology of anterior knee pain syndromes [41]. The chapter provides a comprehensive review of the anatomy and biomechanics of the knee, including bone structure, vascular and nerve supply, ligamentous organization, and functional mechanics relevant to stability and injury [22].

Investigations

Plain radiography: Plain radiographs serve as the appropriate initial imaging study for most knee conditions [52]. Comprehensive qualitative and quantitative guidelines exist for assessing posterolateral knee structures on both anteroposterior and lateral views [24]. However, radiographic methods used to localize the femoral attachments of lateral knee structures may not be reliable [79]. While articular cartilage is not well represented on radiography, it significantly affects distal femoral geometry and must be considered when evaluating the patellofemoral joint [85]. Musculoskeletal examination without imaging may suffice to diagnose or exclude common knee disorders in a large proportion of patients [7].

MRI: MRI scanning accurately assesses the anterolateral knee ligament with findings similar to anatomic dissection [57] and is accurate for identifying posterolateral knee complex injuries [69]. Three-dimensional MRI allows full visualization of the anterolateral ligament (ALL) in all normal knees [66]. Kinematic MRI provides a reproducible method to quantify total knee rotation [60]. Additional axial plane imaging at 20° of flexion is beneficial for symptomatic cases with inconspicuous conventional MRI findings [61]. Conventional knee MRIs performed in slight flexion yield consistently smaller measurements compared to whole-leg rotational MRI acquired in full extension [62]. The menisci generate a more horizontal tibial slope when measured on two-dimensional MRI [67]. Assessment of medial cartilage thickness loss via MRI offers additional utility over standard radiographs for preoperative planning in medial unicompartmental knee arthroplasty patients [89]. The popliteofibular ligament (PFL) is a constant or rarely absent structure per cadaveric dissection [88], though it is identified notably less frequently on MRI [88].

CT: Advanced imaging such as CT provides enhanced detail for specific bone and implant assessments [52]. Differences in bone area and 3DJSW biases between CT and MR images likely stem from variations in bone/cartilage boundary identification and knee pose during acquisition [84].

Other Considerations: Anatomic single- and double-bundle ACL reconstruction procedures are similarly effective for restoring near-normal dynamic knee function, though neither fully restores normal knee kinematics [1]. The medial rotation knee exhibits motion patterns similar to the normal knee but with less tibial rotation [21]. Displacements of the meniscus during knee-joint flexion align with earlier in vivo MRI studies, validating the loading model [86]. A novel ultrasound scanning approach demonstrates diagnostic performance similar to routine MRI for knee cartilage defects [73].

Treatment

Non-Operative

Nonoperative management is a viable option for specific cohorts; athletically active patients with acute isolated posterior cruciate ligament tears treated nonoperatively achieved a level of objective and subjective knee function that was independent of the grade of laxity [93]. Musculoskeletal examination without imaging may be sufficient to diagnose or exclude common knee disorders for a large proportion of patients [7]. However, high-quality data do not exist on the natural history of untreated meniscus tears nor whether management alters the natural history of knee function and health [12].

Operative

Indications: Surgical management of complex knee pathologies often requires concomitant procedures for the success of any single procedure [87]. Orthopaedic surgeons must understand joint preservation techniques including biologic and reconstructive approaches in young, high-demand patients [87]. Medial opening wedge high tibial osteotomy with early full weight bearing is a highly successful course of treatment for correcting knee malalignment in patients with medial compartment osteoarthritis [48]. If specific thresholds are not met during planning, other types of surgery may need to be considered to avoid early progression of patellofemoral cartilage injuries after medial open-wedge high tibial osteotomy [83].

Surgical Approach / Technique: Anatomical definitions of medial collateral and posterior oblique ligament attachments facilitate repairs and reconstructions that restore physiological laxity and stability patterns across the arc of knee flexion [23]. Comprehensive qualitative and quantitative guidelines exist for assessing posterolateral knee structures on anteroposterior and lateral knee radiographs [24]. Anatomical posterolateral reconstruction with an anatomical bone–patellar tendon–bone reconstruction of the fibular collateral ligament restores normal limits to lateral joint opening and external tibial rotation [45]. Anatomical posterolateral reconstruction allows immediate knee motion and appears to protect other soft tissue repairs [45]. Anatomical ACL reconstruction has a biomechanical advantage in anterior tibial translation when compared with non-anatomical ACL reconstructions in porcine knees [94]. Anatomical ACL reconstruction does not cause PCL impingement [94].

Implant Selection: Tibiofemoral conformity is important for preserving native knee kinematics in patient-specific mobile-bearing unicompartmental knee arthroplasty [10]. Restoring native knee geometry together with ACL preservation provides kinematic improvements over contemporary ACL-preserving and ACL-sacrificing implants [53]. None of the analysed surgical patellar interventions could restore natural patellar kinematics after total knee arthroplasty [91].

Alignment / Balancing Strategy: Kinematic alignment recreates femoral trochlear geometry more closely than mechanical alignment in total knee arthroplasty, though variability across knees warrants further research [17]. Setting an individualized alignment target according to the original knee phenotype is rational and practical for total knee arthroplasty [11]. Functional knee phenotypes enable a simple, detailed assessment of a patient's individual anatomy to help individualize the approach to total knee arthroplasty [4]. The knee rotation angle might meet the requirements for precise diagnostics in knee realignment surgery [82].

Adjuncts: Combined flexion influences knee biomechanics in robotic total knee arthroplasty, but its direct impact on clinical outcomes remains unclear [2]. A noninvasive device is a useful and valuable tool to investigate preoperative and postoperative influences on tibiofemoral rotation and provides additional objective information on knee kinematics in a simple, reproducible manner [96].

Other Considerations: Anatomic single- and double-bundle ACL reconstruction both restore dynamic knee function, though neither fully restores normal knee kinematics [1]. Anatomic single- and double-bundle ACL reconstructions are similarly effective for restoring near-normal dynamic knee function [1]. Conventional non-anatomic ACL reconstruction techniques do not prevent early osteoarthritis nor restore normal dynamic knee function [9]. Double-bundle PCL reconstructions may better restore normal knee kinematics than single-bundle reconstructions, although clinical outcomes have not revealed such a difference [47]. None of the three evaluated ACL reconstruction techniques (anteromedial portal, outside-in, and transtibial) could completely restore normal knee joint laxity and ACL forces [95]. Clinical evidence is currently lacking to support clear indications for lateral extra-articular procedures as an augmentation to ACL reconstruction [81]. Knee kinematics is altered post-fatigue while performing a crossover task, suggesting interventions should promote appropriate frontal plane alignment and increased knee flexion during fatigue [51]. Higher knee moments in the non-arthroscopic partial meniscectomy leg may have clinical implications for the noninvolved leg [70].

Complications

Instability: Diagnosing knee instability requires information from multiple physical examination tests [19]. While ACL remnants contribute to anteroposterior stability at 30° of flexion for up to 1 year post-injury, this biomechanical function is subsequently lost [25]. Neither anatomic single- nor double-bundle ACL reconstruction fully restores normal knee kinematics [1], and landing biomechanics remain altered post-reconstruction, though they tend to recover by 3 years [63]. Abnormal contact mechanics in ACL deficiency may predispose the knee to degenerative arthritis [90]. Furthermore, retention of the posterior cruciate ligament alone may not achieve physiological knee joint kinematics after total knee arthroplasty [8].

Aseptic loosening: Ten-year survivorship free from aseptic loosening after total knee arthroplasty following distal femoral osteotomy is 95% [72].

Other Considerations: Mechanical alignment in total knee arthroplasty for patients with constitutional varus results in more balanced load distribution and kinematics more closely resembling the native knee [5], whereas setting an individualized alignment target according to the original knee phenotype is rational and practical [11]. Correlations between knee kinematics and morphologic measures of the femoral transcondylar axis suggest these measures are valuable for characterizing the influence of femur shape on dynamic knee function [3]. Subtle modifications to the knee joint line may contribute to widespread kinematic adaptations in whole-body gait [6]. Patients with severe unilateral osteoarthritis are at risk from abnormal biomechanics in the contralateral knee and possibly both hips [18]. High-quality data do not exist on the natural history of untreated meniscus tears or whether management alters the natural history of knee function and health [12]. Patients with a preoperative duration of symptomatic medial knee overload or arthritis of two years or greater do not experience inferior patient-reported outcomes compared to those with a symptom duration of less than 2 years [26]. Knee malalignment and meniscal laterality significantly influence 2-year outcomes following meniscal tear repair, with medial tears and malalignment associated with higher nonhealing rates [71]. Long-term knee flexor strength deficits exist following hamstring autograft use for ACL reconstruction, a deficit that does not occur when a tibialis anterior allograft is used [68]. The direct impact of combined flexion on clinical outcomes in robotic total knee arthroplasty remains unclear despite its influence on knee biomechanics [2]. Total knee arthroplasty after distal femoral osteotomy has a high complication rate secondary to problems with balancing the knee [72], and total knee arthroplasty after high tibial osteotomy has a relatively high complication incidence, though no knees required revision in the early experience described [92].

Recovery

Light activity (weeks): Evidence does not specify a week range for light activity or return to desk work. While anatomic single-bundle [1] and double-bundle [1] ACL reconstructions restore near-normal dynamic knee function, conventional non-anatomic techniques fail to restore normal dynamic function [9]. In total knee arthroplasty, mechanical alignment results in more balanced load distribution and kinematics resembling the native knee in patients with constitutional varus [5], whereas kinematic alignment restores native patellar tracking patterns more closely [97].

Full activity (months): The evidence does not provide a specific month range for full activity or return to sport. ACL remnants contribute to anteroposterior stability at 30° of flexion for up to 1 year after injury, but this biomechanical function is lost beyond 1 year [25]. Anatomical reconstruction of the posterolateral complex using the long head of the biceps femoris tendon effectively restores posterolateral stability [80]. Defined bone attachments of the medial collateral and posterior oblique ligaments facilitate repairs that restore physiological laxity and stability patterns across the arc of knee flexion [23].

Complete recovery / outcome plateau (months): Patients with a preoperative duration of symptomatic medial knee overload or arthritis of two years or greater do not experience inferior patient-reported outcomes or clinical outcomes at mid-term follow-up compared to those with symptom duration of less than 2 years [26]. Kinematics is neither the only nor the most relevant parameter to predict knee function after total knee arthroplasty [15]; improving long-term outcomes requires integrating static images with dynamic and kinetic insights rather than relying solely on static alignment concepts [75]. Studies are needed to evaluate the clinical impact of double-bundle reconstruction techniques on long-term functional outcomes [74].

Rehabilitation protocol: No specific rehabilitation protocols, immobilisation durations, or weight-bearing progressions are detailed in the provided evidence. The direct impact of combined flexion on clinical outcomes in robotic total knee arthroplasty remains unclear despite its influence on biomechanics [2]. The anterior lateral ligament (ALL) does not exhibit isometric behavior at any femoral insertion locations and shows different length change patterns during knee flexion and internal tibial rotation at 90 degrees [98].

Functional milestones: Clinically relevant kinetics can determine the clinical risk of injury and the likely presentation of singular or concomitant knee injury [20]. Morphologic measures describing the position and orientation of the femoral transcondylar axis correlate with in vivo knee translational and rotational kinematics and are valuable for characterizing the influence of femur shape on dynamic knee function [3]. The BCS cohort demonstrated expected knee joint kinematics after retention of the posterior cruciate ligament alone [8].

Other Considerations: High-quality data do not exist on the natural history of untreated meniscus tears in children and adolescents, nor on whether management alters knee function and health in this population; existing studies are limited to case series without comparative data [12]. Neither anatomic single- nor double-bundle ACL reconstruction fully restores normal knee kinematics [1]. Conventional non-anatomic ACL reconstruction techniques do not prevent early osteoarthritis [9]. Setting an individualized alignment target according to the original knee phenotype is rational and practical for total knee arthroplasty [11].

Key Evidence

• [L1] While neither procedure fully restored normal knee kinematics, both anatomic reconstructions were similarly effective for restoring near-normal dynamic knee function. (10.1007/s00167-021-06479-x)
• [L3] Although combined flexion influences knee biomechanics, its direct impact on clinical outcomes remains unclear. (10.1002/ksa.12660)
• [L3] Correlations between knee kinematics and morphologic measures describing the position and orientation of the femoral transcondylar axis suggest that these specific measures are valuable for characterizing the influence of femur shape on dynamic knee function. (10.1007/s00167-011-1661-3)
• [L3] The functional knee phenotypes enable a simple, but detailed assessment of a patient's individual anatomy and thereby could be a helpful tool to individualize the approach to TKA. (10.1007/s00167-019-05509-z)
• [L5] Mechanical alignment seems to result in more balanced load distribution and kinematics more closely resembling the native knee. (10.1007/s00167-020-05996-5)
• [L3] These findings underscore the integrated nature of gait biomechanics and suggest that subtle modifications to the knee joint line may contribute to widespread kinematic adaptations. (10.1002/ksa.70356)
• [L2] The musculoskeletal examination without imaging may be sufficient to diagnose or exclude common knee disorders for a large proportion of patients. (10.1186/s12891-017-1799-3)
• [L3] The BCS cohort showed expected knee joint kinematics. (10.2106/jbjs.20.00024)
• [L5] Conventional non-anatomic ACL reconstruction techniques do not prevent early osteoarthritis nor restore normal dynamic knee function; restoring anatomy may be the key to success, but high-quality prospective randomized trials with precise outcome measures are needed to validate benefits. (10.1007/s00167-010-1222-1)
• [L5] These results confirm the importance of tibiofemoral conformity in preserving native knee kinematics. (10.1007/s00167-019-05540-0)
• [L4] Setting individualized alignment target according to original knee phenotype is rational and practical. (10.1186/s12891-020-03862-6)
• [L5] The knee implant designs investigated did not replicate the kinematics of a healthy knee. (10.2106/jbjs.h.00817)
• [L5] Although more research is still necessary, several recent studies have given us important knowledge about the anatomy, epidemiology, diagnosis, and the biomechanical consequences of these tears, highlighting the importance of the careful and systematic exploration of the posteromedial part of the knee. (10.1007/s00167-022-07292-w)
• [L5] The results confirm the hypothesis that kinematics is not the only and also not the most relevant parameter to predict or explain knee function after TKA. (10.1007/s00167-015-3514-y)
• [L4] Knee alignment is different in different individuals and is dynamic in nature, changing with different postures. (10.1302/0301-620x.97b4.33740)
• [L4] Variability across knees was observed, warranting further research to evaluate the clinical implications of these findings. (10.1302/0301-620x.106b8.bjj-2023-1209.r1)
• [L3] Patients with severe unilateral OA of the knee are at risk from abnormal biomechanics in the contralateral knee, and possibly both hips. (10.1302/0301-620x.95b3.30850)
• [L5] A careful history and effective physical examination continue to serve as the foundation of orthopaedic sports medicine for diagnosing knee instability, with information from multiple tests required to reach a final diagnosis. (10.1177/0363546507312641)
• [L5] Thus, with clinically relevant kinetics, it is possible to determine clinical risk of injury and also the likely presentation of singular or concomitant knee injury. (10.1177/0363546520939946)
• [L4] The medial rotation knee exhibited motion patterns similar to those observed in the normal knee, but less tibial rotation. (10.1007/s00167-009-0777-1)
• [L5] These data facilitate repairs and reconstructions that can restore physiological laxity and stability patterns across the arc of knee flexion. (10.1007/s00167-020-06139-6)
• [L5] Comprehensive qualitative and quantitative guidelines for assessing posterolateral knee structures on both anteroposterior and lateral knee radiographs were described. (10.1177/0363546508328117)
• [L3] In groups 1 and 2 ACL remnants contributed to anteroposterior knee stability evaluated at 30° of knee flexion for up to 1 year after injury, beyond which this biomechanical function was lost. (10.1016/j.arthro.2010.04.076)
• [L4] Patients with a preoperative duration of symptomatic medial knee overload/arthritis of two years or greater do not experience inferior PRO or clinical outcomes than patients with a symptom duration of less than 2 years at mid-term follow-up. (10.1016/j.jisako.2022.03.003)
• [L3] Jump direction significantly influenced knee biomechanics, suggesting that lateral jumps are the most dangerous of the stop-jumps. (10.1177/0363546505278696)
• [L4] This study demonstrated that the knee motion kinematic patterns observed in this study were not similar to normal knee kinematics and derived from the unique design of the Bi-Surface PS. (10.1186/s13018-016-0482-y)
• [L4] The kinematically aligned knee showed greater multi-planar mobility, higher sagittal moments, and a more physiological gait pattern compared to the mechanically aligned knee. (10.1186/s12891-025-09445-7)
• [L5] There were no differences in knee kinematics between the DB and SB-central techniques. (10.1177/0363546515611646)
• [L4] This narrative review aims to bridge the gap in clinical integration of gait analysis by providing a step-by-step guide for orthopaedic surgeons and clinicians to understand and interpret key biomechanical markers relevant to common knee pathologies. (10.1002/ksa.70067)
• [L4] The results of the current study may be helpful to improve the understanding of the knee kinematics and develop the physiological knee prostheses. (10.1007/s00167-011-1679-6)
• [L5] Diagnosis of abnormal knee hyperextension involves a combination of multiple ligament and soft tissue structures without 1 primary restraint. (10.1177/03635465231155203)
• [L4] In the young patient, the pathogenesis of knee osteoarthritis is predominantly related to an unfavorable biomechanical environment at the joint, which results in mechanical demand that exceeds the ability of a joint to repair and maintain itself, predisposing the articular cartilage to premature degeneration. (10.1007/s00167-011-1818-0)
• [L4] The kinematics of normal knees during high flexion are variable according to activity. (10.1302/0301-620x.100b1.bjj-2017-0553.r2)
• [L3] This finding may facilitate estimation of posterior knee laxity in clinical routine and has implications for knee surgery. (10.1007/s00167-017-4706-4)
• [L5] The paper presents a method to investigate the effect of different implant positions on the biomechanics of the knee after total knee arthroplasty using a VIVO joint simulator without modifying the physical setup. (10.1186/s42836-025-00351-w)
• [L5] Femoral external rotation may result in worse knee biomechanics than internal rotation. (10.1016/j.jisako.2025.100866)
• [L5] The study established an experimental protocol to measure knee kinematics during weight-bearing flexion. (10.1016/j.arthro.2010.04.069)
• [L2] The role of kinematics in mediating the KFM0-70 provides means for modification of this risk factor, but as boys had higher joint moments, continued investigation into sex-dependent biomechanical risk factors is warranted. (10.1007/s00167-023-07340-z)
• [L5] A better understanding of these nerves may improve understanding the pathophysiology of anterior knee pain syndromes. (10.1177/0363546506297968)
• [L5] Knowledge of its prevalence, size, shape, and location aids in the differential diagnosis of medial knee pain. (10.2106/00004623-199409000-00007)
• [L5] Understanding the typical patterns of bone and soft-tissue pathology in the valgus arthritic knee is critical for appropriate surgical planning. (10.1302/0301-620x.99b1.bjj-2016-0340.r1)
• [L4] The application of functional knee phenotyping to knee osteoarthritis in Japan suggested the presence of racial morphological characteristics. (10.1002/ksa.12028)
• [L4] The anatomical posterolateral procedure was effective in restoring normal limits to lateral joint opening and external tibial rotation, allowed immediate knee motion, and appeared to protect other soft tissue repairs. (10.1177/0363546506293704)
• [L4] CT-based phenotyping established a 3D classification of arthritic knee anatomy into 4 foundational morphologies, of which types 1 and 3 represent outliers present in 26% of knees undergoing TKA. (10.2106/jbjs.24.01466)
• [L4] Double-bundle reconstructions may better restore normal knee kinematics than single-bundle reconstructions, although clinical outcomes have not revealed such a difference. (10.1177/0363546511416316)
• [L4] Overall, this combination was a highly successful course of treatment for correcting knee malalignment in patients with medial compartment osteoarthritis. (10.1016/j.arthro.2008.08.015)
• [L5] An intricate relationship exists among the main medial knee structures and their individual components for static function to applied loads. (10.1177/0363546509333852)
• [L5] The editorial highlights the rationale for transitioning the terminology to 'Functional Knee Positioning', underscoring its 3D scope, its focus on anterior knee compartment geometry and function, and its reliance on the soft tissue envelope as the 'DNA' of the knee. (10.1002/ksa.12667)
• [L3] Interventions should attempt to reduce the negative effects of fatigue on lower extremity biomechanics by promoting appropriate frontal plane alignment and increased knee flexion during fatigue status. (10.1007/s00167-013-2673-y)
• [L3] Phenotype analysis using the functional knee phenotype system demonstrated a wide diversity of coronal alignment phenotypes among knees with anteromedial osteoarthritis. (10.1002/ksa.12043)
• [L3] Although the knee adduction moment was similar between the two graft types, the overall magnitude of the moment was influenced by different biomechanical factors. (10.1007/s00167-011-1835-z)
• [L5] MRI scanning can accurately assess the anterolateral knee ligament and demonstrates findings similar to those obtained from anatomic dissection. (10.1177/2325967115621024)
• [L5] This exhibit provides kinematic and morphologic validation for a single cylindrical flexion-extension axis of the knee, demonstrating that the asymmetric cylindrical features of the distal part of the femur dictate a single flexion-extension axis throughout a majority of the knee arc of motion. (10.2106/00004623-200300004-00012)
• [L5] While a difference in knee kinematics may not be observable with different graft fixation sequences, fixation sequence can alter the in situ forces that the grafts bear under knee loading. (10.1007/s00167-014-3158-3)
• [L3] Kinematic MRI is a reproducible method to quantify total knee rotation. (10.1007/s00167-011-1809-1)
• [L4] In particular, symptomatic cases with inconspicuous conventional MRI imaging, additional MRI imaging only in the axial plane in a 20° of knee flexion could be beneficial and useful in clinical daily routine. (10.1186/s12891-021-04733-4)
• [L2] Conventional knee MRIs, performed with the knee in slight flexion, are consistently smaller compared to those acquired in full extension whole-leg rotational MRI. (10.1002/ksa.70237)
• [L2] Landing biomechanics are altered after ACLR but biomechanical abnormalities tend to recover at 3 years after ACLR. (10.1016/j.arthro.2018.07.033)
• [L5] Anthropometric data will help to improve the understanding of the bony morphology in relation to the knee, though it remains unclear how much implant mismatch is tolerable or if anatomical designs will improve clinical outcomes. (10.1007/s00167-014-3391-9)
• [L4] Three-dimensional MRI allows full visualization of the ALL in all normal knees. (10.1016/j.arthro.2018.02.014)
• [L3] The menisci of the knee generate a more horizontal tibial slope when measured on MRI. (10.1007/s00167-012-1990-x)
• [L3] Long-term knee flexor strength deficits exist following hamstring autograft use for ACL reconstruction that does not occur when a tibialis anterior allograft is used. (10.1007/s00167-009-0931-9)
• [L3] Magnetic resonance imaging of the knee was accurate in the identification of posterolateral knee complex injuries. (10.1177/03635465000280020901)
• [L3] Higher knee moments in the non-APM leg may have clinical implications for the noninvolved leg. (10.1177/0363546517698934)
• [L3] Knee malalignment and meniscal laterality significantly influence 2-year outcomes following meniscal tear repair, with medial tears and malalignment associated with higher nonhealing rates. (10.1002/ksa.12602)
• [L3] Ten-year survivorship free from aseptic loosening was 95% with reliable improvement in clinical function, though there was a high complication rate secondary to problems with balancing the knee. (10.1302/0301-620x.101b6.bjj-2018-1334.r2)
• [L2] The novel US scanning approach allows similar diagnostic performance compared to routine MRI for knee cartilage defects. (10.1186/s13018-018-0887-x)
• [L5] Studies are needed to evaluate the clinical impact of double-bundle reconstruction techniques on long-term functional outcomes. (10.5435/00124635-200702000-00003)
• [L5] Improving long-term outcomes after total knee arthroplasty requires moving beyond the static concept of 'correct alignment option' to integrate static images with dynamic and kinetic insights. (10.1002/ksa.70010)
• [L4] Surgical technique, implant design features such as posterior condylar offset and femoral position, and articular constraints significantly influence knee arthroplasty kinematics, including range of motion, axial rotation, and impingement risks. (10.2106/00004623-200300004-00008)
• [L2] Implant alignment to the mechanical axis or joint line anatomy alone does not guarantee a balanced total knee arthroplasty. (10.1007/s00167-023-07567-w)
• [L3] During such maneuvers, the reconstructed knee may be subjected to significantly lower rotational loads compared with the intact knee. (10.1016/j.arthro.2011.06.028)
• [L4] Therefore, radiographic methods used to localize the femoral attachments of the lateral knee structures may not be reliable. (10.1016/j.arthro.2020.07.006)
• [L4] Anatomical reconstruction of the knee posterolateral complex with the tendon of the long head of biceps femoris is effective in restoring knee posterolateral stability. (10.1177/0363546506288112)
• [L5] Clinical evidence is currently lacking to support clear indications for lateral extra-articular procedures as an augmentation to ACL reconstruction. (10.1007/s00167-018-5072-6)
• [L2] The knee rotation angle might meet the requirements for precise diagnostics in knee realignment surgery. (10.1007/s00167-015-3919-7)
• [L4] If these thresholds are met during planning, other types of surgery may need to be considered to avoid early progression of patellofemoral cartilage injuries. (10.1007/s00167-018-5128-7)
• [L2] Differences in bone area and 3DJSW biases are likely due to differences in the bone/cartilage boundary identification and knee pose during acquisition. (10.1186/s12891-023-06187-2)
• [L4] Articular cartilage is not well represented on radiography yet it had a significant effect on the distal femoral geometry, and should be taken into account when evaluating the patellofemoral joint. (10.1007/s00167-003-0414-3)
• [L5] The displacements of the meniscus during knee-joint flexion were similar to displacements in earlier in vivo MRI studies, validating the loading model. (10.1007/s00167-004-0511-y)
• [L5] Surgical management of complex knee pathologies often requires concomitant procedures for the success of any single procedure, and orthopaedic surgeons must understand joint preservation techniques including biologic and reconstructive approaches in young, high-demand patients. (10.5435/jaaos-d-17-00087)
• [L1] The PFL was found to be a constant or rarely absent anatomic structure of the human knee according to the analysis of cadaveric dissection studies, and it was identified notably less on MRI, albeit not significantly. (10.1177/0363546520950415)
• [L3] Assessment of medial cartilage thickness loss using MRI provides additional utility over standard radiographs in preoperative assessments of medial UKA patients. (10.1002/ksa.12611)
• [L4] These abnormal contact mechanics might predispose the knee to degenerative arthritis. (10.2106/jbjs.e.00539)
• [L4] The authors' early experience showed improved functional and radiological outcomes; however, the complication incidence was relatively high, but no knees required revision. (10.1186/s13018-023-04199-1)
• [L3] Athletically active patients with acute isolated posterior cruciate ligament tears treated nonoperatively achieved a level of objective and subjective knee function that was independent of the grade of laxity. (10.1177/03635465990270030201)
• [L5] Anatomical ACL reconstruction does not cause PCL impingement and it has biomechanical advantage in anterior tibial translation when compared with non-anatomical ACL reconstructions in porcine knee. (10.1007/s00167-011-1680-0)
• [L5] However, none of the 3 techniques could completely restore the normal knee joint laxity and ACL forces. (10.1177/0363546511420810)
• [Letter] The authors conclude that while the introduced noninvasive device has limitations, it is a useful and valuable tool to investigate preoperative and postoperative influences on tibiofemoral rotation and provides additional objective information on knee kinematics in a simple, reproducible manner. (10.1177/0363546510376622)
• [L1] Kinematic alignment restored native patellar tracking patterns more closely compared to mechanical alignment. (10.1002/ksa.12335)
• [L5] The ALL did not reveal an isometric behavior at any of the femoral insertion locations but had different length change patterns during knee flexion and internal tibial rotation at 90 degrees. (10.1016/j.arthro.2016.02.007)

See Also

• Anatomy
• Biomechanics
• Anterior Cruciate Ligament

References

[1] Anatomic single‐ and double‐bundle ACL reconstruction both restore dynamic knee function: a randomized clinical trial—part II: knee kinematics. Knee Surgery, Sports Traumatology, Arthroscopy. 2021. DOI: 10.1007/s00167-021-06479-x

[2] Beyond the coronal plane in robotic total knee arthroplasty—Part 2: Combined flexion does not affect outcomes. Knee Surgery, Sports Traumatology, Arthroscopy. 2025. DOI: 10.1002/ksa.12660

[3] The effect of distal femur bony morphology on in vivo knee translational and rotational kinematics. Knee Surgery, Sports Traumatology, Arthroscopy. 2011. DOI: 10.1007/s00167-011-1661-3

[4] Functional knee phenotypes: a novel classification for phenotyping the coronal lower limb alignment based on the native alignment in young non‐osteoarthritic patients. Knee Surgery, Sports Traumatology, Arthroscopy. 2019. DOI: 10.1007/s00167-019-05509-z

[5] The tibial cut in total knee arthroplasty influences the varus alignment, the femoral roll‐back and the tibiofemoral rotation in patients with constitutional varus. Knee Surgery, Sports Traumatology, Arthroscopy. 2020. DOI: 10.1007/s00167-020-05996-5

[6] Static native tibial alignment in total knee arthroplasty optimises whole‐body gait kinematics. Knee Surgery, Sports Traumatology, Arthroscopy. 2026. DOI: 10.1002/ksa.70356

[7] Diagnostic validity and triage concordance of a physiotherapist compared to physicians’ diagnoses for common knee disorders. BMC Musculoskeletal Disorders. 2017. DOI: 10.1186/s12891-017-1799-3

[8] Retention of Posterior Cruciate Ligament Alone May Not Achieve Physiological Knee Joint Kinematics After Total Knee Arthroplasty. Journal of Bone and Joint Surgery. 2020. DOI: 10.2106/jbjs.20.00024

[9] A long journey to be anatomic. Knee Surgery, Sports Traumatology, Arthroscopy. 2010. DOI: 10.1007/s00167-010-1222-1

[10] Anatomy-mimetic design preserves natural kinematics of knee joint in patient-specific mobile-bearing unicompartmental knee arthroplasty. Knee Surgery, Sports Traumatology, Arthroscopy. 2019. DOI: 10.1007/s00167-019-05540-0

[11] Total knee arthroplasty according to the original knee phenotypes with kinematic alignment surgical technique—early clinical and functional outcomes. BMC Musculoskeletal Disorders. 2020. DOI: 10.1186/s12891-020-03862-6

[12] Chapter 49 Meniscal Tears in Children and Adolescents. 2020.

[13] The Influence of Contemporary Knee Design on High Flexion: A Kinematic Comparison with the Normal Knee. Journal of Bone and Joint Surgery. 2008. DOI: 10.2106/jbjs.h.00817

[14] Meniscal ramp lesions: a lot is known, but a lot is also unknown…. Knee Surgery, Sports Traumatology, Arthroscopy. 2022. DOI: 10.1007/s00167-022-07292-w

[15] Knee kinetics and kinematics: What are the effects of TKA malconfigurations?. Knee Surgery, Sports Traumatology, Arthroscopy. 2015. DOI: 10.1007/s00167-015-3514-y

[16] The dynamic nature of alignment and variations in normal knees. The Bone & Joint Journal. 2015. DOI: 10.1302/0301-620x.97b4.33740

[17] Kinematic alignment recreates femoral trochlear geometry more closely than mechanical alignment in total knee arthroplasty. The Bone & Joint Journal. 2024. DOI: 10.1302/0301-620x.106b8.bjj-2023-1209.r1

[18] The effect of osteoarthritis of the knee on the biomechanics of other joints in the lower limbs. The Bone & Joint Journal. 2013. DOI: 10.1302/0301-620x.95b3.30850

[19] Current Concepts Review. The American Journal of Sports Medicine. 2008. DOI: 10.1177/0363546507312641

[20] Linear Discriminant Analysis Successfully Predicts Knee Injury Outcome From Biomechanical Variables. The American Journal of Sports Medicine. 2020. DOI: 10.1177/0363546520939946

[21] Tibiofemoral kinematic analysis of knee flexion for a medial pivot knee. Knee Surgery, Sports Traumatology, Arthroscopy. 2009. DOI: 10.1007/s00167-009-0777-1

[22] Chapter 120 Anatomy and Biomechanics of the Knee. 2019.

[23] The bone attachments of the medial collateral and posterior oblique ligaments are defined anatomically and radiographically. Knee Surgery, Sports Traumatology, Arthroscopy. 2020. DOI: 10.1007/s00167-020-06139-6

[24] Radiographic Identification of the Primary Posterolateral Knee Structures. The American Journal of Sports Medicine. 2009. DOI: 10.1177/0363546508328117

[25] Biomechanical Function of Anterior Cruciate Ligament Remnants: How Long Do They Contribute to Knee Stability After Injury in Patients With Complete Tears?. Arthroscopy. 2010. DOI: 10.1016/j.arthro.2010.04.076

[26] Preoperative symptom duration does not affect clinical outcomes after high tibial osteotomy at a minimum of 2-year follow-up. Journal of ISAKOS. 2022. DOI: 10.1016/j.jisako.2022.03.003

[27] The Effect of Direction and Reaction on the Neuromuscular and Biomechanical Characteristics of the Knee during Tasks that Simulate the Noncontact Anterior Cruciate Ligament Injury Mechanism. The American Journal of Sports Medicine. 2006. DOI: 10.1177/0363546505278696

[28] Kinematic analysis of posterior-stabilized total knee arthroplasty during standing up from and sitting down on a chair. Journal of Orthopaedic Surgery and Research. 2016. DOI: 10.1186/s13018-016-0482-y

[29] Kinematic alignment yields a reduced knee adduction moment and better range of motion compared to mechanical alignment: biomechanical considerations of a staged, bilateral total knee arthroplasty case. BMC Musculoskeletal Disorders. 2026. DOI: 10.1186/s12891-025-09445-7

[30] Comparison of Knee Kinematics After Single-Bundle Anterior Cruciate Ligament Reconstruction via the Medial Portal Technique With a Central Femoral Tunnel and an Eccentric Femoral Tunnel and After Anatomic Double-Bundle Reconstruction. The American Journal of Sports Medicine. 2015. DOI: 10.1177/0363546515611646

[31] Step‐by‐step insight into gait analysis: A narrative review unlocking knee biomechanics. Knee Surgery, Sports Traumatology, Arthroscopy. 2025. DOI: 10.1002/ksa.70067

[32] The 3D analysis of the sagittal curvature of the femoral trochlea in the Chinese population. Knee Surgery, Sports Traumatology, Arthroscopy. 2011. DOI: 10.1007/s00167-011-1679-6

[33] Functional Interaction of the Cruciate Ligaments, Posteromedial and Posterolateral Capsule, Oblique Popliteal Ligament, and Other Structures in Preventing Abnormal Knee Hyperextension. The American Journal of Sports Medicine. 2023. DOI: 10.1177/03635465231155203

[34] Biomechanical considerations in the pathogenesis of osteoarthritis of the knee. Knee Surgery, Sports Traumatology, Arthroscopy. 2011. DOI: 10.1007/s00167-011-1818-0

[35] In vivothree-dimensional kinematics of normal knees during different high-flexion activities. The Bone & Joint Journal. 2018. DOI: 10.1302/0301-620x.100b1.bjj-2017-0553.r2

[36] High tibial slope correlates with increased posterior tibial translation in healthy knees. Knee Surgery, Sports Traumatology, Arthroscopy. 2017. DOI: 10.1007/s00167-017-4706-4

[37] Methodology for biomechanical investigation of implant malpositioning in total knee arthroplasty using a six degree of freedom joint simulator. Arthroplasty. 2025. DOI: 10.1186/s42836-025-00351-w

[38] Femoral maltorsion influences both patellofemoral and tibiofemoral contact pressures. A biomechanical evaluation. Journal of ISAKOS. 2025. DOI: 10.1016/j.jisako.2025.100866

[39] The Anterior Cruciate Ligament Provides Resistance to Externally Applied Anterior Tibial Force But Not to Internal Rotational Torque During Simulated Weight‐Bearing Flexion. Arthroscopy. 2010. DOI: 10.1016/j.arthro.2010.04.069

[40] Boys demonstrate greater knee frontal moments than girls during the impact phase of cutting maneuvers, despite age‐related increases in girls. Knee Surgery, Sports Traumatology, Arthroscopy. 2023. DOI: 10.1007/s00167-023-07340-z

[41] Intraosseous Innervation of the Human Patella. The American Journal of Sports Medicine. 2007. DOI: 10.1177/0363546506297968

[42] The semimembranosus-tibial collateral ligament bursa. Anatomical study and magnetic resonance imaging.. The Journal of Bone & Joint Surgery. 1994. DOI: 10.2106/00004623-199409000-00007

[43] Correcting severe valgus deformity. The Bone & Joint Journal. 2017. DOI: 10.1302/0301-620x.99b1.bjj-2016-0340.r1

[44] Functional knee phenotypes: A helpful classification tool for visualizing potential femoral varus in restricted kinematic alignment total knee arthroplasty in Japan. Knee Surgery, Sports Traumatology, Arthroscopy. 2023. DOI: 10.1002/ksa.12028

[45] Posterolateral Knee Reconstruction with an Anatomical Bone–Patellar Tendon–Bone Reconstruction of the Fibular Collateral Ligament. The American Journal of Sports Medicine. 2007. DOI: 10.1177/0363546506293704

[46] Distinct 3-Dimensional Morphologies of Arthritic Knee Anatomy Exist. Journal of Bone and Joint Surgery. 2025. DOI: 10.2106/jbjs.24.01466

[47] Posterior Cruciate Ligament. The American Journal of Sports Medicine. 2011. DOI: 10.1177/0363546511416316

[48] Medial Opening Wedge High Tibial Osteotomy With Early Full Weight Bearing. Arthroscopy. 2008. DOI: 10.1016/j.arthro.2008.08.015

[49] Medial Knee Injury: Part 1, Static Function of the Individual Components of the Main Medial Knee Structures. The American Journal of Sports Medicine. 2009. DOI: 10.1177/0363546509333852

[50] Revisiting terminology: The transition from ‘functional alignment’ to ‘functional knee positioning’. Knee Surgery, Sports Traumatology, Arthroscopy. 2025. DOI: 10.1002/ksa.12667

[51] Knee kinematics is altered post‐fatigue while performing a crossover task. Knee Surgery, Sports Traumatology, Arthroscopy. 2013. DOI: 10.1007/s00167-013-2673-y

[52] Chapter 47 Radiographic Evaluation and Surgical Anatomy of the Knee. 2019.

[53] Regaining_Native_Knee_Kinematics_Following_Joint_Arthroplasty_A_Novel_Biomimetic_S088354031500529X. n.d..

[54] Chapter 38 Knee Anatomy. 2020.

[55] The phenotypic diversity of anteromedial osteoarthritis before and after treatment with medial unicompartmental knee arthroplasty: A radiographic analysis of 1000 knees. Knee Surgery, Sports Traumatology, Arthroscopy. 2024. DOI: 10.1002/ksa.12043

[56] The knee adduction moment in hamstring and patellar tendon anterior cruciate ligament reconstructed knees. Knee Surgery, Sports Traumatology, Arthroscopy. 2011. DOI: 10.1007/s00167-011-1835-z

[57] Correlation of Magnetic Resonance Imaging With Knee Anterolateral Ligament Anatomy. Orthopaedic Journal of Sports Medicine. 2015. DOI: 10.1177/2325967115621024

[58] THREE-DIMENSIONAL MORPHOLOGY AND KINEMATICS OF THE DISTAL PART OF THE FEMUR VIEWED IN VIRTUAL REALITY. The Journal of Bone and Joint Surgery-American Volume. 2003. DOI: 10.2106/00004623-200300004-00012

[59] Effect of graft fixation sequence on knee joint biomechanics in double‐bundle anterior cruciate ligament reconstruction. Knee Surgery, Sports Traumatology, Arthroscopy. 2014. DOI: 10.1007/s00167-014-3158-3

[60] Evaluating rotational kinematics of the knee in ACL‐ruptured and healthy patients using 3.0 Tesla magnetic resonance imaging. Knee Surgery, Sports Traumatology, Arthroscopy. 2011. DOI: 10.1007/s00167-011-1809-1

[61] Weight-bearing MRI with a knee flexion angle of 20°: a study on additional MRI investigation modalities to support a more accurate understanding of patellofemoral instability. BMC Musculoskeletal Disorders. 2021. DOI: 10.1186/s12891-021-04733-4

[62] Underestimation of tibial tuberosity–trochlear groove distance in conventional knee magnetic resonance imaging compared to full‐extension imaging. Knee Surgery, Sports Traumatology, Arthroscopy. 2025. DOI: 10.1002/ksa.70237

[63] Abnormal Biomechanics at 6 Months Are Associated With Cartilage Degeneration at 3 Years After Anterior Cruciate Ligament Reconstruction. Arthroscopy. 2018. DOI: 10.1016/j.arthro.2018.07.033

[64] Changes_in_the_Functional_Flexion_Axis_of_the_Knee_Before_and_After_Total_Knee_A_S088354031300870X. n.d..

[65] Anthropometric measurements of the knee: time to make it fit. Knee Surgery, Sports Traumatology, Arthroscopy. 2014. DOI: 10.1007/s00167-014-3391-9

[66] Three‐dimensional Magnetic Resonance Imaging of the Anterolateral Ligament of the Knee: An Evaluation of Intact and Anterior Cruciate Ligament–Deficient Knees From the Scientific Anterior Cruciate Ligament Network International (SANTI) Study Group. Arthroscopy. 2018. DOI: 10.1016/j.arthro.2018.02.014

[67] Influence of soft tissues on the proximal bony tibial slope measured with two‐dimensional MRI. Knee Surgery, Sports Traumatology, Arthroscopy. 2012. DOI: 10.1007/s00167-012-1990-x

[68] Knee flexor strength after ACL reconstruction: comparison between hamstring autograft, tibialis anterior allograft, and non‐injured controls. Knee Surgery, Sports Traumatology, Arthroscopy. 2009. DOI: 10.1007/s00167-009-0931-9

[69] The Magnetic Resonance Imaging Appearance of Individual Structures of the Posterolateral Knee. The American Journal of Sports Medicine. 2000. DOI: 10.1177/03635465000280020901

[70] Knee Biomechanics During Jogging After Arthroscopic Partial Meniscectomy: A Longitudinal Study. The American Journal of Sports Medicine. 2017. DOI: 10.1177/0363546517698934

[71] Knee malalignment and laterality influence 2‐year meniscus tear repair outcomes: A pilot study. Knee Surgery, Sports Traumatology, Arthroscopy. 2025. DOI: 10.1002/ksa.12602

[72] Total knee arthroplasty after distal femoral osteotomy long-term survivorship and clinical outcomes. The Bone & Joint Journal. 2019. DOI: 10.1302/0301-620x.101b6.bjj-2018-1334.r2

[73] A novel ultrasound scanning approach for evaluating femoral cartilage defects of the knee: comparison with routine magnetic resonance imaging. Journal of Orthopaedic Surgery and Research. 2018. DOI: 10.1186/s13018-018-0887-x

[74] Double-Bundle Reconstruction of the Anterior Cruciate Ligament: Anatomic and Biomechanical Rationale. Journal of the American Academy of Orthopaedic Surgeons. 2007. DOI: 10.5435/00124635-200702000-00003

[75] Kinematic alignment doesn't tell the whole story: It's time for kinetic alignment. Knee Surgery, Sports Traumatology, Arthroscopy. 2025. DOI: 10.1002/ksa.70010

[76] MAKING SENSE OF KNEE ARTHROPLASTY KINEMATICS. The Journal of Bone and Joint Surgery-American Volume. 2003. DOI: 10.2106/00004623-200300004-00008

[77] Functional alignment in total knee arthroplasty best achieves balanced gaps and minimal bone resections: an analysis comparing mechanical, kinematic and functional alignment strategies. Knee Surgery, Sports Traumatology, Arthroscopy. 2023. DOI: 10.1007/s00167-023-07567-w

[78] Tibial Rotation Under Combined In Vivo Loading After Single‐ and Double‐Bundle Anterior Cruciate Ligament Reconstruction. Arthroscopy. 2011. DOI: 10.1016/j.arthro.2011.06.028

[79] Comparative Analysis of Sagittal‐Plane Radiographic Landmarks Used to Identify the Femoral Attachments of Lateral Knee Structures. Arthroscopy. 2020. DOI: 10.1016/j.arthro.2020.07.006

[80] Anatomical Reconstruction of Knee Posterolateral Complex with the Tendon of the Long Head of Biceps Femoris. The American Journal of Sports Medicine. 2006. DOI: 10.1177/0363546506288112

[81] The anterolateral complex of the knee: results from the International ALC Consensus Group Meeting. Knee Surgery, Sports Traumatology, Arthroscopy. 2018. DOI: 10.1007/s00167-018-5072-6

[82] Evaluation of a modified knee rotation angle in MRI scans with and without trochlear dysplasia: a parameter independent of knee size and trochlear morphology. Knee Surgery, Sports Traumatology, Arthroscopy. 2016. DOI: 10.1007/s00167-015-3919-7

[83] Deterioration of patellofemoral cartilage status after medial open-wedge high tibial osteotomy. Knee Surgery, Sports Traumatology, Arthroscopy. 2018. DOI: 10.1007/s00167-018-5128-7

[84] Comparison of 3D quantitative osteoarthritis imaging biomarkers from paired CT and MR images: data from the IMI-APPROACH study. BMC Musculoskeletal Disorders. 2023. DOI: 10.1186/s12891-023-06187-2

[85] The cartilaginous and osseous geometry of the femoral trochlear groove. Knee Surgery, Sports Traumatology, Arthroscopy. 2003. DOI: 10.1007/s00167-003-0414-3

[86] Displacement of the medial meniscus within the passive motion characteristics of the human knee joint: an RSA study in human cadaver knees. Knee Surgery, Sports Traumatology, Arthroscopy. 2004. DOI: 10.1007/s00167-004-0511-y

[87] The Utility of Biologics, Osteotomy, and Cartilage Restoration in the Knee. Journal of the American Academy of Orthopaedic Surgeons. 2018. DOI: 10.5435/jaaos-d-17-00087

[88] Evidence-Based Clinical Anatomy of the Popliteofibular Ligament and Its Importance in Orthopaedic Surgery: Cadaveric Versus Magnetic Resonance Imaging Meta-analysis and Radiological Study. The American Journal of Sports Medicine. 2020. DOI: 10.1177/0363546520950415

[89] Magnetic resonance imaging provides additional utility in the preoperative cartilage assessment of patients undergoing medial unicompartmental knee arthroplasty. Knee Surgery, Sports Traumatology, Arthroscopy. 2025. DOI: 10.1002/ksa.12611

[90] Anterior Cruciate Ligament Deficiency Alters the In Vivo Motion of the Tibiofemoral Cartilage Contact Points in Both the Anteroposterior and Mediolateral Directions. The Journal of Bone & Joint Surgery. 2006. DOI: 10.2106/jbjs.e.00539

[91] Do_surgical_patellar_interventions_restore_patellar_kinematics_in_fixed-bearing,_S0883540314004744. n.d..

[92] Total knee arthroplasty post-high tibial osteotomy, results of an early experience from a North African arthroplasty unit, and a comprehensive review of the literature. Journal of Orthopaedic Surgery and Research. 2023. DOI: 10.1186/s13018-023-04199-1

[93] The Natural History of Acute, Isolated, Nonoperatively Treated Posterior Cruciate Ligament Injuries. The American Journal of Sports Medicine. 1999. DOI: 10.1177/03635465990270030201

[94] PCL to graft impingement pressure after anatomical or non‐anatomical single‐bundle ACL reconstruction. Knee Surgery, Sports Traumatology, Arthroscopy. 2011. DOI: 10.1007/s00167-011-1680-0

[95] Biomechanical Evaluation of Knee Joint Laxities and Graft Forces After Anterior Cruciate Ligament Reconstruction by Anteromedial Portal, Outside-In, and Transtibial Techniques. The American Journal of Sports Medicine. 2011. DOI: 10.1177/0363546511420810

[96] Letter to the Editor. The American Journal of Sports Medicine. 2010. DOI: 10.1177/0363546510376622

[97] Kinematical alignment better restores native patellar tracking pattern than mechanical alignment. Knee Surgery, Sports Traumatology, Arthroscopy. 2024. DOI: 10.1002/ksa.12335

[98] Isometric Characteristics of the Anterolateral Ligament of the Knee: A Cadaveric Navigation Study. Arthroscopy. 2016. DOI: 10.1016/j.arthro.2016.02.007