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Ligament & Instability

Lateral ankle instability: diagnosis, conservative vs surgical options, and peroneal complex reconstruction techniques.

Overview

The clinical relevance of the anterolateral ligament remains elusive, with MRI evaluation lacking a diagnostic gold standard despite potential reliability in experienced hands [1]. While operative treatment of the anterior cruciate and medial collateral ligaments does not alter late valgus instability prevalence [2], surgical morbidity for anatomical reconstruction of the medial collateral ligament and posteromedial corner remains acceptable, restoring medial instability to acceptable levels at two years [7]. For patellofemoral instability, isolated or associated medial patellofemoral ligament reconstruction using a bioactive synthetic ligament is a valid option that minimizes donor-site morbidity and yields midterm results comparable to autologous grafts [8], though persistent instability, pain, and loss of flexion remain potential complications [3].

In the ankle, arthroscopic repair of every injured ligament in multiligamentous injuries provides the best potential outcomes, offering similar clinical results to isolated lateral injury treatment at two years [14]. Anatomic proximal tibiofibular joint reconstruction for isolated instability demonstrates improved clinical outcomes, return to activities, and a low risk of complications at an average follow-up of 43.2 months [16]. Deltoid ligament repair or reconstruction is reserved for patients with reported ankle instability and peroperatively demonstrated medial pathology [4], while chronic lateral ankle instability cases with prior surgical failure or generalized ligamentous laxity may require tendon graft supplementation [71].

Surgical ligament reconstruction emphasizing posterolateral corner repair appears to improve outcomes in ultra-low-velocity knee dislocations [23]. Combined anterior cruciate and anterolateral ligament reconstruction may be indicated for patients with persistent rotational instability following anterior cruciate ligament reconstruction, though high-level evidence is still required to change surgical practice regarding this approach [26]. Finally, complete medial collateral ligament release for ligament balancing in primary total knee arthroplasty is a safe procedure that does not lead to postoperative laxity [13].

Anatomy & Pathophysiology

Osseous Morphology and Alignment

Distinct characteristics of the incisura fibularis morphology are associated with ligamentous ankle lesions, potentially due to lower osseous resistance against tibiofibular displacement [43]. The accessory anteroinferior tibiofibular ligament is a normal anatomical finding that can lead to anterolateral impingement in cases with coexistent ankle instability [15]. Mediolateral force distribution at the knee joint shifts across activities and is driven by tibiofemoral alignment, meaning the medial force ratio depends on both alignment and activity nature and cannot be generalized to a single value [47].

Ligamentous Pathophysiology and Degeneration

Anatomical features of the ankle may act like domino pieces, where a lateral ankle sprain can initiate a cascade of damage to intra-articular ligaments and cartilage, leading to chronic instability and joint degeneration [62]. Severe ankle instability has nearly three times the chance to develop into ankle osteoarthritis compared to moderate ankle instability in a mouse model [60]. In a biomechanical in vitro setting, the addition of either anterolateral ligament reconstruction or the modified Ellison procedure restored overall native knee kinematics in a combined anterior cruciate ligament plus anterolateral-deficient knee [59]. Construct II of the MCL internal brace maintained tension during valgus load but did not restore valgus opening to the intact state, while Construct I failed to maintain tension [66]. Both single-tunnel and double-tunnel reconstruction of the fibula were able to achieve better results for ankle instability, with no significant difference between the two surgical procedures in biomechanical outcomes [65].

Kinematics and Functional Outcomes

There is a poor correlation between native tibial slope and kinematic testing in the anterior cruciate ligament-deficient knee [46]. Jump direction significantly influences knee biomechanics, with lateral jumps identified as the most dangerous of the stop-jumps during tasks simulating noncontact anterior cruciate ligament injury mechanisms [48]. Gait analysis data suggests patients with multiple ligament knee reconstruction may experience higher magnitude changes in sagittal plane kinematics and kinetics during demanding functional tasks such as stair decent [40]. The contralateral knee can be used as a reliable normal kinematic control in cruciate ligament deficiency [64]. An inability to complete jumping and landing tasks within 2 weeks of a first-time lateral ankle sprain is predictive of eventual chronic ankle instability outcome [57]. Poorer dynamic postural control and lower self-reported function 6 months after a first-time lateral ankle sprain are predictive of eventual chronic ankle instability outcome [57]. A clear interaction between mechanical (ankle arthrometer) and functional (FAAM-G) measures in chronic ankle instability subgroups could not be demonstrated [28]. Further investigations are required to clarify the characteristic foot and ankle malalignment in chronic ankle instability [32].

Classification

Anterolateral Ligament: The nature and clinical relevance of the anterolateral ligament remain elusive [1]. MRI evaluation of the anterolateral ligament may be reliable for experienced individuals but lacks a diagnostic gold standard [1]. A discrete anterolateral ligament was not observed in the referenced study [63]. The anterolateral ligament described in recent studies likely refers to the capsulo-osseous layer or the mid-third capsular ligament [63].

Medial Collateral and Deltoid Ligaments: The superficial medial collateral ligament is the major restraint to anteromedial instability of the knee [30]. A new classification of anteromedial instability has been proposed to support clinical examination and treatment decision [30]. Operative treatment of both the anterior cruciate and medial collateral ligaments or of only the anterior cruciate ligament did not alter the prevalence of late valgus instability [2]. Repair or reconstruction of the deltoid ligament is performed only in patients reporting ankle instability with peroperatively demonstrated medial instability and pathology to the ligament [4]. A uniform standard for diagnosing deltoid ligament injuries is absent, and current diagnostic approaches vary significantly across studies [9]. Current treatment protocols for deltoid injuries require further standardization with an emphasis on proper diagnosis due to the continuing evolution of anatomical understanding [17].

Knee Dislocation and Instability Systems: Consensus for inclusion of various factors in a knee dislocation classification system was not easily achieved [36]. A treatment algorithm for ACL has been developed based on the type and degree of pathologic laxity [52]. The Posterolateral Instability Score (PoLIS) enables an objective assessment and documentation of the injury severity of injuries to the lateral side of the knee joint [55]. Stress radiographs support accurate diagnosis of complex knee injuries and provide an objective measure of knee stability following ligament reconstruction [10].

Other Considerations: Potential complications of medial patellofemoral ligament reconstruction include persistent instability, pain, and loss of flexion [3]. Posterior capsular laxity can occur as an isolated event without concomitant ligamentous injury [6]. Arthroscopic repair of each and every injured ligament in ankle multiligamentous injuries provides the best potential outcomes compared to treating isolated lateral ligament injury [14]. The term mid-flexion instability has entered orthopaedic literature as a concept but has not been confirmed as a distinct clinical entity [58]. The clinical scenario described as mid-flexion instability is more likely generalized instability with the appearance of stability in full extension from tight posterior structures [58].

Clinical Presentation

The clinical evaluation of ligamentous injury begins with a comprehensive history and physical examination to identify specific patterns of instability and associated musculoskeletal conditions. Careful history and examination may reveal a constellation of musculoskeletal conditions associated with generalized joint laxity, where subtle findings on radiographs or MRI can impact decision-making [5]. Acute distal radioulnar joint instability is primarily a clinical diagnosis, and physical examination remains a mainstay of diagnosis [18]. For complex knee injuries, stress radiographs support accurate diagnosis and provide an objective measure of knee stability following ligament reconstruction [10], while stress radiography techniques were accurate and reliable when compared to numerous alternatives in the diagnosis of acute and chronic knee ligament injuries [20].

Diagnostic Specificity: The nature and clinical relevance of the anterolateral ligament remain elusive, and MRI evaluation of the anterolateral ligament may be reliable for experienced individuals but lacks a diagnostic gold standard [1]. There is an absence of a uniform standard for diagnosing deltoid ligament injuries, with current diagnostic approaches varying significantly across studies [9]. Evaluation of the distal syndesmotic ligaments and interosseous membrane is critical in cases of syndesmotic instability, where prompt stabilization is advocated [21]. Instability of the proximal tibiofibular joint is rarely reported and often missed, making understanding the etiology, symptoms, and anatomic variations essential for evaluating symptomatic patients [29].

Physical Examination Maneuvers: The Lachman and pivot shift examinations have complementary roles in assessing the integrity of the ACL and surrounding stabilizers; when combined as diagnostic tools, they achieve far more collectively than what each can achieve alone [33]. Tests for the anterior cruciate ligament-hamstring reflex are reproducible and reliable for clinical diagnosis of functional instability following ACL rupture [31]. Laxity data from in vivo navigation systems may be useful to establish the diagnosis of an ACL injury and evaluation of post-operative results [39].

Operative Decision-Making and Outcomes: Operative treatment of both the anterior cruciate and medial collateral ligaments or of only the anterior cruciate ligament did not alter the prevalence of late valgus instability [2]. Clinical and functional outcomes for patients with complete anterior cruciate ligament tears are generally better with early surgical treatment than with delayed or nonsurgical care [12]. Isolated PCL injuries can often be managed nonsurgically, whereas a new set of diagnostic, treatment, and recovery protocols for multiple ligament injuries led to significant functional improvement [35, 37]. Cruciate ligament injuries are common with rising incidence [37].

Complications and Special Considerations: Potential complications of medial patellofemoral ligament reconstruction include persistent instability, pain, and loss of flexion [3]. Postoperative J-sign and apprehension may be important markers of suboptimal outcomes after isolated MPFL reconstruction for recurrent instability [22]. Repair or reconstruction of the deltoid ligament is performed only in patients reporting ankle instability with peroperatively demonstrated medial instability and pathology to the ligament [4]. The accessory anteroinferior tibiofibular ligament reflects a normal anatomical finding but could lead to anterolateral impingement in cases with coexistent ankle instability [15]. Posterior capsular laxity can occur as an isolated event without concomitant ligamentous injury, and the technique for treating hyperextension should not be undertaken in the presence of associated ligament rupture [6].

Investigations

Plain radiography: Stress radiographs support accurate diagnosis of complex knee injuries and provide an objective measure of knee stability following ligament reconstruction [10]. These techniques were accurate and reliable when compared to numerous alternatives in the diagnosis of acute and chronic knee ligament injuries [20]. However, there is heterogeneity in the available literature regarding stress examination techniques and device utilization [20]. Careful examination comparing the involved and uninvolved knees, combined with stress radiographs, is currently the most accurate way to grade posterolateral corner injuries [80]. Subtle findings on radiographs can impact decision-making in patients with generalized joint laxity [5].

MRI: MRI is recommended for all patients presenting with acute patellar dislocation to evaluate soft tissue damage and guide management [27]. Proper imaging sequences are of crucial importance to reliably follow anterolateral ligament tears to determine their clinical significance [78]. While MRI evaluation of the anterolateral ligament may be reliable for experienced individuals, it lacks a diagnostic gold standard [1]. Smaller structures in posterolateral corner injuries are difficult to assess with MRI [79]. The medial meniscus posterior root tear may occur in severe medial instability from trauma but is often missed on MRI diagnosis [81]. Measurement using open magnetic resonance imaging successfully quantified remaining rotatory instability in anterior cruciate ligament–reconstructed knees [72], and MRI can help predict high-grade rotatory instability to guide surgical planning [77]. Abnormal MRI findings of the lateral collateral ligament were likely to be more frequent in patients with more varus knee alignment [84]. The posterior cruciate ligament inclination angle is higher in anterior cruciate ligament insufficiency, and measurement of this angle using MRI images may allow for detection of ACL insufficiency [83].

Other Considerations: Careful history and examination may reveal a constellation of musculoskeletal conditions associated with generalized joint laxity [5]. Posterior capsular laxity can occur as an isolated event without concomitant ligamentous injury, yet techniques for posterior capsular laxity should not be undertaken in the presence of associated ligament rupture [6]. There is an absence of a uniform standard for diagnosing deltoid ligament injuries, and current diagnostic approaches vary significantly across studies [9]. Acute distal radioulnar joint instability is primarily a clinical diagnosis where physical examination remains a mainstay [18]. The accessory anteroinferior tibiofibular ligament reflects a normal anatomical finding but could lead to anterolateral impingement in cases with coexistent ankle instability [15]. Postoperative J-sign and apprehension may be important markers of suboptimal outcomes after isolated MPFL reconstruction for recurrent instability [22]. Direct visualization is not necessary to report a clinically unstable posterolateral corner injury [79]. Examining the patient with a pivot shift maneuver should remain the gold standard when there is doubt regarding high-grade rotatory instability [77]. The classic dimple sign may be absent in chronic irreducible posterolateral knee dislocation cases [87]. The nature and clinical relevance of the anterolateral ligament remain elusive [1].

Treatment

Non-Operative

Nonsurgical management is advocated for isolated grade I or II posterior cruciate ligament injuries, as well as grade III injuries in patients with mild symptoms or low activity demands [49]. Non-operative functional treatment is favored for complete ruptures of the ankle ligaments [67]. Acceptable outcomes have been recorded in patients treated non-operatively for proximal and midsubstance grade-III medial collateral ligament rupture [73]. Nonoperative management is indicated for grade-I and most grade-II posterolateral corner injuries [61].

Operative

Indications: Surgery is indicated in the acute setting for physically active patients with knee dislocations and in the chronic setting for instability without significant arthrosis [53]. Surgical management of posterior cruciate ligament injuries is reserved for high-demand athletes or patients in whom nonsurgical management has been unsuccessful [49]. Arthroscopic repair of each and every injured ligament in ankle multiligamentous injuries provides the best potential outcomes and is the recommended treatment [14]. Collateral ligament repair is indicated for patients with post-traumatic instability of the metacarpophalangeal joint of the thumb operated on within three weeks of injury [70]. Reconstruction of the collateral ligament by means of a tendon graft is recommended for patients with post-traumatic instability of the metacarpophalangeal joint of the thumb treated more than three weeks after injury [70]. MRI is recommended for all patients presenting with acute patellar dislocation to evaluate soft tissue damage and guide management [27].

Surgical Approach / Technique: Anatomical reconstruction of the medial collateral ligament and posteromedial corner of the knee restores medial instability to an acceptable level clinically at 2 years' follow-up with acceptable surgical morbidity and complications [7]. Combined anterior cruciate ligament reconstruction with either lateral extra-articular tenodesis or anterolateral ligament reconstruction significantly improves clinical outcome and stability after two years [11]. Combined anterior cruciate ligament and anterolateral ligament reconstruction may be indicated for patients with persistent rotational instability after anterior cruciate ligament reconstruction, though high-level evidence is still required [26]. An isolated lateral extra-articular procedure (LEAP) is an effective procedure with good clinical and patient-reported outcomes and low failure rates for patients with persisting rotatory instability after a previous anterior cruciate ligament reconstruction [42]. Nonanatomic lateral extra-articular procedures performed at the time of anterior cruciate ligament reconstruction risk overconstraint, whereas anatomic anterolateral ligament reconstruction does not [68]. One-stage reconstruction of combined ligamentous injuries of the knee is effective and safe and can adequately restore satisfactory stability [45]. Surgical treatment of multiple knee ligament injuries using autografts provided satisfactory stability, range of motion, and subjective functional results [38]. Surgical ligament reconstruction with emphasis on posterolateral corner repair appears to improve outcomes in ultra-low-velocity knee dislocations [23]. Treatment of posterolateral corner injuries depends on severity: nonoperative for grade-I and most grade-II injuries, early repair or reconstruction for acute grade-III injuries, and reconstruction for chronic injuries [61]. Failure to treat posterolateral corner injuries potentially causes cruciate ligament reconstruction failure [61]. Lateral ligament reconstruction for acute severe ankle ruptures is a safe and effective treatment providing a stable ankle and expected return to sports at approximately 10 weeks [19]. Physeal-sparing medial patellofemoral ligament reconstruction is the treatment of choice for skeletally immature patients with recurrent instability [76].

Implant Selection: Isolated or associated MPFL reconstruction with a bioactive synthetic ligament is a valid option for surgical treatment of objective patellofemoral instability, with midterm results comparable to autologous grafts [8].

Alignment / Balancing Strategy: Complete medial collateral ligament release for ligament balancing in primary total knee arthroplasty is a safe procedure that does not lead to postoperative laxity [13].

Pain Management: Potential complications of medial patellofemoral ligament reconstruction include persistent instability, pain, and loss of flexion [3].

Adjuncts: Clinical and functional outcomes for patients with complete anterior cruciate ligament tears are generally better with early surgical treatment than with delayed or nonsurgical care [12].

Other Considerations: The nature and clinical relevance of the anterolateral ligament remain elusive [1]. MRI evaluation of the anterolateral ligament may be reliable for experienced individuals but lacks a diagnostic gold standard [1]. Operative treatment of both the anterior cruciate and medial collateral ligaments or of only the anterior cruciate ligament did not alter the prevalence of late valgus instability [2]. Joint hypermobility is not a contraindication to medial patellofemoral ligament reconstruction, although caution is recommended in managing patient expectations [44]. Completely ruptured collateral ligaments of the proximal interphalangeal joint frequently result in prolonged disability when treated non-operatively [69]. Surgical repair of completely ruptured collateral ligaments of the proximal interphalangeal joint yielded satisfactory results with restored joint stability and pain relief [69]. The generally low methodological quality of studies on posterior cruciate ligament injury management shows that caution is required when interpreting results, and firm recommendations on treatment choice cannot be given at this time [74]. Nonsurgical, reparative, and reconstructive techniques can all be used to manage lateral collateral ligament injury about the knee; the optimal treatment is selected on the basis of injury severity [75].

Complications

Instability: Persistent instability remains a potential complication following medial patellofemoral ligament (MPFL) reconstruction [3]. In the context of combined anterior cruciate and medial collateral ligament injuries, operative treatment does not alter the prevalence of late valgus instability [2]. Posterior capsular laxity may occur as an isolated event without concomitant ligamentous injury [6]. Anatomic proximal tibiofibular joint reconstruction for isolated instability is associated with a low risk of complications or the need for additional procedures [16]. Arthroscopic lateral ankle ligament repair yields favorable clinical outcomes in the short term [24]. Repair or reconstruction of the deltoid ligament is indicated in patients reporting ankle instability with peroperatively demonstrated medial instability and pathology to the ligament [4].

Stiffness / Arthrofibrosis: Knee stiffness requiring manipulation under anesthesia is more common in patients who sustained ruptures of more than two ligaments [86]. This complication is also more frequent in patients treated acutely [86]. Complete MCL release for ligament balancing in primary total knee arthroplasty does not lead to postoperative laxity [13].

General Surgical Morbidity: Pain and loss of flexion are potential complications of MPFL reconstruction [3]. Surgical morbidity and complications for anatomical reconstruction of the medial collateral ligament and posteromedial corner of the knee are at acceptable levels [7]. Isolated or associated MPFL reconstruction with a bioactive synthetic ligament minimizes donor-site morbidity and associated complications [8]. Simultaneous bilateral multiligamentous knee injuries are associated with a higher post-operative complication rate compared to unilateral injuries [54]. Overall complications are higher in patients with more than two ligaments injured in multiligament knee injuries [86]. Knees with all four ligaments injured are more likely to undergo revision surgery [86]. Dynamic intraligamentary stabilization for primary repair of the anterior cruciate ligament has an unacceptably high complication rate [82] and leads to residual anteroposterior knee joint laxity of 3 mm or more in 49.1% of cases [82]. Midterm comprehensive surgical reconstruction including sulcus-deepening trochleoplasty in recurrent patellar dislocations with high-grade trochlear dysplasia shows no complication of subsequent arthritis [25].

Other Considerations: Evidence regarding specific infection rates, aseptic loosening, periprosthetic fracture, thromboembolism, nerve palsy, wound complications, or polyethylene wear is not provided in the current evidence base for this section.

Recovery

Light activity (weeks): Return to desk work and light activities of daily living is generally achievable within 10 weeks following lateral ligament reconstruction for acute severe ruptures [19].

Full activity (months): Patients with complete anterior cruciate ligament tears generally achieve better functional outcomes with early surgical treatment compared to delayed or nonsurgical care [12]. Anatomic reconstruction of the medial collateral ligament and posteromedial corner restores medial instability to an acceptable clinical level at 2 years' follow-up [7]. Clinical outcomes and stability after anterior cruciate ligament reconstruction combined with either lateral extra-articular tenodesis or anterolateral ligament reconstruction improve significantly after two years [11]. Anatomic proximal tibiofibular joint reconstruction for isolated instability allows a return to activities at an average follow-up of 43.2 months [16].

Complete recovery / outcome plateau (months): The long-term results of the Broström procedure for chronic lateral ankle instability remain excellent with 26-year follow-up [51]. Midterm follow-up of comprehensive surgical reconstruction, including sulcus-deepening trochleoplasty for recurrent patellar dislocations with high-grade trochlear dysplasia, demonstrates satisfactory restoration of patellar stability and improvement of knee scores [25]. Patients with a preoperative duration of symptomatic medial knee overload or arthritis of two years or greater do not experience inferior patient-reported or clinical outcomes compared to those with a symptom duration of less than 2 years at mid-term follow-up [88].

Rehabilitation protocol: Surgical morbidity and complications for anatomical reconstruction of the medial collateral ligament and posteromedial corner are at acceptable levels [7]. Isolated or associated medial patellofemoral ligament reconstruction with a bioactive synthetic ligament is a valid option that minimizes donor-site morbidity and associated complications [8]. Results with this bioactive synthetic ligament at midterm follow-up are comparable to autologous graft [8]. Arthroscopic medial capsular plication using the suture anchor technique resulted in a statistically significant improvement in patients' functional outcomes [90]. In this cohort, 13 out of 14 patients did not re-dislocate or experience instability [90]. Debridement of the torn ligament segment combined with resection of the impinging bone was associated with marked symptomatic improvement and full return to activities for a minimum of 2 years in a group of 9 cases [91]. A one-stage protocol with early surgery rather than delayed reconstruction produced better clinical outcomes for multiligament injured knees regardless of whether the injured collateral ligament was medial or lateral [92].

Functional milestones: Operative treatment of both the anterior cruciate and medial collateral ligaments, or of only the anterior cruciate ligament, did not alter the prevalence of late valgus instability [2]. Potential complications of medial patellofemoral ligament reconstruction include persistent instability, pain, and loss of flexion [3]. Lateral ligament reconstruction is a safe and effective treatment for acute severe ruptures providing a stable ankle [19]. Arthroscopic lateral ankle ligament repair yields favorable clinical outcomes in the short term [24]. Midterm follow-up of comprehensive surgical reconstruction including sulcus-deepening trochleoplasty in recurrent patellar dislocations with high-grade trochlear dysplasia showed no complication of subsequent arthritis [25].

Other Considerations: Predictors of poor outcome after surgical treatment of arthrofibrosis following ligament reconstruction include global arthrofibrosis and a greater than 6-month time interval from primary reconstruction and surgical release [89]. Anatomic proximal tibiofibular joint reconstruction for isolated instability had a low risk of complications or need for additional procedures at an average follow-up of 43.2 months [16].

Key Evidence

  • [L5] The nature and clinical relevance of the anterolateral ligament remain elusive, and while MRI evaluation may be reliable for experienced individuals, it lacks a diagnostic gold standard and appropriate conclusions must be approached in a broader context of the literature. (10.1016/j.arthro.2019.04.007)
  • [L3] Operative treatment of both ligaments or of only the anterior cruciate ligament did not alter the prevalence of late valgus instability. (10.2106/00004623-199602000-00002)
  • [L4] However, potential complications, such as persistent instability, pain, and loss of flexion, must be considered. (10.1177/0363546514529640)
  • [L3] It is concluded that repair or reconstruction of the deltoid ligament is only performed in patients reporting ankle instability and with peroperatively demonstrated medial instability and pathology to the ligament. (10.1002/ksa.12459)
  • [L5] Careful history and examination may reveal a constellation of musculoskeletal conditions associated with generalized joint laxity, and subtle findings on radiographs or MRI can impact decision-making. (10.2106/jbjs.18.00458)
  • [L5] The authors state that posterior capsular laxity can occur as an isolated event without concomitant ligamentous injury and that their technique should not be undertaken in the presence of associated ligament rupture. (10.1016/j.arthro.2010.06.015)
  • [L4] Surgical morbidity and complications were at acceptable levels, and the technique restores medial instability to an acceptable level clinically at 2 years' follow-up. (10.1177/0363546509332498)
  • [L4] Isolated or associated MPFL reconstruction with bioactive synthetic ligament is a valid option in surgical treatment of objective PF instability, with results at midterm follow-up comparable to autologous graft, thus minimizing donor-site morbidity and associated complications. (10.1007/s00167-014-2970-0)
  • [L1] The review highlights the absence of a uniform standard for diagnosing deltoid ligament injuries, suggesting that current diagnostic approaches vary significantly across studies. (10.1186/s12891-024-07869-1)
  • [L5] Stress radiographs support accurate diagnosis of complex knee injuries and provide an objective measure of knee stability following ligament reconstruction. (10.1016/j.arthro.2020.11.001)
  • [L1] The clinical outcome and stability after anterior cruciate ligament reconstruction combined with either lateral extraarticular tenodesis or anterolateral ligament reconstruction improved significantly after two years. (10.1186/s13018-025-06561-x)
  • [L2] This study suggests that complete MCL release for ligament balancing is a safe procedure and does not lead to postoperative laxity. (10.1007/s00167-014-3288-7)
  • [L2] Therefore, when treating ankle instability, arthroscopic repair of each and every ligament that appears injured provides the best potential outcomes and is the recommended treatment. (10.1002/ksa.12164)
  • [L5] Although it reflects a normal anatomical finding, it could lead to anterolateral impingement in cases with coexistent ankle instability. (10.1177/0095399703258697)
  • [L4] At an average follow-up of 43.2 months, anatomic PTFJ reconstruction for isolated PTFJ instability provided improvement in clinical outcomes, a return to activities, and a low risk of complications or need for additional procedures. (10.1016/j.arthro.2020.01.056)
  • [L4] Given the continuing evolution of the anatomical understanding of the ligament, the current treatment protocol for deltoid injuries requires further standardization, with an emphasis on proper diagnosis. (10.1007/s00167-012-2159-3)
  • [L4] Acute distal radioulnar joint instability is primarily a clinical diagnosis, and physical examination remains a mainstay of diagnosis. (10.2106/jbjs.rvw.m.00110)
  • [L3] Lateral ligament reconstruction is a safe and effective treatment for acute severe ruptures providing a stable ankle and expected return to sports at approximately 10 weeks. (10.1007/s00167-015-3815-1)
  • [L2] Despite heterogeneity in the available literature with regard to stress examination techniques and device utilization, the data support that stress radiography techniques were accurate and reliable when compared to numerous alternatives in the diagnosis of acute and chronic knee ligament injuries. (10.1007/s00167-023-07617-3)
  • [L5] Evaluation of the distal syndesmotic ligaments and interosseous membrane is critical, and prompt stabilization is advocated in cases of syndesmotic instability. (10.1177/0363546507312162)
  • [L4] These findings support the need to further investigate if postoperative J-sign and apprehension may be important markers of suboptimal outcomes after isolated MPFL reconstruction for recurrent instability. (10.1177/03635465251339822)
  • [L4] Surgical ligament reconstruction with emphasis on posterolateral corner repair appears to improve outcomes. (10.1177/0363546511414855)
  • [L4] The current systematic review demonstrated that arthroscopic lateral ankle ligament repair yields favorable clinical outcomes in the short term. (10.1016/j.arthro.2018.02.034)
  • [L4] Midterm follow-up showed satisfactory restoration of patellar stability and improvement of knee scores with no complication of subsequent arthritis. (10.1177/0363546513482302)
  • [L5] It suggests that combined ACL and ALL reconstruction may be indicated for patients with persistent rotational instability after ACL reconstruction, though high-level evidence is still required to change surgical practice. (10.1016/j.arthro.2014.08.007)
  • [L4] MRI is recommended for all patients presenting with acute patellar dislocation to evaluate soft tissue damage and guide management. (10.1186/1749-799x-7-21)
  • [L4] A clear interaction between mechanical (ankle arthrometer) and functional (FAAM-G) measures could not be demonstrated. (10.1186/s13018-015-0171-2)
  • [L5] Instability of the proximal tibiofibular joint is rarely reported and often missed; understanding its etiology, symptoms, and anatomic variations is essential for evaluating symptomatic patients. (10.5435/00124635-200303000-00006)
  • [L5] Based on the present data a new classification of anteromedial instability is proposed, which may support clinical examination and treatment decision. (10.1007/s00167-020-05947-0)
  • [L4] The tests were reproducible and reliable, allowing the method to be used for further research and clinical diagnosis of functional instability following ACL rupture. (10.1007/s00167-009-0837-6)
  • [L1] Further investigations are required to clarify the characteristic foot and ankle malalignment in CAI to facilitate the development of efficient interventions. (10.1186/s12891-021-04537-6)
  • [Commentary] The Lachman and pivot shift examinations have complementary roles in assessing the integrity of the ACL and surrounding stabilizers; when combined as diagnostic tools, they achieve far more collectively than what each can achieve alone. (10.1016/j.arthro.2020.12.001)
  • [L3] The study established a new set of diagnostic, treatment, and recovery protocols for multiple ligament injuries which led to significant functional improvement. (10.1186/s12891-021-04596-9)
  • [L4] Consensus for inclusion of various factors in a knee dislocation classification system was not easily achieved. (10.1016/j.jisako.2022.02.003)
  • [L4] Surgical treatment of multiple knee ligament injuries using autografts provided satisfactory stability, range of motion, and subjective functional results. (10.1007/s00167-006-0039-4)
  • [L3] The laxity data may be useful to establish the diagnosis of an ACL injury and evaluation of post-operative results. (10.1007/s00167-009-0789-x)
  • [L3] Gait analysis data suggests that patients may be experiencing higher magnitude changes in sagittal plane kinematics and kinetics during demanding functional tasks (stair decent). (10.1007/s00167-008-0681-0)
  • [L1] An isolated LEAP is an effective procedure with good clinical and patient-reported outcomes and low failure rates for patients with persisting rotatory instability after a previous ACL reconstruction. (10.1002/ksa.70373)
  • [L2] Most studies found distinct characteristics of the incisura fibularis morphology associated with ligamentous ankle lesions, potentially due to lower osseous resistance against tibiofibular displacement. (10.1016/j.jisako.2024.100361)
  • [L3] Joint hypermobility is not a contraindication to MPFL reconstruction, although caution is recommended in managing the expectations of patients with hypermobility before consideration of surgery. (10.1302/0301-620x.94b12.29562)
  • [L4] The results showed the effectiveness and safety of one-stage reconstruction of combined ligamentous injuries of the knee that can adequately restore satisfactory stability. (10.1007/s00167-008-0562-6)
  • [L5] There was a poor correlation between native tibial slope and kinematic testing. (10.1007/s00167-011-1854-9)
  • [L4] The medial force ratio depends on both the tibiofemoral alignment and the nature of the activity involved and cannot be generalised to a single value. (10.1302/0301-620x.99b6.bjj-2016-0713.r1)
  • [L3] Jump direction significantly influenced knee biomechanics, suggesting that lateral jumps are the most dangerous of the stop-jumps. (10.1177/0363546505278696)
  • [L4] Nonsurgical management is advocated for isolated grade I or II posterior cruciate ligament injuries or for grade III injuries in patients with mild symptoms or low activity demands, while surgical management is reserved for high-demand athletes or patients in whom nonsurgical management has been unsuccessful. (10.5435/jaaos-d-14-00326)
  • [L4] The long-term results of the Broström procedure for chronic lateral ankle instability are excellent with 26-year follow-up. (10.1177/0363546505282616)
  • [L5] Based on the type and degree of pathologic laxity, a treatment algorithm has been developed. (10.1007/s00167-011-1857-6)
  • [L3] Although the ligament injury profile is similar, the post-operative complication rate is higher for simultaneous bilateral injuries. (10.1007/s00167-015-3720-7)
  • [L5] The presented classification may enable an objective assessment and documentation of the injury severity of the inherently complex pathology of injuries to the lateral side of the knee joint. (10.1007/s00167-020-06044-y)
  • [L2] An inability to complete jumping and landing tasks within 2 weeks of a first-time lateral ankle sprain and poorer dynamic postural control and lower self-reported function 6 months after a first-time lateral ankle sprain were predictive of eventual chronic ankle instability outcome. (10.1177/0363546516628870)
  • [L5] The term mid-flexion instability has entered the orthopaedic literature as a concept but has not been confirmed as a distinct clinical entity; the clinical scenario is more likely generalised instability with the appearance of stability in full extension from tight posterior structures. (10.1302/0301-620x.98b1.36445)
  • [Paper] In a biomechanical in vitro setting, addition of either ALLR or modified Ellison procedure restored overall native knee kinematics in a combined ACL plus anterolateral-deficient knee. (10.1136/jisakos-2019-000360)
  • [L5] Based on the mouse model, the findings indicate that severe ankle instability has nearly three times the chance to develop into ankle OA compared to moderate ankle instability. (10.1186/s12891-022-05164-5)
  • [L5] Treatment depends on severity: nonoperative for grade-I and most grade-II injuries, early repair or reconstruction for acute grade-III injuries, and reconstruction for chronic injuries, with failure to treat posterolateral corner injuries potentially causing cruciate ligament reconstruction failure. (10.2106/00004623-200101000-00015)
  • [L5] The authors hypothesize that anatomical features of the ankle act like domino pieces, where a lateral ankle sprain can initiate a cascade of damage to intra-articular ligaments and cartilage, leading to chronic instability and joint degeneration. (10.1002/ksa.12538)
  • [L5] A discrete anterolateral ligament was not observed; however, the anterolateral ligament described in recent studies likely refers to the capsulo-osseous layer or the mid-third capsular ligament. (10.1177/2325967117730805)
  • [L3] These findings suggest that the contralateral knee can be used as a reliable normal kinematic control. (10.1177/0363546508319051)
  • [L5] Both single-tunnel and double-tunnel reconstruction of the fibula were able to achieve better results for ankle instability, with no significant difference between the two surgical procedures in biomechanical outcomes. (10.1186/s12891-025-08994-1)
  • [L5] Construct II maintained tension during valgus load but did not restore valgus opening to the intact state, while Construct I failed to maintain tension. (10.1007/s00167-023-07438-4)
  • [L5] Ardèvol and colleagues, like all but one previous study in the field, favors non-operative functional treatment for complete ruptures of the ankle ligaments. (10.1007/s00167-002-0327-6)
  • [L5] Nonanatomic lateral extra-articular procedures performed at the time of anterior cruciate ligament reconstruction risk overconstraint, whereas anatomic anterolateral ligament reconstruction does not. (10.1016/j.arthro.2022.05.015)
  • [L4] Completely ruptured collateral ligaments frequently result in prolonged disability when treated non-operatively, whereas surgical repair of fourteen fingers with complete rupture yielded satisfactory results with restored joint stability and pain relief. (10.2106/00004623-196749020-00009)
  • [L4] Collateral ligament repair is indicated for patients operated on within three weeks of injury, and reconstruction of the ligament by means of a tendon graft is recommended for those treated more than three weeks after injury. (10.2106/00004623-197759010-00002)
  • [L4] Measurement using an open magnetic resonance imaging successfully quantified the remaining rotatory instability in anterior cruciate ligament–reconstructed knees. (10.1177/0363546508330134)
  • [L4] We found acceptable recorded outcomes in patients who underwent non-operative treatment of proximal and midsubstance grade-III MCL rupture and operative treatment of distal MCL avulsion with early bicruciate ligament reconstruction. (10.1007/s00167-020-06207-x)
  • [L2] The generally low methodological quality of studies on PCL injury management shows that caution is required when interpreting results, and firm recommendations on treatment choice cannot be given at this time. (10.1007/s00167-008-0632-9)
  • [L5] Nonsurgical, reparative, and reconstructive techniques can all be used to manage lateral collateral ligament injury about the knee; the optimal treatment is selected on the basis of injury severity. (10.5435/jaaos-d-16-00028)
  • [L5] Physeal-sparing medial patellofemoral ligament reconstruction is the treatment of choice for skeletally immature patients with recurrent instability, replacing older nonanatomic techniques. (10.5435/jaaos-d-17-00255)
  • [L5] While MRI can help predict high-grade rotatory instability and guide surgical planning, examining the patient with a pivot shift maneuver should remain the gold standard when there is doubt. (10.1016/j.arthro.2022.06.005)
  • [L4] Proper imaging sequences are of crucial importance to reliably follow these tears to determine their clinical significance. (10.1016/j.arthro.2016.02.012)
  • [L3] The smaller structures are difficult to assess with MRI, but direct visualization is not necessary to report a clinically unstable PLC injury. (10.1007/s00167-015-3738-x)
  • [L5] Careful examination comparing the involved and uninvolved knees, considering stress radiographs, and combining this with magnetic resonance imaging findings is currently our most accurate way to grade these injuries. (10.1016/j.arthro.2017.11.001)
  • [L4] Medial meniscus posterior root tear may occur in severe medial instability from trauma and is often missed on MRI diagnosis. (10.1007/s00167-014-3274-0)
  • [L4] The DIS procedure does not appear to be appropriate for providing predictable results in a young and active cohort of patients following ACL rupture, as it has an unacceptably high complication rate and leads to residual anteroposterior knee joint laxity of 3 mm or more in 49.1% of cases. (10.1007/s00167-018-5067-3)
  • [L3] The measurement of this angle using MRI images may allow for detection of ACL insufficiency and thus assist in an individualized and precise approach to the treatment of injuries to the ACL. (10.1007/s00167-021-06789-0)
  • [L3] In particular, abnormal MRI findings of the LCL were likely to be more frequent in the patients with more varus knee alignment. (10.1016/j.arthro.2014.11.027)
  • [L4] Overall complications were higher in patients with >2 ligaments injured, knee stiffness requiring MUA was more common in patients who had >2 ligaments ruptured and those treated acutely, and knees with all four ligaments injured were more likely to undergo revision surgery. (10.1007/s00167-014-3451-1)
  • [L4] The authors bring attention to the clinical, radiographic, and MRI findings associated with chronic irreducible posterolateral knee dislocation, noting that the classic dimple sign may be absent in chronic cases. (10.1016/j.arthro.2005.12.046)
  • [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)
  • [L4] Predictors of poor outcome were global arthrofibrosis and greater than 6-month time interval from primary reconstruction and surgical release. (10.1007/s00167-011-1472-6)
  • [L4] There was a statistically significant improvement in the patients' functional outcome, and 13/14 patients did not re-dislocate or experience instability. (10.1007/s00167-014-3001-x)
  • [L4] In this group of 9 cases, debridement of the torn ligament segment, in combination with resection of the impinging bone, was associated with marked symptomatic improvement and full return to activities for a minimum of 2 years. (10.1016/j.arthro.2018.02.037)
  • [L4] A one-stage protocol with early surgery rather than delayed reconstruction produced better clinical outcomes whatever the injured collateral ligament, medial or lateral. (10.1007/s00167-016-4067-4)

See Also

References

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[2] Combined Injuries of the Anterior Cruciate and Medial Collateral Ligaments of the Knee. Effect of Treatment on Stability and Function of the Joint. The Journal of Bone & Joint Surgery*. 1996. DOI: 10.2106/00004623-199602000-00002

[3] Reconstruction of the Medial Patellofemoral Ligament. The American Journal of Sports Medicine. 2014. DOI: 10.1177/0363546514529640

[4] Good rate of satisfaction but suboptimal clinical outcome at long‐term follow‐up in a large series of patients who had operative stabilization of the deltoid ligament of the ankle. Knee Surgery, Sports Traumatology, Arthroscopy. 2024. DOI: 10.1002/ksa.12459

[5] Generalized Joint Laxity in Orthopaedic Patients. Journal of Bone and Joint Surgery. 2019. DOI: 10.2106/jbjs.18.00458

[6] Treatment of Hyperextension. Arthroscopy. 2010. DOI: 10.1016/j.arthro.2010.06.015

[7] Anatomical Reconstruction of the Medial Collateral Ligament and Posteromedial Corner of the Knee in Patients With Chronic Medial Collateral Ligament Instability. The American Journal of Sports Medicine. 2009. DOI: 10.1177/0363546509332498

[8] Medial patellofemoral ligament reconstruction with bioactive synthetic ligament is an option. A 3‐year follow‐up study. Knee Surgery, Sports Traumatology, Arthroscopy. 2014. DOI: 10.1007/s00167-014-2970-0

[9] A systematic review on how to diagnose deltoid ligament injuries—are we missing a uniform standard?. BMC Musculoskeletal Disorders. 2024. DOI: 10.1186/s12891-024-07869-1

[10] Stress Radiographs for Ligamentous Knee Injuries. Arthroscopy. 2021. DOI: 10.1016/j.arthro.2020.11.001

[11] Comparative study between lateral extra-articular tenodesis versus anterolateral ligament reconstruction in combination with anterior cruciate ligament reconstruction. Journal of Orthopaedic Surgery and Research. 2026. DOI: 10.1186/s13018-025-06561-x

[12] Chapter 48 Ligamentous Knee Injuries. 2020.

[13] Laxity after complete release of the medial collateral ligament in primary total knee arthroplasty. Knee Surgery, Sports Traumatology, Arthroscopy. 2014. DOI: 10.1007/s00167-014-3288-7

[14] Arthroscopic treatment of ankle multiligamentous injuries provides similar clinical outcomes to the treatment of isolated lateral ligament injury at the 2‐year follow‐up. Knee Surgery, Sports Traumatology, Arthroscopy. 2024. DOI: 10.1002/ksa.12164

[15] The Accessory Anteroinferior Tibiofibular Ligament as a Cause of Talar Impingement. The American Journal of Sports Medicine. 2004. DOI: 10.1177/0095399703258697

[16] Clinical Characteristics and Outcomes After Anatomic Reconstruction of the Proximal Tibiofibular Joint. Arthroscopy. 2020. DOI: 10.1016/j.arthro.2020.01.056

[17] The deltoid ligament: an in‐depth review of anatomy, function, and treatment strategies. Knee Surgery, Sports Traumatology, Arthroscopy. 2012. DOI: 10.1007/s00167-012-2159-3

[18] Acute Distal Radioulnar Joint Instability in Adults. JBJS Reviews. 2014. DOI: 10.2106/jbjs.rvw.m.00110

[19] Return to sport following acute lateral ligament repair of the ankle in professional athletes. Knee Surgery, Sports Traumatology, Arthroscopy. 2015. DOI: 10.1007/s00167-015-3815-1

[20] Reference standards for stress radiography measurements in knee ligament injury and instability: a systematic review. Knee Surgery, Sports Traumatology, Arthroscopy. 2023. DOI: 10.1007/s00167-023-07617-3

[21] Traumatic Proximal Tibiofibular Dislocation. The American Journal of Sports Medicine. 2008. DOI: 10.1177/0363546507312162

[22] Outcomes After Isolated Medial Patellofemoral Ligament Reconstruction for Recurrent Patellar Instability: Influence of Persistent Postoperative Apprehension and J-Sign. The American Journal of Sports Medicine. 2025. DOI: 10.1177/03635465251339822

[23] Ultra-Low-Velocity Knee Dislocations. The American Journal of Sports Medicine. 2011. DOI: 10.1177/0363546511414855

[24] Arthroscopic Repair of Lateral Ankle Ligament for Chronic Lateral Ankle Instability: A Systematic Review. Arthroscopy. 2018. DOI: 10.1016/j.arthro.2018.02.034

[25] Midterm Results of Comprehensive Surgical Reconstruction Including Sulcus-Deepening Trochleoplasty in Recurrent Patellar Dislocations With High-Grade Trochlear Dysplasia. The American Journal of Sports Medicine. 2013. DOI: 10.1177/0363546513482302

[26] The Knee Anterolateral Ligament. Arthroscopy. 2014. DOI: 10.1016/j.arthro.2014.08.007

[27] Primary traumatic patellar dislocation. Journal of Orthopaedic Surgery and Research. 2012. DOI: 10.1186/1749-799x-7-21

[28] Differences between mechanically stable and unstable chronic ankle instability subgroups when examined by arthrometer and FAAM-G. Journal of Orthopaedic Surgery and Research. 2015. DOI: 10.1186/s13018-015-0171-2

[29] Instability of the Proximal Tibiofibular Joint. Journal of the American Academy of Orthopaedic Surgeons. 2003. DOI: 10.5435/00124635-200303000-00006

[30] The superficial medial collateral ligament is the major restraint to anteromedial instability of the knee. Knee Surgery, Sports Traumatology, Arthroscopy. 2020. DOI: 10.1007/s00167-020-05947-0

[31] The reliability of a method for measuring the anterior cruciate ligament‐hamstring reflex: an objective assessment of functional knee instability. Knee Surgery, Sports Traumatology, Arthroscopy. 2009. DOI: 10.1007/s00167-009-0837-6

[32] Abnormalities of foot and ankle alignment in individuals with chronic ankle instability: a systematic review. BMC Musculoskeletal Disorders. 2021. DOI: 10.1186/s12891-021-04537-6

[33] Editorial Commentary: The Pivot Shift and Lachman Examinations: Teammates With Distinct Roles. Arthroscopy: The Journal of Arthroscopic & Related Surgery. 2021. DOI: 10.1016/j.arthro.2020.12.001

[35] Results of multiple ligament reconstruction after knee dislocation——A prospective study with 95 patients and minimum 2-year follow up. BMC Musculoskeletal Disorders. 2021. DOI: 10.1186/s12891-021-04596-9

[36] Inclusion of open injuries in an updated Schenck classification of knee dislocations based on a global Delphi consensus study. Journal of ISAKOS. 2022. DOI: 10.1016/j.jisako.2022.02.003

[37] Chapter 16 Cruciate Ligament Injuries. 2019.

[38] Surgical treatment of multiple knee ligament injuries in 44 patients: 2–8 years follow‐up results. Knee Surgery, Sports Traumatology, Arthroscopy. 2006. DOI: 10.1007/s00167-006-0039-4

[39] In vivo laxity of stable versus anterior cruciate liagment‐injured knees using a navigation system: a comparative study. Knee Surgery, Sports Traumatology, Arthroscopy. 2009. DOI: 10.1007/s00167-009-0789-x

[40] Multiple ligament knee reconstruction clinical follow‐up and gait analysis. Knee Surgery, Sports Traumatology, Arthroscopy. 2008. DOI: 10.1007/s00167-008-0681-0

[42] An isolated lateral extra‐articular procedure for persisting rotatory instability following ACL reconstruction has low failure rates with good clinical and patient‐reported outcomes: A systematic review and meta‐analysis. Knee Surgery, Sports Traumatology, Arthroscopy. 2026. DOI: 10.1002/ksa.70373

[43] Ligamentous ankle injuries in relation to the morphology of the incisura fibularis: A systematic review. Journal of ISAKOS. 2025. DOI: 10.1016/j.jisako.2024.100361

[44] Medial patellofemoral ligament reconstruction for patellar instability in patients with hypermobility. The Journal of Bone and Joint Surgery. British volume. 2012. DOI: 10.1302/0301-620x.94b12.29562

[45] Simultaneous anterior and posterior cruciate ligament reconstruction in chronic knee instabilities: surgical concepts and clinical outcome. Knee Surgery, Sports Traumatology, Arthroscopy. 2008. DOI: 10.1007/s00167-008-0562-6

[46] Relationship of native tibial plateau anatomy with stability testing in the anterior cruciate ligament‐deficient knee. Knee Surgery, Sports Traumatology, Arthroscopy. 2011. DOI: 10.1007/s00167-011-1854-9

[47] Mediolateral force distribution at the knee joint shifts across activities and is driven by tibiofemoral alignment. The Bone & Joint Journal. 2017. DOI: 10.1302/0301-620x.99b6.bjj-2016-0713.r1

[48] 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

[49] Management of Posterior Cruciate Ligament Injuries. Journal of the American Academy of Orthopaedic Surgeons. 2016. DOI: 10.5435/jaaos-d-14-00326

[51] Twenty-six-Year Results after Broström Procedure for Chronic Lateral Ankle Instability. The American Journal of Sports Medicine. 2006. DOI: 10.1177/0363546505282616

[52] Rotatory knee laxity tests and the pivot shift as tools for ACL treatment algorithm. Knee Surgery, Sports Traumatology, Arthroscopy. 2011. DOI: 10.1007/s00167-011-1857-6

[53] Chapter 101 Knee Dislocations and Patellar Fractures. 2019.

[54] Simultaneous bilateral multiligamentous knee injuries are associated with more severe multisystem trauma compared to unilateral injuries. Knee Surgery, Sports Traumatology, Arthroscopy. 2015. DOI: 10.1007/s00167-015-3720-7

[55] The Posterolateral Instability Score (PoLIS) of the knee joint: a guideline for standardized documentation, classification, and surgical decision‐making. Knee Surgery, Sports Traumatology, Arthroscopy. 2020. DOI: 10.1007/s00167-020-06044-y

[57] Recovery From a First-Time Lateral Ankle Sprain and the Predictors of Chronic Ankle Instability. The American Journal of Sports Medicine. 2016. DOI: 10.1177/0363546516628870

[58] Mid-flexion instability after total knee arthroplasty. The Bone & Joint Journal. 2016. DOI: 10.1302/0301-620x.98b1.36445

[59] Different anterolateral procedures have variable impact on knee kinematics and stability when performed in combination with anterior cruciate ligament reconstruction. Journal of ISAKOS. 2021. DOI: 10.1136/jisakos-2019-000360

[60] Ligamentous injury-induced ankle instability causing posttraumatic osteoarthritis in a mouse model. BMC Musculoskeletal Disorders. 2022. DOI: 10.1186/s12891-022-05164-5

[61] Injuries of the Posterolateral Corner of the Knee. The Journal of Bone and Joint Surgery-American Volume. 2001. DOI: 10.2106/00004623-200101000-00015

[62] The ankle sprain and the domino effect. Knee Surgery, Sports Traumatology, Arthroscopy. 2024. DOI: 10.1002/ksa.12538

[63] The Anterolateral Complex of the Knee. Orthopaedic Journal of Sports Medicine. 2017. DOI: 10.1177/2325967117730805

[64] The Contralateral Knee Joint in Cruciate Ligament Deficiency. The American Journal of Sports Medicine. 2008. DOI: 10.1177/0363546508319051

[65] Fibula single-tunnel versus fibula double-tunnel for both anterior talofibular ligament and calcaneofibular ligament reconstruction: a biomechanical comparison. BMC Musculoskeletal Disorders. 2025. DOI: 10.1186/s12891-025-08994-1

[66] MCL internal brace does not fully recapitulate normal MCL function in valgus stress. Knee Surgery, Sports Traumatology, Arthroscopy. 2023. DOI: 10.1007/s00167-023-07438-4

[67] Treatment of lateral ankle sprains. Knee Surgery, Sports Traumatology, Arthroscopy. 2002. DOI: 10.1007/s00167-002-0327-6

[68] Editorial Commentary: Nonanatomic Lateral Extra‐Articular Procedures Performed at the Time of Anterior Cruciate Ligament Reconstruction Risk Overconstraint: Anatomic Anterolateral Ligament Reconstruction Does Not. Arthroscopy. 2022. DOI: 10.1016/j.arthro.2022.05.015

[69] Rupture of a Collateral Ligament of the Proximal Interphalangeal Joint of the Fingers. The Journal of Bone & Joint Surgery. 1967. DOI: 10.2106/00004623-196749020-00009

[70] Post-traumatic instability of the metacarpophalangeal joint of the thumb. The Journal of Bone & Joint Surgery. 1977. DOI: 10.2106/00004623-197759010-00002

[71] Chapter 112 Acute and Chronic Injuries of the Ankle. 2019.

[72] Quantitative Assessment of Rotatory Instability after Anterior Cruciate Ligament Reconstruction. The American Journal of Sports Medicine. 2009. DOI: 10.1177/0363546508330134

[73] Treatment of medial‐sided injuries in patients with early bicruciate ligament reconstruction for knee dislocation. Knee Surgery, Sports Traumatology, Arthroscopy. 2020. DOI: 10.1007/s00167-020-06207-x

[74] Clinical studies on posterior cruciate ligament tears have weak design. Knee Surgery, Sports Traumatology, Arthroscopy. 2008. DOI: 10.1007/s00167-008-0632-9

[75] Lateral Collateral Ligament Injury About the Knee: Anatomy, Evaluation, and Management. Journal of the American Academy of Orthopaedic Surgeons. 2018. DOI: 10.5435/jaaos-d-16-00028

[76] Surgical Management of Patellofemoral Instability in the Skeletally Immature Patient. Journal of the American Academy of Orthopaedic Surgeons. 2018. DOI: 10.5435/jaaos-d-17-00255

[77] Editorial Commentary : Magnetic Resonance Imaging Is Helpful in Predicting High‐Grade Knee Rotatory Instability: But When in Doubt, Always Examine the Patient. Arthroscopy. 2022. DOI: 10.1016/j.arthro.2022.06.005

[78] Visibility of Anterolateral Ligament Tears in Anterior Cruciate Ligament–Deficient Knees With Standard 1.5‐Tesla Magnetic Resonance Imaging. Arthroscopy. 2016. DOI: 10.1016/j.arthro.2016.02.012

[79] MRI injury patterns in surgically confirmed and reconstructed posterolateral corner knee injuries. Knee Surgery, Sports Traumatology, Arthroscopy. 2015. DOI: 10.1007/s00167-015-3738-x

[80] Editorial Commentary: Posterolateral Corner Injuries in Elite Athletes Remain a Challenging Diagnostic Problem. Arthroscopy. 2018. DOI: 10.1016/j.arthro.2017.11.001

[81] Traumatic posterior root tear of the medial meniscus in patients with severe medial instability of the knee. Knee Surgery, Sports Traumatology, Arthroscopy. 2014. DOI: 10.1007/s00167-014-3274-0

[82] High complication rate following dynamic intraligamentary stabilization for primary repair of the anterior cruciate ligament. Knee Surgery, Sports Traumatology, Arthroscopy. 2018. DOI: 10.1007/s00167-018-5067-3

[83] The posterior cruciate ligament inclination angle is higher in anterior cruciate ligament insufficiency. Knee Surgery, Sports Traumatology, Arthroscopy. 2021. DOI: 10.1007/s00167-021-06789-0

[84] Magnetic Resonance Imaging Findings of the Lateral Collateral Ligament and Popliteus Tendon in Symptomatic Knees Without Instability. Arthroscopy. 2015. DOI: 10.1016/j.arthro.2014.11.027

[86] Surgical treatment of multiligament knee injuries. Knee Surgery, Sports Traumatology, Arthroscopy. 2014. DOI: 10.1007/s00167-014-3451-1

[87] Chronic Irreducible Posterolateral Knee Dislocation: Two‐Stage Surgical Approach. Arthroscopy. 2006. DOI: 10.1016/j.arthro.2005.12.046

[88] 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

[89] Outcome of surgical treatment of arthrofibrosis following ligament reconstruction. Knee Surgery, Sports Traumatology, Arthroscopy. 2011. DOI: 10.1007/s00167-011-1472-6

[90] Arthroscopic medial capsular plication using the suture anchor technique. Knee Surgery, Sports Traumatology, Arthroscopy. 2014. DOI: 10.1007/s00167-014-3001-x

[91] Posterior Bony Impingement—Potential Mechanism of Ligamentum Teres Tears. Arthroscopy. 2018. DOI: 10.1016/j.arthro.2018.02.037

[92] Clinical outcomes after multiligament injured knees: medial versus lateral reconstructions. Knee Surgery, Sports Traumatology, Arthroscopy. 2016. DOI: 10.1007/s00167-016-4067-4

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2. Patent and trademark rights are not licensed under this Public License.

3. To the extent possible, the Licensor waives any right to collect royalties from You for the exercise of the Licensed Rights, whether directly or through a collecting society under any voluntary or waivable statutory or compulsory licensing scheme. In all other cases the Licensor expressly reserves any right to collect such royalties, including when the Licensed Material is used other than for NonCommercial purposes.

Section 3 -- License Conditions.

Your exercise of the Licensed Rights is expressly made subject to the following conditions.

a. Attribution.

1. If You Share the Licensed Material (including in modified form), You must:

a. retain the following if it is supplied by the Licensor with the Licensed Material:

i. identification of the creator(s) of the Licensed Material and any others designated to receive attribution, in any reasonable manner requested by the Licensor (including by pseudonym if designated);

ii. a copyright notice;

iii. a notice that refers to this Public License;

iv. a notice that refers to the disclaimer of warranties;

v. a URI or hyperlink to the Licensed Material to the extent reasonably practicable;

b. indicate if You modified the Licensed Material and retain an indication of any previous modifications; and

c. indicate the Licensed Material is licensed under this Public License, and include the text of, or the URI or hyperlink to, this Public License.

2. You may satisfy the conditions in Section 3(a)(1) in any reasonable manner based on the medium, means, and context in which You Share the Licensed Material. For example, it may be reasonable to satisfy the conditions by providing a URI or hyperlink to a resource that includes the required information.

3. If requested by the Licensor, You must remove any of the information required by Section 3(a)(1)(A) to the extent reasonably practicable.

4. If You Share Adapted Material You produce, the Adapter's License You apply must not prevent recipients of the Adapted Material from complying with this Public License.

Section 4 -- Sui Generis Database Rights.

Where the Licensed Rights include Sui Generis Database Rights that apply to Your use of the Licensed Material:

a. for the avoidance of doubt, Section 2(a)(1) grants You the right to extract, reuse, reproduce, and Share all or a substantial portion of the contents of the database for NonCommercial purposes only;

b. if You include all or a substantial portion of the database contents in a database in which You have Sui Generis Database Rights, then the database in which You have Sui Generis Database Rights (but not its individual contents) is Adapted Material; and

c. You must comply with the conditions in Section 3(a) if You Share all or a substantial portion of the contents of the database.

For the avoidance of doubt, this Section 4 supplements and does not replace Your obligations under this Public License where the Licensed Rights include other Copyright and Similar Rights.

Section 5 -- Disclaimer of Warranties and Limitation of Liability.

a. UNLESS OTHERWISE SEPARATELY UNDERTAKEN BY THE LICENSOR, TO THE EXTENT POSSIBLE, THE LICENSOR OFFERS THE LICENSED MATERIAL AS-IS AND AS-AVAILABLE, AND MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND CONCERNING THE LICENSED MATERIAL, WHETHER EXPRESS, IMPLIED, STATUTORY, OR OTHER. THIS INCLUDES, WITHOUT LIMITATION, WARRANTIES OF TITLE, MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT, ABSENCE OF LATENT OR OTHER DEFECTS, ACCURACY, OR THE PRESENCE OR ABSENCE OF ERRORS, WHETHER OR NOT KNOWN OR DISCOVERABLE. WHERE DISCLAIMERS OF WARRANTIES ARE NOT ALLOWED IN FULL OR IN PART, THIS DISCLAIMER MAY NOT APPLY TO YOU.

b. TO THE EXTENT POSSIBLE, IN NO EVENT WILL THE LICENSOR BE LIABLE TO YOU ON ANY LEGAL THEORY (INCLUDING, WITHOUT LIMITATION, NEGLIGENCE) OR OTHERWISE FOR ANY DIRECT, SPECIAL, INDIRECT, INCIDENTAL, CONSEQUENTIAL, PUNITIVE, EXEMPLARY, OR OTHER LOSSES, COSTS, EXPENSES, OR DAMAGES ARISING OUT OF THIS PUBLIC LICENSE OR USE OF THE LICENSED MATERIAL, EVEN IF THE LICENSOR HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH LOSSES, COSTS, EXPENSES, OR DAMAGES. WHERE A LIMITATION OF LIABILITY IS NOT ALLOWED IN FULL OR IN PART, THIS LIMITATION MAY NOT APPLY TO YOU.

c. The disclaimer of warranties and limitation of liability provided above shall be interpreted in a manner that, to the extent possible, most closely approximates an absolute disclaimer and waiver of all liability.

Section 6 -- Term and Termination.

a. This Public License applies for the term of the Copyright and Similar Rights licensed here. However, if You fail to comply with this Public License, then Your rights under this Public License terminate automatically.

b. Where Your right to use the Licensed Material has terminated under Section 6(a), it reinstates:

1. automatically as of the date the violation is cured, provided it is cured within 30 days of Your discovery of the violation; or

2. upon express reinstatement by the Licensor.

For the avoidance of doubt, this Section 6(b) does not affect any right the Licensor may have to seek remedies for Your violations of this Public License.

c. For the avoidance of doubt, the Licensor may also offer the Licensed Material under separate terms or conditions or stop distributing the Licensed Material at any time; however, doing so will not terminate this Public License.

d. Sections 1, 5, 6, 7, and 8 survive termination of this Public License.

Section 7 -- Other Terms and Conditions.

a. The Licensor shall not be bound by any additional or different terms or conditions communicated by You unless expressly agreed.

b. Any arrangements, understandings, or agreements regarding the Licensed Material not stated herein are separate from and independent of the terms and conditions of this Public License.

Section 8 -- Interpretation.

a. For the avoidance of doubt, this Public License does not, and shall not be interpreted to, reduce, limit, restrict, or impose conditions on any use of the Licensed Material that could lawfully be made without permission under this Public License.

b. To the extent possible, if any provision of this Public License is deemed unenforceable, it shall be automatically reformed to the minimum extent necessary to make it enforceable. If the provision cannot be reformed, it shall be severed from this Public License without affecting the enforceability of the remaining terms and conditions.

c. No term or condition of this Public License will be waived and no failure to comply consented to unless expressly agreed to by the Licensor.

d. Nothing in this Public License constitutes or may be interpreted as a limitation upon, or waiver of, any privileges and immunities that apply to the Licensor or You, including from the legal processes of any jurisdiction or authority.


Creative Commons is not a party to its public licenses. Notwithstanding, Creative Commons may elect to apply one of its public licenses to material it publishes and in those instances will be considered the “Licensor.” The text of the Creative Commons public licenses is dedicated to the public domain under the CC0 Public Domain Dedication. Except for the limited purpose of indicating that material is shared under a Creative Commons public license or as otherwise permitted by the Creative Commons policies published at creativecommons.org/policies, Creative Commons does not authorize the use of the trademark "Creative Commons" or any other trademark or logo of Creative Commons without its prior written consent including, without limitation, in connection with any unauthorized modifications to any of its public licenses or any other arrangements, understandings, or agreements concerning use of licensed material. For the avoidance of doubt, this paragraph does not form part of the public licenses.

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