Anatomic Study and Reanalysis of the Nomenclature of the Anterolateral Complex of the Knee Focusing on the Distal Iliotibial Band: Identification and Description of the Condylar Strap

Background: The capsulo-osseous layer (COL), short lateral ligament, mid–third lateral capsular ligament, lateral capsular ligament, and anterolateral ligament (ALL) are terms that have been used interchangeably to describe what is probably the same structure. This has resulted in confusion regarding the anatomy and function of the anterolateral complex of the knee and its relation to the distal iliotibial band (ITB). Purpose: To characterize the macroscopic anatomy of the anterolateral complex of the knee, in particular the femoral condylar attachment of the distal ITB. We identified a specific and consistent anatomic structure that has not been accurately described previously; it connects the deep surface of the ITB to the condylar area and is distinct from the ALL, COL, and Kaplan fibers. Study Design: Descriptive laboratory study. Methods: Sixteen fresh-frozen human cadaveric knees were used to study the anterolateral complex of the knee. Standardized dissections were performed that included qualitative and quantitative assessments of the anatomy through both anterior (n = 5) and posterior (n = 11) approaches. Results: The femoral condylar attachment of the distal ITB was not reliably identified by anterior dissection but was in all posterior dissections. A distinct anatomic structure, hereafter termed the “condylar strap” (CS), was identified between the femur and the lateral gastrocnemius on one side and the deep surface of the ITB on the other, in all posteriorly dissected specimens. The structure had a mean thickness of 0.88 mm, and its femoral insertion was located between the distal Kaplan fibers and the epicondyle. The proximal femoral attachment of the structure had a mean width of 15.82 mm, and the width of the distal insertion of the structure on the ITB was 13.27 mm. The mean length of the structure was 26.33 mm on its distal border and 21.88 mm on its proximal border. The qualitative evaluation of behavior in internal rotation revealed that this anatomic structure became tensioned and created a tenodesis effect on the ITB. Conclusion: There is a consistent structure that attaches to the deep ITB and the femoral epicondylar area. The orientation of fibers suggests that it may have a role in anterolateral knee stability. Clinical Relevance: This new anatomic description may help surgeons to optimize technical aspects of lateral extra-articular procedures in cases of anterolateral knee laxity.

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The Anterolateral Complex of the Knee

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967117730805 ◽

2017 ◽

Vol 5 (10) ◽

pp. 232596711773080 ◽

Cited By ~ 23

Author(s):

Elmar Herbst ◽

Marcio Albers ◽

Jeremy M. Burnham ◽

Freddie H. Fu ◽

Volker Musahl

Keyword(s):

Functional Unit ◽

Femoral Condyle ◽

Biceps Femoris ◽

Anterolateral Ligament ◽

Iliotibial Band ◽

Layer By Layer ◽

Anatomic Structure ◽

Capsular Ligament ◽

Anterolateral Complex ◽

Anterolateral Capsule

Background: Significant controversy exists regarding the anterolateral structures of the knee. Purpose: To determine the layer-by-layer anatomic structure of the anterolateral complex of the knee. Study Design: Descriptive laboratory study. Methods: Twenty fresh-frozen cadaveric knees (age range, 38-56 years) underwent a layer-by-layer dissection to systematically expose and identify the various structures of the anterolateral complex. Quantitative measurements were performed, and each layer was documented with high-resolution digital imaging. Results: The anterolateral complex of the knee consisted of different distinct layers, with the superficial and deep iliotibial band (ITB) representing layer 1. The superficial ITB had a distinct connection to the distal femoral metaphysis and femoral condyle (Kaplan fibers), and the deep layers of the ITB were identified originating at the level of the Kaplan fibers proximally. This functional unit, consisting of the superficial and deep ITB, was reinforced by the capsulo-osseous layer of the ITB, which was continuous with the fascia of the lateral gastrocnemius and biceps femoris muscles. These 3 components of the ITB became confluent distally, and the insertion spanned from the Gerdy tubercle anteriorly to the lateral tibia posteriorly on a small tubercle (lateral tibial tuberosity). Layer 3 consisted of the anterolateral capsule, in which 35% (7/20) of specimens had a discreet mid-third capsular ligament. Conclusion: The anterolateral complex consists of the superficial and deep ITB, the capsulo-osseous layer of the ITB, and the anterolateral capsule. The anterolateral complex is defined by the part of the ITB between the Kaplan fibers proximally and its tibial insertion, which forms a functional unit. 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. Clinical Relevance: The anterolateral knee structures form a complex functional unit. Surgeons should use caution when attempting to restore this intricate structure with extra-articular procedures designed to re-create a single discreet ligament.

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Maxillary Incisive Canal Characteristics: A Radiographic Study Using Cone Beam Computerized Tomography

Radiology Research and Practice ◽

10.1155/2019/6151253 ◽

2019 ◽

Vol 2019 ◽

pp. 1-5 ◽

Cited By ~ 1

Author(s):

Penala Soumya ◽

Pradeep Koppolu ◽

Krishnajaneya Reddy Pathakota ◽

Vani Chappidi

Keyword(s):

Central Incisor ◽

Anatomic Structure ◽

Incisive Canal ◽

Maxillary Central Incisor ◽

Implant Placement ◽

Mean Width ◽

Immediate Implant ◽

Thin Bone ◽

Incisive Foramen ◽

The Mean

Background. The incisive canal located at the midline, posterior to the central incisor, is an important anatomic structure of this area to be considered while planning for immediate implant placement in maxillary central incisor region. The purpose of the present study is to assess incisive canal characteristics using CBCT sections. Materials and Methods. CBCT scans of 79 systemically healthy patients, with intact maxillary incisors, were evaluated by two calibrated and independent examiners. Assessments included (1) mesiodistal diameter, (2) labiopalatal diameter, (3) length of the incisive canal, (4) shape of incisive canal, and (5) width of the bone anterior to the incisive foramen. Results. The mean width of the foramen labiopalatally and mesiodistally was 3.12 ± 0.94 mm and 3.23 ± 0.98 mm, respectively. Mean canal length was 18.63 ± 2.35 mm and males have significantly longer incisive canal than females. The mean width of bone anterior to the incisive canal was 6.32 ± 1.43 mm. As age of the subjects increased, incisive foramen diameter and incisive canal length were found to be increased. Cylindrical shaped incisive canals were seen in most of the individuals followed by funnel shaped and hour-glass shaped canals, and banana-like canal is least prevalent type. Conclusion. The findings from the present study suggest that the diameter and length of incisive canal vary among different individuals and presence of very thin bone anterior to the canal would suggest that a pretreatment CBCT scan is a valuable tool to evaluate anatomic variations, morphology, and dimensions of incisive foramen before immediate implant placement in maxillary central incisor region.

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Segond tibial condyle fracture: lateral capsular ligament avulsion.

Radiology ◽

10.1148/radiology.159.2.3961179 ◽

1986 ◽

Vol 159 (2) ◽

pp. 467-469 ◽

Cited By ~ 111

Author(s):

G W Dietz ◽

D M Wilcox ◽

J B Montgomery

Keyword(s):

Capsular Ligament ◽

Tibial Condyle ◽

Lateral Capsular Ligament ◽

Condyle Fracture

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The Magnetic Resonance Imaging Appearance of Individual Structures of the Posterolateral Knee

The American Journal of Sports Medicine ◽

10.1177/03635465000280020901 ◽

2000 ◽

Vol 28 (2) ◽

pp. 191-199 ◽

Cited By ~ 199

Author(s):

Robert F. LaPrade ◽

Thomas J. Gilbert ◽

Timothy S. Bollom ◽

Fred Wentorf ◽

Gregory Chaljub

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Biceps Femoris ◽

Surgical Reconstruction ◽

Iliotibial Band ◽

Resonance Imaging ◽

Popliteofibular Ligament ◽

Imaging Appearance ◽

Magnetic Resonance Imaging Appearance ◽

Lateral Capsular Ligament

The purpose of this study was to contrast the magnetic resonance imaging appearance of uninjured components of the posterolateral knee with that of injured structures, and to assess the accuracy of magnetic resonance imaging in identifying posterolateral knee complex injuries. Thin-slice coronal oblique T1-weighted images through the entire fibular head were used to identify the posterolateral structures in seven uninjured knees. The appearance of corresponding grade III injuries to these structures was identified prospectively in 20 patients and verified at the time of surgical reconstruction. The sensitivity, specificity, and accuracy of imaging for the most frequently injured posterolateral knee structures in this series were as follows: iliotibial band-deep layer (91.7%, 100%, and 95%), short head of the biceps femoris-direct arm (81.3%, 100%, and 85%), short head of the biceps femoris-anterior arm (92.9%, 100%, and 95%), midthird lateral capsular ligament-meniscotibial (93.8%, 100%, and 95%), fibular collateral ligament (94.4%, 100%, and 95%), popliteus origin on femur (93.3%, 80%, and 90%), popliteofibular ligament (68.8%, 66.7%, and 68%), and the fabellofibular ligament (85.7%, 85.7%, and 85.7%). Magnetic resonance imaging of the knee was accurate in the identification of these injuries.

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Anatomic and Histological Investigation of the Anterolateral Capsular Complex in the Fetal Knee

The American Journal of Sports Medicine ◽

10.1177/0363546517692534 ◽

2017 ◽

Vol 45 (6) ◽

pp. 1383-1387 ◽

Cited By ~ 16

Author(s):

Soheil Sabzevari ◽

Amir Ata Rahnemai-Azar ◽

Marcio Albers ◽

Monica Linde ◽

Patrick Smolinski ◽

...

Keyword(s):

Gestational Age ◽

Histological Analysis ◽

External Rotation ◽

Lower Limbs ◽

Iliotibial Band ◽

Popliteus Tendon ◽

Superficial Fascia ◽

Anterolateral Complex ◽

Anterolateral Capsule ◽

Ligamentous Structure

Background: There is currently disagreement with regard to the presence of a distinct ligament in the anterolateral capsular complex of the knee and its role in the pivot-shift mechanism and rotatory laxity of the knee. Purpose: To investigate the anatomic and histological properties of the anterolateral capsular complex of the fetal knee to determine whether there exists a distinct ligamentous structure running from the lateral femoral epicondyle inserting into the anterolateral tibia. Study Design: Descriptive laboratory study. Methods: Twenty-one unpaired, fresh fetal lower limbs, gestational age 18 to 22 weeks, were used for anatomic investigation. Two experienced orthopaedic surgeons performed the anatomic dissection using loupes (magnification ×3.5). Attention was focused on the anterolateral and lateral structures of the knee. After the skin and superficial fascia were removed, the iliotibial band was carefully separated from underlying structures. The anterolateral capsule was then examined under internal and external rotation and varus-valgus manual loading and at different knee flexion angles for the presence of any ligamentous structures. Eight additional unpaired, fetal lower limbs, gestational age 11 to 23 weeks, were used for histological analysis. Results: This study was not able to prove the presence of a distinct capsular or extracapsular ligamentous structure in the anterolateral capsular complex area. The presence of the fibular collateral ligament, a distal attachment of the biceps femoris, the entire lateral capsule, the iliotibial band, and the popliteus tendon in the anterolateral and lateral area of the knee was confirmed in all the samples. Histological analysis of the anterolateral capsule revealed a loose, hypocellular connective tissue with less organized collagen fibers compared with ligament and tendinous structures. Conclusion: The main finding of this study was that the presence of a distinct ligamentous structure in the anterolateral complex is not supported from a developmental point of view, while all other anatomic structures were present. Clinical Relevance: The inability to prove the existence of a distinct ligamentous structure, called the anterolateral ligament, in the anterolateral knee capsule may indicate that the other components of the anterolateral complex, such as the lateral capsule, the iliotibial band, and its capsule-osseous layer, are more important for knee rotatory stability.

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The Anterolateral Complex of the Knee

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967118s00031 ◽

2018 ◽

Vol 6 (4_suppl2) ◽

pp. 2325967118S0003

Author(s):

Elmar Herbst ◽

Marcio Albers ◽

Andreas Imhoff ◽

Freddie Fu ◽

Volker Musahl

Keyword(s):

Insertion Site ◽

Posterior Part ◽

Biceps Muscle ◽

Capsular Ligament ◽

Femoral Metaphysis ◽

Complex Anatomy ◽

Anterolateral Complex ◽

Anterolateral Capsule ◽

Distal Femoral Metaphysis ◽

Gerdy’S Tubercle

The objective of this study was to clarify the layer-by-layer anatomy of the anterolateral complex of the knee. Twenty fresh-frozen human cadaveric knees (age range 38 - 56 yrs.) without any history of knee injury or surgery were used for this dissection study. After skin and subcutaneous tissue removal, the ITB was incised in its most anterior part and reflected posteriorly followed by blunt dissection of its deeper layers. Subsequently, an incision was made between the ITB and the short head of the biceps muscle with consecutive evaluation of the insertion site of the biceps tendon and its extensions. Once the deep layers of the ITB were identified, the connections to the lateral intermuscular septum and Kaplan fibers were cut. The superficial ITB was then reflected distally in order to assess the geographical relationship between the superficial and deep ITB as well as the distal anteromedial aspect of the biceps muscle. Finally, the anterolateral capsule was incised to evaluate its connections to the surrounding anatomic structures. The anterolateral aspect of the knee consists of three distinct layers. Superficially, the ITB with its insertion to Gerdy’s tubercle and extensions to the patella (iliopatellar band) was appreciated. Posterior reflection of the superficial ITB revealed a firm distinct connection of Kaplan fibers to the distal femoral metaphysis. The deep layer of the ITB runs from the Kaplan fibers in a distal direction and forms a functional arc. This arc is reinforced by the capsulo-osseous layer of the ITB, which originates from an area distal to the Kaplan fibers, the fascia of the lateral gastrocnemius and plantaris muscles. The distal half of the capsulo-osseous layer merges posteriorly with the fascia of the biceps muscle. The three layers of the ITB become confluent distally. Its insertion spanned from Gerdy’s tubercle to an area just posteriorly, with the capsulo-osseous layer forming the posterior part. The biceps muscle has fascial and aporoneurotical extensions, which insert to the proximal tibia together with the capsulo-osseous layer of the ITB. Layer 3 consists of the anterolateral capsule. In 7/20 (35%) specimens the mid-third capsular ligament was observed as a thickening within, but not separate from the anterolateral capsule. The anterolateral complex of the knee consists of the ITB with its three layers, the functional arc formed by the fibers between the distal femoral metaphysis and Gerdy’s tubercle, and the anterolateral capsule. In 35% of specimens a capsular thickening (mid-third capsular ligament) was identified. Surgeons should consider the complex anatomy of this functional unit, i.e. the anterolateral complex, when considering lateral extra-articular procedures.

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