UNASSIGNED: Multiligament knee injuries (MLKI), rare in adolescents, are challenging injuries that require complex surgical reconstruction. Historically, nonanatomic reconstructions have been associated with prolonged immobilization and failure to restore normal knee biomechanics, resulting in arthrofibrosis and high rates of graft failure.
UNASSIGNED: To describe the clinical and patient-reported outcomes (PROs) for adolescent patients treated with single-stage anatomic multiligament knee reconstruction.
UNASSIGNED: Case series; Level of evidence, 4.
UNASSIGNED: A single-center retrospective study was performed of patients ≤18 years old who underwent reconstruction of MLKIs by a single surgeon between 2014 and 2019 using a single-stage anatomic technique, with protected weightbearing and early range of motion. Complications were defined as infection, arthrofibrosis, deep vein thrombosis (DVT) or pulmonary embolus, and secondary surgery. PROs, including the pediatric version of the International Knee Documentation Committee (Pedi-IKDC) and the Tegner activity score, were obtained at a minimum of 2 years postoperatively.
UNASSIGNED: Included were 30 patients (21 male, 9 female; mean age, 15.4 years). The most common ligamentous reconstruction types were anterior cruciate ligament (ACL) + fibular collateral ligament (12 patients; 40%) and ACL + medial collateral ligament (9 patients; 30%). Three patients (10%) had secondary surgeries, including irrigation and debridement of a granuloma, a staged osteochondral allograft transplantation to a lateral femoral condyle impaction fracture, and repair of a medial meniscal tear and lateral femoral condyle fracture associated with new injuries 2 years after ACL + fibular collateral ligament reconstruction. Two patients (7%) developed arthrofibrosis and 1 patient (3%) developed DVT. PRO scores obtained at a mean of 37 months postoperatively included a mean Pedi-IKDC of 87 (range, 52-92) and a median highest Tegner score at any point postoperatively of 9 (range, 5-10). Of the patients who were athletes before their injury, 70% returned to the same or higher level of sport postoperatively.
UNASSIGNED: Reconstruction of MLKI in this series of adolescents with single-stage anatomic techniques and early range of motion resulted in low rates of secondary surgery, few complications, and good knee function as well as PRO scores at mean 3-year follow-up.

OBJECTIVE: To review and update the literature regarding outcomes following surgical management of chronic, grade III posterolateral corner (PLC) injuries, with an emphasis on estimating failure rates based upon objective parameters in light of the 2019 expert consensus, while secondarily comparing the failure rates of anatomic versus non-anatomic reconstruction techniques.
METHODS: A literature search was performed using the PubMed, Embase, MEDLINE, and Cochrane Library databases. Inclusion criteria consisted of level I-IV human clinical studies reporting subjective and objective outcomes in patients following surgical management for chronic (>6 weeks from injury) grade III PLC injuries, with a minimum two-year follow-up. The criterion for objective surgical failure was based on post-operative varus stress radiographs and defined as a side-to-side difference of 3 ​mm or more of lateral gapping.
RESULTS: A total of six studies, consisting of 10 separate cohorts encompassing a total of 230 patients, were identified. PLC reconstruction was performed in all cohorts, with 80 ​% (n ​= ​8/10) of these cohorts utilising an anatomic reconstruction technique. A failure rate ranging from 4.3 ​% to 36 ​% was found. Subgroup analysis revealed a failure rate of 4.3 ​%-24.2 ​% for anatomic reconstruction techniques, whereas a 0 ​%-36 ​% failure rate was found for non-anatomic reconstruction. Arthrofibrosis was the most common complication (range, 0 ​%-12.1 ​%) following surgery. 0 ​%-8 ​% of patients required revision PLC surgery.
CONCLUSIONS: PLC reconstruction yields a wide variability in failure rates according to the side-to-side difference of 3 ​mm or more of lateral gapping on post-operative varus stress radiographs, with low revision rates following anatomic and non-anatomic reconstruction techniques.
METHODS: IV; Systematic Review of Level III and IV studies.

BACKGROUND: The purpose of this study was to determine the clinical significance of signal hyperintensity in the proximal fibular collateral ligament (FCL) on coronal proton density (PD) fat-saturated (FS) MRI of the knee, a common finding. This study is unique in that it characterizes the FCL of a comprehensive, large cohort of both symptomatic and asymptomatic patients, which to our knowledge represents the first study with such broad inclusion criteria.
METHODS: A large case series was performed analyzing MRI of the knee of 250 patients from July 2021 through September 2021 and retrospectively reviewed. All studies were performed on 3-Tesla MRI scanners with a dedicated knee coil and in accordance with standard institutional knee MRI protocol. Signal in the proximal fibular collateral ligament was assessed on coronal PDFS and axial T2-weighted FS images. Increased signal was classified as none, mild, moderate, or severe. A corresponding chart review of clinic notes was performed to determine the presence or absence of lateral knee pain. An FCL sprain or injury was considered present if the medical record described tenderness on palpation of the lateral knee, positive finding against resistance to the leg (varus stress test) or reverse pivot shift, or any clinical suspicion for lateral complex sprain or posterolateral corner injury.
RESULTS: The majority (74%) of knee MRIs demonstrated the presence of increased signal in the proximal fibular collateral ligament on coronal PD FS images. <5% of these patients had associated clinical findings of fibular collateral ligament and/or lateral supporting structure injury.
CONCLUSIONS: Although increased signal in the proximal FCL of the knee is a common finding on coronal PDFS images, the majority are not associated with clinical symptoms. Thus, this increased signal is likely not a pathological finding in the absence of clinical findings of fibular collateral ligament sprain/injury. Our study emphasizes the importance of clinical correlation in identifying increased signal in the proximal FCL as pathologic.

UNASSIGNED: The isometric characteristics of nonanatomic and anatomic posterolateral corner (PLC) reconstruction techniques under weightbearing conditions remain unclear.
UNASSIGNED: To (1) simulate graft elongation patterns during knee flexion for 3 different PLC reconstruction techniques (Larson, Arciero, and LaPrade) and (2) compute the most isometric insertion points of the fibular collateral ligament (FCL) graft strands for each technique and report quantitative radiographic landmarks.
UNASSIGNED: Descriptive laboratory study.
UNASSIGNED: The authors performed a 3-dimensional simulation of 10 healthy knees from 0° to 120° of flexion using weightbearing computed tomography (CT) scans. The simulation was used to calculate ligament length changes during knee flexion for the PLC reconstruction techniques of Larson (nonanatomic single-bundle fibular sling reconstruction), Arciero (anatomic reconstruction with additional popliteofibular ligament graft strand), and LaPrade (anatomic reconstruction with popliteofibular ligament graft strand and popliteus tendon graft strand). The most isometric femoral insertion points for the FCL graft strands were computed within a 10-mm radius around the lateral epicondyle (LE), using an automatic string generation algorithm (0 indicating perfect isometry). Radiographic landmarks for the most isometric points were reported.
UNASSIGNED: Median graft lengthening during knee flexion was similar for the anterior graft strands of all 3 techniques. The posterior graft strands demonstrated significant differences, from lengthening for the Arciero (9.9 mm [range, 6.7 to 15.9 mm]) and LaPrade (10.2 mm [range, 4.1 to 19.7 mm]) techniques to shortening for the Larson technique (-17.1 mm [range, -9.3 to -22.3 mm]; P < .0010). The most isometric point for the FCL graft strands of all techniques was located at a median of 2.2 mm (range, -2.2 to 4.5 mm) posterior and 0.3 mm (range, -1.8 to 3.7 mm) distal to the LE.
UNASSIGNED: Overconstraint can be avoided by tensioning the posterior graft strands in the Larson technique in extension, and in the Arciero and LaPrade techniques at a minimum of 60° of knee flexion. The most isometric point was located posterodistal to the LE.
UNASSIGNED: The described isometric behavior of nonanatomic and anatomic PLC reconstruction techniques can guide optimal surgical reconstruction and prevent graft lengthening and overconstraint of the lateral compartment in knee flexion. Repetitive graft lengthening has been found to be associated with graft failure, and overconstraint favors lateral compartment pressure and cartilage degeneration.

BACKGROUND: The fibular collateral ligament is a permanent and extracapsular ligament of the knee joint. It is located on the lateral aspect of the knee and extends from the lateral epicondyle of the femur to the lateral surface of the head of the fibula. As one of the main knee joint ligaments it is a stabilizer of the posterolateral corner of the knee and resists varus stress. The case report displays the bifurcated variant of the fibular collateral ligament. The aim of this study is to determine which of those bands should be considered dominant.
METHODS: Classical anatomical dissection was performed on the left knee joint. The fibular collateral ligament was thoroughly cleansed around its origin, distal attachments, and course. Appropriate morphometric measurements were collected.
RESULTS: A bifurcated variant of the fibular collateral ligament with inverted proportions of its two bands (main and accessory one) constitutes our findings. It originated on the lateral epicondyle of the femur. Then it divided into two bands (A1 and A2). Band A1 inserted to the head of the fibula. A bony attachment of band A2 was located on the lateral aspect of the lateral condyle of the tibia.
CONCLUSIONS: Although the fibular collateral ligament is a permanent structure it presents morphological variations. It is important to constantly extend morphological knowledge for all scientists concerned in anatomy.

UNASSIGNED: The anterolateral ligament is a fibrous structure in the anterolateral aspect of the knee. Recently this liagament of the knee has gained spotlight in anatomical and imaging studies and has been designated as a new ligament of the knee joint. The anterolateral ligament (ALL) has been postulated to be a restraint against the anterolateral instability of the knee resulting in a positive pivot shift test. The purpose of this study is to provide detailed anatomical characteristics of ALL in the Indian population.
UNASSIGNED: The qualitative and quantitative characteristics of the ALL were observed in 20 embalmed cadaveric specimens. In all but one left male knee specimen (95%) ALL was observed. After isolating the ALL, its length, thickness, width, and points of attachments and dimensions of lateral collateral ligament (LCL) were determined.
UNASSIGNED: The ALL was consistently present in the anterolateral region of the knee separate from the joint capsule. Its proximal attachment to the femur is anterior and distal to the attachment of the LCL. Distally the superficial fibers of the ALL inserted close to the Gerdy\'s tubercle at the level of the fibular head, and the deeper fibers merged with the lateral meniscus. The mean length of the ALL was 43.35 mm ± 4.04 mm in flexion and 40.38 mm ± 4.35 mm in extension. The average width of the ALL was 6.98 mm ± 0.95 mm at its origin and 9.36 mm ± 1.07 mm at its insertion.
UNASSIGNED: The ALL is hypothesized to affect internal tibial rotation and plays a role in the pivot shift phenomenon. ALL rupture could be responsible for rotatory laxity after isolated intraarticular reconstruction of the ACL.

A 25-year-old male college student reported an immediate sharp pain in the lateral aspect of his left knee while playing recreational basketball. He sought a direct-access consultation by a physical therapist. Due to the superficial nature of the fibular (lateral) collateral ligament (FCL), static and dynamic ultrasound imaging was used to visualize the FCL. Complementing the clinical examination findings, use of dynamic imaging strengthened the differential diagnosis of multidirectional laxity and supported the clinical decision of referral. Subsequent follow-up magnetic resonance imaging confirmed tears of the anterior cruciate ligament and FCL.J Orthop Sports Phys Ther 2019;49(3):210. doi:10.2519/jospt.2019.8460.

BACKGROUND: Combined partial lateral collateral and complete anterolateral ligament (PLCCALL) injuries are a specific injury pattern seen in Brazilian jiu-jitsu (BJJ) because of the knee varus-flexion mechanism that frequently occurs during grappling.
OBJECTIVE: The purpose of this study was to evaluate the incidence of this injury pattern in a series of BJJ athletes with an acute knee injury and to evaluate clinical and functional outcomes after nonoperative management at a minimum follow-up of 1 year. Our hypotheses were that PLCCALL injuries are common in BJJ and that nonoperative treatment is associated with excellent clinical outcomes and return to the preinjury level of sport.
METHODS: Case series; Level of evidence, 4.
METHODS: All BJJ athletes who presented with an acute knee injury between July 2013 and June 2017 and who underwent magnetic resonance imaging (MRI) of the knee were included. A specific emphasis was placed on identifying those whose imaging demonstrated PLCCALL injury. Clinical evaluation included physical examination as well as Lysholm and International Knee Documentation Committee (IKDC) scores.
RESULTS: Of the 27 patients analyzed, 7 (25.9%) had MRI-proven PLCCALL injuries. The mean follow-up after nonoperative management was 41.3 months. The mean IKDC and Lysholm scores were 94 and 92 before the injury, 26 and 36 at the initial assessment after the injury, and 83 and 78 at 12-month follow-up, respectively (P < .00001). All 7 patients had returned to their preinjury level of sports by the 12-month follow-up. The mean time between injury and return to competition level was 4.7 months (range, 4-6 months).
CONCLUSIONS: PLCCALL injury is a specific but infrequent injury pattern in BJJ. The prognosis of this injury after nonoperative treatment appears to be excellent. Improved functional scores (IKDC and Lysholm) and changes on MRI demonstrated that the anterolateral ligament has intrinsic healing potential, as the images showed complete healing of the previously documented rupture of the anterolateral ligament from its proximal attachment.

BACKGROUND: The fibular collateral ligament (FCL) is subject to varus forces at all knee flexion angles and is also resistant to external rotation near extension. It originates on the lateral epicondyle of the femur and inserts on the lateral surface of the head of the fibula. However, its anatomical characteristics are inconsistent. Recent publications have focused on morphological variations concerning mainly femoral and fibular attachments, as well as morphometric measurements. Less attention has been paid to the morphology of the FCL and its relationship to the antero-lateral ligament (ALL).
UNASSIGNED: The aim of this paper is therefore to introduce the first complete classification of the FCL that includes all important aspects of morphological variability.
METHODS: Classical anatomical dissection was performed on 111 lower limbs (25 isolated and 86 paired) fixed in 10% formalin solution. The lateral compartment of the knee was investigated in detail.
RESULTS: The fibular collateral ligament was present in all specimens. The FCL originated most commonly (72.1% of cases) from the lateral femoral epicondyle, and the inserted on the lateral surface of the head of the fibula (Type I). In addition, bifurcated (Type IIa - 12.6%) and trifurcated (Type IIb - 0.9%) ligaments were also found with two and three distal bands, respectively. A double FCL was also found (Type III - 6.3%), as was fusion of the FCL and ALL (Type IV - 8.1%).
CONCLUSIONS: The FCL is characterized by high morphological variability. Knowledge of these variants is essential for surgeries performed in this region concerning the FCL and the ALL.
CONCLUSIONS: Distinguishing FCL from the FCL-ALL Complex is necessary when planning surgical procedures.

The posterolateral corner (PLC) of the knee is composed of numerous ligamentous and tendinous structures that provide restraint and stability. This anatomy is complex, and at times controversial. We present a comprehensive review of the normal anatomy and pathology of the PLC. We highlight potential pitfalls of image interpretation and detail what the referring physician needs to know.