Medial Collateral Ligament Complex Research Articles

High prevalence of associated injuries in anterior cruciate ligament tears: A detailed magnetic resonance imaging analysis of 254 patients.

To evaluate the type and prevalence of associated injuries by using magnetic resonance imaging (MRI) in patients with anterior cruciate ligament (ACL) tears. Data from the Natural Corollaries and Recovery after ACL injury multicenter longitudinal cohort study were analyzed. Between May 2016 and October 2018, patients aged between 15 and 40years, who had experienced an ACL tear within the last 6weeks and sought medical attention at one of seven healthcare clinics in Sweden, were invited to participate. The mean time from injury to MRI was 19.6 ± 15.2days. An orthopedic knee surgeon and a musculoskeletal radiologist reviewed all the MRI scans. The following structures were assessed: posterior cruciate ligament (PCL), medial collateral ligament (MCL) complex, lateral collateral ligament (LCL), popliteus tendon, medial meniscus (MM), lateral meniscus (LM), and cartilage. In addition, the presence of bone bruising, impaction fractures in the lateral femoral condyle (LFC) or posterolateral tibia (PLT), and Segond fractures were also assessed. RESULTS: A total of 254 patients (48.4% males) with a mean age of 25.4 ± 7.1 years were included. The prevalence of associated injuries was as follows: PCL (0.4%), MCL {41.3% [superficial MCL and deep MCL (dMCL) 16.5%; isolated dMCL 24.8%]}, LCL (2.4%), MM (57.4%), LM (25.2%), cartilage (15.0%), bone bruising (92.9%), impaction fracture in the LFC (45.7%) and PLT (4.7%), and Segond fracture (7.5%). The prevalence of associated injuries in patients with ACL tears was high. The findings reported in this study may serve as a reference tool for orthopedic surgeons and radiologists in the diagnosis of associated injuries using MRI in patients with ACL tears.

Reconstruction of the Medial Collateral Ligament Complex With a Flat Allograft Semitendinosus Tendon

The aim of this Technical Note is to reconstruct the medial collateral ligament complex with the superior medial collateral ligament and posterior oblique ligament as anatomically as possible. An allograft or contralateral semitendinosus autograft is used for anatomic reconstruction of the superior medial collateral ligament and posterior oblique ligament. After bony fixation, the tendon bundles are sutured to the remnants of the medial collateral ligament complex. Thus, the tubular grafts are pulled apart to form a flat shape that resembles that of the normal medial ligaments.

Ligamentous injuries of the ankle joint : Importance of radiological imaging procedures

Injuries of the ankle joint show lesions of the lateral ligamentous apparatus with an incidence of 1 in 1000cases. With arange of 0.3-0.7 in 1000 cases, injuries of the medial ligamentous apparatus occur more frequently than previously thought and are often overlooked. Correct imaging diagnostics of the ankle ligaments are mandatory for the prognosis and treatment planning. In cases of clinically strong suspicion of ligamentous injury or osteochondral lesions of the ankle joint, after primary radiographic evaluation magnetic resonance imaging (MRI) is primarily recommended for a more precise assessment. Additionally, the sensitivity for assessment of the ligaments with ultrasonography is good (91% vs. 97% with MRI) but its specificity is inferior compared to MRI (63% vs. 93% with MRI). Supination trauma is the most common ankle injury and attention should be paid to the anterior tibiofibular ligament and calcaneofibular ligament. In approximately 50%, injuries to the superficial layer of the medial collateral ligament complex are associated with lesions of the posterior tibiotalar ligament.

Association of medial collateral ligament complex injuries with anterior cruciate ligament ruptures based on posterolateral tibial plateau injuries

BackgroundThe combined injury of the medial collateral ligament complex and the anterior cruciate ligament (ACL) is the most common two ligament injury of the knee. Additional injuries to the medial capsuloligamentous structures are associated with rotational instability and a high failure rate of ACL reconstruction. The study aimed to analyze the specific pattern of medial injuries and their associated risk factors, with the goal of enabling early diagnosis and initiating appropriate therapeutic interventions, if necessary.ResultsBetween January 2017 and December 2018, 151 patients with acute ACL ruptures with a mean age of 32 ± 12 years were included in this study. The MRIs performed during the acute phase were analyzed by four independent investigators—two radiologists and two orthopedic surgeons. The trauma impact on the posterolateral tibial plateau and associated injuries to the medial complex (POL, dMCL, and sMCL) were examined and revealed an injury to the medial collateral ligament complex in 34.4% of the patients. The dMCL was the most frequently injured structure (92.2%). A dMCL injury was significantly associated with an increase in trauma severity at the posterolateral tibial plateau (p < 0.02) and additional injuries to the sMCL (OR 4.702, 95% CL 1.3–133.3, p = 0.03) and POL (OR 20.818, 95% CL 5.9–84.4, p < 0.0001). Isolated injuries to the sMCL were not observed. Significant risk factors for acquiring an sMCL injury were age (p < 0.01) and injury to the lateral meniscus (p < 0.01).ConclusionIn about one-third of acute ACL ruptures the medial collateral ligament complex is also injured. This might be associated with an increased knee laxity as well as anteromedial rotational instability. Also, this might be associated with an increased risk for failure of revision ACL reconstruction. In addition, we show risk factors and predictors that point to an injury of medial structures and facilitate their diagnosis. This should help physicians and surgeons to precisely diagnose and to assess its scope in order to initiate proper therapies. With this in mind, we would like to draw attention to a frequently occurring combination injury, the so-called “unlucky triad” (ACL, MCL, and lateral meniscus).Level of evidence Level III Retrospective cohort study.

Ligamentous injuries of the ankle joint : Importance of radiological imaging procedures

Injuries of the ankle joint show lesions of the lateral ligamentous apparatus with an incidence of 1 in 1000cases. With arange of 0.3-0.7 in 1000 cases, injuries of the medial ligamentous apparatus occur more frequently than previously thought and are often overlooked. Correct imaging diagnostics of the ankle ligaments are mandatory for the prognosis and treatment planning. In cases of clinically strong suspicion of ligamentous injury or osteochondral lesions of the ankle joint, after primary radiographic evaluation magnetic resonance imaging (MRI) is primarily recommended for a more precise assessment. Additionally, the sensitivity for assessment of the ligaments with ultrasonography is good (91% vs. 97% with MRI) but its specificity is inferior compared to MRI (63% vs. 93% with MRI). Supination trauma is the most common ankle injury and attention should be paid to the anterior tibiofibular ligament and calcaneofibular ligament. In approximately 50%, injuries to the superficial layer of the medial collateral ligament complex are associated with lesions of the posterior tibiotalar ligament.

High Prevalence of Superficial and Deep Medial Collateral Ligament Injuries on Magnetic Resonance Imaging in Patients With Anterior Cruciate Ligament Tears

To assess the prevalence of and factors associated with medial collateral ligament (MCL) complex injuries on magnetic resonance imaging (MRI) in patients with anterior cruciate ligament (ACL) tears. Data were extracted from the Natural Corollaries and Recovery After ACL Injury (NACOX) multicenter longitudinal cohort study. Between May 2016 and October 2018, patients who presented to 1 of 7 health care clinics across Sweden with an ACL tear sustained no more than 6 weeks earlier and who were aged between 15 and 40 years at the time of injury were invited to participate. All the patients included in this study underwent MRI. The mean time from injury to MRI was 19.6 ± 15.2 days. An orthopaedic surgeon specializing in knee surgery and a musculoskeletal radiologist reviewed all MRI scans. Injuries to the superficial MCL (sMCL), deep MCL (dMCL), and posterior oblique ligament were identified. Stepwise forward multiple binary logistic regression analyses were used to evaluate patient characteristics (age, sex, body mass index, preinjury Tegner activity level, and activity at injury) and injuries on MRI (lateral meniscus [LM] injury, medial meniscus [MM] injury, pivot shift-type bone bruising, medial femoral condyle [MFC] bone bruising, and lateral femoral condyle [LFC] impaction) associated with the presence of MCL complex tears. In total, 254 patients (48.4% male patients) with a mean age of 25.4 ± 7.1 years were included. The overall prevalence of MCL (sMCL and dMCL) injuries and isolated dMCL injuries was 16.5% (42 of 254) and 24.8% (63 of 254), respectively. No isolated sMCL injuries were found. Posterior oblique ligament injuries were found in 12 patients (4.7%) with MCL (sMCL and dMCL) injuries. An LM injury (odds ratio [OR], 3.94; 95% confidence interval [CI], 1.73-8.94; P= .001) and LFC impaction (OR, 2.37; 95% CI, 1.11-5.07; P= .02) increased the odds of having an MCL injury, whereas an MM injury (OR, 0.26; 95% CI, 0.12-0.59; P= .001) reduced the odds. Isolated dMCL injuries were significantly associated with MFC bone bruising (OR, 4.21; 95% CI, 1.92-9.25; P < .001) and LFC impaction (OR, 3.86; 95% CI, 1.99-7.49; P < .001). The overall combined prevalence of MCL (sMCL and dMCL) injuries and isolated dMCL injuries in patients with ACL tears was high (16.5%+ 24.8%= 41.3%). The presence of an LM injury and LFC impaction increased the odds of having an MCL injury, whereas the presence of an MM injury reduced the odds. MFC bone bruising and LFC impaction were associated with the presence of isolated dMCL injuries. Level III, retrospective cohort study.

Arthroscopic Medial Compartment Drive-Through Sign for Knee Medial Collateral Ligament Complex Injuries

Acute injuries of the knee medial collateral ligament complex concomitant with anterior cruciate ligament injuries are common. The exact site of the injury may be difficult to diagnose preoperatively on magnetic resonance imaging. This study describes an arthroscopic sign that helps determine the site of the knee medial collateral ligament complex injury. The “medial compartment drive-through sign,” visualized during arthroscopy, is described as an excessive opening of the medial compartment. If this excessive opening is above the meniscus, it corresponds to a femoral-sided injury; conversely, if the excessive opening is below the meniscus, then it is a tibial-sided injury. This allows a precise surgical incision to be made, thereby avoiding extensive approaches and possible wound-related complications.

Bone marrow edema of the medioplantar talar head is associated with severe ligamentous injury in ankle sprain

PurposeTo investigate the predictive value of talar head edema (THE) in acute ankle sprain for the presence of concomitant ligament injuries.MethodsThis retrospective study was approved by the ethics committee and informed consent was obtained. One hundred patients (mean age: 37 years ± 14 [standard deviation], range 13–77 years) with MRI of the ankle after acute trauma were included. The cohort in this matched-pair study consisted of 50 patients with THE (group 1) and 50 patients without THE (group 2). Two readers independently evaluated presence and size of bone marrow edema of the talus head and injuries of the lateral, medial, talonavicular, and spring ligament complex. Statistics included intraclass correlation coefficient (ICC) and Kappa statistics as well as parametric and non-parametric tests.ResultsOn average, patients with THE demonstrated significantly more ligament injuries in comparison to patients without THE (3.7 vs. 1.3, p ≤ 0.01). Also, in patients with THE, the number of injured ligaments was significantly higher at the lateral (p = 0.03), medial (p ≤ 0.01), and talonavicular (p ≤ 0.01) compartment in comparison to patients without THE. The most frequently injured ligaments in patients with THE were the anterior talofibular ligament (60%) and the anterior tibiotalar ligament (42%). There was no significant correlation between edema size and the number of injured ligaments or compartments (p = 0.5).ConclusionTHE is associated with more extensive ligamentous ankle injury, in particular to the medial and lateral collateral ligament complex, and therefore indicative of severe ankle trauma.

Treatment of Combined Injuries to the ACL and the MCL Complex: A Consensus Statement of the Ligament Injury Committee of the German Knee Society (DKG).

Background:Different indications and treatment options for combined injuries to the anterior cruciate ligament (ACL) and medial collateral ligament complex (MCL) are not clearly defined.Purpose:To perform a modified Delphi process with the Committee for Ligament Injuries of the German Knee Society (DKG) in order to structure and optimize the process of treating a combined injury to the ACL and MCL.Study Design:Consensus statement.Methods:Scientific questions and answers were created based on a comprehensive literature review using the central registers for controlled studies of Medline, Scopus, and Cochrane including the terms medial collateral ligament, anterior cruciate ligament, MCL, ACL, and outcome used in various combinations. The obtained statements passed 3 cycles of a modified Delphi process during which each was readjusted and rated according to the available evidence (grades A-E) by the members of the DKG Ligament Injuries Committee and its registered guests.Results:The majority of answers, including several questions with >1 graded answer, were evaluated as grade E (n = 16) or C (n = 10), indicating that a low level of scientific evidence was available for most of the answers. Only 5 answers were graded better than C: 3 answers with a grade of A and 2 answers with a grade of B. Only 1 answer was evaluated as grade D. An agreement of >80% (range, 83%-100%) among committee members was achieved for all statements.Conclusion:The results of this modified Delphi process offer a guideline for standardized patient care in cases of combined injuries to the ACL and MCL.

Recognizing the Role of the Posterolateral Corner in Patients Undergoing Total Knee Arthroplasty for Fixed Varus Deformity.

PurposeVarus deformity is the commonest presentation of the arthritic knee requiring surgical intervention. While correctable deformities lend themselves to realignment options like unicompartmental replacement, fixed deformities often need a total knee replacement. Current treatment options for patients with fixed coronal varus malalignment undergoing total knee arthroplasty include varying degrees of medial soft tissue releases, often leading to infringement of the medial collateral ligament complex and increased use of constrained options. We describe the role of the posterolateral (PL) tether in a select subgroup of patients needing release to achieve correction and minimising use of constrained options.Patients and MethodsA total of 384 patients with fixed varus deformity were retrospectively evaluated and categorised on the basis of weight bearing x-rays into four groups, namely, knees with angulation (F1), angulation with subluxation and torsion (F2), medial translation (F3) and deformity with major medial bone loss (F4). From this cohort, we identified patients with a tight PL tether that needed release to achieve good correction. These were predominantly in the F2 and F3 subgroups. Functional scores and outcomes were evaluated at a mean follow-up of 120.23 months.ResultsF1 cohort achieved good correction with medial soft tissue release, while F2 and F3 cohorts often needed a PL release. While functional outcomes and scores were comparable in both groups, survivorship was better in the group where release was done.ConclusionWe recognise the role of the PL tether in a subgroup of patients with recalcitrant fixed varus deformities. Sequential release helped achieve good outcomes with minimal use of constrained options.Level of EvidenceThree.

Ligament Balancing and Constraint in Revision Total Knee Arthroplasty.

Ligament balancing in revision knee arthroplasty is crucial to the success of the procedure. The medial collateral ligament and lateral ligament complex are the primary ligamentous structures that provide stability. Revisions can be performed with nonconstrained cruciate-retaining, posterior cruciate substituting, or anterior-stabilized/ultracongruent inserts when there are symmetrical flexion/extension gaps and intact collateral ligaments. When the collateral ligaments are insufficient either due to attenuation or incompetence from bone loss, a more constrained knee system is needed. Constrained condylar knees provide increased stability to both varus/valgus and rotation forces with a nonlinked construct. This increased constraint, however, does lead to increased stress at the implant-bone interface which requires more robust metaphyseal fixation. In cases of significant soft tissue disruption, severe flexion/extension gap mismatch or extensor mechanism disruption, a rotating hinge knee is needed to restore stability. Advances in revision implant design have led to improved outcomes and longer survivorship then earlier iterations of these implants. Surgeons should always strive to use the least constraint needed to achieve stability but must have a low threshold to increase constraint when ligament integrity is compromised.

Topographic and Histologic Analysis of the Collateral Ligament Complex around the Elbow

Purpose: The purpose of this study was to evaluate topographic anatomy of the footprints of key ligaments of the elbow and assess their relationships with bony parameters using micro-computed tomography (micro-CT). Additionally, the ratios of type I/III collagen at the medial collateral ligament (MCL) and lateral collateral ligament (LCL) of elbow were investigated.Methods: Eleven cadaveric elbows attached by both the MCL and LCL were scanned using micro-CT and reconstructed three-dimensionally. Additionally, the ligaments were examined under polarized light microscopy to determine the histological characteristics of collagen patterns. Results: Areas of footprints of the MCL and LCL attaching onto the humerus were 133.2±25.8 mm² and 128.3±23.2 mm², respectively. Footprint sizes of anterior and posterior bundles of the MCL in the proximal ulna and lateral ulnar collateral ligament (LUCL) attaching to the proximal ulna averaged to 109.9 mm², 89.2 mm², and 89.7 mm², respectively. There were a positive correlation between footprint size of the MCL and LUCL at the humeral side and a negative correlation between the footprint size of the MCL at humeral side and maximal diameter of the radial head. The collagen I/III ratio of the humeral attachment of the MCL was higher than distal attachment of the MCL. Conclusion: This study provides a better understanding of the pathologies of the MCL and LCL complex of the elbow and their relationships with osseous anatomy and may assist the clinician with an anatomic reconstruction of the ligaments.

Epidemiology of complete knee dislocations: an updated classification system

IntroductionCurrent classifications of complete knee dislocations do not capture the extent of the complex concomitant ligamentous and bony injuries, which may have an impact on future outcomes. The purpose of this retrospective study was to evaluate the epidemiology of complete knee dislocations as well as to present an updated classification system based on the author’s experience at a Level-I trauma center.Materials and methodsOnly patients with complete loss of contact of the articulating bones and ≥ 18 years of age who admitted in our level-I trauma center between 2002 and 2019 were included. Patients were identified using a retrospective systematical query in the Hospital Information System (HIS) using the International Statistical Classification of Diseases and Related Health Problems Version10 (ICD-10) codes of the German Diagnosis Related Groups (G-DRG).ResultsFinal data included 80 patients, with the majority of patients being male (n = 64; 80.0%). Mean age was 34.9 years (range: 18–70 years). External protective fixation was applied in 32 patients (40.0%). Reconstruction of the posterior cruciate ligament and the anterior cruciate ligament were performed in 56.3% (n = 45) and 55.0% (n = 44) of cases, respectively. The lateral collateral ligament complex was surgically addressed in 47.5% (n = 38), while the medial collateral ligament complex was reconstructed in 40% (n = 32). Surgery of the lateral meniscus and the medial meniscus was needed in 31.1% (n = 25) and 30.0% (n = 24). Neurovascular surgery occurred in 13.8% (n = 11). From the characteristic injury-patterns the authors of this study present a new classification system that ranks the injuries from Grade-A to Grade-D according to their severity.ConclusionThis retrospective study demonstrates that the historically used classification systems for dislocations of the knee are insufficient for these severe injuries. Concomitant ligamentous, neurovascular, bony, and meniscal injuries were frequent, and required several staged procedures. Consequently, an updated classification system is proposed.

High incidence of superficial and deep medial collateral ligament injuries in \u2018isolated\u2019 anterior cruciate ligament ruptures: a long overlooked injury

PurposeIn anterior cruciate ligament (ACL) injuries, concomitant damage to peripheral soft tissues is associated with increased rotatory instability of the knee. The purpose of this study was to investigate the incidence and patterns of medial collateral ligament complex injuries in patients with clinically ‘isolated’ ACL ruptures.MethodsPatients who underwent ACL reconstruction for complete ‘presumed isolated’ ACL rupture between 2015 and 2019 were retrospectively included in this study. Patient’s characteristics and intraoperative findings were retrieved from clinical and surgical documentation. Preoperative MRIs were evaluated and the grade and location of injuries to the superficial MCL (sMCL), dMCL and the posterior oblique ligament (POL) recorded. All patients were clinically assessed under anaesthesia with standard ligament laxity tests.ResultsHundred patients with a mean age of 22.3 ± 4.9 years were included. The incidence of concomitant MCL complex injuries was 67%. sMCL injuries occurred in 62%, dMCL in 31% and POL in 11% with various injury patterns. A dMCL injury was significantly associated with MRI grade II sMCL injuries, medial meniscus ‘ramp’ lesions seen at surgery and bone oedema at the medial femoral condyle (MFC) adjacent to the dMCL attachment site (p < 0.01). Logistic regression analysis identified younger age (OR 1.2, p < 0.05), simultaneous sMCL injury (OR 6.75, p < 0.01) and the presence of bone oedema at the MFC adjacent to the dMCL attachment site (OR 5.54, p < 0.01) as predictive factors for a dMCL injury.ConclusionThe incidence of combined ACL and medial ligament complex injuries is high. Lesions of the dMCL were associated with ramp lesions, MFC bone oedema close to the dMCL attachment, and sMCL injury. Missed AMRI is a risk factor for ACL graft failure from overload and, hence, oedema in the MCL (especially dMCL) demands careful assessment for AMRI, even in the knee lacking excess valgus laxity. This study provides information about specific MCL injury patterns including the dMCL in ACL ruptures and will allow surgeons to initiate individualised treatment.Level of evidenceIII.

Fixation of Displaced Medial Epicondylar Fractures in Adolescents.

The patient is placed in the supine position, and an examination under anesthesia is performed. If the elbow is stable to valgus load, the patient is placed into a long arm cast and awakened from anesthesia. If the elbow is unstable, the patient is placed in the lateral decubitus position, and the arm is prepared and draped. The fingers and wrist are wrapped with a self-adhesive bandage in flexion to relax the flexor/pronator mass. Under tourniquet control, a curvilinear medial incision is made just dorsal to the medial epicondyle. The ulnar nerve is identified and transposed if necessary. A guidewire is placed through the fracture fragment and used as a joystick. The hand is then positioned on the posterior aspect of the hip to provide varus load to the elbow and assist with reduction. The medial epicondyle is reduced, and the guidewire is advanced unicortically. A 3.0-mm, partially threaded cannulated screw is then advanced over the guidewire. A long arm cast is applied after closure of the wound with buried absorbable sutures. Nonoperative treatment in a cast has been suggested. Surgical variations include supine positioning, bicortical screws, and use of washers. Lateral decubitus positioning and wrapping of the hand and wrist in flexion facilitate reduction by both applying a varus load and relaxing the flexor/pronator mass. Unicortical fixation is sufficient and does not risk injury to anterolateral structures. Washers have a higher complication rate than screws alone and may not be necessary in most cases1.

Does the Coronoid Always Need to Be Fixed in Terrible Triad Injuries of the Elbow? Mid-Term Postoperative Outcomes Following a Standardized Protocol.

The purpose of this study was to investigate mid-term outcomes and complications after operative treatment according to a standardized protocol for terrible triad injuries. Twenty-four patients that were treated by a single surgeon with a standardized surgical protocol were retrospectively reviewed. After the complete reconstruction of radial head and/or lateral collateral ligament (LCL) complex through a lateral approach, coronoid process, and/or medial collateral ligament (MCL) complex through a medial approach were fixed if the elbow is unstable. For coronoid fractures, only type III were fixed in four cases (16.7%). Twenty-two LCL (91.7%) and five MCL (20.8%) complexes were repaired. At the final follow-up, the mean MEPS and Quick-DASH score were 91.5 and 17.3, respectively. There was no recurrent instability after operation in all cases. This study revealed that operative treatment that was based on our standardized protocol for terrible triad injuries yielded satisfactory mid-term clinical and radiographic outcomes without any recurrent instability. These results suggest that Type I and II coronoid fractures in terrible triad injuries do not need to be fixed if the radial head and ligamentous complex are completely reconstructed.

Common Extensor Complex Is a Predictor to Determine the Stability in Simple Posterolateral Elbow Dislocation: Analysis of MR Images of Stable vs. Unstable Dislocation

Simple posterolateral elbow dislocations (SPLED) may be treated nonoperatively using closed reduction, followed by controlled mobilization. However, the extent of soft tissue injuries might affect the choice of treatment, rehabilitation approach, and prognosis. The purpose of this study is to compare the characteristics of soft tissue injuries between patients with unstable and stable SPLED using MRI findings. Thirty MRIs of elbows with SPLED (unstable group (n = 15); stable group (n = 15)) were randomly reviewed by two experienced musculoskeletal radiologists. Soft tissue injuries were characterized as an intact, partial tear or complete tear for the: medial collateral ligament (MCL) complex, common flexor complex, lateral collateral ligament (LCL) complex, common extensor complex, anterior capsule, and posterior capsule. Moderate to substantial interobserver reliability and substantial to perfect intraobserver reliability were observed for medial and lateral complexes in SPLED. The proportion of soft-tissue injuries of the common extensor complex were significantly different between the unstable (four partial tears and 11 complete tears) and stable groups (11 partial tears and four complete tears). In conclusion, based on MRI findings, the degree of common extensor complex injuries may be a predictor of stability and help inform treatment decisions for SPLED.

PEDIATRIC ELBOW COLLATERAL AND ANNULAR LIGAMENT ANATOMY: A CT-BASED CADAVERIC STUDY

Background:The medial and lateral ligamentous complexes of the elbow provide static restraint to the elbow and serve as important components of posteromedial and posterolateral rotatory instability. Many collateral ligament and medial epicondylar injuries require surgical repair in those with open physes. Little is known about the anatomy of the pediatric elbow and the relationship between these ligaments and physes. Purpose: To evaluate the anterior bundle of the medial collateral ligament complex, lateral ulnar collateral ligament, annular ligament, and relationships to the joint surfaces and physes.Methods:Two cadaveric elbows from a 3 year-old donor were dissected. Collateral and annular ligaments were isolated and left intact at their osseous attachment. Pins were placed at the origins and insertions and CT scans were used to establish precise anatomic relationships. All dissections and measurements were performed by a single orthopedic surgeon with specialization in pediatric sports medicine.Results:The MUCL origin was a mean 4.10 mm distal and anterior to the medial epicondyle, 10.09 mm from the distal humeral articular surface, and 9.01 mm distal to the medial physis. The distal insertion of the MUCL spanned a mean 3.09 mm and was posterior and medial to the sublime tubercle. In the longitudinal axis, the MUCL insertion footprint spanned the tubercle. The origin was a mean 1.20 mm proximal to the sublime tubercle and the distal extent averaged 2.53 mm distal to the tubercle. The center of the MUCL insertional footprint was 0.38 mm distal to the tubercle. The center of the MUCL was 3.87 mm from the olecranon articular surface.The annular ligament had consistent medial and lateral attachments to the ulna. Distance from the annular ligament attachments to the tip of the coronoid averaged 4.6 mm (4.46 & 4.74 lateral and medial for left; 4.80 & 5.27 lateral and medial for right).The LUCL origin was distal and anterior to the lateral epicondyle. It was 3.43 mm from the lateral epicondyle, 7.51 mm from the articular surface and 0.74 mm distal to the physis.Conclusions:This study is the first to describe anatomy of the elbow collateral and annular ligaments in pediatric cadaveric specimens, through a reliable, CT-based identification method. Knowledge of the precise ligamentous attachments and relationships to the physis and to the joint surface is important for reconstructive procedures. A better understanding of these relationships may assist with surgical planning that preserves adjacent physeal growth regions.

MRI of the Normal Elbow and Common Pathologic Conditions.

Anatomic and biomechanical knowledge of the supporting structures that provide stability to the medial and lateral elbow is essential to correctly interpret pathologic findings.

Review of Anatomy of the Medial Ulnar Collateral Ligament Complex of the Elbow.

The importance of both the static and dynamic stabilizers of the medial elbow for the throwing athlete has been demonstrated in recent studies. Furthermore, recent anatomic studies have demonstrated the insertion of the anterior bundle (UCL) to be more distal and elongated, which has implications for surgical reconstruction of the UCL. The purpose of this review is to highlight recent anatomic and biomechanical studies evaluating the anatomy and reconstructions of the medial elbow. Recent literature has highlighted the crucial role of the dynamic stabilizers in resisting valgus force, especially during the throwing motion. The dynamic stabilizers of the medial elbow include the flexor pronator mass, specifically the flexor carpi ulnaris (FCU) and flexor digitorum superficialis (FDS). The clinical importance of these findings cannot be under stated, as unrecognized dynamic stabilizer injury can lead to increased stress on a native or reconstructed UCL in the throwing athlete. The medial ulnar collateral ligament complex of the elbow has a crucial role in providing both static and dynamic elbow stability. Most notably, the anterior bundle (UCL) provides the primary resistance to valgus and rotational stresses, especially during throwing motion. An understanding of the humeral and ulnar footprints and their relationships with surrounding structures is necessary to restore the native isometry of the medial complex of the elbow during UCL reconstruction. The flexor pronator musculature plays an essential role in dynamic stability, and the intimate relationship of the FCU and FDS with the ulnar insertion of the UCL should be considered to optimize recovery and outcomes with repair or reconstruction.