Intraoperative navigation system use increases accuracy of glenoid component inclination but not functional outcomes in reverse total shoulder arthroplasty: a prospective comparative study.

BACKGROUND: While the use of computer-assisted navigation systems in prosthetic implantation is steadily increasing, its utility in reverse shoulder arthroplasty (RSA) remains unclear. The purpose of this study was to evaluate the clinical utility of an intraoperative navigation system in patients undergoing RSA. MATERIALS AND METHODS: Patients undergoing navigated or standard RSA at a single institution between September 2020 and December 2021 were prospectively enrolled. Exclusion criteria included noncompliance with study procedures or humeral fracture. Outcome measures included postoperative version and inclination, range of motion (ROM), complications, and patient-reported outcome measurements (PROMs: American Shoulder and Elbow Surgeons score [ASES], Disabilities of the Arm, Shoulder, and Hand score [DASH], Simple Shoulder Test [SST], and Visual Analog Scale [VAS]) at final follow-up. RESULTS: The final cohort contained 16 patients with navigation and 17 with standard RSA at a mean follow-up of 16 months (range 12-18 months). Average age was 72 years (range 66-80 years), 8 male (24%) and 25 female (76%). There were no differences in demographics between groups (p > 0.05). At baseline, the navigated group had a greater proportion of Walch B1 and B2 glenoids (p = 0.04). There were no differences between groups regarding baseplate type and native/planned/postoperative glenoid version and inclination. In both groups, planned and postoperative versions were not significantly different (p = 0.76). Patients who did not have navigation demonstrated significant differences between planned and postoperative inclination (p = 0.04), while those with navigation did not (p = 0.09). PROM scores did not differ between groups at final follow-up for SST (p = 0.64), DASH (p = 0.38), ASES (p = 0.77), or VAS (p = 0.1). No difference in final ROM was found between groups (p > 0.05). Over 50% of all screws in both groups were positioned outside the second cortex (p = 0.37), albeit with no complications. CONCLUSIONS: There were no statistically significant differences in ROM, PROMs, and satisfaction between patients receiving computer-navigated and standard RSA at a short-term follow-up. Despite more severe preoperative glenoid erosion in the navigated group, all patients were able to achieve an appropriate neutral axis postoperatively. The cost effectiveness and appropriate use of computer-navigated RSA warrant specific investigation in future studies. LEVEL OF EVIDENCE: II, prospective cohort study. TRIAL REGISTRATION: 9/1/2020 to 12/31/2021.

A Modified Technique for Two-Stage Revision in Knee PJI Treatment.

Knee PJIs represent one of the most important complications after joint replacement surgery. If the prerequisites for implant retention do not subsist, the surgical treatment of these conditions is performed using one-stage and two-stage revision techniques. In this study, an implemented two-stage revision technique was performed, adopting antibiotic calcium sulfate beads and tumor-like debridement guided by methylene blue, such as described for the DAPRI technique. The aim of the present study is to compare the implemented two-stage revision technique with the standard technique in order to assess its effectiveness. METHODS: Twenty patients affected by knee PJIs were prospectively enrolled in the study and underwent an implemented two-stage revision technique (Group A). Data collected and clinical results were compared with a matched control group treated with a standard two-stage technique (Group B). For each patient, the time of the reimplantation and length of antibiotic systemic therapy were recorded. Each patient underwent routine laboratory tests, including inflammatory markers. RESULTS: In Group A and in Group B, inflammatory markers normalized at 6.5 ± 1.1. weeks and 11.1 ± 2.3 weeks, respectively (p < 0.05). Also, the difference in length of antibiotic therapy and time to reimplantation were significantly shorter in Group A (p < 0.05). No recurrence of infection was found in Group A at the last follow-up. DISCUSSION: The implemented two-stage revision technique demonstrated a faster normalization of inflammatory markers, as well as a decrease in reimplantation time and duration of antibiotic therapy, compared to the traditional technique. The use of calcium sulfate antibiotic beads and tumor-like debridement seems to improve the results and reduce the time of healing. CONCLUSION: The implemented two-stage revision technique seems to improve the results and reduce the time of healing. This leads to a more rapid and less stressful course for the patient, as well as a reduction in health care costs.

"Single-use peripheral" vs "conventional" reaming in total hip arthroplasty: how to respect native centre of rotation and acetabular offset? A CT study.

PURPOSE: The respect of native hip offset represents a mainstay for satisfying results in total hip arthroplasty (THA). Historically, a great interest has been focused on restoration of femoral offset, while only in recent years, acetabular offset (AO) has been considered. The purpose of the current study was to compare the "single-use peripheral" reaming technique with the "conventional" one for the maintenance of the native COR of the hip and AO in patients undergoing to primary THA. METHODS: Eighty patients affected from primary hip osteoarthritis were prospectively enrolled in the study and were divided in two groups (Group A "single-use peripheral" and Group B "conventional" reaming technique). Pre- and post-operatively, AO, acetabular floor distance (AFd) and acetabular version (AV) were assessed through a CT scan. A comparison between groups for the radiological parameters, surgical time and complications was performed. RESULTS: The demographic data were similar in both groups. The complications rate and the AV did not differ statistically between groups. Group A presented a statistically significant shorter surgical time and lower variation between pre- and post-operative AO and AFd. Statistical significance was defined as p < 0.05. CONCLUSIONS: The "single-use peripheral" reaming technique demonstrated to be more reliable in reproducing the native COR and AO of patients undergoing to primary THA than the "conventional" one. The operative time was significantly reduced, and it may lead to a reduction in the infection risk even though it was not observed in the current study. Further research could be useful to validate such findings and to assess clinical impact and long-term survival of the implant.

Saucerization and suture of symptomatic bilateral medial discoid meniscus in a 13 years old male football player: a case report and literature review.

Introduction: Medial discoid meniscus is estimated to occur in 0.06% to 0.3% of the population, being bilateral medial discoid menisci. The current tendency to be very conservative in treating meniscal lesions should be applied to the discoid meniscus, too, so that the cauterization and suture of a torn discoid meniscus are gaining support. Case presentation: We present the case of a 13-years-old Caucasian male competitive football player with a diagnosis of bilateral medial discoid menisci. Arthroscopy of the left symptomatic knee found an incomplete medial discoid meniscus, with an atypical hypertrophic posterior horn and root with a lack of rear tibial attachments. Saucerization to obtain a standard semilunar shape plus outside-in sutures to repair the horizontal tear and stabilize the meniscus's peripheral rim was performed. The asymptomatic right knee was treated conservatively. After seven months, complete resolution of the symptoms in the left knee and no worsening of symptoms in the right knee was reported. Conclusion: Bilateral discoid medial meniscus is a rare abnormality involving active young patients. The conservative treatment is the preferred option in asymptomatic patients. Sauceriziation and eventual repair represent the suggested surgical treatment in symptomatic cases.

Segond Fractures Involve the Anterolateral Knee Capsule But Not the Iliotibial Band.

PURPOSE: To investigate the relationship between the Segond fracture and the anterolateral complex of the knee. METHODS: Between January 2014 and March 2020, patients who presented with an anterior cruciate ligament (ACL) tear requiring acute surgical reconstruction (within 10 days from trauma) were evaluated for inclusion in this study. Patients were included if they had an acute ACL tear with an associated Segond fracture (or "Segond lesion") as detected by radiograph or magnetic resonance imaging. The lateral compartment was exposed in all cases using a 5-cm lateral hockey-stick incision, which was carried down to the iliotibial band. The fascia lata was first inspected and then longitudinally divided along its fibers to expose lateral compartment. The posterolateral corner to Gerdy's tubercle anteriorly was exposed and examined. Once the Segond fracture was identified, it was recorded and photographed. RESULTS: Seventeen patients were enrolled in the study. Dissection of the Segond fracture demonstrated attachment to the anterolateral capsule only. No other discernible attachment to the Segond fracture was noted. Surgical exploration of the anterolateral knee did not reveal injury to the iliotibial band. CONCLUSIONS: Careful dissection of Segond fractures during repair revealed that there is a discernible attachment with the anterolateral capsule to the bone injury in all patients with acute ACL tears undergoing surgical reconstruction and no connections to the iliotibial band. CLINICAL RELEVANCE: The precise pathogenesis of Segond fractures has been the subject of debate, partially due to the complexity of the anatomy of the anterolateral aspect of the knee. Proper understanding of the anatomy of type IV ALL injures with Segond fractures is important to improve treatment of these injuries.

The Segond's fracture and the anterolateral ligament.

The study of Mullins et al. reasonably explains how the Segond's fracture is probably the most frequent avulsion fracture of the tibia plateau, but it does not challenge the hypothesis of the existence of a discrete ligament (the ALL) strong enough to sometimes pull out its bony insertion as a result of a forced internal rotation and of an ACL failure.

Measurement technique for posterior tibial slope on radiographs can affect its relationship to the risk of anterior cruciate ligament rupture.

PURPOSE: The purpose of this study was to determine the most reliable radiographic measurement method to evaluate PTS as a risk factor for ACL reconstruction failure. METHODS: Patients who underwent ACL reconstruction or ACL revision reconstruction between January 2009 and December 2014 by a single surgeon were included. Fifty-two consecutive patients who underwent ACL revision reconstruction were compared to a random selection of 52 patients who underwent primary ACL reconstruction and a control group of 52 patients without ACL injury. ACL reconstruction was performed using either ipsilateral (primary) or contralateral (revision) quadrupled hamstring autograft. Lateral knee radiographs were evaluated using three methods: (1) longitudinal axis, (2) anterior tibial cortex axis, and (3) posterior tibial cortex. RESULTS: A significant difference was found between subjects who underwent ACL reconstruction and control knees (6.79° vs. 5.31°, p = 0.046) using the posterior tibial cortex method. No other statistical significance was found between groups. A multiple linear regression analysis found that the PTS as measured by any method was not affected by the patient's age, sex, height, weight, and BMI. All methods of measurement for PTS demonstrated excellent (ICC > 0.90) intra-rater and inter-rater reliability, but only the posterior tibial cortex method maintained excellent intra-rater and inter-rater reliability (ICC > 0.90) when evaluating patients with ACL revision reconstruction. CONCLUSIONS: The posterior tibial cortex measurement is the most reliable method for analyzing the PTS on lateral knee radiographs in patients undergoing ACL revision reconstruction.

Partial Medial Meniscectomy Using Needle Arthroscopy and a Standardized Local Anesthetic Protocol.

Needle arthroscopic procedures of the knee offer potential advantages over standard arthroscopic procedures. The small size of the instruments allows for surgery without the use of a scalpel or suture, potentially decreased recovery times, and potentially reduced complication rates compared with traditional arthroscopy. In some patients, the procedure can be performed without the use of either general anesthesia or sedation. The purpose of this article is to provide a standardized technique guide for needle arthroscopic partial medial meniscectomy under local anesthesia.

Rupture of the Patellar Tendon After Platelet-Rich Plasma Treatment: A Case Report.

INTRODUCTION: Rupture of the patellar tendon is becoming more and more frequent, even in sports activities overloading the extensor mechanism of the knee. Platelet-rich plasma (PRP) treatment has been recently introduced in treatment for several knee- and sport-related injuries including muscle strain cartilage defect and tendinopathies. The aim of this case report is to present a case of rupture of the patellar tendon occurred after injections of PRP. CASE REPORT: A case of a 40-year-old male soccer player sustaining a patellar tendon rupture after a series of 4 PRP injections. At surgery, a complete rupture in the middle of the patellar tendon was found, with severe degenerative changes of the tendon tissue. This case questions the actual efficacy and safety of PRP in severe degenerative tendinopathies.

High Prevalence of Anterolateral Ligament Abnormalities on MRI in Knees With Acute Anterior Cruciate Ligament Injuries: A Case-Control Series From the SANTI Study Group.

BACKGROUND: Broad variation in the reported rate of magnetic resonance imaging (MRI)-detected abnormalities of the anterolateral structures of the anterior cruciate ligament (ACL)-injured knee suggests a lack of reliability that has limited the use of MRI in clinical decision making. PURPOSE/HYPOTHESIS: The aim of this study was to use MRI to determine the prevalence and spectrum of abnormalities of the anterolateral structures in acute ACL-injured knees, using the contralateral uninjured knee as a reference. We hypothesized that MRI evaluation of the acutely injured knee (using the uninjured knee as a reference) would allow reliable identification of abnormalities of the anterolateral structures. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 3. METHODS: Patients with acute ACL injury underwent MRI scan of both knees. Images were evaluated by 3 observers. Inter- and intraobserver reliabilities were determined for MRI parameters of anterolateral ligament (ALL) injury by use of the kappa (κ) test. Univariate and multivariate analyses were conducted to test associations between ALL abnormality and associated injuries. RESULTS: A total of 34 patients were evaluated. Of these, 30 patients (88.2%) had at least 1 ALL abnormality in the ACL-injured knee (increased signal: n = 27[79.4%]; increased thickness: n = 15[44.1%]; tapering: n = 7[20.6%]; irregularities in the path of the ALL fibers: n = 21[61.7%]). Asymmetries of the genicular vessels were observed in 21 patients (61.7%). ALL abnormality was significantly associated with lateral joint capsular tears (P < .001). No correlation was found between ALL lesions and iliotibial band lesions (P = .49). Inter- and intraobserver reliabilities were very good concerning ALL signal changes and femoral and tibial bone bruises (κ coefficient, 0.81-1). CONCLUSION: MRI evaluation of the ALL was associated with good and very good inter- and intraobserver reliabilities, and it demonstrated abnormalities of the ALL in the majority of acutely ACL-injured knees. The index of suspicion for ALL injury should be elevated by the presence of lesions of the lateral capsule. This suggests that the ALL is part of a wider area of the lateral capsule that is often injured simultaneously in an acute ACL tear.

Anterolateral Ligament Repair Augmented With Suture Tape in Acute Anterior Cruciate Ligament Reconstruction.

Several extra-articular surgical techniques in addition to anterior cruciate ligament reconstruction have been proposed to better restore rotational instability of the knee. One option is surgical repair of the anterolateral ligament in acute cases to achieve an anatomic reconstruction. An additional augmentation to the repair could allow a load-sharing-and thus protective-effect for the repair during the healing process. The purpose of this Technical Note is to describe a primary repair of the anterolateral ligament with suture tape augmentation (Internal Brace; Arthrex, Naples, FL) in a patient with an acute anterior cruciate ligament tear.

Correlation Between Magnetic Resonance Imaging and Surgical Exploration of the Anterolateral Structures of the Acute Anterior Cruciate Ligament-Injured Knee.

BACKGROUND: Combined anterior cruciate ligament (ACL) and anterolateral ligament (ALL) reconstruction is associated with improved clinical outcomes as compared with isolated intra-articular reconstruction, but the indications are not precisely defined. It may be the case that patients with proven anterolateral injury on preoperative imaging are most likely to benefit, but the accuracy of magnetic resonance imaging (MRI) is not known. PURPOSE/HYPOTHESIS: To evaluate the correlation between MRI and surgical exploration in acute ACL-injured knees. The hypothesis was that a positive correlation would be identified between imaging and surgical findings for ALL/capsule and iliotibial band (ITB) injuries and that MRI would be highly sensitive, specific, and accurate. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: Between January and May 2016, patients presenting with acute ACL injuries were considered for study eligibility. Included patients underwent 1.5-T MRI, which was evaluated by 3 investigators who attributed a Ferretti grade of injury to the anterolateral structures. At the time of ACL reconstruction, a lateral exploration was undertaken, and macroscopic injuries were identified. An evaluation of correlation between MRI and surgical exploration findings was performed. RESULTS: Twenty-six patients participated in the study, and 96% had an ALL/capsule injury. The sensitivity, specificity, and accuracy of MRI and the correlation ( K) with surgical exploration findings were as follows, respectively: any ALL/capsule abnormality-88%, 100%, 88.5%, and 0.47; differentiating partial or complete ALL/capsule tears-78.6%, 41.7%, 61.5%, and 0.23; ITB injuries-62.5%, 40%, 50%, and 0.27. The percentage agreement between MRI and surgical findings was 88% for ALL/capsule injury, 65% for ITB injury, and 53% for Ferretti grading. CONCLUSION: Surgical exploration demonstrates that injuries occur to the anterolateral structures in almost all acute ACL-injured knees. MRI is highly sensitive, specific, and accurate for detection of abnormalities of the ALL/capsule and shows a high percentage of agreement with surgical findings. MRI has low sensitivity, specificity, and accuracy for the diagnosis of ITB injury. The Ferretti grade could not be reliably established from MRI, and there was only fair agreement between MRI and surgical findings with respect to ITB abnormalities and determination of whether ALL/capsular tears were partial or complete.

Ultrastructural Assessment of the Anterolateral Ligament.

BACKGROUND: The anterolateral ligament (ALL) has been identified as a structure on the lateral side of the knee, but debate exists regarding whether it is a capsular thickening or a ligament. HYPOTHESIS: A detailed ultrastructural characterization of the ALL and its ultrastructure collagen arrangement will reveal it more closely resembles ligamentous tissue than joint capsule. STUDY DESIGN: Descriptive laboratory study. METHODS: Eight paired knee samples from 4 fresh-frozen male cadavers were used for this study. Samples were harvested from the ALL, the joint capsule, and the medial collateral ligament (MCL). All samples were evaluated with light microscopy (LM), transmission electron microscopy (TEM), and variable pressure scanning electron microscopy (VP-SEM). With LM, the 3 tissues were analyzed and their morphology described. With TEM, the ultrastructure and collagen characteristics were quantified and compared among specimens. Then, the 3-dimensional characteristics were compared with VP-SEM. RESULTS: Ultrastructure analysis demonstrated similar morphology between the ALL and MCL, with significant differences in these 2 structures as compared with the joint capsule. On LM, the ALL and MCL were characterized by the presence of a dense collagen fiber oriented in the longitudinal and transversal directions of the fiber bundles, while the joint capsule was found to have a more disorganized architecture. On TEM, the collagen fibers of the ALL and MCL demonstrated similar ultrastructural morphology, with both having collagen fibers in parallel, longitudinal alignment. A quantitative analysis was also performed, with the mean (± SD) diameter of fibrils in the ALL and MCL being 80 ± 2.66 nm and 150 ± 3.35 nm, respectively (all P < .001). The VP-SEM highlighted that ALL and MCL morphology demonstrated arrangements of fiber bundles that are densely packed and organized, in contrast to the disorganized fibers of the joint capsule. CONCLUSION: The ALL and MCL have comparable ultrastructures that are distinctly different from the joint capsule, as visualized on LM, TEM, and VP-SEM. CLINICAL RELEVANCE: The ALL should be considered a distinctive structure of the knee, although strictly connected to the surrounding capsule.

The unhappy triad of the knee re-revisited.

AIM OF THE STUDY: To describe the surgical findings of the anterolateral complex in patients with the "unhappy triad" lesion of the knee. METHOD: One hundred and twenty-five consecutive patients presenting with acute anterior cruciate ligament (ACL) tears were selected for this study. Only cases, evaluated with a valgus stress test under fluoroscopy, with a medial opening more than 5 mm of the medial collateral ligament (MCL) were included in the study (11 patients). For the included cases, open MCL surgical repair was performed only in cases with a valgus stress test more than 10 mm as revealed by fluoroscopy (3 patients). All included cases (11 patients) underwent ACL reconstruction and exploration of the anterolateral complex that was then assessed, photographed, classified, and eventually repaired. RESULTS: At clinical evaluation under anaesthesia, all patients presented a positive Lachman test and a pivot shift test graded as ++ in four cases and +++ in five cases, not valuable in two cases. At surgical exploration, the anterolateral complex was involved in all cases (11 patients): one case demonstrated a type I injury, eight cases a type II injury, two cases a type III injury, and no patient with a type IV injury (Segond's fracture). All anterolateral complex lesions were repaired by direct suture and re-tensioning. DISCUSSION: On the basis of a recent analysis performed by other authors, we could speculate that injuries of ACL and anterolateral compartment occur in the very early phase of the injury when the knee is forced into internal rotation. The MRI evidence of bone bruising in the lateral compartment in most cases of the present series support the hypothesis of an internal rotation torque. CONCLUSIONS: The unhappy triad of injuries to the knee is actually a tetrad involving not just the ACL, MCL, and medial/lateral meniscus but also involved the anterolateral complex.

Anterior cruciate ligament reconstruction is associated with greater tibial tunnel widening when using a bioabsorbable screw compared to an all-inside technique with suspensory fixation.

PURPOSE: To compare clinical outcomes and tunnel widening following anterior cruciate ligament reconstruction (ACLR) performed with an all-inside technique (Group A) or with a bioabsorbable tibial screw and suspensory femoral fixation (Group B). METHODS: Tunnel widening was assessed using computed tomography (CT) and a previously validated analytical best fit cylinder technique at approximately 1-year following ACLR. Clinical follow-up comprised evaluation with IKDC, KSS, Tegner, Lysholm scores, and knee laxity assessment. RESULTS: The study population comprised 22 patients in each group with a median clinical follow-up of 24 months (range 21-27 months). The median duration between ACLR and CT was 13 months (range 12-14 months). There were no significant differences in clinical outcome measures between groups. There were no differences between groups with respect to femoral tunnel widening. However, there was a significantly larger increase in tibial tunnel widening, at the middle portion, in Group B (2.4 ± 1.5 mm) compared to Group A (0.8 ± 0.4 mm) (p = 0.027), and also at the articular portion in Group B (1.5 ± 0.8 mm) compared to Group A (0.8 ± 0.8 mm) (p = 0.027). CONCLUSION: Tibial tunnel widening after ACLR using hamstring tendon autograft is significantly greater with suspensory femoral fixation and a bioabsorbable tibial interference screw when compared to an all-inside technique at a median follow-up of 2 years. The clinical relevance of this work lies in the rebuttal of concerns arising from biomechanical studies regarding the possibility of increased tunnel widening with an all-inside technique. LEVEL OF EVIDENCE: III.

Isokinetic flexion strength recovery after ACL reconstruction: a comparison between all inside graft-link technique and full tibial tunnel technique.

INTRODUCTION: Recently, a new minimally invasive single bundle technique for anatomic ACL reconstruction has been described, called the 'All-Inside graft-link technique'. One of the advantages of this procedure is the reduced morbidity at the donor site as the graft choice is the quadrupled semitendinosus, thus sparing the gracilis tendon. The aim of this study was to evaluate isokinetic flexion strength recovery in patients who underwent a gracilis sparing technique compared to those with a full-tibial tunnel technique using a doubled gracilis and semitendinosus tendons (DGST) graft. METHODS: Patients were divided into two groups: Group A (22 patients) who underwent ACL reconstruction performed with an All-Inside graft-link technique; Group B (22 patients) who underwent ACL reconstruction with an Out-In technique and DGST graft. At a mean follow-up of 13 months, quadriceps and hamstring isokinetic peak torque deficits were recorded. RESULTS: In group A, the mean side to side peak torque flexion difference between the operated and non-operated limbs was -3% and the mean torque at 30° was -7.5% at high angular velocity (180°/sec); the mean peak flexion torque was 7.2% and the mean torque at 30° was 3.1% at low angular velocity (60°/sec). In group B, the mean side to side peak flexion torque was -3.5% and the mean torque at 30° was -7.6% at high angular velocity (180°/sec); the mean peak flexion torque was -7.2% and the mean torque at 30° was -11% at low angular velocity (60°/sec). A statistically significant difference was found between the two groups at lower angular velocity both for the mean peak flexion torque and the mean torque at 30° (p = 0.009), with better results in the study group. DISCUSSION/CONCLUSION: Gracilis sparing technique is a minimally invasive technique for ACL reconstruction and yielded a significantly better flexion strength recovery at lower angular velocity compared to a full tibial tunnel technique with DGST for ACL reconstruction.

Assessment of the Anterolateral Ligament of the Knee by Magnetic Resonance Imaging.

Purpose The purpose of this study was to describe the anatomy of the anterolateral ligament (ALL) of the knee by the use of 1.5 Tesla (T) magnetic resonance imaging (MRI) in a series of young patients without knee injuries. Methods Subjects aged 18 years or older without an anterior cruciate ligament injury, as confirmed on MRI, were included. MRI examinations were all performed on 1.5 T scans. The ALL was defined as the low signal band originating from the region of the lateral epicondyle of the femur, crossing the proximal surface of the lateral collateral ligament, deep to the iliotibial band, and inserting onto the tibia between the Gerdy's tubercle and the fibular head. Results Twenty-six patients met the eligibility criteria and were enrolled into the study. In one patient, it was not possible to visualize the ALL. In all the other subjects, the ligament originated anterior and distal to the lateral epicondyle and inserted on the proximal tibia approximately 5 mm below the joint line and just distal to the Gerdy's tubercle. It had an average length of 33 ± 1.2 mm, an average width of 5.5 ± 0.3 mm, and an average thickness of 2 mm. Conclusion The ALL is a distinct structure of the anterolateral capsule that can be easily identified using 1.5 T MRI scans. Level of Evidence This is a level IV, observational study.