Posteromedial Corner Research Articles

Acute posterior cruciate ligament injuries: effect of location, severity, and associated injuries on surgical management.

To correlate MRI findings of patients with posterior cruciate ligament (PCL) injury and surgical management. A retrospective search yielded 79 acute PCL injuries (36 ± 16years old, 21F, 58M). Two independent readers graded PCL tear location (proximal, middle, or distal third) and severity (low-grade or high-grade partial/complete) and evaluated injury of other knee structures. When available, operative reports were examined and the performed surgical procedure was compared with injury grade, location, and presence of associated injuries. The most commonly injured knee structures in acute PCL tears were posterolateral corner (58/79, 73%) and anterior cruciate ligament (ACL) (48/79, 61%). Of the 64 patients with treatment information, 31/64 (48%) were managed surgically: 12/31 (39%) had PCL reconstruction, 13/31 (42%) had ACL reconstruction, 10/31 (32%) had posterolateral corner reconstruction, 9/31 (29%) had LCL reconstruction, 8/31 (26%) had meniscectomy, and 8/31 (26%) had fixation of a fracture. Proximal third PCL tear and multiligamentous injury were more commonly associated with surgical management (P < 0.05). Posterolateral and posteromedial corner, ACL, collateral ligament, meniscus, patellar retinaculum, and gastrocnemius muscle injury, and fracture were more likely to result in surgical management (P < 0.05). Patients with high-grade partial/complete PCL tear were more likely to have PCL reconstruction as a portion of surgical management (P < 0.05). Location of PCL tear and presence of other knee injuries were associated with surgical management while high-grade/complete PCL tear grade was associated with PCL reconstruction. MRI reporting of PCL tear location, severity, and of other knee structure injuries is important for guiding clinical management.

Reefing of the Posteromedial Capsule in Anteromedial Rotatory Instability

The posterior oblique ligament (POL) is the main component of the posteromedial corner (PMC) of the knee and plays a crucial role in acting as a secondary restraint against translation, rotation, and valgus forces. Injuries to the PMC often occur in association with acute or chronic deficiency of the anterior cruciate ligament and may result in anteromedial rotatory instability. A surgical technique for treatment of acute and chronic injuries of the posteromedial structures was first established by Hughston in 1973. This procedure involves an advancement and reefing of the POL and adherent posterior capsule to the stout tissue of the intact medial collateral ligament, potentially using suture anchors if the POL tissue is detached from bone. Additionally, in cases of residual laxity, the semimembranosus tendon may be advanced anteriorly to improve dynamic stabilization. This procedure appears to be useful in cases of moderate posteromedial insufficiency and avoids retrieval of a medial tendon graft from the region of the medially stabilizing hamstrings or from the healthy contralateral side.

Surgical Management of the Multiple-Ligament Knee Injury

The management of multiligament knee injury is a complex process starting with the adequate identification of the injury. A detailed physical and radiographic examination with a thorough understanding of knee anatomy is crucial to assess all damaged structures: anterior cruciate ligament, posterior cruciate ligament, posteromedial corner including the medial collateral ligament, and posterolateral corner including the lateral collateral ligament. Several surgical techniques have been developed throughout the years to adequately address these ligament insufficiencies. In this surgical technique description, we describe a reproducible method for the assessment and surgical management of a knee dislocation (KDIV) injury. Our approach includes using anatomic single-bundle cruciate ligament reconstructions with modified Bosworth technique for medial-side injuries and a combination of Müller popliteal bypass and Larson figure-of-8 techniques for posterolateral corner injuries. The orders of surgical steps is described concisely, and technical controversies such as graft choice, tunnel positioning, and sequence of graft fixation are discussed in detail.

Imaging of Ligamentous Structures within the Knee Includes Much More Than the ACL.

Ligamentous structures of the knee are numerous and complex, including the anterior and posterior cruciate ligaments, medial and lateral collateral ligaments, ligaments of the posteromedial and posterolateral corners, and the anterolateral ligament. Clinical assessment after a knee injury is paramount and can direct both the clinician's choice of imaging study and the radiologist's interpretation. Imaging is crucial in that it provides additional information for diagnosis, management, and surgical planning. Multiple imaging modalities can be used in the evaluation of the knee injuries, with radiographs an important baseline study, magnetic resonance imaging as the best tool for a comprehensive assessment including cruciate ligament evaluation, and ultrasound useful in evaluating superficial structures. Knowledge of both normal and pathological appearances of ligamentous structures, as well as typical injury patterns, is useful not only for radiologists but also for clinicians who manage patients with knee pain.

Posteromedial Corner Knee Injuries: Diagnosis, Management, and Outcomes: A Critical Analysis Review.

* The posteromedial corner of the knee comprises the superficial medial collateral ligament (MCL), deep MCL, posterior oblique ligament, oblique popliteal ligament, and posterior horn of the medial meniscus. The main medial knee structure is the superficial MCL.* Injuries to the medial knee are the most common knee ligament injuries. A comprehensive history and physical examination are key to the diagnosis of a posteromedial corner injury. Patients often present with swelling and pain over the medial joint line after an injury involving a valgus and external rotation force. The valgus stress and anteromedial drawer tests can aid the clinician in deciphering whether an isolated medial structure was injured or if a complete posteromedial corner injury is likely.* Valgus stress radiographs can be utilized to quantify the amount of medial joint gapping. A side-to-side difference in gapping of 3.2 mm is consistent with an isolated superficial MCL tear, and a side-to-side difference of ≥9.8 mm is consistent with a complete posteromedial corner injury. Magnetic resonance imaging is also a useful tool in the detection of medial-sided injuries and has been reported to have an 87% accuracy.* Although a large number of medial knee injuries can be treated nonoperatively, complete posteromedial corner injuries may require surgical treatment to restore joint stability and biomechanics. There is heterogeneity between techniques with regard to the type of graft, the tibial and femoral tunnel position, and the tensioning protocol. Anatomic techniques have been reported to better restore knee kinematics and function.

The Posteromedial Corner of the Knee: Anatomy, Pathology, and Management Strategies.

The posteromedial corner of the knee encompasses five medial structures posterior to the medial collateral ligament. With modern MRI systems, these structures are readily identified and can be appreciated in the context of multiligamentous knee injuries. It is recognized that anteromedial rotatory instability results from an injury that involves both the medial collateral ligament and the posterior oblique ligament. Like posterolateral corner injuries, untreated or concurrent posteromedial corner injuries resulting in rotatory instability place additional strain on anterior and posterior cruciate ligament reconstructions, which can ultimately contribute to graft failure and poor clinical outcomes. Various options exist for posteromedial corner reconstruction, with early results indicating that anatomic reconstruction can restore valgus stability and improve patient function. A thorough understanding of the anatomy, physical examination findings, and imaging characteristics will aid the physician in the management of these injuries.

Beveled posteromedial corner of the radial head: a three-dimensional micro-computed tomography modeling study.

The posteromedial quadrant of the radial head is known to be different from the other quadrants. However, the explanation of this unique anatomical feature remains elusive. Hence, this study was designed to address this unique anatomical variance using three-dimensional μCT (micro-computed tomography) analysis. Nine fresh cadaveric radial heads were scanned using μCT. Three-dimensional subchondral bone and cartilage models were rendered. Both models were separated into the four quadrants at both the periphery (rim) and the articulating dish (fovea): anteromedial (AM), posteromedial (PM), posterolateral (PL), and anterolateral (AL). Each quadrant was analyzed in terms of (1) subchondral bone porosity (SBP), (2) mean subchondral bone thickness (MSBT), and (3) mean cartilage thickness (MCT). There was a significant difference between the fovea and the rim in terms of its microarchitectural features. Although within the fovea, the PM quadrant did not differ significantly from the other quadrants, a significant difference was found within the rim. In terms of SBP, PM, AM, PL and AL were calculated as 33, 37, 36 and 35%, respectively. In terms of MSBT, PM, AM, PL and AL were calculated as 0.11, 0.10, 0.09, and 0.09mm, respectively. In terms of MCT, PM, AM, PL and AL were calculated 1.09, 0.81, 0.84 and 0.83mm, respectively. The PM corner of the radial head between the 8 and 9 o'clock positions, was beveled. This might explain why the PM quadrant of the rim differed significantly from the other quadrants in terms of its microarchitectural features.

Multiligamentous Injury of the Knee: MRI Diagnosis and Injury Patterns.

Anterior cruciate and posterior cruciate injuries rarely occur in isolation and are often associated with injuries to the secondary or supporting structures that provide stability against rotational forces. These structures include the posterolateral and posteromedial corner ligaments and tendons, as well as the anterolateral ligament. If injuries to these secondary structures are not appreciated at the time of cruciate ligament reconstruction, an isolated cruciate ligament reconstruction may be predisposed to early failure. Thus it is crucial for radiologists interpreting knee magnetic resonance imaging to understand and report on injury to these ligaments and tendons at the time of initial injury to help the orthopaedic surgeon plan a comprehensive approach to ligament reconstruction. This strategy will ultimately result in improved patient outcomes.

Clinical outcome of primary medial collateral ligament-posteromedial corner repair with or without staged anterior cruciate ligament reconstruction

IntroductionMedial collateral ligament (MCL) is a prime valgus stabilizer of the knee, and MCL tears are currently managed conservatively. However, posteromedial corner (PMC) injury along with MCL tear is not same as isolated MCL tear and the former is more serious injury and requires operative attention. However, literature is scarce about the management and outcome of PMC-MCL tear alongside anterior cruciate ligament (ACL) tear. The purpose of this study is to report the clinical outcome of primary repair of MCL and PMC with or without staged ACL reconstruction. MethodsA retrospective evaluation was performed on patients with MCL-PMC complex injury with ACL tear who underwent primary repair of MCL-PMC tear followed by rehabilitation. Further, several of them chose to undergo ACL reconstruction whereas rest opted conservative treatment for the ACL tear. A total of 35 patients of two groups [Group 1 (n=15): MCL-PMC repaired and ACL conserved; Group 2 (n=20): MCL-PMC repaired and ACL reconstructed] met the inclusion criteria with a minimum follow-up of two years. Clinical outcome measures included grade of valgus medial opening (0° extension and 30° flexion), Lysholm and International knee documentation committee (IKDC) scores, KT-1000 measurement, subjective feeling of instability, range of motion (ROM) assessment and complications. ResultsWhile comparing group 2 versus group 1, mean Lysholm (94.6 vs. 91.06; p=0.017) and IKDC scores (86.3 vs. 77.6; p=0.011) of group 2 were significantly higher than group 1. 60% patients of group 1 complained of instability against none in the group 2 (p<0.0001). All the knees of both the groups were valgus stable with none requiring late reconstruction. The mean loss of flexion ROM in group 1 and 2 was 12° and 9° respectively which was not statistically different (p=0.41). However while considering the loss of motion, two groups did not show any significant difference in clinical scores. ConclusionsPrimary MCL-PMC repair renders the knee stable in coronal plane in both the groups and further ACL reconstruction adds on to the stability of the knee providing a superior clinical outcome. Minor knee stiffness remains a concern after primary MCL-PMC repair but without any unfavorable clinical effect.

Knee Osteoarthritis after Reconstruction of Isolated Anterior Cruciate Ligament Injuries: A Systematic Literature Review.

Purpose The aim of this review was to analyze the current literature on osteoarthritic evolution of knees without any combined meniscal or ligament lesions undergoing anterior cruciate ligament (ACL) reconstruction. Methods A PubMed/MEDLINE research was performed using the following keywords: “Anterior Cruciate Ligament Reconstruction” [Mesh] AND “Osteoarthritis, Knee” [Mesh]. Only English language literature and articles published after 2005 were included. Studies including concomitant meniscal tears, posterior cruciate or collateral ligament injuries, previous surgery in the affected knees, infections, osteochondral defects, loose bodies, synovial plica syndrome, and posteromedial or posterolateral corner injuries were not considered in this review. Results Twelve studies were selected. These papers included 892 patients (mean age at the time of surgery was 22.3 years), with an average follow-up of 11 years. Imaging at follow-up was obtained with standard radiographs in nine studies, magnetic resonance imaging (MRI) in one study, and both X-rays and MRI in two studies. Eight studies reported osteoarthritic evolution, with different prevalence. Conclusion Only few high-quality studies focused on these specific patients have been published. When reconstructed, isolated ACL-deficient knees have a low risk of osteoarthritic evolution, but mild signs of joint degeneration are reported by the current literature. Level of Evidence Level IV, systematic review of level I to level IV studies.

Posteromedial Corner Reconstruction

Objective:Report the experience, after 1-year follow-up, of 30 patients who underwent anatomical knee reconstruction of posteromedial corner (PMC) injuries, using La Prade´s Technique.Methods:Retrospective cohort study of 30 consecutive patients with PMC injuries operated between November 2010 and May 2014 by the same surgical team. Inclusion criteria: patients with clinical presentation and images (stress radiographs and MRI) compatible with PMC injury, who maintained a grade III chronic instability in spite of at least 3 months of orthopedic treatment, who were reconstructed using La Prade’s anatomical technique, and completed at least 12 months of follow-up. Exclusion criteria: discordance between clinical and image studies, grade I or II medial instability, and surgery performed through a different technique. Data was collected by reviewing the electronic files and images. Functional scores (IKDC and Lysholm) were applied and registered in the preoperative evaluation, and then 6 and 12 months after surgery.Results:Thirty patients (28 men and 2 women) met the inclusion criteria. Mean age was 43 years (24-69). The vast majority (28 patients) had a high-energy mechanism of injury. Twenty patients were diagnosed in the acute setting, while 10 had a delayed diagnosis after poor results of concomitant ligament reconstructions. With the exception of 2 patients, who presented with isolated PMC injury, the majority had associated injuries as detailed: 11 cases had PMC + anterior cruciate ligament (ACL) injury, 3 patients had PMC + posterior cruciate ligament (PCL) injury, 3 patients had PMC + meniscal tears, 9 patients had PMC + ACL + PCL injuries, and there were 2 cases of PMC + ACL + PCL + lateral collateral ligament injuries. Mean time for PMC reconstruction surgery was 5 months (range 2-32). Lysholm and IKDC scores were 18,2 (2-69) and 24,3 (9,2-52,9) respectively in the preoperative setting, improving to 76,7 (44-94) and 70,7 (36,8-95,4) after 1-year follow-up. At the end of follow-up, average ROM was 113º (90-140) the majority (24 patients) had type A IKDC stability, and the remaining 6 patients type D IKDC stability.Conclusion:Acceptable results were achieved following reconstruction of PMC injuries in patients with chronic posteromedial knee instability. Improvement in stability and functional scores were observed in all the patients of this cohort after surgery.

Multiligament Injury of the Knee. First Intrarticular or Posterior

Objectives:Show our experience about the multiligament injury of the knee. In the surgical technique it is most popular and recommended stabilized first all posterior and lateral (Ligament cruciate Posterior (LCP) and postero-lateral corner) if is a case. We show our experience stabilized first all intra-articular ACL and LCP.Methods:Prospective study and Case Series. The study includes, 45 cases in 15 years of experience. The patients have two or more ligaments with rupture, and associated lesions, like meniscus, cartilages, fractures, etc. 45 cases with a ACL rupture, 40 PCL, 7 posteromedial corner, 25 postero-lateral corner, 30 meniscus medial, 28 meniscus lateral, 1 vascular lesion, and 3 fibular nerve. In the surgical technique always use autograft. Prefer hamstrings, quadricipital tendon, contralateral hamstrings, BTB and sometimes peroneus brevis. We hope 1 or 2 weeks for the surgery. I never use pump, and use tourniquet for two hours. We start for the meniscus lesions and cartilage lesion and first reconstruction ligaments intra-articular. Finalized we open the tourniquet and stabilized the postero-lateral o posteromedial corner if is necessary. In the first cases we did a surgery in two times, but now we stabilized in one surgical time.Results:3 to 6 days in the hospital 2 weeks immobilized and star rehabilitation with brace for more two weeks. Use crutches for 4-6 weeks. Worked in rehabilitation for a one year and star competition in one year. Complications: 1 case of amputation for vascular lesion, 9 arthrofibrosis, 2 medial instability, 1 lateral instability and1 LCP instability. One case needs a revision two years after the first surgery, for a new trauma in the work. All other cases had a new surgery for revision the residual instability.Conclusion:The multiligament injury of the knee it is not frequently, but every year I receive more cases, and more difficult. In the surgical technique have two options. The more recommended stabilized first all posterior (LCP and postero-lateral corner). Our experience shows no difference in these two options.

Imaging of Athletic Injuries of Knee Ligaments and Menisci: Sports Imaging Series.

Acute knee injuries are a common source of morbidity in athletes and if overlooked may result in chronic functional impairment. Magnetic resonance (MR) imaging of the knee has become the most commonly performed musculoskeletal MR examination and is an indispensable tool in the appropriate management of the injured athlete. Meniscal and ligamentous tearing are the most frequent indications for surgical intervention in sports injuries and an understanding of the anatomy, biomechanics, mechanisms of injury, and patterns of injury are all critical to accurate diagnosis and appropriate management. These will be discussed in reference to meniscal tears and injuries of the cruciate ligaments as well as injuries of the posterolateral and posteromedial corners of the knee. (©) RSNA, 2016.

Osteology of the Late Triassic aetosaur Scutarx deltatylus (Archosauria: Pseudosuchia).

Aetosaurians are some of the most common fossils collected from the Upper Triassic Chinle Formation of Arizona, especially at the Petrified Forest National Park (PEFO). Aetosaurians collected from lower levels of the park include Desmatosuchus spurensis, Paratypothorax, Adamanasuchus eisenhardtae, Calyptosuchus wellesi, and Scutarx deltatylus. Four partial skeletons collected from the park between 2002 and 2009 represent the holotype and referred specimens of Scutarx deltatylus. These specimens include much of the carapace, as well as the vertebral column, and shoulder and pelvic girdles, and a new naming convention proposed for osteoderms descriptions better differentiates portions of the carapace and ventral armor. A partial skull from the holotype specimen represents the first aetosaur skull recovered and described from Arizona since the 1930s. The key morphological feature distinguishing Scutarx deltatylus is the presence of a prominent, triangular boss located in the posteromedial corner of the dorsal surface of the dorsal paramedian osteoderms. Scutarx deltatylus can be distinguished from closely related forms Calyptosuchus wellesi and Adamanasuchus eisenhardtae not only morphologically, but also stratigraphically. Thus, Scutarx deltatylus is potentially an index taxon for the upper part of the Adamanian biozone.

Accuracy of Balancing at Total Knee Surgery Using an Instrumented Tibial Trial

BackgroundBalancing is an important part of a total knee procedure, and in recent years, more emphasis has been given to quantifying the process. MethodsDuring 101 total knee surgeries, initial bone cuts were made using navigation. Lateral and medial contact forces were determined throughout flexion using an instrumented tibial trial. Balancing was defined as a ratio of the medial and total force, the target being 0.5 (equal lateral and medial forces). Based on the initial values, surgical corrections were selected to achieve balancing. The most common corrections were soft tissue releases (63 incidences), including MCL, posterolateral corner, posteromedial corner, and changing tibial insert thicknesses (34 incidences). ResultsAfter final balancing, the mean ratio was 0.52 ± 0.14, between 0.35 and 0.65 being achieved in 80% of cases. In 84% of cases, only 0-2 corrections were required. The average total force on the condyles was 215 ± 86 N. ConclusionOur study provides data to surgeons on the results to expect when balancing a knee, which can enhance both accuracy and consistency of the procedure.

The Medial and Posteromedial Ligamentous and Capsular Structures of the Knee: Review of Anatomy and Relevant Imaging Findings

The medial and posteromedial regions of the knee are important for knee stability but also frequently injured. Medial ligaments and capsule are primary and secondary stabilizers of valgus, rotation, and anterior and posterior translation. In the setting of rupture of the cruciate ligaments, it is important to identify injuries in this region because it can possibly alter the treatment strategy and even delay or prevent successful reconstruction of the cruciate ligaments. Injuries may occur to the superficial and deep medial collateral ligament, the posterior oblique ligament, the posteromedial capsule, and the semimembranosus tendon and its attachments. Meniscocapsular separation is associated with these injuries, and if normal movement of the meniscus and tension of the capsule and ligaments is altered, instability and eventually osteoarthritis may occur. Injuries to the posteromedial corner may be underdiagnosed. This article reviews the anatomy and imaging findings in the medial and posteromedial regions of the knee.

Clinical outcomes after multiligament injured knees: medial versus lateral reconstructions.

The purpose of this study was to analyse the clinical outcomes of multiligament injured knees with respect to the medial collateral ligament and posteromedial corner (PMC) repair or reconstruction versus the posterolateral corner (PLC) reconstruction in patients operated according to a codified surgical protocol. Patients were divided into two groups depending on whether PMC or PLC was injured. Cruciate ligaments as well as PMC or PLC were reconstructed/repaired in a one-stage procedure. At minimum of 1-year follow-up, objective and subjective International Knee Documentation Committee (IKDC) forms, Lysholm score and sports activity level were recorded. Thirty-nine patients with a median follow-up time of 57months (range 12-129) were reviewed. No significant difference was found for functional scores between acute PMC and PLC subgroups. In Group PLC, subjective outcomes tend to be better in the acute than in chronic reconstruction subgroup. A one-stage protocol with early surgery rather than delayed reconstruction produced better clinical outcomes whatever the injured collateral ligament, medial or lateral. In the future, early and chronic reconstructions as well as each injury pattern should be considered as separate entities in studies on multiple ligament injured knees to reach a better level of evidence. IV.

Proximity of the Sciatic Nerve in Relation to the Posterior Approach to the Hip, and its Relationship to Femoral Head Size

The position of the Sciatic nerve is variable, and this study aims to look for the correlation between femoral head size and the distance to the sciatic nerve in order to be able to judge position during the posterior approach to the hip. Methods: 60 Magnetic Resonance Imaging Scans of Hips were identified to examine for position of the sciatic nerve in relation to insertion of obturator externus and the postero-medial corner of the lesser trochanter. The relationship with the femoral head size was also examined Results: The results show that with increasing size of femoral head, the distance to the sciatic increases. The average distances to the Sciatic Nerve from the lesser trochanter was 14.9mm when head size was greater than 45mm and was 13.1mm when head size was below 45mm. Conclusions: There is a proportional increase in distance of sciatic nerve from the hip joint with increase in femoral head size. This study provides evidence on relationship of the nerve to the hip joint which further strengthens our understanding of anatomy and we hope will help to give surgeons a good idea of the proximity of the nerve to their operative field.

Open Anatomic Reconstruction of the Medial Collateral Ligament and Posteromedial Corner

Injuries to the medial collateral ligament (MCL) and posteromedial corner can occur in isolation or in the setting of multiligamentous knee injuries. Reconstruction of the MCL and posteromedial corner is indicated in the setting of a multiligamentous knee injury. Isolated cases failing nonoperative treatment may also undergo surgical treatment. Our preferred technique for anatomic medial-sided knee reconstruction is an open anatomic MCL reconstruction using an Achilles tendon allograft along with direct repair of all associated medial and posteromedial structures.

Selective Medial Release Technique Using the Pie-Crusting Method for Medial Tightness During Primary Total Knee Arthroplasty

BackgroundThe pie-crusting method is popular in releasing lateral tightness during primary total knee arthroplasty (TKA) but is not well described for medial release. We established a selective medial release technique using the pie-crusting technique and investigated the effectiveness and safety of the technique during primary TKA. MethodsWe retrospectively reviewed 729 primary TKAs with varus deformity between October 2009 and June 2012. Medial tightness in flexion was released by traditional subperiosteal stripping for the anterior portion of the medial collateral ligament (aMCL). Medial tightness in extension was released by the pie crusting for the tight fibers in the posterior portion of the MCL and/or posteromedial corner structures (pMCL/PMCS). Clinical outcomes were evaluated by Knee Society (KS) scores and the Western Ontario and McMaster Universities Osteoarthritis Index. Any complications, including late medial instability that may be related to our surgical technique, were carefully inspected. ResultsAmong the 729 knees, 170 (23.3%) required subperiosteal stripping for balancing in flexion only, 186 (25.5%) required the pie-crusting for balancing in extension only and 142 (19.5%) required subperiosteal stripping and the pie-crusting for balancing in flexion and extension. The KS knee score was improved from 52.5 to 83.4, KS function score from 58.2 to 91.9, and Western Ontario and McMaster Universities Osteoarthritis Index from 42.7 to 21.8 (P < .001, all). No specific complications related to our technique were identified. ConclusionsThe selective medial release technique appears to be an effective and safe method to obtain a balanced mediolateral gap in primary TKA.