Capsuloligamentous Structures Research Articles

The relationship between glenoid osteometry and recurrent anterior glenohumeral instability

The most common joint to dislocate is the glenohumeral joint, resulting in chronic pain and limited function. The role of the capsuloligamentous structures and muscle balance in contributing to shoulder stability has been well documented in the literature but the case is not the same for the bony anatomy of the glenoid. There is limited data on the contribution of glenoid osteometry in increasing the risk of anterior shoulder dislocation. This study sought to find out the association between anterior glenohumeral instability and glenoid anteversion/inclination. A retrospective, case-control study was carried out. The study was carried out at the Departments of Radiology and Imaging at two university hospitals. Shoulder Magnetic Resonance Imaging (MRI) scans for 45 patients aged between 18 to 45 years with recurrent anterior shoulder instability were used in the study and compared with a control consisting of shoulder MRIs of 45 patients with other shoulder pathologies but having no incidences of dislocation. A structured data collection tool was used to collect the data. Data was analyzed using Statistical Package for the Social Sciences (SPSS) version 26. The mean age for all the participants was 32.0 (SD 9.0) years. The mean age for the cases was 29.0 (SD 8.7) years, while for the controls was 34.6 (SD 8.5) years. The glenoid was anteverted in 40% and 35.6% of cases and controls respectively (p = 1.00) and retroverted in 60% and 64.4% of cases and controls respectively (p =0.666). Most of the glenoids were superiorly inclined (91.1% and 93.3% for cases and controls respectively. The differences in the glenoid version and inclination between the cases and controls were not statistically significant (p = 0.288 and p = 0.489 for the glenoid version and inclination respectively. Glenoid version and inclination are not significantly increased in patients with anterior shoulder instability compared to unmatched controls.

Posterior Stabilization and Reverse Hill-Sachs Remplissage Using Linked Knotless Anchors

Posterior glenohumeral dislocation can result in impaction fractures to the anteromedial humeral head, known as a reverse Hill-Sachs lesion. They may also cause damage to the posterior capsuloligamentous structures. This can lead to ongoing posterior instability and altered biomechanics resulting in early degenerative changes. Ongoing symptoms may result in challenges to a patient’s day-to-day and sporting activities. Early intervention to stabilize the shoulder may help avoid these. We present a reproducible technique for posterior stabilization using linked knotless anchors to perform a remplissage of the subscapularis into the reverse Hill-Sachs lesion defect that avoids the need for exposure of the subcoracoid bursa.

Case Study on the Role of Neuromotor Re-Education Methods in the Treatment of Charcot Marie-Tooth Disease

The isolated Charcot disease occurs in young people and has a motor onset, being a touch of motor cells, anywhere in the cerebrospinal axis. The paper is a case study of a subject diagnosed with Charcot Marie-Tooth disease. The physical therapy intervention aimed to apply elements of neuromotor re-education methods over a period of nine months. The results reveal that combining neuromotor re-education methods contributes to improving muscle elasticity and capsuloligamentous structures, thus preventing the formation of dysfunctional positions, and induces voluntary motor activity in the affected muscles, thus improving muscle imbalances specific to pathology.

Anterior Opening-Wedge Proximal Tibial Osteotomy for Slope Correction of Genu Recurvatum

Background: Symptomatic genu recurvatum is defined as greater than 5° of knee hyperextension and can be caused by osseous deformity, soft tissue laxity, or a combination. Common symptoms include pain, weakness, instability, decreased range of motion, leg length discrepancy, and stretching of the posterior capsuloligamentous structures of the knee. In instances where the genu recurvatum is caused by reverse tibial slope, literature supports the use of anterior opening-wedge proximal tibial osteotomy (OW PTO) to treat genu recurvatum by increasing tibial slope. Correction of anterior slope to a more anatomic, posterior orientation allows any stressed ligaments to return to their normal tension and restores the native biomechanics of the knee. Indications: The primary indication for OW PTO is genu recurvatum that is nonresponsive to physical therapy or genu recurvatum with concurrent ligamentous injury. The heel-height test provides an objective assessment for the identification and measurement of knee hyperextension. Technique Description: 2 guide pins are placed parallel to the tibial plateau, engaging the posterior cortex. A small micro sagittal saw is used to cut the anterior cortex. Osteotomes are used to complete the osteotomy, preserving a posterior hinge. An opening spreader device is placed and opened slowly while keeping the posterior cortex intact. The new slope is maintained by use of an opening wedge osteotomy plate and screws. Allograft bone graft is packed thoroughly into the osteotomy site. Fluoroscopy is used throughout the case to assess appropriate orientation and depth of the osteotomy, as well as the final opening width. Results: A review of 5 studies demonstrated adequate reduction in hyperextension, with a mean knee hyperextension ranging from 17° to 32° preoperatively and 0° to 7° postoperatively. Patients had significantly improved postoperative clinical outcomes compared with the preoperative state. Discussion/Conclusion: Anterior OW PTO has been shown to be a safe method of accurately correcting tibial plateau slope for the treatment of genu recurvatum. Patients can expect correction of knee hyperextension, restoration of anatomic posterior tibial slope, decreased posterior tibial translation, and increased subjective outcome scores. Patient Consent Disclosure Statement: The author(s) attest that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Turf toe: a review of mechanism, pathoanatomy and management

Turf toe is characterized by sprain or disruption of the plantar capsuloligamentous structures of the first metatarsophalangeal joint and usually occurs due to injury during contact sports such as rugby and American football. The clinical presentation typically includes pain, swelling, and ecchymosis at the plantar surface of the first metatarsophalangeal joint, with associated weakness during push off. Diagnostic evaluation involves thorough physical examination, stressing of ligaments, and imaging with radiographs and magnetic resonance imaging. Treatment is based on classification, but is generally conservative, with surgical management being reserved for patients who fail to improve with non-operative methods. Chronic injuries may be associated with worse outcomes, and therefore early diagnosis and treatment is vital.

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.

The Anterior Fibers of the Superficial MCL and the ACL Restrain Anteromedial Rotatory Instability

Background: There is limited knowledge about how the anterior cruciate ligament (ACL) and capsuloligamentous structures on the medial side of the knee act to control anteromedial rotatory knee instability. Purpose: To investigate the contribution of the medial retinaculum, capsular structures (anteromedial capsule, deep medial collateral ligament [MCL], and posterior oblique ligament), and different fiber regions of the superficial MCL to restraining knee laxity, including anteromedial rotatory instability. Study Design: Controlled laboratory study. Methods: Eight fresh-frozen human cadaveric knees were tested using a 6 degrees of freedom robotic testing system in a position-controlled mode. Loads of 10 N·m valgus rotation, 5 N·m tibial external rotation, 5 N·m tibial internal rotation, and 134 N anterior tibial translation in 5 N·m external rotation were applied at different flexion angles. The motion of the intact knee at 0° to 120° of flexion was replicated after sequential excision of the sartorial fascia; anteromedial retinaculum; anteromedial capsule; anterior, middle, and posterior fibers of the superficial MCL; the deep MCL; the posterior oblique ligament; and the ACL. The reduction in force/torque indicated the contribution of each resected structure to resisting laxity. A repeated-measures analysis of variance with a post hoc Bonferroni test was used to analyze the relative force and torque changes from the intact state. Results: The superficial MCL was the most important restraint to valgus rotation from 0° to 120° and provided the largest contribution to resisting external rotation between 30° and 120° of knee flexion, gradually increasing from 25.2% ± 7.4% at 30° to 36.9% ± 15.4% at 90°. The posterior oblique ligament contributed significantly to resisting valgus rotation only in extension (17.2% ± 12.1%) but was the major restraint to internal rotation at 0° (46.7% ± 13.1%) and 30° (30.4% ± 17.7%) of flexion. The sartorial fascia and anteromedial retinaculum resisted ER at all knee flexion angles (P < .05) and was the single most important restraint in the extended knee (19.5% ± 11%). The capsular structures (anteromedial capsule and deep MCL) had a combined contribution of 20% ± 11.5% at 0° and 23.4% ± 10.5% at 120° of knee flexion but were less important from 30° to 90°. The ACL was the primary restraint to anterior tibial translation in external rotation between 0° and 60° of flexion (50.2% ± 16.9% at 30°), but the superficial MCL was more important at 90° to 120° of knee flexion (36.8% ± 16.4% at 90°). The anterior, middle, and posterior regions of the superficial MCL contributed differently to the simulated laxity tests. The anterior fibers were the most important part of the superficial MCL in resisting external rotation and combined anterior tibial translation in external rotation. Conclusion: The superficial MCL not only was the primary restraint to valgus rotation throughout the range of knee flexion but also importantly contributed to resisting anterior tibial translation in external rotation, particularly in deeper flexion in the cadaveric model. The anterior fibers of the superficial MCL are the most important superficial MCL fibers in resisting anterior tibial translation in external rotation. This study suggests that a medial reconstruction that reproduces the function of the posterior MCL fibers and posterior oblique ligament may not best control anteromedial rotatory instability. Clinical Relevance: Based on these data, there is a need for an individualized medial reconstruction to address different types of medial injury patterns and instabilities.

Beyond the Malleoli: Part 1—Avulsion Fractures of the Tibia and Fibula

Avulsion fractures of the ankle and hindfoot are a diverse group of injuries occurring at level of retinacular, capsuloligamentous, and tendinous attachments. Even small fracture fragments have the potential to cause serious complications (such as ankle instability and accelerated osteoarthritis in the context of avulsion fractures of the surrounding capsuloligamentous supporting structures), if not treated appropriately. This article describes the relevant anatomy, injury mechanisms, classification, nomenclature, imaging, treatment, and complications of ankle and hindfoot avulsion fractures, with the exception of fractures occurring at and in the vicinity of the medial and lateral malleolar tips. In this part 1 of a two-part series, we provide a review of ankle retinacular and distal tibiofibular syndesmotic avulsion fractures.

Patient demographic and magnetic resonance imaging evaluation of isolated posterolateral corner knee injuries.

Posterolateral stability of the knee is maintained by capsular, ligamentous and tendinous structures, which collectively are known as the posterolateral corner (PLC). Injuries to the PLC of the knee rarely occur without associated anterior (ACL) or posterior cruciate (PCL) ligament tears. The main objectives of our study were to report patient demographics and magnetic resonance imaging (MRI) findings of patients with isolated PLC injuries. This study consists of a retrospective analysis of knee MRI from January 2011 to June 2016, in two hospitals in São Paulo, Brazil, where PLC injuries without associated ACL and PCL injuries were identified in MRI by two radiologists specialized in musculoskeletal injuries. Relative and absolute frequencies were used to describe the injuries of each of the PLC structures in the study cases. A total of 23 cases of PLC injuries without associated cruciate ligament injuries were identified. The mean age of patients was 32.0±8.1 years and 91% patients were male. The main sport associated with isolated PLC injury was Brazilian Jiu-Jitsu (48%), followed by soccer (35%). MRI evaluations of the knees showed lateral collateral ligament (LCL) injuries in 70% of cases, popliteus tendon injuries in 26% of cases and distal biceps tendon injuries in 30% of cases. The popliteofibular ligament (PFL) was damaged in 83% of cases. An associated ALL injury was observed in 43% of cases. Isolated PLC injuries occurred mainly in young men when practicing Brazilian Jiu-Jitsu and soccer. The LCL was the most frequently injured larger structure in association, and the capsuloligamentous structures (PFL) were the most frequently injured structures overall. ALL injuries occurred in approximately half of the cases, most often concomitantly with LCL injuries.

Distal Radioulnar Joint: Normal Anatomy, Imaging of Common Disorders, and Injury Classification.

The distal radioulnar joint (DRUJ) is the distal articulation between the radius and ulna, acting as a major weight-bearing joint at the wrist and distributing forces across the forearm bones. The articulating surfaces are the radial sigmoid notch and ulnar head, while the ulnar fovea serves as a critical attachment site for multiple capsuloligamentous structures. The DRUJ is an inherently unstable joint, relying heavily on intrinsic and extrinsic soft-tissue stabilizers. The triangular fibrocartilage complex (TFCC) is the chief stabilizer, composed of the central disk, distal radioulnar ligaments, ulnocarpal ligaments, extensor carpi ulnaris tendon subsheath, and ulnomeniscal homologue. TFCC lesions are traditionally classified into traumatic or degenerative on the basis of the Palmer classification. The novel Atzei classification is promising, correlating clinical, radiologic, and arthroscopic findings while providing a therapeutic algorithm. The interosseous membrane and pronator quadratus are extrinsic stabilizers that offer a minor contribution to the joint's stability in conjunction with the joints of the wrist and elbow. Traumatic and overuse or degenerative disorders are the most common causes of DRUJ dysfunction, although inflammatory and developmental abnormalities also occur. Radiography and CT are used to evaluate the integrity of the osseous constituents and joint alignment. US is a useful screening tool for synovitis in the setting of TFCC tears and offers dynamic capabilities for detecting tendon instability. MRI allows simultaneous osseous and soft-tissue evaluation and is not operator dependent. Arthrographic CT or MRI provides a more detailed assessment of the TFCC, which aids in treatment and surgical decision making. The authors review the pertinent anatomy and imaging considerations and illustrate common disorders affecting the DRUJ. Online supplemental material is available for this article. © RSNA, 2022.

Humeral trochlear morphology does not influence coronoid fractures in elbow dislocation

PurposeTraumatic elbow dislocation is the second most frequent joint dislocation, even though the elbow is a congruent and stable joint. Individual variability in anatomical congruence of the elbow and how it relates to simple or complex instability has rarely been studied in the literature; we hypothesized that a greater articular coverage by the humeral trochlea would be more likely to result in complex dislocation. The aim of this study is to analyze trochlear morphology in simple (SED) and complex elbow dislocation (CED), to assess whether the degree of humeroulnar joint congruence influences the incidence of coronoid fractures in elbow dislocation. The secondary goal is to evaluate the association between trochlear morphology and coronoid fracture pattern.MethodsAll the elbow CT scans of the hospital server were retrospectively analyzed. 62 patients were enrolled and so divided in 2 groups: SED and CED with isolated coronoid fracture. Patients who were skeletally immature, presented with other concomitant elbow fractures, or who previously underwent elbow surgery were excluded. The CT scans were performed after closed reduction and prior to further treatment. Coronoid fracture pattern was classified on CT scan according to Regan-Morrey and O’Driscoll classifications; “grade 0” was assigned to SED. Trochlear coverage was measured and expressed as three angles (anterior, posterior, and distal) and their width/depth ratios. Measurements were taken by four different readers and the assessment was repeated after 15 days.ResultsNo statistically significant difference was found between humeral trochlear morphology of SED and CED patients. There was no association between morphometric measurements and coronoid fracture pattern. The results are strengthened by a good intra- and inter-reader reproducibility of the CT analysis protocol.ConclusionsOur study is the first to evaluate the impact of trochlear morphology on elbow instability. Considering the results, other variables may have a greater impact on coronoid bone damage, such as trauma energy or ligamentous hyperlaxity: in particular, we believe that the capsuloligamentous structures of the elbow might contribute in a preponderant way to articular stability. The CT analysis protocol gave excellent results: reproducible, accurate and easy to perform.Level of evidenceIII.

Anatomical study of the dorsal capsulo-scapholunate septum using high frequency ultrasonography

IntroductionThe dorsal capsulo-scapholunate septum (DCSS) is a recently described capsuloligamentous structure between the dorsal bundle of the scapholunate ligament (SLL) and the joint capsule of the wrist. It acts a secondary stabilizer of the scapholunate joint. The aim of this study was to evaluate the visibility and normal appearance of DCSS on high frequency ultrasound. HypothesisThe DCSS can be analyzed using high frequency ultrasound. Materials and methodsThree cadaveric wrists were dissected in order to study the DCSS; one without labeling and the other two after labeling under ultrasound guidance. On two other wrists, a correlation between the structure considered to be the DCSS on ultrasound and the corresponding CT arthrography and anatomical sections was carried out. Finally, sagittal ultrasound sections of the DCSS region on 42 healthy wrists were analyzed retrospectively. ResultsDuring dissection, the DCSS corresponded to a fibrous structure extending to the dorsal surface of the scaphoid and lunate, with certain fibers converging towards the SLL. On high-frequency ultrasound, a hyperechoic fibrillar structure was visualized at the theoretical position of the DCSS. The dissections performed after ultrasound-guided transfixion showed that its limits corresponded to the limits of the DCSS. The anatomical, CT arthrography and ultrasound sections in the DCSS region were concordant. The DCSS was retrospectively visible on at least one reference ultrasound slice in 90.5% of healthy wrists, and was always hyperechoic. Its average thickness was 1.38±0.24mm. DiscussionOur study describes the normal sonographic characteristics of the DCSS, visible in a majority of healthy patients on high-frequency ultrasound. The analysis of the sonographic characteristics of the DCSS in the context of acute wrist trauma should be evaluated, and a diagnostic decision tree has been proposed. Level of evidenceIV.

Arthroscopic rod technique compared to stress ultrasound in the dynamic evaluation of lateral ligament instabilities of the elbow

IntroductionThe purpose was to compare the arthroscopic rod technique to stress ultrasound in the dynamic assessment of lateral elbow instabilities.Materials and methodsFifteen elbows of eight specimen with a mean age of 66.4 ± 13.3 years were assessed in a prone position following a defined dissection setup. After evaluation of the native status, an arthroscopic dissection of the radial collateral ligament (RCL) or lateral ulnar collateral ligament (LUCL), and finally of entire capsuloligamentous structures was performed. Three raters examined each state (native, RCL or LUCL lesion, complete lesion) with the arthroscopic rod technique in 90° flexion and with stress ultrasound in 30 and 90° flexion. The intra-class correlation coefficient (ICC) was calculated to assess the interrater reliability as well as test–retest reliability for each testing modality (arthroscopy and ultrasound).ResultsThe arthroscopic rod technique showed a superior interrater and test–retest reliability of 0.953 and 0.959 (P < 0.001), respectively, when compared to stress ultrasound with an ICC of 0.4 and 0.611 (P < 0.001). A joint space opening during arthroscopy of > 6 mm humero-ulnar or > 7 mm humero-radial was indicative for a lateral collateral ligament lesion. However, a differentiation between an isolated RCL or LUCL tear was not possible. A lateral joint opening of ≥ 9 mm was only observed in complete tears of the lateral capsuloligamentous complex.ConclusionsThe arthroscopic rod technique showed a superior interrater and test–retest reliability when compared to stress ultrasound. Arthroscopic assessment for radial elbow instability was found to be reliable and reproducible. A joint gapping ≥ 9 mm in the arthroscopic evaluation is a sign for a complete insufficiency of the radial capsuloligamentous complex. However, it is not possible to precisely distinguish between a lesion of the RCL or LUCL by arthroscopy.On the basis of our results, dynamic ultrasound testing may be inappropriate to objectify lateral elbow instability.

Paper 07: Biomechanical Evaluation of Posterior Shoulder Instability with a Clinically Relevant Posterior Bone Loss Model

Objectives: Though recognized as a risk factor, posterior glenoid bone loss has only recently been characterized and is distinctly different than anterior glenoid bone loss patterns. Existing biomechanical studies are limited by employment of anterior glenoid bone loss models which are different in both orientation and morphology than posterior glenoid bone loss, and testing in a single neutral arm position thus not fully accounting for the contribution of capsuloligamentous structures in various at-risk arm positions. The purpose of this study was to evaluate the biomechanical effectiveness of a posterior labral repair in the setting of a clinically relevant bone loss model using 3-dimensional computed tomography modeling of patients with recurrent posterior shoulder instability in various at-risk arm positions. Methods: Ten fresh-frozen cadaveric shoulders (mean age: 55.4 years, range: 39-65) were prepared by removing all tissue except the capsule and distal rotator cuff insertions. A joint coordinate frame was established, the specimens were potted, then mounted to a customized fixture on 6-degrees-of-freedom robotic arm. A posterior labral tear was created, then repaired with 3 horizontal mattress sutures and secured by drilling 6 transosseous holes along the peripheral glenoid face exiting the anterior glenoid neck. The sutures were secured for the labral repair states to the mounted fixture under maximal tension and released for the labral tear states and for creating the sequential bone loss models. Bone loss models were created based off a cohort of CT data on patients undergoing revision posterior labral repair surgery to develop 2 clinically relevant 3D models of glenoid bone loss: the first simulating the mean bone loss in this cohort and represented 7% or small bone loss; the second was the mean + 2SD representing 28% or large bone loss. The bone loss was created on each specimen with a 3mm round burr to match each respective 3D printed template (Figure 1). Each specimen was tested in 7 consecutive states: (1) native anatomy, (2) posterior labral tear (6-9 o’clock), (3) posterior labral repair, (4) mean posterior glenoid bone loss with labral tear, (5) mean posterior glenoid bone loss with labral repair, (6) large posterior glenoid bone loss with labral tear, and (7) large posterior glenoid bone loss with labral repair. Each state underwent 75N of posterior-inferior force and 75N of compression during the four tests at 60 and 90 degrees of flexion and 60 and 90 degrees of scaption. Posterior-inferior translation, lateral translation, and dislocation force were measured for each condition. Statistical analysis was performed using two-factor random-intercepts linear mixed-effects models. Results: Compared to the labral tear state, significant increases in dislocation forces occurred with labral repair independent of bone loss state or arm position with values as follows: 14.8N (60° scaption), 12.2N (90° scaption), 11.1N (60° flexion), and 10.1N (90° flexion) with mean 12.1 ± 2.0N across all arm positions (Figure 2). Dislocation force significantly decreased between no bone loss and small bone loss (mean 12.4 ± 0.7N) and between small bone loss and large bone loss (mean 11.8 ± 2.1N) regardless of labral state in all arm positions (table 1). Posterior-inferior translation significantly decreased with labral repair compared to labral tear states independent of bone loss state in all arm positions (Table 1). Lateral translation of the humeral head significant increased when the labrum was repaired independent of bone loss state in all arm positions except 90° scaption and decreased progressively in all bone loss states in all arm positions (table 1). In the native state, the shoulder significantly translated posterior-inferior in scaption at 60° and 90° elevation compared to flexion (p&lt;0.017) and was most unstable in 60° scaption with 29.9 ± 6.1mm posterior-inferior translation (Figure 3). Conclusions: This is the first study to biomechanically evaluate posterior glenoid bone loss using a clinical model in various at-risk arm positions on a 6 degree-of-freedom robot and through a precise linear effects model has established values for the increase in dislocation force posterior labral repair provides regardless of bone loss. The most significant finding of the study is that independent of bone loss, labral repair reduced posterior dislocation forces by 12.1 ± 2.0N and significantly decreased posterior-inferior translation. With a mean decrease in dislocation force of 12.4 ± 0.7N with small (7%) bone loss, labral repair alone may be enough to restore shoulder stability in most individuals. However, significant increases in posterior bone loss may require bony augmentation for adequate stability based on individual factors such as age and activity level. [Table: see text][Figure: see text][Figure: see text]

Esguince lateral de tobillo con necrosis cutánea no yatrogénica. Presentación de un caso y revisión de los sistemas de clasificación.

Lateral ankle sprain is a frequent injury that heals quickly with correct treatment. We present a case with rare complications, unrelated to inadequate orthopedic treatment. In addition, the study is completed by conducting a review of the literature with the different systems used to classify this type of injury. A 49-year-old male athlete with a lateral ankle sprain while practicing basketball who presented significant edema, which progressed to anterolateral skin necrosis in 2 weeks. After scarectomy, he presented a deep wound with exposure of the capsulo-ligamentous structures, turning the injury into an open one. He associated a complete injury of the superficial peroneal nerve. Outpatient cures were startedwith associated negative pressure therapy, healing the wound after 4 months of evolution, returning to sports practice at 8 months.

Knee Joint Menisci Are Shock Absorbers: A Biomechanical In-Vitro Study on Porcine Stifle Joints

The aim of this biomechanical in vitro study was to answer the question whether the meniscus acts as a shock absorber in the knee joint or not. The soft tissue of fourteen porcine knee joints was removed, leaving the capsuloligamentous structures intact. The joints were mounted in 45° neutral knee flexion in a previously validated droptower setup. Six joints were exposed to an impact load of 3.54 J, and the resultant loss factor (η) was calculated. Then, the setup was modified to allow sinusoidal loading under dynamic mechanical analysis (DMA) conditions. The remaining eight knee joints were exposed to 10 frequencies ranging from 0.1 to 5 Hz at a static load of 1210 N and a superimposed sinusoidal load of 910 N (2.12 times body weight). Forces (F) and deformation (l) were continuously recorded, and the loss factor (tan δ) was calculated. For both experiments, four meniscus states (intact, medial posterior root avulsion, medial meniscectomy, and total lateral and medial meniscectomy) were investigated. During the droptower experiments, the intact state indicated a loss factor of η = 0.1. Except for the root avulsion state (−15%, p = 0.12), the loss factor decreased (p < 0.046) up to 68% for the total meniscectomy state (p = 0.028) when compared to the intact state. Sinusoidal DMA testing revealed that knees with an intact meniscus had the highest loss factors, ranging from 0.10 to 0.15. Any surgical manipulation lowered the damping ability: Medial meniscectomy resulted in a reduction of 24%, while the resection of both menisci lowered tan δ by 18% compared to the intact state. This biomechanical in vitro study indicates that the shock-absorbing ability of a knee joint is lower when meniscal tissue is resected. In other words, the meniscus contributes to the shock absorption of the knee joint not only during impact loads, but also during sinusoidal loads. The findings may have an impact on the rehabilitation of young, meniscectomized patients who want to return to sports. Consequently, such patients are exposed to critical loads on the articular cartilage, especially when performing sports with recurring impact loads transmitted through the knee joint surfaces.

Comparison of a Novel Anatomic Technique and the Docking Technique for Medial Ulnar Collateral Ligament Reconstruction

Background: Current reconstruction techniques do not re-create the distal ulnar collateral ligament (UCL) insertion. Reconstructing the distal extension of the anterior band ulnar footprint may increase elbow stability and resistance against valgus stress after UCL reconstruction (UCLR). Purpose/Hypothesis: The purpose was to test a new technique for UCLR, a modification of the docking technique, aimed at re-creating the distal ulnar footprint anatomy of the anterior band. We hypothesize that this novel “anatomic” technique will provide greater resistance to valgus stress after UCLR when compared with the docking technique. Study Design: Descriptive laboratory study. Methods: Eighteen unpaired cadaveric arms were dissected to capsuloligamentous elbow structures and potted. With use of a servohydraulic load frame, 5 Nċm of valgus stress was placed on the UCL-intact elbows at 30°, 60°, 90°, and 120° of flexion. UCLR was performed on each elbow, randomized to either the docking technique or the anatomic technique. After UCLR, the elbow was again tested at 30°, 60°, 90°, and 120° of flexion. Ulnohumeral joint gapping was calculated using a 3-dimensional motion capture system applied to markers attached to the ulna and humerus. Differences in gapping among the intact state and docking and anatomic techniques were compared using a 2-way analysis of variance with significance set to P < .05. Results: There was no significant difference in gapping between the anatomic and docking technique groups regardless of elbow flexion angle. All reconstructed groups showed increased gapping relative to intact, but all increases were below the clinically relevant level of 1 mm. Conclusion: Ulnohumeral joint gapping and resistance to valgus stress were similar between the anatomic technique and the docking technique for UCLR. Clinical Relevance: This study provides evidence that the anatomic technique is a viable alternative UCLR method as compared with the docking technique in a cadaveric model.

Hip Microinstability: Understanding a Newly Defined Hip Pathology in Young Athletes

Microinstability is an increasingly recognized diagnosis in young athletes presenting with hip pain. Causes of microinstability may include abnormality of the hip bony anatomy, acetabular labral tears, joint capsule laxity or injury, and muscle dysfunction. Borderline hip dysplasia is an increasingly recognized factor predisposing to microinstability. The capsuloligamentous structures of the hip, particularly the iliofemoral ligament, provide important restraints to femoral head motion, and iatrogenic defects can predispose patients to instability after surgery. Injury to the acetabular labrum may disrupt its important hip-stabilizing properties including the suction seal and improved acetabular depth. Hip muscle weakness or imbalance may result in increased femoral head motion within the acetabulum. The diagnosis of hip microinstability can be challenging, and the history is often nonspecific. Physical examination maneuvers include the anterior apprehension, prone instability, axial distraction, and abduction-hyperextension-external rotation tests. Radiographic features may include borderline hip dysplasia, femoral head-neck junction cliff sign, and an elevated femoral-epiphyseal acetabular roof index. Magnetic resonance arthrography may demonstrate a capsular defect, capsular thinning, or labral pathology. Diagnostic intra-articular injection of anesthetic can confirm the intra-articular nature of the pathology. Management of hip microinstability focuses on strengthening the dynamic stabilizers of the hip through focused physical therapy. Surgery may be considered in recalcitrant cases where symptoms persist despite optimization of hip stabilizer strength. In such cases, addressing the primary source of instability through labral repair or reconstruction and capsular repair or plication can be considered. In highly selected cases, surgery can result in excellent outcomes.

Not strong enough? Movements generated during clinical examination of sagittal and rotational laxity in a cadaver knee

ABSTRACT BACKGROUND: Injury to the anterior cruciate ligament (ACL) is associated with sagittal and rotational laxity, which is exacerbated by damage to the anterolateral capsuloligamentous structures, also known as the anterolateral ligament (ALL). The amount of laxity reported in biomechanical studies might be clinically insignificant during a surgeon's examination, possibly influencing clinical judgement. We aimed to measure whether the motion generated by clinicians in a cadaver model after the ACL and ALL were transected is clinically significant METHODS: A group of orthopaedic surgeons and trainees examined a cadaver knee for sagittal and rotational laxity at 30° and 90° with intact ligaments, after the ACL was transected, and after the ACL and ALL were transected. The examiners were blinded to the dissection process. Rotational and sagittal movements during these examinations were recorded by a computer-assisted surgery (CAS) system RESULTS: Twenty-four orthopaedic surgeons took part in the study. The median sagittal plane motion captured by CAS at 30° flexion was 7 mm (IQR 2 mm, p-value 0.32) in the intact knee, 9 mm (IQR 1 mm, p-value 0.34) after the ACL was cut and 9 mm (IQR 3 mm, p-value 0.63) after ACL and ALL were cut. The median arc of rotational motion at 30° was 19° (IQR 7°, p-value 0.12) in the intact knee, 24° (IQR 5°, p-value 0.56) after the ACL was cut, and 22° (IQR 6°, p-value 0.8) after the ACL and ALL were cut. None of the differences in these movements was significant CONCLUSION: The surgeons could not generate significant differences in sagittal or rotational motion in a cadaver model, which could be objectively detected by CAS, when examining the intact knee, ACL deficient (only), or combined ACL and ALL deficient knee. This challenges the utility of known clinical tests and calls for improved objective laxity assessment tools to provide input in clinical decision-making and measure outcomes of these injuries Level of evidence: Level 5 Keywords: knee, anterolateral ligament, anterior drawer's test, pivot shift, rotatory instability, anterior cruciate ligament, iliotibial band, Kaplan fibres

The posterior oblique ligament in MRI of acute knee trauma

To identify the posterior oblique ligament and assess incidence and patterns of injury to the ligament on MRI of acute knee trauma. One hundred twenty-three MRI studies met the study criteria. For each case, the posterior oblique ligament was identified and scored as injured or normal. Incidence of proximal and distal posterior oblique ligament tears was calculated. Fisher's tests were employed to determine significance of association between tears of the posterior oblique ligament and components of the posteromedial corner and other capsuloligamentous structures of the knee. The posterior oblique ligament was reliably identified as a distinct structure in 123 MRI scans that met the criteria and was consistently labeled as intact or torn. Posterior oblique ligament tear was seen in 61.7% of knee trauma with proximal injury in 56.5% and distal injury in 97.3% of positive cases. Posterior oblique ligament disruption was a part of multiligamentous injury in 94.7% of positive cases. Posterior oblique ligament injuries (n = 76) had an extremely significant relationship with oblique popliteal ligament tears (n = 27) (p = 0.0001), semimembranosus tendon insertion tears (n = 15) (p = 0.0005), and medial collateral ligament tears (n = 15) (p = 0.0005) and a highly significant association with medial meniscus tears (n = 68) (p = 0.0049) and posterior cruciate ligament tears (n = 12) (p = 0.0033). The association with anterior cruciate ligament tears (n = 53) was not significant. The posterior oblique ligament is a distinct radiological entity consistently identified in acute trauma MRI. Disruptions of the distal posterior oblique ligament are frequent in complex knee injury, notably in association with oblique popliteal ligament, medial collateral ligament, and semimembranosus tendon tears.