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The subscapularis is the strongest muscle among the rotator cuff muscles, and it provides a coupled balanced force across the glenohumeral joint by resisting the infraspinatus in axial plane and the shearing force of deltoid in the coronal plane. It is important to repair subscapularis tears to maintain the coupled balanced force. Subscapularis tendon tears are difficult to diagnose and treat. Only a small portion of the subscapularis tendon is visualized during routine arthroscopy, as it is largely covered by the middle and inferior glenohumeral ligaments. Various repair techniques have been described in the literature. Here, we describe the anterolateral viewing portal for better visualization of subscapularis and our preferred technique, the lasso-loop technique, which provides better tissue grip and improved functional outcome. [Display omitted] [ABSTRACT FROM AUTHOR]

Purpose: To compare the clinical and radiologic outcomes of arthroscopically assisted coracoclavicular (CC) fixation using multiple soft anchor knots versus hook plate fixation in patients with acute high-grade Rockwood type III and V acromioclavicular (AC) joint dislocations.Methods: This retrospective study included 22 patients with acute Rockwood type III and V AC joint dislocations who underwent arthroscopic fixation or hook plate fixation surgery between February 2016 and March 2018. Patients were categorized into 2 groups: arthroscopically assisted CC fixation using multiple soft anchor knots group (AR, n = 12) and hook plate fixation group (HO, n = 10). We measured the CC distances (CCDs) and CCD ratio at 6 months, 1 year, and last follow-up postoperatively to compare the radiologic results between the groups. Clinical outcomes were assessed at 1 year postoperatively and at the last follow-up using the Visual Analog Scale, American Shoulder and Elbow Surgeons (ASES) scores, and Shoulder Pain and Disability Index (SPADI) scores, and the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire. Magnetic resonance imaging after hook plate removal was used to evaluate the healing ligaments and tendon-bone interface.Results: The patients in the AR group had better ASES, SPADI, and Quick DASH scores than the patients in the HO group at 1 year postoperatively and at last follow-up. The CCD and CCD ratio were significantly better in the AR group than in the HO group at the last follow-up period (P = .007/0.029). Magnetic resonance imaging findings showed grade I in 60% of patients in the AR group and grade III in 60% of patients in the HO group. AC joint arthritic change was observed in 40% of the HO group.Conclusions: The CC fixation method using multiple soft anchor knots showed satisfactory results and had superior CC ligament healing ability and maintenance of CCD than hook fixation.Level Of Evidence: Level III, retrospective therapeutic comparative investigation. [ABSTRACT FROM AUTHOR]

Numerous reports have shown that retracted rotator cuff tears may cause suprascapular nerve injury, and nerve injury causes atrophy and fat accumulation in the rotator cuff muscles. However, the effect of suprascapular nerve injury on rotator cuff enthesis has not been directly defined. This study aimed to investigate the effect of suprascapular nerve injury on rotator cuff enthesis. Twenty-four Wistar albino rats underwent bilateral transection of the suprascapular nerve. Additional 6 rats were used as the sham group. Bilateral supraspinatus and infraspinatus entheses were examined after 1, 4, 8, and 12 weeks of nerve transection. Histomorphometric analyses were performed for each zone of enthesis. Compared with normal enthesis, significant and consistent decrease in cellularity were observed in the tendon and bone at all time points (P <.001). Collagen bundle diameter in the tendon also decreased in a similar manner (P <.001). Apart from the tendon and bone zones, fibrocartilage and calcified fibrocartilage zones showed similar response, and significant decrease in cellularity was observed 8 weeks after nerve transection (P <.001). This study identifies suprascapular nerve injury as an underlying mechanism leading to compromise of the rotator cuff enthesis structure. Suprascapular nerve injury may be considered as an etiologic factor for the impaired healing after repair of a massive tear. [ABSTRACT FROM AUTHOR]

Arthroscopic Bankart repair of anterior instability has shown relatively good results, but its effectiveness is unclear in cases wherein there is a bone defect in the glenoid bone. The surgical management of recurrent anterior shoulder instability with severe glenoid bone loss has been challenging until now. Therefore the Latarjet procedure was introduced as an alternative that provided good results in cases of full instability with a bone defect. In cases of recurrent anterior shoulder instability, bone defects are often present within the glenoid. To restore glenohumeral stability, a bone augmentation procedure is required, and the Latarjet procedure to use bony transfer from the coracoid is the most popular technique. However, resorption of the bone graft with metal screw protrusion is a serious concern, whereas the relative contribution of the dynamic sling effect of the Latarjet procedure remains controversial. The Latarjet procedure also destroys the normal kinematics, resulting in side effects such as scapular dyskinesia. Here we introduce an arthroscopic anterior bone block procedure for reconstructing anterior glenoid bone defects using an autologous iliac crest graft. This technique enables precise bone block placement and fixation using one all-suture anchor instead of screw fixation. [ABSTRACT FROM AUTHOR]

Acromioclavicular (AC) joint dislocation is a common injury, particularly among active young individuals. Numerous surgical procedures for treating acute, high-grade AC joint dislocation have been reported. However, no standard surgical procedure that restores the normal kinematics of the AC joint is available. Among the available coracoclavicular (CC) fixation techniques, cortical button fixation was recently introduced, and it has had successful outcomes. Moreover, it is advantageous because it can be used in arthroscopic procedures. However, because of the limited number of fixation tools, a fundamental problem in terms of horizontal instability and gradual subsidence of cortical buttons has been observed, eventually leading to a threat to vertical stability. Therefore, we developed a unique CC fixation technique with multiple small tunnels using all-suture anchors, which may overcome potential complications caused by cortical buttons that require bone tunnels with relatively large diameters. This arthroscopic CC fixation technique was designed to achieve the ideal horizontal and vertical stability that may restore native AC kinematics. [ABSTRACT FROM AUTHOR]

Purpose: To introduce an arthroscopically assisted coracoclavicular (CC) fixation technique using multiple low-profile devices to evaluate the clinical and radiologic outcomes in patients with acute high-grade acromioclavicular (AC) joint dislocation.Methods: Between July 2014 and September 2015, cases of AC joint dislocation that were treated with arthroscopic CC fixation using multiple low-profile devices with a minimum follow-up of 24 months were included. We measured the vertical coracoclavicular distance (CCD) on the anteroposterior view and the horizontal acromioclavicular distance on 3-dimensional computed tomography images to evaluate the changes in radiologic outcomes before and after surgery. We compared final radiologic outcomes between initial AC reduction groups based on hierarchical clustering. Clinical outcomes were evaluated using the Constant-Murley score.Results: We enrolled 27 patients in total, and the mean follow-up period was 27.2 months. The mean CCD of the injured shoulder was 13.68 ± 3.98 mm preoperatively and decreased to 5.72 ± 1.68 mm immediately postoperatively but increased to 7.32 ± 2.29 mm at last follow-up (P = .07). Horizontal displacement of the distal clavicle was 1.1 ± 1.0 mm immediately postoperatively but decreased to 0.9 ± 0.6 mm at last follow-up (P < .05). In particular, in the 2 groups that were determined using the hierarchical cluster analysis, patients with excellent recovery of the initial CCD (20 patients) showed less of an increase in the CCD at last follow-up than did those in the other group (7 patients) (P < .001). The Constant-Murley score was 93.5 ± 2.7 points on the injured side at last follow-up (P = .074).Conclusions: Our CC fixation technique with multiple low-profile devices exhibited satisfactory clinical and radiologic outcomes. In particular, ensuring good initial recovery of the CCD and the precise placement and location of the AC joints was important in maintaining the proper AC position at the final follow-up.Level Of Evidence: Level IV, case series. [ABSTRACT FROM AUTHOR]

Unlabelled: Shoulder stiffness can be caused by various etiologies such as immobilization, trauma, or surgical interventions. The Upper Extremity Committee of ISAKOS defined the term "frozen shoulder" as idiopathic stiff shoulder, that is, without a known cause. Secondary stiff shoulder is a term that should be used to describe shoulder stiffness with a known cause. The pathophysiology of frozen shoulder is capsular fibrosis and inflammation with chondrogenesis, but the cause is still unknown. Conservative treatment is the primary choice. Pain control by oral medication, intra-articular injections with or without joint distension, and physical therapy are commonly used. In cases with refractory stiffness, manipulation under anesthesia or arthroscopic capsular release may be indicated. Because of various potential risks of complications with manipulations, arthroscopic capsular release is preferred. After the capsular release, stepwise rehabilitation is mandatory to achieve satisfactory outcome.Level Of Evidence: Level V, evidence-based review. [ABSTRACT FROM AUTHOR]

Purpose: To compare the outcome between arthroscopic soft tissue tenodesis (STT) at the rotator interval and bony interference fixation tenodesis (BIFT) at the distal bicipital groove for the long head of the biceps (LHB).Methods: Twenty-five shoulders that underwent arthroscopic STT of the LHB were compared with 28 shoulders that underwent arthroscopic BIFT using a 5.5-mm Bio-Tenodesis screw (Arthrex, Naples, FL). American Shoulder and Elbow Surgeons scores, Constant score, and elbow flexion strength index (EFSI) were checked preoperatively, postoperative 1 year and 2 years. Ultrasound imaging evaluation took place at 1 year and 2 years postoperatively as well.Results: The overall functional outcomes improved after surgery in both groups. The BIFT group showed a significant increase in EFSI (preop: 0.54, postoperative 2 years: 0.94) compared with that of the STT group (preop: 0.52, postoperative 2 years: 0.74) at postoperative 2 years (P = .006). However, no significant difference was seen in the increase of American Shoulder and Elbow Surgeons scores and Constant scores between the two groups. At postoperative 2 years, ultrasound showed seven empty grooves in the STT group, but only two empty grooves in the BIFT group (P = .046).Conclusions: Arthroscopic BIFT for the LHB showed better improvement in EFSI than arthroscopic STT. In addition, the STT group showed a higher failure rate than the BIFT group.Level Of Evidence: Level III, retrospective comparative study. [ABSTRACT FROM AUTHOR]

Purpose: To quantitatively and qualitatively evaluate the impingement behavior between structures within the glenohumeral joint under simulated abduction-external rotation (ABER) motion using finite element analysis.Methods: Computed tomography (CT) scanning of 1 shoulder in a volunteer was performed at 0° and 120° of shoulder abduction with external rotation (ABER position), followed by magnetic resonance imaging at 0° of abduction. The CT and magnetic resonance images were then imported into a customized software program to undergo 3-dimensional reconstruction followed by finite element modeling of the bone and soft tissue including the upper part of the rotator cuff and glenohumeral labral complex. Glenohumeral motion from 0° to the ABER position was simulated by CT images in 2 different humeral positions. On the basis of simulated humeral motion with respect to the scapula, we measured the stress value on the biceps-labral complex and upper part of the rotator cuff as a consequence of their structural deformation. In addition, we intended to design 2 types of labra--a normal stable labrum and an unstable posterosuperior labrum--to evaluate the geometric alteration and resulting stress change on the posterosuperior labrum against a compressive force from the humeral head and rotator cuff.Results: In the ABER position, the posterosuperior labrum was deformed by the humeral head and interposed posterior part of the rotator cuff. When viewed from the rotator cuff, the posterior part of the rotator cuff came into contact with the posterosuperior labrum as external rotation increased. The measured peak contact stress values were 19.7 MPa and 23.5 MPa for the posterosuperior labrum and the upper rotator cuff, respectively. The stress values for both structures decreased to 5.8 MPa and 18.1 MPa, respectively, in the simulated SLAP model. The root of the long head of the biceps became compressed halfway through the range of motion by the humeral head, especially from the part involving horizontal extension and external rotation, resulting in a high stress of 22.4 MPa.Conclusions: In this simulated SLAP model, the posterosuperior labrum was medially displaced by the humeral head and upper rotator cuff in the ABER position, causing a functional loss of the spacer effect.Clinical Relevance: In SLAP lesions, the posterosuperior labrum loses its ability to function as a spacer in certain positions (especially ABER) and may decrease the important spacer effect between the humerus and the rotator cuff; this may lead to posterosuperior subluxation of the humeral head or rotator cuff abnormalities and tears during repetitive ABER tasks. [ABSTRACT FROM AUTHOR]

Background The clavicle hook plate can be used to treat acromioclavicular and coracoclavicular ligament injury or distal clavicular fracture with comminution. However, the hook plate can induce subacromial impingement, resulting in discomfort from the hardware. Methods Our inclusion criteria were (1) men and women aged older than 20 years and (2) the presence of comminuted distal clavicular fractures (Neer type IIB) fixed with a hook plate (Synthes, Oberdorf, Switzerland). Three-dimensional computed tomography was obtained before removal of the hook plate. Seven patients were enrolled prospectively. The mean age was 42 years (range, 24-60 years). Zero degree images and abduction images were obtained. The sagittal cut surface was obtained 5 mm medial from the distal clavicle. The equator of the cut surface of the clavicle was compared with the full abduction model to analyze rotation. The center of the cut surface of the clavicle was compared with the full abduction model to analyze translation. Results The average difference in rotation of the distal clavicle between both shoulders was 16° (range, 3°-22°; P = .001). The mean difference in anterior translation of the distal clavicle was 2.2 mm (range, −0.7 to 5.6 mm; P = .030). Conclusion Hook plate fixation at the acromioclavicular joint causes decreased internal rotation and increased anterior translation of the distal clavicle with respect to the medial acromion, indicating that the scapula relative to the thorax has decreased posterior tilting and increased external rotation in shoulders fixed using a hook plate. [ABSTRACT FROM AUTHOR]

Purpose: To investigate changes in femoral tunnel diameter, dimension, and volume after anterior cruciate ligament reconstruction with notchplasty. Methods: Porcine knee specimens were divided into 2 groups of 10 specimens each. Group A did not receive notchplasty. A 2-mm notchplasty was conducted in group B. Seven-millimeter-diameter femoral tunnels were drilled and a doubled flexor digitorum profundus tendon was inserted and fixed with an EndoButton (Smith & Nephew, Andover, MA) in each knee specimen. Samples were mounted on a materials testing machine. Each group was preloaded at 10 N and subjected to 20 loading cycles (between 0 and 40 N), followed by 1,000 loading cycles in the elastic region (between 10 and 150 N). High-resolution computed tomography with 1.0-mm slices was conducted with all samples before and after testing. A 3-dimensional model was constructed to evaluate the degree of the tunnel change. Results: In group B the mean longest diameter and dimension of the femoral tunnel significantly increased after the test (P = .005 and P = .001, respectively). The volumetric loss of bony structure after the test in group B was significantly greater than that in group A (P = .039). Meanwhile, no significant difference was found before and after the test in terms of tunnel diameter, dimension, and volumetric loss around the tunnel in group A. Conclusions: The intra-articular orifice of the femoral tunnel was enlarged after the uniaxial cyclic loading test after notchplasty. An enlarged tunnel orifice may lead to a discrepancy between the tunnel and the graft at the tunnel aperture. Clinical Relevance: The data may have an implication that suspensory fixation with a notchplasty has a negative effect on the full graft accommodation at the tunnel aperture. Aperture widening may affect graft positioning, leading to subtle changes in graft biomechanics and laxity. [Copyright &y& Elsevier]

Abstract: The goal of this article is to consolidate the International Society of Arthroscopy, Knee Surgery & Orthopaedic Sports Medicine (ISAKOS) Upper Extremity Committee's (UEC's) current knowledge on rotator cuff disease and management, as well as highlight key unresolved issues. The rotator cuff is an anatomically complex structure important for providing glenohumeral function and stability as part of a closed chain system. Current consensus suggests rotator cuff injuries are most accurately diagnosed, at levels similar to diagnosis by magnetic resonance imaging, with a combination of cuff- and impingement-specific clinical tests. Updates in the understanding of acromion morphology, the insertional anatomy of the rotator cuff, and the role of suprascapular nerve release may require changes to current classification systems and surgical strategies. Although initial management focuses on nonoperative protocols, discussion continues on whether surgery for isolated impingement is clinically more beneficial than rehabilitation. However, clear indications have yet to be established for the use of single- versus double-row repair because evidence confirms neither is clinically efficacious than the other. Biceps tenodesis, however, in non-isolated cuff tears has proven more successful in addressing the etiology of shoulder pain and yields improved outcomes over tenotomy. Data reviewing the benefits of tendon transfers, shoulder prostheses, and mechanical scaffolds, as well as new research on the potential benefit of platelet-rich plasma, pluripotential stem cells, and gene therapies, will also be presented. [Copyright &y& Elsevier]

Purpose: The aim of this study was to determine the acromioclavicular (AC) motion and change in length and tension of the coracoclavicular ligament during different positions of shoulder abduction using a 3-dimensional finite element model based on computed tomography images from normal human shoulders. Methods: The right shoulders of 10 living subjects were scanned with a high-resolution computed tomography scanner at 0°, 60°, 120°, and 180° of shoulder abduction. Several modeling programs were used to simulate AC motion. Finite element models of the conoid and trapezoid ligaments were constructed based on each footprint. The tension and length changes of each ligament during shoulder abduction were assessed. Results: The distal clavicle exhibited internal rotation with respect to the medial acromion at 0°, 60°, 120°, and full abduction (3.2° ± 2.9°, 23.2° ± 10.8°, 20.6° ± 3.7°, and 37.1° ± 3.4°, respectively). With horizontal motion, the clavicle translated posteriorly at 60° of abduction (4.4 ± 3.4 mm) and then translated anteriorly at 120° and full abduction (0.4 ± 1.6 mm and 1.9 ± 0.4 mm, respectively). The lengths of the conoid ligament gradually increased at 60° to 180° of shoulder abduction whereas those of the trapezoid ligament remained relatively consistent at 60° to 120° of abduction compared with 0° of abduction. Conclusions: The distal clavicle had a wide range of motion during shoulder abduction, which did not support the concept of synchronous motion with the scapula. The conoid and trapezoid ligaments functioned reciprocally during shoulder abduction. With increasing shoulder abduction, the length of the conoid ligament gradually increased; meanwhile, the trapezoid ligament was relatively consistent and then lax at full abduction. In particular, the conoid ligament may act as a key restraint to prevent excessive retraction of the scapula during shoulder abduction. Clinical Relevance: The data in this study have the potential to suggest that conoid and trapezoid ligaments should be reconstructed separately, and rigid AC fixation in patients with AC separation is not recommended based on the findings of this study. [Copyright &y& Elsevier]

Purpose: The aim of this study was to determine the change in length and tension of the reconstructed anterior cruciate ligament (ACL) double bundles at different knee flexion angles by use of a 3-dimensional finite element model. Methods: The right knees of 12 living subjects were scanned with a high-resolution computed tomography scanner at 0°, 45°, 90°, and 135° of knee flexion. Several modeling programs were used to simulate double-bundle ACL reconstruction. A finite element model of each bundle with a tension of 20 N was put into each tunnel followed by fixation of the bundles. The tension and length changes of each bundle at different knee flexion angles were assessed. Results: For the anteromedial bundle, the length decreased gradually between 45° and 90° of knee flexion and then reached a plateau, whereas the length of the posterolateral bundle significantly decreased at 45° and 90° of flexion but then increased at full flexion. The reaction force of the anteromedial graft slightly decreased at 45° and then remained constant between 90° and 135° of knee flexion. The reaction force of the posterolateral bundle at full extension slightly decreased at 45° and 90° of flexion, followed by a rebound increase at 135°. Conclusions: We found that both bundles functioned throughout the arc of flexion with consistency in tension, although their lengths decreased. The 2 ACL grafts did not function in a reciprocal manner, unlike previous descriptions. Clinical Relevance: The data obtained for length and tension versus flexion angle have the potential to suggest the appropriate knee position for graft fixation and tensioning to be near extension in clinical situations. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to review the isometric point of the posterior cruciate ligament (PCL) based on insertional locations identified in recent anatomic studies by use of a 3-dimensional knee model. Methods: Ten living subjects with healthy knees were evaluated. High-resolution computed tomography scans were performed at 3 positions of 0°, 90°, and 135°, and 3-dimensional knee images were constructed. Customized software was used to define tibial and femoral insertion points of the PCL, based on recently described anatomy. The femoral attachment site of the PCL was divided into 4 sectors (labeled A through D), and the tibial attachment site was divided into 6 sectors (labeled 1 through 6). Twenty-four virtual PCL bundles were created between these sectors, and their length was measured in the 3 knee flexion positions. Results: In 0° and 90° of knee flexion, the virtual bundle showing the least amount of length change (1.10 ± 0.66 mm) was at sector D-6, that is, a posteromedial bundle inserting into the most posterior femoral sector (sector D) and the most distal tibial sector (sector 6). This change was not significantly different compared with all other virtual bundles with tibial points connected to femoral sector D (P > .05). An isometric position for the PCL (length change <2 mm) could not be found in 135° of knee flexion because of lengthening of all virtual bundles. Conclusions: Our data suggest that the femoral attachment point is more important than the tibial attachment point: any of the 6 tibial bundles attached to the most posterior femoral sector had similar isometric properties. Clinical Relevance: Reproducing normal tibial and femoral anatomy underpins PCL surgical reconstruction. These findings suggest that to perform an isometrically accurate PCL reconstruction, particular attention should be paid to the location of the femoral attachment site, once the tibial footprint has been established. There were no isometric points in any virtual PCL bundle in the fully flexed knee because of excessive lengthening. Therefore, to avoid lengthening of the reconstructed graft, we recommend that fixation is performed at knee flexion angles between 0° and 90° and that patients avoid high flexion during postoperative rehabilitation. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to review the isometric point of the posterior cruciate ligament (PCL) based on insertional locations identified in recent anatomic studies by use of a 3-dimensional knee model. Methods: Ten living subjects with healthy knees were evaluated. High-resolution computed tomography scans were performed at 3 positions of 0°, 90°, and 135°, and 3-dimensional knee images were constructed. Customized software was used to define tibial and femoral insertion points of the PCL, based on recently described anatomy. The femoral attachment site of the PCL was divided into 4 sectors (labeled A through D), and the tibial attachment site was divided into 6 sectors (labeled 1 through 6). Twenty-four virtual PCL bundles were created between these sectors, and their length was measured in the 3 knee flexion positions. Results: In 0° and 90° of knee flexion, the virtual bundle showing the least amount of length change (1.10 ± 0.66 mm) was at sector D-6, that is, a posteromedial bundle inserting into the most posterior femoral sector (sector D) and the most distal tibial sector (sector 6). This change was not significantly different compared with all other virtual bundles with tibial points connected to femoral sector D (P > .05). An isometric position for the PCL (length change <2 mm) could not be found in 135° of knee flexion because of lengthening of all virtual bundles. Conclusions: Our data suggest that the femoral attachment point is more important than the tibial attachment point: any of the 6 tibial bundles attached to the most posterior femoral sector had similar isometric properties. Clinical Relevance: Reproducing normal tibial and femoral anatomy underpins PCL surgical reconstruction. These findings suggest that to perform an isometrically accurate PCL reconstruction, particular attention should be paid to the location of the femoral attachment site, once the tibial footprint has been established. There were no isometric points in any virtual PCL bundle in the fully flexed knee because of excessive lengthening. Therefore, to avoid lengthening of the reconstructed graft, we recommend that fixation is performed at knee flexion angles between 0° and 90° and that patients avoid high flexion during postoperative rehabilitation. [Copyright &y& Elsevier]

Spinoglenoid cyst (SGC) is a ganglion arising in the spinoglenoid notch and is thought to be related to SLAP lesion. This cyst often compresses the suprascapular nerve in the spinoglenoid notch. Symptomatic cysts require surgical treatment when conservative treatment fails. In particular, arthroscopic decompression through the torn labral tissue when the cyst is extending into the joint cavity is easy and convenient. However, if the cyst is confined to the spinoglenoid notch, arthroscopic approach through the torn labral tissue is challenging. Thus, we present our preferred technique of addressing the SGC through an additional superior capsular window after completing SLAP repair. We believe that our technique is easy, reproducible, and reasonable. [ABSTRACT FROM AUTHOR]

Abstract: The long head of the biceps brachii tendon arises mainly from the superior glenoid labrum and supraglenoid tubercle. Biceps brachii display anatomic variations, but these are rarely encountered. We report, for the first time, a technique called arthroscopic intra-articular biceps tenoplasty describing restoration of the long head of the biceps tendon using the superior capsule in a case of anomalous congenital split biceps tendon encountered incidentally during diagnostic glenohumeral arthroscopy in a patient who was treated for shoulder instability and SLAP tear. [Copyright &y& Elsevier]