Shoulder. scapula, instability. Rotator cuff

BACKGROUND: Functional shoulder instability (polar type III) is caused by underactivity of rotator cuff and periscapular muscles, which leads to subluxation or dislocation during shoulder movement. While surgical treatment has shown no benefits, aggravates pain, and frequently diminishes function even further, conservative treatment is often ineffective as well. OBJECTIVES: The aim was to investigate the effectiveness of a "shoulder pacemaker" device that stimulates underactive muscles in patients with functional instability during shoulder movement in order to re-establish glenohumeral stability...

Rotator cuff (RC) tears may be associated with increased glenohumeral instability; however, this instability is difficult to quantify using currently available diagnostic tools. Recently, the three-dimensional (3D) reconstruction and registration method of the scapula and humeral head, based on sequences of low-dose biplane X-ray images, has been proposed for glenohumeral displacement assessment. This research aimed to evaluate the accuracy and reproducibility of this technique and to investigate its potential with a preliminary application comparing RC tear patients and asymptomatic volunteers...

HYPOTHESIS: Scapular allograft reconstruction after total scapulectomy preserving the rotator cuff muscles is an oncologically safe procedure and results in good functional outcome with a low complication rate. METHODS: The data of 6 patients who underwent scapular allograft reconstruction after a total scapulectomy for tumor resection were retrospectively reviewed. At least 1 of the rotator cuff muscles was preserved and the size-matched scapular allograft fixed to the residual host acromion with a plate and screws...

INTRODUCTION-OBJECTIVES: To describe the incidence, etiological factors, functional impairment and therapeutic management of scapular fractures after reverse shoulder arthroplasty (RSA) in rotator cuff arthropathy. MATERIAL AND METHOD: A retrospective study was conducted on 126 RSA between 2009 and 2011, in which 4 fractures were identified that were compared with a control group of 40 patients. An analysis was performed on the variables related to the surgical technique, functional results, and quality of life (Constant scale, EQ-5D)...

BACKGROUND: Hill-Sachs lesions are compression fractures that result from shoulder dislocation. They involve "engaging" the humeral head on the anterior glenoid rim when the arm is abducted and externally rotated. The defect grows as the number of dislocations increases. HYPOTHESIS: Arthroscopic remplissage and anterior Bankart repair do not significantly affect infraspinatus strength while ensuring healing of the capsulotenodesis. STUDY DESIGN: Cohort study; Level of evidence, 3...

BACKGROUND: The incidence of scapular winging is unclear, but it may be more common than previously thought. It can be difficult to diagnose because the presenting complaint and physical examination may direct the practitioner toward more common shoulder and neck conditions. Ongoing scapular dysfunction may result in inappropriate or failed surgery. Our goals were to (1) describe the common misdiagnoses (instability, labral abnormality, impingement, and cervical spine disease), the clinical scenarios and examination findings leading to diagnostic difficulty, the definitive treatment options available, and the clinical outcomes and complications; and (2) review the important aspects of the patient history, physical examination of the scapula, and associated studies necessary to make the correct diagnosis of scapular winging...

BACKGROUND: Proximal humeral fractures in four or even only three parts, with metaphyseal hinge distances of <8 mm, represent a serious and widely debated problem. Reduction is complex and plating is often instable, especially in elderly patients. Failures, sometimes involving necrosis of the head, are frequent. Hemiarthroplasty has long been used for 3- or 4-part complex fractures, even in young patients, although often with sub-optimal results, due to reabsorption of tuberosities...

Shoulders with supraspinatus (SSP) tears are associated with significantly larger critical shoulder angles (CSA) compared to disease-free shoulders. We hypothesized that larger CSAs increase the ratio of joint shear to joint compression forces (defined as "instability ratio"), requiring substantially increased compensatory supraspinatus loads. A shoulder simulator with simulated deltoid, supraspinatus, infraspinatus/teres minor, and subscapularis musculotendinous units was constructed. The model was configured to represent either a normal CSA of 33° or a CSA characteristic of shoulders with rotator cuff tears (38°), and the components of the joint forces were measured...

BACKGROUND: Due to its growing popularity golf has now come into the focus of orthopedic sports medicine. With a wide range of age groups and playing levels, orthopedic surgeons will encounter a wide range of musculoskeletal problems which are usually the result of overuse rather than trauma. ANATOMY: The shoulder joint plays an important role in the golf swing whereby not only the muscles around the glenohumeral joint but also the scapula stabilizing muscles are extremely important for an effective golf swing...

BACKGROUND: The biconcave glenoid in patients with primary glenohumeral osteoarthritis represents a surgical challenge because of the associated static posterior instability of the humeral head and secondary posterior glenoid erosion. The purpose of the present study was to evaluate the clinical and radiographic results of reverse total shoulder arthroplasty for the treatment of primary osteoarthritis in patients with a biconcave glenoid without rotator cuff insufficiency. METHODS: We performed a retrospective review of twenty-seven reverse shoulder arthroplasties that were performed from 1998 to 2009 for the treatment of primary glenohumeral osteoarthritis and biconcave glenoid...

The second international consensus conference on the scapula was held in Lexington Kentucky. The purpose of the conference was to update, present and discuss the accumulated knowledge regarding scapular involvement in various shoulder injuries and highlight the clinical implications for the evaluation and treatment of shoulder injuries. The areas covered included the scapula and shoulder injury, the scapula and sports participation, clinical evaluation and interventions and known outcomes. Major conclusions were (1) scapular dyskinesis is present in a high percentage of most shoulder injuries; (2) the exact role of the dyskinesis in creating or exacerbating shoulder dysfunction is not clearly defined; (3) shoulder impingement symptoms are particularly affected by scapular dyskinesis; (4) scapular dyskinesis is most aptly viewed as a potential impairment to shoulder function; (5) treatment strategies for shoulder injury can be more effectively implemented by evaluation of the dyskinesis; (6) a reliable observational clinical evaluation method for dyskinesis is available and (7) rehabilitation programmes to restore scapular position and motion can be effective within a more comprehensive shoulder rehabilitation programme...

PURPOSE: The objective of this study was to investigate the clinical outcome and radiographic findings after arthroscopic superior capsule reconstruction (ASCR) for symptomatic irreparable rotator cuff tears. METHODS: From 2007 to 2009, 24 shoulders in 23 consecutive patients (mean, 65.1 years) with irreparable rotator cuff tears (11 large, 13 massive) underwent ASCR using fascia lata. We used suture anchors to attach the graft medially to the glenoid superior tubercle and laterally to the greater tuberosity...

BACKGROUND: The rotator cuff muscles are the main stabilizer of the glenohumeral joint. After total shoulder arthroplasty using anterior approaches, a dysfunction of the subscapularis muscle has been reported. In the present paper we tested the hypothesis that a deficient subscapularis following total shoulder arthroplasty can induce joint instability. METHODS: To test this hypothesis we have developed an EMG-driven musculoskeletal model of the glenohumeral joint...

PURPOSE: The purpose of this biomechanical study was to compare the classic Latarjet technique and congruent-arc modification with respect to glenohumeral stability, joint stiffness, translation, and range of motion. METHODS: Eight cadaveric forequarters were tested on a shoulder simulator that applied loads independently to the conjoint tendon, long head of biceps, rotator cuff, and deltoid. The test conditions included: intact, 30% glenoid defect, and reconstruction of the defect with the classic and congruent Latarjets...

OBJECTIVE: To compare the effectiveness of specific exercises for the rotator cuff and scapular stabilizers with unspecific exercises in the treatment of subacromial impingement syndrome. DESIGN: Randomized controlled trial with 3 months of follow-up. Participants and the single assessor were blinded to group assignment. Sample size was calculated with 80% power to show a minimum clinically important difference of 10% on the Constant–Murley score at P ≤ 0.05...

PURPOSE: Asymmetric stress imposed on the shoulder can lead to anterior shoulder instability in young athletes who perform repetitive overhead motions. A common treatment, surgical anterior capsule tightening, assumes that the instability is caused by abnormal anterior laxity. This study investigated the possibility that one element of overall imbalance, posterior capsular tightness, could be an underlying reason for shoulder instability. Surgical navigation technology, which is more accurate than whole-body motion-capture systems, was used to study anterior translational motions...

The scapula plays a key role in nearly every aspect of normal shoulder function. Scapular dyskinesis-altered scapular positioning and motion-is found in association with most shoulder injuries. Basic science and clinical research findings have led to the identification of normal three-dimensional scapular kinematics in scapulohumeral rhythm and to abnormal kinematics in shoulder injury, the development of clinical methods of evaluating the scapula (eg, scapular assistance test, scapular retraction test), and the formulation of rehabilitation guidelines...

Shoulder injuries in the throwing athlete are becoming more frequent. Sports specialization at a younger age, playing multiple seasons, increased awareness of injury and injury prevention, advances in diagnosis, and surgical treatment all play a part in the increase in diagnosis of these injuries. Understanding the biomechanics of throwing and pathologies that are encountered in the throwing athlete can aid the clinician in successful diagnosis and nonoperative/operative treatment of the throwing athlete. This article discusses the relevant anatomy, biomechanics, and pathoanatomy of the throwing shoulder...

This study assessed the influence of the medial offset of the proximal humerus on the glenohumeral destabilising forces during arm elevation in the plane of the scapula, using the AnyBody Modeling System. The variability of the medial offset was covered using literature data (minimum, 0 mm; average, 7 mm and maximum, 14 mm). The following parameters were studied: moment arm (MA; middle deltoid), muscle activity and stability ratios. The minimum offset decreased the MA of the middle deltoid ( -11%), increased its activation (+18%) and its superior destabilising action (+40%)...

Reverse total shoulder arthroplasty was developed in the late 1980s for elderly patients with rotator cuff arthropathy. Several biomechanical advantages of the reverse shoulder arthroplasty result in improved deltoid function, which improves shoulder motion and function compared to other types of shoulder arthroplasty. The main indication for the reverse prosthesis is painful rotator cuff tear arthropathy. The indications for reverse shoulder arthroplasty have continued to expand since it was first performed in the United States in 2004...