Imaging shoulder instability in the athlete

ACR Appropriateness Criteria® Shoulder Pain-Atraumatic

Shoulder pain is one of the most common reasons for musculoskeletal-related physician visits. Imaging plays an important role in identifying the specific cause of atraumatic shoulder pain. This review is divided into two parts. The first part provides a general discussion of various imaging modalities (radiographs, arthrography, nuclear medicine, ultrasound, CT, and MRI) and their usefulness in evaluating atraumatic shoulder pain. The second part focuses on the most appropriate imaging algorithms for specific shoulder conditions including: rotator cuff disorders, labral tear/instability, bursitis, adhesive capsulitis, biceps tendon abnormalities, postoperative rotator cuff tears, and neurogenic pain. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Controversies in the Management of the First Time Shoulder Dislocation

Background:

Traditionally, initial management of first anterior shoulder dislocations consists of reduction of the glenohumeral joint followed by a period of immobilization and subsequent physical therapy to recover shoulder range of motion and strength. This traditional approach in management is now controversial due to the high rate of recurrence. The aim of this paper is to review and discuss the literature about the global management of patients presenting with first-time traumatic anterior glenohumeral dislocation, analyzing the factors that affect shoulder instability after the first episode of dislocation.

Methods:

Scientific publications about the management of first-time shoulder dislocations are reviewed. Pubmed is used for that and no limit in the year of publication are stablished. These papers and their conclusions are discussed.

Results:

Younger patients, patient´s activities and the kind of injury are the most important factors related to the shoulder instability after a first time traumatic dislocation. Authors that recommend surgical treatment after the first episode of dislocation argue that the possibilities of recurrence are high and therefore surgery should be performed before its occurrence. Other authors, however, argue that surgical treatment is demanding, and keep in mind that complications, such as recurrence, stiffness and pain after surgery, are still present.

Conclusion:

Currently, there is still no consensus in the literature with regard to the management of first episode of shoulder dislocation. It is necessary to analyze carefully every individual case to manage them more or less aggressive to obtain the best result in our practice.

Glenohumeral Joint Kinematics following Clavicular Fracture and Repairs

Background

The purpose of this biomechanical study was to determine the effect of shortened clavicle malunion on the center of rotation of the glenohumeral (GH) joint, and the capacity of repair to restore baseline kinematics.

Methods

Six shoulders underwent automated abduction (ABD) and abbreviated throwing motion (ATM) using a 7-DoF automated upper extremity testing system in combination with an infrared motion capture system to measure the center of rotation of the GH joint. ATM was defined as pure lateral abduction and late cocking phase to the end of acceleration. Torsos with intact clavicle underwent testing to establish baseline kinematics. Then, the clavicles were subjected to midshaft fracture followed by kinematics testing. The fractured clavicles underwent repairs first by clavicle length restoration with plate fixation, and then by wiring of fragments with a 2-cm overlap to simulate shortened malunion. Kinematic testing was conducted after each repair technique. Center of rotation of the GH joint was plotted across all axes to outline 3D motion trajectory and area under the curve.

Results

Throughout ABD, malunion resulted in increased posterior and superior translation compared to baseline. Plate fixation restored posterior and superior translations at lower abduction angles but resulted in excess anterior and inferior translation at overhead angles. Throughout ATM, all conditions were significantly anterior and superior to baseline. Translation with malunion was situated anterior to the fractured and ORIF conditions at lower angles of external rotation. Plate fixation did not restore baseline anteroposterior or superoinferior translation at any angle measured.

Conclusions

This study illustrates the complex interplay of the clavicle and the GH joint. While abnormal clavicle alignment alters shoulder motion, restoration of clavicle length does not necessarily restore GH kinematics to baseline. Rehabilitation of the injured shoulder must address the osseous injury and the dynamic forces of the shoulder girdle.

What can the Radiologist do to Help the Surgeon Manage Shoulder Instability?

Imaging of the shoulder forms an important adjunct in clinical decision making in patients with shoulder instability. The typical lesions related with classic anterior and anteroinferior shoulder dislocation are an anteroinferior labral avulsion with or without bony fragment of bone loss – a (bony) Bankart lesion – and a posterolateral humeral head impaction fracture – the Hill-Sachs lesions. These are relatively straightforward to identify on imaging, although normal variants of the inferior labrum and variants of labral damage may cause confusion. Other capsuloligamentous lesions, often associated with less typical types of instability, are much more difficult to identify correctly on imaging, as they occur in the anterosuperior part of the glenohumeral joint with its many normal variants or because they result in more subtle, and therefore easily overlooked, changes in morphology or signal intensity. This paper aims at describing the appearance of the normal and pathologic glenohumeral joint related to shoulder instability. Ample reference will be given as to why identification of abnormalities, whether normal or pathologic, is important to the surgeon facing a treatment decision.

Incidence of Posttraumatic Shoulder Dislocation in Poland

Background

The incidence of shoulder joint dislocation has been estimated at 11–26 per 100 000 population per year. In our opinion, basic epidemiological data need to be continually updated in studies of large populations.

To study the incidence of posttraumatic dislocation of the shoulder joint in the Polish population.

Material/Methods

We retrospectively investigated the entire Polish population between 1 January 2010 and 1 January 2015. To identify the study group, data collected in the electronic database of the National Health Fund were used. The study group was divided into subgroups to detect possible differences in the incidence of shoulder dislocation with regard to age, sex, and season of the year (month) when the dislocation occurred.

Results

The cumulative size of the study sample was 192.72 million over the 5 years of the study. We identified 51 409 patients with first posttraumatic shoulder dislocation, at a mean age of 50.83 years (SD 21.12), from 0 to 104 years. The incidence of traumatic shoulder dislocations for the entire study group ranged from 24.75/100 000/year (number of posttraumatic shoulder dislocations per 100 000 persons per year) to 29.09/100 000/year, for a mean of 26.69/100 000/year.

Conclusions

In this study, the overall incidence of first-time posttraumatic shoulder dislocations in the Polish general population was 26.69 per 100 000 persons per year. These results are higher than estimates presented by other authors. It is necessary to study, regularly update, and monitor this problem in the general population.

Beyond the Cuff: MR Imaging of Labroligamentous Injuries in the Athletic Shoulder

Shoulder disease is common in the athletic population and may arise as a consequence of a single traumatic episode or multiple repeated events. Associated labroligamentous injuries can result in substantial disability. Specific athletic and occupational activities result in predictable injury patterns. Imaging in general and magnetic resonance (MR) imaging, in particular, are vital in establishing the correct diagnosis and excluding common mimicking conditions, to ensure timely and appropriate management. In this review, the utility of MR imaging and MR arthrography will be explored in evaluation of shoulder disease, taking into account normal variants of the labroligamentous complex. Subsequently, broad categories of labral lesions and instability, external and internal impingement, as well as nerve entrapment syndromes, will be discussed, while emphasizing their imaging findings in the clinical context and illustrating key features. More recent concepts of internal impingement and secondary subacromial impingement will also be clarified.

Results of Arthroscopic Bankart Lesion Repair in Patients with Post-Traumatic Anterior Instability of the Shoulder and a Non-Engaging Hill-Sachs Lesion with a Suture Anchor after a Minimum of 6-Year Follow-Up

Background

Shoulder instability is an important clinical problem. Arthroscopic surgery is an established treatment modality in shoulder instability, but it continues to be associated with a high rate of recurrences and complications. The purpose of the study was to analyze late outcomes of arthroscopic repair of Bankart lesions in patients with post-traumatic anterior shoulder instability and non-engaging Hill-Sachs lesion, with special focus on the incidence and causes of recurrences and complications.

Material/Methods

We investigated 92 patients (92 shoulders) who underwent surgery on account of post-traumatic anterior shoulder instability. The duration of follow-up ranged from 6 to 12.5 years (mean: 8.2 years). All patients were operated on in the lateral decubitus position using FASTak 2.8-mm suture anchors (FASTak, Arthrex, Naples, Florida). Treatment outcomes were evaluated using the Rowe and University of California at Los Angeles rating system (UCLA).

Results

According to Rowe scores, there were 71 (81.5%) excellent, 12 (12.6%) good, 5 (5.3%) satisfactory, and 2 (2.1%) poor results. Rowe scores improved in a statistically significant manner (p=0.00) post-surgery, to a mean of 90 (range: 25–100). Treatment outcomes measured as UCLA scores improved in a statistically significant manner (p=0.00), reaching post-operative levels of 12–35 (mean: 33.5). There were 9 recurrences, 1 case of axillary nerve praxia, and 1 case of anchor loosening.

Conclusions

With rigorous criteria for qualifying patients for surgery, arthroscopic treatment of post-traumatic anterior shoulder instability produces good outcomes and low recurrence and complication rates irrespective of the number of previous dislocations, age, or sex.

Throwing injuries of the upper extremity

The overhead throwing motion is a complex sequence of maneuvers that requires coordinated muscle activity in the upper and lower extremities. The shoulder and elbow are subject to multidirectional forces and are particularly vulnerable to injury during specific phases of the overhead throwing motion. Ligamentous, tendinous, neural, and osseous pathology that may occur in the shoulder or elbow of an overhead-throwing athlete will be discussed, with an emphasis on the role of MR imaging and MR arthrography.

Magnetic resonance imaging in glenohumeral instability

The glenohumeral joint enables tremendous range of motion at the expense of stability. Functional stability is maintained by the synchronous coordination of complex static and dynamic structures. Symptomatic glenohumeral instability most often results from injury to the inferior labral-ligamentous complex, the primary passive stabilizer of the shoulder. This article reviews the structures important in glenohumeral stabilization and illustrates their normal appearances and the abnormalities associated with anterior, posterior, and multidirectional instability. These lesions are discussed in the context of therapeutic decision making.

Humeral avulsion of the inferior glenohumeral ligament in college female volleyball players caused by repetitive microtrauma

BACKGROUND

Humeral avulsion of the inferior glenohumeral ligament is a rare injury resulting from hyperabduction and external rotation, and it is most commonly seen with sports-related injuries, including those from volleyball. The anterior band of the inferior glenohumeral ligament is most commonly injured (93%), whereas the posterior band is infrequently injured. The axillary pouch humeral avulsion of the inferior glenohumeral ligament as a result of repetitive microtrauma has not been yet described in the English literature.

HYPOTHESIS

Humeral avulsions of the inferior glenohumeral ligaments are identifiable in volleyball players without acute injuries, and they have a unique pathologic pattern in these athletes.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Four female college volleyball players with pain in their dominant shoulder and with inferior capsular laxity and/or instability—without a known history of trauma or dislocation of the same shoulder—were referred by an experienced sports medicine orthopaedic surgeon for the magnetic resonance arthrogram procedure of the same shoulder. The imaging findings were retrospectively correlated with the initial interpretation and arthroscopic findings.

RESULTS

All 4 patients had an axillary pouch humeral avulsion of the inferior glenohumeral ligament. Three had articular surface partial-thickness rotator cuff tear, and 3 had a labral tear. All were outside hitters or middle blockers who consequently performed multiple hitting maneuvers in practice and games.

CONCLUSION

Repetitive microtrauma from overhead hitting in volleyball generates forces on the inferior capsule of the shoulder joint that may cause inferior capsular laxity and subsequent failure of the humeral side of the axillary pouch portion of the inferior glenohumeral ligament.

Surgical versus nonsurgical treatment in first traumatic anterior dislocation of the shoulder in athletes

Anterior traumatic dislocation is a common problem faced by orthopedic surgeons. After the first episode of shoulder dislocation, a combination of lesions can lead to chronic instability. The management in treatment of young athletes after the first acute anterior shoulder dislocation is controversial. The available literature supports early surgical treatment for young male athletes engaged in highly demanding physical activities after the first episode of traumatic dislocation of the shoulder. This is because of the best functional results and lower recurrence rates obtained with this treatment in this population. However, further clinical trials of good quality comparing surgical versus nonsurgical treatment for well-defined lesions are needed, especially for categories of patients who have a lower risk of recurrence.