Internal Impingement Research Articles

Rotator cuff tears and internal impingement in athletes

Knowledge of rotator cuff tears, especially in young people, and their cause has been vastly expanded in recent years. This is reflected in the understanding of the pathogenesis of these lesions and the specific therapy. In contrast to the mostly degenerative tears in older people, the causes in young, active people differ: traumatic disruption, internal impingement due to instability (PSI, ASI), SLAP lesion, and microtraumatic causes may be found. Recently, connections between the different pathologies like internal impingement and the SLAP lesion were shown. For an accurate diagnosis and differentiation between the different pathologies an exact clinical examination and a high-quality MRI scan with intra-articular contrast enhancer is necessary. The final therapy should be planned based on the causative pathology; then good long-term results will be achieved and return to sports is likely. If there is no structural damage, conservative therapy should be initiated. If there is any structural damage, e.g., SLAP lesion or rotator cuff tear, surgical treatment is indicated. Besides a SLAP repair and rotator cuff suturing, care must be given not to miss an accompanying instability. These instabilities should also be corrected, e.g., with arthroscopic ventral capsular plication, otherwise results are worse.

Instructional Course Lectures Shoulder and Elbow

The Journal of Bone and Joint Surgery. British volumeVol. 89-B, No. 9 Book ReviewsFree AccessInstructional Course Lectures Shoulder and Elbow Edited by J. J. P. Warner Pp. 496 Illinois: American Academy of Orthopaedic Surgeons, 2006. ISBN: 0-89203-389-4. £76.50.R. TurnerR. TurnerSearch for more papers by this authorPublished Online:1 Sep 2007https://doi.org/10.1302/0301-620X.89B9.20188AboutSectionsPDF/EPUB ToolsDownload CitationsTrack CitationsPermissionsAdd to Favourites ShareShare onFacebookTwitterLinked InRedditEmail J. J. P. Warner has brought together many of the leading North American Shoulder and Elbow surgeons to contribute to this volume of Instructional Course Lectures. The essence of the volume is to present thinking on issues in Shoulder and Elbow surgery for the new millennium. Its understandably North American flavour is mostly to its advantage. It is separated into eight sections (five shoulder, three elbow), each section containing a number of similarly constructed articles. Although clearly not designed to be read from cover to cover, the themes tempt the reader onwards.The volume has a heavy arthroscopic weighting, reflecting its provenance, but also the developing technical skills and complexity of equipment in this field; as such, it would have benefited from colour photography. Issues of controversy and debate are aired (SLAP lesions and internal impingement); other areas focus on enhancing surgical skills. I particularly liked Yamaguchi’s article on making the transition from mini-open to entirely arthroscopic rotator cuff repair. Many colleagues will be encouraged by this.Unfortunately, some articles do fail to capture the imagination, particularly in the Shoulder Arthroplasty section. A well referenced section on glenoid replacement is found but there is no mention of humeral surface replacement and very little on reverse polarity prostheses. The sections on the elbow are impressive, particularly those on trauma. The volume can be recommended alone for the articles on the stiff elbow by Jupiter and the unstable elbow by O’Driscoll. Minor criticisms apart, there is much for the budding Shoulder and Elbow surgeon to learn here, and much for the older lags to enjoy. The Editor is to be congratulated on a work essential for any Shoulder and Elbow unit.FiguresReferencesRelatedDetails Vol. 89-B, No. 9 Metrics History Published online 1 September 2007 Published in print 1 September 2007 InformationCopyright © 2007, The British Editorial Society of Bone and Joint Surgery: All rights reservedPDF download

Management of Internal Impingement and Partial Rotator Cuff Tears in the Throwing Athlete

Internal impingement is a condition that can cause significant disability to the elite throwing athlete. Unlike classical impingement, internal impingement is thought to occur when the undersurface of the rotator cuff and greater tuberosity come in contact with the posterosuperior glenoid and labrum during the late cocking and early acceleration phase of throwing, when the arm is in the abducted and maximally externally rotated position. Although several theories have been proposed as to the exact mechanism of this condition, all theories lead to similar pathology. This includes rotator cuff pathology, typically partial undersuface tears, and posterosuperior labral pathology. Ultimately, the thrower’s mechanics and core body fitness are of utmost importance. Treatment of internal impingement is initially nonoperative, with special emphasis on core strength, stability, and flexibility, in addition to optimization of throwing mechanics. If surgical intervention is indicated, we prefer to eliminate pain generators within the shoulder, repair structural damage if necessary, and minimize the potential for postoperative motion loss. Techniques for superior labral repair, intratendinous rotator cuff repair, and partial articular-sided rotator cuff repair are reviewed.

Shoulder MR arthrography of the posterior labrocapsular complex in overhead throwers with pathologic internal impingement and internal rotation deficit

To determine if overhead-throwing athletes with internal impingement pain and internal rotation deficit have thickening of the posterior inferior labrocapsular complex on MR arthrogram images. This study was approved and a waiver of consent granted by our institutional review board. Twenty-six overhead-throwing athletes with internal impingement pain and internal rotation deficit, and 26 controls who had undergone MR arthrograms, were retrospectively examined. The MR studies were combined and read in a blind fashion. On an axial image through the posteroinferior glenoid rim, the readers measured the labral length, capsule-labrum length, and the posterior recess angle. A t-test was used to determine statistical significance. The mean labral length was 4.9 mm [standard deviation (SD) 1.4 mm] for the controls, and 6.4 mm (SD 1.6 mm) for the athletes (P = 0.001). The mean capsule-labrum length was 5.4 mm (SD 2.1 mm) for the controls, and 8.8 mm (SD 2.9 mm) for the athletes (P < 0.001). The mean posterior recess angle measured 65 degrees (SD 27 degrees) for the controls and 94 degrees (SD 38 degrees) for the athletes (P = 0.002). Overhead-throwing athletes with internal impingement pain and internal rotation deficit tend to have a thicker labrum and a shallower capsular recess in the posterior inferior shoulder joint than do non-overhead-throwing athletes. In many, the posteroinferior capsule is also thickened. These MR findings should alert the radiologist to closely inspect the posterior cuff and posterosuperior labrum for the tears associated with internal impingement.

Resonancia magnética de la inestabilidad glenohumeral: nuevos conceptos

The shoulder is the most unstable joint in the human body and is therefore susceptible not only to acute dislocations but also to minimal states of subluxation related to overuse. The latter condition is known as microinstability and is translated clinically into internal impingement syndromes. Both in dislocations due to acute traumatism and in microinstability, a series of injuries to the glenoid lip, glenohumeral capsule, the articular cartilage, the head of the humerus, the tendons of the rotator cuff, the long tendon of the biceps, the glenohumeral ligaments, and coracohumeral ligament can occur. Glenoid lip lesions are the most common and may present as isolated lesions or in combination with lesions of any of the other structures. These lesions most often affect the anteroinferior margin of the glenoids (the classic Bankard lesion), with different characteristics and variations on its location, (Bankard variants). Another predominant location of glenoid lip lesions is the superior margin (SLAP lesions). Magnetic resonance imaging (MRI), especially after intra-articular injection of contrast material, has shown great diagnostic accuracy in this type of lesions, although the interpretation of these images requires knowledge not only of the different lesions and combinations of lesions, but also of the normal variants that can easily be confused with these lesions.

Chondral print on humeral head: an indirect sign of long head biceps tendon instability

Long head biceps (LHB) tendon pathologies are becoming increasingly recognized causes of shoulder pain in the published literature. Instability of LHB presenting as dislocation or subluxation has been recently recognized as a possible cause of disabling pain or discomfort of the shoulder. A clinical diagnosis of LHB instability is very difficult and often confounding because of association with other shoulder pathologies. However, an early diagnosis of LHB instability is important in order to prevent the evolution of lesions of the biceps pulley until an internal anterosuperior impingement of the shoulder (ASI) and subscapular tear occur. The advent of arthroscopy contributed to enhance understandings. The goal of this article is to describe an arthroscopic sign, the chondral print on the humeral head, associated with a LHB instability, that when present can be very useful to help the surgeon to make the diagnosis of unstable LHB tendon.

Scapular Dysfunction in Throwers with Pathologic Internal Impingement

Case control group study. To compare scapular position and orientation between baseball players with and without pathologic internal impingement. Scapular dysfunction has been implicated as a contributor to throwing-related pathologic internal impingement of the shoulder due to its role in increasing the contact between the greater tuberosity and posterior-superior glenoid, thereby impinging the posterior rotator cuff tendon(s) and labrum. However, to date, no definitive data demonstrate this scapular dysfunction in throwing athletes. The purpose of this study was to assess, in a controlled laboratory environment, whether scapular position and orientation would be different in throwing athletes diagnosed with pathologic internal impingement than in a control group of throwing athletes. Eleven throwing athletes diagnosed with pathologic internal impingement, using both clinical examination and a magnetic resonance arthrogram, were demographically matched with a control group of 11 throwers with no history of upper extremity injury. An electromagnetic tracking device was used to measure scapular internal/external rotation, anterior/posterior tilt, upward/downward rotation, sternoclavicular protraction/retraction, and elevation/depression during humeral elevation within the scapular plane. Comparisons were made between groups with analysis of variance models (P<.05). The individuals in the pathologic internal impingement group demonstrated statistically significant increased sternoclavicular elevation when elevating their humerus from 30 degrees to 120 degrees (P = .002) and from 60 degrees to 120 degrees (P = .003), compared to the control group. Furthermore, these patients also had increased posterior scapular tilt position (P = .016). No statistically significant differences were present in any other scapular variables measured. Based on the results of this study, throwing athletes diagnosed with pathologic internal impingement present with statistically significant increases in sternoclavicular elevation and scapular posterior tilt position during humeral elevation in the scapular plane.

Glenohumeral Range of Motion Deficits and Posterior Shoulder Tightness in Throwers with Pathologic Internal Impingement

Background Alterations in glenohumeral range of motion, including increased posterior shoulder tightness and glenohumeral internal rotation deficit that exceeds the accompanying external rotation gain, are suggested contributors to throwing-related shoulder injuries such as pathologic internal impingement. Yet these contributors have not been identified in throwers with internal impingement. Hypothesis Throwers with pathologic internal impingement will exhibit significantly increased posterior shoulder tightness and glenohumeral internal rotation deficit without significantly increased external rotation gain. Study Design Case control study; Level of evidence, 3. Methods Eleven throwing athletes with pathologic internal impingement diagnosed using both clinical examination and a magnetic resonance arthrogram were demographically matched with 11 control throwers who had no history of upper extremity injury. Passive glenohumeral internal and external rotation were measured bilaterally with standard goniometry at 90 ° of humeral abduction and elbow flexion. Bilateral differences in glenohumeral range of motion were used to calculate glenohumeral internal rotation deficit and external rotation gain. Posterior shoulder tightness was quantified as the bilateral difference in passive shoulder horizontal adduction with the scapula retracted and the shoulder at 90 ° of elevation. Comparisons were made between groups with dependent t-tests (P< .05). Results The throwing athletes with internal impingement demonstrated signif icantly greater glenohumeral internal rotation deficit (P= .03) and posterior shoulder tightness (P= .03) compared with the control subjects. No significant differences were observed in external rotation gain between groups (P= .16). Clinical Relevance These findings could indicate that a tightening of the posterior elements of the shoulder (capsule, rotator cuff) may contribute to impingement. The results suggest that management should include stretching to restore flexibility to the posterior shoulder.

Clinical Evaluation of Impingement

Theories about the etiologies of anterior and lateral shoulder pain have changed greatly since "impingement disease" was first described. It is thought that such pain may be caused by contact between the rotator cuff and the acromion and coracoacromial ligament, but the exact pathophysiology of rotator cuff disease remains unclear. The shoulder is notoriously difficult to examine because of the variability of the physical findings in patients with rotator cuff disease. New concepts of impingement, such as coracoid impingement and internal impingement, have been advanced. Although no test is definitive for all causes of anterior and lateral shoulder pain, as the pathophysiology of these conditions becomes better understood the ability to evaluate them clinically also improves.

In vivo anatomy of the Neer and Hawkins sign positions for shoulder impingement

The Neer and Hawkins impingement signs are commonly used to diagnose subacromial pathology, but the anatomy of these maneuvers has not been well elucidated in vivo. This 3-dimensional open magnetic resonance imaging study characterized shoulder anatomy and rotator cuff impingement in 8 normal volunteers placed in the Neer and Hawkins positions. Subacromial and intraarticular contact of the rotator cuff was graded, and minimum distances were computed between the tendon insertion sites and the glenoid, acromion, and coracoid. Both the Neer and Hawkins maneuvers significantly decreased the distance from the supraspinatus insertion to the acromion and posterior glenoid and from the subscapularis insertion to the anterior glenoid. However, the Hawkins position resulted in significantly greater subacromial space narrowing and subacromial rotator cuff contact than the Neer position. In the Hawkins position, subacromial contact of the supraspinatus and infraspinatus was observed in 7 of 8 and 5 of 8 subjects, respectively. In contrast, rotator cuff contact with the acromion did not occur in any subject in the Neer position. Intraarticular contact of the supraspinatus with the posterosuperior glenoid was observed in all subjects in both positions. Subscapularis contact with the anterior glenoid was also seen in 7 of 8 subjects in the Neer position and in all subjects in the Hawkins position. This extensive intraarticular contact suggests that internal impingement may play a role in the Neer and Hawkins signs.

Numerical approach to hole shape effect on film cooling effectiveness over flat plate including internal impingement cooling chamber

Numerical approach have been conducted on a flat, three-dimensional discrete-hole film cooling geometries that included the mainflow, injection tubes, impingement chamber, and supply plenum regions. The effects of blowing ratio and hole’s shape on the distributions of flow field and adiabatic film cooling effectiveness over a flat plate collocated with two rows of injection holes in staggered-hole arrangement were studied. The blowing ratio was varied from 0.3 to 1.5, while the density ratio of the coolant to mainstream is kept at 1.14. The geometrical shapes of the vent of the cooling holes are cylindrical round, simple angle (CYSA), forward-diffused, simple angle (FDSA) and laterally diffused, simple angle (LDSA). Diameter of different shape of cooling holes in entrance surface are 5.0 mm and the injection angle with the main stream in streamwise and spanwise are 35° and 0° respectively. Ratio of the length of the cooling holes and the diameter in the entrance surface is 3.5. The distance between the holes in the same row as well as to the next row is three times the diameter of hole in the entrance surface. The governing equation is the fully elliptic, three-dimensional Reynolds-averaged Navier–Stokes equations. The mesh used in the finite-volume numerical computation is the multi-block and body-fitted grid system. The simulated streamwise distribution of spanwise-averaged film cooling effectiveness exhibited that low Reynolds number k– ε model can give close fit to the experimental data of the previous investigators. Present study reveals that (1) the geometrical shape of the cooling holes has great effect on the adiabatic film cooling efficiency especially in the area near to the cooling holes. (2) The thermal-flow field over the surface of the film-cooled tested plate dominated by strength of the counter-rotating vortex pairs (CRVP) that generated by the interaction of individual cooling jet and the mainstream. For LDSA shape of hole, the CRVP are almost disappeared. The LDSA shape has shown a highest value in distribution of spanwise-averaged film cooling effectiveness when the blowing ratio increased to 1.5. It is due to the structure of the LDSA is capable of reducing the momentum of the cooling flow at the vent of the cooling holes, thus reduced the penetration of the main stream. (3) The structure of the LDSA can also increase the lateral spread of the cooling flow, thus improves the spanwise-averaged film cooled efficiency.

Imaging of the Overhead Throwing Athlete

Knowledge of overhead throwing biomechanics is crucial to understand specific injuries encountered in throwing athletes on diagnostic imaging. Most specific injuries of overhead throwing athletes occur at the shoulder and elbow. Throwing athletes are susceptible to rotator cuff tears from tensile overload and external and internal impingement. The labrum is also commonly degenerated or torn secondary to overuse syndrome, internal impingement, and microtrauma. The elbow is typically injured secondary to excessive valgus forces during throwing. The ulnar collateral ligament, ulnar nerve, and common flexor tendon origin are all at increased risk of injury. Capitellar osteochondral injuries and loose intra-articular bodies are also frequent. Knowledge of injury pathophysiology is crucial to understanding the treatment rationale in throwing athletes.

MRI of Internal Impingement of the Shoulder

Internal impingement is a condition that occurs in athletes in which the shoulder is put in extreme abduction and external rotation during overhead movements. During this motion, the posterior fibers of the supraspinatus tendon, anterior fibers of the infraspinatus tendon, or both can get impinged between the humeral head and the posterior glenoid. The purpose of this study was to evaluate the ability of MRI to show the findings of internal impingement of the shoulder. As opposed to our six patients with clinically and surgically diagnosed internal impingement, the control patients had isolated pathology in the rotator cuff, labrum, or humeral head. We found that the constellation of findings of undersurface tears of the supraspinatus or infraspinatus tendon and cystic changes in the posterior aspect of the humeral head associated with posterosuperior labral pathology is a consistent finding diagnostic of internal impingement.

Update of Imaging of Sports Injuries to the Upper Extremity: Shoulder and Elbow

AbstractThis is an update on both clinical and imaging aspects of athletic injuries to the shoulder and elbow. This article focuses on injuries that are primarily seen in athletes. The lesions discussed in this update are: Bennett lesion of the shoulder, internal (posterosuperior) impingement of the shoulder, little leaguer's shoulder, little leaguer's elbow (both medial epicondylar avulsion injuries and osteochondral injuries of the capitellum) and tears of the medial ulnar collateral ligament.

Topical Glyceryl Trinitrate Application in the Treatment of Chronic Supraspinatus Tendinopathy

Background Topical glyceryl trinitrate therapy has previously demonstrated short-term pain reduction in patients with supraspinatus tendinopathy. Hypothesis Topical glyceryl trinitrate improves outcome measures in patients with supraspinatus tendinopathy. Study Design Randomized controlled clinical trial; Level of evidence, 1. Methods Fifty-three patients (57 shoulders) were recruited, and the authors completed a prospective, randomized, double-blinded, placebo-controlled clinical trial of continuous topical glyceryl trinitrate treatment (1.25 mg/24-h glyceryl trinitrate). Results The glyceryl trinitrate group had significantly reduced shoulder pain with activity, at night, and at rest at week 24 (P =. 03); reduced internal rotation impingement at week 24 (P =. 02); increased range of motion in abduction and internal rotation at week 24 (P =. 04); and increased force at weeks 12 and 24 with supraspinatus muscle testing (P =. 001), external rotation (P =. 04), internal rotation (P =. 01), adduction (P =. 04), and subscapularis pushoff (P =. 01). Forty-six percent of patients on glyceryl trinitrate patches were asymptomatic with activities of daily living at 6 months compared with 24% of patients with tendon rehabilitation alone (P =. 007, χ2 analysis). Mean effect size for all outcome measures was 0.26. Discussion Topical glyceryl trinitrate treatment significantly improved pain scores, range of motion, internal rotation impingement, muscular force, and patient outcomes in patients with supraspinatus tendinopathy. Topical glyceryl trinitrate should be included as part of nonsurgical management of chronic tendinopathies.

Experimental and Numerical Study of Impingement on an Airfoil Leading Edge With and Without Showerhead and Gill Film Holes

This experimental investigation deals with impingement on the leading edge of an airfoil with and without showerhead film holes and its effects on heat transfer coefficients on the airfoil nose area as well as the pressure and suction side areas. a comparison between the experimental and numerical results are also made. the tests were run for a range of flow conditions pertinent to common practice and at an elevated range of jet Reynolds numbers (8000–48,000). The major conclusions of this study were: (a) The presence of showerhead film holes along the leading edge enhances the internal impingement heat transfer coefficients significantly, and (b) while the numerical predictions of impingement heat transfer coefficients for the no-showerhead case were in good agreement with the measured values, the case with showerhead flow was under-predicted by as much as 30% indicating a need for a more elaborate turbulence modeling.

Atomization Performance of an Atomizer with Internal Impingement

This paper describes the atomization performance of a newly designed atomizer with internal impinging mechanisms inside the atomizer. The spray drop size distribution was measured by a Malvern RT-Sizer. Results show that the Sauter mean diameter below 10µm has been achieved with GLR of 0.14. The minimum mean drop size can be lowered to 4.0µm under a test condition of the liquid pressure and gas pressure of 2.5bar and 3.5bar, respectively. This test suggests that extra fine atomization on the liquid phase can be achieved under low pressure conditions using this particular atomizer. Such performance cannot be easily achieved with the conventional nozzle design. Results also show that better atomization performance can be achieved by increasing the internal impinging angle and the orifice diameter. An empirical formula of SMD, in terms of operating conditions and nozzle length scale is also presented in this paper.

Internal impingement: findings on magnetic resonance imaging and arthroscopic evaluation.

The purpose of this study was to examine preoperative shoulder magnetic resonance imaging (MRI) and intraoperative arthroscopic findings in throwing athletes with a clinical diagnosis of internal impingement. Retrospective review. A retrospective review of the surgical indications for 769 shoulder arthroscopic procedures performed from 1997 to 2000 revealed 9 throwing athletes with a diagnosis of severe internal impingement. Each had failed treatment that included a minimum of 3 months of rehabilitation. Preoperative MRIs in all 9 were read by a fellowship-trained musculoskeletal radiologist blinded to the operative findings. Findings at arthroscopy were culled from the operative reports. On both MRI and at arthroscopy, all 9 athletes had posterosuperior labral lesions, 1 had a humeral head articular cartilage lesion, and 1 had a SLAP lesion. Additional findings on MRI included humeral head edema, subchondral cystic changes, posterosuperior glenoid sclerosis, and rotator cuff tendonopathy predominantly in the infraspinatus. At arthroscopy, there were additional findings of articular-sided partial rotator cuff tears not shown on MRI. Both MRI and arthroscopic findings described labral and humeral head articular cartilage lesions. These findings may be indicative of internal impingement in throwing athletes. Level III, diagnostic.

Internal impingement: Findings on magnetic resonance imaging and arthroscopic evaluation

Internal impingement: Findings on magnetic resonance imaging and arthroscopic evaluation

Arthroscopic Treatment of Internal Impingement of the Shoulder

Shoulder and Sports Medicine Service The Hospital for Special Surgery New York, New York Address correspondene and reprint requests to David W. Altchek, MD, Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021 (e-mail:[email protected]).