The disabled throwing shoulder: spectrum of pathology Part I: pathoanatomy and biomechanics

Tight shoulders: A clinical, kinematic and strength comparison of symptomatic and asymptomatic male overhead athletes before and after stretching

A tightness of the posterior structures of the throwing shoulder has been hypothesised to be associated with injuries and pain because of alterations of the scapular kinematics and muscular imbalances. The aims of this study were to identify the clinical and biomechanical profile of symptomatic and asymptomatic overhead athletes with a tight shoulder and to evaluate the efficiency of a self-applied stretching program. Twenty male overhead athletes were recruited. Half of them reported a painful shoulder at the beginning of the study. For four weeks, the volunteers performed daily stretching exercises. Before and after the stretching program, gleno-humeral mobility, scapular kinematics, rotator muscles strength and pain were evaluated. Before stretching, the main difference between the groups was more impingement syndrome and rotator cuff tendon lesion positive tests in the symptomatic group (p < 0.027, effect size = 0.51). After the program, pain reported by the symptomatic volunteers was reduced by approximately 40% and the gleno-humeral internal rotation bilateral difference was significantly reduced by 77.6% (p < 0.009, effect size = 0.84). In the symptomatic group, the scapula at rest was significantly more posteriorly tilted (p = 0.027, effect size = 0.69) after the stretching; a position that has been shown to limit the risk of impingement. The absence of significant differences of the profiles of the symptomatic and asymptomatic overhead athletes before stretching may indicate that the initiation of early prevention programs, including self-applied stretching, should not rely solely on biomechanical and clinical parameters and might be recommended to all players with a tight shoulder.

Glenoid Retroversion Associates With Asymmetric Rotator Cuff Muscle Atrophy in Those With Walch B-type Glenohumeral Osteoarthritis

BACKGROUND

Our purpose was to determine whether glenoid retroversion associates with asymmetric rotator cuff muscle atrophy in eccentric glenohumeral osteoarthritis (GHOA) and if this asymmetry is worsening of GHOA-related atrophy.

METHODS

Two groups of shoulder magnetic resonance images were studied: patients older than 50 years without a rotator cuff tear or GHOA (control group) and patients preoperative to anatomic total shoulder arthroplasty (GHOA group). Retroversion and rotator cuff muscle cross-sectional areas were measured using reliable and accurate techniques. Proportional muscle areas were created by dividing by total cuff area to correct for differences in overall patient size. Walch grades were assigned via consensus.

RESULTS

The control group consisted of 102 patients and the GHOA cohort consisted of 141 patients. Within the eccentric GHOA group, retroversion associated with relative increasing supraspinatus (r = 0.268, P = 0.035), increasing infraspinatus (r = 0.273, P = 0.032), and decreasing subscapularis areas (r = -0.343, P = 0.006). However, the combined GHOA group had a significantly higher relative subscapularis area than the control group (P = 0.026).

CONCLUSION

In the eccentric GHOA, increasing retroversion is associated with increasing volume of the posterior cuff relative to the anterior cuff muscles, which is a reversal of the asymmetric increasing volume of the anterior cuff relative to the posterior cuff muscles seen with concentric GHOA.

LEVEL OF EVIDENCE

Diagnostic, level III.

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A journal article's title gives authors one chance to make a first impression and communicate succinctly the findings from their important research. The goal of a research article rests in disseminating information. Both authors and academic journals benefit from increasing the number of times an investigation is cited. A scientific manuscript title accurately summarizes the research using key words that can be identified with search engines. This review aims to condense evidence-based research to improve a scientific manuscript title for both clarity and impact.

Comparison of the Medial And Lateral Rotations of the Shoulder Between Non-Athletes and Professional Squash Athletes

Objective  To compare the medial and lateral rotations of the shoulders and the distances between the coracoid process and the cubital fossa of non-athletic individuals to those of elite squash players.

Method  The cross-sectional study was performed between March and August 2017. Male and female non-athletes ( n  = 628) were selected at the Orthopedic Emergency Service of our institution. The inclusion criteria were: age between 18 and 60 years, no physical disabilities or cognitive impairments and absence of pain in the upper limbs. Elite squash players ( n  = 30) of various nationalities were selected at an event held in our city. All of the athletes had practiced this sport under high performance requirements for > 10 years and/or 10.000 hours, and all were asymptomatic. Demographic and clinical data were collected through interviews, while physical examinations and shoulder assessments were performed by a single orthopedic practitioner.

Results  If compared with non-athletes, elite squash players presented significant ( p  < 0.001) mean losses of 23°34' in medial rotation and significant ( p  < 0.003) mean gains of 10°23' in lateral rotation of the dominant shoulders. There was a significant difference ( p  < 0.008) between non-athletes and athletes regarding the distance between the coracoid process and the cubital fossa in the dominant arm.

Conclusion  Intensive squash practice causes adaptive changes that trigger glenohumeral medial rotation deficit, accompanied by significant lateral rotation gain, and can generate pathogenic alterations in the shoulder.

Thrower's Shoulder: An Approach to MR Imaging Interpretation

In this article, the authors aim to focus on the challenges of interpreting shoulder MR imaging in the throwing athlete with an approach formed by evidence-based literature and clinical experience, with a particular focus on superior labrum tears.

Glenoidplasty With Posterior Labral Reattachment for Posterosuperior Glenoid Impingement

Background

Posterosuperior glenoid impingement (PSGI), also known as shoulder internal impingement, is a cause of shoulder pain in athletes involved in overhead-throwing sports. PSGI is a condition mostly treated by rehabilitation. Surgery is indicated after unsatisfactory nonoperative management. However, with most of the surgical techniques proposed, the shoulder remains persistently painful during sport activity.

Hypothesis

We aimed to evaluate the efficiency of adding posterior labral reattachment to glenoidplasty as a surgical treatment for PSGI. Our hypothesis was that posterior labral reattachment would have a positive effect on shoulder pain. To our knowledge, this combined procedure has not been previously described.

Study Design

Case series; Level of evidence, 4.

Methods

We retrospectively reviewed 11 male patients with PSGI treated with glenoidplasty and posterior labral reattachment at a single institution during a 7-year period and with a minimum 30-month follow-up after surgery. Most patients were recreational athletes, with 5 of them practicing at the national level and 1 being a professional athlete. Patients completed an online questionnaire consisting of the Simple Shoulder Test (SST), the Kerlan-Jobe Orthopaedic Clinic (KJOC) shoulder and elbow questionnaire, and a specific PSGI survey. Pre- and postoperative shoulder pain were analyzed using the paired t test, with significance set at P < .05.

Results

All 11 patients investigated sought surgery because of persistent shoulder pain while practicing their sport. The patients underwent glenoidplasty and posterior labral fixation, and data for 9 patients were available for analysis (mean age, 29 years; range, 24-42 years). At a minimum 30-month follow-up, most patients (77.8%) showed decreased pain, and 8 patients were able to return to their previous sports activities, with 7 returning at the same or higher level. There was 1 patient who had to change sports because of a lack of force, while a second patient temporarily changed sport and then returned to his sport but at an inferior level. Pre- and postoperative pain differed significantly (P < .05). Surgery did not impair daily life in all patients.

Conclusion

Glenoidplasty associated with posterior labral reattachment significantly diminished shoulder pain in athletes involved in throwing sports. Most patients were able to return to their previous sport at the same or higher level. Posterior labral fixation may improve the benefit of glenoidplasty by decreasing pain.

Pitcher Shoulder: Update Article

Most shoulder injuries occur due to repetitive overhead movements. Before studying the treatment of these shoulder injuries, it is paramount that health professionals have an understanding of the etiology of and the underlying mechanisms for shoulder pathologies. The act of overhead throwing is an eloquent full-body motion that requires tremendous coordination from the time of force generation to the end of the pitch. The shoulder is a crucial component of the upper-body kinetic chain, as it transmits force created in the lower body to the arm and hand to provide velocity and accuracy to the pitch.

Pitching shoulder passive flexibility: torque-angle analysis for external rotation and internal rotation

In this study, a custom device was developed to analyse the pitching shoulder's external rotation (ER) and internal rotation (IR) passive flexibility. We analysed three novel measures: the resistance onset angle (ROA = angle where the shoulder begins stretching), rotational stiffness, and torque at the end range of motion (ROM). The purpose was to conduct a bilateral analysis to determine if there are significant differences between the throwing and non-throwing shoulder. Participants were 30 upper level pitchers (13 division I, 17 minor league). During testing, pitchers laid supine on a treatment table and the arm was secured to a rotational wheel with the shoulder abducted 90° and elbow flexed 90°. Dependent t-tests revealed significant (p < 0.01) and relatively extreme bilateral differences for all three variables. The throwing shoulder had: increased ER ROA (9°), decreased IR ROA (5.3°), increased ER stiffness (17%), increased IR stiffness (34%), increased ER torque (21%), and increased IR torque (30%). Secondary correlation analysis was completed to determine if the torque-angle variables were good predictors of the end ROM. Stiffness correlations were weak for ER (r = 0.35, p = 0.048) and IR (r = 0.42, p = 0.017) but ROA correlations were strong for ER (r = 0.85, p < 0.001) and IR (r = 0.86, p < 0.001).

The Relationship Between Humeral Torsion and Arm Injury in Baseball Players: A Systematic Review and Meta-analysis

CONTEXT

Humeral torsion (HT) has been linked to various injuries and benefits. However, the exact interplay between HT, shoulder range of motion (ROM), competition level differences, and injury risk is unclear.

OBJECTIVE

To determine the relationship between HT, ROM, and injury risk in baseball players. Secondarily, to determine HT based on competition level.

DATA SOURCES

PubMed, Embase, Web of Science, CINAHL, and Cochrane databases were searched from inception until November 4, 2018.

STUDY SELECTION

Inclusion criteria consisted of (1) HT measurements and (2) arm injury or shoulder ROM.

STUDY DESIGN

Systematic review.

LEVEL OF EVIDENCE

Level 3.

DATA EXTRACTION

Two reviewers recorded patient demographics, competition level, HT, shoulder ROM, and injury data.

RESULTS

A total of 32 studies were included. There was no difference between baseball players with shoulder and elbow injuries and noninjured players (side-to-side HT difference: mean difference [MD], 1.75 [95% CI, -1.83 to 2.18]; dominant arm: MD, 0.17 [95% CI, -1.83 to 2.18]). Meta-regression determined that for every 1° increase in shoulder internal rotation (IR), there was a subsequent increase of 0.65° in HT (95% CI, 0.28 to 1.02). HT did not explain external rotation (ER ROM: 0.19 [95% CI, -0.24 to 0.61]) or horizontal adduction (HA ROM: 0.18 [95% CI, -0.46 to 0.82]). There were no differences between HT at the high school, college, or professional levels.

CONCLUSION

No relationship was found between HT and injury risk. However, HT explained 65% of IR ROM but did not explain ER ROM or HA ROM. There were no differences in HT pertaining to competition level. The majority of IR may be nonmodifiable. Treatment to restore and maintain clinical IR may be important, especially in players with naturally greater torsion. HT adaptation may occur prior to high school, which can assist in decisions regarding adolescent baseball participation.

Glenohumeral Internal Rotation Deficit: Prime Suspect or Innocent Bystander?

PURPOSE OF REVIEW

Glenohumeral internal rotation deficit (GIRD) is a term used in the literature to describe the physiological adaptation that occurs in the dominant arm of the overhead-throwing athlete. The meaning of this term and the clinical significance and the rationale for its treatment have all been described with some ambiguity within the literature. GIRD as a measurement is multivariate. There is an adaptive bony component in humeral retroversion (HR) and muscular contributions in the form of thixotropy which can confound the capsular component of GIRD. Emerging diagnostic tools such as ultrasound can help differentiate between the bony and soft tissue contributions as well as provide a dynamic assessment in the throwing shoulder. The purpose of this review is to describe and differentiate between anatomical GIRD (aGIRD) and pathological GIRD (pGIRD), discuss the clinical significance of pGIRD and values reported within the literature, and describe its measurement and clinical treatment.

RECENT FINDINGS

Recent literature has demonstrated that GIRD alone is not associated with injury risk of the upper extremity in the overhead athlete. Although past literature has demonstrated pGIRD as increasing injury risk, other variables such as external rotation (ER) deficit, horizontal adduction deficit, and shoulder flexion deficit have been associated with injury of the upper extremity while GIRD did not. Further, an appreciation for the difference between adaptive GIRD and pathologic GIRD has recently been emphasized to ensure optimal treatment addresses the pathologic portion of GIRD. The recent focus on early treatment approaches to pGIRD may play a role in its diminished risk association. This review offers the term humeral retroversion (HR) Corrected GIRD as a more clinically sensitive value that may provide the clinician a more precise rationale for the treatment of pGIRD. Currently, diagnostic ultrasound is a reliable and valid method for measuring HR in the overhead-throwing athlete. Future research that validates clinical methods for assessing HR could provide utility for clinical decision-making in the absence of diagnostic ultrasound.

Upper Extremity and Hip Range of Motion Changes Throughout a Season in Professional Baseball Players

BACKGROUND

Loss of upper and lower extremity range of motion (ROM) is a significant risk factor for injuries in professional baseball players.

PURPOSE/HYPOTHESIS

The purpose was to determine changes in ROM in professional baseball players over the course of a single season and their careers. We hypothesized that pitchers and position players would lose ROM, specifically total shoulder motion (total ROM [TROM]) and hip internal rotation (IR), over the course of a season and their careers.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Upper and lower extremity ROM measurements were recorded during pre-, mid-, and postseason on all professional baseball players for a single organization between 2011 and 2018. ROM measurements were compared for pitchers and position players over the course of the season and their careers. Also, ROM measurements over the pre-, mid-, and postseason were compared between pitchers and position players.

RESULTS

A total of 166 professional baseball players (98 pitchers, 68 position players) were included. Pitcher hip external rotation (ER; P < .001), IR (P = .010), and TROM (P < .001) for lead and trail legs decreased over the course of the season. Pitcher shoulder ER (P = .005), TROM (P = .042), and horizontal adduction (P < .001) significantly increased over the course of the season. Position player shoulder flexion (P = .046), hip ER (P < .001, lead leg; P < .001, trail leg), and hip TROM (P = .001; P = .002) decreased over the course of the season. Position player shoulder ER (P = .031) and humeral adduction (P < .001) significantly increased over the course of the season. Over the course of pitchers' careers, there was decreased shoulder IR (P = .014), increased shoulder horizontal adduction (P < .001), and hip IR (P = .042) and hip TROM (P = .027) for the lead leg. Position players experienced loss of hip TROM (P = .010, lead leg; P = .018, trail leg) over the course of their careers. Pitchers started with and maintained more shoulder ER and gained more shoulder TROM over a season as compared with position players.

CONCLUSION

Pitchers and position players saw overall decreases in hip ROM but increases in shoulder ROM over the course of the season and career.

Posterior shoulder tightness can be a risk factor of scapular malposition: a cadaveric biomechanical study

BACKGROUND

Scapular malposition and posterior shoulder tightness are key pathologic processes in the shoulder of throwing athletes. The objective of this study was to investigate the effects of posterior capsule tightness, posterior rotator cuff muscle tightness, or both on scapular position.

METHODS

Ten shoulders from 5 fresh frozen cadaveric male torsos were tested in maximum internal, neutral, and maximum external shoulder rotations at 0°, 45°, and 90° of shoulder abduction. Scapular rotation-namely, upward and downward rotation, internal and external rotation, and anterior and posterior tilt-and the scapula-spine distance were measured by using a MicroScribe digitizer (Revware, Raleigh, NC, USA). Each shoulder underwent 4 experimental stages: intact; isolated posterior rotator cuff muscle (infraspinatus and teres minor) tightness; both posterior rotator cuff muscle and capsule tightness; and isolated posterior capsule tightness.

RESULTS

Posterior muscle tightness significantly decreased upward rotation (P< .05) only in maximum shoulder internal rotation at 45° or 90° of shoulder abduction, whereas posterior capsule tightness did not affect upward rotation (P= .09 to .96). Posterior capsule tightness significantly increased scapular internal rotation (P< .01), but posterior muscle tightness did not change scapular internal rotation (P= .62 to .89). Posterior capsule tightness significantly increased both the superior and inferior scapula-spine distance (ie, caused scapular protraction) in maximum shoulder external rotation at 90° of abduction (P< .01).

CONCLUSION

Posterior shoulder tightness resulted in scapular malposition. However, the muscular and capsular components of that tightness affected the scapular position differently. For the treatment of scapula malposition, stretching of the posterior shoulder capsule and muscles is recommended.

Effects of self-stretching with mobilization on shoulder range of motion in individuals with glenohumeral internal rotation deficits: a randomized controlled trial

BACKGROUND

The combined effects of cross-body stretching and dorsal glide mobilization have not been examined previously, although both stretching and mobilization maneuvers are effective for improving shoulder range of motion (ROM). Thus, the aim of this study was to demonstrate the effects of stretching with mobilization (SWM) on glenohumeral (GH) internal rotation (IR) and horizontal adduction (HA) ROM.

METHODS

Forty individuals with GH IR deficits were randomized to perform simultaneous combined cross-body stretching and dorsal glide mobilization (SWM group, comprising 10 male and 10 female patients) or cross-body stretching alone (stretching group, comprising 10 male and 10 female patients). GH IR ROM, HA ROM, and shoulder mobility were assessed before and immediately following interventions. Group and time differences were analyzed using 2-way repeated-measures analysis of variance.

RESULTS

Greater changes in GH IR ROM (6°, P < .001), HA ROM (10°, P < .001), and shoulder mobility (-2 cm, P = .018) were observed in the SWM group than in the stretching group, although significant increases were observed in GH IR ROM (SWM group, P < .001; stretching group, P < .001), HA ROM (SWM group, P < .001; stretching group, P = .042), and shoulder mobility (SWM group, P < .001; stretching group, P < .001) after both interventions.

CONCLUSION

This study shows that SWM could be a useful exercise for shoulder ROM recovery in individuals with GH IR deficits.

Glossary of terms for musculoskeletal radiology

Members of the International Skeletal Society compiled a glossary of terms for musculoskeletal radiology. The authors also represent national radiology or pathology societies in Asia, Australia, Europe, and the USA. We provide brief descriptions of musculoskeletal structures, disease processes, and syndromes and address their imaging features. Given the abundance of musculoskeletal disorders and derangements, we chose to omit most terms relating to neoplasm, spine, intervention, and pediatrics. Consensus agreement was obtained from 19 musculoskeletal radiology societies worldwide.

Type V superior labral anterior-posterior (SLAP) lesion in recurrent anterior glenohumeral instability

BACKGROUND

The literature has reported debatable diagnostic accuracy of clinical provocative tests for a type II superior labral anteroposterior (SLAP) lesion, especially in the context of a type V SLAP (concurrent Bankart and type II SLAP) lesion. This study was conducted to determine whether the investigated provocative tests offer reliable predictive values in the diagnosis of type II SLAP lesions in patients with recurrent anterior glenohumeral (GH) instability.

METHODS

This prospective case-control study carried out between September 2014 and September 2018 included 51 patients with post-traumatic recurrent anterior GH instability. Patients were prospectively evaluated for type II SLAP lesions by 9 provocative tests: Jobe relocation test, abduction-external rotation test, anterior slide test, biceps load test I, biceps load test II, pain provocation test, labral tension test, crank test, and the O'Driscoll dynamic labral shear test. The results of these tests were compared with findings of diagnostic arthroscopic GH examinations (control).

RESULTS

Statistical analysis revealed the mean age of the studied group to be 26.1 ± 7.56 years, with male predominance (50 patients; 98.04%). Arthroscopic examination revealed a Bankart lesion in isolation and in association with a type II SLAP lesion (ie, a type V SLAP lesion) in 15 (29.4%) and 36 (70.6%) patients, respectively. The anterior slide test yielded the highest positive and lowest negative likelihood ratios (2.91 and 0.52, respectively).

CONCLUSION

Except for the anterior slide test, which can be validated for the clinical diagnosis of type II SLAP lesions in patients with traumatic recurrent anterior GH instability, the investigated tests offer poor predictive values and should be cautiously used in clinical practice.

Restriction in the hip internal rotation of the stride leg is associated with elbow and shoulder pain in elite young baseball players

BACKGROUND

Evidence is scarce concerning the relationship of physical dysfunction of the trunk and lower extremities with elbow and shoulder pain in young baseball players. This study aimed to examine the association of joint flexibility of the trunk and lower extremities and dynamic postural control with elbow and shoulder pain among elite young baseball players.

METHODS

We analyzed baseball players (aged 9-12 years) who participated in the National Junior Sports Clubs Baseball Festival. Range of motion in external rotation and internal rotation (IR) of the hip, as well as the finger-to-floor distance and heel-to-buttock distance, was measured. The straight-leg-raise test was also conducted. Dynamic postural control was evaluated using the Star Excursion Balance Test. Multivariable logistic regression analyses were conducted to examine the association of physical function with the elbow or shoulder pain incidence.

RESULTS

Of 210 players surveyed, 177 without elbow or shoulder pain were included in the analysis. Of the participants, 16 (9.0%) reported having elbow or shoulder pain during the tournament. Participants with the incidence of elbow or shoulder pain had a significant restriction in hip IR of the stride leg compared with those without pain (35.8° vs. 43.7°, P = .022). There were no significant associations of other joint flexibilities and the Star Excursion Balance Test with elbow or shoulder pain.

CONCLUSION

Decreased hip IR range of motion of the stride leg was significantly associated with the elbow or shoulder pain incidence. Players, coaches, and clinicians should consider the physical function of the trunk and lower extremities for the prevention of elbow and shoulder pain.

Analysis of the presence and influence of Glenohumeral Internal Rotation Deficit on posterior stiffness and isometric shoulder rotators strength ratio in recreational and amateur handball players

OBJECTIVE

To determine whether recreational and amateur handball players exhibit Glenohumeral Internal Rotation Deficit (GIRD), and if it is accompanied by posterior stiffness and changes in shoulder rotators strength.

DESIGN

Cross-Sectional Study; SETTING: Research laboratory.

PARTICIPANTS

Indoor and beach handball players, members of handball teams or engaged in some handball recreational group.

MAIN OUTCOME MEASURES

Range of motion (ROM) of internal rotation (IR) and horizontal adduction (HA), and isometric internal and external rotators strength. Based on the ROM of internal rotation, they were allocated to groups with and without GIRD.

RESULTS

The dominant shoulder of GIRD group obtained a lower ROM of IR compared to the non-dominant shoulder of the same group (p < 0.01) and to the dominant (p = 0.02) and non-dominant (p = 0.01) shoulders of the group without GIRD. Less horizontal adduction was observed in both groups (p = 0.01), as well as greater external rotator strength (p = 0.01) and external/internal rotators strength ratio (p < 0.04) in the dominant shoulder. The rotators strength ratio was greater in GIRD group (p < 0.01).

CONCLUSIONS

The present study showed the dominant shoulder had greater posterior stiffness and external rotator strength, regardless of GIRD. Also the group with GIRD showed higher rotators strength ratio.

Comparison of shoulder range of motion, strength, and upper quarter dynamic balance between NCAA division I overhead athletes with and without a history of shoulder injury

OBJECTIVE

To determine differences in shoulder range of motion, strength, and upper quarter dynamic balance between collegiate overhead athletes with and without a history of a shoulder injury.

DESIGN

Cross-sectional study.

SETTING

Athletic training clinic.

PARTICIPANTS

58 overhead athletes who were fully participating in NCAA Division I overhead sports (baseball, softball, volleyball, and tennis) and free of any current shoulder injury were included. Participants were divided into a shoulder injury history group (n = 25) and uninjured group (n = 33). Participants in the shoulder injury history group had a previously resolved shoulder injury.

MAIN OUTCOME MEASURES

Active range of motion assessments for shoulder internal rotation, external rotation, and horizontal adduction. Isometric strength assessments for shoulder IR and ER. The Upper Quarter Y-Balance Test.

RESULTS

The shoulder injury history group demonstrated a lower Upper Quarter Y-Balance Test mean score in the superolateral direction (p = .03, d = 0.56), but no group differences existed for other results (p > .05).

CONCLUSIONS

Overhead athletes with a history of shoulder injury had worse upper quarter dynamic balance versus those without the history. From a clinical perspective, the findings may have significant implications for developing shoulder re-injury prevention and rehabilitation protocols in relation to their shoulder injury history.

Molecular Pattern and Density of Axons in the Long Head of the Biceps Tendon and the Superior Labrum

The type II superior labrum anterior to posterior (SLAP) repair is a viable option in young and demanding patients, although a prolonged period of pain after surgery is described in the literature. The reason for this fact remains unknown. Thus, the purpose of this study was to investigate the molecular pattern of the biceps tendon anchor, where the sutures for repair are placed. The long head of the biceps tendon (LHBT), including the superior labrum, was dissected in the setting of reverse total shoulder arthroplasty. Immunohistochemical staining was performed using neurofilament (NF) and protein gene product (PGP) 9.5 as general markers for axons and calcitonin gene-related peptide (CGRP) and substance P for nociceptive transmission. A quantitative assessment was performed according to the two regions of interest (ROIs), i.e., the anterosuperior (ROI I) and the posterosuperior labrum (ROI II). Eleven LHBTs with a mean age of 73 years (range: 66–87 years) were harvested intraoperatively. Six LHBTs were gained in osteoarthrosis and five in fractures. We found an inhomogeneous distribution of axons in the anterosuperior and posterosuperior parts of the labrum in all the specimens irrespective of the age, gender, and baseline situation. There was a significantly higher number (p < 0.01) as well as density (p < 0.001) of NF-positive axons in ROI I compared to ROI II. Nociceptive fibers were always found along the NF-positive axons. Thus, our results indicate that the biceps tendon anchor itself is a highly innervated region comprising different nerve qualities. The anterosuperior labrum contains a higher absolute number and density of axons compared to the posterosuperior parts. Furthermore, we were able to prove the presence of nociceptive fibers in the superior labrum. The results obtained in this study could contribute to the variability of pain after SLAP repair.

Is posterosuperior contact a normal occurrence in the shoulder?

Posterosuperior (or internal) impingement at the shoulder is defined as contact between the underside of the supraspinatus or infraspinatus tendons with the posterosuperior labrum during extreme external rotation and abduction. In many cases, this contact damages the tendon and causes mirror posterosuperior labrum deterioration. The primary aim of this study was to define whether this contact occurs normally in patients who do not have a rotator cuff tear.

METHODS

We evaluated 100 shoulders in 100 patients. All patients were operated on in the beach chair position. After introducing the scope through the posterior portal, contact between the articular side of the rotator cuff and the posterosuperior labrum was noted as being present or absent when the arm was cocked in 90° abduction and 90° external rotation (90/90) then the arm was cocked in 140° abduction and maximum external rotation (140/Max).

RESULTS

Contact was observed in 69% of patients in the 90/90 cocked position and in 94% of patients in the 140/Max cocked position. We found a correlation between the presence of rotator cuff and/or labrum lesions and the patient regularly performing arm-cock movements (p=0.035).

DISCUSSION

Contact between the underside of the supraspinatus tendon and the posterosuperior labrum occurs physiologically. Repetitive arm-cock movements may contribute to macroscopic lesions of the underside of the rotator cuff and posterosuperior labrum.

LEVEL OF EVIDENCE

IV, basic science study.

The association between a low critical shoulder angle and SLAP lesions

PURPOSE

To evaluate the critical shoulder angle (CSA), acromion index (AI) and further acromion parameters in patients with isolated SLAP lesions compared with patients without SLAP lesions.

METHODS

Between 2012 and 2016, the CSA, AI, lateral acromion angle (LAA) and acromion slope (AS) were radiologically examined in consecutive patients > 18 years having had a shoulder arthroscopy with isolated SLAP lesion types II-IV. These were compared to controls without SLAP lesions and without (control group I) or with (control group II) complete supraspinatus tendon (SSP) tears.

RESULTS

75/103 patients with isolated SLAP lesion types II-IV with a mean age of 46.5 years (± 13.0, 18.1-76.3) were analyzed, 61% of them being male. For control, n = 211 consecutive patients (47% male) with an intact SSP and SLAP complex and a mean age of 52.3 years (± 15.0, 18.6-88.4) and n = 115 patients (60% male) with an intact SLAP complex but complete SSP tears, mean age 66.6 years (± 9.3, 44.7-87.9) were examined. The CSA in SLAP patients was 29.6° (± 3.5, 21.0-38.0), 33.8° (± 3.7, 25.1-46.9) in no SLAP and no SSP (p < 0.001) and 36.7° (± 3.6, 29.1-46.6) in no SLAP but SSP (p < 0.001). The area under the curve (AUC) for CSA was 0.83 for SLAP lesions resulting in a probability of 83% for patients with SLAP lesion to be associated with a specific CSA.

CONCLUSIONS

Isolated SLAP lesion types II-IV are associated with a low CSA < 30°. The AI, the AS as well as the LAA showed no correlation with SLAP lesions.

LEVEL OF EVIDENCE

Retrospective comparative study, Level III.

Internal impingement of the shoulder in overhead athletes: Retrospective multicentre study in 135 arthroscopically-treated patients

BACKGROUND

Internal impingement of the shoulder (IIS) is the leading cause of chronic shoulder pain in overhead throwing athletes. No consensus exists about which techniques are optimal when surgery is in order. The available studies are limited by small sample sizes and short follow-ups. The primary objective of this study was to assess return-to-sports (RtS) outcomes after surgical treatment for IIS. A favourable RtS outcome (RtS+) was defined as returning to the previous sport at the same or a higher level.

HYPOTHESIS

The main hypothesis was that surgical treatment resulted in an RtS+ outcome. The secondary hypothesis was that epidemiological factors, pre- and intra-operative anatomical factors, and specific surgical procedures were associated with higher RtS+ rates.

MATERIAL AND METHODS

A retrospective multicentre design was used. We included 135 patients with IIS managed arthroscopically using any of the following procedures: anterior capsulorrhaphy, posterior capsulotomy/capsulectomy, postero-superior labral debridement, posterior glenoidplasty, and rotator cuff tear debridement or repair. Follow-up was at least 1 year. The patients were divided into two groups based on whether they had an RtS+ outcome as defined above or an RtS- outcome defined as a return to the previous sport at a lower level, a switch to another sport, or an inability to engage in any sport. The Kerlan-Jobe Orthopaedic Clinic (KJOC) and Constant's score were used to evaluate subjective and objective shoulder function.

RESULTS

Mean follow-up was 7.9 years. Of the 135 patients, 120 (90%) returned to sports after surgery including 70 (52%) to the previous sport at the same level (RtS+ outcome). By univariate analysis, the following factors were associated with an RtS+ outcome: male sex, rotator cuff tear documented intra-operatively, absence of a greater tuberosity cyst on pre-operative imaging studies, and cuff tear debridement. Anterior capsulorrhaphy was associated with worse post-operative pain.

DISCUSSION

The RtS+ rate in this study differed from previously reported values, due to differences in the sports practiced by the patients and to considerable variability in the surgical techniques used. The positive association between presence of a rotator cuff tear and an RtS+ outcome is at variance with most of the previously published data. Some of the apparent discrepancies between our results and those from other countries may be ascribable to differences in the most popular sports.

LEVEL OF EVIDENCE

IV.

Internal impingement of the shoulder: An international survey of 261 orthopaedic surgeons

BACKGROUND

Internal impingement of the shoulder (IIS) is a specific disorder of young overhead-throwing athletes that was first described in 1991. The many non-operative and surgical treatments suggested to date have produced mixed outcomes. The objective of this study was to compare the practices of surgeons in France versus other countries regarding the diagnosis and treatment of IIS.

HYPOTHESIS

Diagnostic and therapeutic practices regarding IIS differ between surgeons in France and in other countries.

MATERIAL AND METHODS

A 21-item questionnaire in French and English was emailed to the 1300 members of the French Arthroscopy Society and to surgeons from countries other than France. The questionnaire collected information on knowledge about IIS (2 items), the frequency of IIS in clinical practice (2 items), the diagnosis of IIS (6 items), the non-operative and surgical treatment of IIS (3 and 5 items, respectively), and return-to-sports rates after treatment for IIS (3 items).

RESULTS

The completed questionnaire was sent back by 261 surgeons, 206 in France and 55 in other countries, including 42 in Japan. Among the respondents, 90% knew about IIS. Experience with IIS in terms of number of patients seen or surgical treatments performed was greater in the international group (45% vs. 19% in France, p<0.001). Posterior shoulder pain in the arm cocking position was the most widely recognised symptom (99% in France, 74% internationally, p<0.001), followed by excessive external rotation during arm abduction (55% vs. 65%, p=0.23). The most commonly sought lesions were those of the postero-superior labrum and articular surface of the rotator cuff. Rotator cuff debridement was among the surgical options according to most respondents (74% vs. 70%). In contrast, postero-superior glenoidplasty was cited almost only by surgeons in France (67% vs. 4%, p<0.001). The proportion of patients who are able to return to sports was estimated at 50% to 75% by most respondents.

DISCUSSION

Most respondents had theoretical knowledge about IIS, but surgery was rarely performed in France. Only very few athletes in France play baseball, which is responsible for most sports injuries of the shoulder seen in Japan. This fact, combined with differences in the lesions or even the diagnoses, may have contributed to the differences in the responses to the survey items between the French and international groups.

Evaluation and Management of Scapular Dyskinesis in Overhead Athletes

PURPOSE OF REVIEW

This review will outline scapular function in throwing, discuss scapular dyskinesis as an impairment of function that can be associated with throwing injuries and altered performance, and present an algorithm that encompasses guidelines for evaluation and can serve as a basis for treatment.

RECENT FINDINGS

Optimal scapular function is integral to optimal shoulder function. Multiple roles of the scapula in arm function and throwing have been identified while scapular dysfunction continues to be associated with various shoulder pathologies. Although scapular motion alterations may be common in overhead athletes, various reports have shown that identification and management of the alterations can result in improved rehabilitation and performance outcomes. Baseball throwing occurs as the result of integrated, multisegmented, sequential joint motion, and muscle activation within the kinetic chain. The scapula is a key component link within the chain through its function to maximize the scapulohumeral rhythm and efficient throwing mechanics. Evaluation and management beginning with the scapula can produce improved outcomes related to shoulder pathology in overhead athletes.

Anomalous insertion of the pectoralis minor tendon at the greater tuberosity

We present a case of ectopic insertion of the whole tendon of the pectoralis minor muscle associated with impingement syndrome. Based on this case, we performed a review of the literature focused on the association between this ectopic tendon insertion and anterior shoulder pain.

Unstable Osteochondritis Dissecans of the Glenoid Fixed with Autogenous Osteochondral Plugs in a College Baseball Player: A Case Report

CASE

A 19-year-old college baseball outfielder presented with a 3-month history of right shoulder pain. Radiographs, computed tomography, and magnetic resonance imaging showed a large osteochondral defect at the posterosuperior aspect of the glenoid. Arthroscopic evaluation identified an unstable fragment that was partially attached. Fixation of the osteochondral fragment was achieved with autogenous osteochondral plugs through a posterior arthrotomy. At 8 months after surgery, the patient was able to return to his former competitive level of performance.

CONCLUSION

Osteochondritis dissecans (OCD) rarely affects the glenoid. Fixation of a large glenoid OCD lesion with autogenous osteochondral plugs was a successful treatment in this patient.

BASEBALL PLAYERS DIAGNOSED WITH ULNAR COLLATERAL LIGAMENT TEARS DEMONSTRATE GREATER SIDE TO SIDE DIFFERENCES IN PASSIVE GLENOHUMERAL ABDUCTION RANGE OF MOTION COMPARED TO HEALTHY CONTROLS

Background

Numerous studies have shown that baseball players develop range of motion adaptations in their throwing arm. While some of these shoulder range of motion adaptations can lead to greater throwing velocity, excessive changes in shoulder range of motion can increase the risk of injury to the ulnar collateral ligament (UCL).

Purpose/Hypotheses

The purpose of this study was to compare the passive GH-ABD ROM measures of baseball players with a diagnosed UCL tear (UCL group) to a group of age, activity, and position matched healthy controls (CONT group). The primary hypothesis was that baseball players with an UCL tear would have a greater loss of passive glenohumeral abduction range of motion in their throwing shoulder than healthy controls. A secondary hypothesis was that baseball players with an UCL tear would demonstrate similar glenohumeral abduction range of motion in their non-throwing arm and increased side-to-side glenohumeral abduction differences compared to the healthy cohort.

Study Design

Retrospective prospective case-control study.

Results

The UCL group had significantly greater glenohumeral abduction range of motion on their throwing shoulder (132.5 °±8.3 °) than the CONT group (120.19 °±11.2 °, p = 0.000). Similarly, the UCL group had increased glenohumeral abduction range of motion on their non-throwing shoulder (141.2 °±9.5 °) compared to the CONT group (124.1 °±11.4 °, p = 0.000). Additionally, the UCL group had a greater glenohumeral abduction difference (-8.7 °±8.4 °) than the CONT group (-3.8 °±7.7 °, p = 0.001).

Conclusion

In contrast to the original hypotheses, high school and collegiate baseball players that sustained an UCL injury presented with greater glenohumeral abduction range of motion in both their throwing and non-throwing shoulders compared to healthy controls. However, the finding of greater side-to-side glenohumeral abduction range of motion deficits in the UCL group when compared to the matched healthy controls confirms the secondary hypothesis.

Level of Evidence

Level 3.

Do anatomic changes found in the throwing arm after a season of pitching resolve with off-season rest? A dynamic ultrasound study

Hypothesis

Our hypothesis was that seasonal adaptive changes in the ulnar collateral ligament (UCL), ulnohumeral joint space (UHJS), and glenohumeral internal rotation deficit (GIRD) of the pitching extremity would subsequently resolve with off-season rest.

Methods

Eleven collegiate pitchers underwent preseason, postseason, and off-season evaluations including physical examination; dynamic ultrasound imaging of the UCL and UHJS; and the short version of the Disabilities of the Arm, Shoulder and Hand (QuickDASH) questionnaire. Ultrasound images were evaluated by 2 fellowship-trained musculoskeletal radiologists.

Results

All 11 pitchers were included in the final analysis, with an average age of 20.1 years and with 14.1 years of playing experience. After a season of pitching, we found significant increases in GIRD (P = .004) and UCL thickness (P = .033) and nonsignificant increases in both unloaded (P = .069) and loaded (P = .122) UHJS. Preseason GIRD correlated with this increase in loaded UHJS (r = 0.80, P = .003). The increase in UCL thickness was significantly greater in pitchers with GIRD greater than 10° (P < .05). After the off-season, UCL thickness returned to baseline and significant decreases were noted in both unloaded (P = .004) and loaded (P = .041) UHJS, but a progression in GIRD was found (P = .021). Pitchers with GIRD of 10° or less showed greater improvement in UHJS after the off-season (P < .05).

Conclusions

The pitching season produced adaptive changes in the throwing elbow that subsequently resolved after off-season rest. However, shoulder range-of-motion deficits were progressive and did not resolve. Ultrasound adaptations of the pitching elbow were significantly related to GIRD.

Reduced shoulder strength and change in range of motion are risk factors for shoulder injury in water polo players

OBJECTIVE

To determine whether pre-season shoulder ROM and strength can be used to identify athletes at risk of future shoulder injury.

DESIGN

Prospective cohort.

SETTING

High performance sports institute.

PARTICIPANTS

76 sub-elite water polo players.

MAIN OUTCOME MEASURES

Mean pre-season shoulder internal (IR) and external rotation (ER) ROM and strength values compared by gender, dominance and prospective injury status.

RESULTS

14-dominant shoulder injuries were recorded. There was a significant difference (p = 0.05) in total ROM difference (TROM) between the prospectively injured and no injury groups (-17.2°(30.4);-0.8°(13.3)), and dominant side ER strength (11.7%(2.4) vs 14.5%(2.8), p = 0.03) and IR strength (16.5%(3.0) vs 21.6%(4.9) as a percentage body weight (PBW) were also significantly different (p ≤ 0.03). Separate significant associations were found between future episodes of shoulder injury and; dominant shoulder TROM difference of ≥7.5°(OR 3.6,95%CI 0.8-16.0), ER strength as a PBW≤12.5%(OR 5.2,95%CI 1.0-27.9), and IR strength as a PBW≤16.8%(OR 13.8,95%CI 2.2-88.0).

CONCLUSION

Pre-season dominant TROM difference, and reduced shoulder IR and ER strength relative to body weight were significant predictors for future shoulder injury. Although further investigation with a larger sample size is required, achieving optimal values on these measures may reduce future episodes of shoulder injury in water polo players.

Clinical and Biomechanical Evaluation of the Softball Pitcher: A Review of Current Concepts and Clinical Commentary

BACKGROUND

The windmill softball pitch (WSP) is a vastly understudied human motion relative to its counterpart the overhand baseball pitch (OBP). A large body of research has been conducted to understand the kinematics and kinetics of the OBP. Better understanding of the kinematics and kinetics of the WSP may help provide better pitch volume guidelines, physical performance preparation, and injury prevention programs.

EVIDENCE ACQUISITION

A comprehensive review of the literature was performed to gain a full understanding of all currently available biomechanical and clinical evidence surrounding the WSP and related softball injuries.

STUDY DESIGN

Clinical Review.

LEVEL OF EVIDENCE

Level 5.

RESULTS

The softball pitch is a highly complex series of coordinated movements, in which the force generated by the large muscles of the lower extremity and trunk during the wind-up and stride phases are transferred to the ball through the shoulder and arm. Biomechanical evidence has demonstrated relatively equivocal distraction forces at the shoulder for both the softball pitch and baseball pitch.

CONCLUSIONS

Altered pitching biomechanics, high pitch velocity, elevated pitch counts, decreased rest between outings, and increased pitcher fatigue may increase tissue stress on the upper extremity of a softball pitcher. There is convincing evidence that each of these variables have a compounding effect on injury risk for a softball pitcher. Therefore, coaches and clinicians need more research to promote upper extremity health in the softball pitcher at all levels of competition including pitch volume guidelines and injury prevention strategies.

SLAP IV IN OVERHEAD SPORTS PRACTICE

Superior labral tear from anterior to posterior (SLAP) is the most common disease in overhead sports practice.

Association of Upper Extremity Pain With Softball Pitching Kinematics and Kinetics

Background:

There is a paucity of research regarding the relationship between fastpitch softball pitching mechanics and reported pain. Thus, understanding the pitching mechanics of athletes pitching with upper extremity pain and those pain free is paramount.

Purpose:

To examine lower extremity pitching mechanics, upper extremity kinetics, and upper extremity pain in National Collegiate Athletic Association (NCAA) Division I female softball pitchers.

Study Design:

Descriptive laboratory study.

Methods:

A total of 37 NCAA Division I female softball pitchers (mean age, 19.84 ± 1.28 years; mean height, 173.67 ± 7.77 cm; mean weight, 78.98 ± 12.40 kg) from across the United States were recruited to participate. Participants were divided into 2 groups: upper extremity pain (n = 13; mean age, 19.69 ± 1.18 years; mean height, 172.60 ± 11.49 cm; mean weight, 86.75 ± 13.02 kg) and pain free (n = 24; mean age, 19.91 ± 1.35 years; mean height, 174.26 ± 4.96 cm; mean weight, 74.78 ± 9.97 kg). An electromagnetic tracking system was used to obtain kinematic and kinetic data during the riseball softball pitch.

Results:

At foot contact (F_3,33 = 7.01, P = .001), backward elimination regression revealed that stride length, trunk rotation, and center of mass (COM) significantly explained about 33% of variance with softball pitchers experiencing upper extremity pain (adjusted R² = 0.33).

Conclusion:

At foot contact, the kinematic variables of increased trunk rotation toward the pitching arm side, increased stride length, and a posteriorly shifted COM were associated with upper extremity pain in collegiate softball pitchers. Variables early in the pitching motion that do not set a working and constructive proximal kinetic chain foundation for the rest of the pitch to follow could be associated with breakdowns more distal in the kinetic chain, possibly increasing the susceptibility to upper extremity pain.

Clinical Relevance:

The identification of pitching mechanics associated with pain allows clinicians to develop exercises to avoid such mechanics. Avoiding mechanics associated with pain may help reduce the prevalence of pain in windmill softball pitchers as well as help coaches incorporate quantitative biomechanics into their instruction.

Scapular Dyskinesia, the forgotten culprit of shoulder pain and how to rehabilitate

The improper movement of the scapula during shoulder movement is termed scapular dyskinesis and is an often-forgotten cause of pain and dysfunction. The scapula is a key part of the upper limb kinematic chain and is a vital component of the glenohumeral rhythm; which is a major determinant of the efficiency and efficacy of the upper limb. We provide an overview of the complex regional anatomy of the shoulder girdle and how this allows the scapula to act as a both a dynamic and static stabilizer to the upper limb. We explore the normal biomechanics and the aetiology, epidemiology and pathological occurrences which can disrupt the normal function and lead to scapula dyskinesis. Scapula dyskinesis is a poorly understood condition and provides a challenge for the clinician in both diagnosis and management. We provide a summary of the clinical assessment which is most likely to identify the source of the pathology and guides the treatment which is largely rehabilitation of the musculature with focused and specialized physiotherapy.

The Influence of Glenohumeral Joint Posterior Capsule Tightness and Impingement Symptoms on Shoulder Impairments and Kinematics

BACKGROUND

Posterior capsule tightness (PCT) and shoulder impingement syndrome (SIS) symptoms are both associated with altered shoulder biomechanics and impairments. However, their combined effect on kinematics, pain, range of motion (ROM), strength, and function remain unknown.

OBJECTIVE

The purpose of this study was to determine if the combination of PCT and SIS affects scapular and humeral kinematics, glenohumeral joint ROM, glenohumeral joint external rotation strength, pain, and function differently than does either factor (PCT or SIS) alone.

DESIGN

The design was a cross-sectional group comparison.

METHODS

Participants were placed into 1 of 4 groups based on the presence or absence of SIS and PCT: control group (n = 28), PCT group (n = 27), SIS group (n = 25), and SIS + PCT group (n = 25). Scapular kinematics and humeral translations were quantified with an electromagnetic motion capture system. Shoulder internal rotation and external rotation ROM, external rotation strength, and pain and Shoulder Pain and Disabilities Index scores were compared between groups with ANOVA.

RESULTS

The SIS group had greater scapular internal rotation (mean difference = 5.13°; 95% confidence interval [CI] = 1.53°-8.9°) and less humeral anterior translation (1.71 mm; 95% CI = 0.53-2.9 mm) than the other groups. Groups without PCT had greater internal rotation ROM (16.05°; 95% CI = 5.09°-28.28°). The SIS + PCT group had lower pain thresholds at the levator scapulae muscle (108.02 kPa; 95% CI = 30.15-185.88 kPa) and the highest Shoulder Pain and Disabilities Index score (∼ 44.52; 95% CI = 33.41-55.63).

LIMITATIONS

These results may be limited to individuals with impingement symptoms and cannot be generalized to other shoulder conditions.

CONCLUSIONS

Decreased ROM and lower pain thresholds were found in individuals with both impingement symptoms and PCT. However, the combination of factors did not influence scapular and humeral kinematics.

Editorial Commentary: Is an Arthroscopic Single-Row Repair Effective for the Treatment of Chronically Retracted, Full-thickness Subscapularis Tears?

Retraction and scarring of subscapularis tears make arthroscopic fixation technically challenging. The ideal arthroscopic technique is still under debate, with new studies examining the importance of repairing the "leading edge." Regardless of single- or double-row fixation, it is our opinion that restoring the native anatomy as well as any concomitant biceps pathology is essential for postoperative success.

Review of Shoulder Range of Motion in the Throwing Athlete: Distinguishing Normal Adaptations from Pathologic Deficits

PURPOSE OF REVIEW

Overhand (OH) throwers demonstrate a unique motion profile of the shoulder joint complex. This manuscript reviews normal adaptations in the OH thrower and contrast findings with pathologic motion deficits.

RECENT FINDINGS

Multiple adaptations in range of motion have been associated with increased risk for arm injury. The use of a more conservative cutoff value for glenohumeral internal rotation deficit and horizontal adduction in younger throwers may help reduce injury risk. Deficits in glenohumeral internal rotation, total range of motion, shoulder flexion, and external rotation insufficiency have all been proposed as means to identify OH throwers at risk for arm injury, but conflicting evidence exists. Understanding normal adaptation due to repetitive stress of throwing is essential to effective management of these athletes. Adaptive change in bone and soft tissues is normal and contributes to the unique motion profiles expected in throwers. The causative link between normal adaptation and shoulder and elbow injury remains uncertain.

Prevalence and Site of Rotator Cuff Lesions in Shoulders With Recurrent Anterior Instability in a Young Population

Background

Partial articular supraspinatus tendon avulsion (PASTA) lesions are often seen in shoulders of throwing athletes. PASTA lesions in anterior instability are also found in recurrent anterior glenohumeral instability.

Purpose

To investigate the prevalence and location of rotator cuff tears (RCTs), including PASTA lesions, in shoulders with recurrent anterior instability.

Study Design

Case series; Level of evidence, 4.

Methods

A total of 842 shoulders in 801 patients with recurrent anterior instability (647 men, 154 women; mean age, 24 years; age range, 13-40 years) who underwent arthroscopic surgery at the age of 40 years or younger were enrolled. During surgery, the thickness and the sites of RCTs as well as patient factors associated with RCTs were examined.

Results

RCTs were found in 57 shoulders (7%) in 56 patients. There were 4 shoulders with full-thickness RCTs and 54 shoulders with PASTA lesions. All lesions but 1 involved the anterior border of the supraspinatus (SSP). Participation in high-level athletics and older age at injury were associated with RCTs.

Conclusion

The incidence of RCTs was 7% in shoulders with recurrent anterior instability at age 40 years or younger. Most RCTs were PASTA lesions that involved the anterior border of the SSP.

The efficacy and fidelity of clinical interventions used to reduce posterior shoulder tightness: a systematic review with meta-analysis

BACKGROUND

Posterior shoulder tightness (PST) has been implicated in the etiology of numerous shoulder disorders and is a source of stiffness in both postoperative and nonsurgical cohorts. Identifying efficacious interventions to address PST has the potential to impact patient outcomes in both operative and nonoperative cohorts. Our purpose was to analyze the efficacy of nonoperative clinician-assisted interventions used to mitigate PST.

METHODS

We performed a systematic review and meta-analysis. Relevant studies were assessed for inclusion, and selected studies were identified from the PubMed, Embase, Cochrane, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases by a biomedical librarian. Data extracted from the selected studies underwent quality appraisal using Grading of Recommendations, Assessment, Development, and Evaluation analysis; fidelity assessment; and meta-analysis.

RESULTS

The search identified 374 studies, with 13 ultimately retained. Grading of Recommendations, Assessment, Development, and Evaluation analysis revealed areas of concern regarding consistency and imprecision of reporting within the included studies overall. Treatment fidelity assessment showed that only 3 of the 13 studies received a rating of good to excellent, indicating a high risk of bias. When clinician-assisted interventions were compared with no treatment, meta-analysis showed a moderate effect size in favor of clinician-assisted interventions for improving range of motion. When a multimodal treatment approach for PST was compared with active comparator interventions, a small effect size was present for improving range of motion in favor of the multimodal approach.

CONCLUSION

The efficacy of clinician-assisted interventions for reducing PST was identified when using both a single treatment and multimodal treatments. Current evidence focuses mostly on populations with PST who were not seeking care and the immediate- to short-term effects of clinician-assisted interventions, which may limit generalization of findings.

The sub-supraspinatus recess and superior labral motion: an arthroscopic analysis

BACKGROUND

Minimal information exists regarding the sub-supraspinatus recess superior to the labrum and inferior to the supraspinatus. Furthermore, movement of the superior labrum during glenohumeral range of motion has not previously been defined. The objectives of this arthroscopic study were to describe the (i) sub-supraspinatus recess dimensions and (ii) superior labral motion.

METHODS

Forty-four patients were enrolled and underwent standardized arthroscopic assessment. Analysis consisted of static measurement of the sub-supraspinatus recess depth, as well as the amount of labral motion during passive shoulder motion. Labral movement was categorized relative to the glenoid rim (lateral to the rim, to the rim, or medial to the rim).

RESULTS

All patients had a well-defined sub-supraspinatus recess varying from a depth of 0 mm to 5 mm (n = 10; 22.7%), 5 mm to 10 mm (n = 23; 52.3%) or >10 mm (n = 11; 25%). External rotation in abduction demonstrated the greatest labral movement (p < 0.001) with 28 (80%) shoulders moving medial to the rim.

CONCLUSIONS

The sub-supraspinatus recess is consistently present with an average depth of 5 mm to 10 mm. Superior labral motion is present in most patients and is most pronounced in external rotation in abduction. This finding likely has clinical implications for superior labral repair surgery, especially for overhead athletes and laborers who require external rotation in an abducted position for a successful outcome.

Relationship between bilateral humeral retroversion angle and starting baseball age in skeletally mature baseball players-existence of watershed age

BACKGROUND

Repetitive pitching in childhood was thought to restrict the physiological derotation process of the humeral head. Some studies reported that the side-to-side differences of humeral retroversion in baseball players occurred between the age of 9 and 11 years. The present study investigated the relationship between bilateral humeral retroversion angle and starting baseball age in skeletally mature baseball players.

METHODS

One hundred and seventeen male baseball players, who belonged to a college or amateur team, were investigated. Bilateral humeral retroversion was assessed using an ultrasound-assisted technique as described by previous studies. All players were divided into four groups: players who had started playing baseball before the age of 6 years, between 7 and 8 years, between 9 and 10 years and after 11 years. Bilateral humeral retroversion angle was compared among the four starting age groups.

RESULTS

All players started playing baseball between 5 and 12 years. Comparing the throwing arm, humeral retroversion in starting age group 11-12 (72°) was significantly smaller than the other 3 groups (81°, 82°, and 80° for groups 5-6, 7-8, and 9-10, respectively). Comparing the non-throwing arm revealed no significant differences among the 4 starting age groups (71°, 72°, 70°, and 66° for groups 5-6, 7-8, 9-10, and 11-12, respectively).

CONCLUSIONS

Skeletally mature baseball players who started playing baseball after 11 years had significantly smaller humeral retroversion in the throwing arm than those who started baseball before 11 years.

Effect of Posterior Capsule Tightness and Humeral Retroversion on 5 Glenohumeral Joint Range of Motion Measurements: A Cadaveric Study

BACKGROUND

Altered glenohumeral joint range of motion can be caused by increased humeral retroversion (HR) and/or posterior capsule tightness (PCT). To make informed clinical decisions, it is vital to understand how HR and PCT alterations, individually and in combination, affect joint range of motion measurements.

PURPOSE

To evaluate the effect of experimental tissue alterations on clinical range of motion measures.

STUDY DESIGN

Controlled laboratory study.

METHODS

Five clinical measurements were quantified in 8 fresh-frozen cadavers under 4 experimentally created conditions: baseline (no alterations), HR condition (20° increase in HR by transecting the bone), PCT condition (20% decrease in length via thermal energy), and PCT + HR combined. Clinical measurements included bicipital forearm angle, low flexion, glenohumeral internal and external rotation, and horizontal adduction. All measurements were taken by the same blinded tester. Separate 1-factor repeated measures analyses of variance were used to evaluate the effect of the alterations on each clinical measurement.

RESULTS

There was a significant main effect of condition for bicipital forearm angle ( P = .02, F = 4.03), low flexion ( P = .02, F = 3.86), internal rotation ( P = .03, F = 3.65), and external rotation ( P < .001, F = 15.15) but not for horizontal adduction ( P = .29, F = 1.33). The HR condition resulted in a decreased bicipital forearm angle of 16.1° and 15.8° as compared with the PCT and PCT + HR conditions, respectively. When compared with baseline, the PCT + HR condition decreased the low flexion test by 13.5°, and the HR condition decreased internal rotation range of motion by 14.2°. All conditions increased external rotation when compared with baseline.

CONCLUSION

Greater measurement changes were noted in both HR conditions, suggesting that bony alterations influence motion to a greater extent than posterior capsule alterations.

CLINICAL RELEVANCE

Clinicians should be aware that humeral retroversion will influence the measurement of posterior shoulder tightness.

The differences of humeral torsion angle and the glenohumeral rotation angles between young right-handed and left-handed pitchers

BACKGROUND

The differences between young right-handed and left-handed baseball players are not well known. This study compared the range of the shoulder motion and humeral torsion angle (HTA) between right-handed and left-handed young baseball pitchers.

METHODS

A total of 65 young baseball pitchers (age, 9-12 years; 46 right-handed throwers, R group; and 19 left-handed throwers, L group) were analyzed. The glenohumeral internal rotation (IR) angle and external rotation (ER) angle were measured at 90° shoulder abduction, and HTA was assessed using indirect ultrasonographic techniques. The side-to-side difference in HTA (d-HTA), glenohumeral ER difference (GERD), and glenohumeral IR deficit (GIRD) were calculated. The adjusted GIRD and adjusted GERD were defined as the angles obtained by subtracting d-HTA from GIRD and GERD, respectively, to exclude the influence of humeral retrotorsion difference.

RESULTS

HTA and ER of the throwing limb were significantly greater than those of the nonthrowing limb in the R group (HTA: 84° vs. 77°; P < .001, ER: 116° vs. 111°; P < .001), but no significant differences were observed in the L group (HTA: 79° vs. 77°, P = .103; ER: 113° vs. 114°, P = .380). Compared with the R group, the L group showed a significantly smaller d-HTA (2° vs. 8°, P < .001) and GERD (5° vs. -2°, P = .004), but no significant difference was observed in adjusted GERD between the groups (-3° vs. -4°, P = .690).

CONCLUSION

Compared with the right-handed pitchers, the side-to-side differences of glenohumeral external rotation angle and humeral torsion angle were significantly smaller in the left-handed pitchers at a young age.