Periostin Is a Biomarker for Anterior Shoulder Instability: Proteomic Analysis of Synovial Fluid

BACKGROUND

The incremental biological changes in the synovial microenvironment of the shoulder in acute and chronic instability that may contribute to joint degeneration are poorly understood. Proteomic analysis of synovial fluid in patients with shoulder instability may improve our understanding of proteins that are shed into shoulder synovial fluid after an injury.

HYPOTHESIS

Injury-specific factors such as the direction of instability and the severity of glenoid and humeral bone loss are associated with the proteome of synovial fluid in patients with shoulder instability.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Synovial fluid lavage samples were compared between patients with anterior (n = 12) and posterior (n = 8) instability and those without instability (n = 5). Synovial proteins were identified with liquid chromatography-tandem mass spectrometry. Orthogonal validation of protein targets found to be significant on tandem mass spectrometry was performed in a separate set of prospective patients with Western blotting. Data were processed and analyzed, and P values were adjusted with the Benjamini-Hochberg method for multiple comparisons.

RESULTS

A total of 25 patients were included. Tandem mass spectrometry identified 720 protein groups in synovial fluid of patients with shoulder instability. There were 4 synovial proteins that were significantly expressed in patients with anterior instability relative to posterior instability: periostin (POSTN) (adjusted P value = .03; log fold change [logFc] = 4.7), transforming growth factor beta-induced protein ig-h3 (adjusted P value = .05; logFc = 1.7), collagen type VI alpha-3 chain (adjusted P value = .04; logFc = 2.6), and coagulation factor V (adjusted P value = .04; logFc = -3.3). Among these targets, POSTN showed a moderate correlation with the Hill-Sachs lesion size (r = 0.7). Prospective validation with Western blotting confirmed a significantly higher level of POSTN in synovial fluid of patients with anterior instability (P = .00025; logFc = 5.1).

CONCLUSION

Proteomic analysis enriched our understanding of proteins that were secreted into shoulder synovial fluid of patients with shoulder instability. The identification of POSTN, a proinflammatory catabolic protein involved with tissue remodeling and repair, as a significant target in anterior shoulder instability is a novel finding. Therefore, further study is warranted to determine the role that POSTN may play in the progression of bone loss and posttraumatic osteoarthritis.

CLINICAL RELEVANCE

Proteomic analysis of synovial fluid in patients with shoulder instability improved our understanding of this abnormality after an injury.

Shoulder Proprioception: A Review

The purpose of this review is to provide a comprehensive resource for shoulder proprioception assessment and its integration into clinical decision making as well as targeted rehabilitation protocols. Data for this review were acquired from peer-reviewed articles from computerized online databases, namely PubMed and Medline, published between 1906 and 2021. The development of digital/smart phone goniometers can improve shoulder joint range of motion (ROM) measurements and demonstrate comparable measurement accuracy to the universal standard goniometer. The inclinometer offers a portable and cost-effective method for measuring shoulder joint angles and arcs of motion in the vertical plane. Two types of dynamometers, the computerized isokinetic machine and the handheld hydraulic dynamometer, are reliable tools for objective shoulder rotator cuff strength assessment. Motion analysis systems are highly advanced modalities that create three-dimensional models of motion arcs using a series of cameras and reflective beads, offering unparalleled precision in shoulder proprioception measurement; however, they require time-consuming calibration and skilled operators. Advancements in wearable devices and compact mobile technology such as iPhone applications may make three-dimensional motion analysis more affordable and practical for outpatient settings in the future. The complex interplay between proprioception and shoulder dysfunction is not fully understood; however, shoulder proprioception can likely both contribute to and be caused by shoulder pathology. In patients with rotator cuff tears, glenohumeral osteoarthritis, and shoulder instability, clinicians can track proprioception to understand a patient's disease progression or response to treatment. Finally, rehabilitation programs targeting shoulder proprioception have shown promising initial results in restoring function and returning athletes to play.

Arthroscopic Shoulder Stabilization in High School Football Players

Background

Destabilizing shoulder injuries are common in high school American football players; however, the rate of recurrent glenohumeral instability and return to play after arthroscopic labral stabilization surgery remains unknown.

Purpose/Hypothesis

The purpose of this study was to determine the rate of recurrent instability on return to competitive high school football after arthroscopic shoulder labral stabilization and capsulorrhaphy procedures. It was hypothesized that the instability rate would be greater in players with more years of eligibility remaining (YER) to play at the high school level.

Study Design

Case series; Level of evidence, 4.

Methods

Consecutive male high school football players with at least 1 YER who sustained at least 1 anterior traumatic inseason shoulder instability episode and underwent arthroscopic stabilization between 2012 and 2017 were identified. Patients and/or families were contacted by phone to discuss (1) recurrent instability episodes and (2) return to competitive sport and/or recreational athletic activity. Statistical analysis was conducted using chi-square tests to compare recurrent shoulder instability with return to play and YER.

Results

A total of 45 football players aged 14 to 17 years were included, with a mean follow-up of 4.1 years. Most patients (60%) chose not to return to competitive football, due mainly to fear of recurrent injury. Overall, the recurrent instability rate was 15.6% (7/45). The instability rate in players who returned to football was 16.7%, with 66.7% requiring revision surgery. The instability rate in patients who did not return to football was 14.8%, with no revision procedures required. In players who returned to football, the instability rate in YER group 4 was significantly higher than that in YER groups 1 to 3 (42% vs 10.5%, respectively, P = .03), with each year of play conferring an additional 10% risk of reinjury. There was a significant difference in the type of recurrent instability in players who returned to any sport versus those who did not (P = .029).

Conclusion

High school football players who returned to competitive play after arthroscopic shoulder stabilization surgery experienced a higher rate of recurrent instability that was dependent on their YER. Over half of the players chose not to return to football, with fear of reinjury being the most common reason.

Sex-Related Differences in Shoulder Complex Joint Dynamics Variability During Pediatric Manual Wheelchair Propulsion

More than 80% of adult manual wheelchair users with spinal cord injuries will experience shoulder pain. Females and those with decreased shoulder dynamics variability are more likely to experience pain in adulthood. Sex-related differences in shoulder dynamics variability during pediatric manual wheelchair propulsion may influence the lifetime risk of pain. We evaluated the influence of sex on 3-dimensional shoulder complex joint dynamics variability in 25 (12 females and 13 males) pediatric manual wheelchair users with spinal cord injury. Within-subject variability was quantified using the coefficient of variation. Permutation tests evaluated sex-related differences in variability using an adjusted critical alpha of P = .001. No sex-related differences in sternoclavicular or acromioclavicular joint kinematics or glenohumeral joint dynamics variability were observed (all P ≥ .042). Variability in motion, forces, and moments are considered important components of healthy joint function, as reduced variability may increase the likelihood of repetitive strain injury and pain. While further work is needed to generalize our results to other manual wheelchair user populations across the life span, our findings suggest that sex does not influence joint dynamics variability in pediatric manual wheelchair users with spinal cord injury.

Minimal but potentially clinically relevant anteroinferior position of the humeral head following traumatic anterior shoulder dislocations: A 3D-CT analysis

In unstable shoulders, excessive anteroinferior position of the humeral head relative to the glenoid can lead to a dislocation. Measuring humeral head position could therefore be valuable in quantifying shoulder laxity. The aim of this study was to measure (1) position of the humeral head relative to the glenoid and (2) joint space thickness during passive motion in unstable shoulders caused by traumatic anterior dislocations and in contralateral uninjured shoulders. A prospective cross-sectional CT-study was performed in patients with unilateral anterior shoulder instability. Patients underwent CT scanning of both injured and uninjured side in supine position (0° abduction and 0° external rotation) and in 60°, 90°, and 120° of abduction with 90° of external rotation without an external load. Subsequently, 3D virtual models were created of the humerus and the scapula to create a glenoid coordinate system to identify poster-anterior, inferior-superior, and lateral-medial position of the humeral head relative to the glenoid. Joint space thickness was defined as the average distance between the subchondral bone surfaces of the humeral head and glenoid. Fifteen consecutive patients were included. In supine position, the humeral head was positioned more anteriorly (p = 0.004), inferiorly (p = 0.019), and laterally (p = 0.021) in the injured compared to the uninjured shoulder. No differences were observed in any of the other positions. A joint-space thickness map, showing the bone-to-bone distances, identified the Hill-Sachs lesion footprint on the glenoid surface in external rotation and abduction, but no differences on average joint space thickness were observed in any position.

Variability in quantifying the Hill-Sachs lesion: A scoping review

Background

Currently, is there no consensus on a widely accepted measurement technique for calculating the Hill-Sachs lesion (HSL). The purpose of this review is to provide an overview of the techniques and imaging modalities to assess the HSL pre-operatively.

Methods

Four online databases (PubMed, Embase, MEDLINE, and COCHRANE) were searched for literature on the various modalities and measurement techniques used for quantifying HSLs, from data inception to 20 November 2021. The Methodological Index for Non-Randomized Studies tool was used to assess study quality.

Results

Forty-five studies encompassing 3413 patients were included in this review. MRA and MRI showed the highest sensitivity, specificity, and accuracy values. Intrarater and interrater agreement was shown to be the highest amongst MRA. The most common reference tests for measuring the HSL were arthroscopy, radiography, arthro-CT, and surgical techniques.

Conclusion

MRA and MRI are reliable imaging modalities with good test diagnostic properties for assessment of HSLs. There is a wide variety of measurement techniques and imaging modalities for HSL assessment, however a lack of comparative studies exists. Thus, it is not possible to comment on the superiority of one technique over another. Future studies comparing imaging modalities and measurement techniques are needed that incorporate a cost-benefit analysis.

Development of a more biofidelic musculoskeletal model with humeral head translation and glenohumeral ligaments

Computational musculoskeletal modeling is useful for understanding upper extremity biomechanics, especially when in vivo tests are unfeasible. A musculoskeletal model of the upper limb with increased biofidelity was developed by including humeral head translation (HHT) and ligaments. The model was validated and ligament contribution and effect of shoulder (thoracohumeral) elevation on HHT was evaluated. Humerus translated superiorly with increased elevation, with translations closely matching (avg. difference 2.83 mm) previous in vitro studies. HHT and ligament inclusion in the model will improve biomechanical predictions of upper extremity movements and study of conditions, like subacromial impingement, rotator cuff tear, or shoulder instability.

Glenoid-Based Reference System to Differentiate Shoulder Pathologies on Plain Radiographs

BACKGROUND

Shoulder radiographs are utilized for evaluation and the planning of treatment of various pathologies. Making a diagnosis of these pathologies on plain radiographs occurs by recognizing the relationship of the humeral head on the registry of the glenoid. Quantification of these changes in registry does not currently exist. We hypothesize that a geometric relationship of the humeral head and the glenoid exists that is defined on an anteroposterior Grashey view radiograph by the relationship of the best-fit circle of the humeral head relative to the best-fit circle of the glenoid such that relative measurements will define the normal shoulder and the pathologic shoulder.

METHODS

One hundred fifty-six shoulders were included: 53 normal shoulders, 51 with primary glenohumeral osteoarthritis (GHOA), and 52 with cuff-tear arthropathy (CTA). Humeral head best-fit circle was utilized to define the Circle of the Humeral Head (cHH). A glenoid best-fit circle (cG) was defined by the following rules: (1) best-fit of the glenoid articular surface, (2) defined by the acromion such that it either (a) reaches maximal interaction with the inferior surface of the acromion, or (b) the perimeter of the circle is at the lateral-most point of the acromion. The relationship between cHH and cG is defined by measurement of cHH in horizontal and vertical planes relative to the glenoid circle reference. The Horizontal Displacement Angle (HDA) measures the horizontal position of cHH relative to cG, representing degree of medialization towards the glenoid. The Vertical Displacement Angle (VDA) measures the vertical position of cHH relative to cG, representing degree of superiorization towards the acromion. Angles were compared by diagnosis and sex.

RESULTS

The average HDA was 61.0 (60.3-61.7, 95% CI) degrees in normal shoulders, 79.9 (76.9-82.9, 95% CI) degrees in GHOA, and 63.4 (61.7-65.1, 95% CI) degree in CTA (p < 0.001). The average VDA was 43.1 (42.2-44.0, 95% CI) degrees in normal shoulders, 40.9 (39.9-42.0, 95% CI) degrees in GHOA, and 59.7 (57.6-61.7, 95% CI) degrees in CTA (p < 0.001). Interobserver reliability was 0.991 (0.94-1.0, 95% CI) and intraobserver reliability was 0.998 (0.99-1.0, 95% CI). The geometric relationship of cHH to the Glenoid Circle reference was plotted for each group.

CONCLUSION

A geometric relationship exists of the humeral head in reference to the glenoid circle. Together, the Horizontal Displacement Angle and the Vertical Displacement Angle distinguish between a normal shoulder, GHOA, and CTA. This suggests that this novel methodology may provide a preoperative planning tool that is easily accessible.

Inconsistency in Shoulder Arthrometers for Measuring Glenohumeral Joint Laxity: A Systematic Review

There is no consensus on how to measure shoulder joint laxity and results reported in the literature are not well systematized for the available shoulder arthrometer devices. This systematic review aims to summarize the results of currently available shoulder arthrometers for measuring glenohumeral laxity in individuals with healthy or injured shoulders. Searches were conducted on the PubMed, EMBASE, and Web of Science databases to identify studies that measure glenohumeral laxity with arthrometer-assisted assessment. The mean and standard deviations of the laxity measurement from each study were compared based on the type of population and arthrometer used. Data were organized according to the testing characteristics. A total of 23 studies were included and comprised 1162 shoulders. Populations were divided into 401 healthy individuals, 278 athletes with asymptomatic shoulder, and 134 individuals with symptomatic shoulder. Sensors were the most used method for measuring glenohumeral laxity and stiffness. Most arthrometers applied an external force to the humeral head or superior humerus by a manual-assisted mechanism. Glenohumeral laxity and stiffness were mostly assessed in the sagittal plane. There is substantial heterogeneity in glenohumeral laxity values that is mostly related to the arthrometer used and the testing conditions. This variability can lead to inconsistent results and influence the diagnosis and treatment decision-making.

Bodyblade™ Training in Athletes with Traumatic Anterior Shoulder Instability

Background

The Bodyblade™ has the potential of enhancing conservative management of Traumatic Anterior Shoulder Instability (TASI).

Purpose

The purpose of this study was to compare three different protocols: Traditional, Bodyblade™, and Mixed (Traditional & Bodyblade™) for shoulder rehabilitation on athletes with TASI.

Study Design

Randomized-controlled longitudinal training study.

Methods

Thirty-seven athletes (age = 19.9±2.0 years) were allocated into Traditional, Bodyblade™, and Mixed (Traditional/Bodyblade™) training groups (3×week for 8-weeks). The traditional group used resistance bands (10-15 repetitions). The Bodyblade™ group transitioned from classic to the pro model (30-60-s repetitions). The mixed group converted from the traditional (weeks 1-4) to the Bodyblade™ (weeks 5-8) protocol. Western Ontario Shoulder Index (WOSI) and the UQYBT were evaluated at baseline, mid-test, post-test, and at a three-month follow-up. A repeated-measures ANOVA design evaluated within and between-group differences.

Results

All three groups significantly (p=0.001, eta2: 0.496) exceeded WOSI baseline scores (at all timepoints) with training (Traditional: 45.6%, 59.4%, and 59.7%, Bodyblade™: 26.6%, 56.5%, and 58.4%, Mixed: 35.9%, 43.3% and 50.4% respectively). Additionally, there was a significant (p=0.001, eta2: 0.607) effect for time with mid-test, post-test and follow-up exceeding baseline scores by 35.2%, 53.2% and 43.7%, respectively. The Traditional and Bodyblade™ groups (p=0.049, eta2: 0.130) exceeded the Mixed group UQYBT at post-test (8.4%) and at three-month follow-up (19.6%). A main effect (p=0.03, eta2: 0.241) for time indicated that WOSI mid-test, post-test and follow-up exceeded the baseline scores by 4.3%, 6.3% and 5.3%.

Conclusions

All three training groups improved their scores on the WOSI. The Traditional and Bodyblade™ groups demonstrated significant improvements in UQYBT inferolateral reach scores at post-test and three-month follow-up compared to the Mixed group. These findings could lend further credibility to the role of the Bodyblade as an early to intermediate rehabilitation tool.

LEVEL OF EVIDENCE

3.

American Shoulder and Elbow Surgeons SLAP/Biceps Anchor Study Group Evidence Review: Pathoanatomy and Diagnosis in Clinically Significant Labral Injuries

Glenoid superior biceps-labral pathology diagnosis, treatment and outcomes is an evolving area of shoulder surgery. Historically, described as SLAP tears (Superior Labrum Anterior Posterior) these lesions were identified as a source of pain in throwing athletes. Diagnosis and treatments applied to these SLAP lesions resulted in less than optimal outcomes in some patients and a prevailing sense of confusion. The purpose of this paper is to perform a re-appraisal of the anatomy, examination, imaging and diagnosis by the ASES/SLAP Biceps Study Group. We sought to capture emerging concepts and suggest a more unified approach to evaluation and identify specific needs for future research.

Ninety-day complication rate based on 532 Latarjet procedures in Dutch hospitals with different operation volumes

BACKGROUND

In this study, we aimed to provide insight into the 90-day complication rates following the Latarjet procedure. Data from 2015 were collected from multiple hospitals in the Netherlands, with different volumes of Latarjet procedures. Our second aim was to examine which patient and surgical factors were associated with complications.

METHODS

We conducted a retrospective chart review of 13 hospitals between 2015 and 2022. Data regarding complications within 90 days of Latarjet procedures were extracted. The effect of sex, age, body mass index (BMI), smoking, previous shoulder operations, fixation material, hospital volume, screw size, and operation time on the complication rate was assessed by multivariable logistic regression analysis.

RESULTS

Of the 532 included patients, 58 (10.9%) had complications. The most common complications were material failure (n = 19, 3.6%) and nerve injury (n = 13, 2.4%). The risk of complications was lower for male patients than for female patients (odds ratio, 0.40; 95% confidence interval, 0.21-0.77; P = .006). Age, BMI, smoking, previous shoulder operations, type of fixation material, hospital volume, screw size, and operation time were not associated with complications.

CONCLUSION

The 90-day complication rate after the Latarjet procedure was 10.9% and was higher in female patients than in male patients. Age, BMI, smoking, previous shoulder operations, type of fixation material, hospital volume, screw size, and operation time did not affect complication rates. We advise setting up a national registry to prevent under-reporting of complications.

Open Inferior glenohumeral joint dislocation with complete range of motion recovery: Case Report and literature review

Luxatio erecta is an inferior glenohumeral dislocation. It is an uncommon pathology with a prevalence of 0.5% of all shoulder dislocations. An open luxatio erecta presentation is rarer. After an extensive literature search, we only could find three complete case reports. From these cases, 2 out of 3 developed complications such as infections and severely limited range of motion, especially in flexion and abduction. We report the case of a 39-year-old man with an open inferior glenohumeral joint dislocation with complete rotator cuff tear and fracture of the greater tuberosity secondary to a motor vehicle accident. He was treated with open reduction, glenohumeral capsulorrhaphy, and transosseous rotator cuff repair with good clinical outcome. In conclusion, an open inferior shoulder dislocation is rare, less than 0.1% of all dislocations, with a high incidence of nerve injury. We suggest prompt surgical treatment with immediate administration of antibiotic therapy, wound debridement, irrigation, open reduction, and repair of the rotator cuff as an adequate protocol and focused rehabilitation with early mobilization of the glenohumeral joint.

Literature Review of Subscapularis Tear, Associated injuries, and the Available Treatment Options

The population of Hawai'i is uniquely connected to the Ocean and to open water sports. Shoulder injuries, particularly those to the rotator cuff, are among the most common injuries sustained to athletes participating in ocean sports such as surfing, paddling, and swimming. In addition, rotator cuff injuries increase in prevalence with advanced age. As a consequence, the number of patients in Hawai'i who present with an injury to the subscapularis tendon will continue to rise. However, limited research has been done to delineate the involvement of subscapularis injuries in this population. This article covers the anatomy and function of the subscapularis, the epidemiology and classification of tears in this tendon, and the management of tears. The anatomy section will cover innervation, vascular supply and insertional anatomy of the subscapularis tendon. The function of the subscapularis in regards to both stability and motion of the glenohumeral joint will be examined. The focus of the article will then shift to the tears of the subscapularis, starting with an in depth look at the epidemiology and classification of these tears. The article will then cover the different imaging modalities and their utility in regards to subscapularis tears. Finally, the operative and non-operative management and indications for each modality will be discussed in detail.

Articular Cartilage Defects of the Glenohumeral Joint: A Systematic Review of Treatment Options and Outcomes

OBJECTIVE

To report radiographic and magnetic resonance imaging findings, patient-reported outcomes, and complications and/or reoperations following nonarthroplasty surgical intervention for focal glenohumeral cartilage defects.

DESIGN

A literature search was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Patients were included if they possessed a chondral defect of the humeral head, glenoid, or both, which had been treated with a joint preserving nonarthroplasty procedure. Risk of bias assessment was performed using the Methodological Index for Non-Randomized Studies scoring system. Study demographics, surgical technique, imaging findings, patient-reported outcomes, complications, failures, and reoperations were collected.

RESULTS

Fourteen studies with 98 patients (100 shoulders) met the inclusion criteria. Patient ages ranged from 7 to 74 years. The nonarthroplasty surgical techniques utilized included microfracture (67 shoulders), osteochondral transplantation (28 shoulders), chondrocyte transplantation (4 shoulders), and internal fixation (1 shoulder). The rates of radiographic union and progression of osteoarthritis ranged between 90% to 100% and 57% to 100%, respectively. Visual analog scores ranged from 0 to 1.9 at final follow-up. Mean postoperative ASES (American Shoulder and Elbow Surgeons) shoulder scores ranged from 75.8-100. Mean postoperative CSS (Constant Shoulder Score) scores ranged from 83.3-94. Mean postoperative SSV (Subjective Shoulder Value) ranged from 70% to 99%. Failure and reoperation rates ranged between 0% to 35% and 0% to 30%, respectively, with the most common reoperation being conversion to prosthetic arthroplasty.

CONCLUSIONS

In this systematic review, nonarthroplasty surgical techniques demonstrated acceptable rates of radiographic healing, improved patient reported outcomes, minimal complications, and low rates of failure or reoperation. Joint preserving techniques are likely viable options to prolong function of the native shoulder and provide short- to midterm pain relief in young and highly active patients.

LEVEL OF EVIDENCE

Level IV.

Rehabilitation of the Shoulder Subluxation Based on Ultrasonographic Findings among Post Stroke Subjects: A Case Series

Background

Up to three-fourths of the poststroke subjects may experience shoulder subluxation as a challenging complication. The existing rehabilitation management is based on the clinical assessment. Ultrasonographic evaluation demonstrates findings, which cannot be discerned by the usual methods.

Objectives

To determine the effect of rehabilitation protocol based on the sonographic findings of the subluxed shoulder on reduction of the subluxation and upper limb motor recovery.

Materials and Methods

Setting: Department of Occupational therapy of a Rehabilitation Institute. Study Design: A prospective case series. Subjects: 08 Poststroke hemiparetic patients with subluxed shoulder. Outcome measure: Ultrasongraphy of the bilateral shoulder joints, Fingerbreadth palpation method, Visual analog scale (VAS), Fugl-Meyer assessment of upper extremity (FMA-UE). Intervention: As per the findings of the sonography, management in the form of shoulder support, physical agent modalities, motor therapy, and precautions and positioning was provided to the subjects for the period of 3 months.

Results

Post intervention, the participants showed 1 to 6 mm of reduction of acromion-greater tuberosity distance in addition to the reduction of atrophy and soft tissue or joint effusion. Furthermore, the participants also exhibited FMA-UE change ranging from 5 to 21.

Conclusion

The ultrasonographic evaluation explores objective measurement and involvement of specific soft tissues among poststroke subject with the shoulder subluxation. The management based on the sonographic findings is an objective and valid approach.

Thumb to spinous process is a false metric for glenohumeral internal rotation

Background

The measurement of internal rotation by noting the maximal vertebral level reached by the patient's thumb behind their back is an established physical examination technique, as outlined in the American Shoulder and Elbow Surgeons Shoulder Assessment Form.7 The purpose of the present study is to correlate real-time glenohumeral internal rotation with thumb to spinous process movement to determine the accuracy of the technique.

Methods

Healthy volunteers with no previous history of shoulder injury or symptoms were recruited from the local medical school population. Ultrasound probe was placed over the anterolateral shoulder, and relevant anatomy was identified. Internal rotation was evaluated by measuring displacement of the peak of the medial aspect of the bicipital groove relative to the anterior glenoid rim with the arm held in defined positions of progressively increasing internal rotation. The difference in displacement between arm positions was calculated and recorded.

Results

A total of 20 participants (11 women/9 men, aged 22-42 years) were recruited for measurement. A mixed-model repeated-measures analysis of variance was used. The most significant differences in displacement, and therefore internal rotation, were observed between the neutral and anterior superior iliac spine (0.21 ± 0.39 mm, P= .0269) and between the anterior superior iliac spine and peak iliac crest (0.26 ± 0.44 mm, P= .0163). After the peak iliac crest, there was no further statistically significant change in rotation.

Conclusion

The present study suggests that most glenohumeral internal rotation occurs before reaching the arm behind the back. Although not directly studied, this supports the notion that the maximal vertebral level reached involves an interplay of various joint motions. While the thumb to spinous process maneuver remains a functional evaluation, our results suggest a different examination technique be used to more accurately test glenohumeral internal rotation.

Effectiveness of early versus delayed rehabilitation following total shoulder replacement: A systematic review

Objective

To investigate the effectiveness of early versus delayed rehabilitation following total shoulder replacement.

Design

Intervention systematic review with narrative synthesis.

Literature search

MEDLINE, EMBASE, CINAHL, Scopus and the Cochrane Library were searched from inception to the 29^th of July 2021.

Study selection criteria

Randomised controlled trials comparing early versus delayed rehabilitation following primary anatomic, primary reverse, or revision total shoulder replacement.

Data synthesis

A revised Cochrane risk of bias assessment tool for randomised controlled trials was used, as well as the Grading of Recommendations Assessment, Development and Evaluation approach to evaluate the quality of evidence. A narrative synthesis was undertaken.

Results

Three eligible randomised controlled trials (n = 230) were included. There was very low-quality evidence of no statistically significant difference (P > 0.05) in pain, shoulder function, health-related quality of life or lesser tuberosity osteotomy healing at 12 months between early or delayed rehabilitation. There was conflicting and very low-quality evidence of a difference between the effect of early and delayed rehabilitation on shoulder range of movement. There was limited, very low-quality evidence of statistically significantly improved pain and function (P < 0.05) in the early post-operative period with early rehabilitation following anatomic total shoulder replacement.

Conclusions

No differences were seen in patient-reported or clinician-reported outcomes at 12 months post-surgery between early and delayed rehabilitation following total shoulder replacement. There is very low-quality evidence that early rehabilitation may improve shoulder pain and function in the early post-operative phase following anatomic total shoulder replacement.

The potential impact from glenohumeral internal rotation deficit to the knee kinematics in baseball pitchers: A case-control study

A recent study suggested that baseball pitchers with glenohumeral internal rotation deficit (GIRD) may tend to use trunk rotation as compensation to adjust ball placement, which may lead to subsequent counter movement at the knee of the leading leg.This study aims to investigate the kinematic characteristics of the counter movements between the femur and the tibia (knee torsion), from the landing of the leading leg until the follow-through phase, during throwing between pitchers with and without GIRD at the dominant arm.This is a case-control study. Twenty-one senior high school baseball pitchers were recruited in this study. The glenohumeral internal and external rotation, hip internal and external rotation of all participants were measured. Eight pitchers without GIRD and 13 pitchers with GIRD were enrolled into the control group and experiment group, respectively. The maximal angular movement between the femur and the tibia (knee torsion) of the leading leg was measured, using The Zebris 3D (Zebris Medizintechnik GmbH, Isny, Germany) motion analysis system, in the interval from the landing until the follow-through phase during pitching a fastball to the bottom-outside corner with their dominant arm.The results showed that the maximal knee torsion of the leading leg in the experimental group (13.67 ± 0.9 degrees) was significantly greater than the control group (4.25 ± 1.369 degrees) (P < .05).Pitchers with GIRD had greater counter movement in the knee joint than pitchers without GIRD.

The Bankart repair: past, present, and future

Arthur Sidney Blundell Bankart was a London-based orthopedic surgeon who discovered the essential lesion in recurrent anterior shoulder instability in 1923. He pioneered a technique, the Bankart repair, to re-establish stability to the glenohumeral joint, without sacrificing native joint motion. In this article, the original Bankart repair is compared to the modern arthroscopic Bankart repair, accompanied by a surgical video of Blundell Bankart performing the Bankart repair in 1951, shortly before his death. Bankart's original description included an open repair with a coracoid osteotomy and subscapularis tenotomy and repair. The history of the technique, its utility in present day, and the future of the Bankart repair are discussed.

Incidence of and Risk Factors for Glenohumeral Osteoarthritis After Anterior Shoulder Instability: A US Population-Based Study With Average 15-Year Follow-up

Background:

The rate of osteoarthritis (OA) in patients with a history of previous anterior shoulder instability (ASI) varies within the literature, with the majority of studies investigating rates after surgical stabilization. ASI appears to lead to increased rates of OA, although risk factors for developing OA in cohorts treated nonoperatively and operatively are not well-defined.

Purpose:

To determine the incidence of clinically symptomatic OA and identify potential risk factors for the development of OA in patients younger than 40 years with a known history of ASI.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

An established, geographically based database was used to identify patients in the United States who were younger than 40 years and were diagnosed with ASI between 1994 and 2014. Patient information, including demographic, imaging, and surgical details, was collected. Comparative analysis was performed between groups with and without OA at final follow-up as well as between patients who underwent surgical and nonsurgical management.

Results:

The study population consisted of 154 patients with a mean follow-up of 15.2 years (range, 5.1-29.8 years). The mean age at initial instability event was 20.9 years (95% CI, 19.9-22.0 years). Overall, 22.7% of patients developed clinically symptomatic glenohumeral OA. Multivariate analysis revealed that current or former smokers (odds ratio [OR], 4.3; 95% CI, 1.1-16.5; P = .030), hyperlaxity (OR, 10.1; 95% CI, 1.4-72.4; P = .020), laborer occupation (OR, 6.1; 95% CI, 1.02-36.1; P = .043), body mass index (BMI) (OR, 1.2; 95% CI, 1.03-1.3; P = .012), and age at initial instability (OR, 1.1; 95% CI, 1.02-1.2; P = .013) as potential independent risk factors when accounting for other demographic and clinical variables.

Conclusion:

In a US geographic population of patients younger than 40 years with ASI, approximately one-fourth of patients developed symptomatic OA at a mean follow-up of 15 years from their first instability event. When accounting for differences in patient demographic and clinical data, we noted a potentially increased risk for the development of OA in patients who are current or former smokers, have hyperlaxity, are laborers, have higher BMI, and have increased age at initial instability event. Smoking status, occupation, and BMI are modifiable factors that could potentially decrease risk for the development of symptomatic OA in these patients.

Softball pitching mechanics and shoulder injuries: a narrative review

Softball is the third most popular women's collegiate sport in the United States, with 19,680 total athletes as of the 2015-2016 season. Despite its popularity and growth in recent years, research focusing on the biomechanics of the windmill pitch and its associated shoulder injuries is relatively scarce. The incidence of shoulder injury is highest during the preseason and the beginning of the regular season. The windmill pitch can be divided into distinct phases, with the shoulder experiencing the greatest force during the delivery phase. Significant demands placed on the shoulder during the windmill pitch put pitchers at a higher risk of developing shoulder injuries than position players. Maximum shoulder compression/distraction forces during the windmill pitch have been shown to be comparable to those experienced during the baseball overhand throw, dispelling the myth that the windmill pitch is not taxing on the shoulder. Injuries associated with the high compression/distraction forces include lesions to the rotator cuff, glenoid labrum, and biceps brachii. Pitcher-specific training, cross-training, and whole-body conditioning should be incorporated into current training regimens to decrease the risk of shoulder injuries.

Image guidance used for large joint and bursa injections; a survey study

Objectives: To determine the current rates of use of available image guidance modalities for large joint and bursal injections, in addition to their relationships to physician demographics.Methods: An electronic survey was sent to 3,400 members of the American Medical Society for Sports Medicine (AMSSM), examining types of guidance used for each large joint and bursal injection.Results: A total of 674 sports medicine physicians responded to the survey. Intra-articular hip and glenohumeral joint injections were more commonly performed with ultrasound guidance, while palpation-guidance was more common with all other injections. Physicians who specialized in Physical Medicine & Rehabilitation (PM&R) were more likely to use ultrasound for trochanteric bursa (p = 0.007, OR = 4.16 [1.46-11.8]), while internal medicine-, pediatrics-, and family medicine-trained physicians were more likely to use palpation guidance for at least one joint (p < 0.05). Physicians with fewer years of experience were more likely to use ultrasound for glenohumeral joint injections (p ≤ 0.002 for all age groups with less than 20 years of experience, ORs ranging from 6.3 to 9.2).Conclusion: Palpation-guidance is the most common technique used for large joint and bursal injections, other than for glenohumeral and hip joint injections. PM&R-trained physicians and those with less experience tend to use ultrasound more frequently.

Recurrent Shoulder Posteroinferior Subluxation Status Post Reverse Remplissage

Posterior shoulder dislocation is an uncommon injury that typically follows intense contraction of the external rotator muscles, such as from seizure activity, high-velocity trauma, or intense electrical shock. The diagnosis is often missed or delayed, leading to complications such as functional deficits or osteonecrosis of the humeral head. Closed reduction can be utilized following an initial occurrence, however, repeated insult to the glenohumeral joint may lead to posterior instability. A reverse Hill-Sachs lesion, a vertical impacted fracture of the anteromedial aspect of the humeral head, can occur. Surgical treatment options for posterior instability include the modified McLaughlin procedure also known as the reverse remplissage procedure. Unfortunately, the success rates of this procedure are controversial.

POSTERIOR SHOULDER TIGHTNESS AND SUBACROMIAL IMPINGEMENT CHARACTERISTICS IN BASEBALL PITCHERS: A BLINDED, MATCHED CONTROL STUDY

BACKGROUND

Baseball pitchers frequently develop varying levels of posterior shoulder tightness (PST) and often present with characteristics associated with subacromial impingement.

PURPOSE

To determine if a group of baseball pitchers with excessive PST (bilateral internal rotation ROM difference >18 ° and bilateral total arc of motion difference >5 °) have differences in subacromial joint space, forward scapular posture, or glenohumeral elevation range of motion (ROM) when compared to a control group.

STUDY DESIGN

Descriptive, cross-sectional study.

METHODS

Thirty-five asymptomatic professional baseball pitchers with excessive PST were matched with 35 pitchers with acceptable levels of PST. The investigators measured subacromial space using diagnostic ultrasound, glenohumeral elevation ROM using a digital goniometer, and scapular posture using a double square, and were blinded to the group of each participant. Separate t-tests were used to determine significant differences between groups (p < 0.05).

RESULTS

The excessive PST group presented with significantly less subacromial space (p = .0007) and glenohumeral elevation ROM (p = .03) compared to the acceptable level PST group. The excessive PST group also had significantly more forward scapular posture than the control group (p = .03).

CONCLUSION

The baseball pitchers with excessive PST had less subacromial space and glenohumeral elevation ROM, as well as more forward scapular posture in their throwing arms compared to pitchers with acceptable levels of PST.

LEVEL OF EVIDENCE

3.

Shoulder Dislocations in the Emergency Department: A Comprehensive Review of Reduction Techniques

BACKGROUND

Shoulder dislocations are a common presentation to the emergency department and one of the most frequent types of joint dislocations. Studies have found that delays from presentation to first reduction attempt and failed attempt at initial reduction are associated with lower rates of overall reduction success.

DISCUSSION

This article reviews 26 total reduction techniques, as well as a variety of modifications to these techniques. Each technique has distinct advantages and limitations associated with its use. While there are limited data comparing specific techniques, the individual success rates of most maneuvers range from 60-100%.

CONCLUSION

It is essential for emergency physicians to be familiar with multiple different reduction techniques in case the initial reduction attempt is unsuccessful or patient-specific characteristics limit the ability to perform certain techniques. This article reviews several reduction maneuvers for shoulder dislocations, variations on these techniques, and advantages and disadvantages for each approach. It is intended to serve as a resource for those interested in expanding their knowledge of shoulder reduction techniques.

Acute Effects of Pectoralis Minor Self-Mobilization on Shoulder Motion and Posture: A Blinded and Randomized Placebo-Controlled Study in Asymptomatic Individuals

CONTEXT

Tightness of the pectoralis minor is a common characteristic that has been associated with aberrant posture and shoulder pathology. Determining conservative treatment techniques for maintaining and lengthening this muscle is critical. Although some gross stretching techniques have been proven effective, there are currently no empirical data regarding the effectiveness of self-myofascial release for treating tightness of this muscle.

OBJECTIVE

To determine the acute effectiveness of a self-myofascial release with movement technique of the pectoralis minor for improving shoulder motion and posture among asymptomatic individuals.

DESIGN

Randomized controlled trial.

SETTING

Orthopedic rehabilitation clinic.

PARTICIPANTS

A total of 21 physically active, college-aged individuals without shoulder pain volunteered to participate in this study.

MAIN OUTCOME MEASURES

Glenohumeral internal rotation, external rotation, and flexion range of motion (ROM), pectoralis minor length, and forward scapular posture were measured in all participants. The intervention group received one application of a self-soft-tissue mobilization of the pectoralis minor with movement. The placebo group completed the same motions as the intervention group, but with minimal pressure applied to the xiphoid process. Separate analyses of covariance were used to determine differences between groups (P < .05).

RESULTS

Separate analyses of covariance showed that the self-mobilization group had significantly more flexion ROM, pectoralis minor length, and less forward scapular posture posttest than the placebo group. However, the difference in forward scapular posture may not be clinically significant. No differences were found between groups for external or internal rotation ROM.

CONCLUSIONS

The results of this study indicate that an acute self-myofascial release with movement is effective for improving glenohumeral flexion ROM and pectoralis minor length, and may assist with forward scapular posture. Clinicians should consider this self-mobilization in the prevention and rehabilitation of pathologies associated with shortness of the pectoralis minor.

Imaging Quantification of Glenoid Bone Loss in Patients With Glenohumeral Instability: A Systematic Review

To listen to the podcast associated with this article, please select one of the following: iTunes, Google Play, or direct download. OBJECTIVE. The purpose of this study is to determine the most accurate imaging techniques to measure glenoid bone loss in anterior glenohumeral instability through a systematic review of existing literature. MATERIALS AND METHODS. We performed a comprehensive literature search of five databases for original research measuring glenoid bone loss at radiography, CT, or MRI, using prospective or retrospective cohort, case-control, or cadaveric study designs up to January 2018. The Quality Assessment of Diagnostic Accuracy Studies-2 tool aided qualitative assessment of the methods. Data extraction included results, index test interobserver agreement, and accuracy analysis. RESULTS. Twenty-seven studies (evaluating 1425 shoulders) met inclusion criteria after full-text review by two independent readers. Glenoid bone loss was assessed, comparing several index tests to nonimaging (n = 18 studies) and imaging (n = 11) reference standards. Compared with arthroscopic or cadaveric measurements, 2D CT was accurate in six of seven studies (86%), 3D CT was accurate in eight of 10 studies (80%), 2D MRI was accurate in five of seven studies (71%), 3D MRI was accurate in four of four studies (100%), and radiographs were accurate in zero of four studies (0%). Best-fit circle methods (glenoid width or Pico surface area) were the most common and both were accurate (86-90% and 75-100%, respectively) using CT and MRI. Studies had good external validity (78%). Most risk for bias arose from patient selection and reference standards. Only two studies reported sensitivity and specificity, both comparing CT to arthroscopy using different bone loss thresholds (20% and 25%). CONCLUSION. CT and MRI (2D or 3D) accurately measure glenoid bone loss in anterior shoulder instability, but radiographs do not. Best-fit circle measurement techniques are reliable and accurate. Current literature about glenoid bone loss is heterogeneous, and future studies should focus on diagnosis of clinically relevant glenoid bone loss.

Small anteroposterior inclination of the acromion is a predictor for posterior glenohumeral erosion (B2 or C)

BACKGROUND

Anatomic factors associated with static posterior translation of the humeral head with or without glenohumeral osteoarthritis are unknown. We tested the hypothesis that there is an association between glenoid wear, glenoid version, and/or anteroposterior acromial tilt.

METHODS

Ninety-nine patients with glenohumeral joint degeneration involving advanced glenoid cartilage wear and/or rotator cuff disease scheduled for anatomic or reverse total shoulder replacement underwent standardized conventional radiographic and computed tomographic shoulder imaging. Measurements included glenoid version, humeral torsion, posterior acromial slope, and critical shoulder angle. The glenoid shape was classified according to Walch et al, and the integrity of the rotator cuff was assessed.

RESULTS

Patients with glenoid type B2 or C had a median of 4° more glenoid retroversion (P = .022), a 5° less steep acromion (posterior acromial slope, 61° vs 56°; P = .004), and a higher combined score (glenoid version minus slope; odds ratio, 0.93 [95% confidence interval, 0.89-0.97]; P < .001; cutoff, -27°) than those with type A or B1. When the rotator cuff was torn, osteoarthritic changes were milder than when the cuff was intact (eg, P < .001 for supraspinatus).

CONCLUSION

The study's hypothesis that the bony anatomy of the scapula and in particular the acromion is correlated with the type of glenoid wear was confirmed. Both a more horizontal acromial orientation in the sagittal plane and increased posterior glenoid version are found in osteoarthritis of the shoulder associated with eccentric, posterior glenoid wear. Tears of the rotator cuff are significantly associated with concentric osteoarthritis of the glenoid.

A reduction in the rate of nerve injury after Latarjet: a before-after study after neuromonitoring

BACKGROUND

Neurologic dysfunction is a known complication after the open Latarjet procedure. Although the reported clinical incidence is variable, a prior neuromonitoring study demonstrated a significant incidence of nerve dysfunction during surgery, presumably from nerve stretch. We aimed to determine whether a nerve stretch-reduction protocol reduced the incidence of neurologic injury after the open Latarjet procedure.

METHODS

In a nonrandomized study, 38 patients (group 1) who underwent surgery before our neuromonitoring study were compared with 48 patients (group 2) who underwent surgery after this study. Follow-up was at least 3 months or until documented resolution of nerve dysfunction.

RESULTS

There were no significant demographic differences between the groups. In group 1, there were 7 nerve injuries, of which all but 2 recovered. In group 2, there were 3 nerve injuries, of which all but 1 recovered. The overall incidence of nerve injury was 18.4% (group 1) vs. 6.3% (group 2); however, the incidence of permanent motor dysfunction was 5.3% (group 1) vs. 2.1% (group 2). These differences were not significant, likely due to the small number of patients included.

CONCLUSIONS

We observed a reduction of nerve injury with the implementation of a nerve stretch-reduction protocol during the Latarjet procedure; however, we could not demonstrate statistical significance. This trend represents an important finding that modification of surgical technique can reduce the incidence of nerve injury with the Latarjet procedure.

Anterior Shoulder Instability: A Systematic Review of the Quality and Quantity of the Current Literature for Surgical Treatment

Background

Anterior shoulder instability is the most common sequela of shoulder dislocation and can result in repeated dislocations or subluxation of the glenohumeral joint. Anterior shoulder instability can be treated conservatively or surgically with several procedures.

Purpose

To date, arthroscopic Bankart is the most common surgical procedure for the treatment of anterior shoulder instability. No previous studies have compared all anterior shoulder surgical procedures. In this study, the authors performed a systematic review of journal articles describing all surgical procedures for anterior shoulder instability to determine the scientific evidence and level of recommendation.

Study Design

Systematic review; Level of evidence, 4.

Method

A comprehensive literature search was conducted (July 19, 2016) with 4 reputed databases: PubMed, EMBASE, the Cochrane databases, and Web of Science. The articles found in the literature search were screened by 2 reviewers on the basis of their titles, abstracts, and full text. Data were extracted from relevant studies, and potentially relevant records were selected for full-text review. Included articles were classified according to their scientific quality (level of evidence, 1-5). The studies were then combined for each surgical procedure, and a grade of recommendation was assigned for each procedure: grade A, treatment recommendation based on level 1 evidence studies; B, based on level 2 or 3 evidence studies; C, based on level 4 or 5 evidence and could represent conflicting results; or I, insufficient evidence to recommend a treatment. As such, the grade of recommendation provides a summary score for the quality and quantity of available literature to support the surgical procedures reviewed here.

Results

The systematic literature review generated 11,281 articles. After screening, 655 articles were included. Results revealed 31 surgical procedures for shoulder instability following dislocation: 10 surgical procedures were given an A or B recommendation; 11, a C recommendation; and 10, an I recommendation.

Conclusion

This review identified many surgical procedures to treat anterior shoulder instability. Ten of these surgical procedures had an abundant amount of published articles to describe their safety and efficacy. Arthroscopic Bankart and open Bankart were the most commonly reported procedures that cite satisfactory postoperative outcomes and limited complications. Publications on the other surgical procedures were less common. Surgeons should be careful when recommending surgery, and they should choose the appropriate surgical procedure based on evidence-based literature.

Pectoral girdle and forelimb musculoskeletal function in the echidna (Tachyglossus aculeatus): insights into mammalian locomotor evolution

Although evolutionary transformation of the pectoral girdle and forelimb appears to have had a profound impact on mammalian locomotor and ecological diversity, both the sequence of anatomical changes and the functional implications remain unclear. Monotremes can provide insight into an important stage of this evolutionary transformation, due to their phylogenetic position as the sister-group to therian mammals and their mosaic of plesiomorphic and derived features. Here we build a musculoskeletal computer model of the echidna pectoral girdle and forelimb to estimate joint ranges of motion (ROM) and muscle moment arms (MMA)-two fundamental descriptors of biomechanical function. We find that the echidna's skeletal morphology restricts scapulocoracoid mobility and glenohumeral flexion-extension compared with therians. Estimated shoulder ROMs and MMAs for muscles crossing the shoulder indicate that morphology of the echidna pectoral girdle and forelimb is optimized for humeral adduction and internal rotation, consistent with limited in vivo data. Further, more muscles act to produce humeral long-axis rotation in the echidna compared to therians, as a consequence of differences in muscle geometry. Our musculoskeletal model allows correlation of anatomy and function, and can guide hypotheses regarding function in extinct taxa and the morphological and locomotor transformation leading to therian mammals.

An assessment of quality of randomized controlled trials in shoulder instability surgery using a modification of the clear CLEAR-NPT score

BACKGROUND

The present study aimed to evaluate the methodological quality and determine the quality of reporting of randomized controlled trials (RCTs) that assess surgical treatment for shoulder instability.

METHODS

A Cochrane, Pubmed, EMBASE and Trip database search was performed, including the relevant literature, regarding RCTs that report on shoulder instability published between January 1994 and January 2017. Methodological quality was assessed with a modification of the Checklist to Evaluate A Report of a Nonpharmacologic Trial (CLEAR-NPT). Points were assigned based on 18 items regarding patient characteristics, randomization, care provider characteristics, surgical details and blinding, with a total score ranging from 0 points to 18 points. Missing items were verified with the corresponding authors of the studies. Quality of reporting corresponds to the total scores including the items that were additionally provided by the authors.

RESULTS

We included 22 studies. Of these, nine corresponding authors provided additional information. The average methodological quality was 16.9 points (11 studies) and the average quality of reporting was 9.5 points (22 studies). Items scoring worst included information regarding the surgeon's experience, the patients' level of activity, comorbidities, analyzing according to 'intention-to-treat' principles, and blinding of care providers, participants and assessors.

CONCLUSIONS

RCTs reporting on shoulder instability surgery are well performed but poorly reported.

Differentiation of bony and soft-tissue adaptations of the shoulder in professional baseball pitchers

BACKGROUND

Baseball pitching places tremendous forces on the arm, which may lead to structural tissue adaptations that are represented by changes in rotational range of motion (ROM). These adaptations often include both bony and soft tissue; however, the contribution of each tissue to the change in motion is not always clinically attainable. The purposes of this study were to determine the adaptations of ROM, bone, and soft tissue bilaterally and to examine the correlation between clinical ROM and humeral retroversion (HR)-corrected ROM. We hypothesized that glenohumeral internal rotation (IR) and total motion would be decreased and glenohumeral external rotation (ER), posterior capsule thickness (PCT), and HR would be increased in the dominant arm; that HR-corrected ROM would be significantly different than clinical ROM; and that HR-corrected ROM would be correlated with total motion difference.

METHODS

Thirty professional baseball pitchers participated in this study. HR, PCT, and glenohumeral IR and ER were evaluated in the dominant and nondominant shoulders of each subject.

RESULTS

The dominant arm exhibited significantly more retroversion, ER, and PCT than the nondominant arm. The dominant arm also had significantly less IR and total motion than the nondominant arm. The total ROM difference was significantly correlated with both HR-corrected glenohumeral IR deficit and ER gain.

CONCLUSION

HR-corrected glenohumeral IR deficit and ER gain may more accurately reflect the contribution of soft-tissue changes to ROM. Unfortunately, measurement of HR is not always clinically attainable, making clinical management difficult.

Total shoulder arthroplasty with minimum 5-year follow-up: does the presence of subchondral cysts in the glenoid increase risk of failure?

BACKGROUND

This study evaluated the effect of cystic changes in the glenoid on postoperative outcomes and implant survival after total shoulder arthroplasty (TSA).

MATERIALS AND METHODS

From 2004 to 2012, 75 patients underwent TSA for primary osteoarthritis with minimum 5-year follow-up. Preoperative 3-dimensional models based on computed tomography imaging were created for all patients. A qualitative evaluation of cystic osteoarthritis was performed through survey grading by 3 fellowship-trained shoulder surgeons. The extent of cyst formation in the glenoid (no cysts, small, medium, or large) was assigned for every patient. In addition, quantitative evaluation was performed on 3-dimensional glenoid models. Functional outcomes, radiographic findings, and the need for revision were compared between group 1 (large and medium cysts) and group 2 (small and no cysts).

RESULTS

Qualitative evaluation of cyst formation resulted in the following distribution: no cysts in 8 patients (11%), small cyst formation in 27 (36%), medium cysts in 19 (25%), and large cysts in 21 patients (28%; κ = 0.605). The difference in total cyst volume between group 1 and group 2 was significant (P = .004). The overall revision rate was 7% (5 of 75). All revised patients were in the groups with medium or large cysts. There were no statistical differences in American Shoulder and Elbow Surgeons (ASES) Standardized Shoulder Assessment scores or presence of radiographic loosening among the study groups.

CONCLUSION

Qualitative computed tomography evaluation of cystic osteoarthritis correlates with quantitative analysis of cyst volume. Severe cyst formation portends a higher risk of failure at midterm follow-up. Cystic disease did not affect functional outcome or the presence of radiographic glenoid loosening.

Development of the human shoulder joint during the embryonic and early fetal stages: anatomical considerations for clinical practice

Although several studies have been published regarding the morphology and anatomical variations of the human shoulder joint, most have dealt with adult individuals. Those looking into the development of the joint have been focused on specific structures or have observed specimens in advanced gestational stages. The goal of this paper is to perform a complete analysis of the embryonic and early fetal development of the elements in the shoulder joint, and to clarify some contradictory data in the literature. In our study, serial sections of 32 human embryos (Carnegie stages 16-23) and 26 fetuses (9-13 weeks) were analyzed. The chondrogenic anlagen of the humerus and the medial border of the scapula can be observed from as early as Carnegie stage 17, whereas that of the rest of the scapula appears at stage 18. The osteogenic process begins in week 10 for the humeral head and week 11 for the scapula. At stage 19 the interzone becomes apparent, which will form the glenohumeral joint. In the next stage the glenohumeral joint will begin delaminating and exhibiting a looser central band. Denser lateral bands will join the humeral head (caput humeri) and the margins of the articular surface of the scapula, thus forming the glenoid labrum, which can be fully appreciated by stage 22. In 24-mm embryos (stage 21) we can observe, for the first time, the long head of the biceps tendon (which is already inserted in the glenoid labrum by week 9), and the intertubercular sulcus, whose depth is apparent since week 12. Regarding ligamentous structures, the coracohumeral ligament is observed at the end of Carnegie stage 23, whereas the primitive glenohumeral ligament already appeared in week 10. The results of this study provide a detailed description of the morphogenesis, origin and chronological order of appearance of the main intrinsic structures of the human shoulder joint during late embryonic and early fetal development. We expect these results to help explain several functional aspects of the shoulder joint, and to clarify some contradictory data in the literature regarding this complex anatomical and biomechanical structure, helping future researchers in their efforts.

Long-term Clinical Outcomes After Microfracture of the Glenohumeral Joint: Average 10-Year Follow-up

BACKGROUND

Microfracture is an effective surgical treatment for full-thickness cartilage defects of the knee; however, little is known regarding long-term outcomes after microfracture in the shoulder.

PURPOSE

To present long-term clinical outcomes of patients undergoing microfracture of full-thickness articular cartilage defects of the glenohumeral joint.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Sixteen consecutive patients (17 shoulders) were retrospectively reviewed who underwent arthroscopic microfracture of the humeral head and/or glenoid surface, with or without additional procedures between 2001 and 2008 and with a minimum follow-up of 8.5 years. All patients completed pre- and postoperative surveys containing the visual analog scale, American Shoulder and Elbow Surgeons form, and Simple Shoulder Test. Complications and reoperations were analyzed. Failure was defined by biological resurfacing or conversion to arthroplasty.

RESULTS

Of the original 16 patients (17 shoulders), 13 patients (14 shoulders) were available for mean follow-up at 10.2 ± 1.8 years after microfracture (range, 8.5-15.8 years), for an overall clinical follow-up rate of 82%. The patients (6 men, 7 women) were 36.1 ± 12.9 years old at time of microfracture. The average size of humeral head defects was 5.20 cm² (range, 4.0-7.84 cm²), and the average size of glenoid defects was 1.53 cm² (range, 1.0-3.75 cm²). Four patients (4 shoulders) underwent at least 1 reoperation, and 3 were considered to have structural failures. The average time to failure was 3.7 years after microfracture (range, 0.2-9.6 years). The overall survival rate was 76.6% at 9.6 years. For these patients, there were statistically significant improvements in visual analog scale, Simple Shoulder Test, and American Shoulder and Elbow Surgeons scores as compared with preoperative values at long-term follow-up ( P < .05 for all), without any significant change from short-term (mean, 2.3 years) to long-term (mean, 10.2 years) follow-up. There was no significant difference in Single Assessment Numeric Evaluation or Short Form-12 Physical or Mental scores between short- and long-term follow-up. When compared with short-term follow-up, in which 2 patients had already failed, 1 additional patient progressed to failure at 9.6 years after the original microfracture. Two patients (2 shoulders) were considered to have clinical failure. Owing to the overall number of failures (3 structural failure and 2 clinical failure), the total long-term success rate of glenohumeral microfracture is 66.7% in the current study.

CONCLUSION

Treating full-thickness symptomatic chondral defects of the glenohumeral joint with microfracture can result in long-term improved function and reduced pain for some patients. However, in this case series, 21.4% of patients required conversion to arthroplasty <10 years after the index microfracture procedure, and 33% to 42% of patients were considered to have potential clinical failure. Additional studies with larger patient cohorts are needed.

Optimal management of glenohumeral osteoarthritis

Glenohumeral osteoarthritis (OA) is defined as progressive loss of articular cartilage, resulting in bony erosion, pain, and decreased function. This article provides a gross overview of this disease, along with peer-reviewed research by experts in the field. The pathology, diagnosis, and classification of this condition have been well described. Treatment begins with non-operative measures, including oral and topical anti-inflammatory agents, physical therapy, and intra- articular injections of either a corticosteroid or a viscosupplementation agent. Operative treatment is based on the age and function of the affected patient, and treatment of young individuals with glenohumeral OA remains controversial. Various methods of surgical treatment, ranging from arthroscopy to resurfacing, are being evaluated. The roles of hemiarthroplasty, total shoulder arthroplasty, and reverse shoulder arthroplasty are similarly reviewed with supporting data.

Translational manipulation under anesthesia for patients with frozen shoulder: a case series study with five-year health care utilization and post-manipulative arthroscopic findings

Study Design

Case series study.

Objectives

Although there have been no reported complications from translational manipulation under anesthesia (tMUA) for individuals with adhesive capsulitis (AC) there are no cases reporting surgical findings post tMUA. Also, there are no studies evaluating health care utilization following tMUA. The purpose of this study was to: (1) report clinical outcomes following tMUA, (2) describe relevant health care costs and utilization following tMUA, and (3) summarize findings from two cases receiving joint arthroscopy following tMUA.

Methods

Fourteen Individuals with AC underwent tMUA. Range of motion (ROM) and Shoulder Pain and Disability Index (SPADI) values were collected at baseline and six weeks follow-up. Shoulder-related health care cost and utilization were analyzed for a five-year period following tMUA. Two additional patients with AC underwent tMUA followed by arthroscopic assessment for evidence of iatrogenic injury.

Results

Thirteen patients completed the six-week follow-up. Mean change scores for ROM and SPADI values were flexion; +38.5°, abduction; +71.1°, external rotation (shoulder abducted); +49.8°, internal rotation (shoulder abducted); +26.6°, SPADI scores; +44.4. 13 patient records were analyzed for health care utilization. Ten of the 13 patients utilized no additional shoulder-related health care. Surgical evaluation revealed no evidence of iatrogenic injury.

Discussion

Clinical outcomes were similar to previous studies. Utilization data indicated that for the majority of patients, little shoulder-related health care was utilized. Surgical evaluation provided further evidence that tMUA performed by a physical therapist is safe. Future research will be required to establish a causal relationship between tMUA and the results observed in this study.

Level of Evidence

Therapy, Level 4.

Ibuprofen impairs capsulolabral healing in a rat model of anterior glenohumeral instability

BACKGROUND

Failure of glenoid labrum and capsular healing after glenohumeral dislocation can lead to persistent shoulder instability. The purpose of this study was to determine the effect of nonsteroidal anti-inflammatory drugs (NSAIDs) on the healing glenoid labrum and capsule after glenohumeral dislocation in a rat model.

METHODS

Sixty-six rats had surgically induced anterior-inferior labral tears and anterior glenohumeral dislocation. Postoperatively, the animals were assigned to either normal (n = 32) or ibuprofen drinking water (n = 31). Animals were euthanized at 2 and 4 weeks postoperatively for biomechanical testing and histologic analysis.

RESULTS

The maximum load increased from 2 to 4 weeks after injury in the NSAID groups but not in the control groups. At 2 weeks, the maximum load was lower in the NSAID group compared with the control group. In a matched comparison between injured and uninjured limbs, the maximum load was significantly decreased in the injured limb of the 2-week NSAID group. At 4 weeks, the NSAID group had decreased stiffness compared with the 4-week control group.

CONCLUSIONS

In a new rat model of glenohumeral instability, the postinjury administration of ibuprofen resulted in decreased capsulolabral healing. A matched pair analysis of injured to uninjured limbs supported the findings of impaired healing in the NSAID-treated animals. These findings demonstrate that the use of NSAIDs after glenohumeral dislocation may impair capsulolabral healing and should be limited or avoided to optimize glenohumeral stability.

An Effective Treatment in the Austere Environment? A Critical Appraisal into the Use of Intra-Articular Local Anesthetic to Facilitate Reduction in Acute Shoulder Dislocation

Acute shoulder dislocation is a common injury in the outdoor environment. The objective of this systematic review of the literature was to determine if intra-articular local anesthetic (IAL) is an effective treatment that could have prehospital application. A methodical search of MEDLINE, PubMed, and EMBASE databases targeted publications from January 1, 1990 until January 1, 2017. Eligible articles compared IAL with other analgesic techniques in patients 16 years or older experiencing acute glenohumeral dislocation. Reduction success, complications, and patient-reported outcome measures underwent comparison. All identified publications originated from the hospital setting. Procedural success rates ranged widely among randomized control trials comparing IAL with intravenous analgesia and sedation (IAL 48-100%, intravenous analgesia and sedation 44-100%). A pooled risk ratio [RR] favored intravenous analgesia and sedation (RR 0.91, 95% confidence interval [CI] 0.84-0.98), but there was significant inconsistency within the analysis (I² = 75%). IAL provided lower complication rates (4/170, 2%) than intravenous analgesia and sedation (20/150, 13%) (RR 1.11, 95% CI 1.04-1.19, I² = 63%). One trial found a clinically relevant reduction in visual analogue pain scores when comparing IAL against no additional analgesia in the first minute (IAL 21±13 mm; control 49±15 mm; P<0.001) and fifth minute (IAL 10±10 mm; control 40±14 mm, P<0.001) after reduction. The results suggest that IAL is an effective intervention for acute anterior shoulder dislocation that would have a place in the repertoire of the remote physician. Further research might be beneficial in determining the outcomes of performing IAL in the prehospital setting.

The effects of a conservative rehabilitation program for multidirectional instability of the shoulder

BACKGROUND

Conservative management is commonly recommended as the first-line treatment for multidirectional instability (MDI) of the shoulder. Despite this, the evidence for efficacy of treatment is limited, and until recently, guidance for clinicians on conservative rehabilitation programs has been inadequate. This study evaluated the effectiveness of a physiotherapy-led exercise program for participants with MDI.

METHODS

In a single-group study design, 43 participants (16 male, 27 female; mean age, 19.8 years, standard deviation, 4.9 years) diagnosed with MDI undertook a 12-week exercise program. Primary outcome measures were the Melbourne Instability Shoulder Score, Western Ontario Shoulder Instability Index, and Oxford Shoulder Instability Score. Secondary outcomes were strength and scapular position. All measures were taken at baseline and repeated at the conclusion of the program. Test differences before and after rehabilitation were evaluated with dependent t tests and single-group effect size calculations (standardized mean difference [SMD]) to provide a measure of the magnitude of the difference.

RESULTS

Large effects were found between pre- and postrehabilitation scores on all functional instability questionnaires, with the Western Ontario Shoulder Instability Index demonstrating the largest effect (SMD, -3.04). Scapular upward rotation improved significantly in the early ranges of abduction (0°-60°), with moderate to large effects (SMDs, 0.54-0.95). All strength measures significantly improved, with large differences identified (SMDs, 0.69-2.08).

CONCLUSION

The identified improvement in functional status, shoulder muscle strength, and scapular positioning after rehabilitation allows greater confidence in the value of conservative management of MDI and informs further research by way of clinical trials in the area.

Successful Return to Sport After Arthroscopic Shoulder Stabilization Versus Nonoperative Management in Contact Athletes With Anterior Shoulder Instability: A Prospective Multicenter Study

BACKGROUND

The debate continues regarding the optimal treatment of intercollegiate contact athletes with in-season anterior shoulder instability.

PURPOSE

To examine return to sport and recurrent instability in the season after the index in-season anterior instability event.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Forty-five contact intercollegiate athletes treated nonoperatively or with arthroscopic stabilization were prospectively followed in a multicenter observational study to evaluate return to play (RTP) and recurrent instability in the season after an initial in-season anterior glenohumeral instability event. Baseline data collection included sport played, previous instability events, direction of instability, type of instability (subluxation or dislocation), and treatment method (nonoperative management or arthroscopic stabilization). All nonoperatively treated athletes underwent a standardized accelerated rehabilitation program without shoulder immobilization. Surgical stabilization was performed arthroscopically in all cases, and successful RTP was evaluated during the next competitive season after complete rehabilitation.

RESULTS

Thirty-nine of 45 intercollegiate contact athletes had remaining National Collegiate Athletic Association eligibility and were followed through the subsequent competitive season after the index instability event. Of the 10 athletes electing nonoperative treatment, 4 (40%) successfully returned to play without recurrence during the subsequent season. Of the 29 athletes treated surgically, 26 (90%) were able to successfully return to play without recurrence the following season (recurrence: n = 1; inadequate function: n = 2). Athletes who underwent surgical reconstruction before the next season were 5.8 times (95% CI, 1.77-18.97; P = .004) more likely to complete the subsequent season without recurrent instability. Of the 29 athletes electing surgical stabilization, there was no difference (risk ratio, 0.95; 95% CI, 0.10-9.24; P > .99) in RTP between the 9 stabilized after a single instability event (90% RTP rate) and the 20 stabilized after multiple in-season recurrent instability events (89% RTP rate).

CONCLUSION

Collegiate contact and collision athletes with in-season anterior shoulder instability are significantly more likely to successfully return to sport without subsequent instability events the next season if they undergo surgical repair in the off-season.

Hyaluronic Acid Intra-Articular Injections in Patients Affected by Moderate to Severe Glenohumeral Osteoarthritis: A Prospective Randomized Study

Purpose  The aim of this study was to evaluate the efficacy and safety of intra-articular injection treatment with high molecular weight HA (Hyalubrix, 30 mg/2 mL, molecular weight > 1,500 kDa) in patients affected by moderate to severe glenohumeral osteoarthritis (OA).

Methods  Seventy-eight patients, affected by shoulder OA grade II–IV were randomized in two groups. Patients included in case group were treated with three intra-articular injections of HA and a specific physiotherapy program, whereas patients included in the control group received the only physical therapy. The follow-up examination was 6 months for both groups. The evaluation of functional status of treated shoulder, range of motion, and pain was performed before treatment and at the final follow-up examination by means of the Constant score. The safety evaluation of the treatment was also performed recording any adverse events.

Results  Statistical analysis revealed a significant difference ( p  < 0.05) between the two groups in terms of pain reduction and improvement in the activities of daily living. In particular, case group subjects affected by grade III and IV OA had a significant improvement in the Constant score (18.2 ± 5.4 and 19.2 ± 5.9, respectively).

Conclusion  This study showed that the combination of intra-articular injection of hyaluronic acid (Hyalubrix, 30 mg/2 mL) with physical therapy program was more effective in comparison with the only physical therapy in reducing pain in patients affected by glenohumeral OA.

Level of Evidence  Level II, randomized controlled study.

Current Concepts in the Management of Shoulder Instability

Shoulder instability ranges from subtle instability to frank dislocation. Our understanding on the subject is getting better. Patient lifestyle, increased awareness/expectations, better availability of information, improved imaging modalities, and increased awareness about the previously less known concepts in instability all add to the challenges of managing the problem. History and clinical examination without over reliance on imaging remain essential. We used Embase, PubMed, Medline, CINAHL, Cochrane Library, Scottish Intercollegiate Guidelines Network and Google Scholar search for published literature in English. We used various combinations of the keywords, namely, human shoulder instability, sports injuries, dislocation, surgery, latarjet, glenohumeral, glenoid, and arthroscopy from 1980 to March 2017. The systematic search captured 310 publications. After applying initial exclusion criteria, 41 abstracts were assessed for eligibility. Of these, we selected 20 full-text articles with the majority of focus primarily on surgical management of traumatic shoulder instability. A tailor-made approach for the management of the individual patient is essential and should involve shared decision making. In this article, we have tried to simplify and present the current evidence in the management of traumatic shoulder instability, particularly in sportsperson.

Sleeper stretch accelerates recovery of glenohumeral internal rotation after pitching

BACKGROUND

The natural time course for recovery of glenohumeral internal rotation (IR) loss after a throwing episode is unknown. In addition, the effect of the sleeper stretch on the time course for recovery of motion after a throwing episode has never been investigated. Therefore, the objectives of this study were to (1) to determine the natural time course for spontaneous recovery of IR after a throwing episode and (2) to evaluate the effect of the sleeper stretch on the time course for recovery of IR after a throwing episode.

METHODS

The study participants were 17 male high school baseball pitchers (aged 17.7 ± 0.9 years). A crossover designed was used over a 2-week period. For week 1, glenohumeral IR and external rotation (ER) were evaluated in the dominant shoulder 1 day before a throwing episode and at 2 hours, 1 day, 2 days, 3 days, 4 days, and 5 days after pitching. During week 2, participants completed a sleeper stretch protocol before measurements.

RESULTS

The natural time course of spontaneous recovery for IR after a throwing episode was 4 days. Stretching reduced the time course of recovery for IR to 2 days.

CONCLUSION

A sleeper stretch program for high school baseball pitchers can accelerate the recovery of commonly observed IR loss and also may mitigate the cumulative effects observed over the course of a season.

Biomechanical Evaluation of Glenoid Version and Dislocation Direction on the Influence of Anterior Shoulder Instability and Development of Hill-Sachs Lesions

BACKGROUND

Abnormal glenoid version is a risk factor for shoulder instability. However, the degree to which the variance in version (both anteversion and retroversion) affects one's predisposition for instability is not well understood.

PURPOSE

To determine the influence of glenoid version on anterior shoulder joint stability and to determine if the direction of the humeral head dislocation is a stimulus for the development of Hill-Sachs lesions.

STUDY DESIGN

Controlled laboratory study.

METHODS

Ten human cadaveric shoulders (mean age, 59.4 ± 4.3 years) were tested using a custom shoulder dislocation device placed in a position of apprehension (90° of abduction with 90° of external rotation). Glenoid version was adjusted in 5° increments for a total of 6 version angles tested: +10°, +5°, 0°, -5°, -10°, and -15° (anteversion angles are positive, and retroversion angles are negative). Two humeral dislocation directions were tested. The first direction was true anterior through the anterior-posterior glenoid axis. The second dislocation direction was 35° inferior from the anterior-posterior glenoid axis based on the deforming force role of the pectoralis major. The force and energy to dislocate were recorded.

RESULTS

Changes in glenoid version manifested a linear effect on the dislocation force. The energy to dislocate increased as a second-order polynomial as a function of increasing glenoid retroversion. Glenoid version of +10° anteversion and -15° retroversion was highly unstable, resulting in spontaneous dislocation in one-quarter (10/40) and one-half (25/40) of the specimens anteriorly and posteriorly, respectively, in the absence of an applied dislocation force. The greater tuberosity was observed to engage with the anterior glenoid rim, consistent with Hill-Sachs lesions, 40% more frequently when the dislocation direction was true anterior compared with 35° inferior from the anterior-posterior glenoid axis. The engagement of the greater tuberosity caused an increase in the energy required to dislocate.

CONCLUSION

Glenoid version has a direct effect on the force required for a dislocation. An anterior-inferior dislocation direction requires less energy for a dislocation and results in a lower risk of the development of a Hill-Sachs lesion than a direct anterior dislocation direction.

CLINICAL RELEVANCE

Consideration should be given to glenoid version when choosing a surgical treatment option for anterior shoulder instability.

[Bristow-Latarjet Technique for anterior glenohumeral instability]

BACKGROUND

In treatment of anterior shoulder instability, many surgical techniques have been described, all of them with advantages and disadvantages. Our goal is to study the half term results on patients that underwent open Bristow-Latarjet surgery considering the preoperative ISIS value.

MATERIAL AND METHODS

This is a retrospective study of 33 patients which underwent open Bristow-Latarjet surgery in our center between 2005 and 2012. Average age of 33.2 years and follow up of 75 months. Results were taken by Rowe and Constant scores, DASH questionnaire and we also recorded a subjective assessment of the result by each patient.

RESULTS

No recurrence was reported. No reoperations. Mean Rowe score was 74.6 points and mean Constant score was 70 points. In the disability questionnaire (DASH), the mean value was 22.9 points. The outcome assessment by the patients was positive in 78.8%. The migration of a screw occurred in one patient but he still asymptomatic. No other complication was identified.

CONCLUSIONS

The Bristow-Latarjet technique is a reliable technique, with few complications and with an excellent rate of recurrence in treatment of chronic shoulder instability as reported in literature; it should be used as primary surgery in some cases and the preoperative ISIS score is an excellent and simple guide to select correctly the surgical technique for each patient.

Redislocation risk after an arthroscopic Bankart procedure in collision athletes: a systematic review

BACKGROUND

The purpose of this review was to determine the redislocation risk for collision athletes after an arthroscopic Bankart repair and to compare the redislocation rate between collision athletes and noncollision athletes after an arthroscopic Bankart repair.

METHODS

A PubMed and Embase query was performed, screening all relevant literature of arthroscopic Bankart procedures mentioning redislocation rates in collision athletes. Studies with a follow-up <2 years or lacking information on redislocation rates in collision athletes were excluded. We used the modified Coleman Methodology Score to assess the quality of included studies. Finally, the data in all the studies were combined and analyzed.

RESULTS

There were 1012 studies screened on title and abstract, of which 111 studies were full-text screened, and finally 20 studies were included. Four studies reported on collision athletes only, whereas 16 compared collision with noncollision athletes. Fourteen studies reported increased redislocation rates for collision athletes in comparison to noncollision athletes (absolute risk difference varying from 0.4% to 28.6%), whereas 2 studies reported decreased rates (absolute risk differences of -6% and -2.4%). A combined analysis revealed that collision athletes have an increased absolute risk of 8.09 with 95% CI from 3.61 to 12.57% for development of postoperative instability in comparison to noncollision athletes (P = .001).

CONCLUSION

Collision athletes have an increased risk for redislocation in comparison to noncollision athletes after an arthroscopic Bankart repair, although there were no differences in return to sport.