Functional Anatomy and Biomechanics of Shoulder Stability in the Athlete

Suprascapular Nerve Pulsed Radiofrequency as an Effective Pain Relief Strategy in Supraspinatus Muscle Tendon Tears

INTRODUCTION

The supraspinatus muscle tendon is the most frequently rotator cuff muscle torn. Reliable shoulder pain relief strategies are needed for patients with severe pain, refractory to conservative management, and without surgical indication.

MATERIALS AND METHODS

We conducted a retrospective analysis in a Portuguese reference Rehabilitation Centre during the 1st of January 2020 and the 30th of June 2021, including all patients with partial or complete supraspinatus tendon tear, older than 50 years, who presented with severe pain and who were submitted to suprascapular nerve pulsed radiofrequency.

RESULTS

We included 32 patients in our retrospective analysis, mainly female (53%) with a mean age of 66.50 years old. Most of the patients reported right shoulder pain (21 patients, 66%). The mean baseline pain, reported on the numeric rating scale, was 8.00 ± 0.88. Compared to baseline, mean pain reduced 4.00 ± 3.19 at three months (p<0.001), 3.59 ± 3.13 at six months (p<0.001) and 2.94 ± 2.78 at 12 months (p<0.001). From the 3rd to the 12th month there was an increase of 1.06 ± 2.77 in mean pain (p=0.038). There was no difference (p>0.05) in average pain at 0, 3, 6, or 12 months between patients who were simultaneously submitted to an intra-articular shoulder injection.

DISCUSSION

Our analysis revealed 36% average shoulder pain reduction for, at least, 12 months following suprascapular nerve pulsed radiofrequency, with a peak pain reduction of 50% at three months. Slow fading of pain reduction in the following nine months was seen, however, compared to baseline, pain reduction was always statistically significant. Cortico-anaesthetic intra-articular shoulder injections seem not to add benefit in shoulder pain reduction when performed simultaneously with suprascapular nerve pulsed radiofrequency.

CONCLUSION

Suprascapular nerve pulsed radiofrequency seems to be an effective strategy for shoulder pain reduction, in patients with severe pain, refractory to other management modalities. Nonetheless, larger prospective studies, analyzing shoulder functionality and quality of life lost scores, besides pain reduction, should be pursued.

Quality of life following an open Latarjet-Bristow procedure in a general population with recurrent anterior shoulder instability

BACKGROUND

Despite the extensive literature on anterior glenohumeral instability, to date, there are no studies that report on the quality of life following a Latarjet-Bristow procedure with recurrent anterior shoulder instability. The purpose of this study was to evaluate the quality of life in patients who had a Latarjet-Bristow procedure.

METHODS

A single-center retrospective review with a prospective recall of patients who underwent a Latarjet-Bristow technique for recurrent anterior glenohumeral instability between January 2017 and March 2020. Outcomes measures included health-related quality of life using the Short Form-36 (SF-36) questionnaire and patient-related outcome measures using the Western Ontario Shoulder Instability Index and Rowe scores.

RESULTS

A total of 66 patients were identified to participate in the study; 40 (60.6%) responded and were included in the analysis. There were nine females and 31 males, with a median age of 32 years (27.5‒41 years). Three cases had bilateral anterior shoulder instability with a single joint being operated and three patients were epileptic. Physical and mental components summary of the SF-36 showed a better health-related quality of life in the general population. There was a significant strong correlation between SF-36 and Western Ontario Shoulder Instability Index. However, SF-36 and Rowe score showed a fair correlation.

CONCLUSION

The Latarjet-Bristow procedure improves the quality of life in a general population similarly to an athletic population. The number of episodes of dislocation before surgery and the delayed surgical intervention did not increase the recurrent anterior shoulder instability rates postoperatively.

Exercise Selection and Common Injuries in Fitness Centers: A Systematic Integrative Review and Practical Recommendations

Weight resistance training (RT) is an essential component of physical conditioning programs to improve the quality of life and physical fitness in different ages and populations. This integrative review aimed to analyze the scientific evidence on the relationship between exercise selection and the appearance of musculoskeletal injuries in physical fitness centers (PFC). The PubMed or Medline, EMBASE or Science Direct, Google Scholar and PEDro databases were selected to examine the available literature using a Boolean algorithm with search terms. The review process was performed using the five-stage approach for an integrative review and it was reported according to the PRISMA in Exercise, Rehabilitation, Sport Medicine and Sports Science (PERSiST) guidelines. A total of 39 peer-reviewed articles (Price index = 71.7%) met the inclusion criteria and evaluated the link between exercise selection and the incidence of injuries in exercisers who regularly attend PFC. Most injuries occur to the shoulders, elbows, vertebrae of the spine, and knees. Although the injury etiologies are multifactorial, the findings of the reviewed articles include the impacts of overuse, short post-exercise recovery periods, poor conditioning in the exercised body areas, frequent use of heavy loads, improper technique in certain exercises, and the abuse of performance- and image-enhancing drugs. Practical recommendations addressed to clinical exercise physiologists, exercise professionals, and health professionals are given in this paper. The exercise selection in RT programs requires professional supervision and adhering to proper lifting techniques and training habits that consider the anatomical and biomechanical patterns of the musculoskeletal structures, as well as genetic, pedagogical, and methodological aspects directly related to the stimulus-response process to mitigate the occurrence of RT-related injuries in PFC.

Magnetic resonance arthrography in patients with multidirectional instability: could inferior capsulsar width be considered the cornerstone in the diagnosis of non-traumatic shoulder instability?

OBJECTIVES

To provide quantitative anatomical parameters in patients with and without non-traumatic multidirectional instability using MR arthrography (MR-a).

MATERIALS AND METHODS

One hundred and seventy-six MR-a performed from January 2020 to March 2021 were retrospectively evaluated. Patients were divided according to the presence of clinically diagnosed multidirectional shoulder instability (MDI). Each MR-a was performed immediately after intra-articular injection of 20 ml of gadolinium using the anterior approach. The width of the axillary recess, the width of the rotator interval, and the circumference of the glenoid were measured by three independent radiologists, choosing the average value of the measurements. The difference between the mean values of each of the three parameters between the two study groups was then assessed.

RESULTS

Thirty-seven patients were included in the study (20 in the MDI group, 17 in the control group). The mean axillary recess width in the MDI group was significantly greater than in the control group (t(33) = 3.15, p = .003); rotator interval width and glenoid circumference measurements were not significantly different (t(35) = 1.75, p = .08 and t(30) = 0,51, p = .6, respectively).

CONCLUSIONS

Inferior capsular redundancy may be an important predisposing factor in MDI, while glenoid circumference is not related to MDI. The relationship between the width of the rotator interval and shoulder instability remains debated.

Management of Locked Posterior Shoulder Dislocation with Reverse Hill-Sachs Lesions via Anatomical Reconstructions

Objective

To evaluate the outcomes of locked posterior shoulder dislocation with reverse Hill–Sachs lesions in patients treated with anatomical reconstructions.

Methods

Patients who were treated at our institution between January 2016 and June 2020 were retrospectively reviewed. The demographics of the patients including gender, age, occupation, and dominant arm were recorded. Eleven cases from 10 patients qualified in this study. Nine males and one female were included. The mean age of the patients was 44.8 years (range, 33–54 years). Mechanism of injury, duration between injuries and definitive diagnosis, misdiagnosis, size of humeral head impaction, treatment maneuver, and details of operation performed were reviewed. Plain radiographs and computed tomography (CT) scan were taken to determine the size of defects preoperatively and fracture healing during follow‐up. During surgery, the deltopectoral approach was employed. Anatomical reconstruction procedure including reduction, disimpaction, bone grafting, and fixation were sequentially performed. Either cancellous autograft from iliac crest or allograft were used and the fractures were anatomically reduced and stabilized by screws or plates. Visual Analog Scale (VAS) and Constant–Murley score were recorded to determine the functional outcomes preoperatively, at 3 months and 6 months postoperatively, and at the last follow‐up. The range of motion in forward flexion was recorded at 6 months follow‐up postoperatively.

Results

Causes of injuries included epileptic seizure in four cases, fall in three cases, and road traffic accident in three cases. Misdiagnoses occurred in five out of 10 patients. The mean time between injury and definitive treatment among those misdiagnosed was 112 days. The mean size of the impacted reverse Hill–Sachs lesions was 33.95% (range, 19.1%–42.6%). All patients received surgical management with anatomical reconstruction approach, including open reduction, disimpaction, bone grafting, and internal fixation. The mean amount of bleeding during operation was 450 mL. The mean follow‐up period was 22.6 months. Fracture healing was observed by 8 weeks in all cases postoperatively and evidence of bone grafting could not be further detected on CT scan at 6 month during follow‐up. VAS was significantly lower at the last follow‐up (0.68 ± 0.21) in comparison to preoperative scores (4.96 ± 0.97) (P < 0.05). Constant–Murley was improved significantly at the last follow‐up (91.7 ± 8.3) in comparison to that preoperatively (40.6 ± 10.3) (P < 0.05). The mean range of motion in forward flexion was 38.25° ± 9.36° preoperatively and significantly improved to 162.48° ± 12.68° at 6‐month follow‐up (P < 0.05).

Conclusion

The anatomical reconstruction procedure by open reduction and bone augmentation for the treatment of locked posterior shoulder dislocation with reverse Hill–Sachs lesion was promising in both fracture healing and functional outcomes.

How to Measure Glenoid Bone Stock and Version and Why It Is Important: A Practical Guide

Shoulder osteoarthritis (OA) is a common and debilitating condition and a source of high morbidity and medical expenditures across the world among individuals older than 60 years. Shoulder OA results in the gradual destruction of articular cartilage of the humeral head and glenoid component, causing inflammation, pain, and a restricted range of motion. Most patients are diagnosed with shoulder OA after experiencing shoulder pain and stiffness, and the diagnosis is often made after medical and physical histories are obtained and physical and imaging examinations are performed. Use of various surgical techniques such as total anatomic or reverse shoulder arthroplasty and hemiarthroplasty has increased in recent years, resulting in reduced morbidity and improved functional status of patients. However, the rate of surgical complications such as premature loosening of components is significant, reducing the effectiveness of such procedures. Data in the literature indicate that high-grade fatty infiltration of the rotator cuff muscle before surgery is associated with postoperative glenoid component loosening. High-grade rotator cuff fatty infiltration and atrophy have been found to be associated with more severe Walch classification-based glenoid morphology subtypes, increased joint line medialization, glenoid bone loss, and increased pathologic glenoid version. The authors describe how advanced imaging techniques are used for preoperative evaluation of the shoulder and discuss how to measure glenoid version and bone stock and classify glenoid morphology types on the basis of Walch classification, as these parameters are commonly used in surgical planning. Methods involving the use of Friedman and paleoglenoid lines for respective measurements are illustrated by using three-dimensional CT and MRI case examples. ^©RSNA, 2020.

[Shoulder instability: review of current concepts of diagnosis and treatment]

OBJECTIVE

To conduct a systematic review of modern literature data on the modern approaches in diagnosis and treatment of shoulder instability.

MATERIAL AND METHODS

Searching for literature data was performed using the Pubmed and Google Scholar databases.

RESULTS

The authors analyzed the results of conservative treatment of patients with shoulder instability and emphasized higher risk of instability recurrence, degeneration of anatomical structures and functional impairment in these patients. Surgery is advisable to restore shoulder stability and normalize its function. Several methods for stabilizing the shoulder have been proposed.

The approaches to diagnosis and treatment of shoulder instability have been updated.

CONCLUSION

Successful treatment of shoulder instability is based on qualitative and complete assessment of soft tissues and bone structures. An individual approach considering bone tissue deficiency and individual needs of the patient is required.

A Comprehensive View of Frozen Shoulder: A Mystery Syndrome

Frozen shoulder is a common epidemiological affliction. Data acquired from people who suffer from this type of damage in other joints such as the hip, wrist and ankle also exist; although these syndromes are less common. Treatment for frozen shoulder is primarily physical (physiotherapy, manual therapy), secondary medical (corticosteroid injections) and finally surgical but with limited success. The difficulty in treating this type of condition successfully lies in the lack of knowledge about the risk factors involved and the pathophysiology underlying this mysterious syndrome. This review gives an overview of the current scientific position of frozen shoulder in terms of evolutionary factors, etiology, the different mechanisms of action involved, current treatment options and other possible interventions based on recent discoveries of pathophysiological mechanisms. The overall objective is to clarify several unknown aspects of a syndrome that affects up to 5% of the world's population.

Biomechanics of all-out handcycling exercise: kinetics, kinematics and muscular activity of a 15-s sprint test in able-bodied participants

This study aims to quantify the kinematics, kinetics and muscular activity of all-out handcycling exercise and examine their alterations during the course of a 15-s sprint test. Twelve able-bodied competitive triathletes performed a 15-s all-out sprint test in a recumbent racing handcycle that was attached to an ergometer. During the sprint test, tangential crank kinetics, 3D joint kinematics and muscular activity of 10 muscles of the upper extremity and trunk were examined using a power metre, motion capturing and surface electromyography (sEMG), respectively. Parameters were compared between revolution one (R1), revolution two (R2), the average of revolution 3 to 13 (R3) and the average of the remaining revolutions (R4). Shoulder abduction and internal-rotation increased, whereas maximal shoulder retroversion decreased during the sprint. Except for the wrist angles, angular velocity increased for every joint of the upper extremity. Several muscles demonstrated an increase in muscular activation, an earlier onset of muscular activation in crank cycle and an increased range of activation. During the course of a 15-s all-out sprint test in handcycling, the shoulder muscles and the muscles associated to the push phase demonstrate indications for short-duration fatigue. These findings are helpful to prevent injuries and improve performance in all-out handcycling.

Neuromuscular shoulder activity during exercises with different combinations of stable and unstable weight mass

BACKGROUND

Recent shoulder injury prevention programs have utilized resistance exercises combined with different forms of instability, with the goal of eliciting functional adaptations and thereby reducing the risk of injury. However, it is still unknown how an unstable weight mass (UWM) affects the muscular activity of the shoulder stabilizers. Aim of the study was to assess neuromuscular activity of dynamic shoulder stabilizers under four conditions of stable and UWM during three shoulder exercises. It was hypothesized that a combined condition of weight with UWM would elicit greater activation due to the increased stabilization demand.

METHODS

Sixteen participants (7 m/9 f) were included in this cross-sectional study and prepared with an EMG-setup for the: Mm. upper/lower trapezius (U.TA/L.TA), lateral deltoid (DE), latissimus dorsi (LD), serratus anterior (SA) and pectoralis major (PE). A maximal voluntary isometric contraction test (MVIC; 5 s.) was performed on an isokinetic dynamometer. Next, internal/external rotation (In/Ex), abduction/adduction (Ab/Ad) and diagonal flexion/extension (F/E) exercises (5 reps.) were performed with four custom-made-pipes representing different exercise conditions. First, the empty-pipe (P; 0.5 kg) and then, randomly ordered, water-filled-pipe (PW; 1 kg), weight-pipe (PG; 4.5 kg) and weight + water-filled-pipe (PWG; 4.5 kg), while EMG was recorded. Raw root-mean-square values (RMS) were normalized to MVIC (%MVIC). Differences between conditions for RMS%MVIC, scapular stabilizer (SR: U.TA/L.TA; U.TA/SA) and contraction (CR: concentric/eccentric) ratios were analyzed (paired t-test; p ≤ 0.05; Bonferroni adjusted α = 0.008).

RESULTS

PWG showed significantly greater muscle activity for all exercises and all muscles except for PE compared to P and PW. Condition PG elicited muscular activity comparable to PWG (p > 0.008) with significantly lower activation of L.TA and SA in the In/Ex rotation. The SR ratio was significantly higher in PWG compared to P and PW. No significant differences were found for the CR ratio in all exercises and for all muscles.

CONCLUSION

Higher weight generated greater muscle activation whereas an UWM raised the neuromuscular activity, increasing the stabilization demands. Especially in the In/Ex rotation, an UWM increased the RMS%MVIC and SR ratio. This might improve training effects in shoulder prevention and rehabilitation programs.

Reverse total shoulder arthroplasty: an imaging overview

Although not as common as hip or knee arthroplasty, shoulder arthroplasty is becoming a more common procedure. Reverse total shoulder arthroplasty (RTSA) is known to be an effective surgical procedure for massive irreparable rotator cuff tears, comminuted proximal humerus fractures, and revision shoulder arthroplasty. The utilization of RTSA has been increasing, and although complications following reverse arthroplasty have been reported, there are few reports in the literature that focus on the imaging features of RTSA. Herein, we demonstrate the biomechanics of RTSA, prosthesis components, indications, and imaging features of the normal postoperative appearance and various complications after RTSA. Familiarization with the normal and abnormal imaging appearances after RTSA can be helpful for appropriate management of patients.

Helical axis analysis to quantify humeral kinematics during shoulder rotation

Information pertaining to the helical axis during humeral kinematics during shoulder rotation may be of benefit to better understand conditions such as shoulder instability. The aim of this study is to quantify the behavior of humeral rotations using helical axis (HA) parameters in three different conditions. A total of 19 people without shoulder symptoms participated in the experiment. Shoulder kinematics was measured with an optoelectric motion capture system. The subjects performed three different full range rotations of the shoulder. The shoulder movements were analyzed with the HA technique. Four parameters were extracted from the HA of the shoulder during three different full-range rotations: range of movement (RoM), mean angle (MA), axis dispersion (MDD), and distance of their center from the shoulder (D). No significant differences were observed in the RoM for each condition between left and right side. The MA of the axis was significantly lower on the right side compared to the left in each of the three conditions. The MDD was also lower for the right side compared to the left side in each of the three conditions.The four parameters proposed for the analysis of shoulder kinematics showed to be promising indicators of shoulder instability.

Glenohumeral Dislocation Arthropathy: Etiology, Diagnosis, and Management

Dislocation arthropathy describes the development of progressive degenerative changes of the glenohumeral joint in the setting of instability. Although the specific etiology remains unclear, the trauma of a single dislocation, repetitive injury associated with recurrent dislocations, changes in shoulder biomechanics, and complications associated with instability surgery have all been implicated in its development. Pain and restricted range of motion are the most common patient complaints. Conservative management, consisting of pain control, activity modification, and physical therapy, is the first-line treatment after the development of arthropathy. If conservative management fails, multiple surgical options exist. Arthroscopic débridement can be attempted in young, active patients and in those patients with mild-to-moderate arthropathy. Open subscapularis lengthening and capsular release can be done in patients with prior instability repairs that are overly tight. In young patients with minimal bone loss and glenoid wear, surface replacement arthroplasty and hemiarthroplasty are surgical options. In older patients with moderate-to-severe arthropathy, total shoulder or reverse shoulder arthroplasty is the preferred treatment option. Further study is needed to better predict which patients will develop dislocation arthropathy and will thus benefit from early surgical intervention.

Concurrent validity of handheld dynamometer measurements for scapular protraction strength

BACKGROUND

Handheld dynamometers (HHD) provide quick and low-cost assessments of muscle strength and their use has been increasing in clinical practice. There is no available data related to the validity of HHD for this measurement.

OBJECTIVE

To verify the concurrent validity of scapular protraction measurements using an HHD.

METHODS

Individuals with traumatic anterior glenohumeral instability were allocated in Instability Group (n=20), healthy swimmers were allocated in Athletes Group (n=19) and healthy subjects were allocated in Sedentary Group (n=21). Concurrent validity was verified by the Pearson correlation test between HHD and isokinetic measurements. The agreement between instruments was verified by Bland-Altman plots, for each of the two HHD positions.

RESULTS

A moderate correlation was observed between seated (r=0.59) and lying supine HHD (r=0.54) and isokinetic dynamometer measurements for the all groups. Separated group analysis exhibited a strong correlation between seated HHD and isokinetic dynamometer measurements in the Instability Group (r=0.80), Sedentary Group (r=0.79) and Athletes Group (r=0.76). The Bland-Altman plot showed greater agreement in the seated position than the lying supine position when comparing measurements with the HHD and isokinetic in both the general sample and separated groups.

CONCLUSION

The HHD may be considered a valid tool for assessing scapular protraction muscle strength among healthy athletes, non-athletes and subjects with shoulder instability. We recommend to assess subjects in the seated position and to be aware that the HHD tends to overestimate the peak force, compared with the gold-standard isokinetic dynamometer.

New concepts of radiologic preoperative evaluation of anterior shoulder instability: on-track and off-track lesions

The shoulder is the most frequently dislocated joint in the body due to a larger range of motion and a small area of articulation between the humeral and glenoid surfaces. Traumatic shoulder dislocations, especially those associated with injury to the labroligamentous or bony stabilizers of the joint, lead to further reduction of articular surface contact with resultant glenohumeral instability and recurrent shoulder dislocations. Imaging plays an increasingly important role in the preoperative evaluation of patients with traumatic shoulder instability by evaluating glenohumeral bone loss (uni- or bipolar), assessing soft tissue injuries and identifying patients at risk of postoperative recurrence. Quantification of bone loss is key to differentiate engaging vs. non-engaging Hill-Sachs lesions, while newer concepts of "on-track" vs. "off-track" lesions are being discussed that can determine the required surgical approaches. In this article, we review the preoperative imaging approaches, traditional treatments, outline the bone loss measurement strategies and review these new tracking concepts with relevant case examples.

Rotator cuff muscular integrity after arthroscopic revision of a Bankart repair

INTRODUCTION

Recurrent shoulder instability after arthroscopic Bankart repair is still a common complication. For primary Bankart repair studies have shown that the rotator cuff can recover completely. The ability of muscles to regenerate after arthroscopic revision Bankart repair (ARBR) has not been studied. Does the ARBR using a three-portal method allows complete muscle integrity compared with an uninjured imaging control group (ICG)?

MATERIALS AND METHODS

Twenty-two (1 female, 21 males) physically active patients (mean age at follow-up 28.5 ± 7.1 years; mean follow-up 27.5 months ± 8.5) were assessed. ARBR with a three-portal method was carried out in all patients according to previous primary arthroscopic stabilization of the shoulder (revision Bankart group). Muscle atrophy of the subscapularis muscle (SSC), supraspinatus muscle (SSP) and infraspinatus muscle (ISP) was assessed by making lateral and vertical measurements by magnetic resonance imaging (MRI). Fatty infiltration was detected by standardized assessment from variations in intensity. Detailed clinical examination of the rotator cuff was carried out. MRI assessment was compared with that of a control group of 22 healthy volunteers of same age and activity level (ICG).

RESULTS

For the SSC, no muscle impairment was noted compared with the ICG [superior atrophy index (sAI_SSC), p = 0.439; inferior atrophy index (iAI_SSC), p = 0.555; superior fatty infiltration index (sFDI_SSC), p = 0.294; inferior fatty infiltration index (iFDI_SSC), p = 0.62]. In investigation of the SSP and ISP, fatty infiltration was not shown (FDI_SSP, p = 0.454; sFDI_ISP, p = 0.504), though persistent muscle atrophy was found even > 2 years after surgery compared with the ICG (AI_SSP, p = 0.0025; sAI_ISP, p = 0.0009; iAI_ISP, p = 0.0004).

CONCLUSION

ARBR using a three-portal method allowed good muscular integrity compared with the ICG, but with persistent slight muscular atrophy of the SSP and ISP.

Outcomes Following Arthroscopic Repair of Posterior Labral Tears in Patients Older Than 35 Years

Although the results of arthroscopic management of posterior labral pathology in young athletes have been reported extensively in the literature, the clinical outcomes in older patients are unknown. This retrospective review included patients older than 35 years who underwent arthroscopic posterior labral repair. Functional outcome scores were collected, and subgroup analyses were performed to evaluate the impact of patient-specific factors. Forty-three patients met the inclusion criteria; average follow-up was 36.9 months (range, 24-54 months). Mean patient age at the time of surgery was 40.9 years (range, 35-57 years). Average outcome scores at final follow-up were Quick Disabilities of the Arm, Shoulder and Hand Scale (QuickDASH), 19±22; Simple Shoulder Test (SST), 9.9±3; Western Ontario Shoulder Instability Index (WOSI), 601±546; and Single Assessment Numeric Evaluation (SANE), 79.6%±23.4%. No significant differences in outcomes were observed in patients with preoperative symptomatic instability, active workers' compensation claims, or traumatic injury (P>.05). The presence of intraoperatively definable chondral damage (Outerbridge grade III or higher) was associated with significantly worse final functional outcomes (QuickDASH: 29 vs 11.9, P=.03; SST: 8.5 vs 10.9, P=.02; WOSI: 875 vs 407, P=.01; and SANE: 70.6% vs 86%, P=.05). One patient (2%) experienced a minor postoperative complication, and 3 patients (7%) required subsequent procedures: 2 total shoulder arthroplasties and 1 revision labral repair. The results of arthroscopic posterior labral repair in patients older than 35 years were variable and worse than those previously reported in younger patients. The presence of chondral damage at the time of the index procedure was a negative predictive factor. [Orthopedics. 2017; 40(2):e305-e311.].

Arthroscopic treatment of the atraumatic shoulder instability: a case series with two-year follow-up evaluation

BACKGROUND

The purpose of this work is to evaluate the results of arthroscopic capsulolabroplasty in patients affected by atraumatic shoulder instability (ASI).

METHODS

A retrospective review was performed of 10 patients (7 women and 3 men) who underwent arthroscopic treatment of symptomatic ASI. Mean age at evaluation was 27.9 (19-35) years and the mean follow-up was 23.3 (12-37) months. We evaluated recurrence rate, range of movement, apprehension and relocation tests, hyperlaxity, and sport activity. The ASES score, the Rowe score, the Simple Shoulder Test (SST) and Visual Analogue Scale (VAS) were also used as outcomes measure.

RESULTS

None of the patients experienced episodes of dislocation or subluxation after surgery. The apprehension and relocation tests produced positive results in 2 patients. Six out of 10 patients reported apprehension with the arm in specific positions. The ASES mean score was 93.4 (55-100); the Rowe mean score was 85.5 (70-100); the SST mean score was 9.1 (5.8-10). On average, external rotation is reduced by 10° in adduction, and by 8° in abduction in 6 out of 10 patients; internal rotation is reduced on average by 6.6° in abduction with the arm abducted, and was overall limited in 6 out of 10 patients.

CONCLUSIONS

Arthroscopic capsulolabroplasty ensures excellent results in patients showing atraumatic shoulder instability in terms of recurrence. Still, an underlying insecurity persists and the risk of residual stiffness is tangible.

LEVEL OF EVIDENCE

V.

Physical exam of the adolescent shoulder: tips for evaluating and diagnosing common shoulder disorders in the adolescent athlete

PURPOSE OF REVIEW

In the young athlete, the shoulder is one of the most frequently injured joints during sports activities. The injuries are either from an acute traumatic event or overuse. Shoulder examination can present some challenges; given the multiple joints involved, the difficulty palpating the underlying structures, and the potential to have both intra- and/or extra-articular problems.

RECENT FINDINGS

Many of the shoulder examination tests can be positive in multiple problems. They usually have high sensitivity but low specificity and therefore low predictive value. The medical history coupled with a detailed physical exam can usually provide the information necessary to obtain an accurate diagnosis. A proficient shoulder examination and the development of an adequate differential diagnosis are important before considering advanced imaging.

SUMMARY

The shoulder complex relies upon the integrity of multiple structures for normal function. A detailed history is of paramount importance when evaluating young athletes with shoulder problems. A systematic physical examination is extremely important to guiding an accurate diagnosis. The patient's age and activity level are very important when considering the differential diagnosis. Findings obtain through history and physical examination should dictate the decision to obtain advanced imaging of the shoulder.

The Rotator Cuff and the Superior Capsule: Why We Need Both

Tears of the rotator cuff are frequent. An estimated 250,000 to 500,000 repairs are performed annually in the United States. Rotator cuff repairs have been successful despite fatty infiltration and atrophy of the rotator cuff muscles. Although the emphasis in rotator cuff repair has historically focused on re-establishing the tendon attachment, there is growing interest in and understanding of the role of the superior capsule. The superior capsule is attached to the undersurface of the supraspinatus and infraspinatus muscle-tendon units, and it resists superior translation of the humeral head. Herein, we propose that it is the defect in the superior capsule that is the "essential lesion" in a superior rotator cuff tear, as opposed to the defect in the rotator cuff itself. We propose that rotator cuff repair must restore the normal capsular anatomy to provide normal biomechanics of the joint and thus a positive clinical outcome.

Humeral elevation reduces the dynamic control ratio of the shoulder muscles during internal rotation

OBJECTIVES

To determine the differences in the dynamic control ratio of the glenohumeral joint rotators, during internal rotation at 20° and 60° of humeral elevation in the scapular plan. Dynamic control ratio (DCR) is defined as the ratio between eccentric action of the lateral rotators and the concentric action of the medial rotators.

DESIGN

A cross-sectional laboratory study.

METHODS

Thirty asymptomatic participants (men n=14, women n=16, mean age=29.4±8.9years, BMI: 24.1±5.4) were tested. Peak torque generated by the concentric action of the MR and the eccentric action of the LR of the shoulder joint and the DCR were evaluated on the dominant arm using an isokinetic dynamometer at 20° and 60° of humeral elevation at a speed of 20°/s.

RESULTS

There was a significant decrease in the DCR at 60° humeral elevation when compared to 20° humeral elevation (p<0.05). This decrease was due to the significant decrease in eccentric peak torques at 60° humeral elevation when compared to 20° (p<0.05). However, there was no significant difference in the concentric peak torques between 20° and 60° (p>0.05).

CONCLUSIONS

The significant decrease in the DCR as a consequence of a decrease in the eccentric peak torque of the LR when the humerus is in a more elevated position suggests that the introduction of humeral elevation can be used as a progression for improving the eccentric action of the shoulder LR and subsequently the dynamic control of the shoulder.

Changes in the loadings on the shoulder girdle in the case of scapulothoracic fusion

BACKGROUND

Scapulothoracic fusion (STF) may be an alternative and salvage procedure in the treatment of scapular winging. The biomechanical effects of this procedure on the shoulder girdle have not been previously considered. The purpose of this study is to demonstrate the relationship between STF and the stress distribution pattern of the shoulder girdle.

METHODS

Three-dimensional solid modeling of the shoulder girdle was carried out using virtual finite element modeling. STF was applied to the reference model obtained in a computer environment. Dynamic and nonlinear analysis was performed.

RESULTS

Stress distributions in joints and ligaments were calculated. With respect to loading on the joints, maximum equivalent stresses increased on acromioclavicular (AC) and GH joints in the case of STF during abduction and flexion respectively.

CONCLUSION

Results revealed that STF is a non-physiological, static procedure leading to load increase on GH and AC joint cartilages, which may be a cause of potential joint osteoarthritis. Copyright © 2015 John Wiley & Sons, Ltd.

Differences in glenohumeral joint morphology between patients with anterior shoulder instability and healthy, uninjured volunteers

BACKGROUND

Traumatic glenohumeral joint (GHJ) dislocations are common, resulting in significant shoulder disability and pain. Previous research indicates that bony morphology is associated with an increased risk of injury in other joints (eg, the knee), but the extent to which bony morphology is associated with traumatic GHJ dislocation is unknown. This study assessed GHJ morphology in patients with anterior GHJ instability and in a control population of healthy volunteers.

METHODS

Bilateral computed tomography scans were used to measure GHJ morphology in both shoulders of 11 patients with instability and 11 control subjects. Specific outcome measures included the glenoid radius of curvature (ROC) in the anterior/posterior (A/P) and superior/inferior (S/I) directions, humeral head ROC, A/P and S/I conformity index, and A/P and S/I stability angle.

RESULTS

Compared with the control subjects, the glenoid of the instability the injured shoulder in patients with instability was flatter (ie, higher ROC) in the A/P (P = .001) and S/I (P = .01) directions and this finding was also true for uninjured, contralateral shoulder (A/P: P = .01, S/I: P = .03). No differences in GHJ morphology were detected between the instability patients' injured and contralateral shoulders (P > .07). Similarly, no differences in GHJ morphology were detected between the control subjects' dominant and nondominant shoulders (P > .51).

CONCLUSIONS

There are significant differences in GHJ morphology between healthy control subjects and both shoulders (injured and uninjured, contralateral) of patients diagnosed with anterior instability after GHJ dislocation. These findings are important clinically because they suggest that glenoid morphology may influence the risk of GHJ dislocation.

Upper limb kinematics after arthroscopic and open shoulder stabilization

BACKGROUND

Shoulder joint stability mediated by proprioception is often quantified by arm repositioning tests (i.e., static end-position accuracy), overlooking ongoing movement quality. This study assessed movement quality by adopting smoothness-related kinematic descriptors. We compared performance of healthy controls with that of patients in arthroscopic shoulder stabilization and open shoulder stabilization groups. We hypothesized that arm kinematics after arthroscopic intervention would more closely resemble healthy movements compared with patients after open shoulder stabilization surgery.

METHODS

Healthy controls (N = 14) were compared with patients after arthroscopic shoulder stabilization (N = 10) and open shoulder stabilization (N = 12). Right-hand dominant subjects (the affected side in patients) performed 135 unconstrained 3-dimensional pointing movements toward visual targets (seen through pinhole goggles; i.e., no arm vision). Arm kinematic data were recorded and offline analyzed to obtain hand tangential velocity profiles further used to compute the acceleration-to-movement time ratio, peak-to-mean velocity ratio, and number of velocity peaks ("symmetry," "proportion," and "fragmentation" features, respectively). Parametric and nonparametric statistics were used for comparisons (P ≤ .05).

RESULTS

Control and arthroscopic shoulder stabilization groups presented similar acceleration-to-movement time ratio and peak-to-mean velocity ratio. Both groups differed from the open shoulder stabilization group (P = .001). Distributions of velocity peaks for control and arthroscopic shoulder stabilization groups were similar, whereas open shoulder stabilization and control subjects differed significantly (P = .028).

CONCLUSIONS

Movement quality mediated by proprioception in arthroscopic shoulder stabilization patients matches that of healthy controls, whereas performance in open shoulder stabilization patients seems inferior compared with that in healthy controls, as assessed by smoothness-related measures (less symmetrical, more fragmented movements).

Structural and clinical integrity of the rotator cuff in athletes after arthroscopic Bankart repair using the three-portal technique

INTRODUCTION

Muscular recovery of structural integrity after arthroscopic Bankart repair using the para- and trans-musculotendinous three-portal technique has not been investigated.

MATERIALS AND METHODS

Twenty-seven athletes [mean age 26.9 years, (group 1; G1)] were prospectively and longitudinally monitored after arthroscopic Bankart repair using the three-portal technique by magnetic resonance imaging (MRI) and specific clinical muscular testing. The muscular integrity was assessed at the subscapularis (SSC) for the para-tendinous anteroinferior portal, the supraspinatus (SSP) for the trans-tendinous suprabicipital portal, and the infraspinatus (ISP) for the trans-tendinous posterior portal. Muscular atrophy was assessed by standardized ratios of transverse and vertical diameters for the SSC and ISP, as defined by cross-sectional area ratios for the SSP. Fatty infiltration was assessed by signal intensity analysis for the upper and lower SSC, SSP, and upper ISP as a ratio with the lower ISP. These parameters were analyzed for pre-operative (T0), 1-year (T1), and 2-year status (T2), and compared to 27 healthy volunteers [mean age 29.4 years, (group 2, G2)].

RESULTS

The structural integrity assessments were performed after 14.8 (T1) and 32.0 months (T2). The SSC analysis revealed no muscular impairments in the upper and lower portions between T0 and T2 or compared to G2. MRI analysis for SSP and ISP showed full muscular recovery without any changes between T0 and T2 or deficits compared to G2. The number of pre-operative dislocations had no influence on the muscular integrity. MR analysis detected signs of overuse syndrome in 15 % at T0, 41 % at T1, and 63 % at T2; 77, 22, and 26 % of patients at T0, T1, and T2, respectively, were symptomatic.

CONCLUSIONS

Arthroscopic Bankart repair using the three-portal technique prevents full muscular integrity for para-tendinous anteroinferior portals at the SSC, the trans-tendinous suprabicipital portal through the SSP, and the trans-tendinous portal through the ISP.