Glenohumeral joint volume reduction with progressive release and shifting of the inferior shoulder capsule

Imaging modalities for atraumatic shoulder hypermobility: a scoping review

BACKGROUND

Objective measures from imaging studies have the potential to assist in timely diagnosis of atraumatic shoulder hypermobility to better guide management. The aim of this scoping review is to examine imaging modalities and techniques used to characterize atraumatic shoulder hypermobility.

METHODS

MEDLINE, EMBASE, SPORTDiscus, Cochrane Library, and Web of Science were searched up to May 2024 for any primary study investigating imaging findings seen in atraumatic shoulder hypermobility. Patients with unilateral instability were excluded given its frequent association with traumatic origin.

RESULTS

Eighteen observational studies met inclusion criteria. Results were divided into outcomes relating to capsular redundancy, glenohumeral anatomy, and muscle activation. Five studies using magnetic resonance arthrography (MRA) demonstrated statistically significant increases in capsular cross-sectional area (CSA), while a significant superior capsular elongation was reported by two studies in patients with multidirectional instability (MDI). Labrocapsular distance, glenocapsular ratio, and the presence of a combined sail and triangle sign on MRA were highly sensitive and specific parameters for identifying MDI. There were inconsistent findings for alterations of glenohumeral anatomy. Ultrasound assessments of acromiohumeral distance (AHD) were significantly increased in patients with MDI, but not in shoulders with hypermobility alone. Similarly, muscle activity measured by electromyography or glenohumeral translations differed significantly in patients with MDI, but not in those with hypermobility alone.

CONCLUSION

Radiographic markers of capsular redundancy (e.g., CSA, labrocapsular distance, glenocapsular ratio), AHD, and muscular activity are useful in the diagnosis of MDI. However, there are no definitive imaging markers for diagnosing atraumatic shoulder hypermobility without MDI.

Computed Tomography Scan Versus Saline Load Test for Detection of Traumatic Shoulder Arthrotomy: A Cadaveric Study

OBJECTIVES

Traumatic shoulder arthrotomy (TSA) is a rare injury that is commonly detected through saline load test (SLT). There are no studies that have studied the ability of computed tomography (CT) scan to detect a TSA. The purpose of this study is to determine the ability of CT scan to detect a TSA and compare it with the SLT.

METHODS

Twelve cadaveric shoulders were included in the study. Before intervention, a CT scan was conducted to determine presence of intra-articular air. After confirmation that no air was present, an arthrotomy was made at the anterior or posterior portal site. A CT was obtained postarthrotomy to evaluate for intra-articular air. Each shoulder then underwent an SLT to assess the sensitivity of SLT and the volume needed for extravasation.

RESULTS

Twelve shoulders were included after a pre-intervention CT scan. Six shoulders received an arthrotomy through the anterior portal and six shoulders received an arthrotomy through the posterior portal. After the arthrotomy, air was visualized on CT scan in 11 of the 12 shoulders (92%). All 12 shoulders demonstrated extravasation during SLT. The mean volume of saline needed for extravasation was 29 mL with an SD of 10 and range of 18-50 mL.

CONCLUSIONS

CT scan is a sensitive modality (sensitivity of 92%) for detection of TSA. In comparison, SLT is more sensitive (sensitivity of 100%) and outperforms CT scan for the diagnosis of TSA in a cadaveric model. Further research is needed to solidify the role that CT imaging has in the diagnosis of TSAs.

Comprehensive Review of Multidirectional Instability of the Shoulder

Multidirectional instability of the shoulder can result from underlying atraumatic laxity, from repetitive microtrauma, or from a traumatic injury and often occurs in association with generalized ligamentous laxity or underlying connective tissue disorders. It is critical to differentiate multidirectional instability from unidirectional instability with or without generalized laxity to maximize treatment success. Although rehabilitation is still considered the primary treatment method for this condition, surgical treatment in the form of open inferior capsular shift or arthroscopic pancapsulolabral plication is indicated if conservative treatment fails. Recent biomechanical and clinical research has shown that there is still room for improvement in the treatment methods offered to this specific patient cohort. Potential treatment options, such as various methods to improve cross-linking of native collagen tissue, electric muscle stimulation to retrain the abnormally functioning dynamic stabilizers of the shoulder, and alternative surgical techniques such as coracohumeral ligament reconstruction and bone-based augmentation procedures, are brought forth in this article as potential avenues to explore in the future.

Management of Shoulder Instability in Patients with Underlying Hyperlaxity

PURPOSE OF REVIEW

Shoulder instability in patients with underlying joint hyperlaxity can be challenging to treat. Poorly defined terminology, heterogeneous treatments, and sparse reports on clinical outcomes impair the development of best practices in this patient population. This article provides a review of the current literature regarding optimal management of patients suffering from shoulder instability with concomitant hyperlaxity of the shoulder, from isolated shoulder joint hyperlaxity to congenital hypermobility spectrum disorders (HSD).

RECENT FINDINGS

Current research shows specialized physiotherapy protocols focused on strengthening of periscapular muscles and improvement of sensorimotor control are a promising non-surgical therapeutic avenue in certain patients, which can be augmented by device-based intervention in select cases. If surgical treatment is warranted, arthroscopic techniques such as pancapsular shift or plication continue to demonstrate favorable outcomes and are currently considered the benchmark for success. The long-term success of more recent innovations such as coracoid process transfers, conjoint tendon transfers, subscapularis tendon augmentation, and capsular reconstruction remains unproven. For patients affected by connective tissue disorders, treatment success is generally less predictable, and the entire array of non-operative and operative interventions needs to be considered to achieve the best patient-specific treatment results. In the treatment of shoulder instability and concomitant hyperlaxity, specialized physiotherapy protocols augmented by device-based interventions have emerged as powerful, non-operative treatment options for select patients. Successful surgical approaches have been demonstrated to comprehensively address capsular redundancy, labral lesions, and incompetence of additional passive stabilizers in a patient-specific fashion, respective of the underlying connective tissue constitution.

Influence of joint volume on range of motion after arthroscopic rotator cuff repair

BACKGROUND

Capsular contracture is a well-known etiology in the primary stiff shoulder; thus capsular contracture and resultant decreased joint volume could lead to postoperative stiffness, which is a commonly reported morbidity after arthroscopic rotator cuff repair (ARCR). The purpose of this study was (1) to quantify the joint volume (total joint volume and each quadrant compartmental volume) using computed tomography arthrography (CTA) and (2) to demonstrate the relationship between joint volume and postoperative range of motion (ROM) after ARCR.

MATERIALS AND METHODS

Eighty-three patients (60 ± 5.11 years, men = 26, women = 57) who had undergone ARCR between January 2015 to December 2020 due to small to medium full-thickness tear and followed by CTA 6 months postoperatively were retrospectively reviewed. An image reconstruction program (3D Slicer, version 4.11.2 software) was used to calculate the joint volume (total joint volume and quadrant compartment joint volumes; anteroinferior, anterosuperior, posterosuperior and posteroinferior). For shoulder ROM, data including scaption (Sc), external rotation on side (ERs), external rotation at 90° (ER90), and internal rotation on back (IRb) were collected 6 months postoperatively. An evaluation of the correlation between joint volume and each shoulder motion was performed.

RESULTS

There were moderate correlations between the total joint volume and each motion (Sc: Pearson coefficient, 0.32, p = 0.0047; ERs: Pearson coefficient, 0.24, p = 0.0296; ER90: Pearson coefficient, 0.33, p = 0.0023; IRb: Pearson coefficient, 0.23, p = 0.0336). Among the quadrant compartments, the anteroinferior (Sc: Pearson coefficient, 0.26, p = 0.0199; ERs: Pearson coefficient, 0.23, p = 0.0336; ER90: Pearson coefficient, 0.25, p = 0.0246; IRb: Pearson coefficient, 0.26, p = 0.0168) and posterosuperior (Sc: Pearson coefficient, 0.24, p = 0.029; ER90: Pearson coefficient, 0.29, p = 0.008; IRb: Pearson coefficient, 0.22, p = 0.0491) and posteroinferior (Sc: Pearson coefficient, 0.30, p = 0.0064; ER90: Pearson coefficient, 0.29, p = 0.0072) showed moderate correlations with each shoulder motion.

CONCLUSION

Total joint volume, anteroinferior compartment joint volume, posterosuperior compartment joint volume and posteroinferior compartment joint volume were related to postoperative ROM after ARCR. Perioperative methods to increase the joint volume, especially the anteroinferior, posterosuperior and posteroinferior parts of the capsule may prevent postoperative stiffness after ARCR.

LEVEL OF EVIDENCE

Level III; Retrospective Case-Control Study.

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.

Open Stabilization Procedures of the Shoulder in the Athlete: Indications, Techniques, and Outcomes

Shoulder instability is a relatively common injury especially in the young athletic population and its surgical management continues to remain a controversial topic in sports medicine orthopedics. Anterior instability is the most common type encountered and is estimated to have an incidence rate of 0.08 per 1000 person-years in the general population; however, this figure is likely higher in the young athletic population. While in recent practice, arthroscopic surgery has become the new gold standard for management, reported failure rates as high as 26% and high recurrence rates in specific subpopulations such as young men in high collision sports have led to the consideration of alternative open procedures such as open Bankart repair, Latarjet, capsular shift, and glenoid bone grafting. These procedures may be preferred in specific patient subgroups such as young athletes involved in contact sports and those with Hill-Sachs defects and multidirectional instability, with postoperative recurrence rates of instability as low as 10%. The purpose of this review is to provide an overview of different open surgical techniques in the management of shoulder instability and summarize patient outcomes including recurrence rates for shoulder instability, return to sport, range of motion (ROM), muscle strength, and complications either individually by procedure or in comparison with other techniques, with special focus on their impact in the athletic population.

Arthroscopic Bankart repair with an individualized capsular shift restores physiological capsular volume in patients with anterior shoulder instability

PURPOSE

Capsular volume reduction in the context of anterior arthroscopic shoulder stabilization represents an important but uncontrolled parameter. The aim of this study was to analyse capsular volume reduction by arthroscopic Bankart repair with an individualized capsular shift in patients with and without ligamentous hyperlaxity compared to a control group.

METHODS

In the context of a prospective controlled study, intraoperative capsular volume measurements were performed in 32 patients with anterior shoulder instability before and after arthroscopic Bankart repair with an individualized capsular shift. The results were compared to those of a control group of 50 patients without instability. Physiological shoulder joint volumes were calculated and correlated with biometric parameters (sex, age, height, weight and BMI).

RESULTS

Patients with anterior shoulder instability showed a mean preinterventional capsular volume of 35.6 ± 10.6 mL, which was found to be significantly reduced to 19.3 ± 5.4 mL following arthroscopic Bankart repair with an individualized capsular shift (relative capsular volume reduction: 45.9 ± 21.9%; P < 0.01). Pre-interventional volumes were significantly greater in hyperlax than in non-hyperlax patients, while post-interventional volumes did not differ significantly. The average shoulder joint volume of the control group was 21.1 ± 7.0 mL, which was significantly correlated with sex, height and weight (P < 0.01). Postinterventional capsular volumes did not significantly differ from those of the controls (n.s.).

CONCLUSION

Arthroscopic Bankart repair with an individualized capsular shift enabled the restoration of physiological capsular volume conditions in hyperlax and non-hyperlax patients with anterior shoulder instability. Current findings allow for individual adjustment and intraoperative control of capsular volume reduction to avoid over- or under correction of the shoulder joint volume. Future clinical studies should evaluate, whether individualized approaches to arthroscopic shoulder stabilization are associated with superior clinical outcome.

Influence of Glenoid Labral Bumper Height and Capsular Volume on Clinical Outcomes After Arthroscopic Bankart Repair as Assessed With Serial CT Arthrogram: Can Anterior-Inferior Volume Fraction Be a Prognostic Factor?

BACKGROUND

Arthroscopic labral repair combined with capsular plication decreases joint volume and restores glenoid labral bumper height; thus, the procedure helps decrease capsular redundancy. However, the decreased volume and restored glenoid labral bumper height could change over time, which could influence the outcome of the operation.

PURPOSE

To (1) measure glenoid labral bumper height and capsular volume quantitatively in serial computed tomography arthrography (CTA) and evaluate the relationship between bumper height and joint volume and (2) compare the difference in bumper height and joint volume between groups with and without apprehension after arthroscopic Bankart repair.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Patients who had undergone arthroscopic Bankart repair between January 2012 and June 2016, and were assessed by CTA 3 to 6 months and 12 to 18 months after the operation were included. An image reconstruction program (3-dimensional slicer) was used to calculate inferior, anterior-inferior, and posterior-inferior joint volumes; the ratio of the anterior-inferior volume to the inferior volume was defined as the anterior-inferior volume fraction (VF_AI). We also measured glenoid labral bumper height at the 5-, 4-, and 3-o'clock positions.

RESULTS

A total of 50 patients were enrolled as study participants (mean age, 25.2 ± 9.29 years). Of these, 10 patients had either redislocation or apprehension, and 40 patients had neither. A significant correlation was observed between 5-o'clock glenoid labral bumper height and VF_AI on early CTA (3-6 months) and late CTA (12-18 months) (early CTA: Pearson coefficient, -0.335, P = .040; late CTA: Pearson coefficient, -0.468, P = .003). VF_AI at the early CTA was 42.20 ± 10.15 in the group with apprehension and 33.49 ± 9.66 in the group without apprehension; a significant difference was observed. VF_AI at the late CTA was 45.84 ± 11.97 in the group with apprehension and 37.65 ± 9.70 in the group without apprehension and thus showed a significant difference between the 2 groups. However, the 3-, 4-, and 5-o'clock glenoid labral bumper heights on early and late CTAs did not show a statistically significant difference between the 2 groups.

CONCLUSION

Early postoperative VF_AI is related to postoperative apprehension and redislocation and might be reduced by increasing the 5-o'clock glenoid labral bumper height.

High- vs Low-Dose Corticosteroid Injection in the Treatment of Adhesive Capsulitis with Severe Pain: A Randomized Controlled Double-Blind Study

Objective

To compare the degree of pain relief between high-dose (40 mg of triamcinolone acetonide) and low-dose (20 mg of triamcinolone acetonide) corticosteroid injections in patients with severe pain due to adhesive capsulitis.

Design

A prospective, randomized, double-blind, dose-comparative study.

Subjects

A total of 32 patients who were diagnosed with adhesive capsulitis and who expressed severe pain intensity, 8 or more points on a numeric rating scale (NRS).

Methods

Patients received injections of high- or low-dose triamcinolone acetonide under ultrasound guidance. NRS, Shoulder Pain and Disability Index (SPADI), and the passive range of motion (PROM) in four directions were evaluated before and three weeks after the injection.

Results

NRS scores showed significant improvement three weeks after the injection in both groups (P = 0.01 in both the low-dose group and high-dose group), but there was no statistically significant difference between the two groups (P = 0.63). SPADI score significantly improved at three weeks after the injection in both groups (P = 0.02 in the low-dose group and P < 0.01 in the high-dose group), but group difference was not observed (P = 0.06). The change of PROM in four directions after the injection did not show any significant difference between the low- and high-dose groups.

Conclusions

Injection of 20 mg of triamcinolone acetonide is sufficient to elicit symptom relief in patients with severe adhesive capsulitis; hence, 20 mg of triamcinolone acetonide can be recommended in patients with adhesive capsulitis with severe pain.

Three-dimensional Capsular Volume Measurements in Multidirectional Shoulder Instability

Background

In a previous study undertaken to quantify capsular volume in rotator cuff interval or axillary pouch, significant differences were found between controls and patients with instability. However, the results obtained were derived from two-dimensional cross sectional areas. In our study, we sought correlation between three-dimensional (3D) capsular volumes, as measured by magnetic resonance arthrography (MRA), and multidirectional instability (MDI) of the shoulder.

Methods

The MRAs of 21 patients with MDI of the shoulder and 16 control cases with no instability were retrospectively reviewed. Capsular areas determined by MRA were translated into 3D volumes using 3D software Mimics ver. 16 (Materilise, Leuven, Belgium), and glenoid surface area was measured in axial and coronal MRA views. Then, the ratio between capsular volume and glenoid surface area was calculated, and evaluated with control group.

Results

The ratio between 3D capsular volume and glenoid surface area was significantly increased in the MDI group (3.59 ± 0.83 cm³/cm²) compared to the control group (2.53 ± 0.62 cm³/cm²) (p<0.01).

Conclusions

From these results, we could support that capsular volume enlargement play an important role in MDI of the shoulder using volume measurement.

What Are the Effects of Capsular Plication on Translational Laxity of the Glenohumeral Joint: A Study in Cadaveric Shoulders

BACKGROUND

Surgical treatment for shoulder instability generally involves labral repair with a capsular plication or imbrication. Good results are reported in both open and arthroscopic procedures, but there is no consensus on the amount or location of capsular plication that is needed to achieve stability and anatomic anterior, posterior, and inferior translation of the joint.

QUESTIONS/PURPOSES

(1) What are the separate and combined effects of increasing plication magnitude and sequential additive plications in the anterior, posterior, and inferior locations of the joint capsule on glenohumeral joint translation in the anterior, posterior, and inferior directions? (2) What plication location and magnitude restores anterior, posterior, and inferior translation to a baseline level?

METHODS

Fourteen cadaveric shoulders were dissected down to the glenohumeral capsule and underwent instrumented biomechanical testing. Each shoulder was loaded with 22 N in anterior, posterior, and inferior directions at 60° abduction and neutral rotation and flexion and the resulting translation were recorded. Testing was done over baseline (native), stretched (mechanically stretched capsule to imitate a lax capsule), and 5-mm, 10-mm, and 15-mm plication conditions. Individually, for each of the 5-, 10-, and 15-mm increments, plications were done in a fixed sequential order starting with anterior plication at the 3 o'clock position (Sequence I), then adding posterior plication at the 9 o'clock position (Sequence II), and then adding inferior plication at the 6 o'clock position (Sequence III). Each individual sequence was tested by placing 44 N (10 pounds) of manual force on the humerus directed in an anterior, posterior, and inferior direction to simulate clinical load and shift testing. The effect of plication magnitude and sequence on translation was tested with generalized estimating equation models. Translational differences between conditions were tested with paired t-tests.

RESULTS

Translational laxity was highest with creation of the lax condition, as expected. Increasing plication magnitude had a significant effect on all three directions of translation. Plication location sequence had a significant effect on anterior and posterior translation. An interaction effect between plication magnitude and sequence was significant in anterior and posterior translation. Laxity in all directions was most restricted with 15-mm plication in anterior, posterior, and inferior locations. For anterior translational laxity, at 10-mm and 15-mm plication, there was a progressive decrease in translation magnitude (10-mm plication anterior only: 0.46 mm, plus posterior: 0.29 mm, plus inferior, -0.12 mm; and for 15-mm anterior only: -0.53 mm, plus posterior: -1.00 mm, plus inferior: -1.66 mm). For posterior translational laxity, 10-mm and 15-mm plication also showed progressive decrease in magnitude (10-mm plication anterior only: 0.46 mm, plus posterior: -0.25 mm, plus inferior: -1.94; and for 15-mm anterior only: 0.14 mm, plus posterior: -1.54 mm, plus inferior: -3.66). For inferior translational laxity, tightening was observed only with magnitude of plication (anterior only at 5 mm: 0.31 mm, at 10 mm: -1.39, at 15 mm: -3.61) but not with additional plication points (adding posterior and inferior sequences). To restore laxity closest to baseline, 10-mm AP/inferior plication best restored anterior translation, 15-mm anterior plication best restored posterior translation, and 5 mm posterior with or without inferior plication best restored inferior translation.

CONCLUSIONS

Our results suggest that (1) a 10-mm plication in the anterior and posterior or anterior, posterior, and inferior positions may restore anterior translation closest to baseline; (2) 10-mm anterior and posterior or 15-mm anterior plications may restore posterior translation closest to baseline; and (3) 5-mm anterior and posterior or anterior, posterior, and inferior plications may restore inferior translation closest to baseline. Future studies using arthroscopic techniques for plication or open techniques via a true surgical approach might further characterize the effect of plication on glenohumeral translation.

CLINICAL RELEVANCE

This study found that specific combinations of plication magnitude and location can be used to restore glenohumeral translation from a lax capsular state to a native state. This information can be used to guide surgical technique based on an individual patient's degree and direction of capsular laxity. In vivo testing of glenohumeral translation before and after capsular plication will be needed to validate these cadaveric results.

Effect of arthroscopic techniques on joint volume in shoulder instability: Bankart repair versus capsular shift

PURPOSE

The evaluation of glenohumeral joint volume in both unstable (with/without laxity) and stable shoulders (subacromial impingement) and volume reduction potential of arthroscopic techniques: (labral anchor repair vs. capsular shift).

METHODS

Material was based on 133 patients: anterior shoulder instability without laxity (group I, n = 49), with laxity (group II, n = 22) and subacromial impingement (control group, n = 62) operated in 2010-2011. Group I received arthroscopic Bankart repair, group; II - arthroscopic anterior capsular plication, control group - subacromial decompression. Joint volume was measured by fluid aspiration into the syringe via arthroscope, before and after procedure. Then volume reduction potential was calculated.

RESULTS

The following average values of initial joint volume were recorded: group I - 26.8 ml group II - 43.7 ml and the control group - 25.6 ml with significant differences: impingement vs. instability + laxity (p < 0.00001), impingement vs. instability without laxity (p = 0.0001). There was no significant difference between groups I and II. Joint volume was significantly reduced after labral repair (by average of 37 %, 13.8 ml, p < 0.0001). Capsular shift led to an even greater and more significant volume decrease (61 %, 26.7 ml, p < 0.001). Joint volume in the control group was reduced only by 11 %, 3.8 ml (p = 0.046).

CONCLUSIONS

Patients with unstable shoulders have enlarged joint volume as compared to patients with subacromial impingement. Arthroscopic techniques lead to a significant joint volume reduction, with the most powerful effect for capsular shift. Level of Evidence - Level 2.

History of shoulder instability surgery

PURPOSE

The surgical management of shoulder instability is an expanding and increasingly complex area of study within orthopaedics. This article describes the history and evolution of shoulder instability surgery, examining the development of its key principles, the currently accepted concepts and available surgical interventions.

METHODS

A comprehensive review of the available literature was performed using PubMed. The reference lists of reviewed articles were also scrutinised to ensure relevant information was included.

RESULTS

The various types of shoulder instability including anterior, posterior and multidirectional instability are discussed, focussing on the history of surgical management of these topics, the current concepts and the results of available surgical interventions.

CONCLUSIONS

The last century has seen important advancements in the understanding and treatment of shoulder instability. The transition from open to arthroscopic surgery has allowed the discovery of previously unrecognised pathologic entities and facilitated techniques to treat these. Nevertheless, open surgery still produces comparable results in the treatment of many instability-related conditions and is often required in complex or revision cases, particularly in the presence of bone loss. More high-quality research is required to better understand and characterise this spectrum of conditions so that successful evidence-based management algorithms can be developed.

LEVEL OF EVIDENCE

IV.

Multidirectional Instability of the Shoulder: A Systematic Review

PURPOSE

To analyze outcomes of surgical and conservative treatment options for multidirectional instability (MDI).

METHODS

A systematic review of the literature according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was performed. A comprehensive search of the PubMed, MEDLINE, CINAHL, Cochrane, EMBASE, and Google Scholar databases using various combinations of the keywords "shoulder," "multidirectional instability," "dislocation," "inferior instability," "capsulorrhaphy," "capsular plication," "capsular shift," "glenoid," "humeral head," "surgery," and "glenohumeral," over the years 1966 to 2014 was performed.

RESULTS

Twenty-four articles describing patients with open capsular shift, arthroscopic treatment, and conservative or combined management in the setting of atraumatic MDI of the shoulder were included. A total of 861 shoulders in 790 patients was included. The median age was 24.3 years, ranging from 9 to 56 years. The dominant side was involved in 269 (58%) of 468 shoulders, whereas the nondominant side was involved in 199 (42%) shoulders. Patients were assessed at a median follow-up period of 4.2 years (ranging from 9 months to 16 years). Fifty-two of 253 (21%) patients undergoing physiotherapy required surgical intervention for MDI management, whereas the overall occurrence of redislocation was seen in 61 of 608 (10%) shoulders undergoing surgical procedures. The redislocation event occurred in 17 of 226 (7.5%) shoulders with open capsular shift management, in 21 of 268 (7.8%) shoulders with arthroscopic plication management, in 12 of 49 (24.5%) shoulders undergoing arthroscopic thermal shrinkage, and in 11 of 55 (22%) shoulders undergoing arthroscopic laser-assisted capsulorrhaphy.

CONCLUSIONS

Arthroscopic capsular plication and open capsular shift are the best surgical procedures for treatment of MDI after failure of rehabilitative management. Arthroscopic capsular plication shows results comparable to open capsular shift.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I to IV studies.

Factors affecting capsular volume changes and association with outcomes after Bankart repair and capsular shift

BACKGROUND

Capsular laxity is a main contributing factor in recurrent shoulder instability and is suggested to be correlated with increased capsular volume. Arthroscopic capsular shift combined with Bankart repair can reduce the capsular volume and reinforce the redundant capsule; however, as the capsuloligamentous structure has viscoelastic properties, it is possible for the shifted and tensioned capsule of the glenohumeral joint to slowly stretch out again over time, resulting in an increase in capsular volume.

PURPOSE

To analyze changes in capsular volume of the glenohumeral joint over time after arthroscopic Bankart repair and capsular shift, the factors associated with these changes, and their relevance to outcomes.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Included in this study were 105 patients (mean age, 25.8 ± 8.2 years) who underwent arthroscopic Bankart repair and capsular shift for anterior shoulder instability and computed tomography arthrography (CTA) at 3 months and 1 year postoperatively and whose various functional outcomes were evaluated preoperatively and at the last follow-up (>12 months). Among these patients, 27 also had preoperative CTA. These 27 patients were used to make comparisons between preoperative and 3-month postoperative CTA measurements, and all 105 patients were used for all other comparisons. Two raters measured the separate anterior and posterior capsular volume and cross-sectional area at the 5-o'clock position using 3-dimensional (3D) Slicer software. These measurements were subsequently adjusted for each glenoid size. The changes in capsular volume and cross-sectional area at the 5-o'clock position over time, the factors related to higher change in anterior capsular volume, and their correlation with outcomes were evaluated.

RESULTS

Three months postoperatively, the total and anterior capsular volume and anterior cross-sectional area significantly decreased; however, these values increased again at 1 year postoperatively (all P < .01). The inter- and intraobserver reliabilities of the measurements were excellent (interclass correlation coefficient = 0.717-0.945). Female sex, being an elite athlete, and more dislocations before surgery were related to a higher increase in anterior capsular volume at 1 year (all P < .05). Eight patients had redislocation, and 18 exhibited positive apprehension test postoperatively, and these patients showed significantly higher increases in anterior and total capsular volume at 1 year than did those without redislocation or positive apprehension sign (all P < .01). However, with the exception of Rowe score, a higher increase in anterior capsular volume was not related to functional outcome measures.

CONCLUSION

Surgeons should be aware of the re-increase in anterior capsular volume or restretching trait of the anterior capsule over time, even after successful arthroscopic Bankart repair and capsular shift. In this study, women, elite athletes, and those with frequent dislocations were at high risk of capsular restretching. An increase in capsular volume was related to redislocation and positive apprehension sign as well as with Rowe score.

Pediatric and adolescent shoulder instability

Instability of the shoulder is a common issue faced by sports medicine providers caring for pediatric and adolescent patients. A thorough history and physical examination can help distinguish traumatic instability from multidirectional or voluntary instability. A systematic understanding of the relevant imaging characteristics and individual patient disease and goals can help guide initial treatment. Given the high risk of recurrent instability, young, active patients who seek to return to competitive contact sports should consider arthroscopic stabilization after a first-time instability event. MDI should be treated initially with conservative rehabilitation. Patients who fail extensive conservative treatment may benefit from surgical stabilization. Arthroscopic techniques may now approach the results found from traditional open capsular shift procedures. Future studies should be designed to examine the outcomes in solely pediatric and adolescent populations after both conservative and operative treatment of shoulder instability.

Management of multidirectional instability of the shoulder

Multidirectional shoulder instability is defined as symptomatic instability in two or more directions. Instability occurs when static and dynamic shoulder stabilizers become incompetent due to congenital or acquired means. Nonspecific activity-related pain and decreased athletic performance are common presenting complaints. Clinical suspicion for instability is essential for timely diagnosis. Several examination techniques can be used to identify increased glenohumeral translation. It is critical to distinguish increased laxity from instability. Initial management begins with therapeutic rehabilitation. If surgical management is required, capsular plication has been used successfully. Advanced arthroscopic techniques offer several advantages over traditional open approaches and may have similar outcomes. The role of rotator interval capsular plication is controversial, but it may be used to augment capsular plication in patients with specific patterns of instability. Despite encouraging results, outcomes remain inferior to those associated with traumatic unidirectional instability.

Arthroscopic capsular shift technique and volume reduction

Multidirectional instability is very complex pathology. Excessively redundant capsule is one of the important reasons causing symptomatic laxity in multiple planes. Arthroscopic techniques are not able to reproduce the potential of open methods to reduce the joint volume. Most of the studies based their measurements on cadaver model. The aim of the study was to develop simple and reproducible technique to perform arthroscopic capsular shift and measure its volume reduction potential in both cadaveric and clinical setting. Technique is described in the paper. Capsular shift was applied both in cadaver and clinical scenario. Based on group of 5 cadaver shoulder specimen, glenohumeral joint volume was reduced from average of 19.4 ± 7.8 ml to 11.9 ± 4.5 ml following arthroscopic capsular shift (37.9% volume reduction). Clinical material consisted of 12 consecutive patients shoulder with instability and joint laxity undergoing the arthroscopic capsular shift. Average glenohumeral volume before capsular shift was 43.5 ± 10 ml and was reduced to 17.5 ± 4.3 ml (58.8% volume reduction). Arthroscopic capsular shift presented in this paper seems to be relatively easy to perform and safe procedure. The technique provides significant decrease in joint volume in both cadaveric and clinical parts of the study.

Arthroscopic management of multidirectional instability

The most critical step in successful treatment of shoulder instability does not lie in surgical technique, but in accurate assessment of factors contributing to instability. Multidirectional instability (MDI) is initially treated with rehabilitation. The primary goal of rehabilitation is strengthening of the dynamic stabilizers, including the rotator cuff and scapular stabilizers. There are several surgical techniques described to manage MDI, ranging from the classic Neer inferior capsular shift to a variety of arthroscopic procedures. This article focuses on the arthroscopic management of MDI.