Arthroscopic versus open rotator interval closure: biomechanical evaluation of stability and motion

Taping Adjunct to Strengthening and Proprioception in a Hill-Sachs Lesion Patient: A Case Report

A Hill-Sachs lesion is a bony defect in the head of the humerus due to recurrent dislocation, which results in friction between the humeral head and the glenoid fossa. This recurrent incident of dislocation that occurs in the anterior direction eventually leads to a Bankart lesion (a defect in the glenoid rim). A 21-year-old male, a recreational football player, reported recurrent shoulder dislocation, complaining of pain and difficulty doing certain activities. He had hypermobility of the shoulder joint during joint play assessment. Proprioception is the sense of the position and movement of one's own body. Exercises that improve proprioception can help improve shoulder stability and reduce the risk of shoulder injuries. Proprioception has shown significant positive results in shoulder dislocations. A physiotherapy protocol was designed that included strengthening of shoulder and scapular musculatures, proprioceptive exercises, and plyometric exercises for developing agility. All these exercises were given with taping for the shoulder joint. Taping helps stabilize the shoulder and normalizes muscle function. With the help of physiotherapy, patients can avoid invasive procedures for restoring stability in non-traumatic recurrent shoulder dislocations.

Editorial Commentary: Hyperlaxity Is a Common Factor in Failed Arthroscopic Bankart Repair

Hyperlaxity is a common factor in failed arthroscopic Bankart repair. The best treatment for patients with instability, hyperlaxity, and minimal bone loss is still controversial. Patients with hyperlaxity often have subluxations rather than frank dislocation, and concurrent traumatic structural lesions are infrequent. Conventional arthroscopic Bankart repair with or without capsular shift poses a risk of recurrence because of soft tissue insufficiency. The Latarjet is not a good procedure in patients with hyperlaxity and instability, especially an inferior component, and risks include a higher degree of postoperative osteolysis after Latarjet with an intact glenoid. The arthroscopic Trillat procedure may be used to treat this challenging patient group by repositioning the coracoid medially and downward by a partial wedge osteotomy. The coracohumeral distance and shoulder arch angle are decreased after performing the Trillat, which may reduce instability, and the Trillat procedure mimics the sling effect of the Latarjet. However, complications should be considered due to the procedure's nonanatomic nature, such as osteoarthritis, subcoracoid impingement, and loss of motion. Other options to improve inferior stability include robust rotator interval closure, coracohumeral ligament reconstruction, and posteroinferior/inferior/anteroinferior capsular shift. The addition of posteroinferior capsular shift and rotator interval closure in the medial lateral direction also benefits this vulnerable patient group.

Effect of intraarticular pressure on glenohumeral kinematics during a simulated abduction motion: a cadaveric study

BACKGROUND

The current understanding of glenohumeral joint stability is defined by active restrictions and passive stabilizers including naturally-occurring negative intraarticular pressure. Cadaveric specimens have been used to evaluate the role of intraarticular pressure on joint stability, although, while the shoulder's negative intraarticular pressure is universally acknowledged, it has been inconsistently accounted for.

HYPOTHESIS

During continuous, passive humeral abduction, releasing the native intraarticular pressure increases joint translation, and restoring this pressure decreases joint translations.

STUDY DESIGN

Descriptive Laboratory Study.

METHODS

A validated shoulder testing system was used to passively abduct the humerus in the scapular plane and measure joint translations for seven (n = 7) cadaveric specimens. The pressure within the glenohumeral joint was measured via a 25-gauge needle during passive abduction of the arm, which was released and subsequently restored. During motion, the rotator cuff muscles were loaded using stepper motors in a force feedback loop and electromagnetic sensors were used to continuously measure the position of the humerus and scapula. Joint translation was defined according to the instant center of rotation of the glenohumeral head according to the recommendations by the International Society of Biomechanics.

RESULTS

Area under the translation versus abduction angle curve suggests that releasing the pressure within the capsule results in significantly less posterior translation of the glenohumeral head as compared to intact (85-90˚, p < 0.05). Posterior and superior translations were reduced after 70˚ of abduction when the pressure within the joint was restored.

CONCLUSION

With our testing system employing a smooth continuous passive motion, we were able to show that releasing intraarticular pressure does not have a major effect on the path of humeral head motion during glenohumeral abduction. However, both violating the capsule and restoring intraarticular pressure after releasing alter glenohumeral translations. Future studies should study the effect of simultaneous external rotation and abduction on the relationship between joint motion and IAP, especially in higher degrees of abduction.

CLINICAL RELEVANCE

Thoroughly simulating the glenohumeral joint environment in the cadaveric setting may strengthen the conclusions that can be translated from this setting to the clinic.

Multidirectional instability of the shoulder: surgical techniques and clinical outcome

Multidirectional instability of the shoulder has a complex pathoanatomy. It is characterized by a redundant glenohumeral capsule and increased joint volume. Subtle clinical presentation, unclear trauma history and multifactorial etiology poseses a great challenge for orthopedic surgeons in terms of diagnosis. Generally accepted therapeutic approach is conservative and the majority of patients achieve good results with rehabilitation. In patients who are symptomatic despite appropriate rehabilitation, surgical intervention may be considered. Good results have been obtained with open inferior capsular surgery, which has historically been performed in these patients. In recent years, advanced arthroscopic techniques have taken place in this field, and similar results compared to open surgery have been obtained with the less-invasive arthroscopic capsular plication procedure.

Indications and outcomes of glenoid osteotomy for posterior shoulder instability: a systematic review

Background

There is limited evidence examining glenoid osteotomy as a treatment for posterior shoulder instability.

Methods

A search of Medline, Embase, PubMed and Cochrane Central Register of Controlled Trials was conducted from the date of origin to 28th November 2019. Nine out of 3,408 retrieved studies met the inclusion criteria and quality was assessed using the Methodological Index for Non-randomized Studies tool.

Results

In 356 shoulders, the main indication for osteotomy was excessive glenoid retroversion (greater than or equal to approximately −10°). The mean preoperative glenoid version was −15° (range, −35° to −5°). Post-operatively, the mean glenoid version was −6° (range, −28° to 13°) and an average correction of 10° (range, −1° to 30°) was observed. Range of motion increased significantly in most studies and all standardized outcome scores (Rowe, Constant–Murley, Oxford instability, Japan Shoulder Society Shoulder Instability Scoring and mean shoulder value) improved significantly with high rates of patient satisfaction (85%). A high complication rate (34%, n = 120) was reported post-surgery, with frequent cases of persistent instability (20%, n = 68) and fractures (e.g., glenoid neck and acromion) (4%, n = 12). However, the revision rate was low (0.6%, n = 2).

Conclusion

Glenoid osteotomy is an appropriate treatment for posterior shoulder instability secondary to excessive glenoid retroversion. However, the high rate of persistent instability should be considered when making treatment decisions. Level of Evidence: Systematic review; Level 4

The Angular Relationships Between the Coracohumeral Ligament and Adjacent Shoulder Structures Are Variable

Purpose

To describe the arthroscopic anatomy of the coracohumeral ligament (CHL) in relation to visible anatomic reference points to aid in the execution of a more effective arthroscopic medial-lateral rotator interval closure.

Methods

Detailed dissection to identify the CHL was performed in 4 shoulders from 2 fresh-frozen donor cadavers with a deltopectoral approach. The angular relationship between the CHL and the superior border of the subscapularis tendon was determined via gross dissection. Arthroscopic images were used to determine the angular position of the CHL in relation to both the glenoid articular surface and the intraarticular segment of the tendon of the long head of the biceps brachii (LHB).

Results

Analysis of 4 cadaveric shoulders via gross dissection demonstrated the CHL to subtend a mean angle of 29° (range 16° to 39°) with respect to the superior border of the subscapularis tendon. Arthroscopic analysis of 4 cadaveric shoulders demonstrated the CHL to subtend a mean angle of 59° (range 38° to 77°) with respect to the glenoid articular surface. Additionally, arthroscopic analysis of 2 cadaveric shoulders demonstrated the CHL to subtend a mean angle of 29° (range 11° to 47°) with respect to the LHB tendon.

Conclusion

Although the position of the CHL in relation to the subscapularis tendon, glenoid articular surface, and LHB tendon demonstrates a moderate degree of anatomic variability, these structures provide valuable anatomic reference points for the identification of the course of this significant static shoulder stabilizer.

Clinical Relevance

Comprehensive understanding of the angular relationships between the CHL and adjacent shoulder structures may assist with the execution of a more effective arthroscopic rotator interval closure.

Risk Factors for Recurrent Anterior Glenohumeral Instability and Clinical Failure Following Primary Latarjet Procedures: An Analysis of 344 Patients

BACKGROUND

Patients with a greater risk of recurrent instability and inferior clinical outcomes following a primary Latarjet procedure can be preoperatively identified on the basis of clinical, radiographic, and demographic criteria. The purpose of this study was to identify risk factors influencing the rates of recurrent anterior glenohumeral instability and clinical failure following a primary Latarjet procedure.

METHODS

All patients who underwent a primary Latarjet procedure were prospectively enrolled and evaluated. The Western Ontario Shoulder Instability Index (WOSI) and Single Assessment Numeric Evaluation (SANE) outcome scores were collected at a minimum 5-year follow-up along with evidence of recurrent instability. Recurrent instability (recurrent subluxation or dislocation) was considered as a failure. Clinical failure was defined as a postoperative WOSI score of ≥630 points (≤70% normal) or a SANE score of ≤70 points.

RESULTS

From 2004 to 2014, 344 patients (358 shoulders) with a mean age of 30.6 years (range, 16 to 68 years) were enrolled and had a mean follow-up time of 75 months (range, 61 to 89 months). The median postoperative WOSI score was 265 points (range, 0 to 1,100 points), and the median SANE score was 88 points (range, 50 to 100 points). Recurrence occurred in 17 shoulders (4.7%), 5 with dislocation and 12 with subluxation; and 28 (8.2%) of 341 shoulders without recurrent instability were clinical failures following a Latarjet procedure. The risk factors for recurrence included atraumatic dislocation (odds ratio [OR], 4.6; p < 0.01) and bilateral instability (OR, 4.0; p = 0.01), whereas the risk factors for clinical failure (WOSI score of ≥630 points or SANE score of ≤70 points) were female sex (OR, 2.8; p < 0.01) and bilateral instability (OR, 4.6; p = 0.01).

CONCLUSIONS

Outcomes at a mean of >6 years following a primary Latarjet procedure for anterior shoulder instability were very good, with an overall recurrence rate of 4.7%. An additional 8.2% of cases were defined as clinical failures. Patients with an atraumatic mechanism of primary dislocation, bilateral instability, and female sex were identified to be at a greater risk of recurrence or clinical failure. Although additional work is necessary, patients with capsuloligamentous laxity, relatively atraumatic instability history, bilateral instability, and female sex may be preoperatively identified as having a higher risk of treatment failure after a primary Latarjet procedure.

LEVEL OF EVIDENCE

Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Effect of rotator cuff muscle activation on glenohumeral kinematics: A cadaveric study

Healthy shoulder function requires the coordination of the rotator cuff muscles to maintain the humeral head's position in the glenoid. While glenohumeral stability has been studied in various settings, few studies have characterized the effect of dynamic rotator cuff muscle loading on glenohumeral translation during shoulder motion. We hypothesize that dynamic rotator cuff muscle activation decreases joint translation during continuous passive abduction of the humerus in a cadaveric model of scapular plane glenohumeral abduction. The effect of different rotator cuff muscle activity on glenohumeral translation was assessed using a validated shoulder testing system. The Dynamic Load profile is a novel approach, based on musculoskeletal modeling of human subject motion. Passive humeral elevation in the scapular plane was applied via the testing system arm, while the rotator cuff muscles were activated according to the specified force profiles using stepper motors and a proportional control feedback loop. Glenohumeral translation was defined according to the International Society of Biomechanics. The Dynamic load profile minimized superior translation of the humeral head relative to the conventional loading profiles. The total magnitude of translation was not significantly different (0.805) among the loading profiles suggesting that the compressive forces from the rotator cuff primarily alter the direction of humeral head translation, not the magnitude. Rotator cuff muscle loading is an important element of cadaveric shoulder studies that must be considered to accurately simulate glenohumeral motion. A rotator cuff muscle activity profile based on human subject muscle activity reduces superior glenohumeral translation when compared to previous RC loading profiles.

Rotator Interval Plication: The "Seamster" Technique

The indications and best technique for plication of the rotator interval capsule, performed as a supplemental procedure at the time of arthroscopic shoulder stabilization, remain a controversial topic. There are currently no well-accepted surgical indication guidelines that have been established. Several biomechanical studies, however, have demonstrated the important contribution of the rotator interval capsule to stability of the glenohumeral joint, and the utilization of rotator interval plication in patients with glenohumeral instability has been supported in several publications. The indications for and surgical steps to accomplish the arthroscopic "seamster" technique for rotator interval plication, used by the authors for >20 years, is described.

Arthroscopic treatment of posterior instability of the shoulder with an associated reverse Hill-Sachs lesion using an iliac bone-block autograft

Posterior dislocation of the shoulder is often accompanied by an impression fracture in the anterior surface of the humeral head, called a reverse Hill-Sachs injury. This bone defect can engage on the posterior glenoid rim, which can lead to recurrent instability and progressive joint destruction. We describe a new arthroscopic procedure that fills the reverse Hill-Sachs lesion with an iliac bone-block autograft and repairs the posterior articular capsule arthroscopically, which can stabilize the posterior shoulder. It avoids the need to detach the subscapularis tendon and can reduce the risks associated with open procedures. LEVEL OF EVIDENCE: V, technical note.

Rotator interval closure: inconsistent techniques and its association with anterior instability. A literature review

The Rotator interval (RI) is an anatomic space in the anterosuperior part of the glenohumeral joint. An incompetent or lax RI has been implicated in various conditions of shoulder instability and therefore RI has been frequently touted as an area that is important in preserving stability of the shoulder. Biomechanical studies have shown that repair of RI ligamentous and capsular structures decreases glenohumeral joint laxity in various directions. Clinical studies have reported successful outcomes after repair or plication of these structures in patients undergoing shoulder stabilization procedures. Although varieties of methods have been described for its closure, the optimal surgical technique is unclear with various inconsistencies in incorporation of the closure tissue. This in particular makes the analysis of the RI closure very difficult. The purposes of this study are to review the structures of the RI and their contribution to shoulder instability, to discuss the biomechanical and clinical effects of plication of RI structures in particular to anterior glenohumeral instability, to delineate the differences between an arthroscopic and open RI closure. Additionally, we have proposed a new classification system describing various techniques used during RI closure.

Coracohumeral Ligament Reconstruction for Patients With Multidirectional Shoulder Instability

Coracohumeral ligament pathology arises from acute trauma, capsular thickening, or congenital connective tissue disorders within the glenohumeral joint. Recent studies have highlighted the significance of this pathology in multidirectional shoulder instability because insufficiency of the rotator interval has become increasingly recognized and attributed to failed shoulder stabilization procedures. The diagnosis and subsequent treatment of coracohumeral ligament pathology can be challenging, however, because patients usually present with a history of failed surgical stabilization and persistent laxity. At the time of presentation, most patients have undergone failed nonoperative treatments and are indicated for surgical intervention. One of the options for the treatment of coracohumeral ligament pathology is reconstruction. The purpose of this Technical Note is to describe our preferred surgical technique for the reconstruction of the coracohumeral ligament. Research was performed at the Steadman Philippon Research Institute.

Multidirectional Shoulder Instability With Bone Loss and Prior Failed Latarjet Procedure: Treatment With Fresh Distal Tibial Allograft and Modified T-Plasty Open Capsular Shift

Recurrent multidirectional shoulder instability (MDI) is a challenging clinical problem, particularly in the setting of connective tissue diseases, and there is a distinct lack of literature discussing strategies for operative management of this unique patient group. These patients frequently present with significant glenoid bone loss, patulous and abnormal capsulolabral structures, and a history of multiple failed arthroscopic or open instability procedures. Although the precise treatment algorithm requires tailoring to the individual patient, we have shown successful outcomes in correcting recurrent MDI in the setting of underlying connective tissue disorders by means of a modified T-plasty capsular shift and rotator interval closure in conjunction with distal tibial allograft bony augmentation. The purpose of this Technical Note was to describe a technique that combines a fresh distal tibial allograft for glenoid bony augmentation with a modified T-plasty capsular shift and rotator interval closure for the management of recurrent shoulder MDI in patients presenting with Ehlers-Danlos syndrome or other connective tissue disorders after failed Latarjet stabilization.

Outcomes After Arthroscopic Rotator Interval Closure for Shoulder Instability: A Systematic Review

PURPOSE

(1) To systematically assess the clinical outcomes of arthroscopic rotator interval closure (RIC) procedures for shoulder instability and (2) to report the different technical descriptions and surgical indications for this procedure.

METHODS

Two independent reviewers searched 4 databases (PubMed, Embase, Web of Science, and Cochrane) from database inception until October 15, 2017. The inclusion criteria were studies that reported outcomes of shoulder stabilization using arthroscopic RIC as an isolated or adjunctive surgical procedure. The methodologic quality of studies was assessed with the Methodological Index for Non-Randomized Studies tool and Grading of Recommendations Assessment, Development and Evaluation system for randomized controlled trials.

RESULTS

Fifteen studies met our search criteria (524 patients). Of the studies, 12 were graded Level IV evidence; 2, Level III; and 1, Level II. Six different RIC technique descriptions were reported, with 2 studies not defining the details of the procedure. The most common method of RIC was arthroscopic plication of the superior glenohumeral ligament to the middle glenohumeral ligament (8 of 15 studies). The most commonly used patient-reported outcome measure was the Rowe score, with all studies reporting a minimum postoperative score of 80 points. The rate of return to preinjury level of sport ranged from 22% to 100%, and the postoperative redislocation rate ranged from 0% to 16%.

CONCLUSIONS

The indications for RIC were poorly reported, and the surgical techniques were inconsistent. Although most studies reported positive clinical results, the heterogeneity of outcome measures limited our ability to make definitive statements about which types of rotator interval capsular closure are warranted for select subgroups undergoing arthroscopic shoulder stabilization.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II through IV studies.

Editorial Commentary: Rotator Interval Closure of the Shoulder Continues to Be a Challenge in Consensus on Treatment

In discussions of repair or plication of rotator interval capsular tissue and the respective surgical techniques, there is great variability in the procedures used to accomplish this, as well as a lack of consensus in defining rotator interval closure and the complex associated anatomy. The concept of rotator interval closure and how it is performed has shown wide variation and numerous definitions. In the future, it is recommended that one truly define what type of closure is performed, what tissues are imbricated, and where these tissues are imbricated, because both medial and lateral imbrications around the joint can have significant differences in terms of rotation, stability, and overall efficacy. Through this work, we can improve diagnostic capabilities, as well as examination capabilities, and better delineate the overall rotator interval closure procedure based on diagnostic and clinical findings. In this manner, we will be better able to define when rotator interval closure is necessary and most beneficial to patients. In our opinion, clinical indications for rotator interval closure are as follows: (1) multidirectional instability with increased capsular volume, (2) anterior instability-and especially a failed arthroscopic instability repair-that could benefit from imbrication of the coracohumeral ligament, (3) a sulcus that persists in external rotation in the setting of symptomatic instability, and (4) posterior instability with a multidirectional component.

Arthroscopic Bone Graft Procedure Combined With Arthroscopic Subscapularis Augmentation for Recurrent Anterior Instability With Glenoid Bone Defect

Glenoid bone loss and capsular deficiency represent critical points of arthroscopic Bankart repair failures. The purpose of this Technical Note is to present an all-arthroscopic bone block procedure associated with arthroscopic subscapularis augmentation for treating glenohumeral instability with glenoid bone loss and anterior capsulolabral deficiency. Two glenoid tunnels are set up from the posterior to the anterior side using a dedicated bone block guide, and 4 buttons are used to fix the graft to the glenoid. The subscapularis tenodesis is performed using a suture tape anchor. This combined arthroscopic technique (bone block associated with arthroscopic subscapularis augmentation) could be a valid and safe alternative to the arthroscopic or open Latarjet procedures.

Shoulder Instability: Common Problems and Solutions

Operative treatment of the unstable shoulder historically has a high success rate. However, the complication rate has risen. This article reviews the pearls and pitfalls to attempt to elucidate the etiology for these complications and failures. Preoperative assessment of the unstable shoulder ultimately is critical to avoid complications, including history, physical examination, and key radiographic features. Intraoperative techniques include appropriate soft tissue mobilization, multiple points of fixation, avoidance of hardware-related problems, and appropriate management of the capsule and bone defects. Finally, postoperative rehabilitation is equally important to regain physiologic range of motion in a safe, supervised fashion.

Arthroscopic bone graft procedure combined with arthroscopic subscapularis augmentation (ASA) for recurrent anterior instability with glenoid bone defect: a cadaver study

BACKGROUND

Glenoid bone loss and capsular deficiency represent critical points of arthroscopic Bankart repair failures. The purpose of this study was to evaluate an all-arthroscopic bone block procedure associated with arthroscopic subscapularis augmentation (ASA) for treating gleno-humeral instability with glenoid bone loss (GBL) and anterior capsulo-labral deficiency. Our hypothesis was that these two procedures could be combined arthroscopically. The feasibility of this technique and its reproducibility, and potential neurovascular complications were evaluated.

METHODS

A tricortical bone graft was harvested from the cadaveric clavicle, and in one case a Xenograft was used. An anterior-inferior GBL of about 25% was created. Two glenoid tunnels were set up from the posterior to the anterior side using a dedicated bone block guide, and four buttons were used to fix the graft to the glenoid. The subscapularis tenodesis was performed using a suture tape anchor. Afterwards, the shoulder was dissected to study the relationship between all portals and nerves. The size of the bone block, its position on the glenoid and the relationship with the subscapularis tendon were investigated.

RESULTS

In all seven specimens (five left and two right shoulders), the bone block was flush with the cartilage and fixed to the anterior-inferior part of the glenoid. No lesions of the surrounding neurovascular structures were observed. No interference was found between the two bone block tunnels and the anchor tunnel used for the tenodesis.

CONCLUSIONS

This study demonstrated the feasibility and reproducibility of this combined arthroscopic technique (bone block associated with ASA) in the treatment of anterior shoulder instability associated with anterior bone loss and anterior capsular deficiency.

Posterior Glenohumeral Instability: Evidence-based Treatment

Posterior glenohumeral instability is an increasingly important clinical finding in athletic patients. Over the last decade, basic and clinical research has improved our understanding of the pathoanatomy and biomechanics of this challenging disorder, as well as our ability to diagnose and appropriately treat it. Although recurrent posterior shoulder instability is not as common as anterior instability, it is prevalent among specific populations, including football and rugby players, and may be overlooked by clinicians who are unaware of the typical physical examination and radiographic findings.

Soft tissue-based surgical techniques for treatment of posterior shoulder instability

Posterior shoulder instability is a rare clinical condition that encompasses different degrees of severity including various possible pathologies involving the labrum, capsule, bony lesions, and even locked posterior dislocation. When focusing on soft tissue involvement, the diagnosis of posterior instability may be difficult to make because frequently patients report vague symptoms not associated with a clear history of traumatic shoulder dislocation. Pathological soft tissue conditions associated with posterior instability in most cases are related to posterior labral tear and/or posterior capsular detensioning/tear. The diagnosis can be facilitated by physical examination using specific clinical tests (i. e., jerk test, Kim test, and reinterpreted O’Brien test) together with appropriate imaging studies (i. e., magnetic resonance arthrography). Arthroscopy may help in a complete evaluation of the joint and allows for the treatment of soft tissue lesions in posterior instability. Caution is warranted in the case of concomitant posterior glenoid chondral defect as a potential cause of poor outcome after soft tissue repair in posterior instability.

Arthroscopic plication for multidirectional instability: 50 patients with a minimum of 2 years of follow-up

BACKGROUND

Treatment of patients who have not improved after physiotherapy for multidirectional instability (MDI) remains challenging, with no agreed best practice. The purpose of this study was to ascertain whether arthroscopic plication is safe and effective for these patients.

METHODS

Fifty consecutive patients who had not improved after at least 6 months of specialized shoulder physiotherapy for symptomatic MDI and no labral lesion at arthroscopy underwent arthroscopic plication between 2006 and 2013. Outcome measures were preoperative and postoperative Oxford Instability Scores (OIS), recurrence of instability, return to work and sport, surgical complications, and patient satisfaction.

RESULTS

The study comprised 32 male and 18 female patients, with a mean age of 26 years (range, 16-46 years). Complete OISs were available in 43 of 50 patients, and 41 patients had good or excellent postoperative OIS. The mean OIS was 16.2 preoperatively compared with 42.5 postoperatively (P < .001). There was no difference in OIS improvement between male and female patients (P = .962) or in those aged younger than 25 years vs. older than 25 years (P = .789). Patients with Beighton scores of 4 to 9 showed smaller OIS improvement (P = .030) and were less likely to achieve excellent postoperative OISs (P = .010). There were 2 patients with recurrent instability. All patients successfully returned to work, and 45 of 50 patients returned to the same level of sport. Surgical complications were shoulder stiffness in 1 patient that resolved with physiotherapy and 1 superficial wound infection that was successfully treated with flucloxacillin. Forty-seven of 50 patients were satisfied.

CONCLUSION

Arthroscopic plication is a safe and effective treatment for MDI in patients without labral lesions who have not improved after 6 months of specialized shoulder physiotherapy.

Biomechanical effects of rotator interval closure in shoulder arthroplasty

BACKGROUND

Subscapularis dysfunction remains a significant problem after shoulder arthroplasty. Published techniques have variable recommendations for placing a rotator interval closing suture in attempts to off-load the subscapularis repair site, the implications of which have yet to be examined in the literature. The goals of this study were to investigate the biomechanical benefit of the rotator interval closing suture on the subscapularis repair strength and to analyze the effect on shoulder range of motion.

METHODS

Sixteen matched cadaveric shoulders underwent a subscapularis tenotomy and shoulder arthroplasty. The subscapularis tenotomy was repaired, and motion at physiologic torsional force was recorded. One of each matched pair was randomly assigned to receive an additional rotator interval closure suture. Each specimen then underwent a standardized cyclic loading with measurement of gap formation and load to failure.

RESULTS

The rotator interval closing suture significantly increased the ultimate load to failure of the subscapularis repair (452 N vs. 219 N; P = .002) and decreased gap formation at the subscapularis repair site. Measurement of the shoulder motion showed no significant difference between shoulders with and without the rotator interval closing suture.

DISCUSSION

We report the additional biomechanical benefit that the rotator interval closing suture provides to the subscapularis repair site after shoulder arthroplasty. This suture acts to improve the load to failure of the subscapularis repair and to decrease gap formation under cyclic load. Furthermore, it does not detrimentally affect shoulder external rotation or overall arc of rotation. Our findings support the application of this off-loading technique after subscapularis repair during shoulder arthroplasty.

History of surgical intervention of anterior shoulder instability

BACKGROUND

Anterior glenohumeral instability most commonly affects younger patients and has shown high recurrence rates with nonoperative management. The treatment of anterior glenohumeral instability has undergone significant evolution over the 20th and 21 centuries.

METHODS

This article presents a retrospective comprehensive review of the history of different operative techniques for shoulder stabilization.

RESULTS

Bankart first described an anatomic suture repair of the inferior glenohumeral ligament and anteroinferior labrum in 1923. Multiple surgeons have since described anatomic and nonanatomic repairs, and many of the early principles of shoulder stabilization have remained even as the techniques have changed. Some methods, such as the Magnusson-Stack procedure, Putti-Platt procedure, arthroscopic stapling, and transosseous suture fixation, have been almost completely abandoned. Other strategies, such as the Bankart repair, capsular shift, and remplissage, have persisted for decades and have been adapted for arthroscopic use.

DISCUSSION

The future of anterior shoulder stabilization will continue to evolve with even newer practices, such as the arthroscopic Latarjet transfer. Further research and clinical experience will dictate which future innovations are ultimately embraced.

Biomechanical effects of anterior capsular plication and rotator interval closure in simulated anterior shoulder instability

PURPOSE

The purpose of this study was to determine the effect of a stepwise arthroscopic anterior plication and arthroscopic-equivalent rotator interval (RI) closure on glenohumeral range of motion, kinematics, and translation in the setting of anterior instability.

METHODS

Six cadaveric shoulders were stretched to 10 % beyond maximum external rotation (ER) to create an anterior shoulder instability model. Range of motion, kinematics, and glenohumeral translations were recorded for the following conditions: (1) intact, (2) stretched, (3) after anterior capsular plication, and (4) after RI closure.

RESULTS

The total range of motion after capsular stretching increased significantly in the 60° abduction position (p = 0.037). Average ER and total rotation were significantly decreased from the intact and stretched conditions by both repair conditions at 60° and 0° of glenohumeral abduction (p < 0.05), with no significant difference between plication and additional RI closure. At 0° abduction and 0° ER, glenohumeral translation decreased significantly from the stretched condition after RI closure with 10 and 15 N anterior and 10 N posterior loads (p < 0.05). At 30° ER, translation after RI closure was significantly less than both the intact and stretched conditions with 10 N anterior loads (p = 0.009; p = 0.004). These changes in translational stability were not seen with plication alone.

CONCLUSIONS

Anterior capsular plication reduced glenohumeral range of motion back to the intact state, and often tighter. RI closure did not contribute significantly to the reduction in the range of motion, but had implications regarding glenohumeral translation. Caution should be taken when performing anterior plication and combined repairs to avoid overtightening. Intraoperative translations could be useful when debating RI closure in patients with unidirectional anterior glenohumeral instability.

The effect of the rotator interval on glenohumeral kinematics during abduction

Background

The rotator interval (RI) has been exploited as a potentially benign point of entry into the glenohumeral (GH) joint. Bounded by the supraspinatus, subscapularis and coracoid process of the scapula, the RI is believed to be important in the shoulder’s soft tissue balancing and function. However, the role of the RI in shoulder kinematics is not fully understood. The purpose of this study is to describe the effect of the RI on GH motion during abduction of the arm.

Methods

Six shoulders from three cadaveric torsos were studied to assess the impact of changes in the RI during abduction under four conditions: Intact (Baseline), Opened, Repaired (repaired with side-to-side tissue approximation, no overlap) and Tightened (repaired with 1 cm overlap). For each group, the GH translation and area under the Curve (AUC) were measured during abduction using an intact cadaveric shoulder (intact torso).

Results

GH kinematics varied in response to each intervention and throughout the entire abduction arc. Opening the RI caused a significant change in GH translation. The Repair and Tightened groups behaved similarly along all axes of GH motion.

Conclusions

The RI is central to normal GH kinematics. Any insult to the tissue’s integrity alters the shoulder’s motion throughout abduction. In this model, closing the RI side-to-side has the same effect as tightening the RI. Since suture closure may offer the same benefit as tightening the RI, clinicians should consider this effect when treating patients with shoulder laxity. This investigation provides an improved perspective on the role of the RI on GH kinematics during abduction. When managing shoulder pathology, surgeons should consider how these different methods of RI closure affect the joint’s motion. In different circumstances, the surgical approach to the RI can be tailored to address each patient’s specific needs.

The Rotator Interval of the Shoulder: Implications in the Treatment of Shoulder Instability

Biomechanical studies have shown that repair or plication of rotator interval (RI) ligamentous and capsular structures decreases glenohumeral joint laxity in various directions. Clinical outcomes studies have reported successful outcomes after repair or plication of these structures in patients undergoing shoulder stabilization procedures. Recent studies describing arthroscopic techniques to address these structures have intensified the debate over the potential benefit of these procedures as well as highlighted the differences between open and arthroscopic RI procedures. The purposes of this study were to review the structures of the RI and their contribution to shoulder instability, to discuss the biomechanical and clinical effects of repair or plication of rotator interval structures, and to describe the various surgical techniques used for these procedures and outcomes.

Rotator Interval Lesion and Damaged Subscapularis Tendon Repair in a High School Baseball Player

In 2013, a 16-year-old baseball pitcher visited Nobuhara Hospital complaining of shoulder pain and limited range of motion in his throwing shoulder. High signal intensity in the rotator interval (RI) area (ball sign), injured subscapularis tendon, and damage to both the superior and middle glenohumeral ligaments were identified using magnetic resonance imaging (MRI). Repair of the RI lesion and partially damaged subscapularis tendon was performed in this pitcher. During surgery, an opened RI and dropping of the subscapularis tendon were observed. The RI was closed in a 90° externally rotated and abducted position. To reconfirm the exact repaired state of the patient, arthroscopic examination was performed from behind. However, suture points were not visible in the >30° externally rotated position, which indicates that the RI could not be correctly repaired with the arthroscopic procedure. One year after surgery, the patient obtained full function of the shoulder and returned to play at a national convention. Surgical repair of the RI lesion should be performed in exactly the correct position of the upper extremity.

Pectoralis minor tendon in the rotator interval: arthroscopic, magnetic resonance imaging findings, and clinical significance

BACKGROUND

Although insertional variation of the pectoralis minor on the rotator interval has been reported, more detailed characteristics as seen on magnetic resonance imaging (MRI) or arthroscopy and clinical significance have been rarely discussed. This study evaluated the prevalence of tendinous insertion of the pectoralis minor by arthroscopy and diagnostic performances of MRI and suggests its clinical implication in rotator cuff repair.

MATERIALS AND METHODS

The study prospectively recruited 99 consecutive patients for arthroscopic exploration of pectoralis minor insertion. Preoperative MRIs were evaluated to detect tendinous insertion of the pectoralis minor by 2 independent, blinded observers, and these results were correlated with arthroscopy as the gold standard. During arthroscopy, the effect of this variation on supraspinatus tendon tear and repair was evaluated.

RESULTS

Tendinous insertion of the pectoralis minor was found in 11 patients (11%) at arthroscopy. The sensitivity and specificity of MRI were 64% (95% confidence interval [CI], 31%-89%), the specificity was 82% (95% CI, 72%-89%), and the accuracy was 80% (95% CI, 72%-88%). Intraobserver and interobserver reliability tests showed moderate agreements. In 7 patients, it tethered the retracted supraspinatus tendon from mobilization and gave rise to tension on the repaired cuff, which warranted complete resection of the pectoralis minor tendon for a tension-free cuff repair.

CONCLUSIONS

Tendinous insertion of the pectoralis minor existed with 11% prevalence in our series and could be preoperatively detected on MRI. During arthroscopic rotator cuff repair, it can be an obstacle to supraspinatus tendon mobilization and repair.

Identification and treatment of existing copathology in anterior shoulder instability repair

Recurrent anterior instability is a common finding after traumatic glenohumeral dislocation in the young, athletic patient population. A variety of concomitant pathologies may be present in addition to the classic Bankart lesion, including glenoid bone loss; humeral head bone loss; rotator interval pathology; complex/large capsular injuries including humeral avulsions of the glenohumeral ligaments (HAGL lesions), SLAP tears, near circumferential labral tears, and anterior labral periosteal sleeve avulsions (ALPSA lesions); and rotator cuff tears. Normal anatomic variations masquerading as pathology also may be present. Recognition and treatment of these associated pathologies are necessary to improve function and symptoms of pain and to confer anterior shoulder stability. This review will focus on the history, physical examination findings, imaging findings, and recommended treatment options for common sources of copathology in anterior shoulder instability repair.

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.

Anterior glenohumeral instability: a pathology-based surgical treatment strategy

The glenohumeral joint is the most frequently dislocated major joint, and most cases involve an anterior dislocation. Young male athletes competing in contact sports are at especially high risk of recurrent instability. Surgical timing and selection of surgical technique continue to be debated. Full characterization of the injury requires an accurate history and physical examination. Diagnostic imaging assists in identifying the underlying anatomic lesions, which range from no discernible lesion to significant bone loss of the glenoid or humeral head and/or capsulolabral stretching or avulsion from the glenoid or humerus. Historically, open Bankart repair has been considered to be the standard method of managing capsulolabral injuries, but comparable results have been achieved with arthroscopic techniques. In the setting of anterior glenoid bone loss >20% of the articular surface, iliac crest bone grafting or coracoid transfer via the Bristow or Latarjet procedures has demonstrated satisfactory outcomes. Favorable results have been reported with bone grafting or remplissage for engaging Hill-Sachs lesions and those that affect >30% of the humeral circumference.

Role of the superior labrum after biceps tenodesis in glenohumeral stability

BACKGROUND

Little is known about the role that a torn superior labrum (SLAP) plays in glenohumeral stability after biceps tenodesis. This biomechanical study evaluated the contribution of a type II SLAP lesion to glenohumeral translation in the presence of biceps tenodesis. The authors hypothesize that subsequent to biceps tenodesis, a torn superior labrum does not affect glenohumeral stability and therefore does not require anatomic repair in an overhead throwing athlete.

METHODS

Baseline anterior, posterior, and abduction and maximal external rotation glenohumeral translation data were collected from 20 cadaveric shoulders. Translation testing was repeated after the creation of anterior (n = 10) and posterior (n = 10) type II SLAP lesions. Translation re-evaluation after biceps tenodesis was performed for each specimen. Finally, anatomic SLAP lesion repair and testing were performed.

RESULTS

Anterior and posterior SLAP lesions led to significant increases in glenohumeral translation in all directions (P < .0125). Biceps tenodesis showed no significance in stability compared with SLAP alone (P > .0125). Arthroscopic repair of anterior SLAP lesions did not restore anterior translation compared with the baseline state (P = .0011) but did restore posterior (P = .823) and abduction and maximal external rotation (P = .806) translations. Repair of posterior SLAP lesions demonstrated no statistical difference compared with the baseline state (P > .0125).

CONCLUSIONS

With no detrimental effect on glenohumeral stability in the presence of a SLAP lesion, biceps tenodesis may be considered a valid primary or revision surgery for patients suffering from symptomatic type II SLAP tears. However, biceps tenodesis should be considered with caution as the primary treatment of SLAP lesions in overhead throwing athletes secondary to its inability to completely restore translational stability.

Arthroscopic anatomy of the subdeltoid space

From the first shoulder arthroscopy performed on a cadaver in 1931, shoulder arthroscopy has grown tremendously in its ability to diagnose and treat pathologic conditions about the shoulder. Despite improvements in arthroscopic techniques and instrumentation, it is only recently that arthroscopists have begun to explore precise anatomical structures within the subdeltoid space. By way of a thorough bursectomy of the subdeltoid region, meticulous hemostasis, and the reciprocal use of posterior and lateral viewing portals, one can identify a myriad of pertinent ligamentous, musculotendinous, osseous, and neurovascular structures. For the purposes of this review, the subdeltoid space has been compartmentalized into lateral, medial, anterior, and posterior regions. Being able to identify pertinent structures in the subdeltoid space will provide shoulder arthroscopists with the requisite foundation in core anatomy that will be required for challenging procedures such as arthroscopic subscapularis mobilization and repair, biceps tenodesis, subcoracoid decompression, suprascapular nerve decompression, quadrangular space decompression and repair of massive rotator cuff tears.

Revision posterior shoulder stabilization

BACKGROUND

Revision arthroscopic posterior glenohumeral stabilization requires a thorough understanding of the static and dynamic stabilizers of the glenohumeral joint. The evaluation of these patients is complex but critical given the variety of possible underlying lesions.

METHOD

We reviewed the literature surrounding recurrent and revision posterior instability biomechanics, etiology, evaluation, treatment, and outcomes. We also reviewed our own database of posterior instability cases and isolated revision procedures to review our own outcomes and to highlight overall concepts.

DISCUSSION/CONCLUSION

Although other authors have argued that performing a revision procedure indicates for an open procedure and osseous augmentation, our experience has been that revision posterior stabilization arthroscopic soft-tissue repair alone may be indicated in selected patients. After identification of posterior glenoid bone loss/effective retroversion and mechanical failure of prior repairs, the majority of the patients with recurrence of posterior instability likely have either recurrent or persistent labral pathology or patulous capsules with occult multi-directional instability primarily manifesting in the posterior direction. These patients are best served with capsular shift, reefing, and plication, often requiring 180-270° repair and 4 or greater suture anchors. Because of significant heterogeneity in the clinical outcomes reported to date further research will be necessary to define the clinical outcomes in revision posterior stabilization.

Modified arthroscopic McLaughlin procedure for treatment of posterior instability of the shoulder with an associated reverse Hill-Sachs lesion

Traumatic posterior shoulder dislocations are often accompanied by an impression fracture on the anterior surface of the humeral head known as a "reverse Hill-Sachs lesion". This bony defect can engage on the posterior glenoid rim and subsequently lead to recurrent instability and progressive joint destruction. We describe a new modified arthroscopic McLaughlin procedure, which allows for filling of the bony defect with the subscapularis tendon and subsequently prevents recurrence of posterior instability. This technique creates a double-mattress suture providing a large footprint for the subscapularis and a broader surface area to allow for effective tendon to bone healing. Furthermore, it obviates the need for detaching the subscapularis tendon and avoids the morbidity potentially associated with open procedures. Level of evidence V.

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 rotator interval closure by purse string suture for symptomatic inferior shoulder instability

Multidirectional instability of the shoulder is a complex condition that can be difficult to diagnose and treat. Clinically, it is characterized by symptomatic global laxity of the glenohumeral joint and may present either traumatically or atraumatically, unilaterally or bilaterally, and with or without generalized joint laxity. Capsular plication is a primary treatment option in these patients and is used to tension the redundant or lax capsule. We evaluated the role of rotator interval closure in restoring stability as a primary procedure in patients with multidirectional instability and a positive and painful sulcus sign.Twenty adult patients (16 men and 4 women) presenting with multidirectional instability were evaluated clinically and radiologically to assess the degree and direction of instability, were treated by arthroscopic rotator interval closure and inferior capsular plication, and were followed up for a minimum of 2 years. Clinical and functional results were excellent at 2-year follow-up. The results of the study indicate that the closure of the rotator interval in patients with symptomatic inferior instability will have a long-lasting effect on the stability and function of the shoulder, as the closure improves not only the static restraints but also the dynamic restraints of the shoulder through the improved proprioception secondary to restoration of the rotator interval structures.

Posterior instability of the shoulder: diagnosis and management

Recurrent posterior instability of the shoulder can be difficult to diagnose and technically challenging to treat. Although not as common as anterior instability, recurrent posterior shoulder instability is prevalent among certain demographic and sporting groups, and may be overlooked if one is not aware of the typical examination and radiographic findings. The diagnosis itself can be difficult as patients typically present with vague or confusing symptoms, and treatment has evolved from open to arthroscopic surgical techniques. This article is intended to review the anatomy and biomechanics associated with posterior shoulder instability, to discuss the pathogenesis and presentation of posterior instability, and to describe the variety of treatment options and clinical results.

Multimedia article. The rotator interval: pathology and management

The rotator interval describes the anatomic space bounded by the subscapularis, supraspinatus, and coracoid. This space contains the coracohumeral and superior glenohumeral ligament, the biceps tendon, and anterior joint capsule. Although a definitive role of the rotator interval structures has not been established, it is apparent that they contribute to shoulder dysfunction. Contracture or scarring of rotator interval structures can manifest as adhesive capsulitis. It is typically managed nonsurgically with local injections and gentle shoulder therapy. Recalcitrant cases have been successfully managed with an arthroscopic interval release and manipulation. Conversely, laxity of rotator interval structures may contribute to glenohumeral instability. In some cases this can be managed with one of a number of arthroscopic interval closure techniques. Instability of the biceps tendon is often a direct result of damage to the rotator interval. Damage to the biceps pulley structures can lead to biceps tendon subluxation or dislocation depending on the structures injured. Although some authors describe reconstruction of this tissue sling, most recommend tenodesis or tenotomy if it is significantly damaged. Impingement between the coracoid and lesser humeral tuberosity is a relatively well-established, yet less common cause of anterior shoulder pain. It may also contribute to injury of the anterosuperior rotator cuff and rotator interval structures. Although radiographic indices are described, it appears intraoperative dynamic testing may be more helpful in substantiating the diagnosis. A high index of suspicion should be used in association with biceps pulley damage or anterosuperior rotator cuff tears. Coracoid impingement can be treated with either open or arthroscopic techniques. We review the anatomy and function of the rotator interval. The presentation, physical examination, imaging characteristics, and management strategies are discussed for various diagnoses attributable to the rotator interval. Our preferred methods for treatment of each lesion are also discussed.

Arthroscopic rotator interval closure in shoulder instability repair: a retrospective study

BACKGROUND

Arthroscopic Bankart repair (ABR) is a standard treatment for recurrent anterior shoulder instability. Young age, hyperlaxity, loss of bone stock and multidirectional or voluntary type of instability are all associated with failure of this procedure. Rotator interval laxity is associated with shoulder instability, whereas rotator interval closure increases humeral head stability and reduces shoulder range of motion.

METHODS

The records of patients with recurrent anterior shoulder dislocations who underwent ABR with or without arthroscopic rotator interval closure (ARIC) in our department between 1999 and 2007 were reviewed. Rates of recurrent dislocation or symptomatic subluxation as well as functional outcome were evaluated using Walch-Dupley score.

RESULTS

Three (8.1%) of the 37 ABR+ARIC patients (age 19-44 years, 32 males) had re-dislocated their shoulder at 42±16 months following the procedure, all of which had systemic joint hyperlaxity. Six (13%) of the 46 ABR patients (age 19-39 years, 42 males) had re-dislocated their shoulder at 13±14 months, three of which had systemic joint hyperlaxity and dislocated their shoulder within 1 year following the operation. Systemic joint hyperlaxity (28% of ABR and 41% of ABR+ARIC patients) was significantly associated with recurrent dislocation and poor functional outcome. ABR+ARIC patients had slightly more limited range of motion with similar good and excellent functional results (75%) at final follow up time.

CONCLUSIONS

Systemic joint hyperlaxity is a risk factor for failure of ABR. When ARIC is performed in combination with ABR, it may have an additive effect on shoulder stability.

Consensus statement on shoulder instability

The understanding and treatment of shoulder instability comprise a rapidly evolving area of interest in orthopaedics. Evaluation methods are becoming more specific in showing the exact pathologies causing the symptoms. Magnetic resonance arthrography and arthroscopy have contributed to this development. The patient with an unstable shoulder should be thoroughly evaluated through their history and specific clinical tests of the shoulder as well as the scapulothoracic joint. Often, shoulder instability can be classified after this primary evaluation. Magnetic resonance arthrography and arthroscopy are the gold standards in soft-tissue evaluation, whereas specialized radiographic examinations and computed tomography scans are used to assess bony defects. Patients are treated according to the pathology found on preoperative or pretreatment evaluation. Multiple factors need to be considered before the treatment program is instituted, including the patient's age, activity demands, associated pathology and dysfunction, soft-tissue pathology, degree of instability, direction, frequency, and etiology. Treatment can be nonoperative or arthroscopic or open repair. Soft-tissue pathology and bony defects should be addressed, and the surgeon's preferred method and skills are important in choosing the right treatment for the patient. The patient should be informed about possible complications, restrictions during the treatment period, and the prognosis for the particular type of instability. To improve progress in shoulder orthopaedics, one of the most important factors can be a universal agreement on an outcome measurement tool that is well designed and validated.

Quantification of active ROM after arthroscopic Bankart repair with rotator interval closure

Several series report patients homogeneously treated using arthroscopic Bankart repair exclusively, or in some cases arthroscopic Bankart repair with rotator interval closure. Current international literature has few reports on arthroscopic Bankart repair with rotator interval closure procedures undertaken on a homogeneous series of patients. The purpose of this study was to evaluate the residual active range of motion (ROM) and clinical outcome in this patient population. Fourteen patients affected by recurrent anterior instability were consecutively treated. Rowe, Walch-Duplay, and UCLA scores, as well as differences in active ROM of both shoulders (treated and contralateral), were recorded. A significant reduction in active external rotation was noted along the side of the arm (P<.001) and at 90 degrees of abduction (P=.007). The average reduction was 12.14 degrees and 7.21 degrees, respectively, which represents 17.8% and 8% of the arc of motion of the opposite side in external rotation. No significant differences were found for flexion, abduction, and internal rotation. According to Walch-Duplay and Rowe scores, 71.4% and 85.7% of patients had excellent or good results. Arthroscopic Bankart repair with rotator interval closure results in a reduction of external rotation and provides satisfactory stability results.

Biomechanical analysis comparing a traditional superior-inferior arthroscopic rotator interval closure with a novel medial-lateral technique in a cadaveric multidirectional instability model

BACKGROUND

Commonly performed arthroscopic rotator interval closure techniques that imbricate the rotator interval in a superior-inferior direction have been unable to reproduce the stabilizing effects of an open medial-lateral rotator interval imbrication.

HYPOTHESIS

The medial-lateral rotator interval closure will allow less inferior and posterior glenohumeral translation than the superior-inferior rotator interval closure, and the medial-lateral rotator interval closure will result in less loss of external rotation than the superior-inferior closure.

STUDY DESIGN

Controlled laboratory study.

METHODS

Eight match-paired cadaveric shoulders were stretched to 10% beyond the maximum range of motion in 0 degrees and 60 degrees of glenohumeral abduction to create a multidirectional instability model. Shoulders were then repaired using a superior-inferior rotator interval closure or an arthroscopic medial-lateral rotator interval closure with an anchor in the humeral head. Rotational range of motion, glenohumeral translation, and humeral head apex position were measured for intact, stretched, and repaired conditions in both 0 degrees and 60 degrees of glenohumeral abduction.

RESULTS

In 0 degrees of abduction, after both rotator interval closure techniques, external rotation decreased significantly (by 4.4%; P < .05) relative to the stretched state and was restored to the intact state. In 60 degrees of abduction, only the medial-lateral rotator interval closure restored range of motion to the intact state. In 60 degrees of abduction, the medial-lateral rotator interval closure was more effective in reducing posterior translation than was the superior-inferior closure (P = .03).

CONCLUSION

The medial-lateral rotator interval closure restored range of motion to the intact state better than the superior-inferior closure. Compared with the superior-inferior rotator interval closure, the medial-lateral closure significantly decreased posterior translation with the shoulder in abduction and external rotation.

CLINICAL RELEVANCE

Arthroscopic medial-lateral rotator interval closure with a suture anchor in the humeral head can be considered in the surgical treatment of patients with multidirectional instability, especially those with a component of posterior instability, without concern for excessive loss of range of motion.

Treating the athlete with anterior shoulder instability

Acute traumatic anterior shoulder dislocation is a relatively common occurrence in the athletic population. Although the overall incidence of traumatic shoulder instability in the general population is only 1.7%, the incidence in a high physical-demand population is two-fold greater. Instability often becomes a recurrent pattern and jeopardizes athletic performance and participation. A thorough assessment and discussion with the patient with respect to treatment decision-making are critical in the management of anterior shoulder instability.