Contact pressure and glenohumeral translation following subacromial decompression: how much is enough?

Augmented Fixation in Transverse Midshaft Humerus Fractures Using a Nitinol Staple: Surgical Technique and Case Series

Maintaining the reduction of a transverse humeral shaft fracture can be particularly challenging while applying a compression plate for definitive fixation. Nitinol compression staples are being increasingly utilized in orthopedic surgery due to their unique ability to apply continuous compression between staple legs at body temperature. We have found them to be particularly useful in the maintenance of the reduction of transverse humeral shaft fractures before compression plate application. This simple technique allows for the removal of reduction clamps and precise plate placement. We describe our technique for using nitinol compression staples to augment fracture fixation in transverse humeral shaft fractures as well as our experience using this technique in a case series of 4 patients.

Subacromial contact after acromioplasty in the rotator cuff deficient shoulder

Subacromial impingement (SAI) is associated with shoulder pain and dysfunction and is exacerbated by rotator cuff tears; however, the role of acromioplasty in mitigating subacromial contact in the rotator cuff deficient shoulder remains debated. This study aimed to quantify the influence of isolated and combined tears involving the supraspinatus on subacromial contact during abduction; and second, to evaluate the influence of acromioplasty on joint space size and subacromial contact under these pathological conditions. Eight fresh-frozen human cadaveric upper limbs were mounted to a computer-controlled testing apparatus that simulated joint motion by simulated force application. Shoulder abduction was performed while three-dimensional joint kinematics was measured using an optoelectronic system, and subacromial contact evaluated using a digital pressure sensor secured to the inferior acromion. Testing was performed after an isolated tear to the supraspinatus, as well as tears involving the subscapularis and infraspinatus-teres minor, both before and after acromioplasty. Rotator cuff tears significantly increased peak subacromial pressure (p < 0.001), average subacromial pressure (p = 0.001), and contact force (p = 0.034) relative to those in the intact shoulder. Following acromioplasty, significantly lower peak subacromial contact pressure, force and area were observed for all rotator cuff tears involving the supraspinatus at 30° of abduction (p < 0.05). Acromioplasty predominantly reduces acromion thickness anteriorly thereby reducing subacromial contact in the rotator cuff deficient shoulder, particularly in early to mid-abduction where superior glenohumeral joint shear force potential is large. These findings provide a biomechanical basis for acromioplasty as an intervention for SAI syndrome and as an adjunct to rotator cuff repairs.

Effect of Modified Arthroscopic Latarjet on Acromiohumeral Distance at 5-Year Follow-up

Background:

It is unclear whether coracoacromial ligament release during the Latarjet procedure will increase superior translation of the shoulder joint.

Purpose:

To evaluate whether a modified suture button Latarjet procedure can decrease the acromiohumeral distance (AHD).

Study Design:

Case series; Level of evidence, 4.

Methods:

A retrospective analysis was conducted among 155 patients who underwent a modified suture button Latarjet procedure between 2013 and 2015. AHD was measured on bilateral computed tomography scans taken preoperatively and on scans of the affected shoulder taken on postoperative day 1 and postoperative month (POM) 6, POM 36, and POM 60. At each time point, we recorded pain on a visual analog scale (VAS) and objective shoulder function using the American Shoulder and Elbow Surgeons, Rowe, and Walch-Duplay scores. Preoperative and final follow-up VAS and functional scores were compared using the paired t test. Pairwise comparison of AHD values at each follow-up time point were compared with the preoperative intact side using the paired t test. Intra- and interobserver reproducibility of the AHD measurements was evaluated using the intraclass correlation coefficient.

Results:

A total of 104 patients who met the criteria completed the final follow-up, which occurred at 62.6 ± 2.4 months (mean ± SD). When compared with presurgery, the VAS and all functional scores improved significantly at the last follow-up (P < .001 for all). Intra- and interobserver intraclass correlation coefficients indicated good reliability for the ADH measurements. Preoperatively, there were no differences in AHD values between the intact and affected shoulders (7.8 ± 0.8 mm for both; P = .851). The AHD values at postoperative day 1 and POM 6, POM 36, and POM 60 were 9.6 ± 0.7 mm, 8.6 ± 0.9 mm, 8.0 ± 0.8 mm, and 7.9 ± 0.8 mm, respectively, all of which were larger than those of the preoperative intact side (P < .001 for all).

Conclusion:

The modified suture button Latarjet procedure not only offered satisfactory therapeutic effects but also did not decrease the AHD at 5-year follow-up.

Clinical outcome and return to sports activity after surgical treatment for recurrent shoulder instability with a modified Latarjet procedure

INTRODUCTION

The Latarjet procedure is an attractive surgical option for the management of chronic anterior shoulder instability. The original surgical approach involves the vertical tenotomy of the subscapularis tendon. Alternatively, the subscapularis muscle is split longitudinally and the tendon left attached at the lesser tuberosity.

HYPOTHESIS

The hypothesis is that the longitudinal split is of functional advantage and may lead to better functional results and earlier return to sports activities compared to the vertical tenotomy.

MATERIAL AND METHODS

Thirty-two patients were included in this retrospective cohort study. In 14 patients, the subscapularis tendon was vertically incised (group A), whereas in 18 patients, the subscapularis muscle was split longitudinally (group B). Patients were evaluated at 1 year (FU1) and 2 years (FU2) after the Latarjet procedure. Results at follow-up were correlated with patient-specific data and compared with the preoperative status. Primary outcomes were the functional assessment based on Western Ontario Shoulder Instability (WOSI) index and Constant Score (CS) and the assessment of the return to sports activity. Patients' demographics, duration of surgery, and the rate of recurrent dislocations were recorded as secondary variables.

RESULTS

All patients started their sports activities with a mean±SD of 12.41±1.24 weeks. Interestingly, the time from surgery to full recovery of sports activities was significantly longer for group A (mean±SD of 30.17±10.36 weeks) compared to group B (mean±SD of 20.71±3.67 weeks). There is a statistically significant decrease of the WOSI score from the preoperative level compared to FU1 and FU2, indicating a decrease in instability related symptoms during the entire follow up period with no statistically significant difference between group A and B. There is an increase in shoulder function during the entire follow up period based on the CS. Most interestingly, there is a statistically significant difference between group A and B at FU1, indicating a significantly better shoulder function for group B at the early follow up timepoint (FU1). At the later follow up timepoint (FU2), no difference exists in the individual items. However, a significantly better total CS remains in group B, indicating an overall improved function compared to group A.

DISCUSSION/CONCLUSION

The longitudinal split of subscapularis muscle is a safe approach which leads to quicker functional recovery and return to sports activity compared to the vertical tenotomy, which is a benefit especially for active individuals. It is therefore recommended as the standard surgical approach.

LEVEL OF EVIDENCE

III; Retrospective cohort study.

Variation in management of humeral and clavicular shaft fractures amongst fellowship trained orthopedic traumatologists

Background

There exists a wide variety of opinions on the appropriate management of diaphyseal humeral and clavicular fractures amongst orthopedic surgeons.

The purpose of this study is to determine if there is a preference amongst orthopedic traumatologists on treatment of diaphyseal humerus and clavicle fractures with respect to various patient populations.

Methods

A 6-question survey was created using Surveymonkey.com and distributed via the Orthopedic Trauma Association (OTA) website to fellowship trained orthopedic surgery traumatologists to survey the preferred management of a simple oblique middle 1/3rd diaphyseal humerus fracture and a middle 1/3rd displaced diaphyseal clavicle fracture in the following 3 clinical settings: a healthy laborer, an older patient with co-morbidities, and if the surgeon themselves sustained the injury. The ratio of operative to non-operative management was calculated for all 6 questions. A chi-square value was performed to determine if the results are clinically significant based on the clinical scenario.

Results

There was 56 responses to the survey that were included in the analysis. Overall, there was a statistically significant trend towards surgical management of the surgeon’s own diaphyseal humerus fractures (55%) compared to that of healthy patients (41%) and those with medical comorbidities (21%) (p = 0.02) A similar trend was noted for operative management for diaphyseal clavicle fractures by the surgeon on their own fractures (43%) compared to that of healthy patients (38%) and those with medical comorbidities (18%) (p = 0.02).

Conclusion

While there are an increasing number of relative indications for treatment of diaphyseal humerus shaft and clavicle fractures, the results of this survey indicate that fellow-ship-trained orthopedic trauma surgeons prefer surgical management of simple humerus and clavicular fractures in young, healthy patients as well as in themselves.

Shoulder biomechanics in normal and selected pathological conditions

The stability of the glenohumeral joint depends on soft tissue stabilizers, bone morphology and dynamic stabilizers such as the rotator cuff and long head of the biceps tendon. Shoulder stabilization techniques include anatomic procedures such as repair of the labrum or restoration of bone loss, but also non-anatomic options such as remplissage or tendon transfers.

Rotator cuff repair should restore the cuff anatomy, reattach the rotator cable and respect the coracoacromial arch whenever possible. Tendon transfer, superior capsular reconstruction or balloon implantation have been proposed for irreparable lesions.

Shoulder rehabilitation should focus on restoring balanced glenohumeral and scapular force couples in order to avoid an upward migration of the humeral head and secondary cuff impingement. The primary goal of cuff repair is to be as anatomic as possible and to create a biomechanically favourable environment for tendon healing.

Cite this article: EFORT Open Rev 2020;5:508-518. DOI: 10.1302/2058-5241.5.200006

Reconstruction of the Coracoacromial Ligament during a Modified Latarjet Procedure for the Treatment of Shoulder Instability: Clinical Outcome at Minimum 5 Years Follow-Up

OBJECTIVE

The function of the coracoacromial ligament (CAL) in superior shoulder stability has been well established, and the release of the CAL with the Latarjet procedure leads to increased superior humeral translation. A surgical technique was developed recently to reconstruct the CAL during a modified Latarjet procedure, and the clinical outcome of this technique at medium-term follow-up is yet to be determined.

METHODS

Twenty-six patients with chronic post-traumatic anterior shoulder instability were included in this retrospective case-control study. Patients in group 1 (n = 12) were surgically treated with the classic congruent-arc Latarjet, where the CAL is sacrificed. In group 2 (n = 14), the CAL was reconstructed using a pectoralis minor fascia flap (PMFF). Primary outcomes were the return to sports activity and functional assessment based on the Western Ontario Shoulder Instability Index (WOSI) and the Constant Score (CS) at minimum 5 years follow-up. Patient's demographics, sport activities, duration of surgery, the rate of recurrent dislocations, and specific complications related to the surgical technique were recorded as secondary variables.

RESULTS

There was a decrease of the WOSI in both groups, indicating a decrease of symptoms at follow-up compared to the preoperative level. There was no statistically significant difference between groups 1 and 2 for the total WOSI as well as for all subscales. There was an increase of the CS in both groups in all four items at follow-up compared to preoperatively, indicating an increase in shoulder function at follow-up. There was a statistically significant difference between groups 1 and 2 for the total CS, as well as for the items power, mobility, and activity, but not for pain. Most patients (n = 20) returned to their preoperative sports activity, 13 at the same level. However, seven patients who used to perform their sports competitively chose to perform their activity at a noncompetitive level after the Latarjet procedure. All were younger than 35 years of age. Six patients did not return to their preoperative sports activity. All except one were over 35 years of age. The duration of surgery ranged from 75 to 125 minutes with a mean ± SD of 94.23 ± 15.06 minutes for both groups with no significant difference between the groups (p = 0.117). None of the patients had intra- or postoperative complications related to the surgical procedure. Especially, no patient had recurrent dislocations of the affected shoulder following the Latarjet procedure.

CONCLUSION

The use of a PMFF is a safe technique for reconstruction of the CAL, which does not result in a longer surgery time or higher rate of complications. The reconstruction of the CAL during the modified Latarjet procedure may lead to better functional results in medium-term follow-up.

Arthroscopic Transfer of the Conjoined Tendon-Coracoid Tip Complex for Anterior Shoulder Instability

In the treatment of anterior shoulder instability, there are various conditions in which a sling effect is needed to enhance anterior stability. The traditional Bristow-Latarjet procedure provides a sling effect but destroys or does not purposely protect the coracoacromial (CA) arch, which may result in superior instability. To preserve the CA arch and create a sling to enhance the anterior-inferior side of the shoulder, we introduce an arthroscopic technique to transfer the conjoined tendon-coracoid tip complex (CTCTC) with the intention to keep the CA ligament intact to the utmost. The indications for CTCTC transfer are patients younger than 45 years who participate in competitive sports, require forceful external rotation and abduction movements of the shoulder, and/or have capsule-ligament insufficiency. The main steps of this procedure include detaching the CTCTC, fashioning the coracoid tip to obtain a coracoid pillar, braiding the CTCTC, creating a glenoid tunnel and socket, placing a guide suture through the glenoid tunnel and subscapularis, passing the CTCTC through the subscapularis and into the glenoid socket, and performing suspension fixation of the CTCTC.

Contact pressure of the coracoacromial arch in shoulders with joint contracture: A cadaveric study

BACKGROUNDS

There have been many reports describing that the capsular fibrosis of the shoulder joint is the main cause of frozen shoulder, whereas others reported the significance of subacromial impingement as an etiological factor. The purpose of this study was to investigate the contact pressure between the coracoacromial arch and the rotator cuff tendons to clarify the contact phenomenon in shoulders with joint contracture.

METHODS

Fourteen fresh-frozen cadaveric shoulders were used. Specimens were divided into two groups: normal group (8 shoulders, definition: more than 61° of flexion and abduction and more than 21° of external rotation) and joint contracture group (6 shoulders, definition: less than 60° of flexion and abduction and less than 20° of external rotation). Contact pressure and area beneath the coracoacromial arch were measured by a flexible force sensor during flexion, abduction, internal and external rotation in adduction and abduction, extension and horizontal extension motions.

RESULTS

The peak contact pressure under the acromion was observed at 90° in flexion and abduction in the normal group, whereas that in the contracture group was observed at 30° in flexion (P = 0.037) and at 30° in abduction (P = 0.041). Contact pressure in the contracture group was significantly higher than that in the normal group at 20° and 30° of abduction (P = 0.043, P = 0.041, respectively). There were no significant differences of contact pressure during other motions. Although no significant differences of contact pressure beneath the coracoacromial ligament were observed, contact area significantly increased in extension and horizontal extension motion.

CONCLUSION

The contact between the acromion and the rotator cuff was observed in lower angles of flexion and abduction in shoulders with contracture than in those without. When treating patients with shoulder contracture, we need to perform rehabilitation taking such an abnormal movement into consideration.

Arthroscopic Transfer of the Long Head of the Biceps Brachii for Anterior Shoulder Instability

In the treatment of anterior shoulder instability, there are various conditions in which a sling effect is needed to enhance anterior stability. The traditional Latarjet procedure provides a sling effect but destroys the coracoacromial arch, which may result in superior instability. To preserve the coracoacromial arch and create a sling to enhance the anterior-inferior side of the shoulder, we introduce an arthroscopic technique to transfer the long head of the biceps (LHB) brachii. Indications of LHB transfer are patients younger than 45 years of age who participate in competitive sports, require forceful external rotation and abduction movement of the shoulder, and/or have capsule-ligament insufficiency, as well as patients 45 years o or older who have combined SLAP lesions (type II or IV). The main steps of this procedure include detaching the LHB, retrieving and braiding the LHB, creating a glenoid tunnel, placing a guide suture through the subscapularis and glenoid tunnel, passing the LHB through the subscapularis and into the glenoid tunnel, and suspension fixation of the LHB.

Reconstruction of the coracoacromial ligament during a modified Latarjet procedure: a case series

Background

The coracoacromial ligament (CAL) is an important restraint to superior shoulder translation. CAL release with the Latarjet procedure leads to increased superior humeral translation. Therefore, a surgical technique was developed to reconstruct the CAL during a modified Latarjet procedure.

Methods

Between May 2010 and July 2011, six patients (five were male, one was female; age 23–41 years) with chronic post-traumatic anterior shoulder instability were treated surgically with a modified congruent-arc Latarjet procedure (modLAT) with additional reconstruction of the CAL using a newly developed procedure, the pectoralis minor fascia flap (PMFF). Clinical follow-up was performed for up to 36 months, and patients were evaluated using a Rowe score.

Results

All six patients experienced chronic, post-traumatic anterior shoulder instability and had experienced multiple re-dislocations after initial treatment. The preoperative assessment showed a defect of the anterior glenoid in three cases, and the mean Rowe score was 16.67 (5–25). Open modLAT with PMFF resulted in a stable shoulder function with no re-dislocations. The Rowe score increased from 77.5 (65–90) at 12 weeks to 95 (90–100) at 12 months and plateaued thereafter. Operative duration was 95 min (78–112 min), and there were no intra- or postoperative complications. All patients returned to their preoperative sports activity, three at the same level.

Conclusion

The PMFF is a safe technique for reconstruction of the CAL during a modLAT procedure. Patients had improved shoulder function and no re-dislocations after the surgery.

A review of biomechanics of the shoulder and biomechanical concepts of rotator cuff repair

In this article, we describe the basic knowledge about shoulder biomechanics, which is thought to be useful for surgeons. Some clinical reports have described that the excellent outcome after cuff repair without acromioplasty and a limited acromioplasty might be enough for subacromial decompression. It was biomechanically demonstrated that a 10-mm medial shift of the tendon repair site has a minimum effect on biomechanics. Many biomechanical studies reported that the transosseous equivalent repair was superior to other techniques, although the tendon may lose its inherent elasticity. We herein introduce our recent experiment data and latest information on biomechanics.

A biomechanical assessment of superior shoulder translation after reconstruction of anterior glenoid bone defects: The Latarjet procedure versus allograft reconstruction

Background:

The coracoacromial ligament (CAL) is an important restraint to superior shoulder translation. The effect of CAL release on superior stability following the Latarjet is unknown; therefore, our purpose was to compare the effect of two Latarjet techniques and allograft reconstruction on superior instability.

Materials and Methods:

Eight cadaveric specimens were tested on a simulator. Superior translation was monitored following an axial force in various glenohumeral rotations (neutral, internal, and external) with and without muscle loading. Three intact CAL states were tested (intact specimen, 30% glenoid bone defect, and allograft reconstruction) and two CAL deficient states (classic Latarjet (classicLAT) and congruent-arc Latarjet (congruentLAT)).

Results:

In neutral without muscle loading, a significant increase in superior translation occurred with the classicLAT as compared to 30% defect (P = 0.046) and allograft conditions (P = 0.041). With muscle loading, the classicLAT (P = 0.005, 0.002) and the congruentLAT (P = 0.018, 0.021) had significantly greater superior translation compared to intact and allograft, respectively. In internal rotation, only loaded tests produced significant results; specifically, classicLAT increased translation compared to all intact CAL states (P < 0.05). In external rotation, only unloaded tests produced significant results with classicLAT and congruentLAT allowing greater translations than intact (P ≤ 0.028). For all simulations, the allograft was not significantly different than intact (P > 0.05) and no differences (P = 1.0) were found between classicLAT and congruentLAT.

Discussion:

In most simulations, CAL release with the Latarjet lead to increased superior humeral translation.

Conclusion:

The choice of technique for glenoid bone loss reconstruction has implications on the magnitude of superior humeral translation. This previously unknown effect requires further study to determine its clinical and kinematic outcomes.