Neuropathy of the suprascapular and axillary nerves in rotator cuff arthropathy: a prospective electrodiagnostic study.

PURPOSE: Prevalence of axillary (AN) and/or suprascapular (SSN) neuropathy in rotator cuff tear arthropathy (RCTA) is unknown. We aimed to prospectively evaluate for preoperative neurodiagnostic abnormalities in order to determine their prevalence, location, and influence on reverse shoulder arthroplasty (RSA) outcomes. METHODS: Patients who underwent RSA for RCTA were prospectively included. An electromyography and nerve conduction study were performed pre and post-surgery. Clinical situation: VAS, Relative Constant-Murley Score (rCMS) and ROM over a minimum of two years follow-up. RESULTS: Forty patients met the inclusion criteria; mean follow-up was 28.4 months (SD 4.4). Injuries in RCTA were present in 83.9% (77.4% in AN and 45.2% in SSN). There were no differences on preoperative VAS, ROM, and rCMS between patients with and without preoperative nerve injuries. Four acute postoperative neurological injuries were registered under chronic preoperative injuries. Six months after RSA, 69% of preoperative neuropathies had improved (82.14% chronic injuries and 77.7% disuse injuries). No differences in improvement between disuse and chronic injuries were found, but patients with preoperative neuropathy that had not improved at the postoperative electromyographic study at six months, scored worse on the VAS (1.44 vs 2.66; p .14) and rCMS (91.6 vs 89.04; p .27). CONCLUSIONS: The frequency of axillary and suprascapular neuropathies in RCTA is much higher than expected. Most of these injuries improve after surgery, with almost complete neurophysiological recovery and little functional impact on RSA. However, those patients with preoperative neuropathies and absence of neurophysiological improvement six months after surgery have lower functional results.

Single injection combined suprascapular and axillary nerve block: A randomised controlled non-inferiority trial in healthy volunteers.

BACKGROUND: A shoulder block without lung affection is desirable. In this study, we compared a low versus a high volume of a modified supraclavicular brachial plexus block. We hypothesised that a low volume of local anaesthetic would provide non-inferior block success rate with better preserved lung function. METHODS: Healthy volunteers were randomised to receive ultrasound guided 5 or 20 ml ropivacaine 0.5% at the departure of the suprascapular nerve from the brachial plexus. Primary outcome was successful shoulder block-defined as cutaneous sensory affection of the axillary nerve and motor affection of the suprascapular nerve (>50% reduction in external rotation force measured with dynamometry). We used a non-inferiority margin of 20%. Secondary outcome was change in lung function measured with spirometry. RESULTS: Thirteen of 16 (81.3%; 95% confidence interval [CI] 57.0% to 93.4%) in the 5 ml group and 15 of 16 (93.8%; 95% CI 71.7% to 98.9%) in the 20 ml group had successful shoulder block (p = .6). The ratio of the event rates of the 20 ml (standard) and 5 ml (intervention) groups was (15/16)/(13/16) = 0.937/0.813 = 1.15 (95% CI 0.88 to 1.51). All mean reductions in lung function parameters were non-significantly lower in the 5 ml group compared with the 20 ml group. CONCLUSION: For our primary outcome, the 95% CI of the difference of event ratio included the non-inferiority margin. We are therefore unable to conclude that 5 ml LA is non-inferior to 20 ml LA with respect to block success rate.

High-Resolution Ultrasound Imaging of Axillary Nerve and Relevant Injury.

OBJECTIVE: To evaluate the feasibility of axillary nerve (AN) visualization in healthy volunteers and the diagnostic value of AN injury via high-resolution ultrasonography (HRUS). METHODS: AN was examined by HRUS on both sides of 48 healthy volunteers and oriented the transducer according to three anatomical landmarks: quadrilateral space, anterior to subscapular muscle, and posterior to axillary artery. The maximum short-axis diameter (SD) and cross-sectional area (CSA) of AN were measured at different levels, and AN visibility was graded by using a five-point scale. The patients suspected of having AN injury were assessed by HRUS, and the HRUS features of AN injury were observed. RESULTS: AN can be visualized on both sides in all volunteers. There was no significant difference in SD and CSA of AN at the three levels between the left and right sides or in SD between males and females. However, the CSA of males at different levels was slightly larger than those of females (P < .05). In most volunteers, AN visibility at different levels was excellent or good, and AN was best displayed anterior to subscapular muscle. Rank correlation analysis revealed that the degree of AN visibility had correlation with height, weight, and BMI. A total of 15 patients diagnosed with AN injury, 12 patients showed diffuse swelling or focal thickening in AN, and 3 patients showed AN discontinuity. CONCLUSION: HRUS is able to reliably visualize AN, and it could be considered as the first choice for diagnosing AN injury.

Comprehensive arthroscopic management without axillary nerve release or subacromial decompression achieves satisfactory and durable results in young patients with glenohumeral osteoarthritis.

PURPOSE: The comprehensive arthroscopic management (CAM) procedure is a useful joint-preserving option for young or active patients with glenohumeral osteoarthritis (GHOA). Our objective was to evaluate the results and prognostic factors of the CAM procedure without direct axillary nerve release or subacromial decompression. METHODS: A retrospective observational study among patients with GHOA who underwent the CAM procedure was conducted. Neither axillary nerve neurolysis nor subacromial decompression was performed. Both primary and secondary GHOA were considered; the latter was defined as a history of shoulder pathology (mainly instability or proximal humerus fracture). The American Shoulder and Elbow Surgeons scale, Simple Shoulder Test, Visual Analogue Scale, activity level, Single Assessment Numeric Evaluation, EuroQol 5 Dimensions 3 Levels, Western Ontario Rotator Cuff Index, and active range of motion (aROM) were analysed. RESULTS: Twenty-five patients who underwent the CAM procedure met the inclusion criteria. After a mean follow-up of 42.4 ± 22.9 months, we found improvement (p < 0.001) in all postoperative values of the different scales. The procedure increased aROM overall. Patients with arthropathy due to instability showed worse results. The rate of CAM failures, defined as conversion to shoulder arthroplasty, was 12%. CONCLUSIONS: This study showed that the CAM procedure without direct axillary nerve neurolysis or subacromial decompression might be a valid alternative in active patients with advanced GHOA to improve shoulder function (aROM and scores), decrease pain, and delay arthroplasty. This technique showed good subjective functional scores, high patient satisfaction, and a low rate of complications. LEVEL OF EVIDENCE: IV.

Posterior Deltoid Function After Transfer of Branch to the Long Head Triceps Brachii of the Radial Nerve to the Anterior Branch of the Axillary Nerve.

PURPOSE: The aim of this study was to evaluate the function of the posterior part of the deltoid after nerve transfer of the long head triceps branch of the radial nerve to the anterior branch of the axillary nerve in patients with an upper brachial plexus injury or isolated axillary nerve injury. METHODS: We retrospectively reviewed 26 patients diagnosed with an upper brachial plexus injury or isolated axillary nerve injury who underwent nerve transfer of the long head triceps muscle branch of the radial nerve to the anterior branch of the axillary nerve in our institute between 2012 and 2017. Data on age, sex, the mechanism of injury, the pattern of injury, and operative treatment were collected from medical records. Preoperative and postoperative clinical examinations, including motor powers of shoulder abduction and extension according to Medical Research Council grading, were evaluated. At a minimum of 2 years after the operation, we evaluated the recovery of the posterior deltoid function using the swallow-tail test. RESULTS: Twenty-two patients (84.6%) had recovery of posterior deltoid function confirmed by the swallow-tail test. There were 23 patients (88.5%) who achieved at least Medical Research Council grade 4 of shoulder abduction. CONCLUSIONS: Nerve transfer from the branch to the long head triceps to the anterior branch of the axillary nerve is an effective technique for restoring deltoid function in an upper brachial plexus injury or isolated axillary nerve injury. This technique can provide shoulder abduction and shoulder extension, which are the functions of the posterior deltoid muscle. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Transdeltoid Approach to Axillary Nerve Repair: Anatomical Study and Case Series.

PURPOSE: In cases of isolated paralysis of the axillary nerve, dissection of the distal stump at the posterior deltoid border can be difficult because of scarring from an injury or previous surgery. To overcome this, we propose dissecting the anterior division of the axillary nerve (ADAN) using a deltoid-splitting approach. We investigated the anatomy of the ADAN as it pertains to the transdeltoid approach and report the clinical application of this approach in 9 patients with isolated axillary nerve injury. METHODS: The axillary nerve and its branches were dissected in 9 fresh cadaver specimens. In the clinical series, 1 patient with a lesion confined to the ADAN underwent nerve grafting. In the remaining 8 patients, the ADAN was repaired by transferring the triceps lower medial head and anconeus (TLMA) motor branch via a single-incision or double-incision posterior arm approach. RESULTS: The posterior division of the axillary nerve does not travel around the humerus. It innervated the posterior deltoid and teres minor muscles. At the posterior margin of the humerus, the ADAN ran adjacent to the teres minor tendon. The ADAN's trajectory on the lateral side of the humerus was 65 mm (SD ± 8 mm) from the midpoint of the acromion. One centimeter from the origin, the ADAN offered a prominent branch to the middle deltoid and wound around the humerus anteriorly at the surgical neck just distal to the infraspinatus tendon. A transdeltoid approach was feasible in all our patients. The TLMA was reached without any tension in the ADAN. Middle deltoid strength in 1 patient who had received a graft scored M3, while anterior and middle deltoid strength in the remaining patients who underwent nerve transfers scored M4. CONCLUSIONS: With axillary nerve lesions, reinnervation of the ADAN is a priority. The transdeltoid approach between the posterior and middle deltoid offers a direct and feasible approach to the ADAN. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.

Successful Glenohumeral Shoulder Reduction With Combined Suprascapular and Axillary Nerve Block.

BACKGROUND: Anterior glenohumeral dislocation is a common injury seen in the emergency department (ED) that sometimes requires procedural sedation for manual reduction. When compared with procedural sedation for dislocation reductions, peripheral nerve blocks provide similar patient satisfaction scores but have shorter ED length of stays. In this case report, we describe the first addition of an ultrasound-guided axillary nerve block to a suprascapular nerve block for reduction of an anterior shoulder dislocation in the ED. CASE REPORT: A 34-year-old man presented to the ED with an acute left shoulder dislocation. The patient was a fit rock climber with developed muscular build and tone. An attempt to reduce the shoulder with peripheral analgesia was unsuccessful. A combined suprascapular and axillary nerve block was performed with 0.5% bupivacaine, allowing appropriate relaxation of the patient's musculature while providing excellent pain control. The shoulder was then successfully reduced without procedural sedation. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Procedural sedation for reduction of anterior shoulder dislocations is time consuming, resource intensive, and can be risky in some populations. The addition of an axillary nerve block to a suprascapular nerve block allows for more complete muscle relaxation to successfully reduce a shoulder dislocation without procedural sedation.

The surgical anatomy of the axillary approach for nerve transfer procedures targeting the axillary nerve.

PURPOSE: The exact relational anatomy for the anterior axillary approach, targeting the axillary nerve for nerve transfers/grafts, has not been fully investigated. Therefore, this study aimed to dissect and document the gross anatomy surrounding this approach, specifically regarding the axillary nerve and its branches. METHODS: Fifty-one formalin-fixed cadavers (98 axilla) were bilaterally dissected simulating the axillary approach. Measurements were taken to quantify distances between identifiable anatomical landmarks and relevant neurovascular structures encountered during this approach. The musculo-arterial triangle, described by Bertelli et al., to aid in identification on localization of the axillary nerve, was also assessed. RESULTS: From the origin of the axillary nerve till (1) latissimus dorsi was 62.3 ± 10.7 mm and till (2) its division into anterior and posterior branches was 38.8 ± 9.6 mm. The origin of the teres minor branch along the posterior division of the axillary nerve was recorded as 6.4 ± 2.9 mm in females and 7.4 ± 2.8 mm in males. The musculo-arterial triangle reliably identified the axillary nerve in only 60.2% of the sample. CONCLUSION: The results clearly demonstrate that the axillary nerve and its divisions can be easily identified with this approach. The proximal axillary nerve, however, was situated deep and therefore challenging to expose. The musculo-arterial triangle was relatively successful in localising the axillary nerve, however, more consistent landmarks such as the latissimus dorsi, subscapularis, and quadrangular space have been suggested. The axillary approach may serve as a reliable and safe method to reach the axillary nerve and its divisions, allowing for adequate exposure when considering a nerve transfer or graft.

Arthroscopic Lower Trapezius Tendon Transfer for a Patient with Axillary Nerve Injury and Concomitant Rotator Cuff Tear: A Case Report and Technical Notes.

Introduction: Concomitant nerve injuries with musculoskeletal injuries present a challenging problem. The goals of nerve reconstruction for the shoulder include shoulder abduction and external rotation. When patients fail to achieve acceptable shoulder external rotation and shoulder abduction, tendon transfers such as trapezius transfer offer a reliable option in the subsequent stage. Case Presentation: A 32-year-old male presented with weak external rotation in his left shoulder, after previous axillary nerve reconstruction. He received the ipsilateral lower trapezius transfer with the aim of improving the external rotation. Discussion: The lower trapezius restores a better joint reaction force in both the compressive-distractive and anterior-posterior balancing and provides a centering force through the restoration of the anterior-posterior force couple. Conclusion: We believe that the ipsilateral lower trapezius transfer to the infraspinatus is a good outcome and is effective in improving overall shoulder stability and the shoulder external rotation moment arm or at least maintaining in neutral position with the arm fully adducted in patients with post axillary nerve injuries post unsatisfactory nerve reconstruction to increase the quality of life and activities of daily living.

Possible donor nerves for axillary nerve reconstruction in dual neurotization for restoring shoulder abduction in brachial plexus injuries: a systematic review and meta-analysis.

Restoring shoulder abduction is one of the main priorities in the surgical treatment of brachial plexus injuries. Double nerve transfer to the axillary nerve and suprascapular nerve is widely used and considered the best option. The most common donor nerve for the suprascapular nerve is the spinal accessory nerve. However, donor nerves for axillary nerve reconstructions vary and it is still unclear which donor nerve has the best outcome. The aim of this study was to perform a systematic review on reconstructions of suprascapular and axillary nerves and to perform a meta-analysis investigating the outcomes of different donor nerves on axillary nerve reconstructions. We conducted a systematic search of English literature from March 2001 to December 2020 following PRISMA guidelines. Two outcomes were assessed, abduction strength using the Medical Research Council (MRC) scale and range of motion (ROM). Twenty-two studies describing the use of donor nerves met the inclusion criteria for the systematic review. Donor nerves investigated included the radial nerve, intercostal nerves, medial pectoral nerve, ulnar nerve fascicle, median nerve fascicle and the lower subscapular nerve. Fifteen studies that investigated the radial and intercostal nerves met the inclusion criteria for a meta-analysis. We found no statistically significant difference between either of these nerves in the abduction strength according to MRC score (radial nerve 3.66 ± 1.02 vs intercostal nerves 3.48 ± 0.64, p = 0.086). However, the difference in ROM was statistically significant (radial nerve 106.33 ± 39.01 vs. intercostal nerve 80.42 ± 24.9, p < 0.001). Our findings support using a branch of the radial nerve for the triceps muscle as a donor for axillary nerve reconstruction when possible. Intercostal nerves can be used in cases of total brachial plexus injury or involvement of the C7 root or posterior fascicle. Other promising methods need to be studied more thoroughly in order to validate and compare their results with the more commonly used methods.

Efficacy and safety of a 3D-printed arthrodesis prosthesis for reconstruction after resection of the proximal humerus: preliminary outcomes with a minimum 2-year follow-up.

BACKGROUND: The purpose of this study was to investigate the feasibility of using a three-dimensional (3D)-printed arthrodesis prosthesis for reconstruction of the proximal humeral defect after tumor resection. METHODS: A novel proximal humeral prosthesis was designed to restore bone continuity and shoulder arthrodesis and was fabricated via 3D printing technology. Ten patients with primary malignancies in the proximal humerus underwent intra-articular resection and replacement with this prosthesis from 2017 to 2019. Baseline and operative data, oncological and prosthetic survival, and functional status were summarized. RESULTS: This cohort consisted of 9 males and 1 female with a mean age of 32.1 ± 16.1 years. Diagnoses included 5 cases of osteosarcoma, 3 cases of chondrosarcoma and 1 each case of undifferentiated pleomorphic sarcoma and malignant myoepithelioma. The mean operative duration, intraoperative hemorrhage and postoperative length of hospitalization were 151.5 ± 61.0 min, 410.0 ± 353.4 ml and 5.3 ± 1.9 d, respectively. The mean follow-up duration was 29.3 ± 6.4 months, with a minimum of 24 months for the surviving patients. Two patients experienced local recurrence, and four patients developed distant metastases. Detachment of the taper occurred in two patients. One was managed conservatively, and the other received amputation due to concurrent tumor recurrence. The mean MSTS-93 and ASES scores and ranges of forwards flexion and abduction were 24.9 ± 3.1, 79.4 ± 8.3, 71.3 ± 19.4°, and 61.3 ± 16.4°, respectively. The functional outcomes were independent of the preservation of the axillary nerve. Histological study of the glenoid component showed evidence of bone ingrowth at the bone-prosthesis porous interface. CONCLUSION: Application of the 3D-printed arthrodesis prosthesis might be a safe and efficacious method for functional reconstruction in patients who underwent resection of the proximal humerus, especially for those without preservation of the axillary nerve.

Patterns of Nerve Injury and Recovery Rates of Infraclavicular Brachial Plexus Lesions Following Anterior Shoulder Dislocation.

PURPOSE: We reviewed our cases of infraclavicular brachial plexus injuries associated with anterior shoulder dislocation to determine patterns of injury, recovery rates, and factors associated with a poor motor outcome. METHODS: This was a retrospective review of patients who had sustained a concomitant nerve injury following dislocation of the glenohumeral joint treated with closed manipulation. The data collected included patient demographics, injury factors, and patterns of neurological deficits. The Medical Research Council (MRC) grade for motor power was the primary outcome measure, where a grade of 4 or 5 was regarded as achieving good motor recovery. Univariate and multivariable analyses were used to identify factors associated with persistent motor weakness (MRC grades 0-3) at the final follow-up. RESULTS: Between 2015 and 2019, 61 patients were assessed. There were 36 males and 25 females, with a median age of 64 years (interquartile range [IQR], 53-73 years). Four patterns of injury were identified: (1) isolated axillary nerve lesions; (2) single cord lesions; (3) combined lesions involving the medial and posterior cords; and (4) diffuse lesions affecting all 3 cords. Of 28 patients with isolated axillary nerve injuries, 22 recovered. All lateral cord injuries (11/11) and 20 of 24 posterior cord injuries recovered spontaneously. Recovery of hand intrinsic function from medial cord injuries had the worst outcome, with 14 of 27 patients not recovering beyond MRC grades 0 to 3. The median duration of dislocation before reduction was 6 hours (IQR, 3-12 hours). A multivariate analysis showed an association between the duration of shoulder dislocation and the likelihood of persistent motor weakness. CONCLUSIONS: Shoulder dislocations with motor deficits should be regarded as orthopedic emergencies and reduced expediently. Persistent motor weakness may be associated with a prolonged duration of dislocation prior to glenohumeral relocation. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic IV.

Elongation of the brachial plexus after reverse shoulder arthroplasty: an anatomical study.

INTRODUCTION: The use of reverse shoulder arthroplasty (RSA) is becoming more extended and its clinical results are good or excellent according to the literature. The main biomechanical characteristic of RSA is that it lowers and medializes the centre of rotation of the shoulder causing an arm lengthening. Although the number of neurological complications is low (5%), there are more neurophysiological changes in the brachial plexus with RSA than with the anatomic shoulder arthroplasty. The main goal of this study was to quantify the lengthening of the terminal branches of the brachial plexus suffered after RSA implantation. MATERIALS AND METHODS: 20 Embalmed cadavers were analysed. Four distances using bone references were employed to measure the lengthening of the arm and subacromial space. The brachial plexus and its terminal branches (radial, axillary, ulnar, musculocutaneous and median nerves) and the axillary artery, were identified and marked. Measurements were made to determine the change of position of the neurovascular structures, the arm lengthening and the lengthening of each nerve before and after the implantation of RSA. Two models of RSA were used: SMR®(Lima) and Delta Xtend®(DePuy-Synthes). RESULTS: The mean arm elongation was 10.5 mm. The subacromial space suffers an elongation of 20.5-29.8%. All the neurovascular structures suffered elongation: median nerve 23.1%, musculocutaneous nerve 22.1%, ulnar nerve 19%, radial nerve 17%, axillary nerve 12-14.5%, axillary artery 24.8%. There were no differences in the results between the types of prosthesis. CONCLUSIONS: Due to its design, the RSA causes an arm lengthening which is reflected by the elongation of the neurovascular structures of the arm.

Complications after open Latarjet procedure: influence of arm positioning on musculocutaneous and axillary nerve function.

BACKGROUND: Alterations in the anatomical relationships of the musculocutaneous (MCN) and axillary nerves and the influence of arm positioning on these relationships after a Latarjet procedure have been demonstrated in the cadaver, but there are no studies in the literature that establish if there is any neurophysiological repercussion. METHODS: We retrospectively identified 24 patients with a primary or revision open Latarjet procedure. A prospective clinical (Constant-Murley, Rowe and Walch-Duplay and active range of motion), radiographic (with CT), and electrodiagnostic evaluation was made at the most recent follow-up. RESULTS: Nonunion occurred in four patients (22%); there were, as well, one case of partial coracoid reabsorption (5%) and two (11%) with mild glenohumeral osteoarthritis. In the anatomical position, we found no alterations in the musculocutaneous nerve and two cases (11%) in the axillary nerve slight motor unit loss. In the risk position, 11 cases (61%) had neurophysiological involvement (36% had neurophysiological changes in the musculocutaneous nerve and 64% in the axillary nerve). No differences between patients with or without neurophysiologic changes were found: Constant 87/83; Rowe 89/90; Walch-Duplay 84/78; Forward elevation 175º/170º, abduction 165°/175°; external rotation 48°/45°. CONCLUSION: The rate of clinical electromyographic changes in the axillary and MCN in the abducted and externally rotated arm position (risk dislocation position) is higher than in neutral position. Nonunion of the coracoid process must play a role in these neurophysiological changes. Although in the medium-term they don't have clinical impact, further randomized prospective studies with a larger sample size are necessary to determine their true repercussion. LEVEL OF EVIDENCE: Level IV.

Anatomy of the nerves to the teres minor and the long head of the triceps brachii for electromyography.

BACKGROUND: We investigated the branching pattern and topographic anatomy of the nerves to the teres minor (Tm) and the long head of the triceps brachii (LHT) in relation to reference lines extending between surface landmarks, to identify the innervation patterns of, and the optimal needle placement points within, the Tm and the LHT. METHODS: The anatomical courses of the nerves to the Tm and the LHT were investigated in 37 upper limbs of fresh-frozen cadavers. Distances from the acromion to nerve penetration points, and crossing points of reference lines with the Tm and LHT were measured in 27 cadaveric upper limbs. RESULTS: The Tm was innervated by the axillary nerve in all specimens in three patterns, and the LHT was innervated exclusively by the radial nerve. Our dissection and measurements indicate that the midpoint of the reference line from the acromion to the inferior angle of the scapula is the optimal needle insertion point for the Tm. The target point for the LHT appears to be the one-third point of the reference line from the acromion to the medial epicondyle, or the two-thirds point of the reference line from the acromion to the axillary fold. CONCLUSIONS: We investigated the branching pattern of the nerves to the Tm and the LHT and propose optimal needle placement points for electromyography of the Tm and LHT.

Dexmedetomidine combined with suprascapular nerve block and axillary nerve block has a synergistic effect on relieving postoperative pain after arthroscopic rotator cuff repair.

PURPOSE: Suprascapular nerve block (SSNB) is the most commonly used block for the relief of postoperative pain from arthroscopic rotator cuff repair and can be used in combination with axillary nerve block (ANB). Dexmedetomidine (DEX) is a type of alpha agonist that can elongate the duration of regional block. The aim of this study was to compare the effects of the use of dexmedetomidine combined with SSNB and ANB with those of the use of SSNB and ANB alone on postoperative pain, satisfaction, and pain-related cytokines within the first 48 h after arthroscopic rotator cuff repair. METHODS: Forty patients with rotator cuff tears who had undergone arthroscopic rotator cuff repair were enrolled in this single-center, double-blinded randomized controlled trial study. Twenty patients were randomly allocated to group 1 and received ultrasound-guided SSNB and ANB using a mixture of 0.5 ml (50 µg) of DEX and 9.5 ml of 0.75% ropivacaine preemptively. The other 20 patients were allocated to group 2 and underwent ultrasound-guided SSNB and ANB alone using a mixture of 0.5 ml of normal saline and 9.5 ml of ropivacaine. The visual analog scale (VAS) for pain and patient satisfaction (SAT) scores were postoperatively checked within 48 h. The plasma interleukin (IL)-6, IL-8, IL-1ß, cortisol, and serotonin levels were also postoperatively measured within 48 h. RESULTS: Group 1 showed a significantly lower mean VAS (visual analog scale of pain) score 1, 3, 6, 12, 18 and 24 h after operation, and a significantly higher mean SAT (patient satisfaction) score 1, 3, 6, 12, 18, 24 and 36 h after the operation than group 2. Group 1 showed a significantly lower mean plasma IL-8 level 1 and 48 h after the operation, and a significantly lower mean IL-1ß level 48 h after the operation than group 2. Group 1 showed a significantly lower mean plasma serotonin level 12 h after the operation than group 2. The mean timing of rebound pain in group 1 was significantly later than that in group 2 (36 h > 23 h, p = 0.007). Six patients each in groups 1 and 2 showed rebound pain. The others did not show rebound pain. CONCLUSIONS: Ultrasound-guided SSNA and ANB with DEX during arthroscopic rotator cuff repair resulted in a significantly lower mean VAS score and a significantly higher mean SAT score within 48 h after the operation than SSNB and ANB alone. Additionally, SSNB and ANB with DEX tended to result in a later mean timing of rebound pain accompanied by significant changes in IL-8, IL-1ß, and serotonin levels within 48 h after the operation. The present study could provide the basis for selecting objective parameters of postoperative pain in deciding the optimal use of medication for relieving pain. LEVEL OF EVIDENCE: Level I. TRIAL REGISTRATION: 2015-20, ClinicalTrials.gov Identifier: NCT04398589. IRB NUMBER: 2015-20, Hallym University Chuncheon Sacred Heart Hospital.

Surgical Treatment of Iatrogenic Nerve Injury Following Arthroscopic Capsulolabral Repair.

PURPOSE: Case reports of nerve injuries following arthroscopic capsulolabral repair emphasize the proximity of major nerves to the glenoid. This study describes preoperative localization using nerve-sensitive magnetic resonance imaging in a small cohort of patients with iatrogenic nerve injuries following arthroscopic capsulolabral repair and the outcomes of nerve repair in these patients. METHODS: Cases of iatrogenic nerve injury following arthroscopic capsulolabral repair referred to 2 surgeons from January 2017 to December 2019 were identified. Clinical charts, electrodiagnostic testing, magnetic resonance imaging studies, and operative reports were reviewed. RESULTS: Four cases of iatrogenic nerve injury were identified. The time to presentation to our institution ranged from 2 weeks to 8 years. The axillary nerves in 3 cases were tethered by a suture at the inferior glenoid, whereas 1 case had a suture tied around the radial and median nerves inferior to the glenohumeral joint capsule. One case underwent excision and nerve transfer, 1 underwent excision and nerve repair, and 2 underwent suture removal and neurolysis. Open and arthroscopic approaches, including a recently described approach to the axillary nerve in the "blind zone," were used. Three cases demonstrated good recovery of all affected motor and sensory functions after surgery. At the 10-month follow-up, 1 case had persistent weakness, but there was evidence of axonal regeneration on electrodiagnostic testing. CONCLUSIONS: Arthroscopic capsulolabral repair places regional nerves, particularly the axillary nerve, at risk owing to their proximity to the joint capsule and inferior glenoid. Patients with neuropathic pain in the distribution of affected nerves with corresponding sensorimotor loss following arthroscopic capsulolabral surgery should undergo focused magnetic resonance imaging with nerve-sensitive sequences and electrodiagnostic testing to localize the injury. The use of multiple surgical windows to the axillary nerve in the "blind zone" enables full visualization for neurolysis, suture removal, and nerve repair or transfer. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.

Defining the proximity of the axillary nerve from defined anatomic landmarks: an in vivo magnetic resonance imaging study.

BACKGROUND: The location of the axillary nerve in the shoulder makes it vulnerable to traumatic or iatrogenic injury. Cadaveric studies have reported the location of the axillary nerve but are limited because of tissue compression, dehydration, and decay. Three-Tesla (T) magnetic resonance imaging (MRI) allows high anatomic resolution of neural structures. The aim of our study was to better define the location of the axillary nerve from defined bony surgical landmarks in vivo, using MRI scan. METHODS: Using MRI, we defined a number of anatomic points and measured the distance from these to the perineural fat surrounding the axillary nerve using simultaneous tracker lines on both images. Two observers were used. RESULTS: A total of 187 consecutive 3-T MRI shoulder scans were included. Mean age was 57.9 years (range 18-86). The axillary nerve was located at a mean of 14.1 mm inferior from the bony glenoid at the anterior border, 11.9 mm from the midpoint, and 12.0 mm from the posterior border. There was a significant difference between distance at the anterior border and midpoint (P < .001), and between the anterior and posterior borders (P < .001). The axillary nerve was located at a mean of 12.6 mm medial to the humeral shaft at the anterior border, 9.9 mm at the midpoint, and 8.6 mm from the posterior border. There was a significant difference between distance at the anterior border and midpoint (P = .008) and between the anterior and posterior borders (P = .002). The mean distance of the axillary nerve from the anterolateral edge of the acromion was 53.3 mm (95% confidence interval [CI] 52.3, 54.2; range 33.9-76.3). The mean distance of the axillary nerve from the inferior edge of the capsule was 2.7 mm (95% CI 2.9, 3.1; range 0.3-9.9). There was a positive correlation between humeral head diameter and axillary nerve distance from the inferior glenoid (R2 = 0.061, P < .001). There was a positive correlation between humeral head diameter and distance from the anterolateral edge of the acromion (R2 = 0.140, P < .001). CONCLUSION: Our study has defined the proximity of the axillary nerve from defined anatomic landmarks. The proximity of the axillary nerve to the inferior glenoid and medial humeral shaft changes as the axillary nerve passes from anterior to posterior. The distance of the axillary nerve from the anterolateral edge of the acromion remains relatively constant. Both sets of distances may be affected by humeral head size. The study has relevance to the shoulder surgeon when considering "safe zones" during arthroscopic or open surgery.

COMPARISON OF THE ONSET OF SENSORY BLOCK USING LIDOCAINE 1.5% WITH ADRENALINE OR LIDOCAINE 1.5% WITH ADRENALINE AND DEXAMETHASONE IN ULTRASOUND GUIDED AXILLARY NERVE BLOCK FOR BELOW ELBOW SURGERIES.

OBJECTIVE: The aim: To demonstrate the onset of dexamethasone when added to lidocaine in ultrasound regional axillary brachial block. PATIENTS AND METHODS: Materials and methods: 30 patients participated in this study in Al-wasity hospital from June 1st to December 1st 2019; all were of ASA I-II type, aged 18-65 years old. All patients were scheduled for upper limb below elbow surgery with peripheral nerve block. They were divided randomly in to 2 groups: Group A: received 20 ml of lidocaine 1.5% with adrenaline 1:200000; Group 2 : received 20 ml of lidocaine with adrenaline and dexamethasone 8 mg. There was no significant differences among the groups regarding the change in pulse rate, MAP and Oxygen saturation. The group B was faster than group A (p value < 0.001) in both the time of cold sensory block onset and pinprick sensory block onset at all dermatome (C5,C6,C7,C8,T1). RESULTS: Results: A variety of adjuvants have been used with peripheral nerve block to decrease the onset time, improve block quality, and prolong analgesia. Steroids have been shown to be beneficial in improving block onset. CONCLUSION: Conclusions: Adding dexamethasone to lidocaine enhanced the onset time of the block with no hemodynamic effect.

Optimal reference electrode placement for accessory and axillary nerve conduction studies.

BACKGROUND: Various techniques are described for proximal motor nerve conduction studies (NCSs). We investigated alternative reference electrode (E2) locations for accessory and axillary NCSs. METHODS: Multi-channel recordings were made from trapezius or deltoid referred to different sites, and from those sites referred to a remote electrode. Responses were compared using grouped statistics, and correlation analysis. RESULTS: For accessory NCSs, all belly:E2 montages showed comparable responses but axillary NCSs were more variable. Low amplitude contamination was seen at the sternum and contralateral acromion but greater distortion using other potential E2 sites. In both accessory and axillary studies, the ipsilateral acromion showed moderate activity, which correlated with the belly:remote response. CONCLUSIONS: Variation in E2 electrode sites may significantly distort the measured compound muscle action potential (CMAP). For accessory and axillary NCS, a sternal reference has favorable characteristics. Other sites, such as ipsilateral acromion or deltoid insertion, may not yield a representative CMAP.