Risk of Axillary Nerve Injury With Medial Support Screws in Intramedullary Nails: An Anatomical Study.

BACKGROUND: In recent years, intramedullary nails with medial support screws for proximal humeral fractures have become available. Although these devices have a potential risk of iatrogenic axillary nerve injury, no studies have investigated the anatomical relationship between the medial support screws in the modern intramedullary nail and the axillary nerve. This study aimed to clarify the anatomical relationship between the medial support screws in the intramedullary nail and the axillary nerve. MATERIALS AND METHODS: In total, 29 cadaveric shoulders (mean age: 82.6 years old (range: 61-105); 15 males and 14 females) were included in this study. Shoulders within whole-body cadavers were used in all cases. A single proximal humeral nail with medial support screws (ARISTO Proximal Humeral Nail; MDM, Tokyo, Japan) was used. The distance of each medial support screw from the axillary nerve and its branches was measured. RESULTS: In two (6.90%) of 29 shoulders, the axillary nerves came into contact with the medial support screws. In the remaining 27 of 29 shoulders (93.1%), the nerves were located proximal to the medial support screws. CONCLUSION: Medial support screws in proximal humeral fracture nails had the potential to injure the axillary nerve and its branches.

Diagnosis and treatment approach of delayed presentation of anterior branch axillary nerve injury following shoulder dislocation: case report.

In this case report, a unique instance of delayed isolated anterior branch axillary nerve injury following shoulder dislocation is highlighted. The patient, a 55-year-old manual laborer, presented with severe deltoid wasting and reduced power 18 months postdislocation, necessitating a specialized treatment approach. The use of axillary nerve neurolysis and an innovative upper trapezius to anterior deltoid transfer via a subacromial path posterior to the clavicle, facilitated by an autologous semitendinosus graft, resulted in significant improvement with 160 degrees of abduction and Grade 4+ power Medical Research Council grading (MRC) at the 5-year follow-up.

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.

COVID-19 Vaccines and Axillary Nerve Dysfunction: A Case Report.

COVID-19 resulted in a worldwide pandemic and the rapid introduction of vaccines in an attempt to mitigate it. Neuritis and neuropathy after intramuscular injection had been previously seen with influenza vaccines and appear to be a side effect of the COVID-19 vaccine as well. In the following report, we present the case of a 43-year-old female who developed axillary nerve symptoms after administration of the COVID-19 vaccine and her subsequent recovery.

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.

Simultaneous Bilateral Anterior Shoulder Dislocation After Low-Energy Trauma: A Case Report.

Unilateral shoulder dislocation is known to be one of the most common joint dislocations. However, simultaneous bilateral shoulder dislocations are rare, especially anterior dislocations. We report a case of an 84-year-old woman who presented to the urgency room with symmetrical bilateral anterior shoulder dislocation 12 hours after falling on a treadmill. She presented with bilateral pain, functional impairment, prominent acromion, flattened shoulder, and, in the right upper limb, paresthesias on the dorsum of the hand and extension deficit of the fingers. Closed reduction of both shoulders was performed under sedation, and she was immobilized bilaterally with an arm sling in internal rotation. A full recovery was achieved six months after the injury.

The Proximity of the Axillary Nerve During Keyhole Tenodesis of the Long Head of the Biceps Tendon: A Cadaveric Study.

Background: Over time, surgical management for conditions involving the long head of the biceps tendon (LHBT) has evolved. Some techniques, such as keyhole tenodesis proposes bicortical drilling, however, carries an axillary nerve injury risk. The goal of our cadaveric study was to see if we could keep a safe zone between the point of exit of keyhole tenodesis of biceps and axillary nerve. Methodology: The study was performed on ten shoulders from five fresh frozen cadavers. Between the lower border of the transverse humeral ligament (THL) and the superior margin of the pectoralis major insertion at the lowest limit of the bicipital groove, a beath pin was driven through with the help of the modified tip aimer tibial jig procured from the anterior cruciate ligament reconstruction (ACL) set, which was fixed at an arc of 45°. The distance between the axillary nerve and beath pin at the exit point was measured. Results: The biceps tendon musculotendinous junction was followed all the way to the inferiorly and biceps tendon was found in the groove. The average distance from the axillary nerve to the exit point of the beath pin was 17.7 mm (range 14.4-20.9 mm, 95% CI). Conclusion: The axillary nerve is not injured during bicortical drilling when keyhole tenodesis of biceps is performed at the distal limit of the groove of biceps. The area in the biciptal groove between inferior margin of THL and superior border of pectoralis major insertion is safe area for biceps tenodesis.

Is there any clinical significance of axillary nerve electrophysiological changes in the deltoid split approach?

Purpose: The clinical effects of axillary nerve injury in the deltoid splitting approach are controversial. This study investigated the axillary nerve function with clinical and electrophysiologically in proximal humeral fracture patients with internal fixation using the deltoid split approach. We also aimed to investigate the effects of this damage on deltoid muscle volume and discuss the effects of volumetric changes and nerve damage on patients' clinical outcomes. Methods: study designed prospectively with 25 consecutive patients who received open reduction and internal fixation of proximal humerus fracture through a deltoid splitting approach. We performed clinical, electrophysiological, and radiological examinations during minimum follow-up time of 24 months. Electrophysiological examination comprised electromyoneurography (EMNG). Functional results followed by Constant-Murley and Disabilities of the Arm, Shoulder, and Hand scores. Deltoid volumes were evaluated with magnetic resonance imaging. Results: Twenty-five patients operated on with open reduction internal fixation were prospectively observed. In the EMNG measurements of the patients on the 45th postoperative day, partial degeneration was observed in the anterior part of the axillary nerve in all cases (100%). In the control EMNG measurements performed at the 12th month, normal values were obtained for 15 (60%) of the patients, while findings of ongoing regeneration were detected for 10 (40%) of the patients and normal values at all patients at the 24th month. The difference between abnormal and normal EMNG groups' on 12th month Constant-Murley scores was not statistically significant in any period. Only anterior muscle thickness was statistically higher in the normal patient group than with abnormal EMNG results. Conclusions: In proximal humeral fractures treated with the deltoid split approach, there may be iatrogenic damage of the anterior branch of the axillary nerve. Axillary nerve damage does not affect the patients' clinical scores in the early and mid-terms. Level of evidence: LEVEL III.

The humeral suspension technique: a novel operation for deltoid paralysis.

Isolated deltoid paralysis is a rare pathology that can occur after axillary nerve injury due to shoulder trauma or infection. This condition leads to loss of deltoid function that can cause glenohumeral instability and inferior subluxation, resulting in rotator cuff muscle fatigue and pain. To establish dynamic glenohumeral stability, a novel technique was invented. Humeral suspension is achieved using a double button implant with non-resorbable high strength cords between the acromion and humeral head. This novel technique was used in two patients with isolated deltoid paralysis due to axillary nerve injury. The results indicate that the humeral suspension technique is a method that supports centralizing the humeral head and simultaneously dynamically stabilizes the glenohumeral joint. This approach yielded high patient satisfaction and reduced pain. Glenohumeral alignment was improved and remained intact 5 years postoperative. The humeral suspension technique is a promising surgical method for subluxated glenohumeral joint instability due to isolated deltoid paralysis.

Increased Medial Displacement of the Humeral Shaft of at Least 40% Correlates With an Increased Incidence of Nerve Injury in Proximal Humerus Fractures.

BACKGROUND: Peripheral nerve and infraclavicular brachial plexus injury following proximal humerus fractures are commonplace, but diagnosing a concomitant nerve injury in the acute setting is challenging. Fracture displacement has been identified as a qualitative risk factor for nerve injury, and additional attention should be paid to the neurologic exams of patients with proximal humerus fractures with significant medial shaft displacement. However, a quantitative relationship between the risk of nerve injury and medialization of the humeral shaft has not been shown, and additional risk factors for this complication have not been assessed. The aim of this study was to identify the risk factors for a neurologic deficit following a proximal humerus fracture, with particular interest in the utility of the magnitude of medial shaft displacement as a predictor of neurologic dysfunction. METHODS: A retrospective chart review was performed on all proximal humerus fractures in a 3-year period (2012-2015) at a level one trauma center. Isolated greater tuberosity fractures (OTA 11-A1) were excluded. Fracture displacement was measured on initial injury AP shoulder radiograph and expressed as a percentage of humeral diaphyseal width. All orthopedic inpatient documentation was assessed to identify clinical neurologic deficits. RESULTS: We identified 139 patients for inclusion. There were 22 patients (16%) with new neurologic deficits at presentation (8 axillary nerve, 2 radial nerve, 12 infraclavicular brachial plexus or multiple nerve injuries). The average shaft medial displacement in patients with neurologic injuries was 59% vs. 21% without nerve deficits (p=0.03). Using a 40% medial displacement threshold, the odds ratio for a nerve injury was 5.24 (95% CI 1.54 - 17.77, p=.008). CONCLUSION: Increased medial displacement of the humeral shaft following proximal humerus fracture is associated with an increased incidence of nerve injury at the time of initial presentation. This finding is not meant to be a surrogate for a high-quality neurologic exam in all patients with proximal humerus fractures. However, improved knowledge of the specific risk factors for an occult neurologic injury will improve the clinician's ability to accurately diagnose and properly treat proximal humerus fractures and their sequelae.Level of Evidence: III.

Erecta dislocation of the shoulder joint-A rare injury: About four cases.

A nonresolving axillary nerve injury is a rare associated complication to an inferior dislocation of the shoulder joint. This worsen the midterm outcome of the shoulder. So, neurovascular status must be checked by regular clinical testing and by an electromyography in all cases of inferior dislocation of the shoulder joint.

Risk of Axillary Nerve Injury in Standard Anterolateral Approach of Shoulder: Cadaveric Study.

Introduction: The anterolateral acromion approach of the shoulder is popular for minimally invasive plate osteosynthesis (MIPO) technique. However, there are literatures describing the specific risks of injury of the axillary nerve using this approach. Nevertheless, most of the studies were done with Caucasian cadavers. So, the purpose of this study was to evaluate the risk of iatrogenic axillary nerve injury from using the anterolateral shoulder approach and further investigate the location of the axillary nerve, associated with its location and arm length in the Asian population that have shorter arm length compared to the Caucasian population. Materials and Methods: Seventy-nine shoulders in fourty-two embalmed cadavers were evaluated. The bony landmarks were drawn, and a vertical straight incision was made 5cm from tip of the acromion (anterolateral approach), to the bone. The iatrogenic nerve injury status and the distance between the anterolateral edge of the acromion to the axillary nerve was measured and recorded. Results: In ten of the seventy-nine shoulders, the axillary nerve were iatrogenically injured. The average anterior distance was 6.4cm and the average arm length was 30.2cm. The anterior distance and arm length ratio was 0.2. Conclusion: Our results demonstrated that the recommended safe zone at 5cm from tip of acromion was not suitable with Asian population due to shorter arm length, compared to Caucasian population. The location of axillary nerve could be predicted by 20% of the total arm-length.

Eficacia del tratamiento quirúrgico mediante neurotización radial en pacientes con lesión traumática aislada de nervio axilar / Efficacy of surgical treatment by radial nerve transfer in patients with traumatic isolated axillary nerve injury

Resumen: Objetivo: Determinar la eficacia del tratamiento quirúrgico mediante neurotización radial en pacientes con diagnóstico de lesión traumática aislada de nervio axilar. Material y métodos: Se presenta una serie de siete casos, seis hombres y una mujer, con promedio de edad de 51.6 años, con diagnóstico de lesión traumática aislada de nervio axilar tratados quirúrgicamente entre Enero 2013 y Diciembre 2016. Todos los pacientes fueron tratados mediante transferencia nerviosa de rama motora radial de la cabeza medial del tríceps, entre el sexto y decimoséptimo mes después del traumatismo, con un seguimiento mínimo de 12 meses. Se evaluó la eficacia del tratamiento mediante la Medical Research Council (MRC) y el cuestionario DASH. Resultados: En el análisis bivariado encontramos diferencias estadísticamente significativas con respecto al grado de mejoría de fuerza de rotación externa y de abducción medido por MRC preoperatoria y postoperatoria (p < 0.05). Los resultados también demostraron una significancia estadística en el rango de movimiento de abducción postoperatorio de hombro (p = 0.01). El cuestionario DASH demostró un porcentaje promedio de discapacidad de 20.29% después de 12 meses de seguimiento. Conclusión: La neurotización radial en pacientes con diagnóstico de lesión traumática aislada de nervio axilar proporciona un excelente grado de mejoría de fuerza de rotación externa y abducción, además de mejorar significativamente el rango de abducción del hombro; también se demostró, mediante cuestionario DASH, que el porcentaje de discapacidad es bajo.

Abstract: Purpose: To determine the efficacy of surgical treatment by radial nerve transfer in patients with a diagnosis of isolated axillary nerve traumatic injury. Material and methods: We present a series of seven cases, six men and one woman, with a mean age of 51.6 years, with a diagnosis of isolated traumatic axillary nerve injury between January 2013 and December 2016. All patients were treated by radial motor branch nerve transfer of the medial triceps head between the sixth and seventeenth months after trauma, with a minimum follow-up of 12 months. The efficacy of the treatment was evaluated by the Medical Research Council (MRC) and the DASH questionnaire. Results: In the bivariate analysis we found statistically significant differences regarding the degree of external rotation and abduction strength measured by preoperative and postoperative MRC (p < 0.05). The results also demonstrated a statistical significance in the range of postoperative shoulder abduction movement (p = 0.01). The DASH questionnaire showed an average percentage of disability of 20.29% after 12 months of follow-up. Conclusion: Radial nerve transfer in patients diagnosed with axillary nerve traumatic injury provides an excellent degree of improvement in external rotation and abduction strength, in addition to significantly improving the shoulder abduction range, it was also demonstrated by DASH questionnaire that the percentage disability is low.

[MIPPO and ORIF for the treatment of elderly proximal humerus fractures of type Neer II:a case control study].

OBJECTIVE: To compare the clinical efficacy of minimally invasive percutaneous plate osteosynthesis(MIPPO)and open reduction and internal fixation (ORIF) in treating senile NEER IIproximal humerus fractures. METHODS: From March 2014 to March 2016, 46 elderly patients with Neer II proximal humerus fractures were retrospectively reviewed. Among them, 20 patients in MIPPO group included 9 males and 11 females with an average age of (70.4±4.4) years old; while 26 patients in ORIF group included 11 males and 15 females with an average age of (70.9±4.0) years old. The length of hospital stay, times of fluoroscopy, beginning time of function rehabilitation, healing time of fracture, Constant Murley score of the shoulder joint at 3, 6, 12 months after operation and complications were observed and compared. RESULTS: All patients were followed up for 12 to 24 months with an average of 16.8±3.7. The healing time of fracture, beginning time of function rehabilitation in MIPPO group were(13.0±0.8) weeks, (3.0±0.9) days respectively and shorter than those in ORIF group which were (13.8±1.4) weeks and(6.8±1.3) days. The times of fluoroscopy in MIPPO group was 19.2±3.7 and more than that in ORIF group which was 12.1±3.4. At 3 and 6 months after operation, Constant Murley score in MIPPO group were 81.3±3.9, 86.6±5.4 and more than that in ORIF group which were 69.5±6.6, 80.5±6.7. There were no differences between two groups in the length of hospital stay, Constant Murley score at 12 months after operation and grading at the final follow-up. There was one fracture redisplacement in each group. And 1 case of axillary nerve injury in MIPPO group, 2 cases of delayed union in ORIF group. No incision infection, screw loosening or plate break was found. CONCLUSIONS: MIPPO and ORIF are both effective in treating Neer II proximal humeral fractures. MIPPO technique has the advantages of faster recovery, earlier rehabilitative exercise and better shoulder function. The disadvantages are more exposure to radiationd and the possibility of axillary nerve injure.

[Efficacy of surgical treatment by radial nerve transfer in patients with traumatic isolated axillary nerve injury]. / Eficacia del tratamiento quirúrgico mediante neurotización radial en pacientes con lesión traumática aislada de nervio axilar.

PURPOSE: To determine the efficacy of surgical treatment by radial nerve transfer in patients with a diagnosis of isolated axillary nerve traumatic injury. MATERIAL AND METHODS: We present a series of seven cases, six men and one woman, with a mean age of 51.6 years, with a diagnosis of isolated traumatic axillary nerve injury between January 2013 and December 2016. All patients were treated by radial motor branch nerve transfer of the medial triceps head between the sixth and seventeenth months after trauma, with a minimum follow-up of 12 months. The efficacy of the treatment was evaluated by the Medical Research Council (MRC) and the DASH questionnaire. RESULTS: In the bivariate analysis we found statistically significant differences regarding the degree of external rotation and abduction strength measured by preoperative and postoperative MRC (p 0.05). The results also demonstrated a statistical significance in the range of postoperative shoulder abduction movement (p = 0.01). The DASH questionnaire showed an average percentage of disability of 20.29% after 12 months of follow-up. CONCLUSION: Radial nerve transfer in patients diagnosed with axillary nerve traumatic injury provides an excellent degree of improvement in external rotation and abduction strength, in addition to significantly improving the shoulder abduction range, it was also demonstrated by DASH questionnaire that the percentage disability is low.

OBJETIVO: Determinar la eficacia del tratamiento quirúrgico mediante neurotización radial en pacientes con diagnóstico de lesión traumática aislada de nervio axilar. MATERIAL Y MÉTODOS: Se presenta una serie de siete casos, seis hombres y una mujer, con promedio de edad de 51.6 años, con diagnóstico de lesión traumática aislada de nervio axilar tratados quirúrgicamente entre Enero 2013 y Diciembre 2016. Todos los pacientes fueron tratados mediante transferencia nerviosa de rama motora radial de la cabeza medial del tríceps, entre el sexto y decimoséptimo mes después del traumatismo, con un seguimiento mínimo de 12 meses. Se evaluó la eficacia del tratamiento mediante la Medical Research Council (MRC) y el cuestionario DASH. RESULTADOS: En el análisis bivariado encontramos diferencias estadísticamente significativas con respecto al grado de mejoría de fuerza de rotación externa y de abducción medido por MRC preoperatoria y postoperatoria (p 0.05). Los resultados también demostraron una significancia estadística en el rango de movimiento de abducción postoperatorio de hombro (p = 0.01). El cuestionario DASH demostró un porcentaje promedio de discapacidad de 20.29% después de 12 meses de seguimiento. CONCLUSIÓN: La neurotización radial en pacientes con diagnóstico de lesión traumática aislada de nervio axilar proporciona un excelente grado de mejoría de fuerza de rotación externa y abducción, además de mejorar significativamente el rango de abducción del hombro; también se demostró, mediante cuestionario DASH, que el porcentaje de discapacidad es bajo.

MIPPO and ORIF for the treatment of elderly proximal humerus fractures of type Neer II:a case control study / 中国骨伤

<p><b>OBJECTIVE</b>To compare the clinical efficacy of minimally invasive percutaneous plate osteosynthesis(MIPPO)and open reduction and internal fixation (ORIF) in treating senile NEER IIproximal humerus fractures.</p><p><b>METHODS</b>From March 2014 to March 2016, 46 elderly patients with Neer II proximal humerus fractures were retrospectively reviewed. Among them, 20 patients in MIPPO group included 9 males and 11 females with an average age of (70.4±4.4) years old; while 26 patients in ORIF group included 11 males and 15 females with an average age of (70.9±4.0) years old. The length of hospital stay, times of fluoroscopy, beginning time of function rehabilitation, healing time of fracture, Constant Murley score of the shoulder joint at 3, 6, 12 months after operation and complications were observed and compared.</p><p><b>RESULTS</b>All patients were followed up for 12 to 24 months with an average of 16.8±3.7. The healing time of fracture, beginning time of function rehabilitation in MIPPO group were(13.0±0.8) weeks, (3.0±0.9) days respectively and shorter than those in ORIF group which were (13.8±1.4) weeks and(6.8±1.3) days. The times of fluoroscopy in MIPPO group was 19.2±3.7 and more than that in ORIF group which was 12.1±3.4. At 3 and 6 months after operation, Constant Murley score in MIPPO group were 81.3±3.9, 86.6±5.4 and more than that in ORIF group which were 69.5±6.6, 80.5±6.7. There were no differences between two groups in the length of hospital stay, Constant Murley score at 12 months after operation and grading at the final follow-up. There was one fracture redisplacement in each group. And 1 case of axillary nerve injury in MIPPO group, 2 cases of delayed union in ORIF group. No incision infection, screw loosening or plate break was found.</p><p><b>CONCLUSIONS</b>MIPPO and ORIF are both effective in treating Neer II proximal humeral fractures. MIPPO technique has the advantages of faster recovery, earlier rehabilitative exercise and better shoulder function. The disadvantages are more exposure to radiationd and the possibility of axillary nerve injure.</p>

Effect of patient positioning in axillary nerve safety during arthroscopic inferior glenohumeral ligament plication.

PURPOSE: To evaluate the risk of injuring the axillary nerve during an inferior glenohumeral ligament (IGHL) plication and finding out whether shoulder position (either beach chair position or lateral decubitus position) has any effect in this risk. METHODS: The axillary nerve (AN) was identified through a 3-cm posterior incision in 12 cadaveric shoulders. Under arthroscopic visualization, a curved indirect suture-passing device was placed through the posterior and anterior bands of the IGHL. The distances between the device and the AN were measured with the shoulder specimen placed at simulated lateral decubitus position and beach chair position. RESULTS: There were no cases of nerve injury nor the suture-passing device came closer than 10 mm to the nerve. There was an increase in the injury risk to the AN when inserting the device at the posterior band of the IGHL in the beach chair position [median 13 mm (range 10-21 mm)] compared to the risk in the lateral decubitus position [22.5 mm (20-26 mm), significant differences, p < 0.001]. When the device was inserted at the anterior band of the IGHL, there were no significant differences (n.s.) [lateral decubitus position: 18 mm (14-24 mm) vs. 16 mm (13-18 mm)]. When comparing differences between bands, there were no differences in the beach chair position, but the risk was lower for the posterior band in the lateral decubitus position (p < 0.001). CONCLUSIONS: During plication of the posterior band of the IGHL, the risk is higher if the procedure is performed in the beach chair position. The posterior plication is safer than the anterior plication in lateral decubitus position. CLINICAL RELEVANCE: This study helps the surgeon to better understand the proximity of the nerve to the IGHL and to highlight that the risk of nerve injury during capsular plication might be reduced in the lateral decubitus position.

Effectiveness of the extended surgical approach to visualize the axillary nerve in the blind zone in an arthroscopic axillary nerve injury model.

INTRODUCTION: The aims of this study were to create a model of axillary nerve (AN) injury during an arthroscopic capsular plication to analyze the site for potential nerve injury and to determine the AN length that can be visualized through standard and extended anterior, axillary, and posterior approaches. MATERIAL AND METHODS: Six arthroscopic inferior capsular plications were performed in 3 human adult frozen cadavers. A nonabsorbable suture was used to plicate the inferior capsule aiming at capturing the AN (at a location closest to the joint capsule). We then attempted to explore the AN through 3 different surgical approaches (each approach was performed in 2 shoulders): a standard and an extended anterior, axillary, and posterior approach. Surgical clips were used to mark the AN length that was visualized through each approach. RESULTS: The AN injury was located in a range from 5.4 to 7.8 cm from its origin from the posterior cord. This location corresponds with the previously described AN injury zone B (blind) and zone C (circumflex). Compared to the standard approaches, the extended anterior, axillary, and posterior approaches improved the visualization of the AN by 3.6, 1.5, and 2.8 cm, respectively. None of these approaches independently was sufficient to expose the entire course of the AN. CONCLUSIONS: The blind zone is a potential location for AN injury after inferior capsular plication. On the basis of this study, a combination of a standard and an extended surgical approach may lead to better exposure of most of the AN length.

Proximity of the axillary nerve during bicortical drilling for biceps tenodesis.

PURPOSE: Pathology of the biceps tendon can contribute to significant shoulder pain and dysfunction for which biceps tenodesis may be indicated. A variety of techniques tenodesing the biceps tendon have been described. Recently, tenodesis using a uni- or bicortical button has been advocated. This cadaveric study investigates the proximity of the axillary nerve to the position of bicortical drill passages during biceps tenodesis. METHODS: Twelve cadaveric shoulder specimens were used. The axillary nerve was marked during a preparatory dissection using wire. Drills were passed through the humerus at the proximal and distal ends of the bicipital groove, and at the superior insertion point of pectoralis major (PM). These were left in situ. The distances between these drills and the axillary nerves were measured using computed tomography imaging. RESULTS: The drill bits placed at the superior insertion of PM were in closest proximity to the axillary nerve (3D distance mean 10.7 mm, 95 % confidence interval 7.2-14.2 mm). A drill placed at the distal end of the bicipital groove was a mean distance of 18.2 mm from the nerve. CONCLUSIONS: This study highlights the need for caution when drilling the posterior humeral cortex during biceps tenodesis, particularly during drilling at the superior insertion of PM as this is the location that poses the highest risk to the axillary nerve. To our knowledge, this is the first cadaveric study to radiologically assess the proximity of the axillary nerve to the positions of biceps tenodesis. Surgeons should therefore be cautious when performing bicortical drilling for biceps tenodesis, and a supero-lateral drill trajectory would pose a smaller risk to the axillary nerve.

Nerve Transfers for Treatment of Isolated Axillary Nerve Injuries.

BACKGROUND: The most common neurological defect in traumatic anterior glenohumeral dislocation is isolated axillary nerve palsy. Most recover spontaneously; however, some have persistent axillary neuropathy. An intact rotator cuff may compensate for an isolated axillary nerve injury; however, given the high rate of rotator cuff pathology with advancing age, patients with an axillary nerve injury are at risk for complete shoulder disability. OBJECTIVE: To review reconstruction of the axillary nerve to alleviate shoulder pain, augment shoulder stability, abduction and external rotation to alleviate sole reliance on the rotator cuff to move and stabilize the shoulder. METHODS: A retrospective review of 10 patients with an isolated axillary nerve injury and an intact rotator cuff who underwent a triceps nerve branch to axillary nerve transfer was performed. Patient demographics, surgical technique, deltoid strength, donor-site morbidity, complications and time to surgery were evaluated. RESULTS: Ten male patients, mean age 38.3 years (range 18 to 66 years), underwent a triceps to axillary nerve transfer for isolated axillary nerve injury 7.4 months (range five to 12 months) post-traumatic shoulder dislocation. Deltoid function was British Medical Research Council grade 0/5 in all patients preoperatively and ≥3/5 deltoid strength in eight patients at final follow-up (14.8 months [range 12 to 25 months]). There were no complications and no donor-site morbidity. CONCLUSION: A triceps to axillary nerve transfer for isolated axillary neuropathy following traumatic shoulder dislocation improved shoulder pain, stability and deltoid strength, and potentially preserves shoulder function with advancing age by alleviating sole reliance on the rotator cuff for shoulder abduction and external rotation.

HISTORIQUE: La paralysie isolée du nerf axillaire est la principale anomalie neurologique après une dislocation glénohumérale traumatique antérieure. La plupart guérissent spontanément, mais certains souffrent de neuropathie axillaire persistante. Une coiffe des rotateurs intacte peut compenser une lésion isolée du nerf axillaire. Cependant, compte tenu du fort taux de pathologies de la coiffe des rotateurs liées au vieillissement, les patients ayant une lésion du nerf axillaire risquent une invalidité complète de l'épaule. OBJECTIF: Examiner la reconstruction du nerf axillaire pour soulager la douleur de l'épaule et en accroître la stabilité, l'abduction et la rotation externe afin d'éviter de se fier uniquement à la coiffe des rotateurs pour bouger et stabiliser l'épaule. MÉTHODOLOGIE: Les chercheurs ont procédé à l'analyse rétrospective de dix patients ayant une lésion isolée du nerf axillaire et une coiffe des rotateurs intacte qui ont subi un transfert de la branche du nerf du triceps sur le nerf axillaire. Ils ont évalué la démographie des patients, la technique chirurgicale, la force du deltoïde, la morbidité du site du donneur, les complications et le délai avant l'opération. RÉSULTATS: Dix patients de sexe masculin, d'un âge moyen de 38,3 ans (plage de 18 à 66 ans), ont subi un transfert du nerf du triceps sur le nerf axillaire en raison d'une lésion isolée du nerf axillaire, et ce, 7,4 mois (plage de cinq à 12 mois) après une dislocation traumatique de l'épaule. Chez tous les patients avant l'opération, la fonction du deltoïde était de 0 sur une échelle de 5 selon le British Medical Research Council, tandis que la force du deltoïde était d'au moins 3 sur 5 chez huit patients au suivi final (14,8 mois [plage de 12 à 25 mois]). Il n'y a eu aucune complication et aucune morbidité au site du donneur. CONCLUSION: Le transfert du nerf du triceps sur le nerf axillaire pour soigner une neuropathie axillaire isolée après une dislocation traumatique de l'épaule soulageait la douleur et la stabilité de l'épaule et la force du deltoïde et assurait la préservation potentielle de la fonction de l'épaule malgré le vieillissement, car la coiffe des rotateurs n'était plus l'unique mode d'abduction et de rotation externe de l'épaule.