Surgical anatomy of spinal accessory nerve: is trapezius functional deficit inevitable after division of the nerve?

Spinal Accessory to Suprascapular Nerve Transfer in Traumatic Brachial Plexus Injury: A Comparative Study of Shoulder Recovery Outcomes in the Anterior versus Posterior Approach and Surgeons' Preference

BACKGROUND

Conventionally, neural transfer of the spinal accessory nerve to the suprascapular nerve for shoulder abduction in traumatic brachial plexus injury is performed via the anterior approach. However, important advantages of the posterior approach have made it an alternative option, such as the proximity of neural coaptation to the muscle to be reinnervated and negating the effects of a second injury to the suprascapular nerve.

METHODS

Retrospective data was collected from 30 patients with brachial plexus injury who underwent spinal accessory nerve to suprascapular nerve transfer over 4 years. There were 15 patients in the anterior-approach group (group A) and 15 in the posterior-approach group (group B). Functional outcome at the shoulder was measured as muscle power and active range of motion at 18 months, and data on patients' satisfaction levels and surgeons' perceptions was also collected.

RESULTS

No statistical difference was found in the muscle strength achieved in the 2 groups (P = 0.34), but significant recovery was found in the external rotation achieved by group B (P = 0.02). Statistical difference was insignificant in the 2 groups' active range of motion during abduction and external rotation. The satisfaction index of patients was 86.7% in group B as compared to 68% in group A. Surgeons' perspective showed a faster speed of suprascapular nerve exploration in the posterior approach, with better visibility of supraspinatus muscle contraction, and overall surgeons preferred the posterior approach.

CONCLUSIONS

External rotation at the shoulder is better via the posterior approach, but no difference in abduction was noted. Patients who underwent the posterior approach were more satisfied with the recovery, and surgeons preferred the posterior approach.

Anatomical variations in the course of spinal accessory nerve in the neck triangles: A descriptive study

BACKGROUND

Spinal Accessory Nerve (SAN), which innervates the sternocleidomastoid (SCM) and trapezius muscles, is closely related to the internal jugular vein (IJV) in the anterior triangle of the neck and passes superficially in the posterior triangle. Injury to SAN is a major complication of level II neck dissection, leading to shoulder syndrome. The present study aims to assess the course and its relation to the SCM muscle and IJV in the Tamil ethnolinguistic groups in South India.

METHODS AND MATERIALS

The anterior and posterior triangles of the neck were dissected in 28 formalin-fixed adult cadavers. The course of the SAN and the entry and exit points of SAN along the SCM muscle were assessed using the mastoid process as the reference. Recorded data was analyzed using SPSS software.

RESULTS

The SAN was anteriorly related to the IJV in 58.73%, posteriorly in 37.5%, and pierced through the IJV in 3.57% of the specimens. The entry and exit points of SAN from the mastoid process were 37.86±7.26mm and 48.55±8.22mm, respectively. In 86.67% of the cases, the SAN traversed through the SCM muscle, and in 13.33%, it was deep to the SCM.

CONCLUSION

The present study reports that the SAN is variable in its course, and relation to SCM and IJV. Knowledge about the variant anatomy of the SAN in the triangles of the neck is important and it aids surgeons to prevent iatrogenic injuries to SAN or IJV and enhance surgical safety in neck procedures.

Spinal accessory nerve anatomy in the posterior cervical triangle: A systematic review with meta-analysis

This study aimed to investigate the anatomy of the spinal accessory nerve (SAN) in the posterior cervical triangle, especially in relation to adjacent anatomical landmarks, along with a systematic review of the current literature with a meta-analysis of the data. Overall, 22 cadaveric and three prospective intraoperative studies, with a total of 1346 heminecks, were included in the analysis. The major landmarks relevant to the entry of the SAN at the posterior border of the SCM muscle (PBSCM) were found to be the mastoid apex, the great auricular point (GAP), the nerve point (NP), and the point where the PBSCM meets the upper border of the clavicle. The SAN was reported to enter the posterior cervical triangle above GAP in 100% of cases and above NP in most cases (97.5%). The mean length of the SAN along its course from the entry point to its exit point from the posterior triangle of the neck was 4.07 ± 1.13 cm. The SAN mainly gave off 1 or 2 branches (32.5% and 31%, respectively) and received either no branches or one branch in most cases (58% and 23%, respectively) from the cervical plexus during its course in the posterior cervical triangle. The major landmarks relevant to the entry of the SAN at the anterior border of the TPZ muscle (ABTPZ) were found to be the point where the ABTPZ meets the upper border of the clavicle and the midpoint of the clavicle, along with the mastoid apex, the acromion, and the transverse distance of the SAN exit point to the PBSCM. The results of the present meta-analysis will be helpful to surgeons operating in the posterior cervical triangle, aiding the avoidance of the iatrogenic injury of the SAN.

A Randomised Control Trial Comparing the Outcomes of Anterior with Posterior Approach for Transfer of Spinal Accessory Nerve to Suprascapular Nerve in Brachial Plexus Injuries

Background: In brachial plexus surgery, a key focus is restoring shoulder abduction through spinal accessory nerve (SAN) to suprascapular nerve (SSN) transfer using either the anterior or posterior approach. However, no published randomised control trials have directly compared their outcomes to date. Therefore, our study aims to assess motor outcomes for both approaches. Methods: This study comprises two groups of patients. Group A: anterior approach (29 patients), Group B: Posterior approach (29 patients). Patients were allocated to both groups using selective randomisation with the sealed envelope technique. Functional outcome was assessed by grading the muscle power of shoulder abductors using the British Medical Research Council (MRC) scale. Results: Five patients who were operated on by posterior approach had ossified superior transverse suprascapular ligament. In these cases, the approach was changed from posterior to anterior to avoid injury to SSN. Due to this reason, the treatment analysis was done considering the distribution as: Group A: 34, Group B: 24. The mean duration of appearance of first clinical sign of shoulder abduction was 8.16 months in Group A, whereas in Group B, it was 6.85 months, which was significantly earlier (p < 0.05). At the 18-month follow-up, both intention-to-treat analysis and as-treated analysis were performed, and there was no statistical difference in the outcome of shoulder abduction between the approaches for SAN to SSN nerve transfer. Conclusions: Our study found no significant difference in the restoration of shoulder abduction power between both approaches; therefore, either approach can be used for patients presenting early for surgery. Since the appearance of first clinical sign of recovery is earlier in posterior approach, therefore, it can be preferred for cases presenting at a later stage. Also, the choice of approach is guided on a case to case basis depending on clavicular fractures and surgeon preference to the approach. Level of Evidence: Level II (Therapeutic).

Does Age Affect the Rate of Spinal Nerve Injury after Selective Neck Dissection? Age as a Prognostic Factor of Spinal Nerve Injury after Selective Neck Dissection

OBJECTIVE

The objective of this study is to investigate whether age is a significant risk factor for spinal nerve injury following selective neck dissection (SND) in patients with head and neck cancer.

METHODS

A retrospective cohort study was conducted on patients who had undergone SND for head and neck cancer at a tertiary hospital between 2020 and 2022. The primary outcome was the incidence of spinal nerve injury after SND. The secondary outcomes included the types and severity of spinal nerve injury and the impact of age on these outcomes.

RESULTS

A total of 78 patients were included in the study and subdivided into two groups. Two shoulder-specific questionnaires (the Shoulder Pain and Disability Index (SPADI) and the Shoulder Disability Questionnaire (SDQ)) were administered to assess shoulder morbidity postoperatively. Twelve patients showed shoulder impairment following surgery. We divided the sample into two age-based groups; the older group showed a higher rate of SAN injury and the younger group showed a lower rate of improvement over time.

CONCLUSION

This study suggests that age is a significant risk factor for spinal nerve injury following SND in patients with head and neck cancer. Older patients are more likely to experience spinal nerve injury after SND than younger patients. The findings of this study may help in the development of strategies to prevent spinal nerve injury in older patients undergoing SND for head and neck cancer.

Is there any difference between anterior and posterior approach for the spinal accessory to suprascapular nerve transfer? A systematic review and meta-analysis

Dual nerve transfer of the spinal accessory nerve to the suprascapular nerve (SAN-SSN) and the radial nerve to the axillary nerve is considered to be the most feasible method of restoration of shoulder abduction in brachial plexus injuries. Supraspinatus muscle plays an important role in the initiation of abduction and its functional restoration is crucial for shoulder movements. There are two possible approaches for the SAN-SSN transfer: the more conventional anterior approach and the posterior approach in the area of scapular spine, which allows more distal neurotization. Although the dual nerve transfer is a widely used method, it is unclear which approach for the SAN-SSN transfer results in better outcomes. We conducted a search of English literature from January 2001 to December 2021 using the PRISMA guidelines. Twelve studies with a total 142 patients met our inclusion criteria. Patients were divided into two groups depending on the approach used: Group A included patients who underwent the anterior approach, and Group B included patients who underwent the posterior approach. Abduction strength using the Medical Research Scale (MRC) and range of motion (ROM) were assessed. The average MRC grade was 3.57 ± 1.08 in Group A and 4.0 ± 0.65 (p = 0.65) in Group B. The average ROM was 114.6 ± 36.7 degrees in Group A and 103.4 ± 37.2 degrees in Group B (p = 0.247). In conclusion, we did not find statistically significant differences between SAN-SSN transfers performed from the anterior or posterior approach in patients undergoing dual neurotization technique for restoration of shoulder abduction.

Extradural Contralateral Ventral Root Transfer to Treat Lower Limb Motor Dysfunction in Paraplegia

STUDY DESIGN

Eight cadavers were included in this anatomical study.

OBJECTIVE

This study aimed to confirm the anatomical feasibility of extradural transfer of the contralateral T11 ventral root (VR) to the ipsilateral L2 level and the contralateral L1 VR to the ipsilateral L3 level to restore lower limb function in cases of paraplegia.

SUMMARY OF BACKGROUND DATA

Motor dysfunction due to hemiplegia significantly affects the daily life of patients. To date, unlike in cases of upper limb dysfunction, there are few studies on the surgical management of lower limb movement dysfunction.

MATERIALS AND METHODS

Eight cadavers were included in this study to confirm the feasibility of the nerve transfer. After separating the VR and dorsal root at each level, the VRs at the T11 and L1 levels were anastomosed with the VRs of L2 and L3, respectively. The length of the VRs of donor roots and the distance between the donor and recipient nerves were measured. H&E staining was performed to verify the number of axons and the cross-sectional area of the VRs. Lumbar x-rays of 60 healthy adults were used to measure the distance between the donor and recipient nerves.

RESULTS

After exposing the bilateral extradural each root, the VRs could be easily isolated from the whole root. The distance between the VRs of T11 and L2, L1, and L3 was significantly longer than the length of the donor nerve. Therefore, the sural nerve was used for grafting. The measurements performed on the lumbar x-rays of the 60 healthy adults confirmed the results. The number of axons and cross-sectional area of the VRs were measured.

CONCLUSION

Our study confirmed the anatomical feasibility of transferring the VRs of T11 to L2 and that of L1 to L3 to restore lower limb function in cases of hemiplegia.

LEVEL OF EVIDENCE

5.

Change in shoulder external rotation strength and motion after lower trapezius transfer to the infraspinatus in children with obstetric brachial plexus palsy

PURPOSE

Quantifying changes in shoulder external rotation range of motion and strength after lower trapezius transfer in children with obstetric brachial plexus palsy (OBPP).

METHODS

This prospective study included five children with sequelae of OBPP, with a mean age of 6.4 years (range: 4-12 years) who underwent lower trapezius tendon transfer to restore active external rotation (ER) of the shoulder. Pre-operatively and at a 12-month follow-up assessment, we analyzed the passive and active shoulder ER, the modified Mallet score, and the shoulder rotator muscles strength using an isokinetic device.

RESULTS

Clinical parameters improved significantly after trapezius transfer pre-operative passive ER from -8° (range: -20-0°) to 37° (range: 15-50°) (p = 0.035), the modified Mallet score from 13 (range: 10-15) to 18 (range: 17-19) (p = 0.035). Strength testing revealed improved ER muscle strength in all five cases; the mean Peak Torque increased from 1.95 to 4.46 N·m, albeit non-significantly (p = 0.062). Two patients exhibited a winged scapula post-operatively.

CONCLUSION

Lower trapezius transfer seems encouraging to restore shoulder external rotation in OBPP children but with non-significant strength improvement.

TRIAL REGISTRATION

18/07/31/5783, December 22, 2018.

Outcomes of Shoulder Functions in Spinal Accessory to Suprascapular Nerve Transfer in Brachial Plexus Injury: A Comparison between Anterior and Posterior Approach

Background  Restoration of shoulder functions is important in brachial plexus injury (BPI). The functional outcomes of spinal accessory nerve (SAN) to suprascapular nerve (SSN) transfer by the anterior supraclavicular approach and the posterior approach is a matter of debate. This article aims to compare the outcomes of the shoulder functions by the SAN to the SSN transfer using the two approaches. Methods  Retrospective data was collected in 34 patients who underwent SAN to SSN transfer from January 2016 to June 2018. Group A included 16 patients who underwent nerve transfers by anterior approach, and Group B included 18 patients who underwent nerve transfers by posterior approach. Functional outcomes were measured by grading the muscle power as per the British Medical Research Council (MRC) grading (graded as M) and the range of motions (ROM) of the shoulder at 6 months and 18 months. Results  Early recovery was seen in group B with 7 patients (39%) showing M1 abduction power at 6 months as compared with one patient (6%) in group A . This difference was statistically significant ( p value = 0.04). At 18 months, 10 patients (62%) in group A had good recovery (MRC grade ≥3), while 13 patients (72%) in group B had a good recovery. This difference was not found to be statistically significant (Fisher exact test p value = 0.71) There was no statistical difference in the outcomes of ROM in shoulder abduction, external rotation, and motor power at 18 months of follow-up. Conclusions  Early recovery was observed in the anterior approach group at 6 months, however, there was no significant difference in the outcomes of shoulder functions in muscle power and ROM in the two groups at 18 months of follow-up.

Brachial Plexus Birth Injuries: A Critical Analysis Review

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The incidence of brachial plexus birth injury (BPBI) in the United States is declining and now occurs in <1 per 1,000 births.

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The gold standard for predicting the need for early intervention remains serial examination.

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Early treatment of BPBI with reconstructive surgery requires the ability to perform both interposition nerve grafting and nerve transfers.

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Given the heterogeneity of lesions, the evidence is largely limited to retrospective comparative studies and case series.

Prevention and Treatment of Nerve Injuries in Shoulder Arthroplasty

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Nerve injuries during shoulder arthroplasty have traditionally been considered rare events, but recent electrodiagnostic studies have shown that intraoperative nerve trauma is relatively common.

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The brachial plexus and axillary and suprascapular nerves are the most commonly injured neurologic structures, with the radial and musculocutaneous nerves being less common sites of injury.

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Specific measures taken during the surgical approach, component implantation, and revision surgery may help to prevent direct nerve injury. Intraoperative positioning maneuvers and arm lengthening warrant consideration to minimize indirect injuries.

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Suspected nerve injuries should be investigated with electromyography preferably at 6 weeks and no later than 3 months postoperatively, allowing for primary reconstruction within 3 to 6 months of injury when indicated. Primary reconstructive options include neurolysis, direct nerve repair, nerve grafting, and nerve transfers.

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Secondary reconstruction is preferred for injuries presenting >12 months after surgery. Secondary reconstructive options with favorable outcomes include tendon transfers and free functioning muscle transfers.

Accessory Nerve Anatomy in Anterior and Posterior Cervical Triangle: A Fresh Cadaveric Study

Objective

To understand the variations and normal course of the accessory nerve (CNXI) to help more accurate and confident neck dissection.

Methods

The course of the CNXI in the neck, its relationship to the surrounding anatomic structures and the factors affecting its course were investigated.

Results

A total of 100 neck dissections were performed on 50 fresh cadavers. Eleven division variations were observed at the anterior triangle. The location of CNXI at the posterior border of the sternocleidomastoid muscle (PBSCM) was investigated and the ratio between the distance from the mastoid apex (MAA) to CNXI at the PBSCM and the distance from MAA to the posterior border where the PBSCM is attached to the clavicle increased as height of the subject increased (p<0.05).

Conclusion

It must be kept in mind that it is better to search for CNXI in taller subjects more inferiorly at the posterior border of the sternocleidomastoid muscle.

ANALYSIS OF FATTY DEGENERATION OF THE TRAPEZIUS MUSCLE AFTER USE OF ACCESSORY NERVE

Objective:

To investigate, through magnetic resonance imaging, the occurrence of fatty degeneration of the trapezius in adult patients undergoing nerve transfer procedure, using the spinal accessory nerve.

Methods:

A total of 13 patients meeting the criteria of unilateral brachial plexus injury and more than one year of postoperative care after nerve transfer surgery underwent an MRI scan of the trapezius. A T1-weighted 3D sequence was used, with the IDEAL technique using 8.0 mm cut thickness, 8.0 mm cut spacing, TR of 100 ms, TE of 3.45 ms, flip angle of 10 degrees, 20 cuts, on the sagittal plane. The images of the upper, transverse and lower parts of the trapezius muscle were then classified according to the degree of fatty degeneration, compared with the contralateral side, using the Goutallier score.

Results:

For the upper trapezius there was a change of the degeneration state in 23% (p = 0.083), for the transverse section there was a change in 84.6% (p = 0.003), for the lower one there was a change in 92.3% (p = 0.002).

Conclusion:

The upper trapezius did not undergo significant degeneration after transfer. The lower and transverse trapezius suffered fatty degeneration in most patients, indicating severe functional impairment. Level of Evidence IV, Case series.

Preoperative Evaluation of Iatrogenic Spinal Accessory Nerve Palsy: What Is the Place for Electrophysiological Testing?

PURPOSE

Electrophysiological testing has been used for the early diagnosis of iatrogenic spinal accessory nerve palsy in clinical practice. However, the presence of low-amplitude compound action potential in 70% to 90% of the patients suffering from iatrogenic nerve transection was reported in several studies. We have encountered the same issue and made minor modifications to the methods of electrophysiological testing. The purpose of this study was to retrospectively evaluate the reliability of our modified electrophysiological testing as preoperative examination in patients receiving surgical revision.

METHODS

In this study, we compared preoperative electrophysiological testing results with intraoperative diagnosis in the 24 patients with iatrogenic spinal accessory nerve palsy who were referred to our hospital from 2009 to 2018.

RESULTS

During operation, 20 patients were diagnosed with neurotmesis and the remaining 4 patients were found axonotmesis depending on the results of surgical exploration and intraoperative electrophysiological examination. Six of the 20 patients with neurotmesis demonstrated a low-amplitude compound muscle action potential of the upper trapezius during preoperative electrophysiological testing. Needle electromyography revealed voluntary motor unit potentials in 8 of the 20 patients. Meanwhile, concomitant great auricular nerve or dorsal scapular nerve injuries were preoperatively revealed in 7 of 24 patients.

CONCLUSIONS

The rate of low-amplitude compound muscle action potentials in these patients suffering from spinal accessory nerve neurotmesis was about 30% with our modified electrophysiological testing. We should be aware of this pitfall before surgical nerve repair. Furthermore, electrophysiological testing is an informative preoperative examination revealing the concomitant nerve injuries.

The Relation of the Extracranial Spinal Accessory Nerve to the Sternocleidomastoid Muscle and the Internal Jugular Vein

The spinal accessory nerve (SAN) exhibits variant anatomy in its relation to the internal jugular vein (IJV) as well as the sternocleidomastoid muscle (SCM). These variations are important in locating the nerve during surgical neck procedures to avoid its inadvertent injury. These variations, however, are not conserved among different populations and data from the Kenyan setting are partly elucidated. This study, therefore, aims to determine the variant anatomical relationship of the SAN to the SCM and IJV in a select Kenyan population. Forty cadaveric necks were studied bilaterally during routine dissection and the data collected were analyzed using SPSS version 21. Means and modes were calculated for the point of entry of the SAN into the posterior triangle of the neck as well as for its relation to the SCM. Side variations for both of these were analyzed using Student's t -test. Data relating the SAN to the IJV were represented in percentages and side variations were analyzed using the chi-square test. The SAN point of entry into the posterior triangle of the neck was 5.38 cm (3.501-8.008 cm) on the left side and 5.637 cm (3.504-9.173 cm) on the right side ( p  = 0.785) from the mastoid process. The nerve perforated the SCM in four cases (10%) on the left side and in eight cases (20%) on the right ( p  = 0.253). The SAN lay predominantly medial to the IJV on both sides of the neck, 87.5% on the left side of the neck versus 82.5% on the right ( p  = 0.831). In conclusion, the variant relation of the SAN to the IJV and SCM as observed in this setting is an important consideration during radical neck procedures and node biopsies.

Contralateral medial pectoral nerve transfer with free gracilis muscle transfer in old brachial plexus palsy

BACKGROUND

There is a very small chance of success for nerve reconstruction in patients with old total brachial plexus palsy who visit after 2 y or suffer from flail upper extremity after the failure of previous operations.

MATERIALS AND METHODS

For these individuals, the surgeon has to find a recipient motor nerve to perform free gracilis muscle transplantation. In this study, contralateral medial pectoral nerve from the intact side was transferred to the damaged side as a recipient nerve. Then, in the second operation, approximately 15 mo later, the free gracilis muscle transfer was performed. The gracilis muscle was removed and transferred to provide elbow and finger flexion.

RESULTS

In a retrospective study (over 10 y), we reviewed 68 patients for whom this method had been performed. After 1 y, the results were investigated using the Medical Research Council grading system. Five patients did not participate in the study, and the muscle underwent necrosis in two patients. M3 and M4 muscle power was regained in 26 (42.6%) and 21 (34.4%) patients, respectively.

CONCLUSIONS

Contralateral pectoral nerve transfer followed by free muscle transplantation can be a good option for patients with old total brachial plexus palsy.

Intraoperative Nerve Stimulation During Brachial Plexus Surgery: Comparison Between a Totally Disposable Nerve Stimulator and Nerve Stimulator Normally Used for Nerve Blocks

BACKGROUND

Intraoperative nerve stimulation is done routinely in brachial plexus and peripheral nerve surgery as well as in selective neurectomy in spastic patients.

OBJECTIVE

The current study compares the use of 2 different devices for nerve stimulation: a totally disposable nerve stimulator and a nerve stimulator used for nerve blocks by anesthetists.

METHODS

A retrospective study of 60 patients who underwent brachial plexus surgery: In 30 patients, we used the totally disposable nerve stimulator (group 1) and in another 30 patients, we used the anesthesia device (group 2). The cost of disposable materials used for nerve stimulation was calculated in each group. The same surgeon performed all operations, and he was asked to give his subjective opinion regarding the convenience and ease of use of the device in each group.

RESULTS

The main advantages of the totally disposable device are its placement totally within the sterile field, and it is operated by the surgeon without the need to communicate with the anesthetist. However, the totally disposable device had several major disadvantages when compared to the anesthesia device. Firstly, the disposable stimulator can only deliver 0.5, 1.0, and 2.0 mA stimuli, while the anesthesia device can deliver stimuli of 0.1 to 5 mA (in 0.1 mA increments). Secondly, the disposable stimulator frequently fails to operate during surgery, and this is not experienced with the anesthesia device. Finally, the cost of disposables is less using the anesthesia device.

CONCLUSION

Our center has stopped using the disposable nerve stimulator in favour for the anesthesia device.

Topographic anatomy of the great auricular point: landmarks for its localization and classification

PURPOSE

The great auricular point (GAP) marks the exit of the great auricular nerve at the posterior border of the sternocleidomastoid muscle (SCM). It is a key landmark for the identification of the spinal accessory nerve, and its intraoperative localization is vital to avoid neurological sequelae. This study delineates the topography and surface anatomy landmarks that used to localize the GAP.

METHODS

Thirty cadaveric heminecks were dissected on a layer-by-layer approach. The topography of the GAP was examined relative to the insertion point of the SCM at the clavicle, tip of the mastoid process, and angle of the mandible. The GAP and its relation to the SCM were determined as a ratio of the total length of the SCM.

RESULTS

The GAP was demonstrated to be in a predictable location. The mean length of the SCM was 131.4 ± 22 mm, and the mean distance between the GAP and the mastoid process was found to be 60.4 ± 13.76 mm. The ratio of the GAP location to the total SCM length ranged between 0.33-0.57. The mean distance between the angle of the mandible and the GAP was determined to be 57 ± 22.2 mm. Based on the midpoint of the SCM, the GAP was above it in 66.7 % of subjects and classified to Type A, and below it in 33.3 % of subjects appointed to Type B.

CONCLUSIONS

The anatomical landmarks utilized in this study are helpful in predicting the location of the GAP relative to the midpoint of the SCM and can reduce neural injuries within the posterior triangle of the neck.

Nerve Transfers to Restore Shoulder Function

The restoration of shoulder function after brachial plexus injury represents a significant challenge facing the peripheral nerve surgeons. This is owing to a combination of the complex biomechanics of the shoulder girdle, the multitude of muscles and nerves that could be potentially injured, and a limited number of donor options. In general, nerve transfer is favored over tendon transfer, because the biomechanics of the musculotendinous units are not altered. This article summarizes the surgical techniques and clinical results of nerve transfers for restoration of shoulder function.

Patient outcome after surgical management of the spinal accessory nerve injury: A long-term follow-up study

Objectives:

A lesion in the spinal accessory nerve is typically iatrogenic: related to lymph node biopsy or excision. This injury may cause paralysis of the trapezius muscle and thus result in a characteristic group of symptoms and signs, including depression and winging of the scapula, drooped shoulder, reduced shoulder abduction, and pain. The elements evaluated in this long-term follow-up study include range of shoulder motion, pain, patients’ satisfaction, delay of surgery, surgical procedure, occupational status, functional outcome, and other clinical findings.

Methods:

We reviewed the medical records of a consecutive 37 patients (11 men and 26 women) having surgery to correct spinal accessory nerve injury. Neurolysis was the procedure in 24 cases, direct nerve repair for 9 patients, and nerve grafting for 4. Time elapsed between the injury and the surgical operation ranged from 2 to 120 months. The patients were interviewed and clinically examined after an average of 10.2 years postoperatively.

Results:

The mean active range of movement of the shoulder improved at abduction 44° (43%) in neurolysis, 59° (71%) in direct nerve repair, and 30° (22%) in nerve-grafting patients. No or only slight atrophy of the trapezius muscle was observable in 75%, 44%, and 50%, and no or controllable pain was observable in 63%, 56%, and 50%. Restriction of shoulder abduction preceded deterioration of shoulder flexion. Patients’ overall dissatisfaction with the state of their upper extremity was associated with pain, lower strength in shoulder movements, and occupational problems.

Conclusion:

We recommend avoiding unnecessary delay in the exploration of the spinal accessory nerve, if a neural lesion is suspected.

MRI findings of spinal accessory neuropathy

AIM

To characterise the magnetic resonance imaging (MRI) appearance of patients with spinal accessory nerve (SAN) denervation.

MATERIAL AND METHODS

Twelve patients who had SAN denervation on electromyography (EMG) were included. The sternocleidomastoid and trapezius muscles and the SAN were assessed using MRI.

RESULTS

Trapezius muscle atrophy was seen in 11 (92%), and of those patients, T2/short tau inversion recovery (STIR) signal hyperintensity was also demonstrated in seven (58%). All three patients with prior neck surgery had scarring around the SAN, and one of these patients demonstrated a neuroma, which was confirmed surgically.

CONCLUSION

Features of SAN neuropathy on MRI include atrophy and T2/STIR signal hyperintensity of the trapezius, and in patients who have had posterior triangle neck surgery, scarring may be seen around the nerve.

Surgical anatomy of the lower trapezius tendon transfer

BACKGROUND

The precise surgical anatomy of the lower trapezius tendon transfer has not been well described. A precise anatomic description of the different trapezius segments and the associated neurovascular structures is crucial for operative planning and execution. We aimed (1) to establish a reliable demarcation between the middle and lower trapezius, (2) to establish the precise relationship of the main neurovascular pedicle to the muscle belly, and (3) to evaluate the utility of the relationships established in (1) and (2) by using the results of this study to perform cadaveric lower trapezius tendon harvest.

METHODS

In phase 1, a single surgeon performed all measurements using 10 cadavers. In phase 2, 10 cadaveric shoulders were used to harvest the tendon by using the relationships established in phase 1.

RESULTS

We found anatomically distinct insertion sites for the lower and middle trapezius. The lower trapezius inserted at the scapular spine dorsum and the middle trapezius inserted broadly along the superior surface of the scapular spine. The distance from tip of tendon insertion to the nearest nerve at the most superior portion of the lower trapezius was 58 mm (standard deviation ± 18). By use of these relationships, there were no cases of neurovascular injury during our cadaveric tendon harvests.

CONCLUSION

The lower trapezius can be reliably and consistently identified without violating fibers of the middle trapezius. Muscle splitting can be performed safely without encountering the spinal accessory nerve (approximately 2 cm medial to the medial scapular border).

Reconstruction of shoulder abduction by multiple nerve fascicle transfer through posterior approach

PURPOSE

To evaluate the feasibility and clinical efficacy of multiple nerve fascicle transfer through posterior approach for reconstruction of shoulder abduction in patients with C5 or upper brachial plexus injury.

METHODS

11 patients (aged between 17 and 56 years) with dysfunction of shoulder abduction post C5 or upper brachial plexus injury were recruited in this study. Among them, four out of 11 patients also had dysfunction of elbow flexion simultaneously. The duration from injury to the surgery ranged from 4 to 12 months, with an average of 6.7 months. The affected shoulder joints showed abduction, extension and elevation dysfunction, but the muscle strength of shoulder shrugging and elbow extension was graded to M4 or higher. Accessory nerve was transferred to the suprascapular nerve and triceps muscle was branched to the axillary nerve through posterior approach. Ulnar fascicle was transferred to the motor branches of biceps for the 4 patients involved with elbow flexion dysfunction.

RESULTS

Ten out of 11 cases were followed-up for 15-36 months. Neo-potential of deltoid and supraspinatus/infraspinatus was documented at 4-5 months post surgery. Shoulder abduction (and elbow flexion) was reanimated at 4-8 months post surgery. Significant improvement was observed at 15-36 months post surgery, shoulder abduction regained to 40-160° (mean: 92.5°), muscle strength of supraspinatus/infraspinatus and deltoid were graded to M3-M5 (mean: 4.0 and 4.1); 3 cases muscle strength of elbow flexion was graded from M4 to M5- (mean: 4.4) with 1 case loss. Shoulder shrugging of trapezius was graded to M5 in 5 cases, M5- in 2 cases, M4 in 2 cases and M3 in 1 case (mean: 4.5). All cases showed normal elbow extension and muscle strength of triceps (M5).

CONCLUSION

It is feasible to carry out multiple nerve fascicle transfers for early reconstruction of shoulder abduction by posterior approach. Patients who received this procedure achieved good functional recovery and their donor site morbidity/injury was minimal.

Posterior approach for accessory-suprascapular nerve transfer: an electrophysiological outcomes study

The aim of this study was to retrospectively investigate the electrophysiological results obtained after employing the posterior approach for spinal accessory nerve-suprascapular nerve (SAN-SSN) transfer, and to compare this with the traditional anterior approach. SAN-SSN transfer was performed in 74 patients with brachial plexus injury. The posterior approach was used in 35 patients and the anterior approach was used in 39 patients. Electrophysiological examination was conducted and analyzed postoperatively. There was no significant difference between approaches in the time it took for the infraspinatus to show low-incidence motor unit action potentials (MUAPs) and an incomplete interference pattern. In addition, the final ratio of patients that showed regeneration potential of the infraspinatus was not significantly different between the approaches. Furthermore, latency and wave amplitude showed a linear regression with post-operative time in the posterior approach group. In the posterior approach group, the final abduction of the shoulder was positively correlated with the amplitude. The posterior approach for SAN-SSN is an effective potential alternative technique that may be appropriate for some clinical situations.

Spinal accessory neuropathy in patients with chronic neck pain

AIM: To assess the presence of spinal accessory neuropathy in patients with chronic neck pain.

METHODS: Patients with pain either regional or focal in the neck or shoulders for at least 6 mo (chronic neck pain) were recruited randomly from the Rheumatology and Rehabilitation Outpatient Clinic at the Faculty of Medicine-Suez Canal University. Two groups were compared: 30 patients with chronic neck pain with mean age (36.97 ± 12.45 years) and 10 apparently healthy controls. Trapezius muscle examination including inspection and range of motion both active and passive was performed. A full clinical neurological examination was carried out to exclude peripheral neuropathy and motor neuron disease. According to the subject’s type of work, cases were categorized into labor-intensive and non-labor intensive tasks. A nerve conduction study (NCS) was performed on spinal accessory nerves at both sides for all patients and controls. Parameters including latencies and amplitudes of compound motor action potential (CMAP) were compared with the chronicity of neck pain using the neck disability score. This cross sectional study was carried in the Rheumatology and Rehabilitation Department, at Suez Canal University Hospital, Ismailia, Egypt.

RESULTS: Physical examination revealed that 80% of cases had spinal trapezius muscle spasm. Restricted neck motion was present in 16.6% of cases. No one suffered from muscle wasting or weakness. Pain was bilateral in 18 patients (60%), localized to the right side in six patients (20%) and localized to the left side in six patients (20%). The causes of neck pain in the patients studied were nonspecific, due to physical stresses, cervical spondylosis and mild cervical disc herniation. Mean disease duration in patients with labor-intensive tasks was (3.9 ± 2.1 years), which was longer than that in patients with non-labor intensive tasks (3.1 ± 1.9 years); however, this difference was statistically insignificant. Spinal accessory NCSs were performed while subjects were in sitting positions and relaxed with naturally suspended arms to minimize muscular movement. The results of electrophysiological studies revealed that mean right and left latencies of the spinal accessory nerve were 2.96 ± 0.69 ms, 2.98 ± 0.61 ms in the patient group and 2.44 ± 0.38 ms, 2.33 ± 0.36 ms in control group respectively. These differences were statistically significant with P = 0.028 and 0.006 respectively. Spinal accessory NCS showed normal CMAP amplitude in both patients and controls. Comparing the results of the neck disability index (NDI) to different characteristics in patients with chronic neck pain, showed that patients with labor-intensive work had a higher NDI score mean (34.7 ± 9.5) compared to those with non-labor-intensive work, with significant statistical difference (P = 0.011). In addition, mean NDI scores were higher in males, and patients aged over 40 years and this difference was statistically significant (P = 0.007 and P = 0.009 respectively). Correlation studies between right and left spinal accessory nerve latencies and disability percent calculated using the NDI revealed a positive correlation. Moreover, there was a positive correlation between age and disability percent.

CONCLUSION: This study demonstrates electrophysiological evidence of demyelination in a significant proportion of patients with chronic cervical pain.

Ultrasound visualization of the spinal accessory nerve in vivo

BACKGROUND

Inadvertent injury of the spinal accessory nerve during surgical procedures is a cause of significant morbidity with medicolegal repercussions. Surface anatomy is an unreliable guide to the nerve's location. We suggest that ultrasound can be used to map the course of the nerve in the posterior triangle of the neck.

MATERIALS AND METHODS

Fifty healthy subjects (28 females, mean age 37 y) were scanned using a VF13-5 linear probe and a Siemens Sonoline Antares ultrasound machine (Siemens Medical Solutions USA Inc., Malvern, PA). The caliber, course, and distribution of the nerve in the posterior triangle of the neck were recorded.

RESULTS

The nerve was visualized bilaterally in all subjects, running superficially across the posterior triangle with either a straight (56%) or tortuous (44%) course at a depth of about 3 mm beneath the skin surface. It had a mean caliber of 0.76 ± 0.12 mm. It exited the posterior border of sternocleidomastoid at a mean of 6.7 (4.0-9.4) cm below the mastoid process and 1.1 (0.1-2.1) cm above the great auricular point and penetrated the anterior border of trapezius 5.4 (2.1-9.2) cm above the clavicle. Importantly, 58% of nerves divided into 2-4 branches before penetrating trapezius; the nerve branched on at least one side in 49 of 50 individuals.

CONCLUSIONS

The spinal accessory nerve and its anatomical variants can be consistently and reliably demonstrated by ultrasound in normal individuals. Surface anatomical landmarks are not a reliable guide to the position and course of the nerve in the posterior triangle. Preoperative mapping of the nerve with ultrasound may reduce the risk of iatrogenic injury.

Study of the cervical plexus innervation of the trapezius muscle

OBJECT

There is conflicting and often anecdotal evidence regarding the potential motor innervation of the trapezius muscle by cervical nerves, with most authors attributing such fibers to proprioception. As knowledge of such potential motor innervations may prove useful to the neurosurgeon, the present study aimed to elucidate this anatomy further.

METHODS

Fifteen adult cadavers (30 sides) underwent dissection of the posterior triangle of the neck and harvesting of cervical nerve fibers found to enter the trapezius muscle. Random fibers were evaluated histologically to determine fiber type (that is, motor vs sensory axons).

RESULTS

In addition to an innervation from the spinal accessory nerve, the authors also identified cervical nerve innervations of all trapezius muscles. For these innervations, 3 sides were found to have fibers derived from C-2 to C-4, 2 sides had fibers derived from C-2 to C-3, and 25 sides had fibers derived from C-3 to C-4. Fibers derived from C-2 to C-4 were classified as a Type I innervation, those from C-2 to C-3 were classified as a Type II innervation, and those from C-3 to C-4 were classified as a Type III innervation. Immunohistochemical analysis of fibers from each of these types confirmed the presence of motor axons.

CONCLUSIONS

Based on the authors' study, cervical nerves innervate the trapezius muscle with motor fibers. These findings support surgical and clinical experiences in which partial or complete trapezius function is maintained after injury to the spinal accessory nerve. The degree to which these nerves innervate this muscle, however, necessitates further study. Such information may be useful following nerve transfer procedures, denervation techniques for cervical dystonia, or sacrifice of the spinal accessory nerve due to pathological entities.

Transitional Nerve: A New and Original Classification of a Peripheral Nerve Supported by the Nature of the Accessory Nerve (CN XI)

Classically, the accessory nerve is described as having a cranial and a spinal root. Textbooks are inconsistent with regard to the modality of the spinal root of the accessory nerve. Some authors report the spinal root as general somatic efferent (GSE), while others list a special visceral efferent (SVE) modality. We investigated the comparative, anatomical, embryological, and molecular literature to determine which modality of the accessory nerve was accurate and why a discrepancy exists. We traced the origin of the incongruity to the writings of early comparative anatomists who believed the accessory nerve was either branchial or somatic depending on the origin of its target musculature. Both theories were supported entirely by empirical observations of anatomical and embryological dissections. We find ample evidence including very recent molecular experiments to show the cranial and spinal root are separate entities. Furthermore, we determined the modality of the spinal root is neither GSE or SVE, but a unique peripheral nerve with a distinct modality. We propose a new classification of the accessory nerve as a transitional nerve, which demonstrates characteristics of both spinal and cranial nerves.

Outcome following spinal accessory to suprascapular (spinoscapular) nerve transfer in infants with brachial plexus birth injuries

The purpose of this study is to evaluate the value of distal spinal accessory nerve (SAN) transfer to the suprascapular nerve (SSN) in children with brachial plexus birth injuries in order to better define the application and outcome of this transfer in these infants. Over a 3-year period, 34 infants with brachial plexus injuries underwent transfer of the SAN to the SSN as part of the primary surgical reconstruction. Twenty-five patients (direct repair, n = 20; interposition graft, n = 5) achieved a minimum follow-up of 24 months. Fourteen children underwent plexus reconstruction with SAN-to-SSN transfer at less than 9 months of age, and 11 underwent surgical reconstruction at the age of 9 months or older. Mean age at the time of nerve transfer was 11.6 months (range, 5-30 months). At latest follow-up, active shoulder external rotation was measured in the arm abducted position and confirmed by review of videos. The Gilbert and Miami shoulder classification scores were utilized to report shoulder-specific functional outcomes. The effects of patient age at the time of nerve transfer and the use of interpositional nerve graft were analyzed. Overall mean active external rotation measured 69.6°; mean Gilbert score was 4.1 and the mean Miami score was 7.1, corresponding to overall good shoulder functional outcomes. Similar clinical and shoulder-specific functional outcomes were obtained in patients undergoing early (<9 months of age, n = 14) and late (>9 months of age, n = 11) SAN-to-SSN transfer and primary plexus reconstruction. Nine patients (27%) were lost to follow-up and are not included in the analysis. Optimum results were achieved following direct transfer (n = 20). Results following the use of an interpositional graft (n = 5) were rated satisfactory. No patient required a secondary shoulder procedure during the study period. There were no postoperative complications. Distal SAN-to-SSN (spinoscapular) nerve transfer is a reliable option for shoulder reinnervation in infants with brachial plexus birth injuries. Direct transfer seems to be the optimum method. The age of the patient does not seem to significantly impact on outcome.

Surgical challenges associated with the morphology of the spinal accessory nerve in the posterior cervical triangle: functional or structural?

Object

The spinal accessory nerve (SAN) has been reported to have a distinctly coiled appearance in its course through the posterior cervical triangle of the neck. As this is unusual compared with other peripheral nerves including the cranial nerves, the present histological analysis was performed to further elucidate the reason for this anatomy with potential application in nerve injury and repair.

Methods

Ten adult cadavers underwent dissection of the neck. The SAN was harvested proximally and within the posterior cervical triangle. For comparison with other cranial nerves within the neck, the cervical vagus and hypoglossal nerves were also harvested. All nerves underwent histological analysis. Additionally, 2 human fetuses (11 and 20 weeks' gestation) underwent examination of the SAN in the posterior cervical triangle, and 3 randomly selected specimens were submitted for electromicroscopy.

Results

All SANs were found to have a straight gross configuration proximal to the posterior triangle and a coiled appearance within this geometrical area. Histologically, no differences were identified for the SAN in these 2 locations (that is, proximal to and within the posterior cervical triangle). The histology of the SAN both with routine analysis and electron microscopy was similar in both regions and to nerves used as controls (for example, vagus and hypoglossal nerves). Interestingly, both fetal specimens were found to have coiled SANs in the posterior cervical triangle.

Conclusions

Based on this study, it appears that the tortuous course of the SAN in the posterior triangle arises from functional as opposed to structural forces. It is hoped that this analysis will provide some insight into the nature behind the morphology observed in the SAN within the posterior cervical triangle and aid in future investigations regarding its injury. Moreover, such a coiled nature of this nerve may assist the neurosurgeon in identifying it during, for example, neurotization procedures.

TRANSFER OF A FASCICLE FROM THE POSTERIOR CORD TO THE SUPRASCAPULAR NERVE AFTER INJURY OF THE UPPER ROOTS OF THE BRACHIAL PLEXUS

OBJECTIVE

A new nerve transfer technique using a healthy fascicle of the posterior cord for suprascapular nerve reconstruction is presented. This technique was used in a patient with posttraumatic brachial plexopathy resulting in upper trunk injury with proximal root stumps that were unavailable for grafting associated with multiple nerve dysfunction.

CLINICAL PRESENTATION

A 45-year-old man sustained a right brachial plexus injury after a bicycle accident. Clinical evaluation and electromyography indicated upper trunk involvement. Trapezius muscle function and triceps strength were normal on physical examination.

INTERVENTION

The patient underwent a combined supra- and infraclavicular approach to the brachial plexus. A neuroma-in-continuity of the upper trunk and fibrotic C5 and C6 roots were identified. Electrical stimulation of the phrenic and spinal accessory nerves produced no response. The suprascapular nerve was dissected from the upper trunk, transected, and rerouted to the infraclavicular fossa. A healthy fascicle of the posterior cord to the triceps muscle was transferred to the suprascapular nerve. At the time of the 1-year follow-up evaluation, arm abduction against gravity and external rotation reached 40 and 34 degrees, respectively.

CONCLUSION

The posterior cord can be used as a source of donor fascicle to the suprascapular nerve after its infraclavicular relocation. This new intraplexal nerve transfer could be applied in patients with isolated injury of the upper trunk and concomitant lesion of the extraplexal nerve donors usually used for reinnervation of the suprascapular nerve.

Iatrogenic injury to the accessory nerve

We describe two patients with uncommon causes of iatrogenic injuries and review the anatomy, presentation, possibilities of repair, and results. The incidence of such nerve injuries during lymph node biopsies is 3%-10%, but the diagnosis is often delayed. Symptoms are shoulder pain and inability to abduct the arm beyond the horizontal plane. Surgical repair may improve function and pain and should be performed early, preferably within six months, but prevention of nerve injury is most important.

Phrenic nerve neurotization utilizing the spinal accessory nerve: technical note with potential application in patients with high cervical quadriplegia

INTRODUCTION

High cervical quadriplegia is associated with high morbidity and mortality. Artificial respiration in these patients carries significant long-term risks such as infection, atelectasis, and respiratory failure. As phrenic nerve pacing has been proven to free many of these patients from ventilatory dependency, we hypothesized that neurotization of the phrenic nerve with the spinal accessory nerve (SAN) may offer one potential alternative to phrenic nerve stimulation via pacing and may be more efficacious and longer lasting without the complications of an implantable device.

MATERIALS AND METHODS

Ten cadavers (20 sides) underwent exposure of the cervical phrenic nerve and the SAN in the posterior cervical triangle. The SAN was split into anterior and posterior halves and the anterior half transposed to the ipsilateral phrenic nerve as it crossed the anterior scalene muscle.

RESULTS

The mean distance between the cervical phrenic nerve and the SAN in the posterior cervical triangle was 2.5 cm proximally, 4 cm at a midpoint, and 6 cm distally. The range for these measurements was 2 to 4 cm, 3.5 to 5 cm, and 4 to 8.5 cm, respectively. The mean excess length of SAN available after transposition to the more anteromedially placed phrenic nerve was 5 cm (range 4 to 6.5 cm). The mean diameter of these regional parts of the spinal accessory and phrenic nerves was 2 and 2.5 mm, respectively. No statistically significant difference was found for measurements between sides.

CONCLUSIONS

To our knowledge, using the SAN for neurotization to the phrenic nerve for potential use in patients with spinal cord injury has not been previously explored. Following clinical trials, these data may provide a mechanism for self stimulation of the diaphragm and obviate phrenic nerve pacing in patients with high cervical quadriplegia. Our study found that such a maneuver is technically feasible in the cadaver.

Iatrogenic spinal accessory nerve injury in children

Injury to the spinal accessory nerve in the posterior triangle of the neck results in trapezius paralysis and shoulder dysfunction. The most common etiology is iatrogenic and has been reported extensively in adults. We report 3 cases of spinal accessory nerve injury recognized postoperatively in children and discuss the microsurgical treatment, results, and simple strategies to avoid this complication.

Accessory nerve: anatomy and surgical identification

The XIth cranial nerve or accessory nerve provides the motor supply to the sternocleidomastoid and trapezius muscles. It is frequently encountered during neck surgery, and as such is at risk of iatrogenic injury, resulting in the ‘shoulder syndrome’. Historically, the nerve was sacrificed on oncological grounds during radical neck dissection. However, the basis for sacrifice is unfounded in the majority of cases, and accessory nerve sparing selective neck dissection has equal oncological efficacy. The path of the nerve in the neck is very variable, and there is not a wholly reliable landmark for its identification. However, there are a number of methods described in the literature to guide the surgeon in its identification. This paper provides a systematic review of all the methods available for identification of the accessory nerve, and comments on the reliability of each. In doing so, the detailed anatomy of the accessory nerve is also described.

Heterotopic nerve transfers: recent trends with expanding indication

There has been increasing enthusiasm for heterotopic nerve transfers for brachial plexus palsy as well as peripheral mononeural dysfunction. The concept of nerve transfer surgery is not new; the first publications on the topic date back to the early 1900s. A wide variety of potential donor nerves are available including the intercostal nerves, the spinal accessory nerve, the phrenic nerve, the ipsilateral medial pectoral nerve, partial ulnar nerve, partial median nerve, thoracodorsal nerve, radial nerve to the triceps, and the ipsilateral C7 or the contralateral C7 nerve roots. Treatment strategies include avoidance of interposed nerve grafting, isolated motor recipient nerve, early transfer, neurorrhaphy close to target motor end plates, and similar diameter between donor nerve and recipient nerves.

Posterior approach technique for accessory-suprascapular nerve transfer: A cadaveric study of the anatomical landmarks and number of myelinated axons

Accessory-suprascapular nerve transfer by the anterior supraclavicular approach technique was suggested to ensure transferrance of the spinal accessory nerve to healthy recipients. However, a double crush lesion of the suprascapular nerve might not be sufficiently demonstrated. In that case, accessory-suprascapular nerve transfer by the posterior approach would probably solve the problem. The aim of this study was to evaluate the anatomical landmarks and histomorphometry of the spinal accessory and suprascapular nerve in the posterior approach. Dissection of fresh cadaveric shoulder in a prone position identified the spinal accessory and suprascapular nerve by the trapezius muscle splitting technique. After that, nerves were taken for histomorphometric evaluation. The spinal accessory nerve was located approximately halfway between the spinous process and conoid tubercle. The average distance from the conoid tubercle to the suprascapular nerve (medial edge of the suprascapular notch) is 3.3 cm. The mean number of myelinated axons of the spinal accessory and suprascapular nerve was 1,603 and 6,004 axons, respectively. The results of this study supported the brachial plexus reconstructive surgeons, who carry out accessory-suprascapular nerve transfer by using the posterior approach technique. This technique is an alternative for patients who have severe crushed injury of the shoulder or suspected double crush lesion of the suprascapular nerve.

Restoration of shoulder function with nerve transfers in traumatic brachial plexus palsy patients

Shoulder stabilization is of utmost importance in upper extremity reanimation following paralysis from devastating injuries. Although secondary procedures such as tendon and muscle transfers have been used, they never achieve a functional recovery comparable to that following successful reinnervation of the supraspinatus, deltoid, teres minor, and infraspinatus muscles. Early restoration of suprascapular and axillary nerve function through timely brachial plexus reconstruction offers a good opportunity to restore shoulder-joint stability, adequate shoulder abduction, and external rotation function. Overall, in our series, 79% of patients achieved good and excellent shoulder abduction (muscle grade, +3 or more), and 55% of patients achieved good or excellent shoulder external rotation after reinnervation of the suprascapular nerve. The best results were seen when direct neurotization of the suprascapular nerve from the distal spinal accessory nerve or neurotization by the C5 root was carried out. Concomitant neurotization of the axillary nerve yields improved outcomes in shoulder abduction and external rotation function.

Refinements in the technique for repair of the accessory nerve

Trapezius muscle palsy after accessory nerve injury leads to periscapular pain and shoulder motion deficit. The results of accessory nerve repair generally are good, but surgery is difficult. The difficulty consists of finding the nerve stumps that are embedded in fat and scar tissue from previous surgeries or injuries. Five patients with accessory nerve lesions had surgery and grafting of the accessory nerve. We dissected the proximal stump of the accessory nerve within the fibers of the sternocleidomastoid muscle and in the vicinity of the greater auricular nerve. To achieve dissection of the distal nerve stump, the deep cervical fascia was detached from the trapezius muscle 3 cm cephalad to the clavicle. The detached fascia and the trapezius muscle were flipped similar to book pages. The motor branches entering the trapezius muscle were visualized and followed toward the accessory nerve. A sural nerve graft with a mean length of 6.6 cm was used for grafting. Uncomplicated identification of the nerve stumps was possible in all patients. After accessory nerve grafting, pain and motion consistently improved in all patients. The technique proposed here ensures reliable and rapid identification of the divided stumps of the accessory nerve.

Shoulder function following partial spinal accessory nerve transfer for brachial plexus birth injury

Over a 5-year-period, 26 infants underwent a partial transfer of the spinal accessory nerve into the suprascapular nerve using a nerve graft, as part of the repair of a brachial plexus birth injury. At a minimum follow-up of 2.5 years, all children had shoulder function of Grade 4 or better using a modified Gilbert Scale. Average lateral rotation was measured at 53 degrees.

Suprascapular Nerve Reconstruction in 118 Cases of Adult Posttraumatic Brachial Plexus

BACKGROUND

Shoulder stabilization is of utmost importance in upper extremity reanimation following paralysis from devastating brachial plexus injuries. The purpose of this report is to present the authors' experience with suprascapular nerve reconstruction in 118 cases of adult brachial plexus lesions. Outcomes were analyzed in relation to various factors, including patient age, denervation time, donor nerve used, and functional restoration achieved in the supraspinatus versus the infraspinatus muscles.

METHODS

The medical records of 118 adult patients operated on by a single surgeon between 1978 and 2002 who had suprascapular nerve reconstruction were reviewed; 102 patients had adequate follow-up. Direct neurotization of the suprascapular nerve was carried out in 78 patients, while in 40 patients, interposition nerve grafts were used. In 80 patients, the distal spinal accessory was used as the motor donor nerve for suprascapular nerve neurotization, while in 10 patients, other extraplexus motor donors were used. In 28 patients, intraplexus motor donors were used to reinnervate the suprascapular nerve.

RESULTS

Results were good or excellent in 79 percent of the patients for the supraspinatus muscle and in 55 percent for the infraspinatus. There was a statistically significant difference between direct spinal accessory to suprascapular nerve neurotization and accessory to suprascapular via a nerve graft. Early surgery and less than 6 months of denervation time yielded significantly better results than late surgery and more than 6 months of delay in the treatment.

CONCLUSIONS

Suprascapular nerve neurotization is a high priority in upper limb reanimation for restoration of glenohumeral joint stability, shoulder abduction, and external rotation. Concomitant neurotization of the axillary nerve yields improved outcomes in shoulder abduction function. The best results are seen when direct neurotization of the suprascapular nerve is performed within 6 months from the injury.