Posterior division of ipsilateral C7 transfer to C5 for shoulder abduction limitation

Background

Reparation of C5 by proximal selective ipsilateral C7 transfer has been reported for the treatment of neurogenic shoulder abduction limitation as an alternative to the reparation of the suprascapular nerve (SSN) and the axillary nerve (AXN) by distal nerve transfers. However, there is a lack of evidence to support either strategy leading to better outcomes based on long-term follow-up.

Objective

The purpose of the study was to investigate the safety and long-term outcomes of the posterior division of ipsilateral C7 (PDIC7) transfer to C5 in treating neurogenic shoulder abduction limitation.

Methods

A total of 27 cases with limited shoulder abduction caused by C5 injury (24 cases of trauma, 2 cases of neuritis, and 1 case of iatrogenic injury) underwent PDIC7 transfer to the C5 root. A total of 12 cases (11 cases of trauma and 1 case of neuritis) of C5 injury underwent spinal accessory nerve (SAN) transfer to SSN plus the triceps muscular branch of the radial nerve (TMBRN) transfer to AXN. The patients were followed up for at least 12 months for muscle strength and shoulder abduction range of motion (ROM).

Results

In cases that underwent PDIC7 transfer, the average shoulder abduction was 105.9° at the 12-month follow-up. In total, 26 of 27 patients recovered at least M3 (13 reached M4) (Medical Research Council Grading) of the deltoid. In cases that underwent SAN transfer to SSN plus TMBRN to AXN, the average shoulder abduction was 84.6° at the 12-month follow-up. In total, 11 of 12 patients recovered at least M3 (4 reached M4) of the deltoid.

Conclusion

Posterior division of ipsilateral C7 transfer is a one-stage, safe, and effective surgical procedure for patients with neurogenic shoulder abduction limitation.

Plasticity of the Central Nervous System Involving Peripheral Nerve Transfer

Peripheral nerve injury can lead to partial or complete loss of limb function, and nerve transfer is an effective surgical salvage for patients with these injuries. The inability of deprived cortical regions representing damaged nerves to overcome corresponding maladaptive plasticity after the reinnervation of muscle fibers and sensory receptors is thought to be correlated with lasting and unfavorable functional recovery. However, the concept of central nervous system plasticity is rarely elucidated in classical textbooks involving peripheral nerve injury, let alone peripheral nerve transfer. This article is aimed at providing a comprehensive understanding of central nervous system plasticity involving peripheral nerve injury by reviewing studies mainly in human or nonhuman primate and by highlighting the functional and structural modifications in the central nervous system after peripheral nerve transfer. Hopefully, it will help surgeons perform successful nerve transfer under the guidance of modern concepts in neuroplasticity.

Transfer of a C7 Fascicle for the Pectoralis Major to the Suprascapular Nerve: A 3-Year Follow-Up Patient Series

BACKGROUND

In patients with C5-C6 brachial plexus injury, spinal accessory nerve transfer to the suprascapular nerve is usually performed for the restoration of shoulder abduction. In order to minimize donor deficits, we transferred one fascicle of the ipsilateral C7 root, dedicated to the pectoralis major muscle, to the suprascapular nerve.

METHODS

Ten patients with a mean age of 33 years (range, 19 to 51 years) were operated on at a mean delay of 4 months after their trauma (range, 2 to 7 months). Patients had C5-C6 brachial plexus palsy with avulsed roots on spinal magnetic resonance imaging scan. In addition to the partial C7 transfer, patients sustained nerve transfers to the posterior branch of the axillary nerve and to the motor branches of the musculocutaneous nerve for the biceps and brachialis muscles.

RESULTS

At a mean follow-up of 36 months (range, 29 to 42 months), mean shoulder abduction and external rotation ranges of motion were, respectively, 99 degrees (range, 60 to 120 degrees; p = 0.001) and 58 degrees (range, 0 to 80 degrees; p = 0.001). In nine patients, shoulder abduction strength was graded M4, according the British Medical Research Council grading scale, against 1.6 kg (range, 1 to 2 kg), and was graded M3 in one patient. External rotation strength was graded M4 in nine patients and M3 in one patient. Residual strength of the pectoralis major muscle was graded M4+ in every patient.

CONCLUSIONS

C7 partial transfer to the suprascapular nerve showed satisfactory results at long-term follow-up for active shoulder abduction and external rotation recovery in C5-C6 brachial plexus palsies. This technique replaced spinal accessory nerve transfer in the authors' practice.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Transfer of the rhomboid nerve for restoration of shoulder external rotation in partial brachial plexus palsy

Restoration of shoulder external rotation in partial brachial plexus palsies is a real challenge. The transfer of the spinal accessory nerve to the suprascapular nerve remains the gold standard. This transfer, however, cannot be always performed. Therefore, in these cases, we previously proposed the transfer of the rhomboid nerve to the suprascapular nerve through a posterior approach. The goal of the present study is to assess this technique through a short series. Eight male patients had a partial plexus palsy. Five patients had C5, C6 root injuries, two patients had C5, C6, C7 root injuries, and one patient had C5 to C8 root injuries. No patients had C5 or C6 root avulsions. In one patient, the spinal accessory nerve was injured and in seven patients, the proximal suprascapular nerve was not available. All patients underwent a transfer from the rhomboid nerve to the suprascapular nerve. Concerning shoulder elevation, transfers from the branch of the long head of the triceps or ulnar nerve fascicle were transferred to the axillary nerve. For elbow flexion, fascicles from the ulnar nerve, median nerve, or both were used. For elbow extension, three intercostal nerves in one patient and one fascicle from the ulnar nerve in two patients were transferred to the branch of the long head of the triceps. For wrist and finger extension, palliative surgery was proposed. All patients recovered external shoulder rotation (from 70-110º) and shoulder elevation (range, 80-140º). Active elbow flexion was coded M4 in seven patients and M3 in one patient. All patients recovered active elbow extension. The transfer of the rhomboid nerve to the suprascapular nerve is an efficient procedure for shoulder external rotation in partial brachial plexus palsies without C5 root avulsion. The results in terms of range-of-motion are, however, poorer than with the spinal accessory nerve. Therefore, this technique is appropriate if the spinal accessory nerve is injured or if the suprascapular nerve is not available in the cervical area. This technique must be associated with another transfer to the axillary nerve for shoulder elevation. The study of more patients will be necessary to confirm these results.

Direct transfer of C7 pectoral fascicles to the suprascapular nerve in C5/C6 brachial plexus palsies: an anatomical study

We investigated a technique to reconstruct the suprascapular nerve in patients with C5/C6 brachial plexus palsies, using pectoral fascicles from the ipsilateral C7 root. Using a supraclavicular approach in eight cadavers, the suprascapular nerve was placed side by side with an anterior quadrant fascicle from the C7 root. Several criteria were assessed, including the fascicle length, the overlap between the two nerves and their respective diameters. The mean length of the C7 fascicles was 19.3 mm, with a mean overlap of 4.7 mm. The suprascapular nerve and the C7 fascicles had mean diameters of 2.2 mm and 2.1 mm, respectively. Pectoral fascicles from C7 seem to be an option for reconstruction of the suprascapular nerve in C5/C6 palsies. Clinical studies will be required to establish the potential limitations of this transfer, especially in cases with complex lesions of the suprascapular nerve.

Elbow flexion reconstruction with nerve transfer or grafting in patients with brachial plexus injuries: A systematic review and comparison study

INTRODUCTION

Posttraumatic brachial plexus (BP) palsy was used to be treated by reconstruction with nerve grafts. For the last two decades, nerve transfers have gained popularity and believed to be more effective than nerve grafting. The aim of this systematic review was to compare elbow flexion restoration with nerve transfers or nerve grafting after traumatic BP injury.

METHODS

PRISMA-IPD structure was used for 52 studies included. Patients were allocated as C5-C6 (n = 285), C5-C6-C7 (n = 150), and total BP injury (n = 245) groups. In each group, two treatment modalities were compared, and effects of age and preoperative interval were analyzed.

RESULTS

In C5-C6 injuries, 93.1% of nerve transfer patients achieved elbow flexion force ≥M3, which was significantly better when compared to 69.2% of nerve graft patients (p < 0.001). For improved outcomes of nerve transfer patients, shorter preoperative interval was a significant factor in all injury patterns (p < 0.001 for C5-C6 injuries and total BP injuries, p = 0.018 for C5-C6-C7 injuries), and young age was a significant factor in total BP injury pattern (p = 0.022).

CONCLUSIONS

Our analyses showed that nerve transfers appear superior to nerve graftings especially in patients with a C5-C6 injury. Unnecessary delays in surgery must be prevented, and younger patients may have more chance for better recovery.

LEVEL OF EVIDENCE

Level II.

Super-selective cervical nerve root stimulation in contralateral C7 transfer: An intraoperative study

OBJECTIVE

We designed this study using super-selective intraoperative cervical nerve root stimulation aiming to support decision making about complete or partial contralateral C7 (cC7) nerve root transfer in patients with multiple cervical root avulsion injury.

METHODS

Super-selective intraoperative stimulations of anterior, lateral, medial and posterior aspect of C5-C8 nerve roots were performed. Compound muscle action potentials (CMAP) were recorded in the lateral part of the deltoid (DM), long head of biceps brachii (BCM), brachioradial (BRM), long head of triceps brachii (TCM), and extensor digitorum communis (EDC) muscle. Muscle strength was documented immediately after cC7 transfer procedures and on scheduled follow-up visits according to the Medical Research Council (MRC) scale.

RESULTS

In the DM, stimulation of the posterior aspect of C5 resulted in the largest CMAP amplitudes (2.0 mV ± 1.9; 80% ± 28.3). The BCM CMAPs induced by the different aspects of C6 all revealed homogenous stimulation results. Stimulation of the lateral aspect of C7 induced the largest amplitude of TCM CMAPs (1.3 mV ± 1.0; 67.1% ± 43.3). CMAP amplitudes of individual muscles and individual contributions of cervical nerve roots to the TCM varied between subjects. Overall donor side morbidity was low, no permanent motor deficit occurred.

CONCLUSION

A super-selective intraoperative cervical nerve root stimulation may help minimize donor side morbidity in transfer procedures. Individual differences of cervical nerve root innervation pattern need to be addressed in future electrophysiological studies.

SIGNIFICANCE

Our study outlines individual differences of cervical nerve root innervation pattern.

Congenital subaxial cervical subluxation presenting as a bilateral Erb's palsy: surgical management, rehabilitation, and outcome

INTRODUCTION

Subaxial spine injuries during infancy are uncommon.

CASE REPORT

We present the case of an infant referred to our brachial plexus clinic with proximal weakness of both arms noted immediately following a complicated breech delivery. Nerve conduction studies were consistent with bilateral proximal upper plexus injury; however, radiological evaluation revealed a C4-C5 subluxation and MRI features of bilateral C5 root avulsions. He was immobilized in a cervical-body orthosis and underwent open reduction and posterior C4-C5-C6 fixation at 10 weeks age using luque rods, sublaminar wires, and rib graft. The spine was immobilized in a custom molded cervicothoracic brace for a total of 3 months, and a home exercise program prescribed. Follow-up radiographic evaluation showed good posterior bony fusion by 2 months but persistent bilateral proximal upper limb weakness with reduced compound motor action potential (CMAP) amplitudes of the axillary and musculocutaneous nerves. Bilateral supraclavicular exploration and C5 root neurotization using the ipsilateral C7 nerve roots were performed at 7 months of age. Voluntary biceps activity followed by voluntary external rotation with gravity eliminated was noted within the next 2-3 months. He progressed to develop near normal motor control of bilateral upper limbs within 1 year.

CONCLUSIONS

We wish to report this rare entity and our favorable outcome using a strategy of early spinal stabilization and neurotization repair to restore function following proximal nerve root injury.

Effect of Collateral Sprouting on Donor Nerve Function After Nerve Coaptation: A Study of the Brachial Plexus

Background

The aim of the present study was to evaluate the donor nerve from the C7 spinal nerve of the rabbit brachial plexus after a coaptation procedure. Assessment was performed of avulsion of the C5 and C6 spinal nerves treated by coaptation of these nerves to the C7 spinal nerve.

Material/Methods

After nerve injury, fourteen rabbits were treated by end-to-side coaptation (ETS), and fourteen animals were treated by side-to-side coaptation (STS) on the right brachial plexus. Electrophysiological and histomorphometric analyses and the skin pinch test were used to evaluate the outcomes.

Results

There was no statistically significant difference in the G-ratio proximal and distal to the coaptation in the ETS group, but the differences in the axon, myelin sheath and fiber diameters were statistically significant. The comparison of the ETS and STS groups distal to the coaptation with the controls demonstrated statistically significant differences in the fiber, axon, and myelin sheath diameters. With respect to the G-ratio, the ETS group exhibited no significant differences relative to the control, whereas the G-ratio in the STS group and the controls differed significantly. In the electrophysiological study, the ETS and STS groups exhibited major changes in the biceps and subscapularis muscles.

Conclusions

The coaptation procedure affects the histological structure of the nerve donor, but it does not translate into changes in nerve conduction or the sensory function of the limb. The donor nerve lesion in the ETS group is transient and has minimal clinical relevance.

Isolated C5-C6 avulsion in obstetric brachial plexus palsy treated by ipsilateral C7 neurotization to the upper trunk: outcomes at a mean follow-up of 9 years

Cervical root avulsions are the worst pattern of injury in obstetrical brachial plexus injury (OBPI). The prognosis is poor and the treatment is mainly surgical with extraplexual neurotizations or muscle transfers. We present the outcomes of a technique performed in our institution to treat C5-C6 avulsion in obstetrical brachial plexus injury. This technique consists of a total ipsilateral C7 neurotization to the upper trunk. Ten babies with isolated C5-C6 root avulsion were operated on; we were able to review nine of them at over 12 months follow-up. The shoulder and the elbow function were assessed, as well as the Mallet Score. The mean follow-up was 9.2 years (SD 5.7). After a follow-up of 6 years, elbow flexion was restored with a range of motion ⩾130° and a motor function ⩾M3 in all patients. The average Mallet score was 18.1 (SD 1.2). This approach appears to be a viable alternative to extraplexual neurotizations for the treatment of C5-C6 nerve root avulsion.

Lesiones altas del plexo braquial. Reconstrucción con técnicas combinadas de neurotización e injertos nerviosos

<p>Las lesiones altas del plexo braquial  son  reconstruidas  con neurotización e  injerto nervioso. El  nervio espinal accesorio,  la raíz   C7,  ramas del tríceps, y  el nervio mediano y cubital son los más  usados para transferencias.</p><p>Se muestra la experiencia con  neurotización de la rama inferior del nervio espinal accesorio (NEA) al nervio supraescapular (NSE), transferencia nerviosa de fascículos del nervio cubital o del mediano, y en ocasiones  injertos nervioso hacia el nervio musculocutáneo  y al tronco posterior, y reconstrucción del nervio axilar  en algunos casos.</p><p><strong>Materiales y métodos</strong></p><p>Se revisan 42  pacientes  con  lesiones altas de plexo braquial, operados  mediante combinación de   neurotización  e injertos nerviosos. Seguimiento mínimo de 15 meses.</p><p><strong>Resultados  </strong></p><p>40 pacientes fueron por accidente en moto. En 22 se  transfirió únicamente el NSE con el NEA, recuperando  abducción de hombro  de 33º  En 8  pacientes  que se combinó con reparación del axilar, mejoró la abducción a 81º.</p><p>En 30 pacientes con neurotización del nervio cubital o mediano para el bíceps, se obtuvo respuesta  entre 3 y 4 meses. Al  final  flexión  del codo de 116º y M4.</p><p><strong>Discusión</strong></p><p>Los mejores resultados  en  hombro  fueron con la combinación  de NSE y del nervio axilar, logrando 81º de abducción. La rotación externa  mejoro  en 28.5% de los pacientes, siendo una respuesta tardía</p><p>La neurotización  del bíceps con fascículos del cubital consiguió una flexión    de 116º, muy  comparable con otras series. Hoy  esta técnica es el  <em>gold estándar</em>   para la reconstrucción de  flexión del codo. </p>

Total ipsilateral C7 root neurotization to the upper trunk for isolated C5-C6 avulsion in obstetrical brachial plexus palsy: a preliminary technical report

BACKGROUND

C5-C6 root avulsion in obstetrical brachial plexus palsy (OBPP) is a rare injury with poor prognosis usually associated with breech delivery. The treatment is challenging and requires high microsurgical skills. The triple nerve transfer (spinal accessory nerve, ulnar fascicles, and triceps long or lateral head branch) represents the gold standard treatment. The total ipsilateral C7 nerve root neurotization is a promising technique, which has never been described in OBPP.

OBJECTIVE

The total ipsilateral C7 nerve root is used as a neurotizer transferred to the upper trunk as an alternative method to other intra- or extra-plexual reconstruction techniques.

METHODS

During brachial plexus surgical exploration, an intraoperative neurostimulation was performed to confirm the integrity of C7 and the lesion of C5 and C6. The entire C7 nerve root and the upper trunk are cut. The C7 root was transferred to the upper trunk with a fibrin sealant.

RESULT

This technique was easily performed with a single approach and avoided intercalated nerve grafts. The C7 nerve root provided a large number of nerve fibers with an adequate diameter to be transferred to the upper trunk. We illustrated this technique with a typical case of a child at 8 years of follow-up.

CONCLUSION

The total ipsilateral transfer of the C7 root to the upper trunk is a viable alternative procedure for newborns with C5-C6 avulsion.