Objective To analysis the electrophysiological dominance weight of the triceps brachii muscle/extensordigitorum communis muscle innervated by brachial plexus and to conclude its effect on the ipsilateral C7 transfer so as to offer electrophysiological data for the safety and indication of i psilateral C7 transfer. Methods From August 2007 to October 2007, 15 patients with complete brachial plexus nerve root avulsion received contralateral C7 transfer. There were 13 males and 2 females aged 18-49 years (28 years on average). Injury was caused by fall ing in 1 case, by crush in 2 cases and by traffic accident in 12 cases, involving left side in 8 cases and right side in 7 cases. The upper, middle and lower trunk of the brachial plexus were stimulated respectively, the compound muscle action potential (CMAP) at the triceps brachii muscle/extensor digitorum communis muscle was recorded, and then the electrophysiological dominance weight of the triceps brachii muscle/extensor digitorum communis muscle innervated by brachial plexus was confirmed according to the comparison of the ampl itude percentage of the CMAP by three trunks. The muscle strength of triceps brachii muscle/extensor digitorum communis muscle was evaluated and the electromyogram was taken 6 months after operation. Results All patients were followed up for 6 months. Concerning the electrophysiological dominance weight, the triceps brachii muscle was mainly innervated by uppermiddle trunk in 3 cases (20%), by middle-lower trunk in 3 cases (20%), by whole trunk in 7 cases (47%) and by middle trunk in 2 cases (13%). While the extensor digitorum communis muscle was mainly innervated by middle-lower trunk in 3 cases (20%), by whole trunk in 10 cases (67%) and by lower trunk in 2 cases (13%). Concerning the triceps brachii muscle, 2 patients got the muscle strength of 4 grade with recruitment simple phase at 1 month after operation and returned to normal at 3 month after operation, while 13 patients got the muscle strength of 5 grade with recruitment simple or mixed phase at 1 month after operation. Concerning the extensor digitorum communis muscle, the muscle strength and the recruitment phase of all 15 patients recovered to normal at 1 month after operation. Conclusion To patients with various kinds of electrophysiological dominance weight, the cutting of C7 does not substantially damage the triceps brachii muscle or extensor digitorum communis muscle, indicating that the ipsilateral C7 transfer is safe and feasible. However, it should be appl ied prudently for the patients with high dominance weight since it may result in the short-term decrease of triceps brachii muscle strength.
The results of nerve transposition for root avulsion of brachial plexas in 21 cases were reported. The methods of the nerve transposition were divided into four groups as followings: By transfer of phrenic nerve, accesory nerve, the motor branches of cervical plexus and intercostal nerves in cease; By transfer of phrenic nerve, accessory nerve and the motor branches of cervical plexus in 6 cases; By transfer of phrenic nerve and accessory nerve in 9 cases, and by transfer of phrenic nerve or the motor branches of cervical plexus or intercostal nerve in 5 cases. During operation, in 1 cases variation of the brachial plexus was found. Injury to the subclavian artery occurred in 4 cases and they were repaired, which is good for the blood circulation of the upper arm and nerve regeneration. Nineteen cases were followed up with good results. The overall excellent and good rate was 73.7%. It was considered that transposition of nerve should be a routine operation for the treatment of root avulsion of brachial plexus and the accompanied arterial injury should be repaired at the same time during operation, and the latter would be advantageous to enhance functional recovery of nerve.
OBJECTIVE To observe the ultrastructural changes and number of satellite cells in different muscles with different denervation interval and investigate the mechanism of denervation atrophy. METHODS Muscles of different denervation interval were harvested, which were 6 biceps brachii and 6 abductor digiti minimi. The ultrastructure of the samples were observed under transmission electron microscope. The number of nucleus and satellite cells were counted to calculate the percentage content of satellite cells. RESULTS In early stage of denervation, the myofilament and sarcomere of the majority were well oriented. The nucleoli of some muscle cell nucleus were enlarged and pale. Vacuolarization was also seen in some mitochondria. There was no obvious proliferation of collagen fiber around myofibers. After denervation of half a year, rupture and disorientation of myofilament was seen. The nucleus became smaller, dark stained, and some of them were condensed. There was proliferation of fibroblasts, adipose cells and collagen fibers around myofibers. Motor endplate was not recognized one year after denervation. In the early stage of denervation, satellite cell percentage of the two muscles was relatively high. It then declined with time. One year after denervation, satellite cells were scarcely detected. Comparison of the curves for satellite cell declination in two muscles revealed that the declination of the abductor digiti minimi was faster than that of biceps brachii. Decrease of the former started 3 months after denervation, while the latter started after 6 months. CONCLUSION Disappearing of motor endplate and proliferation of collagen fibers are main factors that affect the treatment outcome in late cases. Decrease of satellite cell number is another cause. The correlation of less satellite cell in abductor digiti minimi and poorer recovery of hand intrinsic muscles indicates that increment of satellite cells in long-term denervated muscles may be one of the effective measures to improve treatment outcome.
OBJECTIVE: To investigate the variation of neurotrophic factors expression in spinal cord and muscle after root avulsion of brachial plexus. METHODS: Forty-eight Wistar rats were involved in this study and according to the observing time in 1st day, 1st week, 4th week, 8th week, and 12th week after avulsion, and the control, were divided into 6 groups. By immunohistochemical and hybridization in situ assays, the expression of nerve growth factor (NGF) on muscle, basic fibroblast growth factor(bFGF) and its mRNA on the neurons of corresponding spinal cord was detected. Computer image analysis system was used to calculate the result. RESULTS: After the root avulsion of brachial plexus occurred, expression of NGF increased and reached to the peak at the 1st day. It subsided subsequently but was still higher than normal control until the 12th week. While expression of bFGF and its mRNA increased in the neurons of spinal cord and reached to the peak at the 1st week. Then it dropped down and at the 12th week it turned lower than normal control. CONCLUSION: After root avulsion of brachial plexus, neurotrophic factors expression increase on target muscle and neurons of corresponding spinal cord. It maybe the autoregulation and may protect neuron and improve nerve regeneration.
Objective To investigate the sensation of the fingers innervated by the brachial plexus roots and provide the theoretic basis for diagnosis of a brachial plexus injury. Methods From June 2003 to January 2005，10 patients (8 males, 2 females; age,18-47 years) with complete brachial plexus avulsion were involved in this study, who underwent thecontralateral C7 nerve root transfer. The latency and amplitude of the sensory nerve actiopotential(SNAP) were record at the C5 T1 nerve roots when stimulation was given at the fingers.Results When the thumb and the index finger were stimulated and SNAP was recorded at all the roots of the brachial plexus in all the patients, we found that there was a higher amplitude and a shorter latency at the C5-7 roots than at the C8 and T1 roots(P＜0.05). When the middle finger was stimulated and SNAP was recorded at the C7,8 and T1 roots, we found that there was the highest amplitude and the shortest laency at the C7 root(P＜0.01). When the ring finger was stimulated and SNAP was recorded at the C7,8and T1 roots, we found that there was a higher amplitude and a shorter latency at the C8 and T1 roots than at the C7 root(P＜0.01). When the little finger was stimulated and SNAP was recorded at the C7,8and T1 roots, we found that there was the highest amplitude and the shortest latency at the T1 root(P＜0.01). ConclusionThe sense of the thumband the index finger is mainly nnervated by the C5-7 roots, the middle finger sense is mainly innervated by the C7 root, the ring finger sense is mainly innervated by the C8 and T1 roots, and the little finger sense is mainly innervated by the T1 root.
Objective To provide the anatomical basis of contralateral C7 root transfer for the recovery of the forearm flexor function. Methods Thirty sides of adult anti-corrosion specimens were used to measure the length from the end of nerves dominating forearm flexor to the anastomotic stoma of contralateral C7 nerve when contralateral C7 nerve transfer was used for repair of brachial plexus lower trunk and medial cord injuries. The muscle and nerve branches were observed. The length of C7 nerve, C7 anterior division, and C7 posterior division was measured. Results The length of C7 nerve, anterior division, and posterior division was (58.8 ± 4.2), (15.4 ± 6.7), and (8.8 ± 4.4) mm, respectively. The lengths from the anastomotic stoma to the points entering muscle were as follow: (369.4 ± 47.3) mm to palmaris longus, (390.5 ± 38.8) mm (median nerve dominate) and (413.6 ± 47.4) mm (anterior interosseous nerve dominate) to the flexor digitorum superficialis, (346.2 ± 22.3) mm (median nerve dominate) and (408.2 ± 23.9) mm (anterior interosseous nerve dominate) to the flexor digitorum profundus of the index and the middle fingers, (344.2 ± 27.2) mm to the flexor digitorum profundus of the little and the ring fingers, (392.5 ± 29.2) mm (median nerve dominate) and (420.5 ± 37.1) mm (anterior interosseous nerve dominate) to the flexor pollicis longus, and (548.7 ± 30.0) mm to the starting point of the deep branch of ulnar nerve. The branches of the anterior interosseous nerve reached to the flexor hallucis longus, the deep flexor of the index and the middle fingers and the pronator quadratus muscle, but its branches reached to the flexor digitorum superficials in 5 specimens (16.7%). The branches of the median nerve reached to the palmaris longus and the flexor digitorum superficial, but its branches reached to the deep flexor of the index and the middle fingers in 10 specimens (33.3%) and to flexor hallucis longus in 6 specimens (20.0%). Conclusion If sural nerve graft is used, the function of the forearm muscles will can not be restored; shortening of humerus and one nerve anastomosis are good for forearm flexor to recover function in clinical.
Objective To investigate the results of two stage multiple nerves transfer for treatment of complete brachial plexus root avulsion. Methods Eight patients with complete brachial plexus avulsion, aging 18-38 years andwith a mean 6 months interval of injury and repair, were surgically treated with the following procedures. One stage surgical procedure was that the contralateral C7 never root was transferred to the ulnar nerve, the phrenic nerve to theanterior division of upper trunci plexus brachialis and the accessory nerve to the suprascapular nerve. Two stage surgical procedure was that the ulnar nerve was transferredto the median nerve , the intercostal nerves to the radial nerve and the thoracodorsal nerve. Results All patients were followed upfrom 13 months to 25 months(21 months on average), muscle reinnervation was observed in all patients. Return of muscle power of M3 or better are regarded as effective. The effective recovery results were 75% in musculocutaneous nerve, 37.5% in suprascapular nerve, 37.5% in radial nerve, 75% in thoracodorsal nerve and 62.5% in median nerve. In sensory recovery of the median nerve, 4 patients obtained S3, 3 patients S2 and 1 patient S1. Conclusion Two stage multiple nerves transfer for treatment of root avulsion of brachial plexus can achieve better motor function results and is safe and effective. The procedure should be recommended for treatmentof root avulsion of brachial plexus in selected patients with complete brachial plexus root avulsion, especially in young patients with a short interval between injury and repair. It isone of the alternative options.
Objective To investigate the quantity and distribution of motor fiber of rat’s C7 nerve root. Methods Motor fiber quantity and section area in the main nerves of the upper extremity and the fascicles of C7 in 30 SD rats were analyzed.Results Fascicles and certain amount (207) of motor fibers from the anterior division of C7 were distributed to musculocutaneous nerve and median nerve, the orientation of these fibers were not clear. The ones (323) from posterior division were to the axillary, radial, and dorsal thoracic nerves, thus the orientation of these fascicles was relatively definite. Conclusion Thedistribution of the motor fibers and fascicles in the divisions of C7 in rat is similar to human beings, so rat is a relatively good model for the study of selective C7 nerve root transfer.
Objective To investigate the survival effect and reaction mechanismsof motor neurons after reimplantation of the avulsed root into the spinal cord,and to observe the survival and differentiation in the spinal cord after brachial plexus roots avulsion. Methods Thirty adult Wistar rats were randomly devided into the control group and the experimental group (n=15). Laminectomy of C4-6 was performed via a posterior approach. The ventral and dorsal roots of C5，6 were both avulsed from the spinal cord outside the dura mater and within the vertebral canal.For the experimental group, the ventral root of C6 wasreimplanted into the ventralhorn under microscope. The dorsal root was left. The ventral and dorsal roots of C5 were placed inside the nearby muscles. For the control group, the ventral and dorsal roots of both C5 and C6 were placed inside the nearby muscles. At 2, 4, 6, 8, 12 weeks postoperatively, the C6 spinal cord was stained with HE. The changes of the number and morphology of motor neurons were observed onHEstained sections. The C6 spinal nerve root was stained with silver nitrate, andthe regeneration of nerve fiber was observed. Results All rats were recovered well and their wounds were healed at primary stage. The gross observation showed that the avulsed nerve roots in control group adhered to adjacent muscles, however the one in experimental groups which had been implanted into spinal cord adhered to scar tissues and were not separated from spinal cord. At each time point postoperatively, the HEstained transverse sections showed that the number of motor neurons decreased significantly with soma swollen and atrophied, Nissle bodies decreased or disappeared. The survival rates of motor neurons in the control group were 60.9％±5.8%,42.3％±3.5％,30.6％±6.1％27.5％±7.9％ and 20.4％±6.8％ respectively；in the experimental group,the survival rates were 67.1％±7.4％,56.3％±4.6％,48.7％±8.8％,44.2％±5.5％ and 42.5％±8.3％ respectively. The survival rates of motor neurons in the experimental group was higher than those in the control group at all time points,showing statistically significant difference（Plt;0.01）.At 12 weeks postoperatively, thesilver nitrate stained specimen from the C6 nerve root showed regeneration of the motor neurons in the ventral horn into the reimplanted nerve root through axon in the experimental group,but the degeneration of the nerve fiber appeared and the number of the myelinated nerve fiber decreased in the control group. Conclusion Through reimplantationof the avulsed ventral nerve root into the ventral horn, degeneration of the motor neurons in the ventral horn can be reduced. After reimplantation of avulsed nerve root, there is axonal regrowth of motor neurons into the spinal nerve root and regeneration of the myelinated nerve fiber also appears.
ObjectiveTo investigate the mechanisms,diagnosis,and surgical procedures of simultaneous lesions of the rotator cuff and the brachial plexus. MethodsBetween July 2006 and June 2012,7 patients with rotator cuff tear associated with brachial plexus injury were treated.There were 3 males and 4 females with a mean age of 47.3 years (range,37-72 years).The reasons of injury were traumatic shoulder dislocation in 6 cases and falling injury from height in 1 case,with a mean disease duration of 17 days (range,5-31 days).The average American Shoulder and Elbow Surgeons (ASES) score was 55.86±9.42,and visual analogue scale (VAS) score was 7.14±1.35.There were 3 cases of large rotator cuff tears (>3 cm) and 4 cases of massive rotator cuff tears (>5 cm) according to Gerber standard;1 case had upper trunk injury of the brachial plexus and 6 cases had bundle branch injury of the brachial plexus according to GU Yudong's classification.The functional score of brachial plexus score was 7.43±1.27 according to the functional assessment standard by Hand Surgery Branch of Chinese Medical Association.All patients accepted arthroscopic rotator cuff repairing,and 1 case received surgical neurolysis of brachial plexus. ResultsAll incisions healed by first intention without complication.All the 7 patients were followed up 18 to 25 months (mean,20.4 months).The function,muscle strength,and sensation of the shoulder were improved obviously.The shoulder ASES score was 84.71±8.06 and was significantly better than preoperative score (t=-8.194,P=0.000).The VAS score was 2.71±1.50 and was significantly better than preoperative score (t=7.750,P=0.000).The functional score of brachial plexus was 14.00±1.16 and was significantly better than preoperative score (t=-11.500,P=0.000). ConclusionIt is difficult to simultaneously diagnose lesions of the rotator cuff and the brachial plexus;orthopedists should pay attention to possible patients to avoid missed diagnosis and diagnostic errors.Nerve nutrition,physical therapy,and arthroscopic rotator cuff repair can achieve good effectiveness.