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Post-traumatic brachial plexus paralysis: current management of reconstruction
Current Orthopaedics (2001) 15, 76d83 ^ 2001 Harcourt Publishers Ltd doi:10.1054/cuor.2001.0169, available online at http://www.idealibrary.com on
MASTERCLASS
Post-traumatic brachial plexus paralysis: current management of reconstruction M. D. Vekris*, and P. N. SoucacosR *Orthopaedic Department of Ioannina University Hospital, Ioannina Medical School, Ioannina, Greece RDepartment of Orthopaedic Surgery, University of Ioannina, School of Medicine, Ioannina, Greece
Summary Post-traumatic brachial plexus paralysis is usually caused by high-velocity motor vehicle accidents that occur in the young productive population. The socioeconomic impact is considerably high, since after the injury the patient faces either permanent disability of the paralysed extremity and/or a prolonged time of recuperation. The prognosis is grave if multiple root avulsions are present. The current management of these devastating injuries involves an early, aggressive microsurgical reconstruction of the brachial plexus, combining various neurotizations with intraplexus and extraplexus ipsilateral and contralateral nerve donors, with conventional or vascularized nerve grafts and secondary functional enhancement with vascularized and neurotized muscle transfers. This multistaged microsurgical approach if applied early offers, especially in young patients, satisfactory function, even in cases with multiple avulsions. ^ 2001 Harcourt Publishers Ltd
INTRODUCTION Post-traumatic brachial plexus paralysis affects mostly young people and is associated with a devastating socioeconomic and psychological hardship. Over recent years, the number of severe brachial plexus injuries has increased, mainly because of the increased survival rate after motor vehicle accidents due to the application of advanced resuscitation techniques. Avulsion injuries of the brachial plexus result in the most devastating palsies of the affected upper extremity. The prognosis is grave and the functional results limited. Precise and careful evaluation of the plexus lesion is of paramount importance, since it permits more accurate prognosis and allows a more realistic plan for reconstruction. The difficulty in plexus reconstruction vs peripheral nerve repair is dual; firstly, the lack of adequate nerve grafts to bridge extensive and massive plexus defects and secondly, in the case of avulsions, the lack of adequate proximal intraplexus donors (roots) which are in continuity with the spinal cord. These factors make the anatomical restoration of the brachial plexus practically impossible, with the exception of partial plexus injuries. The challenge for the reconstructive
Correspondence to: PNS.
microsurgeon is to identify and sacrifice less important functions in order to direct motor fibres and use them to neurotize more important targets for restoration of basic functions to the flail and anaesthetic arm. Despite attempts at brachial plexus reconstruction introduced early in the 20th century, a non-operative approach was recommended due to poor results, although exploration was recommended to determine prognosis.1}7 For the flail and anaesthetic arm, the alternative was to amputate through the arm, fuse the shoulder and fit the patient with a prosthesis,8 or use specialized splints (flail arm splint).9 During the last few decades, the introduction of microsurgical techniques10}12 and the principle of tension-free repair 13,14 in peripheral nerve surgery, has led to the better understanding of the nature of brachial plexus injuries and the experience gained over the years has improved the outcome of brachial plexus reconstruction even in severe palsies involving root avulsions. The patient should be informed of the multistaged reconstruction required and become familiar with the possibility of a partial return of function and use of the paralysed extremity as an accessory extremity during daily activities. Since no patient wants amputation of the paralysed limb, preferring to use it even partially, the surgeons effort focuses on maximizing the motor and
POST-TRAUMATIC BRACHIAL PLEXUS PARALYSIS: CURRENT MANAGEMENT OF RECONSTRUCTION sensory recovery by whatever means seem appropriate. The whole spectrum of reconstruction aims to regain important functions of the upper extremity (i.e. shoulder stability, elbow flexion, elbow extension, protective sensation in the hand and, if feasible, hand reanimation).
DIAGNOSIS Preoperative examination A precise preoperative assessment includes an explicit history of the injury and the patient’s physical status, a comprehensive physical examination and various paraclinical examinations, including radiological and electrophysiological studies. The history is of paramount importance since usually the patients arrive for plexus reconstruction several weeks or months after the injury. An explicit history can reveal the mechanism of the injury and the velocity of the impact; high-velocity injuries indicate root avulsion. Concomitant fractures and/or dislocations around the shoulder and/or vascular injury of the subclavian or axillary vessels indicate extensive impact to the plexus with possible double level of injury and additional scar tissue that will make exploration of the plexus more difficult. The presence of a vein graft to bridge a vessel defect should make the surgeon more cautious. Clinical examination starts with observation of muscle atrophy, scars, contractures, neurotrophic vasomotor changes and the presence of Horner’s sign, which indicates lower root avulsion. The muscle strength of all muscles of the upper extremity should be examined, from the shoulder to the hand, and recorded according to the British Medical Research Council (MRC) Scale of M0}M5 using # and ! between each grade i.e. M3#. The passive range of motion of all joints is assessed, to reveal joint contractures. The sensory status of the extremity is examined, for light touch, static and moving two-point discrimination, and vibration modalities with tuning forks. The ninhydrine sweat test reveals damage to the sympathetic chain and is an indicator of lower root avulsion. The presence of pain and its characteristics (e.g. location, frequency, duration, quality and intensity), as well as, the requirement for medication and changes in characteristics of the pain since the accident, combined with the sensory status of the extremity help to rule out avulsion. The examination should include inspiration and expiration chest radiographs and/or chest fluoroscopy, to rule out phrenic nerve palsy (indicator of upper root avulsion). Other plain radiographs are useful if there is evidence from the history of fracture or dislocation. Ectopic ossification may be present and is not rare in coma patients who have stayed in ICU. An arteriogram of the upper extremity is necessary in cases of previous
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vessel injury and/or reconstruction with a vein graft, and is also required when free muscle transfers are being contemplated. The combination of a cervical myelogram, introduced by Murphey15 and a CT post myelogram is considered the best method to examine the ventral and dorsal rootless and to exclude avulsions, with a low rate (3.5%) of false negatives.16 Conventional MRI is good for assessing the plexus beyond the foramina, although the recently introduced technique of MR myelography surpasses conventional myelography with an accuracy similar to that for CT post myelogram.17 The presence of pseudomeningocoels indicates root avulsion. Electrodiagnostic evaluation includes electromyography,18 nerve conduction velocities, sensory action potentials19 and the percutaneous lamina stimulation test.20 In the latter examination, tiny volleys of electrical stimulation are applied to each exiting root and the patient perceives the dermatome subserved by this root. A positive response is strong evidence against avulsion. The presence of sensory nerve action potential (SNAP) and normal sensory conduction velocity in the peripheral nerves innervating a flail and anesthetic extremity, invariably implies root avulsion. These preoperative data are necessary in order to arrive at a prognosis and establish a reasonable reconstructive plan. The final diagnosis, though, is made at operation.
BRACHIAL PLEXUS EXPLORATION AND INTRAOPERATIVE DIAGNOSIS Exploration of the entire supraclavicular and infraclavicular brachial plexus is necessary to identify the roots and the injured plexus elements. In post-ganglionic lesions and if there is any residual function, intraoperative electrical nerve stimulation with 0.5}2.0 mA intensity is helpful, particularly in cases of neuroma-incontinuity. In order to rule out root avulsions intraoperatively, various methods are in use. Cross-sections of the roots are sent to the pathology laboratory for immediate histological evaluation to identify axons and/or ganglion cells and/or excessive scar tissue. If ganglion cells are present, the root is considered avulsed and therefore cannot be used as a donor for neurotization. Additional histochemistry of the roots with carbonic anhydrase21 and cholinesterase22 can be processed immediately in specialized centres to receive further information regarding the sensorimotor distribution at a biopsy site. Somatosensory evoked potentials (SEPs) record the response of the opposite brain hemisphere to electrical stimuli at the root level utilizing superficial recording electrodes and are reported to be a reliable in ruling out avulsion.23
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CURRENT ORTHOPAEDICS
Recently, motor evoked potentials (MEPs) have been used to diagnose avulsion of the anterior rootlets (motor fibres).24 This method records action potentials at the root level after transcranial electrical stimulation of the brain. The presence of a response indicates a connection and therefore the absence of avulsion of that root from the spinal cord. The authors use a scale of intraoperative assessment of the severity of the lesion, the Total Severity score which was introduced by Terzis et al.25 Each root is graded as follows: (0) avulsion, (1) avulsion/rupture, (2) rupture, (3) rupture/traction, (4) traction, (5) normal. The total severity score of the normal brachial plexus is 25. The lower the severity score, the worse the injury and the prognosis and the fewer the available intraplexus donors for neurotization.
TIMING OF RECONSTRUCTION The optimal time for reconstruction in the treatment of closed traction injuries was the subject of controversy in the past. The attitude of ‘wait and see’ has no place today in the management of these injuries, since there is minimal or no benefit from late nerve reconstruction, especially one performed after 2 years of denervation. Magalon et al.26 and Brunelli27 suggested an emergency repair of lesions associated with vascular trauma, while Alnot28 advocates exploration of the plexus during vascular repair and reconstruction at a secondary stage. Sedel29 reports that the results obtained from repairs done up to 9 months after the injury were better than those achieved with more delayed reconstruction. The authors believe that aggressive early reconstruction within 6 weeks to 3 months post injury, offers the most rewarding results.25
BRACHIAL PLEXUS RECONSTRUCTION In post-ganglionic supraclavicular and infraclavicular injuries most of the distal plexus elements can usually be reconstructed with restoration of the anatomical pathways. Neurolysis is useful in the presence of scar tissue and in neuroma-in-continuity where there is response during intraoperative electrical stimulation. Nerve grafting is the most common method of reconstruction in post-ganglionic injuries, utilizing conventional nerve grafts to bridge the defects (Figs 1}7). The most popular sensory nerves used as grafts are the following in order of preferences, sural, saphenous, medial brachial and antebrachial cutaneous and superficial radial. Vascularized nerve grafts were added to the armamentarium of brachial plexus surgeons.30,31 These
Figure 1 Sixteen-year-old female sustained a close range gunshot injury to the left axilla (on 15/04/1999). The left infraclavicular brachial plexus was injured with a concominant injury of the subclavian-axillary vessels. Arterial repair was performed immediately post-injury via a vein graft. Preoperative examination (4 months after injury), shows a paralysed, anaesthetic extremity which retained only slight shoulder abduction.
Figure 2 Four months post injury (16/8/1999), exploration of the left brachial plexus was performed. A large neuroma with excessive scar tissue was found at the infraclavicular area of the plexus. Intraoperative findings included: (1) rupture of the posterior cord proximal to the origin of the axillary nerve, (2) rupture of the lateral cord proximal to the origin of the musculocutaneous nerve, and (3) a mixed lesion to the medial cord with rupture of its contribution to the median nerve. In addition, traction injury of the ulnar nerve was also observed. Although the ulnar nerve was in continuity, it was covered with excessive scar tissue for a length of approximately 10 cm.
grafts maintain their blood supply and survive transfer even if placed in a scarred bed. Thus, the intraneural environment is optimally preserved and axonal carrythrough is not compromised even when a nerve trunk is transferred (i.e. ulnar nerve).32
POST-TRAUMATIC BRACHIAL PLEXUS PARALYSIS: CURRENT MANAGEMENT OF RECONSTRUCTION
Figure 3 Reconstruction of the brachial plexus included the following: (1) thorough microneurolysis of the cords, the distal stumps, as well as of the ulnar, thoracodorsal and suprascapular nerves, (2) nerve grafting from the lateral cord to the musculocutaneous and median nerves, and from the medial cord tot he median nerve, (3) nerve grafting from the posterior cord to the axillary, triceps branches and the radial nerve.
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Figure 5 Note the strong elbow flexion with full active range of motion. The patient is able to lift a handbag easily.
Figure 6 Hand function is restored. Note the powerful finger flexion.
Figure 4 Tendon transfers of reinnervated muscles were also performed (9/2000) to enhance hand function. These included: pronator teres to extensor carpi radialis brevis, flexor carpi ulnaris to extensor digitorum communis and palmaris longus to extensor pollicis longus. The patient during the last follow-up visit (4/2001) demonstrates excellent shoulder function and elbow extension.
In cases of root avulsions, reconstructive surgeons have promoted the use of various extraplexus motor and sensory donors in their effort to neurotize selected muscles and in order to achieve essential function in the shoulder, elbow and hand. Yeoman and Seddon33 introduced neurotization of the musculocutaneous nerve with intercostal nerve transfer in cases of avulsion. In addition, the use of branches of the ipsilateral cervical
Figure 7 Patient demonstrates excellent function of the thumb and strong grip. The patient is pain-free and has almost normal return of sensation (mean static two point discrimination is 10 mm).
80 plexus,34 contralateral lateral pectoral nerve,35 accessory nerve,36 hypoglossal nerve,37,38 phrenic nerve and contralateral C7,39,40 selective contralateral C741 and selective ulnar nerve to musculocutaneous42 are also applied. There is some controversy regarding the level of distal coaptation of the nerve grafts during neurotization procedures. Bentolila et al.43 reported better outcomes when the grafts were coapted distally to the lateral or posterior cord in relation to more distal coaptations near the distal target (i.e. musculocutaneous). On the contrary, Alnot28 and Terzis et al.25 stated that nerve grafting is more rewarding when the nerve grafts are coapted distally to the peripheral nerve rather than to proximal plexus elements (i.e. cords). The authors concur with this notion, since this way the majority of the nerve fibres will be driven to the desired target, and not lost in random reinnervation.
Strategy of reconstruction Post-ganglionic lesions The roots are not avulsed and the injury extends for variable lengths and involves trunks, divisions and/or cords. The reconstruction with neurolysis and nerve grafts can be global and anatomical. In extended injuries, direct neurotization procedures can be used if lack of nerve grafts and anatomical restoration is not feasible. Care should be taken to connect the anterior part of the proximal plexus elements with the lateral and medial cord and the posterior to the posterior cord to avoid co-contraction. If there is avulsion of the peripheral nerves from the muscle, direct implantation of the nerve grafts in multiple places of the muscle belly is a method of reinnervation.
Preganglionic lesions The lower roots are avulsed more frequently and in this case the others are involved to a variable degree, following the rule that the further a root is from the avulsion, the less the insult. The prognosis is better if the avulsion affects the upper plexus because in this case the hand is spared. If C5 and/or C6 are avulsed, usually selective regions of the posterior division of C7 are guided to the posterior cord and parts from the anterior division of C7 are guided to the lateral cord. In adults, neurotization of C8 and T1 is not justified, since the long distances do not offer the possibility of recovery of the small muscles of the hand. If only C5 and C6 are available, the suprascapular nerve is neurotized from the terminal branch of the accessory nerve, while conventional nerve grafts or
CURRENT ORTHOPAEDICS the ipsilateral ulnar nerve is utilized as a vascularized nerve graft to connect C5 and C6 with the musculocutaneous, axillary, median and radial nerves. The ulnar nerve, based on the superior ulnar collateral vessels, can connect two or three targets at the same time with the donor root(s), using the ‘loop’ technique introduced by Terzis in 1981.33 Through perineurial windows the fascicles are divided, for coaptation to the root(s) and the distal targets, maintaining the nerve’s epineurial blood supply. If only C5 is available and the brachial plexus is prefixed, a similar strategy of reconstruction is followed. If the brachial plexus is postfixed and the C5 root is tiny, then it is connected only to the musculocutaneous nerve with conventional nerve grafts and the ulnar nerve is reserved, to be used for connection with the contralateral C7 and the ipsilateral median nerve at the second stage. The posterior cord elements including the axillary nerve, the nerve branch to the triceps and radial nerve are neurotized by extraplexus motors including ipsilateral intercostals, partial phrenic and cervical plexus motors. In case of global avulsion, the lack of intraplexus donors leads the surgeon to seek axonal pools in extraplexus ipsilateral or contralateral donors. It is of paramount importance to assure good condition of the ipsilateral nerves, since in these devastating injuries, these may be involved to a variable degree. The neurotizations most used are the following: (1) Accessory nerve is used for suprascapular neurotization directly. (2) Intercostals are used to neurotize either anterior or posterior targets, but not both, to avoid co-contraction. Direct coaptation to the recipient nerve is preferable. For the musculocutaneous nerve, one needs at least three intercostals. (3) The phrenic, the cervical plexus motor branches, the partial hypoglossal and the anterior and posterior division of the contralateral C7 are used to neurotize as many targets as possible. Sometimes in order to match the axonal number of the target to the lesser number axons offered by the donors, two or more donor nerves may be driven to the same important target i.e. musculocutaneous nerve. Protective sensation is given to the median nerve from sensory branches of the intercostals and/or from the sensory supraclavicular nerves. Furthermore, nerve grafts, connected proximally with various motor donors, are banked subcutaneously at the arm or elbow level for future neurotization of free muscle transfers.
PAIN MANAGEMENT If the extremity is totally flail and anesthetic, usually with intolerable constant pain, the patient often seeks relief
POST-TRAUMATIC BRACHIAL PLEXUS PARALYSIS: CURRENT MANAGEMENT OF RECONSTRUCTION even with amputation; a method which is not acceptable today. Control of the pain can be achieved either by conservative methods (i.e. pharmaceutical agents and/or electrical stimulation) or if it persists, with surgical intervention consisting of coagulation, at the levels of the avulsed roots of the dorsal root entry zones in the spinal cord (DREZ procedure introduced by Nashold44). This procedure should precede the nerve reconstruction. After brachial plexus micro-reconstruction, the pain is dramatically decreased and the majority of the patients have no pain or very mild and tolerable pain.25,28,45 The pain decrease is directly associated with sensation improvement postoperatively. The restoration of protective sensation allows the patient to recognize the position of the extremity in space and avoid injuries, while any return of afferent input, even protective, blocks dramatically the nociceptive afferent pathways. Relief of pain permits the patient to focus on the rehabilitation of his extremity and improve its dexterity and overall function, which returns many months later.
SECONDARY PROCEDURES Procedures such as muscle transfers and wrist fusion are necessary to improve function, especially in late cases where the muscle targets have atrophied. Pedicled muscle or tendon transfers46} 49 are used to enhance the function of the paretic arm. Advances in microsurgery brought the era of free functional muscle transfer to brachial plexus paralysis management.50}52 The transferred free muscles are neurotized either by previously banked nerve grafts or directly from local motor donors (e.g. intercostal nerves). The most commonly restored functions are elbow flexion and extension, finger flexion and extension and, in some cases, shoulder abduction and intrinsic substitution. Latissimus dorsi and rectus femoris transfer, are good candidates for elbow flexion restoration. For hand reanimation, gracilis and rectus femoris can be used.25 Some surgeons prefer to restore two functions with one muscle transfer i.e. elbow flexion and finger flexion or elbow extension and finger extension.52,53
OUTCOME OF RECONSTRUCTION Important factors determining the prognosis of the lesion are the age of the patient, the denervation time, meaning the time interval between the injury and the surgery, and the severity score, which is a scale introduced by Terzis to grade the degree of root injury at exploration.25 The consensus today is that the best results are obtained in younger patients with short denervation time (less than 6 months) and higher severity score.25,54}56
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Most authors report better results in upper root palsies and there are two reasons for this. Firstly, the hand is spared and secondly, the muscle targets of reconstruction are closer to the plexus. The later also explains the better outcome for proximal muscles e.g. supraspinatus, biceps, etc. Many authors25,45,55,57}59 prefer to use intraplexus motor donors for neurotizations, when they are available, since they give better results. The reason for this is that the intraplexus donors have a greater number of axons than the extraplexus ones and therefore the chances for successful neurotization are greater. It seems that some of the extraplexus donors give consistently superior results when they are used with specific targets (i.e. shoulder and elbow). The use of intercostal nerves to directly neurotize the musculocutaneous continue to be a standard approach in the reconstruction of severe plexus lesions, especially avulsions. The results are good to excellent (more than M3) in 60}70% of the patients.13,25,45,59,60}62 Ogino and Naito63 consider intercostal transfer as a useful procedure to provide elbow flexion and protective sensation to the hand. The accessory nerve is another reliable donor. Direct neurotization of the suprascapular nerve yields results comparable to repair using intraplexus donors. Neurotization of the suprascapular nerve gives 75% good or excellent (M3# to M4#) results.25 Millesi13 reported that neurotization of the suprascapular and axillary nerves with the accessory nerve gave stability to the shoulder in more than 60% of patients. Various authors28,43,62,64 reported good to excellent result (M3# or more) in 55}80% of patients, with respect to recovery of biceps function after transfer of the spinal accessory nerve to the musculocutaneous nerve. Other extraplexus donors give less rewarding results; the explanation for this, in the case of cervical plexus motors, is probably related to the fact that a small number of fibres destined initially for short distances are now being forced on a long journey. In the case of the contralateral C7, the length of the cross-chest nerve grafts imposes necessary delay prior to target connection. Gu et al.54,65 showed good results in 75% of musculocutaneous neurotization with the phrenic, as well as recovery of the biceps up to M3 in 60% of the case and recovery of the triceps up to M4 in 50% of cases with contralateral C7 neurotizations. The results were good in 50% of the suprascapular and axillary neurotizations with motor branches of the cervical plexus. Cervical plexus motors and contralateral C7 gave, overall, an inferior outcome in relation to hand reanimation.25 Restoration of hand function remains the most difficult task for the reconstructive microsurgeon. Nevertheless, it must always be pursued, despite the fact that the results of hand reanimation using neurotizations are not
82 as successful as elbow flexion restoration. The good results range from 15 to 40% in various series regarding finger extension and flexion, regardless of the donor nerve that is used for neurotization of the radial and median nerves.25,45,54,66 If we can find means to preserve the muscle targets, especially the distal ones, we believe that we can expect better functional restoration in the hand. In global avulsions, in late cases, or in the reconstruction of distal targets such as the hand, free muscle transfers and other secondary procedures can improve the final outcome.25,53,67 From the above reports, it seems that certain muscle groups (shoulder abductors and external rotators, supinators and extensors) have an inferior response to reconstruction. Narakas and Hentz45 mentioned that this paradox could be explained partially, on the basis of embryological origin of the various muscles. It seems that the upper extremity is built to give preference of restoration of the flexors, which are vital for the survival of the organism.
CONCLUSIONS Post-traumatic brachial plexus injuries represent a challenge to the reconstructive microsurgeon. Usually these are devastating lesions, the product of highvelocity injuries. Early, aggressive, microsurgical reconstruction should be the method of choice in the management of these injuries. The current sophisticated techniques of nerve reconstruction (neurotizations utilizing every available ipsilateral and contralateral intraplexus and extraplexus donors, with conventional and/or vascularized nerve grafts), in combination with secondary free functional muscle transfers, give a satisfactory outcome even in multiple avulsion injuries. Amputation is no longer an option today, even in the face of global avulsion.
REFERENCES 1. Stevens J H. Brachial plexus paralysis. In: Godman E A (ed). The Shoulder. Brooklyn, NY; G Mill, 1934. 2. Barnes R. Traction injuries of the plexus in adults. J. Bone Jt Surg 1949; 31B: 10}16. 3. Larsen E H. Injuries of the brachial plexus in adults. J Bone Jt Surg 1955; 37B: 733}734. 4. Tracy J F, Brannon E W. Management of brachial plexus injuries (traction type). J Bone Jt Surg 1958; 40(A): 1031. 5. Bonney G. Prognosis in traction lesions of the brachial plexus. J Bone Jt Surg 1959; 41B: 4}35. 6. Leffert R D, Seddon H. Infraclavicular brachial plexus injuries. J Bone Jt Surg 1965; 49B: 9}22. 7. Nelson K G, Jolly P C, Thomas P A. Brachial plexus injuries associated with missile wounds of the chest. A report of 9 cases from Vietnam. J Trauma 1968; 8: 268}275. 8. Flether I. Traction lesions of the brachial plexus. Hand 1969; 1: 29.
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9. Wynn Parry C B. Rehabilitation of patients following traction injuries of the brachial plexus. Hand Clin 1995; 11(4): 517}533. 10. Kurze T. Microtechniques in neurological surgery. Clin Neurosurg 1964; 11: 128}137. 11. Millesi H. Brachial plexus injuries. Management and results Clin Plast Surg 1984; 11: 115}120. 12. Narakas A. The surgical management of brachial plexus injuries. In: Daniel R K, Terzis J K (eds). Reconstructive Microsurgery. vol. 1 Boston: Little-Brown, 1977. 13. Millesi H. Nerve grafting. Clin Plast Surg 1984; 11: 105}113. 14. Terzis J K, Faibisoff B, Williams B. The nerve gap: suture under tension vs graft. Plast Reconstr Surg 1975; 56(2): 166}170. 15. Murphey F, Hartung W, Kirklin J W. Myelographic demonstration of avulsing injury of the brachial plexus. Am J Roentgenol 1947; 58(1): 102}105. 16. Marshall R W, De Silva R D D. Computerized axial tomography in traction injuries of the brachial plexus. J Bone Jt Surg 1986; 68B: 734}738. 17. Nakamura T, Yabe Y, Horiuchi Y, Takayama S. Magnetic resonance myelography in brachial plexus injury. J Bone Jt Surg 1997; 79B: 764}769. 18. Hodes R R, Larrabee M C, German W. The human electromyogram in response to nerve stimulation and the conduction velocity of motor axons. Arch Neurol Psychiatr 1948; 60: 340. 19. Dawson G D, Scott J W. The recording of nerve action potentials through skin in man. J Neurol Neurosurg Psychiatr 1949; 12: 259. 20. Liberson W T, Terzis J K. Contribution of clinical neurophysiology and rehabilitation medicine to the management of brachial plexus palsy. In: Terzis J K (ed). Microreconstruction of Nerve Injuries. Philadelphia: W B Saunders, 1987. 21. Carson K A, Terzis J K. Carbonic anhydrase histochemistry: a potential diagnostic method for peripheral nerve repair. Clin Plast Surg 1985; 12: 227}232. 22. Kanaya F, Ogden L, Breidenbach W C, Tsai T M, Scheker L. Sensory and motor fiber differentiation with Karnovsky staining. J Hand Surg 1991; 16(A): 851}858. 23. Oberle J, Antoniadis G, Rath S A et al. Radiological investigations and intra-operative evoked potentials for the diagnosis of nerve root avulsion: evaluation of both modalities by intradural root inspection. Acta Neurochir (Wien) 1998; 140: 527}531. 24. Turkof E, Millesi H, Turkof R, Pfundner P, Mayr N. Intraoperative electroneurodiagnostics (transcranial electrical motor evoked potentials) to evaluate the functional status of anterior spinal roots and spinal nerves during brachial plexus surgery. Plast Reconstr Surg, 1997; 99: 1632}1641. 25. Terzis J K, Vekris M D, Soucacos P N. Outcomes of brachial plexus reconstruction in 204 patients with devastating paralysis Plast Reconstr Surg 1999; 104(5): 1221}1240. 26. Magalon G, Bordeaux J, Legre R. Emergency vs delayed repair of severe brachial plexus injuries. Clin Orthop 1988; 237: 32}35. 27. Brunelli G A, Brunelli G R. Preoperative assessment of the adult plexus patient. Microsurgery 1995; 16: 17}21. 28. Alnot J. Traumatic brachial plexus lesions in the adult. Indications and results. Hand Clin 1995; 11(4): 623}631. 29. Sedel L. Repair of severe traction lesions of the brachial plexus. Clin Orthop 1988; 237: 62}66. 30. Taylor G I, Ham F J. The free vascularized nerve graft: a further experimental and clinical application of microvascular techniques. Plast Reconstr Surg 1976; 57: 413}426. 31. Daniel R K. Terzis J K, Schwarz G. Neurovascular free flaps. A preliminary report. Plast Reconstr Surg 1975; 56(1): 13}20. 32. Terzis J K, Breidenbach W. The anatomy of free vascularized nerve grafts. In: Terzis J K (ed). Microreconstruction of Nerve Injuries. Philadelphia: W B Saunders, 1987. 33. Yeoman P M, Seddon H J. Brachial plexus injuries. Treatment of the flail arm. J Bone Jt Surg 1961; 43B: 493.
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34. Brunelli, G. Neurotization of avulsed roots of the brachial plexus by means of anterior nerves of the brachial plexus. Int J Microsurg 1980; 2: 55}58. 35. Gibert A. Neurotization by contralateral pectoral nerve. Presented at the 10th Symposium on the Brachial Plexus, Lausanne, Switzerland, 1992. 36. Allieu Y, Privat J M, Bonnel F. Paralysis in root avulsion of the brachial plexus: neurotization by the spinal accessory nerve. Clin Plast Surg 1984; 11: 133}136. 37. Narakas A. Thoughts on neurotization or nerve transfers in irreperable nerve lesions. Clin Plast Surg 1984; 11: 153}159. 38. Chuang D. Neurotization procedures for brachial plexus injuries. Hand Clin 1995; 11(4): 633}645. 39. Gu Y D, Wu M M, Zhen Y L et al. Phrenic nerve transfer for brachial plexus motor neurotization. Microsurgery 1989; 10: 287}289. 40. Gu Y D, Zhang G M, Chen D S et al. Cervical nerve root transfer from contralateral normal side for treatment of brachial plexus root avulsion. Chin Med J (Engl) 1991; 104: 208}211. 41. Terzis J K. Contralateral C7: a powerful source of motor neurons for devastating brachial plexus paralysis. Presented at the 7th annual meeting of European Association of Plastic Surgeons, Innsbruck, Austria, 1996. 42. Loy S, Bhatia A, Asfazadourian H, Oberlin C. Ulnar nerve fascicle transfer onto to the biceps muscle nerve in C5}C6 or C5}C6}C7 avulsions of the brachial plexus. Eighteen cases. Ann Chir Main Memb Super 1997; 16: 275}284. 43. Bentolila V, Nizard R, Bizot P, Sedel L. Complete traumatic brachial plexus palsy. Treatment and outcome after repair. J Bone Surg 1999; 81(A): 20}28. 44. Friedman A H, Nashold Jr B S, Bronec P R. Dorsal root entry zone lesions for the treatment of brachial plexus avulsion injuries: a follow-up study. Neurosurgery 1988; 22(2): 369}373. 45. Narakas A, Hentz V. Neurotization in brachial plexus injuries: indications and results. Clin Orthop 1988; 237: 43}56. 46. Zancolli E A, Zancolli E R. Palliative surgical procedures in sequelae of obstetrical palsy. Hand Clin 1988; 4: 643}669. 47. Marshall R W, Williams D H, Birch R, Bonney G. Operations to restore elbow flexion after brachial plexus injuries. J Bone Jt Surg 1988; 70B: 577}582. 48. Aziz W, Singer R M, Wolff T W. Transfer of the trapezius for flail shoulder after brachial plexus injury. J Bone Jt Surg 1990; 72B: 701}704. 49. Brunelli G A, Vigasio A, Brunelli G R. Modified Steindler procedure for elbow flexion restoration. J Hand Surg 1995; 20A: 743}746. 50. Manktelow R T, McKee N H. Free muscle transplantation to provide active finger flexion. J Hand Surg 1978; 3: 416}426.
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51. Terzis J K, Sweet R C, Dykes R W, Williams H B. Recovery of function in free muscle transplants using microneurovascular anastomoses. J Hand Surg Am 1978; 3(1): 37}59. 52. Doi K. New reconstructive procedure for brachial plexus injury. Clin Plast Surg, 1997; 24: 75}85. 53. Berger A, Becker M. Brachial plexus surgery: our concept of the last twelve years. Microsurgery 1994; 15: 760}767. 54. Gu Y, Wu M, Zheng Y et al. Microsurgical treatment for root avulsion of the brachial plexus. Chinese Med J 1987; 100(7): 519}522. 55. Hentz V, Narakas A. The results of microneurosurgical reconstruction in complete brachial plexus palsy. Assessing outcome and predicting results. Orthop Clin North Am 1988; 19(1): 107}114. 56. Nagano A. Treatment of brachial plexus injury. J Orthop Sci 1998; 3: 71}80. 57. Allieu Y, Cenac P. Neurotization via the spinal accessory nerve in complete paralysis due to multiple avulsion injuries of the brachial plexus. Clin Orthop 1988; 237: 67}74. 58. Allieu Y, Chammas M, Picot M C. Paralysis of the brachial plexus caused by supraclavicular injuries in the adult. Long-term comparative results of nerve grafts and transfers Rev Clin Orthop Reparatrice Appar Mot 1997; 83: 51}59. 59. Kawai H, Kawabata H, Masada K, Ono K, Yamamoto K, Tsuyuguchi Y, Tada K. Nerve repairs for traumatic brachial plexus palsy with root avulsion. Clin Orthop 1988; 237: 75}86. 60. Nagano A, Tsuyama N, Ochiai N, Hara T, Takahashi M. Direct nerve crossing with the intercostal nerve to treat avulsion injuries of the brachial plexus. J Hand Surg 1989; 14(6): 980}985. 61. Malessy M J, Thomeer R T. Evaluation of intercostal to musculocutaneous nerve transfer in reconstructive brachial plexus surgery. J Neurosurg 1998; 88: 266}271. 62. Waikakul S, Wongtragul S, Vanadurongwan V. Restoration of elbow flexion in brachial plexus avulsion injury: comparing spinal accessory nerve transfer with intercostal nerve transfer. J Hand Surg 1999; 24(A): 571}577. 63. Ogino T, Naito T. Intercostal nerve crossing to restore elbow flexion and sensibility of the hand for a root avulsion type of brachial plexus injury. Microsurgery 1995; 16: 571}577. 64. Songcharoen P, Mahaisavariya B, Chotigavanich C. Spinal accessory neurotization for restoration of elbow flexion in avulsion injuries of the brachial plexus. J Hand Surg 1996; 21(A): 387}390. 65. Gu Y D, Chen D S, Zhang G M et al. Long-term functional results of contralateral C7 transfer. J Reconstr Microsurg 1998; 14: 57}59. 66. Sedel L. The results of surgical repair of brachial plexus injuries. J Bone Jt Surg 1982; 64(B): 54}66. 67. Chung D C, Carver N, Wei F C. Results of functioning free muscle transplantation for elbow flexion. J Hand Surg 1996; 21(A): 1071}1077.
MASTERCLASS
Post-traumatic brachial plexus paralysis: current management of reconstruction M. D. Vekris*, and P. N. SoucacosR *Orthopaedic Department of Ioannina University Hospital, Ioannina Medical School, Ioannina, Greece RDepartment of Orthopaedic Surgery, University of Ioannina, School of Medicine, Ioannina, Greece
Summary Post-traumatic brachial plexus paralysis is usually caused by high-velocity motor vehicle accidents that occur in the young productive population. The socioeconomic impact is considerably high, since after the injury the patient faces either permanent disability of the paralysed extremity and/or a prolonged time of recuperation. The prognosis is grave if multiple root avulsions are present. The current management of these devastating injuries involves an early, aggressive microsurgical reconstruction of the brachial plexus, combining various neurotizations with intraplexus and extraplexus ipsilateral and contralateral nerve donors, with conventional or vascularized nerve grafts and secondary functional enhancement with vascularized and neurotized muscle transfers. This multistaged microsurgical approach if applied early offers, especially in young patients, satisfactory function, even in cases with multiple avulsions. ^ 2001 Harcourt Publishers Ltd
INTRODUCTION Post-traumatic brachial plexus paralysis affects mostly young people and is associated with a devastating socioeconomic and psychological hardship. Over recent years, the number of severe brachial plexus injuries has increased, mainly because of the increased survival rate after motor vehicle accidents due to the application of advanced resuscitation techniques. Avulsion injuries of the brachial plexus result in the most devastating palsies of the affected upper extremity. The prognosis is grave and the functional results limited. Precise and careful evaluation of the plexus lesion is of paramount importance, since it permits more accurate prognosis and allows a more realistic plan for reconstruction. The difficulty in plexus reconstruction vs peripheral nerve repair is dual; firstly, the lack of adequate nerve grafts to bridge extensive and massive plexus defects and secondly, in the case of avulsions, the lack of adequate proximal intraplexus donors (roots) which are in continuity with the spinal cord. These factors make the anatomical restoration of the brachial plexus practically impossible, with the exception of partial plexus injuries. The challenge for the reconstructive
Correspondence to: PNS.
microsurgeon is to identify and sacrifice less important functions in order to direct motor fibres and use them to neurotize more important targets for restoration of basic functions to the flail and anaesthetic arm. Despite attempts at brachial plexus reconstruction introduced early in the 20th century, a non-operative approach was recommended due to poor results, although exploration was recommended to determine prognosis.1}7 For the flail and anaesthetic arm, the alternative was to amputate through the arm, fuse the shoulder and fit the patient with a prosthesis,8 or use specialized splints (flail arm splint).9 During the last few decades, the introduction of microsurgical techniques10}12 and the principle of tension-free repair 13,14 in peripheral nerve surgery, has led to the better understanding of the nature of brachial plexus injuries and the experience gained over the years has improved the outcome of brachial plexus reconstruction even in severe palsies involving root avulsions. The patient should be informed of the multistaged reconstruction required and become familiar with the possibility of a partial return of function and use of the paralysed extremity as an accessory extremity during daily activities. Since no patient wants amputation of the paralysed limb, preferring to use it even partially, the surgeons effort focuses on maximizing the motor and
POST-TRAUMATIC BRACHIAL PLEXUS PARALYSIS: CURRENT MANAGEMENT OF RECONSTRUCTION sensory recovery by whatever means seem appropriate. The whole spectrum of reconstruction aims to regain important functions of the upper extremity (i.e. shoulder stability, elbow flexion, elbow extension, protective sensation in the hand and, if feasible, hand reanimation).
DIAGNOSIS Preoperative examination A precise preoperative assessment includes an explicit history of the injury and the patient’s physical status, a comprehensive physical examination and various paraclinical examinations, including radiological and electrophysiological studies. The history is of paramount importance since usually the patients arrive for plexus reconstruction several weeks or months after the injury. An explicit history can reveal the mechanism of the injury and the velocity of the impact; high-velocity injuries indicate root avulsion. Concomitant fractures and/or dislocations around the shoulder and/or vascular injury of the subclavian or axillary vessels indicate extensive impact to the plexus with possible double level of injury and additional scar tissue that will make exploration of the plexus more difficult. The presence of a vein graft to bridge a vessel defect should make the surgeon more cautious. Clinical examination starts with observation of muscle atrophy, scars, contractures, neurotrophic vasomotor changes and the presence of Horner’s sign, which indicates lower root avulsion. The muscle strength of all muscles of the upper extremity should be examined, from the shoulder to the hand, and recorded according to the British Medical Research Council (MRC) Scale of M0}M5 using # and ! between each grade i.e. M3#. The passive range of motion of all joints is assessed, to reveal joint contractures. The sensory status of the extremity is examined, for light touch, static and moving two-point discrimination, and vibration modalities with tuning forks. The ninhydrine sweat test reveals damage to the sympathetic chain and is an indicator of lower root avulsion. The presence of pain and its characteristics (e.g. location, frequency, duration, quality and intensity), as well as, the requirement for medication and changes in characteristics of the pain since the accident, combined with the sensory status of the extremity help to rule out avulsion. The examination should include inspiration and expiration chest radiographs and/or chest fluoroscopy, to rule out phrenic nerve palsy (indicator of upper root avulsion). Other plain radiographs are useful if there is evidence from the history of fracture or dislocation. Ectopic ossification may be present and is not rare in coma patients who have stayed in ICU. An arteriogram of the upper extremity is necessary in cases of previous
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vessel injury and/or reconstruction with a vein graft, and is also required when free muscle transfers are being contemplated. The combination of a cervical myelogram, introduced by Murphey15 and a CT post myelogram is considered the best method to examine the ventral and dorsal rootless and to exclude avulsions, with a low rate (3.5%) of false negatives.16 Conventional MRI is good for assessing the plexus beyond the foramina, although the recently introduced technique of MR myelography surpasses conventional myelography with an accuracy similar to that for CT post myelogram.17 The presence of pseudomeningocoels indicates root avulsion. Electrodiagnostic evaluation includes electromyography,18 nerve conduction velocities, sensory action potentials19 and the percutaneous lamina stimulation test.20 In the latter examination, tiny volleys of electrical stimulation are applied to each exiting root and the patient perceives the dermatome subserved by this root. A positive response is strong evidence against avulsion. The presence of sensory nerve action potential (SNAP) and normal sensory conduction velocity in the peripheral nerves innervating a flail and anesthetic extremity, invariably implies root avulsion. These preoperative data are necessary in order to arrive at a prognosis and establish a reasonable reconstructive plan. The final diagnosis, though, is made at operation.
BRACHIAL PLEXUS EXPLORATION AND INTRAOPERATIVE DIAGNOSIS Exploration of the entire supraclavicular and infraclavicular brachial plexus is necessary to identify the roots and the injured plexus elements. In post-ganglionic lesions and if there is any residual function, intraoperative electrical nerve stimulation with 0.5}2.0 mA intensity is helpful, particularly in cases of neuroma-incontinuity. In order to rule out root avulsions intraoperatively, various methods are in use. Cross-sections of the roots are sent to the pathology laboratory for immediate histological evaluation to identify axons and/or ganglion cells and/or excessive scar tissue. If ganglion cells are present, the root is considered avulsed and therefore cannot be used as a donor for neurotization. Additional histochemistry of the roots with carbonic anhydrase21 and cholinesterase22 can be processed immediately in specialized centres to receive further information regarding the sensorimotor distribution at a biopsy site. Somatosensory evoked potentials (SEPs) record the response of the opposite brain hemisphere to electrical stimuli at the root level utilizing superficial recording electrodes and are reported to be a reliable in ruling out avulsion.23
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CURRENT ORTHOPAEDICS
Recently, motor evoked potentials (MEPs) have been used to diagnose avulsion of the anterior rootlets (motor fibres).24 This method records action potentials at the root level after transcranial electrical stimulation of the brain. The presence of a response indicates a connection and therefore the absence of avulsion of that root from the spinal cord. The authors use a scale of intraoperative assessment of the severity of the lesion, the Total Severity score which was introduced by Terzis et al.25 Each root is graded as follows: (0) avulsion, (1) avulsion/rupture, (2) rupture, (3) rupture/traction, (4) traction, (5) normal. The total severity score of the normal brachial plexus is 25. The lower the severity score, the worse the injury and the prognosis and the fewer the available intraplexus donors for neurotization.
TIMING OF RECONSTRUCTION The optimal time for reconstruction in the treatment of closed traction injuries was the subject of controversy in the past. The attitude of ‘wait and see’ has no place today in the management of these injuries, since there is minimal or no benefit from late nerve reconstruction, especially one performed after 2 years of denervation. Magalon et al.26 and Brunelli27 suggested an emergency repair of lesions associated with vascular trauma, while Alnot28 advocates exploration of the plexus during vascular repair and reconstruction at a secondary stage. Sedel29 reports that the results obtained from repairs done up to 9 months after the injury were better than those achieved with more delayed reconstruction. The authors believe that aggressive early reconstruction within 6 weeks to 3 months post injury, offers the most rewarding results.25
BRACHIAL PLEXUS RECONSTRUCTION In post-ganglionic supraclavicular and infraclavicular injuries most of the distal plexus elements can usually be reconstructed with restoration of the anatomical pathways. Neurolysis is useful in the presence of scar tissue and in neuroma-in-continuity where there is response during intraoperative electrical stimulation. Nerve grafting is the most common method of reconstruction in post-ganglionic injuries, utilizing conventional nerve grafts to bridge the defects (Figs 1}7). The most popular sensory nerves used as grafts are the following in order of preferences, sural, saphenous, medial brachial and antebrachial cutaneous and superficial radial. Vascularized nerve grafts were added to the armamentarium of brachial plexus surgeons.30,31 These
Figure 1 Sixteen-year-old female sustained a close range gunshot injury to the left axilla (on 15/04/1999). The left infraclavicular brachial plexus was injured with a concominant injury of the subclavian-axillary vessels. Arterial repair was performed immediately post-injury via a vein graft. Preoperative examination (4 months after injury), shows a paralysed, anaesthetic extremity which retained only slight shoulder abduction.
Figure 2 Four months post injury (16/8/1999), exploration of the left brachial plexus was performed. A large neuroma with excessive scar tissue was found at the infraclavicular area of the plexus. Intraoperative findings included: (1) rupture of the posterior cord proximal to the origin of the axillary nerve, (2) rupture of the lateral cord proximal to the origin of the musculocutaneous nerve, and (3) a mixed lesion to the medial cord with rupture of its contribution to the median nerve. In addition, traction injury of the ulnar nerve was also observed. Although the ulnar nerve was in continuity, it was covered with excessive scar tissue for a length of approximately 10 cm.
grafts maintain their blood supply and survive transfer even if placed in a scarred bed. Thus, the intraneural environment is optimally preserved and axonal carrythrough is not compromised even when a nerve trunk is transferred (i.e. ulnar nerve).32
POST-TRAUMATIC BRACHIAL PLEXUS PARALYSIS: CURRENT MANAGEMENT OF RECONSTRUCTION
Figure 3 Reconstruction of the brachial plexus included the following: (1) thorough microneurolysis of the cords, the distal stumps, as well as of the ulnar, thoracodorsal and suprascapular nerves, (2) nerve grafting from the lateral cord to the musculocutaneous and median nerves, and from the medial cord tot he median nerve, (3) nerve grafting from the posterior cord to the axillary, triceps branches and the radial nerve.
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Figure 5 Note the strong elbow flexion with full active range of motion. The patient is able to lift a handbag easily.
Figure 6 Hand function is restored. Note the powerful finger flexion.
Figure 4 Tendon transfers of reinnervated muscles were also performed (9/2000) to enhance hand function. These included: pronator teres to extensor carpi radialis brevis, flexor carpi ulnaris to extensor digitorum communis and palmaris longus to extensor pollicis longus. The patient during the last follow-up visit (4/2001) demonstrates excellent shoulder function and elbow extension.
In cases of root avulsions, reconstructive surgeons have promoted the use of various extraplexus motor and sensory donors in their effort to neurotize selected muscles and in order to achieve essential function in the shoulder, elbow and hand. Yeoman and Seddon33 introduced neurotization of the musculocutaneous nerve with intercostal nerve transfer in cases of avulsion. In addition, the use of branches of the ipsilateral cervical
Figure 7 Patient demonstrates excellent function of the thumb and strong grip. The patient is pain-free and has almost normal return of sensation (mean static two point discrimination is 10 mm).
80 plexus,34 contralateral lateral pectoral nerve,35 accessory nerve,36 hypoglossal nerve,37,38 phrenic nerve and contralateral C7,39,40 selective contralateral C741 and selective ulnar nerve to musculocutaneous42 are also applied. There is some controversy regarding the level of distal coaptation of the nerve grafts during neurotization procedures. Bentolila et al.43 reported better outcomes when the grafts were coapted distally to the lateral or posterior cord in relation to more distal coaptations near the distal target (i.e. musculocutaneous). On the contrary, Alnot28 and Terzis et al.25 stated that nerve grafting is more rewarding when the nerve grafts are coapted distally to the peripheral nerve rather than to proximal plexus elements (i.e. cords). The authors concur with this notion, since this way the majority of the nerve fibres will be driven to the desired target, and not lost in random reinnervation.
Strategy of reconstruction Post-ganglionic lesions The roots are not avulsed and the injury extends for variable lengths and involves trunks, divisions and/or cords. The reconstruction with neurolysis and nerve grafts can be global and anatomical. In extended injuries, direct neurotization procedures can be used if lack of nerve grafts and anatomical restoration is not feasible. Care should be taken to connect the anterior part of the proximal plexus elements with the lateral and medial cord and the posterior to the posterior cord to avoid co-contraction. If there is avulsion of the peripheral nerves from the muscle, direct implantation of the nerve grafts in multiple places of the muscle belly is a method of reinnervation.
Preganglionic lesions The lower roots are avulsed more frequently and in this case the others are involved to a variable degree, following the rule that the further a root is from the avulsion, the less the insult. The prognosis is better if the avulsion affects the upper plexus because in this case the hand is spared. If C5 and/or C6 are avulsed, usually selective regions of the posterior division of C7 are guided to the posterior cord and parts from the anterior division of C7 are guided to the lateral cord. In adults, neurotization of C8 and T1 is not justified, since the long distances do not offer the possibility of recovery of the small muscles of the hand. If only C5 and C6 are available, the suprascapular nerve is neurotized from the terminal branch of the accessory nerve, while conventional nerve grafts or
CURRENT ORTHOPAEDICS the ipsilateral ulnar nerve is utilized as a vascularized nerve graft to connect C5 and C6 with the musculocutaneous, axillary, median and radial nerves. The ulnar nerve, based on the superior ulnar collateral vessels, can connect two or three targets at the same time with the donor root(s), using the ‘loop’ technique introduced by Terzis in 1981.33 Through perineurial windows the fascicles are divided, for coaptation to the root(s) and the distal targets, maintaining the nerve’s epineurial blood supply. If only C5 is available and the brachial plexus is prefixed, a similar strategy of reconstruction is followed. If the brachial plexus is postfixed and the C5 root is tiny, then it is connected only to the musculocutaneous nerve with conventional nerve grafts and the ulnar nerve is reserved, to be used for connection with the contralateral C7 and the ipsilateral median nerve at the second stage. The posterior cord elements including the axillary nerve, the nerve branch to the triceps and radial nerve are neurotized by extraplexus motors including ipsilateral intercostals, partial phrenic and cervical plexus motors. In case of global avulsion, the lack of intraplexus donors leads the surgeon to seek axonal pools in extraplexus ipsilateral or contralateral donors. It is of paramount importance to assure good condition of the ipsilateral nerves, since in these devastating injuries, these may be involved to a variable degree. The neurotizations most used are the following: (1) Accessory nerve is used for suprascapular neurotization directly. (2) Intercostals are used to neurotize either anterior or posterior targets, but not both, to avoid co-contraction. Direct coaptation to the recipient nerve is preferable. For the musculocutaneous nerve, one needs at least three intercostals. (3) The phrenic, the cervical plexus motor branches, the partial hypoglossal and the anterior and posterior division of the contralateral C7 are used to neurotize as many targets as possible. Sometimes in order to match the axonal number of the target to the lesser number axons offered by the donors, two or more donor nerves may be driven to the same important target i.e. musculocutaneous nerve. Protective sensation is given to the median nerve from sensory branches of the intercostals and/or from the sensory supraclavicular nerves. Furthermore, nerve grafts, connected proximally with various motor donors, are banked subcutaneously at the arm or elbow level for future neurotization of free muscle transfers.
PAIN MANAGEMENT If the extremity is totally flail and anesthetic, usually with intolerable constant pain, the patient often seeks relief
POST-TRAUMATIC BRACHIAL PLEXUS PARALYSIS: CURRENT MANAGEMENT OF RECONSTRUCTION even with amputation; a method which is not acceptable today. Control of the pain can be achieved either by conservative methods (i.e. pharmaceutical agents and/or electrical stimulation) or if it persists, with surgical intervention consisting of coagulation, at the levels of the avulsed roots of the dorsal root entry zones in the spinal cord (DREZ procedure introduced by Nashold44). This procedure should precede the nerve reconstruction. After brachial plexus micro-reconstruction, the pain is dramatically decreased and the majority of the patients have no pain or very mild and tolerable pain.25,28,45 The pain decrease is directly associated with sensation improvement postoperatively. The restoration of protective sensation allows the patient to recognize the position of the extremity in space and avoid injuries, while any return of afferent input, even protective, blocks dramatically the nociceptive afferent pathways. Relief of pain permits the patient to focus on the rehabilitation of his extremity and improve its dexterity and overall function, which returns many months later.
SECONDARY PROCEDURES Procedures such as muscle transfers and wrist fusion are necessary to improve function, especially in late cases where the muscle targets have atrophied. Pedicled muscle or tendon transfers46} 49 are used to enhance the function of the paretic arm. Advances in microsurgery brought the era of free functional muscle transfer to brachial plexus paralysis management.50}52 The transferred free muscles are neurotized either by previously banked nerve grafts or directly from local motor donors (e.g. intercostal nerves). The most commonly restored functions are elbow flexion and extension, finger flexion and extension and, in some cases, shoulder abduction and intrinsic substitution. Latissimus dorsi and rectus femoris transfer, are good candidates for elbow flexion restoration. For hand reanimation, gracilis and rectus femoris can be used.25 Some surgeons prefer to restore two functions with one muscle transfer i.e. elbow flexion and finger flexion or elbow extension and finger extension.52,53
OUTCOME OF RECONSTRUCTION Important factors determining the prognosis of the lesion are the age of the patient, the denervation time, meaning the time interval between the injury and the surgery, and the severity score, which is a scale introduced by Terzis to grade the degree of root injury at exploration.25 The consensus today is that the best results are obtained in younger patients with short denervation time (less than 6 months) and higher severity score.25,54}56
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Most authors report better results in upper root palsies and there are two reasons for this. Firstly, the hand is spared and secondly, the muscle targets of reconstruction are closer to the plexus. The later also explains the better outcome for proximal muscles e.g. supraspinatus, biceps, etc. Many authors25,45,55,57}59 prefer to use intraplexus motor donors for neurotizations, when they are available, since they give better results. The reason for this is that the intraplexus donors have a greater number of axons than the extraplexus ones and therefore the chances for successful neurotization are greater. It seems that some of the extraplexus donors give consistently superior results when they are used with specific targets (i.e. shoulder and elbow). The use of intercostal nerves to directly neurotize the musculocutaneous continue to be a standard approach in the reconstruction of severe plexus lesions, especially avulsions. The results are good to excellent (more than M3) in 60}70% of the patients.13,25,45,59,60}62 Ogino and Naito63 consider intercostal transfer as a useful procedure to provide elbow flexion and protective sensation to the hand. The accessory nerve is another reliable donor. Direct neurotization of the suprascapular nerve yields results comparable to repair using intraplexus donors. Neurotization of the suprascapular nerve gives 75% good or excellent (M3# to M4#) results.25 Millesi13 reported that neurotization of the suprascapular and axillary nerves with the accessory nerve gave stability to the shoulder in more than 60% of patients. Various authors28,43,62,64 reported good to excellent result (M3# or more) in 55}80% of patients, with respect to recovery of biceps function after transfer of the spinal accessory nerve to the musculocutaneous nerve. Other extraplexus donors give less rewarding results; the explanation for this, in the case of cervical plexus motors, is probably related to the fact that a small number of fibres destined initially for short distances are now being forced on a long journey. In the case of the contralateral C7, the length of the cross-chest nerve grafts imposes necessary delay prior to target connection. Gu et al.54,65 showed good results in 75% of musculocutaneous neurotization with the phrenic, as well as recovery of the biceps up to M3 in 60% of the case and recovery of the triceps up to M4 in 50% of cases with contralateral C7 neurotizations. The results were good in 50% of the suprascapular and axillary neurotizations with motor branches of the cervical plexus. Cervical plexus motors and contralateral C7 gave, overall, an inferior outcome in relation to hand reanimation.25 Restoration of hand function remains the most difficult task for the reconstructive microsurgeon. Nevertheless, it must always be pursued, despite the fact that the results of hand reanimation using neurotizations are not
82 as successful as elbow flexion restoration. The good results range from 15 to 40% in various series regarding finger extension and flexion, regardless of the donor nerve that is used for neurotization of the radial and median nerves.25,45,54,66 If we can find means to preserve the muscle targets, especially the distal ones, we believe that we can expect better functional restoration in the hand. In global avulsions, in late cases, or in the reconstruction of distal targets such as the hand, free muscle transfers and other secondary procedures can improve the final outcome.25,53,67 From the above reports, it seems that certain muscle groups (shoulder abductors and external rotators, supinators and extensors) have an inferior response to reconstruction. Narakas and Hentz45 mentioned that this paradox could be explained partially, on the basis of embryological origin of the various muscles. It seems that the upper extremity is built to give preference of restoration of the flexors, which are vital for the survival of the organism.
CONCLUSIONS Post-traumatic brachial plexus injuries represent a challenge to the reconstructive microsurgeon. Usually these are devastating lesions, the product of highvelocity injuries. Early, aggressive, microsurgical reconstruction should be the method of choice in the management of these injuries. The current sophisticated techniques of nerve reconstruction (neurotizations utilizing every available ipsilateral and contralateral intraplexus and extraplexus donors, with conventional and/or vascularized nerve grafts), in combination with secondary free functional muscle transfers, give a satisfactory outcome even in multiple avulsion injuries. Amputation is no longer an option today, even in the face of global avulsion.
REFERENCES 1. Stevens J H. Brachial plexus paralysis. In: Godman E A (ed). The Shoulder. Brooklyn, NY; G Mill, 1934. 2. Barnes R. Traction injuries of the plexus in adults. J. Bone Jt Surg 1949; 31B: 10}16. 3. Larsen E H. Injuries of the brachial plexus in adults. J Bone Jt Surg 1955; 37B: 733}734. 4. Tracy J F, Brannon E W. Management of brachial plexus injuries (traction type). J Bone Jt Surg 1958; 40(A): 1031. 5. Bonney G. Prognosis in traction lesions of the brachial plexus. J Bone Jt Surg 1959; 41B: 4}35. 6. Leffert R D, Seddon H. Infraclavicular brachial plexus injuries. J Bone Jt Surg 1965; 49B: 9}22. 7. Nelson K G, Jolly P C, Thomas P A. Brachial plexus injuries associated with missile wounds of the chest. A report of 9 cases from Vietnam. J Trauma 1968; 8: 268}275. 8. Flether I. Traction lesions of the brachial plexus. Hand 1969; 1: 29.
CURRENT ORTHOPAEDICS
9. Wynn Parry C B. Rehabilitation of patients following traction injuries of the brachial plexus. Hand Clin 1995; 11(4): 517}533. 10. Kurze T. Microtechniques in neurological surgery. Clin Neurosurg 1964; 11: 128}137. 11. Millesi H. Brachial plexus injuries. Management and results Clin Plast Surg 1984; 11: 115}120. 12. Narakas A. The surgical management of brachial plexus injuries. In: Daniel R K, Terzis J K (eds). Reconstructive Microsurgery. vol. 1 Boston: Little-Brown, 1977. 13. Millesi H. Nerve grafting. Clin Plast Surg 1984; 11: 105}113. 14. Terzis J K, Faibisoff B, Williams B. The nerve gap: suture under tension vs graft. Plast Reconstr Surg 1975; 56(2): 166}170. 15. Murphey F, Hartung W, Kirklin J W. Myelographic demonstration of avulsing injury of the brachial plexus. Am J Roentgenol 1947; 58(1): 102}105. 16. Marshall R W, De Silva R D D. Computerized axial tomography in traction injuries of the brachial plexus. J Bone Jt Surg 1986; 68B: 734}738. 17. Nakamura T, Yabe Y, Horiuchi Y, Takayama S. Magnetic resonance myelography in brachial plexus injury. J Bone Jt Surg 1997; 79B: 764}769. 18. Hodes R R, Larrabee M C, German W. The human electromyogram in response to nerve stimulation and the conduction velocity of motor axons. Arch Neurol Psychiatr 1948; 60: 340. 19. Dawson G D, Scott J W. The recording of nerve action potentials through skin in man. J Neurol Neurosurg Psychiatr 1949; 12: 259. 20. Liberson W T, Terzis J K. Contribution of clinical neurophysiology and rehabilitation medicine to the management of brachial plexus palsy. In: Terzis J K (ed). Microreconstruction of Nerve Injuries. Philadelphia: W B Saunders, 1987. 21. Carson K A, Terzis J K. Carbonic anhydrase histochemistry: a potential diagnostic method for peripheral nerve repair. Clin Plast Surg 1985; 12: 227}232. 22. Kanaya F, Ogden L, Breidenbach W C, Tsai T M, Scheker L. Sensory and motor fiber differentiation with Karnovsky staining. J Hand Surg 1991; 16(A): 851}858. 23. Oberle J, Antoniadis G, Rath S A et al. Radiological investigations and intra-operative evoked potentials for the diagnosis of nerve root avulsion: evaluation of both modalities by intradural root inspection. Acta Neurochir (Wien) 1998; 140: 527}531. 24. Turkof E, Millesi H, Turkof R, Pfundner P, Mayr N. Intraoperative electroneurodiagnostics (transcranial electrical motor evoked potentials) to evaluate the functional status of anterior spinal roots and spinal nerves during brachial plexus surgery. Plast Reconstr Surg, 1997; 99: 1632}1641. 25. Terzis J K, Vekris M D, Soucacos P N. Outcomes of brachial plexus reconstruction in 204 patients with devastating paralysis Plast Reconstr Surg 1999; 104(5): 1221}1240. 26. Magalon G, Bordeaux J, Legre R. Emergency vs delayed repair of severe brachial plexus injuries. Clin Orthop 1988; 237: 32}35. 27. Brunelli G A, Brunelli G R. Preoperative assessment of the adult plexus patient. Microsurgery 1995; 16: 17}21. 28. Alnot J. Traumatic brachial plexus lesions in the adult. Indications and results. Hand Clin 1995; 11(4): 623}631. 29. Sedel L. Repair of severe traction lesions of the brachial plexus. Clin Orthop 1988; 237: 62}66. 30. Taylor G I, Ham F J. The free vascularized nerve graft: a further experimental and clinical application of microvascular techniques. Plast Reconstr Surg 1976; 57: 413}426. 31. Daniel R K. Terzis J K, Schwarz G. Neurovascular free flaps. A preliminary report. Plast Reconstr Surg 1975; 56(1): 13}20. 32. Terzis J K, Breidenbach W. The anatomy of free vascularized nerve grafts. In: Terzis J K (ed). Microreconstruction of Nerve Injuries. Philadelphia: W B Saunders, 1987. 33. Yeoman P M, Seddon H J. Brachial plexus injuries. Treatment of the flail arm. J Bone Jt Surg 1961; 43B: 493.
POST-TRAUMATIC BRACHIAL PLEXUS PARALYSIS: CURRENT MANAGEMENT OF RECONSTRUCTION
34. Brunelli, G. Neurotization of avulsed roots of the brachial plexus by means of anterior nerves of the brachial plexus. Int J Microsurg 1980; 2: 55}58. 35. Gibert A. Neurotization by contralateral pectoral nerve. Presented at the 10th Symposium on the Brachial Plexus, Lausanne, Switzerland, 1992. 36. Allieu Y, Privat J M, Bonnel F. Paralysis in root avulsion of the brachial plexus: neurotization by the spinal accessory nerve. Clin Plast Surg 1984; 11: 133}136. 37. Narakas A. Thoughts on neurotization or nerve transfers in irreperable nerve lesions. Clin Plast Surg 1984; 11: 153}159. 38. Chuang D. Neurotization procedures for brachial plexus injuries. Hand Clin 1995; 11(4): 633}645. 39. Gu Y D, Wu M M, Zhen Y L et al. Phrenic nerve transfer for brachial plexus motor neurotization. Microsurgery 1989; 10: 287}289. 40. Gu Y D, Zhang G M, Chen D S et al. Cervical nerve root transfer from contralateral normal side for treatment of brachial plexus root avulsion. Chin Med J (Engl) 1991; 104: 208}211. 41. Terzis J K. Contralateral C7: a powerful source of motor neurons for devastating brachial plexus paralysis. Presented at the 7th annual meeting of European Association of Plastic Surgeons, Innsbruck, Austria, 1996. 42. Loy S, Bhatia A, Asfazadourian H, Oberlin C. Ulnar nerve fascicle transfer onto to the biceps muscle nerve in C5}C6 or C5}C6}C7 avulsions of the brachial plexus. Eighteen cases. Ann Chir Main Memb Super 1997; 16: 275}284. 43. Bentolila V, Nizard R, Bizot P, Sedel L. Complete traumatic brachial plexus palsy. Treatment and outcome after repair. J Bone Surg 1999; 81(A): 20}28. 44. Friedman A H, Nashold Jr B S, Bronec P R. Dorsal root entry zone lesions for the treatment of brachial plexus avulsion injuries: a follow-up study. Neurosurgery 1988; 22(2): 369}373. 45. Narakas A, Hentz V. Neurotization in brachial plexus injuries: indications and results. Clin Orthop 1988; 237: 43}56. 46. Zancolli E A, Zancolli E R. Palliative surgical procedures in sequelae of obstetrical palsy. Hand Clin 1988; 4: 643}669. 47. Marshall R W, Williams D H, Birch R, Bonney G. Operations to restore elbow flexion after brachial plexus injuries. J Bone Jt Surg 1988; 70B: 577}582. 48. Aziz W, Singer R M, Wolff T W. Transfer of the trapezius for flail shoulder after brachial plexus injury. J Bone Jt Surg 1990; 72B: 701}704. 49. Brunelli G A, Vigasio A, Brunelli G R. Modified Steindler procedure for elbow flexion restoration. J Hand Surg 1995; 20A: 743}746. 50. Manktelow R T, McKee N H. Free muscle transplantation to provide active finger flexion. J Hand Surg 1978; 3: 416}426.
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51. Terzis J K, Sweet R C, Dykes R W, Williams H B. Recovery of function in free muscle transplants using microneurovascular anastomoses. J Hand Surg Am 1978; 3(1): 37}59. 52. Doi K. New reconstructive procedure for brachial plexus injury. Clin Plast Surg, 1997; 24: 75}85. 53. Berger A, Becker M. Brachial plexus surgery: our concept of the last twelve years. Microsurgery 1994; 15: 760}767. 54. Gu Y, Wu M, Zheng Y et al. Microsurgical treatment for root avulsion of the brachial plexus. Chinese Med J 1987; 100(7): 519}522. 55. Hentz V, Narakas A. The results of microneurosurgical reconstruction in complete brachial plexus palsy. Assessing outcome and predicting results. Orthop Clin North Am 1988; 19(1): 107}114. 56. Nagano A. Treatment of brachial plexus injury. J Orthop Sci 1998; 3: 71}80. 57. Allieu Y, Cenac P. Neurotization via the spinal accessory nerve in complete paralysis due to multiple avulsion injuries of the brachial plexus. Clin Orthop 1988; 237: 67}74. 58. Allieu Y, Chammas M, Picot M C. Paralysis of the brachial plexus caused by supraclavicular injuries in the adult. Long-term comparative results of nerve grafts and transfers Rev Clin Orthop Reparatrice Appar Mot 1997; 83: 51}59. 59. Kawai H, Kawabata H, Masada K, Ono K, Yamamoto K, Tsuyuguchi Y, Tada K. Nerve repairs for traumatic brachial plexus palsy with root avulsion. Clin Orthop 1988; 237: 75}86. 60. Nagano A, Tsuyama N, Ochiai N, Hara T, Takahashi M. Direct nerve crossing with the intercostal nerve to treat avulsion injuries of the brachial plexus. J Hand Surg 1989; 14(6): 980}985. 61. Malessy M J, Thomeer R T. Evaluation of intercostal to musculocutaneous nerve transfer in reconstructive brachial plexus surgery. J Neurosurg 1998; 88: 266}271. 62. Waikakul S, Wongtragul S, Vanadurongwan V. Restoration of elbow flexion in brachial plexus avulsion injury: comparing spinal accessory nerve transfer with intercostal nerve transfer. J Hand Surg 1999; 24(A): 571}577. 63. Ogino T, Naito T. Intercostal nerve crossing to restore elbow flexion and sensibility of the hand for a root avulsion type of brachial plexus injury. Microsurgery 1995; 16: 571}577. 64. Songcharoen P, Mahaisavariya B, Chotigavanich C. Spinal accessory neurotization for restoration of elbow flexion in avulsion injuries of the brachial plexus. J Hand Surg 1996; 21(A): 387}390. 65. Gu Y D, Chen D S, Zhang G M et al. Long-term functional results of contralateral C7 transfer. J Reconstr Microsurg 1998; 14: 57}59. 66. Sedel L. The results of surgical repair of brachial plexus injuries. J Bone Jt Surg 1982; 64(B): 54}66. 67. Chung D C, Carver N, Wei F C. Results of functioning free muscle transplantation for elbow flexion. J Hand Surg 1996; 21(A): 1071}1077.