External Neurolysis Research Articles

Surgical management and results of 135 tibial nerve lesions at the Louisiana State University Health Sciences Center.

This retrospective study presents 33 years of clinical and surgical experience with 135 tibial nerve lesions to review operative techniques and their results and to provide management guidelines for the proper selection of surgical candidates. Between 1967 and 1999, 135 patients with tibial nerve lesions at the knee level or below were managed surgically at the Louisiana State University Health Sciences Center. We reviewed these cases. Of the 135 cases, traumatic injury accounted for 71, tarsal tunnel syndrome for 46, and nerve sheath tumor for 18. Of 22 lesions not in continuity, functional recovery of Grade 3 or better was achieved in 4 (67%) of 6 patients who required end-to-end suture repair and 11 (69%) of 16 patients who required graft repair. One hundred thirteen tibial nerve lesions in continuity underwent primarily external or internal neurolysis or resection of the lesions. A few received end-to-end suture or graft repair. Direct intraoperative recording of nerve action potentials guided case management decisions. Among the 113 patients with lesions in continuity, 76 (81%) of 94 patients receiving neurolysis, 5 (83%) of 6 receiving suture repair, and 11 (85%) of 13 receiving graft repair recovered function to Grade 3 or better. Repair results were best in patients with recordable nerve action potentials treated by external neurolysis. Results were poor in a few patients with very lengthy lesions in continuity and in reoperated patients with tarsal tunnel syndrome. Surgical exploration and repair of tibial nerve lesions, including nerve sheath tumors and tarsal tunnel syndromes, achieved excellent outcomes.

Decompression of peripheral nerves for diabetic neuropathy in the lower extremity

Consideration of the presence of a compressive neuropathy overlying an existing diabetic neuropathy in symptomatic patients and surgical decompression of these compressed nerves in selected patients is presented. The short-term results of 33 lower extremities treated with external neurolysis of the common peroneal, deep peroneal, and tarsal tunnel nerves are presented with a mean follow-up time of 3 months (range, 1 to 6 months). The surgery was performed in an attempt to relieve pain and to restore normal sensation in the foot. All procedures were performed under spinal or general anesthesia. Candidates for the procedure were type 1 or type 2 diabetics with symptomatic somatosensory neuropathy (pain, burning, tingling, and/or numbness) and preoperative computer-assisted neurosensory testing that confirmed the presence of elevated nerve threshold levels and axonal degeneration in the foot and leg. External neurolysis of the involved nerves provided good to excellent results in 90.0% of those patients with preoperative neuropathic pain, and restored sensation at good to excellent levels in 66.7% of those patients with preoperative neuropathic numbness. The mean visual analog score for pain assessment was 9.0 preoperatively and 3.2 postoperatively for those patients with pain as a symptomatic complaint (n = 30). There were 4 complications (12%) and all were early cases consisting of a noninfected wound dehiscence of the tarsal tunnel incision, which went on to heal without consequence. These initial short-term results suggest that external neurolysis of the common peroneal, deep peroneal, and tarsal tunnel nerves in selected patients with symptomatic diabetic neuropathy and an overlying compression neuropathy as determined by using computer-assisted neurosensory testing appears to be an effective treatment for providing pain relief and restoration of sensation in the foot.

Le lambeau à « voile carrée » dans les lésions du nerf médian au poignet. Éléments d’anatomie et revue de vingt cas opérés

Following an anatomical study on the vascular supply of the upper limb, we propose a new adipo-fascial flap at the wrist. The fat pad of pronator quadratus lies over the muscle and is vascularised by a recurrent branch arising from the anastomotic "cross-road" of the anterior interosseous, radial and ulnar arteries, at the radio-carpal joint. The peripheral extensions of the adipose tissue have to be anchored to the palmar fascia of the muscle in order to hoist the flap as a "square sail". The flap is then distally rotated in order to cover the traumatized median nerve segment at the wrist, for 2.5-3 cm of length. The authors present a review of the clinical applications (1995-2001) on painful neuromas of the median nerve at the wrist, where traumatic and iatrogenic injuries frequently occur. The surgical procedure consists of external neurolysis followed by coverage of the nerve using this vascularised flap. The results confirm the usefulness of vascularised fat flaps in creating an optimal perineural environment in terms of biological and mechanical quality. The advantage offered by this particular local flap is that it can be speedily raised. Because of its limited length the flap is only able to cover the median nerve at the level of the carpal tunnel: its indications are therefore very selective but not rare, due to the frequency of median nerve injuries at this level. Clinical results were very satisfactory: in the twenty cases reviewed, resolution of the symptoms of algodystrophy and causalgia was consistently observed, sometimes to an extraordinary degree, and associated with an improvement in the neurological deficit.

Nontraumatic paralysis of the radial nerve with multiple constrictions

Purpose: To present an uncommon lesion of radial nerve paralysis with multiple constrictions. Method: Eight patients were treated in our department between January 1994 and August 2000. There were 4 men and 4 women with a mean age of 26 years (10-43 y). The radial nerves of all patients were explored. There were 1 to 5 segmental constrictive lesions at the main trunks of the radial nerves or the posterior interosseous nerves; no obvious extrinsic compression was noted. Epineurolysis was performed in 3 patients, in the other 5 patients the constricted portions of the nerves were resected, and neurorrhaphy was performed in 2 patients, nerve-grafting in 3. Histologic examination of the resected portions showed concentration of inflammatory cells around the vessels in the perineurium. Results: The patients were followed-up for 6 months to 4 years after surgery. Seven patients had at least grade 4 muscle strength in the involved muscles. One patient who was treated by external neurolysis 15 months after onset had no signs of recovery 10 months after surgery. Conclusions: Nontraumatic paralysis of the radial nerve with multiple constrictions is very uncommon. The etiology may be a focal inflammatory response around the feeding arteries in the perineurium. (J Hand Surg 2003;28A:199-205.

External neurolysis of the lingual nerve

The lingual nerve is sometimes injured during the surgical removal of an impacted mandibular third molar. The level of sensory recovery was studied in 10 patients who underwent external neurolysis of the lingual nerve. The mean time from third molar surgery to neurolysis was 13.5 months (range 9–24 months). Seven of the 10 patients showed significant improvement, three patients regaining normal sensation. Three patients showed no improvement. These results show that external neurolysis should be considered for patients with altered sensation in the distribution of the lingual nerve.

Evaluation of the Late Neurologic Deficits Accompanied by Hypertrophic Scars and Keloids in Children With Elbow Fractures

In this study, the relation between hypertrophic scar and keloid (HSc) lesions around incisions and late neurologic deficits was investigated in operated elbow fractures in children. Six elbow fracture patients with HSc lesions were evaluated for neurologic deficits with late onset. The fractures were all closed and treated with open reduction and internal fixation. No neurologic deficit was detected before surgery and in the early postoperative periods. Late neurologic deficits observed in these patients were evaluated according to British Medical Research Committee scoring scale on admission and after therapy. In the reoperations for neurologic deficits, the nerve segments were found to be compressed in intensive scar tissue. Typical pseudoneuromas were observed in the proximal part of compression; however, the corporal integrity of the nerves was not interrupted. External neurolysis were performed in all patients. Excellent improvements in sensory and motor functions were detected and no recurrence occurred in follow-up. Elbow fracture patients, especially those with HSc lesions around their incisions, should be followed up for possible neurologic deficits with late onset.

Anterior intramuscular transposition with ulnar nerve decompression at the elbow.

The effectiveness of decompression and anterior intramuscular transposition of the ulnar nerve for treatment of severe cubital tunnel syndrome was evaluated. A consecutive series of 39 anterior intramuscular transpositions were reviewed. One surgeon performed the transpositions between 1993 and 1997 in 34 patients who presented with clinically severe cubital tunnel syndrome. Clinical outcome and satisfaction with surgery were assessed. The results showed early clinical improvement of 77% of patients (mean followup, 3.34 months). With repeated assessments later, the same group of patients had clinical improvement of 62% (mean followup, 30.9 months). Patients younger than 50 years, individuals who underwent external neurolysis, or patients who had a previously failed subcutaneous transposition had fewer satisfactory results.

Decompression of the common peroneal nerve: experience with 20 consecutive cases.

A retrospective review of 20 patients with common peroneal nerve palsy treated with decompression between 1986 and 1997 was undertaken. Subjects were evaluated preoperatively and postoperatively by electromyography, nerve conduction, and clinical measures. The mean interval between the onset of symptoms to surgery (operative delay) was 15.9 months. The mean postoperative follow-up was 32.2 months with a minimum follow-up of 1 year. Decompression was performed at the level of the fibular neck and slightly distally at the tendinous origin of the peroneus longus using a standard approach to release tight fascial structures or scar tissue. External neurolysis was performed using the operating microscope in two cases for which scarring of the nerve was identified intraoperatively. Postoperatively, 19 of 20 patients showed improvement in ankle dorsiflexion as assessed by the Medical Research Council scale. Electromyographic examination was useful in the preoperative evaluation and selection of patients for decompression surgery. In conclusion, decompression even after a 1-year delay may offer benefit and suggest early intervention in patients with a severe lesion.

Analysis of release of the first branch of the lateral plantar nerve

The authors conducted a retrospective study of the release of the first branch of the lateral plantar nerve in the treatment of chronic heel pain unrelieved by conservative treatment modalities. A total of 17 patients (18 feet) were evaluated following external neurolysis for heel pain caused by entrapment of the first branch of the lateral plantar nerve. The average postoperative follow-up time was 32.8 months, with a range of 10 to 72 months. Every patient deemed the surgery successful. At the time of follow-up examination, nine feet were asymptomatic and nine feet experienced mild pain after extended activity. There was one postoperative complication, medial calcaneal nerve entrapment; it was successfully treated with neurectomy.

Compression of the ulnar nerve in Guyon's canal by uremic tumoral calcinosis

We describe the case of a 70-year-old woman with chronic renal failure on haemodialysis presenting with an ulnar nerve compression in Guyon's canal secondary to uremic tumoral calcinosis. Excision of calcium deposits and external neurolysis of the ulnar nerve were successfully performed. Simultaneously, the hyperphosphatemia and hypercalcemia were corrected. The pathogenesis of this condition is different from primary tumoral calcinosis. Clinical and radiological features and therapy are discussed. Uremic tumoral calcinosis is an unusual etiology of ulnar nerve compression in Guyon's canal not previously reported in dialysis patients.

Bilateral suprascapular nerve entrapment syndrome associated with rotator cuff tear

A 51-year-old man had bilateral posterior aching of the shoulder and atrophy of the supraspinatus and infraspinatus muscles caused by suprascapular nerve entrapment syndrome associated with rotator cuff tears. Electromyography and a nerve conduction study revealed denervation potentials and delayed nerve conduction velocities. Cutting of the superior transverse scapular ligament and external neurolysis of the nerve on both sides followed by anterior acromioplasty brought diminished pain, weakness, and atrophy of the supraspinatus and infraspinatus muscles. Although suprascapular nerve entrapment syndrome is an infrequently recognized cause of disability in the shoulder region, awareness of its clinical presentation (referred shoulder pain with associated weakness and atrophy of the supraspinatus and infraspinatus muscles) can lead to a correct early diagnosis. So far a bilateral suprascapular nerve entrapment syndrome has rarely been described.1,3,5 To

Pronator Teres Syndrome Associated with Mononeuritis Multiplex in Polyarteritis Nodosa.

A case of pronator teres syndrome associated with mononeuritis multiplex in polyarteritis nodosa is reported. External neurolysis of the median nerve at the proximal forearm and prednisolone were effective for treatment of the disease.

Compression syndromes of the axillary nerve and the suprascapular nerve

We report on seven patients with altogether four paralyses of the axillary and six paralyses of the suprascapular nerve without a singular trauma. In one patient, the paralysis of the axillary nerve developed spontaneously over night after a period of habitual dislocations of the shoulder joint. Another patient developed a paralysis of the suprascapular nerve after prolonged wearing of a rucksack. Three of the remaining five patients developed both an axillary and suprascapular paresis without any preceeding trauma or irritation. In two further patients, an isolated suprascapular paralysis developed without trauma. An analysis of the intraoperative findings in these five patients shows in all cases adhesions of the nerve with the surrounding tissues at the site of the suprascapular notch respectively the quadrilateral space. In all three cases of axillary nerve paralysis there was in addition a narrow quadrilateral space. However only in three of five suprascapular nerve lesions there was a narrow suprascapular notch. In the two remaining cases adhesions alone had caused the paralysis and produced a serpentine deformity of the nerve. It is concluded that inflammatory processes cause the paralysis and the adhesions. Compression in the narrow space and fibrous changes are responsible for maintaining the paralysis after the inflammation has subsided. Macroscopically unchanged nerves underwent external neurolysis. With fibrous changes an epineuriotomy and with more pronounced changes an epineuriectomy were performed. The results are discussed.

Retrospective analysis of neurapraxia and axonotmesis injuries of select peripheral nerves of the foot and ankle and their conservative and surgical treatment (external neurolysis and neurectomy)

There is a paucity of scientific literature that has reviewed the conservative and surgical treatment efficacy for the management of injuries causing neurapraxia and axonotmesis. This retrospective study evaluates the clinical outcomes of certain treatments for these injuries. Twenty-seven patients fulfilled the inclusion/exclusion criteria for the study, and represented both genders and a wide variety of ages, weights, levels of education, and backgrounds. Surgical intervention resulted in a slightly better clinical outcome when compared to conservative therapies. Patients undergoing surgery for a single nerve problem improved more than those who underwent surgery when three or more nerves were involved. Failure was most often associated with: 1) multiple nerve injuries, 2) a previous history of psychopathology, and 3) application of conservative therapy without surgical intervention for single nerve injury.

The effect of aprotinin on extraneural scarring in peripheral nerve surgery: an experimental study.

Extraneural scarring is one of the factors negatively influencing the result of peripheral nerve surgery. Many organic materials have been used to prevent fibrosis. The effect of aprotinin on peripheral nerve scarring in rats was investigated in this study. Three types of surgical intervention were carried out; namely external neurolysis (I), abrasive injury (II), and anastomosis (III). The coded samples which consisted of pure collagen fibers soaked with aprotinin or phosphate-buffered saline were applied around the left sciatic nerves of rats whereas only sham operations were performed on the right sciatic nerves. Animals were sacrificed after 4 or 6 weeks. Neurological examination, gross evaluation of extraneural fibrosis, and histological study were undertaken. The results have demonstrated that aprotinin is a promising agent in the prevention of extraneural scarring.

Management of true recurrent carpal tunnel syndrome: is it worthwhile to bring vascularized tissue?

Since 1989, 13 consecutive cases of true recurrent carpal tunnel have been operated on. Average delay before reoperation was 20 months (3 to 60 months). Intraoperative findings were univocal: extensive fibrosis with nerve adhesion to the roof of the carpal tunnel and a lack of nerve gliding. Surgery performed was: extensive external neurolysis from distal forearm to distal to carpal tunnel to allow a complete freedom of the nerve. A vascularized flap was never performed. Mean follow-up was 27.5 months (range 4 to 74 months). Results were: complete relief of symptoms in 75%; improvement with complete disappearance of nocturnal symptoms but persistent dysesthesia in 17%; no improvement in one patient (Sudeck's dystrophy). Interests of this study are: homogeneous population (only true recurrence), no bias from work compensation, consecutive cases, one surgeon, standardized surgical procedure and one independent observer. Results suggest that main factor for true recurrent carpal tunnel syndrome is lack of normal gliding of the nerve and that an extensive neurolysis helps to restore this gliding.

Value of nerve action potentials in the surgical management of traumatic nerve lesions.

The goals of the study were to investigate the value of intraoperative electrically evoked nerve action potentials (NAPs) in the surgical treatment of traumatic peripheral nerve injuries (nerve lesions in continuity). Sixty-four patients with 76 traumatic nerve lesions in continuity were investigated intraoperatively by stimulating and recording NAP from the whole nerve across the suspected lesion site. Among the 76 nerves (nerve lesions) were 43 with incomplete and 33 with complete loss of function. In cases (nerves) with complete loss of function (n = 33), the surgical procedure (external neurolysis, internal neurolysis, or nerve repair) was performed according to the microscopic aspect of the nerve and the result of the intraoperative electrophysiological testing. In cases (nerves) with incomplete loss of function (n = 43), the surgical procedure was performed solely according to the microscopic aspect of the nerve and independently from the result of the intraoperative electrophysiological testing. Of 43 nerves with incomplete loss of function, we were able to record reproducible NAPs in 41 (95%) across the lesion site, thus demonstrating a high reliability of the method. Of 33 nerves with complete loss of function, a reproducible NAP could be recorded only in 3. Assuming an axonotmetic lesion in regeneration, we did nothing else on the nerve with excellent clinical results (full recovery). Of the remaining nerves with no NAP, 24 showed a caliber shift of the nerve (in 20 cases a thickening of the nerve, suggesting a neuroma in continuity). A grafting procedure was performed, and the histological evaluation revealed a neurotmetic lesion. However, in six patients with no NAP, there was no clear caliber shift of the nerve. The epineurium was opened and an internal neurolysis performed showing fascicles in continuity. Three patients had good and three had partial (but useful) recovery. In nerve lesions in continuity with complete loss of nerve function, intraoperative NAPs are able to detect axonotmetic lesions in regeneration. Thus, unnecessary further surgical procedures can be avoided. On the other end of the spectrum, no recordable NAP together with a caliber shift of the nerve (suggesting a neuroma in continuity) may facilitate the surgeon's decision for a grafting procedure without a time-consuming internal neurolysis. But there is also evidence from our data that not every nerve lesion in continuity without a NAP needs to be grafted.

INJURY TO THE BRACHIAL PLEXUS BY A FRAGMENT OF BONE AFTER FRACTURE OF THE CLAVICLE

Clavicular fractures are occasionally responsible for lesions of the brachial plexus. The symptoms are usually delayed and due to compression by hypertrophic callus, nonunion or a subclavian pseudoaneurysm. We describe a patient in whom a displaced bone fragment was pressing on the retroclavicular part of the brachial plexus, leading to early symptoms of a lesion of the posterior cord. Internal fixation of the clavicle and external neurolysis of the brachial plexus gave an almost full recovery.

ADCON®-T/N reduces in vivo perineural adhesions in a rat sciatic nerve reoperation model

Excessive perineural scarring may affect the result of peripheral nerve surgery. The ability of a novel implant material (ADCON-T/N) to prevent this complication was tested in 38 rats. Four weeks after a bilateral sciatic nerve external neurolysis, a secondary bilateral lysis of the adhesions was performed; ADCON-T/N was locally implanted at one side, while the contralateral side was left untreated. Four or 8 weeks later, perineural adhesions were dissected in 24 animals and graded blindly. Significantly fewer perineural adhesions were found in ADCON-T/N treated nerves compared with controls at both 4 and 8 weeks. Residual implant material or adverse effects were not observed at either time. Histological examination of the neurolysis sites in another 14 animals confirmed these findings at both time intervals. This study shows that ADCON-T/N is effective in inhibiting perineural adhesions, is resorbed within 4 weeks and is well tolerated.

Circumferential wrapping of a flap around a scarred peripheral nerve for salvage of end-stage traction neuritis

Nine patients with chronic severe pain due to end-stage traction neuritis of an intact peripheral nerve underwent external neurolysis and epineurectomy or epineurectomy and internal neurolysis followed by circumferential wrapping of the involved segment of nerve with a pedicle flap or free flap consisting of either subcutaneous fat tissue, fascia, or muscle. Seven patients (77%) followed for between 1 and 5 years had substantial relief of pain. Two patients (22%) had no decrease in their pain at all. Circumferential wrapping may cushion the nerve from external pressure on the overlying skin, may isolate the nerve from the traction forces of adjacent moving tendons to allow improved gliding of the nerve, and may promote revascularization of a scarred nerve. This surgery may be indicated for patients with persistent pain following multiple carpal tunnel or cubital tunnel surgeries.