Akira Nagano

Direct nerve crossing with the intercostal nerve to treat avulsion injuries of the brachial plexus

One hundred seventy-nine patients with root avulsion brachial plexus injuries were treated with direct nerve crossing with the intercostal nerve and 159 cases were followed more than 1 1/2 years after the operation. When suture was done to the musculocutaneous nerve, 90% of 10 children who had operation within 7 months of injury and 81.8% of 110 adults, younger than 40 years with operation within 6 months of injury regained grade 3 or 4 elbow flexion power. This direct method seems to produce better results than those of nerve crossing, which uses intermediary nerve grafts.

Usefulness of Myelography in Brachial Plexus Injuries

Ninety brachial plexus lesions have been examined by myelography and the results classified into six types. These were compared against the level of lesion found at exploration of the brachial plexus with electrophysiological investigations carried out during the operation. The results show that myelography can be a reliable and useful pre-exploratory measure to assess the level of the lesion of each injured root.

Restoration of elbow flexion in root lesions of brachial plexus injuries

A retrospective review of 87 patients with loss of elbow flexion secondary to root injuries of the brachial plexus was carried out. Results of nerve grafting, direct nerve transfer with the intercostal nerve, or tendon transfer were analyzed, and treatment recommendations were developed. Nerve transfer provided good or excellent results for injuries that included avulsion of the C5 and/or C6 roots. Nerve grafts were used successfully in cases of single or combined ruptures of C5 and C6. Tendon transfers provided good or excellent results in C5-C6 or C5-C7 avulsions, where nerve grafting was not possible and transferable muscles had good strength. Somatosensory evoked potentials were necessary to demonstrate nerve root avulsions in cases in which the roots appeared ruptured on visual inspection.

Spontaneous anterior interosseous nerve palsy with hourglass-like fascicular constriction within the main trunk of the median nerve

Interfascicular neurolysis was performed in nine patients with spontaneous anterior interosseous nerve palsy. In eight of these patients, an hourglass-like constriction in the fascicles forming the anterior interosseous nerve was found within the main trunk of the median nerve at 2-7.5 cm above the medial epicondyle. The clinical signs and symptoms of these eight patients were similar to those that have been described to isolated neuritis. While the etiology remains unknown, when spontaneous anterior interosseous nerve palsy is suspected to be caused by isolated neuritis, interfascicular neurolysis should be performed to confirm the lesion and to discover whether fascicular constriction is present.

Arc osteotomy of the humerus to correct cubitus varus.

The appearance of the elbow after corrective osteotomy for cubitus varus often is different from that of the unaffected side, even if the carrying angle of the affected side is corrected to match that of the unaffected side. Not only must the carrying angle formed by the humerus and the ulna be corrected, but the lateral shift between the humeral axis and the ulnar axis also should be corrected to achieve a matching appearance after corrective osteotomy. Based on this concept, a technique of arc osteotomy was developed to correct simultaneously both the angle and the lateral shift of the affected elbow joint to match those of the unaffected side. This new method has been used to treat 12 patients. The length of followup averaged 28 months, with a range of 8 to 70 months. The carrying angle was corrected from 22° varus on average to 6° valgus on average, with a difference between the right and left side of 2° on average. No complication was observed during the treatment. The average range of motion of the elbow joint was from 0° extension to 125° flexion preoperatively and from 6° hyperextension to 134° flexion postoperatively.

RESULTS OF NERVE GRAFTING FOR INJURIES OF THE AXILLARY AND SUPRASCAPULAR NERVES

We report the results in 33 patients who had nerve grafting of the axillary or the suprascapular nerve or of both. There were 32 men and one woman; their mean age was 21 years and the average interval between injury and operation was three months. At a mean follow-up of 27 months, the deltoid had recovered to M3 or better in 23 of 30 patients (77%) and the infraspinatus in 18 of 25 patients (72%). Shoulder elevation had reached 120 degrees or more in 27 patients (82%), with external rotation of 30 degrees or more in 27 (82%). Twenty-six patients (79%) could reach to the top of their head with their hand. Recovery of muscle strength, range of movement and shoulder function were satisfactory when surgery was performed within four months of the injury. Early exploration and nerve grafting can lead to a good functional recovery, but thorough exploration and careful repair of both nerves are essential.

Investigation of brachial plexus injuries by intraoperative cortical somatosensory evoked potentials

SummaryWith the intention of estimating the extent and site of damage in brachial plexus injuries which involve close to the root outlet and also the distal portion, cortical somatosensory evoked potentials (SEP) were recorded in 21 patients by directly stimulating the exposed brachial plexus. In 38 avulsed nerve roots which showed positive sensory action potentials (SNAP)/nerve action potentials (NAP) in their peripheral part, 15 roots (nine patients) were apparently in continuity and confirmed as root avulsion injury by the absence of cortical SEP. However, 11 roots (ten patients) which showed neither SNAP nor SEP would suggest either extensive lesions involving root and more distal segment or a combination of root avulsion and postganglionic injury. Fourteen patients who showed a positive Tinels sign had at least one root with a postganglionic type lesion, but cortical SEP evoked by stimulation of the most proximal root zone sometimes revealed a reduced amplitude and prolonged latency. This would indicate the retrograde extension of damage. To confirm the extent and degree of the nerve lesions in brachial plexus injuries, an intraoperative SEP and NAP recording is very useful, practical, and also indispensable.ZusammenfassungZur Schätzung des Grades und der Lokalisation der Armplexusverletzungen, die entweder in der Nähe des Austrittspunkts der Nervenwurzel oder weiter distal stattfand, waren die mit einer somatosensorischen Reizung erregten Hirnrindenaktions-potentiale abgeleitet und aufgezeichnet wurden. Anhand der 21 Patienten wurden die Armgeflechte ausgesetzt und direkt elektrisch stimuliert. Unter 38 ausgerissenen Nervenwurzeln, die positives sensorisches Aktionspotential in ihren peripheren Teilen zeigten, waren 15 Wurzeln (neun Patienten) scheinbar in Kontinuität, wurden jedoch wegen der Negativität des sensorisch erregten Rindenpotentials als Wurzelausriß-typverletzung bestimmt. Im Gegenteil, 11 Nervenwurzeln (zehn Patienten), die weder somatosensorisches Rindenaktionspotential noch sensorisches Nervenaktionspotential zeigten, würden entweder ausgedehnte Schädigungen an der Wurzel und mehr distalen Teilen oder eine Kombination von Wurzelausriß und postganglionischer Läsion vermuten lassen. Vierzehn Patienten, die ein positives Tinelsches Zeichen zeigten, hatten mindestens eine Wurzel mit einer postganglionischen Verletzung, oder ihr durch die Reizung der extrem proximalen Wurzel erregtes Rindenaktionspotential zeigte öfters eine reduzierte Schwingungsweite und eine Verzögerung der Latenzzeit. Dies würde auf eine retrograde Extension der Läsion hinweisen. Die intraoperative somatosensorische Rindenpotentialsleitung ist ein sehr wertvolles, praktisches und auch unentbehrliches Verfahren, um den Grad und die Lokalisation der Armplexusverletzungen zu bestimmen.

Mutations in the N-terminal globular domain of the type X collagen gene (COL10A1) in patients with Schmid metaphyseal chondrodysplasia

Schmid metaphyseal chondrodysplasia (SMCD) is a relatively common, heritable osteochondrodysplasia characterized by short‐limbed short stature with normal facies, and generalized metaphyseal dysplasias of the long and short tubular bones. Several mutations of the type X collagen gene (COL10A1) have been reported in patients with SMCD, all in the C‐terminal globular domain. To address whether mutations in other domains can cause SMCD, we examined the coding region of the COL10A1 gene in DNA samples from six Japanese families affected with SMCD, by direct sequencing. We detected novel mutations in three unrelated SMCD patients; one was a one‐base deletion in the C‐terminal globular domain and others were de novo missense mutations in the N‐terminal globular domain. All three cases revealed a typical clinical phenotype for SMCD. Thus, we have demonstrated that mutations of COL10A1 in regions other than the C‐terminal globular domain can cause SMCD, and the results suggest that the N‐terminal globular domain also plays an important role in formation of type X collagen. Hum Mutat 9:131–135, 1997.

Shoulder arthrodesis by external fixation.

The choice of pin site in shoulder arthrodesis after brachial plexus injury is important for efficient external fixation. The pins are inserted into the coracoid process from the anterior aspect and the scapular spine from the acromion. This insertion method holds the scapula more rigid and allows the patient to lie supine. Moreover, it makes it possible to correct the fixation angle after the operation. In 11 cases of brachial plexus injury, solid bony arthrodesis was obtained within three months.

Dyggve-Melchior-Clausen syndrome without mental retardation (Smith-McCort dysplasia): morphological findings in the growth plate of the iliac crest.

Dyggve-Melchior-Clausen syndrome without mental retardation (Smith-McCort dysplasia) (SM) has clinical and radiographic findings similar to those of Dyggve-Melchior-Clausen syndrome (DMC) except for mental retardation. Iliac crest biopsies from two patients with SM were examined. The lace-like appearance of the iliac crests, which is a characteristic radiological sign of SM and DMC, was caused by bone tissue deposited in a wavy pattern at the osteochondral junction. The growth plate showed abnormal enchondral ossification with no columnarization of chondrocytes. Electron microscopy demonstrated chondrocytes with dilated cisternae of rough endoplasmic reticulum containing fine granular or amorphous material, similar to those reported in cases of DMC. Thus, SM has pathologic changes in common with DMC as a rough endoplasmic reticulum storage disorder, even though the mental condition is different.