S. Hattori

New procedure on making a thumb—One-stage reconstruction with free neurovascular flap and iliac bone graft

A new method for reconstruction of an amputated thumb with a free neurovascular flap and an iliac bone graft in one stage is described. The method consists of fbur operative steps: (1) preparation of the recipient hand, (2) elevation of a free dorsalis pedis flap, (3) iliac bone graft, and (4) transfer of the flap with microvascular anastornoses. Four successful results with this operation are presented. The method, which reconstructs the thumb in a single operation, is suitable for patients who refuse other reconstructive methods which sacrifice uninjured digits or toes.

Enlargement of the lumbar vertebral canal in lumbar canal stenosis.

A new surgical technique, enlargement of the spinal canal, was carried out on eight patients with lumbar canal stenosis. The conditions of all the patients have improved, and there have been no complications so far. A laminectomy is performed in which both sides of the pars interarticularis are cut out with an osteotome to eliminate the cause of the stenosis. The ventral side of the removed lamina is then ground with a surgical air drill to enlarge the posterior area of the lumbar canal. The lamina is subsequently replaced and fixed with screws. This method makes it possible to remove the cause of the stenosis. By replacing the removed lamina, the additional advantage of avoiding weakening vertebral stability is afforded.

Diagnosis of the level and severity of cord lesion in cervical spondylotic myelopathy. Spinal evoked potentials.

Experimental and clinical studies were performed to measure the segmental spinal evoked potential (SEP) of the cervical cord after stimulation of the median nerve, to determine the location, severity, and outcome of cord lesion in patients who had cervical spondylotic myelopathy. The SEP in control subjects consisted of two waves, the primary reactive R-wave and the secondary reactive N-wave. The R-wave related to both the dorsal root potential and the funiculus posterior potential; the N-wave related to the post-synaptic potential in the spinal cord. In the early stages of cervical spondylotic myelopathy, the N-wave weakens or disappears at the level of lesion. Then, as damage progresses, the R-wave also weakens or disappears.

Evaluation of cervical cord function using spinal evoked potentials from surface electrode.

Spinal evoked potentials from cervical skin surface (surface spinal evoked potentials) were measured to evaluate spinal cord function as a convenient method that precludes inserting electrodes into the epidural space, and results were compared with those of the former epidural recording method. Surface spinal evoked potentials were obtained from cervical skin surface over the C3, C5, and C7 spinous processes after median nerve stimulation in 18 normal subjects and 37 patients with a cervical lesion. In normal subjects, surface spinal evoked potentials consisted of three negative waves (N1, N2, N3). Abnormal N2 (80%) and abnormal N3 (100%) were observed in cervical myelopathy, and abnormal N2 was observed only in radiculopathy; this allows for differentiation between myelopathy and radiculopathy. Comparing preoperative and postoperative surface spinal evoked potentials, it was seen that improvement of clinical symptoms was proportional to that of surface spinal evoked potentials.

Evaluation of cervical cord function in cervical spondylotic myelopathy and/or radiculopathy using both segmental conductive spinal-evoked potentials (SEP)

To evaluate the function of the cervical cord and to diagnose the level and severity of cervical cord lesions in myelopathy, both segmental and conductive spinal evoked potentials (SEP) were measured in 73 patients with cervical spondylotic myelopathy and/or radiculopathy. In normal subjects, segmental SEPs consisted of two waves (R and N waves). Ascending conductive SEPs also consisted of two waves (first and second waves). The function of the cervical cord, including roots, grey matter, and white matter, can be measured by the combined method using both segmental and conductive SEPs, and this allows differentiation among radiculopathy and various types of myelopathy.

Free Neurovascular Flap from the First Web Space of the Foot for Reconstruction of the Mutilated Hand

Two cases, to which a free first web space flap or a free hemipulp flap from the foot were applied for restoring sensation to the mutilated hand are reported. The free neurovascular flap from the foot has advantages in reconstruction of the mutilated hand, when a traditional neurovascular island flap for sensory recovery of the hand is not available.