✓ The authors present a case of a rare cutaneous lesion resembling a human finger that protruded from the posterior thoracic region of a 7-month-old girl who was examined after the fingerlike protrusion was noted at birth. The protrusion measured 3 cm in length and 1 cm in diameter. It was located at the level of T-12 and was surrounded by angiomatous and lipomatous tissue. A computerized tomography scan demonstrated three bones in the protrusion, including deformities of the T-9 and T-10 and T-11 dysraphism. Magnetic resonance imaging revealed a hyperintense signal on the T1-weighted sequence and a hypointense signal on the T2-weighted sequence, which was visualized at the attachment to the spinal cord from T9–11. After removal of the fingerlike structure and subcutaneous mass, a T10–11 laminectomy and removal of the intradural mass were performed. Histological examination showed that the appendage was composed of nail, three bones, cartilage, and normal skin. This appendage can be recognized not only as a variant type of caudal appendage but as an ectopic finger and fingernail. The authors discuss the developmental differences among the protrusion in the present case and ordinary caudal appendages.
Eiichi Ishikawa, Akira Matsumura, Takashi Enomoto, Takao Tsurubuchi and Tadao Nose
Yoshiro Ito, Koji Tsuboi, Hiroyoshi Akutsu, Satoshi Ihara and Akira Matsumura
✓ The authors discuss the results obtained in patients who underwent foramen magnum decompression for longstanding advanced Chiari I malformation in which marked spinal cord atrophy was present. This 50-year-old woman presented with progressive quadriparesis and sensory disorders. Magnetic resonance imaging revealed the descent of cerebellar tonsils and medulla associated with remarkable C1—L2 spinal cord atrophy. After a C-1 laminectomy—based foramen magnum decompression, arachnoid dissection and duraplasty were undertaken. These procedures resulted in remarkable neurological improvement, even after 40 years of clinical progression. Spinal cord atrophy may be caused by chronic pressure of entrapped cerebrospinal fluid in the spinal canal.
Akira Matsumura, Takashi Namikawa, Minori Kato, Tomonori Ozaki, Yusuke Hori, Noriaki Hidaka and Hiroaki Nakamura
The purpose of this study was to assess the clinical results of posterior corrective surgery using a multilevel transforaminal lumbar interbody fusion (TLIF) with a rod rotation (RR) and to evaluate the segmental corrective effect of a TLIF using CT imaging. The medical records of 15 consecutive patients with degenerative lumbar kyphoscoliosis (DLKS) who had undergone posterior spinal corrective surgery using a multilevel TLIF with an RR technique and who had a minimum follow-up of 2 years were retrospectively reviewed. Radiographic parameters were evaluated using plain radiographs, and segmental correction was evaluated using CT imaging. Clinical outcomes were evaluated with the Scoliosis Research Society Patient Questionnaire-22 (SRS-22) and the SF-36.
The mean follow-up period was 46.7 months, and the mean age at the time of surgery was 60.7 years. The mean total SRS-22 score was 2.9 before surgery and significantly improved to 4.0 at the latest follow-up. The physical functioning, role functioning (physical), and social functioning subcategories of the SF-36 were generally improved at the latest follow-up, although the changes in these scores were not statistically significant. The bodily pain, vitality, and mental health subcategories were significantly improved at the latest follow-up (p < 0.05).
Three complications occurred in 3 patients (20%). The Cobb angle of the lumbar curve was reduced to 20.3° after surgery. The overall correction rate was 66.4%. The pelvic incidence–lumbar lordosis (preoperative/postoperative = 31.5°/4.3°), pelvic tilt (29.2°/18.9°), and sagittal vertical axis (78.3/27.6 mm) were improved after surgery and remained so throughout the follow-up. Computed tomography image analysis suggested that a 1-level TLIF can result in 10.9° of scoliosis correction and 6.8° of lordosis.
Posterior corrective surgery using a multilevel TLIF with an RR on patients with DLKS can provide effective correction in the coronal plane but allows only limited sagittal correction.
Hiroshi Taneichi, Kota Suda, Tomomichi Kajino, Akira Matsumura, Hiroshi Moridaira and Kiyoshi Kaneda
There are no published reports of unilateral transforaminal lumbar interbody fusion (TLIF) in which two Brantigan I/F cages were placed per level through a single portal to achieve bilateral anterior-column support. The authors describe such a surgical technique and evaluate the clinical outcomes of this procedure.
Data obtained in 86 (93.5%) of the first 92 consecutive patients who underwent the procedure were retrospectively reviewed; the minimum follow-up duration was 2 years. The clinical outcomes were evaluated using the Japanese Orthopaedic Association (JOA) scoring system. Disc height, disc angle, cage positioning in the axial plane, and fusion status were radiographically evaluated.
The mean follow-up period was 33.8 months. The mean improvement in the JOA score was 77.2%. Fusion was successful in 93% of the cases. According to the Farfan method, the mean anterior and posterior disc heights increased from 20.2 and 16.9% preoperatively to 35.9 and 22.7% at follow up, respectively (p < 0.01). The mean disc angle increased from 4.8° preoperatively to 7.5° at last follow-up examination (p < 0.01). Two cages were correctly placed to achieve bilateral anterior-column support in greater than 85% of the cases. The following complications occurred: hardware migration in two patients and deep infection cured by intravenous antibiotic therapy in one patient.
Unilateral TLIF involving the placement of two Brantigan cages per level led to good clinical results. Two Brantigan cages were adequately placed via a single portal, and reliable bilateral anterior-column support was achieved. Although the less invasive unilateral approach was used, the outcomes were as good as those in many reported series of posterior lumbar interbody fusion in which the Brantigan cages were placed via the bilateral approach.
Akira Matsumura, Takashi Namikawa, Hidetomi Terai, Tadao Tsujio, Akinobu Suzuki, Sho Dozono, Hiroyuki Yasuda and Hiroaki Nakamura
The authors compared the clinical outcomes of microscopic bilateral decompression via a unilateral approach (MBDU) for the treatment of degenerative lumbar scoliosis (DLS) and for lumbar canal stenosis (LCS) without instability. The authors also compared postoperative spinal instability in terms of different approach sides (concave or convex) following the procedure.
The authors retrospectively reviewed data obtained in 50 consecutive patients (25 in the DLS group and 25 in the LCS group) who underwent MBDU; the minimum follow-up period was 2 years. Patients with DLS were divided into 2 subgroups according to the surgical approach side: a concave group (23 segment) and a convex group (17 segments). The Japanese Orthopaedic Association Scale scores for the assessment of low-back pain were evaluated before surgery and at final follow-up. The Japanese Orthopaedic Association Scale scores and recovery rates were compared between the DLS and LCS groups, and between the convex and concave groups. Cobb angle and scoliotic wedging angle (SWA) were evaluated on standing radiographs before surgery and at final follow-up. Facet joint preservation (the percentage of preservation) was assessed on pre- and postoperative CT scans, compared between the LCS and DLS groups, and compared between the concave and convex groups. The influence of approach side on postoperative progression of segmental instability was also examined in the DLS group.
The mean recovery rate was 58.7% in the DLS and 62.0% in the LCS group. The mean recovery rate was 58.6% in the convex group and 60.6% in the concave group. There were no significant differences in recovery rates between the LCS and DLS groups, or between the DLS subgroups. The mean Cobb angles in the DLS group were significantly increased from 12.7° preoperatively to 14.1° postoperatively (p < 0.05), and mean preoperative SWAs increased significantly from 6.2° at L3–4 and 4.1° at L4–5 preoperatively to 7.4° and 4.9°, respectively, at final follow-up (p < 0.05). There was no significant difference in percentage of preservation between the DLS and LCS groups. The mean percentages of preservation on the approach side in the DLS group at L3–4 and L4–5 were 89.0% and 83.1% in the convex group, and those in the concave group were 67.3% and 77.6%, respectively. The percentage of preservation at L3–4 was significantly higher in the convex than the concave group. The mean SWA had increased in the concave group (p = 0.01) but not the convex group (p = 0.15) at final follow-up.
The MBDU can reduce postoperative segmental spinal instability and achieve good postoperative clinical outcomes in patients with DLS. The convex approach provides surgeons with good visibility and improves preservation of facet joints.
Sho Dohzono, Akira Matsumura, Hidetomi Terai, Hiromitsu Toyoda, Akinobu Suzuki and Hiroaki Nakamura
Minimally invasive decompressive surgery using a microscope or endoscope has been widely performed for the treatment of lumbar spinal canal stenosis (LSS). In this study the authors aimed to assess outcomes following microscopic bilateral decompression via a unilateral approach (MBDU) in terms of postoperative bone regrowth and preservation of the facet joints in patients with degenerative lumbar spondylolisthesis (DS) as compared with those in patients with LSS.
In the period from May 1998 to February 2007 at the authors' institution, 85 patients underwent MBDU at L4–5. Clinical outcome was evaluated before surgery and at the final follow-up using the Japanese Orthopaedic Association (JOA) score for low-back pain. The following radiographic parameters were assessed at the L4–5 segment before surgery and at the final follow-up: 1) percentage slip on standing lateral radiographs, 2) percentage slip on dynamic radiographs, 3) disc arc on dynamic radiographs, and 4) percentage of facet joint preservation on CT. Bone regrowth on the ventral and dorsal sides of the facet joint on CT were assessed at the final follow-up.
The cases of 47 patients (23 with DS at L-4 and 24 with LSS at L4–5 without instability) who had a follow-up of at least 2 years were retrospectively reviewed. The improvement ratio in the JOA score, that is, the percentage improvement as indicated by the difference between preoperative and postoperative JOA scores, was not significantly different between patients with DS and LSS. The percentage slip had progressed at the latest follow-up in both groups (1.4% and 1.1%, respectively), and there was no significant difference between the 2 groups. The percentage of facet joint preservation in the DS and LSS groups was 72.8% and 83.4%, respectively, on the approach side and 95.5% and 96.5% on the contralateral side. Facet joint preservation was significantly less on the approach side than on the contralateral side in both groups. The average amount of bone regrowth on the dorsal and ventral sides of the facet joint was 3.4 and 0.9 mm, respectively, in the DS group and 2.0 and 1.0 mm in the LSS group. The difference between the 2 groups was not significant. Facet joint preservation and bone regrowth were not correlated with clinical outcomes.
Microscopic bilateral decompression via a unilateral approach can prevent postoperative spinal instability because of good preservation of the posterior elements including the facet joints, which is thought to be the main reason for the relatively small amount of bone regrowth after surgery.