Predictors for clinical outcomes of tubular surgery for endoscopic decompression in selected patients with lumbar spinal stenosis.

INTRODUCTION: The success rate of decompression surgery for lumbar spinal stenosis (LSS) has been reported to vary from 60 to 80%. The purpose of this study was to analyze the predictors for clinical outcomes after tubular surgery for endoscopic decompression (microendoscopic decompression) for LSS. MATERIALS AND METHODS: A total of 100 patients with degenerative LSS (M/F: 61/39, Age: mean 69.7 years), who underwent microendoscopic decompression and had a minimum 2-year follow-up (FU) after surgery, were reviewed. All patients suffered from leg-related symptoms predominantly without severe mechanical back pain, preoperatively. The presence of chronic arterial occlusion of the lower limbs was ruled out. The primary outcome measure was clinical evaluation at 2-year FU using the Oswestry Disability Index (ODI). Furthermore, numeric rating scales, Japanese Orthopedic Association (JOA) lumbar score and JOA Back Pain Evaluation Questionnaire were used for secondary outcome measures. Based on findings of univariable analyses, multivariable logistic regression analysis was applied to identify preoperative predictors for the clinical outcomes. RESULTS: Sixty-eight patients (68%) were assessed as good outcomes, on the basis of minimum clinically important difference of the ODI (13 points ≤) and final ODI score (< 30 points). The secondary outcomes were further support for the primary outcome. In multivariable logistic regression analysis, co-existence of intradiscal vacuum phenomenon with LSS (odds ratio [OR] 8.26; 95% confidence interval [95% CI] 2.32-29.34; p = 0.001) and ischemic cardiovascular comorbidities (OR, 13.3; 95% CI, 1.9-92.57; p = 0.009) were significantly associated with poor clinical outcomes. CONCLUSIONS: We found co-existence of intradiscal vacuum phenomenon with LSS and ischemic cardiovascular comorbidity to be preoperative predictors of less favorable clinical outcomes after microendoscopic decompression in selected patients of LSS. Although the conclusion obtained from restricted state, the information would be able to help in patient selection of the tubular surgery for endoscopic decompression for LSS.

Occipital bone erosion induced by C1 pedicle screw as a late complication of atlantoaxial fixation: a case report and literature review.

PURPOSE: The objective of this case report is to highlight occipital bone erosion as an unusual late complication of C1-C2 instrumented fixation. CASE PRESENTATION: A 60-year-old man of a displaced Anderson type II odontoid fracture was surgically treated by C1-C2 pedicle screw fixation. Occipital bone erosions, caused by a repeat irritation of the end of rod to the occipital bone, were detected on multiplane reconstructed computed tomography at 3 months after surgery. The lesion progressed over time with increasing the C2 anteversion on radiological evaluations. Eventually, the bony shell had been reactively formed around the protruded screw-rod construct and the Oc-C1 segment had been spontaneously stabilized. Fortunately, he had experienced no symptoms caused by the lesion at 5-year follow-up. CONCLUSION: The occipital bone erosion is an unusual late complication in C1-C2 posterior fixation using C1 pedicle screw. The increasing occipital-C1 lordosis compensating for the great C2 anteversion (high C2 slope) was related to the progression of the lesion. In C1-C2 pedicle screw fixation, surgeons should recognize a possibility of this complication and realize a relation between the occurrence of the lesion and the sagittal alignment of the cervical spine to take measures to avoid the complication.

Traumatic boutonniere deformity of the second toe caused by sumo wrestling: A case report.

INTRODUCTION: Traumatic boutonniere deformities of the fingers are well documented unlike those of the lesser toes. With few existing reports on boutonniere deformities of the lesser toes, the related pathology and treatment guidelines remain unclear. PRESENTATION OF CASE: We present a case of traumatic boutonniere deformity of the second toe caused by sumo wrestling in a 23-year-old man. A flexion deformity of the proximal interphalangeal joint and hyperextension of the distal interphalangeal joint of the right second toe were observed, including a torn central slip and plantarly displaced lateral bands during surgery. Surgical repair of the extensor mechanism and temporary pinning led to good clinical results. DISCUSSION: Acute traumatic boutonniere deformity of the interphalangeal joint of the lesser toe is very rare. The mechanism of boutonniere deformity in this case is thought to be due to forced passive flexion exerted on an actively extended PIP joint, which is similar to that seen in fingers. CONCLUSION: We describe the pathophysiology of a case of boutonniere deformity of the lesser toe and suggest the effectiveness of surgical treatment.

Spontaneous Flexor Tendon Rupture due to Primary Distal Radioulnar Joint Osteoarthritis.

Spontaneous flexor tendon rupture is rare, occurring most commonly in the little finger or flexor pollicis longus. To the best of our knowledge, there have been no reports of spontaneous flexor tendon rupture due to primary distal radioulnar joint (DRUJ) osteoarthritis (OA). We present a case of spontaneous flexor tendon rupture in the index finger due to primary DRUJ OA in a 71-year-old female farmer. Surgical exploration confirmed that, at the wrist joint level, the flexor digitorum profundus of the index finger had undergone degeneration and complete rupture. The flexor digitorum superficialis of the index finger was elongated and thinned. A bony spur toward the volar side was covered with synovial fluid from a pinhole-sized perforation of the capsule. The combination of direct friction from the DRUJ spur and the matrix metalloproteinases in the synovial fluid from the perforation of the DRUJ capsule may have caused the spontaneous flexor tendon rupture. Palmar-side symptoms associated with DRUJ OA should be carefully examined because of the risk of spontaneous flexor tendon rupture.

Surgical Outcomes of Minimally Invasive Stabilization for Spinal Fractures in Patients with Ankylosing Spinal Disorders.

STUDY DESIGN: A retrospective study. PURPOSE: To evaluate the clinical and radiological outcomes of ankylosing spinal disorder (ASD) patients with spinal fractures treated by minimally invasive stabilization (MISt) using percutaneous pedicle screws (PPSs). OVERVIEW OF LITERATURE: ASDs, such as ankylosing spondylitis (AS) and diffuse idiopathic skeletal hyperostosis (DISH), increase susceptibility to spinal fractures because of extremely decreased spinal flexibility. Such fractures tend to be unstable and, consequently, should be treated with multiple-segmental internal fixation. However, conventional internal fixation procedures can severely damage the soft tissue, resulting in severe hemorrhage. Therefore, MISt is the preferred approach to treat spinal fractures in ASD patients. METHODS: Nine ASD patients (four males and five females; three AS and six DISH patients) with spinal fractures who were treated by MISt using PPSs, were reviewed from April 2009 to August 2016. One patient died of aspiration pneumonia during follow-up (FU), and the remaining eight patients underwent clinical and radiological evaluation. RESULTS: The mean age at surgery was 79.6 years (range, 68-95 years). The mean duration of postoperative FU was 14.2 months (range, 3-30 months). All treated fractures were anterior and posterior element injuries with distraction. Three patients presented delayed onset preoperative neurological deficit following trauma. The mean operation time was 179.6 minutes (range, 92-340 minutes). The mean hemorrhage was 103.6 mL (range, unquantifiable to 480 mL). Radiological evaluations at FU showed preservation of the acceptable postoperative correction of the fractured vertebra, as there were no re-collapses of the fractured vertebrae during FU. CONCLUSIONS: ASD patients must be acknowledged as highly susceptible to unstable spinal fractures, even after relatively mild trauma. MISt using PPSs may be an effective treatment for spinal fractures in such patients.

Minimally Invasive Transtubular Endoscopic Decompression for L5 Radiculopathy Induced by Lumbosacral Extraforaminal Lesions.

STUDY DESIGN: Retrospective study. PURPOSE: This study aimed to evaluate the efficacy of minimally invasive transtubular endoscopic decompression for the treatment of lumbosacral extraforaminal lesion (LSEFL). OVERVIEW OF LITERATURE: Conventional procedures for surgical decompression for the treatment of LSEFL involve certain technical challenges because the lumbosacral extraforaminal region has unique anatomical features. Moreover, the efficacy of minimally invasive procedures performed via the posterolateral approach for LSEFL has been reported. METHODS: Twenty-five patients who had undergone minimally invasive transtubular endoscopic decompression for the treatment of LSEFL and could be followed up for at least 1 year postoperatively were enrolled. Five of these patients had a history of lumbar surgery, and seven had concomitant adjacent-level spinal stenosis. The clinical outcomes were evaluated using the Japanese Orthopaedic Association (JOA) lumbar score, numeric rating scale (NRS), and the JOA Back Pain Evaluation Questionnaire (JOABPEQ). The mean postoperative follow-up (FU) duration was 3.8 years. RESULTS: All procedures could be completed without any severe surgical complications, and all patients could resume their previous activity level within 1 month postoperatively. The JOA score significantly increased from 14.1±4.0 at baseline to 23.1±3.7 at the 1-year FU and 22.1±3.8 at the last FU. Similarly, there were significant improvements in the postoperative NRS and JOABPEQ scores. An additional surgery was performed in two patients (8%) during the FU period. Patients with degenerative scoliosis exhibited significantly poorer outcomes compared with those without this condition. CONCLUSIONS: Transtubular endoscopic decompression can overcome certain technical challenges involved in the conventional procedures for LSEFL treatment; therefore, it can be recommended as a useful procedure for treating LSEFL. This procedure can provide some benefits to LSEFL patients and offer a well-illuminated surgical field and high surgical safety for the surgeon. However, the procedure should be carefully adapted for LSEFL patients with concomitant degenerative scoliosis.

Percutaneous Transpedicular Interbody Fusion Technique in Percutaneous Pedicle Screw Stabilization for Pseudoarthrosis Following Pyogenic Spondylitis.

This report introduces a percutaneous transpedicular interbody fusion (PTPIF) technique in posterior stabilization using percutaneous pedicle screws (PPSs). An 81-year-old man presented with pseudoarthrosis following pyogenic spondylitis 15 months before. Although no relapse of infection was found, he complained of obstinate low back pain and mild neurological symptoms. Radiological evaluations showed a pseudoarthrosis following pyogenic spondylitis at T11-12. Posterior stabilization using PPSs from Th9 to L2 and concomitant PTPIF using autologous iliac bone graft at T11-12 were performed. Low back pain and neurological symptoms were immediately improved after surgery. A solid interbody fusion at T11-12 was completed 9 months after surgery. The patient had no restriction of daily activity and could play golf at one year after surgery. PTPIF might be a useful option for perform segmental fusion in posterior stabilization using PPSs.

Risk Factor Analysis for C5 Palsy after Double-Door Laminoplasty for Cervical Spondylotic Myelopathy.

STUDY DESIGN: A retrospective comparative study. PURPOSE: To clarify the risk factors related to the development of postoperative C5 palsy through radiological studies after cervical double-door laminoplasty (DDL). OVERVIEW OF LITERATURE: Although postoperative C5 palsy is generally considered to be the result of damage to the nerve root or segmental spinal cord, the associated pathology remains controversial. METHODS: A consecutive case series of 47 patients with cervical spondylotic myelopathy treated by DDL at our institution between April 2008 and April 2015 were reviewed. Postoperative C5 palsy occurred in 5 of 47 cases after DDL. We investigated 9 radiologic factors that have been reported to be risk factors for C5 palsy in various studies, and statistically examined these between the two groups of palsy and the non-palsy patients. RESULTS: We found a significant difference between patients with and without postoperative C5 palsy with regards to the posterior shift of spinal cord at C4/5 (p=0.008). The logistic regression analyses revealed posterior shift of the spinal cord at C4/5 (odds ratio, 12.066; p=0.029; 95% confidence interval, 1.295-112.378). For the other radiologic factors, there were no statistically significant differences between the two groups. CONCLUSIONS: In the present study, we showed a significant difference in the posterior shift of the spinal cord at C4/5 between the palsy and the non-palsy groups, indicating that the "tethering phenomenon" was likely a greater risk factor for postoperative C5 palsy.

Clinical and Radiological Study Focused on Relief of Low Back Pain After Decompression Surgery in Selected Patients With Lumbar Spinal Stenosis Associated With Grade I Degenerative Spondylolisthesis.

STUDY DESIGN: A retrospective study. OBJECTIVE: The aim of the present study was to identify the clinical and radiological features of low back pain (LBP) that was relieved after decompression alone of lumbar spinal stenosis (LSS) associated with grade I lumbar degenerative spondylolisthesis (LDS). SUMMARY OF BACKGROUND DATA: Although decompression and fusion are generally the recommended surgical treatments of LDS, several authors have reported that some patients with LDS could obtain good clinical results including relief from LBP by decompression alone. The pathogenesis of relief from LBP after decompression is, however, not known. METHODS: Forty patients with LSS associated with grade I LDS, who underwent a minimally invasive surgical-decompression were enrolled in the present study. All patients complained preoperatively of predominantly leg-related symptoms and LBP (≥ 4 points on Numeric Rating Scale). Clinical and radiological assessments were performed 1 year after surgery (a relief of LBP: Numeric Rating Scale reduction ≥3 points and valuation ≤3 points) and at the last follow-up. We conducted a comparative study between patient groups with and without the relief from LBP (groups R and N, respectively). RESULTS: Twenty-nine patients were distributed to group R and the remaining 11 patients to group N. Preoperatively, there was a significant difference between the two groups for age and radiographic flexibility for lumbar extension. Postoperatively, there was a positive correlation between improvement in both LBP and leg symptoms. The clinical outcomes of group R were significantly better than those of group N throughout follow-up period (mean 37 mo). In group R, sagittal lumbopelvic radiographic parameters improved significantly after surgery. CONCLUSION: Although the causes of LBP are varied in each patients, our results show that concomitant LSS itself might cause LBP in some patients with grade I LDS, because it involves impingement of the neural tissue and discordant sagittal lumbopelvic alignment. LEVEL OF EVIDENCE: 3.

Cervical myelopathy caused by disc herniation at the segment of existing osteochondroma in a patient with hereditary multiple exostoses.

Hereditary multiple exostoses (HME) is a benign hereditary disorder characterized by multiple osteochondromas. Osteochondroma appears occasionally in the spinal column as a part of HME. A 37-year-old man presented with a history of HME and cervical compressive myelopathy caused by intraspinal osteochondroma arising from the lamina of the C5 and disc herniation at the C5-6. He was treated by open-door laminoplasty at the C5 and C6 with excision of the tumor. The neurological symptoms were immediately relieved after surgery. Magnetic resonance images demonstrated a sufficient decompression of the spinal cord with a spontaneous regression of the herniated disc at one year after surgery. There was no recurrence of the tumor and no appearance of kyphosis and segmental instability of the cervical spine on postoperative imaging studies for three years after surgery. The patient could be successfully treated by laminoplasty with excision of the tumor and without removal of the herniated disc.

Long-term follow-up of a case of aneurysmal bone cyst in the lumbar spine.

BACKGROUND CONTEXT: Aneurysmal bone cyst (ABC) in the spine is relatively rare, so little is known about the natural history of the disease. PURPOSE: The purpose of this study was to describe a spinal ABC that was followed for an extended period from lesion enlargement to spontaneous regression. STUDY DESIGN: Case report. METHODS: A 63-year-old woman had a 1-year-long history of mild low back and bilateral leg pain without any significant neurologic deficits caused by lumbar spinal stenosis. At her first visit to our hospital, magnetic resonance imaging (MRI) showed a small cystic lesion on the left side of the L5 vertebral body. The patient's clinical symptom progression and MRI and computed tomography evaluations were reported for >13 years. RESULTS: After 6 years, the cystic lesion enlarged significantly and extended into the left pedicle and transverse process of the L5 vertebra. The lesion was diagnosed as an ABC based on multilocular cysts with fluid-fluid levels on MRI and bony septations on computed tomography. Thirteen years after the first visit, the lesion regressed spontaneously without a clear reason, such as biopsy or fracture, and most of the lesion was replaced by fatty marrow. The patient's symptoms stabilized without neurologic deterioration during the follow-up period. CONCLUSIONS: Although spinal ABC is an expandable cystic lesion, we should consider that such a lesion in an elderly patient could spontaneously regress.

Translaminar microendoscopic herniotomy for cranially migrated lumbar disc herniations encroaching on the exiting nerve root in the preforaminal and foraminal zones.

STUDY DESIGN: Case series. PURPOSE: The aim of this study was to describe translaminar microendoscopic herniotomy (TL-MEH) for cranially migrated lumbar disc herniations encroaching on the exiting nerve root in the preforaminal and foraminal zones and to report preliminary results of the procedure. OVERVIEW OF LITERATURE: Conventional interlaminar approaches for preforaminal and foraminal lumbar disc herniations result in extensive removal of the lamina and facet joint to remove disc fragments safely. More destructive approaches increase the risk of postoperative segmental instability. METHODS: TL-MEH is a minimally invasive procedure for herniotomy via the translaminar approach using a microendoscopic technique. TL-MEH was performed in seven patients with a cranially migrated lumbar disc herniation encroaching on the exiting nerve root. The disc fragments were located in the preforaminal zone in four patients, and in the preforaminal and foraminal zones in three. RESULTS: All patients experienced immediate relief from symptoms after surgery and satisfactory results at the final follow-up. Surgical complications, such as a dural tear, nerve injury, and surgical site infection, were not investigated. CONCLUSIONS: TL-MEH seemed to be an effective and safe alternative minimally invasive surgical option for patients with a cranially migrated lumbar disc herniation encroaching the exiting nerve root in the preforaminal and foraminal zones.