Surgical management of thoracic myelopathy from long-segment epidural lipomatosis with skip hemilaminotomies: illustrative case

BACKGROUND Thoracic spinal epidural lipomatosis (SEL) involves the pathological overgrowth of histologically normal, unencapsulated adipose tissue that can compress the spinal cord and cause myelopathy. SEL has been associated with multiple medical conditions, including Scheuermann kyphosis (SK). Optimal treatment strategies for SEL, especially in the setting of a sagittal spinal deformity, remain unclear. OBSERVATIONS In this report, the authors discussed surgical management of a patient with thoracic SEL and SK using skip hemilaminotomies for resection of the epidural adipose tissue. To the authors’ knowledge, only one other report described a similar surgical technique in a patient who did not have a spinal deformity. LESSONS When conservative efforts fail, thoracic SEL may require surgical treatment. Surgical planning must account for co-medical conditions such as SK. The described approach involving skip laminotomies, which minimizes spine destabilization, is a viable option to treat SEL spanning multiple spinal segments. Prognosis after surgical treatment varies and is impacted by multiple factors, including severity of preoperative neurological deficits.

Thoracic meningioma with ossification: Case report

Background: The incidence of spinal meningiomas is 0.33/100000 population, and ossified spinal meningiomas are even less commonly encountered. Case Description: A 64-year-old male presented with a progressive T4-level thoracic myelopathy. MR imaging revealed an intradural extramedullary mass that significantly compressed the spinal cord. The accompanying CT demonstrated hyperdensities within the lesion consistent with punctate calcification vs. ossification (i.e. consistent with histological bone formations within tumor). The patient underwent complete resection of the tumor resulting in a full recovery of neurological function within 6 postoperative weeks. The pathological specimen showed findings consistent with an ossified spinal meningioma. Conclusion: Here, we identified a rare case of an ossified thoracic T4 meningioma occurring in a 64-year-old male.

Anterior decompression through a posterior approach for thoracic myelopathy caused by ossification of the posterior longitudinal ligament: a novel concept in anterior decompression and technical notes with the preliminary outcomes

OBJECTIVE Various surgical procedures are used to manage thoracic myelopathy due to ossification of the posterior longitudinal ligament (OPLL). However, the outcomes of surgery for thoracic OPLL are generally unfavorable in comparison to surgery for cervical OPLL. Previous studies have shown a significant risk of perioperative complications in surgery for thoracic OPLL. Thus, a safe and secure surgical method to ensure better neurological recovery with less perioperative complications is needed. The authors report a novel concept of anterior decompression through a posterior approach aimed at anterior shift of the OPLL during surgery rather than extirpation or size reduction of the OPLL. This surgical technique can securely achieve anterior shift of the OPLL using a curved drill, threadwire saw, and curved rongeur. The preliminary outcomes were investigated to evaluate the safety and efficacy of this technique. METHODS This study included 10 consecutive patients who underwent surgery for thoracic OPLL. Surgical outcomes, including the ambulatory status, Japanese Orthopaedic Association (JOA) score, and perioperative complications, were investigated retrospectively. In this surgery, pedicle screws are introduced at least three levels above and below the corresponding levels. The laminae, facet joints, transverse processes, and pedicles are then removed bilaterally at levels wherein subsequent anterior decompression is performed. For anterior decompression, the OPLL and posterior portion of the vertebral bodies are partially resected using a high-speed drill with a curved burr, enabling the removal of osseous tissues just ventral to the spinal cord without retracting the dural sac. To securely shift the OPLL anteriorly, the intact PLL and posterior portion of the vertebral bodies cranial and caudal to the lesion are completely resected using a threadwire saw and/or curved rongeur. Rods are connected to the screws, and bone grafting is performed for posterolateral fusion. RESULTS Five patients were nonambulatory before surgery, but all were able to walk at the final follow-up. The average JOA score before surgery and at the final follow-up was 3.2 and 8.8 points, respectively. Notably, the mean recovery rate of JOA score was 72%. Furthermore, no patients showed neurological deterioration postoperatively. CONCLUSIONS The surgical technique is a useful alternative for safely achieving sufficient anterior decompression through a posterior approach and may consequently reduce the risk of postoperative neurological deterioration and improve surgical outcomes in patients with thoracic OPLL.

Thoracic ventral spinal cord herniation with progressive myelopathy – A case report and review of the literature

Background: Idiopathic spinal cord herniation (ISCH) is a rare, underrecognized, and often misdiagnosed entity of unclear pathogenesis that typically presents as a slowly progressive thoracic myelopathy. There are less than 200 such cases reported in the literature. ISCH diagnosis and treatment are often delayed contributing to greater fixed neurological deficits, often leading to costly, unnecessary imaging studies, and inappropriate surgery. Case Description: Here, a 48-year-old female presented with trauma-induced ISCH characterized by gradually worsening lower extremity myelopathy. Conclusion: Idiopathic spinal cord herniation (ISCH) is rare, often underdiagnosed posttraumatic myelopathy that, when accurately diagnosed and treated, can result in good outcomes.

A Rare T2-T3 Synovial Facet Cyst Causing Progressive Myelopathy

Intraspinal extradural synovial cysts are a rare occurrence at the spinal cord level and thus a rare cause of myelopathy. Synovial cysts usually present in the more mobile lumbar and cervical parts of the spine; however, they may also arise in the thoracic spine. We present a case of a 59-year-old male with a left upper thoracic synovial cyst at T2-3 causing disabling, progressive myelopathy, and an incomplete spinal cord injury syndrome with inability to ambulate. An urgent decompressive laminectomy with bilateral facetectomies, cyst excision, and posterior fusion was performed. Subsequently, the patient recovered full function. Synovial cysts should be considered in the differential diagnosis of progressive thoracic myelopathy. This is only the sixth reported case of a synovial cyst of this kind occurring between the levels of T1 and T7. Urgent surgical decompression is the recommended treatment.

Outcome of Thoracic Column Antedisplacement and Fusion in Treatment of Thoracic Myelopathy Caused by Ossification of Posterior Longitudinal Ligament: A Case Series Study

BACKGROUND Up to date, surgical outcome of multilevel thoracic ossification of posterior longitudinal ligament (T-OPLL) with high canal occupation ratio is less satisfactory. OBJECTIVE To explore the result of thoracic column antedisplacement and fusion (TCAF) in treatment of multilevel T-OPLL with high canal occupation ratio. METHODS A total of 5 patients who underwent TCAF procedure for T-OPLL were retrospectively reviewed. Parameters including extent of OPLL, thickness of the maximal OPLL (max-OPLL), maximal canal occupying ratio (max-COR) of OPLL, effective canal diameter (ECD) at the max-OPLL level, antedisplacement distance of thoracic columns, ASIA grades, Japanese Orthopedic Association (JOA) scores, and complications were collected and analyzed at preoperation and the last follow-up. RESULTS All patients (5 F, mean age 61.0 yr, mean follow-up 18.0 months) underwent TCAF successfully and no spinal cord injury or cerebrospinal fluid leakage occurred. The mean extent of OPLL was 2.8 vertebral bodies. The mean preoperative thickness of the max-OPLL was 5.9 mm. The average antedisplacement distance of thoracic columns was 5.6 mm. The mean ECD was improved from 6.5 mm to 10.9 mm, and the max-COR was improved from 50.7% to 7.1% at last follow-up. Two patients showed improvement in ASIA grades and JOA scores were significantly improved from 5.6 points to 10.4 points at final follow-up. The overall therapeutic results of 1 patient were classified into good and 4 into fair at last follow-up. CONCLUSION TCAF may be a safe and effective procedure in treatment of multilevel T-OPLL with high canal occupation ratio.

T11/T12 ossification of the yellow ligament contributing to thoracic myelopathy in patient with posterior fossa arachnoid cyst and acquired incidental Chiari I malformation/syrinx

Background: Thoracic ossification of the yellow ligament (OYL) may contribute to myelopathy. In the case presented, the patient additionally had a chronic posterior fossa arachnoid cyst with an acquired Chiari I malformation and cervicothoracic syrinx. Case Description: A 40-year-old female with a posterior fossa arachnoid cyst found 17 years ago, and newly acquired Chiari I malformation (tonsils down 5 mm) with a C7-T5 syrnix, presented with the new onset of lower extremity myelopathy. The MR documented marked dorsolateral cord compression due to T11/T12 OYL. Six months following a laminectomy for resection of OYL, the patient was asymptomatic. Conclusion: In patients presenting with the new onset of lower extremity myelopathy, evaluation of the complete neuraxis may be warranted. Here, the patient has an unchanged posterior fossa arachnoid cyst with an acquired Chiari I malformation/C7-T5 syrinx. However, the patient’s symptoms were fully attributed to the MR-documented T11/T12 OYL that was successfully resected.

Full-Endoscopic Decompression with the Application of an Endoscopic-Matched Ultrasonic Osteotome for Removal of Ossification of the Thoracic Ligamentum Flavum

Background: Resection of the ossification of the thoracic ligamentum flavum (OTLF) with a high-speed burr may cause a high rate of perioperative complications, such as dural laceration and/or iatrogenic spinal cord injury. Objectives: The aim of this study was to investigate the safety and feasibility of the endoscopicmatched ultrasonic osteotome in full-endoscopic spinal surgery for direct removal of OTLF. Study Design: Retrospective study. Setting: All data were from Honghui Hospital in Xi’an. Methods: This study conducted between December 2017 and December 2018, included 27 consecutive patients who met the study criteria, had single-level OTLF, and underwent fullendoscopic decompression under local anesthesia. The postoperative follow-up was scheduled at 1, 3, 6, and 12 months postoperatively. Outcomes evaluations included the Visual Analog Scale (VAS) score for lower extremity pain and the modified Japanese Orthopaedic Association (mJOA) score and improvement rate for the assessment of thoracic myelopathy. Removal of OTLF was measured by comparing the pre- and postoperative computed tomography (CT) and magnetic resonance imaging (MRI) scans. Results: The operation was completed in all patients without conversion to open surgery. The operation time ranged from 65 to 125 minutes (average, 83.7 ± 12.3 minutes). All patients were followed up for 12 to 18 months, with an average follow-up of 14.3 ± 1.3 months. Satisfactory neurologic decompression was confirmed by postoperative CT and MRI, and no revision surgery was required. The VAS and mJOA scores showed statistically higher improvement at the 1-month follow-up and the last follow-up compared with the preoperative assessment (P < 0.05). According to the improvement rate at the final follow-up, 20 cases were classified as good, 6 cases were fair, and 1 case remained unchanged. Limitations: A single-center, noncontrol study. Conclusions: The endoscopic-matched ultrasonic osteotome can be considered quite safe and feasible for direct removal of OTLF during full-endoscopic spinal surgery in strictly selected patients, as this allows for effective direct decompression of OTLF while minimizing trauma and instability. In addition, because of the design characteristics of the ultrasonic osteotome, surgical complications, especially dural tears and spinal cord injury, can also be effectively controlled. Key words: Percutaneous endoscopic spinal surgery, ultrasonic osteotome, ossification of thoracic ligamentum flavum, microsurgery, thoracic myelopathy, minimally invasive procedures