Clinical and Short-Term Radiographic Outcomes of Minimally Invasive Transforaminal Lumbar Interbody Fusion With Expandable Lordotic Devices.

BACKGROUND: Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) is a well-accepted procedure for the treatment of degenerative lumbar disease. However, its ability to restore lumbar lordosis has been limited. Development of expandable lordotic interbody devices has challenged this limitation, furthering the scope of minimally invasive surgery. OBJECTIVE: To evaluate the radiographic and clinical effects of expandable lordotic interbody devices placed through an MIS-TLIF approach. METHODS: We conducted a retrospective review of 32 1-level and 18 2-level MIS-TLIFs performed using lordotic expandable interbody devices. Lumbar radiographic measurements, Oswestry Disability Index scores (ODI), and Visual Analogue Scale scores (VAS) were obtained at preoperative, 6 wk follow up, and last follow up time points. Last follow up occurred at a mean of 11.5 ± 7.6 mo (mean ± SD). RESULTS: At 6-wk follow-up, segmental lordosis, disc height, and foraminal height increased by an average of 3.4°, 6.4 mm, and 4.4 mm, respectively. Only the 2-level group showed a significant increase in lumbar lordosis of 5.8°. No significant changes occurred in sacral slope, pelvic tilt, or pelvic incidence. Average ODI and VAS decreased by -12.0 and -4.5, respectively. Postoperative lumbar lordosis inversely correlated with preoperative lordosis in patients with an initial Pelvic Incidence to Lumbar Lordosis mismatch (PI-LL) of >10°, (r = -0.5, P = .009). CONCLUSION: When applied across 2-levels, MIS-TLIF using expandable lordotic interbody devices produced a significant increase in lumbar lordosis. Preoperative lumbar lordosis was found to be a predictor of postoperative lumbar lordotic change in patients with sagittal imbalance.

Minimally Invasive Transforaminal Lumbar Interbody Fusion: 2-Dimensional Surgical Video.

This operative video is a detailed look at minimally invasive transforaminal lumbar interbody fusion. We provide a step-by-step guide with appropriate narration and operative video to enhance the educational experience. We review clinical and radiographic evaluation, patient positioning, intraoperative navigation, localization, percutaneous pedicle screw placement, minimally invasive approach, disc space preparation, placement of interbody device, and closure. By presenting up-to-date minimally invasive and intraoperative navigation techniques, this video provides educational benefit to all neurosurgeons regardless of training level.

Marginal En Bloc Resection of C2-C3 Chordoma with Bilateral Vertebral Artery Preservation and Mesh Cage Reconstruction with Review of Previously Published Cases.

BACKGROUND: Chordomas arise from remnants of the notochord and occur throughout the neuroaxis. En bloc resection of chordomas can prove especially challenging in the upper cervical spine secondary to the unique structural anatomy and intimate relationship to the vertebral arteries and spinal cord. CASE DESCRIPTION: We describe the resection of a C2-C3 chordoma in a 55-year-old woman in 2-stage fashion with preservation of the vertebral arteries. First, a posterior instrumented fusion and removal of the posterior elements was performed, followed by an anterior transmandibular en bloc resection with cage reconstruction with kick-plate support achievable with off-the-shelf products. CONCLUSIONS: Chordomas in the upper cervical spine pose a surgical challenge but are amenable to en bloc resection. With careful planning and intraoperative adaptability, the surgeon can achieve a suitable reconstruction with off-the-shelf products.

Secondary malignancy following radiotherapy for thyroid eye disease.

AIM: To describe the first case of a secondary meningioma in a patient after radiation treatment for thyroid eye disease (TED). Secondarily to identify any additional cases of secondary malignancy resulting from radiotherapy for thyroid eye disease from our institutional experience. BACKGROUND: Thyroid eye disease (TED) is a self-limiting auto-immune disorder causing expansion of orbital soft tissue from deposition of glycosaminoglycans and collagen, leading to significant cosmetic and functional morbidity. Established management options for TED include: glucocorticosteroids, orbital radiotherapy, and surgical orbital decompression. Two large series on radiotherapy for TED have been reported without any cases of secondary malignancy. MATERIALS AND METHODS: The case of a patient with visual failure, found to have a sphenoid wing meningioma after previous TED radiotherapy is described. We then reviewed 575 patients with at least 3-year follow-up receiving radiotherapy for TED at British Columbia Cancer Agency to identify other possible secondary malignancies. RESULTS: The patient had postoperative improvement in her vision without any identified complications. Three additional cases of hematologic malignancy were identified. The calculated risk in our population of developing a radiation-induced meningioma after TED with at least 3 years of follow-up of is 0.17% (1/575); with hematopoetic malignancies the risk for secondary malignancy is 0.7% (4/575). CONCLUSIONS: Our calculated risk for secondary malignancy (0.17%, 0.7%) is similar to the reported theoretical risk published in the literature (0.3-1.2%). There is real risk for the development of a secondary malignancy after radiotherapy treatment of TED and treatment options should include consideration for this potential.

Cervical radiographic parameters in 1- and 2-level anterior cervical discectomy and fusion.

OBJECTIVE Anterior cervical discectomy and fusion (ACDF) is one of the most commonly performed spine procedures. It can be used to correct cervical kyphotic deformity, which is the most common cervical deformity, and is often performed using lordotic interbody devices. Worsening of the cervical sagittal parameters is associated with decreased health-related quality of life. The study hypothesis is that through the use of machined lordotic allografts in ACDF, segmental and overall cervical lordosis can be maintained or increased, which will have a positive impact on overall cervical sagittal alignment. METHODS Seventy-four cases of 1-level ACDF (ACDF1) and 2-level ACDF (ACDF2) (40 ACDF1 and 34 ACDF2 procedures) were retrospectively reviewed. Upright neutral lateral radiographs were assessed preoperatively and at 6 weeks and 1 year postoperatively. The measured radiographic parameters included focal lordosis, disc height, C2-7 lordosis, C1-7 lordosis, T-1 slope, and C2-7 sagittal vertical axis. Correlation coefficients were calculated to determine the relationships between these radiographic measurements. RESULTS The mean values were as follows: preoperative focal lordosis was 0.574°, disc height was 4.48 mm, C2-7 lordosis was 9.66°, C1-7 lordosis was 42.5°, cervical sagittal vertebral axis (SVA) was 26.9 mm, and the T-1 slope was 33.2°. Cervical segmental lordosis significantly increased by 6.31° at 6 weeks and 6.45° at 1 year. C2-7 lordosis significantly improved by 1 year with a mean improvement of 3.46°. There was a significant positive correlation between the improvement in segmental lordosis and overall cervical lordosis. Overall cervical lordosis was significantly negatively correlated with cervical SVA. Improved segmental lordosis was not correlated with cervical SVA in ACDF1 patients but was significantly negatively correlated in ACDF2 patients. There was also a significant positive correlation between the T-1 slope and cervical SVA. CONCLUSIONS In the study population, the improvement of focal lordosis was significantly correlated with an improvement in overall lordosis (C1-7 and C2-7), and overall lordosis as measured by the C2-7 Cobb angle was significantly negatively correlated with cervical SVA. Using lordotic cervical allografts, we successfully created and maintained significant improvement in cervical segmental lordosis at the 6-week and 1-year time points with values of 6.31° and 6.45°, respectively. ACDF is able to achieve statistically significant improvement in C2-7 cervical lordosis by the 1-year followup, with a mean improvement of 3.46°. Increasing the number of levels operated on resulted in improved cervical sagittal parameters. This establishes a baseline for further examination into the ability of multilevel ACDF to achieve cervical deformity correction through the intervertebral correction of lordosis.

Intramedullary Spinal Cord Tumors: Part II-Management Options and Outcomes.

Study Design Broad narrative review. Objectives Intramedullary spinal cord tumors (IMSCT) are uncommon lesions that can affect any age group or sex. However, numerous IMSCT exist and the clinical course of each tumor varies. The following article addresses the various management options and outcomes in patients with IMSCT. Methods An extensive review of the peer-reviewed literature was performed, addressing management options and clinical outcomes of patients with IMSCT. Results Early diagnosis and intervention are essential to obtain optimal functional outcome. Each IMSCT have specific imaging characteristics, which help in the clinical decision-making and prognostication. A comprehension of the tumor pathology and the clinical course associated with each tumor can allow for the proper surgical and nonsurgical management of these tumors, and reduce any associated morbidity and mortality. Recent advances in the operative management of such lesions have increased the success rate of tumor removal while minimizing iatrogenic-related trauma to the patient and, in tandem, improving patient outcomes. Conclusions Awareness and understanding of IMSCT is imperative to design proper management and obtain optimal patient outcomes. Meticulous operative technique and the use of surgical adjuncts are essential to accomplish proper tumor removal, diminish the risk of recurrence, and preserve neurologic function. Operative management of IMSCT should be individualized and based on tumor type, location, and dimensional extensions. To assist with preoperative and intraoperative decision-making, a general algorithm is provided.

Intramedullary Spinal Cord Tumors: Part I-Epidemiology, Pathophysiology, and Diagnosis.

Study Design Broad narrative review. Objectives Intramedullary spinal cord tumors (IMSCT) are rare neoplasms that can potentially lead to severe neurologic deterioration, decreased function, poor quality of life, or death. As such, a better understanding of these lesions is needed. The following article, part one of a two-part series, addresses IMSCT with regards to their epidemiology, histology, pathophysiology, imaging characteristics, and clinical manifestations. Methods The authors performed an extensive review of the peer-reviewed literature addressing the aforementioned objectives. Results Numerous IMSCT exist with varying epidemiology. Each IMSCT has its own hallmark characteristics and may vary with regards to how aggressively they invade the spinal cord. These lesions are often difficult to detect and are often misdiagnosed. Furthermore, radiographically and clinically, these lesions may be difficult to distinguish from one another. Conclusions Awareness and understanding of IMSCT is imperative to facilitate an early diagnosis and plan management.

A minimally invasive approach to defects of the pars interarticularis: Restoring function in competitive athletes.

OBJECTIVES: To understand that young athletes have a higher incidence of pars interarticularis defects than the general population. This may be due to an immature spine put under higher stress loads at an early age. Traditionally, surgery was reserved for those who failed conservative therapy, and consisted of open exposure, bone grafting and placement of pedicle screws. This leads to a long recovery period and limited ability to return to competitive sport. METHODS: Four collegiate and professional level athletes, three high school athletes, and one member of the National Guard presented with back pain from spondylolysis without spondylolisthesis. All underwent minimally invasive surgery (MIS) to directly repair the pars defect, for a total of sixteen pars defects repaired in eight patients. Described is an application of a MIS pars repair technique that has not previously been reported, which recreates the normal anatomy rather fusing across a motion segment. RESULTS: Five patients were discharged the day following surgery and three were discharged on postoperative day 2. Six of the patients returned to their previous level of competitiveness. Two were unable to achieve the same level of play, both of whom failed to fuse the spondylolysis. Patients all initially reported clinical improvement postoperatively and there was overall mean improvement on patient reported outcome measures (SF36 physical and mental component scores, visual analog scale, and Oswestry disability index). CONCLUSION: MIS advantages include less muscle tissue disruption and restoration of the natural anatomy. This leads to a more rapid recovery, decreased perioperative pain, minimal blood loss, earlier mobilization and decreased hospital length of stay. Overall this allows the athlete to start therapy earlier and return to competition sooner and at his/her pre-operative competitive level. The described MIS repair technique outcomes are similar to those that have been reported in the literature and have allowed a high rate of return to athletics in high performing patients; critical to their quality of life.

Pelvic reconstruction after subtotal sacrectomy for sacral chondrosarcoma using cadaveric and vascularized fibula autograft: Technical note.

A novel method of spinopelvic ring reconstruction after partial sacrectomy for a chondrosarcoma is described. Chondrosarcoma is one of the most common primary malignant bone tumors, and en bloc resection is the mainstay of treatment. Involvement of the pelvis as well as the sacrum and lumbar spine can result in a technically difficult challenge for en bloc resection and for achievement of appropriate load-bearing reconstruction. After en bloc resection in their patient, the authors achieved reconstruction with a rod and screw construct including vascularized fibula graft as the main strut from the lumbar spine to the pelvis. Additionally, a cadaveric allograft strut was used as an adjunct for the pelvic ring. This is similar to a modified Galveston technique with vascularized fibula in place of the Galveston rods. The vascularized fibula provided appropriate biomechanical support, allowing the patient to return to independent ambulation. There was no tumor recurrence; neurological status remained stable; and the allograft construct integrated well and even increased in size on CT scans and radiographs in the course of a follow-up longer than 7 years.

A tail of sacral agenesis: delayed presentation of meningocele in sacral agenesis.

INTRODUCTION: Sacral agenesis is a congenital condition associated with multiple orthopedic, spinal, abdominal and thoracic organ deformities. Meningocele is commonly found among patients with sacral agenesis. DESCRIPTION: We present the first case in the literature describing a delayed presentation of terminal (posterior) meningocele in an adult patient born with sacral agenesis. CONCLUSION: Surgical repair was performed and is the best treatment option for significantly large lesions, with postoperative CSF leak being the main complication.