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Adam S. Kanter and Gurpreet S. Gandhoke

Since its inception in the year 2001 the minimally invasive trans-psoas Lateral Lumbar Interbody Fusion (LLIF) approach has gained significant favor among spine surgeons. It is now routinely utilized to treat an array of spinal pathologies including degenerative disc disease, low grade spondylolisthesis, and adult spinal deformity. The intent of this video is to provide a step by step account of the basic procedural details when performing the LLIF procedure for a single level broad based degenerated lumbar disc with herniation.

The video can be found here: http://youtu.be/dZFMqmCz6Q8.

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Adam S. Kanter and Praveen V. Mummaneni

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Adam S. Kanter, Michael Y. Wang and Praveen V. Mummaneni

Object

Patients with ankylosing spondylitis (AS) who present with cervical spine fractures represent a unique challenge to spine surgeons. These injuries often result in neurological deficits that necessitate early and aggressive surgical management with posterior and/or anterior fixation. The authors introduce a clinical problem-solving algorithm to assist in the surgical management of instability and deformity in this exigent patient population.

Methods

Thirteen patients with AS and fractures of the cervical spine were radiographically evaluated to determine if spinal realignment was obtainable with cervical manipulation or traction. Seven patients had flexible deformities that were stabilized with either anterior or posterior fixation only, and 6 patients had fixed deformities and required circumferential anterior–posterior instrumentation. All patients were observed for neurological outcome, radiographic evidence of bone fusion, and complications.

Results

With the use of the authors' treatment algorithm, all patients were able to achieve satisfactory spinal realignment and bone fusion; 92% of patients achieved postoperative stability or improvement in Nurick and modified Japanese Orthopaedic Association scale scores. One patient experienced neurological deterioration following surgery, and 1 patient died at an acute rehabilitative facility following discharge.

Conclusions

Patients with AS are highly susceptible to extensive neurological injury and spinal deformity after sustaining cervical fractures from even minor traumatic forces. These injuries are uniquely complex in nature and require considerable scrutiny and aggressive surgical management to optimize spinal stability and functional outcomes. The authors' clinical problem-solving algorithm will assist spine surgeons in providing optimal care in this difficult population.

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Vincent Y. Wang, Adam S. Kanter and Praveen V. Mummaneni

✓Ossified ligamentum flavum (OLF) in the thoracic spine is a rare cause of myelopathy, often presenting with progressive symptomatology over an extended period of time. Surgical decompression via wide laminectomy has been the mainstay of treatment for this symptomatic disease phenomenon, but complications such as kyphotic deformity have developed due to extensive bone removal and release of the posterior tension band. The authors present a case of OLF excised via a minimally invasive microsurgical approach in which an expandable tubular retractor system was used. This approach enables complete decompression of the spinal canal while minimizing nerve, vascular, and musculoskeletal disruption, thus maintaining the native biomechanical disposition of the intact vertebral column.

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Gurpreet S. Gandhoke, Christian Ricks, Zachary Tempel, Brian Zuckerbraun, D. Kojo Hamilton, David O. Okonkwo and Adam S. Kanter

In deformity surgery, anterior lumbar interbody fusion provides excellent biomechanical support, creates a broad surface area for arthrodesis, and induces lordosis in the lower lumbar spine. Preoperative MRI, plain radiographs, and, when available, CT scan should be carefully assessed for sacral slope as it relates to pubic symphysis, position of the great vessels (especially at L4/5), disc space height, or contraindication to an anterior approach. This video demonstrates the steps in an anterior surgical procedure with minimal open exposure.

The video can be found here: https://youtu.be/r3bC4_vu1hQ.

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John H. Chi, Sanjay S. Dhall, Adam S. Kanter and Praveen V. Mummaneni

Object

Thoracic disc herniations can be surgically treated with a number of different techniques and approaches. However, surgical outcomes comparing the various techniques are rarely reported in the literature. The authors describe a minimally invasive technique to approach thoracic disc herniations via a transpedicular route with the use of tubular retractors and microscope visualization. This technique provides a safe method to identify the thoracic disc space and perform a decompression with minimal paraspinal soft tissue disruption. The authors compare the results of this approach with clinical results after open transpedicular discectomy.

Methods

The authors performed a retrospective cohort study comparing results in 11 patients with symptomatic thoracic disc herniations treated with either open posterolateral (4 patients) or mini-open transpedicular discectomy (7 patients). Hospital stay, blood loss, modified Prolo score, and Frankel score were used as outcome variables.

Results

Patients who underwent mini-open transpedicular discectomy had less blood loss and showed greater improvement in modified Prolo scores (p = 0.024 and p = 0.05, respectively) than those who underwent open transpedicular discectomy at the time of early follow-up within 1 year of surgery. However, at an average of 18 months of follow-up, the Prolo score difference between the 2 surgical groups was not statistically significant. There were no major or minor surgical complications in the patients who received the minimally invasive technique.

Conclusions

The mini-open transpedicular discectomy for thoracic disc herniations results in better modified Prolo scores at early postoperative intervals and less blood loss during surgery than open posterolateral discectomy. The authors' technique is described in detail and an intraoperative video is provided.

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Zachary J. Tempel, Gurpreet S. Gandhoke, Christopher M. Bonfield, David O. Okonkwo and Adam S. Kanter

Object

A hybrid approach of minimally invasive lateral lumbar interbody fusion (LLIF) followed by supplementary open posterior segmental instrumented fusion (PSIF) has shown promising early results in the treatment of adult degenerative scoliosis. Studies assessing the impact of this combined approach on correction of segmental and regional coronal angulation, sagittal realignment, maximum Cobb angle, restoration of lumbar lordosis, and clinical outcomes are needed. The authors report their results of this approach for correction of adult degenerative scoliosis.

Methods

Twenty-six patients underwent combined LLIF and PSIF in a staged fashion. The patient population consisted of 21 women and 5 men. Ages ranged from 40 to 77 years old. Radiographic measurements including coronal angulation, pelvic incidence, lumbar lordosis, and sagittal vertical axis were taken preoperatively and 1 year postoperatively in all patients. Concurrently, the visual analog score (VAS) for back and leg pain, the Oswestry Disability Index (ODI), and Short Form-36 (SF-36) Physical Component Summary (PCS) and Mental Component Summary (MCS) scores were used to assess clinical outcomes in 19 patients.

Results

At 1-year follow-up, all patients who underwent combined LLIF and PSIF achieved statistically significant mean improvement in regional coronal angles (from 14.9° to 5.8°, p < 0.01) and segmental coronal angulation at all operative levels (p < 0.01). The maximum Cobb angle was significantly reduced postoperatively (from 41.1° to 15.1°, p < 0.05) and was maintained at follow-up (12.0°, p < 0.05). The mean lumbar lordosis–pelvic incidence mismatch was significantly improved postoperatively (from 15.0° to 6.92°, p < 0.05). Although regional lumbar lordosis improved (from 43.0° to 48.8°), it failed to reach statistical significance (p = 0.06). The mean sagittal vertical axis was significantly improved postoperatively (from 59.5 mm to 34.2 mm, p < 0.01). The following scores improved significantly after surgery: VAS for back pain (from 7.5 to 4.3, p < 0.01) and leg pain (from 5.8 to 3.1, p < 0.01), ODI (from 48 to 38, p < 0.01), and PCS (from 27.5 to 35.0, p = 0.01); the MCS score did not improve significantly (from 43.2 to 45.5, p = 0.37). There were 3 major and 10 minor complications.

Conclusions

A hybrid approach of minimally invasive LLIF and open PSIF is an effective means of achieving correction of both coronal and sagittal deformity, resulting in improvement of quality of life in patients with adult degenerative scoliosis.

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Matthew J. Tormenti, Matthew B. Maserati, Christopher M. Bonfield, David O. Okonkwo and Adam S. Kanter

Object

The authors recently used a combined approach of minimally invasive transpsoas extreme lateral interbody fusion (XLIF) and open posterior segmental pedicle screw instrumentation with transforaminal lumbar interbody fusion (TLIF) for the correction of coronal deformity. The complications and radiographic outcomes were compared with a posterior-only approach for scoliosis correction.

Methods

The authors retrospectively reviewed all deformity cases that were surgically corrected at the University of Pittsburgh Medical Center Presbyterian Hospital between June 2007 and August 2009. Eight patients underwent combined transpsoas and posterior approaches for adult degenerative thoracolumbar scoliosis. The comparison group consisted of 4 adult patients who underwent a posterior-only scoliosis correction. Data on intra- and postoperative complications were collected. The pre- and postoperative posterior-anterior and lateral scoliosis series radiographic films were reviewed, and comparisons were made for coronal deformity, apical vertebral translation (AVT), and lumbar lordosis. Clinical outcomes were evaluated by comparing pre- and postoperative visual analog scale scores.

Results

The median preoperative coronal Cobb angle in the combined approach was 38.5° (range 18–80°). Following surgery, the median Cobb angle was 10° (p < 0.0001). The mean preoperative AVT was 3.6 cm, improving to 1.8 cm postoperatively (p = 0.031). The mean preoperative lumbar lordosis in this group was 47.3°, and the mean postoperative lordosis was 40.4°. Compared with posterior-only deformity corrections, the mean values for curve correction were higher for the combined approach than for the posterior-only approach. Conversely, the mean AVT correction was higher in the posterior-only group. One patient in the posterior-only group required revision of the instrumentation. One patient who underwent the transpsoas XLIF approach suffered an intraoperative bowel injury necessitating laparotomy and segmental bowel resection; this patient later underwent an uneventful posterior-only correction of her scoliotic deformity. Two patients (25%) in the XLIF group sustained motor radiculopathies, and 6 of 8 patients (75%) experienced postoperative thigh paresthesias or dysesthesias. Motor radiculopathy resolved in 1 patient, but persisted 3 months postsurgery in the other. Sensory symptoms persisted in 5 of 6 patients at the most recent follow-up evaluation. The mean clinical follow-up time was 10.5 months for the XLIF group and 11.5 months for the posterior-only group. The mean visual analog scale score decreased from 8.8 to 3.5 in the XLIF group, and it decreased from 9.5 to 4 in the posterior-only group.

Conclusions

Radiographic outcomes such as the Cobb angle and AVT were significantly improved in patients who underwent a combined transpsoas and posterior approach. Lumbar lordosis was maintained in all patients undergoing the combined approach. The combination of XLIF and TLIF/posterior segmental instrumentation techniques may lead to less blood loss and to radiographic outcomes that are comparable to traditional posterior-only approaches. However, the surgical technique carries significant risks that require further evaluation and proper informed consent.

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Lateral lumbar interbody fusion in the elderly: a 10-year experience

Presented at the 2018 AANS/CNS Joint Section on Disorders of the Spine and Peripheral Nerves

Nitin Agarwal, Andrew Faramand, Nima Alan, Zachary J. Tempel, D. Kojo Hamilton, David O. Okonkwo and Adam S. Kanter

OBJECTIVE

Elderly patients, often presenting with multiple medical comorbidities, are touted to be at an increased risk of peri- and postoperative complications following spine surgery. Various minimally invasive surgical techniques have been developed and employed to treat an array of spinal conditions while minimizing complications. Lateral lumbar interbody fusion (LLIF) is one such approach. The authors describe clinical outcomes in patients over the age of 70 years following stand-alone LLIF.

METHODS

A retrospective query of a prospectively maintained database was performed for patients over the age of 70 years who underwent stand-alone LLIF. Patients with posterior segmental fixation and/or fusion were excluded. The preoperative and postoperative values for the Oswestry Disability Index (ODI) were analyzed to compare outcomes after intervention. Femoral neck t-scores were acquired from bone density scans and correlated with the incidence of graft subsidence.

RESULTS

Among the study cohort of 55 patients, the median age at the time of surgery was 74 years (range 70–87 years). Seventeen patients had at least 3 medical comorbidities at surgery. Twenty-three patients underwent a 1-level, 14 a 2-level, and 18 patients a 3-level or greater stand-alone lateral fusion. The median estimated blood loss was 25 ml (range 5–280 ml). No statistically significant relationship was detected between volume of blood loss and the number of operative levels. The median length of hospital stay was 2 days (range 1–4 days). No statistically significant relationship was observed between the length of hospital stay and age at the time of surgery. There was one intraoperative death secondary to cardiac arrest, with a mortality rate of 1.8%. One patient developed a transient femoral nerve injury. Five patients with symptomatic graft subsidence subsequently underwent posterior instrumentation. A lower femoral neck t-score < −1.0 correlated with a higher incidence of graft subsidence (p = 0.006). The mean ODI score 1 year postoperatively of 31.1 was significantly (p = 0.003) less than the mean preoperative ODI score of 46.2.

CONCLUSIONS

Stand-alone LLIF can be safely and effectively performed in the elderly population. Careful evaluation of preoperative bone density parameters should be employed to minimize risk of subsidence and need for additional surgery. Despite an association with increased comorbidities, age alone should not be a deterrent when considering stand-alone LLIF in the elderly population.

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Stephen M. Pirris, Sanjay Dhall, Praveen V. Mummaneni and Adam S. Kanter

Surgical access to extraforaminal lumbar disc herniations is complicated due to the unique anatomical constraints of the region. Minimizing complications during microdiscectomies at the level of L5–S1 in particular remains a challenge. The authors report on a small series of patients and provide a video presentation of a minimally invasive approach to L5–S1 extraforaminal lumbar disc herniations utilizing a tubular retractor with microscopic visualization.