Single-center, consecutive series study of the use of a novel platelet-rich fibrin matrix (PRFM) and beta-tricalcium phosphate in posterolateral lumbar fusion.

PURPOSE: To evaluate the radiographic and clinical outcomes of the combination of platelet-rich fibrin matrix (PRFM) with beta-tricalcium phosphate (ß-TCP) and bone marrow aspirate (BMA) as a graft alternative in posterolateral lumbar fusion procedures. METHODS: Researchers evaluated 50 consecutive patients undergoing one-level to three-level posterolateral lumbar fusion procedures, resulting in a total of 66 operated levels. The primary outcome was evidence of radiographic fusion at 1-year follow-up, assessed by three independent evaluators using the Lenke scoring system. Secondary outcomes included back and leg VAS scores, incidence of reoperations and complications, return-to-work status, and opioid use. RESULTS: At 1-year follow-up, radiographic fusion was observed in 92.4% (61/66) of operated levels. There was significant improvement in VAS scores for both back and leg pain (p < 0.05). Compared to baseline figures, the number of patients using opioid analgesics at 12-months decreased by 38%. The majority (31/50) of patients were retired, yet 68% of employed patients (n = 19) were able to return to work. No surgical site infections were noted, and no revision surgery at the operated level was required. CONCLUSIONS: This is the first report to analyze the combination of PRFM with ß-TCP and BMA for PLF procedures. Our results indicate a rate of fusion similar to those reported using iliac crest bone graft (ICBG), while avoiding donor site morbidity related to ICBG harvesting such as hematoma, pain, and infection. These slides can be retrieved under Electronic Supplementary Material.

Acute Tetraplegia after Posterior Cervical Laminectomy for Chronic Myelopathy.

Spinal cord injury (SCI) during revision surgery for persistent multilevel cervical myelopathy (MCM) after an initial anterior procedure is rare. However, the pathophysiology of MCM, even prior to surgery, is a risk-factor for neurological deterioration due to the development of a "sick cord", which reflects pathological changes in the spinal cord that lower the threshold for injury. We report a case of persistent MCM despite a three-level ACDF and corpectomy who developed an incomplete C6 tetraplegia during revision cervical laminectomy and posterior instrumentation. Intraoperative neuromonitoring signal-changes occurred in the absence of mechanical trauma. Postoperative MRI of the cervical spine demonstrated increased T2 hyperintensity and cord expansion at C3 and C4 compared to the pre-laminectomy MRI. The patient has not made improvements in her neurological status at 13 months postoperatively. The pathophysiology of MCM is discussed in addition to perioperative imaging, neuromonitoring, and use of steroids.

Minimally Invasive Lateral Interbody Fusion in the Treatment of Scoliosis Associated with Myelomeningocele.

INTRODUCTION: Surgical correction of spinal deformity in myelomeningocele is associated with high rates of pseudarthrosis and implant failure. The anterior fusion is traditionally a wide exposure from the thorax to the sacrum. We report minimally invasive lateral interbody fusion (MILIF) to address the issue of fusion between vertebrae with marginal posterior elements while minimizing the morbidity of an open approach. MATERIALS AND METHODS: We performed a single-center, retrospective review of patients with myelomeningocele and severe scoliosis who underwent posterior spinal fusion (PSF) and staged MILIF for anterior fusion of the thoracolumbar/lumbar spine. We identified four patients with high risk of curve progression who met the following inclusion criteria: diagnosis of myelomeningocele, severe scoliosis (Cobb angle>70°), PSF using greater than 80% pedicle screws, age greater than 10 years at time of surgery, and a minimum follow-up of two years. Radiographic, clinical, and complication data were reviewed. RESULTS: All four patients achieved fusion (100%). The average age at index surgery was 12.8 years (range, 11-16) and follow-up was 3.2 years (range, 2-4.9). The average preoperative coronal Cobb angle measured 111° (range, 74-140°). The average postoperative Cobb angle at follow-up measured 37° (range, 23-42°). The MILIF procedure was performed an average of six months after the index procedure. After anterior fusion, all patients spent one day in the pediatric ICU and an average of 5.5 days in the hospital (range, 4-7). One patient (25%) developed a postoperative wound infection after PSF which required irrigation and debridement in the operating room. CONCLUSION: MILIF as an adjunct to posterior spinal fusion for severe scoliosis associated with myelomeningocele may provide acceptable fusion rates, curve correction, maintenance of correction at mid-term follow-up, and be associated with less morbidity than the traditional anterior approach.

The Effects of Marijuana Use on Lumbar Spinal Fusion.

MINI: This study compared clinical and patient-reported outcomes following transforaminal lumbar interbody fusion between patients who use or do not use marijuana. We found that patients who use marijuana are younger, but do not demonstrate any differences in preoperative or postoperative Oswestry disability index scores or rates of fusion. STUDY DESIGN: A retrospective cohort study. OBJECTIVE: The purpose of this study was to evaluate marijuana usage and its effect on outcomes following transforaminal lumbar interbody fusion (TLIF). SUMMARY OF BACKGROUND DATA: As marijuana becomes legalized throughout the United States, its medicinal and recreational usage is becoming more mainstream. Clinicians currently have little guidance regarding both short-term and long-term effects of marijuana usage on surgical interventions. While the rate of lumbar spinal fusion in the United States continues to grow, the effect of marijuana usage on fusion remains uncertain. METHODS: One hundred two patients who underwent TLIF performed by the same surgeon were followed for 12 months. Patients were self-reported for marijuana usage (n = 36). Patient reported outcome measures included preoperative Oswestry disability index (ODI), 6-month ODI, and 12-month ODI, as well as length of stay (LOS), complications, return to operating room (OR), revision surgery, and confirmed fusion. Continuous variables were compared using the independent two-sample t test or analysis of variance (ANOVA), whereas categorical variables were analyzed using the chi-square or Fischer exact tests. Adjusted analysis was performed using a multivariate logistic regression model. RESULTS: Marijuana usage was associated with a younger population (P < 0.001), but showed no difference regarding sex or body mass index compared with the non-usage group. There was no statistically significant difference in complications, return to OR, or revision surgery between groups. When controlling for factors such as age and preoperative ODI, multivariate analysis demonstrated that marijuana usage did not limit postoperative ODI reduction. The marijuana usage group demonstrated shorter LOS (2.42 vs. 3.00 d, P = 0.020). Fusion rates at 12 months were similar between groups (96% vs. 92.3%, P = 0.678). ODI was similar between groups at all time points. CONCLUSION: Perioperative outcomes were similar in patients who underwent TLIF regardless of marijuana usage. LEVEL OF EVIDENCE: 3.

A retrospective cohort study. The purpose of this study was to evaluate marijuana usage and its effect on outcomes following transforaminal lumbar interbody fusion (TLIF). As marijuana becomes legalized throughout the United States, its medicinal and recreational usage is becoming more mainstream. Clinicians currently have little guidance regarding both short-term and long-term effects of marijuana usage on surgical interventions. While the rate of lumbar spinal fusion in the United States continues to grow, the effect of marijuana usage on fusion remains uncertain. One hundred two patients who underwent TLIF performed by the same surgeon were followed for 12 months. Patients were self-reported for marijuana usage (n = 36). Patient reported outcome measures included preoperative Oswestry disability index (ODI), 6-month ODI, and 12-month ODI, as well as length of stay (LOS), complications, return to operating room (OR), revision surgery, and confirmed fusion. Continuous variables were compared using the independent two-sample t test or analysis of variance (ANOVA), whereas categorical variables were analyzed using the chi-square or Fischer exact tests. Adjusted analysis was performed using a multivariate logistic regression model. Marijuana usage was associated with a younger population (P < 0.001), but showed no difference regarding sex or body mass index compared with the non-usage group. There was no statistically significant difference in complications, return to OR, or revision surgery between groups. When controlling for factors such as age and preoperative ODI, multivariate analysis demonstrated that marijuana usage did not limit postoperative ODI reduction. The marijuana usage group demonstrated shorter LOS (2.42 vs. 3.00 d, P = 0.020). Fusion rates at 12 months were similar between groups (96% vs. 92.3%, P = 0.678). ODI was similar between groups at all time points. Perioperative outcomes were similar in patients who underwent TLIF regardless of marijuana usage. Level of Evidence: 3.

Distal Fusion Level Selection in Scheuermann's Kyphosis: A Comparison of Lordotic Disc Segment Versus the Sagittal Stable Vertebrae.

STUDY DESIGN: Retrospective study. OBJECTIVE: To compare 2 methods of selecting the lowest instrumented vertebra (LIV) on the rates of revision surgery for distal junctional kyphosis (DJK) following treatment for Scheuermann's kyphosis (SK). METHODS: A retrospective review of patients who have undergone surgical treatment for SK was performed. Forty-four patients were divided into 2 groups based on intervention: Group 1 (n = 26) included patients who had an LIV distal to or at the sagittal stable vertebrae (SSV), and Group 2 (n = 18) included patients who had an LIV proximal to the SSV. For each group, demographic, radiographic, and revision surgery data was analyzed. RESULTS: The average follow-up was 3.1 years. There were no differences among demographic variables between the groups. Preoperative and postoperative thoracic kyphosis, lumbar lordosis, and sagittal balance were not different between groups. Postoperatively, Group 1 demonstrated a significantly greater average lordotic disc angle below the LIV compared with Group 2 (Group 1, -6.2 ± 4.3° vs Group 2, -2.9 ± 5.8°; P = .02). In a subgroup analysis, extending fusions to the sagittal stable vertebra rather than the first lordotic disc resulted in fewer distal LIV complications necessitating revision surgery compared with fusing short of the SSV (5% vs 36.3%, P = .04). CONCLUSION: The SSV method may reduce complications secondary to distal junctional failure, but at the expense of incorporating additional motion segments in a typically young population.

Bisphosphonate's and Intermittent Parathyroid Hormone's Effect on Human Spinal Fusion: A Systematic Review of the Literature.

There has been a conscious effort to address osteoporosis in the aging population. As bisphosphonate and intermittent parathyroid hormone (PTH) therapy become more widely prescribed to treat osteoporosis, it is important to understand their effects on other physiologic processes, particularly the impact on spinal fusion. Despite early animal model studies and more recent clinical studies, the impact of these medications on spinal fusion is not fully understood. Previous animal studies suggest that bisphosphonate therapy resulted in inhibition of fusion mass with impeded maturity and an unknown effect on biomechanical strength. Prior animal studies demonstrate an improved fusion rate and fusion mass microstructure with the use of intermittent PTH. The purpose of this study was to determine if bisphosphonates and intermittent PTH treatment have impact on human spinal fusion. A systematic review of the literature published between 1980 and 2015 was conducted using major electronic databases. Studies reporting outcomes of human subjects undergoing 1, 2, or 3-level spinal fusion while receiving bisphosphonates and/or intermittent PTH treatment were included. The results of relevant human studies were analyzed for consensus on the effects of these medications in regards to spinal fusion. There were nine human studies evaluating the impact of these medications on spinal fusion. Improved fusion rates were noted in patients receiving bisphosphonates compared to control groups, and greater fusion rates in patients receiving PTH compared to control groups. Prior studies involving animal models found an improved fusion rate and fusion mass microstructure with the use of intermittent PTH. No significant complications were demonstrated in any study included in the analysis. Bisphosphonate use in humans may not be a deterrent to spinal fusion. Intermittent parathyroid use has shown early promise to increase fusion mass in both animal and human studies but further studies are needed to support routine use.

Biomechanics of Degenerative Spinal Disorders.

The spine has several important functions including load transmission, permission of limited motion, and protection of the spinal cord. The vertebrae form functional spinal units, which represent the smallest segment that has characteristics of the entire spinal column. Discs and paired facet joints within each functional unit form a three-joint complex between which loads are transmitted. Surrounding the spinal motion segment are ligaments, composed of elastin and collagen, and joint capsules which restrict motion to within normal limits. Ligaments have variable strengths and act via different lever arm lengths to contribute to spinal stability. As a consequence of the longer moment arm from the spinous process to the instantaneous axis of rotation, inherently weaker ligaments (interspinous and supraspinous) are able to provide resistance to excessive flexion. Degenerative processes of the spine are a normal result of aging and occur on a spectrum. During the second decade of life, the intervertebral disc demonstrates histologic evidence of nucleus pulposus degradation caused by reduced end plate blood supply. As disc height decreases, the functional unit is capable of an increased range of axial rotation which subjects the posterior facet capsules to greater mechanical loads. A concurrent change in load transmission across the end plates and translation of the instantaneous axis of rotation further increase the degenerative processes at adjacent structures. The behavior of the functional unit is impacted by these processes and is reflected by changes in the stress-strain relationship. Back pain and other clinical symptoms may occur as a result of the biomechanical alterations of degeneration.

Neurological complications in adult spinal deformity surgery.

The number of surgeries performed for adult spinal deformity (ASD) has been increasing due to an aging population, longer life expectancy, and studies supporting an improvement in health-related quality of life scores after operative intervention. However, medical and surgical complication rates remain high, and neurological complications such as spinal cord injury and motor deficits can be especially debilitating to patients. Several independent factors potentially influence the likelihood of neurological complications including surgical approach (anterior, lateral, or posterior), use of osteotomies, thoracic hyperkyphosis, spinal region, patient characteristics, and revision surgery status. The majority of ASD surgeries are performed by a posterior approach to the thoracic and/or lumbar spine, but anterior and lateral approaches are commonly performed and are associated with unique neural complications such as femoral nerve palsy and lumbar plexus injuries. Spinal morphology, such as that of hyperkyphosis, has been reported to be a risk factor for complications in addition to three-column osteotomies, which are often utilized to correct large deformities. Additionally, revision surgeries are common in ASD and these patients are at an increased risk of procedure-related complications and nervous system injury. Patient selection, surgical technique, and use of intraoperative neuromonitoring may reduce the incidence of complications and optimize outcomes.

Percutaneous Sacroiliac Screw Fixation of the Posterior Pelvic Ring.

Percutaneous sacroiliac (SI) screw fixation is indicated for unstable posterior pelvic ring injuries, sacral fractures, and SI joint dislocations. This article provides a review of indications and contraindications, preoperative planning, imaging techniques and relevant anatomy, surgical technique, complications and their management, and outcomes after SI screw insertion.